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'''Feedback to this page''': '''[mailto:e-beam@nanolab.dtu.dk?Subject=Feed%20back%20from%20page%20http://labadviser.nanolab.dtu.dk/index.php?title=Specific_Process_Knowledge/Lithography click here]'''
= Purpose, location and technical specifications =
= Purpose, location and technical specifications =


==Type and location of machine==
The JEOL JBX-9500FS electron beam lithography system is a spot electron beam lithography system designed for use in writing patterns (10 nm - 1 µm) in electron sensitive resists.


The JEOL JBX-9500FS electron beam lithography system is a spot electron beam lithography system designed for use in writing patterns with dimensions from nanometers to sub-micrometers.
The JEOL JBX-9500FS was purchased in 2012 and is installed in E-1 and E-2 at DTU Nanolabv. The main console of the e-beam writer is installed in E-2 which is a class 10 (ISO 4) cleanroom with tight temperature and moisture control.  
 


Substrates that needs e-beam exposure should be mounted in a cassette and transferred into the writer via the robot loader (autoloader).
The computer controlling the e-beam (EWS/9500) and the computer supporting the conversion of e-beam files are located in E-1 which is a class 100 (ISO 5) cleanroom.


== Authorization ==


To request for an e-beam training session, contact e-beam@danchip.dtu.dk; a DTU Danchip personnel will hereafter provide a time slot. For safety reasons, even fully trained users are only authorized to mount substrates into the e-beam cassettes but not authorized to load the cassettes into the autoloader.
*Only authorized users are allowed to use this machine. You require at least 4 training sessions to be authorized.
*No unauthorized users are allowed into the e-beam room E-2 unless they are accompanied with a member of DTU Nanolab staff.
*In E-2, all users must keep within the area between the front side of the machine and the table with the pre-aligner setup. Only JEOL staff or DTU Nanolab staff may access the backside of the machine.
*No users, not even authorised users, are allowed to load a substrate into the autoloader (robot loader).
*After your exposure, fully trained users can unload their cassettes from the autoloader and unmount their substrates .
*If you are prohibited to unmount your substrates before another user requires the cassette, you must accept that either the next user or DTU Nanolab personel unmount your substrates.
   
   


To use the e-beam writer, book the machine via LabManager, and ask help from DTU Danchip staff to load your cassette into the robot loader (autoloader).
'''Any violation of the above rules will result in eviction from the cleanroom.'''
<br>
<br>


==Original JEOL Manual==


After your exposure, fully trained users can unload their cassettes from the autoloader, unmount their substrates and re-load an empty cassette into the autoloader.
The original JEOL manual for the e-beam writer JEOL JBX-9500FS is located on the O-drive: O:\CleanroomDrive\_Equipment\E-beam


If you are prohibited to unmount your substrates before another user requires the cassette, you must accept that either the next user or DTU Danchip personel unmount your substrates.
<br>
<br>


== Location ==
== Techical Specification ==


The e-beam writer is located in a class 10 (ISO 4) cleanroom with tight temperature and moisture control. The room must only be entered when the machines or equipment inside the room is intended to be used. Always wear face-mask and an extra pair of gloves when handling cassettes.
The computer controlling the e-beam (EWS/9500) is located in the controller room which is a class 100 cleanroom area. The computers supporting the conversion of the e-beam files are also located in the controller room.
Manuals
There are 3 manuals for the e-beam writer; apart from the main manual (this manual) there is a sdf and jdf-file manual, and a BEAMER manual. They can both be accessed from LabManager under Technical documents.
The original JEOL manual for the e-beam writer FS9500 is located on the O-drive: O:\CleanroomDrive\_Equipment\E-beam
Technical Specification
The system can be characterized as follows:
The system can be characterized as follows:


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*The maximum field-size without stitching is 1000µm x 1000µm.
*The maximum field-size without stitching is 1000µm x 1000µm.
*The machine has cassettes that can contain either 6 wafers of 2” in size, 2 or 3 wafers of 4” in size, 1 wafer of 6” in size, 1 wafer of 8” in size, 4 chips of different sizes(slot sizes 4 mm, 8 mm, 12 mm, and 20 mm)
*The machine has cassettes that can contain either 6 wafers of 2” in size, 2 or 3 wafers of 4” in size, 1 wafer of 6” in size, 1 wafer of 8” in size, 4 chips of different sizes(slot sizes 4 mm, 8 mm, 12 mm, and 20 mm)
<br>


[[File:colomn.png|400px]][[File:colomn2.png|400px]]
[[File:colomn.png|400px]][[File:colomn2.png|400px]]
 
Pattern writing using the e-beam is implemented on a wafer or chip which has been coated with an electron beam sensitive resist. Both positive and negative types of resists for pattern writing can be used. In either case, the resist sensitivity Q (C/cm2) is a function of the beam current, I (A), the pattern writing area, A (cm2), and the pattern writing time t (s), as given below:
== Rough estimation of exposure time ==
<span style="font-size: 90%; text-align: right;">[[Specific_Process_Knowledge/Lithography/EBeamLithography/JBX9500Manual#top|Go to top of this page]]</span>
 
Pattern writing using the e-beam writer is implemented on a wafer or chip which has been coated with an electron sensitive resist. Both positive and negative types of resists for pattern writing can be used. In either case, the resist sensitivity Q (C/cm2) is a function of the beam current, I (A), the pattern writing area, A (cm2), and the pattern writing time t (s), as given below:


Q = It/A
Q = It/A


The e-beam scanning speed f (Hz) is a function of the e-beam scanning step, p (shot step), as shown below:
The e-beam scanning frequency f (Hz) is a function of the e-beam scanning step, p (shot step), as shown below:


f = I /(Qp2)
f = I /(Qp2)


The e-beam writer has scan speeds up to 100 MHz available. The dose, Q, shot step, p, and current, I, is chosen to meet the requirement of the pattern to be written, the writing time available, and also to meet the requirement f<100MHz.
The e-beam writer has scan speeds up to 100 MHz available. The dose, Q, shot step, p, and current, I, is chosen to meet the requirement of the pattern to be written, the writing time available, and also to meet the requirement f < 100MHz.
 
== Rough estimation of exposure time ==
 
[[File:currentbeamsize.jpg|400px|right]]


Based on the equations above, a rough estimate of the exposure time is easily calcualted. In the second sheet of the e-beam logbook, a simple program for calculating the scan speed frequency and an estimation of the exposure time can be found. Note, that the actual writing time will exceed the exposure-time, as the exposure-time calculation doesn’t include pre-calibrations and stage movement during exposure.
Based on the equations above, a rough estimate of the exposure time is easily calcualted. In the second sheet of the e-beam logbook, a simple program for calculating the scan speed frequency and an estimation of the exposure time can be found. Note, that the actual writing time will exceed this estimated exposure-time, as the exposure-time calculation does not include pre-calibrations and stage movement during exposure.




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The machine has a number of objective apertures (no. 15 on above illustration of the column) in order to obtain different beam diameters in different current ranges. The available apertures are:
{| cellpadding="2" style="border: 2px solid darkgray;"
! width="500" |
|- border="0"
|[[File:currentbeamsize.jpg|400px]]
|- align="center"
|Beam diameter versus Beam current: The machine have three operating objective apertures (no. 15 on above illustration of the column) in order to obtain different beam diameters in different current ranges. The available apertures are called 'aperture 5' (60 µm), 'aperture 6' (100 µm) and 'aperture 7' (200 µm).
|}


The beam diameter changes as a function of aperture size and beam current.




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= Mounting of chips or wafers into cassette =
= Mounting of chips or wafers into cassette =
<span style="font-size: 90%; text-align: right;">[[Specific_Process_Knowledge/Lithography/EBeamLithography/JBX9500Manual#top|Go to top of this page]]</span>


Authorized users are allowed to unload a cassette from the robot loader (autoloader) and mount their substrate but '''not''' allowed to load the cassette into the loader after mount.
Authorized users are allowed to unload a cassette from the robot loader (autoloader) and mount their substrate but '''not''' allowed to load the cassette into the loader after mount.


We have one chip cassette, 2 2" cassettes, 2 4" cassettes, many 6" cassettes and 1 8" cassette. Some cassettes are made of Aluminum, others of Titanium. The thermal expansion coefficient of Ti is much lower than of Al; bear this in mind if you have crucial patterns to expose.  
We have one chip cassette, 2 2" cassettes, 2 4" cassettes, many 6" cassettes and 1 8" cassette. Some cassettes are made of Aluminum, others of Titanium. The thermal expansion coefficient of Ti is much lower than of Al; if the temperature difference of the cassette itself and the stage of the e-beam writer is lagre (> 0.1 degree), the expansion/compression during writing might be too large for critical patterns.


'''Keep''' an eye on the wafer orientation when you mount; the 2" aluminum cassette still have wafer orientation flat-up.
'''Keep''' an eye on the wafer orientation when you mount; the 2" aluminum cassette still have wafer orientation flat-up.




{| cellpadding="2" style="border: 2px solid darkgray;" align="right"
{| cellpadding="2" style="border: 2px solid darkgray;" align="center"
! width="200" |  
! width="250" |  
! width="200" |  
! width="250" |  
! width="200" |  
! width="250" |  
! width="200" |  
! width="250" |  
! width="200" |  
! width="250" |  
|- border="0"
|- border="0"
| [[File:IMG_0239.jpg|150px]]  
| [[File:Chip.jpg|190px]] [[File:IMG_6675.jpg|190px]]
|[[File:IMG_6440.jpg|150px]] [[File:IMG_6441.jpg|150px]]
|[[File:2inchTi.jpg|190px]] [[File:IMG_6441.jpg|190px]]
| [[File:IMG_6433.jpg|150px]]  [[File:IMG_6434.jpg|150px]]
| [[File:2inchAl.JPG|190px]]  [[File:IMG_6434.jpg|190px]]
| [[File:IMG_6436.jpg|150px]] [[File:IMG_6437.jpg|150px]]
| [[File:4inchTi.jpg|190px]] [[File:IMG_6437.jpg|190px]]
|[[File:IMG_6438.jpg|150px]]  [[File:IMG_6439.jpg|150px]]
|[[File:4inchAl.jpg|190px]]  [[File:IMG_6439.jpg|190px]]
|- align="center"
|- align="center"
| chip Al/Cu cassette || 2" Ti cassette; wafer orientation is flat-down || 2" Al cassette; wafer orientation is flat-up || 4" Ti cassette; wafer orientation is flat-down || 4" Al cassette; wafer orientation is flat-down
| chip Al/Cu (position A - D) cassette and a close-up of slot 3B (12 mm) || 2" Ti cassette; position A - F; wafer orientation is flat-down || 2" Al cassette; position A - F; wafer orientation is flat-up || 4" Ti cassette; position A, B, and C; wafer orientation is flat-down || 4" Al cassette; position D, and E; wafer orientation is flat-down


|}
|}




<br> <br> <br> <br>
<br>  
 


[[File:HowToMount.jpg|right|500px]]


Wafer cassettes must be handled with great care and with an extra pair of clean gloves (to be found inside the e-beam room). Prevent any form of impact of the cassette and never touch the delicate parts of the cassette, i.e. the reference plane, reference marks or grounding pins. Take care that the cassette is not scratched against the metal table, always keep cleanroom side-sealed lintfree tissues between cassette and table.


General rules for handling cassettes and mounting wafers and chips into cassettes:
General rules for handling cassettes and mounting wafers and chips into cassettes:


*Always wear face-mask and a new pair of gloves
*'''Always wear''' face-mask and a new pair of gloves
*Never touch the reference planes, i.e. the six polished areas on the front side of the cassette
*'''Never put cassettes directly on the table; use lint-free cleanroom tissues'''
*Never lift the cassette in the hook
*'''Never touch''' the reference planes, i.e. the six polished areas on the front side of the cassette
*Always check the wafer for loose parts or flakes before loading. In case of loose parts or flakes, stop mounting, discard or rework the sample and rethink your process.
*'''Never lift''' the cassette in the hook
*Always check the cassette for loose parts, dust and particles.
*'''Always check''' the wafer for loose parts or flakes before loading. In case of loose parts or flakes, stop mounting, discard or rework the sample and rethink your process.
*For chips: Make sure the chip size is at least 2 mm larger than the slot opening. Be careful when mounting the plate; it will get stuck easily if mounted askew. Always check that the 12 large screws are tight.
*'''Always check''' the cassette for loose parts, dust and particles.
*For wafers: When mounting a wafer, hold the spring (wafer securing pin) back when putting the wafer and the plate into the cassette, especially on the 2" cassette (the spring can lift the wafer). Tighten the leaf spring first, then release the spring and tighten the rotation lock lever.
*'''For chips:''' Make sure the chip size is at least 2 mm larger than the slot opening. Be careful when mounting the plate; it will get stuck easily if mounted askew. Always check that the 12 large screws are tight.
*Inspect the front side of the cassette carefully after mounting the chip/wafer; a small gap between substrate and cassette will lead to a failure in HEIMAP and no exposure is thus possible.
*'''For wafers:''' When mounting a wafer, hold the spring (wafer securing pin) back when putting the wafer and the plate into the cassette, especially on the 2" cassette (the spring can lift the wafer). Tighten the leaf spring first, then release the spring and tighten the rotation lock lever.
*'''Inspect''' the front side of the cassette carefully after mounting the chip/wafer; a small gap between substrate and cassette will lead to a failure in HEIMAP and no exposure is thus possible.


   
   
Seen from the front-side of the cassette with the hook to the right, the workpiece windows (wafer positions) are named A, B, C etc in reading-direction from top left to bottom right.


<br clear="all">
= Optical pre-alignment of wafers =
<span style="font-size: 90%; text-align: right;">[[Specific_Process_Knowledge/Lithography/EBeamLithography/JBX9500Manual#top|Go to top of this page]]</span>
[[File:prealign1.jpg|600px|right]]
[[File:prealign2..jpg|300px|right]]
'''1.''' Carefully position the cassette face down on the optical aligner stage; make sure that the cassette is completely aligned with the stage before clamping the cassette to the stage. The hook of the cassette should turn away from yourself, i.e. towards D-3.


[[File:CassetteMount.png|600px]]
'''2.''' Open the Pre-Alignment Microscope System (PAMS) tool and Kappa Image Base from the Desktop if not already open. In Kappa Image Base, click ‘Open/Close Control Dialog’ in ‘Camera’. Click on the screen-icon to open camera view and the ‘>>’-icon to open the control dialog. If no contact can be reached to the camera via Kappa Image Base, restart the computer.


[[File:CassetteMount2.png|600px]]
'''3.''' Turn on the yellow light. Align the stage to the zero-marker, and press x and y on the sensor controller. This zeros the position of the software according to zero of the stage. Always zero the stage at maximum magnification.


= Optical pre-alignment of wafers =


[[File:prealign1.jpg|600px|right]]
'''4.''' In PAMS, choose JBX-9300FS and correct wafer size and position in the workpiece window. Enter the P and Q mark design positions (i.e. L-edit coordinates).


1. Carefully position the cassette face down on the optical aligner stage; make sure that the cassette is completely aligned with the stage before clamping the cassette to the stage. The hook of the cassette should turn away from yourself, i.e. towards the wall.


2. Open the Pre-Alignment Microscope System (PAMS) tool and Kappa Image Base from the Desktop. In Kappa Image Base, click ‘Open/Close Control Dialog’ in ‘Camera’. Click on the screen-icon to open camera view and the ‘>>’-icon to open the control dialog. If no contact can be reached to the camera via Kappa Image Base, restart the computer (login: cleanroom, password: Renrum12).
'''5.''' Find the P mark at maximum magnification. Click ‘Get P’. Repeat the procedure with the Q mark. Calculate gain and rotation by clicking 'Calculate' and log the results in the Log-window by clicking 'Log result'. Switch off the yellow light after use. Make sure that the rotation is < 0.5 degrees and Gain is close to 1. If this is not the case, you might have entered wrong design coordinates for P and Q or found the wrong marks on the chips or wafer.


3. Turn on the yellow light. Align the stage to the zero-marker, and press x and y on the sensor controller. This zeros the position of the software according to zero of the stage. Always zero the stage at maximum magnification.


'''6.''' Save the alignment information (File/Save). The file should be saved under your name and date, eg ‘mettekjan312012.txt’, in the folder ‘C:\Alignment data’.  This file can be transferred to your office computer by citrix remote.


4. In PAMS, choose JBX-9300FS and correct wafer size and position in the workpiece window. Enter the P and Q mark design positions (i.e. L-edit coordinates).


'''7.''' In the jdf-file, the design coordinates of the P and Q marks should be defined. In the sdf-file the mark-detection should be set to semi-automatic 'S'. In the sdf-file, enter the material center offset out put from PAMS.


5. Find the P mark at maximum magnification. Click ‘Get P’. Repeat the procedure with the Q mark. Calculate gain and rotation by clicking 'Calculate' and log the results in the Log-window by clicking 'Log result'. Switch off the yellow light after use.


{| class = "collapsible collapsed" width=65% style = "border-radius: 10px; border: 1px solid #CE002D;"
! width=100% | ========= OUTPUT OF PAMS ALIGNMENT ON 4" WAFER IN SLOT A ============
|-
|
<pre>
PAMS Metrology Tool version 2.0.4b2


6. Save the alignment information (File/Save). The file should be saved under your name and date, eg ‘mettekjan312012.txt’, in the folder ‘C:\1 temp’. This file should be transferred to the e-beam computer 9500 by using FFFTP to the folder ‘\home\eb0\jeoleb\job\mark’.
JBX-9300FS Wafer 4 inch A <>
Result Recorded 2015-10-29 16:24:01
              local            stage          (uncorrected)
Window    cc (    0,     0)  ( 90000, 55000)
Material cc (    12,  -32)  ( 90012, 55032)


Global mark P:
  designed    (-17500,    0)  ( 72500, 55000)
  measured    (-17487,    -5)  ( 72513, 55005)  ( 72714, 55242)


7. In the jdf-file, the theoretical (L-edit/CleWin) position of the P and Q marks should be defined. In the sdf-file the mark-detection should be set to semi-automatic 'S' (see section 7 in this manual and the separate sdf- and jdf-file preparation manual).
Global mark Q:
  designed    ( 17500,    0)  (107500, 55000)
  measured    ( 17553,  -60)  (107553, 55060) (107775, 55293)


Gain 1.001144
Rotation 0.089933 degrees


OFFSET(    12,  -32) ;(Material center)
OFFSET(    13,    -5) ;(P mark)
end<> 
</pre>


|-
|}


Load and unload of cassettes into/from the e-beam writer
<br clear="all">


= Load and unload of cassettes into/from autoloader =
= Load and unload of cassettes into/from autoloader =
<span style="font-size: 90%; text-align: right;">[[Specific_Process_Knowledge/Lithography/EBeamLithography/JBX9500Manual#top|Go to top of this page]]</span>


[[File:IMG_0186.jpg|600px|right]]
[[File:IMG_0186.jpg|600px|right]]


For safety reasons, users are only authorized to unload cassettes from the autoloader and to load empty cassettes into the autoloader.  
For safety reasons, users are only authorized to unload cassettes from the autoloader.  




Load and unload of cassettes into the autoloader can only be done via the touch-screen on the autoloader itself.
Load and unload of cassettes into the autoloader can only be done via the touch-screen on the autoloader itself.


To load a cassette:
'''To load a cassette into the autoloader:'''


#Set the interface in LOCAL, by clicking REMOTE (clicking this button toggles between REMOTE and LOCAL)
#Set the interface in LOCAL by clicking REMOTE (clicking this button toggles between REMOTE and LOCAL)
#Click OPEN and open the door
#Click OPEN and open the door
#Carefully put the cassette onto the platform with the hook away from yourself
#Carefully put the cassette onto the platform with the hook away from yourself
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To unload a cassette:
'''To unload a cassette from the autoloader:'''


#Set the interface in LOCAL, by clicking REMOTE (clicking this button toggles between REMOTE and LOCAL)
#Set the interface in LOCAL, by clicking REMOTE (clicking this button toggles between REMOTE and LOCAL)
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#Close the door and click CLOSE
#Close the door and click CLOSE
#Set the autoloader back in REMOTE
#Set the autoloader back in REMOTE
<br clear="all">
= Open EBX Menu (if not already open)=
[[File:ebxmenu.png|right|700px]]
On desktop one,
* Click on the arrow above 'CPU', and open a console
* In the console, type 'ebxmenu'
<br clear="all">


= Transfer of cassettes between autoloader and e-beam writer =
= Transfer of cassettes between autoloader and e-beam writer =
<span style="font-size: 90%; text-align: right;">[[Specific_Process_Knowledge/Lithography/EBeamLithography/JBX9500Manual#top|Go to top of this page]]</span>
[[File:LoaderControl2.jpg|right|500px]]


You can load the cassette into the e-beam writer from the loader control program (Ldr) from EBX Menu. This operation requires the autoloader to be in REMOTE.
You can load the cassette into the e-beam writer from the loader control program (Ldr) from EBX Menu. This operation requires the autoloader to be in REMOTE.
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If you by accident unload a cassette without evacuating the exchange-chamber, you must tick 'EXCH EVAC' and load your cassette onto stage and unload it to the autoloader again.
If you by accident unload a cassette without evacuating the exchange-chamber, you must tick 'EXCH EVAC' and load your cassette onto stage and unload it to the autoloader again.


[[File:LoaderControl2.jpg|500px]]
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= Calibration of condition file =
= Calibration of condition file =
<span style="font-size: 90%; text-align: right;">[[Specific_Process_Knowledge/Lithography/EBeamLithography/JBX9500Manual#top|Go to top of this page]]</span>


[[File:ebxmenu.jpg|400px]]
[[File:clb.png|left|600px]]
[[File:CLB.jpg|400px]]


<br>
<br>
<br>
From the EBX menu on workspace 1, open the calibration window ‘Clb’. From this window, a previously used condition file (calibration file) dedicated to a certain aperture setting and current setting is loaded, re-calibrated, and saved again.
From the EBX menu on workspace 1, open the calibration window ‘Clb’. From this window, a previously used condition file (calibration file) dedicated to a certain aperture setting and current setting is loaded, re-calibrated, and saved again.


Calibration of condition files normally consists of a numer of subprograms listed in the table below. The subprograms listed in the blue part of the table are a part of the 'daily' batch of programs.
<br clear="all">
 
== Table of subprograms to execute during calibration ==
Calibration of condition files normally consists of a number of subprograms listed in the table below. The subprograms listed in the blue part of the table are a part of the 'daily' batch of programs.


{|border="1" cellspacing="0" cellpadding="3" style="text-align:left;"  style="width: 75%"
{|border="1" cellspacing="0" cellpadding="3" style="text-align:left;"  style="width: 75%"
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|-
|-
|-style="background:WhiteSmoke; color:black"
|-style="background:WhiteSmoke; color:black"
!style="background:#ADD8E6; color:Black"|SFOCUS
!style="background:#ADD8E6; color:Black"|[[Specific_Process_Knowledge/Lithography/EBeamLithography/JBX9500Manual#SFOCUS|SFOCUS]]
|This subprogram finds the minimum beam diameter by scanning an AE mark while changing the focus of the objective lens. The objective lens is defined to be in focus where the machine finds the minimum beam diameter. This program can also be used to obsrve the depth of focus of a certain condition file.
|This subprogram finds the minimum beam diameter by scanning an AE mark while changing the focus of the objective lens. The objective lens is defined to be in focus where the machine finds the minimum beam diameter. This program can also be used to observe the depth of focus of a certain condition file. '''The SFOCUS''' subprogram does not work well for currents above 6 nA, why SFOCUS is deleted in 'daily' routines of condition files with currents larger than 6 nA.
|-
|-


|-
|-
|-style="background:WhiteSmoke; color:black"
|-style="background:WhiteSmoke; color:black"
!style="background:#ADD8E6; color:Black"|PDEFBE
!style="background:#ADD8E6; color:Black"|[[Specific_Process_Knowledge/Lithography/EBeamLithography/JBX9500Manual#PDEFBE|PDEFBE]]
|Using a BE mark, this subprogram corrects deflection gain and rotation of the main deflector
|Using a BE mark, this subprogram corrects deflection gain and rotation of the main deflector. The system positions the BE mark in the corners of the main field (which is a 1000 x 1000 µm2 square) and scans the mark using the primary deflector only.
|-
|-


|-
|-
|-style="background:WhiteSmoke; color:black"
|-style="background:WhiteSmoke; color:black"
!style="background:#ADD8E6; color:Black"|DISTMEM
!style="background:#ADD8E6; color:Black"|[[Specific_Process_Knowledge/Lithography/EBeamLithography/JBX9500Manual#DISTMEM_and_DISTBE|DISTMEM]]
|This subprogram measures the distortion of the beam deflection within the field, writes to the deflection distortion correction memory, and create a deflection distortion correction file. The program sets the distortion directly below the beam (center of the field) to zero.  
|This subprogram measures the distortion of the beam deflection 7 x 7 positions within the main writing field and generates a distortion correction table. The system positions the BE mark in all 49 positions and uses only the primary deflector to scan the BE mark in every 49 positions. The program sets the distortion directly below the beam (center of the field) to zero. The distortion correction memory in every position in the main writing field is generated by a linear approximation based on the 7 x 7 table. For 0.2 nA or 2 nA, a reasonable convergence value is e.g. 6 nm.
|-
|-


|-
|-
|-style="background:WhiteSmoke; color:black"
|-style="background:WhiteSmoke; color:black"
!style="background:#ADD8E6; color:Black"|DISTBE
!style="background:#ADD8E6; color:Black"|[[Specific_Process_Knowledge/Lithography/EBeamLithography/JBX9500Manual#DISTMEM_and_DISTBE|DISTBE]]
|This subprogram measures and corrects the deflection distortion of the beam in the entire writing field (using both deflectors to deflect the beam). The most important input parameter of this subprogram is the ''''allowable convergence value''' which ideally is set to a few nanometers above the convergence value output of PDEFBE. For 0.2 nA, a reasonable convergence value is e.g. 8 nm.
|This subprogram measures the distortion of the beam deflection 7 x 7 positions within the main writing field and generates a distortion correction table. The system positions the BE mark in all 49 positions and uses only the primary deflector to scan the BE mark in every 49 positions. The program sets the distortion directly below the beam (center of the field) to zero. The distortion correction memory in every position in the main writing field is generated by a cubic approximation based on the 7 x 7 table. For 0.2 nA or 2 nA, a reasonable convergence value is e.g. 8 nm.
|-
|-


|-
|-
|-style="background:WhiteSmoke; color:black"
|-style="background:WhiteSmoke; color:black"
!style="background:#ADD8E6; color:Black"|SUBDEFBE
!style="background:#ADD8E6; color:Black"|[[Specific_Process_Knowledge/Lithography/EBeamLithography/JBX9500Manual#SUBDEFBE|SUBDEFBE]]
|Using a BE mark, this subprogram corrects deflection gain and rotation of the secondary (sub) deflector
|Using a BE mark, this subprogram corrects deflection gain and rotation of the secondary (sub) deflector. The system positions the BE mark in the corners of the subfield (which is a 4 x 4 µm2 square) and scans the mark using the sub deflector only.
|-
|-


|-
|-
|-style="background:WhiteSmoke; color:black"
|-style="background:WhiteSmoke; color:black"
!DRIFT
![[Specific_Process_Knowledge/Lithography/EBeamLithography/JBX9500Manual#DRIFT|DRIFT]]
|
|This subprograms scans the DRIFT mark. The DRIFT mark can either be a BE mark or an alignment mark on the substrate. By scanning the DRIFT mark during exposure, the machine can positionally adjust the exposed pattern during writing, i.e. positional drift due to cassette heat-up or warm-up during writing can be corrected. This is done by using the the path DRF5M in the jdf-file.
|-
|-


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|-
|-
|-style="background:WhiteSmoke; color:black"
|-style="background:WhiteSmoke; color:black"
!HEIMAP
![[Specific_Process_Knowledge/Lithography/EBeamLithography/JBX9500Manual#HEIMAP|HEIMAP]]
|
|This subprogram measures the height of the substrate to be exposed. The size and workpiece position of the substrate (e.g. 4B) should be entered along with information of desired area to measure height. This area should always be larger than the area of the exposed pattern. The system will focus the beam to the average of the height mesaured in HEIMAP, but '''only''' if you expose in mask writing mode (i.e. no aligning) and execute HEIMAP in your initial calibration (e.g. by using path DRF5M).
|-
|-


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|-
|-
|-style="background:WhiteSmoke; color:black"
|-style="background:WhiteSmoke; color:black"
!SETWFR
![[Specific_Process_Knowledge/Lithography/EBeamLithography/JBX9500Manual#SETWFR|SETWFR]]
|
|This subprograms scans the global marks of the substrate. You need to enter the theoretical positions of the global marks (in wafer coordinate system) and the offset found during pre-aligning. When SETWFR has succeeded in finding your global marks, it will give you a corrected offset, that should be entered in your sdf-file.
|-
|-


|-
|-
|-style="background:WhiteSmoke; color:black"
|-style="background:WhiteSmoke; color:black"
!CHIPAL
![[Specific_Process_Knowledge/Lithography/EBeamLithography/JBX9500Manual#CHIPAL|CHIPAL]]
|
|This subprogram scan a set of chip marks on the substrate. You need to enter theoretical position of a chip on your wafer (in wafer coordinate systems) and the theoretical positions of the chip marks on that chip (in chip coordinate system). CHIPAL will then scan 1 or 4 chip marks (mode 1 or mode 4).
|-
|-




|}
|}
<br>
<br>


== Detailed description on calibration procedure ==
<span style="font-size: 90%; text-align: right;">[[Specific_Process_Knowledge/Lithography/EBeamLithography/JBX9500Manual#top|Go to top of this page]]</span>


=== Load and restore a condition file ===


=== Load and restore a condition file ===


*Load and restore a condition file, click ‘Select condition file...’, choose the file from the list, e.g. ‘0.2nA_ap7’ and click OK. Restore the file by clicking ‘RESTOR/Edit Parameter...’. From the RESTOR window, click ‘Excecute’; the machine will now restore the conditions of the colum, this will take a few minutes. Exit the RESTOR window by clicking ‘Cancel’.
*Load and restore a condition file, click ‘Select condition file...’, choose the file from the list, e.g. ‘0.2nA_ap7’ and click OK. Restore the file by clicking ‘RESTOR/Edit Parameter...’. From the RESTOR window, click ‘Excecute’; the machine will now restore the conditions of the colum, this will take a few minutes. Exit the RESTOR window by clicking ‘Cancel’.


=== CURRNT, INITAE, and INITBE ===   
=== Execute CURRNT, INITAE, and INITBE ===   
 


*Execute ‘CURRNT’ click ‘CURRNT/Execute’. The program ends by stating the average value of five measurements of the e-beam current; write this average current in the logbook.
*Execute ‘CURRNT’ click ‘CURRNT/Execute’. The program ends by stating the average value of five measurements of the e-beam current; write this average current in the logbook.
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=== Execute 'daily' ===
=== Execute 'daily' ===


*Execute the pre-defined set of sub-programs called ‘daily’: click 'Commands/Batch...'. Click ‘Condition file...’, choose ‘daily’, and click OK and execute. This set of programs takes around 8-10 minutes to run.
*Execute the pre-defined set of sub-programs called ‘daily’: click 'Commands/Batch...'. Click ‘Condition file...’, choose ‘daily’, and click OK and execute. This set of programs takes around 8-10 minutes to run.


=== SFOCUS ===
=== Execute DRIFT ===


=== PDEFBE ===
* Click 'DRIFT' and 'Edit parameters'.
* Select ‘Acquisition of bottom BE mark’, and click ‘Save’ and ‘Execute’. Exit the window by clicking ‘Cancel’.
* If you are calibrating the high current of a double-current exposure you should increase the scan width to 40 microns and note the position of the drift mark. When calibrating the low current of a double-current exposure, make sure DRIFT scans the same drift mark as the high-current condition file. Check [[Specific_Process_Knowledge/Lithography/EBeamLithography/FilePreparation#Double_current_exposure|here]] what to write in your sdf file for double current exposures.
* Read the subsection on DRIFT subprogram if you wish to use a global mark as DRIFT mark (recommended in certain cases)


=== DISTBE ===
=== Execute HEIMAP ===


=== SUBDEFBE ===
*Click 'HEIMAP' and 'Edit parameters'.
*In the HEIMAP window, you should type in the correct substrate type and workpiece window.
*Measure 5 x 5 points in X and Y
* Adjust the pitch (µm) of the 5 points in X and Y to cover the entire pattern on your substrate.
* Click ecxecute. Repeat HEIMAP for all substrates on stage (e.g. 4A and 4B)
* click 'Cancel' when HEIMAP have been executed on all substrates


== DRIFT ==
=== Execute SETWFR and CHIPAL ===
*Edit and execute ‘DRIFT’: click ‘DRIFT/Edit Parameter...'. Select ‘Acquisition of bottom BE mark’, and click ‘Save’ and ‘Execute’. Exit the window by clicking ‘Cancel’. If you are calibrating the high current of a double-current exposure you should increase the scan width to 40 microns and note the position of the drift mark. When calibrating the low current of a double-current exposure, make sure DRIFT scans the same drift mark as the high-current condition file.
If you have alignment of your pattern to an existing pattern on your substrate. Read more about SETWFR and CHIPAL in the subsections below.


== HEIMAP ==
=== Execute SAVE ===
* Click 'SAVE' and 'Edit parameters'
* In the SAVE window, click 'Acquisition of latest status' and (after the parameters appear in the window) click 'Apply/Save'. Note in the status line that the condition file has been saved.


= Exposure of mgn-files =
<span style="font-size: 90%; text-align: right;">[[Specific_Process_Knowledge/Lithography/EBeamLithography/JBX9500Manual#top|Go to top of this page]]</span>


''' Mask writing mode (first print) '''
With the path DRF5M, which is recommended for first print exposures (mask writing mode), HEIMAP is executed right before the machine starts the exposure and the machine will use the HEIMAP settings saved at this point.


The e-beam software can only save and use one pitch-setting, even if you expose two wafers/chips. Therefore, perform and save HEIMAP with the settings you wish to perform right before exposure.
#Open the exposure program, ‘Exp’, from the EBX Menu.
#Find and load your magazine file: click ‘File/Magazine File’ and choose the magazine file from the location ‘/home/eb0/jeoleb/job/danchip’.
#Check that the name of the desired magazine-file appears in the Magazine filename field, then click ‘Execute’.
#Click ‘YES’ if you agree on the information in the ‘Pattern Writing Execution Check’-window.


Before the exposure starts, some inital calibration will be performed such as CURRNT and HEIMAP. When measuring HEIMAP, the last saved condition of HEIMAP will be used.


''' Direct writing mode (with alignment) '''
When the exposure is performed in direct writing mode, i.e. the pattern is aligned to P and Q marks on the wafer and/or virtual chip mark detection is obtained, the result of HEIMAP is discarded and can be omitted in initial calibration. In this case, HEIMAP can be executed to check the substrate has been mounted correctly in the cassette.


After finished exposure, the machine will display whether the exposure succeeded.


HEIMAP measures the height of the substrate with a laser beam, the beam spot size onto the substrate is 0.94 mm x 0.08 mm. It is important to measure height at substrate positions where the beam is not deflected from holes or mesas.
= Alignment of exposure to existing pattern on wafer =


If you need to align an exposure to an existing pattern on a wafer you need wafer marks (or global marks) to align your exposure to. This requires global marks and chip marks on the wafer, optimization of gain settings of backscattered electron detector ('''ACGRG'''), and execution of subprograms that detects global marks and chip marks ('''SETWFR''' and '''CHIPAL'''). This section describes these procedures in detail.


#Click 'HEIMAP/Edit Parameters...'. Enter
'''Please note that manual alignment (using the SEM) is not allowed.''' You should use semi-automatic alignment only. In rare cases where semi-automatic alignment is impossible, you should remove the resist around the wafer marks before loading the wafer/chip into the machine.


*Material type: Wafer (unless you expose a mask)
== Design of global marks and chip marks ==
*Material size: The size of loaded wafer in units of inches, i.e. 2, 4 or 6. If you use the chip cassette or the 65mm stamp cassette, choose 3".
<span style="font-size: 90%; text-align: right;">[[Specific_Process_Knowledge/Lithography/EBeamLithography/JBX9500Manual#top|Go to top of this page]]</span>
*Multi-piece window: the location of the wafer/chip. You should perform HEIMAP on all loaded wafers/chips.
*Zigzag: use X->Y
*Number of height measurement points X, Y: standard is 5 in both X- and Y-direction.
*Height data measurement pitch: define the pitch of the measurements points to fit the size of the exposed pattern.
*Insert an offset to the measurements if your pattern is located away from (0,0).
*DO NOT change any other parameters in HEIMAP


{| cellpadding="2" style="border: 2px solid darkgray;" align="right"
! width="200" |
! width="200" |
! width="250" |
! width="300" |
|- border="0"  align="center"
| [[File:mark example2.png|100px]]
| [[File:GlobalMark.png|120px]]
| [[File:P Q marks and chip marks.png|250px]]
| [[File:Chip example.png|150px]]
|- align="center"
| Definition of length and width of global mark, use L = 500-1000 µm, W 3-5 µm || Text around mark is '''not''' recommended || Fabricate 2 - 3 P and Q marks. Place the P marks on the left side of the wafer and Q marks to the right. Do not place the marks closer than 15 mm to the edges of the wafer.|| Example of chip with 4 chip marks. Always position the chip marks outside the chip pattern. Position of chip marks are entered in jdf file using chip coordinate system, i.e. center of chip is (0,0).
|}


#Save the settings by clicking 'Save', and execute the program.
'''1 Material:'''


#When the program has been executed, the result of the test will appear in the result-display area of the calibration window. The measured height in the 25 points should not deviate more than +/- 50 mu.
Global marks or chip marks should be clearly visible in a 100keV SEM, i.e. preferably defined by Ti/Au or another 'heavy' metal, alternatively the wafer marks should be etched. In Si, etched mark should be around 1 µm deep in order to be detectable by the machine. Shallow etched (even 200 nm etched profiles) global marks or global marks in Si or marks defined by a light metal as Al can be hard to locate manually as well as automatically by the machine.


'''2 Design: '''
# (Execute SETWFR and CHIPAL - If you are aligning in semi-automatical mode, see section 7)


* Global marks: You need at least two wafer marks, a P mark and a Q mark. It is recommended to have many P and Q marks available on the wafer to choose from. The x-coordinate of the P mark should be smaller than the x-coordinate of the Q mark. The global marks should either be crosses or L-shaped, they should be as narrow as possible and 500 - 1000 microns in length. If the wafer contains a number of identical marks, the marks should be marked in order to identify the 'right' alignment mark (the scan width of the SEM is 1 mm x 1 mm). Text around the wafer mark is NOT recommended. Wafer marks formed as crosses with lengths of 1000 microns and 3-5 microns in width are recommended.
* Chip marks: Prepare 1 or 4 chip marks on every chip. The chip marks can be smaller than global marks, as only very fine alignment is performed with chip marks. The chip marks should either be crosses or L-shaped and text around the marks is NOT recommended.


#Save the condition file by clicking 'Save/Edit Parameter...'. Click 'Acquisition of latest status' to the right and (after the parameters appear in the window) click 'Apply/Save'. Note in the status line that the condition file has been saved.
= Exposure of mgn-files =
#Open the exposure program, ‘Exp’, from the EBX Menu.
#Find and load your magazine file: click ‘File/Magazine File’ and choose the magazine file from the location ‘/home/eb0/jeoleb/job/danchip’.
#Check that the name of the desired magazine-file appears in the Magazine filename field, then click ‘Execute’.
#Click ‘YES’ if you agree on the information in the ‘Pattern Writing Execution Check’-window.
Before the exposure starts, some inital calibration will be performed such as CURRNT and HEIMAP. When measuring HEIMAP, the last saved condition of HEIMAP will be used.


<br>


After finished exposure, the machine will display whether the exposure succeeded.
== Optimise gain settings on back-scattered electron detector: AGCRG ==
 
<span style="font-size: 90%; text-align: right;">[[Specific_Process_Knowledge/Lithography/EBeamLithography/JBX9500Manual#top|Go to top of this page]]</span>
= Alignment of wafers or chips =
Alignment of wafer or chip requires specific training.
 
First time you align on a set of wafer marks, you need to optimise the gain settings of the scan. This is done by the subprogram ACGRG.
 
When the gain settings are known, you can execute SETWFR and CHIPAL.
 
== AGCRG ==


{| cellpadding="2" style="border: 2px solid darkgray;" align="right"
{| cellpadding="2" style="border: 2px solid darkgray;" align="right"
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<br>
<br>


== SETWFR ==
== Subprogram that scan global marks: SETWFR ==
<span style="font-size: 90%; text-align: right;">[[Specific_Process_Knowledge/Lithography/EBeamLithography/JBX9500Manual#top|Go to top of this page]]</span>


[[File:SETWFR.png|600px]]
[[File:SETWFR.png|600px]]
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*Choose measurement mode 'Semi Auto'
*Choose measurement mode 'Semi Auto'
*enter the material size and slot number (e.g 4A)
*enter the material size and slot number (e.g 4A)
*enter the material center offset (from the pre-alignment) and L-edit coordinates of P mark and Q mark.
*enter the material center offset (from the pre-alignment) and design coordinates (from L-edit/Clewin) of P mark and Q mark.
*In P-mark rough/fine scan settings, adjust scan settings and enter the width of your marks. Also check the gain settings are ok.
*In P-mark rough/fine scan settings, adjust scan settings and enter the width of your marks. Also check the gain settings are ok.
*Repeat point 4 for Q-mark rough/fine
*Repeat point 4 for Q-mark rough/fine
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'''When the subprogram 'SETWFR' has found the P and Q marks'''
'''When the subprogram 'SETWFR' has found the P and Q marks'''


When SETWFR executes successfully feedback the 'P mark offset' to the OFFSET in the sdf file and re-compile the mgn-file.
 
 
When SETWFR has been executed succesfully, it will give you a corrected offset; use the offset in the section 'P-point mark measurement results' which can be found around halfways in the output (here highlighted with an arrow --->):
{| class = "collapsible collapsed" width=100% style = "border-radius: 10px; border: 1px solid #CE002D;"
! width=100% | ========= OUTPUT of SETWFR Final result ==================
|-
|
<pre>
[Measurement information]
Linear scaling value      = 1.000000
Start time                = Thu Aug  6 09:17:01 2015
End time                  = Thu Aug  6 09:18:02 2015
 
[Deflector]
P-point fine scan            = PDEF
Q-point fine scan            = PDEF
 
[Measurement condition information]
Material type                = Wafer
Material size          [inch] = 4.0
Multi-piece window            = 4A
Measurement mode              = Semi-auto
AGC execution                = No
Height measurement            = No
HEIGHT automatic calculation  = No
SUBHEI automatic calculation  = No
 
[Parameter for pattern writing height correction calculation]
PDEF  GAIN  X,Y          =      -9999      -10571
      ROT  X,Y          =      12605        12962
SUBDEF SHIFT X,Y          =          -3          11
      GAIN  X,Y          =        1677          649
      ROT  X,Y          =        -695        1043
The Objective lens        =      29866
DF offset                  =          0
 
Beam shift value after objective lens correction [nm] =        0.0          0.0
Beam shift value after DFOCUS OFFSET  correction [nm] =        0.0          0.0
Height                                          [um] =    0.000000
 
[Parameter for pattern writing height correction calculation]
PQ GAIN coefficient    [nm/100mm] = 5.567214e+02  5.567214e+02
 
[PDEF DAC value calculated from PQ GAIN/ROT]
PDEF  GAIN  X,Y          =          90          89
      ROT  X,Y          =      -5490        -5501
 
[SUBDEF DAC value calculated from PQ GAIN/ROT]
SUBDEF SHIFT X,Y          =          0            0
      GAIN  X,Y          =        -21          -12
      ROT  X,Y          =        -322          323
 
[PDEF DAC value calculated from lens4 + height]
PDEF  GAIN  X,Y          =          0            0
      ROT  X,Y          =          0            0
 
[SUBDEF DAC value calculated from lens4 + height]
SUBDEF SHIFT X,Y          =          0            0
      GAIN  X,Y          =          0            0
      ROT  X,Y          =          0            0
 
[Total component DAC value of PQ correction]
PDEF  GAIN  X,Y          =          90          89
      ROT  X,Y          =      -5490        -5501
SUBDEF SHIFT X,Y          =          0            0
      GAIN  X,Y          =        -21          -12
      ROT  X,Y          =        -322          323
The Objective lens        =          0
DF offset                  =          0
 
Material correction coefficient SHIFT X,Y        [nm] = 55513.827000  -40956.899500
                                GAIN  X,Y  [nm/100mm] =  556.721379  556.721379
                                ROT  X,Y      [rad] =  -0.005500    -0.005500
Material center position X,Y                    [um] =  90000.0000  55000.0000
Material rotation angle                      [degree] = -0.3151517494
Reference height                                [um] =    0.000000
Average height                                  [um] =    0.000000
 
[P-point mark measurement result]
Design position (material coordinates)      X,Y[um] = -35000.0000      0.0000
Observation position (material coordinates) X,Y[um] = -34944.1516  -233.4722
--->  Offset                                      X,Y[um] =    55.8484  -233.4722
Mark rotation angle(+clockwise)            [degree] = -3.119790e-01
Height measurement                                  = No height measurement
Height                                        [um] = 0.000000e+00
 
 
[Q-point mark measurement result]
Design position (material coordinates)      X,Y[um] =  35000.0000      0.0000
Observation position (material coordinates) X,Y[um] =  35055.1792    151.5585
Offset                                      X,Y[um] =    55.1792    151.5585
Mark rotation angle(+clockwise)            [degree] = -3.308954e-01
Height measurement                                  = No height measurement
Height                                        [um] = 0.000000e+00
 
[P-point correction data]
PDEF  GAIN  X,Y          =      -10089      -10660
      ROT  X,Y          =      18095        18463
SUBDEF SHIFT X,Y          =          -3          11
      GAIN  X,Y          =        1698          661
      ROT  X,Y          =        -373          720
The Objective lens        =      29866
DF offset                  =          0
 
Beam shift value after objective lens correction [nm] =        0.0          0.0
Beam shift value after DFOCUS OFFSET correction [nm] =        0.0          0.0
Height                                          [um] =    0.000000
 
P-point mark shift [um] =    55.3296,    -42.8961
 
HEIGHT
The amount of minute compensation of a focus lens                [point] = 0
The amount of minute compensation of beam position shift      X    [nm] = 0.0
                                                                Y    [nm] = 0.0
The amount of minute compensation of a main deflector gain    X [point] = 0
                                                                Y [point] = 0
The amount of minute compensation of a main deflector rotation X [point] = 0
                                                                Y [point] = 0
SUBHEI
The amount of minute compensation of a sub deflector shift    X [point] = 0
                                                                Y [point] = 0
The amount of minute compensation of a sub deflector gain      X [point] = 0
                                                                Y [point] = 0
The amount of minute compensation of a sub deflector rotation  X [point] = 0
                                                                Y [point] = 0
 
======================================================
</pre>
 
|-
|}
 
<br> <br>


<br clear="all" />
<br clear="all" />
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[[File:RoughScanGain.png|400px|right]]
[[File:RoughScanGain.png|400px|right]]


'''If the program cannot find the marks''', you can either adjust the scan conditions, or gain settings. Also, test SETWFR again with 'OFFSET (P-mark)' from the pre-aligner output.
'''If the program cannot find the marks''', the machine will ask you whether you wish to find the marks manually by using the SEM. Before you do that, adjust the parameters of SETWFR with one (or all) of the follwing things and execute SETWFR again:


# Increase the rough scan width of both P and Q mark to around 300 µm
# Change the scan position of both P and Q mark so it scans the opposite arm as before, i.e. scans at -30 µm instead of +30 µm
# Set the BE coarse gain to 60 in the rough scan of P and Q mark (see under 'Gain' tab)
# Change the interlaced scan from 'X -> Y' to 'Y -> X', 'X only', or 'Y only' (see under 'Scan' tab)


Find the mark manually and let SETWFR scan the mark to align the sample:
If nothing of the above work, accept to find the mark manually by using the SEM. Please be aware that you should only '''roughly''' find the mark with the SEM, i.e. center it on the screen, and '''not''' align with the SEM.


As a last alternative, you can chose to find the mark manually; this is however not recommended.
As a last alternative, you can chose to find the mark manually; SETWFR will ask you whether you wish to find the mark manually, click OK.
 
SETWFR will ask you whether you wish to find the mark manually, click OK.


*In 'sspvideo' click 'change/SEM'
*In 'sspvideo' click 'change/SEM'
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Please note that you should NOT align with the SEM but only roughly center the mark so you are sure the mark will be scanned with your scan settings.
Please note that '''you should not align with the SEM but only roughly center the mark so you are sure the mark will be scanned with your scan settings.'''




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== CHIPAL ==
== Subprogram that detects chip marks: CHIPAL ==
<span style="font-size: 90%; text-align: right;">[[Specific_Process_Knowledge/Lithography/EBeamLithography/JBX9500Manual#top|Go to top of this page]]</span>


[[File:CHIPAL.png|500px]]
[[File:CHIPAL.png|500px]]
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If the program can not detect your chip marks, change the scan conditions ('RG mark detection condition') and try again.
If the program can not detect your chip marks, change the scan conditions ('RG mark detection condition') and try again.


= Double current exposure =
<span style="font-size: 90%; text-align: right;">[[Specific_Process_Knowledge/Lithography/EBeamLithography/FilePreparation#top|Go to top of this page]]</span>
Before running a double-current exposure, you should receive training from a person from the e-beam staff. If this procedure is not performed correctly, it might end up in large pattern shifts.
A double-current exposure requires calibration of 2 condition files, of which you should calibrate the large current first and the small current afterwards. If the two patterns are aligned to each other, one should make sure the two condition files scan the same drift mark. The procedure is as follows:
# Load, restore and calibrate the condition file with the large current. When you scan the drift mark (using DRIFT), note the position of the drift mark (the position is written in the result display area of the calibration window).
# Increase the scan width in DRIFT to 40 µm in both X and Y. Save and execute DRIFT again.
# Save the condition file as usual.
# Load, restore and calibrate the condition file with the smallest current. When you scan the drift mark, make sure it scans the same mark as on the former condition file, i.e. that the two positions are equal within a few µm. If they are not, call a person from the e-beam team for help.
# Save the condition file as usual.
When you start the exposure, you call the condition file with the small current first. When the condition file with the large current is called, the state of the machine is restored to the condition file by the command 'RESTOR 1' in the sdf-file:
<pre>
_____________________________________________________________
MAGAZIN    'DOUBLE'         
       
#4                                         
%4A                                     
JDF    'smallcurrent',1                             
ACC 100                                 
CALPRM '0.2na_ap5'                 
DEFMODE 2                           
RESIST 240                             
SHOT A,8                               
OFFSET(0,0)                         
#4                                         
%4A                                     
JDF    'largecurrent',1                             
ACC 100                                 
CALPRM '10na_ap6'
DEFMODE 2   
RESTOR 1                        Coloumn is restored to 10na_ap6 and lenses are demagnetized             
RESIST 240                             
SHOT A,18                               
OFFSET(0,0)
END 4                                     
______________________________________________________________
</pre>
Using the 'RESTOR' command without '1' the condition file will be restored without demagnetizing of the lenses.


<br clear="all" />
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= Detailed descriptions of subprograms =
<span style="font-size: 90%; text-align: right;">[[Specific_Process_Knowledge/Lithography/EBeamLithography/JBX9500Manual#top|Go to top of this page]]</span>
== SFOCUS ==
<span style="font-size: 90%; text-align: right;">[[Specific_Process_Knowledge/Lithography/EBeamLithography/JBX9500Manual#top|Go to top of this page]]</span>
{| cellpadding="2" style="border: 2px solid darkgray;" align="left" width="900px"
! width="400" |
|- border="0"
|[[File:SFOCUS.png|500px]]
|SFOCUS uses the bottom AE mark to measure the beam diameter while adjusting the objective lens. The objective lens is defined to be in focus where the machine finds the minimum beam diameter. This program can also be used to observe the depth of focus of a certain condition file. The graph shows the beam diameter versus position of objective lens. The position of the objective lens is converted to a difference in substrate height by executing the subprogram 'HCOEFFI'. <br><br> Please note, that SFOCUS does not work well for currents larger than 6 nA; at higher currents the focus should be set manually. This is to be done by DTU Nanolab staff only.
|}
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== PDEFBE ==
<span style="font-size: 90%; text-align: right;">[[Specific_Process_Knowledge/Lithography/EBeamLithography/JBX9500Manual#top|Go to top of this page]]</span>
By using the (bottom) BE mark (specified in INITBE), the machine measures the gain and rotation of the main deflector ('''P'''rimary '''DEF'''lector using '''BE''' mark).
The machines measures over a field specified in the subprogram but no larger than the main field size (1 mm x 1 mm). 
The output of PDEFBE looks like this:
{| width=100% style = "border-radius: 10px; border: 1px solid #CE002D;"
! width=100% | ========= PDEFBE Final result (0.2nA ap5) ==================
|-
|
Field size              [um] = 960.0000
Number of bottom mark retries = 1
Deflector                    = PDEF
Previous DAC[point]            Shift value[nm]          Corrected DAC[point]
GAIN (X  Y) =  -9320    -9932                0.0          1.4          -9323    -9936
ROT  (X  Y) =  17541    17800                -0.5        -0.6          17543    17806
Height conversion conefficient        = 0.435090
Height offset                        = -138.560000
Height correction coefficient                  X            Y
GAIN  X,Y                    = 1.121066e+01  1.123170e+01
ROT  X,Y                    = -4.416959e+00  -4.248694e+00
Distortion conversion coefficient              X            Y
GAIN  X,Y                    = 0.000000e+00  0.000000e+00
ROT  X,Y                    = 0.000000e+00  0.000000e+00
Reference height [um] =      0.667
difference between the bottom BE mark and the reference plane [um] =      -0.064
difference between the top BE mark and the bottom BE mark  [um]    =      47.544
===========================================================================================
|-
|}
The most important output of PDEFBE is the gain shift value which is 1.4 nm (in Y); the maximum allowable gain correction in this condition file (0.2nA ap5) is 6 nm. If PDEFBE did not reach a shift value below 6 nm within 3 retries for this condition file, the scan position on the BE mark should be shifted or a new BE mark should be used instead.
== DISTMEM and DISTBE ==
<span style="font-size: 90%; text-align: right;">[[Specific_Process_Knowledge/Lithography/EBeamLithography/JBX9500Manual#top|Go to top of this page]]</span>
DISTMEM and DISTBE measures the distortion of the beam over the entire writing field, i.e. positional errors in the beam over the entire writing field.
Both programs use the bottom BE mark to detect these errors. The stage moves the mark to 7 x 7 positions distributed over 1 x 1 mm^2 writing field. At each position, the beam is deflected by the primary deflector to scan the mark. The distortion is defined as the offset between the actual stage position and position of the mark measured by the beam.
After measuring all 7 x 7 points, the machine generate a distortion correction table and measures again. This procedure is repeated until the maximum offset is as specified in 'allowable convergence value' in DISTBE or DISTMEM.
DISTBE generates the correction table for every position in the main writing field by cubic approximation between measurement points. DISTMEM generates the correction table for every position in the main writing field by linear approximation between measurement points.
We empirically found that executing DISTMEM before executing DISTBE gives the best results.
If the convergence value is not met after 3-4 measurements, the scan position on the BE mark should be changed as described in troubleshooting.
{| class = "collapsible collapsed" width=100% style = "border-radius: 10px; border: 1px solid #CE002D;"
! width=100% | ========= OUTPUT of DISTBE Final result (2nA ap5) ==================
|-
|
<pre>
[Measurement information]
Linear scaling value      = 1.000000
Start time                = Wed May  6 12:02:27 2015
End time                  = Wed May  6 12:08:50 2015
Measurement result file  = 20150506120227.distbe.bat.ic
Deflector                = PDEF
[Height measurement]
Reference height              [um] =      0.000
[Main deflector result]
DISTBE measurement condition information
Register clear mode                = Off
Field size                    [um] =    980.0000
Zigzag                            = X -> Y
Measurement starting point        = Top left
Number of to-and-fro measurements  =          1
Number of measurement points in the 1st quadrant =          4
Measurement pitch [ 1/ 3]    [um] =    163.3000
Measurement pitch [ 2/ 3]    [um] =    163.3000
Measurement pitch [ 3/ 3]    [um] =    163.4000
Stage fixing flag                  = Stage shift
Number of retries                  =          1
Amount of field center shift                    X, Y [nm] =        -2.2          0.7
Scanning position                                X, Y [nm] =    -17200.0    -17200.0
distortion result [nm]
    X      |  -490.0000 |  -326.7000 |  -163.4000 |    0.0000 |  163.4000 |  326.7000 |  490.0000 |
------------+-------------------------------------------------------------------------------------------
  490.0000 |        3.3        -2.1        -1.7        -1.4        -2.9        -2.9          2.7 
  326.7000 |      -4.0        -1.3        -1.3        -1.2        -1.1        -2.2        -1.8 
  163.4000 |      -3.0        -1.1        -0.6        -0.2        -0.6        -1.2        -1.7 
    0.0000 |      -1.6        -0.3          0.1          0.0        -0.3        -0.4        -1.9 
  -163.4000 |      -1.0        -0.7          0.0        -0.5          0.0        -0.5        -1.1 
  -326.7000 |      -3.2        -1.6        -0.9        -0.7        -0.8        -1.6        -2.9 
  -490.0000 |        3.3          3.1        -2.9        -3.0        -3.1          1.4          1.4 
    Y      |  -490.0000 |  -326.7000 |  -163.4000 |    0.0000 |  163.4000 |  326.7000 |  490.0000 |
------------+-------------------------------------------------------------------------------------------
  490.0000 |        1.3        -5.5        -1.9        -2.9        -3.8          3.9          2.9 
  326.7000 |      -2.0        -1.2          1.7        -1.0        -3.1          2.6        -2.6 
  163.4000 |      -1.7        -1.2          0.1        -2.7        -4.4          2.4        -2.4 
    0.0000 |      -2.4        -0.4          3.2          0.0        -2.9          3.9        -1.9 
  -163.4000 |      -2.1          0.4          3.1        -0.7        -4.8          0.3        -5.0 
  -326.7000 |      -0.9          0.1          1.8        -0.9        -3.0          3.7        -3.6 
  -490.0000 |        2.6          2.4          1.5        -2.0        -5.2          1.9          1.2 
</pre>
|-
|}
<br> <br>
== SUBDEFBE ==
<span style="font-size: 90%; text-align: right;">[[Specific_Process_Knowledge/Lithography/EBeamLithography/JBX9500Manual#top|Go to top of this page]]</span>
By using the (bottom) BE mark (specified in INITBE), the machine measures the gain and rotation of the subsidary (secondary) deflector (SUBsidary DEFlector using BE mark).
The machines measures over a field specified in the subprogram but no larger than the main field size (4 µm x 4 µm).
== DRIFT ==
<span style="font-size: 90%; text-align: right;">[[Specific_Process_Knowledge/Lithography/EBeamLithography/JBX9500Manual#top|Go to top of this page]]</span>
You can choose any mark as a DRIFT mark. In a standard exposure, a (bottom plane) BE mark is used as DRIFT mark, but you can ask the machine to use one of your global marks as well, i.e. P or Q marks. This requires alignment in semi-automatic mode, however.
{| cellpadding="2" style="border: 2px solid darkgray;" align="right"
! width="200" |
! width="200" |
! width="200" |
|- border="0"
|[[File:DriftParameters.png|500px]]
|[[File:drift.png|500px]]
|[[file:DRIFT mark.png|450px]]
|- align="center"
|In the DRIFT subprogram window, you can either use the <br> '''1''' BE mark: click 'acquisition of Bottom BE mark' or <br> '''2''' use your own global mark: tick 'rough scan not available' and enter the stage position of your global mark. Adjust the scan conditions to fit your marks. || DRIFT measurements (by PATH DRF5M) during a 7 hour long exposure. The machine will positionally correct for the displacement it observes during exposure, i.e. the maximum pattern displacement is the drift between every measurement point (5 min).  || According to this table (provided by JEOL) a global mark (P) can be used as a DRIFT mark in automatic or semi-automatic alignment mode if CHIPAL 0, V1, V4 or S is used. A chip mark can be used as a DRIFT mark in any case where CHIPAL is defined to CHIPAL 1 or CHIPAL 4.
|}
<br clear="all" />
== HEIMAP ==
<span style="font-size: 90%; text-align: right;">[[Specific_Process_Knowledge/Lithography/EBeamLithography/JBX9500Manual#top|Go to top of this page]]</span>
HEIMAP is a sub program that measures height of the substrate with an IR laser. The incidence angle of the laser is 73 degrees.
{| cellpadding="2" style="border: 2px solid darkgray;" align="right"
! width="200" |
! width="200" |
|- border="0"
|[[File:HEIMAP1.png|400px]]
|[[File:HEIMAP2.png|400px]] [[File:HEIMAP3.png|400px]]
|
|- align="center"
|Results of HEIMAP can be found in the Map Analysis program (EBXMENU/Analysis/Map). In mask writing mode (i.e. without alignment), the system focusses the beam to the average height of all successfully measured points performed in HEIMAP. || HEIMAP measures the height of the substrate with two laser beams forming a x-shaped spot on the substrate. The spot size on the substrate has a width of 0.94 mm in X-direction. The laser beams have an incident angle of 17 degrees.
|}
''' Mask writing mode (first print) '''<br>
With the path DRF5M, which is recommended for first print exposures (mask writing mode), HEIMAP is executed right before the machine starts the exposure and the machine will use the HEIMAP settings saved at this point.
It is important to measure height over an area that cover the entire pattern to be exposed. Also, make sure not measure height too close to the rim of the cassette (0.5-1 cm depending on cassette) or at substrate positions where the laser beam is deflected from holes or mesas.
The e-beam software can only save and use one pitch-setting, even if you expose two wafers/chips. Therefore, perform and save HEIMAP with the settings you wish to perform right before exposure.
''' Direct writing mode (with alignment) '''<br>
When the exposure is performed in direct writing mode, i.e. the pattern is aligned to P and Q marks on the wafer and/or virtual chip mark detection is obtained, the result of HEIMAP is '''discarded''' and can be omitted in initial calibration. In this case, HEIMAP can be executed to check the substrate has been mounted correctly in the cassette.
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= Troubleshooting =
= Troubleshooting =
<span style="font-size: 90%; text-align: right;">[[Specific_Process_Knowledge/Lithography/EBeamLithography/JBX9500Manual#top|Go to top of this page]]</span>


'''No EBX Menu is open in any of the desktops:''' Open a console (click on arrow above the text ‘CPU’ on bottom menu bar) and from location (DTU)/ type ‘ebxmenu’.
'''No EBX Menu is open in any of the desktops:''' Open a console (click on arrow above the text ‘CPU’ on bottom menu bar) and from location (DTU)/ type ‘ebxmenu’.
Line 523: Line 973:


== Basic unix operations ==
== Basic unix operations ==
<span style="font-size: 90%; text-align: right;">[[Specific_Process_Knowledge/Lithography/EBeamLithography/JBX9500Manual#top|Go to top of this page]]</span>


<pre>
<pre>
Line 534: Line 985:


== Calibration problems ==
== Calibration problems ==
<span style="font-size: 90%; text-align: right;">[[Specific_Process_Knowledge/Lithography/EBeamLithography/JBX9500Manual#top|Go to top of this page]]</span>


'''No current can be detected when executing CURRNT:''' Use another condition file or call one of the contact persons to get help.
'''No current can be detected when executing CURRNT:''' Use another condition file or call one of the contact persons to get help.
Line 574: Line 1,026:


== Alignment problems ==
== Alignment problems ==
<span style="font-size: 90%; text-align: right;">[[Specific_Process_Knowledge/Lithography/EBeamLithography/JBX9500Manual#top|Go to top of this page]]</span>


'''SETWFR cannot detect my P and Q marks:''' Unload your wafer/chip, remove the resist from your wafer marks and repeat your exposure with manual alignment:
'''SETWFR cannot detect my P and Q marks:''' Unload your wafer/chip, remove the resist from your wafer marks and repeat your exposure with manual alignment:
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