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Thope (talk | contribs)
DCH-Employees-701, NLAB-Employees-701, NLAB-LabmanagerAllUsers, NLAB-Nlab347-labadviser-users-35231
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= Proximity Effect Correction =
= Proximity Effect Correction =
Apart from conversion to V30 the prime use of Beamer is to do Proximity Effect Correction (PEC). This is done through the PEC node. The PEC node has a quite a few options and different ways to define a Point Spread Function (PSF). The PSF is a radially symmetric function around the beam spot that defines dose received by the resist both due to the incident beam but also from scattered electrons. The PSF used in Beamer can be defined in two ways; either based on gaussian functions where the user supplies the parameters used to define the functions, or the PSF can be based on Monte Carlo simulations of electron scattering. In any case the PSF is mainly dependent on beam energy (acceleration voltage) and substrate material. The JEOL 9500 system is always used at 100 kV, the Raith eLine system can however be used at any acceleration voltage between 1 and 30 kV. The PSF changes drastically with acceleration voltage and it is very important to use a PSF generated at the correct acceleration voltage. Beamer comes with its own Monte Carlo simulator called Tracer. In Tracer one can set up a substrate material stack and simulate electron scattering at the desired acceleration voltage. The PSF can be output as a file and loaded into Beamer for PEC.
Apart from conversion to V30 the prime use of Beamer is to do Proximity Effect Correction (PEC). This is done through the PEC node. The PEC node has a quite a few options and different ways to define a Point Spread Function (PSF). The PSF is a radially symmetric function around the beam spot that defines dose received by the resist both due to the incident beam but also from scattered electrons. The PSF used in Beamer can be defined in two ways; either based on gaussian functions where the user supplies the parameters used to define the functions, or the PSF can be based on Monte Carlo simulations of electron scattering. In any case the PSF is mainly dependent on beam energy (acceleration voltage) and substrate material. The JEOL 9500 system is always used at 100 kV, the Raith eLine system can however be used at any acceleration voltage between 1 and 30 kV. The PSF changes drastically with acceleration voltage and it is very important to use a PSF generated at the correct acceleration voltage. Beamer comes with its own Monte Carlo simulator called Tracer. In Tracer one can set up a substrate material stack and simulate electron scattering at the desired acceleration voltage. The PSF can be output as a file and loaded into Beamer for PEC.
= Simple conversion from GDSII to v30 =
{| cellpadding="2" style="border: 2px solid darkgray;" align="right"
! width="300" |
! width="300" |
! width="300" |
|- border="0"
|[[File:beamer1.jpg|350px|left]]
|[[File:beamer2.jpg|350px|center]]
|[[File:beamer3.jpg|350px|right]]
|- align="center"
| Import a GDSII-file by dragging the 'Import' module to the process flow area. Select the file. In the 'Import Layout' window, type the layer number to import or type * if you wish to import all layers. || Export the GDSII file to v30 by dragging an 'Export' module on top of the 'Import' icon. An 'Export JEOL' window appears.  || In the tab 'General' of this export window, choose JBX9500FS (100kV). In the tab 'Advanced', type the correct field size (maximum is 1000 mm in both X and Y). The fields will be distributed automatically by choosing 'Fixed'. In case you have small patterns, is it recommended to tick 'Center to Field'.
|}
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[[File:beamer12.jpg|400px|right]]
'''If your pattern is larger than one field size''', it will be stitched by several fields. In the tab 'Multipass', you can choose to smooth the stitching errors by overlapping the fields to be stitched or by multipass method.
There are 3 types of '''overlap''' methods; for all 3 methods you define an overlap width:
'''a)''' standard: the overlap will be exposed with half dose both of field 1 and field2; <br>
'''b)''' interleaving: the overlap will be finger-jointed by field 1 and field 2; <br>
'''c)''' interleaving with extra field: the overlap will be finger-jointed by field 1, field 2 and an extra field 3, as illustrated to the right. <br>
The '''multipass''' method smooths the field stitching errors by writing the pattern with half dose in different areas of the main deflector; by this method, pattern located in the corner of a writing field will be written partly by the corner of a writing field and partly by the central part of the writing field.
<br clear="all" />


=Dose variations=
=Dose variations=
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