View source for Specific Process Knowledge/Lithography/Strip

'''Feedback to this page''': '''[mailto:labadviser@danchip.dtu.dk?Subject=Feed%20back%20from%20page%20http://labadviser.danchip.dtu.dk/index.php/Specific_Process_Knowledge/Lithography/Strip click here]'''

= Strip Comparison Table =
{| border="2" cellspacing="0" cellpadding="2" 

!colspan="2" border="none" style="background:silver; color:black;" align="center"|Equipment 
|style="background:WhiteSmoke; color:black"|<b>[[Specific_Process_Knowledge/Lithography/Strip#Plasma asher|Plasma asher]]</b>
|style="background:WhiteSmoke; color:black"|<b>[[Specific_Process_Knowledge/Lithography/Strip#Plasma Asher 2|Plasma Asher 2]]</b>
|style="background:WhiteSmoke; color:black"|<b>[[Specific_Process_Knowledge/Lithography/Strip#III-V Plasma Asher|III-V Plasma Asher]]</b>
|style="background:WhiteSmoke; color:black"|<b>[[Specific_Process_Knowledge/Lithography/Strip#Rough and Fine Strip|Resist strip]]</b>
|style="background:WhiteSmoke; color:black"|<b>[[Specific Process Knowledge/Lithography/LiftOff|Lift-off]]</b>

|-
!style="background:silver; width:100px; color:black;" align="center"|Purpose 
|style="background:LightGrey; color:black"|
|style="background:WhiteSmoke; color:black"|
All purposes
|style="background:WhiteSmoke; color:black"|
Clean wafers only, no metal 
|style="background:WhiteSmoke; color:black"|
III-V materials only
|style="background:WhiteSmoke; color:black"|
Resist strip, no metal
|style="background:WhiteSmoke; color:black"|
Lift-off

|-
!style="background:silver; color:black" align="center" valign="center" rowspan="1"|Method
|style="background:LightGrey; color:black"|
|style="background:WhiteSmoke; color:black"|
Plasma ashing
|style="background:WhiteSmoke; color:black"|
Plasma ashing
|style="background:WhiteSmoke; color:black"|
Plasma ashing
|style="background:WhiteSmoke; color:black"|
Solvent and ultra sound
|style="background:WhiteSmoke; color:black"|
Solvent and ultra sound

|-
!style="background:silver; color:black" align="center" valign="center" rowspan="3"|Process parameters
|style="background:LightGrey; color:black"|Process gasses
|style="background:WhiteSmoke; color:black"|
*O<sub>2</sub> (0 - 400 sccm)
*N<sub>2</sub>
*CF<sub>4</sub>
|style="background:WhiteSmoke; color:black"|
*O<sub>2</sub> (0 - 400 sccm)
*N<sub>2</sub>
|style="background:WhiteSmoke; color:black"|
*O<sub>2</sub> (flow unknown)
|style="background:WhiteSmoke; color:black"|
*NA
|style="background:WhiteSmoke; color:black"|
*NA

|-
|style="background:LightGrey; color:black"|Max. process power
|style="background:WhiteSmoke; color:black"|
*1000 W
|style="background:WhiteSmoke; color:black"|
*1000 W
|style="background:WhiteSmoke; color:black"|
*100% (power unknown)
|style="background:WhiteSmoke; color:black"|
*NA
|style="background:WhiteSmoke; color:black"|
*NA

|-
|style="background:LightGrey; color:black"|Solvent
|style="background:WhiteSmoke; color:black"|
*NA
|style="background:WhiteSmoke; color:black"|
*NA
|style="background:WhiteSmoke; color:black"|
*NA
|style="background:WhiteSmoke; color:black"|
*NMP (Remover 1165)
*Rinse in IPA
|style="background:WhiteSmoke; color:black"|
*NMP (Remover 1165)
*Rinse in IPA

|-
!style="background:silver; color:black" align="center" valign="center" rowspan="3"|Substrates
|style="background:LightGrey; color:black"|Batch size
|style="background:WhiteSmoke; color:black"|
*1 small sample
*1 50 mm wafer
*1 - 30 100 mm wafers
*1 - 25 150 mm wafers
|style="background:WhiteSmoke; color:black"|
*1 small sample
*1 50 mm wafer
*1 - 30 100 mm wafers
*1 - 25 150 mm wafers
|style="background:WhiteSmoke; color:black"|
*1 small sample
*1 50 mm wafer
*1 100 mm wafer
|style="background:WhiteSmoke; color:black"|
*1 - 25 100 mm wafers
*1 - 25 150 mm wafers
|style="background:WhiteSmoke; color:black"|
*1 - 25 100 mm wafers
*1 - 25 150 mm wafers

|-
|style="background:LightGrey; color:black"|Allowed materials
|style="background:WhiteSmoke; color:black"|
Silicon, glass, and polymer substrates

Film or pattern of all but Type IV
|style="background:WhiteSmoke; color:black"|
No metal!

Silicon, glass, and polymer substrates

Film or pattern of photoresist/polymer
|style="background:WhiteSmoke; color:black"|
Silicon, III-V, and glass substrates

Film or pattern of all but Type IV
|style="background:WhiteSmoke; color:black"|
No metal!

Silicon, glass, and polymer substrates

Film or pattern of photoresist/polymer
|style="background:WhiteSmoke; color:black"|
Silicon and glass substrates

Film or pattern of all but Type IV
|- 
|}

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= Plasma ashing =


{| border="2" cellspacing="0" cellpadding="4" align="left"
! 
! Photoresist stripping
! Descum after lithography
! Surface treatment of plastic, ceramic and metal
! Ashing of organic material
|- 
|'''Process pressure'''
|0.8- 1.2mbar
|0.5- 1.0mbar 
|0.5- 1.0mbar 
|0.8-1.5mbar
|-
|'''Process gases'''
|
*O<sub>2</sub> (400 sccm)
*N<sub>2</sub> (0-70 sccm)
|
*O<sub>2</sub> (70-210 sccm)
*N<sub>2</sub> (0-70 sccm)
|O<sub>2</sub>, CF<sub>4</sub>, N<sub>2</sub> or their mixtures
|O<sub>2</sub>
|-
|'''Process  power'''
|600-1000W
|150-300W
|150-300W
|1000W or less for heat- sensitive materials
|-
|'''Process  time'''
|5-60 minutes
|1-5 minutes
|a few seconds to a few minutes
|Between 0.5 and 20 hours, depending on the material
|-
|'''Batch size'''
|1-30
|1-10
|1 wafer at a time
|1 wafer at a time, use a container, e.g Petri dish
|-
|}

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A typical process time for stripping of 1.5 µm AZ5214e resist is 15-25 min and for stripping of 9.5 µm AZ4562 resist is 20-35 min with the process parameters: 210 ml O<math>_2</math>/min or mixture of 210 ml O<math>_2</math>/min and 70 ml N<math>_2</math>/min, power 1000 W.

A Descum process in manuel mode: O2: 70 sccm, N2: 70 sccm, power: 150 W, time: 10 min. Be sure to wait for cooling if the machine has been used at 100 0W right before.
At a load at 2 Fused silica wafers resist removed 0.01-01,5 um

==Plasma asher==
[[Image:plasmaasher2.JPG|300x300px|thumb|The Plasma asher is placed in C-1]]

'''Feedback to this section''': '''[mailto:labadviser@danchip.dtu.dk?Subject=Feed%20back%20from%20page%20http://labadviser.danchip.dtu.dk/index.php/Specific_Process_Knowledge/Lithography/Strip#Plasma_asher click here]'''

The Plasma asher (300 auto load model) can be used for the following process:

*Photoresist stripping
*Surface cleaning after storage
*Surface cleaning after processes using oil pump or diffusion pump vacuum
*Surface cleaning as part of photolithography after wet developing of lacquer structures prior to wet or plasma etching
*Stripping of photoresist layers after etching, including after being exposed to high temperatures as after implantation, ion etching, sputter etching, RIE
*Removal of organic passivating layers and masks
*Etching of glass and ceramic
*Etching of SiO<math>_2</math>, Si<math>_3</math>N<math>_4</math>, Si
*Removal of polyimide layers

The machine can be used for almost every materials, but if you have any doubt about your materials are compatible with the plasma process it is better to ask photolithography group at Danchip.

'''The user manual, user APV, and contact information can be found in [http://labmanager.danchip.dtu.dk/function.php?module=Machine&view=view&mach=55 LabManager]'''

===Process Information===
*[[Specific Process Knowledge/Etch/Etching of Silicon Oxide/SiO2 etch using Plasma Asher |SiO2 etch using Plasma Asher 1]]

==Plasma Asher 2==
[[Image:Plasma_Asher_6inch.jpg|300x300px|thumb|Plasma asher for removing AZ resist on 6" wafers: positioned in E-5]]

'''Feedback to this section''': '''[mailto:labadviser@danchip.dtu.dk?Subject=Feed%20back%20from%20page%20http://labadviser.danchip.dtu.dk/index.php/Specific_Process_Knowledge/Lithography/Strip#Plasma_Asher_2 click here]'''

The Plasma Asher 2 is the same as Plasma Asher 1 but has another loading system which is more convenient for batch loading of 6inch substrates. 

In this machine, only O2 and N2 gases are used for processes (in PlasmaAsher1, CF4 is used as well).

The typical process parameters when operating the equipment:
*Photeresist stripping
Pressure:	0.8 - 1.0 mbar

Gas:	O2

Power:	600 - 1000 watts

Time:	5 -30 min., depending on photoresist type and thickness

A typical process time for stripping of 1.5 um AZ5214e resist is 25 min for 6 wafers load in a boat, recipe 1. 

A Descum process in manuel mode:O2:70, N2:70, power:150W, time:10min Be sure to wait for cooling if the mashine has been used at 1000W right before.
At a load at 2 Fused silicawafers resist removed 0.01-01,5um

The other materials have not been tested yet.

'''The user manual, user APV, and contact information can be found in [http://labmanager.danchip.dtu.dk/function.php?module=Machine&view=view&mach=200 LabManager]'''

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==III-V Plasma Asher==
[[Image:III-V_asher.jpg|300x300px|thumb|Plasma asher for removing resist on III-V samples: positioned in A-5]]

'''Feedback to this section''': '''[mailto:labadviser@danchip.dtu.dk?Subject=Feed%20back%20from%20page%20http://labadviser.danchip.dtu.dk/index.php/Specific_Process_Knowledge/Lithography/Strip#III-V_Plasma_Asher click here]'''

Diener Pico Plasma Asher for III-V materials.

'''The user manual and contact information can be found in [http://labmanager.danchip.dtu.dk/function.php?module=Machine&view=view&mach=186 LabManager]'''

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=Rough and Fine Strip=

[[Image:Lift-off wet bench.JPG|300x300px|thumb|Acetone strip bench in D-3]]

{| border="1" cellspacing="0" cellpadding="4" align="left"
|[[Image:Acetone_rough.jpg|150x150px|thumb|Acetone bath "rough" for removing most of the resist]]
|[[Image:Acetone_fine.jpg|150x150px|thumb|Acetone bath "fine" for removing the rest of the resist incl. ultrasound]]
|-
|}

'''Feedback to this section''': '''[mailto:labadviser@danchip.dtu.dk?Subject=Feed%20back%20from%20page%20http://labadviser.danchip.dtu.dk/index.php/Specific_Process_Knowledge/Lithography/Strip#Rough_and_Fine_Strip click here]'''

This acetone strip is only for wafers without metal and SU-8.

There are two acetone bath: one rough for stripping the most of the resist from the surface and one fine with a ultrasound for cleaning the  resists remains.


'''Here are the main rules for acetone strip use:'''
*Place the wafers in a wafer holder and put them in the first bath for 2-5 min, this time is depending how much resist you have on the surface. 
*After the rough strip place your wafers directly in the final bath, switch on for the ultra sound  and strip them for 2-3 min.
*Rinse your wafers for 4-5 min. in running water after stripping .


'''Contact information can be found in LabManager: [http://labmanager.danchip.dtu.dk/function.php?module=Machine&view=view&mach=70 Rough Strip] [http://labmanager.danchip.dtu.dk/function.php?module=Machine&view=view&mach=72 Fine Strip]'''

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==Overview of acetone benches==

{| border="2" cellspacing="0" cellpadding="4" align="left"
! 
! Acetone strip 
! Lift-off 
|- 
|'''General description'''
|
wet stripping of resist
|
lift-off process
|-
|'''Chemical solution'''
|CH<sub>3</sub>COCH<sub>3</sub>
|CH<sub>3</sub>COCH<sub>3</sub>
|-
|'''Process temperature'''
|20 <sup>o</sup>C

|20 <sup>o</sup>C

|-

|'''Batch size'''
|
1-25 wafers at a time
|
1-25 wafer at a time
|-
|'''Size of substrate'''
|
4" wafers
|
4" wafers
|-
|'''Allowed materials'''
|
*Silicon
*Silicon Oxide
*Silicon Nitride
*Silicon Oxynitride

|
*All metals

|-
|}