Direct-Write Lithography Recipes: Difference between revisions

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== [[Maskless Aligner (Heidelberg MLA150)]] ==
==[[Maskless Aligner (Heidelberg MLA150)]]==
For CAD design tips and requirements, see these pages:

*[[MLA150 - Design Guidelines|Design Guidelines + Tips]] - ''useful info for designing your CAD files, alignment marks etc.''
*[[MLA150 - CAD Files and Templates|CAD Files and Templates]] - example CAD files etc.

Photolithography Recipes for the [[Maskless Aligner (Heidelberg MLA150)|Heidelberg MLA150]]. All recipes were characterized on blank Silicon wafers. For different substrate coatings/materials, you will likely need to run a focus-exposure matrix ("series" exposure mode), using our params as a starting point.
Photolithography Recipes for the [[Maskless Aligner (Heidelberg MLA150)|Heidelberg MLA150]]. All recipes were characterized on blank Silicon wafers. For different substrate coatings/materials, you will likely need to run a focus-exposure matrix ("series" exposure mode), using our params as a starting point.


These recipes use the same spin and bake params as our contact aligner and stepper recipes, using built-in hotplates on the photoresist spinner benches.
These recipes use the same spin and bake params as our contact aligner and stepper recipes, using built-in hotplates on the photoresist spinner benches.


'''''Any I-Line PR is usable''''', although we only characterized a select few below. Run your own Focus-Exposure Matrix to characterize a new PR.
=== Positive Resist (MLA150) ===

''We found that positive PR's worked well with the 405nm laser - the 375nm laser would likely also work. Sub-micron features are possible. Overexposure is recommended to avoid stitching and horiz/vert discrepancies, compensate using CD Bias [[MLA150 - Design Guidelines#High-Resolution Writing|as described here]].''
'''<u>Note:</u>''' On this tool, it is common to have to run a Focus-Exposure Matrix (aka. FEM), via "''Series''" exposure mode, for each new layer structure and/or critical feature size. The layer structure can strongly affect the exposure parameters. See the [[ASML Stepper 3 Standard Operating Procedure#Tips for FEM analysis|FEM Analysis Tips page]] for how to choose the proper exposure parameters.

The [[MLA150 - Troubleshooting#Out Of Focus Exposures|'''MLA''' '''Troubleshooting > Out-of-Focus Exposures''']] section can help you avoid bad exposures, please read it!

===Positive Resist (MLA150)===
''We found that positive PR's worked well with the 405nm laser - the 375nm laser would likely also work. Sub-micron features are possible. Overexposure is recommended to avoid stitching and horiz/vert discrepancies; compensate for widening/narrowing using CD Bias [[MLA150 - Design Guidelines#High-Resolution Writing|as described here]].''

Note: calibrations done with the "HIMT design" will show higher dose, due to using only dark-field line/space patterns.


{| class="wikitable" border="1" style="border: 1px solid #D0E7FF; background-color:#ffffff; text-align:center;"
{| class="wikitable" style="border: 1px solid #D0E7FF; background-color:#ffffff; text-align:center;" border="1"
|- bgcolor="#D0E7FF"
|- bgcolor="#D0E7FF"
! width="100" |Resist
! width="100" |Resist
Line 20: Line 33:
! width="125" |Exposure Dose (mJ/cm<sup>2</sup>)
! width="125" |Exposure Dose (mJ/cm<sup>2</sup>)
! width="100" |DeFocus
! width="100" |DeFocus
!Rehydrate*
! width="75" |PEB
! width="75" |PEB**
! width="100" |Developer
! width="100" |Developer
! width="125" |Developer Time
! width="125" |Developer Time
! width="300" |Comments
! width="300" |Comments
|-
|-
|[[:File:AXP4000pb-Datasheet.pdf|AZ4110]]
|[[Media:AXP4000pb-Datasheet.pdf|AZ4110]]
|4 krpm, 30s
|4 krpm, 30s
|95°C, 60s
|95°C, 60s
Line 32: Line 46:
|240
|240
|5
|5
|
|''none''
|''none''
|AZ400K:DI 1:4
|AZ400K:DI 1:4
|50s
|50s
|Used MLA design (good for isolated lines 0.8-1um)
|Used HIMT design (good for isolated lines 0.8-1um)
|-
|-


|[[:File:AXP4000pb-Datasheet.pdf|AZ4330]]
|[[Media:AXP4000pb-Datasheet.pdf|AZ4330]]
|4 krpm, 30s
|4 krpm, 30s
|95°C, 60s
|95°C, 60s
Line 45: Line 60:
|320
|320
|6
|6
|
|''none''
|''none''
|AZ400K:DI 1:4
|AZ400K:DI 1:4
|90s
|90s
|Used MLA design
|Used HIMT design
|-
|-
|[[:File:Az p4620 photoresist data package.pdf|AZ4620]]
|[[Media:AXP4000pb-Datasheet.pdf|AZ4620]]
|
|
|
|
|
Line 62: Line 79:
|
|
|-
|-
|[[:File:SPR220-Positive-Resist-Datasheet.pdf|SPR 220-3.0]]
|[[Media:SPR220-Positive-Resist-Datasheet.pdf|SPR 220-3.0]]
|2.5 krpm, 30s
|2.5 krpm, 30s
|115°C, 90s
|115°C, 90s
Line 69: Line 86:
|325
|325
| - 4
| - 4
|
|115°C, 90s
|115°C, 90s
|AZ300MIF
|AZ300MIF
|60s
|60s
|Used MLA design
|Used HIMT design. 0.6-0.9µm line/space.
|-
|-
|[[:File:SPR955-Positive-Resist-Datasheet.pdf|SPR 955-CM0.9]]
|[[Media:SPR220-Positive-Resist-Datasheet.pdf|SPR 220-7.0]]
|3.5 krpm, 30s
|105°C/2min
Cool 1min
|~ 7.0µm
|375
|~550mJ
| -20
|>1hr
|115°C, 90s
|AZ300MiF
|70s
|Rehydration after exposure is necessary, to prevent bubbles at PEB.
|-
|[[Media:SPR955-Positive-Resist-Datasheet.pdf|SPR 955-CM0.9]]
|3 krpm, 30s
|3 krpm, 30s
|95°C, 90s
|95°C, 90s
Line 81: Line 113:
|250
|250
| - 7
| - 7
|
|110°C, 90s
|110°C, 90s
|AZ300MIF
|AZ300MIF
|60s
|60s
|Used MLA design
|Used HIMT design
|-
|-
|[[:File:3600 D, D2v Spin Speed Curve.pdf|THMR-3600HP]]
|[[Media:3600 D, D2v Spin Speed Curve.pdf|THMR-3600HP]]
|1.5 krpm, 45s;
|1.5 krpm, 45s;
250 rpm/s
250 rpm/s
Line 94: Line 127:
|180–220
|180–220
|<nowiki>-4</nowiki>
|<nowiki>-4</nowiki>
|
|100°C, 60s
|100°C, 60s
|AZ300MiF
|AZ300MiF
Line 100: Line 134:


lower dose for clear-field, higher dose for dark-field.
lower dose for clear-field, higher dose for dark-field.
|-
| colspan="12" |*''Rehydration'': After exposure, leave sample in lab air (ok to cover in tray, with tinfoil). Allows water vapor in air to diffuse into PR to complete chemical reaction.
<nowiki>**</nowiki>''PEB: Post-exposure bake'': after exposure, before develop
|}
|}


=== Negative Resist (MLA150) ===
===Negative Resist (MLA150)===
''We found that all the negative PR's we tested required the 375nm in order to be fully exposure with reasonable dose.''
''We found that all the negative PR's we tested required the 375nm in order to be fully exposed with reasonable dose/time.''


{| class="wikitable" border="1" style="border: 1px solid #D0E7FF; background-color:#ffffff; text-align:center;"
{| class="wikitable" style="border: 1px solid #D0E7FF; background-color:#ffffff; text-align:center;" border="1"
|- bgcolor="#D0E7FF"
|- bgcolor="#D0E7FF"
! width="100" |Resist
! width="100" |Resist
Line 114: Line 151:
! width="125" |Exposure Dose (mJ/cm<sup>2</sup>)
! width="125" |Exposure Dose (mJ/cm<sup>2</sup>)
! width="100" |DeFocus
! width="100" |DeFocus
! width="75" |PEB
! width="75" |PEB*
! width="75" |Flood
! width="75" |Flood*
! width="100" |Developer
! width="100" |Developer
! width="125" |Developer Time
! width="125" |Developer Time
! width="300" |Comments
! width="300" |Comments
|-
|-
|[[:File:AZ5214-Negative-Resist-Datasheet.pdf|AZ5214]]
|[[Media:AZ5214-Negative-Resist-Datasheet.pdf|AZ5214]]
|6 krpm, 30s
|6 krpm, 30s
|95°C, 60s
|95°C, 60s
Line 133: Line 170:
|Used UCSB design. Good for up to ~1.3um open line space.
|Used UCSB design. Good for up to ~1.3um open line space.
|-
|-
|[[Media:AZnLOF2020-Negative-Resist-Datasheet.pdf|AZnLOF2020]]
|AZnLOF2020
|4 krpm, 30s
|4 krpm, 30s
|110°C, 60s
|110°C, 60s
Line 146: Line 183:
|Used UCSB design. Good for 2um open line space.
|Used UCSB design. Good for 2um open line space.
|-
|-
|[[:File:SU-8-2075-revA.pdf|SU-8 2075]]
|[[Media:SU-8-2075-revA.pdf|SU-8 2075]]
|
|
|
|
Line 158: Line 195:
|
|
|Extremely viscous. Pour into a wide-mouthed bottle, dispense directly from bottle. Replace napkin at end.
|Extremely viscous. Pour into a wide-mouthed bottle, dispense directly from bottle. Replace napkin at end.
|-
| colspan="12" |*PEB: post-exposure bake. For AZ 5214-IR, this performs Image Reversal, and requires Flood Exposure with the [[Contact Aligner (SUSS MA-6)|MA6]] or [[Suss Aligners (SUSS MJB-3)|MJB]] aligner afterwards, before developing.
|}
|}


=== Greyscale Lithography (MLA150) ===
===Greyscale Lithography (MLA150)===
''AZ4620 is the manufacturer-recommended PR for greyscale litho.''
''AZ4620 is the manufacturer-recommended PR for greyscale litho.''

{| class="wikitable" border="1" style="border: 1px solid #D0E7FF; background-color:#ffffff; text-align:center;"
Please see the [[MLA150 - Design Guidelines#Limitations%20.26%20Workarounds|'''MLA150 - Greyscale Design Guidelines & Limitation''']]
{| class="wikitable" style="border: 1px solid #D0E7FF; background-color:#ffffff; text-align:center;" border="1"
|- bgcolor="#D0E7FF"
|- bgcolor="#D0E7FF"
! width="100" |Resist
! width="100" |Resist
Line 168: Line 209:
! width="75" |Bake
! width="75" |Bake
! width="75" |Thickness
! width="75" |Thickness
!Laser
! width="125" |Exposure Dose (mJ/cm<sup>2</sup>)
! width="125" |Exposure Dose (mJ/cm<sup>2</sup>)
! width="100" |Focus Offset
! width="100" |Focus Offset
!Rehydrate*
! width="75" |PEB
! width="75" |Flood
! width="75" |PEB**
! width="100" |Developer
! width="100" |Developer
! width="125" |Developer Time
! width="125" |Developer Time
!Reflow***
! width="300" |Comments
! width="300" |Comments
|-
|-
|[[Media:Az p4620 photoresist data package.pdf|AZ4620]]
|AZ4620
| krpm/30”
|? krpm/30”
|95°C, 60”
|95°C, 60”
|
|
Line 183: Line 226:
|
|
|
|
|60"
|
|
|AZ300MIF
|AZ300MIF
|60s
|60s
|
| align="left" |
| align="left" |''To Be Added''
*''TBD''
|-
|[[Media:SPR220-Positive-Resist-Datasheet.pdf|SPR 220-7.0]]
|3.5 krpm, 30s
|105°C/2min
Cool 1min
|~ 7.0µm
|375
|~624mJ to clear large mm-area,
520mJ to clear ~5µm lines.
| -20
|≥1hr
|115°C, 90s
|AZ300MiF
|70s
|TBD
|<small>Author Credit:</small>
* <small>Patrick Curtis, 2022</small>
* <small>Biljana Stamenic 2023</small>
* <small>Demis D. John 2023</small>
|-
|
| colspan="12" |Notes on SPR 220-7 Greyscale: Rehydration after exposure is necessary, to prevent bubbles at PEB.
Stitching leaves ridges in Y-direction with ~5% height of removed PR depth. Can be reduced via reflow, but significantly affects PR profile.

<small>Author Credit: Patrick Curtis, 2022 & Biljana Stamenic 2023 & Demis D. John 2023; Please see our [[Frequently Asked Questions#Publications acknowledging the Nanofab|publications policy]].</small>
|-
| colspan="13" |*''Rehydration'': After exposure, leave sample in lab air (ok to cover in tray, with tinfoil). Allows water vapor in air to diffuse into PR to complete chemical reaction.
<nowiki>**</nowiki>''PEB: Post-exposure bake'': after exposure, before develop

<nowiki>***</nowiki>''Reflow'': To smooth out stitching lines. Will change sharp vertical profiles considerably, only good for gradually-sloped profiles.
|}
|}

Revision as of 14:13, 17 July 2024

Maskless Aligner (Heidelberg MLA150)

For CAD design tips and requirements, see these pages:

Photolithography Recipes for the Heidelberg MLA150. All recipes were characterized on blank Silicon wafers. For different substrate coatings/materials, you will likely need to run a focus-exposure matrix ("series" exposure mode), using our params as a starting point.

These recipes use the same spin and bake params as our contact aligner and stepper recipes, using built-in hotplates on the photoresist spinner benches.

Any I-Line PR is usable, although we only characterized a select few below. Run your own Focus-Exposure Matrix to characterize a new PR.

Note: On this tool, it is common to have to run a Focus-Exposure Matrix (aka. FEM), via "Series" exposure mode, for each new layer structure and/or critical feature size. The layer structure can strongly affect the exposure parameters. See the FEM Analysis Tips page for how to choose the proper exposure parameters.

The MLA Troubleshooting > Out-of-Focus Exposures section can help you avoid bad exposures, please read it!

Positive Resist (MLA150)

We found that positive PR's worked well with the 405nm laser - the 375nm laser would likely also work. Sub-micron features are possible. Overexposure is recommended to avoid stitching and horiz/vert discrepancies; compensate for widening/narrowing using CD Bias as described here.

Note: calibrations done with the "HIMT design" will show higher dose, due to using only dark-field line/space patterns.

Resist Spin Cond. Bake Thickness Laser (nm) Exposure Dose (mJ/cm2) DeFocus Rehydrate* PEB** Developer Developer Time Comments
AZ4110 4 krpm, 30s 95°C, 60s ~ 1.1 µm 405 240 5 none AZ400K:DI 1:4 50s Used HIMT design (good for isolated lines 0.8-1um)
AZ4330 4 krpm, 30s 95°C, 60s ~ 3.3 µm 405 320 6 none AZ400K:DI 1:4 90s Used HIMT design
AZ4620
SPR 220-3.0 2.5 krpm, 30s 115°C, 90s ~ 2.7 µm 405 325 - 4 115°C, 90s AZ300MIF 60s Used HIMT design. 0.6-0.9µm line/space.
SPR 220-7.0 3.5 krpm, 30s 105°C/2min

Cool 1min

~ 7.0µm 375 ~550mJ -20 >1hr 115°C, 90s AZ300MiF 70s Rehydration after exposure is necessary, to prevent bubbles at PEB.
SPR 955-CM0.9 3 krpm, 30s 95°C, 90s ~ 0.9 µm 405 250 - 7 110°C, 90s AZ300MIF 60s Used HIMT design
THMR-3600HP 1.5 krpm, 45s;

250 rpm/s

100°C, 60s 0.430µm 405 180–220 -4 100°C, 60s AZ300MiF 20s ~0.4nm line/space:

lower dose for clear-field, higher dose for dark-field.

*Rehydration: After exposure, leave sample in lab air (ok to cover in tray, with tinfoil). Allows water vapor in air to diffuse into PR to complete chemical reaction.

**PEB: Post-exposure bake: after exposure, before develop

Negative Resist (MLA150)

We found that all the negative PR's we tested required the 375nm in order to be fully exposed with reasonable dose/time.

Resist Spin Cond. Bake Thickness Laser (nm) Exposure Dose (mJ/cm2) DeFocus PEB* Flood* Developer Developer Time Comments
AZ5214 6 krpm, 30s 95°C, 60s ~ 1.0 µm 375 35 - 5 110°C, 60s 60" AZ300MIF 60s Used UCSB design. Good for up to ~1.3um open line space.
AZnLOF2020 4 krpm, 30s 110°C, 60s ~ 2.1µm 375 340 - 3 110°C, 60s none AZ300MIF 90s Used UCSB design. Good for 2um open line space.
SU-8 2075 ~70µm 375 Extremely viscous. Pour into a wide-mouthed bottle, dispense directly from bottle. Replace napkin at end.
*PEB: post-exposure bake. For AZ 5214-IR, this performs Image Reversal, and requires Flood Exposure with the MA6 or MJB aligner afterwards, before developing.

Greyscale Lithography (MLA150)

AZ4620 is the manufacturer-recommended PR for greyscale litho.

Please see the MLA150 - Greyscale Design Guidelines & Limitation

Resist Spin Cond. Bake Thickness Laser Exposure Dose (mJ/cm2) Focus Offset Rehydrate* PEB** Developer Developer Time Reflow*** Comments
AZ4620 ? krpm/30” 95°C, 60” AZ300MIF 60s To Be Added
SPR 220-7.0 3.5 krpm, 30s 105°C/2min

Cool 1min

~ 7.0µm 375 ~624mJ to clear large mm-area,

520mJ to clear ~5µm lines.

-20 ≥1hr 115°C, 90s AZ300MiF 70s TBD Author Credit:
  • Patrick Curtis, 2022
  • Biljana Stamenic 2023
  • Demis D. John 2023
Notes on SPR 220-7 Greyscale: Rehydration after exposure is necessary, to prevent bubbles at PEB.

Stitching leaves ridges in Y-direction with ~5% height of removed PR depth. Can be reduced via reflow, but significantly affects PR profile.

Author Credit: Patrick Curtis, 2022 & Biljana Stamenic 2023 & Demis D. John 2023; Please see our publications policy.

*Rehydration: After exposure, leave sample in lab air (ok to cover in tray, with tinfoil). Allows water vapor in air to diffuse into PR to complete chemical reaction.

**PEB: Post-exposure bake: after exposure, before develop

***Reflow: To smooth out stitching lines. Will change sharp vertical profiles considerably, only good for gradually-sloped profiles.