Contact Alignment Recipes

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Notes

Below is a listing of contact lithography recipes for use with designated aligners.

Based on your sample reflectivity, absorption, and surface topography the exposure time parameters may vary. This listing is a guideline to get you started.

For best resolution using thin resists, you will need to remove any edge bead before contact and exposure. This can be done with a razor blade (not for brittle substrates), or EBR-100 on a cotton swab (wipe off excess liquid before using), or lithgraphically with a tin-foil mask, flood exposure and develop.

Also, hard contact mode will give you the most intimate contact between sample and mask, giving the best resolution. However for flat unpatterned substrates, this can cause wafers to stick to the mask plate.

Post develop bakes (not listed, aka. "hard bake") are used to make the resist more etch resistant and depend on subsequent processes. Unless otherwise noted, all exposures are done on silicon wafers.

Suss Aligners (SUSS MJB-3)

Positive Resist (MJB-3)

Unless otherwise noted, bakes are on hot plates and the exposure of the resist is done using no filtering at 7.0 mW/cm2. Only Channel @2 is used/calibrated. Power of the lamp is set using the 405 nm (h-line) detector.

Resist	Spin Cond.	Bake	Thickness	Exposure Time	Developer	Developer Time	Comments
AZ4110	4 krpm/30”	95°C/60”	~ 1.1 um	8”	AZ400K:DI 1:4	50"
AZ4210	4 krpm/30”	95°C/60”	~ 2.1 um	13”	AZ400K:DI 1:4	70”
AZ4330	4 krpm/30”	95°C/60”	~ 3.3 um	18”	AZ400K:DI 1:4	90”
SPR220-3.0	3.5 krpm/30”	115°C/90”	~ 2.5 um	25”	AZ300MIF	50”	Post Bake 115°C /60” Better Cl2 etch resistance than 4330 More Information
SPR220-7.0	3.5 krpm/45”	115°C/120”	~ 7.5 um	60”	AZ300MIF	70”	More Information

Negative Resist (MJB-3)

Unless otherwise noted, bakes are on hot plates and the exposure of the resist is done using no filtering at 7.0 mW/cm2. Power of the lamp is set using the 405 nm (h-line) detector. In general, many negative resists require post-exposure-bakes (PEB) / flood exposures in order to make the negative tone of the image. All flood exposures are done in broadband light using any contact aligner. Also, because the tone is negative, a shorter first exposure time will result in more undercut, which is desirable for single-layer lift-off processes. Under these conditions more develop time will also give more undercut.

Resist	Spin Cond.	Bake	Thickness	Exposure Time	PEB*	Flood**	Developer	Developer Time	Comments
AZ5214**	6 krpm/30”	95°C/60”	~ 1 um	5”	110°C/60”	60”	AZ400K:DI 1:5.5 or AZ300MIF	60" 45"	Concentrated 400K Dev. Etches 5214
AZ5214**	6 krpm/30”	95°C/60”	~ 1 um	10”	110°C/60”	60”	AZ300MIF	45”	Using i-line filter in MJB-3. 0.7 um resolution possible
AZnLOF2020	3 krpm/30”	110°C/90”	~ 2.1 um	10”	110°C/60”		AZ300MIF	60”	Use i-line filter For Undercut More Information
NR9-6000PY	3 krpm/30”	140°C/180”	~ um	30”	100°C/60”		AZ300MIF	30”	Before litho, do Gasonics #3, 120"; Bake at 140 C, 5' Spin-on HMDS 3krpm 30", prior to NR9-6000PY
*PEB: post-exposure bake. For AZ 5214-IR, this performs Image Reversal ** To use AZ5214 as a negative PR requires Flood Exposure with the MA6 or MJB aligner after PEB, before developing. See here for a basic AZ5214 process, it is different than typical negative resists.

Contact Aligner (SUSS MA-6)

Positive Resist (MA-6)

Unless otherwise noted, bakes are on hot plates and the exposure of the resist is done using no filtering at 9 mW/cm2 (Channel 1). Power of the lamp is set using the 365 nm (i-line) detector. For reference, this would equate to 17.5 mW/cm² when measured with a 405 nm (h-line) detector.

For the MA-6 aligner, using Channel 1, the exposure times given below are the same as the MJB-3 except they have been reduced by a factor of 2.4.

Resist	Spin Cond.	Bake	Thickness	Exposure Time	Developer	Developer Time	Comments
AZ4110	4 krpm/30”	95°C/60”	~ 1.1 um	3.3”	AZ400K:DI 1:4	50"
AZ4210	4 krpm/30”	95°C/60”	~ 2.1 um	5.4”	AZ400K:DI 1:4	70”
AZ4330	4 krpm/30”	95°C/60”	~ 3.3 um	7.5”	AZ400K:DI 1:4	90”
SPR955CM-0.9	3 krpm/30”	95°C/60”	~ 0.9 um	8”	AZ300MIF	70”	Post Exposure Bake 110°C /60”
SPR220-3.0	3.5 krpm/30”	115°C/90”	~ 2.5 um	10.4”	AZ300MIF	50”	Post Bake 115°C /60” Better Cl2 etch resistance than 4330
SPR220-7.0	3.5 krpm/45”	115°C/120”	~ 7.5 um	25”	AZ300MIF	70”

Negative Resist (MA-6)

Unless otherwise noted, bakes are on hot plates and the exposure of the resist is done using no filtering at 9 mW/cm2 (Channel 1). Power of the lamp is set using the 365 nm (i-line) detector. For reference, this would equate to 17.5 mW/cm² when measured with a 405 nm (h-line) detector.

In general, many negative resists require post-exposure-bakes (PEB) / flood exposures in order to make the negative tone of the image. All flood exposures are done in broadband light using any contact aligner. Also, because the tone is negative, a shorter first exposure time will result in more undercut, which is desirable for single-layer lift-off processes. Under these conditions more develop time will also give more undercut. For the MA-6 aligner, using Channel 1, the exposure times given below are the same as the MJB-3 except they have been reduced by a factor of 2.4.

Resist	Spin Cond.	Bake	Thickness	Exposure Time	PEB*	Flood Exposure**	Developer	Developer Time	Comments
AZ5214**	6 krpm/30”	95°C/60”	~ 1 um	2.1”	110°C/60”	30"	AZ400K:DI 1:5.5 or AZ300MIF	60" 45"	Concentrated (undiluted) 400K Dev. Etches 5214
AZnLOF2020	3 krpm/30”	110°C/90”	~ 2.1 um	4.2”	110°C/60”		AZ300MIF	60”	For Undercut
AZnLOF2035	2.5 krpm/30”	110°C/60”	~ 3.5 um	5.0”	110°C/60”		AZ300MIF	70”	For Undercut
NR9-6000PY	3 krpm/30”	140°C/180”	~ um	13.1”	100°C/60”		AZ300MIF	30”	Before litho, do Gasonics #3, 120"; Bake at 140 C, 5' Spin-on HMDS 3krpm 30", prior to NR9-6000PY
*PEB: post-exposure bake. For AZ 5214-IR, this performs Image Reversal ** To use AZ5214 as a negative PR requires Flood Exposure with the MA6 or MJB aligner after PEB, before developing. See here for a basic AZ5214 process, it is different than typical negative resists.

SU-8 Recipes

Staff-developed recipes for SU-8:

• SU-8-2005 Recipe
• SU-8-2010 Recipe
• SU-8-2015 Recipe