Contact Lithography Recipes

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. The recipes are tabulated to give you the values of the key parameters you will need to establish your recipe. For wafer cleaning and preparation including HMDS use, please refer to the cleaning and preparation section in the lithography section of this web site. For best resolution using thin resists, you will need to remove any edge bead before contact and exposure. Also, hard contact mode will give you the most intimate contact between sample and mask, giving the best resolution. Post develop bakes (not listed) are used to make the resist more etch resistant and depend on subsequent processes. Unless otherwise noted, all exposures are done on silicon wafers. 

 

Positive Resist

Unless otherwise noted, bakes are on hot plates and the exposure of the resist is done using no filtering at 7.5 mW/cm2.  Power of the lamp is set using the 405 nm (h-line) detector.  For the MA-6 aligner, using Channel 1, reduce exposure times by a factor of 2.4.

Resist

Spin Cond.

Bake

Thickness

Exp. Time

Developer

Dev. Time

Comment

SPR510A

4 krpm/30”

95°C/60”

~ 0.9 um

20”

AZ300MIF

30”

More Details Here

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 Details Here

SPR220-7.0

3.5 krpm/45”

115°C/120”

~ 7.5 um

60”

AZ300MIF

70”

More Details Here

 

Negative Resist

Unless otherwise noted, bakes are on hot plates and the exposure of the resist is done using no filtering at 7.5 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.  For the MA-6 aligner, using Channel 1, reduce exposure times by a factor of 2.4.

Resist

Spin Cond.

Bake

Thickness

Exp. Time

PEB

Flood

Developer

Dev. Time

Comment

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 Details Here

 

2-Layer Lift-Off

Below are links to more detailed recipes using 2-layer processes for lift-off purposes. For a general description of lift-off techniques, please see the lift-off techniques page in the lithography section.

2-layer positive and negative processes using PMGI as underlayer

 

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