Stepper Recipes

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Below is a listing of stepper lithography recipes. Stepper 1 and Stepper 2 are i-line systems with good piece handling capabilities.  Stepper 3 is a DUV (248nm) system.  DUV resists do not work for i-line and i-line resists do not work for DUV.  Based on your sample reflectivity, absorption (or whether or not you use an ARC layer), and surface topography the exposure time / focus offset 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. Underlayers such as LOL2000 or PMGI can be used on the stepper systems.  See the underlayer datasheets for details.   Post develop bakes (not listed) are used to make the resist more etch resistant and depend on subsequent processes. Care should be taken with post development bakes as resist reflow can occur. Unless otherwise noted, all exposures are done on flat, silicon wafers.

Parameters are indicated in separate tables for each stepper system. Multiply the exposure times by 0.30 (from the 6300 system) to get a starting exposure time for the GCA Autostep200 system. You will need to do a focus and/or exposure array to get optimal process parameters. 

Contents

Stepper 1 (GCA 6300)

Positive Resist (GCA 6300)

Unless otherwise noted, bakes are on hot plates. For recipes with CEM, the CEM is spun on after the first resist bake, exposure is then done, and the CEM is rinsed off with DI water before the PEB. CEM generally improves resolution and process tolerance at the expense of higher exposure time.

Resist Spin Cond. Bake Thickness Exposure Time Focus Offset PEB Developer Developer Time Comments
SPR955CM0.9 3 krpm/30” 95°C/60” ~ 0.9 um 1.2” 0 110°C/60” AZ300MIF 60"
SPR955CM0.9 3 krpm/30” 95°C/60” ~ 0.9 um 3.0” 4 110°C/60” AZ300MIF 60"
SPR955CM0.9

CEM365iS

3 krpm/30”

5 krpm/30”

95°C/90” ~ 0.9 um 2.2” -10 110°C/60” AZ300MIF 60"
SPR950-0.8 4 krpm/30” 95°C/60” ~ 0.8 um 1.0” 0 105°C/60” AZ300MIF 60"
SPR955CM-1.8 4 krpm/30” 90°C/90” ~ 1.8 um 2.3” 0 110°C/90” AZ300MIF 60"
SPR955CM-1.8 4 krpm/30” 90°C/90” ~ 1.8 um 1.7” -5 110°C/90” AZ300MIF 60"


SPR220-3.0 2.5 krpm/30” 115°C/90” ~ 2.7 um 2.4” 10 115°C/90” AZ300MIF 60"
SPR220-7.0 3.5 krpm/45” 115°C/120” ~ 7.0 um 4.5” 0 *50°C/60”

115°C/90”

AZ300MIF 120"
  • 1.0 um isolated lines; 1.25 um isolated spaces
    • Let sample sit in air for 20 minutes before PEB, step to 50°C for 60” first, then 115°C
  • See SPR220-7 Data File

Negative Resist (GCA 6300)

Unless otherwise noted, bakes are on hot plate. 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 Focus Offset PEB Flood Developer Developer Time Comments
AZ5214 6 krpm/30” 95°C/60” ~ 1.0 um 0.2” 0 110°C/60” 60" AZ300MIF 60"
  • 0.7 um res. possible 
nLOF5510 3 krpm/30” 90°C/60” ~ 0.93 um 0.74” -6 110°C/60” 0 AZ300MIF 60"
  • 0.5 um line openings good dense or isolated
  • Use heated 1165 stripper for removal or lift-off
  • See nLOF5510 data file
nLOF2020 4 krpm/30” 110°C/60” ~ 2 um 0.55” -6 110°C/60” 0 AZ300MIF 90"
  • ~ .85 um line opening/lift-off good. Isolated mesas can be smaller.
  • Use heated 1165 stripper for removal or lift-off Sensetive to PEB temp.
  • See nLOF2020 Data File

Stepper 2 (AutoStep 200)

Positive Resist (AutoStep 200)

Unless otherwise noted, bakes are on hot plates. For recipes with CEM, the CEM is spun on after the first resist bake, exposure is then done, and the CEM is rinsed off with DI water before the PEB. CEM generally improves resolution and process tolerance at the expense of higher exposure time.

NOTE: The bolded exposure times were found by multiplying the exposure times from the GCA 6300 system by 0.30. They should be sued as a starting point. You will need to do an exposure array to get precise times for the Autostep system. In general, the resolution achievable is ~ 100 nm smaller for the Autostep200 system.

Resist Spin Cond. Bake Thickness Exposure Time Focus Offset PEB Developer Developer Time Comments
SPR955CM-0.9 3 krpm/30” 95°C/90” ~ 0.9 um 0.35” 0 110°C/90” AZ300MIF 60”
SPR955CM-0.9 3 krpm/30” 95°C/90” ~ 0.9 um 0.8” 0 110°C/90” AZ300MIF 60”
  • 0.5um holes
SPR955CM-1.8 4 krpm/30” 95°C/90” ~ 1.8 um 0.4” -1 110°C/90” AZ300MIF 60”
SPR950-0.8 4 krpm/30” 95°C/60” ~ 0.8 um 0.30” 0 105°C/60” AZ300MIF 60"
SPR220-3.0 2.5 krpm/30” 115°C/90” ~ 2.7 um 0.72” 10 115°C/90” AZ300MIF 60"
  • 0.5 um isolated lines
SPR220-7.0 3.5 krpm/45” 115°C/120” ~ 7.0 um 1.35" 0 *50°C/60”

115°C/90”

AZ300MIF 120"
  • 1.0 um isolated lines; 1.25 um isolated spaces
    • Let sample sit in air for 20 minutes before PEB, step to 50°C for 60” first, then 115°C

Negative Resist (AutoStep 200)

Unless otherwise noted, bakes are on hot plate. 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.

NOTE: The bolded exposure times were found by multiplying the exposure times from the GCA 6300 system by 0.30. They should be sued as a starting point. You will need to do an exposure array to get precise times for the Autostep system. In general, the resolution achievable is ~ 100 nm smaller for the Autostep200 system.

Resist Spin Cond. Bake Thickness Exposure Time Focus Offset PEB Flood Developer Developer Time Comments
nLOF5510 3 krpm/30” 90°C/60” ~ 0.93 um .25” -1 110°C/60” 0 AZ300MIF 60”
AZ5214 6 krpm/30” 95°C/60” ~ 1.0 um 0.06” 0 110°C/60” 60" AZ300MIF 60"
  • 0.7 um res. possible
nLOF2020 4 krpm/30” 110°C/60” ~ 2 um 0.17” -6 110°C/60” 0 AZ300MIF 90"
  • ~ .85 um line opening/lift-off good. Isolated mesas can be smaller.
  • Use heated 1165 stripper for removal or lift-off Sensetive to PEB temp.

Stepper 3 (ASML DUV)

Positive Resist (ASML DUV)

Anti-reflective coatings are, in general, used for the ASML stepper. LOL2000 and PMGI can also be used.  For AR2 coatings, spin coat at 3500rpm for a 670A thick coating.  Bake at 220C for 60s on a hotplate.  This AR coating is removed via oxygen plasma.  RIE 5 parameters are 20sccm, 10mT, 100W for 40s.  For DS-K101, spin at 5000rpm and bake at 185C for 60s.  This AR coating develops away and undercuts in AZ300MIF.  For isolated lines, this can cause them to lift-off.  If undercut rate is too high, increase bake temperature.  

Resist Spin Cond. Bake Thickness Exposure Dose(mj) Focus Offset PEB Developer Developer Time Comments
UV6-0.7 3.5 krpm/30” 135°C/60” 630nm 17 -0.2 135°C/90” AZ300MIF 45”
  • 200nm dense line/space
  • NA 0.57, Sigma 0.75
  • Eo ~ 5.5mj
UV210-0.3 5.0 krpm/30” 135°C/60” 230nm 20 -0.1 135°C/90” AZ300MIF 45"
  • 150nm dense line/space
  • NA 0.63, Sigma_o 0.8, Sigma_i 0.5
UV210-0.3 3.0 krpm/30” 135°C/90” 260nm 85 -0.2 135°C/90” AZ300MIF 80”
  • 170nm isolated holes
  • NA 0.63, Sigma_o 0.8, Sigma_i 0.5

Negative Resist (ASML DUV)

Anti-reflective coatings are, in general, used for the ASML stepper. LOL2000 and PMGI can also be used. For AR2 coatings, spin coat at 3500rpm for a 670A thick coating. Bake at 220C for 60s on a hotplate. This AR coating is removed via oxygen plasma. RIE 5 parameters are 20sccm, 10mT, 100W for 40s. For DS-K101, spin at 5000rpm and bake at 185C for 60s. This AR coating develops away and undercuts in AZ300MIF. For isolated lines, this can cause them to lift-off. If undercut rate is too high, increase bake temperature.


Resist Spin Cond. Bake Thickness Exposure Dose (mj) Focus Offset PEB Flood Developer Developer Time Comments
UVN2300-0.5 2.5 krpm/30” 110°C/60” 550nm 23 +0.2 105°C/60” Not Used AZ300MIF 40”
  • 200nm isolated line
  • NA 0.57, Sigma 0.5
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