Unaxis wafer coating procedure

Important Notes

• Maximum 0.5µm of deposition prior to chamber cleaning, in order to maintain low particle counts.
• See the ICP-PECVD Unaxis Recipes page for thin-film properties of each of the following recipes.
• We highly recommend using the Surfscan particle counter to monitor particle counts on look-ahead wafers prior to deposition.
  • You must measure particle count on wafers before and after the deposition. We usually run "SiO2 HDR-Std" recipe. See the procedures on the Surfscan page.
  • If you note abnormally high particle counts for G4 (>200):
    • Run chamber clean
    • Chamber season on a clean test wafer
    • Retest Particle counts
      • If particle counts are still high, notify the tool supervisor.
• For new recipes (as of Dec. 2019), users may only edit Deposition Time, no other recipe modifications or customizations are permitted without staff approval.

Unaxis SiO2 Low Dep. Rate @250C deposition

a) Prepare wafers:

• Regular 4 " Si wafer ~500µm thick for seasoning [W2-coat, stored in separate box for Unaxis Seasoning, chase 6]
• Your substrate for deposition (if smaller than 4", needs to be loaded on an Si carrier wafer)
• Thick 4" AlN wafer~(0.8-1mm) for cleaning [shiny side down]

b) Load all 3 wafers in a cassette, making sure major flat is facing outside (toward you). Try to align flats for all three wafers.

c) Edit standard recipes (for seasoning, deposition, and cleaning). You can ONLY change the time in these recipes.

• Seasoning recipe name: SiO2 seasoning, t=2min
  • There is only one SiO2 seasoning recipe that is used for both LDR and HDR depositions. The goal in this step is to prepare the chamber and deposit ~200nm of SiO2 on walls.
• Deposition recipe name:  SiO2 LDR 250°C, t=780sec
• Cleaning recipe name: Post dep PD, t=900sec

d) Run the job (first run seasoning, then deposition on your substate and cleaning at the end).

• You should monitor process at the very beginning to make sure there are no any issues with the run.

e) Unload wafers when all runs are finished.

Unaxis SiO2 High Dep Rate 250°C deposition

a) Prepare wafers:

• Regular 4 " Si wafer ~500µm thick for seasoning [W1-coat, stored in separate box for Unaxis Seasoning, chase 6]
• Your substrate for deposition (if smaller than 4", needs to be loaded on a Si carrier wafer)
• Thick 4" AlN wafer~(0.8-1mm) for cleaning [shiny side down]

b) Load all wafers in a cassette, making sure major flat is facing outside (toward you). Try to align flats for all three wafers.

c) Edit standard recipes (for seasoning, deposition, and cleaning). You can ONLY change the time in the recipe.

• Seasoning recipe name: SiO2 seasoning, t=2min
  • There is only one SiO2 seasoning recipe that is used for both LDR and HDR depositions. The goal in this step is to prepare the chamber and deposit ~200nm of SiO2 on walls.
• Deposition recipe name: SiO2 HDR 250°C, t=180 sec
• Cleaning recipe name: Post dep PD, t=900sec

d) Run the job (first run seasoning, then deposition on your substate and cleaning at the end).

• You should monitor process at the very beginning to make sure there are no any issues with the run.

e) Unload wafers when all runs are finished.

Unaxis SiN 250°C deposition

a) Prepare wafers:

• Regular 4 " Si wafer ~500µm thick for seasoning [W3-coat, stored in separate box for Unaxis Seasoning, chase 6]
• Your substrate for deposition (if smaller than 4", needs to be loaded on an Si carrier wafer)
• Thick 4" AlN wafer~(0.8-1mm) for cleaning [shiny side down]

b) Load all wafers in a cassette, making sure major flat is facing outside (toward you). Try to align flats for all three wafers.

c) Edit standard recipes (for seasoning, deposition, and cleaning). You can ONLY change the time in the recipe.

• Seasoning recipe name: SiN seasoning, t=5min
• Deposition recipe name: SiN 250°C, t=480sec
• Cleaning recipe name: Post dep PD, t=1500sec

d) Run the job (first run seasoning, then deposition on your substate and cleaning at the end).

• You should monitor process at the very beginning to make sure there are no any issues with the run.

e) Unload wafers when all runs are finished.

Unaxis SiN Low-Stress 250°C deposition

a) Prepare wafers:

• Regular 4 " Si wafer ~500µm thick for seasoning [W4-coat, stored in separate box for Unaxis Seasoning, chase 6]
• Your substrate for deposition (if smaller than 4", needs to be loaded on an Si carrier wafer)
• Thick 4" AlN wafer~(0.8-1mm) for cleaning [shiny side down]

b) Load all wafers in a cassette, making sure major flat is facing outside (toward you). Try to align flats for all three wafers.

c) Edit standard recipes (for seasoning, deposition, and cleaning). You can ONLY change the time in the recipe.

• Seasoning recipe name: SiN seasoning, t=2min
• Deposition recipe name: SiN LS 250°C, t=180sec
• Cleaning recipe name: Post dep PD, t=1500sec

d) Run the job (first run seasoning, then deposition on your substate and cleaning at the end).

• You should monitor process at the very beginning to make sure there are no any issues with the run.

e) Unload wafers when all runs are finished.