Wafer Scanning/Coating Process Traveler ( combined/less detailed)
WIP....
The wafers for process calibration are ordered from SVM (https://www.svmi.com/). These are: 4” Si wafers, P/Boron, <100>, 1-30 ohm-cm, 525 +/-25 microns, Polished/Etched, Particles: <=10 @ >=0.3 microns, and have low LPD count (LPD= light particle detection, LPD<100).
Scan Before Deposition
Log in (access code is boss).
Scan the wafers using the standard recipes: "UCSB Gain4 (measuring small particles 0.16-1.6um ), and " UCSB Gain2 measuring small particles 1.6-28um).
Record: LPD Cnt (sum of all particles #1- #8), particles #1(0.160-0.213)um, particles #8(1.20-1.60)um, and Haze (region(%), average(ppm), peak(ppm)).
Take a picture of the scan.
Log out.
Wafer Coating Process traveler
Test run with "dummy wafer"
Sometimes the first wafer, after seasoning, might have high particle count. It is recommended to run the process on a dummy wafer to catch the particle, before the run on "real wafer". Here are the process instructions:
Prepare three 4" Si wafers : for seasoning, deposition (use one of previously scanned Si wafers) and cleaning.
Load wafers in a cassette, making sure major flat is facing outside (toward you). Try to align flats for all three wafers.
Load/Edit/Verify standard recipes (for seasoning, deposition, and cleaning). You can change ONLY the time in recipes.
Example for the standard "SiO2 LDR 250°C"
· Load seasoning recipe " SiO2 seasoning" , time=2min
· Load deposition recipe "SiO2 LDR 250°C" , time=780 sec
· Load cleaning recipe "Post dep PD", t=900sec
Run the process Unload the wafers and check particle count on wafer with SiO2 film deposited If the particle count is normal (LPD<500) , you can proceed to deposition of "real wafers".
If the particle count is high (scan looks bad), you could run longer clean and try again. If the particle count is still high, please contact the tool owner.
Run on "real wafers"
The each film that you want to deposit in this tool, you should run: seasoning, deposition and cleaning.
We have seasoning recipes for each film. There is only one SiO2 seasoning recipe. This same recipe is used for seasoning for both LDR and HDR depositions. The seasoning recipes are exactly the same as deposition recipes, the time for coating is different. The goal in seasoning step is to prepare the chamber and deposit ~200nm of film on walls.
There are four standard recipes for deposition:
"SiO2 LDR film @250°C" (seasoning 2min, deposition=780sec, clean=900sec)
"SiO2 HDR film @250°C" (seasoning 2min, deposition=180sec, clean=900sec)
"SiN film @250°C " (seasoning 5min, deposition=480sec, clean=1500sec)
"SiN LS film @250°C " (seasoning 2min, deposition=180sec, clean=1500sec)
There is one recipe for cleaning "Post dep PD". The time for cleaning will depend of the thickness of the film previously deposited.
Scan After process calibration
Log in (access code is boss).
Scan the wafers using the standard recipes: "UCSB Gain4 (measuring small particles 0.16-1.6um ), and " UCSB Gain2 measuring small particles 1.6-28um).
Record: LPD Cnt (sum of all particles #1- #8), particles #1(0.160-0.213)um, particles #8(1.20-1.60)um, and Haze (region(%), average(ppm), peak(ppm)).
Take a picture of the scan.
Log out.