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Qual Procedure

The procedure for running the qual on the HD PECVD system is outlined. Interested labmembers are encouraged to run a qual. Lab Staff will run quals at a regular intervals or as problems with the tool are reported.


The quals are run in the following sequence of steps:

 Requires two test runs, one for SiO and one for SiN

1. verify the heat exchanger is at temp, 90C

2. preparing for run:

   A. run recipe HD_Etchback until chamber thickness is 0

   B. run recipe that is going to be used for the film to ensure the chamber is covered with the same material

   C. clean the wafer in the wbdiff with 10 min in NH4OH bath, 10 min in HCl bath, and 30 seconds in 50:1 HF bath

3. run the no film measurement on the StressTest

   A. save file as hdqx, where hd stands for the machine, q for qual, and x is the number of the qual wafer

   B. id = qx

   C. comment = date

4. deposit films

   A. for SiO film, use recipe HD_SiO for 480 secs

   B. for SiN film, use recipe HD_SiNx for 480 secs

5. run the single StressTest measurement

   A. report stress in MPa



1. run the measurements on the Woollam (thickness and refractive index) using STS PECVD Nitride and Silicon Oxide (100 - 10,000 Ang) respectively

   A. report average thickness and standard deviation in nm (Woollam is in A)

   B. report index of refraction

2. perform HF etch in 50:1, BOE 6:1 and BOE 20:1 for 30secs or 60 secs

   A. measure bath temperature (let thermometer stabilize for 5 min inside bath before reading it)

   B. run control wafer: Thermal Oxide (from Nancy Latta)

3. measure thickness on the Woollam again

4. calculate etch rate

   A. report in nm/min

      i) recall Woollam is in A and the etch time is 30s

      ii) get the difference from step 6 to step 8 and calculate for nm/min

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