Comment lampoly SNF 2010-12-09 20:11:41: Update on the Problems with the Lam Etcher

mcvittie at snf.stanford.edu mcvittie at snf.stanford.edu
Thu Dec 9 20:11:42 PST 2010


Hi,
I was asked to see if I could solve some of the persistent problems with the Lam. Here what I found:
1. Fluctuations in rf levels -- This seems to be caused by noise on the ac line. For now I was able to reduce the fluctuations by powering the top rf generation by power from a diferent service isle. It was further reduced by changing out one of the rf generations with one which is less sensitive to the noise. We are working on finding the source noise in the AC power.
2. Some Recipes Not Matching -- Reducing the rf fluctuations has appeared to improved this problem. In addition, I shifted the match position for the std poly etch process to bring the others recipes into the capture range of the matching network. I also noticed that some of tune and load pre-sets need to adjusted to give better matching.
3. RF power calibration -- The top rf power was significantly out of calibration. Much of this was do to the changing of the generation. I used the maximum power value for the top generator in the configuration table to bring the power level shown in the control screen into calibration.
4. Correct ground problems -- I found some loose and missing ground wires in addition to some missing shielding. Some of this has been fixed and the rest is being working on. 
  Thanks, Jim 




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