true at snf.stanford.edu
Fri Jun 20 17:19:15 PDT 2003
What you told me on Wed was that you would "dictate" the new policy to
the non-GaAs, and you continue to be uninterested in involving us in the
discussion. I looked at the log book and counted the number of logs for
GaAs (including AlGaAs of course) and for non-GaAs materials. Here are
GaAs 15 14
Non-GaAs 32 33
Currently, there is twice as much use for non-GaAs materials. If you
really want to break up the week, the allocation should follow the
usage. It is not fair to "dictate" to the majority users what the new
policy will be. Why are you so insistent on not having a user's meeting
or even giving us the data? You are skipping the trial and going
straight to the sentencing.
PS. If you do divide the week, we are still going to have the issue of
maintaining "good" chamber conditions during the non-GaAs days.
Jim McVittie wrote:
>As I told you earlier today, I am in the process of reviewing the use of the
>PQ since it is presently not meeting its primary function of supporting the
>fabrication of III-V devices. I understand your concerns about its future
>availability for non-III-V materials. We are exploring ways of getting the
>tool back on-track for III-V etching and keeping it available for the etching
>non-III-V materials. Since I view the III-V users as the primary owners of
>this tool, I am first focusing on what it will take to meet their needs. The
>non-III-V users are important but the bottom line is this tool was
>specifically purchased for III-V material etching and it absolutely must meet
>this need first. Presently, we are looking at a plan that would slit up the
>use of the tool over the week into a III-V use period and a non-III-V period.
>The plan would be that a specific set of cleaning and seasoning steps would be
>run at the start of each III-V use period to get the chamber to a baseline
>condition where consistent GaAs/AlGaAs etching is achieved. Since we really do
>not understand what this baseline condition is, this will take some
>experimentation to achieve. I have an optical spectrometer (200 to 1000nm)
>which maybe useful here.
>As for the non-III-V materials, there are lots of questions which I can not
>answer right now. For one it is not clear that all the present processes are
>compatible with the III-V etching. I am still going over the recent problems
>to see if there is a consistent pattern that need more study. For another,
>the non-III-V materials probably need their own cleaning/season procedure to
>get consistent results. Here the users will have to work out their procedures
>for the different materials. There is also the question of allowing new
>processes into the etcher. We may have been too loose in the past and let we
>want to be as flexible as possible.
>Once I have a proposal that satisfies the III-V users, I will send it out to
>everyone for comments. If you want to propose something for the non-III-V
>use period, it is fine with me. Hopefully, we can come up with something that
>meets all the users needs.
> Thanks, Jim
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