jim kruger jimkruger at yahoo.com
Fri Jun 5 19:22:15 PDT 2009

PQuest seems to be working OK except:

still no chuck heaters but cooling flow seems better, i.e "plasma heating" seems less than before.

RF power must be divided by about a factor of 2 again to get the same bias voltage as earlier this year,  and what seems to be the same etch selectivity.
 This is a second factor of 2:  a recipe that used 40 watts RF last year required only 20 watts after the Holiday shutdown modifications.  After the latest repairs now the required RF is now 9 watts.

He blow-by is bad on standard wafers (6 or 7, with 8 = max.).  I found today that thick (850um), double polished wafers give a perfect seal.
  The He offsets have been zeroed.  Perfect seal used to show 3 sccm He (so 11 sccm flow with no wafer).  Now perfect is 0 sccm He and "no wafer" = 8.


--- On Fri, 6/5/09, Andrei Faraon <faraon at stanford.edu> wrote:

> From: Andrei Faraon <faraon at stanford.edu>
> Subject: Pquest
> To: jimkruger at yahoo.com
> Date: Friday, June 5, 2009, 11:09 AM
> Hi Jim,
> I just wanted to ask you about the current status for
> pquest. Is it
> operating OK? Any advice on the etching parameters?
> -- 
> Andrei Faraon
> Stanford University, Applied Physics
> 316 Via Pueblo Mall
> Stanford, CA, 94305
> Mobile: 650 714 7881
> Office: 650 723 2279
> www.stanford.edu/~faraon


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