From mdickey at snf.stanford.edu Tue Aug 6 09:28:34 2002 From: mdickey at snf.stanford.edu (Mike Dickey) Date: Tue, 06 Aug 2002 09:28:34 -0700 Subject: Test Message-ID: <3D4FF931.4B4D4D7E@snf.stanford.edu> Pull and clean is done, ready for testing From rcrane at snf.stanford.edu Tue Aug 6 18:27:11 2002 From: rcrane at snf.stanford.edu (Dick Crane) Date: Tue, 06 Aug 2002 18:27:11 -0700 Subject: Silane for the LP tubes Message-ID: <3D50776F.701E0714@snf.stanford.edu> It is with great embarrassment that I am writing this email concerning running out of silane late Sunday night. How could this happen? When it happened several months ago I instituted some changes in our method of monitoring the process gases. Cylinder weight or pressure was checked and recorded daily. Trends were plotted. Arrangements with purchasing were made to insure replacement product would be here in a timely fashion. We haven't had an another oops until now. What happened? As of last week the projected run out time was next week. After-the-fact calculations suggest there was enough silane to go into this week. The cylinder supplies BPSG, SiGe, Poly, and Tystar tubes. The multiple user aspect further complicates predicating use rates. Two sources of error are being pursued: 1.The cylinder pressure gauge may have an offset and/or be non-linear. The gauge will be replaced at next cylinder change. 2. The gas volume vs. pressure curve may be non-linear at low pressures. More important is how to not have this happen again. Action items: 1. I am pursuing an automatic changeover, two cylinder manifold which would allow a second cylinder of silane to come on line when the first cylinder reaches a predetermined level. This change would also make the 24 hr leak test invisible to users. Because of permits and construction issues, this upgrade will take a few months to implement. 2. For the time being, when the cylinder reaches the 25% volume remaining level, a "Silane Budget Sheet" will be posted near the cleanroom entrance and a notice will be sent to users. Silane users will need to sign up for the number of ccs to be used. The procedure will allow users with critical runs to chose between running now, close to the end, or waiting for a cylinder change in a few days. The budget sheet should answer the question of "Is there enough silane to complete my run this evening (or weekend)?" and help coordinate use between users of different tubes. Gas data is taken every weekday morning before 0700. Please feel free to ask me, Ted, Ray, or Mike Dickey what the silane level at any time during the day. I would also like to ask for your help. If you have run scheduled which uses a large amount of silane, please notify us ahead of time. My apologies to the two users who ran out this weekend, Dick From dlaser at stanford.edu Fri Aug 30 07:01:41 2002 From: dlaser at stanford.edu (Dan Laser) Date: Fri, 30 Aug 2002 07:01:41 -0700 (PDT) Subject: res removed 1430-1830 Message-ID: sorry for the late notice