From hopcroft at snf.stanford.edu Sat Dec 3 15:13:21 2005 From: hopcroft at snf.stanford.edu (Matt Hopcroft) Date: Sat, 3 Dec 2005 15:13:21 -0800 (PST) Subject: Response Summary: stsetch systematic problems In-Reply-To: Message-ID: Hello, I received a number of helpful and interesting replies to my email last week about the sts. Thanks to all who replied! Here is a summary of the answers: Executive Summary: The chamber pressure has been increasing over time due to machine aging. Increased pressure causes reduced sidewall polymerization, leading to sidewall blowouts. Conversely, increased pressure can contribute to micromasking ("grass") and imcomplete etching. Doing a chamber clean before etching is recommended. Summary: 1) Other people have noticed an increase in problems within a 12-18 month timeframe. 2) A likely issue is changing pressure in the chamber during the etch. The chamber pressure has apparently increased since the etch recipes were first developed. Increased chamber pressure can cause reduced polymerization during the passivation step and lead to sidewall blowouts. 3) Two maintenance issues should be considered: the condition of the vacuum foreline (which evacuates gas from the etch chamber) and the APC valve (which regulates the chamber pressure). These both affect the pressure in the chamber. users reported better results immediately after the foreline had been cleaned and with decreased APC settings (for decreased pressure). 4) The "footing" and "mousebite" pictures that I showed are not good examples of either. They are more accurately described as sidewall etching due polymer breakdown related to point 2). 5) The incomplete etching problems are most likely lithography issues specific to our design and exacerbated by point 2). Possible Remedies: - Running a chamber clean (O2 clean) and then seasoning the chamber with a dummy wafer before etching device wafers. - Modifying recipes to increase the CF4 polymerization levels and reduce etch pressure. - Monitor and record the actual chamber pressures during your etch observe how they correlate with your results. -Matt Hopcroft hopcroft at snf.stanford.edu From mcvittie at snf.stanford.edu Mon Dec 5 11:36:27 2005 From: mcvittie at snf.stanford.edu (Jim McVittie) Date: Mon, 05 Dec 2005 11:36:27 -0800 Subject: Response Summary: stsetch systematic problems References: Message-ID: <439496BB.8F92F648@snf.stanford.edu> Matt, Last year, when the STS process engineer was here from the UK. I had a brief disccussion with him about our problem with byproduct buildup in our vacuum line for STS1. He said on the older systems most users had gone to adding O2 to their processes to prevent the problem. On the new sydsem to eliminate the problem everything is heated until the water cooled trap. Jim Matt Hopcroft wrote: > Hello, > I received a number of helpful and interesting replies to my > email last week about the sts. Thanks to all who replied! Here is a > summary of the answers: > > Executive Summary: > > The chamber pressure has been increasing over time due to machine > aging. Increased pressure causes reduced sidewall polymerization, leading > to sidewall blowouts. Conversely, increased pressure can contribute to > micromasking ("grass") and imcomplete etching. Doing a chamber clean > before etching is recommended. > > Summary: > > 1) Other people have noticed an increase in problems within a 12-18 month > timeframe. > > 2) A likely issue is changing pressure in the chamber during the > etch. The chamber pressure has apparently increased since the etch > recipes were first developed. Increased chamber pressure can cause reduced > polymerization during the passivation step and lead to sidewall blowouts. > > 3) Two maintenance issues should be considered: the condition of the > vacuum foreline (which evacuates gas from the etch chamber) and the APC > valve (which regulates the chamber pressure). These both affect the > pressure in the chamber. users reported better results immediately > after the foreline had been cleaned and with decreased APC settings (for > decreased pressure). > > 4) The "footing" and "mousebite" pictures that I showed are not good > examples of either. They are more accurately described as sidewall etching > due polymer breakdown related to point 2). > > 5) The incomplete etching problems are most likely lithography issues > specific to our design and exacerbated by point 2). > > Possible Remedies: > > - Running a chamber clean (O2 clean) and then seasoning the chamber with a > dummy wafer before etching device wafers. > > - Modifying recipes to increase the CF4 polymerization levels and reduce > etch pressure. > > - Monitor and record the actual chamber pressures during your etch observe > how they correlate with your results. > > -Matt Hopcroft > hopcroft at snf.stanford.edu From huangzb at stanford.edu Tue Dec 6 12:40:56 2005 From: huangzb at stanford.edu (Zubin Huang) Date: Tue, 6 Dec 2005 12:40:56 -0800 Subject: cancel reservation from 4:00 to 7:00 am on Wednesday Message-ID: <002d01c5faa5$5c0e8350$eb7640ab@RPLZubin> Cancel reservation from 4:00 to 7:00 am on Wednesday. Sorry for the late notice. Zubin -------------- next part -------------- An HTML attachment was scrubbed... URL: From lscjblue at yahoo.com Sat Dec 10 11:54:05 2005 From: lscjblue at yahoo.com (Ping Zhang) Date: Sat, 10 Dec 2005 11:54:05 -0800 (PST) Subject: STSETCH is free 2PM to 5PM today Message-ID: <20051210195405.58614.qmail@web31515.mail.mud.yahoo.com> Sorry of the late notice. Ping Zhang From bwchui at yahoo.com Sun Dec 11 17:17:54 2005 From: bwchui at yahoo.com (Benjamin Chui) Date: Sun, 11 Dec 2005 17:17:54 -0800 (PST) Subject: STS free tonight 0000-0400, tomorrow 0000-0400 Message-ID: <20051212011754.44579.qmail@web36513.mail.mud.yahoo.com> STS free tonight 0000-0400, tomorrow 0000-0400 Happy etching! Ben From lscjblue at yahoo.com Mon Dec 12 13:25:44 2005 From: lscjblue at yahoo.com (Ping Zhang) Date: Mon, 12 Dec 2005 13:25:44 -0800 (PST) Subject: Free from 8 to 11PM tonight Message-ID: <20051212212544.4653.qmail@web31506.mail.mud.yahoo.com> Enjoy. Ping Zhang From kimsora at stanford.edu Mon Dec 12 19:30:27 2005 From: kimsora at stanford.edu (Sora Kim) Date: Mon, 12 Dec 2005 19:30:27 -0800 Subject: Free from 8 to 11pm tonight. Message-ID: <000e01c5ff95$90479ef0$948d0c80@kimsora> Moved reservation to tomorrow morning. Sora -------------- next part -------------- An HTML attachment was scrubbed... URL: From iwjung at stanford.edu Tue Dec 13 04:00:15 2005 From: iwjung at stanford.edu (Il Woong Jung) Date: Tue, 13 Dec 2005 04:00:15 -0800 Subject: icp comm failure error Message-ID: <1134475215.439eb7cf4407d@webmail.stanford.edu> The STSetcher had a icp comm failure and now my wafer is stuck in the chamber. Ilwoong From kimsora at stanford.edu Tue Dec 13 10:23:34 2005 From: kimsora at stanford.edu (Sora Kim) Date: Tue, 13 Dec 2005 10:23:34 -0800 Subject: [STS] Done early. Message-ID: <1134498213.439f11a60486b@webmail.stanford.edu> The STS is available now. Sora From aeonia at stanford.edu Tue Dec 13 23:36:14 2005 From: aeonia at stanford.edu (Hyeun-su Kim) Date: Tue, 13 Dec 2005 23:36:14 -0800 Subject: [stsetch]free from 4am to 8am Message-ID: <1134545774.439fcb6ed74cd@webmail> From iwjung at stanford.edu Wed Dec 14 15:11:26 2005 From: iwjung at stanford.edu (Il Woong Jung) Date: Wed, 14 Dec 2005 15:11:26 -0800 Subject: reservation removed from 1-7am Thursday morning Message-ID: <200512142311.jBENBSL2029618@smtp3.Stanford.EDU> Reservation removed. Wafers won't be ready. Il Woong Jung ------------------------ EL Ginzton Labs 450 Via Palou 41C Stanford, CA 94305 office) 650-723-1992 lab) 650-723-6104 -------------- next part -------------- An HTML attachment was scrubbed... URL: