From mcvittie at snf.stanford.edu Tue Jul 5 10:20:42 2005 From: mcvittie at snf.stanford.edu (Jim McVittie) Date: Tue, 05 Jul 2005 10:20:42 -0700 Subject: STS shower head thru etch effect References: <20050630203922.53430.qmail@web309.biz.mail.mud.yahoo.com> Message-ID: <42CAC169.1EE754F5@snf.stanford.edu> Jaime, It sounds like you are seeing a charging effect. Back in the early 90's, I did a bit of work on etch profile distortion due charging. We did etching experiments, direct charging measurements and simulations. See papers below. The work was done on one of the Dryteks for trenches etched in the range of 5 to 10 deep. In general, charging is due to plasma non-uniformity although the pattern on your wafer can have a strong effect. In the Drytek case we used a magnet to cause plasma non-uniformity. You are the first user to ever report this effect on STS-1 so I suspect a temporary hardware problem could be the cause. Can you give me more details on what you are seeing, such as how the tilt varies across the wafer. Also are you seeing a lot of etch rate non-uniformity. Jim S. Murakawa and J.P. McVittie, "Ion Trajectory Distortion and Profile Tilt by Surface Charging in Plasma Etching", Appl. Phys. Letts., vol. 64(12), pp.1558-1560, Mar., 1994. S. Murakawa and J.P. McVittie, "Direct Measurement Of Surface Charging Potential In Plasma Etching", Proceedings 2nd Intnl. Conf. Reactive Plasmas, pp. 747-750, Jan. 1994, Yokohama, Japan, also in Jpn. J. Appl. Phys., Vol. 33, pp. 4446-4449, Part 1, July 1994. S. Murakawa and J.P. McVittie, "Mechanism of Surface Charging Effects on Etching Profile Defects", Proceedings of Symp. on Dry Process ( IEE Japan), pp. 39-44, Nov. 1993, Tokyo, Japan, also in Jpn. J. Appl. Phys., Vol.33, pp.2184-2188, 1994. jgarate at invensense.com wrote: > Part 1.1 Type: Plain Text (text/plain) > Encoding: 8bit From kenney at slac.stanford.edu Tue Jul 5 10:43:02 2005 From: kenney at slac.stanford.edu (Chris Kenney) Date: Tue, 5 Jul 2005 10:43:02 -0700 (PDT) Subject: STS shower head thru etch effect In-Reply-To: <42CAC169.1EE754F5@snf.stanford.edu> References: <20050630203922.53430.qmail@web309.biz.mail.mud.yahoo.com> <42CAC169.1EE754F5@snf.stanford.edu> Message-ID: We also observed a shower-head effect several years ago on STS1 and we thought it might be associated with use of the aluminum holder. Although we don't generally look for them, we haven't noticed tilted features before or since. Thanks for providing the references. Chris On Tue, 5 Jul 2005, Jim McVittie wrote: > Jaime, > > It sounds like you are seeing a charging effect. Back in the early 90's, > I did a bit of work on etch profile distortion due charging. We did > etching experiments, direct charging measurements and simulations. See > papers below. The work was done on one of the Dryteks for trenches > etched in the range of 5 to 10 deep. In general, charging is due to > plasma non-uniformity although the pattern on your wafer can have a > strong effect. In the Drytek case we used a magnet to cause plasma > non-uniformity. You are the first user to ever report this effect on > STS-1 so I suspect a temporary hardware problem could be the cause. Can > you give me more details on what you are seeing, such as how the tilt > varies across the wafer. Also are you seeing a lot of etch rate > non-uniformity. > > Jim > > S. Murakawa and J.P. McVittie, "Ion Trajectory Distortion and Profile > Tilt by Surface Charging in Plasma Etching", Appl. Phys. Letts., vol. > 64(12), pp.1558-1560, Mar., 1994. > > S. Murakawa and J.P. McVittie, "Direct Measurement Of Surface Charging > Potential In Plasma Etching", Proceedings 2nd Intnl. Conf. Reactive > Plasmas, pp. 747-750, Jan. 1994, Yokohama, Japan, also in Jpn. J. Appl. > Phys., Vol. 33, pp. 4446-4449, Part 1, July 1994. > > S. Murakawa and J.P. McVittie, "Mechanism of Surface Charging Effects on > Etching Profile Defects", Proceedings of Symp. on Dry Process ( IEE > Japan), pp. 39-44, Nov. 1993, Tokyo, Japan, also in Jpn. J. Appl. > Phys., Vol.33, pp.2184-2188, 1994. > > > jgarate at invensense.com wrote: > > > Part 1.1 Type: Plain Text (text/plain) > > Encoding: 8bit > > From kenney at slac.stanford.edu Tue Jul 5 10:54:31 2005 From: kenney at slac.stanford.edu (Chris Kenney) Date: Tue, 5 Jul 2005 10:54:31 -0700 (PDT) Subject: STS shower head thru etch effect In-Reply-To: References: <20050630203922.53430.qmail@web309.biz.mail.mud.yahoo.com> <42CAC169.1EE754F5@snf.stanford.edu> Message-ID: Sorry to over load all the STS users' mailboxes, but I've attached an image of the tilt we observed. To set the scale this is a 525 micron thick wafer and this image was taken near the wafer's edge. As you can see the tilt angle varied strongly with distance from the edge. On Tue, 5 Jul 2005, Chris Kenney wrote: > We also observed a shower-head effect several years ago on STS1 > and we thought it might be associated with use of the aluminum holder. > > Although we don't generally look for them, we haven't noticed tilted > features before or since. > > Thanks for providing the references. > > Chris > > On Tue, 5 Jul 2005, Jim McVittie wrote: > > > Jaime, > > > > It sounds like you are seeing a charging effect. Back in the early 90's, > > I did a bit of work on etch profile distortion due charging. We did > > etching experiments, direct charging measurements and simulations. See > > papers below. The work was done on one of the Dryteks for trenches > > etched in the range of 5 to 10 deep. In general, charging is due to > > plasma non-uniformity although the pattern on your wafer can have a > > strong effect. In the Drytek case we used a magnet to cause plasma > > non-uniformity. You are the first user to ever report this effect on > > STS-1 so I suspect a temporary hardware problem could be the cause. Can > > you give me more details on what you are seeing, such as how the tilt > > varies across the wafer. Also are you seeing a lot of etch rate > > non-uniformity. > > > > Jim > > > > S. Murakawa and J.P. McVittie, "Ion Trajectory Distortion and Profile > > Tilt by Surface Charging in Plasma Etching", Appl. Phys. Letts., vol. > > 64(12), pp.1558-1560, Mar., 1994. > > > > S. Murakawa and J.P. McVittie, "Direct Measurement Of Surface Charging > > Potential In Plasma Etching", Proceedings 2nd Intnl. Conf. Reactive > > Plasmas, pp. 747-750, Jan. 1994, Yokohama, Japan, also in Jpn. J. Appl. > > Phys., Vol. 33, pp. 4446-4449, Part 1, July 1994. > > > > S. Murakawa and J.P. McVittie, "Mechanism of Surface Charging Effects on > > Etching Profile Defects", Proceedings of Symp. on Dry Process ( IEE > > Japan), pp. 39-44, Nov. 1993, Tokyo, Japan, also in Jpn. J. Appl. > > Phys., Vol.33, pp.2184-2188, 1994. > > > > > > jgarate at invensense.com wrote: > > > > > Part 1.1 Type: Plain Text (text/plain) > > > Encoding: 8bit > > > > > -------------- next part -------------- A non-text attachment was scrubbed... Name: tiltvariation.jpg Type: application/octet-stream Size: 22862 bytes Desc: URL: From mcvittie at snf.stanford.edu Tue Jul 5 12:48:42 2005 From: mcvittie at snf.stanford.edu (Jim McVittie) Date: Tue, 05 Jul 2005 12:48:42 -0700 Subject: STS shower head thru etch effect References: <20050630203922.53430.qmail@web309.biz.mail.mud.yahoo.com> <42CAC169.1EE754F5@snf.stanford.edu> Message-ID: <42CAE41A.97968E12@snf.stanford.edu> Chris, Our charging results were similar to tilt shown in your SEM. In Fig 3 of the APL paper I referenced, we show a profile tilt which varied from 30 to 5 degree as a function of distance from an open area when using a resist mask. The 5 degree tilt occurred at about 220 um from the opening while the 30 degree tilt occurred near the opening. For the same process and pattern, we got no tilt when we used a Cr mask. The same paper shows ion trajectory simulations for different surface charging potentials. At a potential of 55V, the simulated incident angle of the ion trajectories as a function of distance from the open area agreed very closely with the measure profile tilts. From a charging viewpoint, the Al ring in the holder could behave similar to the open areas in our work. In our simulations, we assumed the open exposed Si areas were grounded while the resist surface was charged. In later work, we actually measured surface charging voltages, which agreed with our simulations. Jim , the charging work I referenced, we same behavior Chris Kenney wrote: > Sorry to over load all the STS users' mailboxes, but I've > attached an image of the tilt we observed. To set the scale > this is a 525 micron thick wafer and this image was > taken near the wafer's edge. As you can see the tilt angle > varied strongly with distance from the edge. > > On Tue, 5 Jul 2005, Chris Kenney wrote: > > > We also observed a shower-head effect several years ago on STS1 > > and we thought it might be associated with use of the aluminum holder. > > > > Although we don't generally look for them, we haven't noticed tilted > > features before or since. > > > > Thanks for providing the references. > > > > Chris > > > > On Tue, 5 Jul 2005, Jim McVittie wrote: > > > > > Jaime, > > > > > > It sounds like you are seeing a charging effect. Back in the early 90's, > > > I did a bit of work on etch profile distortion due charging. We did > > > etching experiments, direct charging measurements and simulations. See > > > papers below. The work was done on one of the Dryteks for trenches > > > etched in the range of 5 to 10 deep. In general, charging is due to > > > plasma non-uniformity although the pattern on your wafer can have a > > > strong effect. In the Drytek case we used a magnet to cause plasma > > > non-uniformity. You are the first user to ever report this effect on > > > STS-1 so I suspect a temporary hardware problem could be the cause. Can > > > you give me more details on what you are seeing, such as how the tilt > > > varies across the wafer. Also are you seeing a lot of etch rate > > > non-uniformity. > > > > > > Jim > > > > > > S. Murakawa and J.P. McVittie, "Ion Trajectory Distortion and Profile > > > Tilt by Surface Charging in Plasma Etching", Appl. Phys. Letts., vol. > > > 64(12), pp.1558-1560, Mar., 1994. > > > > > > S. Murakawa and J.P. McVittie, "Direct Measurement Of Surface Charging > > > Potential In Plasma Etching", Proceedings 2nd Intnl. Conf. Reactive > > > Plasmas, pp. 747-750, Jan. 1994, Yokohama, Japan, also in Jpn. J. Appl. > > > Phys., Vol. 33, pp. 4446-4449, Part 1, July 1994. > > > > > > S. Murakawa and J.P. McVittie, "Mechanism of Surface Charging Effects on > > > Etching Profile Defects", Proceedings of Symp. on Dry Process ( IEE > > > Japan), pp. 39-44, Nov. 1993, Tokyo, Japan, also in Jpn. J. Appl. > > > Phys., Vol.33, pp.2184-2188, 1994. > > > > > > > > > jgarate at invensense.com wrote: > > > > > > > Part 1.1 Type: Plain Text (text/plain) > > > > Encoding: 8bit > > > > > > > > > > ------------------------------------------------------------------------ > Name: tiltvariation.jpg > tiltvariation.jpg Type: JPEG Image (image/jpeg) > Encoding: BASE64 > Download Status: Not downloaded with message From aminn at stanford.edu Tue Jul 5 14:16:55 2005 From: aminn at stanford.edu (Amin Nikoozadeh) Date: Tue, 5 Jul 2005 14:16:55 -0700 Subject: STS available 2:30 to 4PM today Message-ID: Sorry for the late notice, --Amin From aminn at stanford.edu Wed Jul 6 14:53:00 2005 From: aminn at stanford.edu (Amin Nikoozadeh) Date: Wed, 6 Jul 2005 14:53:00 -0700 Subject: Res removed today 8:30PM-12 Message-ID: Sorry for the late notice, --Amin From ianw at stanford.edu Mon Jul 11 18:18:09 2005 From: ianw at stanford.edu (Ian Wong) Date: Mon, 11 Jul 2005 18:18:09 -0700 Subject: res removed tomorrow night (starting at 8:30pm) Message-ID: <1121131089.42d31a51c5edf@webmail> wafers not ready From iwjung at stanford.edu Wed Jul 13 17:02:17 2005 From: iwjung at stanford.edu (Il Woong Jung) Date: Wed, 13 Jul 2005 17:02:17 -0700 Subject: sts free 3am-6am Thursday Message-ID: <200507140002.j6E02I4p015541@smtp1.Stanford.EDU> 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: From iwjung at stanford.edu Thu Jul 14 20:57:03 2005 From: iwjung at stanford.edu (Il Woong Jung) Date: Thu, 14 Jul 2005 20:57:03 -0700 Subject: sts free 3am- 7am Message-ID: <200507150357.j6F3v4Ha003184@smtp3.Stanford.EDU> Wafers done already. 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: From bwchui at yahoo.com Thu Jul 14 23:40:37 2005 From: bwchui at yahoo.com (Benjamin Chui) Date: Thu, 14 Jul 2005 23:40:37 -0700 (PDT) Subject: STS free friday noon to 1600 Message-ID: <20050715064037.23614.qmail@web40626.mail.yahoo.com> Litho problems will prevent me from getting my wafers ready for the STS friday. Sorry for the short notice. Ben From latta at snf.stanford.edu Tue Jul 19 11:06:10 2005 From: latta at snf.stanford.edu (Nancy Latta) Date: Tue, 19 Jul 2005 11:06:10 -0700 (PDT) Subject: Etcher free until 1:00 today Message-ID: From griffin at stanford.edu Thu Jul 21 10:59:35 2005 From: griffin at stanford.edu (Peter Griffin) Date: Thu, 21 Jul 2005 10:59:35 -0700 (PDT) Subject: STS - cancelled Thur 1-4pm In-Reply-To: <062520050036.2031.42BCA6FE000D7654000007EF21587667559D0A9B080C079DA1030C@att.net> Message-ID: Sorry for late notice, litho delayed samples Peter From cbuie at stanford.edu Thu Jul 21 15:44:28 2005 From: cbuie at stanford.edu (Cullen R. Buie) Date: Thu, 21 Jul 2005 15:44:28 -0700 Subject: STSETCH Open, 4-8pm today Message-ID: <1121985868.42e0254c7c9e1@webmail.stanford.edu> All, Sorry for the mass email but I had to cancel my reservation of STS today from 4-8pm. It's open if you need it. Sorry for the inconvenience. -- Cullen Buie Department of Mechanical Engineering Stanford University Building 530, Room 224 Stanford, CA. 94305-3030 Tel: (650) 725-9495 Fax: (650) 723-7657 From cm_richter at att.net Fri Jul 22 19:26:15 2005 From: cm_richter at att.net (cm_richter at att.net) Date: Sat, 23 Jul 2005 02:26:15 +0000 Subject: STS Etcher: Cancelled Reservation Saturday 8am to 10am Message-ID: <072320050226.2763.42E1AAC70000799200000ACB21603760219D0A9B080C079DA1030C@att.net> What a great way to start your morning with an etcher by your side! From enwang at stanford.edu Sat Jul 23 08:54:41 2005 From: enwang at stanford.edu (Evelyn Ning-Yi Wang) Date: Sat, 23 Jul 2005 08:54:41 -0700 Subject: stsetch free 11:00- 14:00 today Message-ID: <1122134081.42e2684189a9c@webmail.stanford.edu> stsetch free 11:00- 14:00 today Sorry for the late notice Thanks, Evelyn From cm_richter at att.net Mon Jul 25 06:55:20 2005 From: cm_richter at att.net (C. Richter) Date: Mon, 25 Jul 2005 06:55:20 -0700 Subject: STS Etcher: Cancelled Reservation Today at 4pm to 8pm Message-ID: <42E4EF48.4070105@att.net> Sorry for the late notice. -Claudia From cm_richter at att.net Tue Jul 26 11:47:29 2005 From: cm_richter at att.net (cm_richter at att.net) Date: Tue, 26 Jul 2005 18:47:29 +0000 Subject: STS Etch: Cancelled Reservation from 3pm to 7pm Message-ID: <072620051847.25918.42E68541000490240000653E21602807419D0A9B080C079DA1030C@att.net> My wafers have some damage and have no wafers for today's time. Claudia From cm_richter at att.net Wed Jul 27 13:11:39 2005 From: cm_richter at att.net (cm_richter at att.net) Date: Wed, 27 Jul 2005 20:11:39 +0000 Subject: STS Etcher: Cancelled Reservation Saturday 3pm to 7pm Message-ID: <072720052011.5697.42E7EA7B000159210000164121603762239D0A9B080C079DA1030C@att.net> No plans for this Saturday night? From enwang at stanford.edu Wed Jul 27 17:30:27 2005 From: enwang at stanford.edu (Evelyn Ning-Yi Wang) Date: Wed, 27 Jul 2005 17:30:27 -0700 Subject: stsetch free now til 19:00 Message-ID: <1122510627.42e82723d8f93@webmail.stanford.edu> stsetch free now til 19:00 today couldn't remove reservation From enwang at stanford.edu Wed Jul 27 21:42:19 2005 From: enwang at stanford.edu (Evelyn Ning-Yi Wang) Date: Wed, 27 Jul 2005 21:42:19 -0700 Subject: stsetch free 11:00 to 3:00 today Message-ID: <1122525739.42e8622b90b80@webmail.stanford.edu> stsetch free 11:00 to 3:00 today Sorry for the late notice. From cm_richter at att.net Thu Jul 28 19:01:31 2005 From: cm_richter at att.net (cm_richter at att.net) Date: Fri, 29 Jul 2005 02:01:31 +0000 Subject: STS Free until 9pm tonight Message-ID: <072920050201.13550.42E98DFB0002D40B000034EE21603762239D0A9B080C079DA1030C@att.net> Ran out of wafers for now. -Claudia From enwang at stanford.edu Fri Jul 29 16:03:55 2005 From: enwang at stanford.edu (Evelyn Wang) Date: Fri, 29 Jul 2005 16:03:55 -0700 Subject: stsetch free from 2:00-4:00 today Message-ID: <6.1.2.0.2.20050729160329.01ff8c60@enwang.pobox.stanford.edu> stsetch free from 2:00-4:00 today From mehdij at stanford.edu Sat Jul 30 16:54:39 2005 From: mehdij at stanford.edu (Mehdi Javanmard) Date: Sat, 30 Jul 2005 16:54:39 -0700 Subject: stsetch free from 7-11:00 today In-Reply-To: <6.1.2.0.2.20050729160329.01ff8c60@enwang.pobox.stanford.ed u> References: <6.1.2.0.2.20050729160329.01ff8c60@enwang.pobox.stanford.edu> Message-ID: <6.0.1.1.2.20050730165403.01b77ec0@mehdij.pobox.stanford.edu> stsetch free from 7pm-11:00pm today