From gth at snf.stanford.edu Fri Jul 4 16:22:46 2008 From: gth at snf.stanford.edu (gth at snf.stanford.edu) Date: Fri, 4 Jul 2008 16:22:46 -0700 Subject: Problem drytek2 SNF 2008-07-04 16:22:46: Timer 1 pot needs to be changed, Message-ID: this is the third time i am logging this bad pot problem Timer 1 RF level Pot needs a change. Power fluctuates like crazy with a hissing noise. thanks From gth at snf.stanford.edu Mon Jul 7 09:17:52 2008 From: gth at snf.stanford.edu (gth at snf.stanford.edu) Date: Mon, 7 Jul 2008 09:17:52 -0700 Subject: Problem drytek2 SNF 2008-07-07 09:17:51: power does not reach 500W Message-ID: both for descum and PR strip seems like the same sticky pot issue, which i reported earlier From jrjain at snf.stanford.edu Mon Jul 7 13:18:19 2008 From: jrjain at snf.stanford.edu (jrjain at snf.stanford.edu) Date: Mon, 7 Jul 2008 13:18:19 -0700 Subject: Problem drytek2 SNF 2008-07-07 13:18:18: Process 1 RF potentiometer problem Message-ID: Echoing GTH's post and providing details. I also saw problems with the potentiometer. Specifically, when trying to tweak the RF even slightly, the power becomes very erratic, rapidly dropping from 500 down to ~300 (sometimes even down to 0), then jumping back up to 450, etc. There is also an unusual whining sound (from the drytek, not the user), both when the RF is tweaked and when it is left alone. This seems to only happen at certain positions of the potentiometer (comes and goes as rotate tuner). From shott at snf.stanford.edu Mon Jul 7 15:51:04 2008 From: shott at snf.stanford.edu (shott at snf.stanford.edu) Date: Mon, 7 Jul 2008 15:51:04 -0700 Subject: Comment drytek2 SNF 2008-07-07 15:51:03: Pot ordered .... Message-ID: I've ordered the appropriate Bourns 10-turn wirewound 20 kohm linear 2W pot (Bourns part number 3540S-1-203). I will need to make sure that I know how to apppropriately shutdown the system in order to pull out the appropriate sub-assembly and replace the part. At this point, I believe that the system must be fully powered down and the pumps must be turned off in order to safely make this replacement. John From rparsa at snf.stanford.edu Tue Jul 8 15:13:28 2008 From: rparsa at snf.stanford.edu (rparsa at snf.stanford.edu) Date: Tue, 8 Jul 2008 15:13:28 -0700 Subject: Problem drytek2 SNF 2008-07-08 15:13:27: Forward RF power is zero Message-ID: I was using Proc. #1 and played with the knobs for several but the forward power didn't move from zero. From shott at snf.stanford.edu Tue Jul 8 16:41:32 2008 From: shott at snf.stanford.edu (shott at snf.stanford.edu) Date: Tue, 8 Jul 2008 16:41:32 -0700 Subject: Shutdown drytek2 SNF 2008-07-08 16:41:32: Shutting down for RF control pot replacement Message-ID: Powering down the system to investigate the failing pot for RF control of channel 1. John From shott at snf.stanford.edu Tue Jul 8 20:53:48 2008 From: shott at snf.stanford.edu (shott at snf.stanford.edu) Date: Tue, 8 Jul 2008 20:53:48 -0700 Subject: Shutdown drytek2 SNF 2008-07-08 16:41:32: Shutting down for RF control pot replacement Message-ID: Rats!!! While I have a nice, new replacement potentionmeter, I got stymied by the small allen hex head num that holds the knob on the 10-turn potentiometer. This one seems different (and smaller) that most of the others that we have in the basement. Most of the others seem to be 0.050 inch. This one is smaller than that .... slightly larger than the next smaller english size of 0.035. I think that it may be 1.0 mm, but, thus far at least, have been unable to find a 1mm allen wrench. So, I failed miserably .... and ended up getting nothing done. So, beware of channel 1 .... the RF pot is still liikely noisy. Sorry, John From shott at snf.stanford.edu Wed Jul 9 07:39:37 2008 From: shott at snf.stanford.edu (shott at snf.stanford.edu) Date: Wed, 9 Jul 2008 07:39:37 -0700 Subject: Problem drytek2 SNF 2008-07-04 16:22:46: Timer 1 pot needs to be changed, Message-ID: RF level pot was extracted and found to be worn that resulted in variable resistance, particularly during adjustment. Replaced with an identical Bourn 10-turn, 20kohm 2W pot. System has been returned to service. John From shott at snf.stanford.edu Wed Jul 9 07:39:47 2008 From: shott at snf.stanford.edu (shott at snf.stanford.edu) Date: Wed, 9 Jul 2008 07:39:47 -0700 Subject: Problem drytek2 SNF 2008-07-07 09:17:51: power does not reach 500W Message-ID: RF level pot was extracted and found to be worn that resulted in variable resistance, particularly during adjustment. Replaced with an identical Bourn 10-turn, 20kohm 2W pot. System has been returned to service. John From shott at snf.stanford.edu Wed Jul 9 07:39:55 2008 From: shott at snf.stanford.edu (shott at snf.stanford.edu) Date: Wed, 9 Jul 2008 07:39:55 -0700 Subject: Problem drytek2 SNF 2008-07-07 13:18:18: Process 1 RF potentiometer problem Message-ID: RF level pot was extracted and found to be worn that resulted in variable resistance, particularly during adjustment. Replaced with an identical Bourn 10-turn, 20kohm 2W pot. System has been returned to service. John From shott at snf.stanford.edu Wed Jul 9 07:40:06 2008 From: shott at snf.stanford.edu (shott at snf.stanford.edu) Date: Wed, 9 Jul 2008 07:40:06 -0700 Subject: Problem drytek2 SNF 2008-07-08 15:13:27: Forward RF power is zero Message-ID: RF level pot was extracted and found to be worn that resulted in variable resistance, particularly during adjustment. Replaced with an identical Bourn 10-turn, 20kohm 2W pot. System has been returned to service. John From shott at snf.stanford.edu Wed Jul 9 07:40:14 2008 From: shott at snf.stanford.edu (shott at snf.stanford.edu) Date: Wed, 9 Jul 2008 07:40:14 -0700 Subject: Comment drytek2 SNF 2008-07-07 15:51:03: Pot ordered .... Message-ID: RF level pot was extracted and found to be worn that resulted in variable resistance, particularly during adjustment. Replaced with an identical Bourn 10-turn, 20kohm 2W pot. System has been returned to service. John From shott at snf.stanford.edu Wed Jul 9 08:22:56 2008 From: shott at snf.stanford.edu (shott at snf.stanford.edu) Date: Wed, 9 Jul 2008 08:22:56 -0700 Subject: Shutdown drytek2 SNF 2008-07-09 08:22:55: Testing ... Message-ID: Testing forward RF power after r\pot replacement ... From eenriquez at snf.stanford.edu Wed Jul 9 09:09:41 2008 From: eenriquez at snf.stanford.edu (eenriquez at snf.stanford.edu) Date: Wed, 9 Jul 2008 09:09:41 -0700 Subject: Comment drytek2 SNF 2008-07-09 09:09:41: RF tested OK Message-ID: Ran program 1 (O2 plasma) for 10 minutes after John replaced the RF control potentiomenter. RF was very stable. From shott at snf.stanford.edu Wed Jul 9 11:28:43 2008 From: shott at snf.stanford.edu (shott at snf.stanford.edu) Date: Wed, 9 Jul 2008 11:28:43 -0700 Subject: Shutdown drytek2 SNF 2008-07-09 08:22:55: Testing ... Message-ID: RF level 1 pot has been replaced and now functions smoothly. I was also able to get well above 500 watts of forward power. The only trouble I haqd was in tuning the RF with channel one that is likely a pilot problem. I ended up with a Coil setting of 116 and a cap setting of 788. Afterwards, Elmer suggesting setting the cap at 50% (using the red indicator on the capacitor shaft and then tining the coil to ingnie a plasma and then fine tining from there. All should be smooth now ... From king at snf.stanford.edu Fri Jul 11 00:13:39 2008 From: king at snf.stanford.edu (king at snf.stanford.edu) Date: Fri, 11 Jul 2008 00:13:39 -0700 Subject: Problem drytek2 SNF 2008-07-11 00:13:38: Proc #3 RF level Pot Message-ID: limits out around 425 - 450W; cannot reach 500W for nitride process. Was tuned to about 20W reflected. From ofidaner at snf.stanford.edu Fri Jul 11 05:53:17 2008 From: ofidaner at snf.stanford.edu (ofidaner at snf.stanford.edu) Date: Fri, 11 Jul 2008 05:53:17 -0700 Subject: Shutdown drytek2 SNF 2008-07-11 05:53:16: RF does not turn on Message-ID: From eenriquez at snf.stanford.edu Fri Jul 11 15:05:56 2008 From: eenriquez at snf.stanford.edu (eenriquez at snf.stanford.edu) Date: Fri, 11 Jul 2008 15:05:56 -0700 Subject: Comment drytek2 SNF 2008-07-11 15:05:55: Update Message-ID: Defective RF generator ?? Power output is varying. Connected to a dummy load and was only able to get 450 W out (max is 1000 W). When I was connected to system (match network + chamber), at times the bird watt meter as well as the systems RF meter read about 800 W. Check the other process programs (2 & 3) and had similar results. From king at snf.stanford.edu Sat Jul 12 15:21:55 2008 From: king at snf.stanford.edu (king at snf.stanford.edu) Date: Sat, 12 Jul 2008 15:21:55 -0700 Subject: Comment drytek2 SNF 2008-07-12 15:21:55: Message-ID: From lindaw at snf.stanford.edu Mon Jul 14 09:55:24 2008 From: lindaw at snf.stanford.edu (lindaw at snf.stanford.edu) Date: Mon, 14 Jul 2008 09:55:24 -0700 Subject: Comment drytek2 SNF 2008-07-14 09:55:23: any news on when drytek2 might be back up? Message-ID: Any updates on drytek2 status? Waiting on parts? trying to find parts to order? Scavenging in the basement for parts? Anything? Thanks. From ryw at snf.stanford.edu Mon Jul 14 15:23:26 2008 From: ryw at snf.stanford.edu (ryw at snf.stanford.edu) Date: Mon, 14 Jul 2008 15:23:26 -0700 Subject: Comment drytek2 SNF 2008-07-14 15:23:25: anything new on the drytek2? Message-ID: From lindaw at snf.stanford.edu Mon Jul 14 20:20:39 2008 From: lindaw at snf.stanford.edu (lindaw at snf.stanford.edu) Date: Mon, 14 Jul 2008 20:20:39 -0700 Subject: Comment drytek2 SNF 2008-07-14 20:20:39: The process 1 pot has been a bit flakey for awhile Message-ID: but does that justify the shutdown of the tool? Can we yellow light this tool for process 2 & 3 only at this time? I know that I am dead in the water, and others I have spoken too are also feeling the pain. Can we get some kind of update please? From eenriquez at snf.stanford.edu Tue Jul 15 14:39:04 2008 From: eenriquez at snf.stanford.edu (eenriquez at snf.stanford.edu) Date: Tue, 15 Jul 2008 14:39:04 -0700 Subject: Shutdown drytek2 SNF 2008-07-11 05:53:16: RF does not turn on Message-ID: RF seems more stable now after we retightened the RF connection to the matching network and generator. Installed a birdwatt meter in order to get a confirmation of the RF power going to the chamber. Meter is located above the matching network controller. From eenriquez at snf.stanford.edu Tue Jul 15 14:39:14 2008 From: eenriquez at snf.stanford.edu (eenriquez at snf.stanford.edu) Date: Tue, 15 Jul 2008 14:39:14 -0700 Subject: Comment drytek2 SNF 2008-07-11 15:05:55: Update Message-ID: Noted From eenriquez at snf.stanford.edu Tue Jul 15 14:40:10 2008 From: eenriquez at snf.stanford.edu (eenriquez at snf.stanford.edu) Date: Tue, 15 Jul 2008 14:40:10 -0700 Subject: Comment drytek2 SNF 2008-07-14 15:23:25: anything new on the drytek2? Message-ID: RF seems more stable now after we retightened the RF connection to the matching network and generator. Installed a birdwatt meter in order to get a confirmation of the RF power going to the chamber. Meter is located above the matching network controller. From eenriquez at snf.stanford.edu Tue Jul 15 14:40:19 2008 From: eenriquez at snf.stanford.edu (eenriquez at snf.stanford.edu) Date: Tue, 15 Jul 2008 14:40:19 -0700 Subject: Comment drytek2 SNF 2008-07-12 15:21:55: Message-ID: RF seems more stable now after we retightened the RF connection to the matching network and generator. Installed a birdwatt meter in order to get a confirmation of the RF power going to the chamber. Meter is located above the matching network controller. From eenriquez at snf.stanford.edu Tue Jul 15 14:40:25 2008 From: eenriquez at snf.stanford.edu (eenriquez at snf.stanford.edu) Date: Tue, 15 Jul 2008 14:40:25 -0700 Subject: Comment drytek2 SNF 2008-07-14 09:55:23: any news on when drytek2 might be back up? Message-ID: RF seems more stable now after we retightened the RF connection to the matching network and generator. Installed a birdwatt meter in order to get a confirmation of the RF power going to the chamber. Meter is located above the matching network controller. From eenriquez at snf.stanford.edu Tue Jul 15 14:42:16 2008 From: eenriquez at snf.stanford.edu (eenriquez at snf.stanford.edu) Date: Tue, 15 Jul 2008 14:42:16 -0700 Subject: Comment drytek2 SNF 2008-07-14 20:20:39: The process 1 pot has been a bit flakey for awhile Message-ID: Shutdown was not because of pot 1. See Update on 7/11 regarding the RF power fluctuation. From king at snf.stanford.edu Tue Jul 15 16:39:58 2008 From: king at snf.stanford.edu (king at snf.stanford.edu) Date: Tue, 15 Jul 2008 16:39:58 -0700 Subject: Comment drytek2 SNF 2008-07-15 16:39:58: unnecessary shutdown Message-ID: Linda is right: The system was working well enough and did not require a four day shutdown over the weekend. From eenriquez at snf.stanford.edu Wed Jul 16 07:50:01 2008 From: eenriquez at snf.stanford.edu (eenriquez at snf.stanford.edu) Date: Wed, 16 Jul 2008 07:50:01 -0700 Subject: Comment drytek2 SNF 2008-07-15 16:39:58: unnecessary shutdown Message-ID: Sorry you're wrong. The RF power level was unstable on all three recipe channels. I observed the power go from 0 W to over 800 W by itself. One user complained that he over etched his wafer. Please keep sending these very useful comments and thank you for input. From gth at snf.stanford.edu Thu Jul 17 12:25:23 2008 From: gth at snf.stanford.edu (gth at snf.stanford.edu) Date: Thu, 17 Jul 2008 12:25:23 -0700 Subject: Problem drytek2 SNF 2008-07-17 12:25:23: Proc#1 RF level Pot Message-ID: same problem as Robin reported. doing PR descum 450W-475W, rarely reaches 500W 20W reflected power. please check From eenriquez at snf.stanford.edu Thu Jul 17 13:11:02 2008 From: eenriquez at snf.stanford.edu (eenriquez at snf.stanford.edu) Date: Thu, 17 Jul 2008 13:11:02 -0700 Subject: Problem drytek2 SNF 2008-07-17 12:25:23: Proc#1 RF level Pot Message-ID: User was concerned about the stability of the RF during his 30 second process. Suggested warming up the RF generator for 3 minutes and tuning the matching network (with a dummy wafer loaded) before running his actual wafers. Ran his process after we warmed up the generator. The RF power stabilized within 5 seconds. From eenriquez at snf.stanford.edu Fri Jul 18 14:46:22 2008 From: eenriquez at snf.stanford.edu (eenriquez at snf.stanford.edu) Date: Fri, 18 Jul 2008 14:46:22 -0700 Subject: Comment drytek2 SNF 2008-07-09 09:09:41: RF tested OK Message-ID: Noted From lindaw at snf.stanford.edu Tue Jul 22 11:05:33 2008 From: lindaw at snf.stanford.edu (lindaw at snf.stanford.edu) Date: Tue, 22 Jul 2008 11:05:33 -0700 Subject: Problem drytek2 SNF 2008-07-22 11:05:33: 3rd electrode down from top not working Message-ID: There is no plasma at the 3rd electrode down from the top. Process 2 poly etch. From masato at snf.stanford.edu Tue Jul 22 22:43:45 2008 From: masato at snf.stanford.edu (masato at snf.stanford.edu) Date: Tue, 22 Jul 2008 22:43:45 -0700 Subject: Shutdown drytek2 SNF 2008-07-22 22:43:44: reflected power > 200W Message-ID: We tried to tune the reflected power. However it doesn't work. Once it went less than 20W, it went up (>200W) again. From eenriquez at snf.stanford.edu Wed Jul 23 18:18:23 2008 From: eenriquez at snf.stanford.edu (eenriquez at snf.stanford.edu) Date: Wed, 23 Jul 2008 18:18:23 -0700 Subject: Comment drytek2 SNF 2008-07-23 18:18:22: Update Message-ID: Replaced the worn pick-up arm of the tuning coil but plasma is still unstable. Will check out the RF feedthrough and chamber for any signs of arcing. From lindaw at snf.stanford.edu Wed Jul 23 20:19:24 2008 From: lindaw at snf.stanford.edu (lindaw at snf.stanford.edu) Date: Wed, 23 Jul 2008 20:19:24 -0700 Subject: Comment drytek2 SNF 2008-07-23 20:19:23: Thanks for the update Message-ID: Thanks for the update Elmer, it is very much appreciated. From eenriquez at snf.stanford.edu Thu Jul 24 14:48:31 2008 From: eenriquez at snf.stanford.edu (eenriquez at snf.stanford.edu) Date: Thu, 24 Jul 2008 14:48:31 -0700 Subject: Comment drytek2 SNF 2008-07-23 20:19:23: Thanks for the update Message-ID: Archived From eenriquez at snf.stanford.edu Thu Jul 24 15:05:20 2008 From: eenriquez at snf.stanford.edu (eenriquez at snf.stanford.edu) Date: Thu, 24 Jul 2008 15:05:20 -0700 Subject: Comment drytek2 SNF 2008-07-24 15:05:20: Update Message-ID: Plasma instability seems to be caused by arcing inside the chamber. For a test, I increased the pressure to 600 mT from 150 mT and the plasma was very stable for 15 minutes. Noticed that all of the insulators are heavily coated and some of the teflon retainers have broken off. We will need to rebuild the entire electrode assembly. The system will be available by 6pm next Wednesday From eenriquez at snf.stanford.edu Fri Jul 25 12:05:47 2008 From: eenriquez at snf.stanford.edu (eenriquez at snf.stanford.edu) Date: Fri, 25 Jul 2008 12:05:47 -0700 Subject: Comment drytek2 SNF 2008-07-23 18:18:22: Update Message-ID: Archived From eenriquez at snf.stanford.edu Fri Jul 25 12:08:36 2008 From: eenriquez at snf.stanford.edu (eenriquez at snf.stanford.edu) Date: Fri, 25 Jul 2008 12:08:36 -0700 Subject: Comment drytek2 SNF 2008-07-25 12:08:35: Update Message-ID: Did not have time to work on the system. We will start the electrode rebuild on Monday From cbaxter at snf.stanford.edu Sat Jul 26 09:46:35 2008 From: cbaxter at snf.stanford.edu (cbaxter at snf.stanford.edu) Date: Sat, 26 Jul 2008 09:46:35 -0700 Subject: Comment drytek2 SNF 2008-07-26 09:46:34: backing pump Message-ID: Was going to try check rf, notice pump was off. I tried to re-star pump but no go, when I checked out the pump can't see the oil level, I started to drain the fomblin oil and what's coming from the pump white milky color. It looks like white oil and fomblin somehow got mixed pump will need to change.. From mdickey at snf.stanford.edu Tue Jul 29 14:18:34 2008 From: mdickey at snf.stanford.edu (mdickey at snf.stanford.edu) Date: Tue, 29 Jul 2008 14:18:34 -0700 Subject: Comment drytek2 SNF 2008-07-29 14:18:33: Electrode Message-ID: The replacement parts for rebuilding the electrode have come in and the rebuild is about 90% complete. Will finish up tomorrow and install. From eenriquez at snf.stanford.edu Wed Jul 30 19:07:33 2008 From: eenriquez at snf.stanford.edu (eenriquez at snf.stanford.edu) Date: Wed, 30 Jul 2008 19:07:33 -0700 Subject: Shutdown drytek2 SNF 2008-07-22 22:43:44: reflected power > 200W Message-ID: Cleaned chamber and electrode assembly. Now RF power is very stable. Still have a small problem with the matching network. The Coil and tuning capacitor are near the end of their respective ranges when the reflected power is at a minimum. Need to troubleshoot further but the system is completely operational. I set up program 1 for Descum. Forward power at 500W, ref = 40. Tune cap position indicator is at 6 o'clock position and the coil is fully CCW. I set up program 2 for Poly. Forward power= 400W , ref= 20W. Tune cap at 50% and coil near fully CCW. I set up Program 3 is for Nitride. Foward power = 500W, ref= 20W. Tune cap at ~ 40% and coil near fully CCW. Please run an etch rate test before processing your samples. The etch rates might be dramatically different than the before the PM because the electrodes and ceramics are now clean. From eenriquez at snf.stanford.edu Wed Jul 30 19:08:24 2008 From: eenriquez at snf.stanford.edu (eenriquez at snf.stanford.edu) Date: Wed, 30 Jul 2008 19:08:24 -0700 Subject: Problem drytek2 SNF 2008-07-22 11:05:33: 3rd electrode down from top not working Message-ID: All electrodes are working after the PM. From eenriquez at snf.stanford.edu Wed Jul 30 19:08:39 2008 From: eenriquez at snf.stanford.edu (eenriquez at snf.stanford.edu) Date: Wed, 30 Jul 2008 19:08:39 -0700 Subject: Comment drytek2 SNF 2008-07-24 15:05:20: Update Message-ID: Archive From eenriquez at snf.stanford.edu Wed Jul 30 19:08:49 2008 From: eenriquez at snf.stanford.edu (eenriquez at snf.stanford.edu) Date: Wed, 30 Jul 2008 19:08:49 -0700 Subject: Comment drytek2 SNF 2008-07-25 12:08:35: Update Message-ID: Archived From eenriquez at snf.stanford.edu Wed Jul 30 19:10:30 2008 From: eenriquez at snf.stanford.edu (eenriquez at snf.stanford.edu) Date: Wed, 30 Jul 2008 19:10:30 -0700 Subject: Comment drytek2 SNF 2008-07-26 09:46:34: backing pump Message-ID: Drained and refilled the vacuum pump with fomblin. Still some hydrocarbon left in the oil, but pump is operational. From eenriquez at snf.stanford.edu Wed Jul 30 19:10:43 2008 From: eenriquez at snf.stanford.edu (eenriquez at snf.stanford.edu) Date: Wed, 30 Jul 2008 19:10:43 -0700 Subject: Comment drytek2 SNF 2008-07-29 14:18:33: Electrode Message-ID: Archived From eenriquez at snf.stanford.edu Wed Jul 30 19:11:37 2008 From: eenriquez at snf.stanford.edu (eenriquez at snf.stanford.edu) Date: Wed, 30 Jul 2008 19:11:37 -0700 Subject: Problem drytek2 SNF 2008-07-11 00:13:38: Proc #3 RF level Pot Message-ID: All process RF level pots are operational after the PM From eenriquez at snf.stanford.edu Wed Jul 30 19:19:43 2008 From: eenriquez at snf.stanford.edu (eenriquez at snf.stanford.edu) Date: Wed, 30 Jul 2008 19:19:43 -0700 Subject: Problem drytek2 SNF 2008-07-30 19:19:43: RF Matching network Message-ID: The tuning capacitor and coil are near the end their ranges. Had a difficult time tuning an O2 plasma. Had to set the capacitor at full CW and the coil at full CCW. The other gas were a little easier (cap at ~50%). From lindaw at snf.stanford.edu Thu Jul 31 10:06:06 2008 From: lindaw at snf.stanford.edu (lindaw at snf.stanford.edu) Date: Thu, 31 Jul 2008 10:06:06 -0700 Subject: Problem drytek2 SNF 2008-07-31 10:06:06: etch rate low on 3rd electrode down from top Message-ID: I was stripping 1500A of poly and all wafers on other electodes cleared at 2 min 30 sec, but the wafer on electrode #3, did not clear even after 4 min. There was still visible poly on the surface. It cleared quickly when transferred to the electrode #2. From lindaw at snf.stanford.edu Thu Jul 31 10:21:25 2008 From: lindaw at snf.stanford.edu (lindaw at snf.stanford.edu) Date: Thu, 31 Jul 2008 10:21:25 -0700 Subject: Comment drytek2 SNF 2008-07-31 10:21:23: 4500A poly, not 1500A in above write up. Message-ID: The etch rate is normal except for electrode #3. I just want to clarify. 1500A poly clears at around 50 seconds, which is normal for my process.