From amol at stanford.edu Mon Nov 6 12:11:20 2000 From: amol at stanford.edu (Amol Ramesh Joshi) Date: Mon, 6 Nov 2000 12:11:20 -0800 (PST) Subject: H2SO4 thermometer Message-ID: Hi, I read a note on wbdiff that the thermometer is broken. The problem on Coral says TC is broken. Can someone clarify if the sensor was broken? If the pot was contaminated as a result, has it been cleaned? Thanks, - Amol From beckwith at sunray.snffab.stanford.edu Mon Nov 6 14:32:59 2000 From: beckwith at sunray.snffab.stanford.edu (Sharleen Beckwith) Date: Mon, 6 Nov 2000 14:32:59 -0800 (PST) Subject: Sulfuric hot pot Message-ID: Due to the questionable state of this hot pot, I am giving it an HCl clean. This may take several hours. Since I cannot determine the temperature, I will have to wait a long period of time for the HCl to cool, then guess when it is safe to aspirate. I have also emptied both HF tanks. I am leaving them empty, please fill them as needed. Sharleen From beckwith at snf.stanford.edu Mon Nov 6 19:47:56 2000 From: beckwith at snf.stanford.edu (Sharleen Beckwith) Date: Mon, 6 Nov 2000 19:47:56 -0800 Subject: hot pot problems Message-ID: Folks: Over the weekend the quartz thermocouple sheath in the sulfuric hot pot broke. When Ray looked at it, the thermocouple appeared to be corroded. In an effort to keep the diff bench up and running, it was decided that the thermocouple and quartz sheath from one of the wbnonmetal hot pots could be put in the wbdiff sulfuric hot pot until the new parts arrive. Unfortunately, the second thermocouple broke during the switch. Ray said he will make every effort, first thing in the morning, to replace the thermocouple in wbdiff. It will take longer to get the quartz sheaths, so the sulfuric hot pot in wbnonmetal may be down for a few days. Sharleen From rcrane at snf.stanford.edu Tue Nov 7 14:54:02 2000 From: rcrane at snf.stanford.edu (Dick Crane) Date: Tue, 07 Nov 2000 14:54:02 -0800 Subject: wbdiff repair Message-ID: <3A08880A.FAEB2AA0@snf.stanford.edu> The wbdiff hot pots will be repaired tomorrow. Thermistors and quartz sheaths are being shipped UPS red and should arrive here by 1000, 11/8/00. In the future, spare thermistors, locally made covers, and controllers will be in stock here. Dick Crane Technical Director snf From randythrive at yahoo.com Wed Nov 8 15:03:57 2000 From: randythrive at yahoo.com (Randy True) Date: Wed, 8 Nov 2000 15:03:57 -0800 (PST) Subject: wbdiff band-aid fix Message-ID: <20001108230357.27531.qmail@web3606.mail.yahoo.com> Wbdiff Users-- The current status of the diff bench is that we are still waiting for the thermocouple sheath to arrive. In the meantime, a protocol is being adopted that will still allows users to diff clean their wafers. The power to the sulfuric pot must remain off because of fire concern. It is unplugged in the back. DO NOT turn it back on. This means that users cannot drain the sulfuric pot. Ray will drain the pot (but not refill it) once in the morning and once in the afternoon. After the pot has been drained, the first user should fill the pot. Others should continue to use the bath without adding peroxide for about 2 hours. There will be a sign-up list for filling and adding peroxide. If you walk up to use the bench more than 2 hours after it has been filled or since the last time peroxide has been added, add peroxide. Please be dilligent about both recording the activity and not adding peroxide too often. Also, make sure to go through the wbnonmetal sulfuric before going to the diff bench. If you have any concerns or comments, please contact myself and Ray. Happy cleaning. __Randy True __________________________________________________ Do You Yahoo!? Thousands of Stores. Millions of Products. All in one Place. http://shopping.yahoo.com/ From randythrive at yahoo.com Wed Nov 8 15:35:56 2000 From: randythrive at yahoo.com (Randy True) Date: Wed, 8 Nov 2000 15:35:56 -0800 (PST) Subject: even better fix Message-ID: <20001108233556.1100.qmail@web3606.mail.yahoo.com> So, Ray has done some handy-work and made it possible for users to drain the sulfuric pot. The power is on but the heater is diabled (still do not turn it on). This makes most of the last email moot. I guess proceed as normal, we just will not know the bath temp. Look at the log and if someone has changed the bath or added peroxide recently, it should be OK, otherwise add peroxide. __________________________________________________ Do You Yahoo!? Thousands of Stores. Millions of Products. All in one Place. http://shopping.yahoo.com/ From beckwith at snf.stanford.edu Wed Nov 8 16:45:42 2000 From: beckwith at snf.stanford.edu (Sharleen Beckwith) Date: Wed, 8 Nov 2000 16:45:42 -0800 Subject: even better fix In-Reply-To: <20001108233556.1100.qmail@web3606.mail.yahoo.com> References: <20001108233556.1100.qmail@web3606.mail.yahoo.com> Message-ID: At 3:35 PM -0800 11/8/00, Randy True wrote: >So, Ray has done some handy-work and made it possible >for users to drain the sulfuric pot. The power is on >but the heater is diabled (still do not turn it on). >This makes most of the last email moot. I guess >proceed as normal, we just will not know the bath >temp. Look at the log and if someone has changed the >bath or added peroxide recently, it should be OK, >otherwise add peroxide. My concern is: if someone empties the Sulfuric:H2O2 when it is too hot and then hits the quartz hot pot with cold water we may end up with a cracked quartz hot pot. We have no replacements for these hot pots and the last time Len searched for one he could find no one who manufactured them. I would suggest using the old "empty every 5 days". Just drain out enough of the liquid to leave room for adding more H2O2 instead of completely emptying the entire pot...it should be repaired within the next 5 days. Someone from SNF should make the final call on this. At any rate: PLEASE be careful when you are draining and rinsing the hot pot! Sharleen From rcrane at snf.stanford.edu Thu Nov 9 12:07:24 2000 From: rcrane at snf.stanford.edu (Dick Crane) Date: Thu, 09 Nov 2000 12:07:24 -0800 Subject: Hotpot repair Message-ID: <3A0B03FC.9B8925CC@snf.stanford.edu> Ok, I am the one who stubbed his toe with the inadvertent bench shutdown. Given the failure (and lack of spares) of the temperature sensor for the hot pot and the potential danger of wet bench fires caused by runaway hot pots, I shut down the hot pot heater with the plan of using the self heating action of the H2SO4/H2O2 4:1 mix to allow continued operation of the bench. I was not aware of the drain interlock preventing use of the pot. Shutting down the bench was not the plan and I am sorry for the inconvenience caused. I consider the wbdiff to be a tool of prime importance and is one the highest maintenance priorities in the fab. Replacement sensors have arrived and will be installed today, 11/9/00. You may notice that the quartz sheaths are no longer present. The new sensors, with teflon covers, have worked well in high, minority carrier lifetime processes. Metallic contamination through the teflon is not a worry for our operation. Please see me if you have questions. The future: On Monday on this week, I started reviewing the high priority tools to insure an adequate supply of spares. The wbdiff will soon have a stock of controllers, sensors, general parts and, hopefully, spare hot pots. The goal is high uptime for this important tool. Thanks, Dick Crane technical Director SNF From amol at stanford.edu Fri Nov 10 09:41:22 2000 From: amol at stanford.edu (Amol Ramesh Joshi) Date: Fri, 10 Nov 2000 09:41:22 -0800 (PST) Subject: Possible contamination of wbdiff and wbnonmetal Message-ID: Hi, Today I found a user doing nonstandard 'cleaning' on wbdiff and wbnonmtal. He was etching oxide in 20:1 BOE and 6:1 BOE on wbnonmetal and H2SO4 dip and HCl dip on wbdiff. He was holding just one wafer with teflon tipped METAL tweezers, no cassette! As most users know, teflon on green tipped tweezers tends to wear out after some use. So there is a very high chance that metal may have entered the pots I mentioned above. I do not need to mention safety issue, no matter how careful one is. I have shutdown wbdiff and wbnonmetal. - Amol From jgarate at snf.stanford.edu Fri Nov 10 11:23:04 2000 From: jgarate at snf.stanford.edu (Jaime Garate) Date: Fri, 10 Nov 2000 11:23:04 -0800 Subject: Possible contamination of wbdiff and wbnonmetal References: Message-ID: <3A0C4B18.57E014B6@snf.stanford.edu> Hi, I have talked to the user responsible for this. Not only for the safety issue, but for the cross- contamination issue. He is involve on the clean up. The WBNONMETAL- has been decontaminate and it is okay to use. The WBDIFF- still down under decontamination. (1) You are not allow to dip your metal tweezers at these wet benches at all!!! (2) You are not allow to go from 20:1 or 6:1 on wbnonmetal to a H2S04 dip and HCL dip on wbdiff at all!!! (3) We are all members so please follow the procedures and work safely. Thanks, Jaime Garate Amol Ramesh Joshi wrote: > > Hi, > > Today I found a user doing nonstandard 'cleaning' on wbdiff and > wbnonmtal. He was etching oxide in 20:1 BOE and 6:1 BOE on wbnonmetal and > H2SO4 dip and HCl dip on wbdiff. He was holding just one wafer with teflon > tipped METAL tweezers, no cassette! As most users know, teflon on green > tipped tweezers tends to wear out after some use. So there is a very high > chance that metal may have entered the pots I mentioned above. I do not > need to mention safety issue, no matter how careful one is. I have > shutdown wbdiff and wbnonmetal. > > - Amol From eap at gloworm.Stanford.EDU Sat Nov 11 17:10:49 2000 From: eap at gloworm.Stanford.EDU (Eric Perozziello) Date: Sat, 11 Nov 2000 17:10:49 -0800 (PST) Subject: 6:1 pot on wbdiff decontaminated using HCl/H2O2. Message-ID: <200011120110.RAA00776@gloworm.Stanford.EDU> Hi All, I found a note on the bench this AM that the 6:1 pot had not yet been decontaminated. It was empty. So while I changed the other chemicals, I heavily rinsed it, filled with HCl/H2O2, let it sit, drained, and rinsed and filled w/ DI, drained, ec, and finally refilled with 6:1. I left a note to this effect on the bench. I hope this procedure is correct, as we've used this before in these cases. I didn't use this pot after changing, so if there's From beckwith at snf.stanford.edu Tue Nov 14 15:51:08 2000 From: beckwith at snf.stanford.edu (Sharleen Beckwith) Date: Tue, 14 Nov 2000 15:51:08 -0800 (PST) Subject: no spray rinse in the left dump rinser... Message-ID: this means the handles are not being rinsed at all (using the right dump rinser is not an option, so I suggest you take the cassette handle off and put it in the bottom of the dump rinser. Run the standard 6 cycles. Put the handle back on the cassette. Sharleen From beckwith at snf.stanford.edu Tue Nov 14 15:58:25 2000 From: beckwith at snf.stanford.edu (Sharleen Beckwith) Date: Tue, 14 Nov 2000 15:58:25 -0800 (PST) Subject: Who left the HCl hot pot empty????? Message-ID: When I came in around noon today the HCl hot pot was empty. PLEASE do NOT leave hot pots empty without leaving a note and sending e-mail to the user list (see the e-m address above) explaining why you are doing something like this. I had no way of knowing if there was a problem with the hot pot or not. Given the history of the past two weeks, I assumed the worst (someone had contaminated it) and cleaned it with HCl before I used it. This caused a tremendous back log of people who needed to use the bench (not to mention "wasting" a substantial amount of MY time). We all have to share the equipment in this lab. You are not operating in a vacuum. Whatever you do affects all the people who come after you. Please remember this when you are in the lab! Sharleen From grupp at snow.stanford.edu Sun Nov 19 00:54:13 2000 From: grupp at snow.stanford.edu (Dan Grupp) Date: Sun, 19 Nov 2000 00:54:13 -0800 (PST) Subject: Bench reserved Sunday morning for chemical change Message-ID: No one is signed up for Sun morning, so i don't expect this to be of any inconvenience. Please leave the heaters OFF sunday morning so chemicals may be changed. Thanks, Dan --------------------------------------------------------------------------- Dr. Daniel Grupp, Visiting Scholar Center for Integrated Systems Stanford University Stanford, CA 94305 (650) 724-6911 FAX: 723-4659 ---------------------------------------------------------------------------