From mcvittie at cis.Stanford.EDU Sun May 2 21:01:27 2010 From: mcvittie at cis.Stanford.EDU (Jim McVittie) Date: Sun, 2 May 2010 21:01:27 -0700 (PDT) Subject: STS2 Update Message-ID: STS2 Users, The good news is the recent turbo pump problem was less of an issue than expected. The bad news is there is still an intermittent problem with high reflected power causing the rf power to drop out. Since last week the turbo pump shut down 3 times from overheating. At first Elmer thought the problem was due to a bad bearing in the pump. However, on further inspection he found that the cooling water was dirty and had to be flushed. The pump now appears to be working fine. I did at least 5 hrs of runs on the tool with no pump problems since the flushing. Before the flushing this problem would have shutdown the pump after an few hours of use. Regarding the high reflective power problem, I have learn a lot of things we should be doing differently but there is still an intermittent problem characterized by a sudden drops in the forward power after switching from an dep to an etch step. The dropouts appear to be due a cut back in the forward power when the reflected power suddenly goes out of control and excesses a limit value. I am consulting the with STS but so far we have not determined the cause. When the dropout start occurring repeatedly in a run, the only solution so far is to stop your run and let the tool sit unused for a while. Continuing run with lots of dropouts is not a good idea since they degrade the etch process and are hard on the 3 KW coil generator. The following items MUST be done to minimize the dropout problem and to reduce stress on the coil generator: 1. Run a 10 min O2 clean step before your run. 2. Make sure your recipe starts with a 10s stabilization period so the gas flows, pressure and matching network positions are stabilize before the plasma comes on. 2. Your recipe should have the "Tolerance Recipe" box selected. This insures that the process will quickly fault out if there is a problem with excessive reflected power or other condition, which will damage tool or your wafer. 3. Do not start with a etch (SF6) step for a switched process. 5. Check your tune and load matching network preset positions. I or some knowledgeable can help you do this. I will leave a note on the tool for typical preset values. 6. We still have not corrected the initial rf generator fault, which occurs each time the coil generator turns on after a new wafer has been loaded. You need to use the retry button at the bottom of the error page. Thanks, Jim -- -------------------------------------------------------------- James (Jim) P. McVittie, Ph.D. Sr. Research Scientist Paul G. Allen Building Electrical Engineering Stanford Nanofabrication Facility jmcvittie at stanford.edu Stanford University Office: (650) 725-3640 Rm. 336X, 330 Serra Mall Lab: (650) 721-6834 Stanford, CA 94305-4075 Fax: (650) 723-4659 From mcvittie at cis.Stanford.EDU Mon May 3 12:55:40 2010 From: mcvittie at cis.Stanford.EDU (Jim McVittie) Date: Mon, 3 May 2010 12:55:40 -0700 (PDT) Subject: STS2 Update Additions Message-ID: STS2 Users, I have some additions to my May 2 note. In particular, you also need to pay attention to the pressures, to monitor the forward and reflected coil powers and to remove your wafer from the chamber after every run or plasma test. STS warns that pressures below 10 mT can lead to plasma instabilities, which could be causing some of out problems. They suggest that we either use the AUTO APC pressure mode or check our recipe pressures on a regular basis if we are using manual pressure mode. The reason for checking is that the turbo pump speed will change with time so the pressure you get for a given APC percent setting will change with time. For a repeatable process you want the same pressure during your dep and etch cycle during each run. For each of your recipes you should know what the optimal dep and etch pressures are. If you do not know these pressures, you can go back in the datalog files to a known good run for a given recipe and get the pressures. As an example, for Jim-Etch-Test1 (shallow) recipe the optimum pressures are 15 mT dep and 40 mT etch. Another step, which may help reduce the intermittent high reflective power problem, is to move your wafer back to the carousel after every run or plasma strike. At this point, I have correlation that this helps. In my previous note, I forgot to say that you need to monitor the forward and reflective coil powers during your runs using the trace display on the process monitor screen. Here is an undated list of items, which should be done, to minimize the dropout problem and to reduce stress on the coil generator: 1. Run a 10 min O2 clean step before your run. 2. Make sure your recipe starts with a 10s stabilization period so the gas flows, pressure and matching network positions are stabilize before the plasma comes on. 3. Your recipe should have the "Tolerance Recipe" box selected. This insures that the process will quickly fault out if there is a problem with excessive reflected power or other condition, which could damage tool or your wafer. 4. Do not start with a etch (SF6) step for a switched process. 5. Check your tune and load matching network preset positions. I or some knowledgeable user can help you do this. A starting point for the switched dep/etch process is 42% for the coil load position and 37% for the tune position. 6. Make sure the pressure does not go below 10 mT during your run. If you use manual pressure control, you will need to change the percent setting over time to adjust for changes in the turbo pumping speed. 7. Remove your wafer from the chamber after each run (plasma strike). 8. We still have not corrected the initial rf generator fault, which occurs each time the coil generator turns on after a new wafer has been loaded. You need to use the retry button at the bottom of the error page to continue with your run. 9. During your runs, use the TRACE mode on the Process Monitor screen to monition the forward and reflected powers. If you see more than a few power dropouts, you should abort the run. Thanks, Jim -------------------------------------------------------------- James (Jim) P. McVittie, Ph.D. Sr. Research Scientist Paul G. Allen Building Electrical Engineering Stanford Nanofabrication Facility jmcvittie at stanford.edu Stanford University Office: (650) 725-3640 Rm. 336X, 330 Serra Mall Lab: (650) 721-6834 Stanford, CA 94305-4075 Fax: (650) 723-4659 From milnes_david at yahoo.com Mon May 24 23:27:34 2010 From: milnes_david at yahoo.com (Milnes David) Date: Mon, 24 May 2010 23:27:34 -0700 (PDT) Subject: Dear friend ~~ +--k Message-ID: <797709.91615.qm@web53108.mail.re2.yahoo.com> Dear friend, How are you recently? I bought a laptop from a website: www.mlsoo.com last week. I have got the product. Its quality is very good and the price is competitive. They also sell phones, TV, psp, motor and so on. By the way, they import product from Korea and sell new and original products. They have good reputation and have many good feedbacks. If you need these products, look at this website will be a clever choice. I am sure you will get many surprise and benefits. Greetings! o--1 -------------- next part -------------- An HTML attachment was scrubbed... URL: From shott at stanford.edu Thu May 27 07:24:22 2010 From: shott at stanford.edu (John Shott) Date: Thu, 27 May 2010 07:24:22 -0700 Subject: STS2 update ... Message-ID: <4BFE8096.2000703@stanford.edu> stsetch2 community: I thought that I'd send out an update as to where things stand on stsetch2. Because STS will not schedule visits until a purchase order is in place, we have opened a blanket order with STS that should eliminate future delays when we place a service call to STS. That order was finally opened on Tuesday. Because of uncertainty in the length of time that field service will spend at other sites our best information for STS is that they will be here next week, but we do not yet know which day they will arrive. In the meantime, Jim McVittie and Elmer have been looking closely at the matching network and matching network controller to identify the source of the RF drop outs. Yesterday, they found some intermittent contacts in the wiring harness that senses and controls the position of the variable capacitors in the matching network and are in the process of repairing/replacing the appropriate components to determine if these intermittent contacts on the control side are responsible for the observed dropouts. While it is too early to say that this IS the source of the drop outs ... we need to complete those repairs and then do some long runs to confirm this ... we are actively pursuing this path and should have more definitive information either later today or tomorrow. We know that this is a vitally important tool to many of you and that it has taken a long time to identify the source of these intermittent problems and resolve them. We understand that this tool needs to be in a condition where it runs reliably and that when it fails we need to be able to more quickly call for outside assistance when we cannot resolve that issue ourselves in a timely fashion. We believe that our new open blanket order will eliminate much of the delay in that process in the future. Please let me know if you have any additional questions, John From shott at stanford.edu Fri May 28 14:50:21 2010 From: shott at stanford.edu (John Shott) Date: Fri, 28 May 2010 14:50:21 -0700 Subject: STS Field Service Visit .... Message-ID: <4C003A9D.3000101@stanford.edu> STS Etch Community: We have just received notification from STS that we can expect field service to arrive mid-afternoon next Tuesday. We will have to see how much time they can spend on the tools that afternoon. Because we have issues on both tools that we would like them to work on, I've taken the liberty of reserving both tools during the day on Wednesday, Thursday, and Friday of next week. While work will likely be happening only on one machine at a time, some of that time may be released once we know more about which tool will be the Field Service target each day. We will try to keep you all posted as we learn more. Have a good weekend, John