From flin2 at stanford.edu Thu Mar 2 17:49:30 2006 From: flin2 at stanford.edu (Francis Lin) Date: Thu, 2 Mar 2006 17:49:30 -0800 Subject: radiometer In-Reply-To: <1140890089.440099e9a3c6b@webmail.stanford.edu> References: <1140890089.440099e9a3c6b@webmail.stanford.edu> Message-ID: <1141350570.4407a0aa21c84@webmail.stanford.edu> Hi, all: Just wondering if anyone has a radiometer that I can borrow. Our lab got a new UV lamp and need to determine the UV-B intensity. Thanks! Best Francis Lin From ebasham32 at earthlink.net Thu Mar 2 20:23:19 2006 From: ebasham32 at earthlink.net (Eric) Date: Thu, 2 Mar 2006 20:23:19 -0800 Subject: HP Test Equipment Repair Recommendations In-Reply-To: <1141350570.4407a0aa21c84@webmail.stanford.edu> Message-ID: <001801c63e7a$33aebe20$0400a8c0@newtablet> Howdy Labmembers, Does anyone have a recommendation for a local HP test equipment repair shop? Thanks! Eric From fely at gloworm.Stanford.EDU Fri Mar 3 13:39:49 2006 From: fely at gloworm.Stanford.EDU (Fely Barrera) Date: Fri, 03 Mar 2006 13:39:49 -0800 Subject: EE 310 seminar, March 7, 2006 Message-ID: <200603032139.k23LdnPm014731@gloworm.Stanford.EDU> EE 310 Seminar Date: March 7, 2006 Time: 4:15pm - 5:05 pm Place: Hewlett 102 Title: "Why your mother worries about what you do: the emerging public dialogue over nanotechnology" Speaker: Elizabeth Corcoran Contributing Editor, Forbes magazine Abstract: The term "nanotechnology" pops up regularly in news stories these days-sometimes deservedly and sometimes not. This talk will review the stories and issues that are shaping the public dialogue about nanotechnology-from scare-monger stories (Michael Crichton's "Prey" and Bill Joy's infamous piece in Wired magazine), to stock pickers' erratic enthusiasm for "nano," to government investments in nanotech research, to the recent proposals by groups like the Environmental Defense Fund and the Woodrow Wilson International Center for more environmental regulation and oversight of nanotechnology. Biography: Elizabeth Corcoran is an award-winning journalist who has covered technology for more than 15 years. She is currently a Contributing Editor at Forbes magazine and served as Silicon Valley Bureau Chief for Forbes from February 1999 through May 2002. Prior to joining Forbes, Ms. Corcoran was a staff writer for The Washington Post, responsible for covering Silicon Valley and technology. She has also served as an editor and writer for Scientific American magazine and IEEE Spectrum. She has received awards both for news coverage as well as feature writing and has been named as a "top influencer" for several years by Marketing Computers Media Report. Elizabeth frequently moderates panels and is a regular commentator on radio and TV news programs. From mcvittie at cis.Stanford.EDU Fri Mar 3 16:41:13 2006 From: mcvittie at cis.Stanford.EDU (Jim McVittie) Date: Fri, 3 Mar 2006 16:41:13 -0800 (PST) Subject: Plasma Etch User Mtg March 9, 2006 Message-ID: Hi, The Bay Area plasma etch user gp (PEUG) has bi-monthly mtgs in Sunnyvale. They are open to anyone, who wants to attend. The March mtg to be held on the afternoon of March 9 is especially good. If you are interested in plasma etching, it is a good mtg to attend. Jim McVittie (PEUG Chairman) > > *NCCAVS PEUG User Groups > MARCH Meeting Announcement*** > > > > */NO NEED TO REGISTER -- JUST SHOW UP!!/*** > > > > *Session Topic: *Engineering Plasmas and Processing Equipment for > Applications > > > > *Chair:* Dan Flamm, dlf at mtag.com and > Brett Cruden, NASA Ames UARC, bcruden at arc.nasa.gov > > > > > *Date: March 9, 2006* > > > > *Time:* 2:00-5:00pm > > *Location: *National Semiconductor > > 955 Kifer Rd. > > Sunnyvale, CA > > > > *DIRECTIONS:_ > > _From 101*: Go south on Lawrence Expressway. Turn right on Kifer Rd. > Turn right into the driveway of the National Semiconductor Auditorium > (955 Kifer Rd.) and find parking in the rear parking lot. The > auditorium is on the West Side of the building and can be entered from > the door in the rear next to the company park. > > *From 280*: Go north on Lawrence Expressway. Turn left on Kifer Rd. > Follow directions above. > > > > *_AGENDA:_* > > > > 2:00 - 2:20 pm Refreshments > > 2:20- 2:30 pm PEUG Business Meeting > > 2:30 - 5:00 pm Presentations > > > > 1. *Plasma Challenges for 45/32 nm scaling - Dry Etch Tooling and > Processes, > *Richard Wise, Semiconductor Research and Development Center, IBM > Microelectronics, Hopewell Junction, NY > > > > The anticipated impact of a variety of advanced technologies on > requirements of dry etch process and tooling is discussed in detail. > The impact of metal gate electrodes, high-k gate dielectric materials, > hybrid oriented transistors (HOT), FINFET transistors, new silicide > materials, multiple stressed (tensile/compressive) liners, > fully-silicided gates, embedded Si-Ge (compressive/tensile), and > porous low-k BEOL materials are considered as candidates for > introduction at the 45 and 32 nm nodes. Lithographic exposure > continues to require dry etch processes Additional masking materials > may become necessary as requirements compromise overall etch > selectivity. Expected reduction in available resist material due to > limitations of the lithographic process window (N.A , DOF, resolution) > places increased demand on the dry etch processing chamber. These > reductions in the available mask thickness have driven the > implementation of more highly selective etch processes, with > concurrent tradeoffs in uniformity, defectivity, profile control, line > edge roughness and line edge foreshortening of the transferred > pattern. Dry etch process and tooling needs required to address these > lithographic challenges are discussed. > > > 2. *Kinetics of Downstream Oxide and Silicon Nitride Cleaning Using > Fluorocarbon Gas Mixtures in a Remote Toroidal Discharge, *Herb Sawin, > Massachusetts Institute of Technology, Dept. of Chemical Engineering, > Cambridge, MA** > > * * > > The use of downstream cleaning of deposition chambers has become > common. Use of NF3 feed gases has dominated because of the high > etching rates and lack of residual deposition. While fluorocarbons > are less expensive per mole of fluorine in the feed, the etching rates > have been less than that for complete conversion of the fluorocarbon > to atomic fluorine. In addition, deposits have been observed, > particularly on low temperature surfaces. We have demonstrated that > nearly complete dissociation of fluorocarbon gases to form atomic > fluorine can be achieved using mixtures of C2F6, O2 and N2. This is a > result of nitrogen blocking surface sites that favor the formation of > COF2 rather than CO2. With the nitrogen blocking nearly complete > conversion of the fluorocarbon to atomic fluorine and comparable > etching rates of oxide can be achieved. We have also developed > mixtures for etching silicon nitride much faster than in pure NF3 > discharges. They are particularly fast at room temperature which > suggests that pump exhaust lines can be cleaned as well as the chamber.* > * > 3*. The Spontaneous Etching of Silicon with Halogen Atoms, > *Harold F. Winters, San Jose, CA. > > A recently proposed molecular dynamics simulation of spontaneous > etching of undoped silicon with F has been successful in describing a > variety of experimental observations. Insights gained have been used > to refine a model which explains other spontaneous etch observations, > including etching by halogen atoms and various effects of doping on > spontaneous etching, among others. The model is based on the > assumption that the reaction occurs at negative ion centers on the > silicon surface (e.g. at SiF_3 ^- sites)^ using the umbrella-type > reaction mechanism observed in the simulation. Experimental data show > that the layer thickness is relatively independent of incident flux > and temperature over significant ranges of these parameters. These > results are correlated with various experiments including reaction > probability measurements over the temperature range 200--1000 K and > doping experiments with concentrations from ~10^15 to 10^20 > dopants/cm^3 . It will be shown that one mechanism can be used to > describe the experimental results for the spontaneous etching of S > (111) by both F, Cl, and Br. > > > > A variety of data will be presented and compared with theory. > > > > ********************************************************** > > *_Future Meetings:_* > > *May 11---Damascene Etching*, submit abstracts to Co-Chairs: > Calvin Gabriel, AMD, calvin.gabriel at amd.com > ; Xueyu Qian, AMEC, > XueyuQian at amecnsh.com > > > > *July 13---Frontend Dielectric Etch*, submit abstracts to: Shawming > Ma, Applied Materials, shawming_ma at amat.com > > > > ********************************************************** > > *NCCAVS User Group website: www.avsusergroups.org > > Find:* Meeting Schedules, Announcements, Call for Papers, Committee > Contact Information, Proceedings from monthly meetings and more. > > * * > > *Sign up for a User Group: **www.avsusergroups.org* > > > *********************************************************** > > > From amf at amfitzgerald.com Fri Mar 3 16:58:07 2006 From: amf at amfitzgerald.com (Alissa M. Fitzgerald) Date: Fri, 3 Mar 2006 16:58:07 -0800 Subject: dielectric strength of SNF LTO; spin on dielectrics Message-ID: <005201c63f26$b4c93470$6401a8c0@minicat> Hello labmembers, I am seeking a dielectric that I can put over aluminum, with a *known* dielectric strength, that I can process in SNF. The obvious choices are LTO, PECVD nitride or oxide, or spin-on materials (only interested in those that are approved for lab use). If you have any specific recommendations, I would be very interested to hear from you. If you have dielectric strength data on specific LTO recipes, that would be very, very helpful. I am also interested in vendor options, if you know of any. Again, key issue is that the material dielectric strength must be known, ballpark estimates are fine. Best regards, Alissa Alissa M. Fitzgerald, Ph.D. Managing Member A.M. Fitzgerald & Associates, LLC Technical Consulting Services MEMS | Materials | Sensor Systems 655 Skyway Suite 118 San Carlos, CA 94070 (650) 592-6100 tel/fax www.amfitzgerald.com -------------- next part -------------- An HTML attachment was scrubbed... URL: From zhangy at stanford.edu Mon Mar 6 11:06:37 2006 From: zhangy at stanford.edu (Yuan Zhang) Date: Mon, 06 Mar 2006 11:06:37 -0800 Subject: Au etch Message-ID: <6.2.1.2.2.20060306105908.057d2b10@zhangy.pobox.stanford.edu> Dear labmembers, We are going to deposite, pattern and etch Au in our process. I wonder if anyone has any experience on Au etching. It seems to me Au is not very easy to be etched by either wet etch or dry etch. By the way, would you please let me know if you have any recipy about Pt or Cr etch using any of the tools inside clean room? Thank you very much. I really appreciate your help. Best Regards, Yuan From mtang at stanford.edu Tue Mar 7 14:05:30 2006 From: mtang at stanford.edu (Mary Tang) Date: Tue, 07 Mar 2006 14:05:30 -0800 Subject: Learn how to save someone's life! Message-ID: <440E03AA.9050406@stanford.edu> Greetings labmembers: We?ve just arranged for a First Aid/CPR/AED class to be offered here, on-site. This 8-hour course, offered through Stanford EH&S, will cover basic first aid and simple emergency procedures that you could use to save someone?s life. This course will also cover Cardio-Pulmonary Resuscitation (CPR) and use of the Automated External Defibrillator (AED) ? which are awfully handy skills to know, when someone?s heart stops. If you, like me, were once CPR-certified ages ago, it?s well worth doing again because the recommended best-know-practices (and survival rates) have changed a LOT. Also, we now have two AED systems in this building, so it?s handy to know how to use one (or have someone on-hand who does!) One statistic quoted by EMT professionals is that use of CPR alone may have a survival rate of 2% of less, whereas the combination of CPR and AED has a survival rate of 80% or greater (the American Heart Association doesn?t quote stats, but does say that quick-response CPR/AED is essential for high survival rates.) The class will be held over two days: Monday and Tuesday, April 3-4, from noon to 4 pm. Completion of this course gives you a certification that is valid for two years. Anyone may register for this course. The cost for the class is $65. If you are a Stanford person, your department may cover the cost of this class (and STAP funds certainly will). Class fees may also be transferred to your SNF account, upon request. If you are interested in registering for the class, please get in touch with me. Thanks for your attention! Mary -- Mary X. Tang, Ph.D. Stanford Nanofabrication Facility CIS Room 136, Mail Code 4070 Stanford, CA 94305 (650)723-9980 mtang at stanford.edu http://snf.stanford.edu From jerabek at snf.stanford.edu Wed Mar 8 09:31:34 2006 From: jerabek at snf.stanford.edu (Paul Jerabek) Date: Wed, 8 Mar 2006 09:31:34 -0800 (PST) Subject: Mask writer Message-ID: To whom it may concern: laser mask writer is down for final lens cleaning and optical head adjustment. -Paul From mtang at stanford.edu Wed Mar 8 14:59:09 2006 From: mtang at stanford.edu (Mary Tang) Date: Wed, 08 Mar 2006 14:59:09 -0800 Subject: Removing crystalbond from GaAs? Message-ID: <440F61BD.80009@stanford.edu> Here's a message, relayed from a labmember: / Hello, I am currently using crystalbond 590 (brown wax) for temporary mounting of my GaAs chips to Si handle wafers for Au-bumping and dicing. I have chosen this wax as the Au-bumping step requires process temperatures of ~150 C. Currently, I am having a very hard time removing the samples from the handle wafer. I have gotten some chips off of the Si, however I still cannot completely remove the wax (which is necessary). The wax is contacting a surface with GaAs, SiNx, and Au exposed. The opposite side has PMGI for planarization which I would not like to strip. / / / / If you could recommend a process to successfully remove this material I would greatly appreciate it. Thank you! / / / / Garrett / / ____________________________________________ / / Garrett Cole, Ph.D. Research Scientist Aerius Photonics, LLC / / http://www.aeriusphotonics.com / / office: (805) 642-4645 personal: (805) 450-1083 ____________________________________________ / -- Mary X. Tang, Ph.D. Stanford Nanofabrication Facility CIS Room 136, Mail Code 4070 Stanford, CA 94305 (650)723-9980 mtang at stanford.edu http://snf.stanford.edu From jerabek at snf.stanford.edu Wed Mar 8 15:39:25 2006 From: jerabek at snf.stanford.edu (Paul Jerabek) Date: Wed, 8 Mar 2006 15:39:25 -0800 (PST) Subject: Mask writer Message-ID: To whom it may concern: laser mask writer is back on line. -Paul From mtang at stanford.edu Thu Mar 9 17:22:37 2006 From: mtang at stanford.edu (Mary Tang) Date: Thu, 09 Mar 2006 17:22:37 -0800 Subject: Litho Ovens and Timers Message-ID: <4410D4DD.708@stanford.edu> Hi everyone -- Mahnaz asked me to convey a request. Please do not use the timer controls on the singe oven or other shared bake ovens in the litho area. Once the timers are done, the ovens shut off completely and go cold. If you need a timer, please use your own portable one ($7 at Biostores, for a three-event timer.) Mary -- Mary X. Tang, Ph.D. Stanford Nanofabrication Facility CIS Room 136, Mail Code 4070 Stanford, CA 94305 (650)723-9980 mtang at stanford.edu http://snf.stanford.edu From ndhuang at stanford.edu Thu Mar 9 19:12:06 2006 From: ndhuang at stanford.edu (Ningdong Huang) Date: Thu, 9 Mar 2006 19:12:06 -0800 Subject: Metalica reservation cancelled tonight Message-ID: <1141960326.4410ee8652539@webmail.stanford.edu> Dear labmates, I have to give up Metalica tonight from 7:00-11:00 since it's not working properly. The target status 'not ok' red LED will lit whenever you switch to target B. And after that it's almost impossible to correct the status back to ok. So I give up and will try some other time. Feel free to take the time if you think that you can solve the problem. Sorry about the last minute notice. -- Ningdong Huang, Graduate Student Applied Physics, Stanford University Stanford Synchrotron Radiation Laboratory 650-926-2345 From mtang at stanford.edu Mon Mar 13 15:12:38 2006 From: mtang at stanford.edu (Mary Tang) Date: Mon, 13 Mar 2006 15:12:38 -0800 Subject: IEEE UGIM Call for Papers Message-ID: <4415FC66.1040203@stanford.edu> Greetings labmembers! Just wanted to bring to your attention the IEEE UGIM Symposium, which will be held in San Jose, this June 25-28. It's local, it covers topics near and dear to our hearts, stars one of our own as a featured speaker (Prof. Nishi), and is free (!!) to students who present. For more information, check out the Symposium website (http://www.engr.sjsu.edu/ugim2006/About.html) and this announcement from the conference chair. Hope to see you there! -- Mary *********************************************************************************************** Dear Colleagues, This is a reminder that the deadline for abstract submission for the 16th biennial University, Government, Industry Microelectronics Symposium (UGIM) is this Friday (March 17th). This year's UGIM will be held at San Jose State University in the heart of Silicon Valley on June 25-28,2006. The purpose of this symposium is to bring together leading engineering educators and researchers from university, government, and industry around the world to promote microelectronics and other forms of micro/nano-fabrication. Papers in the area of mixed signal design and test are welcome as well. Representatives of university fabrication labs, ranging from new start-up labs to nationally recognized facilities, have found this symposium an excellent forum for exchanging information. Government agencies such as NSF, NIH, NIST, SEMATECH, SRC, DARPA and ONR regularly participate with papers and updates on funding opportunities. Industry interactions with universities, including technology transfer, collaborative research, and training efforts are frequently presented. For more information on the conference and to submit and abstract, go to: http://www.engr.sjsu.edu/ugim2006/index.htm Sincerely, David Parent, 2006 Conference Chair -- Mary X. Tang, Ph.D. Stanford Nanofabrication Facility CIS Room 136, Mail Code 4070 Stanford, CA 94305 (650)723-9980 mtang at stanford.edu http://snf.stanford.edu From curlwang at stanford.edu Tue Mar 14 15:45:12 2006 From: curlwang at stanford.edu (Ke Wang) Date: Tue, 14 Mar 2006 15:45:12 -0800 (PST) Subject: 3/22: Ke Wang's PhD defense Message-ID: Dear All, In case you are interested, I will be giving my PhD dissertation defense talk next Wednesday. Ke Wang Department of Applied Physics Advisor: Professor James Harris Title: A Carbon Nanotube Microelectrode Array for Neural Stimulation Time: 2:00pm, March 22, 2006, Wednesday (refreshments will be served from 1:45pm) Location: CIS-X Auditorium, Room 101 Abstract: Electrical stimulation of nerve cells is widely employed in neural prostheses (for hearing, vision, and limb movement restoration), clinical therapies (treating Parkinson's disease, dystonia and chronic pain), as well as in basic neuroscience studies. In all these applications, an implanted microelectrode array transduces electrical signals to neurons and modulates their behavior. These stimulating electrodes need to be biocompatible, stable, micro-scaled, and capable of delivering high current while remaining electrochemically safe. This work presents a novel neural interface using multi-walled carbon nanotubes (CNT) as microelectrodes. We synthesized self-assembled CNTs by thermal chemical vapor deposition. The CNTs formed pillars of controllable height projecting orthogonally from the surface. Using conventional silicon-based micro-fabrication processes, these CNT ensembles were integrated onto pre-patterned microcircuitry. The geometry and location of the CNT microelectrodes could be precisely defined. The electrochemical properties of the CNT microelectrode array were characterized by cyclic voltammetry, impedance spectroscopy, and potential transient measurements. Compared to platinum and iridium oxide neural electrodes, these CNT microelectrodes had a wide electrochemical operational window, competitive charge injection limit, and operated capacitively without faradic reactions. These properties have become increasingly important, as applications in the central nervous system require a significant reduction in electrode size. Different surface modification techniques, such as thermal oxidation, chemical oxidation and non-covalent binding, were investigated to functionalize the CNT electrodes and the active interfacial area was considerably increased. The biocompatibility of CNTs was assessed by in vitro cell culture. Retinal ganglion cells and hippocampal neurons were cultured on CNT substrates, and showed comparable viability and neurite outgrowth to cultures on plastic controls. As a proof of concept, in vitro stimulation of primary neurons with the CNT microelectrode array was demonstrated. Neurons could be repeatedly stimulated, indicating good cell excitability and electrode condition. In conclusion, a prototype CNT microelectrode array has been developed. Several critical aspects of CNTs as neural stimulating electrodes were investigated. The advantageous electrochemical, mechanical, and chemical properties of CNTs suggest that they are capable of providing a safer solution for neural stimulation. _____________________________________________ Ke Wang PHD Candidate Department of Applied Physics, Stanford University (O): (650)725-5774 From mbaran at stanford.edu Wed Mar 15 09:54:00 2006 From: mbaran at stanford.edu (Maureen Baran) Date: Wed, 15 Mar 2006 09:54:00 -0800 Subject: Watch Found in the Gowning Room Message-ID: <200603151754.k2FHs1eB019165@smtp3.Stanford.EDU> Dear Labmembers, A watch was found in the gowning room a couple of days ago. If this watch is yours please come by my cubicle (#41) and be prepared to describe it to me before receiving it. Maureen Maureen Baran Stanford Nanofabrication Facility Lab Services Administrator mbaran at stanford.edu 650-725-3664 -------------- next part -------------- An HTML attachment was scrubbed... URL: From nlatta at stanford.edu Wed Mar 15 10:15:51 2006 From: nlatta at stanford.edu (Nancy Latta) Date: Wed, 15 Mar 2006 10:15:51 -0800 Subject: Gladys Sarmiento's departure Message-ID: <441859D7.5000501@stanford.edu> Folks- As you may be aware, Gladys has now left Stanford. Her last day was March 1. She wanted to leave quietly and we?ve respected her request, but she?s promised to come back and visit often. We have a yellow book for you to write memories, good wishes, jokes or just your name. If you have any photos you'd like to add please bring them too. We'd like for this book to be a nice reminder to Gladys of her 20 years here at Stanford. As you probably know, Gladys returns twice a year to her home in the Philippines. It?s a small, rural village where education, especially for girls, typically ends at 12. For years now, Gladys has been funding a scholarship fund to allow students to continue their education -- some of her students have now graduated from college. She has also built a facility which has now become the community center for the village. We think it would be a good way to show our appreciation for Gladys by collecting some funds to help her continue her work with her community. So please come by my office (Gladys's old office) at CIS 145 to sign the book and make a donation to her scholarship fund if you like. But come by soon; we'd like to give her the book on 21 March. -Nancy From raghavs at stanford.edu Thu Mar 16 11:08:30 2006 From: raghavs at stanford.edu (Raghav) Date: Thu, 16 Mar 2006 11:08:30 -0800 Subject: TaN etch Message-ID: <6.2.5.6.2.20060316110615.0291e980@stanford.edu> Hi All i am looking for a wet/dry etch chemistry that would selectively etch Tantalum nitride and not attack Aluminum. any input is greatly appreciated. thanks Raghav From nlatta at stanford.edu Fri Mar 17 16:43:36 2006 From: nlatta at stanford.edu (Nancy Latta) Date: Fri, 17 Mar 2006 16:43:36 -0800 Subject: Last Chance to Sing the Book for Gladys! Message-ID: <441B57B8.2040906@stanford.edu> Folks, We will be leaving the 'goodbye' book for Gladys at the lab entrance for you to sign. Please add your goodbye wishes by Monday at noon. Thanks, -Nancy From kevhuang at stanford.edu Fri Mar 17 20:12:40 2006 From: kevhuang at stanford.edu (Huang Kevin) Date: Fri, 17 Mar 2006 20:12:40 -0800 Subject: dielectric strength of LTO Message-ID: <93586f8c0603172012x1d7024c4r6b53db8b18b04bd0@mail.gmail.com> Hi, Could someone please tell me roughly what the breakdown field is (at DC and in the MHz range) for the LTO from tylanBPSG using the program LTO400? Is it an order of magnitude lower than thermal oxide? Thanks. Kevin -- ================================== Kevin Huang Ph.D. Student, Peumans Group Stanford Organic Electronics Lab Dept. of Electrical Engineering Email: kevhuang at stanford.edu Phone: (650) 725-6924 ================================== -------------- next part -------------- An HTML attachment was scrubbed... URL: From mtang at stanford.edu Mon Mar 20 09:50:13 2006 From: mtang at stanford.edu (Mary Tang) Date: Mon, 20 Mar 2006 09:50:13 -0800 Subject: [Fwd: Learn how to save someone's life!] Message-ID: <441EEB55.5010400@stanford.edu> Hi everyone -- There are still a few spaces left in the April First Aid/CPR/AED session (two weeks from today.) Please let me know if you'd like to register. Thanks! Mary -- Mary X. Tang, Ph.D. Stanford Nanofabrication Facility CIS Room 136, Mail Code 4070 Stanford, CA 94305 (650)723-9980 mtang at stanford.edu http://snf.stanford.edu -------------- next part -------------- An embedded message was scrubbed... From: Mary Tang Subject: Learn how to save someone's life! Date: Tue, 07 Mar 2006 14:05:30 -0800 Size: 2202 URL: From rohank at stanford.edu Mon Mar 20 13:39:31 2006 From: rohank at stanford.edu (Rohan D. Kekatpure) Date: Mon, 20 Mar 2006 13:39:31 -0800 Subject: Isotropic Silicon Wet etch Message-ID: <1142890771.441f21133922a@webmail.stanford.edu> Dear Labmembers, I need to etch ~1um of silicon isotropically. In literature there seem to be 3 ways of doing it: (a) Wet etching in HNA solution (HF + HNO3 + acetic acid) (b) Wet etching in EDP solution (Ethylene diamine pyrochatechol) and (c) dry etching in XeF2. I am flexible as far as requirements of roughness and dimensional tolerences are concerned. I am just interested in knowing what options are available to me within our SNF clean room. My preferred mask would be SiO2. I expect the HF in the HNA solution to attack the SiO2 mask. So if anybody has an idea on the selectivity between SiO2 and Si for an HNA etch, I would appreciate the input. Thank you very much in advance. -Rohan From curlwang at stanford.edu Tue Mar 21 11:07:29 2006 From: curlwang at stanford.edu (Ke Wang) Date: Tue, 21 Mar 2006 11:07:29 -0800 (PST) Subject: 3/22: Ke Wang's PhD defense Message-ID: Dear All, This is just a reminder that I will be giving my PhD dissertation defense talk tomorrow. My apology if you have received this email more than once. Ke Wang Department of Applied Physics Advisor: Professor James Harris Title: A Carbon Nanotube Microelectrode Array for Neural Stimulation Time: 2:00pm, March 22, 2006, Wednesday (refreshments will be served from 1:45pm) Location: CIS-X Auditorium, Room 101 Abstract: Electrical stimulation of nerve cells is widely employed in neural prostheses (for hearing, vision, and limb movement restoration), clinical therapies (treating Parkinson's disease, dystonia and chronic pain), as well as in basic neuroscience studies. In all these applications, an implanted microelectrode array transduces electrical signals to neurons and modulates their behavior. These stimulating electrodes need to be biocompatible, stable, micro-scaled, and capable of delivering high current while remaining electrochemically safe. This work presents a novel neural interface using multi-walled carbon nanotubes (CNT) as microelectrodes. We synthesized self-assembled CNTs by thermal chemical vapor deposition. The CNTs formed pillars of controllable height projecting orthogonally from the surface. Using conventional silicon-based micro-fabrication processes, these CNT ensembles were integrated onto pre-patterned microcircuitry. The geometry and location of the CNT microelectrodes could be precisely defined. The electrochemical properties of the CNT microelectrode array were characterized by cyclic voltammetry, impedance spectroscopy, and potential transient measurements. Compared to platinum and iridium oxide neural electrodes, these CNT microelectrodes had a wide electrochemical operational window, competitive charge injection limit, and operated capacitively without faradic reactions. These properties have become increasingly important, as applications in the central nervous system require a significant reduction in electrode size. Different surface modification techniques, such as thermal oxidation, chemical oxidation and non-covalent binding, were investigated to functionalize the CNT electrodes and the active interfacial area was considerably increased. The biocompatibility of CNTs was assessed by in vitro cell culture. Retinal ganglion cells and hippocampal neurons were cultured on CNT substrates, and showed comparable viability and neurite outgrowth to cultures on plastic controls. As a proof of concept, in vitro stimulation of primary neurons with the CNT microelectrode array was demonstrated. Neurons could be repeatedly stimulated, indicating good cell excitability and electrode condition. In conclusion, a prototype CNT microelectrode array has been developed. Several critical aspects of CNTs as neural stimulating electrodes were investigated. The advantageous electrochemical, mechanical, and chemical properties of CNTs suggest that they are capable of providing a safer solution for neural stimulation. _____________________________________________ Ke Wang PHD Candidate Department of Applied Physics, Stanford University (O): (650)725-5774 From yy7343 at hotmail.com Tue Mar 21 13:21:23 2006 From: yy7343 at hotmail.com (Yahong Yao) Date: Tue, 21 Mar 2006 13:21:23 -0800 Subject: Isotropic Silicon Wet etch In-Reply-To: <1142890771.441f21133922a@webmail.stanford.edu> Message-ID: Hi Rohan, I would think Drytek2 is the most convenient way to accomplish your goal. 1.6um photoresist can serve as the mask. You can find the recipe and etch rate at: http://snf.stanford.edu/Equipment/drytek/drytek2ER.pdf If for some reason, you need to use wet etch, then TMAH (tetramethylammonium Hydroxide) would be a good candidate. Oxide is a very good mask in TMAH (1000A is way enoug for your purpose, but thicker oxide has less pinholes). 20% TMAH in water gives about 4000A/min at about 80C. But the native oxide on open areas will influence the result. Be sure to do a short HF dip (50:1) before you put wafers in TMAH. If you use clean labwares for etching, then your wafers are still clean afterwards. Hope it helps. Yahong >From: "Rohan D. Kekatpure" >To: labmembers at snf.stanford.edu >Subject: Isotropic Silicon Wet etch >Date: Mon, 20 Mar 2006 13:39:31 -0800 > > >Dear Labmembers, > >I need to etch ~1um of silicon isotropically. In literature there seem to >be >3 ways of doing it: (a) Wet etching in HNA solution (HF + HNO3 + acetic >acid) (b) Wet etching in EDP solution (Ethylene diamine pyrochatechol) and >(c) dry etching in XeF2. I am flexible as far as requirements of roughness >and dimensional tolerences are concerned. I am just interested in knowing >what options are available to me within our SNF clean room. > >My preferred mask would be SiO2. I expect the HF in the HNA solution to >attack the SiO2 mask. So if anybody has an idea on the selectivity between >SiO2 and Si for an HNA etch, I would appreciate the input. > >Thank you very much in advance. > >-Rohan From rissman at stanford.edu Tue Mar 21 15:53:38 2006 From: rissman at stanford.edu (Paul Rissman) Date: Tue, 21 Mar 2006 15:53:38 -0800 Subject: industrial labmember meeting - 3/31/06, 4:30 pm, CISX 101 Message-ID: <6.2.5.6.2.20060321154728.027ad8c0@stanford.edu> Professor Nishi would like to meet with the industrial labmember community to discuss a number of topics. The agenda is as follows: 1. new improvements to the capability of SNF, recent and planned. 2. SNF usage numbers. 3. SNF finances as a result of the January, 2005 cap increase. 4. adjustment to the industrial cap The meeting will be Friday, March 31, 2006 at 4:30 pm in CISX 101 From mtang at stanford.edu Thu Mar 23 15:04:02 2006 From: mtang at stanford.edu (Mary Tang) Date: Thu, 23 Mar 2006 15:04:02 -0800 Subject: Upcoming Safety Activities! Message-ID: <44232962.1060007@stanford.edu> Greetings labmembers! Just wanted to update (and invite) everyone to some upcoming safety events. First, we have a fire extinguisher training session scheduled for next Tuesday, at 1:30 pm. (Check out the previous class at: http://snf.stanford.edu/Uli-Fire.html). The session is about an hour in length and you should, by the end of this, come away with a better understanding of fires. There are a few spaces left -- let me know if you would like to register to attend. The class is free for labmembers. Second, we have a CPR/First Aid/AED class scheduled from 12-4 on April 3 and 4 (previous announcement at: http://snf.stanford.edu/cgi-bin/ezmlm-cgi?mss:2156:200603:nlokjfpdldjhpnoigoko.) There are a couple of spots left -- if you are interested, please let me know. Third, the School of Engineering is hosting a special seminar on burns in the CISX Auditorium next week (please see the announcement below.) More safety activities are planned for coming months -- if you have suggestions or ideas on how to improve safety, please discuss them with your favorite staff person or drop a note to safety at snf.stanford.edu Thanks for your attention! Mary **************************************** > *How much do you know about burns? Do you know the difference between > first, second, and third degree burns? Do you know basic first aid for > burns? Would you like to learn more about this topic?* > > *The School of Engineering would like to invite you to attend a one > hour presentation on burn education on March 29, 10 - 11 am, at the > Paul Allen Center For Integrated Systems (CIS) Annex , Room 101-X. The > instructor is Dennis Arnold, a burn nurse from Santa Clara Valley > Medical Center Burn Unit. The topics will include : epidemiology of > burns, mechanism of burns, different types of burns, treatment, > equipment (e.g., first aid, fire blankets), and prevention measures. > > *Please RSVP by email to Jackie Chan (Jackie.chan at stanford.edu) -- Mary X. Tang, Ph.D. Stanford Nanofabrication Facility CIS Room 136, Mail Code 4070 Stanford, CA 94305 (650)723-9980 mtang at stanford.edu http://snf.stanford.edu From mtang at stanford.edu Wed Mar 29 09:33:25 2006 From: mtang at stanford.edu (Mary Tang) Date: Wed, 29 Mar 2006 09:33:25 -0800 Subject: Learn about first aid for burns - today! Message-ID: <442AC4E5.9080504@stanford.edu> Hi everyone -- Just a reminder of the seminar on burns, today, at 10 am, in the CISX Auditorium. The instructor is Dennis Arnold, a burn nurse from Santa Clara Valley Medical Center Burn Unit. The topics will include : epidemiology of burns, mechanism of burns, different types of burns, treatment, equipment (e.g., first aid, fire blankets), and prevention measures. (And for those of us who work in the lab: chemical burns.) This is sponsored by the School of Engineering. Mary -- Mary X. Tang, Ph.D. Stanford Nanofabrication Facility CIS Room 136, Mail Code 4070 Stanford, CA 94305 (650)723-9980 mtang at stanford.edu http://snf.stanford.edu From mcvittie at snf.stanford.edu Wed Mar 29 13:19:02 2006 From: mcvittie at snf.stanford.edu (Jim McVittie) Date: Wed, 29 Mar 2006 13:19:02 -0800 Subject: Isotropic Silicon Wet etch References: Message-ID: <442AF9C6.9EF360DD@snf.stanford.edu> Hi, XeF2 and most so called isotropic plasma etches are not truely isotropic. They usually show a concentration dependence. The problem shows up inside confined structures where one sees that the etch rate is faster near the opening where the F spices enters the structure. Back in the early 80s we developed a true isotrope etch on the Dryteks. The conditions are: 100 CF4/ 10 O2, 750W and 300 mT. The poly etch rate was 3700 A/m and thermalk ox rate was ~ 125A/min. The resist ER was about 5 X faster than ox. We usually did 1 min O2 descum step before the poly etch using 100 O2, 500 w, 150 mT to remove any organics from the poly or Si surface. The results where very isotropic in that the Si removal was the same everywhere in the structure. Note that the poly ER should show some loading effects in that the rates will be lower with larger exposed areas. Jim Yahong Yao wrote: > Hi Rohan, > > I would think Drytek2 is the most convenient way to accomplish your goal. > 1.6um photoresist can serve as the mask. You can find the recipe and etch > rate at: http://snf.stanford.edu/Equipment/drytek/drytek2ER.pdf > > If for some reason, you need to use wet etch, then TMAH (tetramethylammonium > Hydroxide) would be a good candidate. Oxide is a very good mask in TMAH > (1000A is way enoug for your purpose, but thicker oxide has less pinholes). > 20% TMAH in water gives about 4000A/min at about 80C. But the native oxide > on open areas will influence the result. Be sure to do a short HF dip > (50:1) before you put wafers in TMAH. If you use clean labwares for > etching, then your wafers are still clean afterwards. > > Hope it helps. > Yahong > > >From: "Rohan D. Kekatpure" > >To: labmembers at snf.stanford.edu > >Subject: Isotropic Silicon Wet etch > >Date: Mon, 20 Mar 2006 13:39:31 -0800 > > > > > >Dear Labmembers, > > > >I need to etch ~1um of silicon isotropically. In literature there seem to > >be > >3 ways of doing it: (a) Wet etching in HNA solution (HF + HNO3 + acetic > >acid) (b) Wet etching in EDP solution (Ethylene diamine pyrochatechol) and > >(c) dry etching in XeF2. I am flexible as far as requirements of roughness > >and dimensional tolerences are concerned. I am just interested in knowing > >what options are available to me within our SNF clean room. > > > >My preferred mask would be SiO2. I expect the HF in the HNA solution to > >attack the SiO2 mask. So if anybody has an idea on the selectivity between > >SiO2 and Si for an HNA etch, I would appreciate the input. > > > >Thank you very much in advance. > > > >-Rohan From raghavs at stanford.edu Fri Mar 31 18:45:31 2006 From: raghavs at stanford.edu (Raghav Sreenivasan) Date: Fri, 31 Mar 2006 18:45:31 -0800 Subject: Junk Mails Message-ID: <5.2.1.1.2.20060331184103.03529860@raghavs.pobox.stanford.edu> Hi All i have been getting a ton of spam these days and most of them seem to come from one or the other user list at SNF. am i the only one getting these? if not, i hope the system administrators for coral/SNF are doing something about it. i have a number of filters setup in my Eudora and still these e-mails somehow sneak through them and end up in my Inbox. Raghav From shott at snf.stanford.edu Fri Mar 31 20:32:41 2006 From: shott at snf.stanford.edu (John Shott) Date: Fri, 31 Mar 2006 20:32:41 -0800 Subject: Junk Mails In-Reply-To: <5.2.1.1.2.20060331184103.03529860@raghavs.pobox.stanford.edu> References: <5.2.1.1.2.20060331184103.03529860@raghavs.pobox.stanford.edu> Message-ID: <442E0269.9050604@snf.stanford.edu> Raghav: I fear that we all get a ton of spam these days and that the spammers are winning the war against spam filters and the like. I can tell you a bit about my experiences as well as what we are doing ... and what would be hard to do ... related to spam. For starters, this mailing list (labmembers at snf) is far and away the biggest list that we maintain and is moderated. To my knowledge this particular list has not had ANY spam messages slip through since we began moderating it about 18 months ago. Moderation of this list is important because it's a list that's in a lot of folk's inbox, is named on our web, etc. We also maintain approximately 200 other mailing lists: about 100 of the form equipment_name at snf and another 100 of the form equipment_name-pcs at snf that are for technical discussion and problem/comment/shutdown reports of each piece of equipment, respectively. I'll look at some of our archives to see if I can come up with some statistics, but I haven't noticed a huge fraction of spam messages reaching me that come in via these lists in comparison to the overwhelming volume of spam that I receive each day simply addressed to me ... and I'm actually subscibed to all 200 of those lists. Moderation of 200 lists would be onerous and would likely be unpopular in the case of the problem/comment/shutdown lists because of delays in getting reports to the staff that can address them. Limiting postings to only subscribers doesn't work because most of you are subscribed as name at snf.stanford.edu but send/receive email from elsewhere. Limiting postings to only Stanford email addresses won't work because of all of the non-Stanford labmembers. For a long time, at least, those mailing lists were comparatively spam-free ... both because they are typically low-traffic and because the e-mail address never appears on a website where it can readily slurped up by spammers. We don't maintain our own spam filters and rely on the stuff that Stanford provides. I know that's not great, but our computer support staff is rather minimal and thus far, at least, that hasn't been our highest priority. I'll try to take a look at some of the e-mail archives and see if I can generate some more quantitative number as to how prevelant this problem is and will also give some thought to what me might do to improve this situation without reducing the utility of these lists. If labmembers have any suggestions, please send them to me privately and I'll consider your ideas ... we frequently hear and adopt good ideas from labmembers. Thanks, John