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<p class="MsoNormal"><span style="color:#1F497D">Richard,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">At the Cornell NanoScale Facility, we use the foreline cold trap method to pull out most of the deposits that would build up in the foreline areas. We have seen that the flammable deposits that can occur have
mostly been in areas where you can get partial reactivity of the silanes, such as low oxygen environments like vacuum pump exhaust lines post pump, where the high pump nitrogen purge leads to a low oxygen area. We had a problem here with these deposits and
so we added Edwards Gas Reactor Columns (GRC) units immediately after the pump. Attached is a paper we found describing what occurs. The deposits we get in the cold trap have been mostly ammonium chloride which remove easily in warm water.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="color:#1F497D">Dan<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Daniel Woodie<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Safety Manager, College of Engineering<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Cornell University<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">344 Duffield Hall<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Ithaca, NY 14853-2700<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">(607)254-4891<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Off Hour Emergency # - (607)227-2993<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> labnetwork-bounces@mtl.mit.edu [mailto:labnetwork-bounces@mtl.mit.edu]
<b>On Behalf Of </b>Morrison, Richard H., Jr.<br>
<b>Sent:</b> Wednesday, April 11, 2012 8:09 AM<br>
<b>To:</b> labnetwork@mtl.mit.edu<br>
<b>Subject:</b> [labnetwork] Silicon Nitride question<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Hi Everyone,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I am restarting a Silicon Nitride LPCVD process and I have a few questions. The process will use a EBARA dry pump therefore should I use a trap on the vacuum pump inlet to catch any particulate generated?
<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Any issue with excess hydrogen from the process going into the dry pump, do I need a burn box on the vacuum pump exhaust?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">2<sup>nd</sup> question has anybody tried to run the LPCVD process on a wafer with a platinum metal pattern on the surface? I was wondering if there maybe some adverse effect because of the catalytic nature of Platinum.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks<o:p></o:p></p>
<p class="MsoNormal">Rick<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Rick Morrison<o:p></o:p></p>
<p class="MsoNormal">Senior Member Technical Staff <o:p></o:p></p>
<p class="MsoNormal">Group Leader Microfabrication Operations<o:p></o:p></p>
<p class="MsoNormal">Draper Laboratory<o:p></o:p></p>
<p class="MsoNormal">555 Technology Square<o:p></o:p></p>
<p class="MsoNormal">Cambridge, MA 02139<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">W 617-258-3420<o:p></o:p></p>
<p class="MsoNormal">C 508-930-3461<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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