<div>Errol,</div><div> </div><div>we have a gas phase MBE tool here at UofM that is using pure Arsine and Phosphine for process gases. Typically during process we'll use a turbo pump, with the cryo only used in stand-by state. We had the same concerns you do in regard to the cryopump warming up, and off-gassing the contaminated material. What we did was install a check valve (pressure relief) in the vent line. The front side of the check is exposed to the cryopump internals, and the back side of the check valve is on our HPM venturi header that runs throughout the fab area. The back side is always under vacuum (it's on a UPS system so even a power outage won't effect us), and so far has worked flawlessly (+ 4 years). I've attached a picture of the mechanical connections. Let me know if you'd like to discuss this further.<br clear="all">
</div><div><div>Dennis Schweiger</div><div>University of Michigan/LNF</div><div> </div><div>734.647.2055 Ofc</div><div> <br><br></div></div><div class="gmail_quote">On Thu, Dec 6, 2012 at 11:31 AM, Errol V. Porter <span dir="ltr"><<a href="mailto:evporte@uark.edu" target="_blank">evporte@uark.edu</a>></span> wrote:<br>
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<p class="MsoNormal">Greetings members,<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">I wanted to see if there are any members currently using a cryopump on a CVD tool utilizing any of the following gases; germane, hydrogen, methane, silane, diborane or phosphine. Note the main pump being used during processing is a turbopump
with the cryopump being used to keep the tool under vacuum while the tool is not being operated. If there are any users using a similar configuration, how was the pump installed specifically to deal with the effluent that is released during a normal regeneration
cycle.<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">Regards,<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">Errol Porter<u></u><u></u></p>
<p class="MsoNormal">University of Arkansas / HiDEC<u></u><u></u></p>
<p class="MsoNormal">700 W. Research Center Blvd<u></u><u></u></p>
<p class="MsoNormal">Fayetteville, AR 72701<u></u><u></u></p>
<p class="MsoNormal">Tel. <a href="tel:479%20575-2519" target="_blank" value="+14795752519">479 575-2519</a><u></u><u></u></p>
<p class="MsoNormal">Fax <a href="tel:479%20575-2719" target="_blank" value="+14795752719">479 575-2719</a><u></u><u></u></p>
<p class="MsoNormal">email:<span style="color:rgb(31,73,125)"> <a href="mailto:evporte@uark.edu" target="_blank">
<span style="color:blue">evporte@uark.edu</span></a><u></u><u></u></span></p>
<p class="MsoNormal"><span style="color:rgb(31,73,125)"><a href="http://www.hidec.uark.edu" target="_blank"><span style="color:blue">http://www.hidec.uark.edu</span></a><u></u><u></u></span></p>
<p class="MsoNormal"><u></u> <u></u></p>
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