<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
<meta name="Generator" content="Microsoft Word 14 (filtered medium)">
<style><!--
/* Font Definitions */
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman","serif";}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
span.EmailStyle17
{mso-style-type:personal-reply;
font-family:"Calibri","sans-serif";
color:#1F497D;}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}
@page WordSection1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang="EN-US" link="blue" vlink="purple">
<div class="WordSection1">
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Excellent question.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">I cannot quote industry standards nor am I aware any exist, but the bottom line is many pump and purge cycles are in order. I would use the system for the pumping
part of the procedure since it will pump well below what the venturi can provide at the cabinet. I would say that the exact # of cycles is up to you and your available time. If I were challenged with this, I would pump the lines down to the lowest level of
vacuum achievable through your system and still allow it to remain there for at least a half hour (or more if your delivery lines are longer than 50 feet) since there are always some stubborn molecules of gas that have to crash into bends and ultimately enter
the chamber. I would then run pure N2 through the MFC’s at full scale for another half hour before repeating the cycle. I would do this at a minimum of 20 cycles.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">In regards to disposal, I would treat the Phosphine lines as hazardous waste but the Silane lines should be relatively non-toxic aside from possible deposits
of SiO2 (dusting). I hope that other subscribers can correct me if I am wrong about this but my methods have been successful over the years.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Best of luck and be careful,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Steve Paolini<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Equipment dood<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Harvard Center for Nanoscale Systems.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<div>
<div style="border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in">
<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>Hmelo, Anthony B<br>
<b>Sent:</b> Friday, September 09, 2016 9:42 AM<br>
<b>To:</b> labnetwork@mtl.mit.edu<br>
<b>Cc:</b> Hmelo, Anthony B<br>
<b>Subject:</b> [labnetwork] Decommissioning Silane and Phosphene Stainless Gas Delivery Lines<o:p></o:p></span></p>
</div>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">All: <o:p></o:p></p>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal">VINSE is in the process of relocating a PECVD reactor to a new cleanroom facility and I am seeking advice on the industry standards for decommissiong Silane and Phosphene stainless gas delivery lines that run from the respective gas cabinets
to the tool in its current location. Beyond thoroughly purging the lines with nitrogen flow through the tool and exhausting the purge gas through the tool exhaust, are there other considerations involved in abandoning the gas delivery lines? For example,
are the lines considered to be permanently contaminated and will they require special disposal?<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal">Any advice on decommissioning these lines will be deeply appreciated.<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal">With thanks,<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
<div>
<div>
<div>
<p class="MsoNormal"><span style="color:black">Anthony B Hmelo, PhD<o:p></o:p></span></p>
</div>
<div>
<p class="MsoNormal"><span style="color:black"><o:p> </o:p></span></p>
<div>
<p class="MsoNormal"><span style="color:black">Associate Director, VINSE<o:p></o:p></span></p>
</div>
<div>
<p class="MsoNormal"><span style="color:black">Research Associate Professor of Physics and Astronomy<o:p></o:p></span></p>
</div>
<div>
<p class="MsoNormal"><span style="color:black">Research Associate Professor of Materials Science and Engineering<o:p></o:p></span></p>
</div>
<div>
<p class="MsoNormal"><span style="color:black">Vanderbilt University<o:p></o:p></span></p>
</div>
<div>
<p class="MsoNormal"><span style="color:black">Nashville TN 37235<o:p></o:p></span></p>
</div>
<div>
<p class="MsoNormal"><span style="color:black"><o:p> </o:p></span></p>
</div>
<div>
<p class="MsoNormal" style="margin-bottom:12.0pt"><span style="color:black">615-343-7212<o:p></o:p></span></p>
</div>
</div>
</div>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
</div>
</body>
</html>