<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;}
@font-face
{font-family:"Microsoft Sans Serif";
panose-1:2 11 6 4 2 2 2 2 2 4;}
@font-face
{font-family:"Trebuchet MS";
panose-1:2 11 6 3 2 2 2 2 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri","sans-serif";}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:#0563C1;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:#954F72;
text-decoration:underline;}
span.EmailStyle17
{mso-style-type:personal;
font-family:"Calibri","sans-serif";
color:windowtext;}
span.EmailStyle18
{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="#0563C1" vlink="#954F72">
<div class="WordSection1">
<p class="MsoNormal"><span style="color:#1F497D">Hi Vince,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"> Sorry for such a late response but I hadn’t noticed anyone mentioning the pressure of the cavity behind the wafer. Assuming that your system has that capability, the flow of He should be judged by the backside
pressure. As an example, we have many etching systems here with mechanical wafer clamps and we baseline them when new to flow X amount of He for a specified pressure (closed loop system). As you may expect, the flow of He increases as the backside pressure
is called to increase. We use this baseline flow as criteria to either change a seal if applicable, clean the wafer backside or clean the chuck if necessary. We have gotten very good with our tool set to have a seal change or chuck clean at PM intervals. Oh
yeah, beware of the photo users that neglect edge bead removal after coating, it can cause the wafer to stick to the chuck and when it begins to transfer out, the lift will “pop” it off the chuck and most certainly position it in a bad spot.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"> Steve “Equipment Dood” Paolini<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<div>
<p class="MsoNormal"><span style="font-size:14.0pt;color:#1F497D">Steve Paolini<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt;color:#1F497D">Principal Equipment Engineer<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt;color:#1F497D">Harvard University Center for Nanoscale Systems<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt;color:#1F497D">11 Oxford St.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt;color:#1F497D">Cambridge, MA 02138<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt;color:#1F497D">617- 496- 9816<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt;color:#1F497D">spaolini@cns.fas.harvard.edu<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt;color:#1F497D">www.cns.fas.harvard.edu</span><span style="font-size:14.0pt;color:#1F497D"><o:p></o:p></span></p>
</div>
<p class="MsoNormal"><span style="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>Luciani, Vincent (Fed)<br>
<b>Sent:</b> Thursday, February 22, 2018 4:16 PM<br>
<b>To:</b> labnetwork@mtl.mit.edu<br>
<b>Subject:</b> [labnetwork] Helium leak rate on Oxford RIE<o:p></o:p></span></p>
</div>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Hello All,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks for all the great feedback about the backside helium leak rate on the Oxford tools. To sum up it sounds like most labs strive to keep it less than 10 sccm and 6 -12 sccm is a typical range. It is very helpful to see that what
we observe is fairly typical. We have one process that etches at -100 C with very high RF and ICP power that requires < 5 sccm. We can get it there for this user but keeping it there is difficult. For those who asked for the drawings of our modified quartz
plate, I will send that to you individually. I plan to invest in some mechanical design engineering effort to make these cooled chucks perform better. I’ll share anything we come up with.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks again,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Vince<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span style="font-family:"Microsoft Sans Serif","sans-serif"">Vincent K. Luciani<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Microsoft Sans Serif","sans-serif"">NanoFab Manager<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Microsoft Sans Serif","sans-serif""><a href="https://urldefense.proofpoint.com/v2/url?u=http-3A__www.cnst.nist.gov_&d=DwMFAg&c=WO-RGvefibhHBZq3fL85hQ&r=-H4Z_jeDfTYjnKPXor15vLwzBllmg8gFrb9m_k9OGks&m=eV4MYPyzZNXtLwpvNj_ge_JTFFzrUWcRFDWe8LwUlSU&s=Km7eUzO368C8Iuhm32kmTVbbDD2kVN2aK_74cNJvPD4&e="><span style="color:blue">Center
for Nanoscale Science and Technology</span></a><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Microsoft Sans Serif","sans-serif"">National Institute of Standards and Technology<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Microsoft Sans Serif","sans-serif"">100 Bureau Drive, MS 6201<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Microsoft Sans Serif","sans-serif"">Gaithersburg, MD 20899-6200 USA<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Microsoft Sans Serif","sans-serif"">+1-301-975-2886<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Trebuchet MS","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
</body>
</html>