<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<style type="text/css" style="display:none;"><!-- P {margin-top:0;margin-bottom:0;} --></style>
</head>
<body dir="ltr">
<div id="divtagdefaultwrapper" style="font-size:12pt;color:#000000;font-family:Calibri,Helvetica,sans-serif;" dir="ltr">
<p style="margin-top:0;margin-bottom:0">Xin,</p>
<p style="margin-top:0;margin-bottom:0"><br>
</p>
<p style="margin-top:0;margin-bottom:0">One normally does not want a plasma in contact with a stainless steel chamber wall. Typically, there is a plasma potential of around 15V between the plasma and a grounded wall. Ion bombardment of the wall will result
is some sputtering of the surface of the wall. Fe and Ni from SS can be a problem for Si devices.</p>
<p style="margin-top:0;margin-bottom:0">There are several ways to get around sputtering from an SS chamber wall. These include using Al shields on the wall, using a magnetic electron reflector (alternating N/S magnets around the outside of the wall) or using
a glass cylinder between the wall and the wafer. I hope this is helpful.</p>
<p style="margin-top:0;margin-bottom:0"><br>
</p>
<p style="margin-top:0;margin-bottom:0"> Jim </p>
<p style="margin-top:0;margin-bottom:0"><br>
</p>
<div id="Signature">
<div id="divtagdefaultwrapper" dir="ltr" style="font-size: 12pt; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255); font-family: Calibri, Arial, Helvetica, sans-serif, EmojiFont, "Apple Color Emoji", "Segoe UI Emoji", NotoColorEmoji, "Segoe UI Symbol", "Android Emoji", EmojiSymbols;">
<p>James (Jim) McVittie, Ph.D.</p>
<p>Senior Research Engineer</p>
<p>Electrical Engineering</p>
<p>Stanford University</p>
<p><span style="color:rgb(34,34,34); font-family:arial,sans-serif; font-size:13px; line-height:21.4933338165283px">336x Paul G. Allen Bldg</span></p>
<p><span style="color:rgb(34,34,34); font-family:arial,sans-serif; font-size:13px; line-height:21.4933338165283px">420 Via Palou Mall </span></p>
<p><span style="color:rgb(34,34,34); font-family:arial,sans-serif; font-size:13px; line-height:21.4933338165283px">Stanford, CA 94305</span><br>
</p>
<p><span style="color:rgb(34,34,34); font-family:arial,sans-serif; font-size:13px; line-height:21.4933338165283px">mcvittie@stanford.edu</span></p>
<p><span style="color:rgb(34,34,34); font-family:arial,sans-serif; font-size:13px; line-height:21.4933338165283px">650-725-3640</span></p>
</div>
</div>
<br>
<br>
<div style="color: rgb(0, 0, 0);">
<hr style="display:inline-block;width:98%" tabindex="-1">
<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> labnetwork-bounces@mtl.mit.edu <labnetwork-bounces@mtl.mit.edu> on behalf of Xin (Shane) Guo <sguo18@yorku.ca><br>
<b>Sent:</b> Wednesday, October 24, 2018 6:14 AM<br>
<b>To:</b> labnetwork@mtl.mit.edu<br>
<b>Subject:</b> [labnetwork] PECVD/RIE - One-piece aluminum chamber or welded stainless steel</font>
<div> </div>
</div>
<meta content="text/html; charset=utf-8">
<div>
<div dir="ltr">
<div class="x_gmail_default" style="font-family:monospace,monospace; font-size:small">
Dear colleagues</div>
<div class="x_gmail_default" style="font-family:monospace,monospace; font-size:small">
<br>
</div>
<div class="x_gmail_default" style="font-family:monospace,monospace; font-size:small">
We are going to buy an RIE/PECVD system. Some vendors offer one-piece aluminum chambers while others offer welded stainless steel.</div>
<div class="x_gmail_default" style="font-family:monospace,monospace; font-size:small">
<br>
</div>
<div class="x_gmail_default" style="font-family:monospace,monospace; font-size:small">
I understand that one-piece metal is good for keeping the vacuum, but which is more important (one-piece aluminum vs. welded stainless steel), if we have to choose one configuration?</div>
<div class="x_gmail_default" style="font-family:monospace,monospace; font-size:small">
<br>
</div>
<div class="x_gmail_default" style="font-family:monospace,monospace; font-size:small">
Any suggestions and insights are highly welcome.</div>
<div class="x_gmail_default" style="font-family:monospace,monospace; font-size:small">
<br>
</div>
<div class="x_gmail_default" style="font-family:monospace,monospace; font-size:small">
Shane</div>
<div dir="ltr" class="x_gmail_signature">
<div dir="ltr">
<div dir="ltr">
<div dir="ltr">
<div dir="ltr">
<div dir="ltr"></div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</body>
</html>