<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=Windows-1252">
<style type="text/css" style="display:none;"> P {margin-top:0;margin-bottom:0;} </style>
</head>
<body dir="ltr">
<div class="elementToProof" style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Hi Tucson,</div>
<div class="elementToProof" style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
When we use metal targets we check that the target and the dark space shroud are electrically isolated with a meter. This is obviously impractical with a dielectric target but what can happen is that the shroud can short to the target ring. You can use
a nice pointy meter probe to contact the target ring and look for a short to the shroud. Also, you might consider simply increasing the space between shroud and target. On our PVD75 there are several notches in the shroud to set this spacing. </div>
<div class="elementToProof" style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
If you are confident that there is no short then one trick I use regularly is to set the RF power to 50 - 100 W, then turn on the substrate etch with the shutter closed at 100W (the max). This usually works to get the target plasma going. Then turn off
the substrate etch and turn your target power to a low power, something like 10-20W. You will want to ramp this power up slowly (maybe 0.5W/sec or so) to your endpoint so that the target heats slowly. Dielectric targets are notorious for cracking. One other
consideration is to make sure that the target ring is NOT super tight on the target.</div>
<div class="elementToProof" style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
We do not usually put anything between the target and electrode.</div>
<div class="elementToProof" style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<br>
</div>
<div class="elementToProof" style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Regards,</div>
<div class="elementToProof" style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Michael</div>
<div class="elementToProof" style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
</div>
<div id="appendonsend"></div>
<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 <labnetwork-bounces@mtl.mit.edu> on behalf of Richelson, Tucson <tucsonr@illinois.edu><br>
<b>Sent:</b> Friday, August 9, 2024 4:59 PM<br>
<b>To:</b> 'labnetwork@mtl.mit.edu' <labnetwork@mtl.mit.edu><br>
<b>Subject:</b> [labnetwork] Striking plasma on WO3 in Lesker PVD 75 issue</font>
<div> </div>
</div>
<style>
<!--
@font-face
{font-family:Helvetica}
@font-face
{font-family:"Cambria Math"}
@font-face
{font-family:Calibri}
@font-face
{font-family:Verdana}
p.x_MsoNormal, li.x_MsoNormal, div.x_MsoNormal
{margin:0in;
font-size:11.0pt;
font-family:"Calibri",sans-serif}
span.x_EmailStyle17
{font-family:"Calibri",sans-serif;
color:windowtext}
.x_MsoChpDefault
{font-family:"Calibri",sans-serif}
@page WordSection1
{margin:1.0in 1.0in 1.0in 1.0in}
div.x_WordSection1
{}
-->
</style>
<div lang="EN-US" link="#0563C1" vlink="#954F72" style="word-wrap:break-word">
<table border="0" cellspacing="0" cellpadding="0" width="100%" align="left" style="border:0; display:table; width:100%; table-layout:fixed; border-collapse:seperate; float:none">
<tbody style="display:block">
<tr>
<td valign="middle" width="1px" bgcolor="#A6A6A6" cellpadding="7px 2px 7px 2px" style="padding:7px 2px 7px 2px; background-color:#A6A6A6">
</td>
<td valign="middle" width="100%" bgcolor="#EAEAEA" cellpadding="7px 5px 7px 15px" color="#212121" style="width:100%; background-color:#EAEAEA; padding:7px 5px 7px 15px; font-family:wf_segoe-ui_normal,Segoe UI,Segoe WP,Tahoma,Arial,sans-serif; font-size:12px; font-weight:normal; color:#212121; text-align:left; word-wrap:break-word">
<div>You don't often get email from tucsonr@illinois.edu. <a href="https://aka.ms/LearnAboutSenderIdentification">
Learn why this is important</a></div>
</td>
<td valign="middle" align="left" width="75px" bgcolor="#EAEAEA" cellpadding="7px 5px 7px 5px" color="#212121" style="width:75px; background-color:#EAEAEA; padding:7px 5px 7px 5px; font-family:wf_segoe-ui_normal,Segoe UI,Segoe WP,Tahoma,Arial,sans-serif; font-size:12px; font-weight:normal; color:#212121; text-align:left; word-wrap:break-word">
</td>
</tr>
</tbody>
</table>
<div>
<p class="x_MsoNormal" style="line-height:12.0pt; background:#FF4D4D"><b><span style="font-size:10.0pt; color:black">CAUTION:</span></b><span style="font-size:10.0pt; color:black"> This email originated from outside of our organization. Do not click links,
open attachments, or respond unless you recognize the sender's email address and know the contents are safe.</span></p>
<div></div>
<div>
<div class="x_WordSection1">
<p class="x_MsoNormal">Hello,</p>
<p class="x_MsoNormal"> </p>
<p class="x_MsoNormal">I have a Lesker PVD 75. It was working fine last week with a TiO2 target. This week I swapped out the target for WO3 and suddenly the plasma won’t strike.</p>
<p class="x_MsoNormal"> </p>
<p class="x_MsoNormal">Normal Operating Conditions:</p>
<p class="x_MsoNormal">Turbo 30% speed</p>
<p class="x_MsoNormal">Pressure 50mTorr of Argon</p>
<p class="x_MsoNormal">Power 50 W</p>
<p class="x_MsoNormal"> </p>
<p class="x_MsoNormal">I tried putting the TiO2 target back and it wouldn’t strike either.</p>
<p class="x_MsoNormal">Usually I cut a circle of copper fabric and place it between the target and the sputter gun. That has worked for the past year. Usually when the plasma won’t strike, I need to replace the copper fabric. I tried that and it didn’t work.</p>
<p class="x_MsoNormal">Then I put some silver paste on the target and used the copper fabric and it worked! TiO2 had plasma strike.</p>
<p class="x_MsoNormal">I switched back to WO3, and used silver paste and copper fabric, but it won’t strike.
</p>
<p class="x_MsoNormal"> </p>
<p class="x_MsoNormal">Here’s what I’ve tried:</p>
<p class="x_MsoNormal">Turbo 20, 30%</p>
<p class="x_MsoNormal">Pressure 15, 50, 60, 70, 95mTorr of Argon</p>
<p class="x_MsoNormal">Power 50, 60, 70 W</p>
<p class="x_MsoNormal"> </p>
<p class="x_MsoNormal">Any suggestions? What do you normally put between the target and the sputter gun?</p>
<p class="x_MsoNormal"> </p>
<p class="x_MsoNormal"> </p>
<p class="x_MsoNormal"> </p>
<div>
<p class="x_MsoNormal" style="background:white"><i><span style="font-size:10.0pt; font-family:"Arial",sans-serif; color:#1F497D">Best,</span></i><span style="color:#242424"></span></p>
<p class="x_MsoNormal" style="background:white"><i><span style="font-size:10.0pt; font-family:"Arial",sans-serif; color:#1F497D">Tucson Richelson</span></i><span style="color:#242424"></span></p>
<p class="x_MsoNormal" style="background:white"><span style="font-size:10.0pt; font-family:"Arial",sans-serif; color:#1F497D">-------------------------------------------------------------------------</span><span style="color:#242424"></span></p>
<p class="x_MsoNormal" style="background:white"><b><span style="font-size:9.0pt; font-family:"Verdana",sans-serif; color:#242424">Nick Holonyak, Jr. Micro and Nanotechnology Lab (HMNTL)</span></b><span style="color:#242424"></span></p>
<p class="x_MsoNormal" style="background:white"><b><span style="font-size:9.0pt; font-family:"Verdana",sans-serif; color:#242424">University of Illinois</span></b><b><span style="font-size:12.0pt; font-family:"Verdana",sans-serif; color:#242424"><br>
</span></b><span style="color:#242424">Rm 2118, MC-249</span></p>
<p class="x_MsoNormal" style="background:white"><span style="color:#242424">208 North Wright St. Urbana, IL 61801</span></p>
<p class="x_MsoNormal" style="background:white"><span style="color:#242424">Office: +1 (217) 244-5138</span></p>
<p class="x_MsoNormal" style="background:white"><span style="color:#242424">Web: <a href="http://mntl.illinois.edu/" originalsrc="http://mntl.illinois.edu/" shash="JJvBC7XtaTNsnML7kwmP7LYhT9EG35iDtpnilmsKelM1KR8fiyZLGXlb9LSO1rCREqSyNyKIa8ZqX7EmfrPzaZF05XBahzP8hekAqrTW+Boa0p2FsD9PWGG0B8Y76gdXM9i7RbA2rqn9zAxnqIaAFVNfTxiuRZnzidqGaCPJp4s="><span style="color:#0563C1">http://mntl.illinois.edu/</span></a></span><span style=""></span></p>
</div>
<p class="x_MsoNormal">Schedule training: <a href="https://book.ms/b/Training2@uillinoisedu.onmicrosoft.com" originalsrc="https://book.ms/b/Training2@uillinoisedu.onmicrosoft.com" shash="VFsz1h8zWWSvkFVBFXtBxY/MhHVQ8zI35FWgJzQefSyGnziGrXIP72iYK5izf5tWUQBLghb1xQH0LlG6BIdDNnMKRCEWtRNLwPKsVry+P8rW+qFaU3Bwxa3GYwcef8KSWsvgLAz6GNTLB+piC/YDyxoC7FOpBgL2yPYO3vgcVB0=">
<span style="color:blue">https://book.ms/b/Training2@uillinoisedu.onmicrosoft.com</span></a></p>
<p class="x_MsoNormal">Give me feedback: <a href="https://forms.office.com/r/GawstR26J7" originalsrc="https://forms.office.com/r/GawstR26J7" shash="VfXh2pfC6B1XHz5Aum2hqSjbBEbeododp0r5BjuxhQhHVh1fm7lPCFTwVZgxfQSZfnSPctE9kg9A8Z5y3fwIf/J1eK/0HoSdR0yqLPwHqr5eRCZnhvkUPYORC5bmm653U7yT9V/N8VBfbMOK2jG1JTEfwV5BlvUSji5Kgnqyatw=">
<span style="color:blue">https://forms.office.com/r/GawstR26J7</span></a></p>
<p class="x_MsoNormal"><span style="font-size:8.0pt; font-family:"Helvetica",sans-serif">Under the Illinois Freedom of Information Act any written communication to or from university employees regarding university business is a public record and may be subject
to public disclosure.</span><span style="font-size:8.0pt"></span></p>
<p class="x_MsoNormal"> </p>
</div>
</div>
</div>
</div>
</body>
</html>