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You may have succeeded in nearly tuning the matching network but
does the system perform as it used to? (process outcomes?) You
have to know where the RF power is going. You may have deposited a
non-insulating, carbon containing material all over your chamber
including the electrode assembly. Leakage to ground may be causing
your problems. An extended, low power oxygen (plus inert gas
optional) plasma cleaning (hour+) while heating the chamber
components helps if the system is set up to safely use oxygen. In
addition to cleaning the chamber, you may have to take apart, clean,
and rebuild the cathode assembly with new insulators. Instead of
experimenting on the matching network with active plasma
chemistries, it is easier to use a basic discharge (e.g. pure
argon) to diagnose RF components and to keep track of the
parameters for system qualification. <br>
<br>
Verify that the power supply is functioning properly using a vendor
suggested method or a dummy RF load. Ditto for the matching
network. You have to consider very small probability that the
process you ran had nothing to do with the subsequent failure. <br>
<br>
Plasma deposition is a very complex process. Inductively coupled
systems that have simpler internal surfaces are easier to use
instead of cathode based systems with intricate internal structure.
<br>
<br>
Please let the forum know about the solution to your problem once
you resolve it. <br>
Good luck.<br>
<br>
Pramod Karulkar<br>
<pre class="moz-signature" cols="72">Pramod C Karulkar Ph.D.
Home 2*5*3* 3*0*3 0*4*1*8
6024 33rd Street Ct NW
Gig Harbor WA 98335 </pre>
<br>
<br>
<div class="moz-cite-prefix">On 5/20/2013 6:08 AM, N P VAMSI KRISHNA
wrote:<br>
</div>
<blockquote
cite="mid:CA+SWD1XBhQrBJrVW2Ck7OF75T9p6m0sWASxGM2=ZEWRxAnPNiw@mail.gmail.com"
type="cite">
<div dir="ltr">
<div class="gmail_default"
style="font-family:verdana,sans-serif;color:rgb(0,0,102)">Dear
Colleagues,<br>
</div>
<div class="gmail_default"
style="font-family:verdana,sans-serif;color:rgb(0,0,102)">Recently
we had a problem in our RIE (Oxford Plasma lab system 100)
tool. The RF Lower electrode was giving very high reflected
powers for some recipes and DC bias close to 0V and we
realized the auto match capacitors are misaligned. After a
long effort we could got that back to almost normal, by
manually tuning the RF auto match and doing error corrections.
<br>
The last recipe which ran on the tool was depositing C4F8 for
10 min. Before this run chamber was clean. (We normally don't
encourage polymer deposition in our RIE tool for longer
durations) <br>
<br>
</div>
<div class="gmail_default"
style="font-family:verdana,sans-serif;color:rgb(0,0,102)">
Does any one face similar problem or any idea if C4F8 polymer
deposition could do this and why? <br>
<br>
</div>
<br>
-- <br>
<font style="font-family:verdana,sans-serif;color:rgb(0,0,102)">Thanks
& Regards,<br>
<br>
<i><b>Vamsi Krishna</b></i><br>
Sr.Facility Technologist - <font>P<font><font>rocess</font>
Integration</font></font><br>
National Nano Fabrication Center<br>
<span>Center for Nano Science and Engineering (CeNSE)<br>
Indian Institute of Science(IISc)<br>
Banga<font>lore<font> </font></font>560012, <font>INDIA</font></span><br>
Mobile: +91 9880988239</font><br>
<br style="font-family:verdana,sans-serif">
<font style="font-family:verdana,sans-serif" size="1"><i><font
style="font-family:verdana,sans-serif;color:rgb(0,0,102)">A
bird sitting on the branch of a tree is not afraid of the
branch shaking or breaking, because it trusts not the
branches but its OWN WINGS. </font></i></font>
</div>
<br>
<fieldset class="mimeAttachmentHeader"></fieldset>
<br>
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</blockquote>
<br>
<pre class="moz-signature" cols="72">--
</pre>
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