<div dir="ltr">I want to thank everyone who has replied up to this point. I have several new directions to head in and several items that I need to check out. Unfortunately our furnaces suffered a hard shutdown due to loss of power. I will be quite busy bringing them back on line and won't have time to look into this at the moment. I am planning to email each one of you when I have some free time, so look for a response in the future. Thank you again for your willingness to help us resolve this issue. I will also reply to the thread once this problem is finally solved.<div><br></div><div>Terre</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Wed, Aug 4, 2021 at 10:12 AM mark cooper <<a href="mailto:markc@exper-tech.com">markc@exper-tech.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div dir="ltr">
<div style="font-family:Calibri,Arial,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
The soft pump, (sometimes called the half gate) should be non interlocked and allow you to open while you are pulling the load. We did custom tools with a slow pump valve with standard 1/2 inch nupro, a medium pump with a NW25 gate, and a main vacuum valve
with ISO 80 valve, gave more options in the pump down and backfill. <br>
</div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
The ammonium chloride will build up on Nitride, so blanket heaters are always important.
<br>
</div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
The N2 backfill should be able to flow while the process door is open, but make sure the flow it attached to the load area either through a connection to the front flange, or through an rear connected injector.
<br>
</div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
We had built some CVD polysilicon configurations with a blanket or curtain purge in the scavenger box so the wafers would pass through N2.
<br>
</div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
<br>
</div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
<br>
</div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
<br>
</div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
<p style="text-align:justify"><b><i><span style="font-size:13.5pt;font-family:Arial,sans-serif;color:navy">Mark Cooper</span></i></b><span style="font-size:12pt;font-family:"Times New Roman",serif;color:black"></span></p>
<p style="text-align:justify"><b><i><span style="font-size:12pt;color:black">Expertech General Manager</span></i></b><span style="font-size:12pt;font-family:"Times New Roman",serif;color:black"></span></p>
<p style="text-align:justify"><b><i><span style="font-size:12pt;color:black">10 Victor Square, Suite 100</span></i></b><b><span style="font-size:12pt;font-family:"Times New Roman",serif;color:blue"> </span></b><span style="font-size:12pt;font-family:"Times New Roman",serif;color:black"></span></p>
<p style="text-align:justify"><b><i><span style="font-size:12pt;color:black">Scotts Valley, CA. 95066</span></i></b><b><span style="font-size:12pt;font-family:"Times New Roman",serif;color:blue"> </span></b><span style="font-size:12pt;font-family:"Times New Roman",serif;color:black"></span></p>
<p style="text-align:justify"><b><i><span style="font-size:12pt;color:black">Office: (831) 439-9300</span></i></b><b><i><span style="font-size:12pt;font-family:Arial,sans-serif;color:black">
</span></i></b><i><span style="font-size:12pt;font-family:Arial,sans-serif;color:black"> </span></i></p>
<p style="text-align:justify"><b><i><span style="font-family:Arial,sans-serif;color:black">Direct:(831) 440-4422</span></i></b><span style="font-size:12pt;font-family:"Times New Roman",serif;color:black"></span></p>
<p style="text-align:justify"><b><i><span style="font-family:Arial,sans-serif;color:black">Mobile:(831) 332-9396</span></i></b><span style="font-size:12pt;font-family:"Times New Roman",serif;color:black"></span></p>
<p style="text-align:justify"><b><i><span style="font-size:13pt;color:navy"><a href="mailto:markc@exper-tech.com" target="_blank">markc@exper-tech.com</a></span></i></b></p>
<br>
</div>
<div>
<div id="gmail-m_-7076910361568947125appendonsend"></div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
<br>
</div>
<hr style="display:inline-block;width:98%">
<div id="gmail-m_-7076910361568947125divRplyFwdMsg" dir="ltr"><font style="font-size:11pt" face="Calibri, sans-serif" color="#000000"><b>From:</b> labnetwork <<a href="mailto:labnetwork-bounces@mtl.mit.edu" target="_blank">labnetwork-bounces@mtl.mit.edu</a>> on behalf of Mary Tang <<a href="mailto:mtang@stanford.edu" target="_blank">mtang@stanford.edu</a>><br>
<b>Sent:</b> 03 August 2021 17:03<br>
<b>To:</b> Tony Whipple <<a href="mailto:whipp003@umn.edu" target="_blank">whipp003@umn.edu</a>>; Terre Briggs <<a href="mailto:terreb@umich.edu" target="_blank">terreb@umich.edu</a>><br>
<b>Cc:</b> Labnetwork <<a href="mailto:labnetwork@mtl.mit.edu" target="_blank">labnetwork@mtl.mit.edu</a>><br>
<b>Subject:</b> Re: [labnetwork] LPCVD film anomaly</font>
<div> </div>
</div>
<div>
<p>Thanks Tony!</p>
Yes, I was trying to remember what Ted Berg, our furnace guy at the time, did about the "champagne nitride". I don't recall the plumbing solution exactly, but he took a cue from Berkeley and found a way to ensure a constant, low draw during unload.<br>
<p>Mary<br>
</p>
<pre cols="72">--
Mary X. Tang, Ph.D.
Managing Director
Stanford Nanofabrication Facility
Paul G. Allen Building
420 Via Palou Mall
Stanford, CA 94305
<a href="https://snf.stanford.edu" target="_blank">https://snf.stanford.edu</a>
<a href="mailto:mtang@stanford.edu" target="_blank">mtang@stanford.edu</a></pre>
<p><br>
</p>
<div>On 8/3/2021 2:29 PM, Tony Whipple wrote:<br>
</div>
<blockquote type="cite">
<div dir="ltr">
<div>Hello Terre;</div>
<div>I thought I saw this type of image before and we had a similar problem with our LSN process, see image below.</div>
<div>It turned out that with our setup we were having a reaction with residual that would react when we vented the tube. This
<br>
</div>
<div>reaction would cause particles to fall ( rain ) on the wafers when the tube was vented and being unloaded. We had talked
<br>
with Bob Hamilton at Berekley while visiting there and noticed his LPCVD setup and his solution before we noticed the
<br>
</div>
<div>same problem with our LPCVD. After installing the fix we did not have this issue anymore.<br>
<br>
The solution is to provide a very limited small low flowing path around the gate valve so that when the gate valve is closed
<br>
</div>
<div>( such as during tube vent ) the tube still has a small draw on it pulling any reactions toward the pump and away from the
<br>
</div>
<div>wafers. If you have this type of bypass already, the only thing would be to confirm that it is still working I guess. We had a
<br>
</div>
<div>pressure gauge installed next to this to confirm that it was working and not plugged. We would see a pressure change
<br>
</div>
<div>that indicated it needed cleaning soon. <br>
</div>
<div><br>
</div>
<div>Regards, Tony W.<br>
</div>
<div><br>
</div>
<div><br>
</div>
<div><img alt="image.png" width="357" height="176" src="cid:17b131b7205cb971f161"><br>
<br>
</div>
<div><br>
</div>
<div><br>
</div>
</div>
<br>
<div>
<div dir="ltr">On Tue, Aug 3, 2021 at 11:20 AM Terre Briggs <<a href="mailto:terreb@umich.edu" target="_blank">terreb@umich.edu</a>> wrote:<br>
</div>
<blockquote style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div dir="ltr">Hello All,
<div> We are currently having film quality issues with our LPCVD Low Stress Nitride, HTO and Nitride films. Without getting into all of the details just yet I am sharing with you some SEM images. The anomaly, as our furnace manufacturer describes it, are
what look like spheres, or bubbles on the surface of the films. We are pretty confident that the spheres are only on the surface and not down into the film itself.</div>
<div>It is very random across the wafers and across the wafer load. After further processing, the spheres come off and leave behind a divot, or crater on the surface. This can also be seen in the SEM images.</div>
<div> My question is, has anyone ever seen anything like this with any of your LPCVD films? I have been working with Tempress for the last several months to resolve the issue, but they have never seen anything like this, and so far we have not made any progress
in determining the source. Any help would be appreciated. </div>
<div><br>
</div>
<div>Thanks.....Terre</div>
<div> <br>
<div dir="ltr">
<div dir="ltr">
<div>
<div dir="ltr">
<div>
<div dir="ltr">
<div>
<div dir="ltr">
<div>
<div dir="ltr">
<div dir="ltr">
<div><font><font>Terre Briggs</font></font><br>
</div>
<div><font><font>Engineer in Research Sr.</font></font><br>
</div>
<div><font><font>Lurie Nanofabrication Laboratory</font></font><br>
</div>
<div><font><font>University of Michigan</font></font></div>
<div><font><font>1301 Beal Ave.</font></font></div>
<div><font><font>Ann Arbor, MI 48109</font></font></div>
<div><font><font>734-320-4470</font></font></div>
<br>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
_______________________________________________<br>
labnetwork mailing list<br>
<a href="mailto:labnetwork@mtl.mit.edu" target="_blank">labnetwork@mtl.mit.edu</a><br>
<a href="https://mtl.mit.edu/mailman/listinfo.cgi/labnetwork" rel="noreferrer" target="_blank">https://mtl.mit.edu/mailman/listinfo.cgi/labnetwork</a><br>
</blockquote>
</div>
<br>
<fieldset></fieldset>
<pre>_______________________________________________
labnetwork mailing list
<a href="mailto:labnetwork@mtl.mit.edu" target="_blank">labnetwork@mtl.mit.edu</a>
<a href="https://mtl.mit.edu/mailman/listinfo.cgi/labnetwork" target="_blank">https://mtl.mit.edu/mailman/listinfo.cgi/labnetwork</a>
</pre>
</blockquote>
<pre cols="72"></pre>
<div>
<p></p>
<p>Expert Semiconductor Technology, Inc.</p>
<p>Phone: (831) 439-9300</p>
<p>Fax: (831) 439-8139</p>
<p>This email message is for the sole use of the addressee(s) and may contain Expertech confidential and legally privileged information. Access, review, use, disclosure or distribution of this email by anyone other than the intended addressee is unauthorized
and prohibited. If you are not the intended recipient, please notify the sender immediately and destroy all paper and electronic copies of the original message and any attachments.</p>
</div>
</div>
</div>
<div style="font-size:9pt">
<p>mark cooper</p>
<p>Expert Semiconductor Technology, Inc.</p>
<p>Phone: (831) 439-9300</p>
<p>Fax: (831) 439-8139</p>
<p>This email message is for the sole use of the addressee(s) and may contain Expertech confidential and legally privileged information. Access, review, use, disclosure or distribution of this email by anyone other than the intended addressee is unauthorized
and prohibited. If you are not the intended recipient, please notify the sender immediately and destroy all paper and electronic copies of the original message and any attachments.</p>
</div>
</div>
</blockquote></div><br clear="all"><div><br></div>-- <br><div dir="ltr" class="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div dir="ltr"><div><font><font>Terre Briggs</font></font><br></div><div><font><font>Engineer in Research Sr.</font></font><br></div><div><font><font>Lurie Nanofabrication Laboratory</font></font><br></div><div><font><font>University of Michigan</font></font></div><div><font><font>1301 Beal Ave.</font></font></div><div><font><font>Ann Arbor, MI 48109</font></font></div><div><font><font>734-320-4470</font></font></div><br></div></div></div></div></div></div></div></div></div></div></div>