<div dir="ltr">Hi Eva, <div><br></div><div>Out of curiosity, did you previously inspect the wafer in an optical microscope using a higher-mag objective than the one used to capture the images? Given how circular these defects look, and the concentric pattern, my guess is that this is a heating effect, the result of staying too long in one position with a high light intensity.</div><div><br></div><div>Cheers, </div><div> </div><div> – Aaron</div><div><br clear="all"><div><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div dir="ltr"><div dir="ltr"><div><u style="font-size:x-small"> </u><span style="font-size:x-small"> </span><br></div><div><span style="font-size:12.8000001907349px"><font size="1"><p style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="color:rgb(0,0,0);font-family:Arial;white-space:pre-wrap;line-height:1.38;background-color:transparent">Aaron Hryciw, PhD, PEng</span></p><p style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="color:rgb(0,0,0);font-family:Arial;white-space:pre-wrap;line-height:1.38;background-color:transparent">Fabrication Group Manager</span><br></p><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-family:Arial;color:rgb(0,0,0);vertical-align:baseline;white-space:pre-wrap;background-color:transparent">University of Alberta - nanoFAB</span></p><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-family:Arial;color:rgb(0,0,0);vertical-align:baseline;white-space:pre-wrap;background-color:transparent">W1-060 ECERF Building</span></p><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-family:Arial;color:rgb(0,0,0);vertical-align:baseline;white-space:pre-wrap;background-color:transparent">9107 - 116 Street</span></p><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-family:Arial;color:rgb(0,0,0);vertical-align:baseline;white-space:pre-wrap;background-color:transparent">Edmonton, Alberta</span></p><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-family:Arial;color:rgb(0,0,0);vertical-align:baseline;white-space:pre-wrap;background-color:transparent">Canada T6G 2V4 </span><span style="font-family:Arial;color:rgb(0,0,0);vertical-align:baseline;white-space:pre-wrap;background-color:transparent"> </span><span style="font-family:Arial;color:rgb(0,0,0);vertical-align:baseline;white-space:pre-wrap;background-color:transparent"> </span><span style="font-family:Arial;color:rgb(0,0,0);vertical-align:baseline;white-space:pre-wrap;background-color:transparent">Ph: 780-940-7938</span></p><span style="font-family:Arial;color:rgb(0,0,0);vertical-align:baseline;white-space:pre-wrap;background-color:transparent"><a href="http://www.nanofab.ualberta.ca/" style="color:rgb(17,85,204)" target="_blank">www.nanofab.ualberta.ca</a></span><span style="font-family:Arial;color:rgb(0,0,0);vertical-align:baseline;white-space:pre-wrap;background-color:transparent"> </span></font></span><font color="#000000"><br></font><br></div></div></div></div></div></div></div></div></div></div></div></div><br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Fri, Oct 22, 2021 at 5:55 PM Eva Rose <<a href="mailto:eva.rose@gno.de">eva.rose@gno.de</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>
Dear all,<br>
<br>
<br>
did anybody ever see any defects like this on the resist surface
after resist spinning. The diameter varies from about 20um to over
150um.<br>
<br>
<img src="cid:17caaeab150a3a20b871" alt=""><br>
<br>
<img src="cid:17caaeab15074e3f89d2" alt=""><br>
<br>
<br>
Any idea what the reason could be?<br>
<br>
<br>
Best regards,<br>
<br>
Eva<br>
<br>
</div>
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