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Hello,<br>
<br>
My condition is that the PDMS be fully cured. I prefer a vacuum bake,
something like 60 C or higher for 12 hours or more. It also depends on
the size of the sample. If it's "small" I am less concerned than if it
is "big". I'm not worried about beam interaction, just gross
outgassing of the sample.<br>
<br>
If it is a "bulk" PDMS sample you will have to use a very low
accelerating voltage. If it is a thin film on a conductive substrate
that will be much easier. Then you can try higher accelerating
voltages.<br>
<br>
Our SEM can operate at accelerating voltages down to 0.1 KV at a
working distance of 1.5 mm with an in-lens secondary electron
detector. I have imaged glass, quartz, sapphire, polycarbonate, PDMS,
paper, and several other insulators at high magnifications, all without
any coating or other sample preparation. It's not easy but it can be
done.<br>
<br>
I use the fastest scan speed and frame averaging. Sometimes it is
useful to "scoot and shoot". Do the best focusing you can at one
location and then move far enough to get away from any areas that show
charging effects and capture an image.<br>
<br>
Of course, if you have access to an environmental SEM imaging
insulators is easy but the resolution is reduced. Our environmental
SEM has a resolution of about 50 - 100 nm.<br>
<br>
If you like, contact me off line and I can do an image for you.<br>
<br>
michael young wrote:
<blockquote cite="mid:45F0BB3D-3D65-41E9-B89A-55526941FA8F@nd.edu"
type="cite">Greetings, all. I'm looking today for helpful hints - a
client wishes to image a sample which is primarily composed of PDMS.
Anyone done this successfully? Any concerns with regard to SEM chamber
contamination resulting from beam interaction with the PDMS?
<div><br>
</div>
<div>Thanks!</div>
<div><br>
<div> <span class="Apple-style-span"
style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px;">
<div style=""><span class="Apple-style-span"
style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px;">
<div style="">
<div>--</div>
<div>Michael P. Young<span class="Apple-tab-span"
style="white-space: pre;"> </span>
(574) 631-3268 (office)<br>
Nanofabrication Specialist (574) 631-4393 (fax)<br>
Department of Electrical Engineering (765) 412-6728 (cell)<br>
University of Notre Dame <a
moz-do-not-send="true" href="mailto:mike.young@nd.edu">mike.young@nd.edu</a><br>
275 Fitzpatrick Hall<br>
Notre Dame, IN 46556-5637</div>
</div>
</span></div>
</span></div>
</div>
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<pre class="moz-signature" cols="72">--
Joel Pikarsky
"Scourge of the Cleanroom"</pre>
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