Hi,

 I would be surprised if you can write a mask with constantly 200 nm width. I'm
trying to make holes in that range but the laser is too unstable to get a
uniform pattern (or something is wrong with my machine). However, in that regime
you reach the limit of photolithograpgy as well as laser lithography (wavelength
!!!). But, let's assume you could write it, you won't be able to replicate it
with standard UV lithography. I even doubt that you could get anyway a uniform
nanostructured pattern by UVL, even if you perfectly optimize it. The given
resolution for laser writers (for mask fabrication) is something around 1 µm (at
least for our system). But again, let's guess you could do that also, then I'm
relatively sure you won't be able to get a 200 nm wide and 2 µm deep channel.
You need to use e.g. electron beam lithography or focussed ion beam and an
additional process step (e.g. anisotropic Si etching).

good luck


________________________________

Von: mems-talk-bounces@memsnet.org im Auftrag von ???
Gesendet: Mo 01.12.2008 00:17
An: mems-talk@memsnet.org
Betreff: [mems-talk] HIgh aspect ratio channel with sub-micron feature size



Hello!

I'm looking for a cost effective method to create a mask with feature size of
about 0.2~0.5 um.
Would a chrome mask do the job?

Also, the channel depth I'm trying to fabricate is around 2~5 um, which is
approximately 10 times larger than the width of the channel.
With the appropriate mask, would I be able to fabricate the channel using soft
lithography? (I have access to contact mode lithography equipment)

Thank you!