Speculatively, since I have never grown such a thick silicon dioxide
film. I can offer some ideas.

1. Atmospheric thermal oxidation won't work. You would need 900 times
the time to grow a 10,000 ang. Thick film.

2. There are high pressure systems thermal oxidation systems that run at
20 atmospheres, but this would still be a process that is about 45 times
longer than a 1 micron film thermal oxidation. Plus you don't want to
own one of these machines.

3. You might try depositing the film. There are problems with this also.
Films that are perfectly okay at 1 micron film thickness can develop
stress problems when they get thicker. So you might have to anneal the
film after depositing it. You might have to deposit, anneal, deposit,
anneal in some type of cycle. Probably use a atmospheric deposition if
you aren't concerned about depositing over topology. This isn't a
process you would want to go with for manufacturing.

4. Another option is a spin-on glass. However, to have any decent oxide
properties you would need to heat it in a furnace to a good temperature.
Maybe 1100C in pure O2 to make sure all the organics were oxidized out
and the structure compacted. Maybe 1200C in pure O2. On the other hand
it may not have to be so hot. Spin-on glass isn't a compact structure
and O2 probably diffuses fairly rapidly in it to oxidize organics. The
issue would be to anneal the spin-on glass into a decent oxide by
compacting the structure.

Ed

-----Original Message-----
From: mems-talk-bounces@memsnet.org
[mailto:mems-talk-bounces@memsnet.org] On Behalf Of
kamlesh_engg@iitb.ac.in
Sent: Friday, November 21, 2008 2:54 AM
To: mems-talk@memsnet.org
Subject: [mems-talk] SiO2 deposition

hi
   Does anyone know how can i either deposite or grow thick layer of
SiO2 about 30 micron ??
--
Kamlesh Pawar