HI Andy,
You're describing the types of holes you can get from porous etching of
silicon. You should be able to find plenty of papers about it.

Basically, you put diluted HF on one side of the wafer, apply a bias
across it, and illuminate it form the other side. With single crystal
silicon, you end up with cylindrical holes that can run almost all the way
through the wafer.

There's a lot of detail that I'm leaving out, but the papers published on
it should provide a good guide.

Jesse Fowler
  UCLA/MAE Dept., 420 Westwood Plaza, Room 37-129, ENGR IV
  Los Angeles, CA 90095-1597 | (310)825-3977
"Facts are stubborn, but statistics are more pliable."
   -- Mark Twain

On Thu, 29 Apr 2004, Ananth Krishnan wrote:

> Hello,
>
>       I am a student in bioengineering. Could anyone
> guide me a good way to etch cylindrical holes
> (vertical side walls) with critical dimension of
> 1-micron on silicon wafer? Higher the pore density the
> better (without overlapping pores).
>
>       Eagerly waiting for any guidance.
>
> Sincerely,
>
> Andy
>
>
>
>
>
>
>
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