Hi Nancy,

If you are using (100) Si wafers, your pattern should be oriented at 45°
from the major flat. You will obtain vertical sidewalls and a flat bottom.
All these surfaces belonging to the (100) family planes.

Best regards,

Bruno


At 07:06 13/05/2004 -0700, you wrote:
>Good day all,
>
>I am wondering if anyone can help me with the following question by
perhaps pointing me to the appropriate litterature:
>
>I would like to etch vertical trenches in silicon substrates using wet
etch solutions such as KOH. To what angle with respect to the major flat do
I need to pattern my trenches in order to ensure that my sidewalls are
vertical (i.e. 90 degrees)?
>
>Your help is much appreciated!
>
>I thank you in advance...
>
>Best regards,
>
>Nancy
>
>
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