Hi James,

You really only need to immerse the wafer into one bath of anisotropic
etchant.  For this you could use either KOH, TMAH or EDP.  These are in
asscending order of Si:SiO2 etch ratio, with TMAH probably being the
preferred choice since EDP is messy to deal with and relatively highly toxic.

TMAH, with IPA and H2O  should give you a nice etch ...

What were some of the problems that occurred whilst using KOH ?

Regards,

Mike Rosa.


At 08:44 PM 2/15/99 PST, you wrote:
>Dear researchers,
>
>I am currently trying to form pyramids on silicon wafers for use in the
>manufacture of solar cells (texturing).  My process at the moment
>involves a dip in concentrated KOH followed by immersion in a 10% KOH
>solution containing isopropanol. While this works ocasionally It often
>doesn't and I was wondering if anyone can help me with making the
>methind more reliable.
>
>Any information on the anisotropic etching of silicon would also be
>appreciated, particularly on the chemistry of the whole procedure.
>
>Thanks in advance,
>
>James Cotsell
>
>
>

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