Hi Andrea,

I've achieved mirror-smooth (100) surfaces with 9:1 (25wt% TMAH
solution):IPA.  The etch rate was somewhat slower than 25wt% TMAH solution,
I think in the neighborhood of 30µm/hr at 85°C.  In general it is easy to
control the etch rates of wet etchants by controlling the temperature.  I
don't recall what the RMS roughness was.  There are numerous references in
the literature for this sort of thing.

Good luck,


Brian C. Stahl
Graduate Student Researcher
UCSB Materials Research Laboratory
[email protected] / [email protected]
Cell: (805) 748-5839
Office: MRL 3117A


On Sat, Feb 6, 2010 at 2:53 AM, Andrea Mazzolari wrote:

> Hi All,
>
> i need to etch (100) silicon at low etch rate (not more than 20um/hour)
> and i need very very low roughness.
>
> I can not use HNA solutions, i can use KOH or TMAH with surfactants.
> Any suggestion about the optimal etching condition for this job ?
>
> Thanks,
> Andrea