Try to add Ammonium peroxy disulphate and dissolved
silicon to the TMAH solution (25% by weight in water).

pls follow this paper for more info

Dual-doped TMAH silicon etchant for
microelectromechanical structures and systems
applications, by M. Paranjape

Thanks,
Kris
--- Àî¿Æ¼Ñ  wrote:

> Hello,
>
> I did not add dissolved silicon or any other kinds
> of  solutions in the
> TMAH. The TMAH solution made by Moses Lake
> Industries, Inc. is 25% weight in
> water. I just poured the TMAH directly from
> oringinal bottle to the
> chemical reaction container.