Dear users.

I have a question about TMAH etching.
Dual-doped TMAH ( 5% TMAH + Silicic acid + Ammonium persulfate) is widely used
because it is enable to etch Si without attacking Aluminum, in addition to its
CMOS compatibility. Many papers have been published regarding TMAH/dual-doped
TMAH.
However, I found that the Si was etched for a short duration (maybe less then 2
hours) in most papers.

In order to etch through a 3" wafer with dual-doped TMAH, it needs at least 8
hours.
I wonder if there is anyone who etches a wafer through ( 3" or 4") with TMAH/
dual-doped TMAH, with CMOS or any integrated circuit.

Any information would be very helpful.

Thank you very much.

__________________________________________________________
Il-seok  Son (Sunny)
Dept. of Electrical and Computer Engineering
University of Wisconsin - Madison, Sonic MEMS Lab
__________________________________________________________