At the beginning I use with KOH 28.5% 70C .
To improve the surface I tried  TMAH 25% , 80C and I get better surfcae but not
enuogh .
I want to highlight - KOH did not worked it make like scratches on the surfcae.
Pay attanotion - their isn't any mask on the wafer.


--- On Sat, 8/23/08, Shao Guocheng  wrote:

> From: Shao Guocheng 
> Subject: Re: [mems-talk] Thinning silicon wafer <100> by  wet etching
> To: moduli0621@yahoo.com, "General MEMS discussion" 
> Date: Saturday, August 23, 2008, 8:54 AM
> Hi, Moshe:
> what solution  u r using to do the wet etching and
> what's the concentration? u need to give us more details
> about ur etching condition. Normally, 35%w KOH solution at
> around 70C can do a good job. Generally speaking, lower
> etching speed will give u smoother surface.
>
> guocheng shao
>