Hello,

         U can use O2 as a dilution along with SF6,  if you are using 300
SCCM SF6, than you can use 30 SCCM O2, Apart from this also reduce the
platen power, both of thease are degrading your surface roughness.

Let Me know if you got some benifit fron this.

Best Wishes,

Manish hooda
----- Original Message -----
From: "Pradeep Dixit" 
To: "General MEMS discussion" 
Sent: Friday, February 24, 2006 3:43 PM
Subject: [mems-talk] Bottom Surface quality improvement in ALCATEL DRIE
process


> Dear All,
>
> I am facing problem in getting smmoth bottom surface in DRIE process by
> ALCATEL machine.
> Process parameters are - SF6- 300, C4F8- 150, etch/pass - 7/2, Coil
power -
> 1800 W, platen - 80 W, temperature - 10C.
>
> Surface obtained after etching (even after 5 min etch) is rough.
>
> Can any one advice me anything to make the surface smooth or to improve
the
> surface quality after etching process. Can any one suggest some suitable
> recipe for getting smooth surface? I will not mind if this new recipe
affect
> the etch rate. My priority is to get as smooth surface as possible. Will
> reducing the C4F8 will help ?