Hello,

This kind of etching is load dependent, more silicon are you etching lower
is etching rate. Likewise, etching could be depended on masking material.

Best regards,

Danilo

-----Original Message-----
From: mems-talk-bounces+danilo.vrtacnik=fe.uni-lj.si@memsnet.org
[mailto:mems-talk-bounces+danilo.vrtacnik=fe.uni-lj.si@memsnet.org] On
Behalf Of Jie Zou
Sent: Wednesday, June 09, 2010 3:09 AM
To: General MEMS discussion
Subject: Re: [mems-talk] CF4 : O2 RIE of silicon, variability

You may also want to check whether your surface has a thin layer of
native oxide.

Jie

On Mon, Jun 7, 2010 at 7:12 PM, l j  wrote:
> Hello all,
>
> I see great variablity in etch rate of silicon with RIE CF4:O2 etch.
>
> At one point I see etch rate of >1um/min, at other <0.1um/min. This is
at same proces parameter setting (1:12 O2:CF4 ratio, 0.2T, 500W).
>
> Can anyone comment on what might casue such wide variability in etch rate
at nominally constant process parameters?
>
> Thanks in advance,
> K.C.
>