Dear Atteq,

You can try this out. See whether it works with your machine.

Ar: 100 sccm
CF4: 40 sccm
CHF3: 40 sccm
Pressure: 350 mT
RF Power: 300 W

Thanks.

Best regards,
GY

-----Original Message-----
From: mems-talk-bounces@memsnet.org [mailto:mems-talk-bounces@memsnet.org] On
Behalf Of ATEEQ REHMAN
Sent: Tuesday, August 18, 2009 10:29 PM
To: mems-talk@memsnet.org
Subject: [mems-talk] About Chemical Dry etching



Dear All,

I am trying to do the etching of SiO2 using chemical dry etcher. but i didnt got
any recipe for selectivity of SiO2 over Poly-Si. I am trying to get selectivity
of SiO2/Si in CHF3 base plasma.but i am failed to find good selectivity using
CHF3 for SiO2 over Poly-Si. I can use the equipment in this range.

CHF3 = 100 sccm
CF4 = 80 sccm
O2 = 1000 sccm
N2 = 100 sccm
Ar = 140 sccm
 pressure range (100 to 900 mTorr)
RF power (up to 1300 watts)

i cannot find good recipe for this.  if any body can help me and please let me
know how could i start to find my way in this regard.

Thank You,

ATTEQ-UR-REHMAN
M.S-Candidate
Semiconductors Materials & Devices Lab(SMDL)
Department of Electrical Engineering
Building N0-301, Room no 1052-4
Seoul National University.
Tel +82-10-30405297