Hello Hafizah,

In here we also use hot H3PO4 (160°C).
Etchrate on LPCVD SiN is app. 3nm/min
Another method we use is etching in HF[48%], etchrate is also app. 4nm/min

Regards,

Peter Kuijpers
MiPlaza Technology Laboratories
Philips Research Europe
High Tech Campus 04
Postbox HTC-4-1
5656 AE Eindhoven
The Netherlands
Tel.: +31 402743667
         +31 612507027
Email: p.e.m.kuijpers@philips.com


-----Original Message-----
From: mems-talk-bounces@memsnet.org [mailto:mems-talk-bounces@memsnet.org] On
Behalf Of Nor Hafizah Ngajikin
Sent: Friday 30 October 2009 7:36
To: mems-talk@memsnet.org
Subject: [mems-talk] wet etch of 2um Si3N4

Dear all,

I've tried to etch 2 micron thickness of Si3N4 using hot H3PO4. The
concentration of H3PO4 is 85w%. I heat the H3PO4 at 150 degree celcius for 1
hour. Unfortunately, this experiment didn't work as expected. None of the
nitride is etch away.

Can anybody share with me your experience on nitride etch using H3PO4.

Thank you.

Hafizah