You might be able to increase temperature to get lower stress. When the
temperature is about 800C, the stress is about 300-400 MPa, when you
increase to 900C, it can be ~200 MPa. However, you need to check with the
manufacturer of your LPCVD system to confirm if increasing temperature is
fine because some systems are designed for limited temperature.

Good luck,

Hongjun Zeng, PhD
MEMS/Nano Scientist
Nanotechnology Core Facility
(NCF formerly MAL)
University of Illinois at Chicago
3064 ERF Building
842 W. Taylor St., Chicago, IL 60607
Tel. 312-355-1259, Fax: 312-413-0447

-----Original Message-----
From: mems-talk-bounces@memsnet.org [mailto:mems-talk-bounces@memsnet.org]
On Behalf Of ???
Sent: Monday, February 26, 2007 12:09 AM
To: mems-talk@memsnet.org
Subject: [mems-talk] Low Stress Si3N4 in LPCVD

Hi all

    I need to deposite 0.3um LP Si3N4 on <100> Si wafer which is low
stress(<300MPa) and Particle-free. I have search a lot of papers on internet

... The only way to get low stress Si3N4 is increasing DCS/NH3 ratio , but
particle contamination is getting worse. Is there anyone can share
informations about how to deposite low stress Si3N4 in LPCVD without
particle contamination.