[mems-talk] low Stess SiNx deposited by PECVD

[memser]

Hi, I want to get low stress SiNx (tensile) by PECVD (Oxford PlasmaLab System 100),the Process Parameters are as followings, could you tell me which one is suit for me.Or is there any other better one?
1  SiH4/NH3/N2  30/50/1960  Power 17W RF 13.56MHz  Pressure 0.9Torr  Temperature 250
2  SiH4/NH3/N2  2.5/4/100  Power 100W RF 13.56MHz  Pressure 0.9Torr  Temperature 250
3  SiH4/NH3/N2  20/20/980  Power HF/LF 25W/20W 13.56MHz 16s /380KHz 4s Pressure 0.65Torr  Temperature 250
4 5%SiH4/95%N2 40 
  N2 900
  Pressure 0.6mTorr Temperature 250 Power 40W RF 13.56MHz  

And if I change the gas flow with same scale, for exsample:  SiH4/NH3/N2  20/20/980  to SiH4/NH3/N2  2/2/98, the properties of film will be changed? such as stress, refractive index, etc.

Best regards,
Xu Yan