Pressure-dependent transition in the mechanism of remote plasma SiNx deposition

Optical emission properties in remote plasma deposition of SiNx from an N2 electron cyclotron resonance microwave plasma and SiH4 have been investigated over a pressure range of 0.002–0.3 Torr. The deposition process divides into three pressure regions. For p≳0.1 Torr, film deposition results from gas phase reactions between active nitrogen and SiH4. For p<0.02 Torr SiH4 travels back to the plasma and deposition results from radical species created in the N2/SiH4 mixture. At intermediate pressures deposition was negligible because neither process could substantially break down SiH4.