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 SiH 4 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.