THIN-FILM DEPOSITION IN THE AFTERGLOWS OF N-2 AND H-2 MICROWAVE PLASMAS

Deposition of Si and SiN(x) thin films from addition of SiH4 to the afterglow of N2 and H2 microwave plasmas has been compared. Deposition of Si films requires SiH4 concentrations several orders higher than SiH4 for SiN(x) deposition. It is concluded that for Si film deposition, luminescence from the H2 plasma induces SiH4 dissociation and reactions between silane species are necessary for Si film formation. The proposed mechanism supports a deposition model based on the SiH2 radical.