Plasma Enhanced Chemical Vapor Deposition of Silicon Sulfide and Phosphorus Sulfide thin Films

Abstract

ABSTRACTAmorphous SiSx:H (x ∼ 2) films have been synthesized from H2S and SiH4 precursors using a remote plasma enhanced chemical vapor deposition apparatus. Structural studies by solid state nuclear magnetic resonance (NMR) and Raman scattering reveal that the atomic environments in these materials are similar to those observed in melt-quenched silicon sulfide glasses, and are characterized by corner- and edge-shared SiS4/2 tetrahedra. Compared to these glasses, however, the films show consistently higher fractions of corner-sharing S1S4/2 tetrahedra. The ratio of corner- to edge sharing tetrahedra and the Si:S ratio can be influenced by the H2S/S1H4 flow rate ratio during deposition. Thus, PECVD opens up wider opportunities for structural tailoring of amorphous silicon sulfide materials than currently possible by means of the melt-quenching method. Preliminary data for the PECVD synthesis of phosphorus sulfide is also presented.