Defect states and donors in thermally annealed or post-hydrogenated chemically vapor-deposited amorphous SiNx alloy

Thermal annealing and post-hydrogenation effects on the electrical properties of chemically vapor-deposited (CVD) amorphous silicon-nitrogen (a-SiNx ) alloys are studied. Annealing of CVD a-Si and a-SiNx films causes the increases in the ESR centers, the hopping conduction, and the gap-state density evaluated by the field-effect method. The nitrogen incorporation reduces the number of ESR centers in a film. The Fermi level of CVD a-SiNx films is shifted by post-hydrogenation, which suggests that the films include donors. The ημτ products of CVD a-Si and a-SiNx films are increased by post-hydrogenation, exceeding two orders of the magnitude. Post-hydrogenated CVD a-SiNx films show larger ημτ product than post-hydrogenated CVD a-Si.