Conduction Mechanisms in Very Thin Silicon Nitride Films

The steady-state d-c conduction properties of silicon nitride films in the range of 50-100A are reported. The nitride films were formed by vapor dep-osition on degenerate silicon substrates using the si lane-ammonia reaction. The temperature, thickness, and field dependence of current indicates that a transition in current mechanisms occurs at a film thickness of approximately 80A. Below this film thickness, the current is characterized by low temperature dependence and large thickness dependence. At film thickness above this value, the current is proportional to exp [~Vl/2]. Due to their importance in the semiconductor in-dustry, the electrical and physical properties of thin-film insulators have received considerable attention in the literature. Extensive studies have been made con-cerning the electrical characteristics (mostly conduc-tion properties) of these insulators. Previous work