Characterization of Thin Silicon Oxynitride Films Prepared by Low Pressure Rapid Thermal Chemical Vapor Deposition

Abstract

Thin silicon oxynitride (Si‐N‐O) films have been deposited using low pressure rapid thermal chemical vapor deposition (RTCVD), with silane , nitrous oxide , and ammonia as the reactive gases. Structural and kinetic studies indicate that an increase in the flow rate ratio leads to an increased N/O atomic ratio and a decreased Si‐N‐O deposition rate for constant and flow rates. Experimental results show that RTCVD Si‐N‐O films with high throughput at low thermal budget, uniform composition, and atomically flat interface can be achieved using a gas mixture. Electrical characterization of polySi/Si‐N‐O/Si capacitors demonstrates that for flow rate ratios ranging from 20 to 100%, the mid‐gap interface trap densities of the deposited Si‐N‐O films are and Fowler‐Nordheim electron‐tunneling rather than Frenkel‐Poole thermal‐emission is the dominant conduction mechanism in the thin RTCVD Si‐N‐O films.