Plasma Processing for Silicon Oxynitride Films

Abstract

A deposition mechanism involving both homogeneous and heterogeneous reactions of silicon oxynitride film deposition by plasma‐assisted processing has been proposed to explain the experimental results. The competitive role of the species linked to the interface is stressed. A change in the global deposition mechanism results as the oxidizer species is changed. The passivation properties of the film were evaluated, taking as reference both thermal silicon dioxide and plasma‐assisted chemical vapor deposition (PACVD) PSG 4 mole percent films. The silicon oxynitride film etching was investigated and compared with thermal silicon dioxide film etching. The same general trend was found. We correlated the differences between silicon dioxide and oxynitride etch to the nitrogen inside the layer. Special emphasis was placed on understanding the influence of the hydrogen segregated in the film during the etching process.