Physical and barrier properties of plasma-enhanced chemical vapor deposited alpha-SiCN : H films with different hydrogen contents

Abstract

This work investigates the thermal stability and physical and barrier properties of two species of plasma-enhanced chemical-vapor-deposited (PECVD) amorphous silicon-nitrocarbide (alpha-SiCN:H) films with different hydrogen contents and dielectric constants of less than 5. It is found that the alpha-SiCN:H film with a higher hydrogen content has a lower dielectric constant. Both species of alpha-SiCN:H films are thermally stable at temperatures up to 500degreesC. However, a degraded dielectric strength was observed for the alpha-SiCN:H film with a lower k-value of 4, which has a much higher hydrogen content. This may be attributed to hydrogen-related defects, such as Si-H+-Si hydrogen bridges, and numerous Si-H weak bonds produced by the high hydrogen content in the alpha-SiCN:H film.