Remote Plasma Atomic Layer Deposition for Amorphous Silicon Oxycarbonitride Thin Film

Abstract

Amorphous SiOCN thin films were fabricated by adjusting the contents of carbon and nitrogen to improve the electrical and physical disadvantages of SiOC. SiOC was deposited using OMCTS (OctaMethylCycloTetraSiloxane) precursor and O2, Ar, and H2 plasma, and SiOCN was deposited using N2 plasma. We have studied the development of thin films with dielectric constant of 3.0 or less, leakage current of less than 5x10-7 A/cm2, and low wet etching rate by controlling the carbon concentration in the thin film containing in the precursor. The SiOC deposited films using Ar and H2 plasma showed low dielectric constant and low leakage current. However, since the SiOC thin film density was significantly lower than the target of 2.0 g/cm3, it was tried to put nitrogen into the thin film to increase the density of the thin film even if the dielectric constant slightly increased. Thus, SiOCN thin film deposition was studied using N2 plasma to improve the density by control the carbon and nitrogen concentration in the thin film to have better wet etch rate and density.