Film Properties of Low‐k Silicon Nitride Films Formed by Hexachlorodisilane and Ammonia

A low‐temperature process with good step coverage of silicon nitride (SiN) formed by low‐pressure chemical vapor deposition (LPCVD) has been successfully developed by using hexachlorodisilane (HCD). HCD‐SiN showed a higher deposition rate than the conventional LPCVD technique performed at temperatures above 700°C. SiN films can be deposited down to 250°C using HCD. Deposition characteristics, film composition, and film properties under integrated circuit fabrication processes are measured mainly in terms of deposition temperature dependence. A low‐k HCD‐SiN film, formed at 450°C with a permittivity of 5.4, was applied on Cu films as an oxidation and diffusion barrier layer. The film shows excellent barrier properties and is advantageous for realizing high‐performance very large scale integrated devices with Cu interconnects. © 2000 The Electrochemical Society. All rights reserved.