Reaction Mechanisms of Plasma‐ and Thermal‐Assisted Chemical Vapor Deposition of Tetraethylorthosilicate Oxide Films

Abstract

Plasma‐ and thermal‐assisted chemical vapor deposited (CVD) tetraethylorthosilicate (TEOS) oxide films were deposited on silicon substrates using a single‐wafer reactor. The deposition kinetics of both plasma and thermal CVD processes were studied as a function of temperature. Film properties and bonding structure were analyzed for as‐deposited and annealed films using Fourier transform infrared spectroscopy (FTIR), Auger, x‐ray photoelectron spectroscopy (XPS), and nuclear reaction analysis (NRA) techniques. The thermal TEOS films were found to be more porous and to contain more hydrogen, but were more conformal than plasma‐deposited TEOS films. Without a plasma, thermal temperatures can assist gas‐phase reactions between ozone and TEOS (oxidation) to form conformal oxide films at as low as 200°C. With a plasma, both gas‐phase and subsequent surface CVD reactions between TEOS, ozone, and oxygen are substantially enhanced, thus result in CVD films with higher quality.