Characteristics of an Al2O3 thin film deposited by a plasma enhanced atomic layer deposition method using N2O plasma

Abstract

Several properties of ultra thin aluminum oxide films deposited by a plasma enhanced atomic layer deposition (PEALD) method were studied. The Al2O3 films were deposited on an HF cleaned Si (100) substrate using Trimethylaluminum (TMA)-Al(CH3)(3) as an Al source and N2O plasma as an oxidant. High resolution transmission electron microscope (TEM) images showed the existence of an interfacial layer between the Si substrate and the Al2O3 film. Depth profiles obtained by Auger electron spectroscopy (AES) indicated that a small amount of nitrogen was incorporated into the film and that it had accumulated slightly at the interface of the Si/Al2O3. X-ray photoelectron spectroscopy (XPS) data revealed that the as-deposited film showed noise-like weak nitrogen bonding, while the 800 degrees C annealed film showed Si3N4 bonding. Film density was also measured by X-ray reflectometry (XRR).