Plasma-assisted atomic layer growth of high-quality aluminum oxide thin films

Abstract

Thin aluminum oxide (Al2O3) films were grown by the plasma-assisted atomic layer controlled deposition (PAALD) method using Dimethylethylamine alane [(CH3)(2)(C2H5)N:AlH3] (DMEAA). Al was deposited by the PAALD method, then the Al films were oxidized into Al2O3 by plasma oxidation in the same chamber without breaking the vacuum. Al2O3 thin films of 15 nm thickness were prepared by repetition of this process. Thus prepared Al2O3 thin films exhibited a refractive index of 1.68. The thickness and the refractive index fluctuation of the film over a 4 inch wafer were +/-2.3% and +/-1.9%, respectively, for the deposited films. The leakage current density and breakdown field were measured to be about 10(-8) A/cm(2) at 1 MV/cm and 7 MV/cm, respectively. Considerable improvement of the electrical properties was realized by the post oxygen-plasma annealing at 200 degreesC.