Comparison of AlN films grown by RF magnetron sputtering and ion-assisted molecular beam epitaxy

摘要

Crystalline aluminum nitride (AlN) thin films were formed on various substrates by using RF magnetron sputtering of an A1 target in a nitrogen plasma and also by ion-assisted molecular beam epitaxy (IAMBE). Basal-oriented AlN/(111) Si showed a degradation of crystallinity with increased substrate temperature from 550 to 770 C, while the crystallinity of AlN/(0001) Al(sub 2)O(sub 3) samples improved from 700 to 850 C. The optical absorption characteristics of the AlN/(0001) A1(sub 2)O(sub 3) films as grown by both deposition methods revealed a decrease in subbandgap absorption with increased substrate temperature.