Ef. Schubert et al., PROPERTIES OF AL2O3 OPTICAL COATINGS ON GAAS PRODUCED BY OXIDATION OFEPITAXIAL ALAS GAAS FILMS/, Applied physics letters, 64(22), 1994, pp. 2976-2978
Auger analysis of oxidized AlAs epitaxial layers grown by molecular-be
am epitaxy reveals that the composition of the films is stoichiometric
Al2O3. High optical quality of the films is demonstrated by optical r
eflection and transmission measurements. A reflectivity of 6% is measu
red for an antireflection coating on GaAs. Leakage currents in the nA
range and resistivities >5X10(11) OMEGA cm are deduced from current-vo
ltage measurements. Capacitance-voltage measurements on metal-oxide-se
miconductor structures using the Al2O3 films obtained by oxidizing AlA
s, reveal a significant reduction of the interface state density as co
mpared to conventional, electron beam evaporated Al2O3.