Aluminum Nitride Insulator for III-V MIS (Metal-Insulator-Semiconductor) Applications.

A reactive molecular beam epitaxial (MBE) process has been developed to deposit AlN on GaAs substrates. AlN films on GaAs are being investigated for possible metal-insulator-semiconductor (MIS) applications. Following chemical etching, atomically clean GaAs substrates are prepared by thermal cleaning in ultra-high vacuum. AlN is grown by using Al and NH3 sources. In situ Auger electron analysis shows no detectable oxygen or carbon contamination in the AlN films. Auger and x-ray analysis are used to confirm the AlN stoichiometry. The AlN is crystalline and has the wurtzite type of crystal structure which is hexagonal with space group P6 sub 3 mc. Far infrared transmission and Raman scattering measurements also identify the films as stoichiometric AlN. Capacitance-voltage measurements for the MIS structures are reported.