Growth and Characterization of AlN on 6H-SiC Substrates

Abstract

ABSTRACTAIN/SiC structures are of current importance for the development of high temperature electronic devices. A systematic study of the growth and structure of AIN on Lely grown 6H-SiC was performed. The SiC substrates were chemically etched followed by thermal desorption at 875 °C under UHV conditions. AFM and RHEED images show the relative improvement in surface morphology following the cleaning procedure. AIN films were grown on 6H-SiC substrates using plasma source molecular beam epitaxy (PSMBE). Substrate temperatures were varied from 400 °C to 800 °C and deposition energies from 1 eV to 25 eV during AIN growth. The AIN crystal structure and topology were analyzed by RHEED and AFM. The AIN/SiC film microstructure are correlated with the quality of the SiC surface and the parameters of the AIN deposition process. Epitaxial growth of AIN(0002) was strongly dependent on the SiC surface quality and deposition energy. The highest quality AIN was achieved at growth temperatures of approximately 600 °C and 15 eV ion energy. Higher ion energy resulted in amorphous film growth.