Growth of epitaxial layers of gallium nitride on silicon carbide and corundum substrates

Abstract

Single crystal epitaxial layers of gallium nitride have been grown on α-SiC and α-Al 2O 3 substrates in the temperature range 1000– 1150 °C. At lower temperatures polycrystalline deposits are obtained, while at higher temperatures extensive decomposition of the layers becomes apparent. Epitaxial relationships developed are (0001) α−SiC ‖ (0001) GaN, (10 1 0) α−Al 2O 3 , ‖ (10 1 5) GaN, (0001) α− Al 2O 3 ‖ (0001) GaN and (11 2 0) α−Al 2O 3 ‖ (0001) GaN. The GaN adheres badly to the α-SiC and tends to shatter upon cooling. The best GaN surface finishes are obtained with (0001) Czochralski and (11 2 0) flame fusion corundum substrates.