Se-doped GaN Films Grown by Low-Pressure Metalorganic Chemical Vapor Deposition

Abstract

Se-doped GaN films are grown for the first time by low-pressure metalorganic chemical vapor deposition (LP-MOCVD), in which H2Se is used as the Se source gas. Effects of Se doping on electrical properties of GaN films are reported. Se atoms tend to out-diffuse to the surface of the GaN film at high temperature. The N atomic percentage is influenced by the incorporation of H2Se in the MOCVD process. The carrier concentration was found to be significantly affected by the surface defects which develop at high H2Se dosages. The highest free electron concentration obtained is about 1.5×1018 cm-3. Increasing the growth temperature from 1000° C to 1050° C reduces the maximum carrier concentration to about 7×1017 cm-3.