Interrupted Mg doping of GaN with MOCVD for improved p-type layers

Uniformity doping, δ-doping and growth-interruption doping to produce gallium nitride (GaN): Mg has been investigated by low-pressure metal-organic chemical vapor deposition (LP-MOCVD). It was demonstrated by electrical, optical, and surface studies that films produced by growth-interruption-Mg-doping produce the best crystal quality, this doping method increasing self-compensation because of the incorporation of additional impurities during the interruption period. Mg-δ-doping employs GaN:Mg/UGaN superlattices valence band edge oscillation to enhance hole concentration leading to significantly reduced p-type resistivity, enhanced hole mobility. This doping method also leads to improved surface morphology.