Influence of growth pressure of a GaN buffer layer on the properties of MOCVD GaN.

The influence of growth pressure of GaN buffer layer on the properties of MOCVD GaN on α-Al₂O₃ has been investigated with the aid of a home-made in situ laser reflectometry measurement system. The results obtained with in situ measurements and scanning electron microscope show that with the increase in deposition pressure of buffer layer, the nuclei increase in size, which roughens the surface, and delays the coalescence of GaN nuclei. The optical and crystalline quality of GaN epilayer was improved when buffer layer was deposited at high pressure. [ABSTRACT FROM AUTHOR]