T. Bohnen

Realising epitaxial growth of GaN on (001) diamond

By an extensive investigation of the principal growth parameters on the deposition process, we realized the epitaxial growth of crystalline wurtzite GaN thin films on single crystal (001) diamond substrates by metal organic chemical vapor deposition. From the influence of pressure, V/III ratio, and temperature, it was deduced that the growth process is determined by the mass-transport of gallium precursor material toward the substrate. The highest temperature yielded an improved epitaxial relationship between grown layer and substrate. X ray diffraction (XRD) pole figure analysis established the presence of two domains of epitaxial layers, namely (0001) 〈 101− 0〉 GaN∥ (001)[110] diamond and (0001) 〈 101− 0〉 GaN∥ (001) [11−0] diamond, which are 90∘ rotated with respect to each other. The presence of these domains is explained by the occurrence of areas of (2×1) and (1×2) surface reconstruction of the diamond substrate. When applying highly misoriented diamond substrates toward the [110] diamond direction, ...