Microstructures and residual stresses were studied in thin cubic GaN epilayers which were grown onto Si(001) substrates that were coated with a thin flat SiC buffer layer. The SiC layer was an effective buffer layer for GaN growth. There were many stacking faults, micro-twins and micro-hexagonal phases near to the GaN/SiC interface; produced by large compressive stresses. The compressive stress, due to lattice mismatch between GaN and SiC, was largely relaxed within some tens of nm of the interface. The critical film thickness for full strain relief was about 100nm.

Initial Growth of Cubic GaN on Si(001) Coated with a Thin Flat SiC Buffer Layer. D.Wang, Y.Hiroyama, M.Tamura, M.Ichikawa, S.Yoshida: Journal of Crystal Growth, 2000, 220[3], 204-8