Thermal conductivity studies of a GaN-sapphire structure by combined scanning thermal microscopy and electron backscatter diffraction

Scanning thermal microscope (SThM) and electron backscatter diffraction (EBSD) techniques were used to investigate the local thermal-conductivity of a GaN-buffer-sapphire heterostructure. Compared with GaN epilayer, buffer layer displayed the low thermal-conductivity and the high strain state due to the lattice distortion.