DEFECT CHARACTERIZATION OF HIGH THERMAL CONDUCTIVITY CaF2 DOPED AlN CERAMICS BY RAMAN SPECTROSCOPY

Calcium fluoride additive was used to produce high thermal conductivity AlN ceramics which has no grain boundary phase. Thermal conductivity of AlN is determined by the point defect, represented as oxygen related defect, with in the AlN grain. The defect density characterization of high thermal conductivity CaF2 doped AlN ceramics after heat treatment was conducted by Raman spectroscopy. As measure Raman linewidth broadening, the point defect density variation after heat treatment and corresponding thermal conductivity change was investigated