Abstract: Ti/Ni/Au multilayers have been deposited by electron beam evaporation, to metallize CVD diamond wafers. The effect of pre-treatment and post-treatment on adhesion of the multi-layers to the substrates was investigated, and it was found, introducing a pre-fire at elevated temperatures, the adhesion could be improved significantly. Thermal cycling experiments were accomplished according to the Chinese national standard (GJB 126-86), and the multi-layers were not peeled off from the diamond wafers. Rutherford back-scattering spectroscopy (RBS) had been used to characterize the stability of the Ti/Ni/Au metallization scheme at 400℃, 500℃ for 60 min in vacuum. In conclusion, the good adhesion and the stability of the optimized processing between the diamond and the metal-layers can meet the required of the diamond application as heat sink.

Key words: Ti/Ni/Au multilayers have been deposited by electron beam evaporation, to metallize CVD diamond wafers. The effect of pre-treatment and post-treatment on adhesion of the multi-layers to the substrates was investigated, and it was found, introducing a pre-fire at elevated temperatures, the adhesion could be improved significantly. Thermal cycling experiments were accomplished according to the Chinese national standard (GJB 126-86), and the multi-layers were not peeled off from the diamond wafers. Rutherford back-scattering spectroscopy (RBS) had been used to characterize the stability of the Ti/Ni/Au metallization scheme at 400℃, 500℃ for 60 min in vacuum. In conclusion, the good adhesion and the stability of the optimized processing between the diamond and the metal-layers can meet the required of the diamond application as heat sink.