High-Thermal-Conductivity AIN Packages for High-Temperature Electronics

摘要

A novel metallization for aluminum nitride substrates to package silicon carbideintegrated circuits for use at temperatures of 600 deg C and above was investigated. Chemical equilibrium calculations were used to determine the chemical compatibility of several refractory and transition metal disilicides with AlN and SiC. Tungsten disilicide, niobium disilicide, and titanium disilicide were selected for diffusion couple and thin film deposition studies. AlN-WSi2-SiC, AlN-NbSi2-SiC, and AlN-TiSi2-SiC diffusion couples were formed at 1000 deg C and 1200 deg C. WSi2, NbSi2, and TiSi2 thin films were deposited by RF sputtering on AIN substrates and heat treated at 900 deg C, 1000 deg C, and l200 deg C in an argon atmosphere, while WSi2 thin film was deposited on a single crystal SiC wafer and heat treated at 900 deg C. Sheet resistivities were measured, and interfaces were characterized by scanning and transmission electron microscopy imaging, electron diffraction, and energy dispersive x ray microanalysis spectroscopy. The results show that metal silicides appear to be promising as metallization for aluminum nitride for use at 600 deg C and above.