Effect of gas-phase aluminum - nitride-layer morphology on the thermal resistance of Mo - AlN - Mo cylindric packages

Results of measurements of the thermal resistance of Mo-AlN-Mo cylindric packages are related to the microstructure of the ceramic and intermediate layers. It is shown that only a special morphology of the nitride ceramic layer makes it possible to obtain a high-density contact between the ceramic and metal layers which is not destroyed upon subsequent heating of the package and upon thermocycling. The required so-called 'composite' morphology of nitride ceramics can be obtained only within a narrow range of synthesis temperatures.