An investigation of device instabilities arising from the encapsulation material and composition

Two factorial experiments were designed to identify process variables and material compositions for improving hot-carrier-induced MOSFET device instability. The first experiment was designed to identify what factors related to the passivation process are most important. The second experiment concentrated on the composition and thickness of the double-layer nitride-oxide passivation. The results indicate that improvement is achieved by adding an oxide layer under the plasma silicon nitride and performing a sinter prior to the nitride deposition rather than afterwards. The most significant factors were the nitride composition, the thickness of the oxide layer, and the sinter atmosphere