Effect of stress relaxation on the generation of radiation-induced interface traps in post-metal-annealed Al-SiO2-Si devices

We have found experimentally that both the interfacial stress distribution and the generation of interface traps in an Al-SiO2-Si structure change systematically with time lapse between post-metal-anneal treatment and x-ray irradiation, and strong correlation between the two is established. The results suggest that the device radiation sensitivity is modulated by the interfacial stress and/or the oxide bond strain gradient. Two possible mechanisms based on the variations of the interfacial strained bonds are proposed to explain the results.