Sudden failures associated with the gate oxide of CMOS transistors

Sudden failures appearing during static gate bias — temperature aging of CMOS transistors are investigated in this paper. Shorts between the gate and substrate as well as open gate circuits are found to be failure modes appearing during testing. The subsequent failure analysis reveals that the reaction between the aluminium and gate oxide is the failure mechanism, while defects in P⁺-diffusion regions (which are transferred onto the gate oxide) are the cause of the observed failures.