Investigation of Single pMOSFET Gate Oxide Degradation on NOR Logic Circuit Operability

The impact of gate oxide degradation of a single pMOSFET on the performance of the CMOS NOR logic circuit has been examined using a switch matrix technique. A constant voltage stress of -4.0V was used to induce a low level of degradation to the 2.0nm gate oxide of the pMOSFET. Characteristics of the CMOS NOR logic circuit following gate oxide degradation are analyzed in both the DC and V-t domains. The NOR gate rise time increases by approximately 30%, which may lead to timing or logic errors in high frequency digital circuits. Additionally, the voltage switching point of the NOR logic circuit shifts by 9% which could affect operation of analog or mixed signal designs. This shift in NOR logic circuit performance is correlated to an increased channel resistance of the stressed pMOSFET.