Gate Oxide Thickness Dependence of Hot Carrier Induced Degradation on PMOSFETs

Gate oxide thickness dependences of pMOSFET hot carrier degradation characteristics were studied at 300K and 77K. It was found that a thin gate oxide pMOSFET shows superior characteristics regarding hot carrier degradation. Threshold voltage shift becomes very small, with reduction in the gate oxide thickness, due to the tunneling effect. Interface state generation increases with the gate oxide thickness reduction. Fortunately, however, it is not enough to affect device characteristics. It was found that the interface state increase is described by the gate current uniquely, independently from the gate oxide thickness, bias condition, and temperature.