Charge trapping effects and interface state generation in a 40 V lateral resurf pDMOS transistor

This paper investigates the degradation of a lateral resurf 40V pDMOS transistor under hot carrier stress using variable base charge pumping experiments. Upon stressing, the device exhibits N_it formation in the gate overlapped drift region and electron trapping in the drift region birds beak. Injection of electrons occurs at a spot approximately 50 nm from the birds beak tip. The degradation of the electrical parameters upon hot carrier stress is only correlated with the amount of injected electrons, and not with the N_it formation. The trapped electron charge will cause a walk-in of the off-state V_bd.