Drain avalanche hot hole injection mode on PMOSFETs

Hot carrier degradation was studied for surface-channel (p/sup +/ polysilicon-gate) PMOSFETs in comparison with buried-channel (n/sup +/ polysilicon-gate) PMOSFETs. In the shallow gate bias region, a carrier degradation mode by drain avalanche hot-hole injection was found for the surface-channel PMOSFETs. Here, trapped holes and interface state generation, which were not observed in the buried-channel PMOSFETs, were detected. In the deep-gate-bias region, a channel hot-hole interface-state-generation mode without the threshold voltage shift was found for both types of PMOSFETs studied.<
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