Gate current in OFF-state MOSFET

The source of the gate current in MOSFETs due to an applied drain voltage with the gate grounded is studied. It is found that for 100-AA or thinner oxide, the gate current is due to Fowler-Nordheim (F-N) tunneling electrons from the gate. With increasing oxide thickness, hot-hole injection becomes the dominant contribution to the gate current. This gate current can cause I/sub D/ walkout, which is a decrease in the gate-induced drain leakage current, and hole trapping, which becomes important for device degradation study. It can also be used to advantage in EPROM (erasable programmable read-only memory) erasure.<
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