Hot-electron-induced MOSFET degradation at low temperatures

Abstract

The n-channel LDD MOSFET lifetime is observed to follow \tau=(A/I_{d})(I_{sub}/I_{d})^{-n} from 77 to 295 K when the device is stressed near the maximum I sub . Here I d is the drain current and A is the proportionality constant. The experimental result indicates that n is approximately 2.7 and is independent of temperature. However, the proportionality constant A follows A = A_{0} \exp (-E_{a}/kT) , with E_{a} = 39 meV. The smaller proportionality constant at low temperatures suggests that hot-electron injection (HEI) degradation is caused by the electron trapping in the oxide.