A Comprehensive Study of Hot-Carrier Instability in P- and N-Type Poly-SI Gated MOSFET’s

Abstract

A comprehensive comparison of hot-carrier instability between p- and n-type poly Si-gated MOSFET’s is presented in this paper. The electron trapping and interface state generation in the 7 nm gate oxide of MOSFET’s are investigated using uniform hot-electron injection from a buried junction injector (BJI) and channel-hot-carrier stress. From BJI experiments, electron trapping (instead of oxide trap generation) and interface state generation are shown to be the major effects of hot-electron injection. Electron trapping and interface state generation are found to be similar in both p- and n-type poly-Si gated n-MOSFET’s. The dependences of interface state generation by hot electrons on oxide voltages and temperatures are observed to be similar between n- and p-type poly-Si gated MOSFET’s. From the results of channel-hot-carrier stress on surface-channel n- and p-channel MOSFET’s, it was also found that the channel-hot-carrier instabilities of p- and n-type poly-Si gated MOSFET’s are comparable. © 1994 IEEE