Hole energy dependent interface trap generation in MOSFET Si/SiO/sub 2/ interface

Abstract

The nature and composition of generated interface-trap (/spl Delta/N/sub IT/) in p-MOSFETs is studied as a function of hole energy. By observing the time dependence of generation during stress and the amount of recovery after stress, it is shown that /spl Delta/N/sub IT/ is due to both broken /spl equiv/Si--H and /spl equiv/Si--O-- bonds, their ratio governed by hole energy. In the absence of hot holes /spl Delta/N/sub IT/ is primarily composed of broken /spl equiv/Si--H, which show a lower power-law time exponent and a fraction of which anneal after stress. Additional /spl Delta/N/sub IT/ is created in the presence of hot holes, which is due to broken /spl equiv/Si--O-- bonds. These traps show a much larger power-law time exponent, and they do not anneal after stress. These observations have important implications for lifetime prediction under negative bias temperature instability, Fowler-Nordheim, and hot carrier injection stress conditions.