Experimental evidence for recombination-assisted leakage in thin oxides

Carrier separation experiments in degraded p-channel metal-oxide-semiconduc tor devices reveal the occurrence of both electron and hole leakage process es. A detailed study of the excess currents as a function of time after str ess, stress fluence, and polysilicon doping is presented. Evidence for a li near correlation between electron and hole leakage currents is provided, su ggesting that the same defect species are responsible for both leakage phen omena. The dependence on polysilicon gate type confirms this explanation, s upporting a leakage model based on trap-assisted tunneling and recombinatio n in oxide traps. (C) 2000 American Institute of Physics. [S0003-6951(00)03 213-7].