Effects of temperature annealing on charge-injection-induced trapping in gate oxides of metal-oxide-silicon transistors

Temperature-detrapping-anneal treatments combined with charge-injection effects on gate oxides of transistors are studied by using a recently reported trapping-characterization method. Electron detrapping from repulsive traps, as well as from newly generated trapping sites is observed following the annealing step. It is observed that retrapping in both types of traps is made possible by additional charge injection through the oxide. On the other hand, thermal annealing up to 430 °C does not change the density of both types of trapping sites. Although new trapping sites are generated under charge injection, heat treatment up to 430 °C cannot change their existing density, but only their occupation level. As reported previously, surface states were found to be annealed under temperature treatments, but combined with additional charge injection, surface states show an enhanced nonsaturating generation.