MOSFET DEGRADATION STUDIED BY LOW-FREQUENCY NOISE, CHARGE PUMPING, AND STATIC I(U) MEASUREMENTS

MOS transistors with very thin oxide (8-5 nm) are concurrently investigated using static I(U), charge pumping, and low frequency noise measurements before and after Fowler-Nordheim injections. The reliability of the structures is assessed by means of fixed oxide charge, and fast and slow interface trap density variations as a function of stress. The noise characteristics of the devices before and after stress are found to be attributable to carrier number fluctuations. Moreover, it is found that the slow interface trap densities deduced from noise measurements are well correlated to the fast interface state ones measured both, by the subthreshold slope and the charge pumping techniques. This proves the ability of noise measurements to be a useful complementary tool for the characterization of the electrical properties of the silicon-oxide interface.