Spin-dependent trap-assisted tunneling current in ultra-thin gate dielectrics

We have characterized the leak-age current paths of ultra-thin gate dielectrics using spin-dependent tunneling (SDT) spectroscopy. A spin-dependent current was detected in metal-oxide-semiconductor diodes with chemical-vapor-deposition SiN gate films with thickness less than 3 run. We examined the nature of the trap sites in terms of g-value, bias-dependent signal intensity, and magnetic-field orientation dependence. The main feature of the observed spectrum is attributed to a paramagnetic Si site in the SiN films. By using a quantitative model of electron spin-polarization, we were able to estimate the ratio of trap-assisted current to the total leak-age current.