A new technique to measure an oxide trap density in a hot carrier stressed n-MOSFET

We have proposed a new measurement technique to characterize the hot carrier stress generated oxide traps in a n-MOSFET by measuring subthreshold current. In this technique, a specially designed measurement consisting of a series of oxide charge detrapping and subthreshold current measurement phases was performed. An analytical model accounting for the temporal evolution of subthreshold current due to oxide charge detrapping was derived. Our study shows that this method is extremely sensitive to an oxide charge variation. By using this method, the oxide trap growth rates by hot electron stress and hot hole stress were measured.