Local oxide capacitance as a crucial parameter for characterization of hot-carrier degradation in long-channel n-MOSFETs

Abstract

A theoretical model for the MOSFET local oxide capacitance as a crucial parameter for the characterization of hot-carrier degradation has been developed. For this purpose, the conformal mapping technique is used. On the basis of the proposed approach a refined extraction scheme for the defect distribution from charge-pumping measurements has been employed. Assuming the extracted spatial trap distributions at different stress times as input, the transfer characteristics and linear drain current degradation are numerically calculated and compared with the experimental results. A very good agreement is achieved. These results demonstrate that the coordinate dependence of the oxide capacitance is extremely important for an accurate extraction of the defect profile particularly for large stress times. Additionally, the obtained results confirm the findings of our physics-based model of hot-carrier degradation.