A study of electrical characteristic changes in MOSFET by electron beam irradiation

Abstract

Mechanisms for electrical characteristic changes in MOSFET caused by electron beam irradiation were studied using a SEM-based nano-probing system. A shift in V th occurs when a hole is trapped in a defect (oxygen vacancy) in the gate dielectric layer. Holes are generated when the plasmon is excited by electron beam irradiation. Further, an electric field is created by the positive charge-up resulting from electron beam irradiation of the ILD, causing an increase in leakage between gate and drain leading to an increase in I off. This study shows that advanced devices can be measured using a SEM-based nano-probing system without inducing electrical characteristic changes by optimizing the measurement conditions such as acceleration voltage, electron beam current, image magnification, ILD thickness, and electron beam irradiation time.