An evaluation method for dc characteristics shifts in resin-Molded nMOSFETs using drift-diffusion device simulation

Abstract

The electronic performance of semiconductor devices is adversely affected by residual stress during various packaging processes. Very few attempts have been made to develop a simulation method for evaluating this issue. Therefore, we have verified a device simulation method for evaluating stress-induced effects on the DC characteristics of nMOSFETs. Our simulation model includes an electron mobility model that takes the stress effects into consideration. In the electron mobility model, two physical phenomena induced by stress were modeled: the change in the occupancy of electrons in the conduction band and the change in the average electron relaxation time. We evaluated the variation in the DC characteristics of nMOSFET during an actual resin-molding process (OFF process) using the developed device simulation method, and compared the simulation results with experimental results. Our findings show that the simulation method produced a reasonable approximation of the experimental results. It was demonstrated that the simulation is useful for evaluating stress-induced effects on the DC characteristics of nMOSFETs.