Research on the influences of well structure on dose rate effects in 65nm CMOS circuit

Abstract

A short-time high-dose gamma ray will produce many electronhole pairs by the Compton effects in various semiconductor materials. Then pulse current will be generated in the devices and electronic system and affect their normal operation, which is called the Dose Rate Effects (DREs). Based on three-dimensional (3D) technology computer aided design (TCAD) simulations, the impacts of well structures on the DREs in 65-nm bulk CMOS inverter which is the most basic circuit unit are investigated. In this paper, the extend Gamma Radiation Model is used in simulations for effectively simulating the generation of electron-hole pairs in circuits. And present a idea for radiation hardening of bulk silicon CMOS circuits approach to DREs through optimization of well structure. The results of the simulations show that deep P-well (DPW) structure effectively reduces pulse amplitude of the voltage while the deep N-well (DNW) structure reduces the pulse amplitude only in high doping concentration. In addition, the pulse amplitude decreases with the doping concentration of deep well increasing. The mechanism is analyzed from the aspects of charge collection and potential change.