A Model of Gamma-Ray Irradiation Effects in Silicon Dioxide Films and on Silicon Dioxide - Silicon Interface

Abstract

The gamma-ray irradiation causes positive charge traps formation in silicon dioxide films and at silicon dioxide - silicon interface of MOS devices, and the threshold voltage shift in MOS transistors. Here, the Monte Carlo model was used to develop an approach for estimating gammaray induced traps spatially distributed in silicon dioxide films. This is combined with the model of energy distributed traps at silicon dioxide - silicon interface. The developed model enables gammaray induced charge and threshold voltage shift determination as a function of gamma-ray doses. The threshold voltage measurements at a single specified current, both of radiation sensitive and radiation hardened MOS transistors irradiated with different doses of gamma-ray are compared with the developed model and good agreement are obtained.

Modulation phenomena in Si nanowire field-effect transistors characterized using noise spectroscopy and gamma radiation technique

“…Such behavior can be explained by the changing of a trap from neutral to repulsive (positively charged). 36 This fact is additionally confirmed by the shift of the threshold voltage to an increased level corresponding to a more positive potential of Si/SiO 2 interface. Therefore irradiation leads to changes in the charge state of the dielectric traps, which shifts the threshold voltage and, on the other hand, impacts the conditions of the carrier exchange between traps and the conducting channel.…”