Correlation of Radiation-Induced Interface Traps With Band Edge Energy Through Band Structure-Based Analysis of Electrostatics of UTB SOI Devices

Abstract

The effect of Radiation on the semiconductor-oxide interface, inducing interface trap states, has generally only been experimentally measured, which makes it difficult to quantify the impact of this radiation on device electrostatics. For an Ultra-Thin-Body (UTB) MOS device, the 1-D Band structure along the direction of confinement, if solved self-consistently with the 1-D Poisson’s equation, while varying the band edge energy $(\Delta E_{edge})$ at the $Si-SiO_{2}$ interface, can enable the quantification of the effect of interface trap states on channel electrostatics, while also accounting for Quantum Confinement Effects. In this work, we present an approach to correlate the radiation dose to the band edge energy $(\Delta E_{edge})$ , thus enabling the channel thickness dependent band structure-based approach to be used to quantify the effect of these radiation-induced traps on the device electrostatics. We show a methodology that co-relates the interface charge induced by $\Delta E_{edge}$ variation and the charge yield, due to different radiating particles, on the $Si-SiO_{2}$ interface. After identifying appropriate values of $\Delta E_{edge}$ for different particles and doses, the degradation due to radiation on the channel electrostatics can be accurately simulated, for a wide range of channel thicknesses with the atomistic band structure-based methodology. We also show an approach to extend this methodology to lower device temperatures, thus effectively quantifying the effect of radiation dose on UTB device electrostatics for a wide range of device temperatures.