Universal Analytic Model of Irradiation Defect Dynamics in Silica-Silicon Structures

TL;DR

This paper introduces a comprehensive analytic model for irradiation defect dynamics in silica-silicon structures, accounting for dispersive hole diffusion and reversible defect reactions, successfully explaining experimental defect behavior across various doses and rates.

Contribution

The model incorporates dispersive hole diffusion and reversible defect reactions, providing a more accurate explanation of defect dynamics under irradiation than previous models.

Findings

Model explains defect concentration dependence on dose and dose rate

Accounts for dispersive hole diffusion in silica

Reversible defect conversion under irradiation

Abstract

Irradiation damage is a key physics issue for semiconductor devices under extreme environments. For decades, the ionization-irradiation-induced damage in transistors with silica-silicon structures under constant dose rate is modeled by a uniform generation of $E'$ centers in the bulk silica region and their irreversible conversion to $P_b$ centers at the silica-silicon interface. But, the traditional model fails to explain experimentally observed dependence of the defect concentrations on dose, especially at low dose rate. Here, we propose that, the generation of $E'$ is decelerated due to the dispersive diffusion of induced holes in the disordered silica and the conversion of $P_b$ is reversible due to recombination-enhanced defect reactions under irradiation. It is shown that the derived analytic model based on these new understandings can consistently explain the fundamental but puzzling dependence of the defect concentrations on dose and dose rate in a wide range.