Work

Microscopic Analysis of Degradation and Breakdown Kinetics in HfO2 Gate Dielectric after Ions Irradiation

Year: 2025

Type: article

Abstract: High Resolution Image Download MS PowerPoint Slide We combine experiments and simulations to investigate the degradation dynamics and dielectric breakdown (BD) of SiO x /HfO 2 gate stacks irradiated with varying doses of 40 MeV carbon ions. The analysis of postirradiation electrical characteristics (current–voltage, I – V, capacitance–voltage, C – V, and conductance-voltage, G – V ) reveals that the HfO 2 layer is the most affected by irradiation-induced damage, leading to the formation of defects consistent with oxygen vacancies. Postirradiation constant voltage stress (CVS) experiments reveal an inverse dependence of time to breakdown ( t BD ) and Weibull slopes (β) on the irradiation dose. These trends are accurately reproduced by statistical physics-based breakdown simulations only when accounting for partial percolation paths induced by ion strikes during irradiation, as well as a spatially correlated defect generation process during subsequent electrical stress. Our findings are crucial for designing radiation-hardened materials and improving the resilience of electronics operating in harsh environments.

Source: ACS Applied Materials & Interfaces

DOI: 10.1021/acsami.5c09755