Heavy Ion Induced Degradation in SiC Schottky Diodes: Incident Angle and Energy Deposition Dependence

Abstract

-Heavy-ion induced degradation in the reverse leakage current of SiC Schottky power diodes exhibits a strong dependence on the ion angle of incidence. This effect is studied experimentally for several different bias voltages applied during heavy-ion exposure. Additionally, TCAD simulations are used to give insight on the physical mechanisms involved.

Molecular Dynamics Simulations of Heavy Ion Induced Defects in SiC Schottky Diodes

“…The ion energy deposition in these simulations is defined by the average Linear Energy Transfer (LET) (also known as electronic stopping force, S e ) value for 1217-MeV Xe ions, that is 62.4 MeV/(mg/cm 2 ). This corresponds to experimental values used earlier [1], [4], [5].…”

“…The experimental results used to inform the simulations presented in this paper have been published previously [1], [4], [5].…”

“…The leakage current may begin to increase during irradiation at operating biases significantly lower than the rated breakdown voltage [1]- [8]. For the 650 V devices in this work, semi-permanent increases in ion-induced leakage occur at a bias as low as 150 V. Device simulations have been used to attribute this to a highly localized temperature rise that goes above the phase transition temperature of SiC [4], [5]. Even though the temperature recovers after the ion strike, physical modifications of the crystal occur, as evidenced by the changes in the current-voltage characteristics.…”

Single-Event Burnout of SiC Junction Barrier Schottky Diode High-Voltage Power Devices

“…In addition, efficient Schottky switching diodes in SiC can be manufactured that exhibit very low on-state voltage and minimal turn-off switching loss with almost no reverserecovery behavior, which makes SiC a good candidate for space power conversion applications. However, the sensitivity of SiC power devices (MOSFETs and diodes) to particle radiation has been found to be higher than expected, given the wide bandgap and high critical electric field, as shown by multiple researchers who have consistently measured significant leakage current increases and single-event burnout in SiC devices [1][2][3][4][5][6][7][8][9][10][11].…”

“…Additionally, Javanainen et al [10,11] presented data and simulations that suggest that temperature increases are responsible for the gradual degradation behavior of Region 2 of Fig. 1.…”