1Rensselaer Polytechnic Institute, Troy, New York, United States; 2NASA Glenn Research Center, Cleveland, Ohio, United States; *Corresponding Author : jiw2@rpi.edu, (518)276-6602

Joseph A. McPherson1, Peter J. Kowal1, Gyanesh K. Pandey1, T. Paul Chow1, Wei Ji1*, Andrew A. Woodworth2

Energy deposition distribution produced by Ag ion and secondary delta-rays in SiC. Dashed lines represent the outline of the JBS model

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pp. 743-754, Dec. 1987.

D. K. Avasthi, G. K. Mehta, “Ion Matter Interaction,” in Swift Heavy Ions for Materials Engineering and Nanostructuring, vol. 145, Dordrecht, Nether-

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ence, vol. 65, no. 1, pp. 256-261, Jan. 2018.

Heavy Ion Transport

3D Device Simulations

Charge Carrier Distribution

High fidelity radiation transport physics model and device physics simulator are

linked

Data from the radiation transport physics model is fitted to a linear combination of

Gaussian functions

SiC-based power devices are susceptible to heavy ions with relatively low LETs

Triggering and failure mechanisms of SEB are not yet fully understood

Modeling techniques are needed to understand SEB triggers and behaviors

Sentaurus from Synopsys is used for full 3D transient electro-thermal simulations

Notional JBS diode similar to 1200V commercially available devices is modeled

Monte Carlo radiation transport code MCNP6.2 is used for modeling 1289 MeV sil-

ver (Ag) ion strike process in SiC

Heavy ions are highly ionizing and create free electrons (delta-rays)

Motivation

Radial distribution of electron-hole pair density generated at a depth of 20 μm in SiC

Device peak temperature was predicted based on three charge carrier distribution

models: double Gaussian fit, simplistic, and ion core models

Simplistic model uses a constant width and LET while ion core model uses a

Gaussian only for heavy ion contributions

All models reach temperatures over 3000 Kelvin where simulations are terminated

upon achieving burnout condition

Temperature comparison between charge carrier distribution models for a JBS diode biased at 800 volts

This work was supported by an Early Stage Innovations grant (NNX17AD05G) from NASA’s Space Technology Research Grants Pro-

gram. We would like to thank Dr. Roger Martz at Los Alamos National Labs for granting us access to a prerelease version of MCNP6.2 for

this work. PJ Kowal was supported by the Nuclear Regulatory Commission Fellowship Program under the grant NRC-HQ-84-15-G-0018

Program B.

Various heavy ions and their surface LET values in SiC at various energies Significant difference in device response to heavy ion strikes using simple approxi-

mations and those backed by high fidelity radiation simulations

Heavy ion transport model is critical in modeling device response

Results Abstract

Single-event burnout (SEB) phenomenon is studied using a unified physics model

between radiation transport and device response. The charge carrier distribution is

modeled using a double Gaussian function to include ion and delta-ray contribu-

tions. 3D TCAD electro-thermal simulations were performed on a high voltage SiC

JBS diode which agree with experimental results of SEB in SiC power devices.

Conclusions

1200 Volt JBS diode used for simulating electro-thermal behaviors

during heavy ion strike

8 μm

where A, a, B, and b are fitting parameters, x is radius, and φ(x) is charge carrier

density