Heavy-ion induced single event effects and latent damages in SiC power MOSFETs

C Martinella,P Natzke,R.G Alia,Y Kadi,K Niskanen,M Rossi,J Jaatinen,H Kettunen,A Tsibizov,U Grossner,A Javanainen

doi:10.1016/j.microrel.2021.114423

Abstract

The advantages of silicon carbide (SiC) power MOSFETs make this technology attractive for space, avionics and high-energy accelerator applications. However, the current commercial technologies are still susceptible to Single Event Effects (SEEs) and latent damages induced by the radiation environment. Two types of latent damage were experimentally observed in commercial SiC power MOSFETs exposed to heavy-ions. One is observed at bias voltages just below the degradation onset and it involves the gate oxide. The other damage type is observed at bias voltages below the Single Event Burnout (SEB) limit, and it is attributed to alterations of the SiC crystal-lattice. Focused ion beam (FIB) and scanning electron microscopy (SEM) were used to investigate the damage site. Finally, a summary of the different types of damage induced by the heavy ion in SiC MOSFETs is given as a function of the ion LET and operational bias.

Highlights

The wide-bandgap silicon carbide (SiC) semiconductor has emerged as the most viable alternative to silicon (Si) for the next-generation material for high-efficiency and high-power density applications [1,2]
Bare die from the 2nd generation of Cree/Wolfspeed, rated for VDS = 1.2 kV were selected as devices under test (DUTs)
The first experiment was performed with the objective of investi gating the latent gate damage as observed during the post-irradiation gate stress (PIGS) test for devices exposed in the pre-degradation re gion

Summary

Introduction

The wide-bandgap silicon carbide (SiC) semiconductor has emerged as the most viable alternative to silicon (Si) for the next-generation material for high-efficiency and high-power density applications [1,2]. Due to the wide bandgap, the intrinsic carrier density at room temperature (i.e., the electrons and holes generated by thermal excitation), is extremely low, enabling the SiC electronic devices to operate at high temperatures with low leakage current. These properties make SiC an attractive material to manufacture power devices by far exceeding the performance limits of their Si counterparts. Nowadays SiC power MOSFETs are found in a variety of applications in the automotive, photovoltaic and power supply segments [3]

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Results

Discussion

Conclusion