M-center in low-energy electron irradiated 4H-SiC

TL;DR

This study investigates deep-level defects in low-energy electron irradiated 4H-SiC using DLTS techniques, identifying specific carbon interstitial-related defects and demonstrating the effectiveness of Laplace-DLTS in distinguishing similar signals.

Contribution

The paper identifies and assigns specific deep-level defects in 4H-SiC caused by electron irradiation and demonstrates the utility of Laplace-DLTS for defect analysis.

Findings

Identification of EH1, EH3, and M-center as carbon interstitial-related defects.

Assignment of EH1 and EH3 to C_i^(=) (h) and C_i^(0) (h).

Laplace-DLTS effectively distinguishes similar DLTS signals.

Abstract

We report on the low-energy electron irradiated 4H-SiC material studied by means of deep-level transient spectroscopy (DLTS) and Laplace-DLTS. Electron irradiation has introduced the following deep level defects: EH1 and EH3 previously assigned to carbon interstitial-related defects, and M-center, a metastable defect also recently assigned to carbon interstitial defects. We propose that EH1 and EH3 are identical to M1 and M3 and assign them to C_i^(= ) (h) and C_i^(0 ) (h), respectively. Moreover, we provide direct evidence that Laplace-DLTS can be used as an excellent tool to distinguish otherwise identical DLTS signals associated with S1 (VSi) and EH1 (Ci).