High-temperature deep-level transient spectroscopy system for defect studies in wide-bandgap semiconductors

TL;DR

This paper presents a high-temperature DLTS system capable of studying deep defect states in wide-bandgap semiconductors up to 1100 K, enabling insights into defects at higher temperatures than previously possible.

Contribution

A novel HT-DLTS system was developed to measure deep defect states at temperatures up to 1100 K, surpassing previous temperature limits in DLTS characterization.

Findings

Successful measurement of intrinsic defects in 4H-SiC at 300-950 K

System performance aligned with literature on defect states

Electrode quality limited some measurements

Abstract

Full investigation of deep defect states and impurities in wide-bandgap materials by employing commercial transient capacitance spectroscopy is a challenge, demanding very high temperatures. Therefore, a high-temperature deep-level transient spectroscopy (HT-DLTS) system was developed for measurements up to 1100 K. The upper limit of the temperature range allows for the study of deep defects and trap centers in the bandgap, deeper than previously reported by DLTS characterization in any material. Performance of the system was tested by conducting measurements on the well-known intrinsic defects in n-type 4H-SiC in the temperature range 300-950 K. Experimental observations performed on 4H-SiC Schottky diodes were in good agreement with the literatures. However, the DLTS measurements were restricted by the operation and quality of the electrodes.