Reliability comparison of AlGaN/GaN HEMTs with different carbon doping concentration

TL;DR

This paper compares the reliability of AlGaN/GaN HEMTs with different carbon doping levels, showing that higher C doping improves robustness and reduces failure during stress tests.

Contribution

It provides a comparative analysis of the reliability of Fe and C co-doped AlGaN/GaN HEMTs with varying carbon concentrations under different stress conditions.

Findings

High C HEMTs exhibit reduced DIBL and leakage current

Higher C doping leads to improved robustness during stress tests

Failure modes involve drain current and transconductance decrease

Abstract

The reliability of AlGaN/GaN HEMTs adopting Fe and C co-doping, with high and low carbon doping concentration was investigated by means of different stress tests. Firstly, DC and pulsed I-V characterization at room temperature are discussed, then drain step stress tests at different gate voltages are compared, afterwards, the constant stress at different bias points are discussed. Results show that the high C HEMTs showed reduced DIBL, smaller leakage current, as well as decreased electric field, leading to an improved robustness during on-state stress testing, with respect to the reference ones. Failure modes during constant voltage stress consists in a decrease of drain current and transconductance, accelerated by temperature and electric field.