This paper presents an extensive investigation of the properties of the trap with activation energy equal to 0.6 eV, which has been demonstrated to be responsible for current collapse (CC) in AlGaN/GaN HEMTs. The study was carried out on AlGaN/GaN HEMTs with increasing concentration of iron doping in the buffer. Based on pulsed characterization and drain current transient measurements, we demonstrate that for the samples under investigation: 1) increasing concentrations of Fe-doping in the buffer may induce a strong CC, which is related to the existence of a trap level located 0.63 eV below the conduction band energy and 2) this trap is physically located in the buffer layer, and is not related to the iron atoms but—more likely—to an intrinsic defect whose concentration depends on buffer doping. Moreover, we demonstrate that this level can be filled both under OFF-state conditions (by gate-leakage current) and under ON-state operation (when hot electrons can be injected to the buffer): for these reasons, it can significantly affect the switching properties of AlGaN/GaN HEMTs.

Buffer Traps in Fe-Doped AlGaN/GaN HEMTs: Investigation of the Physical Properties Based on Pulsed and Transient Measurements

MENEGHINI, MATTEO;ROSSETTO, ISABELLA;BISI, DAVIDE;STOCCO, ANTONIO;MENEGHESSO, GAUDENZIO;ZANONI, ENRICO
2014

Abstract

This paper presents an extensive investigation of the properties of the trap with activation energy equal to 0.6 eV, which has been demonstrated to be responsible for current collapse (CC) in AlGaN/GaN HEMTs. The study was carried out on AlGaN/GaN HEMTs with increasing concentration of iron doping in the buffer. Based on pulsed characterization and drain current transient measurements, we demonstrate that for the samples under investigation: 1) increasing concentrations of Fe-doping in the buffer may induce a strong CC, which is related to the existence of a trap level located 0.63 eV below the conduction band energy and 2) this trap is physically located in the buffer layer, and is not related to the iron atoms but—more likely—to an intrinsic defect whose concentration depends on buffer doping. Moreover, we demonstrate that this level can be filled both under OFF-state conditions (by gate-leakage current) and under ON-state operation (when hot electrons can be injected to the buffer): for these reasons, it can significantly affect the switching properties of AlGaN/GaN HEMTs.
File in questo prodotto:
Non ci sono file associati a questo prodotto.
Pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11577/3067900
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 118
  • ???jsp.display-item.citation.isi??? 105
social impact