Intentionally Carbon-Doped AlGaN/GaN HEMTs: Necessity for Vertical Leakage Paths

Author

Uren, M.J. ; Silvestri, M. ; Casar, Markus ; Hurkx, Godefridus Adrianus Maria ; Croon, Jeroen A. ; Sonsky, Jan ; Kuball, M.

Author_Institution

Center for Device Thermography & Reliability, Univ. of Bristol, Bristol, UK

Volume

35

Issue

3

fYear

2014

fDate

Mar-14

Firstpage

327

Lastpage

329

Abstract

Dynamic on-resistance (RON) in heavily carbon-doped AlGaN/GaN high electron mobility transistors is shown to be associated with the semi-insulating carbon-doped buffer region. Using transient substrate bias, differences in RON dispersion between transistors fabricated on nominally identical epilayer structures were found to be due to the band-to-band leakage resistance between the buffer and the 2-DEG. Contrary to normal expectations, suppression of dynamic RON dispersion in these devices requires a high density of active defects to increase reverse leakage current through the depletion region allowing the floating weakly p-type buffer to remain in equilibrium with the 2-DEG.

Keywords

III-V semiconductors; aluminium compounds; buffer layers; gallium compounds; high electron mobility transistors; leakage currents; semiconductor doping; wide band gap semiconductors; 2-DEG; AlGaN-GaN:C; HEMT; RON; band-to-band leakage resistance; dynamic on-resistance; epilayer structures; heavily carbon-doped AlGaN-GaN; high electron mobility transistors; p-type buffer; reverse leakage current; semiinsulating carbon-doped buffer region; transient substrate bias; vertical leakage paths; Aluminum gallium nitride; Dispersion; Gallium nitride; HEMTs; MODFETs; Semiconductor device modeling; Substrates; Dynamic ON-resistance; HEMT; carbon doping; current collapse; defects;

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/LED.2013.2297626

Filename

6716010