Total-Ionizing-Dose Radiation Effects in AlGaN/GaN HEMTs and MOS-HEMTs

Author

Xiao Sun ; Saadat, Omair I. ; Jin Chen ; Zhang, E.X. ; Cui, Shuguang ; Palacios, T. ; Fleetwood, D.M. ; Ma, T.P.

Author_Institution

Electr. Eng. Dept., Yale Univ., New Haven, CT, USA

Volume

60

Issue

6

fYear

2013

fDate

Dec. 2013

Firstpage

4074

Lastpage

4079

Abstract

We have investigated the total ionizing dose (TID) radiation effects in AlGaN/GaN MOS-HEMTs as a function of dose and radiation bias, and compared them with conventional HEMTs. Under 10 keV X-ray irradiation, two distinct regimes of threshold voltage (V_th) shifts have been revealed: a rapid V_th shift at low doses for both HEMTs and MOS-HEMTs, and an additional V_th shift only found in MOS-HEMTs for doses up to at least 2 Mrad (SiO₂). The rapid V_th shift anneals quickly and is a strong function of layer material. We attribute this portion of the V_th shift to hole trapping in the AlGaN barrier layer. The V_th shift at high doses found only in MOS-HEMTs is attributed to hole trapping in the gate oxide. By comparing MOSFETs with HfO₂ and Al₂O₃ gate dielectrics that are annealed during processing at various temperatures, we find that 500^°C annealed HfO₂ shows the most promising TID response.

Keywords

III-V semiconductors; aluminium compounds; annealing; gallium compounds; hafnium compounds; high electron mobility transistors; wide band gap semiconductors; Al₂O₃; AlGaN-GaN; HfO₂; MOS-HEMT; SiO₂; TID radiation effect; TID response; X-ray irradiation; annealing; barrier layer; dose function; electron volt energy 10 keV; gate dielectrics; gate oxide; hole trapping; layer material; radiation bias; threshold voltage; total-ionizing-dose radiation effect; voltage shift; Aluminum gallium nitride; Aluminum oxide; Annealing; Gallium nitride; HEMTs; Hafnium oxide; MOSFET; Radiation effects; ${rm Al}_{2}{rm O}_{3}$; ${rm HfO}_{2}$; ALGaN; GaN; HEMT; MOS; annealing; charge trapping; radiation; total ionizing dose;

fLanguage

English

Journal_Title

Nuclear Science, IEEE Transactions on

Publisher

ieee

ISSN

0018-9499

Type

jour

DOI

10.1109/TNS.2013.2278314

Filename

6636118