Electrostatic Mechanisms Responsible for Device Degradation in Proton Irradiated AlGaN/AlN/GaN HEMTs

Author

Kalavagunta, A. ; Touboul, A. ; Shen, L. ; Schrimpf, R.D. ; Reed, R.A. ; Fleetwood, D.M. ; Jain, R.K. ; Mishra, U.K.

Author_Institution

Dept. of Electr. Eng., Vanderbilt Univ., Nashville, TN

Volume

55

Issue

4

fYear

2008

Firstpage

2106

Lastpage

2112

Abstract

Displacement-damage induced degradation in AlGaN/AlN/GaN HEMTs with polarization charge induced 2DEGs is examined using simulations and experiments. Carrier removal in the unintentionally doped AlGaN layer changes the space charge in the structure and this changes the band bending. The band bending decreases the 2DEG density, which in turn reduces the drain current in the device. The effect of the defect energy levels on the 2DEG density is also studied. The interplay between carrier removal, mobility degradation, and the charged defects is analyzed and quantified.

Keywords

III-V semiconductors; aluminium compounds; band structure; carrier density; carrier mobility; defect states; electrostatics; gallium compounds; high electron mobility transistors; proton effects; semiconductor device models; semiconductor thin films; space charge; two-dimensional electron gas; wide band gap semiconductors; 2DEG density; AlGaN-AlN-GaN; HEMT; band bending; carrier removal; charged defects; defect energy levels; device degradation; displacement damage; drain current; electrostatic mechanism; mobility degradation; polarization charge; proton irradiation; space charge; Aluminum gallium nitride; Degradation; Electrostatics; Energy states; Gallium nitride; HEMTs; MODFETs; Polarization; Protons; Space charge; Deep level traps; GaN; displacement damage; high electron mobility transistor (HEMT); polarization charge; proton radiation;

fLanguage

English

Journal_Title

Nuclear Science, IEEE Transactions on

Publisher

ieee

ISSN

0018-9499

Type

jour

DOI

10.1109/TNS.2008.2001705

Filename

4636888