Title :
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
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;
Journal_Title :
Nuclear Science, IEEE Transactions on
DOI :
10.1109/TNS.2008.2001705
