Title :
An Analysis of the Effects of Low-Energy Electron Irradiation of AlGaN/GaN HFETs
Author :
McClory, John W. ; Petrosky, James C. ; Sattler, James M. ; Jarzen, Thomas A.
Author_Institution :
US Army & Air Force Inst. of Technol, WPAFB
Abstract :
The effects of low energy (0.45 MeV) electron radiation on the gate and drain currents of Al0.27Ga0.73N/GaN HFETs are investigated using IV and CV measurements. Following irradiation, the gate and drain currents increase at low temperatures and reach a saturation level. The gate leakage currents do not fully account for the drain current increase. Following a room temperature anneal, the gate and drain currents return to pre-irradiation levels. These results are explained by the buildup of positive charge in the AlGaN layer at low temperature and traps formed via a complexing precursor in the AlGaN layer near the interface. The positive charge increases the carrier concentration in the 2DEG and hence the drain current. The traps act as trap-assisted-tunneling centers that increase the gate leakage current.
Keywords :
III-V semiconductors; aluminium compounds; annealing; carrier density; electron beam effects; gallium compounds; high electron mobility transistors; leakage currents; two-dimensional electron gas; wide band gap semiconductors; 2DEG; Al0.27Ga0.73N-GaN; CV measurement; HFET; IV measurement; carrier concentration; drain current; electron volt energy 0.45 MeV; gate current; gate leakage currents; heterojunction field effect transistors; low-energy electron irradiation; room temperature anneal; temperature 293 K to 298 K; trap-assisted-tunneling centers; Aluminum gallium nitride; Annealing; Current measurement; Electrons; Energy measurement; Gallium nitride; HEMTs; Leakage current; MODFETs; Temperature; Electron irradiation; gallium nitride; heterojunction field effect transistors;
Journal_Title :
Nuclear Science, IEEE Transactions on
DOI :
10.1109/TNS.2007.910121