Title :
Current instabilities in GaN-based devices
Author :
Daumiller, I. ; Theron, Didier ; Gaquiere, Christopher ; Vescan, Andrei ; Dietrich, Robert ; Wieszt, A. ; Leier, Helmut ; Vetury, Rama ; Mishra, Umesh K. ; Smorchkova, I.P. ; Keller, S. ; Nguyen, Cam ; Kohn, Erhard
Author_Institution :
Dept. of Electron Devices, Ulm Univ., Germany
Abstract :
Current dispersion effects have been experimentally investigated in a variety of AlGaN/GaN heterostructure FETs with large signal and switching measurements including HEMTs with doped and undoped barrier layer. A range of dispersion frequencies from 10/sup -3/ Hz to 10 GHz were observed, where the output current amplitude is drastically reduced. Through this effect the full channel charge of an AlGaN/GaN heterostructure FET may be completely depleted under specific bias conditions. This indicates that this phenomena cannot be related to deep traps alone, but is also connected to piezorelated charge states and conduction to these states.
Keywords :
III-V semiconductors; aluminium compounds; doping profiles; gallium compounds; high electron mobility transistors; microwave field effect transistors; semiconductor device measurement; 1E-3 Hz to 10 GHz; AlGaN-GaN; HEMTs; bias conditions; current dispersion effects; dispersion frequencies; doped barrier layer; full channel charge; heterostructure FETs; large signal measurements; output current amplitude; piezorelated charge states; switching measurements; undoped barrier layer; Aluminum gallium nitride; Dispersion; FETs; Frequency; Gallium nitride; HEMTs; MODFETs; Temperature measurement; Time measurement; Voltage;
Journal_Title :
Electron Device Letters, IEEE
