Title :
Access-Region Defect Spectroscopy of DC-Stressed N-Polar GaN MIS-HEMTs
Author :
Sasikumar, A. ; Arehart, A. ; Kolluri, S. ; Wong, M.H. ; Keller, S. ; DenBaars, S.P. ; Speck, J.S. ; Mishra, U.K. ; Ringel, S.A.
Author_Institution :
Dept. of Electr. & Comput. Eng., Ohio State Univ., Columbus, OH, USA
fDate :
5/1/2012 12:00:00 AM
Abstract :
Distinct trap levels in the drain access regions of an N-polar GaN MIS-HEMT are investigated before and after semi-on dc stressing by thermal and optical trap spectroscopies. The most prominent dc stress effect was an increase in concentration of a pre-existing electron trap with an activation energy of 0.54 eV, accompanied by a decrease in concentration of an electron trap with a 0.65-eV activation energy. These distinct states had similar concentrations before stressing, with the 0.54-eV trap concentration dominating (by 6×) after stress. Deeper states revealed via optical measurements showed a mild ~20% increase in total concentration after stressing.
Keywords :
III-V semiconductors; MIS devices; electron traps; gallium compounds; high electron mobility transistors; infrared spectroscopy; wide band gap semiconductors; DC-stressed N-polar GaN MIS-HEMT; GaN; access-region defect spectroscopy; activation energy; distinct trap level; drain access region; electron trap; electron volt energy 0.54 eV; electron volt energy 0.65 eV; optical measurement; optical trap spectroscopy; semi-on dc stressing; thermal trap spectroscopy; Degradation; Electron traps; Gallium nitride; HEMTs; Logic gates; Spectroscopy; Stress; Constant current deep level optical spectroscopy (CID-DLOS); GaN; N-polar; constant current deep level transient spectroscopy (CID-DLTS); dc stressing; deep levels; high-electron-mobility transistor (HEMT); metal-organic chemical vapor deposition (MOCVD); trapping;
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2012.2188710
