Title :
Low dark current GaN avalanche photodiodes
Author :
Yang, B. ; Li, T. ; Heng, K. ; Collins, C. ; Wang, S. ; Carrano, J.C. ; Dupuis, R.D. ; Campbell, J.C. ; Schurman, M.J. ; Ferguson, I.T.
Author_Institution :
Dept. of Electr. & Comput. Eng., Texas Univ., Austin, TX, USA
Abstract :
We report the fabrication and characterization of GaN avalanche photodiodes grown on sapphire by metalorganic chemical vapor deposition. Current-voltage characteristics indicate a gain higher than 23. The photoresponse is independent of the bias voltage prior to the onset of avalanche gain which occurs at an electric field of /spl sim/4 MV/cm. Near avalanche breakdown, the dark current of a 30-/spl mu/m diameter device is less than 100 pA. The breakdown shows a positive temperature coefficient of 0.03 V/K that is characteristic of avalanche breakdown.
Keywords :
III-V semiconductors; MOCVD; avalanche breakdown; avalanche photodiodes; dark conductivity; gallium compounds; optical fabrication; 100 pA; 30 mum; Al/sub 2/O/sub 3/; GaN; GaN avalanche photodiodes; avalanche breakdown; avalanche gain; bias voltage; characterization; current-voltage characteristics; dark current; electric field; fabrication; gain; low dark current avalanche photodiodes; metalorganic chemical vapor deposition; near avalanche breakdown; photoresponse; positive temperature coefficient; sapphire; Avalanche breakdown; Avalanche photodiodes; Chemical vapor deposition; Dark current; Electric breakdown; Gallium nitride; Photoconductivity; Plasma measurements; Substrates; Voltage;
Journal_Title :
Quantum Electronics, IEEE Journal of
