Title :
Multiplication and excess noise characteristics of thin 4H-SiC UV avalanche photodiodes
Author :
Ng, B.K. ; Yan, Fengping ; David, J.P.R. ; Tozer, R.C. ; Rees, G.J. ; Qin, C. ; Zhao, J.H.
Author_Institution :
Dept. of Electron. & Electr. Eng., Univ. of Sheffield, UK
Abstract :
The avalanche multiplication and excess noise characteristics of thin 4H-SiC avalanche photodiodes with an i-region width of 0.1 μm have been investigated. The diodes are found to exhibit multiplication characteristics which change significantly when the wavelength of the illuminating light changes from 230 to 365 nm. These multiplication characteristics show unambiguously that /spl beta/>/spl alpha/ in 4H-SiC and that the /spl beta///spl alpha/ ratio remains large even in thin 4H-SiC diodes. Low excess noise, corresponding to k=0.1 in the local model where k=/spl alpha///spl beta/ for hole injection, was measured using 325-nm light. The results indicate that 4H-SiC is a suitable material for realizing low-noise UV avalanche photodiodes requiring good visible-blind performance.
Keywords :
avalanche breakdown; avalanche photodiodes; impact ionisation; semiconductor device noise; silicon compounds; ultraviolet detectors; wide band gap semiconductors; 0.1 micron; 230 to 365 nm; 4H-SiC UV avalanche photodiodes; SiC; avalanche multiplication; excess noise characteristics; hole injection; i-region width; illuminating light wavelength; impact ionization; local model; low excess noise; low-noise UV avalanche photodiodes; visible-blind performance; Avalanche photodiodes; Dark current; Diodes; Doping; Optical materials; Optical noise; Optical receivers; Signal to noise ratio; Silicon carbide; Wavelength measurement;
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2002.801112