Title :
Low noise GaAs and Al0.3Ga0.7As avalanche photodetectors
Author :
Li, K.F. ; Ong, D.S. ; David, J.P.R. ; Tozer, R.C. ; Rees, G.J. ; Robson, P.N. ; Grey, R.
Author_Institution :
Dept. of Electron. Eng., Sheffield Univ., UK
fDate :
8/1/1999 12:00:00 AM
Abstract :
The avalanche-multiplication and noise characteristics of a series of thin (0.05 μm<w<1 μm) p+-i-n+ GaAs and Al0.3Ga0.7As diodes have been measured. According to the widely used theory of McIntyre, the lowest excess-noise factor should be obtained with materials that have a small ratio of ionisation coefficients, k=β/α. Where a is the ionisation coefficient of the initiating carrier. It has been found, however, that in thin avalanche regions, <1 μm, the assumptions of McIntyre´s noise theory become increasingly invalid and low noise factors can be achieved even when k is of the order of 1. In such thin devices, the dead space becomes a significant fraction of w, reducing the randomness in ionisation path length and hence the noise
Keywords :
III-V semiconductors; aluminium compounds; avalanche photodiodes; gallium arsenide; ionisation; optical noise; semiconductor device noise; (0.3)Ga0.7As photodiodes; Al0.3Ga0.7As; Al0.3Ga0.7As avalanche photodetectors; GaAs; GaAs avalanche photodetectors; GaAs photodiodes; McIntyre´s noise theory; dead space; excess-noise factor; initiating carrier; ionisation coefficients; ionisation path length randomness; low noise avalanche photodetectors; low noise factors; thin avalanche regions;
Journal_Title :
Optoelectronics, IEE Proceedings -
DOI :
10.1049/ip-opt:19990453
