Title :
Gain-bandwidth product analysis of InAlGaAs-InAlAs superlattice avalanche photodiodes
Author :
Watanabe, I. ; Tsuji, M. ; Makita, K. ; Taguchi, K.
Author_Institution :
Opto-Electron. Res. Labs., NEC Corp., Ibaraki, Japan
Abstract :
The gain-bandwidth (GB) product of InAlAs-InAlGaAs quaternary well superlattice avalanche photodiodes (SL-APDs) has been analyzed by solving current-continuity equations including electron and hole impact ionization rates in a separate absorption and multiplication (SAM) structure. The results indicate that the GB product of InAlGaAs quaternary well SL-APDs can be increased to more than 150 GHz by decreasing the thickness of a p/sup +/-InP field buffer layer. This is due to reduced ionization in the p/sup +/-InP field buffer layer, which has an opposite ionization rate ratio compared to the superlattice. This analysis was experimentally confirmed by a GB product of 150 GHz for the SL-APDs with a 33.4 nm thick p/sup +/-InP field buffer layer. The GB product obtained is the largest value in III-V compound-semiconductor APDs, to our knowledge,.
Keywords :
III-V semiconductors; aluminium compounds; avalanche photodiodes; gallium arsenide; impact ionisation; indium compounds; photodetectors; semiconductor quantum wells; semiconductor superlattices; 33.4 nm; III-V compound-semiconductor APD´s; InAlAs-InAlGaAs; InAlAs-InAlGaAs quaternary well superlattice; InAlGaAs-InAlAs; InAlGaAs-InAlAs superlattice avalanche photodiodes; current-continuity equations; electron impact ionization rates; gain-bandwidth product; hole impact ionization rates; opposite ionization rate ratio; p/sup +/-InP field buffer layer; reduced ionization; separate absorption and multiplication structure; thick p/sup +/-InP field buffer layer; Absorption; Avalanche photodiodes; Buffer layers; Charge carrier processes; Dark current; Equations; Impact ionization; Optical receivers; Superlattices; Tunneling;
Journal_Title :
Photonics Technology Letters, IEEE
