Time response modelling in submicron avalanche photodiodes

Author

Hambleton, P.J. ; Plimmer, S.A. ; David, J.P.R. ; Rees, G.J.

Author_Institution

Dept. of Electron. & Electr. Eng., Univ. of Sheffield, UK

Volume

150

Issue

2

fYear

2003

fDate

4/18/2003 12:00:00 AM

Firstpage

167

Lastpage

170

Abstract

Conventional models of the time-dependent current response to an impulse of injected carriers in an avalanche photodiode assume that carriers travel always at their saturated drift velocities. A Monte Carlo model is used to show that, while this assumption is reasonable for a 1.0 μm avalanche region in GaAs, it significantly underestimates the avalanche speed in a submicron device at high electric fields. The disparity is identified as due to an enhancement in the velocities of carriers to ionisation, defined as the path length to ionisation divided by the time to traverse it. Using the mean values of these velocities in the conventional model produces good agreement with the Monte Carlo results. Comparison with a local ionisation model also suggests that thin APDs will operate more quickly than expected.

Keywords

Monte Carlo methods; avalanche photodiodes; carrier mobility; semiconductor device models; 1.0 micron; Monte Carlo model; Monte Carlo results; avalanche photodiode; avalanche region; avalanche speed; high electric fields; injected carriers; ionisation; local ionisation model; path length; saturated drift velocities; submicron avalanche photodiodes; submicron device; time response modelling; time-dependent current response;

fLanguage

English

Journal_Title

Optoelectronics, IEE Proceedings -

Publisher

iet

ISSN

1350-2433

Type

jour

DOI

10.1049/ip-opt:20030328

Filename

1203107