Reduction of Dark Current and Unintentional Background Doping in InGaAsN Photodetectors by Ex Situ Annealing

Tan, S.L., Tan, L.J.J., Goh, Y.L., Zhang, S., Ng, J.S., David, J.P.R., Marko, I.P., Allam, J., Sweeney, S.J. and Adams, A.R. (2010) Reduction of Dark Current and Unintentional Background Doping in InGaAsN Photodetectors by Ex Situ Annealing. In: SPIE Optical Sensing and Detection 2010, Brussels, Belgium, 12-15 Apr 2010, ISBN 9780819481993 (doi: 10.1117/12.853912)

Abstract

InGaAsN is a promising material system to enable low-cost GaAs-based detectors to operate in the telecommunication spectrum, despite the problems posed by the low growth temperature required for nitrogen incorporation. We demonstrate that InGaAsN p+-i-n+ structures with nominal In and N fraction of 10% and 3.8%, grown by molecular beam epitaxy (MBE) under non-optimal growth conditions, can be optimized by post growth thermal annealing to match the performance of optimally grown structures. We report the findings of an annealing study by comparing the photoluminescence spectra, dark current and background concentration of the as-grown and annealed samples. The dark current of the optimally annealed sample is approximately 2 μA/cm2 at an electric field of 100 kV/cm, and is the lowest reported to date for InGaAsN photodetectors with a cut-off wavelength of 1.3 μm. Evidence of lower unintentional background concentration after annealing at a sufficiently high temperature, is also presented.

• Item Type: Conference Proceedings
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Marko, Dr Igor and Sweeney, Professor Stephen
• Authors: Tan, S.L., Tan, L.J.J., Goh, Y.L., Zhang, S., Ng, J.S., David, J.P.R., Marko, I.P., Allam, J., Sweeney, S.J., and Adams, A.R.
• College/School: College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
• Journal Name: Proceedings of SPIE - The International Society for Optical Engineering
• ISSN: 0277-786X
• ISBN: 9780819481993

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