Fabrication and characterization of avalanche photodetectors

Avalanche photodetectors are important for imaging applications because of their high sensitivity and low noise levels. For imaging applications, however, a two-dimensional array of APDs is required, and there are many fabrication issues involved in making such an array over a large area. In this work, fab- rication and characterization of 32 × 32 arrays of InP (indium phosphide) based separated absorption, charge, and multiplication avalanche photode- tectors (SACM APDs) is pursued to address the fabrication issues associated with making a high density array of APDs over a large area. Dark current and photocurrent uniformity of the array are characterized. Leakage current is also analyzed in terms of dark current and cross-talk by examining APDs with different mesa diameters and different separations, respectively. For these results, we find that the dark current of SACM APD devices mainly comes from the junction leakage. Thus, to reduce the dark current we need to improve the design of the epitaxial layers. This work also examines the dependence of cross-talk and the array packing density. A trade-off relation- ship is observed between the packing density of the devices and the leakage current.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Electrical & Computer Engr

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2011

Author dc:creator

• Jeong, Hyejin

Contributors dc:contributor

• Choquette, Kent D.

• avalanche photodetector (APD)
• separated absorption, charge, and multiplication avalanche photodetectors (SACM APDs)
• dark current
• cross-talk

Statement dc:rights

• Copyright Hyejin Jeong 2010

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/18282

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/18282