Passivation of InSb infrared photodetectors
Author(s)
Advisor
Aydınlı, AtillaDate
2010Publisher
Bilkent University
Language
English
Type
ThesisItem Usage Stats
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Abstract
Infrared detectors have wide range applications in both military and civilian life.
One of the most commonly used infrared detectors is InSb detectors. InSb detector
technology has been developing since 1950s. Fabricating p-n diodes to
detect infrared radiation is a common way of constructing InSb detectors. Due
to high free carrier concentration at room temperature, InSb detectors need to
be cooled down to operate properly and usually liquid nitrogen is preferred for
cooling. However, even at 77 K, tunneling and generation-recombination and
surface leakage are not negligible and these effects result in dark current. Improving
the photo current-to-dark current ratio is the main goal in design and
fabrication of InSb photo detectors. One way of decreasing the dark current is
passivating the exposed edges of the detector to reduce surface leakage current.
Passivating the edges can result in decreasing in the surface leakage by eliminating
the surface states (dangling bonds). Dielectric thin films like SiO2 and SiNx
are commonly used for passivation. In this work, different sized detectors are
fabricated and characterized by measuring I-V curves and spectral response. Different
approaches are tested for passivation and a detailed comparison between
detectors with different treatments is presented.