Proceedings Article | 21 January 2012
Philip Klipstein, Olga Klin, Steven Grossman, Noam Snapi, Inna Lukomsky, Michael Yassen, Daniel Aronov, Eyal Berkowitz, Alex Glozman, Osnat Magen, Itay Shtrichman, Rami Frenkel, Eliezer Weiss
KEYWORDS: Sensors, Gallium antimonide, Diffusion, Staring arrays, Gallium arsenide, Solids, Readout integrated circuits, Quantum efficiency, Diodes, Single crystal X-ray diffraction
A bariode is a new type of "diode-like" semiconductor photonic device, in which the transport of majority carriers is
blocked by a barrier in the depletion layer, while minority carriers, created thermally or by the absorption of light, are
allowed to pass freely across the device. In an n-type bariode, also known as an XBnn structure, both the active photon
absorbing layer and the barrier layer are doped with electron donors, while in a p-type bariode, or XBpp structure, they
are both doped with electron acceptors. An important advantage of bariode devices is that their dark current is
essentially diffusion limited, so that high detector operating temperatures can be achieved. In this paper we report on
MWIR n-type bariode detectors with an InAsSb active layer and an AlSbAs barrier layer, grown on either GaSb or
GaAs substrates. For both substrate types, the bariodes exhibit a bandgap wavelength of ~ 4.1 μm and operate with
Background Limited Performance (BLIP) up to at least 160K at F/3. Different members of the XBnn device family are
investigated, in which the contact layer material, "X", is changed between n-InAsSb and p-GaSb. In all cases, the
electro-optical properties of the devices are similar, showing clearly the generic nature of the bariode device
architecture. Focal Plane Array detectors have been made with a pitch of 15 or 30μm. We present radiometric
performance data and images from our Blue Fairy (320×256) and Pelican (640×512) detectors, operating at
temperatures up to 180K. We demonstrate for both GaSb and GaAs substrates that detector performance can be
achieved which is close to "Rule 07", the benchmark for high quality, diffusion limited, Mercury Cadmium Telluride
(MCT) devices.
