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Weiss E.,SCD Semi Conductor Devices | Klin O.,SCD Semi Conductor Devices | Grossmann S.,SCD Semi Conductor Devices | Snapi N.,SCD Semi Conductor Devices | And 8 more authors.
Journal of Crystal Growth | Year: 2012

XB nn mid-wave infrared (MWIR) detector arrays aimed at high operating temperature (HOT) applications, also known as barrier detectors or bariodes, are based on device elements with an InAsSb/AlSbAs heterostructure. There is no depletion layer in the narrow bandgap active layer of such devices, suppressing the usual Generation-Recombination (G-R) and Trap Assisted Tunneling (TAT) mechanisms for dark current that exist in standard narrow bandgap diodes. This yields lower dark currents in bariodes than in diodes with the same bandgap wavelength. InAsSb-bariode detectors, grown on lattice matched GaSb substrates have been shown previously to exhibit low dark current densities of ∼10 -7 A/cm 2 at 150 K. In this communication we show crystallographic and electro-optical characteristics of bariode structures grown on GaAs. Although the 7.8% mismatch causes a high density of dislocations, the devices still demonstrate electr-optical performance comparable with equivalent structures grown on GaSb, both for test devices and for focal plane array detectors (FPAs) with a 640×512 pixel format and a 15 μm pitch. This is in contrast to the behavior reported for InAsSb pin photodiodes grown on lattice mismatched substrates. The large leakage currents seen in the latter and attributed to a TAT mechanism, do not occur in the InAsSb-based bariodes grown on GaAs. © 2011 Elsevier B.V. All rights reserved.

Klin O.,SCD Semi Conductor Devices | Snapi N.,SCD Semi Conductor Devices | Cohen Y.,SCD Semi Conductor Devices | Weiss E.,SCD Semi Conductor Devices
Journal of Crystal Growth | Year: 2015

The performance of focal plane arrays type-II InAs/GaSb superlattices (T2SL) based photo-detectors is limited by their operability (percentage of working pixels). Using preferential chemical etching we formed pits around "killer" defects found in InAs/GaSb T2SL epi-layers grown by MBE on GaSb (100). These pits were then studied with various microscopically methods, including optical, high resolution scanning electron (HRSEM), high resolution transmission electron (HRTEM), and cross-section scanning tunneling (XSTM) microscopies. We have found that these "killer" defects are related to both growth conditions and substrate imperfections. Adjusting these parameters allowed us to reduce "killer" defects density by several orders of magnitude. HRTEM inspection of the defects shows that at high growth temperatures they originate close to the T2SL-GaSb interface, and develop in size during only few SL loops to a straight and narrow "column" through the whole structure. At low growth temperatures most of them are nucleated on stacking fault defects formed on irregularities in the substrate surface. © 2015 Elsevier B.V. All rights reserved.

Lyadov Y.,Technion - Israel Institute of Technology | Akhvlediani R.,Technion - Israel Institute of Technology | Hoffman A.,Technion - Israel Institute of Technology | Klin O.,SCD Semi Conductor Devices | Weiss E.,SCD Semi Conductor Devices
Journal of Applied Physics | Year: 2010

Native oxides and carbonaceous contamination removal from InAs(100) surfaces by thermal annealing at reduced temperatures under molecular hydrogen flow is reported and compared to vacuum annealing at similar temperatures. The thermal annealing experiments were carried out in the 250-360 °C range and at constant hydrogen pressure of 5× 10-6 torr. The complete reduction of native oxides and carbon contamination was achieved at temperatures as low as 300 and 340 °C, respectively, under molecular hydrogen flux. Chemical and compositional monitoring of the surface was performed by x-ray photoelectron spectroscopy and x-ray induced Auger spectroscopy. The surface morphology, before and after annealing, was imaged by atomic force microscope at tapping noncontact mode. © 2010 American Institute of Physics.

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