Passivation of type II InAs / GaSb superlattice photodetectors with atomic layer deposited Al2O3

Date
2012
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Source Title
Proceedings of SPIE
Print ISSN
0277-786X
Electronic ISSN
Publisher
SPIE
Volume
8353
Issue
Pages
83530Z-1 - 83530Z-7
Language
English
Type
Conference Paper
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Abstract

We have achieved significant improvement in the electrical performance of the InAs/GaSb midwave infrared photodetector (MWIR) by using atomic layer deposited (ALD) aluminium oxide (Al2O3) as a passivation layer. Plasma free and low operation temperature with uniform coating of ALD technique leads to a conformal and defect free coverage on the side walls. This conformal coverage of rough surfaces also satisfies dangling bonds more efficiently while eliminating metal oxides in a self cleaning process of the Al2O3 layer. Al2O3 passivated and unpassivated diodes were compared for their electrical and optical performances. For passivated diodes the dark current density was improved by an order of magnitude at 77 K. The zero bias responsivity and detectivity was 1.33 A/W and 1.9 x 1013 Jones, respectively at 4 µm and 77 K. Quantum efficiency (QE) was determined as %41 for these detectors.

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Keywords
Superlattice, Photodetector, InAs/GaSb, Al2O3, ALD, Passivation
Citation
Published Version (Please cite this version)