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Proceedings Paper

Amorphous silicon thin-films for uncooled infrared microbolometer sensors
Author(s): Sameer K. Ajmera; A. J. Syllaios; Greg S. Tyber; Michael F. Taylor; Russell E. Hollingsworth
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Paper Abstract

An important application of thin-film hydrogenated amorphous silicon (α-Si:H) is infrared detection and imaging with microbolometer focal plane arrays. Key α-Si:H electrical transport properties that influence detector design and performance are resistivity and temperature coefficient of resistance (TCR). These properties have been measured over a wide temperature range for p- and n-type doped α-Si:H thin-films deposited by plasma enhanced chemical vapor deposition using silane as a precursor gas. Resistivity near and above room temperature follows an Arrhenius thermally activated dependence. At low temperatures, resistivity transitions from Arrhenius behavior to a variable range hopping mechanism described by the Mott relation and TCR changes at a slower rate than predicted by thermally activated transport alone. Resistivity and TCR are affected by doping and film growth parameters such as dilution of the silane precursor with hydrogen. Resistivity decreases with dopant concentration for both p-type and n-type dopants. Resistivity and TCR increase with hydrogen dilution of silane. TCR and resistivity are interrelated and optimization of thin-film preparation and processing is necessary to obtain high TCR with resistivity values compatible with readout integrated circuit designs. Such optimization of transport properties of α-Si:H films has been applied to the development of high performance ambient operating temperature (uncooled) microbolometer arrays.

Paper Details

Date Published: 3 May 2010
PDF: 8 pages
Proc. SPIE 7660, Infrared Technology and Applications XXXVI, 766012 (3 May 2010); doi: 10.1117/12.850545
Show Author Affiliations
Sameer K. Ajmera, L-3 Communications Electro-Optical Systems (United States)
A. J. Syllaios, L-3 Communications Electro-Optical Systems (United States)
Greg S. Tyber, L-3 Communications Electro-Optical Systems (United States)
Michael F. Taylor, L-3 Communications Electro-Optical Systems (United States)
Russell E. Hollingsworth, ITN Energy Systems (United States)

Published in SPIE Proceedings Vol. 7660:
Infrared Technology and Applications XXXVI
Bjørn F. Andresen; Gabor F. Fulop; Paul R. Norton, Editor(s)

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