Thickness Dependences of Resistivity and Temperature Coefficient of Resistance for Ge Thin Films Sandwiched between Si Layers for Uncooled Infrared Imaging Sensor

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Published 16 November 2011 Copyright (c) 2011 The Japan Society of Applied Physics
, , Citation Kazuhiro Yamaki et al 2011 Jpn. J. Appl. Phys. 50 125801 DOI 10.1143/JJAP.50.125801

1347-4065/50/12R/125801

Abstract

An RF magnetron sputtering technique was used to deposit Ge and stacked Si/Ge films for infrared imaging sensors; the electrical characteristics of these films were estimated. The cross-sectional scanning electron microscope (SEM) image obtained confirmed that a layered Si/Ge structure was deposited on the SiO2 substrate. The layered film, annealed in an Ar atmosphere, exhibited a large temperature coefficient of resistance (TCR) (-3.63%/K) and a low resistivity (64.5 Ω·cm). The conductivity and TCR of Si/Ge films depend on the thickness of the Ge layer. A significant improvement in TCR was achieved by decreasing the thickness of the Ge layer. Ge thin films sandwiched between amorphous silicon layers facilitate the realization of a noncooled bolometer.

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