Performance of microbolometer focal plane arrays under varying pressure

Author

He, X. ; Karunasiri, G. ; Mei, T. ; Zeng, W.J. ; Neuzil, P. ; Sridhar, U.

Author_Institution

Dept. of Electr. Eng., Nat. Univ. of Singapore, Singapore

Volume

21

Issue

5

fYear

2000

fDate

5/1/2000 12:00:00 AM

Firstpage

233

Lastpage

235

Abstract

In this letter, we present a study of imaging using a 128/spl times/128-pixel microbolometer focal plane array (FPA) under varying pressure conditions from 10/sup -5/ torr to the ambient. We have employed bulk micromachining in the fabrication of FPA to reduce the thermal conduction through the air-gap between the membrane and the substrate of the microbolometers. It was found that an image of a soldering iron (200/spl deg/C) was clearly visible even at the ambient pressure. However, at ambient pressure, the increased in thermal conductance resulted in a reduction of contrast of the image compared to the ones obtained at low pressure. The results suggest the possibility of operation of uncooled FPA´s under ambient pressure by proper design of the microbolometer structure.

Keywords

bolometers; focal planes; heat conduction; micromachining; microsensors; 128 pixel; 16384 pixel; 1E-5 to 760 torr; 200 C; bulk micromachining; image contrast; membrane substrate air gap; microbolometer focal plane arrays; microbolometer structure design; soldering iron image; thermal conductance; thermal conduction reduction; uncooled FPA; varying pressure conditions; Air gaps; Biomembranes; Bolometers; Circuits; Fabrication; Micromachining; Resistors; Switches; Thermal conductivity;

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/55.841306

Filename

841306