High-absorption wide-band pixel for bolometer arrays

Abstract

A microbolometer array has pixels with a thin platform of silicon dioxide having a metal absorber layer, and having a resonant gap with a substrate reflector. The pixel resistor of vanadium oxide has low total resistance with metal contacts on opposite edges.

Description

technical field [0001] The present invention relates to thermal imaging, and more particularly to improved pixels or cells for bolometer arrays. Background technique [0002] Night vision and related applications are achieved by receiving infrared radiation emitted by a thermal body by a detector array whose electrical output signals are converted into a visual image. Individual detectors called cells, elements or pixels must be very small. Also they should be sensitive to a very broad infrared spectrum, have minimal noise at ambient temperature, operate with high sensitivity and be cheap to manufacture. [0003] Arrays of uncooled bolometers on semiconductor substrates offer a promising method for room temperature infrared imaging. Such arrays have disadvantages in several different ways. Wide bandwidths are difficult to achieve, and the array is sensitive to a large number of interacting factors in the structure and materials in each individual pixel. When the array is...

AI Technical Summary

Problems solved by technology

Wide bandwidths are difficult to achieve, and the array is sensitive to a large number of interacting factors in the structure and materials in each individual pixel

When the array is not cooled to cryogenic temperatures, noise can overwhelm the useful signal

Good sensitivity to small temperature differences requires high absorption of incident radiation, which is often detrimental to other design metrics

While nanofabrication techniques have been used to fabricate bolometer arrays, achieving operational specifications can result in high manufacturing costs and low yields, especially for arrays with a large number of individual imaging elements or pixels

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