Uncooled infrared bolometer arrays operating in a low to medium vacuum atmosphere: performance model and tradeoffs

Niklaus, Frank; Jansson, Christer; Decharat, Adit; Källhammer, Jan-Erik; Pettersson, Håkan; Stemme, G.

doi:10.1117/12.719163

Cited by 38 publications

(30 citation statements)

References 18 publications

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“…The performance in terms of noise equivalent temperature difference (NETD) is inversely proportional to the area of each pixel [3][4][5]. As the pixel pitch is reduced, it thus becomes increasingly important to optimize each aspect of the bolometer design to retain as much of the performance as possible.…”

Section: Introductionmentioning

confidence: 99%

Toward 17Âµm pitch heterogeneously integrated Si/SiGe quantum well bolometer focal plane arrays

Ericsson¹,

Fischer

Forsberg

et al. 2011

SPIE Proceedings

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Most of today's commercial solutions for un-cooled IR imaging sensors are based on resistive bolometers using either Vanadium oxide (VOx) or amorphous Silicon (a-Si) as the thermistor material. Despite the long history for both concepts, market penetration outside high-end applications is still limited. By allowing actors in adjacent fields, such as those from the MEMS industry, to enter the market, this situation could change. This requires, however, that technologies fitting their tools and processes are developed. Heterogeneous integration of Si/SiGe quantum well bolometers on standard CMOS read out circuits is one approach that could easily be adopted by the MEMS industry. Due to its mono crystalline nature, the Si/SiGe thermistor material has excellent noise properties that result in a state-ofthe-art signal-to-noise ratio. The material is also stable at temperatures well above 450°C which offers great flexibility for both sensor integration and novel vacuum packaging concepts. We have previously reported on heterogeneous integration of Si/SiGe quantum well bolometers with pitches of 40µm x 40µm and 25µm x 25µm. The technology scales well to smaller pixel pitches and in this paper, we will report on our work on developing heterogeneous integration for Si/SiGe QW bolometers with a pixel pitch of 17µm x 17µm.

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Section: Introductionmentioning

confidence: 99%

Toward 17Âµm pitch heterogeneously integrated Si/SiGe quantum well bolometer focal plane arrays

Ericsson¹,

Fischer

Forsberg

et al. 2011

SPIE Proceedings

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“…비냉각 적외선 검출기 기술은 마이크로 볼로미터 기술을 중심으로 발달하여 그 활용범위를 넓혀가고 있으며, 최근의 연구 방향은 고속, 고밀도, 소형, 저 전력 소모, 저가화의 방 향으로 진행되고 있다 [1][2][3][4][5][6] . 소형 저전력의 연구방향은 이동형 시스템을 위한 연구방향으로 소형이란 측면에서는 광학계와 함께 고려되어 렌즈의 구경을 줄이기 위한 감도향상이 요구 되며 전력 소모를 최소화 하기 위하여 열전냉각기 (thermoelectric cooler, TEC)를 사용하지 않고 동작시키는 등의 배터리로 구동되는 시스템이 연구되고 있다 [4][5][6] .…”

Section: 서 론unclassified

Analyses of temperature change of a u-bolometer in Focal Plane Array with CTIA bias cancellation circuit

Park

2011

The Transactions of The Korean Institute of Electrical Engineer

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-In this paper, we study the temperature change of a μ-bolometer focal plane array with a capacitive transimpedance amplifier bias cancellation circuit. Thermal analysis is essential to understand the performance of a μ -bolometer focal plane array, and to improve the temperature stability of a focal plane array characteristics. In this study, the thermal analyses of a μ-bolometer and its two reference detectors are carried out as a function of time. The analyses are done with the 30㎛ pitch 320x240 focal plane array operating of 60 Hz frame rate and having a columnwise readout. From the results, the temperature increase of a μ-bolometer in FPA by an incident IR is estimated as 0.689 ℃, while the temperature increase by a pulsed bias as 7.1 ℃, which is about 10 times larger than by IR. The temperature increase of a reference detector by a train of bias pulses may be increased much higher than that of an active μ -bolometer. The suppression of temperature increase in a reference bolometer can be done by increasing the thermal conductivity of the reference bolometer, in which the selection of thermal conductivity also determines the range of CTIA output voltage.

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“…As briefly mentioned earlier, G ef f consists of a number of components [17], one of which is a thermal conductance component attributed to heat loss between the suspended membrane and the substrate via the support beams, referred to as the beam or leg thermal conductance, G leg and is given by [13,23] It has also recently been proposed to include the constriction resistance that results when two thermal conducting paths of different widths are connected, which leads to a constriction effect experienced by the heat flow. This results in an additional radial thermal resistive component [13,24,25].…”

Section: Operating Principles Of Microbolometersmentioning

confidence: 99%

“…Another component that results in heat flow and contributes to G ef f is the atmospheric or gaseous thermal conductance, G atm , given as [23] …”

Section: Operating Principles Of Microbolometersmentioning

confidence: 99%

An analytic model employing an elliptical surface area to determine the gaseous thermal conductance of uncooled VOx microbolometers

Schoeman

Plessis

2016

Sensors and Actuators A: Physical

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This work presents a detailed overview of the analytic methods for calculating the beam and gaseous thermal conductance components associated with uncooled VO x microbolometers. The conventional method to calculate the gaseous component relies on the assumption that the entire plate is maintained at a uniform temperature, thus the surface area of the plate is used for the calculation. We have observed using an industry leading multiphysics simulator that this assumption is not strictly true for VO x microbolometers as the conduction pattern exhibits an elliptical shape. Based on this, we have developed and propose an analytic method that employs an elliptical surface area scaled appropriately with the device dimensions to obtain an estimate of the average temperature conduction pattern. Prototype devices were manufactured and experimentally characterised. The devices exhibit thermal conduction characteristics comparable to those in literature and industry, and we could achieve 0.5 µW/K under vacuum conditions and 15 µW/K at atmospheric pressure with a TCR of −1 %/K. However, both simulated and experimental result sets of the gaseous thermal conductance exhibit large deviations from the conventional analytic method, on average approximately 40 %. The proposed method reduces this average error significantly to less than 10 % when compared to the simulated results.

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Uncooled infrared bolometer arrays operating in a low to medium vacuum atmosphere: performance model and tradeoffs

Cited by 38 publications

References 18 publications

Toward 17Âµm pitch heterogeneously integrated Si/SiGe quantum well bolometer focal plane arrays

Toward 17Âµm pitch heterogeneously integrated Si/SiGe quantum well bolometer focal plane arrays

Analyses of temperature change of a u-bolometer in Focal Plane Array with CTIA bias cancellation circuit

An analytic model employing an elliptical surface area to determine the gaseous thermal conductance of uncooled VOx microbolometers

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