Noise in micro-bolometers with silicon-germanium thermo-sensing layer

Kosarev, A.; Moreno, Mario; Torres, Alfonso; Rumyantsev, Sergey; Cosme, Ismael

doi:10.1016/j.tsf.2009.09.122

Cited by 7 publications

(3 citation statements)

References 5 publications

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“…In this work, films of horizontally aligned single-walled carbon nanotubes (SWNTs) were thermally and electrically characterized in order to assess their performance as bolometric materials. In the frequency range from 1 to 40 kHz the noise spectra had a 1/f β behavior with a β value varying from β ≈ 0.659 to β ≈ 0.663 depending on the bias voltage, this indicates a semiconductor-like noise behavior similar to the one reported for a-Si:H semiconductor films …”

Section: Discussionsupporting

confidence: 63%

High-Sensitivity Bolometers from Self-Oriented Single-Walled Carbon Nanotube Composites

Vera-Reveles

Simmons

Bravo-Sánchez

et al. 2011

ACS Appl. Mater. Interfaces

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In this work, films of horizontally aligned single-walled carbon nanotubes were thermally and electrically characterized in order to determine the bolometric performance. An average thermal time constant of τ = 420 μs along with a temperature coefficient of resistance of TCR = -2.94% K(-1) were obtained. The maximum voltage responsivity and detectivity obtained were R(V) =230 V/W and D* = 1.22 × 10(8) cm Hz(1/2)/W, respectively. These values are higher than the maximum voltage responsivity (150 V/W) and maximum temperature coefficient of resistance (1.0% K(-1)) previously reported for carbon nanotube films at room temperature. The maximum detectivity was obtained at a frequency of operation of 1.25 kHz.

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Section: Discussionsupporting

confidence: 63%

High-Sensitivity Bolometers from Self-Oriented Single-Walled Carbon Nanotube Composites

Vera-Reveles

Simmons

Bravo-Sánchez

et al. 2011

ACS Appl. Mater. Interfaces

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“…The noise of the system and the total noise (system + microbolometer noise) were measured separately, and a subtraction of both allowed the extraction of the noise of the device; a detailed description of the procedure and setup for noise characterization is described in [13]. Fig.…”

Section: ) Spectral Density Of Noisementioning

confidence: 99%

Microbolometers Based on Amorphous Silicon–Germanium Films With Embedded Nanocrystals

Moreno

Jiménez

Torres

et al. 2015

IEEE Trans. Electron Devices

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In this paper, we have fabricated and characterized uncooled microbolometers using as infrared element intrinsic amorphous silicon-germanium films with embedded nanocrystals with a dimension in the range of ∼2-4 nm. The presence of nanocrystals in the amorphous films reduces the density of defects, improves the transport properties, and specially improves the films stability against radiation. On the other hand, the combination of silicon and germanium in one alloy allows to improve the film conductivity and the temperature coefficient of resistance (TCR), without the necessity of perform doping. Large values of TCR have been demonstrated in the microbolometers, as large as −6.6% K −1 , which in fact is the largest value reported for this kind of devices, and consequently large detectivity values were obtained in the reported devices (2 × 10 9 cmHz 1/2 W −1 ).

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“…Corner frequency can vary from 30 to 350 Hz. Since Hooge [16] there have been no papers reporting on theoretical models and only a few appeared on experimental study of noise in films [15,17] and in microbolometers [18,19].…”

Section: Comparison Of Characteristics Reported For Micro Bolometersmentioning

confidence: 99%

Thin film uncooled microbolometers based on plasma deposited materials

et al. 2014

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We make a summary of our research and development efforts made about microbolometers (MBs) based on plasmaenhanced chemical vapor deposition (PECVD) materials, like noncrystalline semiconductors that provide high temperature coefficient of resistivity values, in conjunction with SiO x and SiN x dielectrics used for thermoisolation, which, together with micromachining, are paving new ways for fabrication of MBs, making them promising for 2D imagers in both infrared and tera-Hertz regions. "bridge" configuration with "planar" and "sandwich" electrodes. This allows placing the read-out circuitry under the bridge, improving use of pixel area. PECVD SiN x films were used as both a support layer and as a coating for improving the response for = 8-12 m. 2D modeling revealed both linear and super linear response to IR intensity. Voltage responsivity R U = (1.2-7) × 10 5 V/W is observed in both "planar" and "sandwich" MBs. The latter shows current responsivity R I = 0.3-14 A/W higher by about three orders of magnitude than the former. A key issue for any detector is the detectivity. Different TSMs show different noise characteristics. Noise in "sandwich" MBs is several orders of magnitude higher than that in "planar" structures. The best parameters observed with TSM Ge-Si:H are: R U = 7.2 × 10 5 V/W, R I = 14 A/W voltage and current detectivities D U * = 8 × 10 9 cm Hz 1/2 W −1 and D I * = 4 × 10 9 cm Hz 1/2 W −1 . Junction structures on top of the "bridge" are also discussed. Finally we describe some reported applications of MBs. PACS Nos.: 07.57.Kp, 52.40.Fd, 61.72.uf. Résumé : Nous présentons un résumé des efforts de RD touchant la fabrication de micro-bolomètres (MB), utilisant des matériaux obtenus par dépôt chimique en phase vapeur assisté par plasma (PECVD), comme des semi-conducteurs non cristallins à haute valeur TCR. Ceci est fait en conjonction avec les diélectriques SiO x et SiN x utilisés pour l'isolation thermique et avec le micro-usinage, pavant le chemin vers la fabrication de MB. Ils deviennent ainsi de très bons candidats comme imageurs 2D dans les régions IR et THz. Nous étudions les matériaux amorphes a-Si:H(B), a-Ge:H, a-GeSi:H et polymorphes p-Ge:H et p-SiGe:H comme senseurs thermiques (TSM) pour MB, dans une configuration de pont avec des électrodes de type plan ou sandwich. Ceci permet de placer le circuit intégré de lecture sous le pont, améliorant la surface d'utilisation des pixels. Nous utilisons des films PECVD de SiN x comme support et comme revêtement pour améliorer la réponse dans le domaine = 8-12 m. Selon la modélisation le système répond à la fois linéairement et supra-linéairement à l'intensité IR. Nous observons une responsivité en voltage R U = (1.2-7) × 10 5 V/W pour MB plan et sandwich. La responsivité en courant du cas sandwich (R I = (0.3-14)A/W) est trois ordres de grandeur plus importante que dans le cas plan. Un facteur important pour tout détecteur est la détectivité. Différents types de TSM montrent des caractéristiques de bruit différentes. Le bruit dans la structure sandwic...

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Noise in micro-bolometers with silicon-germanium thermo-sensing layer

Cited by 7 publications

References 5 publications

High-Sensitivity Bolometers from Self-Oriented Single-Walled Carbon Nanotube Composites

High-Sensitivity Bolometers from Self-Oriented Single-Walled Carbon Nanotube Composites

Microbolometers Based on Amorphous Silicon–Germanium Films With Embedded Nanocrystals

Thin film uncooled microbolometers based on plasma deposited materials

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