GaAs resistor structures for X-ray imaging detectors

Ayzenshtat, G. I.; Budnitsky, D.L.; Koretskaya, O. B.; Novikov, V. A.; Okaevich, L.S.; Потапов, А. И.; Толбанов, О. П.; Tyazhev, A.; Vorobiev, A.P.

doi:10.1016/s0168-9002(02)00951-8

Cited by 36 publications

(19 citation statements)

References 3 publications

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“…Therefore, a sensor bias of was chosen for all other measurements. Although absolute values of the CCE could not be determined here, CCE values of 90% and higher for X-and gamma rays were reported previously [28], [29]. Pulse pile-up, which is another important issue limiting the performance of small pixel detectors at high fluxes, is not addressed in this work, since this concerns features in the readout electronics independently of the sensor material used.…”

Section: A Detector Characterizationmentioning

confidence: 91%

“…This technique previously demonstrated to provide sensors with resistivities in the order of cm [23], [28], [29] via high compensation rates. Due to the high dopant concentration, the width of the space charge regions (SCR) behind the metal (Schottky) contacts are small, leading to the bias voltage dropping mainly across the sensor and thus to a uniform distribution of the electric field [21], [24], [30].…”

Section: Detector Fabrication and Chip Descriptionmentioning

confidence: 99%

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Performance of a Medipix3RX Spectroscopic Pixel Detector With a High Resistivity Gallium Arsenide Sensor

Hamann

Koenig

Zubér

et al. 2015

IEEE Trans. Med. Imaging

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High resistivity gallium arsenide is considered a suitable sensor material for spectroscopic X-ray imaging detectors. These sensors typically have thicknesses between a few hundred μm and 1 mm to ensure a high photon detection efficiency. However, for small pixel sizes down to several tens of μm, an effect called charge sharing reduces a detector's spectroscopic performance. The recently developed Medipix3RX readout chip overcomes this limitation by implementing a charge summing circuit, which allows the reconstruction of the full energy information of a photon interaction in a single pixel. In this work, we present the characterization of the first Medipix3RX detector assembly with a 500 μm thick high resistivity, chromium compensated gallium arsenide sensor. We analyze its properties and demonstrate the functionality of the charge summing mode by means of energy response functions recorded at a synchrotron. Furthermore, the imaging properties of the detector, in terms of its modulation transfer functions and signal-to-noise ratios, are investigated. After more than one decade of attempts to establish gallium arsenide as a sensor material for photon counting detectors, our results represent a breakthrough in obtaining detector-grade material. The sensor we introduce is therefore suitable for high resolution X-ray imaging applications.

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Section: A Detector Characterizationmentioning

confidence: 91%

Section: Detector Fabrication and Chip Descriptionmentioning

confidence: 99%

Performance of a Medipix3RX Spectroscopic Pixel Detector With a High Resistivity Gallium Arsenide Sensor

Hamann

Koenig

Zubér

et al. 2015

IEEE Trans. Med. Imaging

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“…Thin plates (0.3-1.0 mm) of silicon (Si) or gallium arsenide compensated with chromium (GaAs) with 256×256 square pixels are used as a sensor. GaAs sensors are developed and produced in the Tomsk State University (Tomsk, Russia) [4,5,6,7]. The Joint Institute for Nuclear Research (Dubna, Russia) has wide experience in the production and operation of such kind of the detectors since 2008 [2,3].…”

Section: Timepix Detectorsmentioning

confidence: 99%

On the possibility to use semiconductive hybrid pixel detectors for study of radiation belt of the Earth.

Guskov

Shelkov

Smolyanskiy

et al. 2016

J. Phys.: Conf. Ser.

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The scientific apparatus "Gamma-400" designed for study of hadron and electromagnetic components of cosmic rays will be launched to an elliptic orbit with the apogee of about 300 000 km and the perigee of about 500 km. Such a configuration of the orbit allows it to cross periodically the radiation belt and the outer part of magnetosphere. We discuss the possibility to use hybrid pixel detecters based on the Timepix chip and semiconductive sensors on board the "Gamma-400" apparatus. Due to high granularity of the sensor (pixel size is 55 mum) and possibility to measure independently an energy deposition in each pixel, such compact and lightweight detector could be a unique instrument for study of spatial, energy and time structure of electron and proton components of the radiation belt.

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“…Nevertheless, some other workers argue that GaAs doped heavily with Cr is suitable for the purpose because Cr doping compensation will free the material from the adverse effects of EL2 centers while providing a uniform field distribution over the substrate thickness with any type of metal contacts [27,28]. In those studies, µ = 4000 cm 2 V -1 s -1 and ρ = 10 8 to 10 9 Ω cm were obtained by high-temperature diffusion Cr doping of ntype wafers of LEC-grown GaAs.…”

Section: Selection Of a Sensing Materialsmentioning

confidence: 99%

GaAs Pixel-Detector Technology for X-ray Medical Imaging: A Review

2005

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An attempt is made to analyze and summarize the literature data on hybrid x-ray GaAs pixel detectors designed for medical imaging. Criteria are stated for selecting a semiconductor material. It is shown that GaAs is currently preferable to the other semiconductor materials. Detector figures of merit used to select a semiconductor material and a process technology are listed. Major types of x-ray detector based on bulk-grown or epitaxial GaAs are described, namely, the planar Schottky, the planar p-i-n, and the 3D detector. The influence is considered of different process steps (contact formation, passivation coating, hybridization, etc.) on detector figures of merit. Monolithic technology is briefly discussed.

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GaAs resistor structures for X-ray imaging detectors

Cited by 36 publications

References 3 publications

Performance of a Medipix3RX Spectroscopic Pixel Detector With a High Resistivity Gallium Arsenide Sensor

Performance of a Medipix3RX Spectroscopic Pixel Detector With a High Resistivity Gallium Arsenide Sensor

On the possibility to use semiconductive hybrid pixel detectors for study of radiation belt of the Earth.

GaAs Pixel-Detector Technology for X-ray Medical Imaging: A Review

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