1. |
- Bertuccio, Giuseppe, et al.
(author)
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Ultra Low Noise Epitaxial 4H-SiC X-Ray Detectors
- 2009
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In: Materials Science Forum. - : Trans Tech Publications Inc.. - 0255-5476 .- 1662-9752. ; 615-617, s. 845-848
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Journal article (peer-reviewed)abstract
- The design and the experimental results of some prototypes of SiC X-ray detectors are presented. The devices have been manufactured on top of 2 inch 4H-SiC wafer with 115 μm thick undoped high purity epitaxial layer, which constitutes the detection’s active volume. Pad and pixel detectors based on Ni-Schottky junctions have been tested. The residual doping of the epi-layer was found tobe extremely low, 3.7 x 1013 cm-3, allowing to achieve the highest detection efficiency and the lower specific capacitance of the detectors. At 22 °C and in operating bias condition, the reverse current densities of the detector’s Schottky junctions have been measured to be between J = 0.3 pA/cm2 and J = 4 pA/cm2; these values are more than two orders of magnitude lower than those of state of the art silicon detectors. With such low leakage currents, the equivalent electronic noise of SiC pixel detectors is as low as 0.5 electrons r.m.s at room temperature, which represents a new state of the art in the scenario of semiconductor radiation detectors.
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2. |
- Puglisi, Donatella, et al.
(author)
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Diffusion Length in n-doped 4H Silicon Carbide Crystals Detected by Alpha Particle Probe
- 2009
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In: Materials Science Forum. - : Trans Tech Publications Inc.. - 0255-5476 .- 1662-9752. ; 615-617, s. 857-860
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Journal article (peer-reviewed)abstract
- The achievement of nuclear detectors in silicon carbide imposes severe constraints onthe electronic quality and thickness of the material due to the relatively high value of the energyrequired to generate an electron-hole pair (7.8 eV) in this material compared to the value for Si (3.6 eV). In this work, 4H-SiC charged particle detectors were realised using epitaxial layers ofn-type doping as active region. The thickness of the epilayer is always below 80 μm with a netdoping concentration in the range of 8 x 1013 to 1016 cm-3. These properties allowed the fabricationof Schottky diodes that operate well as radiation detectors. At low doping concentration, theepilayer is totally depleted at quite low reverse bias (≈ 50 V), thereby obtaining the maximumactive volume.
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3. |
- Torrisi, Lorenzo, et al.
(author)
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Single crystal silicon carbide detector of emitted ions and soft x rays from power laser-generated plasmas
- 2009
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In: Journal of Applied Physics. - : American Institute of Physics (AIP). - 0021-8979 .- 1089-7550. ; 105, s. 123304-1-123304-7
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Journal article (peer-reviewed)abstract
- A single-crystal silicon carbide SiC detector was used for measurements of soft x rays, electrons, and ion emission from laser-generated plasma obtained with the use of the Prague Asterix Laser System PALS at intensities of the order of 1016 W/cm2 and pulse duration of 300 ps. Measurements were performed by varying the laser intensity and the nature of the irradiated target. The spectra obtained by using the SiC detector show not only the photopeak due to UV and softx-ray detection, but also various peaks due to the detection of energetic charged particles. Time-of-flight technique was employed to determine the ion kinetic energy of particles emitted from the plasma and to perform a comparison between SiC and traditional ion collectors. The detector was also employed by inserting absorber films of different thickness in front of the SiC surface inorder to determine, as a first approximation, the mean energy of the soft x-ray emission from the plasma.
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