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Gated silicon drift detector fabricated from a low-cost silicon wafer.

Matsuura H, Sakurai S, Oda Y, Fukushima S, Ishikawa S, Takeshita A, Hidaka A - Sensors (Basel) (2015)

Bottom Line: The thicknesses of commercial SDDs are up to 0.5 mm, which can detect photons with energies up to 27 keV, whereas we describe GSDDs that can detect photons with energies of up to 35 keV.We simulate the electric potential distributions in GSDDs with Si thicknesses of 0.5 and 1 mm at a single high reverse bias.GSDDs with one gate pattern using any resistivity Si wafer can work well for changing the reverse bias that is inversely proportional to the resistivity of the Si wafer.

View Article: PubMed Central - PubMed

Affiliation: Department of Electrical and Electronic Engineering, Osaka Electro-Communication University, 18-8 Hatsu-cho, Neyagawa, Osaka 572-8530, Japan. matsuura@isc.osakac.ac.jp.

ABSTRACT
Inexpensive high-resolution silicon (Si) X-ray detectors are required for on-site surveys of traces of hazardous elements in food and soil by measuring the energies and counts of X-ray fluorescence photons radially emitted from these elements. Gated silicon drift detectors (GSDDs) are much cheaper to fabricate than commercial silicon drift detectors (SDDs). However, previous GSDDs were fabricated from 10-kΩ·cm Si wafers, which are more expensive than 2-kΩ·cm Si wafers used in commercial SDDs. To fabricate cheaper portable X-ray fluorescence instruments, we investigate GSDDs formed from 2-kΩ·cm Si wafers. The thicknesses of commercial SDDs are up to 0.5 mm, which can detect photons with energies up to 27 keV, whereas we describe GSDDs that can detect photons with energies of up to 35 keV. We simulate the electric potential distributions in GSDDs with Si thicknesses of 0.5 and 1 mm at a single high reverse bias. GSDDs with one gate pattern using any resistivity Si wafer can work well for changing the reverse bias that is inversely proportional to the resistivity of the Si wafer.

No MeSH data available.


Simulated electric potential distribution in the Si substrate inside the p-ring of a 0.5-mm-thick GSDD with Rchip of 3.5 mm and ρSi of 10 kΩ·cm for Gate A. A reverse bias voltage of −60 V was applied to the cathode, p-ring, and seven gates. QF was assumed to be 3 × 1010 cm−2. Equipotential lines are shown at 1 V intervals.
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f2-sensors-15-12022: Simulated electric potential distribution in the Si substrate inside the p-ring of a 0.5-mm-thick GSDD with Rchip of 3.5 mm and ρSi of 10 kΩ·cm for Gate A. A reverse bias voltage of −60 V was applied to the cathode, p-ring, and seven gates. QF was assumed to be 3 × 1010 cm−2. Equipotential lines are shown at 1 V intervals.

Mentions: Figure 2 shows the simulated electric potential distribution in the Si substrate inside the p-ring of the GSDD at VR of −60 V for Gate A. The voltage midway between the p-ring and the cathode was −37 V, and the electric field along the electric potential valley was strong enough to make all the electrons produced by an X-ray photon flow smoothly to the anode. Therefore, the electrons produced within the radius of the inner edge of the p-ring can be directed to the anode, indicating that the effective active area is approximately 18 mm2.


Gated silicon drift detector fabricated from a low-cost silicon wafer.

Matsuura H, Sakurai S, Oda Y, Fukushima S, Ishikawa S, Takeshita A, Hidaka A - Sensors (Basel) (2015)

Simulated electric potential distribution in the Si substrate inside the p-ring of a 0.5-mm-thick GSDD with Rchip of 3.5 mm and ρSi of 10 kΩ·cm for Gate A. A reverse bias voltage of −60 V was applied to the cathode, p-ring, and seven gates. QF was assumed to be 3 × 1010 cm−2. Equipotential lines are shown at 1 V intervals.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4481910&req=5

f2-sensors-15-12022: Simulated electric potential distribution in the Si substrate inside the p-ring of a 0.5-mm-thick GSDD with Rchip of 3.5 mm and ρSi of 10 kΩ·cm for Gate A. A reverse bias voltage of −60 V was applied to the cathode, p-ring, and seven gates. QF was assumed to be 3 × 1010 cm−2. Equipotential lines are shown at 1 V intervals.
Mentions: Figure 2 shows the simulated electric potential distribution in the Si substrate inside the p-ring of the GSDD at VR of −60 V for Gate A. The voltage midway between the p-ring and the cathode was −37 V, and the electric field along the electric potential valley was strong enough to make all the electrons produced by an X-ray photon flow smoothly to the anode. Therefore, the electrons produced within the radius of the inner edge of the p-ring can be directed to the anode, indicating that the effective active area is approximately 18 mm2.

Bottom Line: The thicknesses of commercial SDDs are up to 0.5 mm, which can detect photons with energies up to 27 keV, whereas we describe GSDDs that can detect photons with energies of up to 35 keV.We simulate the electric potential distributions in GSDDs with Si thicknesses of 0.5 and 1 mm at a single high reverse bias.GSDDs with one gate pattern using any resistivity Si wafer can work well for changing the reverse bias that is inversely proportional to the resistivity of the Si wafer.

View Article: PubMed Central - PubMed

Affiliation: Department of Electrical and Electronic Engineering, Osaka Electro-Communication University, 18-8 Hatsu-cho, Neyagawa, Osaka 572-8530, Japan. matsuura@isc.osakac.ac.jp.

ABSTRACT
Inexpensive high-resolution silicon (Si) X-ray detectors are required for on-site surveys of traces of hazardous elements in food and soil by measuring the energies and counts of X-ray fluorescence photons radially emitted from these elements. Gated silicon drift detectors (GSDDs) are much cheaper to fabricate than commercial silicon drift detectors (SDDs). However, previous GSDDs were fabricated from 10-kΩ·cm Si wafers, which are more expensive than 2-kΩ·cm Si wafers used in commercial SDDs. To fabricate cheaper portable X-ray fluorescence instruments, we investigate GSDDs formed from 2-kΩ·cm Si wafers. The thicknesses of commercial SDDs are up to 0.5 mm, which can detect photons with energies up to 27 keV, whereas we describe GSDDs that can detect photons with energies of up to 35 keV. We simulate the electric potential distributions in GSDDs with Si thicknesses of 0.5 and 1 mm at a single high reverse bias. GSDDs with one gate pattern using any resistivity Si wafer can work well for changing the reverse bias that is inversely proportional to the resistivity of the Si wafer.

No MeSH data available.