Germanium microstrip detectors with 50 and 100 μm pitch

doi:10.1016/0168-9002(84)90178-5

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment

Volume 226, Issue 1, 15 September 1984, Pages 117-121

https://doi.org/10.1016/0168-9002(84)90178-5 Get rights and content

Abstract

Multi-electrode germanium detectors are being used as an active target for decay path measurements of charmed mesons. The procedure used to fabricate such detectors is described and a brief analysis of their performance is given.

References (6)

S.R. Amendolia et al., these Proceedings (Semiconductor Detectors '83), p....
F. Celani
Addendum to proposal P170
CERN/SPSC/82-83/SPSC/P170/add.1
(1982)
M.A. Giorgi
S.R. Amendolia
IEEE Trans. Nucl. Sci. NS-30
(1983)

There are more references available in the full text version of this article.

Cited by (5)

Inter-electrode charge collection in high-purity germanium detectors with amorphous semiconductor contacts
2015, Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
Citation Excerpt :
A typical solution involving conventional, impurity-based contacts includes an etching or cutting step to eliminate the low-resistivity material between electrodes. For ion-implanted contacts, standard lithographic and etching processes can be successfully used [10–12]. However, the thicker Li-diffused contact poses a greater challenge because it is not conducive to standard etch processes.
High-purity germanium (HPGe) radiation detectors with segmented signal readout electrodes combine excellent energy resolution with fine spatial resolution, opening exciting possibilities in radiation imaging applications. Segmenting the electrodes provides the ability to determine the positions of radiation interactions in the detector, but it also brings potential challenges that can inhibit performance. A challenge unique to segmented electrode detectors is collection of charge carriers to the gap between adjacent electrodes rather than to the electrodes themselves, which gives a deficit in the summed energy. While amorphous semiconductor electrical contacts have enabled a simplified fabrication process capable of fine electrode segmentation, the amorphous semiconductor passivation layer between electrodes is prone to inter-electrode charge collection. This article presents a study of the impact of fabrication process parameters on the energy deficit due to inter-electrode charge collection for double-sided strip detectors. Eight double-sided strip HPGe detectors were fabricated with amorphous germanium (a-Ge) and amorphous silicon (a-Si) contacts formed by sputter deposition. Each detector was evaluated for inter-electrode charge collection performance, using as a metric the deficit in the summed signal of two adjacent electrodes. It is demonstrated that both a-Ge and a-Si contacts can be produced with nearly non-existent inter-electrode charge collection when the appropriate combination of sputter gas hydrogen content and gas pressure are selected.
Leakage current in high-purity germanium detectors with amorphous semiconductor contacts
2015, Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
Citation Excerpt :
In such detectors, the position measurement is often achieved by dividing or segmenting the electrical contacts into many strips or pixels and then reading out the signals from each of the contact segments. The conventional B implanted contact can be readily segmented [5–8]. However, the Li-diffused contact presents a challenge for segmentation as a result of its thickness and significant diffusion of Li at room temperature [9,10].
Amorphous semiconductor electrical contacts on high-purity Ge radiation detectors have become a valuable technology because they are simple to fabricate, result in thin dead layers, block both electron and hole injection, and can readily be finely segmented as needed for applications requiring imaging or particle tracking. Though significant numbers of detectors have been successfully produced for a variety of applications using the amorphous semiconductor contact technology, there remains a need to better understand the dependence of performance characteristics, particularly leakage current, on the fabrication process parameters so that the performance can be better optimized. To this end, we have performed a systematic study of leakage current on RF-sputter-deposited amorphous-Ge (a-Ge) and amorphous-Si (a-Si) contacts as a function of process and operational parameters including sputter gas pressure and composition, number of detector temperature cycles, and time spent at room temperature. The study focused primarily on the current resulting from electron injection at the contact. Significant findings from the study include that a-Si produces lower electron injection than a-Ge, the time the detector spends at room temperature rather than the number of temperature cycles experienced by the detector is the primary factor associated with leakage current change when the detector is warmed, and the time stability of the a-Ge contact depends on the sputter gas pressure with a higher pressure producing more stable characteristics.
Photomask technique for fabricating high purity germanium strip detectors
1990, Nuclear Inst. and Methods in Physics Research, A
Semiconductor detectors
2011, Experimental Techniques in Nuclear Physics
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1994, Reports on Progress in Physics

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Germanium microstrip detectors with 50 and 100 μm pitch

Abstract

Addendum to proposal P170

CERN/SPSC/82-83/SPSC/P170/add.1

IEEE Trans. Nucl. Sci. NS-30