Ge/GaAs heterostructure matrix detector
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- 作者：P. Kostamo ; A. Sä ; ynä ; tjoki ; L. Knuuttila ; H. Lipsanen ; H. Andersson ; K. Banzuzi ; S. Nenonen ; H. Sipilä ; S. Vaijä ; rvi and D. Lumb
- 关键词：Germanium detector ; Gallium arsenide ; GaAs ; MOVPE ; Heterostructure ; Pixelated ; Segmented ; Matrix
- 刊名：Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
- 出版年：2006
- 出版时间：1 July 2006
- 年：2006
- 卷：563
- 期：1
- 页码：17-20
- 全文大小：146 K
文摘
In this paper we present a novel germanium/gallium arsenide heterostructure X-ray detector with the active volume of germanium. The heterostructure is fabricated by depositing a gallium arsenide layer on a high-purity germanium wafer in a vertical metalorganic vapor-phase epitaxy system. This approach provides a new alternative to traditional lithium diffused n+ contact which is not easily applicable for finely pixelated detectors. The detector chip fabrication utilizing this kind of heterostructure is straightforward and only standard lithographic processes need to be applied. Electrical properties of the small format detector matrices are studied. Very low reverse biased current at 77 K is observed. It is concluded that the diffusion of arsenic in germanium results in an n-type germanium layer under the epitaxial gallium arsenide.