Towards GaAs thin-film tracking detectors
Towards GaAs thin-film tracking detectors
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DOI：
10.1088/1748-0221/16/09/p09012
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发表时间：
2021-09-01
影响因子：
1.3
通讯作者：
Muenstermann, D.
中科院分区：
文献类型：
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作者：
Rangel-Kuoppa, V. -T.;Ye, S.;Muenstermann, D.
硅基跟踪探测器已被用于几个重要的应用中，例如使用粒子束的癌症治疗，以及在欧洲核子研究中心的大型强子对撞机上发现新的基本粒子。III-V族半导体材料是用于该应用的硅的有吸引力的替代物，因为它们具有一些上级物理性质。它们可以满足快速定时探测器的需求，允许具有ps分辨率的飞行时间测量，同时具有辐射耐受性和成本效益。作为一种密度更大，原子序数更高的物质。和比硅高得多的电子迁移率，GaAs表现出更快的信号收集和每μ m传感器厚度更大的信号。在这项工作中，我们报告的n-在-n GaAs薄膜器件的制造旨在服务于下一代高能粒子跟踪探测器。分子束外延（MBE）被用来生长高质量的GaAs薄膜，掺杂水平足够低，以实现完全耗尽的探测器与10 μ m的有效厚度。使用瞬态电流技术（TCT）评估检测器结构的信号收集速度。为了阐明检测器的结构特性，使用开尔文探针力显微镜（KPFM），其证实了在检测器中结的形成，并揭示了本征层中的残留掺杂。我们的研究结果表明，GaAs薄膜是合适的候选人，以实现薄和耐辐射跟踪探测器。
Silicon-based tracking detectors have been used in several important applications, such as in cancer therapy using particle beams, and for the discovery of new elementary particles at the Large Hadron Collider at CERN. III-V semiconductor materials are an attractive alternative to silicon for this application, as they have some superior physical properties. They could meet the demands for fast timing detectors allowing time-of-flight measurements with ps resolution while being radiation tolerant and cost-efficient. As a material with a larger density, higher atomic number.. and much higher electron mobility than silicon, GaAs exhibits faster signal collection and a larger signal per mu m of sensor thickness. In this work, we report on the fabrication of n-in-n GaAs thin-film devices intended to serve next-generation high-energy particle tracking detectors. Molecular beam epitaxy (MBE) was used to grow high-quality GaAs films with doping levels sufficiently low to achieve full depletion for detectors with an active thickness of 10 mu m. The signal collection speed of the detector structures was assessed using the transient current technique (TCT). To elucidate the structural properties of the detector, Kelvin probe force microscopy (KPFM) was used, which confirmed the formation of the junction in the detector and revealed residual doping in the intrinsic layer. Our results suggest that GaAs thin films are suitable candidates to achieve thin and radiation-tolerant tracking detectors.