Optimization of Amorphous Germanium Electrical Contacts and Surface Coatings on High Purity Germanium Radiation Detectors
Optimization of Amorphous Germanium Electrical Contacts and Surface Coatings on High Purity Germanium Radiation Detectors
复制标题
高纯锗辐射探测器上非晶锗电触点和表面涂层的优化
DOI：
10.13140/rg.2.2.34748.08327/1
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
M. Amman
中科院分区：
文献类型：
--
作者：
M. Amman
几十年前开发的半导体探测器制造技术今天被广泛用于从大体积的高纯Ge（HPGe）单晶生产伽马射线探测器。大多数所有这些检测器专门用于光谱测量，并且具有简单的设计，仅具有通过B注入和Li扩散产生的两个基于杂质的电接触。虽然这些技术对于简单的光谱检测器工作良好，但是Li接触特别厚并且缺乏室温稳定性，使得其不适合用于伽马射线成像和粒子跟踪应用所需的许多更复杂的检测器。诸如溅射沉积的非晶Ge（a-Ge）的非晶半导体薄膜是易于制造、薄并且可以精细分段的替代电接触的基础。a-Ge还用作未被电接触覆盖的HPGe表面上的钝化涂层。a-Ge的性质影响所得探测器的性能，并且这些性质基本上取决于溅射沉积工艺参数并且通过溅射沉积工艺参数是可控的。本文的主题是这种互连的制造工艺参数，a-Ge的属性，和探测器的性能。的a-Ge薄膜的电阻，a-Ge接触电子注入，和室温储存稳定性的性能进行了评估作为溅射气体的压力和溅射气体H2组成的溅射工艺参数的函数。两种不同的溅射沉积系统用于生产a-Ge电阻器和具有a-Ge电接触的HPGe探测器。这些样品的电特性作为温度的函数。本文给出了这项研究的总结和讨论的相关性的研究结果，以优化检测器的性能。
Semiconductor detector fabrication technologies developed decades ago are widely employed today to produce gamma-ray detectors from large volume, single crystals of high purity Ge (HPGe). Most all of these detectors are used exclusively for spectroscopy measurements and are of simple designs with only two impurity based electrical contacts produced with B implantation and Li diffusion. Though these technologies work well for the simple spectroscopy detectors, the Li contact in particular is thick and lacks room temperature stability in a manner that makes it inappropriate for many of the more complex detectors needed for gamma-ray imaging and particle tracking applications. Thin films of amorphous semiconductors such as sputter deposited amorphous Ge (a-Ge) are the basis for an alternative electrical contact that is easy to fabricate, thin, and can be finely segmented. The a-Ge also functions well as a passivation coating on the HPGe surfaces not covered by the electrical contacts. The properties of the a-Ge affect the performance of the resultant detectors, and these properties substantially depend on and are controllable through the sputter deposition process parameters. The subject of this paper is this interconnection of fabrication process parameters, a-Ge properties, and detector performance. The properties of a-Ge thin film electrical resistance, a-Ge contact electron injection, and room temperature storage stability were evaluated as a function of the sputter process parameters of sputter gas pressure and sputter gas H2 composition. Two different sputter deposition systems were used to produce a-Ge resistors and HPGe detectors with a-Ge electrical contacts. These samples were electrically characterized as a function of temperature. A summary of this study and discussion of the relevance of the findings to the optimization of detector performance are given in this paper.