Development of Large Area and High Performance Radiation Imaging Detectors for Medical Use

医用大面积高性能辐射成像探测器的开发

基本信息

批准号：
15300181
负责人：
YASUDA Kazuhito
金额：
$ 10.24万
依托单位：
Nagoya Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2005
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-15300181/
关键词：
Radiation detector Cadmium Telluride Metalorganic Vapor Phase Epitaxy Imaging detector CdTe X線検出器 γ線検出器 MOVPE CdZnTe

项目摘要

Development of large area and high performance radiation imaging detectors using thick CdTe layers grown by Metalorganic vapor phase epitaxy (MOVPE) has been studied. The following 3 major achievements were obtained.1.Development of CdTe/n^<+->GaAs heterojunction diode detectors.Heterojunction diode detectors were fabricated using thick p-CdTe layers grown on n^<+->GaAs substrates by MOVPE. Detection and energy discrimination capabilities for the incident gamma ray of 59 keV from Am source were confirmed for the first time. Optimization of the detector structure was also carried out.2.Development of direct growth technique of CdTe lavers on Si substrates by MOVPE.Growth of single crystal CdTe layers directly on Si substrates by MOVPE was achieved for the first time. As a pretreatment before the CdTe growth on Si, the Si substrates were annealed with GaAs pieces in the hydrogen environment. Growth of high quality CdTe thick layers, which were necessary for radiation detectors, was also achieved by using the following growth technique. After the growth of thin CdTe layers on Si substrates, residual stress in the grown layers were relaxed, and thick CdTe layers were grown on them.3.Development of CdTe/n^<+->Si heterojunction diode detectors.On the basis of results obtained in 1 and 2 above, heterojunction diode detectors using thick p-CdTe layers grown directly on n^<+->Si substrates were fabricated. The detectors were confirmed to have good electrical characteristics. Improvements of the detector performance were also studied.Throughout the above studies, fundamental techniques which were inevitable to realize the purposed detectors were established.

人们已经研究了使用金属有机气相外延 (MOVPE) 生长的厚 CdTe 层开发大面积高性能辐射成像探测器。主要取得了以下三项成果：1.CdTe/n^+-GaAs异质结二极管探测器的研制。采用MOVPE技术在n^+-GaAs衬底上生长厚的p-CdTe层，制备了异质结二极管探测器。首次证实了对Am源59 keV入射伽马射线的探测和能量辨别能力。并对探测器结构进行了优化。2.MOVPE在Si衬底上直接生长CdTe层技术的开发。首次实现了MOVPE在Si衬底上直接生长单晶CdTe层。作为在 Si 上生长 CdTe 之前的预处理，Si 衬底与 GaAs 片在氢气环境中进行退火。辐射探测器所需的高质量 CdTe 厚层的生长也是通过使用以下生长技术实现的。在Si衬底上生长薄CdTe层后，松弛生长层中的残余应力，在其上生长厚CdTe层。3.CdTe/n^+-Si异质结二极管探测器的研制。根据上面1和2中获得的结果，使用直接生长在n^+-Si衬底上的厚p-CdTe层制造了异质结二极管探测器。探测器被证实具有良好的电气特性。还研究了探测器性能的改进。通过上述研究，建立了实现目标探测器所必需的基本技术。