Ge薄膜性能及其在光子计数成像探测器中的应用  

Properties of germanium films and their applications to photon counting imaging detectors

作　　者：李云鹏[1,2] 郑鑫[1] 张宏吉[1] 王孝东[1] 陈波[1] 曹健林[1] 

机构地区：[1]中国科学院长春光学精密机械与物理研究所,吉林长春130033 [2]中国科学院大学,北京100049

出　　处：《光学精密工程》2014年第5期1143-1149,共7页Optics and Precision Engineering

基　　金：空间软X射线-极紫外波段复合型望远镜技术研究(No.10878004)

摘　　要：为改善光子计数成像探测器电荷感应层的性能,提高光子计数成像系统的成像质量,分别用直流磁控溅射法(DC)与射频磁控溅射法(RF)制备了不同厚度的Ge薄膜。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、表面轮廓仪、四探针表面电阻测试仪对两种方法所制备的薄膜进行了结构特征与电学性能的表征。结果表明:两种方法所制备的薄膜均为非晶态结构,DC制备的Ge薄膜比RF制备的Ge薄膜稀疏,其不同膜厚下的电阻率均大于RF所制备的薄膜。实验显示,薄膜越厚其电学性能受氧化影响越小,电学性能越稳定。实验对比了不同方阻下Ge薄膜应用于探测器的成像性能,结果表明:方阻在百兆级范围内时成像效果较好,且方阻变化时成像效果变化不大,但方阻大到2GΩ/□时会导致系统分辨率下降。To improve the performance of the charge induce layer in a photon counting imaging detector and to enhance the imaging quality of the photon counting imaging system,different thickness Ge films were deposited by Radio Frequency（RF）magnetron sputtering and Direct Current（DC）magnetron sputtering,respectively.The X-ray Diffraction（XRD）,Scanning Electron Microscopy（SEM）,surface profiler,and the four-point probe surface resistance tester were used to analyze and characterize properties of the films deposited by two methods mentioned above.Research shows that both the Ge films are amorphous structures,and the Ge film prepared by DC is sparser than that prepared by RF,and the resistivities of Ge films with different thicknesses prepared by DC are greater than that of the films deposited by RF.The experiment indicates that the thicker the film,the more stable the electrical properties.Imaging performance of the detector with the Ge film ondifferent sheet resistances is compared experimentally,and it shows that the imaging performance is not only excellent,but also stable within hundreds of MΩ/□,but when the sheet resistance is higher than 2GΩ/□, the resolution of the system will be reduced.

关 键 词：光子计数成像 磁控溅射 非晶Ge薄膜 电荷感应层 

分 类 号：O484.4[理学—固体物理] TP212.14[理学—物理]