Ge薄膜特性及其在光子计数成像系统中的应用  

Properties of Germanium Thin Film and Its Application in Photon Counting Imaging System

作　　者：赵菲菲[1,2] 赵宝升[1] 张兴华[1,2] 李伟[1,2] 邹玮[1] 赛小锋[1] 韦永林[1] 

机构地区：[1]中国科学院西安光学精密机械研究所光电子学室,陕西西安710119 [2]中国科学院研究生院,北京100039

出　　处：《光学学报》2009年第11期3236-3240,共5页Acta Optica Sinica

基　　金：国家自然科学基金(10878005)资助课题

摘　　要：利用电子束真空蒸镀方法制作了Ge薄膜,用作感应读出方式光子计数成像系统的电荷感应层,研究了石英玻璃衬底和陶瓷衬底上Ge薄膜的结构特征、表面形态以及各种工艺参数对薄膜电阻的影响。X射线衍射(XRD)测试表明,两种衬底上沉积的Ge薄膜均为立方相非晶态。场发射扫描电子显微镜(FESEM)图像表明石英玻璃衬底上的薄膜致密平整,陶瓷衬底上的薄膜比较粗糙,厚度较薄时,陶瓷晶界处薄膜不连续导致电阻较大。通过改变沉积速率、薄膜厚度及采用退火的方法可以控制薄膜电阻。对比了采用不同阻值电荷感应层时系统的性能,发现阻值对探测器的分辨率影响小,对计数率影响较大。The Ge thin films applied in photon counting imaging system based on Ge induction readout were fabricated by electron beam evaporation. The structures of Ge thin films deposited on ceramic and quartz glass substrates and influences of technical parameters on resistance were studied. The X-ray diffraction （XRD） analysis of thin films deposited on the two substrates shows that the thin films deposiited on two kinds of substrates both have cubic amorphous Ge structure. The field emission scanning electron microscopy （FESEM） images indicate that the film deposited on quartz glass is more compact and smooth than that deposited on the ceramic substrate. If the film on the ceramic substrate is too thin, the film is discontinuous, which induces the high resistance. The resistance can be controlled by annealing, depositing rate, or thickness of film. The performance of the system, which adopted Ge layers with different resistance, was studied. These results suggest that resistance of the charge induced layer influences spatial resolution less than the counting rate.

关 键 词：薄膜光学 电荷感应层 电子束蒸发 光子计数成像 电荷感应读出方式 

分 类 号：O484.4[理学—固体物理]