【作者】 郎艳菊；

【导师】 金洙吉；

【作者基本信息】 大连理工大学 ， 机械制造及其自动化， 2008， 硕士

【摘要】 碲锌镉(Cd_1-xZn_xTe,简称CZT)晶体是20世纪80年代一种由CdTe发展起来的性能优异的Ⅱ—Ⅵ族三元化合物半导体材料。它主要有两个用途:一是作为外延生长红外探测器材料HgCdTe衬底材料;另一个是最有潜力的室温x/γ射线探测器材料。目前对CZT晶体的加工工艺为:内圆切割—研磨—机械抛光—化学机械抛光,这些加工工艺对晶片造成的损伤会增大表面漏电流,同时缺陷的存在会成为外延生长HgCdTe的缺陷源,对其制作的探测器性能有严重影响。因此,通过对CZT晶体加工表面/亚表面损伤进行检测和分析,以求实现CZT晶体的高效、低损伤超精密加工。本文在分析研究硬脆材料已有的损伤检测方法的基础上,通过大量的试验研究,解决了损伤检测中抛光液和腐蚀液配制的难题,最终确定了适合CZT晶体加工表面/亚表面损伤检测方法。利用纳米压痕试验检测CZT晶体不同晶面以及同一晶面不同晶向的纳米硬度和弹性模量,对力学特性的各向异性进行分析;利用Olympus光学显微镜、扫描电子显微镜（SEM）、Newview5022表面形貌轮廓仪等设备,对CZT加工表面质量进行检测;采用截面显微法检测较大的亚表面损伤,角度抛光法检测较小的亚表面损伤,并试验确定了合适的抛光液和腐蚀液;在此基础上对不同加工工艺条件下的表面/亚表面损伤进行检测、分析。试验结果表明:CZT晶体在不同晶面上以及同一晶面的不同晶向都表现出明显的各向异性;加工工艺从内圆切割—研磨/磨削—抛光,表面质量有明显改善（粗糙度降低,损伤深度不断减小）,材料去除从脆性断裂过渡到塑性去除:采用固结磨料磨削工艺代替研磨和机械抛光,从而解决了磨粒嵌入问题,为后续的化学机械抛光做好准备,最终获得低损伤表面。更多还原

【Abstract】 Cadmium Zinc Telluride (Cd_1-xZn_xTe, CZT) which is developed from CdTe in the eighty age of the twentieth century is one of the excellent ternary semiconducting compunds of II-IV type. It has two primary applications: the one is the substrate for HgCdTe; the other is the most promising detector material. Currently, the processing technology of CdZnTe crystals usually is internal cutting-lapping-mechanical polishing/CMP. The damages which are induced by these processes will seriously influence the performance of the detector, e.g., increasing the surface leakage current and being the defect resource for the epitaxial growth of HgCdTe. Therefore, the surface/subsurface damages are detected and analyzed to achieve the low damage, high effieciency and ultra-precision machining for CZT crystal.Based on the existed methods for detecting the damage of hard-brittle crystal material, a set of methods suitable for CZT crystal are proposed to meet the different requirements by doing abundant experiments, and the problems of choosing slurry and corrosive liquid are resloved. The micro-hardness and elastic modulus of different crystal planes or different directions on the same plane are measured by nanoindentation, and then anisotropic mechanical property is analyed; the surface quality is measured by equipments, e.g. OLYMPUS optical microscope, SEM and 3D surface profiler; cross section method is used when subsurface damage depth （SSD） is larger and angle polishing method is used when SSD is lower, and then the damages induced by different machining processes are assessed.We obtain the following results through detection and analysis: the CZT crystal shows the obvious anisotropic characteristic on different planes and directions; great improvement has been made on the surface quality with lower Ra and SSD from internal cutting to lapping/grinding and polishing, the patten of material removal is transformed from brittle fracture to plastic deformation; grinding is adopted to replace lapping and mechanical polishing, resolving the problem of embedded abrasive grain, then it can make good preparation for CMP and finally obtain CZT crystal surface with low damage.更多还原