A novel approach of chemical mechanical polishing using environment-friendly slurry for mercury cadmium telluride semiconductors.
A novel approach of chemical mechanical polishing using environment-friendly slurry for mercury cadmium telluride semiconductors.
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DOI：
10.1038/srep22466
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发表时间：
2016-03-01
影响因子：
4.6
通讯作者：
Zhang B
中科院分区：
文献类型：
--
作者：
Zhang Z;Wang B;Zhou P;Guo D;Kang R;Zhang B
针对碲化汞镉（HgCdTe 或 MCT）半导体开发了一种新的化学机械抛光 (CMP) 方法。首先采用固定磨料研磨对MCT晶圆进行加工，研磨液为去离子水。其次，使用开发的 CMP 浆料对 MCT 晶圆进行抛光。该CMP浆料主要由SiO2纳米球、H2O2以及苹果酸和柠檬酸组成，与以往的CMP浆料通常使用腐蚀性和有毒化学试剂不同。最后，分别用去离子水和压缩空气对抛光后的MCT晶片进行清洗和干燥。 CMP 的新颖方法是环境友好的。 CMP 后，MCT 晶圆的表面粗糙度 Ra 和峰谷 (PV) 值分别为 0.45 和 4.74 nm。在 MCT 晶圆上的电化学测量中观察到第一和第二次钝化过程。根据 X 射线光电子能谱 (XPS) 和电化学测量提出了 CMP 的基本机制。苹果酸和柠檬酸主导第一个钝化过程，CMP 浆料控制第二个过程。在开发的 CMP 浆料引发的 CMP 后，Te4+3d 峰不存在，表明 MCT 晶圆上氧化膜的去除，而使用单一 H2O2 以及苹果酸和柠檬酸溶液很难实现这一点。
A novel approach of chemical mechanical polishing (CMP) is developed for mercury cadmium telluride (HgCdTe or MCT) semiconductors. Firstly, fixed-abrasive lapping is used to machine the MCT wafers, and the lapping solution is deionized water. Secondly, the MCT wafers are polished using the developed CMP slurry. The CMP slurry consists of mainly SiO2 nanospheres, H2O2, and malic and citric acids, which are different from previous CMP slurries, in which corrosive and toxic chemical reagents are usually employed. Finally, the polished MCT wafers are cleaned and dried by deionized water and compressed air, respectively. The novel approach of CMP is environment-friendly. Surface roughness Ra, and peak-to-valley (PV) values of 0.45, and 4.74 nm are achieved, respectively on MCT wafers after CMP. The first and second passivating processes are observed in electrochemical measurements on MCT wafers. The fundamental mechanisms of CMP are proposed according to the X-ray photoelectron spectroscopy (XPS) and electrochemical measurements. Malic and citric acids dominate the first passivating process, and the CMP slurry governs the second process. Te4+3d peaks are absent after CMP induced by the developed CMP slurry, indicating the removing of oxidized films on MCT wafers, which is difficult to achieve using single H2O2 and malic and citric acids solutions.