Ge单晶片的碱性化学腐蚀抛光研究

Study on the Alkali Etching and Polishing of Single-Crystalline Germanium Wafer

采用湿法化学腐蚀技术,研究Ge单晶片在NaOH-H2O2体系中的化学腐蚀抛光特性。通过改变腐蚀液配比、腐蚀时间、腐蚀容器,分析锗单晶腐蚀抛光过程的机理及其表面状态变化规律。结果表明:锗单晶在碱性腐蚀抛光后的表面平整度能够接近酸腐蚀的单晶表面;在腐蚀过程中,双氧水分解产生的氧离子极少部分用于锗的氧化,但从动力学角度加快了腐蚀速率,促进了表面抛光的程度。在碱腐蚀条件下,锗单晶的腐蚀速率在一定范围内随氢氧化钠浓度增加呈先增后降趋势,表面粗糙度变化趋势与之相反。

The chemical etching and polishing characteristics of single-crystalline germanium in the NaOH-H2O2 system are studied in this work. By adjusting the concentration of etching solution, etching time and etching instruments, the mechanism and the surface morphology of the etching process of singlecrystalline germanium is studied in details. It is found that the surface roughness of single-crystalline ger manium etched by alkali solution is almost the same as that etched by acid solution. During the etching process, only parts of hydrogen peroxide participate in the reaction with germanium, while it did increase the etching rate and improve the surface smoothness as an dynamic factor. In the alkali etching system, the etching rate and the surface roughness of single-crystalline germanium indicate opposite variation trend with the concentration of NaOH.