锗单晶在酸性SiO_(2)抛光液条件下的抛光机理及加工工艺  

Polishing Mechanism and Processing Technology of Germanium Single Crystal Under Acidic SiO_(2) Polishing Solution

作　　者：杲星 顾跃 夏卫东[1] 董鸿林 甘禹 徐扬[1] 丁雨憧[1] GAO Xing;GU Yue;XIA Weidong;DONG Honglin;GAN Yu;XU Yang;DING Yuchong(The 26th Institute of China Electronics Technology Group Corporation, Chongqing 400060, China)

机构地区：[1]中国电子科技集团公司第二十六研究所,重庆400060

出　　处：《压电与声光》2022年第3期467-470,473,共5页Piezoelectrics & Acoustooptics

摘　　要：该文研究了化学机械抛光(CMP)条件下,锗单晶在含HNO_(3)的SiO_(2)抛光液中的腐蚀过程。通过改变抛光时间,分析锗单晶表面状态的变化规律。结果表明,在SiO_(2)抛光液pH值为1~2时,SiO_(2)抛光液中存在Si—OH和Si—O-形式;锗单晶先与HNO_(3)反应生成Ge(NO_(3))_(4),而后Ge^(4+)的含氧酸盐会剧烈水解生成Ge—OH,Ge—OH继续反应并以Ge—OH_(2)^(+)形式存在。由于表面电荷的吸引,Si—O-和Ge—OH_(2)^(+)在锗单晶表面生成Si—O—Ge软化层,从动力学角度加快了腐蚀速率,促进了表面抛光的程度。抛光时间为15~20 min时,机械抛光和侵蚀的法向速度处于平衡状态,CMP抛光后锗单晶表面粗糙度S_(a)≤0.8 nm,10倍显微镜下无划痕、麻点。The corrosion process of germanium single crystal in SiO_(2) polishing solution containing HNO_(3) and under the condition of chemical mechanical polishing(CMP)was studied.By changing the polishing time,the changing law of the surface state of germanium single crystal was analyzed.The results show that when the pH value of SiO_(2) polishing solution is 1~2,there are the forms of Si—OH and Si—O-in SiO_(2) polishing solution;germanium single crystal reacts with nitric acid to form Ge(NO_(3))_(4).Then,the oxygenate of Ge^(4+) will be violently hydrolyzed to generate Ge—OH,and Ge—OH will continue to react in the form of Ge—OH_(2)^(+).Under the attraction of surface charge,Si—O-and Ge—OH_(2)^(+) create Si—O—Ge softening layer on the surface of germanium single crystal,which speeds up the corrosion rate and promotes the degree of surface polishing from the perspective of kinetics.When the polishing time is controlled within 15~20 min,the normal velocity of mechanical polishing and erosion is in equilibrium.After CMP polishing,the surface roughness S_(a) of germanium single crystal is≤0.8 nm,and there are no scratches and pits under 10x microscope.

关 键 词：锗单晶 化学机械抛光 抛光液 粗糙度 

分 类 号：TN384[电子电信—物理电子学] TN305.2