Characterization of critically cleaned sapphire single-crystal substrates by atomic force microscopy

• 作 者: DanZhang You Wang Yang Gan
• 机 构: School of Chemical Engineering and Technology, Harbin Institute of Technology, Harbin 150001, China
• 出 处: 工信部七校青年学者论坛
• 发表日期: 2013年7期
• 关键词: Alpha alumina α-Al2O3 Sapphire Contamination control Wet cleaning method UV-ozon

　　A contaminant-free surface of single-crystal α-Al2O3 (or sapphire) substrates is key to the experimental studies o fits surface and interfacial properties at ambient conditions.Here we critically evaluated meth ods reported in the literature using comprehensive surface analysis techniques including atomic force microscopy, XPS and contact angle measurements.We found that reported methods did not perform well in terms of removing both organic and particulate contaminants from the (0 0 01) basal surface.After thoroughly examining the cleaning effect of various chemical solutions and UV light and plasma irradia tion.and based on modified RCA cleaning protocols, we proposed a new wet-cleaning method showing outstanding cleaning performance.This new reliable method will be very useful for the next-step surface chemistry study of single-crystal c-Al203.It was also demonstrated that AFM, due to its high spatial res olution and sensitivity as a local probe technique, was an indispensable tool for surface contamination control studies.