作　　者： (叶子凡）; (周艳）; (徐莉）; (潘国顺）;

机构地区： 清华大学摩擦学国家重点实验室,北京100084

出　　处： 《纳米技术与精密工程》 2017年第5期342-346,共5页

摘　　要： 在4H-SiC晶片的化学机械抛光(CMP)体系中加入紫外LED系统,研究TiO_2颗粒、紫外LED光功率、抛光温度和抛光液pH值对4H-SiC晶片抛光性能的影响规律,以获得较高的材料去除速率(MRR)和原子级光滑表面,满足LED器件对衬底材料表面的严格要求.结果表明,采用平均粒径25 nm、质量分数为2%的TiO_2颗粒,可显著提高MRR,且减少微划痕等表面缺陷;增大紫外LED功率,MRR随之增大;升高抛光温度,MRR快速提高,并可降低抛光所得表面粗糙度;在CMP体系中加入紫外体系可增加羟基自由基数量,抛光液pH值较低(2.2)也可维持较高MRR值,且抛光液pH值超过10时MRR值大幅提高.采用原子力显微镜(AFM)、光学显微镜来考察4H-SiC晶片抛光后的表面质量.基于各因素的影响规律,最终获得表面粗糙度为0.058 6 nm的4H-SiC晶片表面,且MRR达到352.8 nm/h. This paper discusses the application of photocatalytic oxidation technology in 4H-SiC wafer chemical mechanical polishing （ CMP） . The influences of titania particles, ultraviolet （ UV） LED inten-sity, polishing temperature and pH value of slurry on polishing performance were examined to achieve high material removal rate （MRR） and atomic-level-roughness smooth surface for strict demands of sub-strate in LED industry. Results show that titania particles with average particle size of 25 nm and concen-tration of 2% can reduce micro-scratches and obtain high MRR ; that higher UV-LED intensity leads to higher MRR ; that increasing polishing temperature can not only improve MRR obviously but also decrease surface roughness remarkably ; that photo-induced holes oxidize slurry and generate additional · OH, lead-ing to higher MRR when pH of slurry is 2. 2, and MRR increases significantly when pH of slurry increa-ses to 10. Atomic force microscope （AFM） and optical microscope were used to investigate polishing surface quality. Finally, 4H-SiC wafer surface with roughness Ra of 0. 058 6 nm and MRR of 352. 8 nm/h is obtained.

关 键 词： 晶片 化学机械抛光 紫外