【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TiO₂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TiO₂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.更多还原

【Abstract】 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 intensity,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 substrate in LED industry. Results show that titania particles with average particle size of 25 nm and concentration 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,leading to higher MRR when pH of slurry is 2. 2,and MRR increases significantly when pH of slurry increases to 10. Atomic force microscope( AFM) and optical microscope were used to investigate polishing surface quality. Finally,4H-SiC wafer surface with roughness Raof 0. 058 6 nm and MRR of 352. 8 nm/h is obtained.更多还原