Hybrid Effect Study of Pad-Conditioning/Slurry-Supply by High-Pressure-Micro-Jet (HPMJ) Method during CMP Process

Surface clogging of polishing pad is inevitable during CMP (Chemical Mechanical Polishing) process of semiconductor wafers. In this paper, a novel slurry-feeding system utilizing HPMJ (High Pressure Micro Jet) apparatus was presented as in situ conditioning for CMP process. Clogging of pad surface can be greatly removed; the surface damage of polishing pad can also be extremely reduced by this new method. The experimental results exhibited that the material remove rate (MRR) of HPMJ method was almost constant value 100 mu m h(-1). However, the MRR value of conventional slurry-dripping method was about 50 mu m h(-1). On the other hand, surface roughness Ra changed both in hybrid HPMJ method and conventional slurry-dripping method after long-time continuous CMP process, the average Ra of hybrid HPMJ method was about 30% smaller than that of conventional slurry-dripping method, indicating that better surface quality could be obtained by HPMJ method polishing. It was demonstrated that HPMJ method showed higher MRR and lower surface roughness Ra for polishing process. HPMJ hybrid system mentioned in this study can also be applied to the polishing process of hard-to-process wide bandgap semiconductor substrate materials, such as SiC or GaN. (C) 2020 The Electrochemical Society ("ECS"). Published on behalf of ECS by IOP Publishing Limited.