Abstract: Colloidal silica slurry was used for chemical mechanical polishing (CMP) 4H-type conductive SiC surface to explore the key parameters affecting the surface quality of SiC substrates and obtain higher material removal rate and defect-free surface.The results indicate that SiC surface interact with both hydrogen peroxide (H2O2) and hydroxyl ion (OH-) to form softer oxidations.The removal rate of SiC increase firstly and then remain unchange when the content of H2O2 or OH-is increase under a certain pressure.The removal rate of SiC increase further when the content of OH-is increase under a higher pressure.By optimizing the polishing parameters, the polishing removal rate of SiC is increased to 142 nm/h.The results show that keeping the balance of chemical and mechanical influence is a key factor to obtain the high removal rate and defect free SiC surface.The results of optical surface analyzer (Candela) and atomic force microscope(AFM) show that the wafer surface has no scratch and the surface roughness is 0.06 nm.The densities of defects are less than 1 /cm2 and the surface roughness is 0.16 nm after epitaxial growing a film of SiC.

Key words: Colloidal silica slurry was used for chemical mechanical polishing (CMP) 4H-type conductive SiC surface to explore the key parameters affecting the surface quality of SiC substrates and obtain higher material removal rate and defect-free surface.The results indicate that SiC surface interact with both hydrogen peroxide (H2O2) and hydroxyl ion (OH-) to form softer oxidations.The removal rate of SiC increase firstly and then remain unchange when the content of H2O2 or OH-is increase under a certain pressure.The removal rate of SiC increase further when the content of OH-is increase under a higher pressure.By optimizing the polishing parameters, the polishing removal rate of SiC is increased to 142 nm/h.The results show that keeping the balance of chemical and mechanical influence is a key factor to obtain the high removal rate and defect free SiC surface.The results of optical surface analyzer (Candela) and atomic force microscope(AFM) show that the wafer surface has no scratch and the surface roughness is 0.06 nm.The densities of defects are less than 1 /cm2 and the surface roughness is 0.16 nm after epitaxial growing a film of SiC.