Chemical reaction on silicon carbide wafer (0 0 0 1 and 0 0 0-1) with water molecules in nanoscale polishing

Chemical reactions occurring in atomic level are of importance for the nano-manufacturing process. The tri-bochemistry mechanism for the ultra-precision polishing of 6H-SiC wafers with only deionized water used as the coolant is expounded. Both Si face and C face of 6H-SiC wafers chemically react with water molecules during the interfacial friction and then form silicon dioxide. The silicon dioxide generated on the Si face is crystallized, while that on the C face is amorphous. Reactive molecular dynamics simulations further confirm the findings of the experiments and indicate that the interfacial friction with the diamond abrasives facilitate the destruction of the lattice structure, which promotes the reaction between 6H-SiC and H2O molecules. The reveal of the chemical mechanism for the nanoscale polishing on SiC wafers may guide and optimize the polishing process, thereby improving the nano-machining efficiency.