Control of microscratches in chemical-mechanical polishing process for shallow trench isolation

A method of controlling microscratches on silicon oxide surfaces induced by chemical-mechanical polishing (CMP) process for the planarization of shallow trench isolation is discussed. The frequency of microscratches during polishing shows its high dependency on the characteristics of CMP consumables such as slurry and pad. A diluted slurry solution, pH-controlled with a potassium hydroxide (KOH) solution of pH 13, produces best results in reducing microscratches on silicon oxide surfaces during polishing. In conclusion, careful preparation of the CMP consumables is required to reduce microscratches on silicon oxide during polishing.