Achievement of a near-perfect smooth silicon surface

During the ultra large scale integration (ULSI) process, the surface roughness of the polished silicon wafer plays an important role in the quality and rate of production of devices. In this work, the effects of oxidizer, surfactant, polyurethane pad and slurry additives on the surface roughness and topography of chemical-mechanical planarization (CMP) for silicon have been investigated. A standard atomic force microscopy (AFM) test method for the atomic scale smooth surface was proposed and used to measure the polished silicon surfaces. Finally, compared with the theoretical calculated R _a value of 0.0276 nm, a near-perfect silicon surface with the surface roughness at an atomic scale (0.5 Å) was achieved based on an optimized CMP process.