Abstract
ULSI devices, which consist of fine patterns of less than 0.1μm, require a large silicon wafer having a site flatness better than 0.1μm/□30mm. We have developed an oscillation-speed-control-type sequential grinding and polishing machine. This paper describes pressure the construction of the machine, distributions and removal amounts simulated for various uneven wafers at uniform oscillation speed, the influence of slurry amount for removal rate and a high flatness wafer polished with the developed machine. It was shown that high pressure region is preferentially polished, the slurry can be deceased by 5ml/min with the improved polisher and the machine can accurately polish a 12-inch wafer to less than 0.2μm in flatness by measuring wafer profile on machine and by optimizing the oscillation speed after highly accurate grinding. This result is consistent with the simulation result.
