Abstract: This polishing apparatus permits for polishing of hard-material coated complex films that traditionally have been difficult to polish due to the hardness of the films, the fragility of the substrate, and the inherent distortion of the film. The polishing apparatus includes a rotary turn-table, a holder for a wafer having the film, a shaft connected to the center of the holder for transmitting rotation and pressure to the holder and permitting the holder to incline, an arm rotatably supporting the holder, a cylinder for applying pressure to the center of the shaft, a driving device for rotating the shaft, and at least one auxiliary shaft. The auxiliary shaft pushes peripheral points along a diameter of the holder in order to impart a swaying motion on the holder.

Abstract: A method of producing and polishing a hard-material-coated wafer. A hard-material film is disposed on a substrate to form the wafer and provide the wafer with a convex shape. A surface of the substrate is fixed on a holder of a polishing machine having a whetstone turn-table. The holder is rotated about its axis, and the whetstone turn-table is revolved about its shaft. The convex film surface of the hard-material film is polished on the whetstone turn-table while the inclination angle of the holder relative to the turn-table is changed. In this way, the convex film surface is polished either from its center to its periphery or from its periphery to its center.

Abstract: A hard material-coated wafer that having a distortable substrate and a hard material film deposited thereon by a CVD method is provided. The substrate is substantially flat while in a free-standing state. However, deposition of the hard material film having a Vickers hardness of more than Hv3000 on the substrate causes the substrate to distort into a generally convex-shape. Specifically, the wafer is distorted to the film side with a distortion height H of -150 .mu.m to -2 .mu.m. The resulting wafer can have a total thickness that ranges from 0.1 mm to 2.1 mm; and a diameter that is bigger than 25 mm. Moreover, more than 50% of the film can be polished to a roughness less than Rmax 50 nm and Ra 20 nm.