| 摘要 |
PURPOSE:To enhance flatness of a wafer after a polishing operation by a method wherein a wafer which has been restored to an undistorted state is fixed and its surface is polished. CONSTITUTION:A wafer 1 is etched; its distortion is removed. A polishing plate 2 is placed on a heater 4 and is heated; its surface is coated with a wax 3. The wafer 1 is placed on the wax 3; it is pressurized (normally by hand) and bonded; a primary pasting operation is executed. The polishing plate 2 is put in a thermostatic bath 5 while the wafer 1 is placed; it is kept at a temperature of 130 to 160 deg.C; a secondary pasting operation is executed. Then, the polishing plate 2 is placed on a cooler 7; it is cooled gradually down to room temperature; the polishing plate 2 is loaded on a polishing machine; a polishing operation is executed. That is to say, the plate is put in the thermostatic bath 5; it is heated; its temperature is raised; the secondary pasting operation is executed; then, a viscosity of the wax 3 is lowered; a resistance of the wax 3 to a deformation of the wafer 1 is eliminated; as a result, the wafer is restored to an undistorted state. Thereby, it is possible to obtain the wafer whose warp is small after it has been polished and stripped off; flatness can be enhanced. |
