Abstract: An apparatus for cutting a semiconductor crystal ingot into wafers includes a rotary blade, a first sensor, a second sensor and a computing unit. The blade is of a generally disk shape having a mark put thereon. The first sensor is stationarily located in opposed relation to the blade for sensing a distance between the blade and the first sensor to produce a first signal representative of the distance. The second sensor is stationarily disposed in opposed relation to the blade for detecting the mark of the blade to produce a second signal representative of a position of the mark. The computing unit is connected to the first and second sensors for receiving the first signal from the first sensor in synchronization with the second signal from the second sensor, and computing an amount of warp of the blade as to a fixed position thereof by using the received first signal.

Abstract: Slicing machine having a handle to be driven manually to generate command pulses. By revolving the handle, a feedtable is moved at the operator's command, enabling the positioning of a semiconductor material at the right position to start slicing. The thickness of the first wafer cut off from the material as well as other wafers, has a predetermined thickness, so that no wafer is wasted.