In recent years, in order to attain high breakdown voltage, low loss, use under high temperature environment, and the like in a semiconductor device such as a MOSFET (Metal Oxide Semiconductor Field Effect Transistor), silicon carbide has begun to be employed as a material of a semiconductor device. Silicon carbide is a wide band gap semiconductor having a band gap larger than that of silicon, which has been conventionally widely used as a material for semiconductor devices. Hence, by adopting silicon carbide as a material for a semiconductor device, the semiconductor device can have a high breakdown voltage, reduced on resistance, and the like. Further, the semiconductor device thus adopting silicon carbide as its material has characteristics less deteriorated even under a high temperature environment than those of a semiconductor device adopting silicon as its material, advantageously.
For example, Japanese Patent Laying-Open No. 2012-214376 (Patent Document 1) describes a method for manufacturing a silicon carbide wafer having a distortion of less than 5 μm, a warpage of less than 5 μm, an entire thickness fluctuation of less than 2.0 μm, and a diameter of 75 mm. According to the method for manufacturing the silicon carbide wafer, a silicon carbide boule is sliced into the form of a wafer, and then the silicon carbide wafer is lapped while restricting lapping downward force to be less than downward force bending the wafer.