According to the invention, the feed of the single crystal ingot to the blade of the ID slicer is controlled to increase and decrease alternately in accordance with the predetermined program, so that it is possible to intentionally give controlled irregularity to the surface of {HEAD ~ the wafer} sliced from {TAIL ~ the single crystal ingot} 
According to the invention , the feed of the single crystal ingot to the blade of the ID slicer is controlled to increase and decrease alternately in accordance with the predetermined program , so that it is possible to intentionally give controlled irregularity to the surface of { HEAD ~ the wafer } sliced from { TAIL ~ the single crystal ingot }
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