Abstract: An origin determination method includes the steps of adjusting a positional relation between a chuck table and a grinding unit by a moving mechanism such that lower ends of grinding stones and a holding surface are brought apart along a moving direction, moving the chuck table and the grinding unit relative to each other by the moving mechanism such that the lower ends of the grinding stones and the holding surface are brought closer to each other by a predetermined distance, and determining whether a measurement value of a load applied to the holding surface has reached a threshold. If the measurement value is determined to have reached the threshold, a positional relation between the chuck table and the grinding unit at that time is determined to be an origin of the moving mechanism. Otherwise, the step of moving and the step of determining are then performed again.

Abstract: A wafer polishing method includes moving a polishing pad to a standby position where a gap is defined between the upper surface of a wafer held on a holding unit and the lower surface of the polishing pad, lowering the polishing pad from the standby position by a preset distance at a preset speed, determining whether or not a load measured by a load sensor is greater than or equal to a preset threshold value in a rest condition of the polishing pad after lowering the polishing pad, repeatedly the lowering the polishing pad until it is determined that the load measured by the load sensor is greater than or equal to the threshold value, and polishing the wafer in the condition where a load falling in a predetermined load range including the threshold value.

Abstract: A wafer polishing method includes moving a polishing pad to a standby position where a gap is defined between the upper surface of a wafer held on a holding unit and the lower surface of the polishing pad, lowering the polishing pad from the standby position by a preset distance at a preset speed, determining whether or not a load measured by a load sensor is greater than or equal to a preset threshold value in a rest condition of the polishing pad after lowering the polishing pad, repeatedly the lowering the polishing pad until it is determined that the load measured by the load sensor is greater than or equal to the threshold value, and polishing the wafer in the condition where a load falling in a predetermined load range including the threshold value.