Wafer polishing apparatus

摘要

Sensors (70,72) detect a stock removal of a wafer (50) during polishing, and a CPU (74) calculates the stock removal in accordance with information from the sensors(70,72). The CPU (74) compares the actual stock removal detected by the sensors (70,72) and a model stock removal stored in RAM (84), and determines timings for dressing and replacing said polishing pad (16) in accordance with a difference between the actual stock removal and the model stock removal. The determination results are shown on a display (82).