| 摘要 |
PURPOSE:To improve the acceptance ratio of a semiconductor element on a wafer and the work efficiency by detecting automatically dust on a wafer holding stand for holding the wafer and removing it automatically. CONSTITUTION:A laser beam 2 coming out of a laser beam irradiating device 1 scans the dust 3 on the wafer holding stand 5, which adsorbs the wafer coated with a photoresist, and detects the dust 3 with the aid of a change in the incident light quantity on a light receiving sensor 4 following the scan. The scanning of the laser beam is stopped, simultaneously with the detection of the dust 3 and an ionized gas flow 9 is supplied from an ionized gas flow nozzle 7 to the dust, thereby releasing the electromagnetic attachment of the dust 3. Afterward, a sufficiently accelerated gas blow 10 is ejected to the dust 3 by a gas blow nozzle 8, and the dust 3 is carried in discharging port 11. Thus the acceptance ratio of the semiconductor element and the work efficiency can be improved. |
