| 摘要 |
PURPOSE:To shorten an exhaust time, by providing a discharging and a cleaning electrode consisting of a cathode and an anode covering the cathode in a vacuum vessel, making plus ions discharge to collide them on the surface plane of the vessel, and separating a foreign matte from adsorbing gas. CONSTITUTION:A wafer is placed on a mobile stage 2 of the vacuum vessel 1, a laser beam is emitted from a laser device 5 to make it scan. Reflected light is received at a foreign matter detector 7, then the foreign matter is detected, and it is analyzed by an ion microanalyzer 8, and a mass spectrograph 9. Also, a discharging cathode 15, and the anode 16 being set so as to cover the cathode, are provided. Then, discharging gas 11 is introduced, and the inside of the vessel 1 is exhausted by a vacuum pump 10, and an electron is emitted by heating the cathode 15 by a power source 17, and a glow discharge is generated between the anode 16, and he vessel 1 and the stage 2. The foreign matter is separated from the adsorbing gas by making the plus ion generated by the above discharge collide on the surface of the vessel 1 and the stage 2. Therefore, since discharging and cleaning function is added on an analyzer, it is possible to shorten the exhaust time, and to reduce attainable pressure. |
