| 摘要 |
PURPOSE:To reduce trouble on an etching resulting from dust by mounting mutually opposite electrodes along the path of the flow of a gas generated in a vessel when the reactive gas is introduced, ionizing dust floating between the opposite electrodes and sucking dust to each electrode side. CONSTITUTION:Semiconductor wafers 16 as a material to be etched are set up on a lower electrode 12. High voltage is applied to a second electrode 24 from a DC power supply 27 under the state in which the inside of a vacuum vessel 10 is kept at high vacuum. A reactive gas is introduced into the vacuum vessel 10, and the introduction is continued until the gas reaches to predetermined flow rate and pressure. Much of minute dust flying up and floating between both electrodes 23, 24 are ionized. The ionized dust is moved by an electrostatic field between both electrodes 23, 24, and adheres on the surface of the first electrode 23 or the second electrode 24 in response to polarity by ionization. Accordingly, dust hardly adheres on the surface of the semiconductor wafer 16 as the material to be etched. |
