| 摘要 |
PURPOSE:To suppress the generation of a radical in the side outer than a wafer diameter and to increase the uniformity of the etching by covering the regions of the side outer than the wafer diameter with an insulator in both an upper electrode and a lower electrode and making a plasma region a region nearly equal to the wafer diameter. CONSTITUTION:A part brought into contact with a wafer 7 on a lower electrode 3 between the counter electrodes is made to a projected crosssectional shape and an insulated cover ring 6 is provided around it. In the other upper electrode 2, a dispersion plate 5 is formed with an electrical-conductive member and an insulator 4 is abutted and provided around it. Eventually both the upper and the lower electrodes 2, 3 are made to an electrical double structure wherein only the regions equal to the wafer 7 are made to a conductor and the peripheral parts are made to the insulator. In this constitution, the local concentration of a radical in the peripheral part of the wafer 7 can be avoided and the etching can be uniformly performed.
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