PURPOSE: To correct the distortion of electric field along the peripheral part of a substrate thereby enabling the whole surface of the substrate to be etched evenly by a method wherein a mechanism to form a magnetic field is provided along the peripheral part of the substrate held on a holding mechanism.
CONSTITUTION: An Si wafer 13 is held on the surface of a lower electrode 14 while an upper electrode 7 is lowered down to a position at a specific interval from the wafer 13 in a reaction chamber 1 held in a state of vacuum. Next, this device is impressed with a power from an RF power supply 28 to plasma- etch the wafer 13. At this time, multiple permanent magnets 21 are provided on a clamp ring 15 so as to form a magnetic field along the peripheral part of the wafer 13. Accordingly, the notable decline in the etching rate due to the distortion of the electric field along the peripheral part of the wafer 13 can be avoided by the ring 15 thereby enabling the whole surface of the wafer 13 to be etched evenly.
TAWARA YOSHIFUMI
ARAI IZUMI
