| 摘要 |
PROBLEM TO BE SOLVED: To restrain electron shading phenomena and notching from occurring by a method wherein a bias voltage applied in plasma etching is so varied as to accelerate electrons. SOLUTION: A microwave etching device for processing a polysilicon gate generates plasma of high density through such a manner that microwaves generated through a magnetron 20 are introduced into a discharge tube 22 through a waveguide 21, and the introduced microwaves are turned into plasma of high density through electron cyclotron resonance with a magnetic field formed by a coil 23. A pulse power supply 19 is provided, and a pulse voltage of rise speed 10<3> V/μs or above is applied as a bias voltage through the pulse power supply 19. When the potential of an applied pulse voltage is higher than a plasma potential, electrons are accelerated by a voltage difference (electron accelerating voltage) between a substrate potential and the plasma potential so as to impinge on the base of a fine pattern. By this setup, the positive charge of the fine pattern base is neutralized.
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