| 主权项 |
1. A method for etching in a plasma etching device a substrate with plasma, wherein the plasma etching device includes at least three stages of magnetic field coils arranged concentrically, a chamber main body internally inserted at an inner side of the magnetic field coils, a substrate stage arranged in the chamber main body, an electrode arranged above a top part of the chamber main body, a high frequency antenna arranged on the electrode, and a gas supplying unit connected to the chamber main body, the method comprising:
holding the substrate on the substrate stage; forming an annular zero magnetic field region lying along a circumferential direction of the magnetic field coils at the inner side of a middle stage coil of the magnetic field coils; supplying-etching gas from the gas supplying unit to an interior of the chamber main body; supplying high frequency power to the high frequency antenna and the electrode to form an induced electric field in the zero magnetic field region to generate plasma of the etching gas; and etching the substrate with the plasma generated in the chamber main body, wherein forming an annular zero magnetic field region includes forming the zero magnetic field region in a state in which the chamber main body is internally inserted from an inner side of a lowermost stage coil of the magnetic field coils to the inner side of the middle stage coil so that there is formed the zero magnetic field region near an inner surface of the top part. |
