DEVICE AND METHOD FOR PLASMA ETCHING

摘要

PROBLEM TO BE SOLVED: To keep the uniformity of an etching rate on a surface unchanged even if not only the total flow rate of etching gas but also the aperture rate of a slide valve are changed. SOLUTION: A sample table 2 on which a semiconductor substrate 3 is placed, a gas introduction unit 4 by which etching gas is introduced and a gas exhaust unit 5 through which the gas is exhausted are provided in a chamber 1. A valve element which rotates relatively to a valve seat is provided between the sample table 2 and the gas exhaust unit 5. A slide valve 6 which regulates the quantity of the gas exhausted through the gas exhaust unit 5 by the rotation of the valve element is provided. A spiral coil 8 which generates high frequency induction electric field to generate the plasma of the etching gas is rotatably provided on the chamber 1. A rotation driving means 13 turns the spiral coil 8 following the rotation of the valve element of the slide valve 6 so as to agree the high voltage region of the spiral coil 8 approximately with the exhaust side region of the slide valve 6.