Patent ID: 8906249
Filing Date: 2014-12-09
Classification: C23C,H01J,H05H

Abstract:
1. A dry etching method for processing a substrate by plasma, comprising: providing the substrate on a bottom portion side of a vacuum vessel; placing a beam-shaped structure at an upper opening of the vacuum vessel opposed to the substrate, the beam-shaped structure having an annular outer peripheral portion with a lower surface supported by the vacuum vessel, a central portion located at a center of a region surrounded by the outer peripheral portion in plane view, and a plurality of beam portions extending radially from the central portion to the outer peripheral portion, wherein a region surrounded by the outer peripheral portion, the central portion and the beam portions constitute a window portion; providing a dielectric plate so that its lower surface is supported by an upper surface of the beam-shaped structure; providing a spiral coil for plasma generation on an upper surface side of the dielectric plate; injecting a process gas into the vacuum vessel from a plurality of process gas introducing ports provided in the beam-shaped structure so as to face downward and each have a depression angle directed toward the substrate; injecting an antiwear gas, which includes at least a rare gas, toward a lower surface of the dielectric plate from a plurality of antiwear gas introducing ports which are provided so as to face upward and confront the window portion of the beam-shaped structure and each of which has an elevation angle directed toward the dielectric plate; while injecting the process gas from the process gas introducing ports and injecting the antiwear gas from the antiwear gas introducing ports, evacuating an interior of the vacuum vessel to maintain the interior of the vacuum vessel at a constant pressure; and applying a radio frequency power to the spiral coil to generate plasma in the vacuum vessel so that radicals in the plasma are adsorbed to the substrate and ions in the plasma collide with the substrate, thereby resulting in a surface of the substrate being etched, wherein the antiwear gas injected from the antiwear gas introducing ports is directed to a neighborhood of a high-density plasma generation region generated in a region below the dielectric plate and corresponding to an outer periphery of the spiral coil.