Patent ID: 8231798

Claim:
A plasma processing method comprising: providing a tray formed with a plurality of substrate accommodation holes that penetrate through a thickness thereof, and provided with a substrate support portion that projects from a hole wall of each of the substrate accommodation holes; accommodating substrates in respective substrate accommodation holes of the tray, thereby an outer peripheral edge portion of a lower surface of each of the substrates is supported by the substrate support portions so that the lower surface of each of the substrates is exposed by each of the substrate accommodation holes viewed from a lower surface side of the tray; placing the tray with the plurality of substrates accommodated therein above an upper portion accommodated in a depressurizeable chamber; moving downward the tray toward the upper portion so that the lower surface of the tray is supported by a tray support portion of the upper portion and so that a plurality of substrate placement portions respectively projecting from the tray support portion are inserted to the substrate accommodation holes from the lower surface side of the tray, thereby the lower surface of each of the substrate is placed on a substrate placement surface that is an upper end surface of each of the substrate placement portions, wherein a distance from the tray support portion to an upper surface of the substrate support portion is smaller than a distance from tray support portion to the substrate placement surfaces so that the lower surface of the substrates placed on the substrate placement surfaces are separated to the substrate support portions of the tray with gaps of a predetermined amount; electrostatically attracting each of the substrates to the substrate placement surfaces by applying a dc voltage to an electrostatic attraction electrode at least a portion of which is embedded in the substrate placement portion; circulating a refrigerant so as to cool the upper portion having the tray support portion on which the lower surface of the tray is placed and the substrate placement surfaces on which the substrates are placed; supplying a heat conduction gas to a space formed between the lower surfaces of the substrates and the substrate placement surfaces; and generating plasma in the chamber.