Patent ID: 7736528

Claim:
A plasma processing apparatus, comprising: a tray for conveying a substrate, the tray being formed with a substrate accommodation hole for accommodating the substrate and having a plurality of substrate support portions provided on a hole wall of the substrate accommodation hole at intervals in a circumferential direction of the hole wall, and the substrate support portions projecting from the hole wall; a dielectric member provided with a tray support portion, a substrate placement portion projecting upward from the tray support portion and having a substrate placement surface at its upper end surface on which a lower surface of the substrate is placed, and an electrostatic attraction electrode embedded therein for electrostatically attracting the substrate to the substrate placement surface, an outer peripheral surface of the substrate placement portion being formed with a plurality of receiving grooves extending from the substrate placement surface toward the tray support portion; a dc voltage applying mechanism for applying a dc voltage to the electrostatic attraction electrode; a heat conduction gas supply mechanism for supplying a heat conduction gas between the lower surface of the substrate and the substrate placement surface; wherein, when the substrate is conveyed, an outer peripheral edge of the lower surface of the substrate accommodated in the substrate accommodation hole is supported by the substrate support portions, and wherein, when the substrate is processed, the substrate placement portion is inserted to the substrate accommodation hole, which allows the substrate placement surface to pass in thickness direction of the tray, from a lower surface of the tray so that the lower surface of the tray is placed on the tray support portion of the dielectric member, and a distance from the tray support portion to upper surfaces of the substrate support portions smaller than a distance from the tray support portion to the substrate placement surface results in that the lower surface of the substrate is placed on the substrate placement surface in a manner where the substrate floats above the upper surfaces of the substrate support portions received in the receiving grooves.