WAFER SUPPORTING BOAT AND A RING MOUNTED ON THE SAME

摘要

PURPOSE: A wafer supporting boat is provided to prevent a process defect of a wafer, by transforming a shape of each ring constituting the boat, and by improving uniformity of a thin film formed in the center and outer part of the wafer. CONSTITUTION: A wafer supporting boat(10) comprises first-type rings in an upper region and second-type rings in a lower region. The first-type rings each has an opening in the center. A plurality of tips on which a wafer is placed is established on an outer element in an outer part of the opening. The second-type rings each has an opening in the center. An outer element in an outer part of the opening includes the first surface(42-1) adjacent to the opening and the second surface(42-2) thicker than the first surface. A plurality of tips on which the wafer is placed is established on the second surface.