Reed Smith LLP
Wafer holder
A wafer (22) is placed on an upper surface of a holder body (23), and the holder body is inserted into a plurality of holder-aimed concave recesses (14) formed on supporters (12) accommodated in a heat treatment furnace such that the holder body is held horizontally. The holder body is formed into a disk shape free of recessed cut portions, and the holder body is formed with an upwardly projecting ring-like projection (24) extending in the circumferential direction of the holder body around the axis of the holder body. The wafer holder is constituted such that the wafer is placed on the holder body while contacting with the upper surface of the projection, and such that the outer diameter of the projection is formed to be in a range of 0.5D to 0.98D wherein D is the diameter of the wafer, so that the outer periphery of the wafer is kept from contacting with the projection.Occurrence of slips in the wafer is restricted by preventing warpage of the holder body upon fabricating the holder body. Further, each of wafers having different diameters is assuredly held by the same holder body without deviating from a relevant predetermined position. Moreover, the working operations for loading and unloading the wafer to and from the holder body are smoothly conducted.
Shinku Giken Co., Ltd. Mitsu Engineering & Ship Building Co., Ltd. Mitsubishi Materials Silicon Corporation
H H C H C C
H01L H01L C30B H01L C30B C23C
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Tetsuya Katsuo Makoto Yasuhiko Makoto Fumitomo
Nakai Arai Saito Kawamura Shinohara Kawahara