| 摘要 |
PURPOSE:To eliminate the contact of the mirror face of a wafer with a plurality of spaced ribs and to protect the mirror face of the wafer by providing the plurality of ribs oppositely on both inner faces of the sidewalls of a cage, and forming the ribs obliquely to the faces perpendicular to both the inner faces of the bottom and the sidewalls of the cage. CONSTITUTION:The sidewalls 22, 23 of a cage 2 are bent inward at the bottom face 24, and a wafer is inserted from above to be held in gaps of spaced ribs 26, 27 provided on its inner face. Since the ribs 26, 27 are inclined at an indexing bar 25 to a face 28 perpendicular to both the inner faces of the bottom and the sidewalls 22, 23, the mirror face of the wafer can be held in a noncontact state by inserting the rear face of the wafer toward the bar 25 with its mirror face directed toward its end wall 21. An inclining angle theta may be preferably 1 deg. or more. Accordingly, even when the wafer is conveyed in a state held in the cage 2, the noncontact state of the mirror face is maintained, thereby avoiding the adherence of particles thereto. |
