| 摘要 |
PROBLEM TO BE SOLVED: To apply polishing pressure to a wafer to be polished on both faces between fixed upper and lower plates with high precision. SOLUTION: A fixed upper plate 2 is supported above a fixed lower plate 1 via an elevating mechanism 20. The elevating mechanism 20 is provided with an elevating rod 21 elevated with the rotation of a servo motor 23 and a load cell 22 to detect axial load on the elevating rod 21. The elevating rod 21 suspends and supports the fixed upper plate 2 via springs 29, 29'. The spring 29 is a fixed plate holding spring which is compressed when the fixed upper plate 2 is suspended by the elevating rod 21, while the spring 29' is a fixed plate thrusting spring which is compressed when the fixed upper plate 2 is pushed against the fixed lower plate 1 by the elevating rod 21. The servo motor 2 is operated, while viewing a value for the load cell 22, and the elevating rod 21 is moved to the axial direction so that required polishing pressure can be applied to a wafer with high precision and stability. |
