| 摘要 |
PROBLEM TO BE SOLVED: To prevent the dispersion depending on an attaching position of a wafer and to improve a yield rate by providing a wafer holding surface with void with a specific area occupation rate and flattening the surface excluding voids. SOLUTION: In a grinding process of a wafer, the wafer 2 is attached to a plate 1 by means of the wax 3, or fixed by vacuum suction. The plate 1 is formed by ceramic such as alumina or the like, a holding surface 1a of the wafer 2 has voids 6 with 5-15% area occupation rate, and the surface excluding voids is a flat surface of below 2 μm of flatness. As the surface is free from projecting parts, and has only recessed part formed by voids 6, the wafer 2 can be prevented from being damaged. Further by putting the wax 3 in the recessed parts of the voids 6, a contact angle is reduced, and the wettability of the wax can be improved, which improves a yield rate of the wafer 2. |
