| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve the suction holding capacity to a large-diameter substrate of a substrate holder. SOLUTION: A substrate holder is provided with two or more places of suction ports 10a-10d for sucking a substrate to the topside of a rotary stage 1a which rotates horizontally, sucking and holding the substrate, thus the suction force to the substrate is dispersed. It is better to provide the suction ports 10a-10d in roughly symmetrical positions to the center of the rotary stage 1a. This is provided with horizontal ports 14a-14d made in cross-shaped radial in the direction from the center of rotation to the side, inside the rotary stage 1a. Stopcocks 16a and 16b (16c and 16d) are put into the ends of these horizontal holes 14a-14d so that the air may not leak. Each horizontal hole 14a-14d is connected to the vertical hole 12 provided in vertical direction at the center of a support 1b. Each suction port 10a-10d is connected to each horizontal hole 14a by the connection port opened vertically downward from each suction port 10a-10d.</p> |
