| 摘要 |
<p>PURPOSE: To enable clamping force of an electrostatic chuck for an attraction between the chuck and a wafer to be improved in strength and uniformity by a method, wherein the electrostatic chuck is equipped with an electrode composed of two separated parts. CONSTITUTION: A chuck 10 has a hub 12a and a rim 12b, and the hub 12a and the rim 12b are formed in one piece and electrically connected together but insulated from a doughnut-shaped electrode 14 which is located at the center of the chuck 10. The clamping source of the chuck 10 is formed as a disk of radius R and divided into three ring-shaped regions. The ring-shaped regions are separated by boundaries, a wall 16 and an outer edge 24. The wall 16 is located at a position distant from the center by R/4, and the outer edge 24 is located at a position distant from the center by 3R/4. The clamping surface is possessed of two electrodes 12 and 14, which are isolated from each other and equal in area, and the clamping surface area of the electrodes 12 and 14 are represented by a formula, (πR<2> )/2. Furthermore, the two separate clamping surfaces are symmetrically distributed in area, so that a clamping force which is uniform and strong can be obtained.</p> |
