Patent ID: 9740109
Date: 2017-08-22
CPC Classifications: G03F,H01L

Claim:
1. A holding device that is configured to hold a substrate comprising: a holding member in which a plurality of intake holes used for evacuating air in a space between a substrate and the holding member are formed; and a seal member that has a ring shape and is disposed on a lower surface of a stepped portion of the holding member and that defines the space, wherein, when an inner region of a figure that is concentric with a center of a plane figure of a holding surface of the holding member and that is obtained by reducing a size of the plane figure by ⅔ or more and ⅘ or less is set as a first region, and a region between the first region and the seal member is set as a second region, the plurality of intake holes are formed in such a manner that a relationship of, ratio of total area of intake holes formed in the second region to area of the second region is greater than, ratio of the total area of intake holes formed in a sum region that includes the first region added to the second region to area of the sum region, is satisfied, and wherein the plurality of intake holes are in communication with a common pipe.