BURLS WITH ALTERED SURFACE TOPOGRAPHY FOR HOLDING AN OBJECT IN LITHOGRAPHY APPLICATIONS

摘要

Various burl designs for holding an object in a lithographic apparatus are described. A lithographic apparatus includes an illumination system, a first support structure, a second support structure, and a projection system. The illumination system is designed to receive radiation and to direct the radiation towards a patterning device that forms patterned radiation. The first structure is designed to support the patterning device on the first support structure. The second support structure (402) has a plurality of burls (406) and is designed to support the substrate (408) on the plurality of burls. A topography of a top surface of each of the plurality of burls is not substantially flat, such that a contact area between the substrate and each of the plurality of burls is reduced. The projection system is designed to receive the patterned radiation and to direct the patterned radiation towards the substrate.