Lithographic Apparatus With A Metrology System For Measuring A Position Of A Substrate Table

Abstract

A lithographic apparatus comprises a substrate table for accommodating a substrate; a projection system for imaging a pattern onto the substrate, and a metrology system for measuring a position of the substrate table with respect to the projection system. The metrology system comprises a metrology frame connected to the projection system, a grid positioned stationary with respect to the metrology frame, and an encoder connected to the substrate table and facing the grid for measuring the position of the substrate table relative to the grid. The metrology frame has a surface oriented towards the substrate table, and the surface has been configured, e.g., by writing or etching, so as to form the grid.

Dependencies are inferred from the claim text.