Patent ID: 8384878
Filing Date: 2013-02-26
Classification: G03B,G03F

Abstract:
1. An apparatus comprising: a stage configured to move a substrate; an optical system configured to project an image of a pattern on an original onto the substrate; an alignment detection system configured to detect an image of an alignment mark formed on the substrate and measure a position of the alignment mark; and a focus detection system configured to measure a height of the substrate by projecting an image of an index mark onto the substrate, wherein the stage includes an alignment measurement mark and a focus measurement mark that has a positional relationship with the alignment measurement mark, wherein the alignment detection system measures a position of the alignment measurement mark, wherein the focus detection system measures a position of the image of the index mark by projecting the image of the index mark onto the focus measurement mark, and wherein a difference of the position of the image of the index mark from a designed value is corrected by switching a wavelength of detection light used in the focus detection system.