Patent ID: 6118515
Filing Date: 2000-09-12
Classification: G03F

Abstract:
A scanning exposure method comprising the steps of:illuminating a predetermined illumination region of a pattern on a mask to project the pattern in said illumination region onto a plurality of shot areas on a substrate through an optical projection system;detecting, by a read-ahead system, the height of said substrate in the direction along the optical axis of said optical projection system at a read-ahead region before said exposure region with respect to the scanning direction for said exposure region while scanning said substrate in a predetermined direction with respect to said exposure region conjugate to said illumination region in synchronization with scanning said mask in the direction opposite to said predetermined direction with respect to said illumination region; andwhen shot areas at the outer periphery of said substrate are exposed, scanning said substrate in a direction such that said exposure region moves relatively on the outside of said outer periphery from the inside to the outside of said substrate, while correcting the height of said exposure surface in said shot areas based on the height of said exposure surface of the substrate, which is read ahead at said read-ahead region.