Methods for measuring image-formation characteristics of a projection-optical system

摘要: Methods and apparatus are disclosed for exposing a reticle pattern onto sensitive substrate (such as sensitized semiconductor wafer) by projection-exposure at high focusing precision. According to the method, multiple evaluation marks projected an area of surface form images marks. An image measurement mark is on or near least some Respective Z-direction displacements each relative reference plane detected detecting characteristic respective that varies with change in position mark. Based such measurements, axial relationship projection-optical system can be changed place best-focus before pattern. Associated also disclosed.