Patent ID: 9058457
Filing Date: 2015-06-16
Classification: G03F,G06F,H01L

Abstract:
1. A method of determining focal planes during a photolithographic exposure of a wafer surface, the method comprising: receiving, from a topography mapping tool, data corresponding to a surface topography of the wafer surface; determining by a processing unit, based on the received data corresponding to the surface topography, a plurality of regions of the wafer surface that each comprise a substantially different topography height range having a substantially the same topography height difference; receiving, by the processing unit, reticle design data for exposure on the wafer surface; generating, by the processing unit from the received reticle design data, reticle design data subsets that are each located within a corresponding one of the determined plurality of regions of the wafer surface; determining a best fit focal plane for each of the determined plurality of regions; and exposing the wafer surface with a plurality of reticles that each include a corresponding one of the generated reticle design data subsets located within the corresponding one of the determined plurality of regions, wherein each of the plurality of reticles operates using the best fit focal plane for the corresponding one of the determined plurality of regions.