Patent ID: 8026025
Filing Date: 2011-09-27
Classification: G03F

Abstract:
1. A method of manufacturing an exposure mask, comprising the steps of: preparing a mask blank having a thin film formed on a main surface of a transparent substrate; and patterning the thin film; wherein the transparent substrate of the mask blank has a precision-polished main surface, and wherein with respect to the transparent substrate of the mask blank, height information from a reference plane at a plurality of measurement points provided in a predetermined region on the main surface of the transparent substrate that contacts a mask stage of an exposure apparatus has been obtained as surface shape information of the main surface, height information from the reference plane at the plurality of measurement points where the transparent substrate is set in the exposure apparatus has been simulated based on the surface shape information and shape information of the mask stage including a region where the mask stage contacts the main surface of the transparent substrate, a difference between a maximum value and a minimum value in a predetermined region including a transfer region of the exposure mask has been derived based on the simulated height information from the reference plane to thereby obtain a flatness of the transparent substrate when the transparent substrate is set in the exposure apparatus, the flatness has been judged to satisfy a specification, and the simulated height information has been determined based upon a deflection differential equation in mechanics of materials, the deflection differential equation comprising at least (1) the height information as the surface shape information, (2) a warp of the transparent substrate along an X-direction with respect to the mask stage as fulcrums, and (3) a deflection of the transparent substrate along the X-direction due to gravity, the X-direction being a direction perpendicular to a longitudinal direction of the mask stage.