GRADATION MASK AND ITS MANUFACTURE

摘要

PURPOSE:To provide a gradation mask with stepwise change of the transmittance which can be manufactured in a correct, efficient and inexpensive manner. CONSTITUTION:A gradation mask where the transmittance is changed stepwise in the space over three steps which substantially includes 0% to 100% is manufactured by a manufacturing method including the process where the chromium compound 12 is provided on a transparent substrate 11 to make a film of uniform thickness with transmittance of 0%, the process where the film 12 of chromium compound in the specified region (c) is removed by etching, and the process where etching of the rest of the chromium compound is achieved so that the film thickness in specified region (b) may be the film thickness of the specified intermediate transmittance.