MASK DESIGN DEVICE AND MASK DESIGN METHOD

PROBLEM TO BE SOLVED: To provide a mask design device capable of further reducing loads of design work of a circuit designer in terms of designing a mask pattern.SOLUTION: A mask design device includes: cell data creation means that creates cell data; a layout data design unit that designs layout data of a semiconductor integrated circuit according to the created cell data; and a mask pattern design unit that designs a mask pattern of the semiconductor integrated circuit according to the layout data that is designed by the layout data design unit and structure data that is included in the cell data, and outputs mask data for generating the mask pattern. The mask pattern is constituted of a plurality of hierarchical layers of mask layer patterns. The mask pattern design unit includes: a mask pattern processing unit that designs a mask layer pattern of one hierarchical layer on the basis of a mask layer pattern of another hierarchical layer and physical restrictions of the structure data that is included in the cell data.