Patent Number: 
Section: abstract

A planar pattern (11), having a plurality of apertures of the same size (Wx×Wy), is determined by a two-dimensional layout determination tool (10), and a three-dimensional structure, having a depth d and an undercut amount Uc for making the phase of the transmitted light be shifted by 180 degrees with every even-numbered aperture, is determined by a three-dimensional structure determination tool (20). Simulation of transmitted light is executed for a structural body having the planar pattern (11) and the three-dimensional structure (21) by a three-dimensional simulator (30) to determine the light intensity deviation D of transmitted light for an odd-numbered aperture without a trench and an even-numbered aperture with a trench. At a two-dimensional simulator (40), simulations using a two-dimensional model prepared based on this deviation D are performed to determine a correction amount δ for making the deviation D zero and obtain a new planar pattern (12). The work load spent on designing a trench-type, Levenson-type phase shift mask can be lightened and the working time for the designing process can be shortened.