Patent ID: 7183025

Claim:
A phase difference specifying method comprising: preparing a phase shift mask having a first mask pattern and a second mask pattern, the first mask pattern comprising a backing film having a first shape which enables a first optical image to be formed on a predetermined substrate that is a target of exposure, the first optical image capable of forming a first resist pattern having a first width that changes depending on a distance from the predetermined substrate, the second mask pattern comprising a semi-transmissive film having a second shape which enables a second optical image to be formed on the predetermined substrate, the second optical image capable of forming a second resist pattern having a second width that changes depending on a distance from the predetermined substrate and on a thickness of the semi-transmissive film, the first mask pattern and the second mask pattern being separated from each other by a first interval; forming the first and second resist patterns on the predetermined substrate by exposing the predetermined substrate to light through the phase shift mask, the phase shift mask being arranged at a first position on a predetermined optical axis separated from the predetermined substrate by a first distance; obtaining the difference between the first width of the first resist pattern and the second width of the second resist pattern; and obtaining the difference between the phases of a first light passing through the phase shift mask except for regions where the first and second mask patterns are formed, and a second light passing through the second mask pattern, based on the width difference between the first resist pattern and the second resist pattern.