PHOTOMASK PROVIDED WITH PHASE SHIFT LAYER AND ITS PRODUCTION

摘要

PURPOSE:To produce a photomask provided with a multistage phase shift layer with high accuracy at a small number of stages at low cost in a state where the occurrence rate of defect is low. CONSTITUTION:In order to produce the photomask provided with the phase shift layer which has a light shielding pattern 32 and a phase shifter pattern 33 on a transparent substrate 30 and where the refractive index of the peripheral part 35 of the phase shifter pattern part which is positioned to be isolated from the light shielding pattern on the substrate 30 is different from that of the central part, the refractive index is changed to cause a phase difference on the central part by implanting ion 34 by using an ion beam focusing method only in the peripheral part 35 of the phase shifter pattern part 33 positioned to be isolated from the light shielding pattern 32 on the substrate 30 after forming the light shielding pattern 32 and the phase shifter pattern 33.