DUMMY DIFFRACTION MASK AND FABRICATION METHOD

摘要

A structure and method of transform unresolution diffraction mask is provided to improve resolution of main mask and focusing depth. The mask comprises: an unite-type transform unresolution diffraction mask including a half-tone PSM(phase shift mask) pattern(2) made of Cr formed on a main mask of a quartz substrate(1) and an unresolution diffraction layer(3) formed on the surface of the half-tone PSM; and a separate-type transform unresolution diffraction mask including a Cr layer(2) for forming a half-tone PSM formed on the main mask of a quartz substrate(1) and an unresolution diffraction mask(3) separately form the half-tone PSM on the quartz substrate(1).