Phase shift mask and method of producing the same

TLDR: A phase shift mask, e.g., halftone phase shift masks as discussed by the authors, is a mask that can suppress the occurrence of a sub-peak of light intensity, which has an adverse effect on the image formation, and has a light blocking pattern with a reduced transmittance at a region outside a device pattern area which corresponds to a region subjected to multiple exposure during transfer effected by using the mask.

Abstract: A phase shift mask, e.g. a halftone phase shift mask, which need not to form an ultra-fine pattern and is capable of suppressing during exposure the occurrence of a sub-peak of light intensity, which has an adverse effect on the image formation, and which has a light-blocking pattern with a reduced transmittance at a region outside a device pattern area which corresponds to a region subjected to multiple exposure during transfer effected by using the mask. The halftone phase shift mask has on a transparent substrate (101) a halftone phase shift film (102) comprising a single layer or a plurality of layers. The composition of the halftone phase shift film (102) is changed in a region (107) outside a device pattern area on the transparent substrate (101) which corresponds to a multiple-exposure region by a method wherein the region (107) is irradiated with an electromagnetic wave, a particle beam, heat rays, etc., or a method wherein after a region in which the composition is not desired to change has been masked, the whole blank is exposed to an active atmosphere, thereby reducing the transmittance for exposure light at the region (107).