Multiple exposure method for forming a patterned photoresist layer

A method for forming a patterned layer comprising:

• providing a substrate;
• forming over the substrate a target layer;
• forming upon the target layer a blanket photoresist layer;
• exposing the blanket photoresist layer while employing a first direct write exposure method to form within the blanket photoresist layer an exposed peripheral sub-region of a desired exposed pattern, the exposed peripheral sub-region having an inner border and an outer border;
• photoexposing the blanket photoresist layer while employing a second masked photoexposure method to form within the blanket photoresist layer a masked photoexposed bulk sub-region of the desired exposed pattern, where the masked photoexposed bulk sub-region overlaps the inner border but does not reach the outer border, to form the desired exposed pattern within a once masked photoexposed once direct write exposed blanket photoresist layer;
• developing the once masked photoexposed once direct write exposed blanket photoresist layer to form a patterned photoresist layer;
• and
• employing the patterned photoresist layer as an etch mask for etching the target layer to form a patterned target layer.

A method for forming a phase shift mask comprising:

• providing a transparent substrate;
• forming over the transparent substrate a patterned attenuating phase shift material layer;
• forming aligned upon the patterned attenuating phase shift material layer a patterned opaque material layer;
• forming upon exposed portions of the transparent substrate, the patterned attenuating phase shift material layer and the patterned opaque material layer a blanket photoresist layer;
• exposing the blanket photoresist layer while employing a first direct write exposure method to form within the blanket photoresist layer an exposed peripheral sub-region of a desired exposed pattern, the exposed peripheral sub-region having an inner border and an outer border;
• photoexposing the blanket photoresist layer while employing a second masked photoexposure method to form within the blanket photoresist layer a masked photoexposed bulk sub-region of the desired exposed pattern, where the masked photoexposed bulk sub-region overlaps the inner border but does not reach the outer border, to form the desired exposed pattern within a once masked photoexposed once direct write exposed blanket photoresist layer;
• developing the once masked photoexposed once direct write exposed blanket photoresist layer to form a patterned photoresist layer;
• and
• employing the patterned photoresist layer as an etch mask for further etching the patterned opaque material layer to form a twice patterned opaque material layer border which leaves exposed a surface portion of the patterned attenuating phase shift material layer.