| CPC G03F 1/32 (2013.01) [G03F 1/38 (2013.01); G03F 1/80 (2013.01); H01L 21/3083 (2013.01)] | 20 Claims |
|
1. A method, comprising:
forming a photo resist layer over a mask blank, which includes a mask substrate, a phase shift layer disposed on the mask substrate and a light blocking layer disposed on the phase shift layer;
forming a photo resist pattern by using a lithographic operation;
patterning the light blocking layer by using the photo resist pattern as an etching mask;
patterning the phase shift layer by using the patterned light blocking layer as an etching mask;
covering a border region of the mask substrate, on which the patterned light blocking layer remains, with a sintered body etching hard cover, which does not include an O-ring, while a pattern region of the mask substrate is exposed through an opening of the sintered body etching hard cover, wherein the sintered body etching hard cover is in direct contact with an uppermost surface of patterned light blocking layer in the border region;
etching the patterned light blocking layer in the pattern region through the opening of the sintered body etching hard cover; and
performing a photo-etching operation on the pattern region to remove residues of the light blocking layer.
|