Patent ID: 8012654
Filing Date: 2011-09-06
Classification: G03F,Y10T

Abstract:
1. A photomask comprising a transparent substrate and a mask pattern formed thereon, said substrate comprising phase shift regions formed by etching the transparent substrate, and said mask pattern comprising transparent regions and light-shielding regions, and said mask pattern comprising an etch stop film disposed on the substrate, said etch stop film of single layer or multilayer construction being resistant to fluorine dry etching and removable by chlorine dry etching, a light-shielding film disposed contiguous to said etch stop film and consisting of a single layer or multiple layers composed of a material containing a transition metal and silicon, and an antireflective film disposed contiguous to said light-shielding film and consisting of a single layer or multiple layers, wherein said transition metal is at least one element selected from the group consisting of titanium, vanadium, cobalt, nickel, zirconium, niobium, molybdenum, hafnium, tantalum, and tungsten, and an optical density OD of the combination of etch stop film, light-shielding film and antireflective film is at least 2.5.