Patent ID: 7745842

Claim:
A graytone mask having an opaque section, a light transmission section, and a graytone section, wherein said graytone section permits transmission of a portion of an exposure light so that an area of photoresist film exposed with the graytone mask, corresponding to the graytone section, upon development, remains with a thickness different from an area corresponding to the opaque section or the light transmission section, said mask comprising: a transparent substrate; a semi-transparent film having a transmissivity of 20 to 50% of the exposure light; and an opaque film which substantially reduces the transmission of the exposure light, wherein the semi-transparent film comprises a different material than the opaque film, wherein the opaque section of the mask comprises the semi-transparent film and the opaque film formed on the substrate, wherein the graytone section of the mask comprises the semi-transparent film formed on the substrate.