Patent ID: 7226866

Claim:
A reticle manufacturing method comprising: a step of forming a light shielding layer, a first mask layer, a second mask layer, a lift-off layer, and a third mask layer in this order on a transparent substrate; a step of patterning the third mask layer to form a third mask pattern having a third wide mask portion and a third narrow mask portion; a step of etching the lift-off layer while using the third mask pattern as a mask, to form a lift-off pattern having a wide pattern portion and a narrow pattern portion under the third wide mask portion and the third narrow mask portion respectively; a step of etching the second mask layer while using the lift-off pattern as a mask, to form a second mask pattern having a second wide mask portion and a second narrow mask portion under the wide pattern portion and the narrow pattern portion respectively; a step of retreating side surfaces of the lift-off pattern, to remove the narrow pattern portion and thus lift off the third narrow mask portion on the narrow pattern portion and to reduce an area of the wide pattern portion; a step of etching the first mask layer while using the second mask pattern as a mask, to form a first mask pattern having a first wide mask portion and a first narrow mask portion under the second wide mask portion and the second narrow mask portion respectively; a step of etching the light shielding layer while using the first mask pattern as a mask, to form a light shielding pattern having a wide light shielding portion and a narrow light shielding portion under the first wide mask portion and the first narrow mask portion respectively; a step of etching the transparent substrate while using the light shielding mask pattern as a mask, to reduce a thickness of a portion of the transparent substrate not covered with the second mask pattern and to make portions of the transparent substrate not etched and left under the wide mask portion and the narrow mask portion into a wide convex pattern and a narrow convex pattern respectively; a step of removing the third mask pattern; a step of retreating side surfaces of the first mask pattern to reduce an area of the first wide mask portion; a step of etching the second mask pattern to reduce at least an area of the second wide mask portion smaller than an area of the first wide mask portion; a step of etching the wide light shielding portion while using the first wide mask portion as a mask to reduce an area of the wide light shielding portion; and a step of removing the narrow light shielding portion.