Method of manufacturing a photomask comprising a phase shifter with a

Abstract

In a photomask, phase shifting members can be arranged all over a transfer pattern regardless of the configuration of the transfer pattern without exception. The phase shifting members are each formed in a multi-layer structure in which a first and a second phase shifting members are stacked one atop the other. The phase shifting angles of the first and the second phase shifting members are each smaller than 180 degrees but equal to 180 degrees in total. In an edge region of the phase shifting member not adjacent to a light shielding member, the overlying second phase shifting member extends over an edge of the underlying first phase shifting member and onto a transparent substrate. The edge of the second phase shifting member is finished in a tapering configuration by thermal treatment. Where the first and the second phase shifting members are in a stack, according to the principles of the phase shift method, a high resolution is yielded. At the edge region of the phase shifting member wherein the first phase shifting member extends over the edge of the second phase shifting member, the intensity of light transmitted therethrough would not drop to zero.