IMPROVED EXTREME ULTRAVIOLET LITHOGRAPH SYSTEM, PUPIL PHASE MODULATOR, AND METHOD OF APPLYING AN EXTREME ULTRAVIOLET LITHOGRAPH PROCESS ON A WAFER

摘要

A lithography system comprising: a radiation source (32) configured to generate extreme ultraviolet (EUV) light; a mask (36) defining one or more features of an integrated circuit (IC); an illuminator (34) configured to direct the EUV light onto the mask in an illumination mode, the mask diffracting the EUV light into an o th order beam and a plurality of higher order beams; a wafer stage (42 ) configured to hold a wafer to be patterned according to one or more features defined by the mask; and a pupil phase modulator (600) disposed in a pupil plane between the mask and the wafer stage, wherein the pupil phase modulator is configured to change a phase of the o-th order beam; wherein the illumination mode of the illuminator comprises a first structure that is transparent; the pupil phase modulator (600) comprises a second structure that conforms to the first structure, the second structure configured to o-ter the phase of the beam Order changes; and the second structure comprises a first phase shifting layer (88); and wherein the pupil phase modulator (600) further comprises a second phase shifting layer (86) having a different material composition than the first phase shifting layer.