Patent ID: 7199936

Claim:
A semiconductor substrate processing apparatus comprising: a substrate support to support a semiconductor substrate; an electromagnetic radiation source to emit electromagnetic radiation; a polarization subsystem comprising: a polarizing beam splitter being radially symmetric about a central axis thereof to split the electromagnetic radiation into first and second portions, each of the first and second portions having a plurality of sections, the first portion propagating in a first direction substantially parallel to the central axis of the beam splitter, each respective section of the first portion being linearly polarized in a direction parallel to a line extending between the central axis of the beam splitter and the respective section of the first portion, the second portion propagating radially from the central axis of the beam splitter, each respective section of the second portion being linearly polarized in a direction perpendicular to a line extending between the central axis of the beam splitter and the respective section of the second portion; a wave-plate being radially symmetric about the central axis of the beam splitter to change the linear polarization of the first portion such that each respective section of the first portion is linearly polarized in a direction perpendicular to the line extending between the central axis of the beam splitter and the respective section of the first portion; and at least one reflective device to reflect the second portion from the beam splitter into substantially the first direction, and a reticle positioned between the polarization subsystem and the substrate support, the first and second portions of the electromagnetic radiation to pass through the reticle and onto the semiconductor wafer.