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AssigneeTropel Corporation
InventorsJohn H. Bruning, Anthony R. Phillips, Jr., David R. Shafer, Alan D. White
Estimating the term…
Optimum solutions for three-mirror lenses for projection lithography cameras using X-ray radiation to image a mask on a wafer are represented as single points within regions of two-dimensional magnification space defined by the magnification of a convex mirror as one coordinate and the ratio of the magnifications of a pair of concave mirrors optically on opposite sides of the convex mirror as another coordinate. Lenses within region 30, 50, and preferably within region 40, 60, of such magnification space represent potential solutions that are optimizable by standard computer optical design programs and techniques to achieve extremely low distortion lenses having a resolution of about 0.1 micron or less. Two of these lens systems having large chief ray angles at the mask and chief rays inclined away from the optical axis of the lens system in a direction from the source toward the mask are described in more detail.
A lens system for a projection lithography camera having a source of x-ray radiation, a wafer, and a mask to be imaged on the wafer, the lens system having a convex mirror M.sub.2 arranged optically between concave mirrors M.sub.1 and M.sub.3 to form an imaging system, and the lens system comprising:
A lens system for an x-ray projection lithography camera having a source of x-ray radiation directed from a mask through an imaging system to a wafer so that the mask is imaged on the wafer, the imaging system being formed of a pair of concave mirrors optically on opposite sides of a convex mirror, the lens system comprising:
Dependencies are inferred from the claim text.