Bi-convex solid immersion lens
AssigneeCredence Systems Corporation
InventorsNader Pakdaman, James S. Vickers
Life of this patent
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Abstract
A bi-convex solid immersion lens is disclosed. Unlike conventional plano-convex solid immersion lenses having a flat bottom surface, the disclosed lens has a convex bottom surface. The radius of curvature of the bottom surface is smaller than that of the object to be inspected. This construction allows for a more accurate determination of the location of the inspected feature, and enhances coupling of light between the immersion lens and the inspected object. The disclosed lens is particularly useful for use in microscope for inspection of semiconductor devices and, especially flip-chip (or chip scale) packaged devices. The immersion lens can also be incorporated in a read or read/write head of optical memory media.
Claims20
An arrangement for imaging a semiconductor specimen using a bi-convex immersion lens, comprising:
- a semiconductor specimen;
- a bi-convex solid immersion lens coupled to said specimen so as to capture evanescent wave energy from said specimen;
- wherein said lens comprise:
- an upper convex surface having a first finite radius of curvature and a first boundary;
- a bottom convex surface having a second finite radius of curvature and a second boundary;
- and,
- wherein said first and second boundaries coincide.
A method for imaging a flat, rigid, specimen using a bi-convex immersion lens, comprising:
- situating the specimen onto a carrier;
- coupling the bi-convex lens onto the specimen, so that said bi-convex lens captures evanescent wave energy from said specimen;
- providing an objective lens so as to collect light energy from said bi-convex lens;
- wherein said bi-convex lens comprises an upper convex surface having a first finite radius of curvature and a first boundary, and a bottom convex surface having a second finite radius of curvature and a second boundary, and wherein said first and second boundaries coincide.
Dependencies are inferred from the claim text.