Numerical aperature increasing lens (nail) techniques for high-resolution sub-surface imaging
AssigneeTrustees of Boston University
InventorsStephen B. Ippolito, M. Selim Unlu, Bennett B Goldberg
Life of this patent
Estimating the term…
Abstract
A viewing enhancement lens (18-NAIL) which functions to increase the numerical aperture or light gathering or focusing power of viewing optics such as a microscope (26) used to view structure within a substrate such as a semiconductor wafer or chip or of imaging optics such as media recorders. The result is to increase the resolution of the system by a factor of between n, and n2, where n is the index of retraction of the lens substrate.
Claims52
A lens for use in a system for coupling light into or from a substrate of a material through a surface thereof, said substrate containing a fabricated structure below the surface that emits blackbody radiation, thereby allowing for thermal imaging,
- said lens having a first surface matching the surface of said substrate and a second surface having a convex shape;
- said lens having a zone of focus in which said fabricated structure is contained, when the first surface thereof is in contact with said substrate surface;
- and
- said light passing through said convex surface with phase fronts geometrically distinct from said convex surface shape.
An optical system including a lens for coupling light into or from a substrate,
- the lens having a first surface matching a surface of said substrate and a second surface having a spherical convex shape;
- the lens having a zone of focus, when the first surface thereof is in contact with said substrate surface, within said substrate;
- said light passing through said convex surface with phase fronts geometrically distinct from said convex surface shape;
- wherein said lens has a radius of curvature, R, and said material has an index of refraction, n, and said zone of focus occurs at a radius of R/n from the geometrical center of said spherical convex surface,
- and wherein said zone of focus is aberration corrected and extends over a range of radii such that a surface cutting said zone orthogonal to the radius has a region of aberration corrected focus.
An optical system including an array of lenses for coupling light into or from a substrate, each lens:
- having a first surface matching a surface of said substrate and a second surface having a convex shape;
- and
- having a zone of focus, when the first surface thereof is in contact with said substrate surface, within said substrate;
- said light passing through said convex surface with phase fronts geometrically distinct from said convex surface shape;
- and said optical system being responsive to light from said lenses to provide imaging of objects at said zone of focus.
An optical system including a lens for coupling light into or from a substrate,
- the lens having a first surface matching a surface of said substrate and a second surface having a convex shape;
- the lens having a zone of focus, when the first surface thereof is in contact with said substrate surface, within said substrate;
- said light passing through said convex surface with phase fronts geometrically distinct from said convex surface shape;
- and said optical system being responsive to light from said lenses to provide imaging of objects at said zone of focus,
- the optical system further including an objective lens or set of lenses for adjusting the depth of said zone of focus in said substrate.
An optical system including a lens for coupling light into or from a substrate,
- the lens having a first surface matching a surface of said substrate and a second surface having a convex shape;
- the lens having a zone of focus, when the first surface thereof is in contact with said substrate surface, within said substrate;
- said light passing through said convex surface with phase fronts geometrically distinct from said convex surface shape;
- said optical system being responsive to light from said lenses to provide imaging of objects at said zone of focus,
- said optical system having an objective lens and an exit lens whose principle points are separated by a distance, d, according to the relationship d=f1+f2+f12/R(n+1/n), R being the radius of curvature of the lens and n being an index of refraction for said lens and substrate.
An optical system including a lens for coupling light into or from a substrate,
- the lens having a first surface matching a surface of said substrate and a second surface having a convex shape;
- the lens having a zone of focus, when the first surface thereof is in contact with said substrate surface, within said substrate;
- said light passing through said convex surface with phase fronts geometrically distinct from said convex surface shape;
- said optical system being responsive to light from said lenses to provide imaging of objects at said zone of focus,
- said optical system providing broad spectral chromatic aberration correction at IR wavelengths for thermal imaging.
An optical system including a lens for coupling light into or from a substrate,
- the lens having a first surface matching a surface of said substrate and a second surface having a convex shape;
- the lens having a zone of focus, when the first surface thereof is in contact with said substrate surface, within said substrate;
- said light passing through said convex surface with phase fronts geometrically distinct from said convex surface shape;
- said optical system being responsive to light from said lenses to provide imaging of objects at said zone of focus,
- said optical system providing for operation at near-IR wavelengths for through the substrate visual inspection of semiconductor circuits and devices.
An optical system including a lens for coupling light into or from a substrate,
- the lens having a first surface matching a surface of said substrate and a second surface having a convex shape;
- the lens having a zone of focus, when the first surface thereof is in contact with said substrate surface, within said substrate;
- said light passing through said convex surface with phase fronts geometrically distinct from said convex surface shape;
- said optical system being responsive to light from said lenses to provide imaging of objects at said zone of focus,
- the optical system including a system for measuring Raman scattering.
An optical system including a lens for coupling light into or from a substrate,
- the lens having a first surface matching a surface of said substrate and a second surface having a convex shape;
- the lens having a zone of focus, when the first surface thereof is in contact with said substrate surface, within said substrate;
- said light passing through said convex surface with phase fronts geometrically distinct from said convex surface shape;
- said optical system being responsive to light from said lenses to provide imaging of objects at said zone of focus,
- the optical system including a system for time-resolved measurements.
A lens for coupling light into or from an object a distance X below a surface thereof,
- said lens comprising a material having an index of retraction n substantially equal to the index of refraction of said object,
- said lens having a first surface matching said surface of said object and a second surface opposite said first surface, said second surface having a spherical convex shape with a radius of curvature R,
- and said lens having a thickness D substantially satisfying the following relationship:
- D=R(1+1/n)−X.
An optical system including one or more lenses in combination with one or more lenses of claim 32 to provide correction of chromatic aberration.
An optical system including a lens of claim 32 and being responsive to light from said lens to provide imaging at said distance X below the surface of the object.
A lens for coupling light into or from an object a distance X below a surface thereof, said viewing system having predefined working distance W,
- said lens comprising a material having an index of refraction n substantially equal to the index of refraction of the object,
- and said lens having a lower surface matching the surface of said object and an upper surface having a spherical convex shape with a radius of curvature R, the radius R being less than substantially W/(n+1).
Dependencies are inferred from the claim text.