Patent ID: 8643190

Claim:
A microelectronic structure comprising: a substrate including an aperture at least partially through the substrate; a first comparatively wide region of the aperture located above an upper surface of the substrate, wherein sidewalls of the first comparatively wide region are provided by a dielectric layer through which the first comparatively wide region is present, wherein the sidewalls of the first comparatively wide region are entirely perpendicular to and are in direct contact with a portion of the upper surface of the substrate that constitutes a bottom surface of the first comparatively wide region, and wherein an outer periphery of the portion of the upper surface of the substrate adjoining a bottommost periphery of the sidewalls of the first comparatively wide region; a constricted region of the aperture contiguous with the first comparatively wide region, wherein the constricted region begins at an opening through the portion of the upper surface of the substrate extending into the substrate, the constricted region having a width that is less than a width of the first comparatively wide region, wherein the portion of the upper surface of the substrate continuously encircles the opening and the opening is laterally spaced from the outer periphery of the portion of the upper surface of the substrate; a second comparatively wide region of the aperture contiguous with the constricted region extending further into the substrate, wherein the second comparatively wide region has a greater width than the constricted region; an inward tapered region of the aperture contiguous with the second comparatively wide region extending still further into the substrate; and a conductive material fill in the aperture with a void defined within the conductive material in the second comparatively wide region with the void spaced apart from the substrate.