Method of making conductive paths through a lamina in a semiconductor device
AssigneeInternational Business Machines Corporation
InventorHolger Moritz
Life of this patent
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Abstract
On the layer 12 a mask 3 corresponding to the desired pattern of holes 15 is provided with via openings 14 having overhanging walls. The layer 12 is selectively etched with a method where the etching attack takes place vertically to the layer surface, and wherein the mask 3 is thinned simultaneously, so that holes 15 are obtained having a cross-section increasing toward the mask 3. If subsequently material 16 for filling the holes 15 is applied in a blanket deposition these holes are completely filled when the material 16 has the same thickness as the layer 12 although the openings over the holes are decreasing with increasing thickness of the material 16. The layer 12 consists preferably of an insulation material, the mask 3 of positive photoresist, and the material 16 of a metal.
Claims8
A method of making and filling holes in a lamina disposed on a substrate comprising
- forming on said lamina a mask having a plurality of openings through which said lamina is exposed, each of said openings having overhanging walls such that the area of each opening adjacent to the lamina is greater than the area adjacent to the free surface of the mask,
- subjecting said mask and said lamina to an etching process having a preferred direction of etching perpendicular to the plane of the mask with the etchant being chosen to etch both the mask and the lamina, to thereby etch holes in said lamina and reduce the thickness of the mask,
- subjecting said mask and the openings therein to the deposition of a filler material having a thickness substantially equal to the thickness of said lamina wherein the disposition has a preferential deposition perpendicular to the face of the mask, and
- removing said mask with its overlying layer of filler material to thus fully expose said lamina with its pattern of filled holes.
Dependencies are inferred from the claim text.