Bottom-up plating of through-substrate vias
View Patent ↗According to one embodiment of the present invention, a method of plating a TSV hole in a substrate is provided. The TSV hole may include an open end terminating at a conductive pad, a stack of wiring levels, and a plurality of chip interconnects. The method of plating a TSV may include attaching a handler to the plurality of chip interconnects, the handler having a conductive layer in electrical contact with the plurality of chip interconnects; exposing a closed end of the TSV hole, including the conductive pad, to an electrolyte solution; and applying an electrical potential along an electrical path from the conductive layer to the conductive pad causing conductive material from the electrolyte solution to deposit on the conductive pad and within the TSV hole, the electrical path including the conductive layer, the plurality of chip interconnects, the stack of wiring levels and the conductive pad.
1. A method of plating a through-substrate via (TSV) hole in a substrate, the TSV hole comprising an open end terminating at a conductive pad, a stack of wiring levels superimposed to one another positioned on top of the conductive pad, and a plurality of chip interconnects configured on a top surface of an upper wiring level, the method comprising:
attaching a handler to the plurality of chip interconnects with a temporary solder contact, the handler comprising a conductive layer in electrical contact with the plurality of chip interconnects via the temporary solder contact;
exposing a closed end of the TSV hole, including the conductive pad, to an electrolyte solution; and
applying an electrical potential along an electrical path from the conductive layer to the conductive pad causing conductive material from the electrolyte solution to deposit on the conductive pad and within the TSV hole, the electrical path comprising the conductive layer, the plurality of chip interconnects, the stack of wiring levels and the conductive pad,
wherein the conductive layer is formed on a top surface of the handler, further comprising forming one or more conductive channels extending from the conductive layer to a bottom surface of the handler.
2. The method of claim 1 , further comprising:
depositing a dielectric layer adjacent to a sidewall of the TSV hole.
3. The method of claim 2 , further comprising:
depositing a diffusion barrier layer on top of the dielectric layer.
4. The method of claim 1 , further comprising:
filling the TSV hole with a sacrificial material; and
removing the sacrificial material selective to the conductive pad.
5. The method of claim 1 , wherein the plurality of chip interconnects comprises a controlled collapse chip connection.
6. The method of claim 1 , wherein the plurality of chip interconnects comprises a copper pillar solder bump.
7. The method of claim 1 , wherein the conductive layer comprises a transparent conductive material.
8. The method of claim 1 , wherein the handler comprises a temporary chip attachment pad positioned along a bottom surface of the handler, the electrical path further comprising the temporary chip attachment pad.
9. The method of claim 1 , wherein the handler comprises a temporary chip attachment pad positioned along a bottom surface of the handler, the conductive channel extending from the conductive layer along the top surface of the handler to the temporary chip attachment pad, and the electrical path further comprising the conductive channel and the temporary chip attachment pad.