Bonding process for CMOS image sensor
First Claim
1. A method of making an integrated circuit (IC), comprising:
- forming an electric device on a front side of a substrate;
forming a top metal pad on the front side of the substrate, the top metal pad being coupled to the electric device;
forming a passivation layer on the front side of the substrate, the top metal pad being embedded in the passivation layer;
forming an opening in the passivation layer, exposing the top metal pad;
forming a deep trench in the substrate through the opening without the deep trench extending through the top metal pad;
filling a conductive material in the deep trench and the opening, resulting in a through-wafer via (TWV) feature in the deep trench and a pad-TWV feature in the opening, where the top metal pad being connected to the TWV feature through the pad-TWV feature;
removing excessive conductive material, forming a substantially planar surface;
forming a dielectric layer on the front side of the substrate after removing the excessive conductive material;
grinding the substrate from a backside to expose the TWV feature; and
etching the substrate in a scribe region from the backside to form a scribe-line trench.
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Accused Products
Abstract
The present disclosure provides a method of making an integrated circuit (IC). The method includes forming an electric device on a front side of a substrate; forming a top metal pad on the front side of the substrate, the top metal pad being coupled to the electric device; forming a passivation layer on the front side of the substrate, the top metal pad being embedded in the passivation layer; forming an opening in the passivation layer, exposing the top metal pad; forming a deep trench in the substrate; filling a conductive material in the deep trench and the opening, resulting in a though-wafer via (TWV) feature in the deep trench and a pad-TWV feature in the opening, where the top metal pad being connected to the TWV feature through the pad-TWV feature; and applying a polishing process to remove excessive conductive material, forming a substantially planar surface.
154 Citations
19 Claims
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1. A method of making an integrated circuit (IC), comprising:
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forming an electric device on a front side of a substrate; forming a top metal pad on the front side of the substrate, the top metal pad being coupled to the electric device; forming a passivation layer on the front side of the substrate, the top metal pad being embedded in the passivation layer; forming an opening in the passivation layer, exposing the top metal pad; forming a deep trench in the substrate through the opening without the deep trench extending through the top metal pad; filling a conductive material in the deep trench and the opening, resulting in a through-wafer via (TWV) feature in the deep trench and a pad-TWV feature in the opening, where the top metal pad being connected to the TWV feature through the pad-TWV feature; removing excessive conductive material, forming a substantially planar surface; forming a dielectric layer on the front side of the substrate after removing the excessive conductive material; grinding the substrate from a backside to expose the TWV feature; and etching the substrate in a scribe region from the backside to form a scribe-line trench. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method of forming an integrated circuit, comprising:
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forming a semiconductor device in a front surface of a silicon substrate; forming a multilayer interconnection (MLI) on the semiconductor device from the front side of the silicon substrate; forming a metal pad on the MIA, the metal pad being coupled with the semiconductor device; forming a dielectric layer on the metal pad and the silicon substrate, the metal pad being embedded in the dielectric layer; etching the dielectric layer to form a trench in the dielectric layer, exposing the metal pad and a portion of the dielectric layer adjacent to the metal pad within the trench; performing a dielectric etch on the portion of the dielectric layer adjacent to the metal pad within the trench to form a via in the MLI; performing a silicon etch to continue the via through the silicon substrate to form a through-silicon via (TSV); performing copper metallization on the TSV and the trench; and thereafter applying a chemical mechanical polishing (CMP) process. - View Dependent Claims (11, 12, 13, 14, 15)
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16. An integrated circuit, comprising:
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an electric device formed on a front side of a substrate; a passivation layer formed on the front side of the substrate; a metal pad embedded in the passivation layer and coupled with the electric device; a through-wafer via (TWV) feature disposed in the substrate and extended to a backside of the substrate without passing through the metal pad, wherein the TWV feature is exposed on the backside of the substrate; a pad-TWV metal feature embedded in the passivation layer and contacting the metal pad and the TWV feature, wherein an excess portion of the pad-TWV is removed such that the pad-TWV and the passivation layer have coplanar top surfaces; a dielectric layer formed on the front side of the substrate after removal of the excess portion of the pad-TWV metal feature; and a scribe-line trench etched in a scribe region of the backside of the substrate. - View Dependent Claims (17, 18, 19)
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Specification