# US 2014/0154879 A1 · Methods of forming interconnects and semiconductor structures

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- Number: US 2014/0154879 A1
- Document ID: US20140154879A1
- Status: Published application
- Kind: A1
- Application number: 14/176,547
- Filed: 2014-02-10
- Published: 2014-06-05
- Earliest claimed: 2004-09-02
- Assignees: Micron Technology, Inc.
- Applicants: Micron Technology, Inc.
- Inventors: Salman Akram; James M. Wark; William Mark Hiatt
- Web page: https://patentgrep.com/patent/US20140154879A1

## CPC

- H10W 20/057: {by selectively depositing, e.g. by using selective CVD or plating}
- C23C 18/1607: {by direct patterning}
- C23C 18/1637: {metallic substrate}
- C23C 18/1831: {Use of metal, e.g. activation, sensitisation with noble metals}
- C23C 18/1834: {Use of organic or inorganic compounds other than metals, e.g. activation, sensitisation with polymers}
- H10P 14/46: using a liquid
- H10W 20/023: {the interconnections being through-semiconductor vias}
- H10W 20/0238: {comprising etching via holes through pads or through electrodes}
- H10W 20/0245: {comprising use of blind vias during the manufacture}
- H10W 20/0261: {characterised by the filling method or the material of the conductive fill}
- C23C 18/34: using reducing agents
- C23C 18/36: using hypophosphites
- Y10T 428/12528: Semiconductor component
- Y10T 428/24917: including metal layer
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
- C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04)
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A method of activating a metal structure on an intermediate semiconductor device structure toward metal plating. The method comprises providing an intermediate semiconductor device structure comprising at least one first metal structure and at least one second metal structure on a semiconductor substrate. The at least one first metal structure comprises at least one aluminum structure, at least one copper structure, or at least one structure comprising a mixture of aluminum and copper and the at least one second metal structure comprises at least one tungsten structure. One of the at least one first metal structure and the at least one second metal structure is activated toward metal plating without activating the other of the at least one first metal structure and the at least one second metal structure. An intermediate semiconductor device structure is also disclosed.

## Claims

### Claim 1

A method of forming a semiconductor structure, comprising:
selectively forming nickel over a tungsten material on a substrate without forming the nickel over one or more of an aluminum material and a copper material on the substrate;
activating the aluminum material or the copper material to nickel plating; and
forming nickel over an exposed surface of the aluminum material or the copper material.

### Claim 2 (depends on 1)

The method of claim 1, wherein selectively forming nickel over a tungsten material on a substrate without forming the nickel over one or more of an aluminum material and a copper material comprises:
exposing the substrate to a palladium(II) solution to activate the tungsten material without activating the aluminum material or the copper material; and
exposing the substrate to a nickel plating solution.

### Claim 3 (depends on 1)

The method of claim 1, wherein forming nickel over an exposed surface of the aluminum material or copper material comprises:
exposing the substrate to a zincate solution to activate the aluminum material or the copper material; and
exposing the substrate to a nickel plating solution.

### Claim 4 (depends on 1)

The method of claim 1, wherein selectively forming nickel over a tungsten material on a substrate without forming the nickel over one or more of an aluminum material and a copper material on the substrate comprises forming the nickel over an exposed tungsten lining without forming the nickel over an exposed aluminum bond pad or an exposed copper bond pad.

### Claim 5

A method of forming an interconnect in a semiconductor structure, comprising:
removing a portion of a semiconductor substrate to form a via at least partially extending therethrough, the semiconductor substrate having at least one metal structure comprising at least one of aluminum and copper disposed thereon;
forming tungsten over surfaces exposed within the via;
selectively forming nickel over the tungsten within the via without forming nickel over the at least one of aluminum and copper of the at least one metal structure;
activating the at least one of aluminum and copper of the at least one metal structure to nickel plating; and
forming nickel over an exposed surface of the at least one of aluminum and copper of the at least one metal structure.

### Claim 6 (depends on 5)

The method of claim 5, further comprising filling the remaining portions of the via with solder.

### Claim 7 (depends on 5)

The method of claim 5, further comprising forming at least one of an oxide material and an adhesion material over surfaces exposed within the via before forming the tungsten.

### Claim 8 (depends on 5)

The method of claim 5, wherein forming tungsten over surfaces exposed within the via comprises lining the surfaces exposed within the via with the tungsten.

### Claim 9 (depends on 5)

The method of claim 5, wherein forming tungsten over surfaces exposed within the via comprises forming tungsten over surfaces of at least one of a bond pad, an oxide material, and the semiconductor substrate exposed within the via.

### Claim 10 (depends on 5)

The method of claim 5, wherein selectively forming nickel over the tungsten within the via comprises:
activating the tungsten toward nickel plating without activating the at least one of aluminum and copper; and
exposing the tungsten to a nickel plating solution.

### Claim 11 (depends on 10)

The method of claim 10, wherein activating the tungsten toward nickel plating without activating the at least one of aluminum and copper comprises activating the tungsten by exposing the semiconductor structure to an aqueous solution comprising palladium(II) ions.

### Claim 12 (depends on 11)

The method of claim 11, further comprising exposing the tungsten to an aqueous potassium hydroxide solution before activating the tungsten toward the nickel plating.

### Claim 13 (depends on 5)

The method of claim 5, wherein selectively forming nickel over the tungsten comprises exposing the tungsten over the surfaces exposed within the via to a nickel plating solution.

### Claim 14 (depends on 4)

The method of claim 4, further comprising exposing the at least one metal structure to an aqueous solution comprising sodium hydroxide and at least one of nitric acid and phosphoric acid.

### Claim 15

A method of forming an interconnect, comprising:
forming tungsten over an oxide material lining surfaces within a via extending at least partially through a semiconductor substrate;
forming nickel on the tungsten within the via without forming nickel on at least one exposed bond pad comprising at least one of aluminum and copper;
activating the at least one exposed bond pad toward nickel plating;
forming nickel on the at least one exposed bond pad; and
filling the via with at least one conductive material.

### Claim 16 (depends on 15)

The method of claim 15, wherein forming tungsten over an oxide material lining surfaces within a via extending at least partially through a semiconductor substrate comprises forming the tungsten on a titanium nitride material overlying the oxide material.

### Claim 17 (depends on 15)

The method of claim 15, wherein forming nickel on the tungsten within the via without forming nickel on at least one exposed bond pad comprises:
exposing the semiconductor structure to a palladium(II) solution to activate the tungsten without activating the at least one exposed bond pad; and
exposing the semiconductor structure to a nickel plating solution.

### Claim 18 (depends on 17)

The method of claim 17, wherein the at least one exposed bond pad comprises aluminum, and wherein exposing the semiconductor structure to a palladium(II) solution to activate the tungsten without activating the at least one exposed bond pad comprises activating the tungsten without activating the aluminum.

### Claim 19 (depends on 15)

The method of claim 15, wherein forming nickel on the at least one exposed bond pad comprises:
exposing the semiconductor structure to a zincate solution to activate the at least one exposed bond pad; and
exposing the semiconductor structure to a nickel plating solution.

### Claim 20 (depends on 15)

The method of claim 15, further comprising removing a portion of the semiconductor substrate from a backside of the semiconductor structure to expose the via filled with the at least one conductive material.

### Claim 21

A method of forming an interconnect in a semiconductor structure, comprising:
removing portions of each of a bond pad comprising at least one of aluminum and copper and a semiconductor substrate to form a via extending through the bond pad and at least partially into the semiconductor substrate;
forming an oxide material over surfaces exposed within the via;
forming tungsten over the oxide material;
contacting the tungsten with a nickel plating solution to form nickel over the tungsten without forming nickel over the bond pad;
activating the bond pad toward nickel plating;
contacting the activated bond pad with a nickel plating solution to form nickel over the activated bond pad; and
filling the via with a conductive material.

### Claim 22 (depends on 21)

The method of claim 21, wherein contacting the activated bond pad with a nickel plating solution to form nickel over the activated bond pad comprises nickel plating portions of the bond pad exposed through a passivation material.