# US 7,612,456 B2 · Electronic device, semiconductor device using same, and method for manufacturing semiconductor device

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- Number: US 7,612,456 B2
- Document ID: US7612456B2
- Status: Granted
- Kind: B2
- Application number: 10/577,450
- Filed: 2005-06-16
- Published: 2007-04-05
- Granted: 2009-11-03
- Earliest claimed: 2004-08-11
- Assignees: Rohm Co., Ltd.
- Inventors: Sadamasa Fujii; Taro Nishioka
- Web page: https://patentgrep.com/patent/US7612456B2

## CPC

- H10W 90/701: {characterised by the relative positions of pads or connectors relative to package parts}
- H10W 74/129: {forming a chip-scale package [CSP]}
- H10W 90/00: Package configurations
- H10W 72/072: {of bump connectors}
- H10W 72/07231: {Techniques}
- H10W 72/07236: {Soldering or alloying}
- H10W 72/241: {Dispositions, e.g. layouts}
- H10W 72/251: {Materials}
- H10W 72/252: {comprising solid metals or solid metalloids, e.g. PbSn, Ag or Cu}
- H10W 72/255: {of outermost layers of multilayered bumps, e.g. material of a coating}
- H10W 72/859: {Bump connectors and bond wires}
- H10W 72/90: Bond pads, in general
- H10W 72/9415: {relative to the surface, e.g. recessed, protruding}
- H10W 72/952: {comprising metals or metalloids, e.g. PbSn, Ag or Cu}
- H10W 74/00: Encapsulations, e.g. protective coatings
- H10W 90/722: {between stacked chips}
- H10W 90/756: {between a chip and a stacked lead frame, conducting package substrate or heat sink}
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10

## Abstract

An inventive electronic device includes a substrate, a bump of a first metal material provided on a surface of the substrate, a bonding film of a second metal material provided on a top surface of the bump for bonding the electronic device to an electrical connection portion of a second device, the second metal material having a lower melting point in an elemental state than an alloy of the first metal material and the second metal material, and a diffusion prevention film of a third metal material provided between the top surface of the bump and the bonding film as covering at least part of the top surface of the bump, the third metal material having a lower diffusion coefficient than the second metal material with respect to the first metal material.

## Claims

### Claim 1

An electronic device comprising:
a substrate;
a bump of a first metal material provided on a surface of the substrate;
a bonding film of a second metal material provided on a top surface of the bump for bonding the electronic device to an electrical connection portion of a second device; and
a diffusion prevention film of a third metal material provided between the top surface of the bump and the bonding film, the diffusion prevention film partially covering the top surface of the bump, and the bonding film having a first portion in direct contact with the diffusion prevention film and a second portion in direct contact with the top surface of the bump.

### Claim 2 (depends on 1)

The electronic device as set forth in claim 1, wherein the substrate is a semiconductor substrate, and the electronic device is a semiconductor chip.

### Claim 3 (depends on 1)

The electronic device as set forth in claim 1, wherein
the substrate is a wiring board having a wiring conductor provided on an insulating substrate, and
the bump is provided on the wiring board and connected to the wiring conductor.

### Claim 4 (depends on 2)

A semiconductor device of a chip-on-chip structure comprising a first semiconductor chip and a second semiconductor chip respectively having bumps and connected to each other with the bumps thereof bonded to each other, wherein
at least one of the first semiconductor chip and the second semiconductor chip is the electronic device as recited in claim 2.

### Claim 5 (depends on 2)

A semiconductor device comprising:
a wiring board having a wiring conductor provided on an insulating substrate; and
the electronic device as recited in claim 2, the electronic device being connected to the wiring conductor with the bump thereof opposed to the wiring board.

### Claim 6 (depends on 1)

The electronic device as set forth in claim 1, wherein the second metal material has a lower melting point in an elemental state than an alloy of the first metal material and the second metal material.

### Claim 7 (depends on 1)

The electronic device as set forth in claim 1, wherein the third metal material has a lower diffusion coefficient than the second metal material with respect to the first metal material.

### Claim 8 (depends on 1)

The electronic device as set forth in claim 1, wherein the first metal material is Au or Cu.

### Claim 9 (depends on 1)

The electronic device as set forth in claim 1, wherein the second metal material is Sn, In, or an Sn-In alloy.

### Claim 10 (depends on 1)

The electronic device as set forth in claim 1, wherein the third material is TiW.