Semiconductor device

Patent metadata

Field	Value
Publication number	US-2016380068-A1
Application number	US-201514956977-A
Country	US
Kind code	A1
Filing date	Dec 2, 2015
Priority date	Jun 23, 2015
Publication date	Dec 29, 2016
Grant date	—

Abstract

An emitter electrode includes a first electrode layer, a second electrode layer, and a third electrode layer. The first to third electrode layers are laid in this order on an emitter layer. A solder layer is further laid on the third electrode layer. The first electrode layer covers the emitter layer and a gate oxide film in a front surface of a semiconductor chip. A first electroconductive material forming the first electrode layer has AlSi as its main component. A second electroconductive material forming the second electrode layer has a linear expansion coefficient different from that of the first electroconductive material and is lower in mechanical strength than the first electroconductive material. A third electroconductive material constituting the third electrode layer has a linear expansion coefficient different from that of the first electroconductive material and has solder wettability higher than that of the first electrode layer.

First claim

What is claimed is:

1 . A semiconductor device comprising:
a semiconductor layer; a first electrode layer provided on a front surface of the semiconductor layer and formed of a first electroconductive material; a second electrode layer laid on the first electrode layer and formed of a second electroconductive material having a linear expansion coefficient different from that of the first electroconductive material and lower in mechanical strength than the first electroconductive material; and a third electrode layer laid on the second electrode layer and formed of a third electroconductive material having a linear expansion coefficient different from that of the first electroconductive material and having solder wettability higher than that of the first electroconductive material.

2 . The semiconductor device according to claim 1 , further comprising a barrier metal layer provided between the first electrode layer and the second electrode layer and formed of an electroconductive material higher in mechanical strength than the second electroconductive material.

3 . The semiconductor device according to claim 2 , wherein the electroconductive material of the barrier metal layer is Ti or a Ti alloy.

4 . The semiconductor device according to claim 1 , wherein the first electroconductive material is AlSi and the second electroconductive material is pure aluminum.

5 . The semiconductor device according to claim 4 , wherein the first electroconductive material is AlSi in which the proportion of Si is higher than 1%.

6 . The semiconductor device according to claim 1 , wherein the first electroconductive material is AlSiCu in which the proportion of Si is higher than 1%, and which contains Cu.

7 . The semiconductor device according to claim 1 , further comprising a guard ring provided in the front surface of the semiconductor layer, the guard ring surrounding the first electrode layer as seen in a plan view, wherein the second electrode layer is provided by being extended outward relative to the third electrode layer so that a peripheral edge of the second electrode layer surrounds a peripheral edge of the third electrode layer as seen in the plan view.

8 . The semiconductor device according to claim 1 , further comprising:
a solder layer laid on the third electrode layer; and a lead frame soldered to the third electrode layer by means of the solder layer.

9 . The semiconductor device according to claim 1 , wherein the material of the semiconductor layer is a wide-bandgap semiconductor.

10 . A semiconductor device comprising:
a semiconductor layer; a first electrode layer laid on a front surface of the semiconductor layer and formed of AlCu or AlSiCu; and a second electrode layer laid on the first electrode layer and formed of Cu.

11 . The semiconductor device according to claim 10 , wherein the material of the first electrode layer is AlCu in which the proportion of Cu is higher than 1%.

12 . The semiconductor device according to claim 10 , wherein the material of the first electrode layer is AlSiCu in which the proportion of Si is higher than 1%.

13 . The semiconductor device according to claim 10 , further comprising a barrier metal layer provided between the first electrode layer and the second electrode layer and formed of a material higher in mechanical strength than the second electroconductive material.

14 . The semiconductor device according to claim 13 , wherein the material of the barrier metal layer is Ti or a Ti alloy.

15 . The semiconductor device according to claim 10 , further comprising a guard ring provided in the front surface of the semiconductor layer, the guard ring surrounding the first electrode layer as seen in a plan view, wherein the first electrode layer is provided by being extended outward relative to a peripheral edge of the second electrode layer as seen in the plan view.

16 . The semiconductor device according to claim 10 , further comprising:
a solder layer laid on the second electrode layer; and a lead frame soldered to the second electrode layer by means of the solder layer.

17 . The semiconductor device according to claim 10 , wherein the material of the semiconductor layer is a wide-bandgap semiconductor.

Assignees

• Mitsubishi Electric Corp

Inventors

• Nobukuni Akihiko
• Oki Hirofumi
• Tomomatsu Yoshifumi

Classifications

• H10W90/763

  between laterally-adjacent chips · CPC title

• H10W74/00

  Encapsulations, e.g. protective coatings · CPC title

• H10W72/07351

  characterised by changes in properties of the die-attach connectors during connecting · CPC title

• H10W72/5475

  multiple bond wires connected to common bond pads at both ends of the wires · CPC title

• H10W72/884

  Die-attach connectors and bond wires · CPC title