Power semiconductor device that includes a copper layer disposed on an electrode and located away from a polyimide layer and method for manufacturing the power semiconductor device

• US 10,643,967 B2
• Filed: 04/25/2017
• Issued: 05/05/2020
• Est. Priority Date: 05/18/2016
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Okabe, Hiroaki, Nakanishi, Yosuke
• Primary Examiner(s): Ojeh, Nduka E
• Application Number:
  US16/092,564
• Publication Number:
  US 20190172812A1
• Time in Patent Office: 1,106 Days
• CPC Class Codes: H01L 21/28 Manufacture of electrodes on semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/268 etching for patterning the electrodes H01L21/311, H01L21/3213; multistep manufacturing processes for data storage electrodes H01L29/4011
• CPC Class Codes: H01L 21/3205 Deposition of non-insulating-, e.g. conductive- or resistive-, layers on insulating layers; After-treatment of these layers manufacture of electrodes H01L21/28
• CPC Class Codes: H01L 21/768 Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics
• CPC Class Codes: H01L 2224/02166 Collar structures
• CPC Class Codes: H01L 2224/04026 Bonding areas specifically adapted for layer connectors
• CPC Class Codes: H01L 2224/04042 Bonding areas specifically adapted for wire connectors, e.g. wirebond pads
• CPC Class Codes: H01L 2224/05 of an individual bonding area
• CPC Class Codes: H01L 2224/05124 Aluminium [Al] as principal constituent
• CPC Class Codes: H01L 2224/05647 Copper [Cu] as principal constituent
• CPC Class Codes: H01L 2224/29101 the principal constituent melting at a temperature of less than 400°C
• CPC Class Codes: H01L 2224/32221 the body and the item being stacked
• CPC Class Codes: H01L 2224/45015 being circular
• CPC Class Codes: H01L 2224/45147 Copper (Cu) as principal constituent
• CPC Class Codes: H01L 2224/4847 the connecting portion on the bonding area of the semiconductor or solid-state body being a wedge bond
• CPC Class Codes: H01L 2224/48847 Copper (Cu) as principal constituent
• CPC Class Codes: H01L 2224/4911 the connectors being bonded to at least one common bonding area, e.g. daisy chain
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2224/83801 Soldering or alloying
• CPC Class Codes: H01L 2224/8592 Applying permanent coating, e.g. protective coating
• CPC Class Codes: H01L 2224/92247 the second connecting process involving a wire connector
• CPC Class Codes: H01L 23/3121 : a substrate forming part of the encapsulation
• CPC Class Codes: H01L 23/3171 : the coating being directly applied to the semiconductor body, e.g. passivation layer H01L23/3178 takes precedence
• CPC Class Codes: H01L 23/3192 : Multilayer coating
• CPC Class Codes: H01L 23/522 : including external interconnections consisting of a multilayer structure of conductive and insulating layers inseparably formed on the semiconductor body
• CPC Class Codes: H01L 24/03 : Manufacturing methods
• CPC Class Codes: H01L 24/05 : of an individual bonding area
• CPC Class Codes: H01L 24/32 : of an individual layer connector
• CPC Class Codes: H01L 24/45 : of an individual wire connector
• CPC Class Codes: H01L 24/48 : of an individual wire connector
• CPC Class Codes: H01L 24/49 : of a plurality of wire connectors
• CPC Class Codes: H01L 24/73 : Means for bonding being of different types provided for in two or more of groups H01L24/10, H01L24/18, H01L24/26, H01L24/34, H01L24/42, H01L24/50, H01L24/63, H01L24/71
• CPC Class Codes: H01L 24/85 : using a wire connector wire bonding in general B23K20/004
• CPC Class Codes: H01L 24/92 : Specific sequence of method steps
• CPC Class Codes: H01L 29/12 : characterised by the materials of which they are formed
• CPC Class Codes: H01L 29/1608 : Silicon carbide
• CPC Class Codes: H01L 29/78 : with field effect produced by an insulated gate H01L29/7725, H01L29/775, H01L29/778 take precedence
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00014 : the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/05042 : Si3N4
• CPC Class Codes: H01L 2924/07025 : Polyimide
• CPC Class Codes: H01L 2924/10272 : Silicon Carbide [SiC]
• CPC Class Codes: H01L 2924/13055 : Insulated gate bipolar transistor [IGBT]
• CPC Class Codes: H01L 2924/13091 : Metal-Oxide-Semiconductor Field-Effect Transistor [MOSFET]
• CPC Class Codes: H01L 2924/2064 : larger or equal to 1 micron less than 100 microns
• CPC Class Codes: H01L 2924/20641 : larger or equal to 100 microns less than 200 microns
• CPC Class Codes: H01L 2924/2076 : equal to or larger than 100 microns
• CPC Class Codes: H01L 2924/3511 : Warping
• CPC Class Codes: H01L 2924/3512 : Cracking

Abstract

An electrode is disposed on a semiconductor layer. A polyimide layer has an opening disposed on the electrode, covers the edge of the electrode, and extends onto the electrode. A copper layer is disposed on the electrode within the opening, and located away from the polyimide layer on the electrode. A copper wire has one end joined on the copper layer.

Claims

1. A power semiconductor device comprising:

a semiconductor layer;

an electrode disposed on the semiconductor layer;

a polyimide layer comprising an opening disposed on the electrode, the polyimide layer covering an edge of the electrode and extending onto the electrode;

a copper layer disposed on the electrode within the opening, and located away from the polyimide layer on the electrode; and

a copper wire comprising one end joined on the copper layer,

wherein the copper layer has a larger area than a region in which the copper wire is joined to the copper layer, and

a distance between the copper layer and the polyimide layer is greater than half a thickness of the copper layer.

2. The power semiconductor device according to claim 1, further comprising a silicon nitride layer separating the polyimide layer from the copper layer.

3. The power semiconductor device according to claim 1, wherein the copper wire has a diameter of 100 μ

m or more.

4. The power semiconductor device according to claim 1, further comprising a sealant sealing a gap between the polyimide layer and the copper layer,

wherein the sealant is made of any of a silicone-based material, an epoxy-based material, and a phenol-based material.

5. The power semiconductor device according to claim 1, wherein at least part of the semiconductor layer is made of silicon carbide.

6. A method for manufacturing a power semiconductor device, the method comprising:

forming an electrode on a semiconductor layer;

forming a polyimide layer comprising an opening disposed on the electrode, the polyimide layer covering an edge of the electrode and extending onto the electrode;

forming, on the electrode within the opening, a copper layer located away from the polyimide layer on the electrode; and

joining one end of a copper wire having a diameter of 100 μ

m or more onto the copper layer,

wherein the joining of the one end of the copper wire is performed to the copper layer located away from the polyimide layer by a distance greater than half a thickness of the copper layer.

7. A power semiconductor device comprising:

a semiconductor layer;

an electrode disposed on the semiconductor layer;

a polyimide layer comprising an opening disposed on the electrode, the polyimide layer covering an edge of the electrode and extending onto the electrode;

a copper layer disposed on the electrode within the opening, and located away from the polyimide layer on the electrode;

a copper wire comprising one end joined on the copper layer and having a diameter larger than a thickness of the copper layer; and

a silicon nitride layer partly disposed on the electrode,

wherein the copper layer comprises an edge directly contacting the silicon nitride layer.

8. The power semiconductor device according to claim 7, wherein the silicon nitride layer separates the polyimide layer from the copper layer.

9. The power semiconductor device according to claim 7, wherein the copper wire has the diameter of 100 μ

m or more.

10. The power semiconductor device according to claim 7, further comprising a sealant sealing a gap between the polyimide layer and the copper layer,

wherein the sealant is made of any of a silicone-based material, an epoxy-based material, and a phenol-based material.

11. The power semiconductor device according to claim 7, wherein at least part of the semiconductor layer is made of silicon carbide.