# US 2018/0323261 A1 · Silicon carbide semiconductor device and method for producing same

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- Number: US 2018/0323261 A1
- Document ID: US20180323261A1
- Status: Published application
- Kind: A1
- Application number: 15/772,125
- Filed: 2017-02-28
- Published: 2018-11-08
- Earliest claimed: 2016-04-27
- Assignees: Denso Corporation
- Applicants: Denso Corporation
- Inventors: Jun KAWAI; Kazuhiko SUGIURA; Yasuji KIMOTO; Kayo KONDO
- Web page: https://patentgrep.com/patent/US20180323261A1

## CPC

- H10D 62/8325: {Silicon carbide}
- H10D 12/031: {of IGBTs}
- H10D 30/66: Vertical DMOS [VDMOS] FETs
- H10D 62/83: being Group IV materials, e.g. B-doped Si or undoped Ge
- H10D 64/011: {of electrodes ohmically coupled to a semiconductor}
- H10D 64/0115: {to silicon carbide}
- H10D 64/251: {Source or drain electrodes for field-effect devices}
- H10D 64/62: Electrodes ohmically coupled to a semiconductor
- H10P 14/2904: {Silicon carbide}
- H10P 34/42: with electromagnetic radiation, e.g. laser annealing (laser cutting H10P54/20)
- H10D 62/157: {Impurity concentrations or distributions}
- H10D 62/393: {Body regions of DMOS transistors or IGBTs (cell layout of DMOS H10D62/127)}
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10

## Abstract

A silicon carbide semiconductor device includes: a semiconductor substrate that has a front surface and a rear surface, and is made of silicon carbide; and an ohmic electrode that is ohmically connected to the front surface or the rear surface of the semiconductor substrate. The ohmic electrode includes a metal silicide part and a metal carbide part. The metal silicide part surrounds a periphery of the metal carbide part that has a block shape. The metal silicide part is disposed between the semiconductor substrate and the metal carbide part.

## Claims

### Claim 1

A silicon carbide semiconductor device comprising:
a semiconductor substrate that has a front surface and a rear surface, and is made of silicon carbide; and
an ohmic electrode that is ohmically connected to the front surface or the rear surface of the semiconductor substrate, wherein:
the ohmic electrode includes a metal silicide part and a metal carbide part;
the metal silicide part surrounds a periphery of the metal carbide part that has a block shape; and
the metal silicide part is disposed between the semiconductor substrate and the metal carbide part.

### Claim 2 (depends on 1)

The silicon carbide semiconductor device according to claim 1, wherein:
the metal carbide part has crystallinity.

### Claim 3 (depends on 1)

The silicon carbide semiconductor device according to claim 1,
wherein:
the metal silicide part is amorphous.

### Claim 4 (depends on 1)

The silicon carbide semiconductor device according to claim 1, wherein:
each block of the metal carbide part having the block shape has a maximum dimension which is equal to or more than 3 nm and equal to or less than 40 nm.

### Claim 5 (depends on 1)

The silicon carbide semiconductor device according to claim 1, wherein:
a thickness of a portion of the metal silicide part positioned between the semiconductor substrate and the metal carbide is equal to or more than 1 nm and equal to or less than 3 nm.

### Claim 6 (depends on 1)

The silicon carbide semiconductor device according to claim 1, wherein:
the metal silicide part includes a Ni silicide portion; and
the metal carbide part includes a Mo portion.

### Claim 7

A method for producing a silicon carbide semiconductor device which is provided with an ohmic electrode ohmically connected to a front surface or a rear surface of a semiconductor substrate that has the front surface and the rear surface, and is made of silicon carbide, the method comprising:
forming a first metallic material film and a second metallic material film on the front surface or the rear surface of the semiconductor substrate using first metallic material including a metal element for producing a metal silicide part and second metallic material including a metal element for producing a metal carbide part; and
forming the metal carbide part having a block shape using the metal element included in the second metallic material and a carbon in silicon carbide, and forming the metal silicide part surrounding a periphery of the metal carbide part and disposed between the semiconductor substrate and the metal carbide part using the metal element included in the first metallic material and a silicon in silicon carbide, by irradiating the first metallic material and the second metallic material with a laser beam having an energy density equal to or more than 1.4 J/cm2.

### Claim 8 (depends on 7)

The method for producing a silicon carbide semiconductor device according to claim 7, wherein:
the energy density of the laser beam is equal to or less than 2.0 J/cm2.