# US 12,015,053 B2 · Semiconductor device

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- Number: US 12,015,053 B2
- Document ID: US12015053B2
- Status: Granted
- Kind: B2
- Application number: 17/717,724
- Filed: 2022-04-11
- Published: 2022-11-24
- Granted: 2024-06-18
- Earliest claimed: 2021-05-21
- Assignees: Renesas Electronics Corporation
- Applicants: Renesas Electronics Corporation
- Inventors: Makoto Koshimizu; Yasutaka Nakashiba
- Web page: https://patentgrep.com/patent/US12015053B2

## CPC

- H10D 30/603: {having asymmetry in the channel direction, e.g. lateral high-voltage MISFETs having drain offset region or extended drain IGFETs [EDMOS]}
- H10D 62/102: {Constructional design considerations for preventing surface leakage or controlling electric field concentration}
- H10D 30/0221: {having asymmetry in the channel direction, e.g. lateral high-voltage MISFETs having drain offset region or extended-drain MOSFETs [EDMOS]}
- H10D 30/655: {having edge termination structures}
- H10D 64/516: {the thicknesses being non-uniform}
- H10D 64/685: {being perpendicular to the channel plane}
- H10D 64/691: {comprising metallic compounds, e.g. metal oxides or metal silicates (insulators comprising nitrogen H10D64/693)}
- H10D 30/0281: {of lateral DMOS [LDMOS] FETs}
- H10D 64/111: {Field plates}
- H10D 64/693: {the insulator comprising nitrogen, e.g. nitrides, oxynitrides or nitrogen-doped materials}
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES

## Abstract

A semiconductor device includes a semiconductor substrate, a gate dielectric film formed on the semiconductor substrate, a gate electrode formed on the gate dielectric film, a field plate portion which is integrally formed with the gate electrode, a step insulating film in contact with the field plate portion, a high dielectric constant film in contact with the step insulating film and having a higher dielectric constant than silicon.

## Claims

### Claim 1

A semiconductor device comprising:
a semiconductor substrate;
a gate dielectric film formed on the semiconductor substrate;
a gate electrode formed over the gate dielectric film;
a field plate portion integrally formed with the gate electrode;
a step dielectric film in contact with the field plate portion; and
a high dielectric constant film having a higher dielectric constant than silicon, the high dielectric constant film being in contact with the step dielectric film,
wherein the high dielectric constant film includes:
a first portion sandwiched between the gate dielectric film and the gate electrode; and
a second portion sandwiched between the step dielectric film and the gate dielectric film.

### Claim 2 (depends on 1)

The semiconductor device according to claim 1,
wherein the high dielectric constant film has a function of forming a potential barrier on a surface of the semiconductor substrate by shifting a Fermi level on the surface of the semiconductor substrate located under the step dielectric film.

### Claim 3 (depends on 1)

The semiconductor device according to claim 1,
wherein a material of the high dielectric constant film includes any of HfSiO, HfSiON, HfAlON, Y2O3 or Al2O3.

### Claim 4 (depends on 1)

The semiconductor device according to claim 1,
wherein the high dielectric constant film is formed of a portion sandwiched between the step dielectric film and the gate dielectric film.

### Claim 5 (depends on 1)

The semiconductor device according to claim 1,
wherein the high dielectric constant film is a film covering the gate electrode, the field plate portion and the step dielectric film.

### Claim 6 (depends on 5)

The semiconductor device according to claim 5,
wherein the step dielectric film includes:
a contact portion in contact with the field plate portion; and
a non-contact portion protruded from the field plate portion, and
wherein the non-contact portion includes:
a thin film portion on which a recess portion is formed; and
a thick film portion having a thicker film thickness than the thin film portion.

### Claim 7 (depends on 6)

The semiconductor device according to claim 6,
wherein a film thickness of the thin film portion is equal to a film thickness of the gate dielectric film.

### Claim 8

A semiconductor device comprising:
a semiconductor substrate;
a gate dielectric film formed on the semiconductor substrate;
a gate electrode formed over the gate dielectric film;
a field plate portion integrally formed with the gate electrode;
a step dielectric film in contact with the field plate portion; and
a potential control film in contact with the step dielectric film, the potential control film forming a potential barrier on a surface of the semiconductor substrate located under the step dielectric film.

### Claim 9 (depends on 8)

The semiconductor device according to claim 8,
wherein the potential control film is a film forming the potential barrier on the surface of the semiconductor substrate by shifting a Fermi level on the surface of the semiconductor substrate located under the step dielectric film.

### Claim 10

A semiconductor device comprising:
a semiconductor substrate;
a gate dielectric film formed on the semiconductor substrate;
a gate electrode formed over the gate dielectric film;
a field plate portion integrally formed with the gate electrode;
a step dielectric film in contact with the field plate portion; and
a high dielectric constant film having a higher dielectric constant than silicon, the high dielectric constant film being in contact with the step dielectric film,
wherein the high dielectric constant film has a function of forming a potential barrier on a surface of the semiconductor substrate by shifting a Fermi level on the surface of the semiconductor substrate located under the step dielectric film.