# US 9,437,689 B2 · Ga2O3 semiconductor element

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- Number: US 9,437,689 B2
- Document ID: US9437689B2
- Status: Granted
- Kind: B2
- Application number: 14/343,367
- Filed: 2012-09-07
- Published: 2014-08-07
- Granted: 2016-09-06
- Earliest claimed: 2011-09-08
- Assignees: Tamura Corporation; Nationai Institute of Information and Communications Technology
- Applicants: Kohei Sasaki; Masataka Higashiwaki
- Inventors: Kohei Sasaki; Masataka Higashiwaki
- Web page: https://patentgrep.com/patent/US9437689B2

## CPC

- H10D 30/6755: {Oxide semiconductors, e.g. zinc oxide, copper aluminium oxide or cadmium stannate}
- H10D 30/00: Field-effect transistors [FET] (insulated-gate bipolar transistors H10D12/00)
- H10D 30/60: Insulated-gate field-effect transistors [IGFET] (H10D30/40 takes precedence)
- H10D 30/65: Lateral DMOS [LDMOS] FETs
- H10D 30/657: {having substrates comprising insulating layers, e.g. SOI-LDMOS transistors}
- H10D 30/6729: {characterised by the electrodes}
- H10D 30/6758: {characterised by the insulating substrates}
- H10D 30/87: FETs having Schottky gate electrodes, e.g. metal-semiconductor FETs [MESFET] {(FETs having Schottky contact on top of heterojunction gate H10D30/801)}
- H10D 30/875: {having thin-film semiconductor bodies}
- H10D 62/40: Crystalline structures
- H10D 62/405: {Orientations of crystalline planes}
- H10D 62/60: Impurity distributions or concentrations
- H10D 62/605: {Planar doped, e.g. atomic-plane doped or delta-doped}
- H10D 62/80: characterised by the materials
- H10D 62/8171: {Doping structures, e.g. doping superlattices or nipi superlattices}
- H10D 99/00: Subject matter not provided for in other groups of this subclass
- H10P 14/22: using physical deposition, e.g. vacuum deposition or sputtering
- H10P 14/2918: {being semiconductor metal oxides (Group IIB-VIA materials H10P14/2913)}
- H10P 14/2926: {Crystal orientations}
- H10P 14/3434: {being oxide semiconductor materials (Group IIB-VIA semiconductor materials H10P14/3424)}
- H10P 14/3442: {N-type}
- H10P 14/3446: {Transition metal elements; Rare earth elements}
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10

## Abstract

A Ga2O3 semiconductor element includes: an n-type β-Ga2O3 single crystal film, which is formed on a high-resistance β-Ga2O3 substrate directly or with other layer therebetween; a source electrode and a drain electrode, which are formed on the n-type β-Ga2O3 single crystal film; and a gate electrode, which is formed on the n-type β-Ga2O3 single crystal film between the source electrode and the drain electrode.

## Claims

### Claim 1

A Ga2O3-based semiconductor element, comprising:
a β-Ga2O3 single crystal film that is formed on a main surface of a β-Ga2O3 substrate, the main surface being rotated from 50° to 90° with respect to a (100) plane;
a source electrode and a drain electrode that are formed on a same side of the β-Ga2O3 single crystal film;
a gate electrode that is formed on the β-Ga2O3 single crystal film between the source electrode and the drain electrode;
a first region formed in the β-Ga2O3 single crystal film under the source electrode and the drain electrode and including a controlled first dopant concentration; and
a second region formed to surround the first region and including a controlled second dopant concentration lower than the controlled first dopant concentration,
wherein the β-Ga2O3 substrate includes a p-type dopant to be a high electrical resistance.

### Claim 2 (depends on 1)

The Ga2O3-based semiconductor element according to claim 1, wherein the semiconductor element further comprises a Ga2O3-based MISFET, and
wherein the gate electrode is formed on the β-Ga2O3 single crystal film via a gate insulating film.

### Claim 3 (depends on 1)

The Ga2O3-based semiconductor element according to claim 1, wherein the first region comprises a source region and a drain region formed in the β-Ga2O3 single crystal film under the source electrode and the drain electrode, respectively.

### Claim 4 (depends on 3)

The Ga2O3-based semiconductor element according to claim 3, wherein the β-Ga2O3 single crystal film, the source region and the drain region are n-type, and
wherein the second region comprises a p-type or high-resistance body region formed in the β-Ga2O3 single crystal film so as to surround the source region.

### Claim 5 (depends on 1)

The Ga2O3-based semiconductor element according to claim 1, wherein the semiconductor element further comprises a Ga2O3-based MESFET, and
wherein the gate electrode is formed directly on the β-Ga2O3 single crystal film.

### Claim 6 (depends on 5)

The Ga2O3-based semiconductor element according to claim 5, wherein the β-Ga2O3 single crystal film is n-type, and
wherein the semiconductor element further comprises an n-type source region and an n-type drain region formed in the β-Ga2O3 single crystal film under the source electrode and the drain electrode, respectively.

### Claim 7 (depends on 2)

The Ga2O3-based semiconductor element according to claim 2, wherein the first region comprises a source region and a drain region formed in the β-Ga2O3 single crystal film under the source electrode and the drain electrode, respectively.

### Claim 8 (depends on 1)

The Ga2O3-based semiconductor element according to claim 1, wherein an upper surface of the first region is flush with an upper surface of the β-Ga2O3 single crystal film.

### Claim 9 (depends on 8)

The Ga2O3-based semiconductor element according to claim 8, wherein an upper surface of the second region is flush with an upper surface of the β-Ga2O3 single crystal film.

### Claim 10 (depends on 9)

The Ga2O3-based semiconductor element according to claim 9, wherein the source electrode is disposed on the upper surface of the first region.

### Claim 11 (depends on 9)

The Ga2O3-based semiconductor element according to claim 9, wherein the source electrode abuts the upper surface of the first region.

### Claim 12 (depends on 11)

The Ga2O3-based semiconductor element according to claim 11, wherein the gate electrode is formed on the β-Ga2O3 single crystal film via a gate insulating film disposed on a bottom surface of the gate electrode.

### Claim 13 (depends on 12)

The Ga2O3-based semiconductor element according to claim 12, wherein a bottom surface of the gate insulating film is disposed on the upper surface of the first region.

### Claim 14 (depends on 12)

The Ga2O3-based semiconductor element according to claim 12, wherein a bottom surface of the gate insulating film abuts the upper surface of the first region.

### Claim 15 (depends on 14)

The Ga2O3-based semiconductor element according to claim 14, wherein the bottom surface of the gate insulating film is further disposed on the upper surface of the second region.

### Claim 16 (depends on 15)

The Ga2O3-based semiconductor element according to claim 15, wherein the bottom surface of the gate insulating film further abuts the upper surface of the second region.

### Claim 17 (depends on 16)

The Ga2O3-based semiconductor element according to claim 16, wherein the bottom surface of the gate insulating film further abuts an upper surface of the β-Ga2O3 single crystal film.