# US 12,191,385 B2 · Semiconductor device having a current spreading region

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- Number: US 12,191,385 B2
- Document ID: US12191385B2
- Status: Granted
- Kind: B2
- Application number: 17/669,831
- Filed: 2022-02-11
- Published: 2023-08-17
- Granted: 2025-01-07
- Earliest claimed: 2022-02-11
- Assignees: Infineon Technologies Austria AG
- Applicants: Infineon Technologies Austria AG
- Inventors: Adrian Finney; Harsh Naik; Ingmar Neumann
- Web page: https://patentgrep.com/patent/US12191385B2

## CPC

- H10D 30/668: {having trench gate electrodes, e.g. UMOS transistors}
- H10D 30/0297: {using recessing of the gate electrodes, e.g. to form trench gate electrodes}
- H10D 30/665: {having edge termination structures}
- H10D 62/107: {Buried supplementary regions, e.g. buried guard rings (multi-RESURF H10D62/111)}
- H10D 62/127: {of cellular field-effect devices, e.g. multicellular DMOS transistors or IGBTs}
- H10D 62/157: {Impurity concentrations or distributions}
- H10D 64/01: Manufacture or treatment
- H10D 64/112: {comprising multiple field plate segments}
- H10D 64/117: {Recessed field plates, e.g. trench field plates or buried field plates}
- H10D 64/516: {the thicknesses being non-uniform}
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES

## Abstract

A semiconductor device includes: a semiconductor substrate; a drift zone of a first conductivity type in the semiconductor substrate; an array of interconnected gate trenches extending from a first surface of the semiconductor substrate into the drift zone; a plurality of semiconductor mesas delimited by the array of interconnected gate trenches; a plurality of needle-shaped field plate trenches extending from the first surface into the plurality of semiconductor mesas; in the plurality of semiconductor mesas, a source region of the first conductivity type and a body region of a second conductivity type separating the source region from the drift zone; and a current spreading region of the first conductivity type at the bottom of the gate trenches and having a higher average doping concentration than the drift zone. Methods of producing the semiconductor device are also described.

## Claims

### Claim 1

A semiconductor device, comprising:
a semiconductor substrate;
a drift zone of a first conductivity type in the semiconductor substrate;
an array of interconnected gate trenches extending from a first surface of the semiconductor substrate into the drift zone;
a plurality of semiconductor mesas delimited by the array of interconnected gate trenches;
a plurality of needle-shaped field plate trenches extending from the first surface into the plurality of semiconductor mesas;
in the plurality of semiconductor mesas, a source region of the first conductivity type and a body region of a second conductivity type separating the source region from the drift zone; and
a current spreading region of the first conductivity type at the bottom of the gate trenches and having a higher average doping concentration than the drift zone.

### Claim 2 (depends on 1)

The semiconductor device of claim 1, wherein the gate trenches each include an electrode and a gate dielectric insulating material separating the electrode from the semiconductor substrate.

### Claim 3 (depends on 2)

The semiconductor device of claim 2, wherein the gate dielectric insulating material has an increased thickness at a bottom of the gate trenches.

### Claim 4 (depends on 3)

The semiconductor device of claim 3, wherein the current spreading region has a lower average doping concentration below the bottom of the gate trenches and a higher average doping concentration laterally beyond the bottom of the gate trenches.

### Claim 5 (depends on 2)

The semiconductor device of claim 2, wherein the gate dielectric insulating material has a generally uniform thickness along a bottom and sidewalls of the gate trenches.

### Claim 6 (depends on 1)

The semiconductor device of claim 1, wherein the current spreading region and the body regions adjoin one another at sidewalls of the gate trenches.

### Claim 7 (depends on 1)

The semiconductor device of claim 1, wherein the drift zone separates the current spreading region and the body regions from one another at sidewalls of the gate trenches.