# US 2010/0167516 A1 · Semiconductor device and manufacturing method thereof

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- Number: US 2010/0167516 A1
- Document ID: US20100167516A1
- Status: Published application
- Kind: A1
- Application number: 12/720,713
- Filed: 2010-03-10
- Published: 2010-07-01
- Earliest claimed: 2007-06-20
- Assignees: Mitsubishi Electric Corporation
- Inventors: Tadaharu Minato; Kazutoyo Takano
- Web page: https://patentgrep.com/patent/US20100167516A1

## CPC

- H10D 30/668: {having trench gate electrodes, e.g. UMOS transistors}
- H10D 12/038: {having a recessed gate, e.g. trench-gate IGBTs}
- H10D 12/411: {Insulated-gate bipolar transistors [IGBT]}
- H10D 12/461: {having non-planar surfaces, e.g. having trenches, recesses or pillars in the surfaces of the emitter, base or collector regions}
- H10D 12/481: {having gate structures on slanted surfaces, on vertical surfaces, or in grooves, e.g. trench gate IGBTs}
- H10D 18/655: {produced by insulated gate structures}
- H10D 30/0297: {using recessing of the gate electrodes, e.g. to form trench gate electrodes}
- H10D 64/117: {Recessed field plates, e.g. trench field plates or buried field plates}
- H10D 64/252: {for vertical or pseudo-vertical devices}
- H10D 64/256: {for lateral devices wherein the source or drain electrodes are recessed in semiconductor bodies (source or drain electrodes of TFTs H10D30/673)}
- H10D 62/127: {of cellular field-effect devices, e.g. multicellular DMOS transistors or IGBTs}
- H10D 62/83: being Group IV materials, e.g. B-doped Si or undoped Ge
- H10D 64/62: Electrodes ohmically coupled to a semiconductor
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES

## Abstract

A semiconductor substrate has a trench in a first main surface. An insulated gate field effect part includes a gate electrode formed in the first main surface. A potential fixing electrode fills the trench and has an expanding part expanding on the first main surface so that a width thereof is larger than the width of the trench. An emitter electrode is formed on the first main surface and insulated from the gate electrode electrically and connected to a whole upper surface of the expanding part of the potential fixing electrode. Thus, a semiconductor device capable of enhancing reliability in order to prevent an aluminum spike from generating and a manufacturing method thereof can be provided.

## Claims

### Claim 1

A manufacturing method of a semiconductor device comprising the steps of:
forming a trench in the main surface of a semiconductor substrate;
forming a conductive layer on said main surface so as to fill said trench;
forming a potential fixing electrode filling said trench and having an expanding part expanding on said main surface so that a width thereof is larger than that of said trench, and forming a gate electrode on said main surface by patterning said conductive layer;
forming insulation layers so as to cover said gate electrode and expose said expanding part of said potential fixing electrode; and
forming main electrodes so as to be electrically insulated from said gate electrode and connected to a whole upper surface of said expanding part of said potential fixing electrode.

### Claim 2 (depends on 1)

The manufacturing method of the semiconductor device according to claim 1, wherein
said step of forming said main electrodes comprises the steps of:
forming first metal films so as to be in contact with said expanding part of said potential fixing electrode; and
forming a second metal film having a melting point lower than that of said first metal film, and more readily reacting with the material of said semiconductor substrate than said first metal film, on said first metal films.

### Claim 3 (depends on 2)

The manufacturing method of the semiconductor device according to claim 2, further comprising the step of performing a heat treatment to stabilize said first and second metal films.