Nitride semiconductor device

• US 10,326,012 B2
• Filed: 12/27/2017
• Issued: 06/18/2019
• Est. Priority Date: 02/15/2017
• Status: Expired due to Fees

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Watanabe, Atsushi, Ueda, Hiroyuki, Mori, Tomohiko
• Primary Examiner(s): Nguyen, Dao H
• Application Number:
  US15/855,261
• Publication Number:
  US 20180233591A1
• Time in Patent Office: 538 Days
• Field of Search: 257 76, 257 77, 257139, 257194, 257328, 257329, 257330, 257332, 257E29021, 257E29084, 257E29089, 257E29118, 257E29133, 257E29246, 257E2706, 257E27068, 257E2109, 257E21345, 257E21403, 257E2141, 257E21417, 438138, 438172, 438270, 438316, 438478
• CPC Class Codes: H01L 29/0657 characterised by the shape of the body
• CPC Class Codes: H01L 29/1045 the doping structure being parallel to the channel length, e.g. DMOS like
• CPC Class Codes: H01L 29/2003 Nitride compounds
• CPC Class Codes: H01L 29/205 in different semiconductor regions , e.g. heterojunctions
• CPC Class Codes: H01L 29/41766 with at least part of the source or drain electrode having contact below the semiconductor surface, e.g. the source or drain electrode formed at least partially in a groove or with inclusions of conductor inside the semiconductor H01L29/41733 - H01L29/41758 take precedence
• CPC Class Codes: H01L 29/7783 using III-V semiconductor material
• CPC Class Codes: H01L 29/7788 Vertical transistors
• CPC Class Codes: H01L 29/7802 Vertical DMOS transistors, i.e. VDMOS transistors
• CPC Class Codes: H01L 29/7803 structurally associated with at least one other device assemblies H01L25/00; integrated circuits H01L27/00

Abstract

A semiconductor device includes a semiconductor substrate, a source electrode, a drain electrode, and a gate electrode disposed on the semiconductor substrate via a gate insulator film. The semiconductor substrate includes a first portion constituted of GaN and a second portion constituted of Al_xGa_(1-x)N (0<x≤1). The first portion includes an n-type source region being in contact with the source electrode, an n-type drain region being in contact with the drain electrode, a p-type body region intervening between the source region and the drain region and being in contact with the source electrode, and an n-type drift region intervening between the body region and the drain region and having a carrier density that is lower than a carrier density of the drain region. The second portion includes a barrier region being in contact with each of the source electrode, the body region and the drift region.

Claims

1. A semiconductor device comprising:

a semiconductor substrate comprising a nitride semiconductor;

a source electrode and a drain electrode each disposed on the semiconductor substrate; and

a gate electrode disposed on the semiconductor substrate via a gate insulator film,

wherein

the semiconductor substrate comprises a first portion constituted of GaN and a second portion constituted of Al_xGa_(1-x)N(0<

x≤

1),

the first portion comprises an n-type source region being in contact with the source electrode, an n-type drain region being in contact with the drain electrode, a p-type body region intervening between the source region and the drain region and being in contact with the source electrode, and an n-type drift region intervening between the body region and the drain region and having a carrier density that is lower than a carrier density of the drain region, and

the second portion comprises a barrier region being in contact with each of the source electrode, the body region and the drift region;

wherein

the semiconductor substrate comprises a first surface at which each of the source region, the body region and the drift region is disposed, and

the gate electrode faces a part of the body region extending between the source region and the drift region at the first surface via the gate insulator film.

2. The semiconductor device according to claim 1, wherein the Al_xGa_(1-x)N is AlN.

3. The semiconductor device according to claim 1, wherein

the semiconductor substrate comprises a second surface at which the drain region is disposed, and being located opposite to the first surface, and

the source electrode is disposed on the first surface and the drain electrode is disposed on the second surface.

4. The semiconductor device according to claim 1, wherein the body region is in contact with both the source region and the drift region at the first surface of the semiconductor substrate.

5. The semiconductor device according to claim 1, wherein the drift region is in contact with the gate insulator film at the first surface of the semiconductor substrate.

6. The semiconductor device according to claim 1, wherein the drift region is not in contact with the source electrode.