US 9,287,369 B2Granted

Nitride semiconductor element and nitride semiconductor wafer

AssigneeKabushiki Kaisha Toshiba

InventorsToshiki Hikosaka, Yoshiyuki Harada, Hisashi Yoshida, Naoharu Sugiyama, Shinya Nunoue

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Abstract

According to one embodiment, a nitride semiconductor element includes a foundation layer, a functional layer and a stacked body. The stacked body is provided between the foundation layer and the functional layer. The stacked body includes a first stacked intermediate layer including a first GaN intermediate layer, a first high Al composition layer of Alx1Ga1-x1N (0<x1≦1) and a first low Al composition layer. A compressive strain is applied to the first low Al composition layer. Unstrained GaN has a first lattice spacing. The Alx1Ga1-x1N (0<x1≦1) when unstrained has a second lattice spacing. The first high Al composition layer has a third lattice spacing. An Al composition ratio of the first low Al composition layer is not more than a ratio of a difference between the first and third lattice spacings to a difference between the first and second lattice spacings.

Claims19

Dependent claims

A nitride semiconductor element, comprising:

a stacked body comprising a first stacked intermediate layer comprising:
a first GaN intermediate layer;
a first high Al composition layer of Alx1Ga1-x1N (0<x1≦1) provided on the first GaN intermediate layer;
and
a first low Al composition layer of Aly1Ga1-y1N (0<y1<1 and y1<x1) provided on the first high Al composition layer of Alx1Ga1-x1N (0<x1≦1),
unstrained GaN having a first lattice spacing along a first axis parallel to a major surface,
unstrained Alx1Ga1-x1N (0<x1≦1) having a second lattice spacing along the first axis,
the first high Al composition layer of Alx1Ga1-x1N (0<x1≦1) having a third lattice spacing along the first axis, and
an Al composition ratio of the first low Al composition layer of Aly1Ga1-y1N (0<y1<1 and y1<x1) being not more than a ratio of an absolute value of a difference between the first lattice spacing and the third lattice spacing to an absolute value of a difference between the first lattice spacing and the second lattice spacing.

6 more elements

Dependencies are inferred from the claim text.

Facts

Application: 14/154,829Filed 14 Jan 2014 · continuation
Priority: JP 2012-0523428 Mar 2012
Published: US 2014/0124790 A18 May 2014
Granted: 15 Mar 2016
Term ends: Not estimatedThe source records don’t support an estimate.

Classification15 codes

H10D 62/824
Heterojunctions: comprising only Group III-V materials heterojunctions, e.g. GaN/AlGaN heterojunctions
H10D 30/4732
Having confinement of carriers by multiple heterojunctions, e.g. quantum well HEMT: using Group III-V semiconductor material
H10D 62/605
Impurity distributions or concentrations: planar doped, e.g. atomic-plane doped or delta-doped
H10D 62/8503
Being Group III-V materials, e.g. GaAs: nitride Group III-V materials, e.g. AlN or GaN

Family

Application13/602,868Parent of this continuation · filed 4 Sep 2012
US 2014/0124790 A1Pre-grant publication · published 8 May 2014
US 8,680,537 B2Parent of this continuation
US 2013/0234151 A1Published application
US 9,287,369 B2This patent

From the US filing history. Foreign family members aren’t listed.