Nichia Corporation

Takuya Okada

Junya Narita

Yoshiki Inoue

Katsuyoshi Kadan

Yohei Wakai

Naoya Sako

Daisuke Sanga

Kunihito Sugimoto

Dai Wakamatsu

Keisuke Sejiki

Takao Kosugi

A light-emitting device includes an n-side semiconductor layer comprising an n-type contact layer and an intermediate layer located on the n-type contact layer; an active layer located on the intermediate layer; and a p-side semiconductor layer located on the active layer. The intermediate layer includes at least one stacked portion comprising a first layer and a second layer. The first layer is an n-type nitride semiconductor layer comprising an n-type impurity, Al, and Ga. The second layer is a nitride semiconductor layer that includes Al and Ga, has a lower n-type impurity concentration than the first layer, and has a larger thickness than the first layer. An Al composition ratio of the first layer is higher than an Al composition ratio of the second layer.

Light emitting device

A nitride semiconductor light-emitting element includes: an n-side nitride semiconductor layer; a p-side nitride semiconductor layer; and an active layer between the n-side nitride semiconductor layer and the p-side nitride semiconductor layer. The active layer includes: one or more well layers comprising a first well layer that is nearest to the n-side nitride semiconductor layer, and one or more barrier layers comprising a first barrier layer between the first well layer and the n-side nitride semiconductor layer. The first barrier layer comprises a Si-doped InGaN barrier layer and an undoped GaN barrier layer in this order from the n-side nitride semiconductor layer side.

Nitride semiconductor light-emitting element and method of manufacturing the same

A method of manufacturing a nitride semiconductor light-emitting element includes growing an n-side semiconductor layer, an active layer, and a p-side semiconductor layer. The step of growing the active layer includes growing a first barrier layer before growing a well layer. The step of growing the first barrier layer includes a first stage where a first nitride semiconductor layer containing In is grown with a first concentration of n-type impurity, a second stage where a second nitride semiconductor layer containing In is grown with a second concentration of n-type impurity higher than the first concentration, a third stage where a third nitride semiconductor layer containing In is grown with a third concentration of n-type impurity lower than the second concentration, and a fourth stage where a fourth nitride semiconductor layer is grown under a growth condition in which an amount of an impurity source gas is decreased or stopped.

A method of manufacturing a light emitting element includes providing a wafer having a substrate and a semiconductor layered body provided on an upper surface of the substrate, irradiating the substrate with laser light from a side of a lower surface opposite to the upper surface of the substrate to form modified regions in the substrate, and dividing the wafer into light emitting elements at the modified regions as a starting point. The semiconductor layered body includes a first p-type semiconductor layer made of a nitride semiconductor and provided on the upper surface of the substrate, an n-type semiconductor layer made of a nitride semiconductor and provided on the first p-type semiconductor layer, an active layer made of a nitride semiconductor and provided on the n-type semiconductor layer, and a second p-type semiconductor layer made of a nitride semiconductor and provided on the active layer.

Method of manufacturing light emitting element

The sapphire substrate has a principal surface for growing a nitride semiconductor to form a nitride semiconductor light emitting device and comprising a plurality of projections of the principal surface, wherein an outer periphery of a bottom surface of each of the projections has at least one depression. This depression is in the horizontal direction. The plurality of projections are arranged so that a straight line passes through the inside of at least any one of projections when the straight line is drawn at any position in any direction in a plane including the bottom surfaces of the plurality of projections.

Sapphire substrate having elongated projection and semiconductor light emitting device utilizing the same

LED sapphire substrate with groups of three projections on the surface

The light emitting device comprising a light emitting element; and a wavelength converting member having a first face and a second face, in which light emitted from the light emitting element enters in through the first face, and a part of the second face serves as a light emitting face, wherein the light emitting element further comprises a reflection control structure around the light emitting face of the second face, and the reflection control structure comprises a reflection film on the wavelength converting member and an anti-reflection film on the reflection film.

Sapphire substrate having triangular projections with portions extending in direction of substrate crystal axis

A sapphire substrate having a principal surface for growing a nitride semiconductor to form a nitride semiconductor light emitting device comprises a plurality of projections on the principal surface. Each of the projections has a bottom that has a substantially polygonal shape. Each side of the bottom of the projections has a depression in its center. Vertexes of the bottoms of the respective projections extend in a direction that is within a range of &#xb1;10 degrees of a direction that is rotated counter-clockwise by 30 degrees from a crystal axis 'a' of the sapphire substrate.

Sapphire substrate having triangular projections with bottom sides formed of outwardly curved lines

A sapphire substrate having a principal surface for growing a nitride semiconductor to form a nitride semiconductor light emitting device comprises a plurality of projections on the principal surface. Each of the projections has a bottom that has a substantially polygonal shape. Each side of the bottom of the projections has a depression in its center. Vertexes of the bottoms of the respective projections extend in a direction that is within a range of &#xb1;10 degrees of a direction that is rotated clockwise by 30 degrees from a crystal axis 'a' of the sapphire substrate.

Growing community of inventors

Tokushima, Japan

Takuya Okada