Showa Denko K.k.

Hitoshi Takeda

Hisayuki Miki

Tetsuo Sakurai

Masato Kobayakawa

Hisao Sato

Syunji Horikawa

An object of the present invention is to provide a gallium nitride compound semiconductor multilayer structure useful for producing a gallium nitride compound semiconductor light-emitting device which operates at low voltage while maintaining satisfactory light emission output. The inventive gallium nitride compound semiconductor multilayer structure comprises a substrate, and an n-type layer, a light-emitting layer, and a p-type layer formed on the substrate, the light-emitting layer having a multiple quantum well structure in which a well layer and a barrier layer are alternately stacked repeatedly, said light-emitting layer being sandwiched by the n-type layer and the p-type layer, wherein the well layer comprises a thick portion and a thin portion, and the barrier layer contains a dopant.

Gallium nitride-based compound semiconductor multilayer structure and production method thereof

An object of the present invention is to provide a method for producing a gallium nitride-based compound semiconductor multilayer structure useful for the production of a gallium nitride-based compound semiconductor light-emitting device which can ensure that the operating voltage is reduced, the light emission output is good and the light emission output is less changed due to aging. The inventive production method of a gallium nitride-based compound semiconductor multilayer structure comprises a substrate having thereon an n-type semiconductor layer, a light-emitting layer and a p-type semiconductor layer, the light-emitting layer being disposed between the n-type semiconductor layer and the p-type semiconductor layer, and the light-emitting layer having a multiple quantum well structure formed by alternately stacking a well layer and a barrier layer, wherein at least one well layer has a non-uniform thickness, at least a part of the barrier layer is grown at a higher temperature than the well layer, and the temperature difference between each growth temperature of the well layer, the barrier layer and the p-type semiconductor layer is adjusted to be in a specific range.

Production method of gallium nitride-based compound semiconductor multilayer structure

An object of the present invention is to provide a method for producing a p-type Group III nitride semiconductor which can be used to produce a light-emitting device exhibiting a low operation voltage and a sufficiently high reverse voltage. The inventive method for producing a p-type Group III nitride semiconductor comprises, during lowering temperature after completion of growth of a Group III nitride semiconductor containing a p-type dopant,

P-type Group III nitride semiconductor and production method thereof

An n-type Group III nitride semiconductor stacked layer structure including a first n-type layer which includes a layer containing n-type impurity atoms at a high concentration and a layer containing n-type impurity atoms at a low concentration, a second n-type layer containing n-type impurity atoms at an average concentration smaller than that of the first n-type layer, the second n-type layer neighboring the layer containing n-type impurity atoms at a low concentration in the first n-type layer.

N-type group III nitride semiconductor stacked layer structure

An object of the present invention is to provide a gallium nitride compound semiconductor multilayer structure useful for producing a gallium nitride compound semiconductor light-emitting device which operates at low voltage while maintaining a satisfactory light emission output. The inventive gallium nitride compound semiconductor multilayer structure comprises a substrate, and an n-type layer, an active layer, and a p-type layer formed on the substrate, the active layer being sandwiched by the n-type layer and the p-type layer, and the active layer comprising a thick portion and a thin portion, wherein the active layer has a flat lower surface (on the substrate side) and an uneven upper surface so as to form the thick portion and the thin portion.

A Group III nitride semiconductor light emitting device having a light emitting layer () bonded to a crystal layer composed of an n-type or p-type Group III nitride semiconductor, the Group III nitride semiconductor light emitting device being characterized by comprising an n-type Group III nitride semiconductor layer () having germanium (Ge) added thereto and having a resistivity of 1&#xd7;10to 1&#xd7;10&#x3a9;cm. The invention provides a Ge-doped n-type Group III nitride semiconductor layer with low resistance and excellent flatness, in order to obtain a Group III nitride semiconductor light emitting device exhibiting low forward voltage and excellent light emitting efficiency.

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Ichihara, Japan

Hitoshi Takeda