A method is provided for producing a nitride compound semiconductor device. A growth substrate has a silicon surface. A buffer layer, which comprises Al.sub.xIn.sub.yGa.sub.1-x-yN with 0x1, 0y1 and x+y1, is grown onto the silicon surface of the substrate. A semiconductor layer sequence is grown onto the buffer layer. The buffer layer includes a material composition that varies in such a way that a lateral lattice constant of the buffer layer increases stepwise or continuously in a first region and decreases stepwise or continuously in a second region, which follows the first region in the growth direction. At an interface with the semiconductor layer sequence, the buffer layer includes a smaller lateral lattice constant than a semiconductor layer of the semiconductor layer sequence adjoining the buffer layer.

A method for manufacturing a light emitting device includes a) forming a first light confinement layer having a plurality of openings on or above one main surface of an oriented polycrystalline substrate, said oriented polycrystalline substrate including a plurality of oriented crystal grains; b) stacking an n-type layer, an active layer, and a p-type layer; c) forming a second light confinement layer on said first light confinement layer so that said second light confinement layer covers said plurality of first columnar structures and said second columnar structure; d) forming a transparent conductive film on said second light confinement layer; e) forming a pad electrode on said transparent conductive film; and f) forming a cathode electrode electrically connected to ends of said plurality of first columnar structures closer to said oriented polycrystalline substrate.

Provided is a nitride semiconductor wafer in which, above a nitride semiconductor template having a nitride semiconductor layer as a top layer thereof, a light emitting layer having a multiple quantum well structure that is formed by a regrown nitride semiconductor and a p-type nitride semiconductor layer are stacked. Here, when the light emitting layer having a multiple quantum well structure includes a plurality of well layers and one of the well layers that is the closest to the p-type nitride semiconductor layer is referred to as a top well layer, a distance t from a regrowth interface of the nitride semiconductor layer of the nitride semiconductor template to the top well layer is 1 m or less, and the top well layer has an oxygen concentration of 5.010.sup.16 cm.sup.3 or less.

There is provided a semiconductor multilayer structure, including: an n-type GaN layer; and a p-type GaN layer which is formed on the n-type GaN layer and into which Mg is ion-implanted, and generating an electroluminescence emission having a peak at a photon energy of 3.0 eV or more, by applying a voltage to a pn-junction formed by the n-type GaN layer and the p-type GaN layer.

A nitride semiconductor template includes a substrate, an AlN layer that is formed on the substrate and that includes Cl, and a nitride semiconductor layer formed on the AlN layer. In the AlN layer, a concentration of the Cl in a region on a side of the substrate is higher than that in a region on a side of the nitride semiconductor layer. Also, a light-emitting element includes the nitride semiconductor template, and a light-emitting layer formed on the nitride semiconductor template.

The present invention relates to an ultraviolet light-emitting diode (LED), which includes a gradual superlattice layer. The gradual superlattice layer comprises a first superlattice layer and a second superlattice layer. The first superlattice layer includes a multi-layer structure having repetitive stacks of a unit formed by a first layer and a second layer. The second superlattice layer includes a multi-layer structure having repetitive stacks of a unit formed by a third layer and a fourth layer. The concentrations of aluminum in the first, second, third, and fourth layers decrease sequentially. By disposing the gradual superlattice layer, the quality of the epitaxial structure may be improved apparently.

A light emitting diode includes: a light emitting structure including a first conductive type semiconductor layer, a second conductive type semiconductor layer, and an active layer interposed between the first conductive type semiconductor layer and the second conductive type semiconductor layer; a first contact electrode forming ohmic contact with the first conductive type semiconductor layer; a second contact electrode disposed on the second conductive type semiconductor layer; and an insulation layer disposed on the light emitting structure and insulating the first contact electrode from the second contact electrode, wherein the first conductive type semiconductor layer includes a nitride-based substrate, the nitride-based substrate having a thread dislocation density of 10.sup.4 cm.sup.2 or less, an oxygen impurity concentration of 10.sup.19 cm.sup.3 or less, and an optical extinction coefficient of less than 5 cm.sup.1 at a wavelength of 465 nm to 700 nm.

A semiconductor layer sequence includes an n-conducting n-type side, a p-conducting p-type side, and an active zone between the sides, the active zone simultaneously generating a first radiation having a first wavelength and a second radiation having a second wavelength, the active zone including at least one radiation-active layer having a first material composition that generates the first radiation, the at least one radiation-active layer is oriented perpendicular to a growth direction of the semiconductor layer sequence, the active zone includes a multiplicity of radiation-active tubes having a second material composition and/or having a crystal structure that generates the second radiation, which crystal structure deviates from the at least one radiation-active layer, and the radiation-active tubes are oriented parallel to the growth direction, the radiation-active tubes having an average diameter of 5 nm to 100 nm and an average surface density of the radiation-active tubes of 10.sup.8 1/cm.sup.2 to 10.sup.11 1/cm.sup.2.

A light emitting device that is inexpensive, is easy to manufacture, and has high light extraction efficiency is provided. The light emitting device includes an oriented polycrystalline substrate, a plurality of columnar light emitting parts, and a light confinement layer. The oriented polycrystalline substrate includes a plurality of oriented crystal grains. The plurality of columnar light emitting parts are discretely located on or above one main surface of the oriented polycrystalline substrate in areas in which there are no crystal defects, and are each a columnar part having a longitudinal direction matching a normal direction of the oriented polycrystalline substrate. The light confinement layer is made of a material having a lower refractive index than a material for the plurality of columnar light emitting parts, and is located on or above the oriented polycrystalline substrate so as to surround the plurality of columnar light emitting parts.

A semiconductor light-emitting device including a P-type semiconductor cladding layer, an N-type semiconductor layer, a light-emitting layer, and a hole injection layer is provided. The P-type semiconductor cladding layer is doped with magnesium. The light-emitting layer is disposed between the P-type semiconductor cladding layer and the N-type semiconductor layer. The hole injection layer is disposed between the P-type semiconductor cladding layer and the light-emitting layer. The hole injection layer includes a first super lattice structure formed by alternately stacking a plurality of magnesium nitride layers and a plurality of semiconductor material layers. The chemical formula of each of the semiconductor material layers is Al.sub.xIn.sub.yGa.sub.1-x-yN, and 0x1, 0y1, and 0x+y1.