Abstract: A nitride semiconductor light-emitting device is formed of an n-type nitride semiconductor layer, a trigger layer, a V-pit expanding layer, a light-emitting layer, and a p-type nitride semiconductor layer provided in this order. The light-emitting layer has a V-pit formed therein. The trigger layer is made of a nitride semiconductor material having a lattice constant different from that of a material that forms an upper surface of the n-type nitride semiconductor layer. The V-pit expanding layer is made of a nitride semiconductor material having a lattice constant substantially identical to that of the material that forms the upper surface of the n-type nitride semiconductor layer, and the V-pit expanding layer has a thickness of 5 nm or more and 5000 nm or less.

Abstract: A nitride semiconductor light-emitting device is formed of an n-type nitride semiconductor layer, a trigger layer, a V-pit expanding layer, a light-emitting layer, and a p-type nitride semiconductor layer provided in this order. The light-emitting layer has a V-pit formed therein. The trigger layer is made of a nitride semiconductor material having a lattice constant different from that of a material that forms an upper surface of the n-type nitride semiconductor layer. The V-pit expanding layer is made of a nitride semiconductor material having a lattice constant substantially identical to that of the material that forms the upper surface of the n-type nitride semiconductor layer, and the V-pit expanding layer has a thickness of 5 nm or more and 5000 nm or less.

Abstract: A GaN crystal multi-layer substrate having surfaces with various crystal orientations formed on a sapphire base substrate, such as a substrate whose principal surface is a <11-20> plane which is the a-plane, a <1-100> plane which is the m-plane, or a <11-22> plane having a low threading dislocation density and high crystal quality of a GaN crystal, and a production process therefor.

Abstract: In a semiconductor device fabricated by growing a compound semiconductor layer on a sapphire substrate, a sapphire substrate enabling the semiconductor device to have a high light-extraction efficiency is provided. A plurality of projections 2, 2, . . . are provided at random on a surface of a sapphire substrate 1, and a GaN layer 10 is grown on this surface. Then, a multi-quantum well layer 12, a p-AlGaN layer 14, a p-GaN layer 16, and an ITO layer 18 are formed on the GaN layer 10, and two electrodes 21 and 22 are also formed. In this manner, a semiconductor light-emitting device is fabricated.

Abstract: In a semiconductor device fabricated by growing a compound semiconductor layer on a sapphire substrate, a sapphire substrate enabling the semiconductor device to have a high light-extraction efficiency is provided. A plurality of projections 2, 2, . . . are provided at random on a surface of a sapphire substrate 1, and a GaN layer 10 is grown on this surface. Then, a multi-quantum well layer 12, a p-AlGaN layer 14, a p-GaN layer 16, and an ITO layer 18 are formed on the GaN layer 10, and two electrodes 21 and 22 are also formed. In this manner, a semiconductor light-emitting device is fabricated.

Abstract: A growth plane of substrate 1 is processed to have a concavo-convex surface. The bottom of the concave part may be masked. When a crystal is grown by vapor phase growth using this substrate, an ingredient gas does not sufficiently reach the inside of a concave part 12, and therefore, a crystal growth occurs only from an upper part of a convex part 11. As shown in FIG. 1(b), therefore, a crystal unit 20 occurs when the crystal growth is started, and as the crystal growth proceeds, films grown in the lateral direction from the upper part of the convex part 11 as a starting point are connected to cover the concavo-convex surface of the substrate 1, leaving a cavity 13 in the concave part, as shown in FIG. 1(c), thereby giving a crystal layer 2, whereby the semiconductor base of the present invention is obtained. In this case, the part grown in the lateral direction, or the upper part of the concave part 12 has a low dislocation region and the crystal layer prepared has high quality.

Abstract: A growth plane of substrate 1 is processed to have a concavo-convex surface. The bottom of the concave part may be masked. When a crystal is grown by vapor phase growth using this substrate, an ingredient gas does not sufficiently reach the inside of a concave part 12, and therefore, a crystal growth occurs only from an upper part of a convex part 11. As shown in FIG. 1(b), therefore, a crystal unit 20 occurs when the crystal growth is started, and as the crystal growth proceeds, films grown in the lateral direction from the upper part of the convex part 11 as a starting point are connected to cover the concavo-convex surface of the substrate 1, leaving a cavity 13 in the concave part, as shown in FIG. 1(c), thereby giving a crystal layer 2, whereby the semiconductor base of the present invention is obtained. In this case, the part grown in the lateral direction, or the upper part of the concave part 12 has a low dislocation region and the crystal layer prepared has high quality.

Abstract: A nitride semiconductor light emitting element having a laminate S made of a semiconductor crystal layer, wherein the laminate S includes an n-type layer 2, a light emitting layer 3 and a p-type layer 4. The p-type layer 4 has a p-type contact layer 42 to be in contact with the p-side electrode P2. The p-type contact layer 42 comprises a first contact layer 42a and a second contact layer 42b. The first contact layer 42a is in contact with the p-side electrode P2 on one surface and in contact with the second contact layer 42b on the other surface. The first contact layer 42a is made of Alx1Iny1Gaz1N (0<x1?1, 0?y1?1, 0?z1?1), and the second contact layer 42b is made of Alx2Iny2Gaz2N (0?x2?1, 0?y2?1, 0?z2?1). 0?x2<x1, 0?y1?y2, and the first contact layer 42a has a thickness of 0.5 nm-2 nm.

Abstract: As shown in FIG. 1(a), substrate 1 having a growth plane having a concavo-convex surface is used. When GaN group crystal is vapor phase grown using this substrate, the concavo-convex shape suppresses growth in the lateral direction and promotes growth in the C axis direction, thereby affording a base surface capable of forming a facet plane. Thus, as shown in FIG. 1(b), a crystal having a facet plane is grown in a convex part, and a crystal is also grown in a concave part. When the crystal growth is continued, the films grown from the convex part and the concave part are joined in time to cover a concavo-convex surface and become flat as shown in FIG. 1(c). In this case, an area having a low a dislocation density is formed in the upper part of the convex part where facet plane was formed, and the prepared film has high quality.

Abstract: A growth plane of substrate 1 is processed to have a concavo-convex surface. The bottom of the concave part may be masked. When a crystal is grown by vapor phase growth using this substrate, an ingredient gas does not sufficiently reach the inside of a concave part 12, and therefore, a crystal growth occurs only from an upper part of a convex part 11. As shown in FIG. 1(b), therefore, a crystal unit 20 occurs when the crystal growth is started, and as the crystal growth proceeds, films grown in the lateral direction from the upper part of the convex part 11 as a starting point are connected to cover the concavo-convex surface of the substrate 1, leaving a cavity 13 in the concave part, as shown in FIG. 1(c), thereby giving a crystal layer 2, whereby the semiconductor base of the present invention is obtained. In this case, the part grown in the lateral direction, or the upper part of the concave part 12 has a low dislocation region and the crystal layer prepared has high quality.

Abstract: A growth plane of substrate 1 is processed to have a concavo-convex surface. The bottom of the concave part may be masked. When a crystal is grown by vapor phase growth using this substrate, an ingredient gas does not sufficiently reach the inside of a concave part 12, and therefore, a crystal growth occurs only from an upper part of a convex part 11. As shown in FIG. 1(b), therefore, a crystal unit 20 occurs when the crystal growth is started, and as the crystal growth proceeds, films grown in the lateral direction from the upper part of the convex part 11 as a starting point are connected to cover the concavo-convex surface of the substrate 1, leaving a cavity 13 in the concave part, as shown in FIG. 1(c), thereby giving a crystal layer 2, whereby the semiconductor base of the present invention is obtained. In this case, the part grown in the lateral direction, or the upper part of the concave part 12 has a low dislocation region and the crystal layer prepared has high quality.

Abstract: A growth plane of substrate 1 is processed to have a concavo-convex surface. The bottom of the concave part may be masked. When a crystal is grown by vapor phase growth using this substrate, an ingredient gas does not sufficiently reach the inside of a concave part 12, and therefore, a crystal growth occurs only from an upper part of a convex part 11. As shown in FIG. 1(b), therefore, a crystal unit 20 occurs when the crystal growth is started, and as the crystal growth proceeds, films grown in the lateral direction from the upper part of the convex part 11 as a starting point are connected to cover the concavo-convex surface of the substrate 1, leaving a cavity 13 in the concave part, as shown in FIG. 1(c), thereby giving a crystal layer 2, whereby the semiconductor base of the present invention is obtained. In this case, the part grown in the lateral direction, or the upper part of the concave part 12 has a low dislocation region and the crystal layer prepared has high quality.

Abstract: Concaves and convexes 1a are formed by processing the surface layer of a first layer 1, and second layer 2 having a different refractive index from the first layer is grown while burying the concaves and convexes (or first crystal 10 is grown as concaves and convexes on crystal layer S to be the base of the growth, and second crystal 20 is grown, which has a different refractive index from the first crystal). After forming these concavo-convex refractive index interfaces 1a (10a), an element structure, wherein semiconductor crystal layers containing a light-emitting layer A are laminated, is formed. As a result, the light in the lateral direction, which is generated in the light-emitting layer changes its direction by an influence of the concavo-convex refractive index interface and heads toward the outside.

Abstract: A growth plane of substrate 1 is processed to have a concavo-convex surface. The bottom of the concave part may be masked. When a crystal is grown by vapor phase growth using this substrate, an ingredient gas does not sufficiently reach the inside of a concave part 12, and therefore, a crystal growth occurs only from an upper part of a convex part 11. As shown in FIG. 1(b), therefore, a crystal unit 20 occurs when the crystal growth is started, and as the crystal growth proceeds, films grown in the lateral direction from the upper part of the convex part 11 as a starting point are connected to cover the concavo-convex surface of the substrate 1, leaving a cavity 13 in the concave part, as shown in FIG. 1(c), thereby giving a crystal layer 2, whereby the semiconductor base of the present invention is obtained. In this case, the part grown in the lateral direction, or the upper part of the concave part 12 has a low dislocation region and the crystal layer prepared has high quality.

Abstract: A growth plane of substrate 1 is processed to have a concavo-convex surface. The bottom of the concave part may be masked. When a crystal is grown by vapor phase growth using this substrate, an ingredient gas does not sufficiently reach the inside of a concave part 12, and therefore, a crystal growth occurs only from an upper part of a convex part 11. As shown in FIG. 1(b), therefore, a crystal unit 20 occurs when the crystal growth is started, and as the crystal growth proceeds, films grown in the lateral direction from the upper part of the convex part 11 as a starting point are connected to cover the concavo-convex surface of the substrate 1, leaving a cavity 13 in the concave part, as shown in FIG. 1(c), thereby giving a crystal layer 2, whereby the semiconductor base of the present invention is obtained. In this case, the part grown in the lateral direction, or the upper part of the concave part 12 has a low dislocation region and the crystal layer prepared has high quality.

Abstract: The state of a surface of a substrate 11 or a GaN group compound semiconductor film 12 formed on the substrate 11 is modified with an anti-surfactant material and a GaN group compound semiconductor material is supplied by a vapor phase growth method to form dot structures made of the GaN group compound semiconductor on the surface of the semiconductor film 12, and the growth is continued until the dot structures join and the surface becomes flat. In this case, the dot structures join while forming a cavity 21 on an anti-surfactant region. A dislocation line 22 extending from the underlayer is blocked by the cavity 21, and therefore, the dislocation density of an epitaxial film surface can be reduced. As a result, the dislocation density of the GaN group compound semiconductor crystal can be reduced without using a masking material in the epitaxial growth, whereby a high quality epitaxial film can be obtained.

Abstract: Concaves and convexes 1a are formed by processing the surface layer of a first layer 1, and second layer 2 having a different refractive index from the first layer is grown while burying the concaves and convexes (or first crystal 10 is grown as concaves and convexes on crystal layer S to be the base of the growth, and second crystal 20 is grown, which has a different refractive index from the first crystal). After forming these concavo-convex refractive index interfaces 1a (10a), an element structure, wherein semiconductor crystal layers containing a light-emitting layer A are laminated, is formed. As a result, the light in the lateral direction, which is generated in the light-emitting layer changes its direction by an influence of the concavo-convex refractive index interface and heads toward the outside.

Abstract: The state of a surface of a substrate 11 or a GaN group compound semiconductor film 12 formed on the substrate 11 is modified with an anti-surfactant material and a GaN group compound semiconductor material is supplied by a vapor phase growth method to form dot structures made of the GaN group compound semiconductor on the surface of the semiconductor film 12, and the growth is continued until the dot structures join and the surface becomes flat. In this case, the dot structures join while forming a cavity 21 on an anti-surfactant region. A dislocation line 22 extending from the underlayer is blocked by the cavity 21, and therefore, the dislocation density of an epitaxial film surface can be reduced. As a result, the dislocation density of the GaN group compound semiconductor crystal can be reduced without using a masking material in the epitaxial growth, whereby a high quality epitaxial film can be obtained.

Abstract: A semiconductor light receiving element having a light receiving layer (1) formed from a GaN group semiconductor, and an electrode (2) formed on one surface of the light receiving layer as a light receiving surface (1a) in such a way that the light (L) can enter the light receiving layer is provided. When the light receiving element is of a Schottky barrier type, the aforementioned electrode (2) contains at least a Schottky electrode, which is formed in such a way that, on the light receiving surface (1a), the total length of the boundary lines between areas covered with the Schottky electrode and exposed areas is longer than the length of the outer periphery of the light receiving surface (1a).

Abstract: As an embodiment of the element structure, a structure including, from the downside, a sapphire C-plane substrate 1, a GaN buffer layer 11 grown at a low temperature, an un-doped GaN layer 12, an Si-doped n-GaN contact layer 21, a light emitting layer 3 of a multiple quantum well structure (MQW) having plural well layers, an Mg-doped p-AlGaN cladding layer 22, and an Mg-doped p-GaN contact layer 23 is mentioned. The above-mentioned light emitting layer 3 is capable of multi-wavelength light emission by a multi-layer structure emitting light having at least two peaks in an emission spectrum, which is achieved by, for example, forming plural groups having different band gaps of the well layer. As a result, a light having plural wavelengths is emitted from a single light emitting layer, and by simply injecting current into a pair of p-type and n-type electrodes, a light emitting element emitting multicolor light, particularly white light, can be provided.