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: 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 GaN group crystal base member comprising a base substrate, a mask layer partially covering the surface of said base substrate to give a masked region, and a GaN group crystal layer grown thereon to cover the mask layer, which is partially in direct contact with the non-masked region of the base substrate, use thereof for a semiconductor element, manufacturing methods thereof and a method for controlling a dislocation line. The manufacturing method of the present invention is capable of making a part in the GaN group crystal layer, which is above a masked region or non-masked region, have a low dislocation density.

Abstract: A GaN single crystal having a full width at half-maximum of the double-crystal X-ray rocking curve of 5-250 sec and a thickness of not less than 80 .mu.m, a method for producing the GaN single crystal having superior quality and sufficient thickness permitting its use as a substrate and a semiconductor light emitting element having high luminance and high reliability, comprising, as a substrate, the GaN single crystal having superior quality and/or sufficient thickness permitting its use as a substrate.

Abstract: A group-III nitride based light emitter such as LED and LD, which has a double heterostructure and which comprises a diffusion suppressive layer between a p-type cladding layer and an active layer. The diode having a diffusion suppressive layer of the present invention has higher luminous intensity, greater forward voltage, and longer lifetime than the conventional diodes.

Abstract: A GaN single crystal having a full width at half-maximum of the double-crystal X-ray rocking curve of 5-250 sec and a thickness of not less than 80 .mu.m, a method for producing the GaN single crystal having superior quality and sufficient thickness permitting its use as a substrate and a semiconductor light emitting element having high luminance and high reliability, comprising, as a substrate, the GaN single crystal having superior quality and/or sufficient thickness permitting its use as a substrate.

Abstract: A semiconductor light emitting element comprising an n-type semiconductor substrate and a light emitting part comprising an n-type cladding layer composed of an InGaAlP compound semiconductor material, an active layer and a p-type cladding layer formed in that order from the substrate side by double heterojunction, wherein said semiconductor light emitting element satisfies at least one of the following conditions:A. the thickness of said active layer being greater than 0.75 .mu.m and not more than 1.5 .mu.m, andB. the thickness of said p-type cladding layer being 0.5 .mu.m-2.0 .mu.m. According to the light emitting element of the present invention, an overflow of electron into the p-type cladding layer can be suppressed by setting the thickness of the active layer and the p-type cladding layer to fall within the above-mentioned specific ranges, as a result of which the element shows luminous efficiency peaked within the specified range.

Abstract: In the light emitting element comprising an n-type semiconductor substrate, a lower electrode formed on the lower surface of the substrate, and a light emitting part having a pn junction, which is composed of an InGaAlP compound semiconductor material, a p-type current diffusing layer and an upper electrode which are laminated on the upper surface of the substrate in that order from the substrate side, the improvement wherein a carrier concentration of the current diffusing layer is lower on a light emitting part side thereof than that on an upper electrode side thereof, and at least the upper electrode side of the current diffusing layer is composed of GaP. By employing such structure, diffusion of the dopant to a light emitting part can be suppressed even when the carrier concentration of the upper part of the current diffusing layer is set to be higher, thereby affording a lower resistance of the current diffusing layer as a whole.

Abstract: A semiconductor light emitting element comprising a light emitting part comprising an AlGaInP active layer and a AlGaInP cladding layer, which is formed on a GaAs substrate, and an AlGaAs layer and a Ga.sub.x In.sub.1-x P layer (0.7.ltoreq.x.ltoreq.1.0) deposited in this order on said light emitting part, wherein said Ga.sub.x In.sub.1-x P layer has a thickness of not more than 1.0 .mu.m. According to the present invention, absorption of the emitted light by an electrode contact layer and the occurrence of an interfacial distortion between the electrode contact layer and the layer thereunder can be suppressed, and a semiconductor light emitting element permitting easy production thereof and having a high luminance and a long service life can be provided.

Abstract: A material for a light emitting element most suited for a light emitting diode or laser diode which emits visible light of 550 to 650 nm band wavelength. The material provides an at least two-layered structure composed of a GaAs substrate and a Sn doped InGaP layer developed on the substrate without forming a gradient layer therebetween. The mixed crystal composition of the Sn doped InGaP layer as expressed by the molar fraction of GaP is 0.50 to 0.75.According to the method for developing mixed crystals of InGaP, GaP and InP are dissolved in Sn to make a solution. The solution is allowed to come in contact with a GaAs substrate so that InGaP crystals are developed directly on the GaAs substrate without a gradient layer for coordinating the lattice constant formed on the GaAs substrate.