Abstract: An optical semiconductor device includes a light emitting element disposed on a silicon sub-mount having a light receiving element formed in a surface region. By virtue of integral arrangement of the light emitting element and the light receiving element, a single lens can be used for both optical transmission and optical reception, whereby an optical communication system can be manufactured very inexpensively. Further, transmission and reception can be carried out simultaneously.

Abstract: A planar-type pleochroic light emitting diode and a method of fabricating the same are disclosed, the diode allowing from a single chip a plurality of light emissions having different center wavelengths. Impurity diffusion is carried out by use of a film having a masking effect to an impurity and a different film partially non-uniform in thickness having no masking effect to the impurity to form a plurality of diffusion regions having different depths. The diode has excellent coupling with an optical fiber, can be easily fabricated and is suitable for use in optical multiplex communication.

Abstract: In a prior-art injection type light emitting device which is constructed so that a predetermined range of a p-n junction formed by a semiconductor substrate and an epitaxial layer provided thereon may radiate, a radiation region in the p-n junction becomes larger in area than the region into which current is introduced, on account of the current spreading phenomenon. The construction of a light emitting device free from the phenomenon and a method for manufacturing the light emitting device are disclosed.

Abstract: A light emitting semiconductor device wherein a p-n junction is defined by a ditch and wherein the ditch either extends to a low resistance layer or is away from the low resistance layer at most 1/2 of the width of the ditch is disclosed. It has the merit that the near field pattern is much more uniform than in a prior-art device.

Abstract: A light emitting element made of a group III - V compound semiconductor has a p-n junction and a hetero-junction which are identical; the mixing ratio (band gap) of a p-type layer on the light emitting side is sufficiently smaller than that of an n-type layer on the opposite side. The semiconductor light-emitting element is especially useful as a light source, for optical communications, photoexcitation, etc.

Abstract: A light emitting semiconductor diode comprises a first semiconductor region having a first conductivity type and a narrow forbidden band gap, a second semiconductor region, disposed on the first semiconductor region, having the first conductivity type and a low impurity concentration, a third semiconductor region, disposed on the second semiconductor region, having a second conductivity type which is opposite to the first conductivity type, and an ohmic contact disposed on the surface of the first semiconductor region, which is opposite to the second semiconductor region. The surface has a plurality of holes extending from the outer surface through the first semiconductor region toward a p-n junction between the second and third semiconductor regions, which holes are filled with a highly reflective metal having a high thermal conductivity.

Abstract: In a method for making a light emitting device having hemispherical dome type geometry, a p-conductivity type and then an n-conductivity type layer are successively grown epitaxially on a substrate made of a mixed compound semiconductor crystal having a band gap wider than the two above-mentioned layers. A surface portion of these epitaxially grown layers, which is not covered by a mask deposited on the n-conductivity type layer at a position where a p-n junction is to be formed, is doped with p-conductivity type impurities so that a small n-conductivity type region is surrounded by a region converted into p-conductivity type. The other side of the crystal is formed into a hemispherical shape so that the n-conductivity type region is located at the central portion of the hemisphere.

Abstract: In order to eliminate non-uniformity in the temperature within the plane of a substrate that causes dispersions or variations in the characteristics of a grown layer during liquid phase epitaxial growth and to produce a grown layer having uniform characteristics, an apparatus for crystal growth according to the invention holds a substrate on a jig so that a flat surface of the substrate is arranged tangentially to an isothermal plane within the jig and aslant with respect to any position perpendicular or parallel to the axis or the center plane of the jig. Where a multiplicity of substrates are set, they are held on at least two flat surfaces which are tangential to an identical isothermal plane and which have different slopes.

Abstract: A layer of GaAs.sub.1-x P.sub.x (0<x<1) is epitaxially grown on GaAs which is disposed in a reaction tube at a different location from the Ga source by maintaining the GaAs at a temperature range of from about 750.degree. C. to about 850.degree. C., maintaining the Ga source at a temperature higher than that of the GaAs, introducing As.sub.4 gas, PCl.sub.3 gas and H.sub.2 gas or AsCl.sub.3 gas, P.sub.4 gas and H.sub.2 gas into the reaction tube from the Ga source side, whereby said gases react with the Ga source and produce GaCl gas, and contacting said gases including the GaCl gas with the surface of the GaAs.

Abstract: A longitudinal epitaxial growth device for making a mixed crystal of III.sub.b -V.sub.b group intermetallic compound semiconductor in which a means for inverting the reaction gas flow is disposed between the gallium source and the substrate, the height of the device is reduced, and the length of the gas mixing band is made sufficiently long.

Abstract: In an epitaxial growth method in liquid phase for III-V compound semiconductor crystals a solution for crystal growth is at first heated to a temperature which is higher than the temperature of crystal growth, and then cooled to that temperature, whereby a part of the solution crystallizes out as small crystals. This solution is separated by means of a filter means into two parts, one of which contains the small crystals and the other of which does not. A substrate crystal is brought into contact with the latter.

Abstract: In an epitaxial growth process for compound semiconductor crystals in a liquid phase, a substrate crystal is brought into contact with an etching solution containing as solute a predetermined amount of at least one constituent of the substrate crystal, which is smaller than that of a saturated solution, after heating them at a temperature for crystal growth. The substrate crystal is kept in contact with the solution during a period of time sufficient to remove a surface portion of the substrate crystal. Then the substrate crystal is brought into contact with a solution for crystal growth containing a substance to be grown as solute and a crystal of the substance is grown epitaxially on an exposed clean surface of the substrate crystal.