Abstract: A substrate for a high-intensity LED and the method of epitaxially growing the substrate according to the invention are based on the fact that, in using an AuZn alloy or the like as the ohmic electrode of the p-type Al.sub.x Ga.sub.1-x As layer (2), the higher the carrier concentration of this layer, the smaller the contact resistance and the lower the applied voltage (V.sub.F) necessary for passing a forward current of 10 mA. Joint use is made of gas-phase epitaxy and liquid-phase epitaxy. A layer having a carrier concentration three to five times that of an epitaxial layer formed by liquid-phase epitaxy (LPE) can be realized with excellent reproducibility by gas-phase epitaxy (MOCVD process, MBE process, etc.). By utilizing this p-type Al.sub.x Ga.sub.1-x As layer (2) as an electrode contact layer, contact resistance can be reduced and variance diminished.

Abstract: An epitaxial layer having a double-hetero structure is forming using an MOCVD process or an MBE process, and an epitaxial substrate is formed using an LPE process, thereby forming a substrate which exploits the distinguishing features of both processes. Since the MOCVD process or MBE process exhibits mixed-crystal ratio and film thickness controllability, excellent reproducibility and uniformity are obtained when forming the double-hetero structure on a compound semiconductor substrate. Since the growth process takes place under thermal non-equilibrium, the amount of impurity doping is raised to more than 10.sup.19 cm.sup.3. This is advantageous in terms of forming an electrode contact layer. With the LPE process, the material dissolved in the melt is grown epitaxially on the substrate by slow cooling, and the rate of growth is high. This process is suitable for forming the substrate after removal of the compound semiconductor substrate.

Abstract: A method for generating a strip laser in a buried hetero-structure composed of layers, wherein a raised strip is etched out of the layer structure and the strip is laterally etched with an erosion melt. The lateral edges of the laser active layer are protected by leaving them covered with a portion of the layer dissolved out by the erosion melt. The deposits thus remaining are used to initiate the generation of an epitaxial layer which extends laterally from the laser-active layer.

Abstract: A multiple meltback procedure is described for removing gross contaminants and thermal degradation from InP-containing surfaces. Prior to LPE growth on an InP substrate, the substrate surface is brought into contact briefly (.ltorsim.1 sec) with an essentially pure In melt and is then brought into contact with a slightly undersaturated In/P melt. A similar triple meltback procedure is described for use prior to LPE growth over a mesa (e.g., in the fabrication of buried heterostructures).