Abstract: After distributing a nonmetal element in a region in the vicinity of a surface portion of a semiconductor layer, a metal film is deposited on the semiconductor layer. Next, a semiconductor-metal compound layer is epitaxially grown in the surface portion of the semiconductor layer by causing a reaction between an element included in the semiconductor layer and a metal included in the metal film through annealing carried out on the metal film.

Abstract: In a method of manufacturing a planar buried heterojunction laser a semiconductor structure is etched to delimit a laser stripe upstanding on a confinement layer. Lateral layers surround the laser stripe to constitute the planar buried heterojunction laser. They are formed by a non-selective growth method not only at the sides of said stripe but also on top of said stripe to create a parasitic projection. These layers and the projection are subsequently covered with a contact localizing layer. The projection is then removed to form a contact window in the contact localizing layer for localizing an electrical contact on top of the laser stripe. The invention finds a particular application in the manufacture of lasers for fiber optic telecommunication systems.

Abstract: A method of producing a Czochralski-grown silicon single crystal stably and efficiently with high production yield comprises the steps of setting pulling conditions such that at least a portion of a growing silicon single crystal having a temperature in excess of 1150.degree. C. is spaced upwardly from a surface of silicon melt by a distance greater than 280 mm; and pulling the growing silicon single crystal upward while maintaining the pulling conditions. The silicon single crystal produced by this method has an excellent oxide film dielectric breakdown strength. An apparatus for carrying out the method is also disclosed.