Abstract: A method of fabricating a semiconductor component, the method including at least one step of etching an upper layer formed on a substrate. In the method, prior to forming the upper layer, at least one set made up of marker layers separated by intermediate layers of predetermined thicknesses is caused to be grown, where the marker layers and adjacent intermediate layers have different refractive indices, and then during etching of the upper layer refractive index discontinuities are detected optically and etching is stopped when the sequence of the optically detected discontinuities corresponds to a reference sequence representative of the thicknesses of the intermediate layers.

Abstract: A metal contact is formed by etching a metal film that is locally protected by a spot of photosensitive resin. Thereafter the resin is caused to flow in the presence of vapor of a solvent for the resin, so as to form a protective spot of increased size. This larger spot makes it possible to etch the semiconductor substrate while ensuring that the projection formed in this way is automatically aligned relative to the metal contact. The resin remains photosensitive, thereby enabling subsequent etching. The invention is particularly applicable to the manufacture of avalanche diodes.

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.