Abstract: An optoelectronic device with a very low series resistance has a III-V substrate, a lower, n-doped III-V material semiconducting confinement layer placed on the substrate, an active zone having at least one active, not intentionally doped III-V material semiconducting layer placed on the lower confinement layer, an upper, p-doped III-V material semiconducting confinement layer covering said active zone, the forbidden energy band of the active layer being lower than that of the confinement layers. Two metal coatings are placed on two opposite faces of the device and there is a highly n-doped, quaternary III-V material semiconducting layer for stopping the diffusion of doping ions from the upper confinement layer and placed between the active layer and the upper confinement layer, said stopping layer having a thickness smaller than that of the active layer and also forming part of the active zone.

Abstract: A multi-emitter type semiconductor device having multiple transistors coupled in parallel which utilize a common substrate. Between a selected emitter electrode and a base contact, a stabilizing resistive region is formed in the common substrate. In order to reduce the parasitic effects due to this region an additional emitter ballast resistor may be formed on the surface of an insulating layer over the substrate. This supplemental resistor formed on the insulating layer is made from polycrystalline silicon. Alternatively, the supplemental resistor can be combined with the resistance of the stabilizing region in a single resistor located on the surface of the insulating layer.

Abstract: A high resistive element is provided that constitutes an element of integrated circuits comprising an oxide film formed on a semiconductor substrate and a polysilicon film formed on the oxide film. The high resistive element is prepared by ion injection of silicon ions and conductive impurities in the oxide film through the polysilicon film.