Monolithic semiconductor structure of a heterojunction bipolar transistor and a laser

Claim 1

A monolithic semiconductor structure forming both a bipolar heterojunction transistor and a laser structure, comprising a heterostructure having a first, second and third semiconductor superimposed layers, the first and third layers constituting respectively the collector and the emitter of the transistor and being produced from a first and second III-V materials having a first type of conductivity and the second layer, which is placed between the first and third layers and constitutes the active layer of the laser structure and the base of the transistor, having a second conductivity type differing from the first type and being a super-lattice consisting of first series of GaAs parallel layers having an identical thickness and of a second series of parallel Ga 1-y Al y As layers with 0<y<1 having an identical thickness b satisfying the relation 1.2<b √w<1.9, in which w represents the difference of the conduction energies between GaAs and Ga 1-y Al y As, the layers of said first and second series alternating, the forbidden band widths of said first and second materials being at least equal to the one of Ga 1-y Al y As layers of said super-lattice which defines confinement zones of the carriers solely for the laser structure, oriented parallel to the first and third layers; a first region extending at least from one face to the other of the third layer and having the second conductivity type, said firsr region defining with the third layer the junction of the laser; and means for supplying current to the laser and the transistor.