Mitsubishi Denki Kabushiki Kaisha

Shogo Takahashi

Etsuji Omura

Katsuhiko Goto

Akira Takemoto

Harumi Namba

Tetsuo Shiba

Element production process in a method for producing an embedded type optoelectronic integrated circuit comprising an optical element part and a signal processing part, includes steps of producing a mask film on a surface of the substrate and removing a predetermined region of the film to produce a selective growth mask, producing a concave portion at a predetermined region on the surface of the substrate by etching using the selective growth mask, producing a crystal layer which is to be an optical element part in the concave part by crystal growth using the selective growth mask, flattening the surface of the crystal layer by grinding swelling crystal at the edges of the concave portion, and removing the selective growth mask and conducting mirror polishing by mechanochemical etching. Therefore, even when an optical device is embedded in the substrate using crystal growth method, a step due to swelling crystal does not arise on the substrate and .parts of wafer damaged by grinding is removed. Thus, the following process is eased.

Method for producing an embedded optoelectronic integrated circuit

A semiconductor light emitting device includes a vertical aperture produced at a main surface of a semi-insulating or insulating substrate, a transverse aperture provided in the substrate communicating with the vertical aperture, a conducting semiconductor layer buried in the vertical aperture and the transverse aperture, a groove produced by etching the substrate from the surface thereof until reaching the conducting semiconductor layer at a portion of the transverse aperture, and a light emitting element produced in the groove, and the light emitting region of the element being buried in the groove and connected with the buried conducting semiconductor layer. Accordingly, no pn junction exists at the periphery of the light emitting region, and a semiconductor light emitting element of quite low parasitic capacitance is obtained at high yield. A planar structure in which two electrodes are produced at the same plane is obtained, resulting in ease of integration and enhancement of the integration density.

Method of producing a semiconductor light emitting device disposed in an

A method for diffusing a P type impurity into a semiconductor includes the steps of selectively implanting ions of a first P type impurity into a semiconductor substrate and thermally diffusing a second P type impurity into the semiconductor substrate containing at least a region where the first P type impurity ions are implanted. Therefore, the diffusion speed of the P type impurity is increased in the ion implantation region, whereby the P type impurity diffusion region which almost corresponds to the ion implantation region can be obtained and P type diffusion can be performed in high concentration with high precision.

Semiconductor laser

A method of diffusing a P type impurity into a semiconductor substrate includes selectively implanting ions of a first P type impurity into a semiconductor substrate and thermally diffusing a second P type impurity into the semiconductor substrate at least in a region where the first P type impurity ions are implanted. The diffusion speed of the P type impurity is increased in the ion implantation region whereby a P type impurity diffusion region which nearly corresponds in extent to the ion implantation region is obtained. The P type diffusion region can be precisely produced with a high dopant impurity concentration.

Method of diffusing P type impurity

A semiconductor light emitting device includes a vertical aperture produced at a main surface of a semi-insulating or insulating substrate, a transverse aperture provided in the substrate communicating with the vertical aperture, a conducting semiconductor layer buried in the vertical aperture and the transverse aperture, a groove produced by etching the substrate from the surface thereof until reaching the conducting semiconductor layer at a portion of the transverse aperture, and a light emitting element produced in the groove, and the light emitting region of the element being buried in the groove and connected with the buried conducting semiconductor layer. Accordingly, no pn junction exists at the periphery of the light emitting region, and a semiconductor light emitting element of quite low parasitic capacitance is obtained at high yield. A planar structure in which two electrodes are produced at the same plane is obtained, resulting in ease of integration and enhancement in the integration density.

A planar type semiconductor laser having p-side and n-side electrodes on the same side of the substrate. The substrate carries a number of layers including lower and upper cladding layers sandwiching an active layer. Both of the cladding layers are of n-type material. A pair of p-type diffusion regions serve to define the width of an undisordered active stripe in the active layer. A first relatively deep diffusion region penetrates both cladding layers and extends into the substrate. A second shallower diffusion region spaced, from the first, penetrates only to the lower cladding layer and leaves a channel below the diffusion front in the lower cladding layer for conduction of carriers. The distance between the p-type diffusion regions defines the width of the active layer. An n-side electrode is formed on the upper surface of the semiconductor device and in electrical contact with the n-type cladding layers. A p-side electrode is formed on the upper surface of the semiconductor layer in electrical contact with the first p-type diffusion region.

Semiconductor laser and laser fabrication method

A planar type semiconductor laser having p-side and n-side electrodes on the same side of the substrate. The substrate carries a number of layers including lower and upper cladding layers sandwiching an active layer. Both of the cladding layers are of n-type material. A pair of p-type diffusion regions serve to define the width of an undiordered active stripe in the active layer. A first relatively deep diffusion region penetrates both cladding layers and extends into the substrate. A second shallower diffusion region spaced, from the first, penetrates only to the lower cladding layer and leaves a channel below the diffusion front in the lower cladding layer for conduction of carriers. The distance between the p-type diffusion regions defines the width of the active layer. An n-side electrode is formed on the upper surface of the semiconductor device and in electrical contact with the n-type cladding layers. A p-side electrode is formed on the upper surface of the semiconductor layer in electrical contact with the first p-type diffusion region.

Semiconductor light emitting device disposed in an insulating substrate

A method of producing a semiconductor laser including deposition a first film as a source of n type impurities on a portion of a semiconductor structure produced by growing at least a p type lower cladding layer, a quantum well active layer, and an n type upper cladding layer successively on a substrate, depositing a second film as a source of p type impurities at least on the surface of the semiconductor structure on both sides of and on the first film and annealing to diffuse p and n type impurities at the same time, thereby disordering portions of the quantum well except for the portion becoming an active region with p type impurities reaching at least the p type lower cladding layer, n type impurities reverting the portions of the n type cladding layer to which p type impurities have diffused to n type, and the n type impurities reaching the n type cladding layer but not reaching the active layer.

Method of producing a semiconductor laser

A buried heterojunction semiconductor laser appropriate for integration with other electronic circuitry and method of producing same, in which the width of a central stripe of the active region can be reduced beyond the physical size limitations of the connecting electrode so as to allow the semiconductor laser to oscillate in a stable manner and with low threshold current. The semiconductor laser is provided with a portion of the surface of the upper cladding layer located above the disordered active layer regions electrically connected with the upper cladding layer located above the nondisordered central stripe. As a result, the central stripe electrode can be of a width larger than that of the central stripe itself.

Method of making a semiconductor laser using superlattice disordering

An end face light emitting element having a light emitting region on a semiconductor substrate to emit light from the end face thereof has a light waveguide layer between the light emitting region and the substrate with the light emitting region deformed like a staircase having at least two steps.

End face light emitting element

A method of producing an end surface light emmision type semiconductor device comprising: a process of producing a lower cladding layer, an active layer, and an upper cladding layer on a semiconductor substrate; a process of forming a stripe groove of a predetermined depth reaching the lower cladding layer at a predetermined position of the wafer to produce an output end surface; a process of depositing photosensitive material in the groove; a process of producing a required number of lenses from the photosensitive material; and a process of dividing the wafer into a plurality of lens-appended end surface light emission type semiconductor devices.

Growing community of inventors

Itami, Japan

Shogo Takahashi