Abstract: An optical semiconductor device includes a semiconductor substrate; a light receiving element formed on the semiconductor substrate; a light absorbing element formed on the semiconductor substrate and located adjacent to the light receiving element; and a semiconductor element formed on the semiconductor substrate and used for signal processing. The light absorbing element includes a fifth semiconductor layer, and a light absorption region in the light receiving element has a different structure from a light absorption region in the light absorbing element.

Abstract: An optical semiconductor device is provided with a low concentration p-type silicon substrate (1); a low dopant concentration n-type epitaxial layer (second epitaxial layer) (26); a low dopant concentration p-type anode layer (27); a high concentration n-type cathode contact layer (9); a photodiode (2) made of the anode layer (27) and the cathode contact layer (9); and an NPN transistor (3) formed on the n-type epitaxial layer (26). The anode can be substantially completely depleted in the case where the anode layer (27) has its dopant concentration peak in the vicinity of the interface between the silicon substrate (1) and the n-type epitaxial layer (26). Therefore, high speed and high light receiving sensitivity characteristics can be obtained, and further, any influence of auto-doping from peripheral embedding layers can be controlled, so that a depletion layer can be stably formed in the anode.

Abstract: An optical semiconductor device is provided with a low concentration p-type silicon substrate (1); a low dopant concentration n-type epitaxial layer (second epitaxial layer) (26); a low dopant concentration p-type anode layer (27); a high concentration n-type cathode contact layer (9); a photodiode (2) made of the anode layer (27) and the cathode contact layer (9); and an NPN transistor (3) formed on the n-type epitaxial layer (26). The anode can be substantially completely depleted in the case where the anode layer (27) has its dopant concentration peak in the vicinity of the interface between the silicon substrate (1) and the n-type epitaxial layer (26). Therefore, high speed and high light receiving sensitivity characteristics can be obtained, and further, any influence of auto-doping from peripheral embedding layers can be controlled, so that a depletion layer can be stably formed in the anode.

Abstract: An optical semiconductor device includes a phototransistor for receiving incident light. The phototransistor includes a collector layer of a first conductivity type formed on a semiconductor substrate, a base layer of a second conductivity type formed on the collector layer, and an emitter layer of a first conductivity type formed on the base layer. A thickness of the emitter layer is equal to or less than an absorption length of the incident light in the semiconductor substrate.

Abstract: An optical semiconductor device is provided with a low concentration p-type silicon substrate (1); a low dopant concentration n-type epitaxial layer (second epitaxial layer) (26); a low dopant concentration p-type anode layer (27); a high concentration n-type cathode contact layer (9); a photodiode (2) made of the anode layer (27) and the cathode contact layer (9); and an NPN transistor (3) formed on the n-type epitaxial layer (26). The anode can be substantially completely depleted in the case where the anode layer (27) has its dopant concentration peak in the vicinity of the interface between the silicon substrate (1) and the n-type epitaxial layer (26). Therefore, high speed and high light receiving sensitivity characteristics can be obtained, and further, any influence of auto-doping from peripheral embedding layers can be controlled, so that a depletion layer can be stably formed in the anode.

Abstract: An optical semiconductor device that performs photoelectric conversion, comprising: a semiconductor substrate that includes (i) a first conductivity-type semiconductor region, (ii) a second conductivity-type semiconductor region that is positioned on the first conductivity-type semiconductor region and has a light receiving surface, and (iii) a first conductivity-type contact region that penetrates, from an upper surface of the second conductivity-type semiconductor region, the second conductivity-type semiconductor region so as to be in contact with the first conductivity-type semiconductor region; an electrode pair for drawing current obtained by performing photoelectric conversion of light incident on the light receiving surface, the electrode pair being composed of (i) a first electrode that is positioned on the first conductivity-type contact region and (ii) a second electrode that is positioned on the second conductivity-type semiconductor region so as to be separated from the first electrode; an insula

Abstract: An optical semiconductor device includes: a first conductivity type first semiconductor region; a first conductivity type second semiconductor region formed on the first semiconductor region; a second conductivity type third semiconductor region formed on the second semiconductor region; a photodetector section formed of the second semiconductor region and the third semiconductor region; a micro mirror formed of a trench formed selectively in a region of the first semiconductor region and the second semiconductor region except the photodetector section; and a semiconductor laser element held on the bottom face of the trench. A first conductivity type buried layer of which impurity concentration is higher than those of the first semiconductor region and the second semiconductor region is selectively formed between the first semiconductor region and the second semiconductor region in the photodetector section.

Abstract: An optical semiconductor device includes a light-receiving element on a semiconductor substrate of a first conductivity type, the light-receiving element including a light-receiving portion for converting incident light to an electrical current signal and performing a current amplification. The light-receiving portion includes: a semiconductor layer formed on the semiconductor substrate and having an impurity concentration substantially equal to or less than that of the semiconductor substrate; a first semiconductor region of a second conductivity type formed on the semiconductor layer and having an impurity concentration higher than that of the semiconductor layer; and a second semiconductor region of the first conductivity type selectively formed between the semiconductor substrate and the semiconductor layer and having an impurity concentration higher than those of the semiconductor substrate and the semiconductor layer.

Abstract: A transistor that forms an integrated circuit, a photo detector and a micromirror are mounted on the same semiconductor substrate in an optical semiconductor device of the present invention, which has an antireflection film that is formed on the photo detector, a first insulating film which is formed on the antireflection film and in which an opening is created in the state where the antireflection film is exposed, and an etching stopping film which is formed on the first insulating film and which has been left in the periphery around the opening in the first insulating film on the antireflection film and in the periphery around the portion above the micromirror.

Abstract: An optical semiconductor device includes a semiconductor substrate; a light receiving element formed on the semiconductor substrate; a light absorbing element formed on the semiconductor substrate and located adjacent to the light receiving element; and a semiconductor element formed on the semiconductor substrate and used for signal processing. The light absorbing element includes a fifth semiconductor layer, and a light absorption region in the light receiving element has a different structure from a light absorption region in the light absorbing element.

Abstract: An optical semiconductor device is provided with a low concentration p-type silicon substrate (1); a low dopant concentration n-type epitaxial layer (second epitaxial layer) (26); a low dopant concentration p-type anode layer (27); a high concentration n-type cathode contact layer (9); a photodiode (2) made of the anode layer (27) and the cathode contact layer (9); and an NPN transistor (3) formed on the n-type epitaxial layer (26). The anode can be substantially completely depleted in the case where the anode layer (27) has its dopant concentration peak in the vicinity of the interface between the silicon substrate (1) and the n-type epitaxial layer (26). Therefore, high speed and high light receiving sensitivity characteristics can be obtained, and further, any influence of auto-doping from peripheral embedding layers can be controlled, so that a depletion layer can be stably formed in the anode.

Abstract: An optical semiconductor device includes a first light receiving region and a second light receiving region provided on a substrate and the first and second light receiving regions include light receiving elements, respectively. A first anti-reflection film is formed in the first light receiving region of the substrate and a second anti-reflection film is formed in the second light receiving region of the substrate. The reflectance of the first anti-reflection film for a first wavelength range of light is lower than the reflectance of the second anti-reflection film for the first wavelength range of light and the reflectance of the second anti-reflection film for a second wavelength range of light which is different from the first wavelength range of light is lower than the reflectance of the first anti-reflection film for the second wavelength range of light.

Abstract: An optical semiconductor device is provided with an n-type epitaxial layer (second epitaxial layer) 24 having a low dopant concentration formed on a low concentration p-type silicon substrate 1; a p-type anode layer (first diffusion layer) 25 having a low dopant concentration selectively formed in the n-type epitaxial layer 24 by means of the ion implantation or the like; a high concentration n-type cathode layer (second diffusion layer) 9 formed on the anode layer 25; a light receiving element 2 comprising the anode layer 25 and the cathode layer 9; and a transistor 3 formed on the n-type epitaxial layer 24. A photodiode characterized in its high speed and high receiving sensitivity for light having a short wavelength and a transistor characterized in its high speed can be mounted on the same semiconductor substrate.

Abstract: An optical semiconductor device includes a phototransistor for receiving incident light. The phototransistor includes a collector layer of a first conductivity type formed on a semiconductor substrate, a base layer of a second conductivity type formed on the collector layer, and an emitter layer of a first conductivity type formed on the base layer. A thickness of the emitter layer is equal to or less than an absorption length of the incident light in the semiconductor substrate.

Abstract: The semiconductor laser unit comprises a laser emission part having a plurality of semiconductor laser elements of different laser beam wavelengths, and a mirror part having an optical reflection film for reflecting laser beams emitted from the laser emission part. The mirror part is blocked out into a plurality of areas to which each laser beam emitted from each of the plurality of semiconductor laser elements enters, and at the same time the reflection film having high reflectance for the laser beams that enter selectively on the areas is provided in each of the plurality of areas.

Abstract: An optical semiconductor device includes: a first conductivity type first semiconductor region; a first conductivity type second semiconductor region formed on the first semiconductor region; a second conductivity type third semiconductor region formed on the second semiconductor region; a photodetector section formed of the second semiconductor region and the third semiconductor region; a micro mirror formed of a trench formed selectively in a region of the first semiconductor region and the second semiconductor region except the photodetector section; and a semiconductor laser element held on the bottom face of the trench. A first conductivity type buried layer of which impurity concentration is higher than those of the first semiconductor region and the second semiconductor region is selectively formed between the first semiconductor region and the second semiconductor region in the photodetector section.

Abstract: A semiconductor photodetector device includes: a first semiconductor layer of a first conductivity type; and a second semiconductor layer of a second conductivity type formed on the first semiconductor layer and having a light-receiving region. The first semiconductor layer includes a first region containing an impurity of the first conductivity type at a high concentration and a second region formed on the first region and containing an impurity of the first conductivity type at a concentration lower than that of the first region. The second semiconductor layer includes a third region containing an impurity of the second conductivity type at a concentration higher than that of the second region and a fourth region formed on the third region and containing an impurity of the second conductivity type at a concentration higher than that of the third region.

Abstract: An optical semiconductor device includes a first light receiving region and a second light receiving region provided on a substrate and the first and second light receiving regions include light receiving elements, respectively. A first anti-reflection film is formed in the first light receiving region of the substrate and a second anti-reflection film is formed in the second light receiving region of the substrate. The reflectance of the first anti-reflection film for a first wavelength range of light is lower than the reflectance of the second anti-reflection film for the first wavelength range of light and the reflectance of the second anti-reflection film for a second wavelength range of light which is different from the first wavelength range of light is lower than the reflectance of the first anti-reflection film for the second wavelength range of light.

Abstract: A transistor that forms an integrated circuit, a photo detector and a micromirror are mounted on the same semiconductor substrate in an optical semiconductor device of the present invention, which has an antireflection film that is formed on the photo detector, a first insulating film which is formed on the antireflection film and in which an opening is created in the state where the antireflection film is exposed, and an etching stopping film which is formed on the first insulating film and which has been left in the periphery around the opening in the first insulating film on the antireflection film and in the periphery around the portion above the micromirror.

Abstract: A semiconductor photodetector device includes: a first semiconductor layer of a first conductivity type; and a second semiconductor layer of a second conductivity type formed on the first semiconductor layer and having a light-receiving region. The first semiconductor layer includes a first region containing an impurity of the first conductivity type at a high concentration and a second region formed on the first region and containing an impurity of the first conductivity type at a concentration lower than that of the first region. The second semiconductor layer includes a third region containing an impurity of the second conductivity type at a concentration higher than that of the second region and a fourth region formed on the third region and containing an impurity of the second conductivity type at a concentration higher than that of the third region.