Abstract: A light receiving device includes a silicon substrate, a first P type diffusion layer on the silicon substrate, and a P type semiconductor layer on the P type diffusion layer. On a surface part of the P type semiconductor layer, two N type diffusion layers as light receiving parts, and a second P type diffusion layer between the two N type diffusion layers are provided. On the P type semiconductor layer, an antireflection film structure composed of a first silicon oxide formed by thermal oxidation and a second silicon oxide formed by CVD is provided. A film thickness of the first silicon oxide is set at about 15 nm, thus a defect in a interface between the first silicon oxide and the P type semiconductor layer is prevented. A film thickness of the second silicon oxide is set at about 100 nm, thus a leak current between cathodes is prevented when a power supply voltage is applied for long period of time.

Abstract: A photodetector for an optical encoder has plural sets of segmented photodiodes, each set of which is made by two adjoining segmented photodiodes capable of coping with a scale slit having a reference resolution. Output lines of the two adjoining segmented photodiodes are connected together in each set of the photodiodes. These output lines are connected to output lines of the corresponding segmented photodiodes in the other sets. The two adjoining segmented photodiodes function like one segmented photodiode, and thereby, the resolution of the applied scale slit is made ½ of the reference resolution. Thus, this photodetector easily copes with a scale slit having a half resolution of the reference resolution at low cost only by modification of wiring without changing any configuration of the segmented photodiodes.

Abstract: A light receiving device 12 that receives reflected light condensed by a light receiving condenser means 14 has two first and second electrodes 15, 16 provided on a light receiving surface at prescribed intervals along a baseline that connects a light emitting device 11 with the light receiving device and a resistive region 21 provided between the two electrodes. An electric charge generated at the incident position of light incident on the light receiving surface of the light receiving device 12 becomes a photo current and outputted from the first and second electrodes 15, 16 via the resistive region 21. The resistance value of the resistive region 21 of the light receiving device 12 is distributed so as to be roughly inversely proportional to a distance from the optical axis of the light receiving condenser means 14 to the incident position of a light spot on the light receiving surface.

Abstract: A photodetector for an optical encoder has plural sets of segmented photodiodes, each set of which is made by two adjoining segmented photodiodes capable of coping with a scale slit having a reference resolution. Output lines of the two adjoining segmented photodiodes are connected together in each set of the photodiodes. These output lines are connected to output lines of the corresponding segmented photodiodes in the other sets. The two adjoining segmented photodiodes function like one segmented photodiode, and thereby, the resolution of the applied scale slit is made ½ of the reference resolution. Thus, this photodetector easily copes with a scale slit having a half resolution of the reference resolution at low cost only by modification of wiring without changing any configuration of the segmented photodiodes.

Abstract: A plurality of N-type diffusion layers are formed a specified distance apart on a P-type semiconductor layer. A P-type leak prevention layer formed between at least N-type diffusion layers prevents leaking between the diffusion layers. A dielectric film is formed in at least a light incident area on a P-type semiconductor layer including the diffusion layers and the leak prevention layer. Accordingly, provided are a split type light receiving element positively functioning as a split type light receiving element even when charge is accumulated in the dielectric film and having a uniform sensitivity throughout the entire area on a light receiving surface, and a circuit-built-in light receiving element and an optical disk device using the split type light receiving element.

Abstract: A light receiving element, comprising a semiconductor structure comprising at least a first conductivity type semiconductor layer, a first, second conductivity type semiconductor layer provided on the first conductivity type semiconductor layer in the semiconductor structure, a second, second conductivity type semiconductor layer having an impurity concentration lower than that of the first, second conductivity type semiconductor layer, a second, first conductivity type semiconductor layer provided on the second, second conductivity type semiconductor layer, or a second, first conductivity type semiconductor layer provided within the second, second conductivity type semiconductor layer.

Abstract: A light receiving device includes a silicon substrate, a first P type diffusion layer on the silicon substrate, and a P type semiconductor layer on the P type diffusion layer. On a surface part of the P type semiconductor layer, two N type diffusion layers as light receiving parts, and a second P type diffusion layer between the two N type diffusion layers are provided. On the P type semiconductor layer, an antireflection film structure composed of a first silicon oxide formed by thermal oxidation and a second silicon oxide formed by CVD is provided. A film thickness of the first silicon oxide is set at about 15 nm, thus a defect in a interface between the first silicon oxide and the P type semiconductor layer is prevented. A film thickness of the second silicon oxide is set at about 100 nm, thus a leak current between cathodes is prevented when a power supply voltage is applied for long period of time.

Abstract: A photodiode includes a first conductivity type semiconductor substrate or a first conductivity type semiconductor layer; a second conductivity type semiconductor layer provided on the first conductivity type semiconductor substrate or the first conductivity type semiconductor layer; an anti-reflection film provided on a surface of a portion of the second conductivity type semiconductor layer which is in a light receiving area; a first conductive layer provided in an area in the vicinity of the light receiving area; and a passivation layer provided on the first conductive layer. Light incident on the photodiode is detected by a junction of the one of the first conductivity type semiconductor substrate and the first conductivity type semiconductor layer, and the second conductivity type semiconductor layer. The area in the vicinity of the light receiving area includes a window area having an opening in the passivation layer for partially exposing the first conductive layer.

Abstract: A first P-type diffusion layer and a P-type semiconductor layer are provided on a silicon substrate, and two N-type diffusion layers are provided on a front surface of this P-type semiconductor layer to form two light receiving units. Three-layer translucent films, a first silicon oxide film, a silicon nitride film, and a second silicon oxide film are disposed on the N-type diffusion layers and on the P-type semiconductor layer between the two diffusion layers. Holes produced during a production process and distributed and captured in two interfaces between the three-layer translucent films can reduce a field intensity in the vicinity of the surface of the P-type semiconductor layer to below a conventional level and an inversion of a conductive type to reduce a leak current between the light receiving units accordingly.

Abstract: A light receiving device includes a P type diffusion layer (101), a P type semiconductor layer (102), an N type diffusion layer (103) serving as a light receiving part, and a light transmitting film (104), all formed on a p type silicon substrate (100). The N type diffusion layer (103) has a thickness of 0.8 ?m to 1.0 ?m which is larger than an absorption length of incident light having wavelength of 400 nm, and such a concentration profile that a impurity concentration is not higher than 1E19 cm?3 on a surface and has a peak in a vicinity of the surface. Since recombination of carriers generated by the incident light is prevented in the vicinity of the surface of the N type diffusion layer (103), sensitivity of the light receiving device is enhanced and response speed is increased by the low-resistance N type diffusion layer (103) having a larger junction depth.

Abstract: A photodetector for an optical encoder has plural sets of segmented photodiodes, each set of which is made by two adjoining segmented photodiodes capable of coping with a scale slit having a reference resolution. Output lines of the two adjoining segmented photodiodes are connected together in each set of the photodiodes. These output lines are connected to output lines of the corresponding segmented photodiodes in the other sets. The two adjoining segmented photodiodes function like one segmented photodiode, and thereby, the resolution of the applied scale slit is made ½ of the reference resolution. Thus, this photodetector easily copes with a scale slit having a half resolution of the reference resolution at low cost only by modification of wiring without changing any configuration of the segmented photodiodes.

Abstract: A plurality of N-type diffusion layers (105, 108) are formed a specified distance apart on a P-type semiconductor layer (102). A P-type leak prevention layer (109) formed between at least N-type diffusion layers (105, 108) prevents leaking between the diffusion layers (105, 108). A dielectric film (115) is formed in at least a light incident area on a P-type semiconductor layer (102) including the diffusion layers (105, 108) and the leak prevention layer (109). Accordingly, provided are a split type light receiving element positively functioning as a split type light receiving element even when charge is accumulated in the dielectric film and having a uniform sensitivity throughout the entire area on a light receiving surface, and a circuit-built-in light receiving element and an optical disk device using the split type light receiving element.

Abstract: A corrosion-resistant conductive layer (TiW layer) formed of a corrosion-resistant material is formed to extend from a bonding pad portion to an interconnection portion of a light receiving element. A semiconductor laser device according to the present invention includes the light receiving element.

Abstract: A circuit-incorporating light receiving device includes an integrated circuit and a photodiode. The integrated circuit and the photodiode are provided on a single semiconductor substrate. The integrated circuit includes a transistor having a polycrystalline silicon as an emitter diffusion source and an electrode. Elements included in the integrated circuit are isolated from each other using local oxidization.

Abstract: A light receiving element, comprising a semiconductor structure comprising at least a first conductivity type semiconductor layer, a first, second conductivity type semiconductor layer provided on the first conductivity type semiconductor layer in the semiconductor structure, a second, second conductivity type semiconductor layer having an impurity concentration lower than that of the first, second conductivity type semiconductor layer, a second, first conductivity type semiconductor layer provided on the second, second conductivity type semiconductor layer, or a second, first conductivity type semiconductor layer provided within the second, second conductivity type semiconductor layer.

Abstract: A circuit-incorporating light receiving device includes an integrated circuit and a photodiode. The integrated circuit and the photodiode are provided on a single semiconductor substrate. The integrated circuit includes a transistor having a polycrystalline silicon as an emitter diffusion source and an electrode. Elements included in the integrated circuit are isolated from each other using local oxidization.

Abstract: A circuit-incorporating light receiving device includes an integrated circuit and a photodiode. The integrated circuit and the photodiode are provided on a single semiconductor substrate. The integrated circuit includes a transistor having a polycrystalline silicon as an emitter diffusion source and an electrode. Elements included in the integrated circuit are isolated from each other using local oxidization.

Abstract: A photosensitive device includes a semiconductor substrate and a first semiconductor layer, both of a first conductivity type, with the semiconductor layer being formed on the semiconductor substrate and having a lower impurity concentration than that of the semiconductor substrate. A second semiconductor layer, of a second conductivity type, is formed on the first semiconductor layer and at least one diffusion layer of the first conductivity type is formed from the surface of the second semiconductor layer so as to reach the surface of the first semiconductor layer. The diffusion layer subdivides the second semiconductor layer into a plurality of semiconductor regions At least one photodiode portion for converting signal light into an electrical signal is formed at a junction between at least one of the plurality of semiconductor regions and the first semiconductor layer.

Abstract: A semiconductor device includes: a photosensitive section essentially composed of a PN junction between a semiconductor multilayer structure of the first conductivity type and a first semiconductor layer of the second conductivity type; and a partitioning portion for splitting the photosensitive section into a plurality of regions. The semiconductor multilayer structure of the first conductivity type includes: a semiconductor substrate of the first conductivity type; a first semiconductor layer of the first conductivity type; and a second semiconductor layer of the first conductivity type. The partitioning portion includes a third semiconductor layer of the first conductivity type extending from the first semiconductor layer of the second conductivity type so as to reach the second semiconductor layer of the first conductivity type.

Abstract: A corrosion-resistant conductive layer (TiW layer) formed of a corrosion-resistant material is formed to extend from a bonding pad portion to an interconnection portion of a light receiving element. A semiconductor laser device according to the present invention includes the light receiving element.