Abstract: The present invention relates to a quantum infrared sensor and a gas concentration meter using the same, the quantum infrared sensor having a small and simple device shape and also being capable of performing stable measurement against disturbance changes such as changes in the flow amount and the temperature of gas to be measured. The quantum infrared sensor includes a pair of quantum infrared sensor elements, a pair of optical filters and a holding frame. The pair of optical filters is provided closer to an infrared light source than is the pair of quantum infrared sensor elements. The pair of optical filters is configured to selectively transmit infrared rays in specific different wavelength ranges, respectively. The pair of optical filters is housed in an upper level of the holding frame and provided while facing the pair of quantum infrared sensor elements through a pair of through holes, respectively.

Abstract: Provided is an infrared light emitting device in which dark current and diffusion current caused by thermally excited holes are suppressed. Thermally excited carriers (holes) generated in a first n-type compound semiconductor layer (102) tend to diffuse in the direction of a ? layer (105). But, the dark current by holes is reduced by providing an n-type wide band gap layer (103) with a larger band gap than the first layer (102) and the ? layer (105) that suppresses the hole diffusion between the first layer (102) and the ? layer (105). The wide band gap layer (103) has a band gap shifted relatively to valence band direction by n-type doping and thereby more effectively functions as a diffusion barrier for the thermally excited holes. Namely, the band gap and n-type doping of the wide band gap layer (103) are adjusted to suppress diffusion of the thermally excited carriers.

Abstract: The present invention relates to a quantum infrared sensor and a gas concentration meter using the same, the quantum infrared sensor having a small and simple device shape and also being capable of performing stable measurement against disturbance changes such as changes in the flow amount and the temperature of gas to be measured. The quantum infrared sensor includes a pair of quantum infrared sensor elements, a pair of optical filters and a holding frame. The pair of optical filters is provided closer to an infrared light source than is the pair of quantum infrared sensor elements. The pair of optical filters is configured to selectively transmit infrared rays in specific different wavelength ranges, respectively. The pair of optical filters is housed in an upper level of the holding frame and provided while facing the pair of quantum infrared sensor elements through a pair of through holes, respectively.

Abstract: Provided is an infrared light emitting device in which dark current and diffusion current caused by thermally excited holes are suppressed. Thermally excited carriers (holes) generated in a first n-type compound semiconductor layer (102) tend to diffuse in the direction of a ? layer (105). But, the dark current by holes is reduced by providing an n-type wide band gap layer (103) with a larger band gap than the first layer (102) and the ? layer (105) that suppresses the hole diffusion between the first layer (102) and the ? layer (105). The wide band gap layer (103) has a band gap shifted relatively to valence band direction by n-type doping and thereby more effectively functions as a diffusion barrier for the thermally excited holes. Namely, the band gap and n-type doping of the wide band gap layer (103) are adjusted to suppress diffusion of the thermally excited carriers.

Abstract: An infrared sensor IC and an infrared sensor, which are extremely small and are not easily affected by electromagnetic noise and thermal fluctuation, and a manufacturing method thereof are provided. A compound semiconductor that has a small device resistance and a large electron mobility is used for a sensor (2), and then, the compound semiconductor sensor (2) and an integrated circuit (3), which processes an electrical signal output by the compound semiconductor sensor (2) and performs an operation, are arranged in a single package using hybrid formation. In this manner, an infrared sensor IC that can be operated at room temperature can be provided by a microminiature and simple package that is not conventionally produced.

Abstract: An infrared sensor IC and an infrared sensor, which are extremely small and are not easily affected by electromagnetic noise and thermal fluctuation, and a manufacturing method thereof are provided. A compound semiconductor that has a small device resistance and a large electron mobility is used for a sensor (2), and then, the compound semiconductor sensor (2) and an integrated circuit (3), which processes an electrical signal output by the compound semiconductor sensor (2) and performs an operation, are arranged in a single package using hybrid formation. In this manner, an infrared sensor IC that can be operated at room temperature can be provided by a microminiature and simple package that is not conventionally produced.

Abstract: An infrared sensor IC and an infrared sensor, which are extremely small and are not easily affected by electromagnetic noise and thermal fluctuation, and a manufacturing method thereof are provided. A compound semiconductor that has a small device resistance and a large electron mobility is used for a sensor (2), and then, the compound semiconductor sensor (2) and an integrated circuit (3), which processes an electrical signal output by the compound semiconductor sensor (2) and performs an operation, are arranged in a single package using hybrid formation. In this manner, an infrared sensor IC that can be operated at room temperature can be provided by a microminiature and simple package that is not conventionally produced.

Abstract: A surface acoustic wave element includes a LiNbxTa1−xO3 (‘x’ is 0 or more and 1 or less) film on a (012) sapphire substrate, in which a Love wave is propagated as a surface acoustic wave in a specific direction of the LiNbxTa1−xO3 film. Preferably, a crystal axis of the sapphire substrate and a crystal axis of a (012) LiNbxTa1−xO3 film (‘x’ is 0 or more and 1 or less) are parallel to each other; a surface acoustic wave propagation direction is within a range of ±20 degrees around an axis vertical to a C-axis projection line direction of a crystal axis of the sapphire substrate or the (012) LiNbxTa1−xO3 film.

Abstract: A surface acoustic wave functional element is provided that includes a piezoelectric substrate or a multilayer piezoelectric substrate having a large electromechanical coupling coefficient. Semiconductor layers are formed on the piezoelectric substrate. The semiconductor layers include an active layer and a buffer layer. The buffer layer is formed of a structure that has a lattice constant that is the same as or similar to that of the active layer. In addition, input and output electrodes are formed on both sides of the semiconductor layers. The surface acoustic wave functional element attains a large amplification gain at low voltage, and can be used as part of a transmitting/receiving circuit in a high frequency portion of a mobile communication device.

Abstract: The surface acoustic wave functional element comprises a semiconductor layer provided on a piezoelectric substrate or a piezoelectric film substrate and makes use of interaction between a surface acoustic wave propagating on the substrate and electrons in the substrate layer, but has the semiconductor layer disposed outside above the propagation path for propagating a surface acoustic wave, comprises a plurality of grating electrodes perpendicularly above and to the propagation path and moreover the semiconductor layer comprises an active layer and a buffer layer lattice-matching thereto. By use of this surface acoustic wave functional element, a surface acoustic wave amplifier capable of providing a high amplification gain at a practical low voltage, a surface acoustic wave convolver having a higher efficiency than ever or the like are offered.

Abstract: A surface acoustic wave functional element is provided that includes a piezoelectric substrate or a multilayer piezoelectric substrate having a large electromechanical coupling coefficient. Semiconductor layers are formed on the piezoelectric substrate. The semiconductor layers include an active layer and a buffer layer. The buffer layer is formed of a structure that has a lattice constant that is the same as or similar to that of the active layer. In addition, input and output electrodes are formed on both sides of the semiconductor layers. The surface acoustic wave functional clement attains a large amplification gain at low voltage, and can be used as part of a transmitting/receiving circuit in a high frequency portion of a mobile communication device.

Abstract: The present invention is a method of fabrication of a thin film of In.sub.x Ga.sub.1-x As.sub.y Sb.sub.1-y (0<x.ltoreq.1.0, 0.ltoreq.y.ltoreq.1.0) having no lattice disorder, and its use in a sensor layer to obtain a high sensitivity semiconductor sensor having excellent temperature characteristics. The semiconductor sensor has a high resistance first compound semiconductor layer, a layer of In.sub.x Ga.sub.1-x As.sub.y Sb.sub.1-y (0<x.ltoreq.1.0, 0.ltoreq.y.ltoreq.1.0) grown on this first layer, and an electrode formed on this layer. The first compound semiconductor layer has a lattice constant the same as or nearly the same as that of the crystal of the sensor layer, and a band gap energy greater than that of the crystal. A second compound semiconductor layer similar to the first compound semiconductor layer may be formed on top of the sensor layer. A manufacturing method of such a semiconductor sensor is also included.