Abstract: An optical sensor circuit has a first optical sensor that outputs a signal according to the amount of received light on an opened light-receiving surface, a second optical sensor that is provided near the first optical sensor and outputs a signal according to the amount of received light on a shielded light-receiving surface, and a difference calculating circuit that calculates a difference between the output signal of the first optical sensor and the output signal of the second optical sensor and outputs the difference.

Abstract: A light scattering photometer signal-enhancement systems includes an adaptive sample and subtract circuit controlled by a computer or microcontroller (MCU). The MCU controls the gain of a programmable-gain amplifier (PGA) cascade that is used to amplify the raw photometer signal. In order to maintain the DC accuracy, the DC offset contained in the raw signal from the photometer is estimated by an algorithmic within the MCU and then subtracted from the raw signal before allowing it to be amplified by the PGA cascade. In addition to DC estimation and adaptive cancellation, the MCU applies a digital filtering scheme to compensate irrelevant frequency bands in the amplified signal and offers user determined averaging functions for additional signal conditioning. Moreover, hardware filters are used to prevent signal aliasing by the analog to digital converters (ADC) and a 60 Hz notch filter suppresses general electrical noise.

Abstract: An indicating instrument including a light guiding system having at least a first and second light guides, a sensor disposed at a first end of the first light guide and configured to receive incident ambient light that has traveled through the first light guide, a light-emitting device disposed at a first end of the second light guide and configured to emit light through the second light guide, and a covering body disposed at a second end of the first and second light guides that is opposite to the first ends. Further, the incident ambient light is incident upon the covering body and travels through the first light guide and is received by the sensor, and the light emitted by the light-emitting unit travels through the second light guide and exits the covering body.

Abstract: Ultra-low leakage current backside-illuminated semiconductor photodiode arrays are fabricated using a method of formation of a transparent, conducting bias electrode layer that avoids high-temperature processing of the substrate after the wafer has been gettered. As a consequence, the component of the reverse-bias leakage current associated with strain, crystallographic defects or impurities introduced during elevated temperature processing subsequent to gettering can be kept extremely low. An optically transparent, conductive bias electrode layer, serving as both an optical window and an ohmic backside equipotential contact surface for the photodiodes, is fabricated by etching through the polysilicon gettering layer and a portion of the thickness of heavily-doped crystalline silicon layer formed within, and near the back of, the substrate during the gettering process.

Abstract: The present invention relates to an optical pointing system and a method for calculating a movement value thereof, comprising: an image sensor for detecting light reflected from a worktable surface to generate an image signal, a maximum search window variable circuit for inputting at least one of the image signal and a movement value to change a size of a maximum search window, and a movement value calculation circuit for calculating the movement value of the image signal using the maximum search window with the changed size. Therefore, an exact movement value can be found by changing at least one of the maximum search window and a sampling rate according to at least one of a quantity of light and a movement speed to calculate the movement value.

Abstract: A system and method provide for precision guiding of agricultural vehicles along a series of adjacent paths to form rows for cultivating a field. In one aspect of the invention the vehicle is moved along a first path while receiving positioning information from a navigational system (e.g., RTK GPS). This positioning information is stored in a processor and is used by the processor to compute a second path adjacent to said first path by calculating piecewise perpendicular offsets from the first path at multiple locations along the first path. The process is repeated to compute a third and subsequent paths so as to cover the field. Because of the offset process, the field may be covered with paths that have varying curvature along their length, while providing substantially no gaps or overlaps in the coverage of the field.

Abstract: A camera based inspection system for inspecting glass bottles made in a glass-forming machine. A single picture shows the heat distribution of an inspected portion of the bottle over a period of time whereby the operator will see a loss of stability in the glass process.

Abstract: A system for calibrating a sensor in a vehicle, such as a space capsule or other space borne apparatus, uses an expandable integrating sphere. A sensor in the vehicle measures the energy from an electromagnetic energy source within the integrating sphere through a calibration window. The expandable fluid impermeable integrating sphere expands when filled with a fluid, such that when filled with the fluid, its interior is viewable through the calibration window. The system includes a source of fluid to fill the integrating sphere and a fluid regulator coupled to the vehicle to determine when to supply the fluid to the integrating sphere to maintain an appropriate gas pressure level with the integrating sphere.

Abstract: A plurality of analog signals are detected in a sensor in accordance with a displacement of a scale on which a pattern with a predetermined cycle is formed. The plurality of analog signals are subjected to signal processing in a signal processing portion, and then output from a sensor head. Setup switching is performed by a setup switching portion provided in the sensor head in such a manner that an output signal at this moment complies with a signal input specification of a positional information output device. Further, the sensor, the signal processing portion and the setup switching portion form an integrated circuit.

Abstract: A phantom, adapted to be radiation-imaged to obtain a radiation image for evaluation in inspection of a radiation imaging system, is capable of performing both the quantitative evaluation and the visual evaluation of the radiation image easily with a low cost and increasing accuracy of the constancy evaluation of the radiation imaging system. The phantom includes a base plate; a first member disposed on the base plate and having a first image quality evaluating pattern formed thereon to be used for visual evaluation as to a predetermined image quality evaluation item; and a second member disposed on the base plate and having a second image quality evaluating pattern formed thereon to be used for quantitative evaluation as to the predetermined image quality evaluation item.

Abstract: Signal amplifiers having a non-linear transfer function. A high speed (high bandwidth) circuit with a non-linear transfer function over a limited range of input signal is provided. By appropriate choice of components, the non-linear transfer function can be used to accurately approximate any monotonic function such as a square root transfer function. In another aspect, a piecewise non-linear circuit arrangement using a set of non-linear sub-circuits is provided to accurately generate a desired non-linear transfer function over an extended dynamic range of input signal. In one implementation of such a circuit, each of the sub-circuits approximates the desired non-linear function over a portion of the input range.

Abstract: The invention provides an apparatus that produces analyte ions for detection by a detector. The apparatus includes a matrix based ion source having a target substrate including a carbon nanotube material for producing analyte ions, an ion transport system adjacent to the matrix based ion source for transporting analyte ions from the matrix based ion source; and an ion detector downstream from the ion transport system for detecting the analyte ions. The invention also provides a method for producing and detecting the analyte ions.

Abstract: In a mass spectrometer, ions from an ion source pass through an inlet aperture into a vacuum chamber for transmitting prior to mass analysis by the mass analyzer. The configuration of the inlet aperture forms a sonic orifice or sonic nozzle and with a predetermined vacuum chamber pressure, a supersonic free jet expansion is created in the vacuum chamber that entrains the ions within the barrel shock and Mach disc. Once formed, an ion guide with a predetermined cross-section to essentially radially confine the supersonic free jet expansion can focus the ions for transmission through the vacuum chamber. This effectively improves the ion transmission between the ion source and the mass analyzer.

Abstract: A high sensitivity glow discharge ion source system for analyzing particles includes an aerodynamic lens having a plurality of constrictions for receiving an aerosol including at least one analyte particle in a carrier gas and focusing the analyte particles into a collimated particle beam. A separator separates the carrier gas from the analyte particle beam, wherein the analyte particle beam or vapors derived from the analyte particle beam are selectively transmitted out of from the separator. A glow discharge ionization source includes a discharge chamber having an entrance orifice for receiving the analyte particle beam or analyte vapors, and a target electrode and discharge electrode therein. An electric field applied between the target electrode and discharge electrode generates an analyte ion stream from the analyte vapors, which is directed out of the discharge chamber through an exit orifice, such as to a mass spectrometer.

Abstract: A mass analyzer includes: an ion trap device including an ion trapping space surrounded by a plurality of electrodes; a time-of-flight mass analyzer for determining a mass to charge ratio of ions ejected from the ion trapping space; a trapping voltage generator for generating an ion trapping RF voltage to at least one of the plurality of electrodes; an ejecting voltage generator for generating an ejecting voltage to at least one of the plurality of electrodes to form an ion ejection electric field for ejecting ions trapped in the ion trapping space; and a controller for stopping the ion trapping RF voltage at a timing when ions are trapped in the ion trapping space and the ion trapping RF voltage is at a predetermined phase, and for applying the ion ejecting voltage a predetermined period after the ion trapping RF voltage is stopped.

Abstract: A method of determining a component of a medium comprises illuminating the medium to excite a marker associated with the component. Detected photoluminescent emission from the marker in response to the excitation is compared with one or more emission profiles. The component is identified based on a match between the detected photoluminescent emission and at least one of the emission profiles.

Abstract: A non-destructive in-situ elemental profiling of a layer in a set of layers method and system are disclosed. In one embodiment, a first emission of a plurality of photoelectrons is caused from the layer to be elementally profiled. An elemental profile of the layer is determined based on the emission. In another embodiment, a second emission of a plurality of photoelectrons is also received from the layer, and an elemental profile is determined by comparison of the resulting signals. A process that is altering the layer can then be controlled “on-the-fly” to obtain a desired material composition. Since the method can be employed in-situ and is non-destructive, it reduces turn around time and lowers wafer consumption. The invention also records the composition of all processed wafers, hence, removing the conventional statistical sampling problem.

Abstract: An electron beam inspection apparatus in which the order of inspection is determined to shorten the inspection time is disclosed. The order of inspection is determined by minimizing the total of the moving time and the inspection time as well as by simply optimizing the covered distance. At the time of preparing a recipe to determine the inspection points and the order of inspection, the sequence of a series of inspection points sequentially inspected is changed to optimize the order of inspection. Not only the sequence which minimizes the covered distance is determined but also the order of inspection of the inspection points is optimized in accordance with the charged state, warping of the wafer, the delivery position and other situations.

Abstract: A system and method for detecting radiation indicative of fire, such as forest fire. In one embodiment, a threshold energy level is determined based on ambient sensor conditions. A sensor unit may be setup to scan a predetermined area for electromagnetic radiation. Any detected electromagnetic radiation may then be band pass filtered to a wavelength range centered about a predetermined frequency associated with the presence of fire. The resulting energy level signal may then be further filter to pass only those signals which exhibit a “flicker” frequency. If the resulting filtered signal exceeds the threshold signal, a fire notification signal may then be generated.

Abstract: A flat panel X-ray imager using an amorphous selenium detector which uses a polymer grid structure within the X-ray conversion layer to form an interface between the X-ray conversion layer and the pixel electrodes. The grid structure provides an additional physical barrier between pixel electrodes that reduces electrical bridging due to crystallization of the amorphous selenium due to temperature increases while also reducing the delamination temperature by providing a good anchor to the selenium, as well as a “cushion” for thermal expansion or contraction of the pixel electrodes. The grid can further include one or more grid electrodes for effecting avalanche-gain within the X-ray conversion layer while minimizing dark current entry into the selenium layer from the pixel electrode.

Abstract: A photo-detector having a common electrode comprising a conductive material configured in a non-solid pattern in which there are gaps where there is no conductive material. In one embodiment, the distance (d) or (d?) between conductive portions of the common electrode is in a range from about 3 microns to about 5 microns. Alternatively, in one embodiment, the patterned common electrode covers between 20% to 70% of the surface of the respective photosensor element. A method for making the same is also provided.

Abstract: A radiation detecting apparatus having: a substrate; a phosphor layer which is formed on a principal plane of the substrate and converts a wavelength of a radiation; and a phosphor protective member including a phosphor protective layer which covers the phosphor layer and is adhered to the substrate, wherein the phosphor protective layer is made of a hot melt resin and an upper surface and a side surface of the phosphor layer and at least a part of at least one side surface of the substrate are covered with the phosphor protective layer. Thus, a moisture-proofing effect for penetration of the moisture from an interface between the phosphor layer and the substrate on the side surface side of the substrate can be improved. Further, by using the hot melt resin for the phosphor protective layer, simplification of manufacturing steps, remarkable reduction in the number of working steps, and remarkable reduction in costs of a product can be accomplished.

Abstract: An object of the present invention is to provide a sample repairing apparatus, a sample repairing method and a device manufacturing method using the same method, which can reduce an edge roughness in a repaired pattern and also can provide the repairing of a sample by applying an electron beam-assisted etching or an electron beam-assisted deposition. There is provided a sample repairing method comprising: (a) a step of focusing an electron beam by an objective lens to irradiate a sample: (b) a step of supplying a reactive gas onto an electron beam irradiated surface of said sample: (c) a step of selectively scanning a pattern to be repaired on said sample with the electron beam so as to repair said pattern by applying an etching or a deposition; and (d) a step of providing a continuous exhausting operation by means of a differential exhaust system arranged in said objective lens so as to prevent the reactive gas supplied onto said electron beam irradiated surface from flowing toward an electron gun side.

Abstract: An emitter for an electron-beam projection lithography system includes a photoconductor substrate, an insulating layer formed on a front surface of the photoconductor substrate, a gate electrode layer formed on the insulating layer, and a base electrode layer formed on a rear surface of the photoconductor substrate and formed of a transparent conductive material. In operation of the emitter, a voltage is applied between the base electrode and the gate electrode layer, light is projected onto a portion of the photoconductor substrate to convert the portion of the photoconductor substrate into a conductor such that electrons are emitted only from the partial portion where the light is projected. Since the emitter can partially emit electrons, partial correcting, patterning or repairing of a subject electron-resist can be realized.

Abstract: A lithographic projection apparatus includes reflector assembly, a foil trap, and a housing that is constructed and arranged to contain the reflector assembly and the foil trap. The reflector assembly is connected to the housing via a first wall, and the foil trap is connected to the housing via a second wall. The apparatus also includes a chamber between the foil trap and the reflector assembly. The chamber is defined by the housing, the first wall, and the second wall. The apparatus further includes a pump that is configured to create a vacuum in the chamber.

Abstract: A gas supply unit supplies gas to a certain space via a channel, and includes a first switch mechanism located in the channel for selectively changing the channel of the gas.

Abstract: An optical sensor circuit comprises an optical sensor adapted to sense a position of a component in a semiconductor manufacturing apparatus according to the presence or absence of a flag and output a signal indicative of the position. A position sensing driver receives the signal via a path selected by a plurality of switches and then drives an output signal in response to the signal. The path selected by the plurality of switches causes the optical sensor circuit to act as either a close-type optical sensor circuit or an open-type optical sensor circuit.

Abstract: A solid state relay is formed by mounting a light-emitting element on a light-emitting side lead frame, mounting a light-receiving element or a switching element which operates in response to the light-receiving element and signals from the light-receiving element on a light-receiving side lead frame, arranging these lead frames on the light-emitting side and the light-receiving side to opposite each other, and sealing into one package and is formed by mounting protective element that protects the light-emitting element or the light-receiving element on at least one of the lead frames and arranging the protective element or the protective element and the switching element inside a primary mold resin that seals the light-emitting element and the light-receiving element.

Abstract: Systems and methods provide calibration for a linear array sensor. A test pattern having a plurality of lines is used. Comparison between expected and measured spacing between a pair of neighboring lines is used to determine sensor position displacement.

Abstract: Conventionally, a particle/defect inspection apparatus outputs a total number of detected particles/defects as the result of detection. For taking countermeasures to failures in manufacturing processes, the particles/defects detected by the inspection apparatus are analyzed. Since the inspection apparatus outputs a large number of detected particles/defects, an immense time is required for analyzing the detected particles/defects, resulting in a delay in taking countermeasures to a failure in the manufacturing processes. In the present invention, an apparatus for optically inspecting particles or defects relates a particle or defect size to a cause of failure in an inspection result. A data processing circuit points out a cause of failure from the statistics on the inspection result, and displays information on the inspection result.

Abstract: A device for reading out X-ray information stored in a phosphor plate for simplified and solid guiding and/or holding of phosphor plates, with at the same time a high degree of compactness, includes: a device for holding and/or conveying the phosphor plate in an orientation inclined by an inclination angle ? in relation to a vertical in which the phosphor plate is flat in form; and a read-out device for reading out the flat phosphor plate inclined by the inclination angle ? in relation to the vertical.

Abstract: A radiation image read out from a radiation image sensor, which stores electric charges corresponding to the amount of radiation exposed onto the radiation image sensor upon exposure of radiation carrying thereon a radiation image and stores the radiation image, by causing the radiation image sensor to output an electric signal corresponding to the stored electric charges and by amplifying the output electric signal by a reading amplifier. A part of the stored electric charges are read before reading the radiation image and, the gain of the reading amplifier is changed on the basis of the amount of electric charges of the part of the stored electric charges which has been read before reading the radiation image.

Abstract: Disclosed are non-volatile memory devices that incorporate a series of single or double memory cells. The single memory cells are essentially “U” shaped. The double memory cells comprise two essentially “U” shaped memory cells. Each memory cell comprises a memory element having a bi-stable layer sandwiched between two conductive layers. A temporary conductor may be applied to a series of cells and used to bulk condition the bi-stable layers of the cells. Also, due to the “U” shape of the cells, a cross point wire array may be used to connect a series of cells. The cross point wire array allows the memory elements of each cell to be individually identified and addressed for storing information and also allows for the information stored in the memory elements in all of the cells in the series to be simultaneously erased using a block erase process.

Abstract: Causing the growth of a GaN material with respect to a sapphire substrate using a conventional technique is inevitably followed by the occurrence of dislocations. Using a mask layer results in that the dislocations laterally flow. However, since the GaN crystal collides with a semiconductor layer that laterally grew from an adjacent region, perfect elimination of the dislocations is impossible. In view thereof, the invention is intended to provide a nitride compound-based semiconductor light emitting device which is based on using semiconductor layers that have been formed in a state of the dislocations' being less existent therein and which therefore has excellent property.

Abstract: Semiconductor optoelectronic devices such as diode lasers are formed on InP substrates with an active region with an InAsN or InGaAsN electron quantum well layer and a GaAsSb or InGaAsSb hole quantum well layer which form a type II quantum well. The active region may be incorporated in various devices to provide light emission at relatively long wavelengths, including light emitting diodes, amplifiers, surface emitting lasers and edge-emitting lasers.

Abstract: An electronic device containing a polythiophene derived from a monomer segment or monomer segments containing two 2,5-thienylene segments, (I) and (II), and an optional divalent linkage D wherein A is a side chain; B is hydrogen or a side chain; and D is a divalent linkage, and wherein the number of A-substituted thienylene units (I) in the monomer segments is from about 1 to about 10, the number of B-substituted thienylene units (II) is from 0 to about 5, and the number of divalent linkages D is 0 or 1.

Abstract: Disclosed herein is a composition for forming an organic insulating film and an organic insulating film formed from the composition. An exemplary composition comprises an insulating polymer having a maleimide structure, a crosslinking agent and a photoacid generator so as to form a crosslinked structure. The organic insulating film has excellent chemical resistance to organic solvents used in a subsequent photolithographic process and can improve the electrical properties of transistors.

Abstract: A result of formation of an opening in a semiconductor substrate can be judged without cutting a semiconductor wafer and observing a cross-section of the cut wafer. A semiconductor device of this invention includes a semiconductor substrate, a pad electrode formed on the semiconductor substrate, an opening formed in the semiconductor substrate to expose the pad electrode, a wiring layer connected with the pad electrode through the opening and a monitoring opening formed in a scribe line to monitor a result of the formation of the opening.

Abstract: A structure for preventing deteriorations of a light-emitting device and retaining sufficient capacitor elements' (condenser) required by each pixel is provided. A first passivation film, a second metal layer, a flattening film, a barrier film, and a third metal layer are stacked in this order over a transistor. A side face of a first opening provided with the flattening film is covered by the barrier film, a second opening is formed inside the first opening, and a third metal layer is connected to a semiconductor via the first opening and the second opening. A capacitor element that is formed of a lamination of a semiconductor of a transistor, a gate insulating film, a gate electrode, the first passivation film, and the second metal layer is provided.

Abstract: An electroluminescence display device has a plurality of electroluminescence elements and a driver circuit formed over a substrate. At least a part of the driver circuit is disposed in a display portion of a substrate in order that the size of the display device can be reduced.

Abstract: A thin film semiconductor device which includes an insulating substrate, a semiconductor polycrystal thin film formed over the substrate and a transistor with the thin film as a channel. The polycrystal includes a plurality of crystal grains, with grain boundaries between the crystal grains being recessed. The grain boundaries with the recessed surfaces are the most predominant of all grain boundaries within the channel. With this structure, the polycrystal can be a low temperature polycrystal that can be formed at a temperature of 150° C. or less, thereby achieving a low-cost device with high carrier mobility.

Abstract: A product produced in a PVD method is described, which consists of thin plane-parallel structures having a thickness in the range from 20 to 2000 nm and small dimensions in the range below one mm. Production is carried out by condensation of silicon suboxide onto a carrier passing by way of the vaporisers. The carrier is pre-coated, before condensation of the silicon suboxide, with a soluble, inorganic or organic separating agent in a PVD method. All steps, including that of detaching the product by dissolution, can be carried out continuously and simultaneously at different locations. As final step, the SiOy may be oxidised to SiO2 in an oxygen-containing gas at atmospheric pressure and temperatures of more than 200° C. or SiOy may be converted to SiC at the surface of the plane-parallel structures in a carbon-containing gas at from 500° C. to 1500° C. The products produced in that manner are distinguished by high uniformity of thickness.

Abstract: Provided are an electroluminescence (EL) device and corresponding method for forming a rare earth element-doped silicon (Si)/Si dioxide (SiO2) lattice structure. The method comprises: providing a substrate; DC sputtering a layer of amorphous Si overlying the substrate; DC sputtering a rare earth element; in response, doping the Si layer with the rare earth element; DC sputtering a layer of SiO2 overlying the rare earth-doped Si; forming a lattice structure; annealing; and, in response to the annealing, forming nanocrystals in the rare-earth doped Si having a grain size in the range of 1 to 5 nanometers (nm). In one aspect, the rare earth element and Si are co-DC sputtered. Typically, the steps of DC sputtering Si, DC sputtering the rare earth element, and DC sputtering the SiO2 are repeated 5 to 60 cycles, so that the lattice structure includes the plurality (5-60) of alternating SiO2 and rare earth element-doped Si layers.

Abstract: A light active device includes a semiconductor particulate dispersed within a carrier material. A first contact layer is provided so that on application of an electric field charge carriers having a polarity are injected into the semiconductor particulate through the conductive carrier material. A second contact layer is provided so that on application of the electric field to the second contact layer charge carriers having an opposite polarity are injected into the semiconductor particulate through the conductive carrier material. The semiconductor particulate comprises at least one of an organic and an inorganic semiconductor. The semiconductor particulate may comprise an organic light active particulate that includes at least one conjugated polymer.

Abstract: In order to apply an optical element such as a lens, for example, to an optoelectronic component, the surface (3B), averted from the transmitter or receiver (2), of the filling material (3) is designed directly with a lens profile (7). This is done by filling a defined quantity of the transparent filling material (3) into the recess (1A) of the carrier body (1) for the purpose of embedding the transmitter or receiver (2), and by subsequently impressing a lens profile (7) onto the surface (3B), averted from the transmitter or receiver, of the transparent filling material (3) by means of a punch (8), before the transparent filling material with the lens profile (7) thus impressed is completely cured.

Abstract: A method is provided for forming a buffered-layer memory cell. The method comprises: forming a bottom electrode; forming a colossal magnetoresistance (CMR) memory film overlying the bottom electrode; forming a memory-stable semiconductor buffer layer, typically a metal oxide, overlying the memory film; and, forming a top electrode overlying the semiconductor buffer layer. In some aspects of the method the semiconductor buffer layer is formed from YBa2Cu3O7?X (YBCO), indium oxide (In2O3), or ruthenium oxide (RuO2), having a thickness in the range of 10 to 200 nanometers (nm). The top and bottom electrodes may be TiN/Ti, Pt/TiN/Ti, In/TiN/Ti, PtRhOx compounds, or PtIrOx compounds. The CMR memory film may be a Pr1?XCaXMnO3 (PCMO) memory film, where x is in the region between 0.1 and 0.6, with a thickness in the range of 10 to 200 nm.

Abstract: A thyristor memory device may comprise a capacitor electrode formed over a base region of the thyristor using a replacement gate process. During formation of the thyristor, a base-emitter boundary may be aligned relative to a shoulder of the capacitor electrode. In a particular embodiment, the replacement gate process may comprise defining a trench in a layer of dielectric over semiconductor material. Conductive material for the electrode may be formed over the dielectric and in the trench. It may further be patterned to form a shoulder for the electrode that extends over regions of the dielectric over a base region for the thyristor. The extent of the shoulder may be used to pattern the dielectric and/or to assist alignment of implants for the base and emitter regions of the thyristor.

Abstract: An insulating substrate includes a metal base as a base member, an insulating layer which is a room temperature, aerosol deposited shock solidification film formed on the metal base, and a circuit pattern which is a cold sprayed thermal spray coating formed on the insulating layer. A semiconductor device incorporates the insulating substrate, and thereby has improved heat radiation characteristics.

Abstract: An electric-field control electrode (5) is formed between a gate electrode (2) and a drain electrode (3). A multilayered film including a SiN film (21) and a SiO2 film (22) is formed below the electric-field control electrode (5). The SiN film (21) is formed so that a surface of an AlGaN electron supply layer (13) is covered with the SiN film (21).

Abstract: A bipolar transistor having enhanced characteristics is fabricated by etching a base mesa, which is formed below an emitter mesa (upper emitter layer) and a base electrode, so as to have jut regions on the edges of its generally rectangular region. A mask film, e.g., insulating film, is formed to cover the rectangular region and jut regions, and the base layer is etched by use of the insulating film as a mask to form a base mesa. Consequently, abnormal etching can be prevented from occurring along the base electrode and emitter mesa on the edges of the area where the base electrode and emitter mesa confront each other, and an increase in resistance between the base layer and the emitter layer can be prevented, whereby the bipolar transistor can have enhanced characteristics.