摘要:
A light activated thyristor with high dv/dt capability is provided by disposing first and second thyristors, one a primary and the other a pilot thyristor, in a semiconductor body having first and second major surface. The two thyristors have common first emitter, first base, and second base regions, and have spaced apart second emitter regions adjoining the second major surface of the body. The second emitter region of the second thyristor consists of first and second portions, first portion abutting the second base region of the second thyristor to create a ratarded electrical field. An exposed portion of the second major surface at the second emitter region of the second thyristor activates the second thyristor when electromagnetic radiation of wavelengths corresponding substantially to the energy bandgap of the semiconductor body strikes this exposed portion. The cathode electrode makes ohmic contact with the second emitter region of the first thyristor, and the anode electrode makes ohmic contact with the common first emitter regions. A floating contact also makes ohmic contact to the second emitter region of the second thyristor and the common second base region between the thyristors.
摘要:
In a high-voltage thyristor comprising a semiconductor body having contiguous pnpn four layers, and opposed anode and cathode electrodes and a gate electrode provided for the semiconductor body, one of p-base and n-base regions having an impurity concentration higher than the other has an impurity concentration which is no more than 8.times.10.sup.15 atoms/cm.sup.3 in the vicinity of a junction between the one base region and an adjacent emitter region and which has a gradually decreasing gradient toward the other contiguous base region. The one base region has a sheet resistance of 500 to 1500 ohms/.quadrature.. The realization of a high-voltage, large-diameter and large-current thyristor can be ensured.
摘要翻译:在包括具有相邻pnpn四层的半导体本体和相对的阳极和阴极电极以及为半导体本体提供的栅电极的高压晶闸管中,杂质浓度高于另一半导体的p基极和n基区中的一个 在一个基极区域和相邻的发射极区域之间的结的附近具有不大于8×10 15原子/ cm 3的杂质浓度,并且朝向另一个连续的基极区域具有逐渐降低的梯度。 一个基本区域的薄层电阻为500至1500欧姆/平方厘米。 可以确保高电压,大直径和大电流晶闸管的实现。
摘要:
A novel structure of a high breakdown voltage semiconductor device has a pair of major surfaces on which a pair of main electrodes are formed and a PN junction formed between the pair of major surfaces with a side surface to which the PN junction is exposed being covered with a passivation material. An auxiliary electrode of a conductive member is provided, which is disposed externally of the peripheral edge of the major surface of the semiconductor substrate, and which contacts to the passivation material and is electrically connected to the main electrode. When a voltage for reverse biasing the PN junction is applied between the pair of main electrodes, ions in the passivation material are collected by an electric field established in the passivation material so that the deterioration of the breakdown on the surface of the semiconductor substrate is prevented.
摘要:
A multi-emitter type semiconductor device, namely, a semiconductor device having an arrangement in which a majority of emitter regions are divided by a gate region and surrounded thereby. In the semiconductor device, a member adapted to apply an external control signal to a gate electrode takes the form of a closed-loop shape and the majority of emitter regions are arranged on both sides of the loop. This arrangement ensures that the individual emitter regions, even when the number of the emitter regions is increased to a great extent, can be applied with a uniform control signal, thereby preventing degradation of the turn-off characteristics.
摘要:
A field controlled thyristor is disclosed which comprises a first emitter region exposed to one main surface of a semiconductor substrate and having a first conductivity type, a second emitter region exposed to the other main surface of the substrate and having a second conductivity type, a base region connecting the first and the second emitter region, and a gate region provided in the base region. The gate region consists of a slab-like first portion disposed parallel to both the emitter and a second portion connecting the first slab-like portion with one of the main surfaces of the semiconductor substrate. The impurity concentration of the base region is higher in the portion of the base region nearer to the emitter region having the same conductivity type as that of the base region than in the portion of the base region nearer to the emitter region having the opposite conductivity type to that of the base region. The field controlled thyristor has a high forward blocking voltage gain (anode-cathode voltage/gate bias voltage), a large current rating, and a high switching power capability and its switching time is very short.
摘要:
A semiconductor optical modulator is provided wherein very thin films of two kinds of semiconductors having different band gaps are laminated alternately to form a multi-quantum well (MQW) structure, also called a super-lattice structure, and current is injected into the MQW structure to change the corresponding optical absorption and refractive index characteristic thereof so that a sufficient on/off ratio can be obtained.
摘要:
A semiconductor device is doped with a multiple acceptor impurity having a monovalent energy level for forming a recombination center of carriers within the semiconductor body, and at least one multivalent energy level for capturing carriers within a depletion layer of a PN junction of the semiconductor body.
摘要:
A chaotic character evaluating apparatus includes a processor for predicting future variation in sequential data and a processing for determining a degree of accuracy of the prediction, a processor for predicting variation of the sequential data in reverse and a processor for determining a degree of accuracy of the prediction, and a processing for comparing the degrees of accuracy with each other. If the degrees of the accuracy differ from each other, the variation of the sequential data is determined to be attributable to chaos, while when the degrees of accuracy are substantially equal to each other, the variation in the sequential data is determined to be attributable to noise. Further, a control apparatus for generating a control value from a feedback signal output from an object under control and having chaotic components eliminated is realized. Thus, it is possible to easily and accurately determine whether variation in the sequential data is attributable to chaos or noise.
摘要:
A device for picking up tissues comprises a flexible outer sheath, an extension wire extending through the outer sheath, a connector fixed by one end of the wire and having an outer diameter larger than the inner diameter of the outer sheath for abutting on one end of the outer sheath, a tissue picking-up section connected to said one end of the wire by the connector, a wire holding section for holding the other end of the extension wire and receiving the other end of the outer sheath, a chamber formed in the wire holding section, and a compression spring disposed in the wire holding section for resiliently urging the other end of the outer sheath toward the tissue picking-up section. The device is inserted into an endoscope disposed in a body cavity, and its outer sheath can be easily bent according to the shape of the body cavity.
摘要:
An exposure apparatus for exposing a peripheral portion of a substrate to light comprises a rotating member for rotating a substrate to which a resist is applied, an irradiating system for irradiating the substrate with light which is sensed by the resist, a position detecting system for detecting a relative position between the light and the substrate in a radial direction of the substrate, a moving system for making a relative movement between the light and the substrate in the radial direction of the substrate, a periphery detecting member for detecting outer-periphery information corresponding to a shape of an outer periphery of the substrate, a control system for servo-controlling the moving system in accordance with the outer periphery of the substrate to make the width of the light emitted on the substrate constant, a characteristic detecting member for detecting a specific part of the peripheral portion of the substrate, and a control characteristic changing member for changing a control quantity of the control system at the specific part of the peripheral portion of the substrate.