Abstract: The present invention provides a reverse conducting (RC) thyristor of a planar-gate structure for low-and-medium power use which is relatively simple in construction because of employing a planar structure for each of thyristor and diode regions, permits simultaneous formation of the both region and have high-speed performance and a RC thyristor of a buried-gate or recessed-gate structure which has a high breakdown voltage by the use of a buried-gate or recessed-gate structure, permits simultaneous formation of thyristor and diode regions and high-speed, high current switching performance, and the RC thyristor of the planar-gate structure has a construction which comprises an SI thyristor or miniaturized GTO of a planar-gate structure in the thyristor region and an SI diode of a planar structure in the diode region, the diode region having at its cathode side a Schottky contact between n emitters or diode cathode shorted region and the thyristor region having at its anode side an SI anode shorted structure fo

Abstract: In a gate insulated static induction thyristor with a split gate type shorted cathode structure, a first gate of the split gate structure is used as a cathode short-circuit gate and the cathode region is formed in the second gate. A MOS structure is formed on the second gate as a control gate electrode isolated therefrom. Since the channel integration density is high, the area efficiency increases. The MOS gate structure suppresses the minority carrier (hole) storage effect to permit high-speed swtching of the thyristor, and the shorted cathode structure provides for increased maximum controllable current/voltage durability. The split gate structure can be used in combination with planar, buried, recessed and double gate structures.

Abstract: The present invention is to provide a Static Induction semiconductor device with a Static Induction Schottky shorted structure where the main electrode region is composed of regions of higher and lower impurity densities relative to each other, the main electrode forms an ohmic contact with the higher impurity density region and also forms a Schottky contact with a Static Induction Schottky shorted region of the lower impurity density region surrounded by tile higher impurity density region, and it is excellent in turn-off performance and easy to use, by substantially reducing tile minority carrier storage time, the fall time and the quantity of gate pull-out charges in order that charges may easily be pulled out from the cathode or source electrode as well as from the gate electrode at turn-off.

Abstract: The present invention has for its object to provide a planar MOS-controlled thyristor of improved main thyristor turn-ON characteristics and a vertical MOS-controlled thyristor of improved main thyristor turn-ON characteristics and increased integration density. In the planar MOS-controlled thyristor a p-channel MOSFET for turning OFF the main thyristor and an n-channel MOSFET for turning it ON are provided in an integrated form and a channel is provided between the cathode region and a high resistance layer. The current in the channel can be controlled by the base or gate potential through utilization of the J-FET or static induction effect. In the vertical MOS-controlled thyristor a vertical p-channel MOSFET for turning OFF the main thyristor and a vertical n-channel MOSFET for turning it ON are provided in an integrated form and a base layer or channel is provided between the cathode region and a high resistivity layer.

Abstract: The present invention relates generally to a photodetector, and more particularly to a photodetector formed by a static induction transistor. The present invention includes the following constituent elements:In the photodetector formed by a static induction transistor, an n.sup.+ -type buried layer is provided, as a drain or source region of the photodetector, for limiting the thickness of a high resistivity i-type layer between a p.sup.+ -type region forming a gate and a substrate. Letting the wavelength of light incident to the surface of the photodetector and an absorption coefficient for the incident light be represented by .lambda..sub.i and .alpha..sub.i (.lambda..sub.i), respectively, the distance between the in junction of the abrupt pin junction and the surface of the photodetector x.sub.i is ##EQU1## the ratio between the area A(.lambda..sub.i) of each gate portion for selectively detecting light of the specified wavelength .lambda..sub.i and the total area A.sub.