Abstract: The present invention provides a semiconductor structure which includes at least a p-type silicon carbide single crystal layer having an ?-type crystal structure, containing aluminum at impurity concentration of 1×1019 cm?3 or higher, and having thickness of 50 ?m or greater. Further provided is a method for producing the semiconductor structure of the present invention which method includes at least epitaxial growth step of introducing silicon carbide source and aluminum source and epitaxially growing p-type silicon carbide single crystal layer over a base layer made of silicon carbide single crystal having ?-type crystal structure, wherein the epitaxial growth step is performed at temperature conditions of from 1,500° C. to 1,700° C., and pressure conditions of from 5×103 Pa to 25×103 Pa.

Abstract: The present invention provides a semiconductor structure which includes at least a p-type silicon carbide single crystal layer having an ?-type crystal structure, containing aluminum at impurity concentration of 1×1019 cm?3 or higher, and having thickness of 50 ?m or greater. Further provided is a method for producing the semiconductor structure of the present invention which method includes at least epitaxial growth step of introducing silicon carbide source and aluminum source and epitaxially growing p-type silicon carbide single crystal layer over a base layer made of silicon carbide single crystal having ?-type crystal structure, wherein the epitaxial growth step is performed at temperature conditions of from 1,500° C. to 1,700° C., and pressure conditions of from 5×103 Pa to 25×103 Pa.

Abstract: With a view to preventing increases in forward voltage due to a change with the lapse of time of a bipolar semiconductor device using a silicon carbide semiconductor, a buffer layer, a drift layer and other p-type and n-type semiconductor layers are formed on a growth surface, which is given by a surface of a crystal of a silicon carbide semiconductor having an off-angle ? of 8 degrees from a (000-1) carbon surface of the crystal, at a film growth rate having a film-thickness increasing rate per hour h of 10 ?m/h, which is three times or more higher than conventional counterparts. The flow rate of silane and propane material gases and dopant gases is largely increased to enhance the film growth rate.

Abstract: With a view to preventing increases in forward voltage due to a change with the lapse of time of a bipolar semiconductor device using a silicon carbide semiconductor, a buffer layer, a drift layer and other p-type and n-type semiconductor layers are formed on a growth surface, which is given by a surface of a crystal of a silicon carbide semiconductor having an off-angle ? of 8 degrees from a (000-1) carbon surface of the crystal, at a film growth rate having a film-thickness increasing rate per hour h of 10 ?m/h, which is three times or more higher than conventional counterparts. The flow rate of silane and propane material gases and dopant gases is largely increased to enhance the film growth rate.

Abstract: With a view to preventing increases in forward voltage due to a change with the lapse of time of a bipolar semiconductor device using a silicon carbide semiconductor, a buffer layer, a drift layer and other p-type and n-type semiconductor layers are formed on a growth surface, which is given by a surface of a crystal of a silicon carbide semiconductor having an off-angle ? of 8 degrees from a (000-1) carbon surface of the crystal, at a film growth rate having a film-thickness increasing rate per hour h of 10 ?m/h, which is three times or more higher than conventional counterparts. The flow rate of silane and propane material gases and dopant gases is largely increased to enhance the film growth rate.

Abstract: With a view to preventing increases in forward voltage due to a change with the lapse of time of a bipolar semiconductor device using a silicon carbide semiconductor, a buffer layer, a drift layer and other p-type and n-type semiconductor layers are formed on a growth surface, which is given by a surface of a crystal of a silicon carbide semiconductor having an off-angle ? of 8 degrees from a (000-1) carbon surface of the crystal, at a film growth rate having a film-thickness increasing rate per hour h of 10 ?m/h, which is three times or more higher than conventional counterparts. The flow rate of silane and propane material gases and dopant gases is largely increased to enhance the film growth rate.

Abstract: With a view to preventing increases in forward voltage due to a change with the lapse of time of a bipolar semiconductor device using a silicon carbide semiconductor, a buffer layer, a drift layer and other p-type and n-type semiconductor layers are formed on a growth surface, which is given by a surface of a crystal of a silicon carbide semiconductor having an off-angle ? of 8 degrees from a (000-1) carbon surface of the crystal, at a film growth rate having a film-thickness increasing rate per hour h of 10 ?m/h, which is three times or more higher than conventional counterparts. The flow rate of silane and propane material gases and dopant gases is largely increased to enhance the film growth rate.

Abstract: With a view to preventing increases in forward voltage due to a change with the lapse of time of a bipolar semiconductor device using a silicon carbide semiconductor, a buffer layer, a drift layer and other p-type and n-type semiconductor layers are formed on a growth surface, which is given by a surface of a crystal of a silicon carbide semiconductor having an off-angle ? of 8 degrees from a (000-1) carbon surface of the crystal, at a film growth rate having a film-thickness increasing rate per hour h of 10 ?m/h, which is three times or more higher than conventional counterparts. The flow rate of silane and propane material gases and dopant gases is largely increased to enhance the film growth rate.

Abstract: With a view to preventing increases in forward voltage due to a change with the lapse of time of a bipolar semiconductor device using a silicon carbide semiconductor, a buffer layer, a drift layer and other p-type and n-type semiconductor layers are formed on a growth surface, which is given by a surface of a crystal of a silicon carbide semiconductor having an off-angle ? of 8 degrees from a (000-1) carbon surface of the crystal, at a film growth rate having a film-thickness increasing rate per hour h of 10 ?m/h, which is three times or more higher than conventional counterparts. The flow rate of silane and propane material gases and dopant gases is largely increased to enhance the film growth rate.

Abstract: In a SiC pn diode, the lifetime is controlled by electron beam irradiation of about 3×1013 cm?2 or more. As a result of the life time control, as shown by a current-voltage characteristic (K10) in FIG. 1, the current started to flow at about 32 V and the on-voltage at an applied current of 100 A was 50 V in the SiC pn diode. In this case, the SiC pn diode has a resistance of 0.5? when the SiC pn diode is turned on. The conducting region of the SiC pn diode is 0.4 cm2, and is reduced to 0.2 ?cm2 by increasing the on-resistance by the lifetime control. Therefore, for instance, in an electric circuit device using a diode and a resistor connected in series in prior arts, the resistor can be eliminated.

Abstract: In the temperature measurement method for semiconductor devices, a junction temperature of a SiC GTO is determined by exploiting large temperature dependence of accumulation time ts as turn-OFF characteristic time of the SiC GTO that is a semiconductor switching element. The accumulation time ts is a time duration lasting from rise start time t1 of a gate turn-OFF current Ig until decay start time t2 of an anode current Ia. In this temperature measurement method, measured turn-OFF characteristic time is converted into a junction temperature of the SiC GTO based on relational characteristics between preliminarily measured accumulation time ts and junction temperatures.

Abstract: SiC-IGBTs, which have an inversion-type channel with high channel resistance and have high on-voltage due to an influence from the surface state of the interface between a gate insulating film and a base layer, are required to decrease the on-voltage. An embedded collector region is partially formed in a base layer which is formed on an emitter layer of a SiC semiconductor. A channel layer is formed on the base layer and the embedded collector region to constitute an accumulation-type channel. Consequently, at on time, holes are accumulated in the upper layer portion of the channel layer so that a low-resistant channel is formed. Current by the holes flows to the emitter layer through a channel from the collector region and becomes a base current for an npn transistor composed of the embedded collector region, the base region and the emitter region.

Abstract: A problem to be solved by the present invention is to eliminate variation in potential in a turn-off time period of each GTO element, and to stabilize a gate drawing current by surely performing the turn-off of the GTO element. In an inverter apparatus having a three-phase inverter configured to include paired GTO elements an inverter control portion has a simultaneous switching prevention function of delaying a turn-on operation of each of the GTO elements which correspond to phases other than a phase corresponding to an optional one of the GTO elements and also correspond to an electrode opposite to an electrode corresponding to the optional one of the GTO elements by a predetermined time in a case where a turn-on command signal for turning on each of the GTO elements is generated within a predetermined time period since the turn-off of the optional one of the GTO elements.

Abstract: A snubber circuit as a conventional protection circuit for inverters, which is composed of an anode reactor, a Si diode and a resistance, needs to keep junction temperature of the Si diode at 125° C. or lower during operation and therefore requires mounting of a large-size heat sink, which causes a large number of component parts and difficulty in downsizing. As a diode of a snubber circuit for circulating electomagnetic energy of the anode reactor, a wide gap semiconductor (SiC) diode, which does not need a heat sink or requires only a small-size heat sink, is used. When the current density of SiC diode is made 20 to 30 times larger than the current density during normal temperature operation, ON resistance increases, and therefore it becomes possible to substitute the ON resistance for the resistance of the snubber circuit. The increase in current density increases the temperature of the SiC diode. However, since the SiC diode can operate at temperature near 300° C.

Abstract: A high withstand voltage semiconductor chip mounted on a package or a board is covered with a sealing resin, and the resin is cured while a high voltage is applied between at least one of electrode terminals connected from a chip electrode or the chip via wiring of wires or the like and another electrode that necessitates a dielectric withstand voltage between the electrode and the electrode terminal during the curing. The sealing resin is provided by a synthetic high molecular compound structured in a manner that an organic silicon polymer C is constituted by alternately linearly linking an organic silicon polymer A having a crosslinking structure of siloxane with an organic silicon polymer B having a linear link structure of siloxane (Si—O—Si bond) by siloxane bond and the polymers are three-dimensionally linked together by covalent bond.

Abstract: SiC-IGBTs, which have an inversion-type channel with high channel resistance and have high on-voltage due to an influence from the surface state of the interface between a gate insulating film and a base layer, are required to decrease the on-voltage. An embedded collector region is partially formed in a base layer which is formed on an emitter layer of a SiC semiconductor. A channel layer is formed on the base layer and the embedded collector region to constitute an accumulation-type channel. Consequently, at on time, holes are accumulated in the upper layer portion of the channel layer so that a low-resistant channel is formed. Current by the holes flows to the emitter layer through a channel from the collector region and becomes a base current for an npn transistor composed of the embedded collector region, the base region and the emitter region.

Abstract: A mesa-type wide-gap semiconductor gate turn-off thyristor has a low gate withstand voltage and a large leakage current. Since the ionization rate of P-type impurities greatly increases at high temperatures when compared with that at room temperature, the hole implantation amount increases and the minority carrier lifetime becomes longer. Consequently, the maximum controllable current is significantly lowered when compared with that at room temperature. To solve these problems, a p-type base layer is formed on an n-type SiC cathode emitter layer which has a cathode electrode on one surface, and a thin n-type base layer is formed on the p-type base layer. A mesa-shaped p-type anode emitter layer is formed in the central region of the n-type base layer.

Abstract: With a view to preventing increases in forward voltage due to a change with the lapse of time of a bipolar semiconductor device using a silicon carbide semiconductor, a buffer layer, a drift layer and other p-type and n-type semiconductor layers are formed on a growth surface, which is given by a surface of a crystal of a silicon carbide semiconductor having an off-angle ? of 8 degrees from a (000-1) carbon surface of the crystal, at a film growth rate having a film-thickness increasing rate per hour h of 10 ?m/h, which is three times or more higher than conventional counterparts. The flow rate of silane and propane material gases and dopant gases is largely increased to enhance the film growth rate.

Abstract: A problem to be solved by the present invention is to eliminate variation in potential in a turn-off time period of each GTO element, and to stabilize a gate drawing current by surely performing the turn-off of the GTO element.

Abstract: A buried gate region, a buried gate contact region and a gate contact region are provided on an SiC substrate. Thereby, a depletion layer expands in the channel region, and a high withstand voltage is attained in the normally off state. By applying a voltage of the built-in voltage or less to a gate, the depletion layer in the channel region becomes narrower and an ON-state resistance becomes low. Furthermore, when a voltage of the built-in voltage or more is applied to the gate, holes are injected from the gate so as to cause the conductivity modulation, and the ON-state resistance becomes further low.