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| 20090057686 | SEMICONDUCTOR DEVICE AND ELECTRIC POWER CONVERTER, DRIVE INVERTER, GENERAL-PURPOSE INVERTER AND SUPER-POWER HIGH-FREQUENCY COMMUNICATION EQUIPMENT USING THE SEMICONDUCTOR DEVICE - In a semiconductor device that uses a silicon carbide semiconductor substrate having p type, n type impurity semiconductor regions formed by ion implantation, the electrical characteristics of the end semiconductor device can be improved by decreasing the roughness of the silicon carbide semiconductor substrate surface. The semiconductor device of this invention is a Schottky barrier diode or a p-n type diode comprising at least one of a p type semiconductor region and n type semiconductor region selectively formed in a silicon carbide semiconductor region having an outermost surface layer surface that is a (000-1) surface or a surface inclined at an angle to the (000-1) surface, and a metal electrode formed on the outermost surface layer surface, that controls a direction in which electric current flows in a direction perpendicular to the outermost surface layer surface from application of a voltage to the metal electrode. | 03-05-2009 |
| 20090072244 | METHOD FOR MANUFACTURING SILICON CARBIDE SEMICONDUCTOR DEVICE, AND SILICON CARBIDE SEMICONDUCTOR DEVICE - The object is to provide a method for the fabrication of a semiconductor device having undergone an anneal treatment for the purpose of forming such ohmic contact as enables decrease of ohmic contact resistance and being provided on the (000-1) plane of silicon carbide with an insulating film and provide the semiconductor device. The method for the fabrication of a silicon carbide semiconductor device includes the steps of performing thermal oxidation on the (000-1) plane of a silicon carbide semiconductor in a gas containing at least oxygen and moisture, thereby forming an insulating film in such a manner as to contact the (000-1) plane of the silicon carbide semiconductor, removing part of the insulating film, thereby forming an opening part therein, depositing contact metal on at least part of the opening part, and performing a heat treatment, thereby forming a reaction layer of the contact metal and silicon carbide, wherein the heat treatment is implemented in a mixed gas of an inert gas and hydrogen. | 03-19-2009 |
| 20090134402 | SILICON CARBIDE MOS FIELD-EFFECT TRANSISTOR AND PROCESS FOR PRODUCING THE SAME - In the SiC vertical MOSFET having a low-concentration p-type deposition film provided therein with a channel region and a base region resulting from reverse-implantation to n-type through ion implantation, dielectric breakdown of gate oxide film used to occur at the time of off, thereby preventing a further blocking voltage enhancement. This problem has been resolved by interposing of a low-concentration n-type deposition film between a low-concentration p-type deposition film and a high-concentration gate layer and selectively forming of a base region resulting from reverse-implantation to n-type through ion implantation in the low-concentration p-type deposition film so that the thickness of deposition film between the high-concentration gate layer and each of channel region and gate oxide layer is increased. | 05-28-2009 |
| 20090173949 | SILICON CARBIDE MOS FIELD EFFECT TRANSISTOR WITH BUILT-IN SCHOTTKY DIODE AND METHOD FOR MANUFACTURING SUCH TRANSISTOR - This invention has a cell incorporating a built-in Schottky diode region disposed in at least part of an elementary cell that constitutes an SiC vertical MOSFET provided in a low-density p-type deposit film with a channel region and a base region inverted to an n-type by ion implantation. This built-in Schottky diode region has built therein a Schottky diode of low on-resistance that is formed of a second deficient pan disposed in a high-density gate layer, a second n-type base layer penetrating a low-density p-type deposit layer formed thereon, reaching an n-type drift layer of the second deficient part and attaining its own formation in consequence of inversion of the p-type deposit layer into an n-type by the ion implantation of an n-type impurity from the surface, and a source electrode connected in the manner of forming a Schottky barrier to the surface-exposed part of the second n-type base layer. | 07-09-2009 |
| 20090321746 | SILICON CARBIDE SEMICONDUCTOR DEVICE AND METHOD FOR PRODUCING THE SAME - A low on-resistance silicon carbide semiconductor device is provided that includes an ohmic electrode of low contact resistance and high adhesion strength formed on a lower surface of silicon carbide. | 12-31-2009 |
| 20100012951 | Silicon carbide semiconductor device and method for producing the same - In an SiC vertical MOSFET comprising a channel region and an n-type inverted electron guide path formed through ion implantation in a low-concentration p-type deposition film, the width of the channel region may be partly narrowed owing to implantation mask positioning failure, and the withstand voltage of the device may lower, and therefore, the device could hardly satisfy both low on-resistance and high withstand voltage. In the invention, second inverted layers ( | 01-21-2010 |
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| 20110203822 | OIL PULSE TOOL - According to an aspect of the invention, an oil pulse tool includes: a motor generating a driving force; an oil pulse unit including a shaft, the oil pulse unit being driven by the motor and generating an impact torque on the shaft when the motor passes an impact position; and an output shaft on which a front end tool is attached, the output shaft being fixed to the shaft, wherein the oil pulse tool is provided with a rotational position detecting sensor of detecting a rotational position of the output shaft, and a torque detecting sensor of detecting generation of an impact torque, and the oil pulse tool is provided with detecting means for measuring a state required for reversely rotating the motor by generating an impact, and regularly rotating again the motor and passing a position of generating the impact, and detecting a reduction in a performance of the oil pulse unit by an aging change of the state. | 08-25-2011 |
| 20110214894 | OIL PULSE TOOL - According to an aspect of the invention, an oil pulse tool includes: a motor generating a driving force according to a driving voltage; an oil pulse unit driven by the driving force and generating a torque in a pulse-like shape when the motor passes a strike position on a shaft thereof; and an output shaft on which a front end tool is mounted, the output shaft being connected to the shaft, characterized in that the oil pulse tool further comprises driving adjusting means to control the driving voltage, the driving voltage is reduced during a given period including a timing when the torque is transmitted to the output shaft, and the reduced driving voltage is increased when the given period is finished. | 09-08-2011 |
