Abstract: The leakage current generated in a pn junction region between a gate and a source is reduced in a junction FET using a silicon carbide substrate. In a trench junction FET using a silicon carbide substrate, nitrogen is introduced into a sidewall and a bottom surface of a trench, thereby forming an n type layer and an n+ type layer on a surface of the trench. In this manner, the pn junction region corresponding to the junction region between a p+ type gate region and an n+ type source region is exposed on a main surface of a semiconductor substrate instead of on the damaged sidewall of the trench, and also the exposed region thereof is narrowed. Accordingly, the leakage current in the pn junction region can be reduced.

Abstract: An object of the present invention is to reduce the conducting loss of an existing conversion circuit while suppressing its noise. The present invention is typically a circuit arrangement includes at least one switching device and a free-wheel diode connected in parallel with the switching device. The free-wheel diode is formed by connecting a silicon PiN diode in parallel with a Schottky barrier diode that uses a semiconductor material having a wider band gap than silicon as a base material. The silicon PiN diode and Schottky barrier diode are separate chips.

Abstract: There is no effective method for fabricating a semiconductor power device containing UMOSFET possessing large channel mobility and whose threshold voltage can be lowered with no loss in blocking voltage. A semiconductor device with large blocking voltage is provided utilizing silicon carbide trench MOSFET possessing both narrow regions where the p body concentration is low, and wide regions where the p body concentration is high.

Abstract: A normally-off type junction FET in which a channel resistance is reduced without lowering its blocking voltage is provided. In a junction FET formed with using a substrate made of silicon carbide, an impurity concentration of a channel region (second epitaxial layer) is made higher than an impurity concentration of a first epitaxial layer to be a drift layer. The channel region is formed of a first region in which a channel width is constant and a second region below the first region in which the channel width becomes wider toward the drain (substrate) side. A boundary between the first epitaxial layer and the second epitaxial layer is positioned in the second region in which the channel width becomes wider toward the drain (substrate) side.

Abstract: In a junction FET of a normally-off type, a technique capable of achieving both of improvement of a blocking voltage and reduction of an ON resistance is provided. In a junction FET using silicon carbide as a substrate material, impurities are doped to a vicinity of a p-n junction between a gate region and a channel-formed region, the impurities having a conductive type which is reverse to that of impurities doped in the gate region and same as that of impurities doped in the channel-formed region. In this manner, an impurity profile of the p-n junction becomes abrupt, and further, an impurity concentration of a junction region forming the p-n junction with the gate region in the channel-formed region is higher than those of a center region in the channel-formed region and of an epitaxial layer.

Abstract: A normally-off type junction FET in which a channel resistance is reduced without lowering its blocking voltage is provided. In a junction FET formed with using a substrate made of silicon carbide, an impurity concentration of a channel region (second epitaxial layer) is made higher than an impurity concentration of a first epitaxial layer to be a drift layer. The channel region is formed of a first region in which a channel width is constant and a second region below the first region in which the channel width becomes wider toward the drain (substrate) side. A boundary between the first epitaxial layer and the second epitaxial layer is positioned in the second region in which the channel width becomes wider toward the drain (substrate) side.

Abstract: A circuit device includes at least one switching element and a free wheeling diode connected in parallel to the switching element. The free wheeling diode is made up of a Schottky barrier diode using a semiconductor material having a band gap larger than silicon as its base material and also a silicon PiN diode, which are connected in parallel. The Schottky barrier diode and the silicon PiN diode are provided in the form of separate chips. A circuit system is also provided wherein a diode having a Schottky junction of a compound semiconductor as a rectification element built therein is combined, and a relationship, R2>4L/C, with impedance R (resistance), L (inductance), and C (capacitance) determined by a closed circuit between a power source and a positive or negative terminal when the current of the diode becomes zero during recovery operation, is satisfied.

Abstract: The present invention relates to isophthalic acid derivatives, to a process for their preparation and to their use for producing medicaments for the treatment and/or prophylaxis of diseases in humans and animals, in particular of cardiovascular disorders.

Abstract: A junction FET having a large gate noise margin is provided. The junction FET comprises an n? layer forming a drift region of the junction FET formed over a main surface of an n+ substrate made of silicon carbide, a p+ layer forming a gate region formed in contact with the n? layer forming the drift region and a gate electrode provided in an upper layer of the n+ substrate. The junction FET further incorporates pn diodes formed over the main surface of the n+ substrate and electrically connecting the p+ layer forming the gate region and the gate electrode.

Abstract: An object of the present invention is to reduce the conducting loss of an existing conversion circuit while suppressing its noise. The present invention is typically a circuit arrangement includes at least one switching device and a free-wheel diode connected in parallel with the switching device. The free-wheel diode is formed by connecting a silicon PiN diode in parallel with a Schottky barrier diode that uses a semiconductor material having a wider band gap than silicon as a base material. The silicon PiN diode and Schottky barrier diode are separate chips.

Abstract: The present invention relates to 2-naphthamides, which are useful as an active ingredient of pharmaceutical preparations. The 2-naphthamides of the present invention have IP receptor antagonistic activity, and can be used for the prophylaxis and treatment of diseases associated with IP receptor activity. Such diseases include urological diseases or disorder as follows: bladder outlet obstruction, overactive bladder, urinary incontinence, detrusor hyper-reflexia, detrusor instability, reduced bladder capacity, frequency of micturition, urge incontinence, stress incontinence, bladder hyperreactivity, benign prostatic hypertrophy (BPH), pro-statitis, urinary frequency, nocturia, urinary urgency, pelvic hypersensitivity, urethritis, pelvic pain syndrome, prostatodynia, cystitis, or idiophatic bladder hypersensitivity.

Abstract: The present invention relates to isophthalic acid derivatives, to a process for their preparation and to their use for producing medicaments for the treatment and/or prophylaxis of diseases in humans and animals, in particular of cardiovascular disorders.