Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Electric Corporation

Tatsuo Oomori

Kouichi Ono

Hiroki Ootera

Shigeto Fujita

Kazuyasu Nishikawa

Masakazu Taki

Yoshihiro Ueda

Naruhisa Miura

Masayuki Imaizumi

Kenichi Ohtsuka

Kenji Shintani

Takahiro Ohnakado

A power semiconductor device less prone to cause a reaction between a metal material for interconnection and an electrode or the like connected to a semiconductor region during the high-temperature operation thereof and less prone to be strained during the high-temperature operation thereof. The power semiconductor device can be an SiC power device or the like in which a first metal layer containing at least one selected from the group consisting of Pt, Ti, Mo, W and Ta is formed on a source electrode formed on the semiconductor region, such as a source region or the like. A second metal layer containing at least one selected from the group consisting of Mo, W and Cu is formed on the first metal layer. A third metal layer containing at least one selected from the group consisting of Pt, Mo and W is formed on the second metal layer.

Power semiconductor device

A quarter wavelength transmission line is provided between a signal transmission line for transmitting a high frequency signal and a ground node. The quarter wavelength transmission line has a length equal to a quarter of an effective wavelength of an operation frequency of a semiconductor device. A surge absorbing element is connected between the quarter wavelength transmission line and an internal circuit. The signal transmission line is coupled to the internal circuit through a capacitor. A clamp circuit is provided between a power supply line and a ground line. The clamp circuit clamps the voltage difference between the power supply line and the ground line to a prescribed voltage level or less. A high frequency semiconductor device is thus implemented which is capable of preventing breakdown of an internal circuit element due to an electrostatic discharge phenomenon (ESD) without degrading high frequency characteristics.

Circuit protecting against electrostatic discharge

A plasma processing method includes introducing at least one first processing gas into a processing chamber including a mounting stage supporting a substrate having a surface; generating a plasma in the first processing gas; introducing a second processing gas into a gas storage chamber separated from the processing chamber by a partition opposite the mounting stage and including a plurality of jet holes; and jetting neutral particles of the second processing gas from the gas storage chamber toward the substrate through the jet holes in a direction generally perpendicular to the surface of the substrate, thereby plasma processing the substrate.

Plasma processing apparatus

A plasma processing apparatus has a processing chamber in which are provided one or more radio frequency antennas and a grounded opposite electrode positioned opposite to a sample. The radio frequency antenna,is formed of a material having no more than {fraction (1/100)} the volume resistivity of a material forming the opposite electrode. The radio frequency antenna may be buried in the opposite electrode, with its surface partially exposed to the plasma. Thus, the apparatus can have an enhanced processing rate and also provide a uniform process.

A plasma is supplied from a plasma source to a space between an upper electrode plate and a lower electrode plate disposed opposite to and in parallel with the upper electrode plate when producing a plasma in the space between the electrode plates for plasma processing by applying radio-frequency power to the electrode plates. The plasma source produce a plasma by inductively coupled discharge, radio-frequency discharge or microwave discharge. A plasma processing apparatus is obtained which is capable of producing a parallel-plate plasma by discharge in a space of a relatively low pressure and is capable of processing a large diameter workpiece uniformly at a high processing rate.

A plasma processing apparatus capable of forming plasma uniformly throughout a large surface area whereby a sample having a large diameter can be uniformly processed. The plasma processing apparatus has a first electrode 3 on which a workpiece 2 is placed, a second electrode 4 located to face the first electrode 3, and a plurality of ring-shaped permanent magnets 11 each having the same polarity in their circumferential direction, and the magnets are disposed concentrically or the outer side of the second electrode 4 so that the polarities opposing in the radial direction of adjacent magnets 11 are opposite to each other.

An ion source includes a partial flow generator for generating particle flow including atoms or molecules, a laser beam generator for generating a laser beam with one or a plurality of wavelengths which irradiates the whole or one part of the atoms or molecules in the particle flow near an exhaust nozzle of the particle flow generator, a pair of electrodes for applyinig an electric field over one part or the whole of the particle flow in the downstream region of the region irradiated with the laser beam, and a power supply for applying a voltage to generate the electric field between the electrodes to the electrodes. Wherein the laser has one or a plurality of excitation wavelengths for exciting specific atoms or molecules in the particle flow from a ground state to a highly excited state, that is, the Rydberg state in which the principal quantum number of a valence electron is large, a voltage for generating an electric field more than the minimum electric field for ionizing the atoms or molecules in the Rydberg state is applied between the electrodes after irradiation of the laser beam, and one or a plurality of outlet holes through which an ion beam is drawn out are provided at one part of the electrodes.

Ion source

A dry etching apparatus includes a discharge room in which a gas plasma is created by a discharge, an ejection nozzle for ejecting the plasma gas, a first vacuum room into which the plasma gas is introduced through the ejecting nozzle by supersonic expansion of the plasma gas, and a second vacuum room including a skimmer for extracting a supersonic molecular flow, the supersonic molecular flow of the plasma gas taken into the second vacuum room being blown against the material to be etched.

Dry etching apparatus

The ion current generator is employed for thin film formation, ion implantation, etching, sputtering or the like. A vaporizer supplies material atoms to a predetermined region, and then, the material atoms are excited to a Rydberg state by lasers supplied from laser oscillators. The material atoms thus excited are ionized by an electric field applied from electric field application means, to be lead to a predetermined direction. Accordingly, an ion current can be generated at a high efficiency and low cost.

Ion current generator system for thin film formation, ion implantation,

An ion beam generator having an ion generating section for generating ions where the material to be ionized is introduced and a light source for introducing a light into the ion generating sections. This light has a wavelength such that it excites the material to be ionized to the intermediate state from the ground state of the material by a resonance excitation. The specific material to be taken out as an ion beam is selectively ionized through the intermediate state.

Ion beam generator

A dye laser system for emitting laser beams of various wavelengths, which includes a plurality of dye vessels apart from each other and a mirror for oscillating the laser beams and for reflecting the beams to a beam splitter. Two wavelength selectors are provided for directing a specific wavelength portion of the beams to the beam splitter and for directing a specific wavelength portion of the beams to the mirror.

Laser system

An ion beam generator includes: an ion generating section for generating ions and where the material to be ionized is introduced; a gas discharge device for exciting the material to be ionized to a low excited state; a light source for introducing a light into the ion generating section, which light has a wavelength such that it excites the material to be ionized to an intermediate state from the low excited state of the material by a resonance excitation; and the specific material to be taken out as an ion beam being selectively ionized through the intermediate state.

Growing community of inventors

Tokyo, Japan

Tatsuo Oomori