Mitsubishi Denki Kabushiki Kaisha

Asahi Kasei Kogyo Kabushiki Kaisha

Asahi Kasei Kabushiki Kaisha

Osamu Ishihara

Kazuhiko Sato

Hirofumi Nakano

Satoshi Takahashi

Kenichi Harada

Susumu Hoshi

Naohiko Sato

Akiyoshi Kudo

Takeshi Kuragaki

Hiroshi Sawano

Yukari Hori

Kouji Kasai

Kei Shimazu

Tetsurou Mori

A block copolymer composition comprising:

Block copolymer composition, molded material, resin composition, and molded product

A method of fabricating a thin film piezoelectric device includes preparing a semiconductor substrate having a surface; forming an etch stopping layer having an etching rate on the surface of the semiconductor substrate; forming a first semiconductor layer having an etching rate higher than the etching rate of the etch stopping layer on the etch stopping layer; forming a first electrode on a region of the first semiconductor layer; forming a piezoelectric film on the first electrode; forming a second electrode on the piezoelectric film; and etching a portion of the first semiconductor layer where the first electrode, the piezoelectric film, and the second electrode overlap, from the surface of the first semiconductor layer, selectively with respect to the etch stopping layer, thereby forming a cavity in the first semiconductor layer. Even when a compound semiconductor is employed as the substrate, the etching forming a cavity is stopped at the etch stopping layer in the direction perpendicular to the surface of the first semiconductor layer so that a cavity having a uniform depth is produced with high controllability.

Method of fabricating thin film piezoelectric device

On a semiconductor substrate with an active layer, a first-stage recess groove is formed by photolithography and wet or dry etching. On the semiconductor substrate and the surface of the first-stage recess groove, a surface passivation film a crystalline material such as i-GaAs or an insulating film of, e.g., SiON, is formed. The surface passivation film on an area where an ohmic electrodes is to be formed is removed and the ohmic electrode is formed on the area by vapor deposition. Thereafter, in the first-stage recess groove, a second-stage recess groove is formed by photolithography and wet or dry etching. A gate electrode is formed on the second-stage recess groove by sputtering or the like.

Semiconductor device

The present invention relates to a polyphenylene ether copolymer and thermoplastic resin compositions thereof which are excellent in heat resistance, thermal stability, mechanical strength, moldability and solvent resistance. Particularly, the present invention relates to a polyphenylene ether-polyolefin copolymer formed by covalent bonding between a polyphenylene ether and a polyolefin, each of which has a specific melt viscosity. The copolymer is represented by the formula (1):

Polyphenylene ether copolymer and thermoplastic resin compositions

The invention is connected with a microwave structure, and particularly with the improvement of a microwave circuit of the three plate construction having a plurality of independent circuits formed in an inner level that is sandwiched by two dielectric conductor boards having grounded conductive layers on their outer surfaces, wherein a plurality of through holes are formed to penetrate through the dielectric boards between the neighboring circuits and extending between the conductive layers on the outer surfaces of the boards, the inner surfaces of the through holes being metallized to connect the grounded conductive layers to provide a ground shield between the neighboring circuits.

Microwave ground shield structure

A microwave oscillator including a GaAs field effect transistor having a gate electrode, a drain electrode and a source electrode and disposed on a planar substrate. An elongated gate transmission line is connected to the gate electrode of the field effect transistor and disposed on the substrate and terminated by a matching impedance. An elongated drain transmission line is connected to the drain electrode of the field effect transistor and disposed on the substrate at a predetermined angle to the gate transmission line while an elongated source transmission line is connected to the source electrode and disposed on the substrate for providing the oscillating output. A dielectric resonator is disposed within an angle formed between the gate transmission line and the drain transmission line.

Growing community of inventors

Tokyo, Japan

Osamu Ishihara