Asahi Kasei Kogyo Kabushiki Kaisha

Asahi Kasei Kabushiki Kaisha

Shoichiro Tonomura

Atsushi Aoshima

Hiroyuki Fukui

Toyohiko Kuno

Hisaya Imai

Setsuo Yamamatsu

Takashi Morishita

Masahiro Matsui

Ichiro Doi

Grooves and holes of high aspect ratio are filled completely and uniformly. After forming connection holes ( ) and wiring grooves ( ) in a silicon oxide film ( ) which is formed on a silicon substrate ( ), a TiN film ( ) is formed over the entire surface of the semiconductor substrate and a Ti film ( ) is formed on the region except for the connection holes ( ) and the wiring grooves ( ). Then, in a state where the connection holes ( ) and the wiring groove ( ) are dipped in a plating solution, a plating treatment is carried out under a deposition overvoltage higher than the deposition overvoltage of TiN to copper and lower than the deposition overvoltage of Ti to copper. Since plating is thus applied only to the portion where the TiN film ( ) is exposed, namely, only to the portion of the connection holes ( ) and the wiring grooves ( ), the connection holes ( ) and the wiring grooves ( ) are filled with copper and when they are polished by a chemical and mechanical polishing method to form wirings, satisfactory copper wiring which are uniform and well filled can be obtained.

Wiring forming method for semiconductor device

Semiconductor device

Method and apparatus for total reflection X-ray fluorescence spectroscopy

A high luminance thin-film electroluminescent device comprising a phosphor layer comprising SrS as the host material and a luminous center. The phosphor layer is sandwiched between two insulating layers and two thin-film electrodes are provided on each side of the insulating layers. At least one of the electrodes is transparent, and the excitation spectrum of the phosphor layer exhibits a peak having a maximum value at a wavelength of about from 350 nm to 370 nm. Such a high luminance thin-film electroluminescent device can be prepared by annealing its phosphor layer comprising SrS as the host material at a temperature of at least 650 .degree. C. for at least one hour in an atmosphere of a sulfur-containing gas.

High luminance thin-film electroluminescent device

A process for producing a polyether polyol with a content of 0.5 to 99.5% by weight of oxytetramethylene groups derived from tetrahydrofuran by copolymerizing tetrahydrofuran or a mixture of tetrahydrofuran and other cyclic ether copolymerizable therewith with a polyhydric alcohol having two or more hydroxyl groups per one molecule with the use of a heteropoly-acid and/or its salt as a catalyst, which comprises allowing 0.1 to 15 molecules of water per one heteropoly-anion to exist in the catalyst phase. The above-described polyether polyol is an industrially useful polymer which is a starting material for polyurethane to be used for spandex or a synthetic leather, etc.

Process for producing polyether polyol and a product

A process for purifying a polyalkylene ether, which comprises mixing a polyalkylene ether or a mixture of a polyalkylene ether and an organic solvent containing a heteropoly acid and/or its salt with at least one solvent for purification selected from hydrocarbons having 3 to 15 carbon atoms or halogenated hydrocarbons having 1 to 15 carbon atoms and separating by precipitation the phase composed mainly of the heteropoly acid and/or its salt, and a process wherein the polyalkylene ether or a mixture of a polyalkylene ether and an organic solvent containing a heteropoly acid and/or its salt is brought into contact with a solid adsorbent capable of adsorbing the heteropoly acid and/or its salt in the presence of at least one solvent for purification as described above, either further after the separation according to the process described above, or in the state unseparated. According to the present invention, the heteropoly acid and/or its salt dissolved in the polyalkylene ether or the mixture of the polyalkylene ether with the organic solvent can be removed efficiently in the form which can be reused. Further after the treatment with an adsorbent, the concentration of heteropoly acids in the polyalkylene ether can be reduced to extremely lower.

Process for purification of polyether

A process for producing a polyether polyol with a content of 0.5 to 99.5% by weight of oxytetramethylene groups derived from tetrahydrofuran by copolymerizing tetrahydrofuran or a mixture of tetrahydrofuran and another cyclic ether copolymerizable therewith with a polyhydric alcohol having two or more hydroxyl groups per one molecule with the use of a heteropoly-acid and/or its salt as a catalyst, which comprises allowing 0.1 to 15 molecules of water per one heteropoly-anion to exist in the catalyst phase. The above-described polyether polyol is an industrially useful polymer which is a starting material for polyurethane to be used for spandex or a synthetic leather, etc.

A process for producing a polyoxytetramethylene glycol or a copolymerized polyetherglycol by polymerizing tetrahydrofuran or a mixture of tetrahydrofuran with other cyclic ethers copolymerizable therewith, which comprises using a heteropoly-acid as a catalyst and permitting 0.1 to 15 mol of water per mol of the heteropolyacid to be present in the catalyst phase. The above-described polymer and copolymer are industrially useful polymers which can be used as the primary starting materials for polyurethanes to be used for a spandex and a synthetic leather, solvents, pressured fluids, etc.

Growing community of inventors

Fuji, Japan

Shoichiro Tonomura