Abstract: The disclosure relates to a method for purifying yellow phosphorus including bringing yellow phosphorus and wood-based activated carbon into contact with each other. The disclosure also relates to a method for producing high-purity phosphoric acid including generating a gas of phosphorus pentoxide by burning yellow phosphorus obtained by the purifying method and then hydrating the gas.

Abstract: The present invention provides an electrode for hydrogen generation of which the hydrogen overvoltage is sufficiently low and which is not affected by poisoning due to iron ions, and furthermore, of which the durability is superior because during operations and stop-and-start control, the hydrogen overvoltage does not rise and exfoliation of the supported material does not occur. The present invention also provides a method for manufacturing the aforementioned hydrogen generation electrode and an electrolysis method using the electrode for hydrogen generation as a cathode. An electrode for hydrogen generation is used in which a platinum alloy including platinum and one metal selected from the group consisting of nickel, cobalt, copper, silver, and iron, or an amorphous material of a transition metal element and platinum is supported on a conductive base material.

Abstract: In etching of silicon nitride with a phosphorus type, if etching is carried for a long time, silicon oxide tends to precipitate, and it has been impossible to constantly carry out the etching for a long period of time. By an etching method for silicon nitride using a composition comprising a phosphorus compound, a boron compound, a silicon compound and/or their fluorides thereof, there will be no precipitation of silicon oxide even when the composition is used for a long time. It is particularly preferred to further add nitric acid and/or a nitrate, whereby stability of selectivity will be increased.

Abstract: Cleaning compositions composed of specific amounts of carbonic acid and/or carbonate, hydrogen peroxide, aluminum fluoride and water are highly effective for cleaning electronic devices of resist, resist residues, titanium dioxide, aluminum oxide and silicon dioxide. The compositions contain no hydroxylamine and are thus free of its hazards.

Abstract: The present invention provides an electrode for hydrogen generation of which the hydrogen overvoltage is sufficiently low and which is not affected by poisoning due to iron ions, and furthermore, of which the durability is superior because during operations and stop-and-start control, the hydrogen overvoltage does not rise and exfoliation of the supported material does not occur. The present invention also provides a method for manufacturing the aforementioned hydrogen generation electrode and an electrolysis method using the electrode for hydrogen generation as a cathode. An electrode for hydrogen generation is used in which a platinum alloy including platinum and one metal selected from the group consisting of nickel, cobalt, copper, silver, and iron, or an amorphous material of a transition metal element and platinum is supported on a conductive base material.

Abstract: A cleaning composition for a semiconductor device-manufacturing apparatus comprising, based on the weight of the composition, 0.1-10% by weight of at least one fluorine compound selected from sodium fluoride, potassium fluoride, lithium fluoride and ammonium fluoride; 1-50% by weight of at least one phosphoric ingredient selected from phosphoric acid and a phosphoric acid salt; 0.5-35% by weight of hydrogen peroxide; 0-5% by weight of hydrofluoric acid, and the remainder of water, wherein the ratio (H2O2/F) by weight of hydrogen peroxide to fluorine in the total of the fluorine compound and the hydrofluoric acid is at least 4. The cleaning composition is used for cleaning semiconductor device-manufacturing apparatus having deposited thereon at least one deposited metal ingredient selected from metallic titanium, titanium oxide, titanium nitride, metallic copper, copper oxide, metallic tantalum, tantalum oxide and tantalum nitride to remove these deposited metal ingredients.

Abstract: Cleaning compositions composed of specific amounts of carbonic acid and/or carbonate, hydrogen peroxide, aluminum fluoride and water are highly effective for cleaning electronic devices of resist, resist residues, titanium dioxide, aluminum oxide and silicon dioxide. The compositions contain no hydroxylamine and are thus free of its hazards.