Nissan Chemical Industries Limited

Nissan Chemical Corporation

Hiroaki Sakaida

Eiichiro Ishimizu

Jiahao Liu

Takuya Fukuoka

Eiichirou Ishimizu

Ishimizu Eiichiro

An object is to provide a cage silicate that can be industrially safely and simply produced by using an alkali silicate solution that does not generate alcohol as a Si raw material and using non-toxic quaternary ammonium, and a method for producing the same. The problem is solved by the following cage silicate: A cage silicate consisting of anion component 1 represented by following formula (1), anion component 2 which is a mineral acid ion, cation component 1 represented by following formula (2), and cation component 2 which is an alkali ion, in which, to the mole number in terms of SiO, a ratio of the mole number of water, (HO/SiO), is 0.7 to 30, a ratio of the mole number of alkali ions, (alkali ions/SiO), is 1.0×10to 1.0−10, and a ratio of the mole number of the mineral acid ions, (mineral acid ions/SiO), is 1.0×10to 1.0×10. In formula (2), R represents an alkyl group having 2 to 20 carbon atoms.

Cage silicate and method for producing the same

There are provided a polishing composition that gives, in the step of polishing a wafer, a flat polished surface having a reduced height difference between a central region and a peripheral region (laser mark region) of the wafer, and a method for producing a wafer using the polished composition. A polishing composition comprising water, silica particles, an alkaline substance, and an amphoteric surfactant of formula (1): wherein Ris a Calkyl group, or a Calkyl group containing an amide group; Rand Rare each independently a Calkyl group; and Xis a Canionic organic group containing a carboxylate ion or a sulfonate ion. Silica particles in the form of an aqueous dispersion of silica particles having a mean primary particle diameter of 5 to 100 nm may be used. A method for producing a wafer, wherein in the step of polishing a wafer, polishing is performed until a height difference between a central region and a peripheral region of the wafer becomes 100 nm or less.

Polishing composition containing amphoteric surfactant

There is provided a method for obtaining a purified aqueous solution of silicic acid containing less metal impurities such as Cu and Ni using water glass as a raw material with less number of purification steps than that in conventional methods without using any unnecessary additives. The method for producing a purified aqueous solution of silicic acid, the method comprising the steps of:

Method for producing purified aqueous solution of silicic acid

An object is to provide a polishing liquid composition that can provide hydrophilicity to a wafer surface and effectively improve a haze in polishing of wafers for substrates in electronics industry. The present invention is a polishing liquid composition for wafers, comprising: water; silica particles; an alkaline compound; a polyvinyl alcohol; an anion-modified polyvinyl alcohol; and a surfactant, wherein the mass ratio of the anion-modified polyvinyl alcohol to the polyvinyl alcohol is 0.6 to 5.5. The anion-modified polyvinyl alcohol is preferably a polyvinyl alcohol modified with a carboxy group or a sulfonic acid group.

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Funabashi, Japan

Hiroaki Sakaida