Abstract: A method for producing aromatic carboxylic acids which comprises oxidizing a starting compound selected from the group consisting of alkyl substituted aromatic hydrocarbons and partially oxidized alkyl substituted aromatic hydrocarbons with a molecular oxygen containing gas in the presence of at least one additive selected from the group consisting of aliphatic hydrocarbons, alicyclic hydrocarbons, aliphatic alcohols, alicyclic alcohols, aldehydes, carboxylic acids and ketones and in the presence of a catalyst comprising a heavy metal compound and a bromine compound in a reaction solvent. The aliphatic alcohols, alicyclic alcohols, aldehydes, carboxylic acids and ketones have ten to thirty carbon atoms in the molecule.

Abstract: A method includes the steps of forming an insulating layer on a first conductive layer, forming a connection hole in the insulating layer, performing etching using an ion having a very low etching rate with respect to the first conductive layer and a high etching rate with respect to the insulating layer, thereby forming a taper on a side wall of the connection hole, and forming a second conductive layer on the first layer and the insulating layer. A typical example of an etching ion is an oxygen ion.

Abstract: A process for producing an alkyl-substituted aromatic hydrocarbon, which comprises alkylating an aromatic hydrocarbon with an alkylating agent in the presence of a heteropoly-acid or a salt thereof such as phosphorus tungstate and silicon tungstate as a catalyst. The process is particularly useful for preparing alkyl-substituted naphthalene or naphthalene derivatives.

Abstract: A novel paper sizing composition comprising a ketene dimer and a hydrophilic vinyl polymer containing an alkylmercaptan having 6-22 carbon atoms. The composition has excellent storage and mechanical stability and sizing effect.

Abstract: There is provided a high-purity molybdenum target or high-purity molybdenum silicide target for LSI electrodes which comprises a high-purity metallic molybdenum having an alkali metal content of not more than 100 ppb and a radioactive element content of not more than 10 ppb. Further, a process is provided for producing such target comprising a wet purification processing followed by a series of dry processings.

Abstract: An apparatus for forming a thin film to planarize a surface of a semiconductor device having convex and concave regions, comprising a plasma generating chamber into which are an Ar gas and an O.sub.2 gas are supplied so that a plasma is produced; a specimen chamber in which a substrate electrode upon which a specimen substrate is placed and which is in partial communication with the plasma generating chamber and into which an SiH.sub.4 gas as a film material is introduced; and a bias power source for applying a bias voltage to the substrate electrode so that ions sufficiently impinge substantially vertically upon the electrode to perform ion etching. First, an SiO.sub.2 film is deposited on the specimen substrate by using the O.sub.2 and SiH.sub.4 gases. In the next step, Ar plasma and O.sub.2 plasma are produced in the plasma generating chamber and a bias voltage is applied to the substrate electrode.

Abstract: A high-purity high-melting metal target or high-purity high-melting metal silicide target for LSI electrodes having an alkali metal content of not more than 100 ppb and a radioactive element content of not more than 10 ppb is provided by a wet purification process followed by a series of dry processings. Preferably the high-melting metal is molybdenum, tungsten, titanium, niobium or tantalum. More preferably, the high-melting metal is molybdenum.

Abstract: A multilayer structure comprising a Si layer/ a refractory metal oxide layer/ a refractory metal layer/ is subjected to annealing in an atmosphere of hydrogen or an inert gas mixed with hydrogen, thereby converting the multilayer structure into a multilayer structure comprising a Si layer/an inner SiO.sub.2 layer formed by internal oxidation of Si/a refractory metal layer. The inner SiO.sub.2 layer is selectively formed only on the surface of the refractory metal layer, since Si is internally oxidized from the side of the refractory metal layer. In case of gate electrode of a MISFET, the gate electrode and a contact hole for source or drain electrode are positioned in self-alignment with each other via the inner SiO.sub.2 layer. The distance between the gate electrode and the source or drain electrode is determined by the thickness of the inner SiO.sub.2 layer. A semiconductor device with a high density and a high speed is realized.