Abstract: A novel tantalum compound, a method for producing the novel tantalum compound, and a method for stably forming a tantalum-containing thin film which contains the desired element. The tantalum compound enables one to selectively form a tantalum-containing thin film free of halogen and the like, and various tantalum-containing thin films which contain the desired element.

Abstract: Objects of the present invention are to provide a novel tantalum compound which enables to selectively form a tantalum-containing thin film free of halogen and the like, and various tantalum-containing thin films which contain the desired element, and a method for producing the same, and further provide a method for stably forming a tantalum-containing thin film which contains the desired element. The present invention relates to a tantalum compound represented by the following formula (1) (In the formula, R1 represents a straight-chain alkyl group having from 2 to 6 carbon atoms), or a tantalum compound represented by the general formula (2) (In the formula, R2 represents a straight-chain alkyl group having from 2 to 6 carbon atoms), and a method for producing the same.

Abstract: A novel bismuth compound having excellent vaporization characteristic and/or thermal stability, a process of producing the same and a process of producing a film in the film formation by the CVD process are disclosed. Bismuth compounds each represented by the following formula 1, 5 and 9, processes of producing the same, and processes of producing a film. In the formulae, R1 and R7 each represents a lower alkyl group; R2, R8, R12, and R13 each represents a lower alkyl group, a lower alkoxy group, or the like; m represents the number of the substituent R12 in the range of 0-5; n1, n2, and n3 respectively represent the number of the substituent R2, the number of the substituent R8, and the number of the substituent R13 each in the range of 0-4; and R3 to R6, R9 to R11, R14, and R15 each represents hydrogen, a lower alkyl group, or the like, provided that specific combinations of the substituents are excluded.

Abstract: A novel bismuth compound having excellent vaporization characteristic and/or thermal stability, a process of producing the same and a process of producing a film in the film formation by the CVD process are disclosed. Bismuth compounds each represented by the following formula 1, 5 and 9, processes of producing the same, and processes of producing a film.

Abstract: A near field optical recording medium having a header area in which at least an addressing signal or a timing signal is recorded by means of a concave/convex pattern with laser light using a flying optical head. When a concave/convex portion of the concave/convex pattern is to be detected, either an effect due to a change in returning light caused by distance wherein the reflectance is changed or an effect due to a change in returning light caused by a diffraction effect is sufficiently larger, or a combination of such effects (changes by distance effect and changes by diffraction effect) are not weakened by each other, so that header information recorded by the concave/convex pattern can correctly be reproduced even in a super-high density recording medium using near field light.

Abstract: An optical recording medium able to reproduce address information during seeking in which an optical head moves between tracks, to increase seek speed, to improve recording/reproduction speed and to obtain a good header reproducing signal is achieved by that the concave portions or convex portions constituting a reproducing signal in seeking reproduced even during seek and/or constituting a timing signal for writing a header signal are connected to each other in a direction orthogonal to the tracks, when these concave portions and/or convex portions are placed in positions equivalent to each other in the adjacent tracks.

Abstract: A ruthenium-containing thin film is produced by the chemical vapor deposition method etc. with the use of an organometallic ruthenium compound represented by the general formula (1), specific example of which is (2,4-dimethyl-pentadienyl)(ethylcyclopentadienyl)ruthenium: or an organometallic ruthenium compound represented by the general formula (7), specific example of which is carbonylbis(2-methyl-1,3-pentadiene)ruthenium: as the precursor.

Abstract: A ruthenium-containing thin film is produced by the chemical vapor deposition method etc.

Abstract: A near field optical recording medium having a header area in which at least an addressing signal or a timing signal is recorded by means of a concave/convex pattern with laser light using a flying optical head. When a concave/convex portion of the concave/convex pattern is to be detected, either an effect due to a change in returning light caused by distance wherein the reflectance is changed or an effect due to a change in returning light caused by a diffraction effect is sufficiently larger, or a combination of such effects (changes by distance effect and changes by diffraction effect) are not weakened by each other, so that header information recorded by the concave/convex pattern can correctly be reproduced even in a super-high density recording medium using near field light.

Abstract: A pellicle having a reflection-preventing function comprised of a transparent polyvinyl acetal film and a reflection-preventing film formed on at least one surface of the polyvinyl acetal film. The reflection-preventing film is made of a copolymer of a perfluoroalkyl acrylate or methacrylate with a hydroxyalkyl acrylate or methacrylate having (i) a hydroxyalkyl group having 2-3 OH groups on the terminal or side chain and 3-5 carbon atoms, (ii) a hydroxyalkyl group having an OH group on the terminal or side chain and 2-4 carbon atoms, or (iii) a fluorine-containing hydroxyalkyl group having an OH group on the terminal or side chain and 4-12 carbon atoms.

Abstract: A polyacrylic acid ester derivative having repeating units represented by the formula: ##STR1## (wherein R and R' independently represent a hydrogen atom or a methyl group, R.sub.1 represents a C.sub.1 -C.sub.4 linear or branched alkyl group, A represents a structural unit derived from a group copolymerizable with an acrylic acid ester, and l, m and n are, respectively, from 0.04 to 1.0, from 0 to 0.96 and from 0 to 0.5 in this order, provided that their sum is 1, and when m is not higher than 0.2, n is a number of not higher than 0.01) and having a molecular weight of from about 5,000 to about 1,000,000, is capable of being molded, and is useful as an optical material.