Abstract: A method of forming small through-holes in a thin metal layer including the steps of forming resist films having openings formed in accordance with a predetermined pattern; etching one or both sides of the thin metal plate and stopping etching before through-holes are formed; removing the overhang of the resist film by spraying high pressure fluid onto the etched side of the thin metal plate; covering the surface by an etch-resisting layer; forming through-holes by etching the side not covered; and stripping the etch-resisting layer and the resist film.

Abstract: In oxide film removing equipment for removing a SiO.sub.2 film on a semiconductor substrate by using hydrogen fluoride, a liquid mixture of hydrogen fluoride and methyl alcohol is prepared in a chemical factory beforehand. The liquid mixture of hydrogen fluoride and methyl alcohol is heated to generate azeotropic vapor at a semiconductor works and the vapor is used to remove the SiO.sub.2 film on the substrate. The liquid mixture of hydrogen fluoride and methyl alcohol previously prepared in the chemical factory increases safety during an operation at the semiconductor works.

Abstract: A method for removing a film on a silicon layer formed on a surface of a substrate includes the steps of: (a) placing a substrate in a reaction chamber to be isolated hermetically from the outside air, and (b) feeding anhydrous hydrogen fluoride and alcohol simultaneously into the reaction chamber. Preferably, the method further includes the step of feeding only alcohol into the reaction chamber prior to and/or subsequent to the step (b). An alcohol layer is formed on the substrate surface, whereby the film can be removed uniformly by anhydrous hydrogen fluoride. A by-product of the reaction is taken out from the system of reaction by means of the alcohol on the substrate. No by-product remains on the substrate after the reaction. Since the silicon layer after the reaction is covered with alcohol, re-growth of a native oxide film thereon is also suppressed and on ionic contamination such as fluorine remains on the substrate surface.

Abstract: Disclosed is a photosensitive material which has a first photosensitive layer formed on a support body such as an aluminum plate, a peel-off layer thereon and a second photosensitive layer formed on the peel-off layer in such a manner that the second layer can be photographically exposed to light and photographically developed independently from the first photosensitive layer and the first photosensitive layer may be subsequently photographically exposed with the picture image formed on the second photosensitive layer acting as a photographic mask. After the first photosensitive layer has been photographically developed, the two photosensitive layers may be used for different purposes, for instance, using the first photosensitive layer as a printing plate and the second photosensitive layer as a photographic film for making duplicate printing plates.

Abstract: Disclosed is a chromatic proofreading film which may be conveniently used for the process of ascertaining the color quality in multi-color printing by overlaying color picture images produced from the corresponding color separated picture images. The chromatic proofreading film of this invention has two photosensitive layers, the outer one consisting of a silver halide photosensitive material and the inner one consisting of a non silver salt photosensitive material such as diazo or azide resin, and the inner photosensitive layer is divided into a plurality of regions dyed to different basic colors so that the chromatic proofreading film may be cut apart into a plurality of separate sheets which may be overlaid for the purpose of chromatic proofreading after the film is photographically developed.