Method for forming fine copper particle sintered product type of electric conductor having fine shape, and process for forming copper fine wiring and thin copper film by applying said method

Abstract

The present invention provides a process for forming a copper fine particle sintered product type of a fine-shaped electric conductor showing superior electroconductivity, which comprises steps of drawing a fine pattern with the use of a dispersion containing the copper fine particles having a surface oxide film layer, conducting a treatment for reducing the copper fine particles with the surface oxide film layer or copper oxide fine particles included in the pattern at a comparatively low temperature, and baking the resultant copper fine particles. Specifically, the process carries out the processes of; applying a dispersion containing the copper fine particles having the surface oxide film layer thereon or the copper oxide fine particles with an average particle diameter of 10 μm or smaller onto a substrate; and then performing a series of the heat treatment steps of heating the particles in the coated layer at temperature of 350° C. or lower under an atmosphere containing a vapor and a gas of a compound having reducibility to reduce the oxide film by a reduction reaction which used the compound having reducibility as a reducing agent, subsequently repeating a heat treatment combining an oxidizing treatment of a short time with a re-reducing treatment, and sintering the resultant copper fine particles with each other to form a layer of the sintered product.