Electroplating method

Abstract

The surface of a metal base is electroplated by utilizing an induction codeposition phenomenon using at least one of carbon dioxide and inert gas, an electroplating liquid containing a metal powder dispersed therein, and a surfactant in a supercritical state or a subcritical state. The concentration of the metal in the electroplating liquid is in a saturated or supersaturated state. Accordingly, the dissolution speed of the metal base can be suppressed, and, at the same time, a plating layer having a smooth surface can be formed in a short time by utilizing an induction codeposition phenomenon. The electroplating method can be applied even when the metal base is formed of a metallic thin film provided on a surface of an insulating film provided on the substrate, or even when the metal is copper, zinc, iron, nickel, or cobalt. The above constitution can provide an electroplating method which, in electroplating on the surface of a metal base, can prevent the dissolution of the metal base to realize normal electroplating even in the case of a very thin metal base.

1 . A method for electroplating the surface of a metal base, the method characterized in comprising: performing electroplating by utilizing an induction codeposition phenomenon in a supercritical or a subcritical state using at least one of carbon dioxide and an inert gas, as well as an electroplating solution containing a metal powder which are added in an amount equal to or greater than the amount at which the plating metal could no longer be dissolved dispersed therein, and a surfactant, said metal powder being comprising the same metal as at least on of the metal base and a metal film obtained in electroplating. 
   
   
       2 . (canceled) 
   
   
       3 . The electroplating method according to  claim 1 , characterized in that the average particle diameter of said metal powder is from 1 μm or greater to 100 μm or less. 
   
   
       4 . The electroplating method according to  claim 1 , characterized in that the average particle diameter of said metal powder is from 1 nm or greater to less than 1 μm. 
   
   
       5 . The electroplating method according to  claim 1 , characterized in that a voltage at which said metal base does not dissolve is applied before said metal base is immersed into said electroplating solution. 
   
   
       6 . The electroplating method according to  claim 3 , characterized in that a voltage at which said metal base does not dissolve is applied before said metal base is immersed into said electroplating solution. 
   
   
       7 . The electroplating method according to  claim 4 , characterized in that a voltage at which said metal base does not dissolve is applied before said metal base is immersed into said electroplating solution.