Semiconductor apparatus and process of production thereof

Abstract

A method of producing a semiconductor apparatus, the method including forming metal ball bumps in direct contact with a circuit pattern of a semiconductor device, forming a resin film to seal spaces between the metal ball bumps, cleaning the surfaces of the metal ball bumps projecting out from the resin film using plasma cleaning by removing components inviting a rise in a connection resistance and a decline in a joint strength, forming eutectic solder layers different in composition from the metal ball bumps on the surfaces of the metal ball bumps, cutting the semiconductor substrate into unit semiconductor chips, and mounting at least one of the chips on a mounting board from a bump forming surface side of the chip so as to connect the eutectic solder layers to the mounting board with the resin film directly contacting the chip and not directly contacting the mounting board.

1 . A method of producing a semiconductor apparatus, the method comprising the steps of:
 forming metal ball bumps in direct contact with a circuit pattern of a semiconductor device formed on a semiconductor substrate in a semiconductor wafer state;   forming a resin film on a circuit pattern forming surface of said semiconductor device so as to seal spaces between said metal ball bumps and to become thinner than a height of the metal ball bumps;   cleaning the surfaces of the metal ball bumps projecting out from the resin film using plasma cleaning such that the surfaces are cleaned by removing components inviting a rise in a connection resistance and a decline in a joint strength at least at a connection interface;   after the cleaning step, forming eutectic solder layers different in composition from the metal ball bumps on the surfaces of the metal ball bumps;   after the forming solder layers step, cutting the semiconductor substrate into unit semiconductor chips, each semiconductor chip having at least one of said semiconductor device; and   after the cutting step, mounting at least one of the semiconductor chips on a mounting board from a bump forming surface side of the semiconductor chip so as to connect the eutectic solder layers of the semiconductor chip to the mounting board with the resin film directly contacting the semiconductor chip and not directly contacting the mounting board.   
     
     
         2 . A process of production of the semiconductor apparatus as set forth in  claim 1 , wherein, in said cleaning step, any resin film components deposited on said bumps are removed. 
     
     
         3 . A process of production of a semiconductor apparatus as set forth in  claim 1 , wherein, in said cleaning step, oxides on said bump surfaces are removed. 
     
     
         4 . A process of production of a semiconductor apparatus as set forth in  claim 1 , wherein, in said cleaning step, the cleaning of the surfaces of the bumps is performed by plasma cleaning. 
     
     
         5 . A process of production of a semiconductor apparatus as set forth in  claim 4 , wherein said plasma cleaning is at least sputter etching by discharge plasma of an inert gas. 
     
     
         6 . A process of production of a semiconductor apparatus as set forth in  claim 4 , wherein said plasma cleaning is at least oxygen plasma treatment and then sputter etching by discharge plasma of an inert gas. 
     
     
         7 . A process of production of a semiconductor apparatus as set forth in  claim 4 , wherein said plasma cleaning is at least oxygen plasma treatment and then sputter etching by discharge plasma of a reducing gas. 
     
     
         8 . A process of production of a semiconductor apparatus as set forth in  claim 1 , wherein, in said cleaning step, the cleaning of the surfaces of the bumps is performed by irradiating a laser beam. 
     
     
         9 . A process of production of a semiconductor apparatus as set forth in  claim 1 , wherein, in said cleaning step, the cleaning of the surfaces of the bumps is performed under a reduced pressure atmosphere, an inert gas atmosphere, or a reducing gas atmosphere. 
     
     
         10 . A process of production of a semiconductor apparatus as set forth in  claim 1 , wherein, in said cleaning step, the cleaning of the surfaces of the bumps is performed while applying a gas jet to the bumps to peel off the unnecessary components which are then sucked away. 
     
     
         11 . A process of production of a semiconductor apparatus as set forth in  claim 1 , wherein
 the metal ball bumps formed in the first step are solder bumps.   
     
     
         12 . A process of production of a semiconductor apparatus as set forth in  claim 11 , wherein said solder bumps have a melting point higher than a melting point of said eutectic solder layers and said eutectic solder layers are comprised of a eutectic solder. 
     
     
         13 . A process of production of a semiconductor apparatus as set forth in  claim 12 , wherein, in said forming solder layers step, the eutectic solder layers are formed by a printing method, plating method, or transfer method.