Semiconductor device and manufacturing method thereof

Abstract

A method of manufacturing a semiconductor device includes: preparing a semiconductor element having a first metal layer made of first metal on a surface thereof, and a metal substrate made of second metal, the metal substrate having a fourth metal layer made of fourth metal on a surface thereof, and mounting the semiconductor element on the surface thereof; providing metal nanopaste between the first metal layer and the fourth metal layer, the metal nanopaste being formed by dispersing fine particles made of third metal with a mean diameter of 100 nm or less into an organic solvent; and heating, or heating and pressurizing the semiconductor element and the metal substrate between which the metal nanopaste is provided, thereby removing the solvent. Further, each of the first, third and fourth metals is made of any metal of gold, silver, platinum, copper, nickel, chromium, iron, lead, and cobalt, an alloy containing at least one of the metals, or a mixture of the metals or the alloys. By the manufacturing method, it is possible to bond the semiconductor element to the metal substrate favorably.

1 . A semiconductor device, comprising:
 a semiconductor element having a first metal layer made of first metal on a surface thereof;   a metal substrate made of second metal, the metal substrate having a fourth metal layer made of fourth metal on a surface thereof, and mounting the semiconductor element on the surface thereof; and   a bonding layer which bonds the first metal layer and the fourth metal layer to each other, the bonding layer being provided between the first metal layer and the fourth metal layer,   wherein each of the first, third and fourth metals is made of any metal of gold, silver, platinum, copper, nickel, chromium, iron, lead, and cobalt, an alloy containing at least one of the metals, or a mixture of the metals or the alloys.   
     
     
         2 . A semiconductor device according to  claim 1 ,
 wherein each of the first and fourth metals is any metal of gold, silver, platinum, and copper, or an alloy containing at least one of the metals.   
     
     
         3 . A semiconductor device according to  claim 1 ,
 wherein the second metal is same as the fourth metal.   
     
     
         4 . A semiconductor device according to  claim 1 ,
 wherein the second metal is made of pure aluminum or an aluminum alloy.   
     
     
         5 . A semiconductor device according to  claim 1 , further comprising:
 a first interposed layer made of nickel, a nickel alloy, titanium, or a titanium alloy, the first interposed layer being interposed between the metal substrate and the fourth metal layer.   
     
     
         6 . A semiconductor device according to  claim 1 , further comprising:
 an electrode made of fifth metal, the electrode being provided between the semiconductor element and the first metal layer and brought into contact with the semiconductor element,   wherein the fifth metal is made of pure aluminum or an aluminum alloy.   
     
     
         7 . A semiconductor device according to  claim 6 , further comprising:
 a second interposed layer made of nickel, a nickel alloy, titanium, or a titanium alloy, the second interposed layer being interposed between the electrode and the first metal layer.   
     
     
         8 . A semiconductor device according to  claim 1 , further comprising:
 an insulating plate which electrically insulates one surface of the metal substrate and a surface thereof opposite to the one surface from each other.