Semiconductor device

Abstract

A semiconductor device includes a GaAs substrate having a first major surface and a second major surface opposite to each other; a nickel diffusion barrier disposed on the first major surface of the GaAs substrate. The nickel diffusion barrier consists of a single layer of Pd. A nickel-containing layer is disposed on the nickel diffusion barrier and the nickel diffusion barrier is interposed between the first major surface of the GaAs substrate and the nickel-containing layer. The nickel diffusion barrier prevents nickel from diffusing from the nickel-containing layer into the GaAs substrate.

1 - 14 . (canceled) 
     
     
         15 . A semiconductor device comprising:
 a GaAs substrate having a first major surface and a second major surface opposite to each other;   a nickel diffusion barrier disposed on the first major surface of the GaAs substrate, wherein the nickel diffusion barrier consists of a single layer of Pd; and   a nickel-containing layer disposed on the nickel diffusion barrier, wherein
 the nickel diffusion barrier is interposed between the first major surface of the GaAs substrate and the nickel-containing layer, and 
 the nickel diffusion barrier prevents nickel from diffusing from the nickel-containing layer into the GaAs substrate. 
   
     
     
         16 . The semiconductor device according to  claim 15 , further comprising a circuit, including a grounding electrode, on the second major surface of the GaAs substrate, wherein
 the GaAs substrate includes a through-hole passing through the GaAs substrate from the first major surface to a location of the grounding electrode on the second major surface,   the nickel diffusion barrier is disposed on side surfaces of the through-hole and on an exposed surface of the grounding electrode in the through-hole, and   the nickel-containing layer is disposed on the nickel diffusion barrier in the through-hole.   
     
     
         17 . The semiconductor device according to  claim 16 , wherein the nickel diffusion barrier on the side surfaces of the through-hole has a thickness that is 1/10 or less of thickness of the nickel diffusion barrier on the first major surface. 
     
     
         18 . The semiconductor device according to  claim 15 , further comprising a circuit, including a grounding electrode, on the second major surface of the GaAs substrate, wherein
 the GaAs substrate includes a through-hole passing through the GaAs substrate from the first major surface to a location of the grounding electrode on the second major surface,   the nickel diffusion barrier is disposed on an exposed surface of the grounding electrode in the through-hole, and   the nickel-containing layer is disposed on side surfaces of the through-hole and on the nickel diffusion barrier in the through-hole.   
     
     
         19 . The semiconductor device according to  claim 15 , further comprising a high electrical conductivity metal layer, including a metal selected from the group consisting of Au, Ag, and Cu, disposed on the nickel-containing layer. 
     
     
         20 . The semiconductor device according to  claim 15 , wherein the nickel diffusion barrier is at least 0.05 μm thick.