Metal interconnection structures and methods of forming the same

Abstract

A method of forming a metal interconnection structure is provided. The method includes forming an insulating layer on a semiconductor substrate including a first metal interconnection. The insulating layer is patterned to form an opening that exposes the first metal interconnection. A first diffusion barrier layer is formed on the exposed first metal interconnection. The first diffusion barrier layer comprises at least one of aluminum(Al), zirconium(Zr), silicon(Si), molybdenum(Mo), cobalt(Co), tungsten(W), ruthenium(Ru) and nickel(Ni). A second metal interconnection is formed on the first diffusion barrier layer. Metal atoms from the first metal interconnection are prevented from diffusing into the second metal interconnection by the first diffusion barrier layer. A metal interconnection structure having the first diffusion barrier layer is also provided.

1 . A method of forming a metal interconnection structure, the method comprising:
 forming an insulating layer on a semiconductor substrate including a first metal interconnection;   patterning the insulating layer to form an opening that exposes the first metal interconnection;   forming a first diffusion barrier layer on the exposed first metal interconnection, the first diffusion barrier layer comprising at least one material selected from the group consisting of aluminum(Al), zirconium(Zr), silicon(Si), molybdenum(Mo), cobalt(Co), tungsten(W), ruthenium(Ru), and nickel(Ni); and   forming a second metal interconnection on the first diffusion barrier layer.   
   
   
       2 . The method of  claim 1 , wherein the first metal interconnection comprises copper and the second metal interconnection comprises aluminum. 
   
   
       3 . The method of  claim 1 , further comprising forming a second diffusion barrier layer between the first diffusion barrier layer and the second metal interconnection, wherein the second diffusion barrier layer comprises at least one of titanium(Ti), titanium nitride(TiN), tantalum(Ta) or tantalum nitride (TaN). 
   
   
       4 . The method of  claim 1 , wherein the first diffusion barrier layer is selectively formed only on the exposed first metal interconnection. 
   
   
       5 . The method of  claim 4 , wherein forming the first diffusion barrier layer comprises a chemical vapor deposition (CVD) process, an electroplating process or an electroless plating process. 
   
   
       6 . The method of  claim 1 , wherein forming the first diffusion barrier layer comprises reacting metal in the first metal interconnection with the selected material to form a compound layer. 
   
   
       7 . The method of  claim 1 , wherein forming the first diffusion barrier layer comprises an annealing process to form an oxide of the selected material in the first diffusion barrier layer. 
   
   
       8 . A method of forming a metal interconnection structure, the method comprising:
 forming an insulating layer on a semiconductor substrate including a first metal interconnection;   patterning the insulating layer to form an opening that exposes the first metal interconnection;   forming a first material layer and a second material layer on the exposed first metal interconnection, the first material layer comprising at least one of titanium(Ti), titanium nitride(TiN), tantalum(Ta) or tantalum nitride(TaN), and the second material layer comprising at least one material selected from the group consisting of aluminum(Al), zirconium(Zr), silicon(Si), molybdenum(Mo), cobalt(Co), tungsten(W), ruthenium(Ru) and nickel(Ni);   reacting the first material layer with the second material layer to form a first diffusion barrier layer; and   forming a second metal interconnection on the first diffusion barrier layer.   
   
   
       9 . The method of  claim 8 , wherein the first metal interconnection comprises copper and the second metal interconnection comprises aluminum. 
   
   
       10 . The method of  claim 8 , further comprising forming a second diffusion barrier layer between the first diffusion barrier layer and the second metal interconnection, wherein the second diffusion barrier layer comprises at least one of titanium(Ti), titanium nitride(TiN), tantalum(Ta) or tantalum nitride(TaN). 
   
   
       11 . The method of  claim 8 , wherein forming the first diffusion barrier layer comprises diffusing the selected material of the second material layer into the first material layer. 
   
   
       12 . The method of  claim 8 , wherein the first material layer and the second material layer are formed repeatedly. 
   
   
       13 . The method of  claim 8 , wherein the entire portion of the first material layer reacts with the entire portion of the second material layer to form the first diffusion barrier layer. 
   
   
       14 . The method of  claim 8 , wherein at least one of the first and second material layers remains after formation of the first diffusion barrier layer. 
   
   
       15 . A method of forming a metal interconnection structure, the method comprising:
 forming an insulating layer on a semiconductor substrate including a first metal interconnection;   patterning the insulating layer to form an opening that exposes the first metal interconnection;   forming a first material layer and a second material layer on the exposed first metal interconnection, the first material layer comprising at least one of titanium(Ti) or titanium nitride(TiN), and the second material layer comprising at least one material selected from the group consisting of aluminum(Al), zirconium(Zr), silicon(Si), molybdenum(Mo), cobalt(Co), tungsten(W), ruthenium(Ru) and nickel(Ni);   diffusing the selected material into the first material layer to form a first diffusion barrier layer; and   forming a second metal interconnection on the first diffusion barrier layer.   
   
   
       16 . The method of  claim 15 , wherein the first metal interconnection comprises copper and the second metal interconnection comprises aluminum. 
   
   
       17 . The method of  claim 15 , further comprising forming a second diffusion barrier layer between the first diffusion barrier layer and the second metal interconnection, wherein the second diffusion barrier layer comprises at least one of titanium(Ti), titanium nitride(TiN), tantalum(Ta) and tantalum nitride(TaN). 
   
   
       18 . The method of  claim 15 , wherein the first material layer and the second material layer are formed repeatedly. 
   
   
       19 . A metal interconnection structure, comprising:
 a first metal interconnection and a second metal interconnection; and   a first diffusion barrier layer between the first and second metal interconnections, the first diffusion barrier layer including at least one material selected from the group consisting of aluminum(Al), zirconium(Zr), silicon(Si), molybdenum(Mo), cobalt(Co), tungsten(W), ruthenium(Ru) and nickel(Ni).   
   
   
       20 . The metal interconnection structure of  claim 19 , wherein the first metal interconnection comprises copper and the second metal interconnection comprises aluminum. 
   
   
       21 . The metal interconnection structure of  claim 19 , further comprising a second diffusion barrier layer between the first diffusion barrier layer and the second metal interconnection, wherein the second diffusion barrier layer comprises at least one of titanium(Ti), titanium nitride(TiN), tantalum(Ta) and tantalum nitride(TaN). 
   
   
       22 . The metal interconnection structure of  claim 19 , wherein the first diffusion barrier layer comprises an oxide of the selected material of the first diffusion barrier layer. 
   
   
       23 . The metal interconnection structure of  claim 19 , wherein the first diffusion barrier layer comprises a compound layer formed by reaction of the selected material with metal in the first metal interconnection. 
   
   
       24 . An interconnection structure, comprising:
 a substrate including a first interconnection;   an insulating layer disposed on the substrate and the first interconnection, the insulating layer defining an opening therein;   a first diffusion barrier layer disposed in the opening and on the first interconnection;   a second diffusion barrier layer disposed on the first diffusion barrier layer; and   a second interconnection disposed on the second diffusion barrier layer.   
   
   
       25 . The interconnection structure of  claim 24 , wherein the first diffusion barrier layer is disposed in the bottom of the opening and the second diffusion barrier layer is disposed on the sidewalls of the opening. 
   
   
       26 . The interconnection structure of  claim 24 , wherein the first diffusion barrier layer is disposed in the bottom of the opening and on the sidewalls of the opening. 
   
   
       27 . The interconnection structure of  claim 24 , wherein the second interconnection comprises a plug portion extending into the opening. 
   
   
       28 . The interconnection structure of  claim 24 , further comprising an etch stop layer between the insulating layer and the substrate. 
   
   
       29 . The interconnection structure of  claim 24 , wherein the first interconnection comprises copper and the second interconnection comprises aluminum. 
   
   
       30 . The interconnection structure of  claim 29 , wherein the first diffusion barrier layer comprises aluminum oxide. 
   
   
       31 . The interconnection structure of  claim 29 , wherein the first diffusion barrier layer comprises a copper-aluminum alloy. 
   
   
       32 . The interconnection structure of  claim 24 , wherein the first diffusion barrier layer comprises a titanium or titanium nitride material having a plurality of grains. 
   
   
       33 . The interconnection structure of  claim 32 , wherein the first diffusion barrier layer comprises at least one material selected from aluminum(Al), zirconium(Zr), silicon(Si), molybdenum(Mo), cobalt(Co), tungsten(W), ruthenium(Ru) and nickel(Ni), and wherein regions between the grains are filled with the selected material.