Manufacture method for semiconductor device having improved copper diffusion preventive function of plugs and wirings made of copper or copper alloy

Abstract

(a) A copper alloy film containing at least two types of metal elements in addition to copper is formed on the surface of an insulator containing oxygen and formed on a semiconductor substrate. (b) A metal film made of pure copper or copper alloy is formed on the copper alloy film. (c) After the step (a) or (b), heat treatment is performed under the condition that a metal oxide film is formed on a surface of the insulator through reaction between the oxygen in the insulator and the metal elements in the copper alloy film.

1 . A manufacture method for a semiconductor device comprising steps of:
 (a) forming a barrier metal layer on a surface of an insulator containing oxygen and formed on a semiconductor substrate, the barrier metal layer being made of refractory metal, alloy containing a refractory metal element, or nitride of a refractory metal element;   (b) forming a copper alloy film on the barrier metal layer; and   (c) performing heat treatment under a condition that a metal oxide film is formed through reaction between the oxygen in the insulator and a metal element in the copper alloy film in a state that the insulator contacts the copper alloy film.   
     
     
         2 . The manufacture method for a semiconductor device according to  claim 1 , wherein the copper alloy film contains at one element selected from a group consisting of Al, Mg, Mn, Cr, Ti, Ta, Zr, Sn, In, Zn, Ni and Co. 
     
     
         3 . The manufacture method for a semiconductor device according to  claim 1 , wherein a recess is formed in the insulator, in the steps (a) and (b), the barrier metal layer and the copper alloy layer are formed in conformity with an inner surface of the recess, and a step of forming a metal film filling a space in the recess is provided after the step (b), the metal film being made of copper alloy different from copper alloy of the copper alloy film. 
     
     
         4 . The manufacture method for a semiconductor device according to  claim 3 , wherein the metal film is formed by a plating method, plating solution used for forming the metal film contains at least one type of atoms selected from a group consisting of carbon, oxygen, nitrogen, sulfur and chlorine, and at least one type of atoms selected from the group consisting of carbon, oxygen, nitrogen, sulfur and chlorine in the plating solution is contained in the metal film as impurities. 
     
     
         5 . The manufacture method for a semiconductor device according to  claim 4 , wherein the recess is a wiring trench and the plating method is performed under a condition that a total atom concentration of a carbon atom, an oxygen atom, a nitrogen atom, a sulfur atom and a chlorine atom in the metal film becomes 1×10 19  cm −3  or higher. 
     
     
         6 . The manufacture method for a semiconductor device according to  claim 3 , wherein a recess is formed in the insulator, in the step (b) the copper alloy film filling a space in the recess is formed by a plating method, plating solution used for forming the metal film contains at least one type of atoms selected from a group consisting of carbon, oxygen, nitrogen, sulfur and chlorine, and at least one type of atoms selected from the group consisting of carbon, oxygen, nitrogen, sulfur and chlorine in the plating solution is contained in the metal film as impurities. 
     
     
         7 . The manufacture method for a semiconductor device according to  claim 6 , wherein the recess is a wiring trench and the plating method is performed under a condition that a total atom concentration of a carbon atom, an oxygen atom, a nitrogen atom, a sulfur atom and a chlorine atom in the metal film becomes 1×10 19  cm −3  or higher. 
     
     
         8 . A semiconductor device comprising:
 an insulating film formed on a semiconductor substrate and made of an insulator containing oxygen;   a recess formed in the insulating film;   a conductive member embedded in the recess and made of copper or copper alloy; and   a metal oxide film disposed at an interface between the insulating film and the conductive member, the metal oxide film containing copper and at least two types of metal elements other than the copper,   wherein a partial region of the conductive member contacting the metal oxide film is made of alloy of the copper and at least two types of the metal elements of the metal oxide film.   
     
     
         9 . The semiconductor device according to  claim 8 , wherein the metal oxide film contains one metal element selected from a group consisting of Al, Mg, Mn and Cr and one metal element selected from a group consisting of Ti, Ta and Zr. 
     
     
         10 . A semiconductor device comprising:
 an insulating film formed on a semiconductor substrate and made of an insulator containing oxygen;   a recess formed in the insulating film;   a barrier metal layer covering an inner surface of the recess, the barrier metal layer being made of refractory metal, alloy containing a refractory metal element or nitride of a refractory metal element; and   a copper alloy film formed on the barrier metal layer,   wherein metal oxide is formed in a partial surface region of the insulator through mutual diffusion and reaction between a metal element in the copper alloy film and the oxygen in the insulator film.   
     
     
         11 . A manufacture method for a semiconductor device comprising steps of:
 (a) forming a via hole in a via layer insulating film formed on a semiconductor substrate and made of an insulator containing oxygen;   (b) forming a first copper alloy film on the via layer insulting film, the first copper alloy film filling the via hole;   (c) removing an unnecessary portion of the first copper alloy film and leaving a conductive plug made of copper alloy in the via hole;   (d) forming a wiring layer insulating film made of an insulator containing oxygen on the via layer insulating film;   (e) forming a wiring trench in the wiring layer insulating film;   (f) forming a second copper alloy layer filling the wiring trench in the wiring layer insulating film; and   (g) removing an unnecessary portion of the second copper alloy film and leaving a wiring made of copper alloy in the wiring trench; and further comprising steps of:   (h) after the step (b), performing a first heat treatment to form a via metal oxide film at an interface between the via layer insulating film and the conductive plug through reaction between a constituent element of the conductive plug and the oxygen in the via layer insulating film; and   (i) after the step (f), performing a second heat treatment to form a wiring metal oxide film at an interface between the wiring layer insulating film and the wiring through reaction of a constituent element of the wiring and the oxygen in the wiring layer insulating film.   
     
     
         12 . The manufacture method for a semiconductor device according to  claim 11 , wherein each of the first and second copper alloy films is made of one copper alloy selected from a group consisting of CuAl, CuMg, CuMn, CuCr, CuTi, CuTa, CuZr, CuSn, CuIn, CuZn, CuNi and CuCo. 
     
     
         13 . A semiconductor device comprising:
 a first insulating film formed on a semiconductor substrate and made of insulating material containing oxygen;   a via hole formed through the first insulating film;   a conductive plug embedded in the via hole and made of copper or copper alloy;   a second insulating film formed on the second insulating film;   a wiring trench formed through the second insulating film and exposing an upper surface of the conductive plug;   a wiring embedded in the wiring trench and made of copper or copper alloy having a total atom concentration of a carbon atom, an oxygen atom, a nitrogen atom, a sulfur atom and a chlorine atom higher than a total atom concentration of the conductive plug; and   a metal oxide film formed at an interface between the first insulating film and the conductive plug and made of any one of constituent elements of the conductive plug.   
     
     
         14 . A semiconductor device comprising:
 an insulating film formed on a substrate and made of an insulator containing oxygen;   a recess formed in the insulating film;   a conductive member embedded in the recess and made of copper alloy; and   a metal oxide film disposed at an interface between the insulating film and the conductive member and containing copper, an alloy element in the conductive member other than copper, and another metal element.