Semiconductor device and manufacturing process therefor as well as plating solution
View Patent ↗A semiconductor device of improved stress-migration resistance and reliability includes an insulating film having formed therein a lower interconnection consisting of a barrier metal film and a copper-silver alloy film, on which is then formed an interlayer insulating film. In the interlayer insulating film is formed an upper interconnection consisting of a barrier metal film and a copper-silver alloy film. The lower and the upper interconnections are made of a copper-silver alloy which contains silver in an amount more than a solid solution limit of silver to copper.
1. A process for manufacturing a semiconductor device comprising the steps of:
forming a metal region containing copper on a semiconductor substrate;
contacting the surface of the metal region with a silver-containing liquid; and
heating the metal region, wherein to form a silver content of more than 1 wt % to the total amount of component metals in the metal region after heating, and a silver/copper content of at least 99 wt % to the total amount of component metals in the metal region after heating.
2. A process for manufacturing a semiconductor device comprising the steps of:
contacting a semiconductor substrate or a film formed thereon with a silver-containing solution to precipitate silver;
forming a metal region containing copper on the precipitated silver; and
heating the metal region, wherein to form a silver content of more than 1 wt % to the total amount of component metals in the metal region after heating, and a silver/copper content of at least 99 wt % to the total amount of component metals in the metal region after heating.
3. A process for manufacturing a semiconductor device comprising the steps of:
contacting a device-forming surface of a semiconductor substrate with a silver-containing plating solution; and
forming a silver-containing metal region on the semiconductor substrate, wherein the metal region is a copper-silver alloy having a silver/copper content of at least 99 wt % to the total amount of component metals in the metal region after heating.
4. The process for manufacturing a semiconductor device as claimed in claim 3 , wherein a chloride ion concentration in the plating solution is 100 ppm by weight or less.
5. The process for manufacturing a semiconductor device as claimed in claim 3 , wherein the plating solution contains copper at 0.01 to 5 mol/L, silver at 0.01 to 5 mol/L, ethylenediamine at 0.01 to 5 mol/L and water.
6. The process for manufacturing a semiconductor device as claimed in claim 3 , wherein the plating solution contains copper at 0.01 to 5 mol/L, silver at 0.01 to 5 mol/L, pyrophosphoric acid or its salt at 0.01 to 5 mol/L and water.
7. The process for manufacturing a semiconductor device as claimed in claim 3 , wherein the metal region contains at least one of the group consisting of zirconium, titanium, aluminum, indium, and tin.
8. A process for manufacturing a semiconductor device comprising the steps of:
forming a metal region containing copper on a semiconductor substrate;
contacting the surface of the metal region with a silver-containing liquid; and
heating the metal region, wherein to form a silver content of more than a solid solution limit of silver to copper in the metal region after heating.
9. The process for manufacturing a semiconductor device as claimed in claim 8 , wherein a silver/copper content is at least 99 wt % to the total amount of component metals in the metal region after heating.
10. A process for manufacturing a semiconductor device comprising the steps of:
contacting a semiconductor substrate or a film formed thereon with a silver-containing solution to precipitate silver;
forming a metal region containing copper on the precipitated silver; and
heating the metal region, wherein to form a silver content of more than a solid solution limit of silver to copper in the metal region after heating.
11. The process for manufacturing a semiconductor device as claimed in claim 10 , wherein a silver/copper content is at least 99 wt % to the total amount of component metals in the metal region after heating.
12. A process for manufacturing a semiconductor device comprising the steps of:
contacting a device-forming surface of a semiconductor substrate with a silver-containing plating solution; and
forming a silver-containing metal region on the semiconductor substrate, wherein the metal region is a copper-silver alloy having a silver content of more than a solid solution limit of silver to copper in the metal region after heating.
13. The process for manufacturing a semiconductor device as claimed in claim 12 , wherein a chloride ion concentration in the plating solution is 100 ppm by weight or less.
14. The process for manufacturing a semiconductor device as claimed in claim 12 , wherein the plating solution contains copper at 0.01 to 5 mol/L, silver at 0.01 to 5 mol/L, ethylenediamine at 0.01 to 5 mol/L and water.
15. The process for manufacturing a semiconductor device as claimed in claim 12 , wherein the plating solution contains copper at 0.01 to 5 mol/L, silver at 0.01 to 5 mol/L, pyrophosphoric acid or its salt at 0.01 to 5 mol/L and water.
16. The process for manufacturing a semiconductor device as claimed in claim 12 , wherein the metal region contains at least one of the group consisting of zirconium, titanium, aluminum, indium, and tin.