Semiconductor device having copper wiring
View Patent ↗A first interlayer insulating film made of insulting material is formed over an underlying substrate. A via hole is formed through the first interlayer insulating film. A conductive plug made of copper or alloy mainly consisting of copper is filled in the via hole. A second interlayer insulating film made of insulating material is formed over the first interlayer insulating film. A wiring groove is formed in the second interlayer insulating film, passing over the conductive plug and exposing the upper surface of the conductive plug. A wiring made of copper or alloy mainly consisting of copper is filled in the wiring groove. The total atom concentration of carbon, oxygen, nitrogen, sulfur and chlorine in the conductive plug is lower than the total atom concentration of carbon, oxygen, nitrogen, sulfur and chlorine in the wiring.
1. A semiconductor device comprising:
an underlying substrate;
a first interlayer insulating film formed over the underlying substrate and made of insulating material;
a via hole formed through the first interlayer insulating film;
a conductive plug filled in the via hole and made of copper or an alloy containing mainly copper;
a second interlayer insulating film formed over the first interlayer insulating film and made of insulating material;
a wiring groove formed in the second interlayer insulating film, passing over the conductive plug and exposing an upper surface of the conductive plug; and
a wiring filled in the wiring groove and made of copper or an alloy containing mainly copper;
wherein said conductive plug and said wiring made of said copper or said alloy containing mainly copper contain carbon, oxygen, nitrogen, sulphur and chlorine;
wherein a total atom concentration of carbon, oxygen, nitrogen, sulfur and chlorine in the conductive plug is lower than a total atom concentration of carbon, oxygen, nitrogen, sulfur and chlorine in the wiring.
2. The semiconductor device according to claim 1 , wherein a barrier metal layer for preventing copper diffusion is disposed between an inner surface of the wiring groove and the wiring, and the barrier metal layer is also disposed between the wiring and the conductive plug.
3. The semiconductor device according to claim 1 , wherein the total atom concentration of carbon, oxygen, nitrogen, sulfur and chlorine in the conductive plug is equal to or lower than one tenth of the total atom concentration of carbon, oxygen, nitrogen, sulfur and chlorine in the wiring.
4. The semiconductor device according to claim 2 , wherein the total atom concentration of carbon, oxygen, nitrogen, sulfur and chlorine in the conductive plug is equal to or lower than one tenth of the total atom concentration of carbon, oxygen, nitrogen, sulfur and chlorine in the wiring.
5. The semiconductor device according to claim 1 , wherein the total atom concentration of the conductive plug is lower than 1×10 19 cm −3 and the total atom concentration of the wiring is higher than 1×10 19 cm −3 .
6. The semiconductor device according to claim 2 , wherein the total atom concentration of the conductive plug is lower than 1×10 19 cm −3 and the total atom concentration of the wiring is higher than 1×10 19 cm −3 .
7. The semiconductor device according to claim 3 , wherein the total atom concentration of the conductive plug is lower than 1×10 19 cm −3 and the total atom concentration of the wiring is higher than 1×10 19 cm −3 .