Electrolytic copper plating method, pure copper anode for electrolytic copper plating, and semiconductor wafer having low particle adhesion plated with said method and anode
View Patent ↗The present invention pertains to an electrolytic copper plating method characterized in employing pure copper as the anode upon performing electrolytic copper plating, and performing electrolytic copper plating with the pure copper anode having a crystal grain diameter of 10 μm or less or 60 μm or more. Provided are an electrolytic copper plating method and a pure copper anode for electrolytic copper plating used in such electrolytic copper plating method capable of suppressing the generation of particles such as sludge produced on the anode side within the plating bath upon performing electrolytic copper plating, and capable of preventing the adhesion of particles to a semiconductor wafer, as well as a semiconductor wafer plated with the foregoing method and anode having low particle adhesion.
1. An anode for performing electrolytic copper plating comprising an electrolytic copper plating copper anode having a purity, crystal grain diameter, and oxygen content that enables said copper anode to inhibit generation of sludge in an electrolytic copper plating bath containing a copper sulfate plating liquid, said purity being 3N (99.9 wt %) to 6N (99.9999 wt %), excluding gas components, and said crystal grain diameter being from 100 μm to 2000 μm.
2. An anode according to claim 1 , wherein said crystal grain diameter is 100 μm to 500 μm.
3. An anode according to claim 2 , wherein said purity of said copper anode is 4N (99.99 wt %) to 5N (99.999 wt %), excluding gas components.
4. An anode according to claim 2 , wherein said oxygen content is less than 10 ppm.
5. An anode according to claim 2 , wherein said oxygen content is 1000 to 10,000 ppm.
6. An anode according to claim 5 , wherein said oxygen content is 4000 ppm.