Copper anode or phosphorous-containing copper anode, method of electroplating copper on semiconductor wafer, and semiconductor wafer with low particle adhesion
Provided is a copper anode or a phosphorous-containing copper anode for use in performing electroplating copper on a semiconductor wafer, wherein purity of the copper anode or the phosphorous-containing copper anode excluding phosphorous is 99.99 wt % or higher, and silicon as an impurity is 10 wtppm or less. Additionally provided is an electroplating copper method capable of effectively preventing the adhesion of particles on a plating object, particularly onto a semiconductor wafer during electroplating copper, a phosphorous-containing copper anode for use in such electroplating copper, and a semiconductor wafer comprising a copper layer with low particle adhesion formed by the foregoing copper electroplating.
1. A phosphorous-containing copper anode for use in electroplating copper on a semiconductor wafer, wherein purity of the phosphorous-containing copper anode excluding phosphorous is 99.99 wt % or higher and up to 99.997 wt %, and silicon as an impurity is 10 wtppm or less and sulfur as an impurity is 10 wtppm or less, and a phosphorous content of the phosphorous-containing copper-anode is 100 to 1000 wtppm.
2. The phosphorous-containing copper anode for use in electroplating copper on a semiconductor wafer according to claim 1 , wherein silicon as an impurity is 1 wtppm or less.
3. The phosphorous-containing copper anode for use in electroplating copper on a semiconductor wafer according to claim 2 , wherein as impurity, iron is 10 wtppm or less, manganese is 1 wtppm or less, zinc is 1 wtppm or less, and lead is 1 wtppm or less.
4. The phosphorous-containing copper anode for use in electroplating copper on a semiconductor wafer according to claim 1 , wherein as an impurity, iron is 10 wtppm or less, manganese is 1 wtppm or less, zinc is 1 wtppm or less, and lead is 1 wtppm or less.
5. A method of electroplating copper on a semiconductor wafer including the steps of using a phosphorous-containing copper anode having 100 to 1000 wtppm of phosphorous content in that purity of the phosphorous-containing copper anode excluding phosphorous is 99.99 wt % or higher and up to 99.997 wt %, and silicon as an impurity is 10 wtppm or less and sulfur as an impurity is 10 wtppm or less to electroplate copper on a semiconductor wafer, and forming a copper plated layer with low particle adhesion on the semiconductor wafer.
6. The method of electroplating copper on a semiconductor wafer according to claim 5 , wherein the phosphorous-containing copper anode used during said forming step has silicon as an impurity of 1 wtppm or less.
7. The method of electroplating copper on a semiconductor wafer according to claim 6 , wherein the phosphorous-containing copper anode used during said forming step has as an impurity, iron of 10 wtppm or less, manganese of 1 wtppm or less, zinc of 1 wtppm or less, and lead of 1 wtppm or less.
8. The method of electroplating copper on a semiconductor wafer according to claim 5 , wherein the phosphorous-containing copper anode used during said forming step has as an impurity, iron of 10 wtppm or less, manganese of 1 wtppm or less, zinc of 1 wtppm or less, and lead of 1 wtppm or less.
9. A semiconductor wafer having a copper layer with low generation of particles formed by a process comprising the step of electroplating copper on a semiconductor wafer using a phosphorous-containing copper anode having 100 to 1000 wtppm of phosphorous, a purity excluding phosphorous of 99.99 wt % or higher and up to 99.997 wt %, and silicon as an impurity of 10 wtppm or less and sulfur as an impurity is 10 wtppm or less.