Method and apparatus for electrochemical plating semiconductor wafers
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsChung-Liang Chang, Shau-Lin Shue
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Abstract
A method of electroplating conductive material on semiconductor wafers controls undesirable surface defects by reducing the electroplating current as the wafer is being initially immersed in a plating bath. Further defect reduction and improved bottom up plating of vias is achieved by applying a static charge on the wafer before it is immersed in the bath, in order to enhance bath accelerators used to control the plating rate. The static charge is applied to the wafer using a supplemental electrode disposed outside the plating bath.
Claims20
A method of depositing a conductive material on a substrate, comprising the steps of:
- applying a static electric charge to the substrate prior to immersing in a plating bath;
- immersing the substrate in the plating bath;
- after immersing, passing a first electrical current having a first density through the bath and the wafer;
- and
- after passing the first electrical current, passing a second electrical current through the bath and the wafer, the second electrical current having a second density greater than the first density.
A method of depositing a conductive material on a wafer, comprising the steps of:
- (A) applying a static electric charge to the wafer;
- (B) after step (A), immersing the wafer in an electroplating bath;
- and,
- (C) passing an electrical current through the bath and the wafer to effect electroplating of the conductive material on the surface of the wafer, limiting the electrical current to a density of not greater than 0.1 amps per square centimeter as the wafer is being immersed in the bath.
A system of depositing a conductive material on a substrate, comprising:
- means for providing a solution including the conductive material and a plating accelerator;
- means for applying a static electric charge to the substrate prior to immersing in the solution means;
- means for immersing the substrate in the solution;
- means for passing a first electrical current having a first density through the solution and the wafer after immersing, and thereafter, passing a second electrical current through the solution and the wafer, the second electrical current having a second density greater than the first density.
Dependencies are inferred from the claim text.