Multi step electrodeposition process for reducing defects and minimizing film thickness
The present invention relates to a method for forming a planar conductive surface on a wafer. In one aspect, the present invention uses a no-contact process with electrochemical deposition, followed by a contact process with electrochemical mechanical deposition.
1 . An electrochemical processing method for operating upon a wafer, the wafer having a top surface with first and second cavities disposed thereon, the first cavity having a narrower width than a second cavity, and a conductive layer having a conductive top surface associated therewith disposed on the top surface of the wafer and on the first and second cavities, the method comprising:
performing electrochemical deposition on the conductive layer of the wafer to result in at least the first cavity being at least partially filled with conductive material; and
performing electrochemical mechanical deposition on the conductive layer of the wafer in which the first cavity is at least partially filled with more conductive material to result in at least some of any remaining cavity within the first and second cavities being further filled with more conductive material, wherein physical contact and relative motion is maintained between the conductive top surface of the conductive layer disposed over the top surface of the wafer and a workpiece surface influencing device for at least a period of the electrochemical mechanical deposition.