JP2005509746A5 - - Google Patents

Claims (27)

In an apparatus for electropolishing wafers:
A wafer chuck for holding the wafer;
An actuator for rotating the wafer chuck;
A nozzle configured to electropolish the wafer;
A shroud positioned around the edge of the wafer;
An apparatus for electropolishing a wafer, comprising:   The actuator of claim 1, wherein the actuator is configured to rotate the wafer chuck at a rotational speed sufficient to allow a flow of electrolyte fluid incident on the wafer to flow toward the edge of the wafer. The device described.   The apparatus of claim 2, wherein the electrolyte fluid flows through the edge of the wafer and is incident on the shroud.   The apparatus of claim 2, wherein the wafer is oriented face down, and the flow of electrolyte fluid incident on the wafer flows to the edge of the wafer before falling off the surface of the wafer.   The apparatus of claim 1, wherein the actuator is configured to vary the rotation of the chuck depending on the portion of the wafer that is being electropolished.   The apparatus of claim 5, wherein the actuator is configured to rotate the chuck at a higher speed when the electropolishing portion of the wafer is near center.   The apparatus of claim 1, wherein the wafer chuck is configured to translate relative to the nozzle.   The apparatus of claim 7, wherein the shroud is configured to move relative to the nozzle with the wafer chuck.   8. The apparatus of claim 7, wherein the shroud and the wafer chuck are mechanically coupled for relative movement together with respect to the nozzle.   The apparatus of claim 1, wherein the nozzle is configured to move relative to the wafer chuck.   The apparatus of claim 1, wherein the shroud is positioned about 1 mm to about 10 mm from the edge of the chuck.   The apparatus of claim 1, wherein the shroud is positioned about 5 mm from the edge of the chuck.   The apparatus of claim 1, wherein the shroud sidewall includes an L-shaped cross-section.   The apparatus of claim 1, wherein the shroud sidewalls are tapered.   The apparatus of claim 1, wherein the shroud sidewall extends above or below the chuck.   The apparatus of claim 1, wherein the shroud comprises a plastic material or a ceramic material.   The apparatus of claim 1, wherein the shroud comprises a corrosion resistant metal or alloy.   The apparatus of claim 1, wherein the shroud is coated with an anti-electrolytic fluidic material. In a method of electropolishing a semiconductor wafer,
Electropolishing the wafer with a flow of electrolyte fluid;
Rotating the wafer such that electrolyte fluid incident on the wafer flows across the surface of the wafer toward the edge of the wafer;
Positioning the shroud adjacent to the edge of the wafer;
A method of electropolishing a semiconductor wafer, comprising:   20. The method of claim 19, wherein the wafer is rotated at a rotational speed sufficient to allow electrolyte fluid incident on the wafer to flow toward the edge of the wafer without leaving the surface of the wafer. .   The method of claim 19, wherein the electrolyte fluid flows through the edge of the wafer and impinges on the shroud.   20. The method of claim 19, further comprising varying the chuck rotation as a function of the portion of the wafer being electropolished.   23. The method of claim 22, wherein the wafer is rotated at a higher speed when the electropolished portion of the wafer is near center.   20. The method of claim 19, further comprising translating the wafer relative to a nozzle.   20. The method of claim 19, further comprising moving the shroud relative to the nozzle.   20. The method of claim 19, further comprising moving the shroud and the wafer relative to the nozzle together.   20. The method of claim 19, further comprising moving the nozzle relative to the wafer.