Edge bevel removal of copper from silicon wafers
AssigneeNovellus Systems, Inc.
InventorsSteven T. Mayer, Carl Russo, Evan Patton
Life of this patent
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Abstract
Chemical etching methods and associated modules for performing the removal of metal from the edge bevel region of a semiconductor wafer are described. The methods and systems apply liquid etchant in a precise manner at the edge bevel region of the wafer under viscous flow conditions, so that the etchant is applied on to the front edge area and flows over the side edge and onto the back edge in a viscous manner. The etchant thus does not flow or splatter onto the active circuit region of the wafer.
Claims45
A method of removing unwanted metal deposited on an edge bevel area of a semiconductor wafer, the method comprising:
- rotating the wafer;
- and
- delivering a stream of liquid etchant onto the edge of the rotating wafer such that the liquid etchant selectively flows over the edge bevel area while in the viscous flow regime,
- wherein the liquid etchant substantially removes unwanted metal selectively from the edge bevel area.
A post-electrofill module including components for removing unwanted metal deposited on an edge bevel area of a semiconductor wafer, the module comprising:
- a rotatable chuck;
- and
- a liquid etchant delivery system including a nozzle which delivers a stream of liquid etchant onto the edge of the wafer while it rotates in the chuck, such that the liquid etchant selectively flows over the edge bevel area while in the viscous flow regime,
- wherein the liquid etchant substantially removes unwanted metal selectively from the edge bevel area.
An integrated module including components for electrofilling metal onto a semiconductor wafer and removing unwanted metal deposited on an edge bevel area from the semiconductor wafer, the module comprising:
- a component for electrofilling metal onto the semiconductor wafer
- a rotatable chuck;
- and
- a liquid etchant delivery system including a nozzle which delivers a stream of liquid etchant onto the edge of the wafer while it rotates in the chuck, such that the liquid etchant selectively flows over the edge bevel area while in the viscous flow regime,
- wherein the liquid etchant substantially removes unwanted metal selectively from the edge bevel area.
A method for removing metal from the front edge area of a semiconductor wafer, the method comprising:
- applying an etchant to the front edge area of the semiconductor wafer under viscous flow conditions, so that etchant does not reach the interior active circuit region of the semiconductor wafer.
Dependencies are inferred from the claim text.