Method and apparatus for electropolishing
AssigneeApplied Materials, Inc.
InventorsNicolay Kovarsky, Aron Rosenfeld, Michael Yang, Ivan Rodriguez
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Abstract
The present invention generally includes deposition and electropolishing methods and an apparatus comprising an electroplating cell and auxiliary cell. In one embodiment for electropolishing a substrate, a cycle is performed in which the substrate is alternately placed in an anolyte solution to remove material and a catholyte solution to deposit material. As the cycle is repeated successively, an exposed layer disposed on the substrate is planarized. In another embodiment, an auxiliary cell may be used to deposit the ultrathin seed layer prior to electroplating.
Claims21
A method for electropolishing, comprising:
- a) cyclically processing a substrate to planarize an exposed conductive layer:
- i) exposing the conductive layer to a catholyte solution of a first chemistry;
- and
- ii) exposing the conductive layer to an anolyte solution of a second chemistry;
- and
- b) detecting an endpoint of the plararization process.
A method for electropolishing, comprising:
- providing a first and a second substrate, wherein each substrate has a layer deposited thereon;
- performing a first sequence of:
- exposing the layer of the first substrate to a catholyte solution of a first chemistry;
- exposing the layer of the second substrate to an anolyte solution of a second chemistry;
- providing a current density to both the first catholyte solution and the first anolyte solution;
- performing a second sequence of:
- exposing the layer of the first substrate to an anolyte solution of the second chemistry;
- exposing the layer of the second substrate to a catholyte solution of the first chemistry;
- providing a second current density to both the second catholyte solution and the second anolyte solution;
- repeating at least one of the first and second sequences.
A method for electropolishing, comprising:
- providing a substrate on a substrate chuck within an electropolishing cell, wherein the substrate has a layer deposited thereon;
- contacting an electrolyte to the layer on the substrate within the electropolishing cell;
- cooling the substrate to a temperature below or about the freezing point of the electrolyte;
- and
- electropolishing the layer on the substrate.
A method of depositing a seed layer, comprising:
- positioning a surface of a rotating substrate proximate to but not touching an auxiliary cell;
- moving the auxiliary cell across the surface of the substrate;
- flowing an electrolyte between an inner vessel and an outer vessel of the auxiliary cell and into contact with the surface of the substrate, wherein the outer vessel surrounds the inner vessel;
- and
- applying power to an electrode in fluid contact with the electrolyte.
An apparatus, comprising:
- a contact ring configured to retain a substrate against a substrate support;
- an electroplating cell;
- a robotic arm;
- and
- an auxiliary cell coupled to the robotic arm, wherein the auxiliary cell is located between the contact ring and electroplating cell and wherein the auxiliary cell comprises:
- a chamber connected to the arm, wherein the chamber has an outer vessel surrounding an inner vessel and wherein electrolyte within the inner vessel can overflow into the outer vessel, a diameter of the outer vessel is small relative to the diameter of the substrate;
- an electrode within the inner vessel;
- a diffuser within the inner vessel;
- an inlet manifold coupled to the inner vessel;
- and
- an outlet manifold coupled to the outer vessel.
Dependencies are inferred from the claim text.