Polishing method and electropolishing apparatus
AssigneeSony Corporation
InventorsShuzo Sato, Takeshi Nogami, Zenya Yasuda, Masao Ishihara
Life of this patent
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Abstract
A polishing method for electropolishing a metal film formed on a wafer surface so as to fill concave portions formed on the wafer surface comprises a step of determining an electropolishing end point of the metal film on the basis of a change of a current waveform resulting from electropolishing the metal film. An electropolishing apparatus comprising a current detector for detecting a current waveform resulting from electropolishing a metal film and an end point determination part for determining an electropolishing end point of the metal film on the basis of the change of a current detected with the current detector is used to realize the polishing method.
Claims9
A polishing method for polishing a metal film formed on a wafer surface having concave and convex comprising:
- a step of polishing said metal film by alternating an electropolishing, involving no mechanical polishing element, with a chemical mechanical polishing or chemical buffing involving no electropolishing element, and
- wherein the electropolishing end point in a last electropolishing process among a plurality of electropolishing processes is determined by a change of a current waveform resulting from electropolishing said metal film, and
- wherein said electropolishing is continued past the determined electropolishing end point while reducing a current applied in said electropolishing until a current density in an electropolished surface reaches a predetermined current density or less.
A polishing method for polishing a metal film formed on a wafer surface having concave and convex comprising:
- a step of polishing said metal film by alternating an electropolishing, including no mechanical polishing element, with a chemical mechanical polishing or chemical buffing involving no electropolishing element, and
- wherein the electropolishing end point in a last electronolishing process among a plurality of electropolishing processes is determined by a change of a current waveform resulting from electropolishing said metal film, and
- wherein said electropolishing is continued past the determined electropolishing end point while reducing a current applied in said electropolishing until a current density in an electropolished surface reaches a predetermined current density or less.
A polishing method for polishing a metal film formed on a wafer surface having concave and convex comprising:
- a step of polishing said metal film by alternating an electropolishing, including no mechanical polishing element, with a chemical mechanical polishing or chemical buffing, involving no electropolishing element, there being at least two separate steps of electropolishing and two separate steps of chemical mechanical polishing or chemical buffing,
- wherein the electropolishing end point in a last electropolishing process among a plurality of electropolishing processes is determined by a change of a current waveform resulting from electropolishing said metal film, and
- wherein said electronolishing is continued past the determined electropolishing end point while reducing a current applied in said electropolishing until a current density in an electropolished surface reaches a predetermined current density or less.
Dependencies are inferred from the claim text.