Polishing apparatus and method
View Patent ↗A polishing apparatus and method has a function of polishing a surface of a film formed on a substrate to a flat mirror finish and a function of polishing unnecessary metal film such as copper film deposited on an outer peripheral portion of the substrate to remove such unnecessary metal film. The polishing apparatus comprises a surface polishing mechanism comprising a polishing table having a polishing surface and a top ring for holding the substrate and pressing the substrate against the polishing surface of the polishing table to thereby polish a surface of the substrate, and an outer periphery polishing mechanism for polishing an outer peripheral portion of the substrate.
1. An outer periphery polishing apparatus for polishing an outer peripheral portion of a substrate, comprising:
a substrate holder for holding a substrate so as to allow an outer peripheral portion of the substrate to be exposed;
a polishing unit having an outer periphery polishing surface that is located so as to surround the outer peripheral portion of the substrate while the substrate is held by said substrate holder;
a rotational shaft connected to said polishing unit;
a polishing liquid passage extending through said rotational shaft and being in communication with a liquid supply port;
a moving mechanism for moving at least one of said substrate holder and said polishing unit to bring said substrate holder and said polishing unit into engagement with each other and to separate said substrate holder and said polishing unit from engagement with each other; and
a rotating mechanism for rotating said polishing unit about an axis of said rotational shaft, such that when said rotating mechanism rotates said rotational shaft the polishing liquid is supplied to said outer periphery polishing surface via centrifugal force caused by rotation of said polishing unit about said axis, upon the polishing liquid exiting said supply port after having passed through said polishing liquid passage.
2. The outer periphery polishing apparatus according to claim 1 , wherein said outer periphery polishing surface exhibits an upwardly extending inclination with respect to a horizontal plane defined by the substrate while the substrate is being held by said substrate holder, with said upwardly extending inclination being directed in a radially outward direction with respect to the substrate while the substrate is being held by said substrate holder.
3. The outer periphery polishing apparatus according to claim 1 , wherein the substrate comprises a substrate on which copper interconnects are formed.
4. The outer periphery polishing apparatus according to claim 3 , wherein the polishing liquid has a polishing rate for copper which is at least ten times greater than that for an oxide film or a low-K material.
5. The outer periphery polishing apparatus according to claim 1 , further comprising a pressing mechanism for pressing the outer peripheral portion of the substrate against said outer periphery polishing surface.
6. The outer periphery polishing apparatus according to claim 5 , wherein said outer periphery polishing surface exhibits an upwardly extending inclination with respect to a horizontal plane defined by the substrate while the substrate is being held by said substrate holder, with said upwardly extending inclination being directed in a radially outward direction with respect to the substrate while the substrate is being held by said substrate holder.
7. A polishing apparatus for polishing a workpiece, comprising:
a surface polishing mechanism for polishing a surface of a workpiece, said surface polishing mechanism including a polishing table having a polishing surface and a substrate holder for holding the workpiece and pressing the workpiece against said polishing surface of said polishing table; and
an outer periphery polishing mechanism for polishing an outer peripheral portion of a substrate, said outer periphery polishing mechanism including
(i) said substrate holder, with said substrate holder for holding the substrate so as to allow an outer peripheral portion of the substrate to be exposed,
(ii) a polishing unit having an outer periphery polishing surface that is located so as to surround the outer peripheral portion of the substrate while the substrate is held by said substrate holder,
(iii) a rotational shaft connected to said polishing unit,
(iv) a polishing liquid passage extending through said rotational shaft and being in communication with a liquid supply port,
(v) a moving mechanism for moving at least one of said substrate holder and said polishing unit to bring said substrate holder and said polishing unit into engagement with each other and to separate said substrate holder and said polishing unit from engagement with each other, and
(vi) a rotating mechanism for rotating said polishing unit about an axis of said rotational shaft, such that when said rotating mechanism rotates said rotational shaft the polishing liquid is supplied to said outer periphery polishing surface via centrifugal force caused by rotation of said polishing unit about said axis, upon the polishing liquid exiting said supply port after having passed through said polishing liquid passage.
8. The polishing apparatus according to claim 7 , wherein said substrate holder is movable in a vertical direction and a horizontal direction, and said outer periphery polishing unit is disposed at a location to which said substrate holder is movable and is for polishing the outer peripheral portion of the workpiece by having said outer periphery polishing surface contact the outer peripheral portion of the workpiece while the workpiece is being held by said substrate holder.
9. The polishing apparatus according to claim 7 , wherein the workpiece comprises a substrate on which copper interconnects are formed.
10. The polishing apparatus according to claim 7 , wherein the polishing liquid has a polishing rate for copper which is at least ten times greater than that for an oxide film or a low-K material.
11. The polishing apparatus according to claim 7 , wherein said outer periphery polishing surface exhibits an upwardly extending inclination with respect to a horizontal plane defined by the workpiece while the workpiece is being held by said substrate holder, with said upwardly extending inclination being directed in a radially outward direction with respect to the workpiece while the workpiece is being held by said substrate holder.
12. An outer periphery polishing apparatus for polishing an outer peripheral portion of a substrate having a film formed thereon, said outer periphery polishing apparatus comprising:
a substrate holder for holding a substrate so as to allow an outer peripheral portion of the substrate to be exposed;
a polishing unit having an outer periphery polishing surface that is located so as to surround the outer peripheral portion of the substrate while the substrate is held by said substrate holder;
a rotational shaft connected to said polishing unit;
a polishing liquid passage extending through said rotational shaft and being in communication with a liquid supply port;
a moving mechanism for moving at least one of said substrate holder and said polishing unit to bring said substrate holder and said polishing unit into engagement with each other and to separate said substrate holder and said polishing unit from engagement with each other; and
a rotating mechanism for rotating said polishing unit about an axis of said rotational shaft, such that when said rotating mechanism rotates said rotational shaft the polishing liquid is supplied to said outer periphery polishing surface via centrifugal force caused by rotation of said polishing unit about said axis, upon the polishing liquid exiting said supply port after having passed through said polishing liquid passage.