US 6,309,290 B1 · Chemical mechanical polishing head having floating wafer retaining ring and wafer carrier with multi-zone polishing pressure control

Abstract

The invention provides structure and method for achieving a uniformly polished or planarized substrate such as a semiconductor wafer including achieving substantially uniform polishing between the center of the semiconductor wafer and the edge of the wafer. In one aspect the invention provides a polishing apparatus including a housing, a carrier for mounting a substrate to be polished, a retaining ring circumscribing the carrier for retaining the substrate, a first coupling attaching the retaining ring to the carrier such that the retaining ring may move relative to the carrier, a second coupling attaching the carrier to the housing such that the carrier may move relative to the housing, the housing and the first coupling defining a first pressure chamber to exert a pressure force against the retaining ring, and the housing and the second coupling defining a second pressure chamber to exert a pressure force against the subcarrier. In one embodiment, the couplings are diaphragms. In another embodiment, the invention includes a single-or multiple-chambered wafer carrier or subcarrier capable of modifying a differential polishing pressure across the surface of the wafer or other substrate. The chambered-subcarrier permits customization of polishing pressure across the surface of the wafer to achieve greater material removal uniformity. The invention also provides a retaining ring having a special edge profile that assists in smoothing an pre-compressing the polishing pad to increase polishing uniformity. A method for polishing and a semiconductor manufacture is also provided by embodiments of the invention.

Claims28

Dependent claims

A disc-shaped semiconductor wafer carrier for mounting a semiconductor wafer substrate to be polished or planarized in a semiconductor wafer processing apparatus, said semiconductor wafer carrier comprising:

a disk-shaped block of substantially non-porous material having a first surface for mounting said semiconductor wafer, a second surface, and a third substantially cylindrical surface connecting said first and second surfaces;
said first surface being substantially planar except for a plurality of concentric annular non-planar cavities extending from said substantially planar surface into an interior portion of said wafer carrier;
a fluid communication channel extending from each said cavity to communicate pressurized fluids from external sources of pressurized fluid to said cavities;
said first surface adapted to receive a flexible membrane to cover said cavities and form a plurality of concentric pressure chambers each capable of holding a pressure when said pressurized fluids are communicated from said external sources of pressurized fluids to said cavities;
and
said membrane expanding locally proximate said non-planar cavities when said pressurized fluids are communicated to said chambers and exerting forces on a semiconductor wafer mounted to said membrane.

3 more elements

A polishing apparatus comprising:

a housing;
a disc shaped carrier having a mounting surface for mounting a backside surface of a substrate to be polished;
a retaining ring substantially circumscribing said carrier for retaining said substrate in a pocket formed by said retaining ring and a surface of said carrier;
a first flexible coupling attaching said retaining ring to said carrier such that said retaining ring may translate in at least one dimension and tilt about an axis relative to said carrier;
a second flexible coupling attaching said carrier to said housing such that said carrier may translate in at least one dimension and tilt about an axis relative to said housing;
said housing and said first flexible coupling defining a first chamber in fluid communication with a first source of pressurized gas such that when gas at a first pressure is communicated to said first chamber a first force is exerted against said retaining ring;
and
said housing and said second flexible coupling defining a second chamber in fluid communication with a second source of pressurized gas such that when gas at a second pressure is communicated to said second chamber a second force is exerted against said carrier;
said carrier mounting surface defining a groove proximate a peripheral edge of said carrier and covered by a substantially non-porous thin flexible sheet of material;
said material covered groove forming a third chamber in fluid communication with a third source of pressurized gas such that when gas at a third pressure is communicated to said third chamber a third force is exerted against said material and through said material to said substrate backside surface proximate said groove to thereby modify a polishing pressure proximate the peripheral edge of said substrate.

7 more elements

A polishing apparatus comprising:

a housing;
a disc shaped carrier for mounting a substrate to be polished;
a retaining ring substantially circumscribing said carrier for retaining said substrate in a pocket formed by said retaining ring and a surface of said carrier;
a first flexible coupling attaching said retaining ring to said carrier such that said retaining ring may translate in at least one dimension and tilt about an axis relative to said carrier;
and
a second flexible coupling attaching said carrier to said housing such that said carrier may translate in at least one dimension and tilt about an axis relative to said housing;
said housing and said first flexible coupling defining a first chamber in fluid communication with a first source of pressurized gas such that when gas at a first pressure is communicated to said first chamber a first force is exerted against said retaining ring;
said housing and said second flexible coupling defining a second chamber in fluid communication with a second source of pressurized gas such that when gas at a second pressure is communicated to said second chamber a second force is exerted against said subcarrier;
said disk-shaped carrier comprises:
a disk-shaped block of substantially non-porous material having a first surface for mounting said substrate, a second surface, and a third substantially cylindrical surface connecting said first and second surfaces;
said first surface being substantially planar except for a non-planar cavity extending from said substantially planar surface into an interior portion of said substrate carrier;
a fluid communication channel extending from said cavity to either said second surface or to said third surface to communicate a pressurized fluid from an external source of pressurized fluid to said cavity;
said first surface adapted to receive a flexible membrane to cover said cavity and form a chamber capable of holding a pressure when said pressurized fluid is communicated from said external source of pressurized fluid to said cavity;
and
said membrane expanding when said pressurized fluid is communicated to said third chamber and exerting a force on a substrate mounted to said membrane.

12 more elements

A semiconductor wafer processing apparatus comprising:

a housing;
a disc shaped carrier for mounting a semiconductor wafer substrate to be polished or planarized;
a retaining ring substantially circumscribing said carrier for retaining said substrate in a pocket formed by said retaining ring and a surface of said carrier;
a first flexible coupling attaching said retaining ring to said carrier such that said retaining ring may translate in at least one dimension and tilt about an axis relative to said carrier;
and
a second flexible coupling attaching said carrier to said housing such that said carrier may translate in at least one dimension and tilt about an axis relative to said housing;
said housing and said first flexible coupling defining a first chamber in fluid communication with a first source of pressurized gas such that when gas at a first pressure is communicated to said first chamber a first force is exerted against said retaining ring;
said housing and said second flexible coupling defining a second chamber in fluid communication with a second source of pressurized gas such that when gas at a second pressure is communicated to said second chamber a second force is exerted against said subcarrier;
and
said disk-shaped carrier comprises:
a disk-shaped block of substantially non-porous material having a first surface for mounting said semiconductor wafer, a second surface, and a third substantially cylindrical surface connecting said first and second surfaces;
said first surface being substantially planar except for a plurality of concentric annular non-planar cavities extending from said substantially planar surface into an interior portion of said wafer carrier;
a fluid communication channel extending from each said cavity to communicate pressurized fluids from external sources of pressurized fluid to said cavities;
said first surface adapted to receive a flexible membrane to cover said cavities and form a plurality of concentric pressure chambers each capable of holding a pressure when said pressurized fluids are communicated from said external sources of pressurized fluids to said cavites;
and
said membrane expanding locally proximate said non-planar cavities when said pressurized fluids are communicated to said chambers and exerting forces on a semiconductor wafer mounted to said membrane.

13 more elements

Dependencies are inferred from the claim text.

Chemical mechanical polishing head having floating wafer retaining ring and wafer carrier with multi-zone polishing pressure control

Life of this patent

Chemical mechanical polishing head having floating wafer retaining ring and wafer carrier with multi-zone polishing pressure control

Life of this patent

Abstract

Claims28