Chemical mechanical polishing head assembly having floating wafer carrier and retaining ring
First Claim
1. 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;
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 subcarrier.
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Accused Products
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. The invention also provides a retaining ring having a special edge profile that assists in smoothing an pre-compressing the polisihng pad to increase polisihng uniformity. A method for polisihing and a semiconductor manufacture is also provided.
29 Citations
36 Claims
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1. A polishing apparatus comprising:
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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;
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 subcarrier. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 25, 26, 27, 28, 29, 30)
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24. A substrate retaining ring for a polishing machine, said retaining ring comprising:
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a lower surface for contacting an external polishing pad during polishing;
an inner cylindrical surface disposed adjacent to an outer circumferential surface of said carrier and the periphery of a substrate mounting surface of said carrier, said inner cylindrical surface and said carrier mounting surface periphery forming a pocket for maintaining said substrate during polishing; and
a pad conditioning member disposed at the lower outer radial portion of said retaining ring where said retaining ring contacts said pad during polishing and defining a shape profile transitioning between a first planar surface substantially parallel to a plane of said polishing pad and a second planar surface substantially perpendicular to said polishing pad.
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31. A method of planarizing a semiconductor wafer, said method including:
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supporting a back-side surface of said wafer with a wafer support subcarrier;
applying a polishing force against said support subcarrier to press a front surface of said wafer against a polishing pad;
restraining movement of said wafer from said support subcarrier during polishing with a retaining ring circumferentially disposed around a portion of said subcarrier and said wafer; and
applying a pad conditioning force against said retaining ring to press a front surface of said retaining ring against said polishing pad. - View Dependent Claims (32, 33, 34, 35, 36)
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Specification