Carrier head having retainer ring, polishing system including the carrier head and method of using the polishing system
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsChang-Sheng Lin, Hsin-Hsien Lu
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Abstract
Some embodiments relate to a method of using a polishing system. In this method, a wafer is secured in a carrier head. The carrier head includes a housing, which includes a retaining ring recess, enclosing the wafer. A retaining ring is positioned in the retaining ring recess. The retaining ring surrounds the wafer, and has a hardness ranging from about 5 shore A to about 80 shore D. The wafer is pressed against a polishing pad, and at least one of the carrier head or the polishing pad is moved relative to the other.
Claims20
A method of using a polishing system, the method comprising:
- securing a wafer in a carrier head, the carrier head comprising:
- a housing enclosing the wafer, wherein the housing includes a retaining ring recess;
- and
- a retaining ring positioned in the retaining ring recess, the retaining ring surrounding the wafer and comprising:
- a top pad portion configured to contact a polishing pad;
- and
- a sub pad portion positioned between the top pad portion and the housing, wherein a hardness of the sub pad portion is less than a hardness of the top pad portion;
- pressing the wafer against the polishing pad;
- and
- moving at least one of the carrier head or the polishing pad relative to the other.
A method of polishing a wafer, the method comprising:
- securing the wafer in a carrier head, the carrier head comprising:
- a housing enclosing the wafer, wherein the housing includes a retaining ring recess circumferentially surrounding the wafer;
- and
- a retaining ring, which includes a first ring-shaped layer and a second ring-shaped layer, disposed in the retaining ring recess, the second ring-shaped layer disposed deeper in the retaining ring recess than the first ring-shaped layer and separating the first ring-shaped layer from a bottom of the retaining ring recess, wherein a hardness of the second ring-shaped layer is less than a hardness of the first ring-shaped layer;
- pressing the wafer and second ring-shaped layer against a polishing pad while the wafer is secured in the carrier head;
- and
- moving at least one of the carrier head or the polishing pad relative to the other.
A method, comprising:
- securing a wafer in a carrier head, the carrier head comprising:
- a housing including a retaining ring recess that circumferentially surrounds the wafer;
- and
- a retaining ring positioned in the retaining ring recess, wherein the retaining ring has a compressibility ranging from about 1% to about 50%, wherein the compressibility (C) is based on an equation C=(T1−T2)/T1×100, wherein T1 is a first thickness of the retaining ring under a first compressive stress and T2 is a second thickness of the retaining ring under a second compressive stress which is greater than the first compressive stress;
- using the carrier head to press a face of the wafer against a polishing pad;
- and
- moving at least one of the carrier head or the polishing pad relative to the other to polish the face of the wafer.
Dependencies are inferred from the claim text.