A carrier head for holding a substrate in a polishing system includes a housing, a first flexible membrane secured to the housing to form one or more pressurizable chambers to apply pressure through a central membrane portion of the first flexible membrane to a central portion of a substrate, and a plurality of independently operable piezoelectric actuators supported by the housing, the plurality of piezoelectric actuators positioned radially outward of the central membrane portion and at different angular positions so as to independently adjust pressure on a plurality of angular zones in an annular outer region of the substrate surrounding the central portion of the substrate.

A carrier head for holding a substrate in a polishing system includes a housing, a first flexible membrane secured to the housing to form one or more pressurizable chambers to apply pressure through a central membrane portion of the first flexible membrane to a central portion of a substrate, and a plurality of independently operable piezoelectric actuators supported by the housing, the plurality of piezoelectric actuators positioned radially outward of the central membrane portion and at different angular positions so as to independently adjust pressure on a plurality of angular zones in an annular outer region of the substrate surrounding the central portion of the substrate.

A carrier head for a polishing system includes a housing, a flexible membrane, a first plurality of pressure supply lines, a second plurality of pressure supply lines, and a valve assembly. The flexible membrane defines a multiplicity of independently pressurizable chambers. The valve assembly has a multiplicity of valves with each respective valve of the multiplicity of valves coupled to a respective pressure chamber from the multiplicity of independently pressurizable chambers. Each respective valve is configured to selectively couple the respective pressure chamber to one pressure supply line from a pair of pressure supply lines that include a pressure supply line from the first plurality of pressure supply lines and a pressure supply line from the second plurality of pressure supply lines.

A substrate polishing apparatus includes a top ring for pressing a substrate against a polishing pad to perform substrate polishing; a spectrum generating unit that directs light onto a surface of the substrate of interest for polishing, receives reflected light, and calculates a reflectivity spectrum corresponding to the wavelength of the reflected light; and a storage that stores a plurality of thickness estimating algorithms for estimating the thickness of the polished surface in accordance with the reflectivity spectrum. A plurality of thickness estimating algorithms is selected among the thickness estimating algorithms stored in the storage, and a switching condition is set. The thickness of the polished surface is estimated by using the set thickness estimating algorithms, and if the switching condition is satisfied, the thickness estimating algorithm to be applied is switched.

A substrate polishing apparatus includes a top ring for pressing a substrate against a polishing pad to perform substrate polishing; a spectrum generating unit that directs light onto a surface of the substrate of interest for polishing, receives reflected light, and calculates a reflectivity spectrum corresponding to the wavelength of the reflected light; and a storage that stores a plurality of thickness estimating algorithms for estimating the thickness of the polished surface in accordance with the reflectivity spectrum. A plurality of thickness estimating algorithms is selected among the thickness estimating algorithms stored in the storage, and a switching condition is set. The thickness of the polished surface is estimated by using the set thickness estimating algorithms, and if the switching condition is satisfied, the thickness estimating algorithm to be applied is switched.

To reduce a risk generated at a time of collision of a substrate with a retainer. According to one embodiment, a head for holding a polygonal substrate as a polishing object of a polishing apparatus is provided. The head includes a substrate holding surface configured to hold a substrate and a retainer positioned outside the substrate holding surface. The retainer has an end region. The end region is arranged adjacent to a corner portion of the substrate held onto the head. The end region has an end surface on a side of the substrate holding surface. The end surface is configured to increase in distance from the substrate holding surface with approaching an end portion in a longitudinal direction of the retainer.

To reduce a risk generated at a time of collision of a substrate with a retainer. According to one embodiment, a head for holding a polygonal substrate as a polishing object of a polishing apparatus is provided. The head includes a substrate holding surface configured to hold a substrate and a retainer positioned outside the substrate holding surface. The retainer has an end region. The end region is arranged adjacent to a corner portion of the substrate held onto the head. The end region has an end surface on a side of the substrate holding surface. The end surface is configured to increase in distance from the substrate holding surface with approaching an end portion in a longitudinal direction of the retainer.

In some embodiments, the present disclosure relates to a chemical mechanical planarization (CMP) tool. The CMP tool includes a carrier and a malleable membrane coupled to the carrier and having a lower surface facing away from the carrier. The lower surface of the malleable membrane includes a first malleable material within a central region of the lower surface and a second malleable material within a peripheral region of the lower surface, which surrounds the central region. The first malleable material provides the central region of the lower surface with a first stiffness and the second malleable material provides the peripheral region of the lower surface with a second stiffness that is different than the first stiffness.

In some embodiments, the present disclosure relates to a chemical mechanical planarization (CMP) tool. The CMP tool includes a carrier and a malleable membrane coupled to the carrier and having a lower surface facing away from the carrier. The lower surface of the malleable membrane includes a first malleable material within a central region of the lower surface and a second malleable material within a peripheral region of the lower surface, which surrounds the central region. The first malleable material provides the central region of the lower surface with a first stiffness and the second malleable material provides the peripheral region of the lower surface with a second stiffness that is different than the first stiffness.

A carrier head for chemical mechanical polishing includes a base, an actuator, a substrate mounting surface, and a retainer. The retainer includes an inner section and an outer section connected by a flexure. A bottom of the inner section of the retainer provides an inner portion of a lower surface configured to contact a polishing pad. An inner surface of the inner section extends upwardly from an inner edge of the lower surface to circumferentially surround the substrate mounting surface. The inner section of the retainer is positioned to receive a controllable load from the actuator and is vertically movable relative to the base. A bottom of the outer section of the retainer provides an outer portion of the lower surface. The outer section of the retainer is vertically fixed to the base. The inner section of the retainer is vertically movable relative to the outer section of the retainer.