Friction sensor for polishing system
AssigneeApplied Materials, Inc.
InventorsDominic J. Benvegnu, Bogdan Swedek
Life of this patent
Estimating the term…
Abstract
A system. method and apparatus to monitor a frictional coefficient of a substrate undergoing polishing is described. A polishing pad assembly includes a polishing layer including a polishing surface, and a substrate contacting member flexibly coupled to the polishing layer having a top surface to contact an exposed surface of a substrate. At least a portion of the top surface is substantially coplanar with the polishing surface. A sensor is provided to measure a lateral displacement of the substrate contacting member. Some embodiments may provide accurate endpoint detection during chemical mechanical polishing to indicate the exposure of an underlying layer.
Claims25
An apparatus to monitor a frictional coefficient of a substrate undergoing polishing, comprising:
- a support to hold a polishing article in contact with a substrate;
- a member having a surface to contact an exposed surface of the substrate, the member configured to be laterally displaced relative to the polishing article in response to a frictional force from the substrate;
- a first restorative material configured to apply a force on the member perpendicular to the exposed surface to bias the surface toward the exposed surface, the first restorative material configured to be laterally displaced relative to the polishing article in response to the lateral displacement of the member;
- a second restorative material configured to move in response to the lateral displacement of the member, the second restorative material configured to apply a lateral force on the member to bias the member toward a neutral lateral position relative to the polishing article;
- and
- a sensor mounted on the second restorative material, the sensor configured to generate a signal based on the movement of the second restorative material.
A chemical mechanical polishing apparatus, comprising:
- a support for a polishing article;
- a carrier to hold a substrate against a polishing surface of the polishing article;
- a motor coupled to at least one of the polishing article and carrier for generating relative motion there between;
- a member having a surface to contact an exposed surface of the substrate, the member configured to be laterally displaced relative to the polishing article in response to a frictional force from the substrate;
- a first restorative material configured to apply a force on the member perpendicular to the exposed surface to bias the surface toward the exposed surface, the first restorative material configured to be laterally displaced relative to the polishing article in response to the lateral displacement of the member;
- a second restorative material configured to move in response to the lateral displacement of the member, the second restorative material configured to apply a lateral force on the member to bias the member toward a neutral lateral position relative to the polishing article;
- and
- a sensor mounted on the second restorative material, the sensor configured to generate a signal based on the movement of the second restorative material.
A system to monitor a frictional coefficient of a substrate undergoing polishing, comprising:
- a polishing pad assembly including:
- a polishing article having a polishing surface;
- a support to hold the polishing article in contact with a substrate;
- a member having a surface to contact an exposed surface of the substrate, the member configured to be laterally displaced relative to the polishing article in response to a frictional force from the substrate;
- a first restorative material configured to apply a force on the member perpendicular to the exposed surface to bias the surface toward the exposed surface, the first restorative material configured to be laterally displaced relative to the polishing article in response to the lateral displacement of the member;
- and
- a second restorative material configured to move in response to the lateral displacement of the member, the second restorative material configured to apply a lateral force on the member to bias the member toward a neutral lateral position relative to the polishing article;
- and
- a sensor configured to generate a signal based on the movement of the second restorative material.
Dependencies are inferred from the claim text.