Patent ID: 11904431
Assignee: AXUS TECHNOLOGY, LLC
Field: Machine tools (Mechanical engineering)
Classification: CPC B  H | IPC B  H

Claim 9:
10. A chemical mechanical planarization (CMP) system, comprising:
a carrier configured to retain a substrate;
a platen supporting a polishing pad;
a slip sensor configured to generate a signal indicative of a characteristic of a surface of the polishing pad; and
a processor configured to:
start polishing the substrate,
determine that the CMP system is in a steady-state condition that substantially represents a steady-state of the characteristic of the surface of the polishing pad experienced during polishing the substrate,
receive the signal from the slip sensor over a defined length of time in response to determining that the CMP system is in the steady-state condition,
obtain a set of expected sensor values based on the signal when the CMP system is in the steady-state condition,
compare the signal received from the slip sensor to the set of expected sensor values during CMP polishing, and
detect wafer slip in response to the signal received from the slip sensor during the CMP polishing differing from the set of expected sensor values by more than a threshold value.