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

Claim 0:
1. 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 a first 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 plurality of expected slip sensor values based on the first signal when the CMP system is in the steady-state condition,
receive a second signal from the slip sensor during CMP polishing,
compare the second signal received from the slip sensor to the expected slip sensor values, and
detect wafer slip in response to the second signal received from the slip sensor during the CMP polishing differing from the expected slip sensor values by more than a threshold value.