Patent ID: 9162342
Filing Date: 2015-10-20
Classification: B24B

Abstract:
1. A carrier head unit using sucking force to fix a substrate, the carrier head unit comprising: a head main body that comprises a receiving space in a central portion thereof, the receiving space being opened downward to receive the substrate, a housing part in an edge thereof to surround a side portion of the receiving space, a main passage passing through the head main body to communicate with the receiving space, and a plurality of connecting holes passing through the housing part vertically; a retaining ring coupled to a bottom surface of the housing part of the head main body to close lower portions of the connecting holes; a cover coupled to a top surface of the head main body to close upper portions of the connecting holes; and a control unit comprising a pressure sensor sensing pressure within the main passage, and an alarm notifying a variation of the pressure sensed by the pressure sensor, wherein the control unit is configured to sense a coupling state between the head main body and the retaining ring in real time by sensing a variation in air pressure of the main passage measured by the pressure sensor as external air that is introduced into a space between the head main body and the retaining ring depending on a variation of the coupling state between the head main body and the retaining ring is introduced into the main passage through the plurality of connecting holes and the connecting passage.