Wafer polishing apparatus and method of detecting defect of retainer ring included in the wafer polishing apparatus

A wafer polishing apparatus comprising:

• a base support including a treatment region and a maintenance region;
• a polishing pad on the treatment region of the base support;
• a polishing head on an upper portion of the base support and configured to rotate;
• a polishing head support on the upper portion of the base support and connected to the polishing head, the polishing head support configured to rotate on the base support such that the polishing head is on at least one of the treatment region or the maintenance region of the base support;
• a retainer ring attached to a lower portion of the polishing head;
• an illumination device configured to provide light to at least a part of an inner surface of the retainer ring;
• and
• a camera device configured to capture an image of at least a part of the inner surface of the retainer ring while the polishing head rotates, wherein:
• the illumination device comprises an illumination housing, an illumination light source inside the illumination housing, an illumination lens inside the illumination housing and in front of the illumination light source, and
• an illumination cleaning liquid supply pipe connected to the illumination housing, and
• the illumination cleaning liquid supply pipe is configured to supply the cleaning liquid to a front surface of the illumination lens.

A wafer polishing apparatus comprising:

• a base support including a treatment region and a maintenance region;
• a polishing pad on the treatment region of the base support;
• a polishing head on an upper portion of the base support and configured to rotate;
• a polishing head support on the upper portion of the base support and connected to the polishing head, the polishing head support configured to rotate on the base support such that the polishing head is on at least one of the treatment region or the maintenance region of the base support;
• a retainer ring attached to a lower portion of the polishing head;
• a transfer plate on the maintenance region;
• an illumination device configured to provide light to at least a part of an inner surface of the retainer ring;
• a camera device configured to capture an image of at least a part of the inner surface of the retainer ring while the polishing head rotates, wherein
• the camera device includes a camera housing, a camera lens inside the camera housing, a cover ring on a front surface of the camera lens and configured to expose the camera lens, a camera cleaning liquid supply pipe connected to the cover ring and configured to supply a cleaning liquid to the front surface of the camera lens, a camera cleaning gas supply pipe connected to the cover ring and configured to provide cleaning gas to the front surface of the camera lens, and a protective cap coupled to the cover ring,
• the cover ring is coupled to the camera housing,
• the protective cap is configured to expose at least a part of the front surface of the camera lens and configured to provide a discharge passage of the cleaning gas,
• a cleaning liquid supply pump configured to supply the cleaning liquid to the camera cleaning liquid supply pipe;
• a cleaning gas supply pump configured to supply the cleaning gas to the cleaning gas supply pipe;
• and
• a controller is configured to control the cleaning liquid supply pump and the cleaning gas supply pump, wherein
• the camera device further comprises a camera cleaning liquid spray pipe connected to the camera cleaning liquid supply pipe,
• the camera cleaning liquid spray pipe is in the cover ring, and
• the camera cleaning liquid spray pipe has a spiral shape.