US Patent 10186402 Measurement system and measurement method

A measurement system for measuring a consumption amount of a focus ring in a plasma etching apparatus including a processing chamber, a lower electrode and the focus ring surrounding a periphery of the lower electrode, comprises a sensor substrate having a distance sensor and a measurement unit configured to measure a consumption amount of the focus ring. The measurement unit includes a transfer instruction unit, an acquisition unit and a measurement unit. The transfer instruction unit is configured to instruct a transfer unit to transfer the sensor substrate into the processing chamber. The acquisition unit is configured to acquire information on a physical amount corresponding to a distance from the distance sensor to the focus ring, which is measured by the distance sensor. The measurement unit is configured to measure a consumption amount of the focus ring based on the acquired information on the physical amount.