Patent ID: 11920928
Assignee: TOKYO ELECTRON LIMITED
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. A system for correcting an optical path length measurement error, the system comprising:
a light source configured to generate light;
a first optical unit configured to emit the light to a measurement target object and receive first interference light incident from the measurement target object;
a second optical unit configured to emit the light to a reference object configured to have a constant optical path length with respect to a temperature fluctuation and receive second interference light incident from the reference object;
a spectroscope connected to the first optical unit and the second optical unit and configured to receive the first interference light and the second interference light to be incident; and
a control unit connected to the spectroscope,
wherein the control unit
calculates a fluctuation rate of a measurement optical path length with respect to a reference optical path length under a predetermined temperature environment on the basis of the optical path length of the reference object calculated on the basis of the second interference light incident on the spectroscope under the predetermined temperature environment, and the reference optical path length of the reference object acquired in advance, and
corrects, on the basis of the fluctuation rate, the optical path length of the measurement target object calculated on the basis of the first interference light incident on the spectroscope under the predetermined temperature environment.