Reference wafer for high fidelity in-situ temperature metrology calibration
AssigneeLam Research Corporation
InventorsSongqi GAO, David S. L. MUI
Life of this patent
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Abstract
Systems, methods, and devices for in-situ calibration of a second sensor use a first sensor, with the two sensors operating in different optical regimes and/or based on different optical effects. In some embodiments, the methods employ a reference wafer having two regions that have different optical properties to calibrate a temperature sensor. Prior to the in-situ calibration, the first sensor is calibrated over a range of temperatures. During the in-situ calibration, the first sensor reads a first spot in the first region of the reference wafer and a second sensor reads a second spot in the second region that is close to the first spot.
Claims18
A reference wafer for calibrating sensors comprising:
- a semiconductor substrate having a first surface;
- an IR-emissive film on the first surface in a first region of the semiconductor substrate, wherein a second region of the first surface of the semiconductor surface is uncoated.
A method comprising:
- positioning a reference wafer in a chamber having a first sensor and a second sensor;
- obtaining temperature readings from the first sensor and the second sensor at a plurality of reference substrate temperatures;
- and
- using calibrated temperature information for the first sensor, obtain calibrated sensor information for the second sensor.
An apparatus comprising:
- a processing chamber housing a gas inlet and a substrate support configured to support a semiconductor substrate;
- a first sensor comprising a first emitter and a first detector, the first emitter and first detector located on the same side of the substrate support;
- a second sensor comprising a second emitter and a second detector, the first emitter and first detector located on different sides of the substrate support:
- and
- a controller capable of executing machine readable instructions to calibrate the second sensor using a reference substrate, the machine-readable instructions comprising instructions for:
- obtaining temperature readings from the first sensor and the second sensor at a plurality of reference substrate temperatures;
- and
- using calibrated temperature information for the first sensor, obtain calibrated sensor information for the second sensor.
Dependencies are inferred from the claim text.