Methods and apparatus for removing contamination from lithographic tool
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsZi-Wen Chen, Po-Chung Cheng, Chih-Tsung Shih, Li-Jui Chen, Shih-Chang Shih
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Abstract
Embodiments described herein provide a method for cleaning contamination from sensors in a lithography tool without requiring recalibrating the lithography tool. More particularly, embodiments described herein teach cleaning the sensors using hydrogen radicals for a short period while the performance drifting is still above the drift tolerance. After a cleaning process described herein, the lithography tool can resume production without recalibration.
Claims20
An apparatus for removing contamination from a lithographic tool, the apparatus comprising:
- a sensor that measures an amount of contamination formed on a radiation receiving surface over the sensor in a lithography tool;
- and
- a cleaning module that performs a cleaning session in the lithography tool when the sensor measures a relative radiation intensity reaches a threshold value, wherein the cleaning module includes a radical generator configured to provide radicals to the radiation receiving surface, wherein after the cleaning session, the sensor provides the sensor measurement without being recalibrated,
- wherein the sensor is a spot sensor mounted on a substrate stage in the lithography tool, and the sensor measurement includes the relative radiation intensity defined by a ratio of a radiation intensity measured by the spot sensor through the radiation receiving surface over a radiation intensity dispatched from a radiation source.
A cleaning device comprising:
- semiconductor substrates sequentially patterning by a lithography tool while monitoring a sensor measurement of a sensor in the lithography tool;
- and
- the cleaning device that performs a cleaning session in the lithography tool when the sensor measurement including a relative radiation intensity reaches a threshold value;
- and
- the semiconductor substrates resuming patterning by the lithography tool, wherein during resuming patterning the semiconductor substrates, the sensor provides the sensor measurement without being recalibrated after the cleaning session,
- wherein the sensor is a TIS (transmission image sensor) sensor mounted on a substrate stage in the lithography tool, and the sensor measurement includes the relative radiation intensity measured by the TIS sensor.
A lithography tool, comprising:
- a housing defining an inner volume;
- a substrate stage configured to secure and move a substrate in the inner volume;
- a sensor mounted on the substrate stage, wherein the sensor includes an outer surface configured to receive radiation;
- a radical generator configured to deliver radicals to the inner volume;
- and
- a controller communicatively coupled to the sensor and the radical generator, the controller being configured to:
- monitor a sensor measurement from the sensor indicative of an amount of contamination formed on the outer surface of the sensor;
- and
- cause the radical generator to perform a cleaning session when the sensor measurement reaches a threshold value, the cleaning session comprising providing radicals from the radical generator to the outer surface of the sensor, the sensor being operable to provide the sensor measurement after the cleaning without recalibration,
- wherein the sensor is selected from a group consisting of a TIS (transmission image sensor) sensor, a spot sensor, and an ILIAS (integrated lens interferometer at scanner) sensor mounted on a substrate stage in the lithography tool.
Dependencies are inferred from the claim text.