Methods and systems for reducing particulate deposition on photomask
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsJui Chieh Chen, Yi-Wei Lee
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Abstract
Particulate deposition rate on a photolithographic mask, particularly of tin (Sn) particles produced within an EUV light source, is reduced by producing turbulence within a radiation source chamber of the EUV light source. Turbulence can be produced by changing the temperature, pressure, and/or gas flow rate within the radiation source chamber. The turbulence reduces the number of particles exiting the EUV light source which could be deposited on the photomask.
Claims19
A method for reducing particulate deposition rate on a photomask, comprising:
- generating a plasma that emits EUV radiation in a radiation source chamber and also produces particulates;
- producing turbulence within the radiation source chamber by changing the temperature in the radiation source chamber between a first temperature setpoint and a second temperature setpoint, wherein the first temperature setpoint and the second temperature setpoint differ by at least 50° C.;
- and
- wherein the turbulence reduces a level of particulates exiting the radiation source chamber and entering a processing chamber containing the photomask.
A method for reducing particulate deposition rate on a photomask, comprising:
- generating a plasma that emits EUV radiation in a radiation source chamber and also produces particulates;
- producing turbulence within the radiation source chamber by changing the pressure in the radiation source chamber between a first pressure setpoint and a second pressure setpoint, wherein the first pressure setpoint and the second pressure setpoint differ by at least 10 pascals;
- and
- wherein the turbulence reduces a level of particulates exiting the radiation source chamber and entering a processing chamber containing the photomask.
A method for reducing particulate deposition rate on a photomask, comprising:
- generating a plasma that emits EUV radiation in a radiation source chamber and also produces particulates;
- producing turbulence within the radiation source chamber by changing the gas flow rate into the radiation source chamber of a target gas between a first gas flow rate setpoint and a second gas flow rate setpoint, wherein the first gas flow rate setpoint and the second gas flow rate setpoint differ by at least 0.5 slm;
- and
- wherein the turbulence reduces a level of particulates exiting the radiation source chamber and entering a processing chamber containing the photomask.
Dependencies are inferred from the claim text.