EUV light generation system and electronic device manufacturing method

An extreme ultraviolet (EUV) light generation system configured to generate EUV light by irradiating a target with pulse laser light to turn the target into plasma, the EUV light generation system comprising:

• a chamber;
• a target supply device configured to supply the target to a plasma generation region in the chamber;
• a laser device configured to output the pulse laser light;
• a beam sensor configured to measure one of a position and an angle of an optical axis of the pulse laser light as a first optical characteristic;
• a first reflection control mirror whose angle is controlled so that the first optical characteristic becomes a first target value;
• and
• a processor configured to control the laser device so that the target is irradiated with the pulse laser light;
• the processor being configured to repeatedly calculate, at a plurality of time points, a first corrected angle based on a first attenuation curve defined by the angle of the first reflection control mirror at an end of an immediately preceding irradiation period, the angle of the first reflection control mirror at a cold state, an elapsed time from a start of the pause period, and a first time constant, and to repeatedly change the angle of the first reflection control mirror to the first corrected angle, during a pause period in which output of the pulse laser light is stopped,
• wherein the first time constant includes a plurality of time constants τ1i, and
• assuming that the angle of the first reflection control mirror at the end of the immediately preceding irradiation period is Mc1, the angle of the first reflection control mirror at the cold state is Mi1, the elapsed time is t, the first corrected angle is 01, and a contribution coefficient of the time constant τ1i is Ci, the first attenuation curve is expressed by the following expression (2)
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• θ
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• M
• c
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• M
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An extreme ultraviolet (EUV) light generation system configured to generate EUV light by irradiating a target with pulse laser light to turn the target into plasma, the EUV light generation system comprising:

• a chamber;
• a target supply device configured to supply the target to a plasma generation region in the chamber;
• a laser device configured to output the pulse laser light;
• a beam sensor configured to measure one of a position and an angle of an optical axis of the pulse laser light as a first optical characteristic;
• a first reflection control mirror whose angle is controlled so that the first optical characteristic becomes a first target value;
• and
• a processor configured to control the laser device so that the target is irradiated with the pulse laser light;
• the processor being configured to calculate a first corrected angle based on a first attenuation curve defined by the angle of the first reflection control mirror at an end of an immediately preceding irradiation period, the angle of the first reflection control mirror at a cold state, an elapsed time from a start of the pause period, and a first time constant, and to change the angle of the first reflection control mirror to the first corrected angle, during a pause period in which output of the pulse laser light is stopped,
• wherein, assuming that the angle of the first reflection control mirror at the end of the immediately preceding irradiation period is Mc1, the angle of the first reflection control mirror at the cold state is Mi1, the elapsed time is t, the first time constant is τ1, and the first corrected angle is θ1, the first attenuation curve is expressed by the following expression (1),
• [
• Expression
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• 1
• ]
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• θ
• 1
• =
• M
• c
• ⁢
• 1
• +
• (
• M
• i
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• 1
• -
• M
• c
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• 1
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• ×
• (
• 1
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• t
• /
• τ
• 1
• )
• .
• (
• 1
• )