Apparatus for and method of control for spectrum separation
AssigneeCymer, Inc.
InventorGe Song
Life of this patent
Estimating the term…
Abstract
Apparatus for and methods of rapidly achieving a target peak wavelength separation in a system for producing laser radiation at more than one wavelength in which one or more actuators control wavelength in response to being supplied with a waveform. The characteristics of the waveform are determined using a model reference control system.
Claims25
A laser system comprising:
- a source of laser radiation, the laser radiation being fired in one or more bursts, each burst being made up of a plurality of pulses;
- a wavelength controller arranged to receive the pulses and to control a primary wavelength of some of the pulses toward a first value and to control a primary wavelength of others of the pulses toward a second value different from the first value by a target primary wavelength separation amount, the wavelength controller including at least one actuator operating in response to a control signal to effect wavelength control of the pulses;
- and
- a model reference adaptive control system adapted to generate the control signal based at least in part on a measured primary wavelength separation amount, to cause the wavelength controller to achieve the target primary wavelength separation amount.
2-6. (canceled)
A multifocal imaging photolithography system generating first wavelength pulses of deep ultraviolet radiation having a first primary wavelength and second wavelength pulses of deep ultraviolet radiation having a second primary wavelength differing from the first primary wavelength by a primary separation amount, the multifocal imaging photolithography system comprising:
- a wavelength controller arranged to receive input pulses of deep ultraviolet radiation and to control a primary wavelength of a first subset of the pulses to obtain the first wavelength pulses and to control a primary wavelength of a second subset of the input pulses to obtain the second wavelength pulses in response to a control signal;
- and
- a model reference adaptive control system adapted to generate the control signal based at least in part on a measured primary separation of wavelengths of the first wavelength pulses and the second wavelength pulses to cause the wavelength controller to achieve and maintain a target primary separation amount.
(canceled)
11-12. (canceled)
A system for controlling a wavelength of laser radiation being fired in one or more bursts, each burst being made up of a plurality of pulses, the system comprising:
- a wavelength controller arranged to receive the pulses and to control a primary wavelength of some of the pulses towards a first value and to control a primary wavelength of others of the pulses towards a second value different from the first value by a target primary wavelength separation amount, the wavelength controller including at least one actuator operating in response to a control signal to effect wavelength control of the pulses;
- and
- a model reference adaptive control system adapted to generate the control signal based at least in part on a measured primary separation amount to cause the wavelength controller to achieve the target primary separation amount.
16-17. (canceled)
A method of controlling a multifocal imaging photolithography system to generate first wavelength pulses of radiation having a first primary wavelength and second wavelength pulses of radiation having a second primary wavelength differing from the first primary wavelength by a primary separation amount, the method comprising:
- generating input pulses of laser radiation;
- using a wavelength controller to control a primary wavelength of a first subset of the input pulses to obtain the first wavelength pulses and to control a primary wavelength of a second subset of the input pulses to obtain the second wavelength pulses in response to a control signal;
- comparing a primary wavelength separation of the first wavelength pulses and the second wavelength pulses with a primary wavelength separation obtained from a reference model controlled by a reference signal to obtain an error signal;
- and
- modifying one or more parameters of the control signal at least partially on the basis of the error signal to cause a response of the wavelength controller to the control signal to track a response of the reference model to the reference signal.
(canceled)
Dependencies are inferred from the claim text.