Energy compensation module for light source devices

Abstract

This relates to an energy compensation module for light source devices. [Solution] A system for deep ultraviolet (DUV) photolithography includes a light source device comprising N optical oscillators, where N is an integer of 2 or more, and each of the N optical oscillators is configured to generate a pulse of light in response to an excitation signal; and a control system coupled to the light source device. The control system is configured to determine a corrected excitation signal for a first of the N optical oscillators based on an input signal, the input signal comprising the energy characteristics of a pulse of light generated by another of the N optical oscillators.

Claims

1. A system for deep ultraviolet (DUV) photolithography, A light source device comprising N optical oscillators, where N is an integer of 2 or more, and each of the N optical oscillators is configured to generate a pulse of light in response to an excitation signal, A control system coupled to the light source device, configured to determine a corrected excitation signal for a first of the N optical oscillators based on an input signal, wherein the input signal includes the energy characteristics of a pulse of light generated by another of the N optical oscillators. A system that includes this.

2. The system according to claim 1, wherein the control system is configured to determine the corrected excitation signal, which includes the control system being configured to apply a filter to the input signal to generate a filtered input signal, the excitation signal being the filtered input signal.

3. The system according to claim 2, wherein the filter includes a notch filter that transmits information having frequencies within a first frequency band and substantially blocks information having frequencies outside the first frequency band.

4. The light source device generates an exposure light beam, Each of the N optical oscillators emits a pulse of light at a certain repetition rate. All of the aforementioned N optical oscillators have the same repetition rate. The system according to claim 3, wherein the exposure light beam includes pulses of light from each of the N optical oscillators, which are temporally separated from each other.

5. The system according to claim 3, wherein the filter generates an output based on the input signal and an energy error value, and the control system is configured to determine the corrected input signal based on the output of the filter and the initial input signal.

6. The system according to claim 5, wherein the filter includes a Kalman filter.

7. The system according to claim 3, wherein the control system is further configured to apply feedforward correction to the initial input signal before determining the corrected input signal.

8. The system according to claim 7, wherein the feedforward correction signal is determined based on a first modeled relationship between the energy of the generated light pulse and the excitation amount of the first of the N optical amplifiers, and a second modeled relationship between the energy of the generated light pulse and the excitation amount of the second of the N optical amplifiers.

9. The system according to claim 8, wherein the excitation mechanism in each of the N optical oscillators includes a set of electrodes, the first modeled relationship includes a linear relationship relating the amount of voltage applied to the electrodes of the first of the N optical amplifiers to the energy of the generated light pulses, and the second modeled relationship includes a linear relationship relating the amount of voltage applied to the electrodes of the first of the N optical amplifiers to the energy of the generated light pulses.

10. The system according to claim 9, further comprising a scanner device configured to receive an exposure light beam from the light source device, wherein the control system is implemented as part of the scanner device so that the scanner device provides the corrected excitation signal to the first of the N optical oscillators.

11. The system according to claim 1, further comprising a beam combiner configured to receive light pulses from any of the N optical oscillators and direct the received light pulses as an exposure light beam towards a scanner device.

12. The system according to claim 11, wherein the energy characteristics include a measurement criterion based on optical energy measurements obtained by the scanner device.

13. The system according to claim 1, wherein the energy characteristics include an energy error.

14. The system according to claim 1, wherein the light pulse generated by the other of the N optical oscillators is a first light pulse of the exposure light beam, and the light pulse formed by the first of the N optical oscillators in response to the application of the excitation signal is a second pulse of the exposure light beam, and the second pulse and the first pulse are continuous pulses.

15. A method for deep ultraviolet (DUV) photolithography, The energy error is determined based on the amount of energy of a light pulse emitted from a first of N optical oscillators and received by a scanner device, where N is an integer of 2 or more, and the energy error is the difference between the amount of energy of the light pulse and the target energy. Receiving an initial input signal, wherein the initial input signal is based on the energy error, Based on the initial input signal, a corrected input signal is determined, The corrected input signal is applied to the excitation mechanism of the second of the N optical oscillators, A method that includes this.

16. The method according to claim 15, wherein determining the corrected input signal based on the initial input signal includes filtering the initial input signal.

17. The method according to claim 16, wherein filtering the initial input signal includes applying a notch filter to the initial input signal.

18. The method according to claim 16, wherein filtering the initial input signal includes providing the initial input signal and the energy error to a Kalman filter.

19. The method according to claim 16, wherein filtering the initial input signal includes applying feedforward correction to the initial input signal.

20. The method according to claim 16, wherein the initial input signal is received from a scanner device configured to receive an exposure light beam generated by a plurality of the N optical oscillators.

21. It is a system, A light source device, An optical oscillator configured to generate pulses of light in response to an excitation signal, and A light source device including a spectral adjustment device configured to control the spectral characteristics of the light pulses, A control system coupled to the light source device, configured to determine a corrected excitation signal that adjusts the energy of subsequently generated light pulses, taking into account changes in the configuration of the spectral adjustment device, A system that includes this.

22. The optical oscillator is associated with a plurality of transfer functions, each transfer function being associated with a specific configuration of the spectral tuning device. The system according to claim 21, wherein the control system is configured to determine the corrected excitation signal based on the transfer function associated with the particular configuration of the spectral tuning device used to generate the subsequent pulses of light.

23. The system according to claim 22, wherein the spectral adjustment device includes at least one prism, and each transfer function is associated with a different position of the at least one prism.

24. The system according to claim 23, wherein the spectral characteristics include the central wavelength of the light pulse.

25. The system according to claim 21, wherein each component of the spectral adjustment device is associated with a specific value of the spectral characteristics.

26. The system according to claim 25, wherein each component of the spectral adjustment device is associated with specific values ​​of the central wavelength and bandwidth of the light pulse.

27. The system according to claim 21, wherein the light source device further includes a power amplifier that receives a seed light beam from the optical oscillator, and the system is configured for use in a deep ultraviolet (DUV) lithography system.

28. It is a method, To provide a first excitation signal to an optical oscillator associated with a spectral adjustment device in a first configuration state, thereby generating a first light pulse having a first value of spectral characteristics, Adjusting the spectrum adjustment device to a second configuration state, When the spectral adjustment device is in the second configuration state, the corrected excitation signal is determined based on the energy characteristics of the first light pulse and the transfer function of the optical oscillator. The spectral adjustment device provides the corrected excitation signal to the optical oscillator while it is in the second configuration state to generate a second light pulse having the second value of the spectral characteristics, A method that includes this.

29. The method according to claim 28, wherein the second light pulse has a second value of the energy characteristic, the second value being substantially equal to the first value of the energy characteristic.

30. A method for controlling a light source device to generate a pulsed light beam having at least two spectral peaks separated by a certain spectral distance, The method involves generating a first light pulse from the light source device, wherein the first light pulse has a first wavelength and a first value of energy characteristics. Adjusting at least one component of the light source device, wherein the at least one component is configured to control the spectral characteristics of the light emitted from the light source device. Determining the corrected excitation signal, After adjusting the at least one component to generate a second light pulse from the light source device, the corrected excitation signal is applied to the light source device, wherein the second light pulse has a second wavelength and the first value of the energy characteristic, the pulsed light beam includes at least the first light pulse and the second light pulse, and the spectral distance is the difference between the first wavelength and the second wavelength. A method that includes this.

31. The light source device includes a single optical oscillator, and adjusting the at least one component of the light source device includes adjusting the spectral adjustment device of the single optical oscillator from a first configuration to a second configuration. The aforementioned single optical oscillator is associated with a plurality of transfer functions, each of which corresponds to a specific configuration state of the spectral tuning device. The method according to claim 30, wherein the corrected excitation signal is determined based on the transfer function corresponding to the second configuration state of the spectral adjustment device.

32. The method according to claim 31, wherein adjusting the spectral adjustment device includes operating a dispersive optical element.

33. The light source device includes N optical oscillators, each of which is associated with a transfer function relating to excitation energy and generation energy, and the first of the N optical oscillators generates the first light pulse. Adjusting the at least one component of the light source device includes switching from the first of the N optical oscillators to the second of the N optical oscillators so that the second of the N optical oscillators generates the second pulse of light. The method according to claim 30, wherein the corrected excitation signal is determined based on the transfer function of the second of the N optical oscillators.

34. A control module for a light source device, The light source device is made to generate a first light pulse from the light source device, and the first light pulse has a first wavelength and a first value of energy characteristics. The light source device is configured to adjust at least one component, the at least one component being configured to control the spectral characteristics of the light emitted from the light source device. Determine the corrected excitation signal, After the at least one component is adjusted to generate a second light pulse from the light source device, the corrected excitation signal is applied to the light source device, the second light pulse having a second wavelength and the first value of the energy characteristic, the pulsed light beam comprising at least the first light pulse and the second light pulse, and the spectral distance being the difference between the first wavelength and the second wavelength. A control module configured in such a way.

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