Method for adjusting spectral line width and method for manufacturing electronic device

Abstract

The invention provides a spectral line width adjusting method and an electronic device manufacturing method. The spectral line width adjustment method includes: a first step of adjusting at least one of a timing of a first trigger signal that amplifies a portion of a first pulse laser beam and converts the amplified portion into a second pulse laser beam and a timing of a second trigger signal that amplifies a portion of a second continuous light and converts the amplified portion into a third pulse laser beam; a first spectrum in which the spectrum of a fourth pulse laser beam obtained by sum-frequency mixing the second pulse laser beam and the third pulse laser beam is adjusted to a non-Gaussian shape; and a second step in which a modulation signal generator generates a modulation signal of the same mode synchronized with the light emission trigger signal, and supplies the modulation signal of the same mode to the optical phase modulator, thereby modulating the wavelength of the second continuous light for a time corresponding to one pulse of the third pulse laser light, and outputting the second continuous light. The spectrum of the fourth pulse laser light is adjusted to a second spectrum having a spectral line width wider than the first spectrum.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a method of adjusting spectral line width and a method of manufacturing an electronic device. BACKGROUND

[0002] In recent years, in a semiconductor exposure apparatus, with miniaturization and high integration of semiconductor integrated circuits, improvement of resolution is required. Therefore, shortening of the wavelength of light emitted from an exposure light source has been developed. For example, as a gas laser device for exposure, a KrF excimer laser device which outputs laser light having a wavelength of about 248 nm, and an ArF excimer laser device which outputs laser light having a wavelength of about 193 nm are used.

[0003] The spectral line width of the natural oscillation light of the KrF excimer laser device and the ArF excimer laser device is wide, and is 350 to 400 pm. Therefore, when a projection lens is configured using a material which transmits ultraviolet rays such as KrF and ArF laser light, chromatic aberration sometimes occurs. As a result, the resolution can be reduced. Therefore, it is necessary to narrow the spectral line width of laser light output from the gas laser device to such an extent that chromatic aberration can be ignored. Therefore, in the laser resonator of the gas laser device, in order to narrow the spectral line width, a line narrowing module (LNM) which includes a line narrowing element (etalon, grating, etc.) is sometimes provided. Hereinafter, the gas laser device whose spectral line width is narrowed is referred to as a line narrowed gas laser device.

[0004] Patent Literature 1: International Publication No. WO2024 / 057673

[0005] Patent Literature 2: Japanese Patent Application Publication No. 2010-238684 SUMMARY

[0006] The spectrum width adjustment method of one aspect of the present disclosure is a spectrum width adjustment method of pulsed laser light output from a laser device having: a first semiconductor laser that emits first continuous light; a first amplifier that amplifies a portion of the first continuous light in synchronization with a light emission trigger signal received from an external device to convert it into first pulsed laser light; a second amplifier that amplifies a portion of the first pulsed laser light in accordance with a first trigger signal generated in synchronization with the light emission trigger signal to convert it into second pulsed laser light; a second semiconductor laser that emits second continuous light; a third amplifier that amplifies a portion of the second continuous light in accordance with a second trigger signal generated in synchronization with the light emission trigger signal to convert it into third pulsed laser light; an optical phase modulator disposed on an optical path of the second continuous light between the second semiconductor laser and the third amplifier; a modulation signal generator that outputs a modulation signal provided to the optical phase modulator; and a wavelength conversion system that performs sum frequency mixing of the second pulsed laser light and the third pulsed laser light to convert a wavelength, outputting fourth pulsed laser light, wherein the spectrum width adjustment method includes: a first step of adjusting at least one of a timing of the first trigger signal and a timing of the second trigger signal to adjust a spectrum of the fourth pulsed laser light into a first spectrum that is a non-Gaussian shape; and a second step of causing the modulation signal generator to generate a modulation signal of the same pattern in synchronization with the light emission trigger signal, providing the modulation signal of the same pattern to the optical phase modulator, thereby modulating a wavelength of the second continuous light within a time corresponding to one pulse of the third pulsed laser light, and adjusting the spectrum of the fourth pulsed laser light into a second spectrum having a spectrum width wider than the first spectrum.

[0007] Another aspect of this disclosure discloses a method for manufacturing an electronic device comprising the steps of: generating a fourth pulsed laser using a laser device, outputting the fourth pulsed laser to an exposure device, and exposing the fourth pulsed laser on a photosensitive substrate within the exposure device to manufacture the electronic device. The laser device comprises: a first semiconductor laser emitting a first continuous light; a first amplifier that amplifies a portion of the first continuous light synchronously with a light emission trigger signal received from an external device and converts it into a first pulsed laser; a second amplifier that amplifies a portion of the first pulsed laser according to a first trigger signal generated synchronously with the light emission trigger signal and converts it into a second pulsed laser; a second semiconductor laser emitting a second continuous light; and a third amplifier that amplifies a portion of the second continuous light according to a second trigger signal generated synchronously with the light emission trigger signal and converts it into a third pulsed laser. An optical phase modulator is configured in the optical path of a second continuous light between a second semiconductor laser and a third amplifier; a modulation signal generator outputs a modulation signal to the optical phase modulator; and a wavelength conversion system performs sum-frequency mixing of the second and third pulsed lasers to convert the wavelength and output a fourth pulsed laser. The laser device adjusts at least one of the timing of a first trigger signal and the timing of a second trigger signal to adjust the spectrum of the fourth pulsed laser to a first spectrum with a non-Gaussian shape. The laser device causes the modulation signal generator to generate a modulation signal of the same mode synchronized with the emission trigger signal and provides the modulation signal of the same mode to the optical phase modulator. Thus, the wavelength of the second continuous light is modulated within a time equivalent to one pulse of the third pulsed laser, and the spectrum of the fourth pulsed laser is adjusted to a second spectrum with a spectral width wider than the first spectrum. Attached Figure Description

[0008] Hereinafter, several embodiments of the present disclosure will be described by way of example only, with reference to the accompanying drawings.

[0009] Figure 1 The structure of the comparative example laser device is shown in general.

[0010] Figure 2 The structure of the solid seed source is shown in outline.

[0011] Figure 3 An example of a pseudo-random signal generator is shown.

[0012] Figure 4 A flowchart showing the control example of spectral linewidth in the comparative example is presented.

[0013] Figure 5 A flowchart showing another example of spectral linewidth control in the comparative example is shown.

[0014] Figure 6 The structure of the laser device of Embodiment 1 is shown in general.

[0015] Figure 7 The structure of the solid seed source is shown schematically.

[0016] Figure 8 A timing chart at the time of laser operation execution is shown.

[0017] Figure 9 A flowchart at the time of timing adjustment is shown.

[0018] Figure 10 A flowchart of the first step of Embodiment 1 is shown.

[0019] Figure 11 A timing chart in the first step is shown.

[0020] Figure 12 A spectrum of the fourth pulse laser in the adjustment of the first step is shown.

[0021] Figure 13 A determination example of a non-Gaussian waveform is shown.

[0022] Figure 14 A flowchart of the second step is shown.

[0023] Figure 15 A spectrum of the fourth pulse laser after the search of the second step is shown.

[0024] Figure 16 A flowchart of the first step of Embodiment 2 is shown.

[0025] Figure 17 A spectrum of the fourth pulse laser in the adjustment of the first step is shown.

[0026] Figure 18 A spectrum of the fourth pulse laser after the search of the second step is shown.

[0027] Figure 19 A flowchart of the first step of Embodiment 3 is shown.

[0028] Figure 20 A spectrum of the fourth pulse laser in the adjustment of the first step is shown.

[0029] Figure 21 A spectrum of the fourth pulse laser after the search of the second step is shown.

[0030] Figure 22 A structure example of the exposure apparatus is shown schematically. DETAILED DESCRIPTION

[0031] - TABLE OF CONTENTS - 1. COMPARATIVE EXAMPLE

[0032] 1.1 LASER DEVICE

[0033] 1.1.1 STRUCTURE

[0034] 1.1.2 Action

[0035] 1.2 Structure of Pseudo-random Signal Generator

[0036] 1.3 Example 1 of Action of Pseudo-random Signal Generator

[0037] 1.4 Action / Effect

[0038] 1.5 Example 2 of Action of Pseudo-random Signal Generator

[0039] 1.6 Action / Effect

[0040] 1.7 Problem

[0041] 2. Embodiment 1

[0042] 2.1 Structure

[0043] 2.1.1 Laser Device

[0044] 2.1.2 Solid Seed Source

[0045] 2.2 Action

[0046] 2.2.1 When Laser Operation Execution

[0047] 2.2.2 When Adjustment

[0048] 2.2.2.1 First Step

[0049] 2.2.2.2 Second Step

[0050] 2.3 Action / Effect

[0051] 3. Embodiment 2

[0052] 3.1 Structure

[0053] 3.2 Action

[0054] 3.3 Action / Effect

[0055] 4. Embodiment 3

[0056] 4.1 Structure

[0057] 4.2 Action

[0058] 4.3 Action / Effect

[0059] 5. Method for Manufacturing Electronic Device

[0060] 6. Others

[0061] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The embodiments described below show several examples of the present disclosure, and do not limit the present disclosure. Furthermore, the structures and actions described in each of the embodiments are not necessarily all the structures and actions essential to the present disclosure. In addition, the same reference numerals are assigned to the same structural elements, and repeated description is omitted.

[0062] 1. Comparative Example

[0063] 1.1 Laser Apparatus

[0064] 1.1.1 Structure

[0065] Figure 1 The structure of the laser apparatus 10 of the comparative example is schematically shown. The comparative example of the present disclosure is in a manner recognized only by the applicant, and is not a publicly known example admitted by the applicant himself or herself.

[0066] The laser apparatus 10 has a solid seed source 20 as a master oscillator (MO) that generates pulsed laser light, an excimer amplifier 30 as a power amplifier (PA) that amplifies the output light of the solid seed source 20, a monitor module 40, an output shutter 46, and a laser control processor 50.

[0067] The solid seed source 20 outputs pulsed laser light having a center wavelength of about 193.4 nm.

[0068] The excimer amplifier 30 includes a cell 31, a pulse power module (PPM) 32, a charger 33, a convex mirror 34, and a concave mirror 35. The cell 31 includes windows 36a, 36b, a pair of electrodes 37a, 37b, and an electrically insulating member 38. An ArF laser gas is supplied from a gas supply device not shown into the cell 31. The ArF laser gas includes Ar gas, F2 gas, and Ne gas.

[0069] The PPM 32 includes a switch 39 and a charging capacitor not shown. The charger 33 holds electric energy for supply to the PPM 32. The charger 33 is connected to the charging capacitor not shown. The charger 33 charges the charging capacitor of the PPM 32 in accordance with an instruction from the laser control processor 50.

[0070] The PPM 32 is connected to the electrode 37b inside the cell 31 via a feedthrough in the electrically insulating member 38. The electrode 37a is connected to a ground potential.

[0071] The windows 36a, 36b are configured so that pulsed laser light amplified by excitation by discharge between the electrodes 37a, 37b passes therethrough.

[0072] The convex mirror 34 and the concave mirror 35 are configured so that the pulsed laser output from the solid seed source 20 passes three times through the discharge space between the electrodes 37a, 37b and the beam is enlarged.

[0073] The monitor module 40 includes beam splitters 41, 42, a spectrum monitor 43, and a light sensor 44. The beam splitter 41 is disposed in the optical path of the pulsed laser output from the excimer amplifier 30 so that the pulsed laser reflected at the beam splitter 41 is incident on the beam splitter 42. In addition, the beam splitter 41 can also be disposed outside the monitor module 40.

[0074] The beam splitter 42 is configured so that the pulsed laser reflected at the beam splitter 42 is incident on the spectrum monitor 43, and the pulsed laser transmitted through the beam splitter 42 is incident on the light sensor 44.

[0075] The spectrum monitor 43 monitors the spectrum of the incident pulsed laser and detects the oscillation wavelength of the incident pulsed laser. The spectrum monitor 43 can be, for example, an etalon spectrometer or the like. The etalon spectrometer includes a diffusion plate that diffuses the sampling light, an etalon, a condenser lens disposed on the emission side of the etalon, and a photodiode array disposed on the focal plane of the condenser lens in order to detect the pattern of interference fringes, and by measuring the diameter of the interference fringes, the wavelength can be detected.

[0076] The light sensor 44 detects the pulse energy of the incident pulsed laser. The light sensor 44 can be, for example, a photodiode or the like.

[0077] An emission exit shutter 46 is disposed in the optical path of the pulsed laser output from the laser device 10 to the outside, and is configured to be able to switch between outputting the pulsed laser to the outside and blocking. The pulsed laser transmitted through the beam splitter 41 is emitted from the laser device 10 via the emission exit shutter 46.

[0078] The laser device 10 is connected to an exposure device 60 via a beam delivery unit (BDU) not shown. The BDU is an optical system that delivers the pulsed laser from the laser device 10 to the exposure device 60. The pulsed laser emitted from the laser device 10 is incident on the exposure device 60 via the BDU.

[0079] The exposure device 60 includes an exposure control processor 61. The exposure control processor 61 controls the exposure device 60. In addition, the exposure control processor 61 is connected to the laser control processor 50. The exposure device 60 is an example of the "external device" in the present disclosure.

[0080] The laser control processor 50 receives the target center wavelength, the target line width, the target pulse energy, and the light emission trigger signal from the exposure control processor 61. In addition, the laser control processor 50 transmits the trigger A signal and the charging voltage value to the excimer amplifier 30, and transmits the trigger B signal, the line width control signal, the temperature value, and the current value to the solid seed source 20, and causes the laser device 10 to act, and controls the pulsed laser. In the present specification, the processor is a processing device including a storage device in which a control program is stored, and a CPU (Central Processing Unit) that executes the control program. The processor is specially constituted or programmed in order to execute various processes included in the present disclosure.

[0081] Figure 2 The structure of the solid seed source 20 is schematically shown. The solid seed source 20 includes a first solid laser device 100, a second solid laser device 110, a dichroic mirror 130, a wavelength conversion system 140, a pseudo-random signal generator 150, and a solid seed source control processor 160.

[0082] The solid seed source 20 is a system structure in which the pulsed laser of which the wavelength is about 1554 nm output from the first solid laser device 100 and the pulsed laser of which the wavelength is about 257.6 nm output from the second solid laser device 110 are converted into the pulsed laser of which the wavelength is about 193.4 nm by 2nd harmonic generation in the wavelength conversion system 140.

[0083] The first solid laser device 100 includes a semiconductor laser system 101 and a solid amplifier 102. The semiconductor laser system 101 includes a first semiconductor laser that oscillates in a single longitudinal mode at a wavelength of about 1554 nm in a CW (Continuous Wave) manner, and emits a first continuous light.

[0084] The solid amplifier 102 can be an OPA (Optical Parametric Amplifier). The OPA is, for example, a PPLN (periodically poled lithium niobate), a PPKTP (periodically poled KTP).

[0085] The solid amplifier 102 is configured to pulse-amplify the seed light by the pulsed laser of which the wavelength is 1030 nm as a pump light and the laser output from the semiconductor laser system 101 as the seed light.

[0086] The second solid laser device 110 includes a semiconductor laser system 111, an optical phase modulator 112, a solid amplifier 113, two nonlinear crystals, i.e., an LBO crystal 114 and a CLBO crystal 115, which perform second harmonic generation twice and perform wavelength conversion so that the optical frequency becomes four times, and a dichroic mirror 116. "LBO" is represented by the chemical formula LiB3O5. "CLBO" is represented by the chemical formula CsLiB6O 10 is represented.

[0087] The semiconductor laser system 111 includes a second semiconductor laser that performs CW oscillation of light having a wavelength of approximately 1030 nm in a single longitudinal mode and emits second continuous light.

[0088] The solid amplifier 113 can be configured to include a Yb optical fiber amplifier, a Yb:YAG crystal, for example. The solid amplifier 113 can also be the same structure as the solid amplifier 102.

[0089] The optical phase modulator 112 is disposed on an optical path between the semiconductor laser system 111 and the solid amplifier 113.

[0090] The dichroic mirror 116 is disposed on an optical path between the LBO crystal 114 and the CLBO crystal 115, transmits pulsed laser light having a wavelength of approximately 515 nm with high transmittance, and reflects pulsed laser light having a wavelength of approximately 1030 nm with high reflectance. The dichroic mirror 116 is configured so that the pulsed laser light having a wavelength of approximately 1030 nm, which is reflected with high reflectance, is incident as pump light of the solid amplifier 102. Instead of the dichroic mirror 116, a beam splitter, not shown, can be disposed between the solid amplifier 113 and the LBO crystal 114, and the pulsed laser light emitted from the solid amplifier 113 can be branched so as to be incident to the LBO crystal 114 and the solid amplifier 102, respectively.

[0091] The dichroic mirror 130 is configured to reflect pulsed laser light having a wavelength of approximately 1554 nm, which is output from the first solid laser device 100, with high reflectance, and to transmit pulsed laser light having a wavelength of approximately 257.6 nm, which is output from the second solid laser device 110, with high transmittance, and is configured so that the two kinds of pulsed laser light are coaxially incident to the wavelength conversion system 140.

[0092] The wavelength conversion system 140 includes a CLBO crystal 141 and a CLBO crystal 142, and a rotation stage 143 and a rotation stage 144. The CLBO crystal 141 and the CLBO crystal 142 are disposed above the rotation stage 143 and the rotation stage 144, respectively, which include piezoelectric elements, and are configured so that the incident angle of each crystal can be changed at high speed.

[0093] The pseudo-random signal generator 150 outputs a modulation signal that is supplied to the optical phase modulator 112. The pseudo-random signal generator 150 is configured to output a modulation signal that is a pseudo-random signal having a frequency of approximately 100 MHz, for example. Figure 2A multi-stage shift register and a variable band filter (digital filter) not shown in the figure are constituted.

[0094] The solid seed source control processor 160 controls the wavelength, power, pulse waveform, spectrum, etc. of the laser light output from the solid seed source 20. The solid seed source control processor 160 controls the 1st solid laser device 100, the 2nd solid laser device 110, the dichroic mirror 130, the wavelength conversion system 140, and the pseudo-random signal generator 150 based on the input from the laser control processor 50.

[0095] 1.1.2 Action

[0096] In the solid seed source 20, the wavelength of the pulsed laser light output from the 2nd solid laser device 110 is fixed, and the wavelength of the pulsed laser light output from the 1st solid laser device 100 is changed for each pulse, whereby the wavelength of the pulsed laser light output from the wavelength conversion system 140 can be changed.

[0097] The action of the 2nd solid laser device 110 is described below. The solid seed source control processor 160 fixes the oscillation wavelength of the 2nd solid laser device 110 at 1030 nm. That is, the solid seed source control processor 160 makes the current value of the 2nd semiconductor laser in the semiconductor laser system 111 constant, and makes the 2nd semiconductor laser continuously oscillate, and outputs CW laser light from the 2nd semiconductor laser.

[0098] The CW laser light output from the semiconductor laser system 111 is phase-modulated by the optical phase modulator 112, and is incident on the solid amplifier 113.

[0099] The solid seed source control processor 160 sends a timing signal identical to the trigger B signal acquired from the laser control processor 50 and a reset signal for the shift register of the pseudo-random signal generator 150 to the pseudo-random signal generator 150.

[0100] The pseudo-random signal generator 150 receives the reset signal for the shift register from the solid seed source control processor 160, and generates a pseudo-random signal of the same pattern in synchronization with the trigger B signal.

[0101] The pseudo-random signal is removed of unnecessary spectral components of high frequency components by the variable band filter.

[0102] The optical phase modulator 112 phase-modulates the CW laser light by the pseudo-random signal from the pseudo-random signal generator 150, which is limited to an appropriate band, and changes the spectrum.

[0103] When the cut-off frequency of the variable band filter of the pseudo-random signal generator 150 is changed to the high frequency side, the spectral line width of the light becomes wide, and when it is changed to the low frequency side, the spectral line width of the light becomes narrow. Further, by changing the timing of inputting a reset signal to the shift register of the pseudo-random signal generator 150 and the like, the waveform, spectrum of the pseudo-random signal also changes, and the spectral line width of the laser light output from the optical phase modulator 112 also changes.

[0104] In the case where the spectral line width is controlled, the spectral line width of the laser light is measured, and the frequency of the pseudo-random signal is adjusted in accordance with the measured spectral line width. Specifically, the cut-off frequency of the variable band filter is adjusted.

[0105] The solid seed source control processor 160, in synchronization with the trigger B signal, performs pulse amplification of the CW laser light which has been phase-modulated by the optical phase modulator 112, by the solid amplifier 113. The solid amplifier 113 outputs pulse laser light having a wavelength of 1030 nm.

[0106] The pulse laser light having a wavelength of 1030 nm output from the solid amplifier 113 is converted into second-harmonic light having a wavelength of 515 nm by the LBO crystal 114. The second-harmonic light having a wavelength of 515 nm is highly transmitted through the dichroic mirror 116, and is converted into pulse laser light having a wavelength of 257.6 nm by the CLBO crystal 115. The LBO crystal 114 and the CLBO crystal 115 are examples of the "wavelength conversion crystal" in the present disclosure.

[0107] Here, the dichroic mirror 116 highly reflects the pulse laser light having a wavelength of 1030 nm which has not been subjected to wavelength conversion by the LBO crystal 114, and causes it to be incident as pump light to the solid amplifier 102 of the first solid laser device 100.

[0108] On the other hand, the laser control processor 50 and the solid seed source control processor 160 control the temperature value and / or the current value of the first semiconductor laser in the semiconductor laser system 101 of the first solid laser device 100, whereby it is possible to cause the wavelength of the pulse laser light output from the first solid laser device 100 to change around 1554 nm. The solid seed source control processor 160 can change the oscillation wavelength of the semiconductor laser system 101 for each pulse.

[0109] The pulse laser of which the wavelength is about 1554 nm outputted from the first solid laser device 100 and the pulse laser of which the wavelength is 257.6 nm outputted from the second solid laser device 110 are frequency-converted into the pulse laser of which the wavelength is about 220.9 nm by the CLBO crystal 141 of the wavelength conversion system 140. Further, the pulse laser of which the wavelength is about 220.9 nm and the pulse laser of which the wavelength is about 1554 nm are frequency-converted into the pulse laser of which the wavelength is about 193.4 nm by the CLBO crystal 142. Then, the pulse laser of which the wavelength is about 193.4 nm is outputted from the wavelength conversion system 140.

[0110] The variable range of the wavelength of the pulse laser outputted from the solid seed source 20 is the amplification band of the excimer amplifier 30, i.e., about 193.2 nm to 193.5 nm.

[0111] The trigger A signal is inputted to the switch 39 of the PPM 32 so that the discharge is generated in synchronization with the pulse laser outputted from the solid seed source 20 being incident to the discharge space of the cavity 31 of the excimer amplifier 30. As a result, the pulse laser outputted from the solid seed source 20 is amplified by the excimer amplifier 30 by 3 passes.

[0112] The pulse laser amplified by the excimer amplifier 30 is sampled by the beam splitter 41 and the beam splitter 42 of the monitor module 40, and the spectrum and the pulse energy are measured by the spectrum monitor 43 and the optical sensor 44.

[0113] According to the measured spectrum of the pulse laser outputted from the excimer amplifier 30, the laser control processor 50 transmits the control signal of the center wavelength to the solid seed source control processor 160 so that the center wavelength approaches the target value, i.e., the target center wavelength. The solid seed source control processor 160 transmits the instruction values of the temperature value and the current value to the semiconductor laser system 101 according to the control signal acquired from the laser control processor 50. The semiconductor laser system 101 changes the temperature and the current of the semiconductor laser of the semiconductor laser system 101 according to the instruction values of the temperature value and the current value acquired from the solid seed source control processor 160, and changes the oscillation wavelength.

[0114] Further, according to the measured spectrum of the pulse laser outputted from the excimer amplifier 30, the laser control processor 50 transmits the control signal of the spectral line width to the solid seed source control processor 160 so that the spectral line width approaches the target value, i.e., the target line width. The solid seed source control processor 160 changes the signal bandwidth and the power of the modulation signal outputted from the pseudo-random signal generator 150 according to the control signal acquired from the laser control processor 50.

[0115] The optical phase modulator 112 changes the spectral line width of the laser light output from the optical phase modulator 112 in accordance with the signal bandwidth and power of the output from the pseudo-random signal generator 150.

[0116] Further, the laser control processor 50 changes the charging voltage of the charger 33 so that the measured pulse energy of the pulse laser light output from the excitation laser oscillator 30 approaches the target value, i.e., the target pulse energy.

[0117] With the above-described structure / action, the wavelength of the second continuous light is modulated in a time corresponding to one pulse of the pulse laser light, and the spectral line width of the pulse laser light is adjusted. The same pattern of the pseudo-random signal is generated in synchronization with the trigger B signal synchronized with the generation timing of the pulse laser light, and is superimposed in the optical phase modulator 112. Therefore, the modulation signal of the same waveform per pulse is superimposed in the optical phase modulator 112, and the spectrum of the superimposed signal is also the same per pulse. Therefore, the pulse laser light output from the optical phase modulator 112 is modulated to be the same per pulse, and thus the spectrum is the same per pulse, and the spectral line width is also the same per pulse, which is stable.

[0118] In addition, when the pseudo-random signal generator 150 is caused to act in synchronization with the trigger B signal to change the spectrum, in order to make the shape thereof unimodal, a process of searching for an initial value of the shift register until the spectrum becomes unimodal needs to be performed.

[0119] 1.2 Structure of Pseudo-random Signal Generator

[0120] An initial value setting circuit is added to the pseudo-random signal generator to adjust the initial value of the shift register so that the generated spectrum becomes unimodal.

[0121] Figure 3 An example of the pseudo-random signal generator 150 is shown. The pseudo-random signal generator 150 includes a shift register 151, at least one exclusive OR (XOR) circuit 152, a variable band filter 153, an amplifier 154, a trigger regeneration circuit 155, and an initial value setting circuit 156.

[0122] The shift register 151 is configured so that 36 D flip-flops FF1 to FF36 are connected in series, the Q output of the D flip-flop FF11 of the 11th stage and the Q output of the D flip-flop FF36 of the 36th stage become inputs to the XOR circuit 152, and the output of the XOR circuit 152 is fed back to the D flip-flop FF1 of the 1st stage. Every time the clock is counted 2 36 -1 times (period 2 36-1), the Q output of the D flip-flop FF36 of the 36th stage repeatedly outputs the same random pattern (pseudo-random pattern). The Q output of the D flip-flop FF36 of the 36th stage is input to the variable band filter 153, and the output of the variable band filter 153 is amplified by the amplifier 154 and output. The pass band of the variable band filter 153 and the output power of the amplifier 154 are controlled by the control signal from the solid seed source control processor 160.

[0123] The trigger regeneration circuit 155 generates a timing signal that changes the initial value of the D flip-flops FF1 to FF36, based on the trigger B signal from the solid seed source control processor 160 and the high-speed internal clock of the pseudo-random signal generator 150.

[0124] In the initial value setting circuit 156, in synchronization with the timing signal generated by the trigger regeneration circuit 155, a signal is sent to the SET terminal or the CLR terminal of the D flip-flops FF1 to FF36 by the control signal from the solid seed source control processor 160, so that the initial value of the D flip-flops FF1 to FF36 becomes "0" or "1" ("Low" or "Hi"). For example, in the case where the initial value is set to "0", a signal is sent to the CLR terminal, and in the case where the initial value is set to "1", a signal is sent to the SET terminal.

[0125] In addition, although an example in which 36 stages of D flip-flops are used is shown here, the number of stages of the D flip-flops is not limited to this example, and for example, the number of stages, the feedback positions, and the number of XOR circuits 152 can be appropriately configured and connected in accordance with a known feedback polynomial. Furthermore, the shift register 151 constituted by the plurality of stages of D flip-flops can also be constituted by an FPGA (Field Programmable Gate Array) or the like. Furthermore, although the adjustment of the power of the modulation signal output here is performed by the amplifier 154, a variable attenuator can also be inserted in the rear stage or the front stage of the amplifier 154 to adjust the output power.

[0126] An XNOR circuit can also be used instead of the XOR circuit 152. The pseudo-random signal generator 150 is an example of the "modulation signal generator" in the present disclosure.

[0127] 1.3 Example 1 of the operation of the pseudo-random signal generator

[0128] Figure 4 A flowchart of the control example of the spectral line width in the comparative example is shown. In step S1, the laser control processor 50 measures the spectrum of the output pulsed laser of the excimer amplifier 30 using the spectrum monitor 43 of the monitor module 40.

[0129] In step S2, the laser control processor 50 investigates whether the measured spectrum has unimodality or multimodality, and determines whether the spectrum is unimodal. In the case where the determination result of step S2 is "No", that is, in the case where the spectrum has multimodality, the laser control processor 50 shifts to step S3.

[0130] In step S3, the laser control processor 50 changes the initial value of the shift register 151 by means of the solid seed source control processor 160, and returns to step S1.

[0131] On the other hand, in the case where the determination result of step S2 is "Yes", that is, in the case where the spectrum has unimodality, the laser control processor 50 shifts to step S4.

[0132] In step S4, the laser control processor 50 measures the spectral line width from the obtained spectrum.

[0133] In step S5, the laser control processor 50 calculates the difference between the target line width periodically updated by the exposure control processor 61 and the measurement result of step S4.

[0134] In step S6, the laser control processor 50 determines whether the calculated difference is within the allowable range. In the case where the determination result of step S6 is "Yes", that is, in the case where the difference is within the allowable range, the laser control processor 50 returns to step S1.

[0135] On the other hand, in the case where the determination result of step S6 is "No", that is, in the case where the difference is not within the allowable range, the laser control processor 50 shifts to step S7.

[0136] In step S7, the laser control processor 50 decides the power of the modulation signal from the function representing the relationship between the square root of the power of the modulation signal obtained in advance and the spectral line width and the difference calculated in step S5, changes the power of the modulation signal superimposed in the optical phase modulator 112, and returns to step S1. However, instead of the relationship between the square root of the power of the modulation signal obtained in advance and the spectral line width, a table (list) of the relationship between the square root of the power of the modulation signal and the spectral line width recorded in advance can be used. Further, instead of adjusting the power of the modulation signal, a variable band filter 153 can be used to adjust the bandwidth of the modulation signal.

[0137] 1.4 Action / Effect

[0138] By adjusting the initial value of the shift register 151, it is possible to control the target spectral line width using the unimodal spectrum at all times.

[0139] The linearity between the square root of the power of the modulation signal and the spectral line width is high, and thus, by adjusting the power of the modulation signal, the line width control can be performed more easily and with high precision.

[0140] Furthermore, the linearity between the bandwidth of the modulation signal and the spectral line width is high, and thus, by adjusting the bandwidth of the modulation signal, the line width control can be performed more easily and with high precision.

[0141] 1.5 Example 2 of the operation of the pseudo-random signal generator

[0142] Figure 5 A flowchart of another control example of the spectral line width in the comparative example is shown. In this example, the spectral line width is coarsely adjusted using the bandwidth of the modulation signal, and the spectral line width is finely adjusted using the power of the modulation signal. The processes of steps S1 to S5 are the same as those of the flowchart shown in Figure 4

[0143] In step S8 following step S5, the laser control processor 50 determines whether the difference calculated in step S5 is within the allowable range of the coarse adjustment. In the case where the determination result of step S8 is "NO" determination, that is, in the case where the difference is not within the allowable range of the coarse adjustment, the laser control processor 50 shifts to step S9.

[0144] In step S9, the laser control processor 50 changes the bandwidth of the modulation signal overlapped in the optical phase modulator 112 using the variable-band filter 153. The operation of step S9 can also be performed by the solid seed source control processor 160 in accordance with the instruction of the laser control processor 50. After step S9, the laser control processor 50 returns to step S1.

[0145] In the case where the determination result of step S8 is "YES" determination, that is, in the case where the difference is within the allowable range of the coarse adjustment, the laser control processor 50 shifts to step S10. In step S10, the laser control processor 50 determines whether the difference calculated in step S5 is within the allowable range of the fine adjustment. In the case where the determination result of step S10 is "YES" determination, that is, in the case where the difference is within the allowable range of the fine adjustment, the laser control processor 50 returns to step S1.

[0146] In the case where the determination result of step S10 is "NO" determination, that is, in the case where the difference is not within the allowable range of the fine adjustment, the laser control processor 50 shifts to step S7. The process of step S7 is the same as that of the flowchart shown in Figure 4 After step S7, the laser control processor 50 returns to step S1. The operation of step S7 can also be performed by the solid seed source control processor 160 in accordance with the instruction of the laser control processor 50.

[0147] ​1.6 Effects / Advantages

[0148] By adjusting the initial value of the shift register 151, it is possible to always control the spectral line width of the spectrum targeted using unimodality. Furthermore, by adopting a method of changing the bandwidth of the modulation signal in the case of roughly adjusting the spectral line width, and changing the power of the modulation signal in the case of finely adjusting the spectral line width, the amount of change in the power of the modulation signal is small compared to the case of performing line width control using only the power of the modulation signal. Due to this, the stability of the modulation signal generator as a whole including the pseudo-random signal generator 150 improves, the thermal load and the like applied to the optical phase modulator 112 is small, and stable control is possible.

[0149] Furthermore, compared to the case of performing line width control using only the bandwidth of the modulation signal, the use of the change in the power of the modulation signal enables the setting resolution to be finer.

[0150] 1.7 Problems

[0151] In a technique of adjusting the spectrum of laser light by the pseudo-random signal generator 150 constituted by the multi-stage shift register 151 and the variable band filter 153, and the optical phase modulator 112, when expanding the spectral line width defined by the Full Width at Half Maximum (FWHM), the E95 width, and the like while maintaining unimodality of the Gaussian waveform and the like, the magnitude of the amplitude of the optical phase modulation and the like is limited, and therefore there is a limit to the adjustment range of the spectral line width (particularly, the upper limit value of the spectral line width).

[0152] For example, in the case of obtaining a spectral line width of the wider side of 0.5 pm or more, such as an E95 width of 0.2 pm or more and 0.5 pm or less, required for semiconductor lithography, it is difficult to obtain a sufficiently wide spectral line width by optical phase modulation alone.

[0153] 2. Embodiment 1

[0154] 2.1 Configuration

[0155] 2.1.1 Laser device

[0156] Figure 6 The configuration of the laser device 11 of Embodiment 1 is schematically shown. Regarding the configuration shown in Figure 6 , the differences from Figure 1 will be described. The laser device 11 includes the solid-state seed source 21 instead of the solid-state seed source 20 of Figure 1 .

[0157] 2.1.2 Solid-state seed source

[0158] Figure 7 The configuration of the solid-state seed source 21 is schematically shown. Regarding the configuration shown inFigure 7 The structure shown, the difference is described. Solid seed source 21 instead of the first solid laser device 100 and the second solid laser device 110 includes the first solid laser device 200 and the second solid laser device 210. Figure 2

[0159] The first solid laser device 200 includes a semiconductor laser system 101, a solid amplifier 202, a solid amplifier 203, and a solid amplifier 204.

[0160] The solid amplifier 202 and the solid amplifier 203 can be a semiconductor optical amplifier (SOA). The SOA is, for example, a multiple quantum well structure of InP / InGaAsP or the like.

[0161] The solid amplifier 202 cuts out a part of the CW laser output from the semiconductor laser system 101 in a pulsed manner and amplifies it to become the first pulsed laser PL1 by a trigger 3 signal transmitted by the solid seed source control processor 160. The solid amplifier 202 is an example of the "first amplifier" in the present disclosure.

[0162] The solid amplifier 203 further cuts out a part of the first pulsed laser PL1 and amplifies it to become the second pulsed laser PL2 by a trigger 1 signal transmitted by the solid seed source control processor 160. The trigger 1 signal is an example of the "first trigger signal" in the present disclosure. The solid amplifier 203 is an example of the "second amplifier" in the present disclosure.

[0163] The solid amplifier 204 is, for example, a fiber amplifier doped with Yb or the like among rare earth ions or the like. The solid amplifier 204 amplifies the power of the second pulsed laser PL2 to become the fifth pulsed laser PL5 according to a gain signal transmitted by the solid seed source control processor 160. Hereinafter, the amplification gain of the solid amplifier 204 is set to Gain. The solid amplifier 204 is an example of the "fourth amplifier" in the present disclosure.

[0164] The second solid laser device 210 is a structure that does not include the dichroic mirror 116 with respect to the second solid laser device 110. The solid amplifier 113 cuts out the CW laser output from the semiconductor laser system 111 in a pulsed manner and amplifies it to become the third pulsed laser PL3 by a trigger 2 signal transmitted by the solid seed source control processor 160. The trigger 2 signal is an example of the "second trigger signal" in the present disclosure. The solid amplifier 113 is an example of the "third amplifier" in the present disclosure.

[0165] ​LBO crystal 114 converts the modulated and pulsed third pulse laser PL3 from solid-state amplifier 113, with a wavelength of approximately 1030 nm, into a pulse laser with a wavelength of approximately 515 nm. CLBO crystal 115 converts the pulse laser converted by LBO crystal 114 into a sixth pulse laser PL6 with a wavelength of approximately 257.6 nm.

[0166] A fifth pulsed laser PL5 with a wavelength of approximately 1554 nm, output from the first solid-state laser device 200, and a sixth pulsed laser PL6 with a wavelength of approximately 257.6 nm, output from the second solid-state laser device 210, are sum-frequency mixed by the CLBO crystal 141 of the wavelength conversion system 140, and converted into a pulsed laser with a wavelength of approximately 220.9 nm. Furthermore, the pulsed laser with a wavelength of approximately 220.9 nm is converted by the CLBO crystal 142 into a fourth pulsed laser PL4 with a wavelength of approximately 193.4 nm, which is then output from the solid-state seed source 21.

[0167] The wavelength conversion system 140 can also replace the fifth pulse laser PL5 to perform sum-frequency mixing on the output of the solid-state amplifier 203 of the first solid-state laser device 200, namely the second pulse laser PL2.

[0168] Alternatively, an optical crystal that performs sum-frequency mixing at a wavelength different from the examples described above can be used to construct a wavelength conversion system 140. This system can perform sum-frequency mixing to convert the wavelength of pulsed laser light from the first solid-state laser device 200 and the second solid-state laser device 210, and this output can be set as the output of the solid-state seed source 21. In this case, the pulsed laser light from the first solid-state laser device 200 and the pulsed laser light from the second solid-state laser device 210 can also output wavelengths different from those described above.

[0169] That is, the wavelength conversion system 140 can be configured to perform a sum-frequency mixing of the second pulse laser PL2 or the fifth pulse laser PL5 from the first solid-state laser device 200 and the third pulse laser PL3 or the sixth pulse laser PL6 from the second solid-state laser device 210 to convert the wavelength.

[0170] In addition, the laser control processor 50 and the laser control processor 50 Figure 6 The exposure control processor 61 of the exposure apparatus 60 shown synchronously generates trigger signal A and trigger signal B from the light emission trigger signal. The solid seed source control processor 160 synchronously generates trigger signal 1, trigger signal 2, and trigger signal 3 with trigger signal B. Therefore, trigger signals 1 to 3 are synchronized with the light emission trigger signal.

[0171] 2.2 Actions

[0172] 2.2.1 Laser operation

[0173] Figure 8 A timing chart showing the adjustment completion of the timing described later, and the laser operation execution time when the solid seed source 21 is operated is shown in FIG. 6.

[0174] The solid seed source control processor 160 receives the spectral line width control signal, the temperature value and the current value for the semiconductor laser system 101 and the semiconductor laser system 111, and the trigger B signal from the laser control processor 50, and implements the following controls (1) to (6).

[0175] (1) The solid seed source control processor 160 controls the oscillation wavelength and the output of the CW light of the semiconductor laser system 101 and the semiconductor laser system 111 based on the received temperature value and the current value.

[0176] (2) The solid seed source control processor 160 causes the pseudo-random signal generator 150 to operate after resetting the shift register 151 of the pseudo-random signal generator 150 based on the timing of the trigger B signal.

[0177] (3) As the control of the first solid laser device 200, the solid seed source control processor 160 generates the trigger 3 signal having a pulse width of Wl by adding Delayl as a delay time to the timing of the trigger B signal. The solid amplifier 202 amplifies the CW light having a wavelength of about 1554 nm output from the semiconductor laser system 101, and converts it into the first pulsed laser light PLl. The pulse width of the first pulsed laser light PLl is about Wl.

[0178] (4) The solid seed source control processor 160 generates the trigger 1 signal having a pulse width of W2 by further adding Delay2 as a delay time to the timing of the trigger 3 signal. The solid amplifier 203 further amplifies the first pulsed laser light PLl output from the solid amplifier 202, and cuts it out in a time width having a pulse width of about W2, to generate the second pulsed laser light PL2. The solid seed source control processor 160 can also generate the trigger 1 signal by adding the delay time of Delayl + Delay2 to the trigger B signal.

[0179] (5) The second pulsed laser light PL2 output from the solid amplifier 203 is further amplified in power by the solid amplifier 204 to become the fifth pulsed laser light PL5. The solid seed source control processor 160 controls the Gain of the solid amplifier 204, thereby adjusting the power of the output of the first solid laser device 200, that is, the fifth pulsed laser light PL5.

[0180] (6) On the other hand, as the control of the second solid laser device 210, the solid seed source control processor 160 generates a trigger 2 signal having a pulse width of W3 by adding Delay3 as a delay time in accordance with the timing of the trigger B signal. The solid amplifier 113 amplifies the CW light having a wavelength of about 1030 nm output from the semiconductor laser system 111 and modulated by the optical phase modulator 112, and cuts out the same in a pulsed manner to make the third pulsed laser PL3. The pulse width of the third pulsed laser PL3 is about W3.

[0181] The third pulsed laser PL3 is wavelength-converted into a pulsed laser having a wavelength of about 257.6 nm via the LBO crystal 114 and the CLBO crystal 115, and becomes the sixth pulsed laser PL6 as the output light of the second solid laser device 210.

[0182] Then, the solid seed source control processor 160 adjusts the rotation stages 143 and 144 of the wavelength conversion system 140, and converts the output of the first solid laser device 200, i.e., the fifth pulsed laser PL5, and the output of the second solid laser device 210, i.e., the sixth pulsed laser PL6, into the fourth pulsed laser PL4 having a wavelength of about 193.4 nm by sum frequency mixing twice (the CLBO crystal 141 and the CLBO crystal 142).

[0183] As described above, the output of the solid seed source 21, i.e., the fourth pulsed laser PL4, is generated by the overlap of the timing of the fifth pulsed laser PL5 and the sixth pulsed laser PL6. Therefore, the fourth pulsed laser PL4 can be generated in accordance with the overlap of the trigger 1 signal and the trigger 2 signal.

[0184] As to the operation at the time of the above-described laser operation, as with the laser device 10, the laser control processor 50 receives the target center wavelength, the target line width, the target pulse energy, and the light emission trigger signal from the exposure control processor 61 of the exposure device 60, transmits the trigger A signal and the charging voltage value to the excimer amplifier 30, and transmits the trigger B signal, the line width control signal, the temperature value, and the current value to the solid seed source 21, and causes the laser device 11 to operate, and controls the pulsed laser.

[0185] By the above-described structure and operation, the same pattern of pseudo-random signals is generated in synchronization with the trigger 2 signal synchronized with the timing of the light emission trigger signal, and is overlapped in the optical phase modulator 112, and therefore, the modulation signal having the same waveform for each pulse is overlapped in the optical phase modulator 112, and the spectrum of the overlapped signal is also the same for each pulse. Therefore, the laser output from the optical phase modulator 112 is modulated to be the same for each pulse, and therefore, the spectrum is the same for each pulse, and the line width is also stable for each pulse.

[0186] Further, with the above-described structure and operation, the laser device 11 can output laser light of a single-peak spectrum with a wider width of an adjustment range of a spectral line width than the laser device 10.

[0187] 2.2.2 Adjustment

[0188] A method of timing adjustment for outputting a spectrum of a single-peak spectrum with a wider width of a spectral line width from the solid seed source 21 will be described.

[0189] Figure 9 A flowchart of timing adjustment will be shown. As shown in FIG. 8, timing adjustment includes a first step and a second step performed after the first step. Figure 9

[0190] 2.2.2.1 First Step

[0191] In the first step, at least one of the timing of the trigger 1 signal and the timing of the trigger 2 signal is adjusted, and the spectrum of the fourth pulsed laser light PL4 is adjusted to a first spectrum of a non-Gaussian shape. Here, in the first step, the start timing of the trigger 1 signal is changed, and the spectrum of the fourth pulsed laser light PL4 is measured, and thus the start timing of the trigger 1 signal is searched for which makes the spectrum of the fourth pulsed laser light PL4 a first spectrum of a non-Gaussian shape.

[0192] Figure 10 A flowchart of the first step will be shown. In step S21, the solid seed source control processor 160 stops the pseudo-random signal generator 150. Further, the solid seed source control processor 160 sets Delay2 to 0.

[0193] In step S22, the solid seed source control processor 160 determines whether Delay2 is smaller than (W1-W2). W1 is the width of the trigger 3 signal, and W2 is the width of the trigger 1 signal. In the case where the determination result of step S22 is "No" determination, that is, in the case where Delay2 is not smaller than (W1-W2), the solid seed source control processor 160 shifts to step S23.

[0194] In step S23, the solid seed source control processor 160 determines that there is an error (adjustment is not possible), and ends the processing of timing adjustment.

[0195] On the other hand, in the case where the determination result of step S22 is "Yes" determination, that is, in the case where Delay2 is smaller than (W1-W2), the solid seed source control processor 160 shifts to step S24.

[0196] ​In step S24, the solid-state seed source control processor 160 measures the spectrum of the 4th pulsed laser light PL4. The spectrum of the 4th pulsed laser light PL4 can also be measured by the spectrum monitor 43. In this case, the spectrum monitor 43 measures the spectrum of the light after the 4th pulsed laser light PL4 is amplified by the excimer amplifier 30. Alternatively, a beam splitter can be provided between the solid-state seed source 21 and the excimer amplifier 30, and the spectrum of the 4th pulsed laser light PL4 can be monitored.

[0197] In step S25, the solid-state seed source control processor 160 determines whether the spectrum of the 4th pulsed laser light PL4 is a non-Gaussian waveform, i.e., a non-Gaussian waveform.

[0198] In the case where the determination result in step S25 is "No", i.e., in the case where the spectrum is not a non-Gaussian waveform, the solid-state seed source control processor 160 proceeds to step S26. In step S26, the solid-state seed source control processor 160 adds a certain value to Delay2, and returns to step S22.

[0199] On the other hand, in the case where the determination result in step S25 is "Yes", i.e., in the case where the spectrum is a non-Gaussian waveform, the solid-state seed source control processor 160 proceeds to step S27. In step S27, the solid-state seed source control processor 160 determines whether the difference between the spectral linewidth of the 4th pulsed laser light PL4 and the target linewidth at the time of adjustment is within the allowable range.

[0200] In the case where the determination result in step S27 is "No", i.e., in the case where the difference from the target linewidth at the time of adjustment is not within the allowable range, the solid-state seed source control processor 160 proceeds to step S26.

[0201] On the other hand, in the case where the determination result in step S27 is "Yes", i.e., in the case where the difference from the target linewidth at the time of adjustment is within the allowable range, the solid-state seed source control processor 160 ends the processing of the present flowchart, and determines the value of Delay2. Alternatively, the spectrum of the 4th pulsed laser light PL4 can be measured with respect to all of Delay2, and the most appropriate Delay2 can be selected.

[0202] Figure 11 The timing chart in the 1st step is shown. As shown in Figs. 1 and 2, in the 1st step, the solid-state seed source control processor 160 stops the pseudo-random signal generator 150, becomes a state in which the light phase modulation of the 2nd solid-state laser device 210 is not applied, changes Delay2, and adjusts the 4th pulsed laser light PL4 to have a 1st spectrum having a spectral linewidth wider than the Gaussian shape. Figure 10 Figure 11

[0203] Figure 12 ​​The spectrum of the fourth pulse laser PL4 during the adjustment in step 1 is shown. Regarding... Figure 12 The waveforms A, B, and C shown have Delay2 values ​​of 9nsec, 11nsec, and 13nsec, respectively, Gain values ​​of 0.8V, and E95 widths of 0.08pm, 0.16pm, and 0.23pm, respectively. When changing Delay2, as follows... Figure 12 As shown, the spectrum of the fourth pulse laser PL4 changes from a narrow Gaussian shape (single-peak) to a spectrum with a wider spectral linewidth than the Gaussian shape, and then to a multi-peak spectrum.

[0204] In step 1, select Figure 12 The waveforms B and C shown represent Delay2, which has a wider spectrum. In step 1, when selecting... Figure 12 When waveform A, as shown, becomes a narrow, single-peaked spectrum in Delay2, it is difficult to obtain a wider spectrum when phase modulation based on a pseudo-random signal is applied in step 2.

[0205] In addition, the measured spectrum is fitted using the least squares method with a Gaussian waveform, and the coefficient of determination R is used. 2 Size Figure 10 The determination of whether the fourth laser pulse PL4 in step S25 is a non-Gaussian waveform. For example, in R... 2 When the value is less than 0.9, it is determined to be a non-Gaussian waveform.

[0206] Figure 13 An example of determining a non-Gaussian waveform is shown. Figure 13 F13A and F13B respectively contain graphs showing the measured spectrum and Gaussian fitted waveform. Regarding Figure 13 The spectrum of F13A, R 2 =0.9876, does not satisfy R 2 <0.9. Therefore, the spectrum of F13A is determined to be a Gaussian waveform.

[0207] On the other hand, regarding Figure 13 The spectrum of F13B, R 2 =0.7411, satisfying R 2 <0.9. Therefore, the spectrum of F13B is determined to be a non-Gaussian waveform.

[0208] Further, in the first step, Delay 2 is varied in the range from 0 to (Wl - W2) to adjust the spectrum. In the case where Delay 2 is negative or greater than Wl - W2, the time width of the output of the first solid-state laser device 200, i.e., the fifth pulsed laser light PL5, is shorter than W2. Further, when Delay 2 is shifted to the extent that the overlap in time of the trigger 3 signal and the trigger 1 signal disappears, the output of the fifth pulsed laser light PL5, i.e., the fourth pulsed laser light PL4, of the solid-state seed source 21 disappears, and thus attention is required.

[0209] Also, attention is required to set Delay 3 and W3 so that the trigger 1 signal and the trigger 2 signal produce an overlap.

[0210] By performing adjustment of the timing based on the above, the fourth pulsed laser light PL4 is output from the solid-state seed source 21 according to the timing of the trigger 1 signal.

[0211] The length of Delay 1 + Delay 2 that determines the timing of the trigger 1 signal needs to be adjusted so as to match the optical amplification timing of the excimer amplifier 30. Therefore, in the first step, after adjusting Delay 2, the timing of the trigger 1 signal can be varied with Delay 1, and adjustment can be performed so that the output pulsed laser light of the solid-state seed source 21 overlaps the amplification timing of the excimer amplifier 30. At this time, Delay 3 can also be varied according to the variation of Delay 1 so that the difference in the relative timing of the trigger 3 signal and the trigger 2 signal does not change.

[0212] Alternatively, in the first step, Delay 1 and Delay 3 can be fixed, and after adjusting Delay 2, adjustment can be performed so that the time difference between the trigger A signal and the trigger B signal becomes an appropriate amplification timing.

[0213] 2.2.2.2 Second Step

[0214] In the second step, the pseudo-random signal generator 150 is caused to generate a modulation signal of the same pattern as the emission trigger signal in synchronization therewith, and the modulation signal of the same pattern is supplied to the optical phase modulator 112, whereby the wavelength of the second continuous light is modulated for a time corresponding to one pulse of the third pulsed laser light PL3, and the spectrum of the fourth pulsed laser light PL4 is adjusted to a second spectrum having a spectral line width wider than the first spectrum. Here, in the second step, the pseudo-random signal generator 150 is caused to act, the spectrum of the fourth pulsed laser light PL4 is observed, the initial value of the shift register 151 of the pseudo-random signal generator 150 is changed and searched so that the spectrum of the fourth pulsed laser light PL4 becomes a second spectrum that is unimodal and has a wide width.

[0215] Figure 14A flowchart showing the 2nd step is shown. In step S31, the solid seed source control processor 160 causes the pseudo-random signal generator 150 to act.

[0216] In step S32, the solid seed source control processor 160 measures the spectrum of the 4th pulse laser PL4.

[0217] In step S33, the solid seed source control processor 160 determines whether the spectrum of the 4th pulse laser PL4 is unimodal.

[0218] In the case where the determination result of step S33 is "No", that is, in the case where the spectrum is not unimodal, the solid seed source control processor 160 shifts to step S34. In step S34, the solid seed source control processor 160 updates the initial value of the shift register 151, and returns to step S32.

[0219] On the other hand, in the case where the determination result of step S33 is "Yes", that is, in the case where the spectrum is unimodal, the solid seed source control processor 160 shifts to step S35. In step S35, the solid seed source control processor 160 determines whether the difference between the spectral line width of the 4th pulse laser PL4 and the target line width of unimodality is within the allowable range.

[0220] In the case where the determination result of step S35 is "No", that is, in the case where the difference from the target line width of unimodality is not within the allowable range, the solid seed source control processor 160 shifts to step S34.

[0221] On the other hand, in the case where the determination result of step S35 is "Yes", that is, in the case where the difference from the target line width of unimodality is within the allowable range, the solid seed source control processor 160 ends the processing of the present flowchart, and determines the initial value of the shift register 151. In addition, the evaluation of the spectrum can be performed with respect to all the initial values of the shift register 151, and the most appropriate initial value can be selected.

[0222] Figure 15 A spectrum of the 4th pulse laser PL4 after the search of the 2nd step is shown. Figure 15 The waveforms A, B, C of FIG. 10 are waveforms of the 4th pulse laser PL4 after the initial value of the shift register 151 is determined. Figure 12 The waveforms A, B, C of FIG. 10 are waveforms of the 4th pulse laser PL4 after the initial value of the shift register 151 is determined. Figure 15 The E95 widths of the waveforms A, B, C of FIG. 10 are 0.24 pm, 0.32 pm, and 0.4 pm, respectively. When the waveform C of FIG. 10 is selected in the adjustment of Delay2, a spectrum of a unimodal width wider than that of the waveform B of FIG. 10 is obtained. Figure 12 The E95 widths of the waveforms A, B, C of FIG. 10 are 0.24 pm, 0.32 pm, and 0.4 pm, respectively. When the waveform C of FIG. 10 is selected in the adjustment of Delay2, a spectrum of a unimodal width wider than that of the waveform B of FIG. 10 is obtained. Figure 15 The E95 widths of the waveforms A, B, C of FIG. 10 are 0.24 pm, 0.32 pm, and 0.4 pm, respectively. When the waveform C of FIG. 10 is selected in the adjustment of Delay2, a spectrum of a unimodal width wider than that of the waveform B of FIG. 10 is obtained.Figure 12 When the waveform A has a narrow, unimodal spectrum, it becomes Figure 15 The waveform A has a narrow, single-peaked spectrum.

[0223] 2.3 Functions / Effects

[0224] In the comparative example laser device 10, the output pulsed laser of the solid seed source 20 in a state where the pseudo-random signal generator 150 is stopped and no optical phase modulation of the second solid-state laser device 110 is applied is equivalent to Figure 12 Waveform A. This is because, since the goal is to ultimately make the output pulsed laser of the solid seed source 20 have a single peak (Gaussian shape), if the spectrum also has a single peak (Gaussian shape) without applying phase modulation, it is easy to then activate the pseudo-random signal generator 150, change the initial value of the shift register 151 of the pseudo-random signal generator 150 to search for a single peak shape in the spectrum. Figure 15 Waveform A). Therefore, a design / fabrication is performed to make the spectrum of the pulsed laser output from the solid-state amplifier 102 of the comparative example laser device 10 Gaussian shaped (…). Figure 12 (Waveform A). Furthermore, since the solid-state amplifier 102 uses a pulsed laser with a wavelength of 1030 nm, which cannot be wavelength-converted using an LBO crystal, as the pump light, it is difficult to adjust the timing of the amplification of the solid-state amplifier 102 in accordance with the adjustment of Delay2 in Embodiment 1.

[0225] On the other hand, as a first step, the laser device 11 of Embodiment 1 stops the pseudo-random signal generator 150 and adjusts Delay2 without applying optical phase modulation of the second solid-state laser device 210. Thus, temporarily becoming Figure 12 The spectrum, such as waveform B or waveform C, is not Gaussian in shape and has a spectral linewidth wider than that of a Gaussian shape. Then, as a second step, the laser device 11 is set to a state where optical phase modulation is applied, and the initial value of the shift register 151 of the pseudo-random signal generator 150 is changed to perform a search. Thus, the spectrum is shaped to obtain... Figure 15 The spectrum is broad and unimodal, like waveform B or waveform C. Specifically, through... Figure 12 The waveform C is temporarily adjusted to a multi-peak spectrum, such as... Figure 15 Like waveform C, a wider spectrum can ultimately be obtained.

[0226] 3. Implementation Method 2

[0227] 3.1 Structure

[0228] The laser device of Embodiment 2 has the same configuration as the laser device of Embodiment 1. The laser device 11 of Embodiment 2 differs from the laser device 11 of Embodiment 1 in the content of control performed by the solid-state seed source control processor 160.

[0229] 3.2 Action

[0230] In the first step of Embodiment 2, at least one of the timing of the trigger 1 signal and the timing of the trigger 2 signal is adjusted, and the Gain of the solid-state amplifier 204 is adjusted, to adjust the spectrum of the fourth pulsed laser light PL4 into the first spectrum of a non-Gaussian shape. Here, the Gain is adjusted in addition to the adjustment of Delay 2, to obtain a spectrum of a single peak with a wide width. The second step of Embodiment 2 is the same as that of Embodiment 1.

[0231] Figure 16 A flowchart of the first step of Embodiment 2 is shown. In step S41, the solid-state seed source control processor 160 stops the pseudo-random signal generator 150. Further, the solid-state seed source control processor 160 sets Delay 2 to 0 and sets the Gain to the minimum value.

[0232] The processes of steps S22 to S25 and step S27 are the same as those of Figure 10 In the case where the determination result of step S25 is "Yes" determination and the determination result of step S27 is "Yes" determination, the solid-state seed source control processor 160 ends the process of the present flowchart and determines the values of Delay 2 and Gain.

[0233] On the other hand, in the case where the determination result of step S25 is "No" determination or the determination result of step S27 is "No" determination, the solid-state seed source control processor 160 shifts to step S42. In step S42, the solid-state seed source control processor 160 determines whether the Gain is smaller than the maximum value.

[0234] In the case where the determination result of step S42 is "No" determination, that is, in the case where the Gain is not smaller than the maximum value, the solid-state seed source control processor 160 shifts to step S43. In step S43, the solid-state seed source control processor 160 sets the Gain to the minimum value. Then, in step S26, the solid-state seed source control processor 160 adds a certain value to Delay 2 and returns to step S22.

[0235] On the other hand, in the case where the determination result of step S42 is "Yes" determination, that is, in the case where the Gain is smaller than the maximum value, the solid-state seed source control processor 160 shifts to step S44. In step S44, the solid-state seed source control processor 160 measures the spectrum of the fourth pulsed laser light PL4.

[0236] In step S45, the solid seed source control processor 160 determines whether the spectrum of the 4th pulsed laser PL4 is a non-Gaussian waveform. This determination can be made in the same manner as in step S25.

[0237] In the case where the determination result in step S45 is "No", that is, in the case where the spectrum is not a non-Gaussian waveform, the solid seed source control processor 160 proceeds to step S46. In step S46, the solid seed source control processor 160 increases the Gain by a certain amount, and returns to step S42.

[0238] On the other hand, in the case where the determination result in step S45 is "Yes", that is, in the case where the spectrum is a non-Gaussian waveform, the solid seed source control processor 160 proceeds to step S47. In step S47, the solid seed source control processor 160 determines whether the difference between the spectral line width of the 4th pulsed laser PL4 and the target line width at the time of adjustment is within the allowable range.

[0239] In the case where the determination result in step S47 is "No", that is, in the case where the difference from the target line width at the time of adjustment is not within the allowable range, the solid seed source control processor 160 proceeds to step S46. On the other hand, in the case where the determination result in step S47 is "Yes", that is, in the case where the difference from the target line width at the time of adjustment is within the allowable range, the solid seed source control processor 160 ends the processing of the present flowchart, and determines the values of Delay2 and Gain.

[0240] In the 1st step of Embodiment 2, if the desired multi-peak spectrum can be obtained by adjustment of Delay2 alone, adjustment of Gain can also be omitted in the same manner as in Embodiment 1. On the other hand, in the case where the desired multi-peak spectrum cannot be obtained by adjustment of Delay2 alone, adjustment of Gain is performed. Furthermore, adjustment of Gain can be performed initially, and adjustment of Delay2 can be performed in the case where the desired multi-peak spectrum is not obtained.

[0241] The spectrum can also be investigated for all combinations of Delay2 and Gain, and the best spectrum can be selected.

[0242] 3.3 Effects / Advantages

[0243] Figure 17 The spectrum of the 4th pulsed laser PL4 in the adjustment of the 1st step is shown. With respect to Figure 17 With respect to the waveforms A, B, C shown, Delay2 is 9 nsec, 11 nsec, and 13 nsec, respectively, Gain is 0.8 V, 1.1 V, and 1.4 V, respectively, and the E95 width is 0.08 pm, 0.19 pm, and 0.3 pm, respectively.

[0244] Figure 18 A spectrum of the 4th pulse laser PL4 after the search of the 2nd step is shown. Figure 18 The waveforms A, B, C shown in FIG. 9 are waveforms of the 4th pulse laser PL4 after the shift register 151 is initialized by the waveforms A, B, C shown in FIG. 8. Figure 17 The waveforms A, B, C shown in FIG. 9 are waveforms of the 4th pulse laser PL4 after the shift register 151 is initialized by the waveforms A, B, C shown in FIG. 8. Figure 18 The E95 widths of the waveforms A, B, C shown in FIG. 9 are 0.24 pm, 0.37 pm, and 0.5 pm, respectively.

[0245] As shown in FIG. 10, the combination of the adjustment of Delay2 and the adjustment of Gain results in a spectrum with a wider width. Figure 17 Figure 18 As shown in FIG. 10, the combination of the adjustment of Delay2 and the adjustment of Gain results in a spectrum with a wider width.

[0246] 4. Embodiment 3

[0247] 4.1 Configuration

[0248] The configuration of the laser device of Embodiment 3 is the same as that of the laser device of Embodiment 1. The laser device 11 of Embodiment 3 differs from the laser device 11 of Embodiment 1 in the content of the control implemented by the solid-state seed source control processor 160.

[0249] 4.2 Operation

[0250] In the 1st step of Embodiment 3, the start timing of the trigger 2 signal, that is, Delay3 is changed, and the spectrum of the 4th pulse laser PL4 is measured, whereby the start timing of the trigger 2 signal that makes the spectrum of the 4th pulse laser PL4 into a non-Gaussian shape is searched for. The 2nd step of Embodiment 3 is the same as that of Embodiment 1.

[0251] Figure 19 A flowchart of the 1st step of Embodiment 3 is shown. In step S61, the solid-state seed source control processor 160 stops the pseudo-random signal generator 150. Further, the solid-state seed source control processor 160 sets Delay3 to (Delay1 + Delay2 + W2 - W3).

[0252] In step S62, the solid-state seed source control processor 160 determines whether Delay3 is smaller than (Delay1 + Delay2). In the case where the determination result of step S62 is "No" determination, that is, in the case where Delay3 is not smaller than (Delay1 + Delay2), the solid-state seed source control processor 160 shifts to step S23. The processing of step S23 is the same as that of Embodiment 1. Figure 10

[0253] ​​On the other hand, in a case where the determination result in step S62 is "Yes" determination, that is, in a case where Delay 3 is smaller than (Delay 1 + Delay 2), the solid seed source control processor 160 shifts to step S24.

[0254] The processes in steps S24, S25, and S27 are the same as those in steps S24, S25, and S27 in Embodiment 1. Figure 10 The processes in steps S24, S25, and S27 are the same as those in steps S24, S25, and S27 in Embodiment 1. In a case where the determination result in step S25 is "Yes" determination and the determination result in step S27 is "Yes" determination, the solid seed source control processor 160 ends the process of the present flowchart and determines the value of Delay 3.

[0255] On the other hand, in a case where the determination result in step S25 is "No" determination or the determination result in step S27 is "No" determination, the solid seed source control processor 160 shifts to step S63. In step S63, the solid seed source control processor 160 adds a certain value to Delay 3 and returns to step S62.

[0256] Thus, by adjusting Delay 3, the difference in the pulse cutting timing of the first solid laser device 200 and the second solid laser device 210 is adjusted, and the spectrum of the fourth pulsed laser light PL4 is adjusted to have a wide width and a multi-peak shape. In addition, the spectrum of the fourth pulsed laser light PL4 can be measured with respect to all Delay 3, and the most appropriate Delay 3 can be selected.

[0257] In the adjustment of Delay 3, it is necessary to set Delay 3 and W3 so that the trigger 1 signal and the trigger 2 signal overlap. Specifically, Delay 3 and W3 are set in a manner that satisfies the following Expression 1.

[0258] Delay 1 + Delay 2 + W2 - W3 < Delay 3 < Delay 1 + Delay 2... (Expression 1)

[0259] Further, the adjustment of Delay 3 in the first step of Embodiment 3 can be implemented in combination with the adjustment of Delay 1 of Embodiment 1, can be implemented in combination with the adjustment of Gain of Embodiment 2, and can be implemented in combination with the adjustment of Delay 1 and Gain of Embodiment 2.

[0260] 4.3 Action / Effect

[0261] Figure 20 The spectrum of the fourth pulsed laser light PL4 in the adjustment of the first step is shown. With respect to Figure 20The waveforms A, B, and C shown in FIG. 9 are waveforms of the fourth pulse laser PL4 after the search of the second step. The Delay2 is 9 nsec, the Delay3 is 9962 ns, 9963 ns, and 9964 ns, the Gain is 0.8 V, and the E95 width is 0.08 pm, 0.20 pm, and 0.33 pm, respectively.

[0262] Figure 21 The spectrum of the fourth pulse laser PL4 after the search of the second step is shown. Figure 21 The waveforms A, B, and C shown in FIG. 9 are waveforms of the fourth pulse laser PL4 after the search of the second step. The Delay2 is 9 nsec, the Delay3 is 9962 ns, 9963 ns, and 9964 ns, the Gain is 0.8 V, and the E95 width is 0.08 pm, 0.20 pm, and 0.33 pm, respectively. Figure 20 The waveforms A, B, and C shown in FIG. 9 are waveforms of the fourth pulse laser PL4 after the search of the second step. The Delay2 is 9 nsec, the Delay3 is 9962 ns, 9963 ns, and 9964 ns, the Gain is 0.8 V, and the E95 width is 0.08 pm, 0.20 pm, and 0.33 pm, respectively. Figure 21 The waveforms A, B, and C shown in FIG. 9 are waveforms of the fourth pulse laser PL4 after the search of the second step. The Delay2 is 9 nsec, the Delay3 is 9962 ns, 9963 ns, and 9964 ns, the Gain is 0.8 V, and the E95 width is 0.08 pm, 0.20 pm, and 0.33 pm, respectively.

[0263] As shown in FIG. 9, the E95 width of the fourth pulse laser PL4 after the search of the second step is wider than the E95 width of the fourth pulse laser PL4 before the search of the second step. Figure 20 As shown in FIG. 9, the E95 width of the fourth pulse laser PL4 after the search of the second step is wider than the E95 width of the fourth pulse laser PL4 before the search of the second step. Figure 21 As shown in FIG. 9, the E95 width of the fourth pulse laser PL4 after the search of the second step is wider than the E95 width of the fourth pulse laser PL4 before the search of the second step.

[0264] The processors such as the laser control processor 50 and the exposure control processor 61 can also be physically configured in a hardware form to execute various processes included in the present disclosure. For example, the processors can also be computers including a memory in which a control program that specifies various processes is stored and a processing device that executes the control program. The control program can be stored in one memory or can be stored separately in a plurality of memories that exist physically separately, and various processes can be specified by the control program as a whole. The processing device can be a general-purpose processing device such as a CPU or a special-purpose processing device such as a GPU.

[0265] Further, the processors can also be programmed in a software form to execute various processes included in the present disclosure. For example, the processors can also be obtained by installing functions that execute various processes in a dedicated device such as an ASIC or a programmable device such as an FPGA.

[0266] Various processes included in the present disclosure can be executed by one computer, one dedicated device, or one programmable device, or can be executed by cooperation of a plurality of computers, a plurality of dedicated devices, or a plurality of programmable devices that exist physically separately. Various processes can also be executed by a combination of at least two of one or more computers, one or more dedicated devices, and one or more programmable devices.

[0267] 5. Electronic device manufacturing method

[0268] Figure 22A configuration example of the exposure apparatus 60 is schematically shown. The exposure apparatus 60 includes an illumination optical system 62 and a projection optical system 63. The laser device 11 generates laser light and outputs the laser light to the exposure apparatus 60. The illumination optical system 62 illuminates a reticle pattern of an unillustrated reticle arranged on a reticle stage RT with laser light incident from the laser device 11. The projection optical system 63 reduces and projects the laser light that has passed through the reticle, and forms an image on an unillustrated workpiece arranged on a workpiece stage WT. The workpiece can be a photosensitive substrate such as a semiconductor wafer on which a photoresist is coated.

[0269] The exposure apparatus 60 moves the reticle stage RT and the workpiece stage WT in parallel in synchronization, thereby exposing the workpiece to laser light that reflects the reticle pattern. After the reticle pattern is transferred on the semiconductor wafer by the above exposure process, a semiconductor device can be manufactured by a plurality of processes. The semiconductor device is an example of the "electronic device" in the present disclosure.

[0270] 6. Other

[0271] The above description is not restrictive, but merely illustrative. Therefore, it will be understood by those skilled in the art that modifications can be made to the embodiments of the present disclosure without departing from the scope of the claims. In addition, it will be understood by those skilled in the art that the embodiments of the present disclosure can be used in combination.

[0272] Unless explicitly stated otherwise, the terms used throughout the specification and claims should be interpreted as "non-limiting" terms. For example, the terms "comprise", "have", "include", and the like should be interpreted as "not excluding the presence of other structural elements". In addition, the modifier "one" should be interpreted as meaning "at least one" or "one or more". In addition, the term "at least one of A, B, and C" should be interpreted as "A", "B", "C", "A+B", "A+C", "B+C", or "A+B+C". Furthermore, it should be interpreted as also including combinations of other elements than "A", "B", and "C".

Claims

1. A method for adjusting the spectral linewidth, which is a method for adjusting the spectral linewidth of a pulsed laser output by a laser device, the laser device having: The first semiconductor laser emits the first continuous light; The first amplifier amplifies a portion of the first continuous light in sync with the light emission trigger signal received from an external device, thereby converting it into a first pulsed laser. The second amplifier amplifies a portion of the first pulse laser according to the first trigger signal generated synchronously with the light emission trigger signal, thereby converting it into a second pulse laser; The second semiconductor laser emits the second continuous light; The third amplifier amplifies a portion of the second continuous light according to a second trigger signal generated in sync with the light emission trigger signal, thereby converting it into a third pulsed laser. An optical phase modulator is disposed in the optical path of the second continuous light between the second semiconductor laser and the third amplifier; A modulation signal generator whose output is provided to the optical phase modulator as a modulation signal; as well as A wavelength conversion system performs sum-frequency mixing on the second and third pulse lasers to convert the wavelength and outputs a fourth pulse laser. The method for adjusting the spectral linewidth includes the following steps: Step 1: Adjust at least one of the timing of the first trigger signal and the timing of the second trigger signal to adjust the spectrum of the fourth pulse laser into a non-Gaussian first spectrum; as well as The second step involves generating a modulation signal of the same mode synchronized with the light emission trigger signal using the modulation signal generator, and providing the modulation signal of the same mode to the optical phase modulator. This modulates the wavelength of the second continuous light within a time equivalent to one pulse of the third pulse laser, thereby adjusting the spectrum of the fourth pulse laser to a second spectrum with a spectral width wider than the first spectrum.

2. The method for adjusting spectral linewidth according to claim 1, wherein, The laser device also includes a fourth amplifier, which amplifies the second pulse laser and converts it into a fifth pulse laser. The wavelength conversion system performs a sum-frequency mixing of the fifth and third pulse lasers to convert the wavelength, outputting the fourth pulse laser. In the first step, at least one of the timing of the first trigger signal and the timing of the second trigger signal is adjusted, and the amplification gain of the fourth amplifier is adjusted to adjust the spectrum of the fourth pulse laser to the first spectrum, which is non-Gaussian in shape.

3. The method for adjusting spectral linewidth according to claim 1, wherein, The modulated signal is a pseudo-random signal.

4. The method for adjusting spectral linewidth according to claim 3, wherein, The modulation signal generator includes a shift register.

5. The method for adjusting spectral linewidth according to claim 4, wherein, The modulation signal generator includes an initial value setting circuit. In the second step, the initial value of the shift register is set so that the second spectrum has a single peak.

6. The method for adjusting spectral linewidth according to claim 1, wherein, The first spectrum is multimodal, and the second spectrum is unimodal.

7. The method for adjusting spectral linewidth according to claim 1, wherein, The laser device also includes a wavelength conversion crystal, which converts the wavelength of the third pulse laser to become the sixth pulse laser. The wavelength conversion system performs a sum-frequency mixing of the second and sixth pulse lasers to convert the wavelength and outputs the fourth pulse laser.

8. The method for adjusting spectral linewidth according to claim 1, wherein, The wavelength of the fourth pulse laser is 193 nm.

9. The method for adjusting spectral linewidth according to claim 1, wherein, In the first step, the modulated signal generated by the modulated signal generator is not output.

10. The method for adjusting spectral linewidth according to claim 1, wherein, In the first step, the timing of the first trigger signal is adjusted.

11. The method for adjusting spectral linewidth according to claim 10, wherein, In the first step, the start timing of the first trigger signal is changed, and the spectrum of the fourth pulse laser is measured, thereby searching for the start timing of the first trigger signal that makes the spectrum of the fourth pulse laser non-Gaussian shaped like the first spectrum.

12. The method for adjusting spectral linewidth according to claim 10, wherein, In the first step, the spectrum of the fourth pulse laser is measured for all the start timings of the first trigger signal.

13. The method for adjusting spectral linewidth according to claim 11, wherein, In the first step, the spectrum of the measured fourth pulse laser is fitted using the least squares method with a Gaussian waveform to determine whether the spectrum of the fourth pulse laser is non-Gaussian.

14. The method for adjusting spectral linewidth according to claim 11, wherein, In the first step, the start timing of the first trigger signal, which selects the first trigger signal to make the spectrum of the fourth pulse laser non-Gaussian shaped, is such that the difference between the predetermined target linewidth and the spectral linewidth of the fourth pulse laser is within an acceptable range.

15. The method for adjusting spectral linewidth according to claim 1, wherein, In the first step, the timing of the second trigger signal is adjusted.

16. The method for adjusting spectral linewidth according to claim 15, wherein, In the first step, the start timing of the second trigger signal is changed, and the spectrum of the fourth pulse laser is measured, thereby searching for the start timing of the second trigger signal that makes the spectrum of the fourth pulse laser non-Gaussian shaped like the first spectrum.

17. The method for adjusting spectral linewidth according to claim 16, wherein, In the first step, the spectrum of the fourth pulse laser is measured for the full start timing of the second trigger signal.

18. The method for adjusting spectral linewidth according to claim 16, wherein, In the first step, the spectrum of the measured fourth pulse laser is fitted using the least squares method with a Gaussian waveform to determine whether the spectrum of the fourth pulse laser is non-Gaussian.

19. The method for adjusting spectral linewidth according to claim 16, wherein, In the first step, the start timing of the second trigger signal, which is selected to make the spectrum of the fourth pulse laser non-Gaussian, is such that the difference between the predetermined target linewidth and the spectral linewidth of the fourth pulse laser is within an acceptable range.

20. A method for manufacturing an electronic device, comprising the following steps: The fourth laser pulse is generated by a laser device. The fourth laser pulse is output to the exposure device. The fourth pulse laser is used to expose a photosensitive substrate within the exposure apparatus to manufacture electronic devices. The laser device has: The first semiconductor laser emits the first continuous light; The first amplifier amplifies a portion of the first continuous light in sync with the light emission trigger signal received from an external device, thereby converting it into a first pulsed laser. The second amplifier amplifies a portion of the first pulse laser according to the first trigger signal generated synchronously with the light emission trigger signal, thereby converting it into a second pulse laser; The second semiconductor laser emits the second continuous light; The third amplifier amplifies a portion of the second continuous light according to a second trigger signal generated in sync with the light emission trigger signal, thereby converting it into a third pulsed laser. An optical phase modulator is disposed in the optical path of the second continuous light between the second semiconductor laser and the third amplifier; A modulation signal generator whose output is provided to the optical phase modulator as a modulation signal; as well as A wavelength conversion system performs sum-frequency mixing on the second and third pulse lasers to convert the wavelength and outputs the fourth pulse laser. The laser device adjusts at least one of the timing of the first trigger signal and the timing of the second trigger signal to adjust the spectrum of the fourth pulse laser into a non-Gaussian shaped first spectrum. The laser device causes the modulation signal generator to generate a modulation signal of the same mode synchronized with the light emission trigger signal, and provides the modulation signal of the same mode to the optical phase modulator, thereby modulating the wavelength of the second continuous light within a time equivalent to one pulse of the third pulse laser, and adjusting the spectrum of the fourth pulse laser to a second spectrum with a spectral linewidth wider than the first spectrum.

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