Laser apparatus, exposure apparatus, and method for manufacturing electronic device

Abstract

The laser device includes: a laser oscillator that generates pulsed laser light; an actuator that adjusts a laser parameter of the pulse laser; and a laser control processor that controls the actuator by correcting the operating parameter value of the actuator so that the difference between the measured value of the laser parameter and the target value becomes small, on the basis of the change pattern of the pulse time interval of the pulsed laser light that continuously varies within the burst of the burst oscillation by a command from the exposure device.

Description

Technical Field

[0001] The present disclosure relates to a laser device, an exposure device, and a method for manufacturing an electronic device. Background Art

[0002] In recent years, semiconductor exposure equipment has been required to achieve higher resolution as semiconductor integrated circuits become increasingly miniaturized and highly integrated. Consequently, there has been a trend toward shorter wavelengths of light emitted from exposure light sources. For example, gas lasers used for exposure include KrF excimer lasers, which output laser light with a wavelength of approximately 248 nm, and ArF excimer lasers, which output laser light with a wavelength of approximately 193 nm.

[0003] The spectral line width of the natural oscillation light of KrF excimer laser devices and ArF excimer laser devices is relatively wide, ranging from 350 to 400 pm. Therefore, when a projection lens is constructed using a material that transmits ultraviolet light such as KrF and ArF laser light, chromatic aberration may sometimes occur. As a result, the resolution may be reduced. Therefore, it is necessary to narrow the spectral line width of the laser light output from the gas laser device to a level where chromatic aberration is invisible. Therefore, in order to narrow the spectral line width, a narrowing module (Line Narrowing Module: LNM) containing narrowing elements (etalon, grating, etc.) is sometimes included in the laser resonator of the gas laser device. A gas laser device with a narrowed spectral line width is called a narrowed gas laser device.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: U.S. Patent Application Publication No. 2018 / 309259

[0007] Patent Document 2: U.S. Patent Application Publication No. 2017 / 179677 Summary of the Invention

[0008] A laser device according to one aspect of the present disclosure comprises: a laser oscillator that generates pulsed laser light; an actuator that adjusts laser parameters of the pulsed laser light; and a laser control processor that controls the actuator by correcting an action parameter value of the actuator in such a manner that a difference between a measured value of the laser parameter and a target value becomes smaller, based on a changing pattern of a pulse time interval of the pulsed laser light that continuously changes within a burst of burst oscillation according to an instruction from an exposure device.

[0009] An exposure device according to one aspect of the present disclosure is capable of being connected to a laser device, the laser device including a laser oscillator for generating pulsed laser light, an actuator for adjusting laser parameters of the pulsed laser light, and a laser control processor for controlling the actuator, wherein the exposure device comprises: a projection optical system for forming an image on a wafer surface using pulsed laser light output from the laser device; and an exposure control processor for obtaining measured values ​​of the laser parameters of the pulsed laser light, correcting the action parameter values ​​of the actuator in accordance with a change pattern of the pulse time interval of the pulsed laser light that continuously changes within a burst of burst oscillation so as to reduce the difference between the measured value and the target value, and outputting the corrected values ​​to the laser device.

[0010] A method for manufacturing an electronic device according to one aspect of the present disclosure includes the following steps: generating a pulsed laser by a laser device, outputting the pulsed laser to an exposure device, and exposing the pulsed laser on a photosensitive substrate in the exposure device to manufacture the electronic device, wherein the laser device comprises: a laser oscillator that generates the pulsed laser; an actuator that adjusts the laser parameters of the pulsed laser; and a laser control processor that corrects the action parameter value of the actuator and controls the actuator in a manner that reduces the difference between the measured value of the laser parameter and the target value according to a change pattern of the pulse time interval of the pulsed laser that continuously changes within a burst of burst oscillation based on an instruction from the exposure device.

[0011] A method for manufacturing an electronic device according to one aspect of the present disclosure includes the following steps: generating a pulsed laser by a laser device, the laser device including a laser oscillator for generating the pulsed laser, an actuator for adjusting the laser parameters of the pulsed laser, and a laser control processor for controlling the actuator; outputting the pulsed laser to an exposure device, the exposure device including: a projection optical system for forming an image on a wafer surface using the pulsed laser output from the laser device; and an exposure control processor for obtaining a measured value of the laser parameter, correcting an action parameter value of the actuator in accordance with a change pattern of a pulse time interval of the pulsed laser that continuously changes within a burst of burst oscillation so as to reduce the difference between the measured value and the target value, outputting the corrected value to the laser device, exposing the pulsed laser on a photosensitive substrate in the exposure device to manufacture the electronic device. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Several embodiments of the present disclosure are described below by way of example only with reference to the accompanying drawings.

[0013] Figure 1 The configuration of an exposure system in a comparative example is schematically shown.

[0014] Figure 2 The structure of a laser device according to a comparative example is schematically shown.

[0015] Figure 3An example of a semiconductor wafer exposed by the exposure system is shown.

[0016] Figure 4 An example of a trigger signal sent to a power supply is shown.

[0017] Figure 5 and Figure 6 and Figure 7 The following also shows how the position of the scanning field changes relative to the position of the pulsed laser.

[0018] Figure 6 and Figure 5 and Figure 7 The following also shows how the position of the scanning field changes relative to the position of the pulsed laser.

[0019] Figure 7 and Figure 5 and Figure 6 The following also shows how the position of the scanning field changes relative to the position of the pulsed laser.

[0020] Figure 8 The steps of sequentially exposing a plurality of scanning fields are shown.

[0021] Figure 9 Graphs showing changes in the speed and repetition frequency of the work stage when exposing a scan field in a comparative example.

[0022] Figure 10 Graph showing changes in the speed of the workpiece stage and the repetition frequency during accelerated exposure.

[0023] Figure 11 It is a graph showing changes in the repetition frequency and the measured values ​​of the laser parameters in the comparative example.

[0024] Figure 12 It is a graph showing the change in the continuously changing repetition frequency and the measured value of the laser parameter.

[0025] Figure 13 This is a graph showing the measured values ​​of laser parameters in the first embodiment.

[0026] Figure 14 The structure of the laser device according to the first embodiment is schematically shown.

[0027] Figure 15 This is a flowchart of laser control in the first embodiment.

[0028] Figure 16 This is a flowchart showing a first example of the process of acquiring time-series data of pulse time intervals.

[0029] Figure 17This is a flowchart showing a second example of the process of acquiring time-series data of pulse time intervals.

[0030] Figure 18 An example of time series data of pulse time intervals is shown.

[0031] Figure 19 : is a flowchart showing an example of a process of acquiring a target value of a laser parameter.

[0032] Figure 20 An example of target values ​​of laser parameters is shown.

[0033] Figure 21 This is a flowchart showing a first example of the process of acquiring a data set of correction parameter values.

[0034] Figure 22 This is a flowchart showing a second example of the process of acquiring a data set of correction parameter values.

[0035] Figure 23 This is a flowchart showing an example of a process of updating a correction parameter value while performing one burst oscillation.

[0036] Figure 24 : is a flowchart showing an example of a process of calculating a corrected motion parameter value.

[0037] Figure 25 An example of a parameter table is shown.

[0038] Figure 26 : is a flowchart showing an example of a process of calculating an action parameter value corresponding to a target value.

[0039] Figure 27 This is a graph illustrating a method of calculating an operation parameter value based on the relationship between the operation parameter value and the laser parameter value.

[0040] Figure 28 : is a flowchart showing an example of a process of calculating a correction parameter value for the next burst.

[0041] Figure 29 is a flowchart illustrating an example of a process of calculating a control gradient.

[0042] Figure 30 This is a graph illustrating a method of calculating a control gradient based on the relationship between an operation parameter value and a laser parameter value.

[0043] Figure 31 This is a flowchart of laser control in the first modification of the first embodiment.

[0044] Figure 32 This is a flowchart showing an example of a process for performing one burst oscillation.

[0045] Figure 33 This is a flowchart showing an example of processing for acquiring a data set of correction parameter values ​​in the second modification of the first embodiment.

[0046] Figure 34 This is a flowchart showing an example of processing for acquiring the relationship between the operation parameter value and the laser parameter value in the second modification of the first embodiment.

[0047] Figure 35 Examples of trigger signals in the first adjustment oscillation and the second adjustment oscillation are shown.

[0048] Figure 36 An example of the relationship between the operating parameter value and the laser parameter value obtained by the second adjusted oscillation is shown.

[0049] Figure 37 This is a flowchart of laser control in the second embodiment.

[0050] Figure 38 : is a flowchart showing an example of a process of acquiring a target value of a laser parameter.

[0051] Figure 39 An example of target values ​​of laser parameters is shown.

[0052] Figure 40 This is a flowchart showing an example of a process of acquiring a data set of correction parameter values.

[0053] Figure 41 This is a flowchart showing an example of a process of updating a correction parameter value while performing one burst oscillation.

[0054] Figure 42 An example of a parameter table is shown.

[0055] Figure 43 : is a flowchart showing an example of a process of calculating a corrected motion parameter value.

[0056] Figure 44 This is a graph illustrating a method of calculating an operation parameter value based on the relationship between the operation parameter value and the laser parameter value.

[0057] Figure 45 This is a graph illustrating a method of calculating an operation parameter value based on the relationship between the operation parameter value and the laser parameter value.

[0058] Figure 46 This is a graph illustrating a method of calculating an operation parameter value based on the relationship between the operation parameter value and the laser parameter value.

[0059] Figure 47: is a flowchart showing an example of a process of calculating a correction parameter value for the next burst.

[0060] Figure 48 The structure of the laser device according to the third embodiment is schematically shown.

[0061] Figure 49 This is a flowchart of laser control in the third embodiment.

[0062] Figure 50 This is a flowchart showing an example of a process of updating a correction parameter value while performing one burst oscillation.

[0063] Figure 51 : is a flowchart showing an example of a process of calculating a corrected set voltage value and a corrected set value.

[0064] Figure 52 : is a flowchart showing an example of a process of calculating a correction parameter value for the next burst.

[0065] Figure 53 This is a flowchart of laser control in a modified example of the third embodiment.

[0066] Figure 54 This is a flowchart showing an example of a process for performing one burst oscillation.

[0067] Figure 55 The structure of the laser device according to the fourth embodiment is schematically shown.

[0068] Figure 56 This is a graph showing the relationship between the delay time of the second discharge timing relative to the first discharge timing and the line width of the pulsed laser light output from the laser amplifier.

[0069] Figure 57 The structure of the laser device according to the fifth embodiment is schematically shown.

[0070] Figure 58 The structures of the exposure apparatus and the laser apparatus according to the sixth embodiment are schematically shown. DETAILED DESCRIPTION

[0071] <Content>

[0072] 1. Comparative Example

[0073] 1.1 Structure of Exposure Device 100

[0074] 1.2 Operation of Exposure Device 100

[0075] 1.3 Structure of Laser Device 1

[0076] 1.4 Operation of Laser Device 1

[0077] 1.5 step scan exposure

[0078] 1.6 Issues Associated with Changes in Repetition Frequency f

[0079] 2. Laser device 1a using the correction parameter value ΔAc for each pulse of burst oscillation

[0080] 2.1 Conception

[0081] 2.2 Structure

[0082] 2.3 Action

[0083] 2.3.1 Main Process

[0084] 2.3.2 Obtaining the Time Series Data of Pulse Time Interval ΔT

[0085] 2.3.3 Obtaining the target value Lt of the laser parameter L

[0086] 2.3.4 Acquisition of the Dataset of the Correction Parameter Value ΔAc

[0087] 2.3.5 Sudden Oscillation and Update of Correction Parameter ΔAc

[0088] 2.3.5.1 Calculation of Corrected Action Parameter Value Ac(k)

[0089] 2.3.5.2 Calculation of the correction parameter value ΔAc(k) for the next burst

[0090] 2.4 Function

[0091] 3. Laser device 1a that does not update correction parameter value ΔAc during exposure

[0092] 3.1 Action

[0093] 3.1.1 Main Process

[0094] 3.1.2 Sudden Oscillation

[0095] 3.2 Function

[0096] 4. Laser device 1a performing second adjustment oscillation

[0097] 4.1 Action

[0098] 4.1.1 Acquisition of the Dataset of the Correction Parameter Value ΔAc

[0099] 4.1.2 Second Adjustment Oscillation

[0100] 4.2 Function

[0101] 5. Laser device 1a with synchronous control of pulse energy E, wavelength λ, and line width Δλ

[0102] 6. The laser device 1c receives the set voltage value HV from the exposure device 100

[0103] 6.1 Structure

[0104] 6.2 Action

[0105] 6.2.1 Main Process

[0106] 6.2.2 Sudden Oscillation and Update of Correction Parameter ΔAc

[0107] 6.2.2.1 Calculation of the Corrected Action Parameter Value Ac(k)

[0108] 6.2.2.2 Calculation of the correction parameter value ΔAc(k) for the next burst

[0109] 6.3 Function

[0110] 7. Laser Device 1c Not Updating Correction Parameter Value ΔAc During Exposure

[0111] 8. Laser device 1d that adjusts the spectral line width Δλ by the discharge timing of the laser oscillator 17 and the laser amplifier PO

[0112] 8.1 Structure

[0113] 8.2 Actions

[0114] 9. Laser device 1e including solid-state laser

[0115] 9.1 Structure

[0116] 9.1.1 Laser Oscillator 18

[0117] 9.1.2 Laser Amplifier PA

[0118] 9.2 Action

[0119] 10. Exposure Device 100a Calibrated for Operation Parameter Value A

[0120] 10.1 Structure

[0121] 10.2 Actions

[0122] 10.3 Function

[0123] 11. Others

[0124] Below, embodiments of the present disclosure are described in detail with reference to the accompanying drawings. The embodiments described below illustrate several examples of the present disclosure and do not limit the content of the present disclosure. In addition, the structures and actions described in each embodiment are not necessarily all required structures and actions of the present disclosure. In addition, the same reference numerals are given to the same structural elements, and repeated descriptions are omitted.

[0125] 1. Comparative Example

[0126] Figure 1 The structure of the exposure system in the comparative example is schematically shown. The comparative example of the present disclosure is a method that the applicant recognizes as only known to the applicant, and is not a publicly known example acknowledged by the applicant himself. The exposure system includes a laser device 1 and an exposure device 100. The laser device 1 includes a laser control processor 30. The laser control processor 30 is a processing device including a memory 31 storing a control program and a CPU (central processing unit) 32 that executes the control program. The laser control processor 30 is specially configured or programmed to perform various processes included in the present disclosure. The laser device 1 is configured to output a pulsed laser toward the exposure device 100.

[0127] 1.1 Structure of Exposure Device 100

[0128] Exposure apparatus 100 includes an illumination system 101, a projection system 102, and an exposure control processor 110. Illumination system 101 illuminates the reticle pattern of a mask (not shown) placed on reticle stage RT using pulsed laser light incident from laser device 1. Projection system 102 projects the pulsed laser light transmitted through the reticle into a reduced-size image on a workpiece (not shown) placed on workpiece stage WT. The workpiece is a photosensitive substrate such as a semiconductor wafer coated with a resist film.

[0129] The exposure control processor 110 is a processing device comprising a memory 111 storing a control program and a CPU 112 executing the control program. The exposure control processor 110 is specifically configured or programmed to perform the various processes described herein. The exposure control processor 110 oversees the control of the exposure device 100 and transmits and receives various data and signals to and from the laser control processor 30.

[0130] 1.2 Operation of Exposure Device 100

[0131] The exposure control processor 110 transmits data on target values ​​Lt of laser parameters L and a trigger signal Tr to the laser control processor 30. Laser parameters L include pulse energy E, wavelength λ, and linewidth Δλ, while target values ​​Lt include their target values ​​Et, λt, and Δλt. The laser control processor 30 controls the laser apparatus 1 based on this data and signal. The exposure control processor 110 synchronizes and moves the reticle stage RT and workpiece stage WT parallel to each other in opposite directions. This allows the workpiece to be exposed using pulsed laser light reflecting the reticle pattern.

[0132] Through this exposure process, the mask pattern is transferred onto the semiconductor wafer. Then, electronic devices can be manufactured through multiple processes.

[0133] 1.3 Structure of Laser Device 1

[0134] Figure 2 The structure of the laser device 1 of the comparative example is schematically shown. The laser device 1 includes a laser oscillator 17, a power supply 12, a laser parameter measuring device 16, a shutter 19, and a laser control processor 30. The laser device 1 can be connected to the exposure device 100. Figure 2 The Z axis, V axis, and H axis that are perpendicular to each other are shown in FIG. Pulsed laser light is output from the laser oscillator 17 in the Z direction.

[0135] The laser oscillator 17 includes a laser cavity 10, a discharge electrode 11a, a narrowband module 14, and a spectrum adjuster 15a. The narrowband module 14 and the spectrum adjuster 15a constitute a laser resonator. The laser cavity 10 is arranged on the optical path of the laser resonator. Windows 10a and 10b are provided at both ends of the laser cavity 10. The discharge electrode 11a and a paired discharge electrode (not shown) are arranged inside the laser cavity 10. The discharge electrode (not shown) is located at a position overlapping with the discharge electrode 11a in the V-axis direction perpendicular to the paper. The laser cavity 10 is filled with, for example, a laser gas containing argon or krypton as a rare gas, fluorine as a halogen gas, neon as a buffer gas, and the like.

[0136] The power supply 12 includes a switch 13 and is connected to the discharge electrode 11a and a charger (not shown). The power supply 12 is an example of an actuator in the present disclosure.

[0137] The narrowband module 14 includes a plurality of prisms 14a and 14b, and a grating 14c. Prisms 14a and 14b are arranged in this order on the optical path of light emitted from window 10a. The surfaces of prisms 14a and 14b, through which light enters and exits, are parallel to the V direction. Grating 14c is configured in a Littrow configuration so that the incident angle and diffraction angle of light passing through prisms 14a and 14b coincide. The grooves of grating 14c are oriented parallel to the V direction.

[0138] The prism 14b is supported by a rotating table 14e. The rotating table 14e includes a driver (not shown). The rotating table 14e is an example of an actuator in the present disclosure.

[0139] Spectrum adjuster 15a includes a cylindrical plano-convex lens 15b, a cylindrical plano-concave lens 15c, and a linear stage 15d. The cylindrical plano-concave lens 15c is positioned between the laser cavity 10 and the cylindrical plano-convex lens 15b. The cylindrical plano-convex lens 15b and the cylindrical plano-concave lens 15c are positioned so that the convex surface of the cylindrical plano-convex lens 15b and the concave surface of the cylindrical plano-concave lens 15c face each other. The convex surface of the cylindrical plano-convex lens 15b and the concave surface of the cylindrical plano-concave lens 15c each have a focal axis parallel to the V direction. The flat surface opposite the convex surface of the cylindrical plano-convex lens 15b is coated with a partially reflective film.

[0140] The cylindrical plano-concave lens 15c is supported by a linear stage 15d. The linear stage 15d includes an actuator (not shown). The linear stage 15d is an example of an actuator in the present disclosure.

[0141] A beam splitter 16a is disposed on the optical path of the pulsed laser light output from spectrum adjuster 15a. Beam splitter 16a is configured to transmit a portion of the pulsed laser light toward exposure device 100 with high transmittance and reflect the remaining portion. A laser parameter meter 16 is disposed on the optical path of the pulsed laser light after it is reflected by beam splitter 16a. Laser parameter meter 16 outputs a measured value Lm of the laser parameter L. The measured value Lm includes the measured values ​​Em, λm, and Δλm of the pulse energy E, wavelength λ, and spectral line width Δλ.

[0142] As an example, the laser parameter measurement device 16 includes an energy monitor and a spectrum monitor (not shown). The energy monitor includes a photodiode (not shown) and outputs a signal containing the measured value Em of the pulse energy E of the pulsed laser. The spectrum monitor includes an etalon spectrometer (not shown) and outputs waveform data of the interference fringes of the pulsed laser. A processing device (not shown) included in the laser parameter measurement device 16 calculates the measured values ​​λm and Δλm of the wavelength λ and spectral line width Δλ of the pulsed laser based on the waveform data of the interference fringes. The wavelength λ of the pulsed laser refers to the center wavelength.

[0143] The shutter 19 is located on the optical path of the pulse laser beam after passing through the beam splitter 16a. The shutter 19 is configured to switch between passing and blocking the pulse laser beam toward the exposure device 100.

[0144] 1.4 Operation of Laser Device 1

[0145] The laser control processor 30 receives data on the target value Lt of the laser parameter L and a trigger signal Tr from the exposure control processor 110, and outputs an actuator operating parameter value A based on the target value Lt. The operating parameter value A includes a set voltage value HV for adjusting the pulse energy E, a set value Aλ for the rotation angle of the prism 14b for adjusting the wavelength λ, and a set value AΔλ for the position of the cylindrical plano-concave lens 15c for adjusting the linewidth Δλ. Specifically, the laser control processor 30 transmits the set voltage value HV for the voltage applied to the discharge electrode 11a based on the target value Et of the pulse energy E. The laser control processor 30 transmits the set value Aλ for the rotation angle of the prism 14b based on the target value λt of the wavelength λ to the rotation stage 14e. The laser control processor 30 transmits the set value AΔλ for the position of the cylindrical plano-concave lens 15c based on the target value Δλt of the linewidth Δλ to the linear stage 15d. Furthermore, the laser control processor 30 transmits the trigger signal Tr to the power supply 12.

[0146] When the power supply 12 receives the trigger signal Tr, the switch 13 is turned on. When the switch 13 is turned on, the power supply 12 generates a pulsed high voltage corresponding to the set voltage value HV using electric energy charged by a charger (not shown), and applies the high voltage to the discharge electrode 11a.

[0147] When a high voltage is applied to discharge electrode 11a, a discharge occurs within laser cavity 10. The energy from this discharge excites the laser medium within laser cavity 10, causing it to transition to a higher energy level. As the excited laser medium transitions to a lower energy level, it emits light of a wavelength corresponding to the energy level difference.

[0148] Light generated inside the laser cavity 10 is emitted outside the laser cavity 10 through windows 10a and 10b. Prisms 14a and 14b expand the beam width of the light emitted from window 10a of the laser cavity 10 in the H direction and cause it to enter grating 14c. The light incident on grating 14c from prisms 14a and 14b is reflected by the multiple grooves of grating 14c and diffracted in a direction corresponding to the wavelength of the light. By aligning the incident angle of the light incident on grating 14c with the diffraction angle of diffracted light of the desired wavelength, the wavelength of the diffracted light incident on prism 14b from grating 14c is selected. Prisms 14a and 14b narrow the beam width of the diffracted light incident from grating 14c in the H direction and return the light to the laser cavity 10 through window 10a.

[0149] The cylindrical plano-convex lens 15b included in the spectrum adjuster 15a transmits and outputs a portion of the light emitted from the window 10b of the laser cavity 10 and reflects the other portion and returns to the interior of the laser cavity 10 through the window 10b.

[0150] In this manner, the light emitted from the laser cavity 10 travels back and forth between the band-narrowing module 14 and the spectrum adjuster 15a, being amplified each time it passes through the discharge space within the laser cavity 10. This light is narrowed each time it returns to the band-narrowing module 14. The narrowed light thus oscillated is output from the spectrum adjuster 15a as pulsed laser light.

[0151] The rotation stage 14e included in the bandwidth narrowing module 14 rotates the prism 14b about an axis parallel to the V direction according to the set value Aλ output from the laser control processor 30. This adjusts the selected wavelength of the bandwidth narrowing module 14 and the wavelength λ of the pulsed laser light. Adjustment of the wavelength λ of the pulsed laser light is not limited to the rotation of the prism 14b. Alternatively, the wavelength λ of the pulsed laser light can be adjusted by placing a mirror (not shown) in the bandwidth narrowing module 14 and changing the mirror's orientation to adjust the angle of incidence of the light incident on the grating 14c.

[0152] Linear stage 15d included in spectrum adjuster 15a moves cylindrical plano-concave lens 15c along the optical path between laser cavity 10 and cylindrical plano-convex lens 15b according to set value AΔλ output from laser control processor 30. This adjusts the wavefront of light traveling from spectrum adjuster 15a toward bandwidth narrowing module 14, adjusting the spectral linewidth Δλ of the pulsed laser light.

[0153] The laser parameter meter 16 outputs a measured value Lm of the laser parameter L of the pulsed laser to the laser control processor 30. The measured value Em of the pulse energy E included in the measured value Lm is used by the laser control processor 30 for feedback control of the set voltage value HV. The measured value λm of the wavelength λ included in the measured value Lm is used by the laser control processor 30 for feedback control of the set value Aλ of the rotation angle of the prism 14b. The measured value Δλm of the spectral line width Δλ included in the measured value Lm is used by the laser control processor 30 for feedback control of the set value AΔλ of the position of the cylindrical plano-concave lens 15c.

[0154] 1.5 step scan exposure

[0155] Figure 3 An example of a semiconductor wafer WF exposed by an exposure system is shown. Figure 3, the X-axis and Y-axis that are orthogonal to each other within the surface of the semiconductor wafer WF are shown. The semiconductor wafer WF is, for example, a plate of single crystal silicon having a roughly circular plate shape. The semiconductor wafer WF is coated with, for example, a photosensitive resist film. Exposure of the semiconductor wafer WF is performed in each partition such as scanning fields SF#1, SF#2, etc. Scanning fields SF#1 and SF#2 respectively correspond to areas to which the mask pattern of one mask is transferred. #1 and #2 represent the exposure order. In the case where the exposure order is not specified for explanation, #1, #2, etc. may not be marked. The semiconductor wafer WF is moved to irradiate the first scanning field SF#1 with a pulsed laser, and the scanning field SF#1 is exposed. Then, the semiconductor wafer WF is moved to irradiate the second scanning field SF#2 with a pulsed laser, and the scanning field SF#2 is exposed. Then, the semiconductor wafer WF is moved in the same manner, and all the scanning fields SF are exposed.

[0156] Figure 4 An example of a trigger signal Tr sent to the power supply 12 is shown. When exposing one scanning field SF, pulsed laser light is continuously output at a predetermined repetition frequency. When moving from one scanning field SF to another, the output of pulsed laser light is paused. Continuously outputting pulsed laser light is called a burst. Multiple bursts are required to expose one semiconductor wafer WF. This type of laser oscillation is called a burst oscillation.

[0157] When exposure of the first semiconductor wafer WF#1 is completed, the output of the pulsed laser light to the exposure apparatus 100 is stopped in order to replace the semiconductor wafer WF#1 on the work table WT with the second semiconductor wafer WF#2. However, even with the shutter 19 closed, adjustment oscillation for the purpose of parameter adjustment, etc., can be performed.

[0158] Figures 5 to 7 The figure shows how the position of the scanning field SF changes relative to the position of the pulsed laser. The width of the scanning field SF in the X-axis direction is the same as the width of the pulsed laser beam cross section B in the X-axis direction at the position of the workpiece stage WT. The width of the scanning field SF in the Y-axis direction is larger than the width W of the pulsed laser beam cross section B in the Y-axis direction at the position of the workpiece stage WT.

[0159] according to Figure 5 、 Figure 6 、 Figure 7 The steps of exposing the scanning field SF by the pulse laser are performed in the order of Figure 5As shown, the work table WT is positioned so that the end SFy+ of the scanning field SF in the +Y direction is spaced a predetermined distance in the -Y direction relative to the end By- of the beam cross section B in the -Y direction. Then, the work table WT is accelerated in the +Y direction. Until the end SFy+ of the scanning field SF in the +Y direction coincides with the end By- of the beam cross section B in the -Y direction, the speed of the work table WT is Vy. Figure 6 As shown, the workpiece stage WT is moved so that the position of the scanning field SF moves linearly at a constant speed Vy relative to the position of the beam cross section B, while the scanning field SF is exposed. Figure 7 As shown, the workpiece stage WT is moved until the -Y direction end SFy- of the scanning field SF passes the +Y direction end By+ of the beam cross section B. Then, the exposure of the scanning field SF is completed. In this way, the exposure is performed while the position of the scanning field SF is moved relative to the beam cross section B.

[0160] The time T required to move the scanning field SF at a speed Vy by a distance corresponding to the width W of the beam cross section B of the pulsed laser light is as follows.

[0161] T=W / Vy

[0162] The number Ns of irradiation pulses of the pulsed laser light irradiated to any one location in the scanning field SF is the same as the number of pulses of the pulsed laser light generated in the required time T, as described below.

[0163] Ns=f·T

[0164] Here, f is the repetition frequency of the pulsed laser.

[0165] The number of irradiation pulses Ns is also referred to as the number of gap pulses N. By making the number of irradiation pulses Ns constant at any position in the scanning field SF, the exposure quality in the plane of the scanning field SF becomes constant.

[0166] Figure 8 The following illustrates the steps for sequentially exposing multiple scan fields SF#1, SF#2, and so on. In stepper and scan exposure, the scanning direction switches from the Y direction to the -Y direction, or vice versa, each time the scan field SF#1 moves from the next scan field SF#2. Therefore, it is not possible to move from one scan field SF#1 to the next while maintaining a constant linear motion at velocity Vy. Instead, the velocity component of the workpiece stage WT in the Y direction must be temporarily decelerated to zero and then accelerated in the opposite direction.

[0167] Figure 9This graph shows the changes in the velocity V and repetition rate f of the workpiece stage WT during exposure of the scanning field SF in a comparative example. While the workpiece stage WT is moving linearly at a constant velocity Vy, the scanning field SF is exposed using pulsed laser light at a repetition rate f, such that the number of irradiation pulses Ns remains constant at any position within the scanning field SF. Acceleration from a velocity of zero is required before exposure, and deceleration back to zero is required after exposure. In the comparative example, exposure cannot be performed during the acceleration and deceleration period, potentially hindering improved production efficiency.

[0168] Figure 10 It is a graph showing the changes in the speed V and repetition frequency f of the workpiece stage WT during accelerated exposure. As an exposure technology different from the comparative example, the following technology is proposed: starting the exposure of the scanning field SF before the workpiece stage WT reaches a uniform linear motion, or ending the exposure of the scanning field SF after the workpiece stage WT starts to decelerate. This exposure technology is called accelerated exposure. Acceleration in accelerated exposure refers to a state other than acceleration 0, including deceleration. Figure 9 In the comparative example shown, the repetition frequency f of the pulsed laser during exposure is a constant value. In contrast, during accelerated exposure, the repetition frequency f is changed during exposure to match the change in the speed V of the workpiece table WT, so that the number of irradiation pulses Ns is constant at any position in the scanning field SF.

[0169] In accelerated exposure, exposure begins before the workpiece stage WT reaches velocity Vy. Therefore, the time required from the start to the end of exposure for one scanning field SF is slightly longer than in the comparative example. However, the time required for acceleration from velocity 0 to the start of exposure and the time required for deceleration from the end of exposure to velocity 0 are shorter than in the comparative example, thereby improving overall production efficiency.

[0170] 1.6 Issues Associated with Changes in Repetition Frequency f

[0171] Figure 11 This is a graph showing changes in the repetition frequency f and the measured value Lm of the laser parameter L in the comparative example. When the repetition frequency f changes, the influence of acoustic waves generated within the laser cavity 10 may change, the influence of thermal loads on various optical components may change, or the measured value Lm of the laser parameter L may change due to other factors. However, even if the repetition frequency f changes, when continuously outputting pulsed laser light at the same repetition frequency f as in the comparative example, by performing corrections corresponding to the repetition frequency f based on feedback control of the laser parameter L, the measured value Lm can be brought within the allowable range. For example, the first correction may be performed at the first repetition frequency f1, and the second correction may be performed at the second repetition frequency f2.

[0172] Figure 12Graph showing the continuously changing repetition frequency f and the change in the measured value Lm of the laser parameter L. Figure 12 The variation of the repetition frequency f shown is equivalent to Figure 10 The change in repetition frequency f during the period shown in Figure XII. When outputting pulsed laser light while continuously changing the repetition frequency f, even if correction corresponding to the repetition frequency f is performed based on feedback control for each pulse, it may be difficult to keep the measured value Lm within the allowable range. For example, even if the same correction is performed when the repetition frequency f is increased and reaches the first repetition frequency f1 and when the repetition frequency f is decreased and reaches the first repetition frequency f1, the measured value Lm will not be the same. This is presumably because even if the repetition frequency f remains the same, the density and temperature distribution of the gas in the laser cavity 10, as well as the temperature of the optical element, vary depending on the past history of changes in the repetition frequency f.

[0173] Figure 12 The history h1 of the change in the repetition frequency f up to time t1 is different from the history h2 of the change in the repetition frequency f up to time t2. It is believed that the influence of such a history varies from pulse to pulse. Therefore, when controlling the laser parameter L in the case of continuously changing the repetition frequency f, different corrections may be required depending on the history.

[0174] An object of the present disclosure is to provide a laser device or a control method thereof, which stabilizes a measured value Lm of a laser parameter L at a value close to a target value Lt while continuously changing a repetition frequency f.

[0175] 2. Laser device 1a using the correction parameter value ΔAc for each pulse of burst oscillation

[0176] 2.1 Conception

[0177] Figure 13 This is a graph of the measured value Lm of the laser parameter L in the first embodiment. The repetition frequency f is minimum immediately after the start and immediately before the end of a burst. During the burst, the repetition frequency f gradually increases and then gradually decreases. If the variation pattern of the repetition frequency f is the same in the first and second bursts, the history of the variation of the repetition frequency f is the same for pulses with the same output order in each of the first and second bursts.

[0178] Therefore, a correction parameter value ΔAc for each pulse is calculated based on the difference between the measured value Lm of each pulse in the first burst and the target value Lt. This correction parameter value ΔAc is used to control the laser parameter L for each pulse in the second burst, which is output in the same order. This allows the measured value Lm of each pulse in the second burst to be closer to the target value Lt than the measured value Lm of each pulse in the first burst. Furthermore, by updating the correction parameter value ΔAc while repeatedly performing bursts, the accuracy of the correction parameter value ΔAc can be improved. The correction parameter value ΔAc includes any of the correction parameter value ΔHVc for correcting the set voltage value HV, the correction parameter value ΔAλc for correcting the set value Aλ of the rotation angle of prism 14b, and the correction parameter value ΔAΔλc for correcting the set value AΔλ of the position of the cylindrical plano-concave lens 15c.

[0179] 2.2 Structure

[0180] Figure 14 The structure of the laser device 1a according to the first embodiment is schematically shown. In the laser device 1a, the laser control processor 30 includes an internal trigger oscillator 33. The internal trigger oscillator 33 is configured to generate a trigger signal Tr and transmit it to the power supply 12 even when performing adjustment oscillation (described later), even without receiving a trigger signal Tr from the exposure control processor 110.

[0181] The exposure control processor 110 sends the timing data of the pulse time interval ΔT to the laser control processor 30. The timing data of the pulse time interval ΔT refers to Figure 18 This will be described later.

[0182] The laser control processor 30 is configured to be able to access a parameter table PT. The parameter table PT stores the correction parameter value ΔAc for each pulse in the burst. The parameter table PT is equivalent to the table in the present disclosure. The parameter table PT is further referred to as Figure 25 This will be described later.

[0183] The laser control processor 30 uses the correction parameter value ΔAc to correct the operating parameter value A calculated based on the target value Lt, and transmits the corrected operating parameter value Ac to the corresponding actuator. The corrected operating parameter value Ac includes any one of the corrected set voltage value HVc, the corrected set value Aλc of the rotation angle of the prism 14b, and the corrected set value AΔλc of the position of the cylindrical plano-concave lens 15c.

[0184] 2.3 Action

[0185] 2.3.1 Main Process

[0186] Figure 15This is a flowchart of laser control in the first embodiment. The laser control processor 30 performs burst oscillation using the correction parameter value ΔAc through the following processing, while updating the correction parameter value ΔAc for the next burst.

[0187] In S10, the laser control processor 30 obtains the time series data of the pulse time interval ΔT. Figures 16 to 18 This will be described later.

[0188] In S20, the laser control processor 30 obtains the target value Lt of the laser parameter L. For details of S20, refer to Figure 19 and Figure 20 This will be described later.

[0189] In S30, the laser control processor 30 obtains a data set of correction parameter values ​​ΔAc. Figure 21 and Figure 22 This will be described later.

[0190] In S40, the laser control processor 30 sends a preparation OK signal for accelerated exposure to the exposure control processor 110. Upon receiving the preparation OK signal, the exposure control processor 110 prepares the work stage WT and the like and then sends various data and a trigger signal Tr to the laser control processor 30.

[0191] In S50, the laser control processor 30 performs one burst oscillation using the correction parameter value ΔAc and updates the correction parameter value ΔAc for the next burst. Figures 23 to 30 This will be described later.

[0192] In S80, the laser control processor 30 determines whether to continue the accelerated exposure. For example, if the exposure device 100 has stopped the accelerated exposure and is performing exposure using constant velocity linear motion, it is determined that the accelerated exposure is not to be continued. If the accelerated exposure is not to be continued (S80: No), the laser control processor 30 ends the process in this flowchart. If the accelerated exposure is to be continued (S80: Yes), the laser control processor 30 proceeds to S90.

[0193] At S90, the laser control processor 30 determines whether to update the timing data for the pulse interval ΔT. If the exposure apparatus 100 changes the variation pattern of the pulse interval ΔT, the timing data for the pulse interval ΔT is determined to be updated. If the timing data for the pulse interval ΔT is updated (S90: Yes), the laser control processor 30 returns the process to S10 to retrieve the appropriate correction parameter value ΔAc. If the timing data for the pulse interval ΔT is not updated (S90: No), the laser control processor 30 returns the process to S50.

[0194] 2.3.2 Obtaining the Time Series Data of Pulse Time Interval ΔT

[0195] Figure 16 This is a flowchart showing a first example of a process for acquiring time series data of a pulse time interval ΔT. Figure 16 Equivalent to Figure 15 In S11, the laser control processor 30 obtains the timing data of the pulse time interval ΔT by receiving it from the exposure control processor 110. After S11, the laser control processor 30 ends the processing of this flowchart and returns to Figure 15 The processing shown.

[0196] Figure 17 This is a flowchart showing a second example of the process of acquiring time-series data of the pulse time interval ΔT. Figure 17 Equivalent to Figure 15 In S12, the laser control processor 30 receives the trigger signal Tr from the exposure control processor 110, measures the time interval of the trigger signal Tr, and thereby obtains the timing data of the pulse time interval ΔT. After S12, the laser control processor 30 ends the processing of this flowchart and returns to Figure 15 The trigger signal Tr received in S12 may be a trigger signal Tr generated during exposure in the exposure device 100 or a dummy trigger signal Tr generated when exposure is not performed.

[0197] Figure 18An example of timing data of a pulse time interval ΔT is shown. Let kmax be the number of pulses contained in one burst. As the pulse number k in the burst, integer values ​​from 1 to kmax are assigned according to the output order of the pulses. For each pulse number k, a pulse time interval ΔT is assigned as the time difference from the previous pulse. The pulse time interval ΔT for a specific pulse number k is expressed as pulse time interval ΔT(k). For example, pulse time interval ΔT(2) is the time interval from the output time of the pulse with pulse number 1 to the output time of the pulse with pulse number 2. Pulse time interval ΔT(1) may also be the length of the pause period before the start of the burst, for example. Alternatively, pulse time interval ΔT(1) may be a blank. Instead of pulse time interval ΔT(k), timing data of the reciprocal of pulse time interval ΔT(k), i.e., repetition frequency f, may be obtained.

[0198] 2.3.3 Obtaining the target value Lt of the laser parameter L

[0199] Figure 19 1 is a flowchart showing an example of a process for acquiring a target value Lt of a laser parameter L. FIG. Figure 19 Equivalent to Figure 15 In S21, the laser control processor 30 obtains the target value Lt by receiving it from the exposure control processor 110. After S21, the laser control processor 30 ends the processing of this flowchart and returns to Figure 15 The processing shown.

[0200] Figure 20 An example of the target value Lt of the laser parameter L is shown. The target value Lt can also be set for each pulse number k and stored in association with the pulse number k. The target value Lt for a specific pulse number k is represented as target value Lt(k). Target values ​​Lt(1) to Lt(kmax) can all be the same value.

[0201] 2.3.4 Acquisition of the Dataset of the Correction Parameter Value ΔAc

[0202] Figure 21 This is a flowchart showing a first example of a process for acquiring a data set of correction parameter values ​​ΔAc. Figure 21 Equivalent to Figure 15 In the first example, when exposure is not performed by the exposure device 100, the laser device 1a is used to adjust the oscillation and obtain a data set of the correction parameter value ΔAc.

[0203] In S36, the laser control processor 30 transmits a start signal for adjusting oscillation to the exposure control processor 110. If the laser device 1a can start adjusting oscillation, the exposure control processor 110 transmits a start OK signal to the laser control processor 30.

[0204] In S37, the laser control processor 30 determines whether it has received a start OK signal for adjusting oscillation. If it has not received a start OK signal (S37: No), the laser control processor 30 waits until it receives a start OK signal. If it has received a start OK signal (S37: Yes), the laser control processor 30 proceeds to S38.

[0205] In S38, the laser control processor 30 closes the shutter 19. Alternatively, if another shutter is provided in the exposure device 100 and the shutter 19 is closed before the exposure control processor 110 outputs the start OK signal, the shutter 19 may not be opened or closed.

[0206] In S50, the laser control processor 30 performs one burst oscillation using the correction parameter value ΔAc and updates the correction parameter value ΔAc for the next burst. Figure 15 The same processing is applied to the S50 included in the Figure 15 In the process, the trigger signal Tr is received from the exposure control processor 110 to perform burst oscillation. In contrast, in Figure 21 In the embodiment, the internal trigger oscillator 33 can also generate a trigger signal Tr and perform burst oscillation. Figure 21 In the case of the initial burst oscillation, the correction parameter values ​​ΔAc read in may all be 0. Figure 21 The sudden oscillation performed in S50 is equivalent to the first adjustment oscillation in the present disclosure. Figures 23 to 30 This will be described later.

[0207] In S61, the laser control processor 30 determines whether the measured value Lm of the laser parameter L for all pulses in the burst is within the allowable range. If the measured value Lm of one or more pulses in the burst is outside the allowable range (S61: No), the laser control processor 30 returns the process to S50. The process of S50 may be repeated multiple times until the measured value Lm of all pulses in the burst is within the allowable range. If the measured value Lm of all pulses in the burst is within the allowable range (S61: Yes), the laser control processor 30 proceeds to S62. Alternatively, the process may not only determine whether the measured value Lm of each pulse is within the allowable range, but also evaluate the deviation of the measured value Lm using an indicator such as standard deviation to further determine whether the deviation is within the allowable range.

[0208] In S62, the laser control processor 30 opens the shutter 19. After S62, the laser control processor 30 ends the processing of this flowchart and returns to Figure 15 The processing shown.

[0209] Figure 22 This is a flowchart showing a second example of the process of acquiring a data set of correction parameter values ​​ΔAc. Figure 22 Equivalent to Figure 15 In the second example, the correction parameter value ΔAc is obtained from the past log data (not shown) of the correction parameter value ΔAc. The log data may also be a plurality of change patterns of the pulse time interval ΔT, each of which is stored separately. Figure 25 Such parameter data is shown in the PT table.

[0210] In S31, the laser control processor 30 searches for the log data of the correction parameter value ΔAc, using as search keys the timing data of the pulse time interval ΔT, the target value Lt of the laser parameter L, and other exposure condition data.

[0211] In S32, the laser control processor 30 determines whether there is a data set of correction parameter values ​​ΔAc that matches the search keyword. If there is a data set of correction parameter values ​​ΔAc that matches the search keyword (S32: Yes), the laser control processor 30 advances the process to S33. If there is no data set of correction parameter values ​​ΔAc that matches the search keyword (S32: No), the laser control processor 30 advances the process to S33. Figure 21 Then, in S36, the oscillation adjustment is performed to obtain a data set of the correction parameter value ΔAc.

[0212] In S33, the laser control processor 30 reads the data set of the correction parameter value ΔAc that matches the search keyword from the log data. After S33, the laser control processor 30 ends the processing of this flowchart and returns to Figure 15 The data set of correction parameter values ​​ΔAc read in S33 can also be used to control the pulse laser for performing accelerated exposure.

[0213] Alternatively, after S33, the laser control processor 30 may also cause the process to enter Figure 21 In step S36, the correction parameter value ΔAc read in step S33 is used as the initial value of the correction parameter value ΔAc during the adjustment oscillation. In this case, the measured value Lm of the laser parameter L can be brought into the allowable range as quickly as possible, thereby reducing the number of bursts during the adjustment oscillation and improving the reliability of the correction parameter value ΔAc.

[0214] 2.3.5 Sudden Oscillation and Update of Correction Parameter ΔAc

[0215] Figure 23 4 is a flowchart showing an example of a process of updating the correction parameter value ΔAc while performing one burst oscillation. Figure 23 Shows the equivalent of Figure 15The S50 subroutine, and is also equivalent to Figure 21 The same processing as the subroutine of S50. Figure 15 In S50 of the embodiment, the exposure is accelerated after S40. Figure 21 In S50 , oscillation adjustment is performed after S38 .

[0216] In S51 , the laser control processor 30 sets the value of the pulse number k to 1. (k) is added to the end of each reference numeral indicating a value when the pulse number k is determined for explanation.

[0217] In S54, the laser control processor 30 uses the correction parameter value ΔAc(k) to correct the motion parameter value A(k) calculated based on the target value Lt(k), thereby calculating the corrected motion parameter value Ac(k). Figures 24 to 27 This will be described later.

[0218] In S55, the laser control processor 30 performs laser oscillation of one pulse and generates pulsed laser. Figure 15 The S50 subroutine is performed Figure 23 When the processing is performed, the generated pulse laser is output to the exposure device 100. Figure 21 The S50 subroutine is performed Figure 23 During the processing, the generated pulse laser may not be output to the exposure device 100.

[0219] The processing of S55 is performed at a timing based on the pulse time interval ΔT(k). That is, the time difference between the pulse lasers of pulse number k-1 and pulse number k becomes the pulse time interval ΔT(k). Figure 15 The S50 subroutine is performed Figure 23 When and as Figure 21 The S50 subroutine is performed Figure 23 When the pulse time interval ΔT is processed, the change pattern is the same. Therefore, it is possible to Figure 21 The correction parameter value ΔAc(k) obtained in S50 according to the variation pattern of the pulse time interval ΔT is used to Figure 15 In S50, the action parameter value A(k) is corrected.

[0220] In S56, the laser control processor 30 calculates the correction parameter value ΔAc(k) for the next burst so that the difference between the measured value Lm(k) of the laser parameter L and the target value Lt(k) in the next burst becomes smaller. Figures 28 to 30 This will be described later.

[0221] In S57, the laser control processor 30 determines whether the value of pulse number k has reached the number of pulses kmax for one burst. If the value of pulse number k has not reached the number of pulses kmax (S57: No), in S58, the laser control processor 30 adds 1 to the value of pulse number k to update the value of k, and returns the process to S54. If the value of pulse number k has reached the number of pulses kmax (S57: Yes), one burst has ended, and the laser control processor 30 ends the process of this flowchart and returns to S54. Figure 15 or Figure 21 The processing shown.

[0222] 2.3.5.1 Calculation of Corrected Action Parameter Value Ac(k)

[0223] Figure 24 : is a flowchart showing an example of a process of calculating a corrected motion parameter value Ac(k). Figure 24 Equivalent to Figure 23 The S54 subroutine.

[0224] In S541, the laser control processor 30 reads Figure 19 The target value Lt(k) of the laser parameter L is obtained.

[0225] In S542, the laser control processor 30 calculates the action parameter value A(k) corresponding to the target value Lt(k). At this time, no correction is performed based on the correction parameter value ΔAc(k). Figure 26 and Figure 27 This will be described later.

[0226] In S543, the laser control processor 30 reads the correction parameter value ΔAc(k) from the parameter table PT.

[0227] In S544, the laser control processor 30 adds the correction parameter value ΔAc(k) to the operating parameter value A(k) to calculate the corrected operating parameter value Ac(k). If the correction parameter value ΔAc(k) is 0, the corrected operating parameter value Ac(k) becomes the same as the operating parameter value A(k).

[0228] In S545, the laser control processor 30 controls the actuator using the corrected motion parameter value Ac(k). If the laser parameter L to be controlled is the pulse energy E, the actuator is the power supply 12. If the laser parameter L to be controlled is the wavelength λ, the actuator is the rotary stage 14e. If the laser parameter L to be controlled is the line width Δλ, the actuator is the linear stage 15d. By starting the control of the actuator before the process enters S546, the actuator can be driven as quickly as possible to catch up with S55 (see Figure 23) in one pulse of laser oscillation.

[0229] In S546, the laser control processor 30 writes the correction parameter value ΔAc(k) as the old correction parameter value ΔAcp(k) into the parameter table PT. The old correction parameter value ΔAcp(k) is the correction parameter value used in laser oscillation and is used in S56 (refer to Figure 23 ) in the correction parameter value ΔAc(k). After S546, the laser control processor 30 ends the processing of this flowchart and returns to Figure 23 The processing shown.

[0230] Figure 25 An example of the parameter table PT is shown. The correction parameter value ΔAc(k) is stored in correspondence with the pulse number k and the pulse time interval ΔT(k) of the pulse included in one burst. Furthermore, the old correction parameter value ΔAcp(k) is stored in correspondence with these. Furthermore, the target value Lt(k) of the laser parameter L may also be stored in correspondence with these (see Figure 20 ).

[0231] Figure 26 1 is a flowchart showing an example of a process of calculating an action parameter value A(k) corresponding to a target value Lt(k). Figure 26 Equivalent to Figure 24 The S542 subroutine.

[0232] In S5421, the laser control processor 30 reads the relationship between the action parameter value A and the laser parameter L. The relationship between the action parameter value A and the laser parameter L can also be obtained by referring to Figures 33 to 36 The oscillation is obtained by additional adjustment described later and stored in the memory 31 .

[0233] In S5422, the laser control processor 30 calculates the action parameter value A(k) corresponding to the target value Lt(k) of the laser parameter L based on the relationship between the action parameter value A and the value of the laser parameter L. After S5422, the laser control processor 30 ends the processing of this flowchart and returns to Figure 24 The processing shown.

[0234] Figure 27This graph illustrates a method for calculating the action parameter value A(k) based on the relationship between the action parameter value A and the laser parameter L. The relationship between the action parameter value A and the laser parameter L can be expressed using an approximate formula or table data. When the relationship between the action parameter value A and the laser parameter L is expressed using an approximate formula, the action parameter value A(k) corresponding to the target value Lt(k) can be calculated based on this approximate formula. When the relationship between the action parameter value A and the laser parameter L is expressed using table data, and data corresponding to the target value Lt(k) is not included in the table data, the action parameter value A(k) can also be calculated using linear interpolation.

[0235] 2.3.5.2 Calculation of the correction parameter value ΔAc(k) for the next burst

[0236] Figure 28 : is a flowchart showing an example of a process of calculating a correction parameter value ΔAc(k) for the next burst. Figure 28 Equivalent to Figure 23 The S56 subroutine.

[0237] In S561, the laser control processor 30 obtains the value obtained in S55 (see Figure 23 ) is the measured value Lm(k) of the laser parameter L of the pulsed laser generated in .

[0238] In S562, the laser control processor 30 calculates the difference Le(k) between the measured value Lm(k) and the target value Lt(k) using the following equation.

[0239] Le(k)=Lt(k)-Lm(k)

[0240] In S563, the laser control processor 30 reads the old correction parameter value ΔAcp(k) from the parameter table PT.

[0241] In S564, the laser control processor 30 calculates the control gradient G(k) corresponding to the action parameter value A(k). Figure 29 and Figure 30 This will be described later.

[0242] In S565 , the laser control processor 30 adds the value obtained by dividing the difference Le(k) by the control gradient G(k) to the old correction parameter value ΔAcp(k), thereby calculating the correction parameter value ΔAc(k).

[0243] In S566, the laser control processor 30 writes the correction parameter value ΔAc(k) calculated in S565 into the parameter table PT. The correction parameter value ΔAc(k) is used in the next burst in S54 (refer to Figure 23) in which the action parameter value A(k) is corrected. After S566, the laser control processor 30 ends the processing of this flowchart and returns to Figure 23 The processing shown. Figure 23 Before performing laser oscillation of the next pulse in the current burst ( S55 ), the correction parameter value ΔAc(k) for the next burst is calculated.

[0244] Figure 29 : is a flowchart showing an example of a process of calculating the control gradient G(k). Figure 29 Equivalent to Figure 28 The S564 subroutine.

[0245] In S5641, the laser control processor 30 reads the relationship between the action parameter value A and the value of the laser parameter L. The relationship between the action parameter value A and the value of the laser parameter L can be the same as that in Figure 26 The same relationship is read in.

[0246] In S5642, the laser control processor 30 calculates the control gradient G(k) corresponding to the action parameter value A(k) based on the relationship between the action parameter value A and the laser parameter L. After S5642, the laser control processor 30 ends the processing of this flowchart and returns to Figure 28 The processing shown.

[0247] Figure 30 This graph illustrates a method for calculating the control gradient G(k) based on the relationship between the operating parameter value A and the laser parameter L. When the relationship between the operating parameter value A and the laser parameter L is expressed using an approximate equation, the differential value of the operating parameter value A(k) in this approximate equation can be used as the control gradient G(k). When the relationship between the operating parameter value A and the laser parameter L is expressed using table data, the control gradient G(k) can also be calculated based on the gradients between multiple measurement points close to the operating parameter value A(k).

[0248] 2.4 Function

[0249] (1) According to the first embodiment, the laser device 1a includes: a laser oscillator 17 for generating pulsed laser light; an actuator such as a power supply 12, a rotary stage 14e, and a linear stage 15d for adjusting a laser parameter L of the pulsed laser light; and a laser control processor 30. The laser control processor 30 controls the actuator by correcting an operating parameter value A of the actuator so as to reduce a difference Le between a measured value Lm of the laser parameter L and a target value Lt, based on a variation pattern of a pulse time interval ΔT of the pulsed laser light that continuously varies within a burst of burst oscillation, as instructed by the exposure device 100.

[0250] When the pulse time interval ΔT continuously changes, simply correcting the pulse time interval ΔT may not stabilize the measured value Lm near the target value Lt. By correcting the operating parameter value A based on the changing pattern of the pulse time interval ΔT, the difference Le between the measured value Lm and the target value Lt can be brought within an acceptable range.

[0251] (2) According to the first embodiment, the laser control processor 30 calculates the correction parameter value ΔAc for each pulse based on the difference Le between the measured value Lm of each of the consecutive multiple pulses in the first burst and the target value Lt, and corrects the action parameter value A calculated based on the target value Lt in the second burst after the first burst based on the correction parameter value ΔAc.

[0252] Therefore, in most cases, at least a portion of the variation pattern of the pulse time interval ΔT is the same between bursts. Therefore, by applying the correction parameter value ΔAc calculated in the first burst to the second burst, appropriate correction based on the variation pattern of the pulse time interval ΔT can be performed.

[0253] (3) According to the first embodiment, the laser control processor 30 calculates the correction parameter value ΔAc used in the second burst following the first burst while generating the pulsed laser light in the first burst.

[0254] Thus, while generating the pulsed laser light in the first burst, the correction parameter value ΔAc is calculated based on the difference Le between the measured value Lm and the target value Lt in the first burst. Therefore, the correction parameter value ΔAc can be calculated quickly.

[0255] (4) According to the first embodiment, the laser control processor 30 starts calculating the correction parameter value ΔAc used in the second burst after the first burst, after outputting the first pulse of pulsed laser light in the first burst and before outputting the second pulse of pulsed laser light following the first pulse.

[0256] Thus, the calculation starts before the next pulse is output, and therefore the correction parameter value ΔAc can be calculated quickly.

[0257] (5) According to the first embodiment, the laser control processor 30 calculates the correction parameter value ΔAc based on the old correction parameter value ΔAcp for each pulse used in the first burst and the difference Le between the measured value Lm for each pulse in the first burst and the target value Lt.

[0258] Thus, the old correction parameter value ΔAcp is used, and therefore the accuracy of the correction parameter value ΔAc used in the next burst can be improved.

[0259] (6) According to the first embodiment, the laser control processor 30 calculates the correction parameter value ΔAc(k) by adding the value obtained by dividing the difference Le(k) by the control gradient G(k) obtained based on the operation parameter value A(k) to the old correction parameter value ΔAcp(k).

[0260] Thus, the optimal control gradient G(k) can be changed according to the operation parameter value A(k). Therefore, by obtaining the appropriate control gradient G(k) corresponding to the operation parameter value A(k), the appropriate correction parameter value ΔAc(k) can be calculated.

[0261] (7) According to the first embodiment, the laser control processor 30 is configured to access the parameter table PT storing the correction parameter value ΔAc for each pulse in the variation pattern, and to correct the action parameter value A for each pulse calculated from the target value Lt based on the correction parameter value ΔAc.

[0262] Thus, by accessing the parameter table PT, the operation parameter value A can be quickly corrected.

[0263] (8) According to the first embodiment, the laser control processor 30 is configured to be able to access a parameter table PT that differs for each variation pattern, and to determine the parameter table PT from which the correction parameter value ΔAc is to be read according to the variation pattern.

[0264] Thus, even when the variation pattern of the pulse time interval ΔT changes, an appropriate correction parameter value ΔAc can be obtained.

[0265] (9) According to the first embodiment, the parameter table PT stores data of the pulse time interval ΔT and the correction parameter value ΔAc for each pulse in association with each other.

[0266] Thus, when there is past data corresponding to the same change pattern, the past correction parameter value ΔAc can be used.

[0267] (10) According to the first embodiment, the parameter table PT includes the correction parameter value ΔAc for each pulse included in one burst.

[0268] Thus, by using the parameter table PT corresponding to one burst, it is unnecessary to read a plurality of parameter tables PT in one burst, and the operation parameter value A can be corrected efficiently.

[0269] (11) According to the first embodiment, the parameter table PT is configured to store the correction parameter value ΔAc and the old correction parameter value ΔAcp that was used in the past as the correction parameter value ΔAc. After the laser control processor 30 reads the correction parameter value ΔAc to calibrate the operation parameter value A, it stores the old correction parameter value ΔAcp in the parameter table PT, and updates the correction parameter value ΔAc using the old correction parameter value ΔAcp and stores the updated correction parameter value ΔAc in the parameter table PT.

[0270] Thus, by separately storing the correction parameter value ΔAc and the old correction parameter value ΔAcp, correction of the operating parameter value A using the correction parameter value ΔAc and updating of the correction parameter value ΔAc using the old correction parameter value ΔAcp and the measured value Lm can be smoothly performed.

[0271] (12) According to the first embodiment, the laser control processor 30 performs the first adjustment oscillation of generating a pulsed laser according to the variation pattern of the pulse time interval ΔT and the target value Lt of the laser parameter L, obtains the measured value Lm, and calculates the correction parameter value ΔAc of each pulse according to the difference Le between the target value Lt and the measured value Lm of each pulse, thereby preparing the parameter table PT.

[0272] Thus, by performing adjustment oscillation, an appropriate correction parameter value ΔAc can be obtained.

[0273] (13) According to the first embodiment, the laser control processor 30 performs the following processing multiple times: performs the first adjustment oscillation and creates the parameter table PT, and ends the first adjustment oscillation when the difference Le between the target value Lt and the measured value Lm is within the allowable range.

[0274] Thus, by performing adjustment oscillation multiple times, the accuracy of the correction parameter value ΔAc is improved, and by performing adjustment oscillation until the difference Le falls within the allowable range, an appropriate correction parameter value ΔAc can be obtained.

[0275] Regarding other aspects, the first embodiment is the same as the comparative example.

[0276] 3. Laser device 1a that does not update correction parameter value ΔAc during exposure

[0277] 3.1 Action

[0278] 3.1.1 Main Process

[0279] Figure 31 This is a flowchart of laser control in the first modified example of the first embodiment. Figure 14 In the laser control of the first variant, instead of Figure 15 The processing of S50a and S70a is performed instead of S50.

[0280] In S50a, the laser control processor 30 performs one burst oscillation using the correction parameter value ΔAc. However, the correction parameter value ΔAc is not updated. For details of S50a, refer to Figure 32 This will be described later.

[0281] In S70a, the laser control processor 30 determines whether to perform adjustment oscillation. For example, when a sufficient rest period is expected, such as when replacing a semiconductor wafer WF or a mask in the exposure device 100, it is determined that adjustment oscillation is to be performed. Alternatively, it is possible to determine whether a start OK signal for adjustment oscillation is received from the exposure control processor 110. In this case, the step S70a can be omitted. Figure 21 Alternatively, when the difference between the measured value Lm of the laser parameter L and the target value Lt is greater than the threshold value, it may be determined that the oscillation adjustment is to be performed. When the oscillation adjustment is to be performed (S70a: Yes), the laser control processor 30 returns the process to S30. In S30, as shown in FIG. Figure 21 The process of S50 is performed as described above, and the process of S50a is not performed. When the oscillation adjustment is not performed (S70a: No), the laser control processor 30 advances the process to S80.

[0282] 3.1.2 Sudden Oscillation

[0283] Figure 32 This is a flowchart showing an example of a process for performing one burst oscillation. Figure 32 Equivalent to Figure 31 The S50a subroutine. Figure 32 and Figure 23 The difference is that the processing of S56 is not included.

[0284] 3.2 Function

[0285] (14) In the first variation of the first embodiment, when the first adjustment oscillation is not performed between the first burst and the second burst following the first burst, the laser control processor 30 corrects the action parameter value A using a data set of the same correction parameter value ΔAc in the first burst and the second burst.

[0286] Thus, if the characteristics of the laser device 1a do not fluctuate significantly during exposure, the measured value Lm of the laser parameter L can be kept within the allowable range even without updating the correction parameter value ΔAc during exposure. Furthermore, since the correction parameter value ΔAc is not updated during exposure, the correction parameter value ΔAc does not fluctuate, ensuring stable control.

[0287] Regarding other points, the first modification of the first embodiment is the same as the first embodiment.

[0288] 4. Laser device 1a performing second adjustment oscillation

[0289] 4.1 Action

[0290] 4.1.1 Acquisition of the Dataset of the Correction Parameter Value ΔAc

[0291] Figure 33 This is a flowchart showing an example of processing for obtaining a data set of correction parameter values ​​ΔAc in the second modification of the first embodiment. Figure 14 In the second variant, Figure 21 After S38 and before the first adjustment oscillation in S50, S39e is added to perform the second adjustment oscillation.

[0292] In S39e, the laser control processor 30 performs the second adjustment oscillation and obtains the relationship between the operation parameter value A and the value of the laser parameter L. For details of S39e, refer to Figure 34 The following explains.

[0293] 4.1.2 Second Adjustment Oscillation

[0294] Figure 34 This is a flowchart showing an example of processing for acquiring the relationship between the operating parameter value A and the value of the laser parameter L in the second modification of the first embodiment. Figure 34 Equivalent to Figure 33 The S39e subroutine.

[0295] In S391e, the laser control processor 30 starts laser oscillation at a fixed repetition frequency fa. The laser control processor 30 may also generate a trigger signal Tr of the repetition frequency fa via an internal trigger oscillator 33. The repetition frequency fa is set to a repetition frequency at which the laser parameter L is not easily affected by acoustic waves, for example, 3 kHz or less, preferably 10 Hz to 1 kHz or less.

[0296] Figure 35 Examples of trigger signals Tr in the first and second adjusted oscillations are shown. In the first adjusted oscillation, trigger signal Tr continuously varies the pulse interval ΔT according to the pulse interval ΔT variation pattern. The maximum value of the pulse interval ΔT is ΔTmax. However, the maximum value of the pulse interval ΔT does not include the pause period between bursts. Meanwhile, the pulse interval in the second adjusted oscillation is fixed at 1 / fa, the inverse of the repetition frequency fa, and 1 / fa is longer than ΔTmax.

[0297] Refer again Figure 34In S392e, the laser control processor 30 sets the value of the counter n for counting the drawing number nmax of the operation parameter value A to 0.

[0298] In S393e, the laser control processor 30 adds 1 to the value of the counter n to update the value of n.

[0299] In S394e, the laser control processor 30 sets the operating parameter value A(n). For example, the initial operating parameter value A(1) is set to the lower limit value of the operating parameter value A. The actuator is controlled according to the set operating parameter value A(n) to generate pulsed laser light.

[0300] In S395e, the laser control processor 30 obtains the measured value Lm(n) of the laser parameter L of the generated pulsed laser light from the laser parameter measuring device 16. The measured value Lm(n) may be a value obtained by averaging the measured values ​​Lm of a plurality of pulses of the pulsed laser light.

[0301] In S396e, the laser control processor 30 associates the operation parameter value A(n) with the measurement value Lm(n) and stores them.

[0302] In S397e, the laser control processor 30 determines whether the value of counter n has reached the drawing number nmax. If the value of counter n has reached the drawing number nmax (S397e: Yes), the laser control processor 30 terminates laser oscillation at the repetition frequency fa and ends the processing in this flowchart. If the value of counter n has not reached the drawing number nmax (S397e: No), the laser control processor 30 adds the increment width ΔA to the current operating parameter value A(n) to calculate the next operating parameter value A(n+1), and then returns to S393e.

[0303] Figure 36 An example of the relationship between the operating parameter value A and the laser parameter L obtained by the second adjustment oscillation is shown. The measured value Lm(n) is calculated for each operating parameter value A(n), and by associating them, the relationship between the operating parameter value A and the laser parameter L can be obtained.

[0304] 4.2 Function

[0305] (15) According to the second variant of the first embodiment, the laser control processor 30 performs a second adjustment oscillation to generate a pulsed laser while changing the action parameter value A, obtains the relationship between the action parameter value A and the measurement value Lm, and calculates either the action parameter value A or the correction parameter value ΔAc based on the relationship.

[0306] Thus, the second adjustment oscillation is performed, and the relationship between the operating parameter value A and the value of the laser parameter L is obtained. Based on this relationship, the first adjustment oscillation is performed. Therefore, the operating parameter value A(k) is calculated with high accuracy in the first adjustment oscillation (see Figure 27 ), or calculate the control gradient G(k) (refer to Figure 30 ), the correction parameter value ΔAc(k) can be calculated with high accuracy. For example, the characteristics of the laser device 1a may change due to changes in the gas composition inside the laser cavity 10. Therefore, each time the first adjustment oscillation is performed, it is preferable to perform the second adjustment oscillation before the first adjustment oscillation.

[0307] (16) According to the second modification of the first embodiment, the pulse time interval 1 / fa in the second adjustment oscillation is longer than the longest time interval ΔTmax among the pulse time intervals that vary according to the variation pattern in the first adjustment oscillation.

[0308] This allows the relationship between the operating parameter value A and the laser parameter L to be acquired with little influence of the fluctuation of the pulse time interval ΔT, and enables accurate correction taking into account the influence of the fluctuation of the pulse time interval ΔT.

[0309] The second modification is similar to the first embodiment in other respects. In the second modification, the correction parameter value ΔAc may not be updated during exposure, similar to the first modification.

[0310] 5. Laser device 1a with synchronous control of pulse energy E, wavelength λ, and line width Δλ

[0311] Figure 37 This is a flowchart of laser control in the second embodiment. Figure 14 In the laser control of the second embodiment, instead of the target value Lt of the laser parameter L, target values ​​Et, λt, and Δλt of the pulse energy E, wavelength λ, and line width Δλ are acquired ( S20 b ).

[0312] In the second embodiment, instead of the correction parameter value ΔAc, the correction parameter value ΔHVc for correcting the set voltage value HV, the correction parameter value ΔAλc for correcting the set value Aλ of the rotation angle of the prism 14b, and the correction parameter value ΔAΔλc for correcting the set value AΔλ of the position of the cylindrical plano-concave lens 15c are obtained (S30b), and they are updated (S50b).

[0313] Figure 38 1 is a flowchart showing an example of a process for acquiring a target value Lt of a laser parameter L. FIG. Figure 39 An example of the target value Lt of the laser parameter L is shown. Figure 404 is a flowchart illustrating an example of a process for acquiring a data set of correction parameter values ​​ΔAc. Figure 41 4 is a flowchart showing an example of a process of updating the correction parameter value ΔAc while performing one burst oscillation. Figure 42 An example of the parameter table PT is shown. Figure 43 : is a flowchart showing an example of a process of calculating a corrected motion parameter value Ac(k). Figures 44 to 46 This is a graph illustrating a method of calculating the operating parameter value A(k) based on the relationship between the operating parameter value A and the value of the laser parameter L. Figure 47 Flowcharts illustrating an example of processing for calculating the correction parameter value ΔAc(k) for the next burst. These figures illustrate the case where the pulse energy E, wavelength λ, and line width Δλ are controlled as laser parameters L in synchronization with each pulse of the pulsed laser. Other than this, the figures are identical to the corresponding figures in the first embodiment.

[0314] The three factors of pulse energy E, wavelength λ, and line width Δλ may change in conjunction with each other. For example, after the pulse energy E falls within the allowable range, if the control of wavelength λ and line width Δλ is changed, the pulse energy E may also change. Figure 40 As shown, it is determined whether the measured values ​​Em, λm and Δλm of the pulse energy E, wavelength λ and spectral line width Δλ are all within the allowable range (S61b). If any one of them is outside the allowable range (S61b: No), the correction parameter values ​​ΔHVc, ΔAλc and ΔAΔλc are all updated (S50b), thereby making the measured values ​​Em, λm and Δλm all close to the target values.

[0315] In other respects, the second embodiment is the same as the first embodiment. In the second embodiment, the correction parameter value ΔAc may not be updated during exposure, similarly to the first modification of the first embodiment, and the second adjustment oscillation may be performed, similarly to the second modification of the first embodiment.

[0316] 6. The laser device 1c receives the set voltage value HV from the exposure device 100

[0317] 6.1 Structure

[0318] Figure 48 The structure of a laser device 1c according to a third embodiment is schematically shown. In the third embodiment, the exposure device 100 includes a pulse energy meter 116. The pulse energy meter 116 outputs a measured value Em2 of the pulse energy E to the exposure control processor 110. The exposure control processor 110 outputs a set voltage value HV for adjusting the pulse energy E to the laser control processor 30 instead of a target value Et of the pulse energy E.

[0319] 6.2 Action

[0320] 6.2.1 Main Process

[0321] Figure 49 This is a flow chart of the laser control in the third embodiment. In the laser control in the third embodiment, instead of Figure 37 S50b is executed and S50c is performed.

[0322] In S50c, the laser control processor 30 uses the correction parameter values ​​ΔHVc, ΔAλc, and ΔAΔλc to perform one burst oscillation, while updating the correction parameter values ​​ΔAλc and ΔAΔλc for the next burst. However, the correction parameter value ΔHVc is not updated. This is because, in the exposure device 100, feedback control of the set voltage value HV is performed for each pulse based on the measured value Em2 of the pulse energy E. If the correction parameter value ΔHVc is updated during exposure, the pulse energy E may become unstable. For details of S50c, see Figure 50 The following explains.

[0323] 6.2.2 Sudden Oscillation and Update of Correction Parameter ΔAc

[0324] Figure 50 4 is a flowchart showing an example of a process of updating the correction parameter value ΔAc while performing one burst oscillation. Figure 50 Equivalent to Figure 49 The S50c subroutine. Figure 50 In place of Figure 41 Instead of S54b, perform S52c and S54c. Figure 41 S56b is executed and S56c is processed.

[0325] In S52c, the laser control processor 30 receives the set voltage value HV from the exposure control processor 110. The laser control processor 30 stores the set voltage value HV in the memory 31 as the set voltage value HV(k) corresponding to the pulse number k.

[0326] In S54c, the laser control processor 30 corrects the set voltage value HV(k), the set value Aλ(k), and the set value AΔλ(k), thereby calculating the corrected set voltage value HVc(k), the corrected set value Aλc(k), and the corrected set value AΔλc(k). For details of S54c, refer to Figure 51 This will be described later.

[0327] In S56c, the laser control processor 30 calculates the correction parameter values ​​ΔAλc(k) and ΔAΔλc(k) for the next burst. Figure 52 This will be described later.

[0328] 6.2.2.1 Calculation of the Corrected Action Parameter Value Ac(k)

[0329] Figure 51 1 is a flowchart showing an example of a process of calculating the corrected set voltage value HVc(k), the corrected set value Aλc(k), and the corrected set value AΔλc(k). Figure 51 Equivalent to Figure 50 The S54c subroutine. Figure 51 In place of Figure 43 Instead of S541b and S542b, perform S541c and S542c. Figure 43 S546b is processed and S546c is performed.

[0330] In S541c, the laser control processor 30 may not read the target value Et(k) of the pulse energy E, and in S542c, may not calculate the set voltage value HV(k) corresponding to the target value Et(k). This is because in S52c (refer to Figure 50 ) has been obtained in the set voltage value HV(k). The target value Et of the pulse energy E is adjusted in the oscillation ( Figure 49 However, during exposure ( Figures 50 to 52 ) is not used, so in Figure 49 In S20b, only typical values ​​may be determined.

[0331] In S546c, the laser control processor 30 may not write the correction parameter value ΔHVc(k) as the old correction parameter value ΔHVcp(k) into the parameter table PT. This is because the pulse energy E may be unstable when the correction parameter value ΔHVc(k) is updated in parallel with the feedback control of each pulse in the exposure device 100.

[0332] 6.2.2.2 Calculation of the correction parameter value ΔAc(k) for the next burst

[0333] Figure 52 : is a flowchart showing an example of a process of calculating a correction parameter value ΔAc(k) for the next burst. Figure 52 Equivalent to Figure 50 The S56c subroutine. Figure 52 In the process, the calculation of the correction parameter value ΔHVc(k) based on the measured value Em(k) of the pulse energy E may not be performed.

[0334] 6.3 Function

[0335] (17) According to the third embodiment, the laser parameter L includes the pulse energy E. The laser control processor 30 receives the set voltage value HV for adjusting the pulse energy E as the operation parameter value A from the exposure device 100, and corrects the set voltage value HV using a data set of the same correction parameter value ΔAc in the first burst and the second burst.

[0336] Thus, when receiving the set voltage value HV from the exposure device 100 , the correction parameter value ΔHVc(k) is not updated during exposure, thereby suppressing instability of the pulse energy E and enabling high-precision control based on the set voltage value HV set by the exposure device 100 .

[0337] Regarding other aspects, the third embodiment is the same as the second embodiment. Alternatively, in the third embodiment, the second adjustment oscillation may be performed in the same manner as in the second modification of the first embodiment.

[0338] 7. Laser Device 1c Not Updating Correction Parameter Value ΔAc During Exposure

[0339] Figure 53 This is a flowchart of laser control in a modified example of the third embodiment. Figure 48 In the laser control of the modified example, instead of Figure 49 The processing of S50d and S70a is performed instead of S50c.

[0340] In S50d, the laser control processor 30 performs one burst oscillation using the correction parameter value ΔAc. However, the correction parameter value ΔAc is not updated. For details of S50d, refer to Figure 54 This will be described later.

[0341] The processing of S70a is as follows Figure 31 As described.

[0342] Figure 54 This is a flowchart showing an example of a process for performing one burst oscillation. Figure 54 Equivalent to Figure 53 The S50d subroutine. Figure 54 and Figure 50 The difference is that the processing of S56c is not included.

[0343] Regarding other aspects, the modification of the third embodiment is the same as the third embodiment.

[0344] 8. Laser device 1d that adjusts the spectral line width Δλ by the discharge timing of the laser oscillator 17 and the laser amplifier PO

[0345] 8.1 Structure

[0346] Figure 55 The structure of a laser device 1d according to the fourth embodiment is schematically shown. In the laser device 1d, the laser oscillator 17 includes an output coupling mirror 15 instead of the spectrum adjuster 15a. One surface of the output coupling mirror 15 is coated with a partially reflective film. The output coupling mirror 15 does not necessarily have the function of adjusting the spectral line width Δλ.

[0347] The laser device 1d includes a laser amplifier PO between the laser oscillator 17 and the beam splitter 16a. The laser amplifier PO includes a laser cavity 20, discharge electrodes 21a and 21b, a rear mirror 24, and an output coupling mirror 25. The rear mirror 24 is made of a material that allows pulsed laser light to pass through, and a partial reflection film is coated on one surface thereof. The reflectivity of the rear mirror 24 is set to be higher than the reflectivity of the output coupling mirror 25. The laser cavity 20 is arranged on the optical path of the laser resonator composed of the rear mirror 24 and the output coupling mirror 25. Windows 20a and 20b are provided at both ends of the laser cavity 20. Discharge electrodes 21a and 21b are arranged inside the laser cavity 20. A power supply 22 is connected to the discharge electrode 21a, and the power supply 22 is connected to a charger not shown in the figure. The power supply 22 includes a switch 23.

[0348] In other respects, the above-mentioned components of the laser amplifier PO are the same as the corresponding components of the laser oscillator 17. In addition, as the optical resonator of the laser amplifier PO, a Fabry-Perot type resonator is shown as an example, but the present invention is not limited to this example and the optical resonator may also be a ring resonator.

[0349] 8.2 Action

[0350] The laser control processor 30 sets a target value Et1 of the pulse energy E1 of the pulse laser light B1 output from the laser oscillator 17. The laser control processor 30 also receives, from the exposure control processor 110, the target values ​​Et, λt, and Δλt of the pulse energy E, wavelength λ, and line width Δλ of the pulse laser light B2 output from the laser amplifier PO, the pulse time interval ΔT, and the trigger signal Tr.

[0351] The laser control processor 30 sends set voltage values ​​HV1 and HVc to the power supplies 12 and 22 respectively based on the target values ​​Et1 and Et. The laser control processor 30 sends a first trigger signal Tr1 and a second trigger signal Tr2 to the power supplies 12 and 22 respectively based on the trigger signal Tr.

[0352] Upon receiving the second trigger signal Tr2 from the laser control processor 30, the switch 23 included in the power supply 22 is turned on. When the switch 23 is turned on, the power supply 22 generates a pulsed high voltage using electrical energy charged by a charger (not shown) and applies the pulsed high voltage to the discharge electrode 21a.

[0353] The timing of the second trigger signal Tr2 for switch 23 relative to the timing of the first trigger signal Tr1 for switch 13 is controlled so that the second discharge timing for generating discharge inside the laser cavity 20 is synchronized with the first discharge timing for generating discharge inside the laser cavity 10 by a delay time δT.

[0354] The pulsed laser B1 generated by the discharge in the laser cavity 10 and incident on the laser cavity 20 travels back and forth between the rear mirror 24 and the output coupling mirror 25 and is amplified each time it passes through the discharge space inside the laser cavity 20. The amplified pulsed laser B2 is output from the output coupling mirror 25.

[0355] Figure 56 This graph shows the relationship between the delay time δT of the second discharge timing relative to the first discharge timing and the linewidth Δλ of the pulsed laser light B2 output from the laser amplifier PO. As the delay time δT shortens, the linewidth Δλ increases, while as the delay time δT lengthens, the linewidth Δλ decreases. Therefore, the linewidth Δλ can be adjusted by the delay time δT. The delay circuit (not shown) used to adjust the delay time δT is an example of an actuator in the present disclosure.

[0356] The laser control processor 30 uses the correction parameter value ΔAΔλc to correct the set value AΔλ for the delay time δT, calculated based on the target value Δλt for the spectral linewidth Δλ received from the exposure control processor 110. The corrected set value AΔλc is then calculated to set the delay time δT. This allows for appropriate control of the spectral linewidth Δλ of the pulsed laser B2 even when the pulse interval ΔT continuously changes within a burst. The laser control processor 30 calculates the correction parameter value ΔAΔλc for the next burst based on the difference between the measured value Δλm of the spectral linewidth Δλ and the target value Δλt, and stores it in the parameter table PT.

[0357] In the fourth embodiment, the case where the spectral line width Δλ is adjusted by the delay time δT is described, but the present disclosure is not limited thereto. The spectrum adjuster 15a may also be arranged at the position of the output coupling mirror 15 (see Figure 14 ), the spectrum line width Δλ is adjusted by the spectrum adjuster 15a.

[0358] The laser control processor 30 corrects the set voltage value HV calculated based on the target value Et of the pulse energy E received from the exposure control processor 110 based on the correction parameter value ΔHVc, calculates the corrected set voltage value HVc, and controls the power supply 22. This allows the pulse energy E of the pulsed laser B2 to be appropriately controlled even when the pulse time interval ΔT continuously changes within a burst. The laser control processor 30 calculates the correction parameter value ΔHVc for the next burst based on the difference between the measured value Em of the pulse energy E and the target value Et, and stores it in the parameter table PT.

[0359] In other respects, the fourth embodiment is the same as the first embodiment. Alternatively, in the fourth embodiment, the correction parameter value ΔAc may not be updated during exposure, similar to the first modification of the first embodiment, and the second adjustment oscillation may be performed, similar to the second modification of the first embodiment. Alternatively, in the fourth embodiment, the pulse energy E, wavelength λ, and line width Δλ may be synchronously controlled, similar to the second embodiment. Alternatively, in the fourth embodiment, the set voltage value HV received from the exposure device 100 may be used, similar to the third embodiment.

[0360] 9. Laser device 1e including solid-state laser

[0361] 9.1 Structure

[0362] Figure 57 The structure of a laser device 1e according to the fifth embodiment is schematically shown. The laser device 1e includes a laser oscillator 18, a solid-state laser control processor 180, and a laser amplifier PA. The laser oscillator 18 includes a solid-state laser, and the laser amplifier PA includes a laser cavity containing an excimer laser gas.

[0363] 9.1.1 Laser Oscillator 18

[0364] The solid-state laser control processor 180 is a processing device including a memory 181 storing a control program and a CPU 182 executing the control program. The solid-state laser control processor 180 is specially configured or programmed to execute various processes included in the present disclosure.

[0365] The laser oscillator 18 includes a semiconductor laser 60, a pulse amplifier 71, and a wavelength conversion system 72. The semiconductor laser 60 includes a distributed feedback semiconductor laser (not shown). The distributed feedback semiconductor laser includes a semiconductor laser element (not shown), a Peltier element, and a function generator (not shown). The Peltier element and the function generator are each an example of an actuator in the present disclosure. The pulse amplifier 71 includes a titanium sapphire crystal (not shown) and a pump pulse laser. The titanium sapphire crystal is arranged on the optical path of the CW laser output from the semiconductor laser 60. The wavelength conversion system 72 includes an LBO (lithium triborate) crystal and a KBBF (potassium beryllium fluoroborate) crystal (not shown).

[0366] 9.1.2 Laser Amplifier PA

[0367] The laser amplifier PA includes a laser cavity 40, discharge electrodes 41a and 41b, a concave mirror 44, and a convex mirror 45. The laser cavity 40 contains argon as a rare gas. Windows 40a and 40b are provided at both ends of the laser cavity 40. Discharge electrodes 41a and 41b are arranged inside the laser cavity 40. A power supply 42 is connected to the discharge electrode 41a, and the power supply 42 is connected to a charger (not shown). The power supply 42 includes a switch 43. The power supply 42 is an example of an actuator in the present disclosure.

[0368] Convex mirror 45 is positioned on the optical path of pulsed laser light B1, which is output from laser oscillator 18 and passes through windows 40a and 40b of laser cavity 40. Concave mirror 44 is positioned on the optical path of pulsed laser light B1, which is reflected by convex mirror 45 and passes through windows 40a and 40b of laser cavity 40 again. The focal points of convex mirror 45 and concave mirror 44 coincide with each other. While a laser amplifier PA is shown as an example of an amplifier included in laser device 1e, this is not limiting and the amplifier may also be a laser amplifier PO including a ring resonator, for example.

[0369] 9.2 Action

[0370] The laser control processor 30 receives the pulse energy E, target values ​​Et, λt, and Δλt of the wavelength λ and line width Δλ, the pulse time interval ΔT, and the trigger signal Tr of the pulse laser B2 from the exposure control processor 110 .

[0371] The laser control processor 30 transmits a set voltage value HVc to the power supply 42 based on the target value Et, and transmits set values ​​Aλc and AΔλc to the solid-state laser control processor 180 based on the target values ​​λt and Δλt. The laser control processor 30 transmits a first trigger signal Tr1 and a second trigger signal Tr2 based on the trigger signal Tr to the solid-state laser control processor 180 and the power supply 42, respectively. The solid-state laser control processor 180 transmits the set values ​​Aλc and AΔλc to the semiconductor laser 60 and transmits the first trigger signal Tr1 to the pulse amplifier 71.

[0372] In the semiconductor laser 60, the semiconductor laser element outputs a CW (continuous wave) laser with a wavelength of approximately 773.6nm. The temperature of the semiconductor laser element is adjusted to a set value Aλc by a Peltier element, thereby adjusting the center wavelength of the CW laser output from the semiconductor laser element. In addition, the current supplied to the semiconductor laser element is increased or decreased at a high frequency by a function generator, thereby linearly modulating the center wavelength of the CW laser. The greater the amplitude of the current to be increased or decreased, the greater the spectral line width of the integrated spectral waveform obtained by integrating the spectral waveform of the CW laser within the range of the pulse time width of the pulsed laser emitted from the pulse amplifier 71. By adjusting the amplitude of the current to be increased or decreased to the set value AΔλc, the spectral line width is adjusted.

[0373] In the pulse amplifier 71 , the titanium sapphire crystal is excited by the pump laser light output from the pump pulse laser. The titanium sapphire crystal amplifies the incident CW laser light during the excited period into a pulsed form and emits the pulsed laser light toward the wavelength conversion system 72 .

[0374] The wavelength conversion system 72 emits the fourth harmonic of the pulsed laser light output from the pulse amplifier 71 as pulsed laser light B1. The wavelength λ of the pulsed laser light B1 corresponds to the amplified wavelength of the ArF excimer laser light that constitutes the laser amplifier PA, which is approximately 193.4 nm. If the laser amplifier PA is composed of KrF excimer laser light, the configuration of the semiconductor laser 60 and the wavelength conversion system 72 is selected so that the pulsed laser light B1 is output at a wavelength that corresponds to the amplified wavelength.

[0375] A high voltage is applied to the discharge electrodes 41 a and 41 b so that discharge starts in the discharge space within the laser cavity 40 in synchronization with the timing at which the pulsed laser light B1 from the laser oscillator 18 enters the laser cavity 40 .

[0376] The pulsed laser light B1 incident on the laser amplifier PA passes through the discharge space in the laser cavity 40 and is reflected by the convex mirror 45, with a beam spread angle corresponding to the curvature of the convex mirror 45. The pulsed laser light B1 passes through the discharge space in the laser cavity 40 again.

[0377] The pulsed laser light B1 reflected by the convex mirror 45 and passing through the laser cavity 40 is reflected by the concave mirror 44 and restored to substantially parallel light. The pulsed laser light B1 passes through the discharge space in the laser cavity 40 once more and is emitted to the outside of the laser amplifier PA as pulsed laser light B2.

[0378] In this way, the beam width of the pulse laser B1 is expanded, and the pulse energy is amplified during the period of passing through the discharge space three times.

[0379] The laser control processor 30 uses the correction parameter value ΔAλc to correct the temperature setting value Aλ calculated based on the target value λt of wavelength λ received from the exposure control processor 110. This corrected setting value Aλc is then calculated to set the temperature of the semiconductor laser element. This allows for appropriate control of the wavelength λ of the pulsed laser B2 even when the pulse interval ΔT continuously changes within a burst. The laser control processor 30 calculates the correction parameter value ΔAλc for the next burst based on the difference between the measured value λm of wavelength λ and the target value λt, and stores it in the parameter table PT.

[0380] The laser control processor 30 uses the correction parameter value ΔAΔλc to correct the set value AΔλ of the current amplitude, calculated based on the target value Δλt of the spectral linewidth Δλ received from the exposure control processor 110. The corrected set value AΔλc is then calculated to set the amplitude of the current supplied to the semiconductor laser element. This allows the spectral linewidth Δλ of the pulsed laser B2 to be appropriately controlled even when the pulse interval ΔT continuously varies within a burst. The laser control processor 30 calculates the correction parameter value ΔAΔλc for the next burst based on the difference between the measured value Δλm of the spectral linewidth Δλ and the target value Δλt, and stores it in the parameter table PT. Furthermore, if the laser oscillator 18 is a solid-state laser, even if the pulse interval ΔT continuously varies within a burst, the effect on the wavelength λ and the spectral linewidth Δλ is minimal, thus eliminating the need for correction of the set values ​​Aλ and AΔλ.

[0381] The laser control processor 30 corrects the set voltage value HV calculated based on the target value Et of the pulse energy E received from the exposure control processor 110 based on the correction parameter value ΔHVc, calculates the corrected set voltage value HVc, and controls the power supply 42. This allows the pulse energy E of the pulsed laser B2 to be appropriately controlled even when the pulse time interval ΔT continuously changes within a burst. The laser control processor 30 calculates the correction parameter value ΔHVc for the next burst based on the difference between the measured value Em of the pulse energy E and the target value Et, and stores it in the parameter table PT.

[0382] In other respects, the fifth embodiment is the same as the first embodiment. Alternatively, in the fifth embodiment, the correction parameter value ΔAc may not be updated during exposure, similar to the first modification of the first embodiment, and the second adjustment oscillation may be performed similar to the second modification of the first embodiment. Alternatively, in the fifth embodiment, the pulse energy E, wavelength λ, and line width Δλ may be synchronously controlled, similar to the second embodiment. Alternatively, in the fifth embodiment, the set voltage value HV received from the exposure device 100 may be used, similar to the third embodiment.

[0383] 10. Exposure Device 100a Calibrated for Operation Parameter Value A

[0384] 10.1 Structure

[0385] Figure 58 The structures of the exposure apparatus 100a and the laser apparatus 1f according to the sixth embodiment are schematically shown. The exposure apparatus 100a includes a pulse energy meter 116 and a parameter table PT. The laser apparatus 1f does not need to include the internal trigger oscillator 33 and the parameter table PT.

[0386] 10.2 Action

[0387] The exposure control processor 110 corrects the motion parameter value A calculated based on the target value Lt of the laser parameter L based on the correction parameter value ΔAc stored in the parameter table PT, and transmits the corrected motion parameter value Ac to the laser control processor 30. The laser control processor 30 may not calculate the corrected motion parameter value Ac. The laser control processor 30 controls the actuator using the corrected motion parameter value Ac received from the exposure control processor 110.

[0388] The exposure control processor 110 obtains a measured value Lm of the laser parameter L. For example, the exposure control processor 110 obtains a measured value Em of the pulse energy E from the pulse energy meter 116, and obtains measured values ​​λm and Δλm of the wavelength λ and line width Δλ from the laser control processor 30. The exposure control processor 110 updates the correction parameter value ΔAc based on the difference Le between the measured value Lm and the target value Lt, and stores the updated value in the parameter table PT.

[0389] 10.3 Function

[0390] (18) According to the sixth embodiment, the exposure device 100a is connectable to a laser device 1f, which includes a laser oscillator 17 for generating pulsed laser light, an actuator for adjusting a laser parameter L of the pulsed laser light, and a laser control processor 30 for controlling the actuator. The exposure device 100a includes a projection optical system 102 and an exposure control processor 110. The projection optical system 102 forms an image on the wafer surface using the pulsed laser light output from the laser device 1f. The exposure control processor 110 obtains a measured value Lm of the laser parameter L of the pulsed laser light, and corrects the actuator's operating parameter value A so as to reduce the difference Le between the measured value Lm and the target value Lt based on the variation pattern of the pulse time interval ΔT of the pulsed laser light that continuously changes within the burst of the burst oscillation, and outputs the corrected value to the laser device 1f.

[0391] Thus, by correcting the operating parameter value A according to the change pattern, the difference Le between the measured value Lm and the target value Lt can be made to fall within the allowable range.

[0392] (19) According to the sixth embodiment, the laser parameter L includes the pulse energy E, and the exposure apparatus 100a further includes a pulse energy meter 116 for measuring the pulse energy E. The exposure control processor 110 obtains the pulse energy E measured by the pulse energy meter 116 as a measured value Lm, corrects the set voltage value HV for adjusting the pulse energy E as an operating parameter value A, and outputs the corrected value to the laser apparatus 1f.

[0393] Thus, by using the pulse energy meter 116 included in the exposure apparatus 100 a , the pulse energy E can be controlled with high precision.

[0394] In other respects, the sixth embodiment is the same as the first embodiment. Alternatively, in the sixth embodiment, the correction parameter value ΔAc may not be updated during exposure, as in the first variant of the first embodiment, and the exposure control processor 110 may output a trigger signal Tr and other signals to cause the laser device 1f to perform a second adjustment oscillation, as in the second variant of the first embodiment. Alternatively, in the sixth embodiment, the pulse energy E, wavelength λ, and spectral line width Δλ may be synchronously controlled, as in the second embodiment. Alternatively, in the sixth embodiment, the spectral line width Δλ may be controlled by the delay time δT between the first discharge timing and the second discharge timing given by the laser oscillator 17 and the laser amplifier PO, as in the fourth embodiment. Alternatively, in the sixth embodiment, a solid-state laser may be used as the laser oscillator 18, as in the fifth embodiment.

[0395] 11. Others

[0396] The above description is not limiting, but merely illustrative. Therefore, those skilled in the art will appreciate that modifications can be made to the embodiments of the present disclosure without departing from the scope of the claims. Furthermore, those skilled in the art will appreciate that combinations of the embodiments of the present disclosure can be used.

[0397] Unless otherwise expressly stated, the terms used in this specification and claims as a whole should be interpreted as “non-limiting” terms. For example, terms such as “including”, “having”, “having”, and “equipped” should be interpreted as “excluding the presence of structural elements other than the structural elements to be recorded”. In addition, the modifier “one” should be interpreted as meaning “at least one” or “one or more”. In addition, terms such as “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 these and parts other than “A”, “B”, and “C”.

Claims

1. A laser device comprising: a laser oscillator that generates pulsed laser light; an actuator for adjusting laser parameters of the pulsed laser; and A laser control processor controls the actuator by correcting the action parameter value of the actuator in a manner that reduces the difference between the measured value of the laser parameter and the target value based on the change pattern of the pulse time interval of the pulse laser that continuously changes within the burst of burst oscillation through instructions from the exposure device.

2. The laser device according to claim 1, wherein The laser control processor calculates a correction parameter value for each pulse based on a difference between the measured value of each of the plurality of consecutive pulses in the first burst and the target value. The laser control processor corrects the operation parameter value calculated from the target value in the second burst following the first burst based on the correction parameter value.

3. The laser device according to claim 2, wherein The laser control processor calculates the correction parameter value used in the second burst while generating the pulsed laser light in the first burst.

4. The laser device according to claim 2, wherein The laser control processor starts calculating the correction parameter value used in the second burst after outputting the first pulse in the first burst and before outputting the second pulse following the first pulse.

5. The laser device according to claim 2, wherein The laser control processor calculates the correction parameter value based on an old correction parameter value for each pulse used in the first burst and a difference between the measured value for each pulse in the first burst and the target value.

6. The laser device according to claim 5, wherein The laser control processor calculates the correction parameter value by adding a value obtained by dividing the difference by a control gradient obtained based on the operation parameter value to the old correction parameter value.

7. The laser device according to claim 1, wherein The laser control processor is configured to access a table storing correction parameter values ​​for each pulse in the variation pattern. The laser control processor corrects the motion parameter value for each pulse calculated based on the target value according to the correction parameter value.

8. The laser device according to claim 7, wherein The laser control processor is configured to be able to access the table that is different for each of the change patterns. The laser control processor determines the table of correction parameter values ​​to be read out based on the change pattern.

9. The laser device according to claim 7, wherein: The table stores the data of the pulse time interval and the correction parameter value of each pulse in correspondence.

10. The laser device according to claim 7, wherein The table contains the correction parameter value for each pulse included in one burst.

11. The laser device according to claim 7, wherein The table is configured to store the correction parameter value and an old correction parameter value used in the past as the correction parameter value. After reading the correction parameter value in order to correct the operation parameter value, the laser control processor stores the correction parameter value in the table as the old correction parameter value. The laser control processor updates the correction parameter value using the old correction parameter value and stores it in the table.

12. The laser device according to claim 7, wherein The laser control processor performs a first adjustment oscillation to generate the pulse laser according to the change pattern and the target value, and obtains the measured value. The laser control processor calculates the correction parameter value for each pulse based on the difference between the target value and the measured value for each pulse and creates the table.

13. The laser device according to claim 12, wherein: The laser control processor performs the following processing multiple times: performing the first adjustment oscillation and creating the table, When the difference between the target value and the measured value is within an allowable range, the laser control processor ends the first adjustment oscillation.

14. The laser device according to claim 12, wherein When the first adjustment oscillation is not performed between a first burst and a second burst following the first burst, the laser control processor corrects the operation parameter value using the data set of the correction parameter value that is the same in the first burst and the second burst.

15. The laser device according to claim 12, wherein The laser control processor generates the second adjusted oscillation of the pulse laser while changing the operating parameter value, and obtains the relationship between the operating parameter value and the measured value. The laser control processor calculates either the operation parameter value or the correction parameter value based on the relationship.

16. The laser device according to claim 15, wherein The time interval between pulses in the second adjusted oscillation is longer than the longest time interval among the time intervals between pulses that change according to the change pattern in the first adjusted oscillation.

17. The laser device according to claim 7, wherein The laser parameters include pulse energy, The laser control processor receives a set voltage value for adjusting the pulse energy from the exposure device as the operation parameter value, The laser control processor corrects the set voltage value using the data set of the correction parameter value that is the same in the first burst and the second burst.

18. An exposure device capable of being connected to a laser device, the laser device comprising a laser oscillator for generating pulsed laser light, an actuator for adjusting laser parameters of the pulsed laser light, and a laser control processor for controlling the actuator, wherein: The exposure device comprises: a projection optical system for forming an image on a wafer surface using the pulsed laser light output from the laser device; as well as An exposure control processor obtains the measured value of the laser parameter, corrects the action parameter value of the actuator in a manner that reduces the difference between the measured value and the target value based on the change pattern of the pulse time interval of the pulse laser that continuously changes within the burst of burst oscillation, and outputs it to the laser device.

19. The exposure apparatus according to claim 18, wherein The laser parameters include pulse energy, The exposure device further includes a pulse energy meter for measuring the pulse energy. The exposure control processor obtains the pulse energy measured by the pulse energy meter as the measured value, corrects a set voltage value for adjusting the pulse energy as the operating parameter value, and outputs the corrected value to the laser device.

20. A method for manufacturing an electronic device, comprising the following steps: Generate pulsed laser light through a laser device, Outputting the pulse laser to an exposure device, The pulse laser is exposed on a photosensitive substrate in the exposure device to manufacture an electronic device. The laser device has: a laser oscillator that generates the pulsed laser light; an actuator for adjusting laser parameters of the pulsed laser; and A laser control processor corrects the action parameter value of the actuator and controls the actuator in a manner that reduces the difference between the measured value of the laser parameter and the target value based on the change pattern of the pulse time interval of the pulse laser that continuously changes within the burst of burst oscillation through the instruction of the exposure device.

21. A method for manufacturing an electronic device, comprising the following steps: generating pulsed laser light by a laser device, the laser device including a laser oscillator for generating the pulsed laser light, an actuator for adjusting laser parameters of the pulsed laser light, and a laser control processor for controlling the actuator; The pulse laser is output to an exposure device, the exposure device comprising: a projection optical system for forming an image on a wafer surface using the pulse laser output from the laser device; and an exposure control processor for obtaining a measured value of the laser parameter, correcting an operating parameter value of the actuator in a manner that reduces a difference between the measured value and a target value based on a variation pattern of a pulse time interval of the pulse laser that continuously varies within a burst of burst oscillation, and outputting the corrected value to the laser device. The pulsed laser is exposed on a photosensitive substrate in the exposure device to manufacture an electronic device.

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