Laser device and method for manufacturing electronic device

Abstract

A laser device according to one aspect of the present disclosure is provided with: an oscillation device that outputs pulsed laser light; a beam intensity distribution measurement device that measures the beam intensity distribution of the pulsed laser light; a beam angle distribution measurement device that measures the beam angle distribution of the pulse laser light; a pulse waveform measurement device that measures the pulse waveform of the pulse laser light; a spectrum measurement device that measures the spectrum of the pulse laser light; and a laser controller that calculates speckle contrast on the basis of each measurement data of the beam intensity distribution, the beam angle distribution, the pulse waveform, and the spectrum.

Description

Technical Field

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

[0002] In recent years, in semiconductor exposure devices, as semiconductor integrated circuits become smaller and more highly integrated, there is a demand for improved resolution. Therefore, the wavelength of light emitted from an exposure light source has been shortened. For example, as a gas laser device for exposure, a KrF excimer laser device that outputs a laser with a wavelength of about 248 nm and an ArF excimer laser device that outputs a laser with a wavelength of about 193.4 nm are used.

[0003] The spectral line width of the natural oscillation light of the KrF excimer laser device and the ArF excimer laser device is relatively wide, at 350 to 400 pm. Therefore, when a projection lens is constructed using a material that allows ultraviolet light such as KrF and ArF lasers to pass through, chromatic aberration sometimes occurs. As a result, the resolution may be reduced. Therefore, it is necessary to narrow the spectral line width of the laser output from the gas laser device to a level where chromatic aberration can be ignored. Therefore, in order to narrow the spectral line width, a narrowing module (Line Narrowing Module) containing narrowing elements (etalon, grating, etc.) is sometimes provided in the laser resonator of the gas laser device. In this way, 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 No. 9945730

[0007] Patent Document 2: International Publication No. 2007 / 053335

[0008] Patent Document 3: U.S. Patent Application Publication No. 2020 / 0060557 Summary of the invention

[0009] A laser device according to one aspect of the present disclosure comprises: an oscillator that outputs a pulsed laser; a beam intensity distribution measuring device that measures the beam intensity distribution of the pulsed laser; a beam angle distribution measuring device that measures the beam angle distribution of the pulsed laser; a pulse waveform measuring device that measures the pulse waveform of the pulsed laser; a spectrum measuring device that measures the spectrum of the pulsed laser; and a laser controller that calculates speckle contrast based on the measured data of the beam intensity distribution, beam angle distribution, pulse waveform, and spectrum.

[0010] A method for manufacturing an electronic device according to one aspect of the present disclosure includes the following steps: outputting a pulsed laser from a laser device to an exposure device, exposing the pulsed laser on a photosensitive substrate in the exposure device to manufacture the electronic device, the laser device comprising: an oscillator that outputs a pulsed laser; a beam intensity distribution measuring device that measures the beam intensity distribution of the pulsed laser; a beam angle distribution measuring device that measures the beam angle distribution of the pulsed laser; a pulse waveform measuring device that measures the pulse waveform of the pulsed laser; a spectrum measuring device that measures the spectrum of the pulsed laser; and a laser controller that calculates speckle contrast based on each measured data of the beam intensity distribution, beam angle distribution, pulse waveform and spectrum. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Several embodiments of the present disclosure are described below by way of example only with reference to the accompanying drawings.

[0012] Figure 1 is a diagram showing an example of a speckle image.

[0013] Figure 2 : is a diagram schematically showing the intensity distribution of a speckle image.

[0014] Figure 3 This is a diagram showing an overview of FWHM as an example of the spectral line width.

[0015] Figure 4 This is a diagram showing an overview of E95 as an example of the spectral line width.

[0016] Figure 5 It is a diagram schematically showing the structure of a laser device according to a comparative example.

[0017] Figure 6 It is a diagram for explaining the problems of the laser device of the comparative example.

[0018] Figure 7 This is a diagram schematically showing the structure of the laser device according to the first embodiment.

[0019] Figure 8 This is a diagram schematically showing the configuration of a beam measuring device.

[0020] Fig. 9 It is a diagram schematically showing the structure of a spectrum measuring device.

[0021] Fig.10 This is a diagram showing an example of interference fringes.

[0022] Fig.11 This is a diagram schematically showing the structure of a laser device according to a second embodiment.

[0023] Fig.12 It is a diagram schematically showing the structure of a gas control device.

[0024] Fig.13 is a graph showing the relationship between pulse width and cavity F 2 A diagram showing an example of the relationship between gas pressures.

[0025] Fig.14 It is a flowchart schematically showing the flow of control of the SC.

[0026] Fig.15 This is a diagram schematically showing the structure of a laser device according to a modified example of the second embodiment.

[0027] Fig.16 This is a diagram schematically showing the structure of a wavefront changing device.

[0028] Fig.17 This is a flowchart schematically showing the flow of control of the SC according to the modification of the second embodiment.

[0029] Fig.18 This is a diagram schematically showing the structure of a laser device according to a third embodiment.

[0030] Fig.19 This is a diagram schematically showing the structure of the OPS according to the third embodiment.

[0031] Fig. 20 This is a diagram showing an example of the relationship between SC and spectral line width.

[0032] Fig.21 It is a diagram showing an adjustment example of the control parameters of the SC.

[0033] Fig. 22 This is a flowchart schematically showing the flow of control of the SC according to the third embodiment.

[0034] Fig.23 This is a flowchart schematically showing the flow of control of the SC according to the third embodiment.

[0035] Fig.24 It is a diagram schematically showing the structure of a pulse width changing device according to a first modification.

[0036] Fig.25 This is a diagram schematically showing the structure of a variable reflectivity beam splitter device.

[0037] Fig.26 This is a diagram showing an example of pulse waveforms before and after expansion by OPS.

[0038] Fig. 27 This is a diagram showing an example of the relationship between the reflectivity of the beam splitter and the pulse width.

[0039] Fig.28This is a diagram schematically showing the structure of a pulse width changing device according to a second modification.

[0040] Fig.29 This is a diagram schematically showing the structure of a pulse width changing device according to a third modified example.

[0041] Fig.30 This is a diagram showing an example of the relationship between the pulse width and the concentration of the Ar gas in the chamber.

[0042] Fig.31 It is a diagram schematically showing the structure of the etendue changing device according to the first modification.

[0043] Fig.32 It is a front view schematically showing the structure of the etendue changing device according to the second modified example.

[0044] Fig.33 It is a side view schematically showing the structure of the etendue changing device according to the second modification.

[0045] Fig.34 It is a diagram showing an example of changing the beam angle distribution.

[0046] Fig.35 It is a side view schematically showing the structure of the etendue changing device when adjusting the beam intensity distribution.

[0047] Fig.36 It is a diagram showing an example of changing the beam intensity distribution.

[0048] Fig.37 It is a front view schematically showing the structure of the etendue changing device according to the third modified example.

[0049] Fig.38 It is a side view schematically showing the structure of the etendue changing device according to the third modified example.

[0050] Fig.39 It is a diagram for explaining the operation of changing the gap width.

[0051] Fig.40 It is a front view schematically showing the structure of the etendue changing device according to the fourth modified example.

[0052] Fig.41 It is a side view schematically showing the structure of the etendue changing device according to the fifth modification.

[0053] Fig.42 It is a diagram showing an example of beam angle distribution and beam intensity distribution on the emission plane, Fourier transform plane, and conjugate plane.

[0054] Fig.43It is a diagram showing an adjustment example of the beam angle distribution and the beam intensity distribution by the first variable gap device and the second variable gap device.

[0055] Fig.44 It is a diagram schematically showing the structure of a line width changing device according to a modified example.

[0056] Fig.45 It is a diagram for explaining the operation of the line width changing device.

[0057] Fig.46 This is a diagram showing an example of changing the spectral line width by combining a narrowband device and a wavefront changing device.

[0058] Fig.47 This is a diagram schematically showing a configuration example of an exposure device. DETAILED DESCRIPTION

[0059] <Content>

[0060] 1. Explanation of terms

[0061] 1.1 Speckle contrast

[0062] 1.2 Pulse Width

[0063] 1.3 Spectral line width

[0064] 1.4 Temporal coherence length

[0065] 1.5 Etendue

[0066] 2. Comparative Example

[0067] 2.1 Structure

[0068] 2.2 Actions

[0069] 2.3 Topics

[0070] 3. First Implementation Method

[0071] 3.1 Overall structure

[0072] 3.2 Beam measurement device

[0073] 3.3 Spectrum measurement device

[0074] 3.4 Actions

[0075] 3.5 Effect

[0076] 4. Second Implementation Method

[0077] 4.1 Overall structure

[0078] 4.2 Gas Control Device

[0079] 4.3 Actions

[0080] 4.4 Effect

[0081] 4.5 Variations

[0082] 5. Third Implementation Method

[0083] 5.1 Overall Structure

[0084] 5.2OPS

[0085] 5.3 Action

[0086] 5.3.1 Example of adjusting SC control parameters

[0087] 5.3.2SC Control Flow

[0088] 5.4 Effect

[0089] 6. Modification of the pulse width changing device

[0090] 6.1 First Modification

[0091] 6.2 Second Modification

[0092] 6.3 Third variant

[0093] 7. Modification of etendue changing device

[0094] 7.1 First Modification

[0095] 7.2 Second Modification

[0096] 7.3 The third variant

[0097] 7.4 Variation 4

[0098] 7.5 Fifth variant

[0099] 8. Modification of the spectral line width changing device

[0100] 9. Method for manufacturing electronic devices

[0101] 10. Example of laser controller structure

[0102] Below, the embodiments of the present disclosure are described in detail with reference to the accompanying drawings. The embodiments described below show several examples of the present disclosure and do not limit the content of the present disclosure. In addition, the structures and actions described in the embodiments are not necessarily all necessary for the structures and actions of the present disclosure. In addition, the same reference numerals are marked on the same structural elements and repeated descriptions are omitted.

[0103] 1. Explanation of terms

[0104] 1.1 Speckle contrast

[0105] Speckle refers to the bright and dark spots produced when laser light is scattered in a random medium. As an evaluation index of speckle, speckle contrast (SC) is generally used. SC is expressed by the following equation (1). Here, σ is the standard deviation calculated from the intensity distribution of the speckle image. a is the average intensity of the intensity distribution of the speckle image.

[0106]

Mathematical formula 1

[0107]

[0108] For example, in computing the representation Figure 1 Such a speckle image of the laser SC case, as Figure 2 The intensity of each pixel in the image is plotted as a histogram to produce an intensity distribution. The standard deviation σ and the average intensity I are calculated from the intensity distribution. a , and apply it to the above formula (1), thereby calculating SC.

[0109] 1.2 Pulse Width

[0110] In the present disclosure, the pulse width W of the laser light is defined by TIS (Time-Integral Square) represented by the following equation (2): Here, I(t) represents the light intensity per time t of the pulse waveform.

[0111]

Mathematical formula 2

[0112]

[0113] 1.3 Spectral line width

[0114] Figure 3 An overview of FWHM (Full Width at Half Maximum) is shown as an example of the spectral line width. Figure 4 An overview of E95 is shown as an example of the spectral line width. Figure 3 and Figure 4 In the figure, the horizontal axis shows the wavelength λ and the vertical axis shows the light intensity. The line width is the full width of the light intensity threshold of the spectrum waveform of the laser. In the present disclosure, the relative value of each light intensity threshold to the light intensity peak is called the line width threshold Thresh (0 <Thresh<1)。

[0115] like Figure 3 As shown, the full width of the spectrum waveform at Thresh=0.5 is called FWHM.

[0116] In addition, in the present disclosure, Figure 4 As shown, the energy of the full spectrum with the center wavelength λ 0The full width of the spectrum waveform that occupies 95% of the center is called spectrum purity. The spectrum line width Δλ that becomes this spectrum purity is called E95. Regarding spectrum purity, when the spectrum waveform is set to g(λ), the following equation (3) holds.

[0117]

Mathematical formula 3

[0118]

[0119] 1.4 Temporal coherence length

[0120] In the present disclosure, the central wavelength λ of the laser is used. 0 and the spectral line width Δλ, the temporal coherence length C is defined using the following equation (4): L .

[0121]

Mathematical formula 4

[0122]

[0123] 1.5 Etendue

[0124] In the present disclosure, etendue ET is defined by the following equation (5) using the beam cross-sectional area A and the beam divergence angle Ω of the laser beam. That is, etendue ET is the product of the beam cross-sectional area A and the beam divergence angle Ω.

[0125]

Mathematical formula 5

[0126] ET=A·Ω…(5)

[0127] The beam divergence angle Ω is defined by a solid angle expressed as the area of ​​a portion cut out by a cone surface from a sphere with a radius of 1 centered at the vertex of the angle. The beam divergence angle Ω is expressed by the following equation (6) using the numerical aperture NA and pi.

[0128]

Mathematical formula 6

[0129] Ω=π·NA2…(6)

[0130] 2. Comparative Example

[0131] First, comparative examples of the present disclosure are described. The comparative examples of the present disclosure are methods that the applicant recognizes are known only to the applicant, and are not publicly known examples that the applicant acknowledges.

[0132] 2.1 Structure

[0133] Figure 5The structure of the laser device 2 of the comparative example is schematically shown. The laser device 2 includes an oscillator 10, an optical pulse stretcher (OPS) 11, a monitor module 12, and a laser controller 13. The OPS 11 and the monitor module 12 are sequentially arranged on the optical path of the pulse laser PL output from the oscillator 10. The laser device 2 is an excimer laser device that outputs the pulse laser PL to be incident on the exposure device 3.

[0134] In the present disclosure, the optical path axis direction of the pulsed laser PL is defined as the Z direction. Two directions substantially orthogonal to the Z direction are defined as the H direction and the V direction. The H direction is perpendicular to the Figure 5 The direction is roughly perpendicular to the paper plane.

[0135] The oscillator 10 includes a cavity 20, a charger 21, a pulse power module (PPM) 22, a narrowband device 23, and an output coupling mirror 24. The narrowband device 23 and the output coupling mirror 24 constitute an optical resonator, and the cavity 20 is arranged on the optical path of the optical resonator.

[0136] The chamber 20 includes a pair of electrodes 25a, 25b, an insulating member 26, a front window 27a, and a rear window 27b. Laser gas is sealed inside the chamber 20. The laser gas may include, for example, Ar gas, Kr gas, or Xe gas as an inert gas, F as a halogen gas, or a halogen gas. 2 Gas or Cl 2 Gas, Ne gas as buffer gas. A pair of electrodes 25a, 25b are arranged inside the cavity 20 as electrodes for exciting the laser gas by discharge. The pair of electrodes 25a, 25b extend in the Z direction and face each other with a predetermined gap in the V direction. The discharge direction of the pair of electrodes 25a, 25b is the V direction.

[0137] An opening is formed in the cavity 20, and the opening is blocked by an insulating member 26. A plurality of conductive parts 26a are embedded in the insulating member 26. The electrode 25a is connected to the PPM 22 via the plurality of conductive parts 26a. The electrode 25b is grounded. The plurality of conductive parts 26a apply the high voltage supplied from the PPM 22 to the electrode 25a.

[0138] The front window 27 a and the rear window 27 b are disposed at both ends of the cavity 20 so as to transmit the pulse laser light PL generated in the discharge space between the pair of electrodes 25 a and 25 b .

[0139] The PPM 22 includes a switch 22a. The switch 22a is controlled by the laser controller 13. The charger 21 is connected to the charging capacitor of the PPM 22. The charger 21 receives data of the charging voltage from the laser controller 13.

[0140] The narrowband device 23 includes a prism, a grating, and an actuator (not shown). The actuator is controlled by the laser controller 13 to change the angle of the prism or the grating.

[0141] OPS 11 includes a beam splitter 11a and concave mirrors 11b to 11e. The beam splitter 11a is disposed on the optical path of the pulse laser PL output from the oscillator 10 and has a film that reflects a portion of the pulse laser PL and transmits the other portion. The reflectivity of the beam splitter 11a is preferably about 60%.

[0142] The focal lengths of the concave mirrors 11b to 11e are approximately equal, which is f. The concave mirrors 11b to 11e are configured so that the pulsed laser PL reflected by the beam splitter 11a is inverted into topographic images by the concave mirrors 11b and 11c, and then inverted into topographic images by the concave mirrors 11d and 11e. An image that is rotated forward via the concave mirrors 11b to 11e is formed in the beam splitter 11a. The concave mirrors 11b to 11e constitute a delayed optical path. When the delayed optical path length is set to L, it is preferred that L = 8f. In addition, the delayed optical path length L is set to be longer than the temporal coherence length C of the pulsed laser PL. L long.

[0143] The monitor module 12 includes beam splitters 12a and 12b, a pulse energy measuring device 12c, and a spectrum measuring device 12d. The beam splitter 12a is arranged on the optical path of the pulse laser PL output from the OPS 11, and is formed with a film that reflects a part of the pulse laser PL and transmits another part. The beam splitter 12b is arranged on the optical path of the pulse laser PL after being reflected by the beam splitter 12a, and is formed with a film that reflects a part of the pulse laser PL and transmits another part. The pulse laser PL after passing through the beam splitter 12a is incident on the exposure device 3.

[0144] The pulse energy measuring device 12c is arranged on the optical path of the pulsed laser PL after being reflected by the beam splitter 12b, and measures the pulse energy of the pulsed laser PL. The spectrum measuring device 12d is arranged on the optical path of the pulsed laser PL after passing through the beam splitter 12b, and measures the spectrum of the pulsed laser PL. The measured data of the pulse energy and spectrum are sent to the laser controller 13.

[0145] The laser controller 13 is connected to the exposure controller 3a of the exposure device 3 via a signal line. The laser controller 13 receives a signal from the exposure controller 3a. The signal received by the laser controller 13 includes a target pulse energy Et, a target wavelength λt, and a light emission trigger Tr.

[0146] Alternatively, an amplifier having a configuration including a cavity similar to the cavity 20 may be disposed between the oscillator 10 and the OPS 11 .

[0147] The exposure device 3 is a device for performing exposure using pulsed laser light PL. The exposure device 3 includes a scanner for performing step-and-scan exposure. Step-and-scan exposure is a method of performing exposure by linking a mask plate with a photosensitive substrate such as a semiconductor wafer. In the scanner, exposure based on pulsed laser light PL is performed while scanning a narrow gap-shaped area.

[0148] 2.2 Action

[0149] Next, the operation of the laser device 2 of the comparative example will be described. First, the laser controller 13 receives the target pulse energy Et, the target wavelength λt, and the emission trigger Tr from the exposure controller 3a. The emission trigger Tr is sent from the exposure controller 3a to the laser controller 13 at a predetermined repetition frequency.

[0150] The laser controller 13 turns on the switch 22a of the PPM 22 in synchronization with the light emission trigger Tr. When the switch 22a is turned on, a high voltage is applied between the pair of electrodes 25a and 25b from the PPM 22. As a result, discharge is generated between the pair of electrodes 25a and 25b, and the laser gas is excited. As a result, laser oscillation occurs in the optical resonator, and the pulsed laser PL narrowed by the narrowband device 23 is output from the output coupling mirror 24.

[0151] The pulse laser light PL outputted from the oscillator 10 enters the OPS 11. A part of the pulse laser light PL entering the OPS 11 is reflected by the beam splitter 11a, and light that has been circled once or more in the delay optical path is superimposed, whereby the pulse width W is expanded.

[0152] The pulsed laser PL after the pulse width W is expanded by the OPS 11 is incident on the monitor module 12. A part of the pulsed laser PL incident on the monitor module 12 is reflected by the beam splitter 12a. A part of the pulsed laser PL reflected by the beam splitter 12a is reflected by the beam splitter 12b and is incident on the pulse energy measuring device 12c, thereby measuring the pulse energy. In addition, another part of the pulsed laser PL reflected by the beam splitter 12a passes through the beam splitter 12b and is incident on the spectrum measuring device 12d, thereby measuring the spectrum.

[0153] The laser controller 13 controls the charging voltage of the charger 21 so that the difference between the target pulse energy Et and the measured pulse energy approaches 0. In addition, the laser controller 13 calculates the central wavelength λ from the measured spectrum. 0 , the actuator of the narrowband device 23 is controlled so that the target wavelength λt is aligned with the center wavelength λ 0 The difference is close to 0.

[0154] In this way, the laser controller 13 turns on the switch 22a in synchronization with the light emission trigger Tr, whereby the pulse laser PL is output from the laser device 2. The pulse width W of the pulse laser PL output from the laser device 2 is expanded and has a pulse energy close to the target pulse energy Et and a center wavelength λ close to the target wavelength λt. 0 .

[0155] The pulse laser light PL outputted from the laser device 2 enters the exposure device 3 and is irradiated onto a photosensitive substrate such as a semiconductor wafer (not shown).

[0156] 2.3 Topics

[0157] Wafer exposure requires reducing SC generated by coherence of pulsed laser light PL. In the laser device 2, the pulse width W is extended by OPS 11 for the purpose of reducing coherence of pulsed laser light PL and reducing SC.

[0158] In the performance confirmation of the laser device 2 before shipment, it is confirmed whether it meets the required performance of the SC required by the exposure device 3. Figure 6 As shown, in order to check SC generated by the pulsed laser PL outputted from the laser device 2, an SC measuring device 4 is provided near the emission port of the laser device 2. The SC measuring device 4 measures SC by calculating the standard deviation σ and the average intensity Ia from the intensity distribution of the speckle image.

[0159] However, the laser device 2 has a large volume, so after the laser device 2 is connected to the exposure device 3, it is difficult to remove the exposure device 3 and reconnect the SC measuring device 4. Therefore, after the laser device 2 is connected to the exposure device 3, the SC is almost not measured. Therefore, even if the laser device 2 has some malfunctions or deteriorates over time and the SC deteriorates, it is impossible to directly detect the SC, so the deterioration of the SC has to be estimated by the deterioration of other parameters. In addition, even if the malfunction of the laser device 2 is eliminated, it is still necessary to judge whether the SC has improved by estimation.

[0160] As described above, a technique capable of detecting deterioration of SC in a state where the laser device 2 is connected to the exposure device 3 is required.

[0161] 3. First Implementation Method

[0162] Next, a laser device 2 according to a first embodiment of the present disclosure will be described. Hereinafter, the same components as those of the comparative example are denoted by the same reference numerals, and description thereof will be appropriately omitted.

[0163] 3.1 Overall structure

[0164] Figure 7The configuration of the laser device 2 according to the first embodiment is schematically shown. The laser device 2 according to the present embodiment includes a beam measuring device 14 and a display device 15 in addition to the oscillator 10 , the OPS 11 , the monitor module 12 , and the laser controller 13 .

[0165] The beam measuring device 14 is arranged at the rear stage of the monitor module 12. The beam measuring device 14 measures the beam intensity distribution, beam angle distribution and pulse waveform of the pulsed laser PL after passing through the monitor module 12, and sends the measured data to the laser controller 13. In addition, the beam measuring device 14 may be arranged between the OPS 11 and the monitor module 12.

[0166] In the present embodiment, the laser controller 13 calculates the etendue ET based on the beam intensity distribution and the beam angle distribution measured by the beam measuring device 14, and calculates the pulse width W based on the pulse waveform measured by the beam measuring device 14. Specifically, the laser controller 13 calculates the beam cross-sectional area A of the pulsed laser PL based on the beam intensity distribution, calculates the beam divergence angle Ω of the pulsed laser PL based on the beam angle distribution, and multiplies the beam cross-sectional area A and the beam divergence angle Ω to thereby calculate the etendue ET.

[0167] Furthermore, the laser controller 13 calculates the spectral line width Δλ based on the spectrum measured by the spectrum measuring device 12 d of the monitor module 12 .

[0168] Furthermore, the laser controller 13 calculates SC by the following equation (7) using the calculated etendue ET, line width Δλ, and pulse width W. The following equation (7) means that SC is proportional to the square root of the sum of spatial SC and temporal SC.

[0169]

Mathematical formula 7

[0170]

[0171] Here, N pulse is the number of pulses of the pulsed laser PL used by the exposure device 3 during exposure. c is the speed of light. λ is the wavelength of the pulsed laser PL. In this embodiment, the target wavelength λt received from the exposure device 3 is set to the wavelength λ of the above formula (7). In addition, the laser controller 13 may also set the center wavelength λ calculated based on the spectrum measured by the spectrum measuring device 12d to 0 Let wavelength λ be the wavelength λ in the above equation (7).

[0172] In the present disclosure, the pulse width W is referred to as TIS, and the spectral line width Δλ is referred to as E95. Hereinafter, the pulse width W is expressed as the pulse width TIS, and the spectral line width Δλ is expressed as the spectral line width E95.

[0173] The laser controller 13 obtains the pulse number N from the exposure device 3. pulse , using the obtained pulse number N pulse Calculate SC. In addition, the laser controller 13 may not obtain the pulse number N from the exposure device 3 pulse , and use the pre-stored pulse number N pulse Calculate SC with a fixed value. Number of pulses N pulse The fixed value is, for example, 40 pulses.

[0174] For example, the laser controller 13 calculates the etendue ET, the line width E95, and the pulse width TIS for each pulse of the pulsed laser PL. Alternatively, the laser controller 13 may calculate the number of pulses N used by the exposure device 3 in the exposure of one portion, based on the etendue ET, the line width E95, and the pulse width TIS. pulse The average value of .

[0175] The display device 15 is a liquid crystal display or the like, and displays the SC calculated by the laser controller 13 according to the control of the laser controller 13. In addition, the laser controller 13 transmits the calculated SC to the exposure device 3.

[0176] 3.2 Beam measurement device

[0177] Figure 8 The configuration of the beam measuring device 14 is schematically shown. The beam measuring device 14 includes a beam splitter 30 , a beam intensity distribution measuring device 31 , a beam angle distribution measuring device 32 , and a pulse waveform measuring device 33 .

[0178] The beam splitter 30 is arranged on the optical path of the pulsed laser PL to reflect a part of the pulsed laser PL and transmit the other part. A multilayer film having the same reflectivity for P-polarized light and S-polarized light may be formed on one surface of the beam splitter 30, and an antireflection film may be formed on the other surface.

[0179] The beam intensity distribution measuring device 31 includes a beam splitter 31a, a transfer optical system 31b, and an image sensor 31c. The beam splitter 31a is arranged on the optical path of the pulsed laser PL after being reflected by the beam splitter 30, and reflects a part of the pulsed laser PL and transmits the other part. A multilayer film that makes the reflectivity of P polarized light and S polarized light the same may be formed on one surface of the beam splitter 31a, and an antireflection film may be formed on the other surface.

[0180] The transfer optical system 31b includes a plurality of lenses, and is disposed on the optical path of the pulse laser light PL reflected by the beam splitter 31a. The transfer optical system 31b transfers the beam cross-sectional image of the pulse laser light PL to the image sensor 31c.

[0181] The image sensor 31c is an imaging element such as a two-dimensional CCD (Charge-Coupled Device), and is arranged so that the imaging surface is located at the position of the image transferred by the transfer optical system 31b. The image sensor 31c captures the image of the pulsed laser PL transferred to the imaging surface, thereby generating image data and outputting it to the laser controller 13. The image data corresponds to the measurement data of the beam intensity distribution.

[0182] The beam angle distribution measuring device 32 includes a beam splitter 32a, a focusing optical system 32b, and an image sensor 32c. The beam splitter 32a is arranged on the optical path of the pulsed laser PL after passing through the beam splitter 31a, and reflects a part of the pulsed laser PL and transmits another part. A multilayer film that makes the reflectivity of P polarized light and S polarized light the same may be formed on one surface of the beam splitter 32a, and an anti-reflection film may be formed on the other surface.

[0183] The focusing optical system 32b includes a lens, and is disposed on the optical path of the pulse laser light PL reflected by the beam splitter 32a. The focusing optical system 32b focuses the pulse laser light PL on the image sensor 32c.

[0184] The image sensor 32c is a two-dimensional imaging element such as a CCD, and is arranged so that the imaging surface is located at the position of the image focused by the focusing optical system 32b. The image sensor 32c captures the image of the pulsed laser PL focused on the imaging surface, thereby generating image data and outputting it to the laser controller 13. This image data is equivalent to the measurement data of the beam angle distribution. Therefore, the beam angle distribution measured by the beam angle distribution measuring device 32 can be a focused image of the pulsed laser PL.

[0185] The pulse waveform measuring device 33 includes a high reflection mirror 33a, a diffusion plate 33b and a dual-plane photoelectric tube 33c. The high reflection mirror 33a is arranged on the optical path of the pulse laser PL after passing through the beam splitter 32a, and makes the pulse laser PL highly reflective. A total reflection film may be formed on the surface of the high reflection mirror 33a.

[0186] The diffusion plate 33 b is disposed on the optical path of the pulse laser light PL reflected by the high reflection mirror 33 a , and transmits and diffuses the pulse laser light PL.

[0187] The dual-plane phototube 33 c is disposed at a position capable of receiving the pulse laser light PL diffused by the diffusion plate 33 b . The dual-plane phototube 33 c measures the pulse waveform of the pulse laser light PL and outputs the measured pulse waveform data to the laser controller 13 .

[0188] The laser controller 13 is connected to the image sensors 31c, 32c and the dual-plane phototube 33c. The operations of the image sensors 31c, 32c and the dual-plane phototube 33c are controlled by the laser controller 13.

[0189] The laser controller 13 calculates the beam cross-sectional area A based on the image data output from the image sensor 31c, using as an index a value obtained by dividing the square value of the sum of the intensities of each pixel by the sum of the square values ​​of the intensities of each pixel. In addition, the laser controller 13 calculates the beam divergence angle Ω based on the image data output from the image sensor 32c, using as an index a value obtained by dividing the square value of the sum of the intensities of each pixel by the sum of the square values ​​of the intensities of each pixel.

[0190] 3.3 Spectrum measurement device

[0191] Fig. 9 The structure of the spectrum measuring device 12 d is schematically shown. In this embodiment, an etalon spectrometer is used as the spectrum measuring device 12 d. The spectrum measuring device 12 d includes a diffuser 34 , an etalon 35 , a condenser lens 36 , and an image sensor 37 .

[0192] The diffuser 34 transmits and diffuses the pulse laser light PL incident on the spectrum measuring device 12d. The pulse laser light PL diffused by the diffuser 34 enters the etalon 35 and then enters the condenser lens 36. The pulse laser light PL generates interference fringes on the focal plane of the condenser lens 36.

[0193] The image sensor 37 is disposed on the focal plane of the condenser lens 36, and captures the interference fringes to generate image data and output the image data to the laser controller 13. The image data corresponds to the measured data of the spectrum.

[0194] The radius of the interference fringe is r m The square of is proportional to the wavelength λ of the pulsed laser PL. Therefore, the laser controller 13 can calculate the line width E95 and the center wavelength λ based on the image data output from the image sensor 37. 0 The radius of the interference fringe is r m The relationship between the wavelength λ and the wavelength λ is approximated by the following equation (8).

[0195]

Mathematical formula 8

[0196] λ=λ c +α·r m 2 …(8)

[0197] Here, λ c is the wavelength when the light intensity at the center of the interference fringe is maximum. α is a proportionality constant. The spectrum waveform representing the relationship between the light intensity and the wavelength λ can be calculated by the above formula (8).

[0198] Fig.10 An example of interference fringes is shown. The inner radius r at the half value of the light intensity can be measured. 1 and the outer radius r 2 , use the following formula (9) to calculate the radius r of the interference fringe m The square of .

[0199]

Mathematical formula 9

[0200]

[0201] The laser controller 13 converts the radius r calculated by the above formula (9) into m Convert to wavelength λ, and calculate the central wavelength λ 0 In addition, the laser controller 13 converts the interference fringes into a spectrum waveform using the above equation (8), and calculates the spectrum line width E95 according to the above equation (3).

[0202] 3.4 Action

[0203] Next, the operation of the laser device 2 of the first embodiment is described. As in the comparative example, the laser controller 13 turns on the switch 22a in synchronization with the light emission trigger Tr, thereby outputting the pulse laser PL from the oscillator 10, and the pulse width W is expanded by the OPS 11. The pulse laser PL output from the OPS 11 is incident on the monitor module 12. The monitor module 12 measures the pulse energy and spectrum. The laser controller 13 calculates the spectral line width E95 and the center wavelength λ based on the measured data of the spectrum. 0 .

[0204] The pulsed laser light PL after passing through the monitor module 12 enters the beam measuring device 14. The beam measuring device 14 measures the beam intensity distribution, the beam angle distribution, and the pulse waveform. The laser controller 13 calculates the etendue ET and the pulse width TIS based on the measured data of the beam intensity distribution, the beam angle distribution, and the pulse waveform. Then, the laser controller 13 calculates SC using the calculated etendue ET, the line width E95, and the pulse width TIS.

[0205] The laser controller 13 causes the display device 15 to display the calculated SC, and transmits it to the exposure device 3. The pulsed laser light PL that has passed through the beam measuring device 14 enters the exposure device 3. The other operations of the laser device 2 of this embodiment are the same as those of the comparative example.

[0206] 3.5 Effect

[0207] The laser device 2 of this embodiment calculates SC based on the measured data of the spectrum, beam intensity distribution, beam angle distribution, and pulse waveform, and therefore, without using the SC measuring device 4, it is possible to detect deterioration of SC in a state where the laser device 2 is connected to the exposure device 3. Thus, necessary maintenance can be appropriately performed, and thus the quality of exposure by the exposure device 3 can be maintained at a high quality.

[0208] 4. Second Implementation Method

[0209] Next, a laser device 2 according to a second embodiment of the present disclosure will be described. Hereinafter, the same components as those of the first embodiment are denoted by the same reference numerals, and description thereof will be appropriately omitted.

[0210] 4.1 Overall structure

[0211] Fig.11 The structure of the laser device 2 of the second embodiment is schematically shown. The laser device 2 of this embodiment includes not only the oscillator 10, the OPS 11, the monitor module 12, the laser controller 13, the beam measuring device 14 and the display device 15, but also a gas control device 40 and a pressure sensor 28 for detecting the gas pressure of the laser gas sealed in the cavity 20.

[0212] The gas control device 40 is connected to the chamber 20 via a gas pipe, and controls the concentration of the halogen gas in the chamber 20 to adjust the pulse width TIS. The gas control device 40 is an example of a “pulse width changing device” in the technology disclosed herein.

[0213] In the present embodiment, the laser controller 13 controls the gas pressure via the gas control device 40 and adjusts the pulse width TIS so that the calculated SC becomes equal to or less than the target value SCt.

[0214] 4.2 Gas Control Device

[0215] Fig.12 The structure of the gas control device 40 is schematically shown. The gas control device 40 includes a gas controller 41, a laser gas supply device 42, and an exhaust device 43. The laser gas supply device 42 is connected to a first gas supply source 44, a second gas supply source 45, the chamber 20, and the exhaust device 43 via gas piping.

[0216] The first gas supply source 44 is, for example, a container containing a first gas, which is a mixture of argon gas (Ar) and neon gas (Ne) as inert gases. The first gas is a buffer gas. The second gas supply source 45 is, for example, a container containing a second gas, which is a mixture of fluorine gas (F) as a halogen gas. 2) is a mixture of argon (Ar) and neon (Ne) as inert gases.

[0217] The laser gas supply device 42 includes a first gas injection valve BV, a mass flow controller B-MFC, a bypass valve B-V2, a second gas injection valve F2-V, a mass flow controller F2-MFC and a bypass valve F2-V2. The mass flow controller B-MFC controls the flow rate of the first gas. The mass flow controller F2-MFC controls the flow rate of the second gas. The exhaust device 43 includes an exhaust valve EX-V and an exhaust pump 43a.

[0218] The gas controller 41 transmits and receives signals to and from the laser controller 13, and further receives gas pressure data from the pressure sensor 28. The gas controller 41 controls each part of the laser gas supply device 42 and the exhaust device 43.

[0219] When replacing the laser gas in the cavity 20, the gas controller 41 opens the exhaust valve EX-V after driving the exhaust pump 43a, thereby setting the gas pressure detected by the pressure sensor 28 to a predetermined pressure below the atmospheric pressure. Then, the gas controller 41 closes the exhaust valve EX-V and opens the second gas injection valve F2-V, thereby injecting a predetermined amount of the second gas into the cavity 20. Then, the gas controller 41 closes the second gas injection valve F2-V and opens the first gas injection valve BV to inject the first gas into the cavity 20, thereby setting the gas pressure in the cavity 20 to a predetermined pressure. As a result, the oscillator 10 is in a state capable of laser oscillation.

[0220] When the oscillator 10 performs laser oscillation, the gas controller 41 controls the first gas injection valve BV and the exhaust valve EX-V so that the charging voltage of the charger 21 falls within a predetermined range.

[0221] like Fig.13 As shown in Japanese Patent Publication No. 2001-267662, it is known that the pulse width of the laser is determined by the F 2 This means that the pulse width TIS varies depending on the concentration of the halogen gas in the chamber 20. Therefore, the gas controller 41 controls the concentration of the halogen gas, thereby being able to adjust the pulse width TIS.

[0222] When adjusting the pulse width TIS, the gas controller 41 opens the first gas injection valve BV to relatively reduce the concentration of the halogen gas and injects the first gas into the cavity 20. When adjusting the pulse width TIS, the gas controller 41 opens the second gas injection valve F2-V to relatively increase the concentration of the halogen gas and injects the second gas into the cavity 20. It is preferred that the laser performance be maintained within the range in which the laser performance is obtained. Fig.13 After such characteristics are shown, the injection amounts of the first gas and the second gas are determined.

[0223] 4.3 Action

[0224] Next, the operation of the laser device 2 according to the second embodiment will be described. The operation related to the calculation of SC is the same as that of the first embodiment, so the operation related to the control of SC will be described.

[0225] Fig.14 The flow of SC control is schematically shown. First, the laser controller 13 sets a target value SCt (step S10). The laser controller 13 may obtain the target value SCt from the exposure device 3 or may store it in advance.

[0226] Next, the laser controller 13 calculates SC based on the spectrum, beam intensity distribution, beam angle distribution, and pulse waveform measurement data (step S11). The laser controller 13 determines whether the calculated SC is less than the target value SCt (step S12). When SC is less than the target value SCt (step S12: yes), the laser controller 13 ends the control of SC.

[0227] When SC is larger than the target value SCt (step S12 : No), the laser controller 13 controls the gas control device 40 to increase the pulse width TIS to the adjustment limit (step S13 ). The adjustment limit is determined by the performance of the laser device 2 .

[0228] After increasing the pulse width TIS, the laser controller 13 calculates SC based on the measurement data again (step S14). The laser controller 13 determines whether the calculated SC is less than the target value SCt (step S15). When SC is less than the target value SCt (step S15: Yes), the laser controller 13 ends the SC control.

[0229] When SC is larger than the target value SCt (step S15: No), the laser controller 13 issues a warning (step S16) and stops the control of SC. For example, the laser controller 13 issues a warning by causing the display device 15 to display a message.

[0230] 4.4 Effect

[0231] The laser device 2 of this embodiment includes the gas control device 40, and therefore can perform control so that SC is maintained at or below the target value SCt. Thus, the quality of exposure by the exposure device 3 can be maintained at a high quality.

[0232] 4.5 Variations

[0233] Next, a modification of the second embodiment will be described. Fig.15 The structure of the laser device 2 according to the modification of the second embodiment is schematically shown. The laser device 2 according to this modification is different from the structure of the second embodiment only in that it further includes a wavefront changing device 29 capable of adjusting the spectral line width E95.

[0234] The wavefront changing device 29 is arranged on the optical axis of the optical resonator in the oscillating device 10. For example, the wavefront changing device 29 is arranged on the optical path of the pulsed laser PL between the front window 27a and the output coupling mirror 24. The wavefront changing device 29 changes the wavefront of the pulsed laser PL according to the control of the laser controller 13, thereby adjusting the spectral line width E95. The wavefront changing device 29 is an example of the "spectral line width changing device" of the technology disclosed in the present invention.

[0235] Fig.16 The structure of the wavefront changing device 29 is schematically shown. The wavefront changing device 29 includes a cylindrical plano-concave lens 29a, a cylindrical plano-convex lens 29b, a linear stage 29c and a driver 29d. Anti-reflection films are formed on both surfaces of the cylindrical plano-concave lens 29a. An anti-reflection film is formed on the convex surface of the cylindrical plano-convex lens 29b. A partial reflection film can also be formed on the plane of the cylindrical plano-convex lens 29b to function as an output coupling mirror. In this case, the output coupling mirror 24 can be omitted.

[0236] The linear stage 29 c can move the cylindrical plano-concave lens 29 a in the Z direction. The driver 29 d drives the linear stage 29 c according to the control of the laser controller 13 .

[0237] When the laser controller 13 sends a control signal to the wavefront changing device 29, the distance between the cylindrical plano-concave lens 29a and the cylindrical plano-convex lens 29b is changed by the driver 29d. As a result, the wavefront of the pulsed laser PL reciprocating in the optical resonator is changed, and the spectral line width E95 selected by the grating in the narrowband device 23 is changed. In this way, the spectral line width E95 can be adjusted.

[0238] Fig.17 The flow of SC control according to the modified example of the second embodiment is schematically shown. Fig.17 The flowchart shown is similar to Fig.14 The difference of the flowchart shown is that step S20 is added after step S13. In this modification, after the laser controller 13 increases the pulse width TIS to the adjustment limit by controlling the gas control device 40, it controls the wavefront change device 29 to return the spectral line width E95 to the value before the pulse width TIS is changed (step S20). The value before the pulse width TIS is changed is the value of the pulse width TIS calculated in step S11.

[0239] The line width E95 has a great influence on the exposure performance, so it is preferred that it does not change. However, the line width E95 may change by changing the pulse width TIS. Therefore, in this modification, when the pulse width TIS is increased, the line width E95 is returned to the value before the pulse width TIS is changed. Therefore, in this modification, even if the gas control device 40 makes SC become less than the target value SCt, the change of the line width E95 can be suppressed, and the quality of exposure by the exposure device 3 can be maintained at a high quality.

[0240] 5. Third Implementation Method

[0241] A laser device 2 according to a third embodiment of the present disclosure will be described. Hereinafter, the same components as those of the modified example of the second embodiment are denoted by the same reference numerals, and description thereof will be appropriately omitted.

[0242] 5.1 Overall Structure

[0243] Fig.18 The structure of the laser device 2 of the third embodiment is schematically shown. The laser device 2 of this embodiment is different from the laser device 2 of the modified example of the second embodiment in that an actuator 11f for changing the etendue ET is provided in the OPS 11. The OPS 11 provided with the actuator 11f is an example of the "etendue changing device" of the technology disclosed in the present invention.

[0244] 5.2OPS

[0245] Fig.19 The structure of the OPS 11 of the third embodiment is schematically shown. In this embodiment, the concave mirror 11e among the concave mirrors 11b to 11e is connected to an actuator 11f. The actuator 11f is configured to be able to change the posture of the concave mirror 11e, and the operation is controlled by the laser controller 13. In addition, the actuator 11f is not limited to being connected to the concave mirror 11e, but can also be connected to other concave mirrors.

[0246] In this embodiment, the actuator 11f changes the posture of the concave mirror 11e so that the optical path of the pulsed laser light PL output from the OPS 11 is shifted in the H direction each time it is wrapped around the delay optical path. Fig.19 In FIG. 1 , P0 represents the optical path of the pulsed laser PL output from OPS11 without being bypassed in the delay optical path. P1 represents the optical path of the pulsed laser PL output from OPS11 after being bypassed once in the delay optical path. P2 represents the optical path of the pulsed laser PL output from OPS11 after being bypassed twice in the delay optical path.

[0247] The laser controller 13 controls the amount of deviation of the optical path of the pulsed laser PL output from the OPS 11 in the H direction through the actuator 11f, thereby controlling the beam divergence angle Ω. The larger the deviation in the H direction, the larger the beam divergence angle Ω related to the H direction. By changing the beam divergence angle Ω in this way, the optical etendue ET is changed.

[0248] In addition, the delay optical path length L of OPS11 is set to be longer than the temporal coherence length C of the pulsed laser PL. L Therefore, the pulse laser lights PL of the optical paths P0 to P2 do not interfere with each other.

[0249] 5.3 Action

[0250] Next, the operation of the laser device 2 according to the third embodiment will be described. The operation related to the calculation of SC is the same as that of the first embodiment, so the operation related to the control of SC will be described.

[0251] 5.3.1 Example of adjusting SC control parameters

[0252] In this embodiment, SC can be controlled by adjusting the three control parameters of pulse width TIS, line width E95 and etendue ET. Fig. 20 As shown in FIG. 1 , by increasing the line width E95, SC can be reduced. However, in general, when the line width E95 is changed, the imaging performance of the exposure device 3 changes, so it is preferable to reduce the adjustment amount of the line width E95. In addition, when the optical etendue ET is changed, the amount of light incident on the incident aperture of the exposure device 3 changes, so it is preferable to reduce the adjustment amount of the optical etendue ET. Therefore, when controlling SC, it is preferable to adjust the control parameters in the order of pulse width TIS, optical etendue ET and line width E95.

[0253] Fig.21 An adjustment example of the control parameters of the SC is shown. Fig.21 The relationship between the pulse width TIS and the etendue ET and SC is shown. The etendue ET is different for E1 to E5. The adjustable range of the pulse width TIS is the range of T1 to T2. The adjustable range of the etendue ET is the range of E1 to E5. The adjustable range of TIS and the adjustable range of ET are determined by the performance of the laser device 2. In this adjustment example, the target value SCt of SC is set to 6%.

[0254] For example, when SC is calculated based on the above-mentioned measurement data, the control parameter corresponds to condition C1, and the value of SC is about 8%. Condition C1 is that the pulse width TIS is T1 and the etendue ET is E1. In this case, the pulse width TIS is increased from T1 to T2 while the etendue ET is maintained at E1, and the control parameter is set to condition C2. In condition C2, SC is higher than the target value SCt, so the etendue ET is increased from E1 to E2 while the pulse width TIS is maintained at T2, and the control parameter is set to condition C3. In condition C3, SC becomes less than the target value SCt, so the line width E95 is not adjusted and the control is terminated.

[0255] In the above adjustment example, the pulse width TIS is increased from T1 to T2 which is the adjustment limit at once, but SC may be calculated while increasing the pulse width TIS by a certain amount to the adjustment limit.

[0256] 5.3.2SC Control Flow

[0257] Fig. 22 and Fig.23 The flow of SC control in the third embodiment is schematically shown. First, the laser controller 13 sets a target value SCt (step S30). The laser controller 13 may obtain the target value SCt from the exposure device 3 or may store it in advance.

[0258] Next, the laser controller 13 calculates SC based on the spectrum, beam intensity distribution, beam angle distribution, and pulse waveform measurement data (step S31). The laser controller 13 determines whether the calculated SC is less than the target value SCt (step S32). When SC is less than the target value SCt (step S32: yes), the laser controller 13 ends the control of SC.

[0259] When SC is greater than the target value SCt (step S32: No), the laser controller 13 controls the gas control device 40 to increase the pulse width TIS by a certain amount (step S33). The laser controller 13 determines whether the pulse width TIS after the certain amount of increase is the adjustment limit (step S34). When the pulse width TIS is not the adjustment limit (step S34: No), the laser controller 13 returns the process to step S31.

[0260] When the pulse width TIS is within the adjustment limit (step S34: Yes), the laser controller 13 calculates SC based on the measurement data (step S35). The laser controller 13 determines whether the calculated SC is less than the target value SCt (step S36). When SC is less than the target value SCt (step S36: Yes), the laser controller 13 ends the control of SC.

[0261] When SC is greater than the target value SCt (step S36: No), the laser controller 13 controls the actuator 11f of the OPS 11 to increase the etendue ET by a certain amount (step S37). The laser controller 13 determines whether the etendue ET increased by the certain amount is the adjustment limit (step S38). When the etendue ET is not the adjustment limit (step S38: No), the laser controller 13 returns the process to step S35.

[0262] When the etendue ET is within the adjustment limit (step S38: Yes), the laser controller 13 calculates SC based on the measurement data (step S39). The laser controller 13 determines whether the calculated SC is less than the target value SCt (step S40). When SC is less than the target value SCt (step S40: Yes), the laser controller 13 ends the control of SC.

[0263] When SC is greater than the target value SCt (step S40: No), the laser controller 13 controls the wavefront changing device 29 to increase the spectral line width E95 by a certain amount (step S41). The laser controller 13 determines whether the spectral line width E95 increased by a certain amount is the adjustment limit (step S42). When the spectral line width E95 is not the adjustment limit (step S42: No), the laser controller 13 returns the process to step S39.

[0264] When the line width E95 is within the adjustment limit (step S42: Yes), the laser controller 13 calculates SC based on the measurement data (step S43). The laser controller 13 determines whether the calculated SC is less than the target value SCt (step S44). When SC is less than the target value SCt (step S44: Yes), the laser controller 13 ends the control of SC.

[0265] When SC is larger than the target value SCt (step S44 : No), the laser controller 13 issues a warning (step S45 ) and stops the control of SC.

[0266] 5.4 Effect

[0267] In the present embodiment, when controlling SC, the control parameters are adjusted in order from those having the smallest influence on the exposure performance. Therefore, it is possible to suppress a decrease in the exposure performance associated with the control of SC.

[0268] 6. Modification of the pulse width changing device

[0269] Next, various modified examples of the pulse width changing device are described. In the second and third embodiments, the gas control device 40 is used as the pulse width changing device, but the following pulse width changing device can be used instead of the gas control device 40 or in addition to the gas control device 40.

[0270] 6.1 First Modification

[0271] Fig.24 The structure of the pulse width changing device of the first modification is schematically shown. The pulse width changing device of this modification is composed of an OPS 11 provided with a reflectivity variable beam splitter device 50 instead of the beam splitter 11a. The structure of the concave mirrors 11b to 11e is the same as that of the comparative example.

[0272] Fig.25 The structure of the reflectivity variable beam splitter device 50 is schematically shown. The reflectivity variable beam splitter device 50 includes a beam splitter 51 having a reflectivity distribution, a holder 52, a fixed angle bar 53, a linear stage 54, and a driver 55. The beam splitter 51 is rectangular in shape, and the reflectivity R varies in the longitudinal direction. The holder 52 holds the beam splitter 51 and is connected to the linear stage 54 via the fixed angle bar 53.

[0273] The beam splitter 51 is arranged on the optical path of the pulse laser PL output from the oscillator 10. The linear stage 54 moves the beam splitter 51 in the direction in which the reflectivity R changes while maintaining the incident angle of the pulse laser PL with respect to the beam splitter 51 constant. The driver 55 drives the linear stage 54 according to the control signal sent from the laser controller 13.

[0274] Basically, the higher the reflectivity R of the position of the beam splitter 51 into which the pulse laser PL is incident, the more components of the pulse laser PL surround in the delay optical path of the OPS 11 , and therefore the pulse width TIS of the pulse laser PL output from the OPS 11 becomes longer.

[0275] Fig.26 An example of a pulse waveform before and after expansion based on OPS11 is shown. Fig.26 In FIG. 1 , the dotted line shows the pulse waveform of the pulse laser PL output from the oscillator 10. The solid line shows the pulse waveform of the pulse laser PL after being expanded by OPS11. This is the result of an experiment in which the delayed optical path length L is set to 11.5 m and the reflectivity R of the position where the pulse laser PL is incident is set to 60%. The pulse width TIS of the pulse laser PL output from the oscillator 10 is about 44 ns, and the pulse width TIS of the pulse laser PL after being expanded by OPS11 is about 100 ns.

[0276] Fig. 27 An example of the relationship between the reflectivity R and the pulse width TIS is shown. Fig. 27 It can be seen that by changing the reflectivity R from 0% to 60%, the pulse width TIS changes from about 44 ns to about 100 ns.

[0277] In this modification, the laser controller 13 stores data indicating the relationship between the reflectivity R and the pulse width TIS in advance. When adjusting the pulse width TIS, the laser controller 13 obtains the value of the reflectivity R corresponding to the target pulse width TIS, and sends a control signal to the driver 55 to move the beam splitter 51 so that the reflectivity R at the position where the pulse laser PL is incident becomes the obtained value.

[0278] 6.2 Second Modification

[0279] Fig.28 The structure of the pulse width changing device of the second modification is schematically shown. The pulse width changing device of this modification is configured by adding a variable transmittance ND filter device 60 to the OPS 11 of the comparative example. The structure of the beam splitter 11a and the concave mirrors 11b to 11e is the same as that of the comparative example.

[0280] The variable transmittance ND filter device 60 includes a ND (Neutral Density) filter 61 having transmittance, a holder 62, a fixed angle bar 63, a linear stage 64, and a driver 65. The ND filter 61 is rectangular, and the transmittance varies in the longitudinal direction. The holder 62 holds the ND filter 61 and is connected to the linear stage 64 via the fixed angle bar 63.

[0281] The ND filter 61 is arranged on the delay optical path of the OPS 11. In this modification, the ND filter 61 is arranged on the delay optical path between the beam splitter 11a and the concave mirror 11b so that the pulse laser PL is incident vertically. The linear stage 64 moves the ND filter 61 in the direction of the change in transmittance while maintaining the incident angle of the pulse laser PL relative to the beam splitter 51 constant. The driver 65 drives the linear stage 64 according to the control signal sent from the laser controller 13.

[0282] Basically, the higher the transmittance of the position where the pulse laser PL of the ND filter 61 is incident, the more components of the pulse laser PL surround in the delay optical path of the OPS 11, and therefore the pulse width TIS of the pulse laser PL output from the OPS 11 is longer.

[0283] In this modification, the laser controller 13 stores data indicating the relationship between the transmittance and the pulse width TIS in advance. When adjusting the pulse width TIS, the laser controller 13 obtains the transmittance value corresponding to the target pulse width TIS, and sends a control signal to the driver 55 to move the ND filter 61 so that the transmittance at the position where the pulse laser PL is incident becomes the obtained value.

[0284] 6.3 The third variant

[0285] Fig.29 The structure of the pulse width changing device of the third modification is schematically shown. The pulse width changing device of this modification is configured by adding a third gas supply source 46, a third gas injection valve Ne-V, a mass flow controller Ne-MFC, and a bypass valve Ne-V2 to the gas control device 40 of the second embodiment. The third gas injection valve Ne-V, the mass flow controller Ne-MFC, and the bypass valve Ne-V2 are included in the laser gas supply device 42. The third gas supply source 46 is a container containing neon gas (Ne) as the third gas.

[0286] like Fig.30 As shown in the specification of U.S. Patent No. 6584131, it is known that the pulse width TIS of the laser changes according to the concentration of the Ar gas in the cavity. Therefore, the gas controller 41 controls the concentration of the Ar gas, thereby adjusting the pulse width TIS. In this modified example, the gas controller 41 injects a third gas into the cavity 20 to control the concentration of the Ar gas, thereby adjusting the pulse width TIS.

[0287] It is preferred to find the Fig.30 The gas controller 41 preferably determines the injection amount of the third gas using the characteristic that the pulse width TIS increases as the concentration of the Ar gas decreases, and controls the concentration of the Ar gas.

[0288] The control of SC in this modification is the same as the control described in the second embodiment except that the third gas is injected into the chamber 20 to control the concentration of the Ar gas when adjusting the pulse width TIS.

[0289] Furthermore, the pulse width TIS may be adjusted by combining two or more of the plurality of pulse width changing devices described in the second embodiment and the first to third modifications.

[0290] 7. Modification of etendue changing device

[0291] Next, various modifications of the etendue changing device will be described. The following etendue changing device can be used instead of or in addition to the etendue changing device of the third embodiment.

[0292] 7.1 First Modification

[0293] Fig.31 The structure of the etendue changing device of the first modified example is schematically shown. The etendue changing device of this modified example is configured by connecting an actuator 11g to the concave mirror 11b among the concave mirrors 11b to 11e included in the OPS 11. The actuator 11g is configured to be able to change the posture of the concave mirror 11b, and the operation is controlled by the laser controller 13. In addition, the actuator 11g is not limited to being connected to the concave mirror 11b, and can also be connected to other concave mirrors.

[0294] In the present modification, the actuator 11g changes the posture of the concave mirror 11b so that the optical path of the pulsed laser light PL output from the OPS 11 is shifted in the V direction whenever it goes around in the delay optical path.

[0295] In this modification, the laser controller 13 controls the amount of deviation of the optical path of the pulsed laser PL output from the OPS 11 in the V direction through the actuator 11g, thereby controlling the beam divergence angle Ω. The larger the deviation in the V direction, the larger the beam divergence angle Ω related to the V direction. By changing the beam divergence angle Ω in this way, the optical etendue ET is changed.

[0296] In addition, the actuator 11g may be provided in the OPS 11 of the third embodiment. That is, the actuator 11f and the actuator 11g may be used to control the deviation amount of the optical path of the pulsed laser PL output from the OPS 11 in the H direction and the deviation amount in the V direction. Thus, the beam divergence angle Ω in the H direction and the V direction can be increased.

[0297] Furthermore, by arranging the OPS 11 of the third embodiment and the OPS 11 of the present modification in series on the optical path of the pulsed laser PL, it is also possible to control the deviation amount of the optical path of the pulsed laser PL in the H direction and the deviation amount in the V direction.

[0298] 7.2 Second Modification

[0299] Fig.32 and Fig.33The structure of the etendue changing device of the second modification is schematically shown. The etendue changing device of this modification is composed of a rotating optical device 70, which can selectively arrange a plurality of optical elements 71 with different optical characteristics on the optical path of the pulsed laser PL. The rotating optical device 70 includes a plurality of optical elements 71, a rotating holder 72, a servo motor 73, a fixed angle bar 74, and a driver 75.

[0300] The rotating holder 72 is disc-shaped and holds a plurality of optical elements 71. The plurality of optical elements 71 are arranged concentrically at the center of the rotating holder 72. The center of the rotating holder 72 is connected to a rotating shaft 73a of a servo motor 73. The servo motor 73 rotates the rotating holder 72. The fixed angle bar 74 holds the servo motor 73. The driver 75 drives the linear stage 54 according to a control signal sent from the laser controller 13.

[0301] The rotating holder 72 rotates, whereby the plurality of optical elements 71 are sequentially arranged on the optical path of the pulse laser light PL output from the oscillator 10. The rotating optical device 70 is arranged between the oscillator 10 and the OPS 11, for example.

[0302] Each of the plurality of optical elements 71 is an optical element capable of changing the beam angle distribution or the beam intensity distribution of the pulse laser light PL. For example, each of the plurality of optical elements 71 has different changing characteristics of the beam angle distribution or the beam intensity distribution.

[0303] The plurality of optical elements 71 are diffusers, diffractive optical elements (DOE), computer-generated holograms (CGH), kinoform holograms, etc., and can increase the etendue ET of the incident pulsed laser PL and output it. The optical element 71 can increase the beam angle distribution or beam intensity distribution in only one of the V direction and the H direction.

[0304] In the present modification, when controlling SC, the laser controller 13 rotates the rotary holder 72 to select the optical element 71 to be arranged on the optical path of the pulse laser light PL, thereby adjusting the etendue ET.

[0305] For example, a diffuser plate as the optical element 71 is arranged on the optical path of the pulsed laser PL to increase the beam divergence angle Ω, thereby increasing the etendue ET. In addition, by making the optical element 71 have the function of increasing the beam angle distribution in only one of the V direction and the H direction, it is possible to increase the beam divergence angle Ω in only one of the V direction and the H direction. For example, Fig.34As shown in FIG. 1 , by using a CGH having a function of increasing the beam angle distribution only in the H direction as the optical element 71 , it is possible to increase the beam divergence angle Ω only in the H direction.

[0306] When adjusting the beam intensity distribution, it is sufficient to arrange the optical element 71 on the Fourier transform surface of the emission surface of the oscillator 10. In this case, Fig.35 As shown, in the optical path of the pulsed laser PL output from the oscillator 10, an incident optical system 76a is arranged on the incident side of the optical element 71, and an outgoing optical system 76b is arranged on the outgoing side. In addition, the incident optical system 76a and the outgoing optical system 76b are arranged so that the focal planes coincide with each other and the optical element 71 of the second rotating optical device 70b is located at the focal plane. Thus, the incident optical system 76a performs Fourier transform on the image of the pulsed laser PL at the position of the optical element 71. That is, at Fig.35 In the example shown, the optical element 71 is arranged on the Fourier transform surface.

[0307] The beam intensity distribution is changed by the convolution of the beam intensity distribution on the exit surface and the optical characteristics of the optical element 71. That is, the beam intensity distribution on the conjugate surface conjugate with the exit surface can be adjusted according to the optical characteristics of the optical element 71. Fig.36 As shown, for example, by using DOE as the optical element 71, the beam intensity distribution in the emission surface can be expanded in the H direction.

[0308] In order to change the beam angle distribution or the beam intensity distribution, a prism, a zoom lens, or the like can be used as the optical element 71 .

[0309] 7.3 The third variant

[0310] Fig.37 and Fig.38 The structure of the etendue changing device of the third modification is schematically shown. The etendue changing device of this modification is composed of a variable gap device 80, which can change the gap width in one direction. The variable gap device 80 includes a pair of plates 81a, 81b, a guide 82, a power transmission mechanism 83, an actuator 84, and a driver 85.

[0311] The pair of plates 81a and 81b are held by a guide 82 so as to be movable in the V direction. The power transmission mechanism 83 is connected to an actuator 84, and the distance between the pair of plates 81a and 81b is changed by the actuator 84. The opening between the pair of plates 81a and 81b functions as a gap SL through which the pulse laser light PL output from the oscillator 10 passes.

[0312] In this modification, the laser controller 13 drives the actuator 84 to adjust the width of the gap SL while controlling the SC, thereby adjusting the etendue ET. Fig.39 As shown in FIG. 1 , when the width of the gap SL is narrowed from a state in which the width of the gap SL is wide, the beam intensity distribution or the beam angle distribution is suppressed in the V direction, thereby reducing the etendue ET.

[0313] 7.4 Variation 4

[0314] Fig.40 The structure of the etendue changing device of the fourth modification is schematically shown. The etendue changing device of this modification is composed of a variable gap device 90, which can change the gap width in two directions. The variable gap device 90 includes a pair of plates 91a, 91b and a pair of plates 92a, 92b. In addition, the variable gap device 90 includes the same guide, power transmission mechanism, actuator and driver as the third modification.

[0315] The pair of plates 91a and 91b are held by guides so as to be movable in the V direction. The pair of plates 92a and 92b are held by guides so as to be movable in the H direction. The openings between the pair of plates 91a and 91b and between the pair of plates 92a and 92b function as gaps SL through which the pulsed laser light PL outputted from the oscillator 10 passes.

[0316] In the present modification, the laser controller 13 drives the actuator to adjust the width of the gap SL in the V direction and the H direction when controlling SC, thereby adjusting the etendue ET.

[0317] In the present modification, the width of the gap SL can be freely adjusted in the V direction and the H direction, and therefore the beam divergence angle Ω can also be measured using the variable gap device 90 .

[0318] 7.5 Fifth variant

[0319] Fig.41 The structure of the etendue changing device according to the fifth modification is schematically shown. The etendue changing device according to the present modification is configured by combining a plurality of etendue changing devices.

[0320] The etendue changing device of this modified example includes a first rotating optical device 70a, an incident optical system 76a, a first variable gap device 90a, a second rotating optical device 70b, an exit optical system 76b, and a second variable gap device 90b. The first rotating optical device 70a, the incident optical system 76a, the first variable gap device 90a, the second rotating optical device 70b, the exit optical system 76b, and the second variable gap device 90b are sequentially arranged on the optical path of the pulse laser PL output from the oscillator 10.

[0321] The first rotating optical device 70a and the second rotating optical device 70b have the same structure as the rotating optical device 70 of the second modification. The first variable gap device 90a and the second variable gap device 90b have the same structure as the variable gap device 90 of the fourth modification.

[0322] The incident optical system 76a and the exit optical system 76b are arranged so that the focal planes coincide with each other and the second rotating optical device 70b is located at the focal plane. The first rotating optical device 70a is arranged on the incident side of the incident optical system 76a. In this modification, the optical element of the first rotating optical device 70a is referred to as the first optical element 71a, and the optical element of the second rotating optical device 70b is referred to as the second optical element 71b. The incident optical system 76a performs Fourier transform on the image of the pulsed laser PL at the position of the second optical element 71b. That is, at Fig.41 In the example shown, the second optical element 71b is arranged on the Fourier transform surface.

[0323] The first variable gap device 90a is arranged near the Fourier transform surface. The second variable gap device 90b is arranged on the exit side of the exit optical system 76b. The position of the first rotating optical device 70a and the position of the second variable gap device 90b are in a conjugate positional relationship with each other. In this modification, the first rotating optical device 70a is arranged near the exit surface of the pulsed laser PL, and the second variable gap device 90b is arranged near the conjugate surface conjugate with the exit surface.

[0324] Fig.42 An example of the beam angle distribution and the beam intensity distribution on the emission surface, the Fourier transform surface, and the conjugate surface is shown. In this modification, the beam angle distribution is adjusted by the first optical element 71a, and the beam intensity distribution is adjusted by the second optical element 71b.

[0325] Fig.43 An example of adjustment of the beam angle distribution and the beam intensity distribution by the first variable gap device 90a and the second variable gap device 90b is shown.

[0326] The first optical element 71a and the first variable gap device 90a are used to adjust the beam angle distribution. The beam angle distribution is adjusted by convolution with the first optical element 71a. In addition, the beam angle distribution is adjusted by the gap SL of the first variable gap device 90a. The first optical element 71a can be adjusted in a direction to increase the beam divergence angle Ω, and the first variable gap device 90a can be adjusted in a direction to reduce the beam divergence angle Ω.

[0327] The second optical element 71b and the second variable gap device 90b are used to adjust the beam intensity distribution. The beam intensity distribution is adjusted by convolution with the second optical element 71b. In addition, the beam intensity distribution is adjusted by the gap SL of the second variable gap device 90b. The second optical element 71b can be adjusted in the direction of increasing the beam cross-sectional area A, and the second variable gap device 90b can be adjusted in the direction of reducing the beam cross-sectional area A.

[0328] In this modification, in order to adjust the etendue ET, the laser controller 13 performs the following control. The laser controller 13 rotates the rotating holder 72 of the first rotating optical device 70a, selects the first optical element 71a to be arranged on the optical path of the pulsed laser light PL, and thereby adjusts the beam angle distribution. In addition, the laser controller 13 rotates the rotating holder 72 of the second rotating optical device 70b, selects the second optical element 71b to be arranged on the optical path of the pulsed laser light PL, and thereby adjusts the beam intensity distribution.

[0329] The laser controller 13 also adjusts the gap width of the first variable gap device 90a to adjust the beam angle distribution. The laser controller 13 also adjusts the gap width of the second variable gap device 90b to adjust the beam intensity distribution.

[0330] In the present modification, the beam divergence angle Ω and the beam cross-sectional area A can be adjusted in the increasing direction and the decreasing direction, respectively, and therefore, the etendue ET can be adjusted with a higher degree of freedom.

[0331] Furthermore, the etendue ET may be adjusted by combining two or more of the plurality of etendue changing devices described in the third embodiment and the first to fifth modifications.

[0332] 8. Modification of the spectral line width changing device

[0333] Next, various modifications of the spectral line width changing device are described. In the modification of the second embodiment and the third embodiment, the wavefront changing device 29 is used as the spectral line width changing device, but the following spectral line width changing device can be used instead of the wavefront changing device 29 or on the basis of the wavefront changing device 29.

[0334] Fig.44 The structure of the spectral line width changing device of the modification example is schematically shown. The spectral line width changing device of the modification example is configured by adding a magnification changing mechanism 100 to the narrowing device 23 .

[0335] The narrowband device 23 of this modification includes a plurality of prisms 23a, a grating 23b, a magnification changing mechanism 100, and a driver 101. For example, the plurality of prisms 23a are rectangular prisms. The plurality of prisms 23a widen the beam width of the pulsed laser PL incident from the cavity 20 and make it incident on the grating 23b. In addition, the plurality of prisms 23a narrow the beam width of the pulsed laser PL after being reflected by the grating 23b and make it incident on the cavity 20.

[0336] The magnification changing mechanism 100 is configured to change the spectral line width E95 of the pulse laser PL by changing one of the plurality of prisms 23a to a dispersion prism 23c. Specifically, the magnification changing mechanism 100 includes a moving stage 102 on which a prism 23a and a dispersion prism 23c are mounted. The moving stage 102 moves, whereby the prism 23a and the dispersion prism 23c are selectively arranged on the optical path of the pulse laser PL in the narrowband device 23. The driver 101 drives the moving stage 102 according to the control of the laser controller 13.

[0337] In this modification, the laser controller 13 controls the moving stage 102 to selectively arrange the prism 23a or the dispersion prism 23c on the optical path of the pulsed laser PL, thereby changing the spectral line width E95. Fig.45 As shown, when the dispersion prism 23c is arranged on the optical path of the pulsed laser light PL, the line width E95 increases compared to the case where the prism 23a is arranged.

[0338] In this modification, two prisms with different optical characteristics are selectively arranged on the optical path of the pulsed laser PL in the narrowband device 23, thereby changing the spectral line width E95. Alternatively, three prisms with different optical characteristics may be selectively arranged on the optical path, thereby changing the spectral line width E95. In this way, the adjustable range of the spectral line width E95 can be expanded.

[0339] In addition, if Fig.46As shown, the narrowband device 23 and the wavefront changing device 29 of this modification may be combined. In this case, the laser controller 13 controls the narrowband device 23 and the wavefront changing device 29. For example, after the laser controller 13 performs a rough adjustment of the spectral line width E95 through the narrowband device 23, the laser controller 13 performs a fine adjustment of the spectral line width E95 through the wavefront changing device 29.

[0340] 9. Method for manufacturing electronic devices

[0341] Fig.47 The structure example of the exposure device 3 is schematically shown. The exposure device 3 includes an illumination optical system 200 and a projection optical system 202. The illumination optical system 200 illuminates the mask pattern of the mask (not shown) arranged on the mask stage RT by, for example, the pulsed laser PL incident from the laser device 2. The projection optical system 202 performs reduced projection of the pulsed laser PL transmitted through the mask, and images it on the workpiece (not shown) arranged on the workpiece stage WT. The workpiece is a photosensitive substrate such as a semiconductor wafer coated with a photoresist.

[0342] The exposure device 3 moves the mask stage RT and the work stage WT synchronously and parallelly, thereby exposing the workpiece to the pulsed laser PL reflecting the mask pattern. After the mask pattern is transferred to the semiconductor wafer through the above exposure process, a semiconductor device can be manufactured through multiple processes. The semiconductor device is an example of an "electronic device" in the present disclosure.

[0343] 10. Example of laser controller structure

[0344] In the present disclosure, the laser controller 13 can be implemented by a combination of hardware and software of one or more computers. Software is synonymous with program. A programmable controller is included in the concept of a computer. A computer can be configured to include a CPU (Central Processing Unit) and a memory. The CPU included in a computer is an example of a processor.

[0345] Furthermore, part or all of the functions of the laser controller 13 may be realized using an integrated circuit represented by an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit).

[0346] The above description is not limiting but merely illustrative, and therefore, it is apparent to those skilled in the art that modifications can be made to the various embodiments of the present disclosure without departing from the scope of the claims.

[0347] The terms used in this specification and claims as a whole should be interpreted as "non-limiting" terms. For example, terms such as "including" or "comprising" should be interpreted as "not limited to the parts recorded as included". Terms such as "having" should be interpreted as "not limited to the parts recorded as having". In addition, the modifier "one" recorded in this specification and claims 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", and further, should be interpreted as also including combinations of them and parts other than "A", "B" and "C".

Claims

1. A laser device, comprising: an oscillating device that outputs a pulsed laser; a beam intensity distribution measuring device for measuring the beam intensity distribution of the pulsed laser; a beam angle distribution measuring device for measuring the beam angle distribution of the pulsed laser; a pulse waveform measuring device for measuring the pulse waveform of the pulse laser; a spectrum measuring device for measuring the spectrum of the pulsed laser light; and A laser controller calculates speckle contrast based on the beam intensity distribution, the beam angle distribution, the pulse waveform, and the spectrum.

2. The laser device according to claim 1, wherein: The laser controller calculates a pulse width according to the pulse waveform, calculates an etendue according to the beam intensity distribution and the beam angle distribution, calculates a spectral line width according to the spectrum, and calculates the speckle contrast according to the pulse width, the etendue and the spectral line width.

3. The laser device according to claim 2, wherein: The laser controller sets the speckle contrast to SC, the pulse width to W, the optical etendue to ET, the spectral line width to Δλ, the wavelength of the pulsed laser to λ, the speed of light to c, and the number of pulses of the pulsed laser to N. pulse In the case of, the speckle contrast is calculated by the following formula (1): 【Mathematical formula 1】 4. The laser device according to claim 3, wherein: The pulse width is TIS, and the spectral line width is E95.

5. The laser device according to claim 3, wherein: The pulse number is the number of pulses used by the exposure device during exposure. The laser controller obtains the pulse number from the exposure device.

6. The laser device according to claim 2, wherein: The laser controller calculates a beam cross-sectional area according to the beam intensity distribution, calculates a beam divergence angle according to the beam angle distribution, and multiplies the beam cross-sectional area and the beam divergence angle to thereby calculate the etendue.

7. The laser device according to claim 1, wherein: The laser controller causes a display device to display the calculated speckle contrast.

8. The laser device according to claim 1, wherein: The beam intensity distribution measuring device includes a transfer optical system and an image sensor disposed at a position where the beam cross-sectional image of the pulse laser beam is transferred by the transfer optical system.

9. The laser device according to claim 1, wherein: The beam angle distribution measuring device includes a focusing optical system and an image sensor disposed at a position where the pulse laser light is focused by the focusing optical system.

10. The laser device according to claim 1, wherein: The pulse waveform measuring device includes a diffusion plate and a dual-plane phototube, and the dual-plane phototube is arranged at a position capable of receiving the pulse laser diffused by the diffusion plate.

11. The laser device according to claim 1, wherein: The spectrum measuring device is an etalon spectrometer.

12. The laser device according to claim 2, wherein: The laser device further comprises one or more of a pulse width changing device for changing the pulse width, an etendue changing device for changing the etendue, and a line width changing device for changing the line width. The laser controller controls the one or more devices so that the speckle contrast becomes equal to or less than a target value.

13. The laser device according to claim 2, wherein: The laser device further comprises a pulse width changing device for changing the pulse width, an etendue changing device for changing the etendue, and a line width changing device for changing the line width. The laser controller adjusts the pulse width, the etendue, and the line width in this order so that the speckle contrast becomes equal to or less than a target value.

14. The laser device according to claim 12, wherein: The laser controller obtains the target value from the exposure device.

15. The laser device according to claim 12, wherein: The oscillating device includes a cavity sealed with laser gas, The pulse width changing device controls the concentration of the halogen gas or the concentration of the argon gas in the chamber to change the pulse width.

16. The laser device according to claim 12, wherein: The laser device further comprises an optical pulse stretcher arranged on the optical path of the pulse laser. The pulse width changing device changes the pulse width by controlling the reflectivity of a beam splitter or the transmittance of an ND filter arranged on a delay optical path of the optical pulse stretcher.

17. The laser device according to claim 12, wherein: The etendue changing device controls the posture of one or more concave mirrors among a plurality of concave mirrors constituting the optical pulse stretcher to change the beam divergence angle, thereby changing the etendue.

18. The laser device according to claim 12, wherein: The etendue changing device selectively arranges a plurality of optical elements having different optical characteristics on the optical path of the pulse laser light, thereby changing the etendue.

19. The laser device according to claim 12, wherein: The spectral line width changing device is composed of a wavefront changing device that changes the wavefront of the pulse laser, a narrowband device that narrows the band of the pulse laser, or a combination of the wavefront changing device and the narrowband device.

20. A method for manufacturing an electronic device, comprising the following steps: The laser device outputs pulsed laser light to the exposure device. The pulse laser is exposed on a photosensitive substrate in the exposure device to manufacture an electronic device. The laser device has: an oscillating device that outputs the pulsed laser; a beam intensity distribution measuring device for measuring the beam intensity distribution of the pulsed laser; a beam angle distribution measuring device for measuring the beam angle distribution of the pulsed laser; a pulse waveform measuring device for measuring the pulse waveform of the pulse laser; a spectrum measuring device for measuring the spectrum of the pulsed laser light; and A laser controller calculates speckle contrast based on the beam intensity distribution, the beam angle distribution, the pulse waveform, and the spectrum.

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