Exposure apparatus, control method of exposure apparatus, and product manufacturing method

Abstract

The invention provides an exposure apparatus, a control method of the exposure apparatus, and a product manufacturing method. The exposure apparatus includes: an illumination optical system including a plurality of optical elements that change a wavelength band of light from a light source, and configured to irradiate a surface to be irradiated with light whose wavelength band has been changed by one of the plurality of optical elements; and a control unit configured to control an input power of the light source using a correction value corresponding to a relationship between the illuminance change and the input power of the light source to maintain a constant illuminance on the irradiated surface. The control unit uses different correction values for the plurality of optical elements.

Description

Technical Field

[0001] The present invention relates to an exposure device, a control method for the exposure device, and a product manufacturing method. Background Art

[0002] Exposure apparatuses are used in the photolithography process for manufacturing products such as semiconductor devices. They include a projection optical system, an illumination optical system for illuminating a master plate, and an illumination optical system for projecting the illuminated master plate pattern onto a substrate. The substrate has a photoresist on its surface, so the master plate pattern is transferred to the photoresist by projecting it onto the substrate.

[0003] For example, a mercury lamp is used as the light source of an illumination optical system. By varying the input power of the mercury lamp, its light output can be varied. However, because mercury lamps degrade over time, even with the same input power, the light output cannot be maintained constant. Therefore, as disclosed in Japanese Patent Application Laid-Open No. H6-36984, it is possible to maintain a constant light output from the light source and, consequently, a constant illumination intensity for the illumination optical system by adjusting the input power over a given period of time. This function is also referred to as a constant illumination intensity function.

[0004] The constant illumination function requires pre-measurement of the relationship between the mercury lamp's input power and light output. Because the lamp's light output varies substantially in proportion to its input power, a pre-measured approximation coefficient is used. Using this approximation coefficient, light output and input power can be expressed as: light output = approximation coefficient × input power. While the approximation coefficient is expressed as a first-order approximation coefficient, it can also be expressed as a polynomial approximation coefficient.

[0005] In the illumination optical system, a wavelength filter is used as an optical element that only passes a specific wavelength band. The mercury lamp used in the illumination optical system emits light in a specific wavelength band near the center emission wavelength. In this way, the light amount distribution of the wavelength band emitted by the mercury lamp is called the emission spectrum. The wavelength filter is used to intercept a specific wavelength band from the emission spectrum of the mercury lamp. Generally, when a wavelength filter with a narrow band is used, the influence of chromatic aberration of the projection optical system can be suppressed. Therefore, an improvement in image performance can be expected. On the contrary, when a wavelength filter with a wide band is used, the amount of combined light increases. Therefore, an increase in the illumination of the irradiated surface can be expected. Since the exposure device is used for various processes, a plurality of wavelength filters are installed inside the exposure device so that the wavelength filter can be switched for exposure according to the process.

[0006] However, the emission spectrum of a mercury lamp varies depending on the input power. Therefore, the amount of change in light output relative to the lamp's input power varies depending on the wavelength band intercepted by the wavelength filter. In conventional constant illumination functions, the approximation coefficients used to calculate power adjustment are not separated for each wavelength filter used. Therefore, the constant illumination function can be applied using the optimal approximation coefficients for a specific wavelength filter. However, when switching wavelength filters, errors in the approximation coefficients can occur, making it difficult to maintain ideal constant illumination. Summary of the Invention

[0007] Therefore, according to the embodiment of the present invention, an optimal constant illumination function suitable for a wavelength band is achieved.

[0008] According to one aspect of the present invention, an exposure apparatus includes: an illumination optical system including a plurality of optical elements that change the wavelength of light from a light source, and configured to illuminate an irradiated surface with light whose wavelength has been changed by one of the plurality of optical elements; and a control unit configured to control the input power of the light source using a correction value corresponding to a relationship between illuminance variation and input power of the light source, so as to maintain a constant illuminance on the irradiated surface. The control unit uses different correction values ​​for the plurality of optical elements.

[0009] Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a schematic diagram showing the configuration of an exposure apparatus according to a first embodiment.

[0011] Figure 2A and Figure 2B is a graph showing changes in the wavelength characteristics of the light source with respect to the input power of the light source according to the first embodiment.

[0012] Figure 3 : is a graph showing changes in light output of the light source with respect to input power of the light source according to the first embodiment.

[0013] Figure 4 is a flowchart illustrating the constant illumination function according to the first embodiment.

[0014] Figure 5 is a flowchart illustrating a prerequisite measurement of the constant illuminance function according to the first embodiment.

[0015] Figure 6 is a flowchart illustrating calculation of the power adjustment amount according to the first embodiment.

[0016] Figure 7is a flowchart illustrating a prerequisite measurement of the constant illuminance function according to the second embodiment.

[0017] Figure 8 is a flowchart illustrating calculation of a power adjustment amount according to the second embodiment. DETAILED DESCRIPTION

[0018] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. The following embodiments do not limit the invention disclosed in the claims. In the embodiments, multiple features will be described, but not all of the multiple features are required for the present invention, and multiple features can be combined in any manner. In addition, in the drawings, the same or similar structures are marked with the same reference numerals, and their repeated description will be omitted.

[0019] First embodiment

[0020] Figure 1 1 is a schematic diagram illustrating the configuration of an exposure apparatus 100 according to a first embodiment. Exposure apparatus 100 is, for example, a photolithography apparatus that forms a pattern on a substrate using a process (photolithography process) for manufacturing semiconductor devices, etc. Exposure apparatus 100 exposes a substrate W through a master (mask) R to transfer the master's pattern onto a substrate coated with a resist (resin), forming a latent image pattern in the patterned area of ​​substrate W. In this embodiment, exposure apparatus 100 is a step-and-repeat exposure apparatus (stepper) that exposes substrate W through master R. A step-and-repeat exposure apparatus 100 or another type of exposure apparatus may also be employed.

[0021] The exposure apparatus 100 includes an illumination optical system 101, a plate drive unit 102, a projection optical system 103, a substrate drive unit 104, a storage unit 20, a control unit 21, a power supply unit 22, a light source 1, and an elliptical mirror 2. In this embodiment, a coordinate system is defined in which the axis oriented along the normal direction of the substrate W is referred to as the Z axis, and the axes oriented in directions orthogonal to each other within a plane parallel to the substrate W are referred to as the X axis and the Y axis. In the figure, AX denotes the optical axis.

[0022] The illumination optical system 101 illuminates the original plate R arranged on the illuminated surface (the object surface of the projection optical system 103) using light (luminous flux) from a light source 1. The light source 1 includes, for example, an ultra-high-pressure mercury lamp that emits light such as i-line (wavelength of 365nm). However, the light source 1 is not limited to this and may be a KrF excimer laser that emits light with a wavelength of 248nm, an ArF excimer laser that emits light with a wavelength of 193nm, or an F2 laser that emits light with a wavelength of 157nm. The light source 1 may be an EUV light source that emits extreme ultraviolet light (EUV light) with a wavelength of approximately 11nm to 14nm. The light source 1 emits output light based on the input power from the power supply unit 22.

[0023] A pattern (e.g., a circuit pattern) to be transferred to the substrate W is formed on the master plate R. The master plate R is formed of a material that transmits light from the light source 1 (illumination optical system 101), such as quartz glass used as a base material. For example, the master plate drive unit 102 includes a movable master plate stage that holds the master plate R and a master plate drive mechanism that drives the master plate stage along the X and Z axes.

[0024] The projection optical system 103 projects the pattern of the original plate R illuminated by the illumination optical system 101 onto the substrate W. The projection optical system 103 includes an imaging optical system. The front focus is arranged on the surface (position) where the original plate R is arranged, while the rear focus is arranged on the surface where the substrate W is arranged. In other words, the projection optical system 103 has a conjugate relationship between the position where the original plate R is arranged and the position where the substrate W is arranged.

[0025] The substrate W is a substrate onto which the pattern of the original plate R is transferred, and a resist (photosensitive material) is supplied to the surface of the substrate. The substrate drive unit 104 includes a movable substrate stage that holds the substrate W and a substrate drive mechanism that drives the substrate stage along the X-axis, Y-axis, and Z-axis (as well as the rotational directions ωx, ωy, and ωz).

[0026] Hereinafter, the illumination optical system 101 will be described in detail. The illumination optical system 101 is an illumination mechanism that illuminates a surface with light from a light source 1. The illumination optical system 101 according to this embodiment includes a first relay lens 3, a folding mirror M1, an optical integrator 4, a second condensing lens 5, an extraction mirror 6, an illuminometer 7, a field stop 8, an imaging lens 9, and a folding mirror M2.

[0027] The first relay lens 3 and the folding mirror M1 are included in the first illumination optical system 10. The imaging lens 9 and the folding mirror M2 are included in the imaging illumination optical system 11. Light from the first illumination optical system 10 is incident on the second condenser lens 5 via the optical integrator 4.

[0028] Elliptical mirror 2 has a first focal point and a second focal point, and converges light from light source 1, which is arranged at the first focal point, onto the second focal point. First relay lens 3 comprises an imaging optical system. Its front focal point is arranged at the second focal point of elliptical mirror 2, while its rear focal point is arranged on the incident surface of optical integrator 4. In other words, first relay lens 3 has a conjugate relationship between the second focal point of elliptical mirror 2 and the incident surface of optical integrator 4.

[0029] Thus, according to the present embodiment, the illumination optical system 101 includes the first illumination optical system 10 having a conjugate relationship between the second focus of the elliptical mirror 2 and the incident surface of the optical integrator 4. However, the present invention is not limited thereto and may include a first illumination optical system that does not have such a relationship.

[0030] A wavelength filter F1 is arranged near the pupil surface of the first relay lens 3, an optical element that transmits only light in a specific wavelength band. The wavelength filter defines the exposure wavelength (the wavelength of the light used to expose the substrate W). In this embodiment, the optical elements include two types: a wavelength filter F1 that transmits a narrow wavelength band, and a wavelength filter F2 that transmits a wide wavelength band. When the control unit 21 switches between these wavelength filters according to the exposure conditions, a wavelength band suitable for the conditions can be selected. In other words, the wavelength filters F1 and F2 also function as optical elements that alter the wavelength band of the light from the light source 1. That is, the illumination optical system 101 according to this embodiment illuminates the illuminated surface with light whose wavelength band has been altered by any of the multiple image sensors (wavelength filters F1 and F2) arranged in the illumination optical system 101. Wavelength filters F1 and F2 have different approximation coefficients (correction values) as described below. The approximation coefficient indicates the change in illuminance on the illuminated surface relative to the input power of the light source 1.

[0031] In this embodiment, the two types of wavelength filters described above are used, but the types of wavelength filters are not limited to these two types. The illumination optical system 101 may include two or more types of wavelength filters. Thus, in this embodiment, when the control unit 21 switches between multiple wavelength filters according to predetermined exposure conditions, wavelength filters F1 and F2, which serve as optical elements, are located within the illumination optical system 101.

[0032] Optical integrator 4 is, for example, a fly's eye lens. It is an element that two-dimensionally arranges multiple tiny lenses in the direction of incident light to form multiple secondary light sources. The incident surface and the illuminated surface of each tiny lens of optical integrator 4 are conjugate. The fly's eye lens includes a cylindrical lens or a microlens array, and can be an optical rod or a diffractive optical element.

[0033] The second condenser lens 5 superimposes the light emitted from the various microlenses of the optical integrator 4 onto the field stop 8. The field stop 8 includes a plurality of movable light shielding plates that form any aperture shape and limits the exposure range at the position where the original plate R is arranged as the illuminated surface (and the position where the substrate is arranged). The imaging lens 9 forms an image of the field stop 8 and the original plate R in a conjugate relationship, and illuminates the original plate R with the aperture shape defined by the field stop 8.

[0034] Extraction mirror 6 can reflect a portion of the light that illuminates field stop 8, and illuminometer 7 is positioned at an imaging position where the light reflected by extraction mirror 6 is reflected. The imaging position of illuminometer 7 is equivalent to the position of field stop 8, which is the imaging position of second condenser lens 5. Since field stop 8 is conjugate with original plate R, illuminometer 7 is equivalent to observing the illuminance on original plate R. Control unit 21 receives the illuminance value measured by illuminometer 7. According to this embodiment, the illuminance is the illuminance on the illuminated surface and surfaces located at positions conjugate with the illuminated surface.

[0035] The storage unit 20 is composed of an auxiliary storage device such as a hard disk drive (HDD) or a solid state drive (SSD), and is a storage device that stores various types of setting data or data of various parameters. The storage unit 20 may be an optical disk such as a floppy disk (FD) or a compact disk (CD) that is detachably mounted on the exposure device 100, a magnetic card or an optical card, an IC card, a memory card, or the like.

[0036] The control unit 21 is configured as at least one computer including at least one CPU (processor) or one or more memories. The control unit 21 is connected to the various components of the exposure device 100 via wiring. The memory is configured as random access memory (RAM) and read-only memory (ROM). RAM is volatile memory. For example, SRAM, DRAM, etc. can be used. ROM is non-volatile memory. For example, EEPROM, flash memory, etc. can be used. The ROM or auxiliary storage device stores programs for implementing the functions of the exposure device 100 or data for executing the programs. The program or each piece of data is appropriately loaded into the RAM by the control unit 21 for execution. As a result, each component of the exposure device 100 functions. In this way, the control unit 21 generally controls the operation, adjustment, etc. of the various components of the entire exposure device 100 according to the program stored in the memory. The control unit 21 can be configured integrally with the other components of the exposure device 100, separately from the other components of the exposure device 100, or located at a different location from the exposure device 100 to be remotely controlled.

[0037] In the conventional constant illuminance function, the input power of light source 1 required to maintain the set illuminance is calculated based on the illuminance value received by control unit 21. The light output of light source 1 is set to any value by controlling power supply unit 22 to achieve the calculated input power.

[0038] Will refer to Figure 2A and Figure 2B The relationship between the light emission spectrum of the light source 1 and the input power of the power supply unit 22 is described. Figure 2A and Figure 2B Graph showing how the wavelength characteristics of the light source 1 change with the input power of the light source 1 .

[0039] Figure 2A is a graph showing the change in the emission spectrum of the light source 1. In Figure 2A , the horizontal axis represents the wavelength λ, and the vertical axis represents the light output (illuminance) P at each wavelength. The light source 1 emits light having a specific wavelength band, in which the light output P at the emission center wavelength λ0 is the highest and the emission center wavelength λ0 is the center. For example, Figure 2A shows the change in the emission spectrum when the input power of the light source 1 becomes E1 and E2. E1 and E2 have a relationship of E1 > E2.

[0040] Figure 2B is a graph showing the result obtained by calculating the light output ratio = P E1 / P E2 in the input power E1 and the input power E2. As Figure 2B shown, when the input power of the light source 1 changes, the change in the emission spectrum is not constant at each wavelength, and the change amount of the light output P in the surrounding wavelength band is greater than the change amount of the emission center wavelength λ0.

[0041] In this embodiment, it is assumed that BW1 is the wavelength band transmitted by the wavelength filter F1, and BW2 is the wavelength band transmitted by the wavelength filter F2. As Figure 2A and Figure 2B shown, the wavelength filters F1 and F2 have the same emission center wavelength λ0 of the intercepted wavelength band and different wavelength band (BW1 and BW2) widths. That is, the wavelength filters F1 and F2 change the wavelength band of the light from the light source 1 so that the wavelength band widths are different.

[0042] BW1 and BW2 have a relationship of BW1 < BW2. That is to say, the wavelength filter F2 that transmits a wider wavelength band is also affected by the following surrounding wavelength band compared with the wavelength filter F1 that only transmits the wavelength band near the emission center wavelength λ0, in which the change in the light output P due to the power change is large. Therefore, in the wavelength filter F2 having a wide wavelength band, the change in the light output P due to the power change is large. Thus, since the emission spectrum of the light source 1 changes due to the input power, the change amounts of the light output for each wavelength filter to be used are different.

[0043] Figure 3 is a graph showing the change in the light output P of the wavelength filters F1 and F2 having different wavelength bands (BW1 and BW2) with respect to the input power E of the light source 1. Here, the light output P is measured at the maximum input power E maxThe values ​​when lit are normalized. The relationship between light output P and input power E is linearly approximated. The approximate coefficient of wavelength filter F1 is a1·b1, while the approximate coefficient of wavelength filter F2 is a2·b2. That is, the approximate coefficient is a coefficient corresponding to the relationship between the change in illuminance and the input power E of light source 1, and is also the correction value used by control unit 21 to control the input power E of light source 1, as described below. In this embodiment, control unit 21 uses different correction values ​​corresponding to multiple optical elements to control the input power E of light source 1. The approximate coefficient can be obtained using a preset table, or it can be supplemented and obtained based on the relationship between the change in illuminance and the input power E of light source 1.

[0044] like Figure 2A and Figure 2B As shown, when the luminous spectrum of the light source 1 changes relative to the input power E, in the wide-band wavelength filter F2, the change in the light output P relative to the input power E is large. Therefore, the approximate coefficient a2 of the wavelength filter F2 is greater than the approximate coefficient a1 of the wavelength filter F1. That is, the relationship between the approximate coefficients a1 and a2 is a2>a1. In order to realize the constant illumination function, as described above, it is necessary to measure in advance the approximate coefficient related to the change in the light output P relative to the input power E. Here, the approximate coefficient is different depending on the wavelength band corresponding to the wavelength filter. Therefore, it is necessary to measure the approximate coefficient of each wavelength filter. If the same approximate coefficient is used between different wavelength filters, due to the approximate coefficient error, accurate power adjustment may not be possible, and it may be difficult to maintain the target illumination as the constant illumination function.

[0045] Next, we will refer to Figure 4 A process of realizing the constant illuminance maintaining function according to the present embodiment is described. Figure 4 This is a flowchart showing a process for realizing a constant illuminance maintaining function in the exposure device 100 including a plurality of wavelength filters according to the first embodiment. This is realized by causing the control unit 21 of the exposure device 100 to execute a program stored in a memory or the like. Figure 4 Each step is marked with an S before it, and the step mark is abbreviated.

[0046] In S101, the control unit 21 performs preliminary measurement for the constant illumination function (preliminary measurement of an approximate coefficient related to a change in light output P relative to input power E). Figure 5 Describe the details of the pre-measurement.

[0047] Figure 5 This is a flowchart showing the precondition measurement of the constant illuminance function according to the first embodiment. Figure 5Each step is abbreviated by adding an S before it.

[0048] In S201, the control unit 21 selects a wavelength filter (hereinafter referred to as wavelength filter F) installed in the exposure device 100. n ). When a plurality of wavelength filters are installed in the exposure device 100 as in this embodiment, any one wavelength filter F is selected. n When the exposure apparatus 100 according to the present embodiment is given as an example, the control unit 21 selects the wavelength filter F1 or the wavelength filter F2.

[0049] In S202, the control unit 21 selects the wavelength filter F n In the state of , control unit 21 measures the illuminance I measured by illuminometer 7 while changing the input power E of light source 1. In other words, control unit 21 obtains the measurement result of the illuminance (illuminance at each input power) according to the input power of light source 1. In the process of S202, it is preferable to obtain the measurement result by significantly changing the input power, but the measurement result of the illuminance is obtained when the input power E is changed at least at two points (twice) or more. By having control unit 21 change the input power E of light source 1, the amount of light of each wavelength is changed.

[0050] In S203, the control unit 21 sends the measurement result of the illuminance I relative to the input power E to the storage unit 20 and causes the storage unit 20 to store the measurement result. n and B n In other words, the control unit 21 calculates the approximate coefficient A of the relational expression based on the measurement result measured in S202. n and B n In this embodiment, the first-order approximation coefficient is given as an example of the approximation coefficient, but a higher-order approximation coefficient can also be used. In this embodiment, the wavelength filter F n The approximate coefficient A of the illuminance I and input power E in n and B n Expressed as I = A n ×E+B n .

[0051] In S204, the control unit 21 calculates the approximation coefficient A calculated in S203. n and the wavelength filter F selected in S101 n The information is stored in the storage unit 20 in an associated manner.

[0052] In S205, the control unit 21 determines whether the processing from S201 to S204 has been completed for all wavelength filters installed on the exposure device 100. In other words, the control unit 21 determines whether the approximate coefficients of all wavelength filters installed on the exposure device 100 have been calculated, and stores the information about the calculated approximate coefficients and wavelength filters in the storage unit 20 in association with each other. When the processing from S201 to S204 has not been completed for all wavelength filters installed on the exposure device 100 as a result of the determination, the above-mentioned processing is performed starting from S201. That is, when there are wavelength filters for which the approximate coefficients have not been calculated, the above-mentioned processing is performed on the wavelength filters for which the approximate coefficient values ​​have not been calculated. On the contrary, when the processing from S201 to S204 has been completed for all wavelength filters installed on the exposure device 100, Figure 5 The processing shown ends. That is, the processing of S101 ends.

[0053] When the exposure device 100 according to the present embodiment is given as an example, the control unit 21 first selects the wavelength filter F1, calculates the approximate coefficients of the input power E and the illuminance I in the wavelength filter F1, and stores them in the storage unit 20. Thereafter, after performing the determination process of S205, the wavelength filter F2 is subsequently selected. Then, as in the wavelength filter F1, the approximate coefficients of the illuminance I and the input power E in the wavelength filter F2 are calculated and stored in the storage unit 20. Therefore, since the approximate coefficients for all wavelength filters are calculated and the information on the wavelength filters and the calculated approximate coefficients are stored in the storage unit 20 in association, Figure 5 The indicated processing ends.

[0054] Then, processing returns to Figure 4 In S102, the control unit 21 selects the exposure conditions of the exposure device 100 and determines the wavelength filter F to be used. n Then, the control unit 21 switches the wavelength filter to the determined wavelength filter F n When the present embodiment is given as an example, the control unit 21 determines a wavelength filter to be used according to the exposure condition from among the wavelength filters F1 or F2 and performs switching of the wavelength filter to the determined wavelength filter.

[0055] In S103, the control unit 21 determines (sets) the wavelength filter F determined in step S102. n Target illuminance I when applying the constant illuminance function t . You can filter F for each wavelength to be used n To determine the target illumination I tIn S104, the control unit 21 measures the illuminance I at the current input power E. When the current input power is unclear, the maximum power E that can be input to the light source 1 is set. max , and measures the illuminance I. In S105, the control unit 21 calculates the illuminance I for setting the target illuminance t The power adjustment ΔE will be referred to Figure 6 The details of S105 are described.

[0056] Figure 6 The calculation of the power adjustment amount according to the first embodiment is performed by causing the control unit 21 of the exposure device 100 to execute a program stored in a memory or the like. Figure 6 Each step is marked by adding S before it to shorten the step label.

[0057] In S301, the control unit 21 confirms the wavelength filter F determined based on the exposure condition selected in S102. n In S302, the control unit 21 reads the wavelength filter F confirmed in S301 from the storage unit 20. n The approximate coefficient A n .

[0058] In S303, the control unit 21 calculates the target illuminance I t The required power adjustment amount ΔE is used. The wavelength filter F stored in the storage unit 20 n The approximate coefficient A n And the target illumination I t The difference ΔI (= target illuminance I) between the illuminance I measured in S104 and the target illuminance I t = Current illuminance I), the power adjustment amount ΔE is calculated as Power adjustment amount ΔE = I ÷ A n When the calculation of the power adjustment amount ΔE is completed, the process of S105 ends.

[0059] Then, return to the reference Figure 4 In S106, the control unit 21 adjusts the input power E of the light source 1 by the power adjustment amount ΔE calculated in S105. In this way, when the control unit 21 adjusts the input power E of the light source 1 according to the wavelength filter F based on the power adjustment amount ΔE n When the power E of the light source 1 is controlled (adjusted), the exposure device 100 according to this embodiment can maintain the target illumination I t That is, the illuminance on the illuminated surface can be constantly maintained.

[0060] The exposure device 100 according to the first embodiment can realize the optimal constant illuminance function according to the wavelength band by acquiring different approximation coefficients for the respective wavelength bands to be used.

[0061] Second embodiment

[0062] Next, we will refer to Figure 7 and Figure 8 The exposure device 100 according to the second embodiment is described. The configuration or function of the exposure device 100 according to the second embodiment is the same as that according to the first embodiment, and the description thereof will be omitted. The flowchart for realizing the constant illuminance maintaining function according to the second embodiment is different from that according to the first embodiment. Figure 4 The steps other than those in the first embodiment are similar to those in the first embodiment, but the processing details of S101 and S105 are different from those in the first embodiment. Therefore, the specific processing in the second embodiment will be described below.

[0063] Figure 7 is a flowchart illustrating a prerequisite measurement of the constant illuminance function according to the second embodiment. Figure 8 : is a flow chart showing the calculation of the power adjustment amount according to the second embodiment. In the second embodiment, Figure 7 The first embodiment is shown Figure 4 The flowchart of the details of S101 is shown in FIG. Figure 8 The first embodiment is shown Figure 4 Flowchart of details of S105.

[0064] Below, we will refer to Figure 7 The details of S101 according to the second embodiment (preliminary measurement processing of the constant illuminance function) are described. This is achieved by causing the control unit 21 of the exposure device 100 to execute a program stored in a memory or the like. Figure 7 Each process in. The step numbers are abbreviated by adding S before each step. The exposure device 100 according to the second embodiment includes wavelength filters F1 and F2 similar to the wavelength filters according to the first embodiment, and also includes a reference wavelength filter to be described below. One of the wavelength filters F1 and F2 can be set as a reference wavelength filter. In this way, the exposure device 100 according to the second embodiment also includes a plurality of wavelength filters as in the first embodiment. The wavelength band (first wavelength band) of the reference wavelength filter according to the second embodiment is different from the wavelength band of the wavelength filters F1 and F2.

[0065] In S401, the control unit 21 selects a reference wavelength filter F0 from among a plurality of wavelength filters. The reference wavelength filter F0 is one of a plurality of wavelength filters in the exposure device 100. The reference wavelength filter F0 is set in advance.

[0066] In S402, with the reference wavelength filter F0 selected by the control unit 21 in S401, the control unit 21 measures the illuminance I measured by the illuminometer 7 while changing the input power E of the light source 1. In other words, the control unit 21 obtains the measurement results of the illuminance (illuminance at various input powers) according to the input power of the light source 1. In the process of S402, it is preferable to obtain the measurement results by significantly changing the input power, but the measurement results of the illuminance are obtained when the input power E is changed at least at two points (twice) or more.

[0067] In S403, the control unit 21 calculates the approximate coefficient A0 of the illuminance I relative to the input power E in the reference wavelength filter F0. Since the method of calculating the approximate coefficient A0 is the same as that of the first embodiment, its description will be omitted. As in the first embodiment, the approximate coefficient according to the second embodiment can be a first-order approximate coefficient or a high-order approximate coefficient. In S404, the control unit 21 selects a wavelength filter F0 other than the reference wavelength filter F0 from the plurality of wavelength filters. n In S405, the control unit 21 measures the illuminance I measured by the illuminometer 7 while changing the input power E of the light source 1 in the state where the wavelength filter is switched in S404.

[0068] In S406, the control unit 21 calculates the wavelength filter F n The approximate coefficient A of the illuminance I relative to the input power E n In addition, a wavelength filter F n The approximate coefficient A relative to the input power E n Calculate the approximation coefficient ratio α of the reference wavelength filter F0 relative to the approximation coefficient A0 calculated in S403. n =A n / A0. That is, calculate the approximate coefficient A without the first band n The control unit 21 calculates the approximation coefficient ratio α and the reference wavelength filter F0 as an optical element having a first wavelength band. n Stored in the storage unit 20.

[0069] In S407, the control unit 21 determines whether the calculation of the approximate coefficient ratios of all wavelength filters installed on the exposure device 100 is completed. When the calculation of the approximate coefficient ratios of all wavelength filters installed on the exposure device 100 is not completed, similar processing is performed starting from S404. That is, when there is an uncalculated approximate coefficient ratio α n When the wavelength filter is used, the uncalculated approximate coefficient value is α from S404. nConversely, when the calculation of the approximate coefficient ratios of all wavelength filters installed on the exposure device 100 is completed, Figure 7 The processing shown ends. That is, the processing of S101 according to the second embodiment ends.

[0070] In the following, reference will be made to Figure 8 The details of the process of calculating the power adjustment amount ΔE in S105 according to the second embodiment are described. This is achieved by causing the control unit 21 of the exposure device 100 to execute a program stored in a memory or the like. Figure 8 Each step is abbreviated by adding an S before it.

[0071] In S501, the control unit 21 calculates the power adjustment amount ΔE0 using the approximation coefficient A0 of the reference wavelength filter F0. The power adjustment amount ΔE0 of the reference wavelength filter F0 is expressed as ΔE0=ΔI÷A0. As in the first embodiment, the target illuminance I t The current illuminance I obtains ΔI as the difference from the illuminance I.

[0072] In S502, the control unit 21 determines whether the wavelength filter under the exposure conditions selected in S102 matches the reference wavelength filter F0. If the wavelength filter under the exposure conditions selected in S102 matches the reference wavelength filter F0, the process proceeds to S503. That is, if the reference wavelength filter F0 is selected as the wavelength filter under the exposure conditions, the process proceeds to S503. Conversely, if the wavelength filter under the exposure conditions selected in S102 does not match the reference wavelength filter F0, the process proceeds to S504. That is, if the reference wavelength filter F0 is not selected as the wavelength filter under the exposure conditions, the process proceeds to S504.

[0073] In S503, the control unit 21 determines the power adjustment amount ΔE. Specifically, when processing proceeds to S503, since the reference wavelength filter F0 was not selected as the wavelength filter under the exposure conditions in S502, the control unit 21 determines the ΔE0 calculated in S501 as the power adjustment amount ΔE. Thus, in S503, the power adjustment amount ΔE is determined as power adjustment amount ΔE = power adjustment amount ΔE0.

[0074] In S504, the control unit 21 confirms the approximation coefficient ratio α of the wavelength filter under the exposure condition relative to the reference wavelength filter F0. nThat is, when the process enters S504, since the reference wavelength filter F0 is not selected as the wavelength filter under the exposure condition in S502, the control unit 21 reads the wavelength filter F0 under the exposure condition calculated in S406 from the storage unit 20. n The approximation coefficient is α n .

[0075] In S505, the control unit 21 determines the wavelength filter F under the exposure condition. n At this time, the power adjustment amount ΔE0 in the reference wavelength filter F0 and the approximate coefficient ratio α of the wavelength filter under the exposure condition are used. n , the power adjustment ΔE is expressed as the approximate coefficient ratio α in the power adjustment ΔE n =Power adjustment amount ΔE0 / reference wavelength filter F0 Thus, the process of S105 according to the second embodiment ends.

[0076] In the second embodiment, the storage unit 20 stores the approximate coefficient value ratios of each wavelength filter, rather than the approximate coefficients of each wavelength filter as in the first embodiment. If the approximate coefficients change over time due to changes in light source 1, since the approximate coefficients of all wavelength filters were directly stored in the first embodiment, it would be necessary to remeasure the approximate coefficients. However, in the second embodiment, the relationship between the approximate coefficients of each wavelength filter is stored. Therefore, when only the approximate coefficient of the reference wavelength is remeasured, there is no need to remeasure the approximate coefficients of the other wavelength filters. This reduces computational load and time.

[0077] As described above, in the exposure device 100 according to the second embodiment, in addition to the advantages similar to those of the first embodiment, the calculation load or time can be reduced by measuring only the approximate coefficient of the reference wavelength again instead of measuring the approximate coefficient of another wavelength filter again.

[0078] Embodiment of the method for manufacturing a product

[0079] The product manufacturing method according to an embodiment of the present invention is suitable for manufacturing products such as semiconductor elements, flat panel displays, liquid crystal display elements or MEMS. The manufacturing method includes: a step of exposing a substrate to which a photosensitizer is applied using the above-mentioned exposure device 100 and a step of developing the exposed photosensitizer. An etching step, an ion implementation step, etc. are performed on the substrate using the pattern of the developed photosensitizer as a mask to form a circuit pattern on the substrate. The substrate on which the circuit pattern is formed is cut (processed), and chip mounting, bonding and inspection steps are performed as subsequent steps. The manufacturing method may include other known steps (oxidation, film formation, deposition, doping, planarization, resist stripping, etc.). Compared with the prior art, the product manufacturing method according to this embodiment is advantageous in at least one of the performance, quality, productivity and production cost of the product.

[0080] While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

[0081] The embodiments of the present invention may also be implemented by providing software (including a computer program product including a computer program / instructions) that performs the functions of the above-described embodiments to a system or device via a network or various storage media, and a computer or a central processing unit (CPU, microprocessing unit (MPU)) of the system or device reads and executes the computer program / instructions.

[0082] This application claims the benefit of Japanese Patent Application No. 2024-53419, filed Mar. 28, 2024, which is hereby incorporated by reference herein in its entirety.

Claims

1. An exposure apparatus comprising: an illumination optical system including a plurality of optical elements that change a wavelength band of light from a light source and configured to illuminate an irradiated surface with light whose wavelength band has been changed by one of the plurality of optical elements; as well as a control unit configured to control the input power of the light source using a correction value corresponding to the relationship between the illuminance variation and the input power of the light source to maintain a constant illuminance on the illuminated surface, The control unit uses different correction values ​​for the multiple optical elements.

2. The exposure apparatus according to claim 1, wherein The correction value is an approximate coefficient indicating the variation of the illuminance of the illuminated surface with respect to the input power of the light source.

3. The exposure apparatus according to claim 1, wherein The control unit calculates the correction value based on a measurement result obtained by measuring illuminance while changing input power of a light source for each optical element.

4. The exposure apparatus according to claim 3, wherein The control unit calculates the correction value according to an approximate expression obtained from a measurement result obtained by measuring the illuminance on the illuminated surface at two or more points.

5. The exposure apparatus according to claim 1, wherein The illuminance is the illuminance of the illuminated surface and the surfaces at positions conjugate to the illumination.

6. The exposure device according to claim 1, in, The plurality of optical elements are arranged inside the illumination optical system, and The control unit switches between the plurality of optical elements according to predetermined exposure conditions.

7. The exposure apparatus according to claim 1, wherein The control unit changes input power to the light source to change the amount of light at each wavelength.

8. The exposure apparatus according to claim 1, wherein The plurality of optical elements change wavelength bands of light so that the central wavelengths of the wavelength bands are the same but the wavelength bandwidths are different.

9. The exposure apparatus according to claim 1, wherein The control unit calculates a power adjustment amount for achieving a target illuminance, and adjusts input power of the light source based on the power adjustment amount.

10. The exposure apparatus according to claim 9, wherein The control unit calculates the power adjustment amount based on the correction value and a difference between the target illuminance and a current illuminance.

11. The exposure apparatus according to claim 1, wherein The control unit calculates a ratio of a correction value of an optical element having a wavelength band other than the first wavelength band to a correction value of the optical element having the first wavelength band. 12 . The exposure apparatus according to claim 1 , further comprising a storage unit configured to store the correction value.

13. A method for controlling an exposure device, the method comprising: an irradiation step of irradiating the irradiated surface with light of a wavelength range changed by one of a plurality of optical elements by an illumination optical system, the illumination optical system including a plurality of optical elements that change the wavelength range of light from a light source; as well as a control step of controlling the input power of the light source using a correction value corresponding to the relationship between the illuminance change and the input power of the light source to maintain a constant illuminance on the illuminated surface, Wherein, in the controlling step, different correction values ​​are used for the plurality of optical elements.

14. A method for manufacturing a product, comprising: exposing the substrate using an exposure device; developing the exposed substrate; manufacturing products from the developed substrate, Wherein, the exposure device comprises: an illumination optical system including a plurality of optical elements that change a wavelength band of light from a light source, and irradiating an irradiated surface with light whose wavelength band has been changed by one of the plurality of optical elements; and A control unit controls the input power of the light source using a correction value corresponding to the relationship between the illuminance variation and the input power of the light source to maintain a constant illuminance on the illuminated surface, wherein the control unit uses different correction values ​​for the plurality of optical elements.

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