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

Abstract

To provide an optimum constant illuminance function appropriate for a wavelength band.SOLUTION: An exposure apparatus includes: an illumination optical system including a plurality of optical elements changing a wavelength band of light from a light source and configured to illuminate an illuminated surface with light of which a wavelength band has been changed by one of the optical elements; and a control unit configured to control input power to the light source using a correction value corresponding to a relation of a change in illuminance to the input power to the light source to maintain constant illuminance on the illuminated surface. The control unit uses different correction values for the plurality of optical elements.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an exposure apparatus, a control method for the exposure apparatus, and a method for manufacturing an article. [Background technology]

[0002] An exposure apparatus can be used in a lithography process for manufacturing articles such as semiconductor devices. The exposure apparatus includes an illumination optical system that illuminates an original and a projection optical system that projects the pattern of the illuminated original onto a substrate. The substrate has a photoresist on its surface, and the pattern of the original is projected onto the substrate, thereby transferring the pattern to the photoresist.

[0003] For example, a mercury lamp is used as a light source in an illumination optical system. The light output of the mercury lamp can be changed by changing the input power of the mercury lamp. However, because mercury lamps deteriorate over time, it is not possible to maintain a constant light output even if the same power is input. Therefore, as in Patent Document 1, it is known to maintain a constant light output of the light source and a constant illuminance of the illumination optical system by adjusting the input power every time a certain period of time has passed. This function is called a constant illuminance function.

[0004] For the constant illuminance function, it is necessary to measure the relationship between the input power to the mercury lamp and the light output beforehand. Because the light output of a mercury lamp changes almost proportionally to the input power, an approximation coefficient measured beforehand is used. The light output and input power are expressed using the approximation coefficient as light output = approximation coefficient x input power. Here, the approximation coefficient is stated as a linear approximation coefficient, but it can also be calculated using a polynomial approximation coefficient.

[0005] In addition, wavelength filters are used in illumination optical systems as optical elements that transmit only specific wavelength bands. Mercury lamps used in illumination optical systems emit light with a certain wavelength band relative to the central emission wavelength. The light intensity distribution of the wavelength band emitted by a mercury lamp is called the emission spectrum. Wavelength filters are used to extract specific wavelength bands from the mercury lamp's emission spectrum. Generally, using narrow-band wavelength filters can suppress the effects of chromatic aberration in the projection optical system, and are expected to improve image performance. On the other hand, using broad-band wavelength filters increases the cumulative amount of light transmitted, and is expected to increase the illuminance of the illuminated surface. Since exposure tools are used for a variety of processes, multiple wavelength filters are installed within the exposure tool, allowing exposure by switching wavelength filters according to the process. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 6-365984 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the emission spectrum of a mercury lamp changes depending on the input power. Therefore, the amount of change in light output relative to the input power of the mercury lamp varies depending on the wavelength band selected by the wavelength filter. In conventional constant illuminance functions, the approximation coefficients used to calculate the amount of power adjustment were not separated for each wavelength filter used. Therefore, while it is possible to apply the constant illuminance function using the optimal approximation coefficients for a specific wavelength filter, switching wavelength filters introduces errors in the approximation coefficients, making it difficult to maintain an ideal constant illuminance.

[0008] Therefore, an object of the present invention is to realize an optimum constant illuminance function that is adapted to a wavelength band. [Means for solving the problem]

[0009] In order to achieve the above object, one aspect of the present invention provides an exposure apparatus comprising: an illumination optical system that includes a plurality of optical elements that change the wavelength band of light from a light source, and illuminates an irradiated surface with the light whose wavelength band has been changed by one of the plurality of optical elements; and a control unit that controls the input power to the light source using a correction value that corresponds to the relationship between the input power to the light source and the change in illuminance in order to maintain a constant illuminance on the irradiated surface, wherein the control unit uses different correction values ​​depending on the plurality of optical elements. [Effects of the Invention]

[0010] According to the present invention, it is possible to realize an optimum constant irradiance function that is suited to a wavelength band. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of an exposure apparatus in the first embodiment. [Figure 2] 4 is a diagram showing changes in wavelength characteristics of a light source with respect to input power to the light source in the first embodiment. FIG. [Figure 3] 4 is a diagram showing a change in the optical output of a light source relative to the input power to the light source in the first embodiment. [Figure 4] 10 is a flowchart of a constant illuminance function in the first embodiment. [Figure 5] 10 is a flowchart relating to precondition measurement for a constant illuminance function in the first embodiment. [Figure 6] 4 is a flowchart relating to power adjustment amount calculation in the first embodiment. [Figure 7] 10 is a flowchart relating to precondition measurement for a constant illuminance function in the second embodiment. [Figure 8] 10 is a flowchart relating to power adjustment amount calculation in the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the invention according to the claims. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0013] <Embodiment 1> FIG. 1 is a schematic diagram showing the configuration of an exposure apparatus 100 in this embodiment. The exposure apparatus 100 is also a lithography apparatus used in, for example, a manufacturing process (lithography process) for semiconductor devices and the like, and forms a pattern on a substrate. The exposure apparatus 100 exposes the substrate W through an original (mask) R, and transfers the pattern of the original to a substrate coated with resist (resin), thereby forming a latent image pattern in a pattern area of ​​the substrate W. In this embodiment, the exposure apparatus 100 is a step-and-repeat exposure apparatus (stepper) that exposes the substrate W in one go via the original R. However, the exposure apparatus 100 can also employ a step-and-scan exposure method or other exposure methods.

[0014] The exposure apparatus 100 has an illumination optical system 101, an original driving unit 102, a projection optical system 103, a substrate driving unit 104, a memory 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 along the normal direction of the substrate W is the Z axis, and the axes along directions perpendicular to each other in a plane parallel to the substrate W are the X axis and the Y axis. In the figure, AX indicates the optical axis.

[0015] The illumination optical system 101 uses light (light beam) from the light source 1 to illuminate the original R placed on the illuminated surface (the object surface of the projection optical system 103). The light source 1 includes, for example, an ultra-high pressure mercury lamp that emits light such as i-line (wavelength 365 nm). However, the light source 1 is not limited to this and may also be a KrF excimer laser that emits light with a wavelength of 248 nm, an ArF excimer laser that emits light with a wavelength of 193 nm, or an F2 laser that emits light with a wavelength of 157 nm. The light source 1 may also be an EUV light source that emits extreme ultraviolet light (EUV light) with a wavelength of approximately 11 nm to 14 nm. The light source 1 emits light with an output in accordance with the input power from the power supply unit 22.

[0016] A pattern (e.g., a circuit pattern) to be transferred to the substrate W is formed on the master R. The master R is made of a material that transmits light from the light source 1 (illumination optical system 101), such as quartz glass, as its base material. The master drive unit 102 includes, for example, a movable master stage that holds the master R, and a master drive mechanism that drives the master stage about the X-axis and Z-axis.

[0017] The projection optical system 103 projects the pattern of the original R illuminated by the illumination optical system 101 onto the substrate W. The projection optical system 103 includes an imaging optical system, the front focal point of which is located on the plane (position) where the original R is placed, and the rear focal point of which is located on the plane where the substrate W is placed. In other words, the projection optical system 103 makes the placement positions of the original R and the substrate W conjugate with each other.

[0018] The substrate W is a substrate onto which the pattern of the original R is transferred, and has a resist (photosensitive material) supplied on its surface. The substrate driving unit 104 includes a movable substrate stage that holds the substrate W, and a substrate driving mechanism that drives the substrate stage about the X-axis, Y-axis, and Z-axis (and their rotation directions ωx, ωy, and ωz).

[0019] The illumination optical system 101 will be described in detail below. The illumination optical system 101 is an illumination mechanism that illuminates an illuminated surface with light from the light source 1. The illumination optical system 101 of this embodiment is configured to include a first relay lens 3, a bending mirror M1, an optical integrator 4, a second condenser lens 5, a take-out mirror 6, an illuminance meter 7, a field stop 8, an imaging lens 9, and a bending mirror M2.

[0020] The first relay lens 3 and the bending mirror M1 constitute a first illumination optical system 10. The imaging lens 9 and the bending mirror M2 constitute an imaging illumination optical system 11. Light from the first illumination optical system 10 passes through an optical integrator 4 and enters a second condenser lens 5.

[0021] The elliptical mirror 2 has a first focal point and a second focal point, and collects light from the light source 1 located at the first focal point at the second focal point. The first relay lens 3 includes an imaging optical system, and its front focal point is located at the second focal point of the elliptical mirror 2, and its rear focal point is located on the entrance surface of the optical integrator 4. In other words, the first relay lens 3 makes the second focal point of the elliptical mirror 2 and the entrance surface of the optical integrator 4 conjugate with each other.

[0022] As described above, in this embodiment, the illumination optical system 101 includes the first illumination optical system 10 that establishes a conjugate relationship between the second focal point of the elliptical mirror 2 and the incident surface of the optical integrator 4. However, the present invention is not limited to this, and the illumination optical system 101 may include a first illumination optical system that does not have such a relationship.

[0023] A wavelength filter F1 is disposed near the pupil plane of the first relay lens 3 as an optical element that transmits only light of a specific wavelength band, and this wavelength filter determines the exposure wavelength (the wavelength of the light used to expose the substrate W). In this embodiment, the optical element is configured with two types of wavelength filters: wavelength filter F1 that transmits a narrow wavelength band and wavelength filter F2 that transmits a wide wavelength band. The controller 21 switches between these wavelength filters according to the specified exposure conditions, thereby realizing the selection of a wavelength band suited to the exposure conditions. In other words, the wavelength filters F1 and F2 also function as optical elements that change the wavelength band of light from the light source 1. That is, the illumination optical system 101 in this embodiment illuminates the illuminated surface with light whose wavelength band has been changed by one of multiple image sensors (wavelength filter F1 and wavelength filter F2) disposed within the illumination optical system 101. Furthermore, the wavelength filters F1 and F2 each have a different approximation coefficient (correction value), which will be described later. The approximation coefficient is a coefficient that represents the change in illuminance on the illuminated surface relative to the input power to the light source 1.

[0024] In this embodiment, the two types of wavelength filters described above are used, but the types of wavelength filters are not limited to two, and the illumination optical system 101 may have two or more types of wavelength filters. In this manner, in this embodiment, the control unit 21 switches between multiple wavelength filters in accordance with predetermined exposure conditions, so that wavelength filter F1 and wavelength filter F2, which are optical elements, are present in the illumination optical system 101.

[0025] The optical integrator 4 is, for example, a fly's-eye lens, and is an element in which multiple microlenses are arranged two-dimensionally in accordance with the direction of light incidence to form multiple secondary light sources. The incident surface of each microlens of the optical integrator 4 is in a conjugate relationship with the illuminated surface. Note that the fly's-eye lens includes a cylindrical lens and a microlens array, but may also be an optical rod or a diffractive optical element.

[0026] The second condenser lens 5 superimposes the light emitted from each microlens of the optical integrator 4 onto the field stop 8. The field stop 8 includes multiple movable light-blocking plates that can form any aperture shape, and limits the exposure range on the illuminated surface, which is the position of the original (and further the position of the substrate). The imaging lens 9 forms an image of the field stop 8 and the original R in a conjugate relationship, and illuminates the aperture shape defined by the field stop 8 onto the original R.

[0027] The extraction mirror 6 can reflect a portion of the light illuminating the field stop 8, and an illuminance meter 7 is placed at the imaging position of the light reflected by the extraction mirror 6. The imaging position at which the illuminance meter 7 is located is equivalent to the position of the field stop 8, which is the imaging position of the second condenser lens 5. Furthermore, since the field stop 8 is conjugate with the original R, the illuminance meter 7 is equivalent to observing the illuminance on the original R. The illuminance value measured by the illuminance meter 7 is received by the control unit 21. The illuminance in this embodiment is the illuminance of the irradiated surface and a surface located conjugate with the irradiated surface.

[0028] The storage unit 20 is configured with an auxiliary storage device such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive), and is a storage device that stores various programs, various setting data, various parameter data, etc. Note that the storage unit 20 may be an optical disk such as a flexible disk (FD) or compact disk (CD) that is detachable from the exposure apparatus 100, a magnetic or optical card, an IC card, a memory card, etc.

[0029] The control unit 21 is configured as at least one computer, including at least one CPU (processor), one or more memories, etc. The control unit 21 is also connected to each component of the exposure apparatus 100 via a line. The memory is configured from a RAM (Random Access Memory) and a ROM (Read Only Memory). The RAM is a volatile memory, and may be, for example, an SRAM or a DRAM. The ROM is a non-volatile memory, and may be, for example, an EEPROM or a flash memory. Programs for realizing the functions of the exposure apparatus 100 and data used when the programs are executed are stored in the ROM or an auxiliary storage device. The programs and data are also loaded into the RAM as appropriate by the control unit 21 and executed. This causes each component of the exposure apparatus 100 to function. In this way, the control unit 21 comprehensively controls the operation and adjustment of each component of the entire exposure apparatus 100 in accordance with the programs stored in the memory. Control unit 21 may be configured integrally with other parts of exposure apparatus 100 (in a common housing), or may be configured separately from other parts of exposure apparatus 100 (in a separate housing), or may be installed in a location separate from exposure apparatus 100 and controlled remotely.

[0030] In the conventional constant illuminance function, the control unit 21 calculates the input power to the light source 1 required to maintain the set illuminance from the received illuminance value. The light output of the light source 1 is set to an arbitrary value by controlling the power supply unit 22 so that the calculated input power is achieved.

[0031] The relationship between the emission spectrum of the light source 1 and the input power of the power supply unit 22 will be described below with reference to Fig. 2. Fig. 2 is a diagram showing the change in wavelength characteristics of the light source 1 relative to the input power to the light source 1.

[0032] Figure 2(A) is a diagram showing the change in the emission spectrum of the light source 1. In Figure 2(A), 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 with the highest light output P at the emission center wavelength λ0 and emits light in a certain wavelength band centered around the emission center wavelength λ0. Also, in Figure 2(A), as an example, it shows the change in the emission spectrum when the input power to the light source 1 is changed to E1 and E2. Note that E1 and E2 are in the relationship of E1 > E2.

[0033] Figure 2(B) is a diagram showing the result of calculating the light output ratio = P E1 / P E2 at the input powers E1 and E2. As shown in Figure 2(B), the change in the emission spectrum when the input power to the light source 1 is changed is not constant at each wavelength, and the change amount of the light output P is larger in the wavelength band around the emission center wavelength λ0 than in other wavelength bands.

[0034] In this embodiment, let the wavelength band transmitted by the wavelength filter F1 be BW1, and the wavelength band transmitted by the wavelength filter F2 be BW2. And as shown in Figure 2, the emission center wavelengths λ0 of the wavelength bands cut out by the wavelength filter F1 and the wavelength filter F2 are the same, but the widths of the wavelength bands (BW1, BW2) are different. That is, the wavelength filters F1 and F2 change the wavelength band of the light from the light source 1 so that the bandwidths are different.

[0035] Note that BW1 and BW2 are in the relationship of BW1 < BW2. That is, the wavelength filter F2 that transmits a wider band is more affected by the peripheral wavelength band where the change in the light output P due to the power change is large, compared to the wavelength filter F1 that transmits only the wavelength band near the emission center wavelength λ0. Therefore, the change in the light output P due to the power change is larger for the wavelength filter F2 with a wider wavelength band. Thus, since the emission spectrum of the light source 1 changes depending on the input power, the change amount of the light output is different for each wavelength filter used.

[0036] 3 is a graph showing the change in optical output power P relative to the input power E to the light source 1 when wavelength filters F1 and F2 having different wavelength bands (BW1, BW2) are used. Note that the optical output power P is the maximum input power E. max The relationship between the input power E and the optical output P is linearly approximated, and the approximation coefficients are a1·b1 for wavelength filter F1 and a2·b2 for wavelength filter F2. That is, the approximation coefficients correspond to the relationship between the input power E to light source 1 and the change in illuminance, and are also correction values ​​used by the control unit 21 (described later) to control the input power E to light source 1. In this embodiment, the control unit 21 controls the input power E to light source 1 using different correction values ​​depending on the multiple optical elements. Note that while the approximation coefficients are described using linear approximation formulas, they may also be higher-order approximation formulas. The approximation coefficients may be calculated using a preset table, or may be calculated by interpolating the relationship between the input power E to light source 1 and the change in illuminance.

[0037] As shown in Figure 2, when the emission spectrum of light source 1 changes with respect to input power E, wavelength filter F2, which has a wider wavelength band, experiences a larger change in optical output P with respect to input power E. Therefore, the approximation coefficient a2 of wavelength filter F2 is larger than the approximation coefficient a1 of wavelength filter F1. In other words, the relationship between approximation coefficients a1 and a2 is a2 > a1. To implement the constant illuminance function, as mentioned above, it is necessary to measure in advance the approximation coefficient related to the change in optical output P with respect to input power E. However, the approximation coefficient differs depending on the wavelength band supported by the wavelength filter. Therefore, the approximation coefficient must be measured for each wavelength filter. If the same approximation coefficient were used between different wavelength filters, accurate power adjustment would be impossible due to approximation coefficient error, making it difficult to maintain the target illuminance using the constant illuminance function.

[0038] Next, the process for realizing the constant irradiance maintenance function in this embodiment will be described below with reference to Fig. 4. Fig. 4 is a flowchart showing the process for realizing the constant irradiance maintenance function in exposure apparatus 100 comprising a plurality of wavelength filters in embodiment 1. Each process in Fig. 4 is realized by control unit 21 of exposure apparatus 100 executing a program stored in memory or the like. Each process (step) is represented by adding an S to the beginning, thereby abbreviating the notation of the process (step).

[0039] In S101, the control unit 21 performs a preliminary measurement for the constant illuminance function (preliminarily measuring an approximation coefficient relating to the change in optical output P relative to input power E). Details of the preliminary measurement will be described with reference to FIG.

[0040] Figure 5 is a flowchart relating to the precondition measurement process for the constant illuminance function in embodiment 1. Each process in Figure 5 is realized by control unit 21 of exposure apparatus 100 executing a program stored in memory or the like. Each process (step) is denoted with an S at the beginning, thereby abbreviating the notation of the process (step).

[0041] In S201, the control unit 21 controls the wavelength filter (hereinafter referred to as wavelength filter F) mounted in the exposure apparatus 100. n ) is selected. When multiple wavelength filters are installed in the exposure apparatus 100 as in this embodiment, any one of the wavelength filters F n Taking exposure apparatus 100 of this embodiment as an example, control unit 21 selects either wavelength filter F1 or wavelength filter F2.

[0042] In S202, the control unit 21 determines whether the wavelength filter is the wavelength filter F selected in S201. nIn this state, the illuminance I measured by the illuminometer 7 is measured while changing the input power E to the light source 1. In other words, the control unit 21 acquires measurement results of the illuminance according to the input power to the light source 1 (illuminance for each input power). In the process of S202, it is preferable to acquire measurement results by changing the input power many times, but measurement results of the illuminance when the input power E is changed at least two times or more are acquired. By changing the input power E to the light source 1 by the control unit 21, the amount of light at each wavelength changes.

[0043] In S203, the control unit 21 transmits the measurement result of the illuminance I relative to the input power E to the storage unit 20, and stores it in the storage unit 20. In addition, the approximation coefficient A of the relational expression of the illuminance I relative to the input power E is n , B n In other words, the control unit 21 calculates the approximation coefficient A of the approximation formula from the measurement result measured in S202. n , B n In this embodiment, the first-order approximation coefficients are used as the approximation coefficients, but higher-order approximation coefficients may also be used. n The approximation coefficients for the illuminance I and input power E are A n , B n Then, I=A n ×E+B n It is expressed as:

[0044] In S204, the control unit 21 calculates the approximation coefficient A n and the wavelength filter F selected in S101 n The information is stored in the storage unit 20 in association with (linked to) the above information.

[0045] In S205, the control unit 21 determines whether the processes from S201 to S204 have been completed for all wavelength filters installed in the exposure apparatus 100. In other words, the control unit 21 determines whether approximation coefficients have been calculated for all wavelength filters installed in the exposure apparatus 100, and whether the calculated approximation coefficients have been associated with wavelength filter information and stored in the storage unit 20. If the result of the determination is that the processes from S201 to S204 have not been completed for all wavelength filters installed in the exposure apparatus 100, the same processes as described above are performed from S201. In other words, if there are wavelength filters for which approximation coefficients have not been calculated, the same processes as described above are performed for the wavelength filters for which approximation coefficients have not been calculated. On the other hand, if the processes from S201 to S204 have been completed for all wavelength filters installed in the exposure apparatus 100, the process shown in FIG. 5 is terminated. In other words, the process of S101 is terminated.

[0046] Taking the exposure apparatus 100 of this embodiment as an example, if the controller 21 has selected wavelength filter F1 first, it calculates the approximation coefficients of the illuminance I and input power E for wavelength filter F1 and stores them in the storage unit 20. Thereafter, via the determination process of S205, it next selects wavelength filter F2. Thereafter, as with wavelength filter F1, it calculates the approximation coefficients of the illuminance I and input power E for wavelength filter F2 and stores them in the storage unit 20. In this way, approximation coefficients have been calculated for all wavelength filters, and the calculated approximation coefficients have been associated with the wavelength filter information and stored in the storage unit 20, so the processing shown in FIG. 5 ends.

[0047] Next, returning to FIG. 4, in S102, the control unit 21 selects the exposure conditions of the exposure tool 100 and determines the wavelength filter F to be used. n Then, the control unit 21 determines the wavelength filter F n In the present embodiment, the control unit 21 determines the wavelength filter to be used from wavelength filter F1 or wavelength filter F2 according to the exposure conditions, and switches the wavelength filter to the determined wavelength filter.

[0048] In S103, the control unit 21 determines whether the wavelength filter F n Target illuminance I when applying the constant illuminance function t The wavelength filter F to be used is determined (set). n Target illuminance I t In S104, the control unit 21 measures the illuminance I at the current input power E. If the current input power E is unknown, the maximum power E that can be input to the light source 1 is used. max and measures the illuminance I. In S105, the control unit 21 sets the target illuminance I t The power adjustment amount ΔE is calculated to achieve the above. Details of S105 will be described with reference to FIG.

[0049] Figure 6 is a flowchart relating to power adjustment amount calculation in embodiment 1. Each process in Figure 6 is realized by control unit 21 of exposure apparatus 100 executing a program stored in memory or the like. Furthermore, by adding an S to the beginning of each process (step), the notation of the process (step) is omitted.

[0050] In S301, the control unit 21 selects the wavelength filter F determined based on the exposure conditions selected in S102. n In S302, the control unit 21 checks the wavelength filter F checked in S301 from the storage unit 20. n Approximation coefficient A for n Read out.

[0051] In S303, the control unit 21 sets the target illuminance I t Calculate the power adjustment amount ΔE required to achieve the target illuminance I t and the difference ΔI between the illuminance I measured in S104 (= target illuminance I t - the current illuminance I) and the wavelength filter F stored in the memory unit 20 n Approximation coefficient A for n Using this, the power adjustment amount ΔE = ΔI ÷ A n When the calculation of the power adjustment amount ΔE is completed, the process of S105 ends.

[0052] 4, in S106, the control unit 21 adjusts the input power E to the light source 1 by the power adjustment amount ΔE calculated in S105. n By controlling (adjusting) the power E to the light source 1 based on the power adjustment amount ΔE in accordance with the target illuminance I t That is, the illuminance on the irradiated surface can be kept constant.

[0053] As described above, according to exposure apparatus 100 in the first embodiment, by obtaining different approximation coefficients for each wavelength band used, it is possible to realize an optimal constant irradiance function that is tailored to the wavelength band.

[0054] <Embodiment 2> Next, exposure apparatus 100 of embodiment 2 will be described with reference to Figures 7 and 8. Note that the configurations and functions of exposure apparatus 100 of embodiment 2 are the same as those of embodiment 1, and therefore description thereof will be omitted. Also, the flowchart for realizing the constant irradiance maintenance function in embodiment 2 is similar to that of Figure 4 of embodiment 1 except for some parts, but the details of the processing in S101 and S105 differ from those in embodiment 1. Therefore, processing unique to embodiment 2 will be described below.

[0055] Fig. 7 is a flowchart relating to measurement of preconditions for the constant illuminance function in embodiment 2. Fig. 8 is a flowchart relating to calculation of the amount of power adjustment in embodiment 2. Note that in embodiment 2, Fig. 7 is a flowchart showing details of S101 in Fig. 4 of embodiment 1, and Fig. 8 is a flowchart showing details of S105 in Fig. 4 of embodiment 1.

[0056] Details of S101 in the second embodiment (pre-measurement processing for the constant illuminance function) will be described below with reference to FIG. 7. Each process in FIG. 7 is realized by the control unit 21 of the exposure apparatus 100 executing a program stored in a memory or the like. Each process (step) is denoted by adding an S to the beginning of the process (step) to omit the process (step). Note that the exposure apparatus 100 of the second embodiment has the same wavelength filter F1 and wavelength filter F2 as the first embodiment, and also has a reference wavelength filter, which will be described later. Note that either the wavelength filter F1 or the wavelength filter F2 may be set as the reference wavelength filter. In this way, the exposure apparatus 100 of the second embodiment also has multiple wavelength filters, as in the first embodiment. Note that the wavelength band (first wavelength band) of the reference wavelength filter in the second embodiment is different from the wavelength bands of the wavelength filter F1 and the wavelength filter F2.

[0057] 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 apparatus 100. The reference wavelength filter F0 is set in advance.

[0058] In S402, the control unit 21 measures the illuminance I measured by the illuminometer 7 while changing the input power E to the light source 1, with the wavelength filter being the reference wavelength filter F0 selected in S401. In other words, the control unit 21 acquires measurement results of the illuminance according to the input power to the light source 1 (illuminance for each input power). Note that in the processing of S402, it is preferable to acquire measurement results by changing the input power many times, but the illuminance results when the input power E is changed at least at two or more points are acquired.

[0059] In S403, the control unit 21 calculates an approximation coefficient A0 of the illuminance I with respect to the input power E in the reference wavelength filter F0. The method of calculating the approximation coefficient A0 is the same as in the first embodiment, and therefore the explanation will be omitted. Furthermore, the approximation coefficient in the second embodiment may be a first-order approximation coefficient as in the first embodiment, or a higher-order approximation coefficient may be used. In S404, the control unit 21 calculates an approximation coefficient A0 of the wavelength filters F other than the reference wavelength filter F0 from among the plurality of wavelength filters. n and switches the wavelength filter from the reference wavelength filter F0 to the selected wavelength filter. In S405, the control unit 21 measures the illuminance I measured by the illuminometer 7 while changing the input power E to the light source 1, with the wavelength filter switched in S404.

[0060] In S406, the control unit 21 controls the wavelength filter F n Approximation coefficient A of illuminance I relative to input power E at n Furthermore, the wavelength filter F n Approximation coefficient A of illuminance I relative to input power E at n Using this, the approximation coefficient ratio α n =A n That is, the wavelength filter F0, which is an optical element having the first wavelength band, is compared with the wavelength filter F1, which does not have the first wavelength band. n The control unit 21 calculates the ratio of the approximation coefficients α n is stored in the storage unit 20.

[0061] In S407, the control unit 21 determines whether the calculation of the approximation coefficient ratios has been completed for all wavelength filters installed in the exposure tool 100. If the result of the determination is that the calculation of the approximation coefficient ratios has not been completed for all wavelength filters installed in the exposure tool 100, the same processing is performed from S404. That is, the approximation coefficient ratio α n If there is a wavelength filter for which the approximation coefficient ratio α nThe same processing as above is performed for wavelength filters for which the approximation coefficient ratio has not been calculated. On the other hand, if the calculation of the approximation coefficient ratio has been completed for all wavelength filters installed in the exposure apparatus 100, the processing shown in Fig. 7 ends. In other words, the processing of S101 in the second embodiment ends.

[0062] Details of S105 in embodiment 2 (processing for calculating power adjustment amount ΔE) will be explained below with reference to Figure 8. Each process in Figure 8 is realized by control unit 21 of exposure apparatus 100 executing a program stored in memory or the like. Furthermore, by adding an S to the beginning of each process (step), the notation of the process (step) will be omitted.

[0063] 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. Note that, as in the first embodiment, ΔI, which is the difference in illuminance I, is calculated by dividing the approximation coefficient A0 by the target illuminance I. t -Calculated at the current illuminance I.

[0064] In S502, the control unit 21 determines whether the wavelength filter in the exposure conditions selected in S102 matches the reference wavelength filter F0. If the result of the determination is that the wavelength filter in 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 has been selected as the wavelength filter for the exposure conditions, the process proceeds to S503. On the other hand, if the wavelength filter in 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 has not been selected as the wavelength filter for the exposure conditions, the process proceeds to S504.

[0065] In S503, the control unit 21 determines the power adjustment amount ΔE. That is, when the process proceeds to S503, the reference wavelength filter F0 is selected as the wavelength filter of the exposure conditions in S502, and therefore the control unit 21 determines ΔE0 calculated in S501 as the power adjustment amount ΔE. In this way, in S503, the power adjustment amount ΔE is determined by setting the power adjustment amount ΔE=power adjustment amount ΔE0.

[0066] In S504, the control unit 21 calculates the approximation coefficient ratio α of the wavelength filter under the exposure conditions to the reference wavelength filter F0. n That is, when the process proceeds to S504, since the reference wavelength filter F0 is not selected as the wavelength filter of the exposure conditions in S502, the control unit 21 checks the wavelength filter F of the exposure conditions calculated in S406 from the storage unit 20. n Approximation coefficient ratio α n Read out.

[0067] In S505, the control unit 21 determines whether the wavelength filter F n The power adjustment amount ΔE at this time is determined by the power adjustment amount ΔE0 in the reference wavelength filter F0 and the approximation coefficient ratio α n Using this, power adjustment amount ΔE = power adjustment amount ΔE0 / approximation coefficient ratio α for reference wavelength filter F0 n This completes the process of S105 in the second embodiment.

[0068] In the case of the second embodiment, the approximation coefficient ratios of each wavelength filter are stored in the storage unit 20, instead of the approximation coefficients of each wavelength filter as in the first embodiment. If the approximation coefficients change due to changes in the light source 1 over time or the like, the approximation coefficients need to be measured again because the approximation coefficients for all wavelength filters are directly stored in the first embodiment. However, in the second embodiment, the relationship between the approximation coefficients of each wavelength filter is stored, so it is only necessary to remeasure the approximation coefficient of the reference wavelength, and there is no need to remeasure the approximation coefficients of the other wavelength filters. This reduces the calculation load and time.

[0069] As described above, in the exposure apparatus 100 of the second embodiment, in addition to the same effects as the first embodiment, the calculation load and time can be reduced by re-measuring only the approximation coefficient of the reference wavelength without re-measuring the approximation coefficient of the other wavelength filters.

[0070] <Embodiments of manufacturing methods of articles> The method for manufacturing an article according to an embodiment of the present invention is suitable for manufacturing articles such as semiconductor devices, flat panel displays, liquid crystal display devices, and MEMS. This manufacturing method includes the steps of exposing a substrate coated with a photosensitive agent using the exposure apparatus 100 described above and developing the exposed photosensitive agent. The developed photosensitive agent pattern is then used as a mask to perform etching and ion implantation processes on the substrate, forming a circuit pattern on the substrate. These exposure, development, etching, and other processes are repeated to form a circuit pattern consisting of multiple layers on the substrate. In subsequent processes, the substrate on which the circuit pattern has been formed is diced (processed), followed by chip mounting, bonding, and inspection. This manufacturing method may also include other well-known processes (e.g., oxidation, film formation, vapor deposition, doping, planarization, resist stripping, etc.). The method for manufacturing an article according to this embodiment is advantageous over conventional methods in at least one of the performance, quality, productivity, and production cost of the article.

[0071] The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention.

[0072] The above-described embodiments are merely representative examples, and various modifications and changes can be made to each embodiment when implementing the present invention.

[0073] The disclosure of this embodiment includes the following configuration.

[0074] (Configuration 1) an illumination optical system including a plurality of optical elements that change the wavelength band of light from a light source, and that illuminates an illumination target surface with the light whose wavelength band has been changed by any of the plurality of optical elements; a control unit that controls the input power to the light source using a correction value corresponding to a relationship between the input power to the light source and a change in illuminance in order to keep the illuminance on the illuminated surface constant; the control unit uses different correction values ​​depending on the plurality of optical elements. An exposure apparatus characterized by:

[0075] (Configuration 2) 2. The exposure apparatus according to configuration 1, wherein the correction value is an approximation coefficient that represents a change in illuminance on the illuminated surface relative to the input power to the light source.

[0076] (Configuration 3) 3. The exposure apparatus according to configuration 1 or 2, wherein the control unit calculates the correction value based on a measurement result obtained by measuring illuminance while changing the input power to the light source for each of the optical elements.

[0077] (Configuration 4) 4. The exposure apparatus according to configuration 3, wherein the control unit calculates the correction value from an approximation formula obtained from measurement results obtained by measuring illuminance at at least two points on the illuminated surface.

[0078] (Configuration 5) 5. The exposure apparatus according to any one of configurations 1 to 4, wherein the illuminance is the illuminance of the surface to be irradiated and a surface located at a position conjugate with the surface to be irradiated.

[0079] (Configuration 6) the plurality of optical elements are disposed within the illumination optical system; 6. The exposure apparatus according to any one of configurations 1 to 5, wherein the control unit switches the plurality of optical elements in accordance with predetermined exposure conditions.

[0080] (Configuration 7) 7. The exposure apparatus according to any one of configurations 1 to 6, wherein the control unit changes the input power to the light source, thereby changing the amount of light of each wavelength.

[0081] (Configuration 8) 8. The exposure apparatus according to any one of configurations 1 to 7, wherein the plurality of optical elements change the wavelength bands of the light so that the center wavelengths of the wavelength bands are the same but the wavelength bandwidths are different.

[0082] (Configuration 9) The exposure apparatus described in any one of configurations 1 to 8, wherein the control unit calculates a power adjustment amount to achieve a target illuminance, and adjusts the input power to the light source based on the power adjustment amount.

[0083] (Configuration 10) 10. The exposure apparatus according to configuration 9, wherein the control unit calculates the amount of power adjustment based on the difference between the target illuminance and the current illuminance and the correction value.

[0084] (Configuration 11) The exposure apparatus according to any one of configurations 1 to 10, characterized in that the control unit calculates the ratio of the correction value of an optical element other than the first wavelength band to the correction value of an optical element having the first wavelength band.

[0085] (Configuration 12) 12. The exposure apparatus according to any one of configurations 1 to 11, further comprising a storage unit that stores the correction value.

[0086] (Configuration 13) A method for controlling an exposure apparatus, comprising: an illumination step of illuminating an illumination target surface with light whose wavelength band has been changed by any one of a plurality of optical elements using an illumination optical system including a plurality of optical elements that change the wavelength band of light from a light source; a control step of controlling the input power to the light source using a correction value corresponding to a relationship between the input power to the light source and a change in illuminance in order to keep the illuminance on the illuminated surface constant; In the control step, different correction values ​​are used depending on the plurality of optical elements. 2. A method for controlling an exposure apparatus comprising:

[0087] (Configuration 14) exposing a substrate using the exposure apparatus according to any one of configurations 1 to 12; developing the exposed substrate; manufacturing an article from the developed substrate; A method for manufacturing an article, comprising: [Explanation of symbols]

[0088] 1 light source 21 Control section 22 Power supply section 100 Exposure device 101 Illumination optical system F1, F2 wavelength filters

Claims

1. an illumination optical system including a plurality of optical elements that change the wavelength band of light from a light source, and that illuminates an illumination target surface with the light whose wavelength band has been changed by any of the plurality of optical elements; a control unit that controls the input power to the light source using a correction value corresponding to a relationship between the input power to the light source and a change in illuminance in order to keep the illuminance on the illuminated surface constant; the control unit uses different correction values ​​depending on the plurality of optical elements. An exposure apparatus characterized by:

2. 2. An exposure apparatus according to claim 1, wherein the correction value is an approximation coefficient that represents a change in illuminance on the illuminated surface relative to the input power to the light source.

3. 2. 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 the input power to the light source for each of the optical elements.

4. 4. The exposure apparatus according to claim 3, wherein the control unit calculates the correction value from an approximation formula obtained from measurement results obtained by measuring illuminance at at least two points on the illuminated surface.

5. 2. An exposure apparatus according to claim 1, wherein the illuminance is an illuminance of the surface to be irradiated and a surface located at a position conjugate with the surface to be irradiated.

6. the plurality of optical elements are disposed within the illumination optical system; 2. The exposure apparatus according to claim 1, wherein the control unit switches the plurality of optical elements in accordance with predetermined exposure conditions.

7. 2. The exposure apparatus according to claim 1, wherein the amount of light of each wavelength is changed by changing the input power to the light source using the control unit.

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

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

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

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

12. 2. An exposure apparatus according to claim 1, further comprising a storage unit that stores the correction value.

13. A method for controlling an exposure apparatus, comprising: an illumination step of illuminating an illumination target surface with light whose wavelength band has been changed by any one of a plurality of optical elements using an illumination optical system including a plurality of optical elements that change the wavelength band of light from a light source; a control step of controlling the input power to the light source using a correction value corresponding to a relationship between the input power to the light source and a change in illuminance in order to keep the illuminance on the illuminated surface constant; In the control step, different correction values ​​are used depending on the plurality of optical elements.

2. A method for controlling an exposure apparatus comprising:

14. exposing a substrate using the exposure apparatus according to any one of claims 1 to 12; developing the exposed substrate; manufacturing an article from the developed substrate; A method for manufacturing an article, comprising:

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