JP2005236258A - Optical apparatus and device manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positioning technique for suppressing a positional displacement, due to a disturbance, between optical system elements. <P>SOLUTION: An optical apparatus including an optical system having a first element and a second element, and a support member which supports the optical system, has a first control system which includes the first element and feedback-controls a position of the first element, and a second control system which includes the second element and feedback-controls a position of the second element. The first control system and the second control system are arranged such that a difference between a first transfer function between a displacement of the support member and a displacement of the first element and a second transfer function between the displacement of the support member and a displacement of the second element is not greater than 1/10 with respect to at least a limited frequency band. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention generally relates to optical element positioning technology, and in particular, manufactures various devices such as semiconductor chips such as IC and LSI, display elements such as liquid crystal panels, detection elements such as magnetic heads, and imaging elements such as CCDs. The present invention relates to an optical apparatus such as a projection optical system and an exposure apparatus that perform positioning control of optical system elements (lenses, mirrors, etc.) of an exposure apparatus used in the process. Further, the present invention provides, for example, a plurality of reflective optical elements used in an optical system of an exposure apparatus (hereinafter referred to as “EUV exposure apparatus”) that uses extreme ultraviolet (EUV) light as exposure light. This relates to positioning control against disturbance.

  A semiconductor exposure apparatus is an apparatus for transferring an original (reticle) having many different types of patterns onto a silicon wafer (substrate). In order to create a highly integrated circuit, it is essential to improve not only the resolution performance but also the overlay accuracy.

  Overlay errors in a semiconductor exposure apparatus are classified into alignment errors, image distortions, and magnification errors. The alignment error can be reduced by adjusting the relative displacement between the original (reticle) and the substrate (wafer). On the other hand, image distortion and magnification error can be adjusted by moving some optical elements of the optical system. When moving the optical element, it is necessary to prevent the parallel decentering and tilt decentering error components from increasing.

2. Description of the Related Art Conventionally, there has been proposed an exposure apparatus that provides a sensor that constantly detects the distance from a fixed portion of an optical element and controls the attitude of the optical element in real time (for example, see Patent Document 1 and Patent Document 2). ) A mechanism for controlling six axes of an optical element is also known as positioning control (see, for example, Patent Document 3).
JP 2000-357651 A JP 2002-131605 A JP 2001-231077 A

  In recent years, with higher definition of semiconductor device patterns, optical elements are required to have higher position, posture accuracy, and drive positioning accuracy for correction of aberrations, etc., in order to obtain the required imaging relationship. It is becoming. Disturbances are factors that deteriorate the positioning accuracy. Under the conventional positioning control, the influence of the disturbance can be ignored, but with the demand for high positioning accuracy, the influence of the disturbance cannot be ignored. For example, as in Patent Document 1 and Patent Document 2, in an apparatus that controls the positioning of an optical element only with respect to a fixed portion or a lens barrel, when a disturbance is transmitted from the floor or the like to the lens barrel, each optical element vibrates apart. As a result, a synchronization error occurs and the required imaging performance cannot be obtained.

  An object of the present invention is to provide a positioning technique that suppresses misalignment between a plurality of optical system elements subjected to disturbance.

  A first invention for achieving the above-mentioned object is an optical device including an optical system having first and second elements and a support member that supports the optical system, and includes the first element. A first control system that feedback-controls the position of the first element; and a second control system that includes the second element and feedback-controls the position of the second element; The difference between the first transfer function between the displacement of the member and the displacement of the first element and the second transfer function between the displacement of the support member and the displacement of the second element is at least one. The optical device is characterized in that the first and second control systems are configured to be 1/10 or less in the band of the part.

  The second invention is an optical device including an optical system having first and second elements and a support member that supports the optical system, and a detection system that detects the position of the first element; And a second control system that feedback-controls the position of the second element, the second control system based on the detection result of the detection system. An optical apparatus that controls the position of the second element so as to maintain a predetermined relative position between the first and second elements.

  The third invention is an optical device including an optical system having first and second elements, the base, a first support system for supporting the first element on the base, A second support system for supporting the second element on the base, and a product of a primary natural frequency and a damping factor of the first support system and 1 of the second support system. The first and second support systems are configured such that the difference between the product of the next natural frequency and the damping factor is 20% or less of the product of the first support system. The optical device is characterized.

  Furthermore, the fourth invention includes an exposure step of exposing a pattern to the substrate using the optical device according to the first to third inventions, and a development step of developing the substrate exposed in the exposure step. It is a device manufacturing method characterized.

  ADVANTAGE OF THE INVENTION According to this invention, the positioning technique which suppresses position shift between the some optical system element which receives a disturbance can be provided.

  Embodiments according to the present invention will be described below in detail with reference to the accompanying drawings.

  The outline of the positioning control method of the present invention will be described below with reference to FIGS. Here, FIG. 8 is a schematic block diagram of the positioning control apparatus 100 of the present invention, and FIG. 9 is a flowchart of the positioning control method of the present invention. As shown in FIG. 8, the positioning control device 100 includes fixed portions 120A and 120B fixed to a frame 110 such as a lens barrel, movable portions 130A and 130B, optical elements 140A and 140B, and a PC 170 (limited to a personal computer). If it is a calculation means, it may be replaced with other components). The PC 170 includes a CPU 172 and memories 174, 176, and 178, and the memory 178 functions as compensators 180A and 180B (for example, PID compensators). In addition, what added the capital letter to the reference code shall be summarized by the reference code without the alphabet.

  The optical element 140 is fixed to the fixed unit 120 via the movable unit 130 and the driving unit 150, and fluctuates under the influence of disturbance from the frame 110. The fixed part 120 is fixed to the frame 110 so as not to move, and supports the movable part 130 and the optical element 140. The movable unit 130 moves the optical element 140 in a predetermined direction (for example, one or a plurality of six axes including three axes orthogonal to each other and rotation about each axis), and is driven by the driving unit 150. The drive unit 150 is driven and controlled by the CPU 172 based on information from the compensator 180. The measuring unit 160 measures the position (or posture or rotation) of the optical element 140 in a predetermined direction. In general, as many measuring units 160 as the number of measuring directions are provided. Accordingly, in the six-axis control, six measuring units 160 are provided for each optical element 140. Measurement results from the measurement unit 160 are stored in the memory 174 of the PC 170.

  On the other hand, the drive data of the compensator of each drive unit is sent from the compensator 180 in the memory 178 to the CPU 172. The CPU 172 refers to the measurement result stored in the memory 174 and stores the positioning control data in the memory 176. The positioning control data is supplied from the memory 176 to the driving unit 150 and controls the driving unit 150.

  The control operation is performed based on a positioning control method program stored in the memory 178 or other memory.

  Referring to FIG. 9, first, the control unit 180 acquires the position information of each of the two optical elements 140 from the memory 174 (step 1100). Next, the CPU 172 sets the positioning control data of the two optical elements 140 as the data from the memory 178 so that the disturbance characteristics of the two optical elements 140 substantially match a predetermined frequency band based on the position information. It is created by referring to and stored in the memory 176. Based on the data in the memory 176, the drive unit 150 is driven and controlled (step 1200). As a result, the relative displacement variation between the optical elements 140 can be reduced.

  In at least two positioning devices for positioning at least two optical elements on the same structure, the transmission characteristic of the disturbance to the optical elements (transmission rate in a specific frequency band) is the transmission characteristic of the positioning device to be controlled. And the transfer characteristic of the control system of the positioning device. The frequency band above the control system crossing frequency is determined by the transfer characteristic of the controlled object, and the frequency band below the control system crossing frequency is determined by the transfer characteristic of the control system.

  In order to keep the synchronization error due to the disturbance of the two optical elements within an allowable range for a frequency band equal to or higher than the crossing frequency of the control system, the transfer characteristics of the controlled object are substantially matched, and the difference between the controlled object transfer characteristics is set to a predetermined value. It only has to be within the range. For this purpose, first, it is necessary to use a positioning system based on the same principle for the positioning device for two optical elements. The characteristics of the controlled object are determined by the mass or moment of inertia, rigidity, damping rate, and the like of the optical element 140, the movable unit 130, the fixed unit 120, and the driving unit 150. Therefore, in order for the synchronization error due to the disturbance of the two optical elements to fall within the allowable range, the transfer characteristics of the controlled object are substantially matched, and the difference between the transferred characteristics of the controlled object is within the predetermined range. There is a need to design an optical element positioning device. In the following embodiments, specifically, a fixed part of the movable part including each of the two optical elements (here, it may be a lens barrel, a part of the lens barrel, or a base, a floor, etc.) ) Is within 20% of one transmission rate (or may be 80% or more and 125% or less of one transmission rate), more preferably within 10% (or one of the transmission rates). It may be 90% or more and 111% or less). Moreover, you may comprise so that the difference of a transmission rate may be 1/10 or less, More preferably, it is 1/100 or less.

  In order to keep the synchronization error of the vibrations of the two optical elements due to the disturbance within an allowable range with respect to a frequency band equal to or lower than the cross frequency of the control system, the transfer characteristics of the control system should be substantially matched. In other words, the difference in the transfer characteristics of the control system may be within a predetermined range (the difference in transfer rate in a specific frequency band may be within an allowable range). Ideally, the transmission characteristics of the control systems of the two optical element positioning devices should be perfectly matched. However, the transmission characteristics of the predetermined frequency band are substantially matched, and the difference in the transmission ratio of the control system is determined for the predetermined frequency band. It is possible to keep within a predetermined range.

  As the predetermined frequency band, for example, when an integrator is used for the compensator of the control system, the frequency band below the break frequency of the integrator, for example, an integrator and a differentiator are used for the compensator of the control system. When used, there is a frequency band between the corner frequency of the integrator and the corner frequency of the differentiator.

  The permissible range of the difference in disturbance transmission rate between the two optical elements can be determined by the permissible synchronization error of the two optical elements and the vibration amplitude due to the floor vibration of the structure frame holding the optical elements. The vibration amplitude of the structure frame can be obtained from the vibration amplitude of the floor, the natural frequency and the damping rate of the vibration isolation mount.

  When the vibration amplitude of the floor is 0.1 [μm], the natural frequency of the mount of the structure frame is 1 [Hz], and the damping factor of the mount is ζ = 0.1, the vibration amplitude of the structure frame due to floor vibration Becomes about 1 [nm]. Since the allowable synchronization error of the two optical elements to satisfy the required imaging relationship is about 0.1 [nm], the range of the difference in the transmissibility of the disturbance is 0.1 [nm] / 1 [nm]. = 1/10 or less. That is, the difference between the disturbance transmission rate for the first optical element and the disturbance transmission rate for the second optical element is set to be 1/10 or less of the disturbance transmission rate for the first optical element. Is preferred.

  If the difference in the transmissibility of the disturbance to the two (multiple) optical elements exceeds 1/10, the relative position of the two optical elements will deviate greatly from the predetermined relative position. The optical characteristics deteriorate.

  In addition, it is assumed that a floor having a slightly lower performance than the above-described floor is used. Here, when the vibration amplitude of the floor vibration is 1 [μm], the natural frequency of the mount of the structure frame is 1 [Hz], and the damping factor of the mount is ζ = 0.1, the structure frame by floor vibration is used. The vibration amplitude is about 10 [nm]. Since the allowable synchronization error of the two optical elements for satisfying the required imaging relationship is about 0.1 [nm], the range of the difference in disturbance transmissibility is 0.1 [nm] / 10 [nm]. = 1/100 or less.

  Further, for example, the transmission rate (transmission characteristics) of the disturbance to a movable part such as a mirror, a mask stage, or a wafer stage is preferably substantially matched in a relatively low frequency region, and the transmission rate of the disturbance is a predetermined value of 80 Hz or less. In the frequency band, it is preferable that the transmissibility of disturbance is substantially the same. More preferably, it is desirable that the frequencies substantially coincide with each other in a frequency band of 100 Hz or less.

  Furthermore, it is more preferable that the width of the frequency band at which the transmissibility of disturbance at this time substantially matches is 10 Hz or more. It is more preferable that the width of the frequency band in which the transmissibility of the disturbance is approximately the same is 15 Hz or more.

  Hereinafter, the range of the disturbance characteristics to be matched will be described in detail with reference to examples.

  The exposure apparatus and optical element control method according to the first embodiment of the present invention will be described below. The exposure apparatus of the present embodiment is illustratively an EUV exposure apparatus, and as shown in FIG. 1, a light source 53, an illumination optical system 52, a reticle stage 51 that holds an original (mask or reticle), and projection optics. The system 55 includes a wafer stage 27 that holds a substrate (wafer or the like). Here, FIG. 1 is a simplified optical path diagram of the exposure apparatus.

  The light source 53 generates, for example, EUV light. In an exposure apparatus that uses light having a wavelength of 2 to 40 nm (for example, EUV light or X-ray) as exposure light, a reflective optical element such as a mirror is used. This is because, in such a wavelength range, absorption by a substance becomes very large, and therefore a lens optical system using light refraction as used in visible light or ultraviolet light is not practical. In this case, the original 50 is also a reflective reticle in which a pattern to be transferred by an absorber is formed on a multilayer reflector. In such a reflective optical element, since reflection of light is used, when the optical element is tilted under the influence of disturbance, the reflected light is particularly susceptible to the influence. Therefore, the present invention is particularly effective for an exposure apparatus that uses light having a wavelength of 2 to 40 nm (for example, EUV light or X-ray) as exposure light.

  As the light source 53, for example, a laser plasma light source is used. In this method, a target material in a vacuum vessel is irradiated with high-intensity pulsed laser light to generate high-temperature plasma, and EUV light having a wavelength of, for example, about 13 nm is emitted from the target material. Since any technique known in the art can be applied to the EUV light source, detailed description thereof is omitted here.

  The exposure light emitted from the light source 53 passes through the illumination optical system 52 and is adjusted so as to irradiate the pattern on the original 50. The illumination optical system 52 has a function of propagating EUV light to illuminate the original 50 and includes a plurality of mirrors, an optical integrator, and an aperture. The optical integrator has a role of uniformly illuminating the original 50 with a predetermined numerical aperture. The aperture is provided at a position conjugate with the original 50 and limits an area illuminated by the surface of the original 50 to an arc shape.

  The EUV light selectively reflected by the original 50 is reduced and projected onto the wafer 28 coated with a resist by the projection optical system 55 constituted by several reflecting mirrors, and the pattern on the original 50 is transferred to the wafer 28. .

  The reticle stage 51 is positioned and controlled in six axial directions with respect to the reference structure 41 by a non-contact measuring means 42r, a drive mechanism 71r (not shown), and a compensator (not shown). The six-axis direction here is the XYZ-axis direction and the rotation direction around the XYZ-axis, and any method known in the art such as the method described in Patent Document 3 can be used. The compensator 33r calculates a command value to the drive mechanism 71r based on the measurement information of the non-contact measurement unit 42r. Here, a PID compensator is used as the compensator 33r. As the non-contact measuring means, there is a laser interferometer, for example.

  The illumination area on the original 50 and the projected image of the wafer 28 are limited to a very narrow arc-shaped range having the same image height in order to obtain a good image with reduced aberration of the projection optical system 55, and therefore formed on the original 50. In order to expose all the patterns on the wafer 28, the exposure apparatus 100 employs a so-called scan exposure method in which the reticle stage 51 and the wafer stage 27 perform exposure while scanning in synchronization.

  The wafer stage 27 is arranged so that the mounting surface of the wafer 28 intersects the optical axis direction of the projection optical system 55. The wafer stage 27 is positioned and controlled in six axial directions with respect to the reference structure 41 by a non-contact measuring means 42w, a drive mechanism 71w (not shown), and a compensator 33w (not shown). The compensator 33w calculates a command value to the drive mechanism 71w based on the measurement information of the non-contact measurement unit 42w. Here, a PID compensator is used as the compensator 33w. The six-axis control of the reticle stage is the same as the six-axis control of the wafer stage.

  Next, the projection optical system 55 will be described. The projection optical system shown in FIG. 1 is composed of four multilayer reflection mirrors, but may be composed of other plural sheets such as two, six, and eight. In the order in which the exposure light is irradiated, they are referred to as a first optical element 32m1 and a second optical element 32m2. The shape of the reflecting surface of the mirror is convex, concave spherical or aspherical. The numerical aperture NA is about 0.2 to 0.3.

  The optical element fine movement mechanism 61 will be described using the optical element fine movement mechanism 61m1 of the first optical element 32m1. The optical element fine movement mechanism 61m1 includes a non-contact measurement unit 42m1 for measuring the position of the first movable part 1m1 from the reference structure 41, a drive mechanism 29m1 for driving the first movable part 1m1, and a non-contact measurement. Based on the measurement information of the means 42m1, it comprises a compensator (not shown) that sends a command value to the drive mechanism 29m1. At this time, the reference structure 41 may be a lens barrel, a lens barrel surface plate, a structure frame, or the like.

  The optical element fine movement mechanism 61m1 controls the positioning of the first movable portion 1m1 in the six-axis directions (at least three axes or more) with respect to the reference structure 41 based on the measurement information of the non-contact measurement unit 42m1. The first movable portion 1m1 may include an optical element 32m1, or a holding mechanism 31m1 and an optical element holding block 30m1 for holding the optical element 32m1 in addition to the optical element 32m1.

  The value of the product of the natural frequency and attenuation rate of the optical element having the highest optical sensitivity and its holding mechanism, optical element holding block, and driving mechanism is the characteristic of other optical element positioning devices. The value of the product of the frequency and the damping rate is made to substantially coincide. The product of the natural frequency and the damping factor to be matched substantially matches the product of the natural frequency and the damping factor in all three or three orthogonal directions and the direction of rotation about the three axes. In particular, it is important to match the product of the natural frequency of the lowest order of each axis and the damping factor. The degree to which they are substantially matched is desirably within ± 20% or within ± 10% of the product of the natural frequency and the attenuation factor of the optical element positioning device having the highest optical sensitivity.

  The movable part including the first optical element 32m1 will be referred to as “first movable part” 1m1, and the movable part including the second optical element 32m2 will be referred to as “second movable part” 1m2. Here, the first movable part is 1 m 1, but the first movable part may be any one of 1 m 2, 1 m 3, and 1 m 4.

  As the drive mechanism 29m1 capable of driving the first movable portion 1m1 in the six-axis direction with respect to the fixed portion 2m1, a parallel link mechanism using an actuator such as a piezoelectric element, a six-axis fine movement mechanism using a linear motor, or the like Can be considered. Further, it is desirable to unify the basic principles of the plurality of optical element positioning mechanisms in order to make the transmissibility of the plurality of optical element positioning mechanisms as close as possible. For example, it is preferable to unify all the positioning mechanisms of the plurality of optical elements by either a parallel link mechanism or a linear motor. Of course, a drive mechanism that does not cause contamination problems such as degassing in a high vacuum region other than the linear motor and the parallel link may be adopted as the positioning mechanism.

  Here, a 6-axis fine movement mechanism using a linear motor is used as the drive mechanism 29m1, and a PID compensator is used as the compensator. Assuming that the proportional gain Kpm1 of the PID compensator, the corner frequency Fim1 of the integrator, and the corner frequency Fdm1 of the differentiator, the transfer function of the PID compensator is expressed by the following equation.

  The open loop transmission characteristics of the first movable part 1m1 are shown in FIG. The point where the open loop transfer characteristic intersects with 0 dB is referred to as a crossover frequency Fcm1 (indicated by Fc in FIG. 2). When the crossing frequency is Fcm1 and the mass or moment of inertia of the first movable part 1m1 is Mm1, the proportional gain Kpm1 is expressed by the following equation.

  FIG. 3 shows a transmission characteristic from the displacement of the lens barrel 25 due to the disturbance to the displacement of the first movable portion 1m1. If the rigidity between the lens barrel 25 and the first movable part 1m1 is k1, and the attenuation rate is c1, the disturbance transmission rate between the frequencies Fim1 to Fdm1 having the largest disturbance transmission rate is expressed by the following equation.

  When the magnitude of the displacement due to the disturbance of the lens barrel 25 is Dx, the maximum displacement due to the disturbance of the first movable part 1m1 is expressed by the following equation.

  Similarly, the maximum displacement due to the disturbance of the movable part 1m2 is expressed by the following equation.

  The synchronization error between the first movable part 1m1 and the movable part 1m2 is expressed by the following equation.

  In order to obtain a more accurate imaging relationship, it is necessary to make the synchronization error of each movable part as small as possible. For this purpose, it is only necessary to make the transmission characteristics of the movable parts with respect to the disturbance as similar as possible. That is, the mass or moment of inertia Mm of the movable part, the rigidity k of the movable part and the fixed part, the corner frequency Fim of the integrator of the PID compensator, the corner frequency Fdm of the differentiator of the PID compensator, and the crossing frequency Fcm It is desirable that the values be exactly the same. However, the mass or moment of inertia Mm of the optical element 32m, the rigidity k1 of the movable part and the fixed part, and the damping rate c1 differ depending on the movable part. Therefore, the values of Fdm1, Fcm1, Fdm2, and Fcm2 are adjusted so that the difference in the transmissibility of the disturbance of the movable part expressed by the following formula is within a predetermined range, here, 1/10 or less or 1/100 or less. To do. If position information in the six-axis direction of the control target is obtained from the measurement information using the non-interacting matrix, then the compensator may be adjusted for each axis.

  Furthermore, in order to increase the response of the movable part to the target value, the crossing frequencies Fcm1 and Fcm2 are adjusted as high as possible. Similarly, the break frequency and the crossover frequency of the differentiator of the PID compensator are also adjusted between the movable part 1m1 and the movable part 1m3 and between the movable part 1m1 and the movable part 1m4.

  As described above, it is possible to construct the projection optical system 55 in which each movable part exhibits very excellent synchronization performance against disturbance. In this embodiment, the PID compensator is used, but other control means that play an equivalent role may be used.

  The second embodiment is a modification of the first embodiment, and uses a PID compensator as in the first embodiment. The description will focus on the differences from the first embodiment. When the acceleration A and the angular frequency (frequency multiplied by 2π) are ω, the displacement X is expressed by A / ω / ω. When the frequency increases, the displacement X decreases with the square. Conversely, when the frequency decreases, the displacement X increases with the square. That is, when the acceleration is the same, the vibration amplitude increases as the frequency decreases. Therefore, in the low frequency band, it is important to keep the difference in the transmissibility of disturbance between the two optical elements within a predetermined range and to keep the synchronization error between the two optical elements within an allowable value. In the second embodiment, the difference in the transmissibility of disturbance at a low frequency (frequency band equal to or lower than the frequency Fim) of each movable part including the optical element falls within a predetermined range. The method will be described using the first movable part 1m1 and the second movable part 1m2.

  The difference in the transmissibility of the disturbance in the frequency bands below the frequencies Fim1 and Fim2 of the first and second movable parts is given by the following equation (in FIG. 3, the frequency region below Fi. In FIG. , Fi.)

  The values of Fdm1, Fim1, Fcm1, Fdm2, Fim2, and Fcm2 are adjusted so that the difference in the transmissibility of the disturbance expressed by Formula 8 is within a predetermined range, here 1/10 or less or 1/100 or less. .

  Similarly, between the first movable part 1m1 and the third movable part 1m3, and between the first movable part 1m1 and the fourth movable part 1m4, the contact frequency of the integrator of the PID compensator and the corner frequency of the differentiator. Adjust the crossover frequency.

  As described above, it is possible to construct the projection optical system 55 in which each movable part exhibits very excellent synchronization performance against disturbance.

  The third embodiment is a modification of the first and second embodiments, and uses a PI compensator as the compensator. In the third embodiment, a parallel link mechanism is used as the driving means 29m1, 29m2, 29m3, and 29m4. Similar to the second embodiment, the difference in the transmissibility of disturbance at a low frequency (frequency band below the frequency Fc) of each movable part including the optical element falls within a predetermined range. The description will focus on the differences from the first and second embodiments. The method will be described using the first movable part 1m1 and the second movable part 1m2. The difference in the transmissibility of the disturbance in the frequency band below the frequencies Fcm1 and Fcm2 of the first and second movable parts is given by the following equation (in FIG. 10, the frequency region below Fc. In FIG. Expressed as Fc).

  The values of Fcm1 and Fcm2 are adjusted so that the difference in the transmissibility of the disturbance expressed by Equation 9 falls within a predetermined range, here 1/10 or less or 1/100 or less. Similarly, the crossover frequency is adjusted between the first movable part 1m1 and the third movable part 1m3, and between the first movable part 1m1 and the fourth movable part 1m4. As described above, it is possible to construct the projection optical system 55 in which each movable part exhibits very excellent synchronization performance against disturbance.

  In the fourth embodiment, other optical elements are caused to follow the position variation of the first optical element supported by the holding mechanism from the fixing portion. Thereby, the relative positional relationship according to the target position of a 1st optical element and another optical element can be maintained.

  The first optical element is desirably an optical element having the highest optical sensitivity among the optical elements of the projection system. Here, the optical sensitivity means the degree of change in imaging performance with respect to the eccentricity, tilt, optical axis direction displacement, etc., and sensitivity of the optical element, that is, the eccentricity, tilt, light of the optical element. This means the amount of change in imaging performance with respect to axial misalignment or the like.

  The following is a method for controlling the tracking of the optical element.

  The first optical element is the optical element 32m4 in FIG. 1, and the optical element to be followed is 32m3. The target value of the optical element 32m4 is R4, the positional information of the optical element 32m4 is C4, the target value of the movable part 1m3 including the optical element 32m3 is R3 (however, the target value R3 may be zero), and the movable part 1m3 The control for causing the optical element 32m4 to follow the optical element 32m3 is shown by the block diagram in FIG. 4A, where C3 is the position information of G3 and the transmission characteristic from the fixed part of the movable part 1m3 is G3. However, for simplicity, a block diagram of the uniaxial tracking control is shown. In order to perform 6-axis tracking control, it is necessary to add a non-interacting matrix to the block diagram of FIG. Further, in order to perform aberration correction or the like, a new compensator may be added to the block diagram.

  As described above, the relative positional relationship according to the target values of the optical element 32m4 and the optical element 32m3 can be maintained.

  As described above, a projection optical system that is robust against disturbance can be constructed.

  The fifth embodiment is a modification of the fourth embodiment, and will be described with a focus on differences from the fourth embodiment. In the fifth embodiment, the first optical element has a driving unit and constitutes a feedback control system. Other optical elements are controlled so as to follow the positional variation of the first optical element, as in the fourth embodiment. Thereby, the relative positional relationship between the first optical element and the other optical elements can be kept constant according to the target value.

  The following is a method for controlling the tracking of the optical element.

  The first optical element is the optical element 32m4 in FIG. 1, and the optical element to be followed is 32m3. The target value of the movable part 1m4 including the optical element 32m4 is R4, the positional information of the movable part 1m4 is C4, the transfer characteristic from the fixed part of the movable part 1m4 is G4, and the target value of the movable part 1m3 including the optical element 32m3 is R3. (However, the target value R3 may be zero.) If the position information of the movable part 1m3 is C3 and the transfer characteristic from the fixed part of the movable part 1m3 is G3, the optical element 32m4 is caused to follow the optical element 32m3. This control is shown in the block diagram of FIG. However, for simplicity, a block diagram of the uniaxial tracking control is shown. In order to perform 6-axis tracking control, it is necessary to add a non-interacting matrix to the block diagram of FIG. Further, in order to perform aberration correction or the like, a new compensator may be added to the block diagram.

  As described above, the relative positional relationship according to the target values of the optical element 32m4 and the optical element 32m3 can be maintained.

  As described above, a projection optical system that is robust against disturbance can be constructed.

  In the sixth embodiment, the wafer stage follows the position variation of the first optical element supported by the holding mechanism from the fixed portion. Thereby, the wafer stage can perform scanning and stepping operations while following the relative positional relationship with the first optical element depending on the target position.

  The first optical element is desirably an optical element having the highest optical sensitivity among the optical elements of the projection system. Here, the optical sensitivity means the degree of change in imaging performance with respect to the eccentricity, tilt, optical axis direction displacement, etc., and sensitivity of the optical element, that is, the eccentricity, tilt, light of the optical element. This means the amount of change in imaging performance with respect to axial misalignment or the like.

  The following is a method of wafer stage tracking control.

  The first optical element is the optical element 32m4 in FIG. If the target value of the optical element 32m4 is R4, the positional information of the optical element 32m4 is C4, the target value of the wafer stage 28 is Rw, the positional information of the wafer stage is Cw, and the transfer characteristic of the wafer stage is Gw, the optical element 32m4 The control for causing the wafer stage 28 to follow is shown by the block diagram in FIG. However, for simplicity, a block diagram of the uniaxial tracking control is shown. In order to perform 6-axis tracking control, it is necessary to add a non-interacting matrix to the block diagram of FIG. Further, in order to perform aberration correction or the like, a new compensator may be added to the block diagram.

  As described above, the wafer stage 28 can perform the scan and step operations while following the relative positional relationship with the optical element 32m4 depending on the target value.

  Further, when the reticle stage is caused to follow the first optical element, the same control as in the case of the wafer stage described above may be performed.

  Thus, an exposure apparatus that is robust against disturbance can be constructed.

  The seventh embodiment is a modification of the sixth embodiment, and will be described with a focus on differences from the sixth embodiment. In the seventh embodiment, the first optical element has a driving unit and constitutes a feedback control system. Similar to the sixth embodiment, the wafer stage is controlled so as to follow the position variation of the first optical element. As a result, the wafer stage can perform scanning and stepping operations while following the relative positional relationship with the first optical element depending on the target value.

  The following is a method for controlling the tracking of the optical element.

  The first optical element is the optical element 32m4 in FIG. The target value of the movable part 1m4 including the optical element 32m4 is R4, the positional information of the movable part 1m4 is C4, the transfer characteristic from the fixed part of the movable part 1m4 is G4, the target value of the wafer stage 28 is Rw, and the position of the wafer stage Assuming that the information is Cw and the transfer characteristic of the wafer stage is Gw, the control for causing the optical element 32m4 to follow the wafer stage 28 is shown in the block diagram of FIG. However, for simplicity, a block diagram of the uniaxial tracking control is shown. In order to perform 6-axis tracking control, it is necessary to add a non-interacting matrix to the block diagram of FIG. Further, in order to perform aberration correction or the like, a new compensator may be added to the block diagram.

  As described above, the wafer stage 28 can perform scanning and stepping operations while following the relative positional relationship with the optical element 32m4 depending on the target position.

  Further, when the reticle stage is caused to follow the first optical element, the same control as in the case of the wafer stage described above may be performed.

  Thus, an exposure apparatus that is robust against disturbance can be constructed.

  The present invention can be applied not only to an optical element but also to, for example, a lens barrel 25 and a wafer stage 27. This will be described with reference to FIG. The lens barrel 25 is rigidly connected to the structure frame 24. The structure frame 24 is supported by the base 22 via the structure mount 21. The wafer stage 27 is supported on the wafer stage surface plate 27 via a self-weight compensation spring, wiring, and piping. The wafer stage surface plate 23 is connected to the base 22 via the wafer stage mount 20. Here, as a matter of course, since it is impossible to ideally connect rigidly, what is described as rigidly connected is substantially rigidly connected, particularly a movable part including an optical element (for example, 1 m1) And a fixed part (for example, 2m1) means that the connection is substantially rigid. Of course, there is no need for a rigid connection, and adjustments may be made to eliminate errors in the transmission rate (transmission coefficient), including the natural frequency and damping rate (coefficient) between the lens barrel and the structural frame. Absent.

  When the primary natural frequency between the wafer stage and the base is Fnw, the damping rate is ζw, the primary natural frequency between the structure frame and the base is Fnp, and the damping rate is ζp, 1 between the wafer stage and the base is 1 The product Aw of the next natural frequency and the damping rate is expressed by Fnw · ζw, and the product Ap of the primary natural frequency and the damping rate between the structure frame and the base is expressed by Fnp · ζp.

When Fnw · ζw is used as a reference,
(Fnp · ζp−Fnw · ζw) / Fnw · ζw = ± 20% (or 10%)
By adjusting the values of Fnp, ζp, Fnw, and ζw so that the relationship is established, an exposure apparatus system that is robust against floor vibration can be constructed.

  In reality, the values of Fnw, ζw, and Fnp are often determined by the mechanical structure, but since the value of ζp can be adjusted electrically, the value of ζp is satisfied in order to satisfy the above relational expression. Will be adjusted.

  In this embodiment, the wafer stage mount 20 is provided, but a structure without the wafer stage mount 20 may be used.

  Next, an embodiment of a device manufacturing method using the above-described exposure apparatus will be described with reference to FIGS. FIG. 6 is a flowchart for explaining how to fabricate devices (ie, semiconductor chips such as IC and LSI, LCDs, CCDs, and the like). Here, the manufacture of a semiconductor chip will be described as an example. In step 1 (circuit design), a device is designed. In step 2 (mask production), a mask on which the designed circuit pattern is formed is produced. On the other hand, in step 3 (wafer manufacture), a wafer is manufactured using a material such as silicon or glass. Step 4 (wafer process) is called a pre-process, and an actual circuit is formed on the wafer by lithography using the mask and the wafer. Step 5 (assembly) is called a post-process, and is a process for forming a semiconductor chip using the wafer created in step 4, and includes processes such as an assembly process (dicing and bonding) and a packaging process (chip encapsulation). . In step 6 (inspection), inspections such as an operation confirmation test and a durability test of the semiconductor device created in step 5 are performed. Through these steps, the semiconductor device is completed and shipped (step 7).

  FIG. 7 is a detailed flowchart of the wafer process in Step 4 shown in FIG. In step 11 (oxidation), the surface of the wafer is oxidized. In step 12 (CVD), an insulating film is formed on the surface of the wafer. In step 13 (electrode formation), an electrode is formed on the wafer by vapor deposition or the like. Step 14 (ion implantation) implants ions into the wafer. In step 15 (resist process), a photosensitive agent is applied to the wafer. Step 16 (exposure) uses the exposure apparatus 1 to expose a circuit pattern on the mask onto the wafer. In step 17 (development), the exposed wafer is developed. In step 18 (etching), portions other than the developed resist image are removed. In step 19 (resist stripping), the resist that has become unnecessary after the etching is removed. By repeatedly performing these steps, multiple circuit patterns are formed on the wafer. According to the device manufacturing method of the present embodiment, the disturbance characteristics of a plurality of (reflection-type) optical elements match or the difference is within an allowable range, so that the synchronization error of each optical element is within the allowable range, and a desired An imaging relationship can be achieved, and a high-quality device can be manufactured. Thus, the device manufacturing method using such an exposure apparatus and the resulting device also function as one aspect of the present invention.

  Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the gist thereof. For example, in the present embodiment, the optical elements as the control images of the positioning control match the disturbance characteristics for all of the optical elements of the original plate, the wafer, and the projection optical system, or the difference is within an allowable range. Is selected from at least two optical elements, that is, one optical element constituting the projection optical system, the reticle or mask, the object to be exposed, and the optical element constituting the projection optical system. It is sufficient if the disturbance characteristics of the other optical elements are matched or the difference is within an allowable range. Further, software (program) or hardware for executing the positioning control method of the present invention, and a memory storing the program also constitute one aspect of the present invention.

  Further, in the present embodiment, the word “synchronization or coincidence” is preferably completely synchronized or completely coincident, but is not limited to this. If the error is within 5% of either one, it is assumed that they are synchronized or matched.

  The embodiments of the present invention are listed below.

(Embodiment 1)
A projection optical system that projects a pattern formed on a mask onto an object to be exposed,
A plurality of optical elements and a plurality of positioning mechanisms for positioning each of the plurality of optical elements on an optical path from the mask to the object to be exposed, wherein the plurality of positioning mechanisms are substantially the same mechanism; Characteristic projection optical system.

(Embodiment 2)
A first coefficient determined by a natural frequency and an attenuation factor of a first positioning mechanism for positioning the first optical element of the plurality of optical elements; and a second coefficient of the plurality of optical elements. 2. The projection optical system according to claim 1, wherein the second frequency determined by the natural frequency of the second positioning mechanism for positioning the optical element and the second coefficient substantially match each other.

(Embodiment 3)
A projection optical system having a plurality of optical elements and projecting a pattern formed on a mask onto an object to be exposed,
A first coefficient determined by a natural frequency and an attenuation factor of a first positioning mechanism for positioning the first optical element among the plurality of optical elements; and a second optical element among the plurality of optical elements. A projection optical system characterized in that the natural frequency of the second positioning mechanism for positioning the lens substantially coincides with the second coefficient determined by the damping rate.

(Embodiment 4)
Implementation wherein the accuracy of the position and orientation of the first optical element has the greatest influence on the imaging performance of the projected image projected onto the object to be exposed among the plurality of optical elements. 4. The projection optical system according to aspect 2 or 3.

(Embodiment 5)
Any one of Embodiments 2 to 4, wherein the first coefficient and the second coefficient substantially coincide with each other in at least one of a three-axis direction orthogonal to each other and a direction rotating around the three axes. The projection optical system described in 1.

(Embodiment 6)
A first coefficient determined by the lowest natural frequency and damping factor of the first positioning mechanism, and a second coefficient determined by the lowest natural frequency and damping factor of the second positioning mechanism And the projection optical system according to any one of Embodiments 2 to 5.

(Embodiment 7)
When the first coefficient is K1 and the second coefficient is K2,
| K1-K2 | ≦ 0.2 × K1
The projection optical system according to any one of Embodiments 2 to 6, wherein:

(Embodiment 8)
When the first coefficient is K1 and the second coefficient is K2,
| K1-K2 | ≦ 0.1 × K1
The projection optical system according to any one of Embodiments 2 to 6, wherein:

(Embodiment 9)
Of the plurality of reflecting surfaces of the projection optical system, the last reflecting surface closest to the object to be exposed on the optical path from the pattern to the object to be exposed is the first optical element. The projection optical system according to any one of 2 to 8.

(Embodiment 10)
The projection optical system according to any one of Embodiments 1 to 9, wherein the substantially same mechanism is a mechanism using a parallel link mechanism.

(Embodiment 11)
A transmission rate of disturbance to the first optical element among the plurality of optical elements in the predetermined frequency band, and a transmission rate of disturbance to the second optical element among the plurality of optical elements in the predetermined frequency band. 11. The projection optical system according to any one of Embodiments 1 to 10, wherein the difference is 1/10 or less.

(Embodiment 12)
A transmission rate of disturbance to the first optical element among the plurality of optical elements in the predetermined frequency band, and a transmission rate of disturbance to the second optical element among the plurality of optical elements in the predetermined frequency band. 12. The projection optical system according to any one of Embodiments 1 to 11, wherein the difference is 1/100 or less.

(Embodiment 13)
A transmission rate of disturbance to the first optical element among the plurality of optical elements in the predetermined frequency band, and a transmission rate of disturbance to the second optical element among the plurality of optical elements in the predetermined frequency band. The projection optical system according to any one of Embodiments 1 to 12, wherein the difference is 1/10 or less of the transmissibility of disturbance to the first optical element.

(Embodiment 14)
A transmission rate of disturbance to the first optical element among the plurality of optical elements in the predetermined frequency band, and a transmission rate of disturbance to the second optical element among the plurality of optical elements in the predetermined frequency band. 14. The projection optical system according to any one of embodiments 1 to 13, wherein the difference is 1/100 or less of a transmissibility of disturbance to the first optical element.

(Embodiment 15)
The projection optical system according to any one of Embodiments 11 to 14, wherein the predetermined frequency band is 80 Hz or less.

(Embodiment 16)
The projection optical system according to any one of Embodiments 11 to 14, wherein the predetermined frequency band is 100 Hz or less.

(Embodiment 17)
17. The projection optical system according to any one of embodiments 11 to 16, wherein a width of the predetermined frequency band is 10 Hz or more.

(Embodiment 18)
The projection optical system according to any one of embodiments 11 to 17, wherein a width of the predetermined frequency band is 15 Hz or more.

(Embodiment 19)
19. The projection optical system according to any one of embodiments 11 to 18, wherein the predetermined frequency band is a band lower than an intersection frequency of a control system of the plurality of positioning mechanisms.

(Embodiment 20)
An illumination optical system that illuminates the mask with light from a light source, and the projection optical system according to any one of embodiments 1 to 19 that projects and exposes a pattern of the mask onto an object to be exposed. Exposure equipment.

(Embodiment 21)
A projection optical system that has a plurality of optical elements and a plurality of optical element positioning mechanisms for positioning the plurality of optical elements, and projects a pattern formed on the mask onto an object to be exposed such as a wafer;
A mask stage having a mask positioning mechanism for positioning the mask;
An exposure apparatus comprising a wafer stage having a wafer positioning mechanism for positioning the wafer,
An exposure apparatus, wherein a product of a natural frequency and an attenuation factor of at least two positioning mechanisms among the plurality of optical element positioning mechanisms, the mask positioning mechanism, and the wafer positioning mechanism are substantially equal.

(Embodiment 22)
Of the plurality of optical element positioning mechanisms, the mask positioning mechanism, and the wafer positioning mechanism, the product of the natural frequency and the attenuation rate of the first positioning mechanism is the natural frequency and the attenuation rate of the second positioning mechanism. The exposure apparatus according to Embodiment 21, wherein the exposure apparatus is 80% or more and 125% or less of a product of

(Embodiment 23)
Of the plurality of optical element positioning mechanisms, the mask positioning mechanism, and the wafer positioning mechanism, the product of the natural frequency and the attenuation rate of the first positioning mechanism is the natural frequency and the attenuation rate of the second positioning mechanism. The exposure apparatus according to embodiment 21 or 22, wherein the exposure apparatus is 90% or more and 111% or less of a product of

(Embodiment 24)
The product of the natural frequency and the attenuation factor of each of the plurality of optical element positioning mechanisms, the mask positioning mechanism, and the wafer positioning mechanism is determined by the plurality of optical element positioning mechanisms, the mask positioning mechanism, and the wafer positioning mechanism. 24. The exposure apparatus according to any one of embodiments 21 to 23 (preferably 90%), which falls within a range of 80% to 125% of the product of the natural frequency and the damping rate of one positioning mechanism. Is 111% or less).

(Embodiment 25)
An illumination optical system that illuminates the mask with light from a light source and at least one optical element, and projects the pattern formed on the mask placed on the mask stage onto the object to be exposed placed on the wafer stage An exposure apparatus having a projection optical system
Position information acquisition means for acquiring position information of any one of the first optical element included in the projection optical system, the mask stage, the wafer stage, and the second optical element included in the projection optical system;
Transmission rate of disturbance to the first optical element in a predetermined frequency band, and to any one of the mask stage, the wafer stage, and the second optical element of the projection optical system in the predetermined frequency band The first optical element and any one of the mask stage, the wafer stage, and the second optical element of the projection optical system so that the difference from the disturbance transmission rate is 1/10 or less. An exposure apparatus comprising positioning means for positioning.

(Embodiment 26)
The positioning means includes any one of a transmission rate of disturbance to the first optical element in a predetermined frequency band, and a second optical element included in the mask stage, the wafer stage, and the projection optical system in the predetermined frequency band. Among the second optical elements of the first optical element, the mask stage, the wafer stage, and the projection optical system so that the difference from the transmission rate of the disturbance to one of them is 1/100 or less. The exposure apparatus according to embodiment 25, wherein any one of them is positioned.

(Embodiment 27)
The mechanism for positioning the first optical element and the mechanism for positioning any one of the mask stage, the wafer stage, and the second optical element of the projection optical system both have linear motors. An exposure apparatus according to embodiment 25 or 26.

(Embodiment 28)
The mechanism for positioning the first optical element and the mechanism for positioning any one of the mask stage, the wafer stage, and the second optical element of the projection optical system both have a parallel link mechanism. 27. An exposure apparatus according to Embodiment 25 or 26, which is characterized in that

(Embodiment 29)
A projection optical system for projecting the mask pattern onto the object to be exposed, a first movable part for placing the first member, a first fixed part for holding the first movable part, and a second member are placed. Having a second movable part and a second fixed part for holding the second movable part;
The natural frequency of the first movable part expressed from the rigidity and damping rate of the first movable part and the first fixed part and the mass or moment of inertia of the first movable part, and the first The first coefficient determined by the movable part and the attenuation rate of the first fixed part have the rigidity and attenuation rate of the second movable part and the second fixed part and the mass of the second movable part. Alternatively, the second coefficient determined by the natural frequency of the second movable part expressed from the moment of inertia and the damping factor of the second movable part and the second fixed part is substantially matched. An exposure apparatus.

(Embodiment 30)
In the embodiment 29, the second coefficient determined by the natural frequency and the damping rate of the second positioning mechanism is within ± 20% of the first coefficient determined by the natural frequency and the damping rate of the first positioning mechanism. An exposure apparatus characterized by that.

(Embodiment 31)
In the embodiment 29, the second coefficient determined by the natural frequency and the damping rate of the second positioning mechanism is within ± 10% of the first coefficient determined by the natural frequency and the damping rate of the first positioning mechanism. An exposure apparatus characterized by that.

(Embodiment 32)
A projection optical system for projecting the mask pattern onto the object to be exposed, a first movable part for placing the first member, a first fixed part for holding the first movable part, and a second member are placed. Having a second movable part and a second fixed part for holding the second movable part;
The natural frequency of the first movable part expressed from the rigidity and damping rate of the first movable part and the first fixed part and the mass or moment of inertia of the first movable part, and the first The transmission rate of the disturbance in a predetermined frequency band to the first movable part, the second movable part, and the second fixed part expressed by the movable part and the attenuation rate of the first fixed part The natural frequency of the second movable part expressed by the rigidity and damping rate of the second movable part and the mass or moment of inertia of the second movable part, and the damping rates of the second movable part and the second fixed part Positioning means for positioning the first movable part and the second movable part so that a difference between the disturbance in the predetermined frequency band and the transmission rate to the second movable part is 1/10 or less. An exposure apparatus comprising:

(Embodiment 33)
A projection optical system for projecting the mask pattern onto the object to be exposed, a first movable part for placing the first member, a first fixed part for holding the first movable part, and a second member are placed. A second movable part; a second fixed part that holds the second movable part; a first measurement part that measures the position of the first movable part; and a second that measures the position of the second movable part. Based on the measurement result of the first measurement unit, including a measurement unit, a first drive unit that drives the first movable unit, a second drive unit that drives the second movable unit, and a first differentiator. A first compensator that controls the first drive unit; and a second compensator that includes a second differentiator and controls the second drive unit based on the measurement result of the second measurement unit;
Depending on the rigidity and damping rate of the first drive unit, the mass or moment of inertia of the first movable unit, the break frequency of the first differentiator of the first compensator, and the crossing frequency of the control system of the first movable unit Expressed is the transmission rate of the disturbance in the predetermined frequency band to the first movable part, the rigidity and damping rate of the second drive part, the mass or moment of inertia of the second movable part, the second compensator The difference between the break frequency of the second differentiator and the transmissibility of the disturbance in the predetermined frequency band expressed by the crossing frequency of the control system of the first movable part is 1/10. An exposure apparatus comprising positioning means for positioning the first movable part and the second movable part as described below.

(Embodiment 34)
A projection optical system for projecting the mask pattern onto the object to be exposed, a first movable part for placing the first member, a first fixed part for holding the first movable part, and a second member are placed. A second movable part; a second fixed part that holds the second movable part; a first measurement part that measures the position of the first movable part; and a second that measures the position of the second movable part. Based on the measurement result of the first measurement unit, which includes a measurement unit, a first drive unit that drives the first movable unit, a second drive unit that drives the second movable unit, and a first integrator. A first compensator that controls the first drive unit; and a second compensator that includes a second integrator and controls the second drive unit based on the measurement result of the second measurement unit;
Depending on the rigidity and damping rate of the first drive unit, the mass or moment of inertia of the first movable unit, the break frequency of the first integrator of the first compensator, and the crossing frequency of the control system of the first movable unit Expressed is the transmission rate of the disturbance in the predetermined frequency band to the first movable part, the rigidity and damping rate of the second drive part, the mass or moment of inertia of the second movable part, the second compensator The difference between the break frequency of the second integrator and the transmissibility of the disturbance in the predetermined frequency band expressed by the crossing frequency of the control system of the second movable part is 1/10. An exposure apparatus comprising positioning means for positioning the first movable part and the second movable part as described below.

(Embodiment 35)
A projection optical system for projecting the mask pattern onto the object to be exposed, a first movable part for placing the first member, a first fixed part for holding the first movable part, and a second member are placed. A second movable part; a second fixed part that holds the second movable part; a first measurement part that measures the position of the first movable part; and a second that measures the position of the second movable part. Measurement of the first measurement unit including a measurement unit, a first drive unit for driving the first movable unit, a second drive unit for driving the second movable unit, a first differentiator and a first integrator. A first compensator for controlling the first drive unit based on a result, a second differentiator and a second integrator; and a second controller for controlling the second drive unit based on a measurement result of the second measurement unit. Two compensators,
Rigidity and damping factor of the first drive unit, mass or moment of inertia of the first movable unit, break frequency of the first differentiator of the first compensator, of the first integrator of the first compensator Expressed by the break frequency, the crossing frequency of the control system of the first movable part, the transmission rate of disturbance in the predetermined frequency band to the first movable part, the rigidity and damping rate of the second drive part, The mass or moment of inertia of the second movable part, the corner frequency of the second differentiator of the second compensator, the corner frequency of the second integrator of the second compensator, the control system of the second movable part The first movable part and the second movable part are set such that a difference between the disturbance rate in the predetermined frequency band and the transmission rate to the second movable part is 1/10 or less. Characterized by having positioning means for positioning Light equipment.

(Embodiment 36)
The positioning means has a difference between the disturbance transmission rate to the first member in the predetermined frequency band and the disturbance transmission rate to the second member in the predetermined frequency band is 1/100 or less. The exposure apparatus according to any one of Embodiments 32 to 35, wherein the first member and the second member are positioned as described above.

(Embodiment 37)
37. The exposure according to any one of embodiments 32 to 36, wherein the projection optical system includes a plurality of optical elements, and the first member is one of the plurality of optical elements. apparatus.

(Embodiment 38)
The exposure according to any one of embodiments 32 to 37, wherein the projection optical system includes a plurality of optical elements, and the second member is one of the plurality of optical elements. apparatus.

(Embodiment 39)
38. The exposure apparatus according to any one of embodiments 32 to 37, wherein the second movable portion is a mask stage for mounting the mask or a wafer stage for mounting the object to be exposed.

(Embodiment 40)
40. The exposure apparatus according to any one of Embodiments 25 to 39, wherein the predetermined frequency band is 80 Hz or less.

(Embodiment 41)
41. The exposure apparatus according to any one of Embodiments 25 to 40, wherein the predetermined frequency band is 100 Hz or less.

(Embodiment 42)
42. The exposure apparatus according to any one of embodiments 25 to 41, wherein a width of the predetermined frequency band is 10 Hz or more.

(Embodiment 43)
42. The exposure apparatus according to any one of embodiments 25 to 41, wherein a width of the predetermined frequency band is 15 Hz or more.

(Embodiment 44)
A projection optical system including a plurality of optical elements;
First measuring means for measuring a position from a reference structure of a first movable part including one of the plurality of optical elements;
Second measuring means for measuring the position of the second movable part including the other one of the plurality of optical elements from the reference structure;
A second compensator for controlling the second drive means of the second movable part based on the measurement information of the measurement means;
The second compensator is controlled to cause the first movable part to follow the second movable part based on the measurement result of the first measurement means and the measurement result of the second measurement means. Exposure device.

(Embodiment 45)
45. The exposure apparatus according to embodiment 44, wherein the first movable part includes an optical element having the highest optical sensitivity.

(Embodiment 46)
A projection optical system that includes a plurality of optical elements and projects a mask pattern onto an object to be exposed, a mask stage on which the mask is placed, a driving unit that drives the mask stage, and a reference structure of the mask stage In an exposure apparatus comprising: a first measuring unit that measures a position from: a compensator that controls the driving unit based on measurement information of the measuring unit;
A second measuring means for measuring a position from the reference structure of a movable part including one of the plurality of optical elements;
An exposure apparatus that controls the compensator so that one optical element of the plurality of optical elements follows the mask stage based on a measurement result of the second measuring means.

(Embodiment 47)
A projection optical system that includes a plurality of optical elements and projects a mask pattern onto an object to be exposed, a wafer stage on which the object to be exposed is mounted, a driving unit that drives the wafer stage, and a reference for the wafer stage In an exposure apparatus comprising: a first measuring unit that measures a position from a structure; and a compensator that controls the driving unit based on measurement information of the measuring unit.
A second measuring means for measuring a position from the reference structure of a movable part including one of the plurality of optical elements;
An exposure apparatus that controls the compensator so that one of the plurality of optical elements follows the wafer stage based on a measurement result of the second measurement unit.

(Embodiment 48)
One optical element of the plurality of optical elements is an optical element closest to the mask along an optical path of light emitted from the mask among the plurality of optical elements included in the projection optical system. An exposure apparatus according to embodiment 44 or 47.

(Embodiment 49)
One optical element of the plurality of optical elements is an optical element closest to the object to be exposed along an optical path of light emitted from the mask among the plurality of optical elements included in the projection optical system. 44. An exposure apparatus according to claim 47, wherein:

(Embodiment 50)
50. The exposure apparatus according to any one of Embodiments 25 to 49, wherein the exposure apparatus uses exposure light having a wavelength of 2 to 40 nm.

(Embodiment 51)
39. The exposure apparatus according to any one of Embodiments 1 to 28, 37, and 38, wherein all the optical elements are reflective optical elements.

(Embodiment 52)
51. A step of exposing the object to be exposed using the exposure apparatus according to any one of Embodiments 24 to 50, and a step of performing a predetermined process on the exposed object to be exposed. Device manufacturing method.

(Embodiment 53)
A positioning method for positioning at least two optical elements, which is used in a projection optical system having at least two optical elements and used to project a pattern formed on a reticle or mask onto an object to be exposed,
Obtaining position information of each of the two optical elements;
Positioning the two optical elements such that a difference in the transmission rate of disturbance to the two optical elements in a predetermined frequency band is 1/10 or less,
Controlling the positioning of the two optical elements based on the position information so that the difference in the transmissibility of the disturbance between the two optical elements is 1/10 or less,
The projection optical system includes a plurality of optical elements,
The two optical elements are one optical element constituting the projection optical system, another optical element selected from the reticle or mask, the object to be exposed, and the optical element constituting the projection optical system. A positioning method comprising: an element.

(Embodiment 54)
54. The positioning method according to embodiment 53, wherein the control step controls the positioning of the two optical elements with respect to one of a three-axis direction orthogonal to and a direction rotating around the three axes.

It is the simplified optical path figure of the exposure apparatus as one Embodiment of this invention. It is a figure which shows the transfer characteristic of the movable part containing the optical element shown in FIG. It is a figure which shows the transmission characteristic of the disturbance of the movable part containing the optical element shown in FIG. It is a block diagram which shows the control structure for making a certain optical system element follow another optical system element. It is a block diagram which shows the control structure for making a certain optical system element follow a wafer stage. It is a flowchart for demonstrating manufacture of devices (semiconductor chips, such as IC and LSI, LCD, CCD, etc.). 7 is a detailed flowchart of the wafer process in Step 4 shown in FIG. 6. It is a schematic block diagram of the positioning control apparatus of this invention. It is a flowchart for demonstrating the positioning control method shown in FIG. It is a figure which shows the transmission characteristic of the disturbance of the movable part containing the optical element shown in FIG.

Explanation of symbols

1m1 First movable part 2m1 First fixed part 20 Wafer stage mount 21 Structure mount 22 Base 23 Wafer stage surface plate 24 Structure frame 25 Lens barrel 27 Wafer stage 28 Wafer 29m1 First drive mechanism 30m1 First optical Element holding block 31m1 First holding mechanism 32m1 First optical element 41 Reference structure 42m1, 42r, 42w Non-contact measuring means 50 Reticle 51 Reticle stage 55 Projection optical system 61m1 First optical element fine movement mechanism

Claims (15)

An optical device comprising an optical system having first and second elements and a support member that supports the optical system,
A first control system including the first element and feedback-controlling the position of the first element;
A second control system including the second element and feedback-controlling the position of the second element, and a first transmission between the displacement of the support member and the displacement of the first element The first and second so that the difference between the function and the second transfer function between the displacement of the support member and the displacement of the second element is 1/10 or less in at least some of the bands. An optical apparatus characterized in that a control system is configured.   2. The first and second control systems are configured so that a difference between the first transfer function and the second transfer function is 1/100 or less. Optical device.   The optical device according to claim 1, wherein at least one of the first and second elements includes a reflective element. An optical device comprising an optical system having first and second elements and a support member that supports the optical system,
A detection system for detecting the position of the first element;
A second control system including the second element and feedback-controlling the position of the second element, the second control system based on a detection result of the detection system. And an optical device for controlling the position of the second element so as to maintain a predetermined relative position between the second element and the second element.   The optical apparatus according to claim 4, further comprising a first control system that includes the first element and the detection system and that feedback-controls the position of the first element.   6. The second control system controls the position of the second element based on a difference between a target value of the first control system and a position of the first element. An optical device according to 1.   The second control system determines the position of the second element based on the difference between the target value of the second control system and the target value of the first control system and the position of the first element. The optical device according to claim 5, wherein the optical device is controlled.   The optical device according to claim 4, wherein the first element includes a reflective element.   The second element includes at least one of a reflective element, a first stage for holding and moving an object to be exposed, and a second stage for holding and moving an original having a pattern to be projected. An optical device according to any one of claims 4 to 8. An optical device comprising an optical system having first and second elements,
Base and
A first support system for supporting the first element on the base;
A second support system for supporting the second element on the base, and a product of a primary natural frequency and a damping factor of the first support system; The first and second support systems are configured such that the difference between the product of the primary natural frequency and the damping factor is 20% or less of the product of the first support system. An optical device characterized by the above.   The difference between the product of the first support system and the product of the second support system is 10% or less of the product of the first support system. The optical device according to claim 10, wherein a support system is configured.   The optical apparatus according to claim 10, wherein the first support system includes a first control system that feedback-controls a position of the first element.   The optical apparatus according to claim 10, wherein the second support system includes a second control system that feedback-controls the position of the second element.   The optical apparatus according to claim 1, wherein an original pattern is projected onto a substrate by extreme ultraviolet light through the optical system. An exposure step of exposing a pattern to a substrate using the optical device according to claim 14;
And a developing step for developing the substrate exposed in the exposure step.

Images