Lithographic apparatus and a method for manufacturing a device

Lithography projection device and method of manufacturing a device

The present invention relates to an interference meter calibration and position measurement system, particularly to a system used in a lithographic projection device, which includes: an illumination system that provides irradiation projection beams; and a pattern generation device that imitates the desired pattern Projection light beam; a substrate table, which is used to support a substrate; and a projection system, which mirrors the patterned beam to the target part of the substrate.

The term "pattern generating device" should broadly refer to a device capable of imparting an incident irradiation beam with a pattern cross-section, which corresponds to the pattern to be formed on the target part of the substrate; the term "light valve" will also be used in this text. Generally speaking, the pattern corresponds to a specific functional layer of a device in the target part, such as an integrated circuit or other devices described below. Examples of this pattern generating device include:-a mask stage, which is used to support a mask. The concept of photomask is well-known in lithography. Its photomask type includes binary elements, alternating phase replacement and attenuation phase replacement, and various hybrid photomask types. The selective transmission (in the transmission type mask) or reflection (in the light-transmitting type mask) of this mask in the irradiating beam depends on the pattern on the mask. The mask stage ensures that the mask is fixed at the required position in the incoming irradiation beam, and can be moved relative to the beam if necessary.

-Programmable mirror array. An example of this device is an array addressable surface, which has a viscoelastic control layer and a reflective surface. The basic principle of the device is that the addressing area of the reflective surface reflects incident light as diffracted light, while the unaddressed area reflects the incident light as undiffracted light. Using an appropriate filter, the undiffracted light can be filtered out of the reflected beam, leaving only the diffracted light. In this case, the beam is imaged according to the addressing pattern of the addressable array surface, and the required array addressing can be used The electronic device is completed. More information about this mirror array is disclosed in US Patent Nos. 5,296,891 and 5,523,193, which are cited in the description of this case.

-Programmable LCD. An example of this structure is disclosed in US Patent No. 5,229,872, which is cited in the description of this case. For the purpose of simplification, the rest of this article will specifically refer to the example of the mask stage and the mask; however, the general principles described in this example should be disclosed in the larger range of the aforementioned pattern generating device.

Also for the purpose of simplification, the projection system mentioned later refers to "lens"; however, this term should more broadly include various types of projection systems, such as refractive lenses, reflective lenses, and catadioptric lenses. The illumination system also includes components, the operation of which is based on any design pattern used to guide, image, or control the irradiated projection beam, and the component can also refer to the following general or specific "lens". In addition, the type of lithography device can have two or more substrate stages (and/or two or more mask stages). In this "plurality stage" device, more stages can be used at the same time, although one or A number of other workbenches are used for exposure, and the preparation steps can be completed on one or more workbenches. The two-stage lithography device is disclosed in the US Patent No. 5,969,441 and the US Patent Application No. 09/180,011 (WO 98/40791) recorded on February 27, 1998, which are listed by reference in the description of this case.

The lithography device can be used in the manufacture of integrated circuits (ICs). At this time, the pattern generator forms a circuit pattern corresponding to an individual IC layer. This pattern is mapped onto a target part of a substrate (silicon wafer) (including a Or multiple molds, the surface of the substrate has been coated with a layer of irradiated sensing material (insulating paint). Generally speaking, a single wafer contains the entire network of adjacent target parts, which are continuously irradiated by the projection system at the same time. In a device that uses a mask or a mask stage to generate patterns, there are differences between the two different types of mechanisms. In a type of lithographic projection device, the irradiation of each target part is a single exposure of the entire mask pattern to On the target part, this device usually represents a wafer stepper. In another type of continuous scanning device, the irradiation of each target part is gradual with a projection beam in a known reference direction ("scanning" direction) Scan the mask pattern. At this time, the substrate table parallel to or non-parallel to the direction is synchronously scanned. Generally speaking, since the projection system has a magnification factor M (usually less than 1), the substrate table scanning speed V is the factor M multiplied by The scanning speed of the mask table. More information about the lithography device described here is disclosed in US Patent No. 6,046,792, which is cited in the description of this case.

A continuing demand in the semiconductor industry is to be able to manufacture integrated circuits (ICs) with the highest component density and the smallest feature size. In order to have a smaller image in the lithographic projection device, it needs to use shorter wavelength projection irradiation. Several different types of projection irradiation have been known to us, including extreme ultraviolet (EUV) in the range of 10 to 20 nm. , Electron beam, ion beam and other charged particle flux. These types of illuminating beams fulfill the requirement of maintaining a beam path in a high vacuum. The beam path includes a photomask, a substrate, and optical components. This can prevent the absorption and/or scattering of the beam, and the total pressure must be less than about 10^-6millibar. Optical components irradiated by EUV may be damaged due to the carbon layer deposited on the surface. The additional requirement caused by this is that the pressure of the hydrocarbon part must be lower than 10^-8Or 10^-9millibar.

Under this high-vacuum situation, there must be quite troublesome conditions to work on the components. They must be placed in a vacuum environment and the vacuum chamber must be sealed, especially for any components in the device that must be supplied from the outside into the vacuum chamber. For the components inside the vacuum chamber, it must use materials that eliminate or minimize pollutants from the material itself or the gas absorbed on its surface.

We know that the positioning accuracy of the substrate (wafer) to be exposed relative to the mask (net line) is quite high. Even if different lithography devices are used for different exposures, the wafer passes through 20 to 30 in the process. Times of exposure and various images must be correctly calibrated. Accurate coverage requirements can only make the feature size smaller and the irradiation wavelength shorter.

An object of the present invention is to provide a calibration and/or positioning measurement system that can measure the position of an object in vacuum with high accuracy, that is, it can be used in a lithographic projection device.

According to the present invention, a lithography projection device is provided, which includes: an irradiation system that provides an irradiated projection beam; a pattern generation device that makes the projection beam imitate the pattern according to the required pattern; and a substrate stage that supports a A substrate; and a projection system, which mirrors the beam of the imitation pattern to the target part of the substrate, characterized by: a vacuum chamber, in which at least one of the pattern generating device and the substrate stage, and the object stage is movable; and a The calibration system is configured and configured to calibrate the pattern generating device and the substrate on the substrate stage. The calibration system includes a driven part located in the vacuum chamber and an active part located outside the vacuum chamber.

Since only the driven part of the calibration system in the vacuum chamber is located, the present invention avoids the difficulty of adapting the active part of the calibration system to vacuum and reduces the heat and vibration generated in the vacuum system, which may interfere with exposure and cause positioning inaccuracy.

In the specific embodiment of the present invention, the active and driven parts of the system are connected together by optical fibers. The calibration system is an interferometer system to detect the position of the measurement grating (wafer mark) relative to the reference grating. This system irradiates at least two sequences of diffraction of the measurement grating to the reference grating. The system includes beam splitting The device is used to separate one of the series of illuminations diffracted by the reference grating and the diffracted derivative of the measuring grating from the other series of illuminations diffracted by the measuring grating.

According to another concept of the present invention, a device manufacturing method is provided and the steps include: providing a substrate, at least part of which is covered by a layer of irradiating sensing material; providing an irradiating projection beam using an irradiating system; using a pattern generating device to give Projecting a pattern in the beam profile; projecting the irradiated pattern beam on the target part of the irradiated sensing material layer; and providing a vacuum chamber, which includes a movable substrate stage to fix the substrate; the step is characterized by: in the irradiation and Before the imaging step, a calibration system is used to calibrate the pattern generating device and the substrate on the substrate stage. The calibration system includes a driven part located in the vacuum chamber and an active part located outside the vacuum chamber.

In the manufacturing process using the lithographic projection device according to the present invention, a pattern in the mask is mapped to a substrate, and the substrate is at least partially covered by the irradiated sensing material (insulating paint). Before this imaging step, the substrate goes through different manufacturing processes, such as primer coating, insulating paint coating and soft baking. After exposure, the substrate undergoes other manufacturing processes, such as post-exposure bake (PEB), development, hard bake, and measurement/inspection of image microscopy. This process sequence is used as the basis for generating patterns for individual device layers, namely ICs. The patterned device layer will be subjected to various processes, such as etching, ion implantation (dense liquid treatment), metallization, mechanochemical polishing, etc. It is intended to complete another layer. If there are multiple layers, each layer must go through the entire process or its variants, and the final device array will be on the substrate (wafer). These devices are then separated from each other using cutting or sawing techniques, so individual devices can be mounted on a carrier and connected to pins, etc. More information on this process is revealed in "Microchip Fabrication: A Practical Guide to Semiconductor Processing" (Microchip Fabrication: A Practical Guide to Semiconductor Processing), third edition, authored by Peter van Zant, published by McGraw in 1997 Published by Hill Publishing Co., serial number is ISBN 0-07-067250-4.

Although the device according to the present invention is used in the manufacturing of ICs by referring to this article, we clearly understand that the device has many other possible uses, for example, it can be used in integrated optical systems, pattern guidance and detection of magnetic domain memory, liquid crystal Manufacturing of display panels, thin-film magnetic heads, etc. Skilled technicians recognize that in the other applications described in this article, the terms "wire", "wafer" or "mold" will be replaced by the more common terms "mask", "substrate" and "target area" respectively.

The terms "irradiation" and "beam" herein include all types of electromagnetic radiation or particle flux, which include but are not limited to ultraviolet (UV) irradiation (that is, the wavelength is 365, 248, 193, 157 or 126 nm), the limit Ultraviolet (EUV) irradiation, X-rays, electrons and ions.

The following description of the present invention will refer to specific embodiments and schematic drawings, in which: FIG. 1 is a lithography projection apparatus according to a first specific embodiment of the present invention; FIG. 2 is a plan view of a substrate according to a first specific embodiment of the present invention; FIG. 3 is The optical element diagram of the calibration system in the first embodiment of the present invention; Figure 4 is an enlarged view of the reference marks used in the first embodiment of the present invention; Fig. 5 is the vacuum diagram of the calibration system according to the second embodiment of the present invention Optical component diagram; and Figure 6 is a non-vacuum optical component diagram in the second embodiment of the present invention.

Similar parameters in the illustration indicate similar components.

Specific Example 1

Fig. 1 schematically shows the lithography apparatus according to the present invention. The apparatus includes: an irradiation system LA, EX, IN, CO, which generates an irradiated projection beam PB (that is, UV or EUV irradiation); a first object stage (mask Stage) MT, which has a mask fixing member to support a mask MA (that is, a network cable), and is connected to the first positioning device to accurately position the mask relative to the projection lens PL; a second object stage ( The substrate stage) WT has a substrate holder to support a substrate W (ie a silicon wafer covered with an insulating coating) and is connected to the second positioning device to accurately position the substrate relative to the projection lens PL; a projection lens PL (ie, refraction or refraction reflection system, a mirror group or field diverter array), which maps the irradiated part of the mask MA to the target part C of the substrate W.

As described here, the device is of a pass-through type (that is, it has a pass-through mask). However, it can also be reflective. For example, the irradiation system includes a light source LA (ie, Hg lamp, cutting laser, undulator that surrounds the electron beam path in a storage ring or synchrotron, plasma source or electron or ion beam source) , Which generates an illumination beam, which advances along the different optical elements in the illumination system, namely the beam imaging lens EX, the integrating lens IN and the condenser lens CO. Therefore, the combined beam PB has the required shape and shape in its cross-section. Intensity distribution.

The light beam PB will be in contact with the mask MA. The mask MA is supported by the mask holder on the mask table MT. The beam PB passes through the mask MA and then passes through the projection lens PL, which focuses the beam PB on the target of the substrate W On site C. With the assistance of the interference displacement measuring device IF and the second positioning device, the substrate table WT can accurately move to locate different target parts C in the path of the beam PB. Similarly, the interference displacement device IF and the first positioning device can be used to accurately position the photomask MA relative to the path of the light beam PB, which is after the photomask MA is mechanically retrieved from the photomask library. Generally speaking, the movement of the object table MT and WT is completed with the assistance of a long-stroke module (preliminary positioning) and a short-stroke module (fine-step positioning), which are not clearly shown in FIG. 1.

The device described in this article can be used in two different modes: 1. In the stepping mode, the mask stage MT must remain stationary with a single image of the entire mask (ie a single "flash") to the target site C, and then the substrate stage WT moves in the x and/or y direction, so the beam PB can illuminate different target parts C; 2. In the scan mode, basically the same method is used, except that the known target part is not exposed in a single "flash" . The mask table MT does not move at a speed v in a known direction (the so-called "scan direction", that is, the x direction), so the projection beam PB scans on the mask image; the substrate table WT is at the same or opposite direction at the same time Moving in the direction at a speed of V=Mv, where M is the magnification of the projection lens PL, and M is generally 1/4 or 1/5. At this time, a relatively large target part C can be exposed and the resolution quality is not reduced.

During the process of projecting the image from the mask to the target part C, the mask MA and the substrate W must be accurately aligned. As shown in FIG. 2, one or more marks M are placed on the mask MA.₁, M₂Relative to one or more corresponding reference marks M on the wafer table WT_RThe calibration can complete the accurate calibration, and then the position of the substrate stage relative to the photomask can be known. This calibration uses a projection (actinic) illumination and projection system to mark M₁, M₂Mapping to reference mark M_R, Mark the reference mark M_RIt can be the image detector on the substrate (wafer) table WT. The details of the image detector are not shown in the illustration. More information is disclosed in the European patent application No. 00202960.1, which is the description of this case. Listed by reference (applicant's reference code P-0203). The mask stage and/or wafer stage can move to a calibration position, which can be recorded with the assistance of the interference displacement measurement system IF. However, we can also use other methods for calibrating the mask MA and the substrate table WT.

In addition, the position of the substrate W with respect to the wafer table WT must be known in order to calibrate the substrate W with respect to the mask MA. The additional calibration system 10 of the specific embodiment of the present invention can be used to achieve this purpose. Use the calibration system 10 and move the wafer table WT, one or more marks P in the form of diffraction grating on the wafer and the wafer table₁, P₂, P will be calibrated with respect to the reference mark or grating 13 of the calibration system 10. The recording of the corresponding calibration position with the assistance of the interference displacement measuring device IF will generate the position of the wafer relative to the wafer table. Figure 2 shows the markings P and M on the wafer table WT_RLocated on the same plate, the plate is installed on the wafer table. This type of configuration sometimes represents an "off-axis" calibration system, in which part or all of the calibration process does not need to be completed on the main axis of the mechanism (the optical axis of the projection lens PL).

The wafer and wafer table WT are located in a vacuum chamber VC, which maintains a vacuum during the operation of the device. The calibration system 10 includes a driven part 10a inside the vacuum chamber VC and an active part 10b outside the vacuum chamber VC.

FIG. 3 shows the optical components of the calibration system 10. The driven part 10a in the vacuum chamber VC of the calibration system 10 includes three main areas; an irradiation part 20, an imaging part 30 and a detection part 40. The functions performed by these parts are: collimation and adjustment of the measurement beam 12; projection of the measurement beam 12 onto the wafer mark P and the diffracted radiation image onto the fixed reference grating 13; and separation and synthesis of the diffracted beam Therefore, it can be converted into electronic signals by the lithography control system for use. In this embodiment, the active part 10b outside the vacuum chamber VC is composed of the laser module 80 and the light sensor (not shown in the figure) in FIG. 3, so as to convert the secondary beam separated by the detection part into an electronic control Signal.

The laser module 80 includes a laser 81, which is a 10 mW HeNe laser and emits a light beam with a wavelength of 633 nm. The light beam first passes through the safety shutter 82, the Faraday isolator 90, the piezoelectric amplitude modulator 83, the polarized beam splitter 91 and the attenuator 84, which are used for control purposes. The safety shutter 82 completely blocks the laser beam when it is not needed, especially when the device has been opened for maintenance or for complete reasons. The Faraday isolator 90 can prevent reflections from any optical components in the system from being reflected back to the laser 81 and interfering with its operation, that is, causing frequency delay or mode bounce. The piezoelectric amplitude modulator 83 and the polarized beam splitter 91 are used in the frequency modulation-detection detection method to enhance the ratio of the detector signal to noise. The light beam is coupled in a single-mode polarization maintaining fiber 21, which is optimized by the fiber manipulation device 85 to irradiate the wavelength and enters the vacuum chamber. The laser module 80 also includes a laser power supply 86, an amplitude modulator driver 87 and a control electronics 88 in the same package.

In the irradiation part 20 located in the vacuum chamber VC, the measuring beam 12 leaves the fiber end piece 22, which includes a collimating lens to provide a collimated beam, which is focused on the imaging part 30 by a plano-convex lens 23 The center of the pupil plane. The first plate 24 located in front of the plano-convex lens 23 is used to adjust the measuring beam angle at the pupil of the imaging part 30, and then adjust the beam position at the wafer plane. This initial adjustment uses the XY translation output by the fiber lens To be completed. The second plate 25 is located behind the plano-convex lens 23 and is used to adjust the position of the pupil plane to process the measuring beam 12, and then to adjust the incident angle of the wafer plane. Finally, the 90 mirror 26 guides the measuring beam into the image portion 30.

After entering the image portion, the measuring beam is coupled along the optical axis (Z axis) by a tiny mirror 31, which is installed at the center of the first sequence aperture 32, the purpose of which will be disclosed later.

The image part is a 4-f bi-telecentric optical system with a magnification M=-1 and includes first and second air-spaced double lenses 33, 34. The air-spaced double lenses have a focal length of about 50 mm and are made of SF1. Since optical cements are not suitable for vacuum conditions, for example, simpler achromatic double lenses, it is better to use air-spaced double lenses. The gap accuracy of the individual lens in the double lens is the main determinant of the system performance and can be ensured by accurately machined ceramic spacer balls (the error of the radius is less than 1 μm), which can have a high degree of installation accuracy (i.e. gap). Vacuum suitability and thermal stability. SF1 is a heavy lead glass with a refractive index of about 1.7, which allows the lens to have an appropriate focal length and the radius of curvature will not be too large. The symmetry of the system reduces the aberration caused by the uncertainty in the refractive index of the SF1 glass. The lens should be made of the same batch of glass.

The first sequence aperture 32 and the receiving mirror 31 are installed between the first and second double lenses 33 and 34, so the measuring beam is collimated on the wafer mark P of the substrate W by the first double lens 33. The front mirror 35 enables the calibration system to be positioned at a convenient location, and the incident angle of the measuring beam 12 is perpendicular to the reference mark P. The front reflector 35 can be a Zerodur (TM) substrate with a metal cladding layer (with thermal stability), so as to effectively reflect the S-polarized illumination beam at an incident angle of 45 and the retro-diffraction sequence angle is less than about 54. The reflector can be installed on the Zerodur (TM) frame for better thermal stability.

The irradiated beam is reflected and diffracted at a specific angle in the XZ and YZ planes at the wafer mark P to form a diffraction sequence. The hole size of the first double lens 33 can be selected to be the fourth diffraction sequence at most, and the collimated sequence Focus in the rear focal plane. The parallel sequence passes through the aperture 32 of the first sequence, and its recesses only allow the first and fourth diffraction sequences 12a and 12b to pass. The linear polarizer 36 is used to remove the polarization of the sequences 12a and 12b. Because this phenomenon is slightly elliptical due to the front mirror 35, only the first sequence 12a can pass through the half-wave plate 37, so the linear polarization of the two sequences Separate at 90. The polarizer 36 is made of borosilicate glass with calibrated silver particles. It is an element suitable for vacuum and can effectively reduce the interference between the two beams. The half-wave plate 37 can be a quartz plate of appropriate thickness, which matches the single wavelength of the most measuring beam 12.

The second double lens 34 maps the first and fourth sequences 12a and 12b to the rear focal length plane. The fixed reference grating 13 is positioned in the focal length plane. The reference pattern of the reference grating 13 is derived from the wafer mark P A series of positive and negative sub-beams are formed by hard copies of chromium on the mirrored glass. During the XY movement of the wafer and the wafer table WT and the subsequent wafer mark P calibration process, all the images of the wafer mark at the reference pattern will move correspondingly, and the transmitted light will enter the detection part 40 and be applied Measure.

The light in the first series of light beams 12a will be diffracted at the reference grating 13 to form a diffraction sequence of the light beam, which is spatially separated from the beam formed by the diffraction sequence. The light in the fourth series of light beams 12b is in this Diffraction in the beam. The positive and negative sub-beam diffraction sequence of the first beam 12a and the positive and negative sub-beam diffraction sequence of the fourth beam 12b will overlap. In addition to the spatial separation, since the linear polarization states of the first series of beams 12a and the fourth series of beams 12b are separated by 90, the diffracted beams derived from the first series of beams 12a and the fourth series of beams 12b are The linear polarization state difference is 90. In the detection part 40, the diffracted light beam derived from the first series of light beams 12a and the diffracted light beam derived from the fourth series of light beams 12b are passed through the first and second polarizing beam splitters 41 and 42 and other serial apertures 43. And 44 are separated into first and second signal sub-beams 12c and 12d, respectively.

To accomplish this beam splitting, the beam diffracted by the reference grating 13 is collimated by the first lens 45 and then incident on the first polarized beam splitter 41, which allows the first sequence of beams 12a to be derived The diffracted light beam passes through and is deflected toward the diffracted light beam derived from the fourth sequence of light beams 12b. The diffracted light beam derived from the first series of light beams 12a will pass through the second series of aperture 43 (the diffracted light beams derived from the fourth series of light beams 12b have been blocked), and then are reflected by the second lens 46 on the four optical fiber groups or optical fibers On the bundle, it includes a first detection fiber group 47 installed in a fiber end piece 47a. The positioning of these fibers or fiber bundles corresponds to the four quadrants of the reference mark P described later.

The diffracted light beam derived from the fourth series of light beams 12b is refracted by the first polarized beam splitter 41 to the second polarized beam splitter 42, which turns through the third series of aperture 44, and only the diffracted light beams derived from the fourth series of light beams 12b After passing through the aperture 44, the third lens 48 maps the diffracted light beam to the second detecting fiber group 49 in the fiber end piece 49a.

When passing through the second beam splitter 42, the diffracted light beam is projected onto the attached fiber bundle 52 by the fourth lens 50 and the 90°-turned beam 51, which is installed in the terminal piece 52a. The formed image beam, the third signal sub-beam 12e, has the image of the reference grating 13.

The first, second, and third signal sub-beams 12c, 12d, and 12e use their corresponding detection fiber groups 47, 49, and 52 to leave the vacuum chamber. The first and second signal sub-beams pass the detector to complete the accurate measurement of the reference mark in the calibration scan procedure. The third signal sub-beam reaches the CCD camera to provide a visual indication for the device operator to calibrate.

Figure 4 is a view showing the four quadrants Pa, Pb, Pc, Pd of the wafer mark P. The configuration is such that the diagonally opposite quadrants Pa, Pc have raster lines parallel to the X axis, and the other two quadrants Pb, Pd have parallel The raster line of the Y axis.

Specific Example 2

5 and 6 show the second embodiment of the present invention. Most of the components are the same as those of the first embodiment and the parts not specifically disclosed below are similar to the corresponding parts of the first embodiment. For example, in the second embodiment, the laser module 80, the irradiating part 20 and the imaging part 30 are the same as those in the first embodiment. The main difference between the two embodiments is that the detection part 70 is located outside the vacuum chamber VC.

As shown in FIG. 5, in the second embodiment, the light passing through the reference grating 13 presents the combined image of the gratings Pa, Pb, Pc, Pd and the reference grating 13 and is collected by the fiber cone 60. As shown in FIG. 6, the fiber cone 60 enlarges its image and transmits it to the fiber bundle 61 and leaves the vacuum chamber to reach the detection part 70. The fiber ends become smaller in the fiber cone and packed together, so the image will be enhanced as it passes through the fiber bundle.

The fiber bundle 61 terminates at the end piece 62 and radiates the combined image signal through the window 63 in the wall of the vacuum chamber VC. The combined image is projected on the other side of the vacuum wall by lenses 71, 72 on a known type of light 2 The polar body detector 73 includes a preamplifier and provides electronic calibration signals required by the device control system. The photodiode detector 73 has four quadrants to individually detect the four gratings Pa, Pb, Pc, Pd and the reference grating 13 of the wafer. In order to provide the operator with a visual indication of calibration, a part of the combined image signal is redirected by the polarized beam splitter 74 located between the lenses 71 and 72. This beam is focused by the lens 75 on the crosshair reference at the focal length of the lens 77 Then the beam is focused on the CCD camera 78. To facilitate the configuration of the components of the detection part 70, the corner ridge 79 is located behind the lens 75 so that the orientation of the camera is parallel to the signal.

6 shows how the light from the laser module 80 reaches the window 64 in the wall of the vacuum chamber through the fiber 89, and the light passes through the window to the polarization maintaining fiber 21 and is guided to the irradiated part of the vacuum chamber.

In the modification of the second embodiment, the first and fourth series of light beams can be separated and individually detected outside the vacuum chamber VC to achieve better alignment accuracy, so that the fiber bundle 61 can maintain polarization.

Although the specific embodiments of the present invention have been disclosed above, we understand that the present invention can still be disclosed in different specific embodiments. The description herein does not limit the present invention, and we understand that the present invention can be applied to the substrate and/or photomask stage of the lithography device.

<p>10Calibration system</p><p>10aDriven part</p><p>10bActive part</p><p>12Measuring beam</p><p>12aFirst diffraction sequence</p><p>12bFourth Diffraction Sequence</p><p>12cThe first signal sub-beam</p><p>12dsecond signal sub-beam</p><p>12eThird signal sub-beam</p><p>13Reference grating</p><p>20Illuminated part</p><p>21Polarization maintaining fiber</p><p>22Fiber End Piece</p><p>23Plano-Convex Lens</p><p>24First plate</p><p>25Second plate</p><p>26Mirror</p><p>30Image part</p><p>31Mirror</p><p>32First serial aperture</p><p>33First air-spaced double lens</p><p>34Second Air Spaced Double Lens</p><p>35Front mirror</p><p>36Linear Polarizer</p><p>37Half wave plate</p><p>40Detection part</p><p>41First Polarized Beam Splitter</p><p>42Second Polarized Beam Splitter</p><p>43Second serial aperture</p><p>44The third serial aperture</p><p>45First lens</p><p>46Second lens</p><p>47First detection fiber group</p><p>47aFiber End Piece</p><p>48Third lens</p><p>49Second Detecting Fiber Group</p><p>49aFiber End Piece</p><p>50Fourth lens</p><p>51</p><p>52Detect fiber group</p><p>52aTerminal pieces</p><p>60Fiber cone</p><p>61Fiber Bundle</p><p>62Terminal pieces</p><p>63Window</p><p>64Window</p><p>70Detection part</p><p>71Lens</p><p>72Lens</p><p>73Optical diode detector</p><p>74Polarized beam splitter</p><p>75Lens</p><p>76Cross wire reference</p><p>77Lens</p><p>78CCD camera</p><p>79Edge corner</p><p>80Laser Module</p><p>81Laser</p><p>82Safe Shutter</p><p>83Piezoelectric amplitude modulator</p><p>84Attenuator</p><p>85Fiber control device</p><p>86Laser Power Supply</p><p>87Amplitude Modulator Driver</p><p>88Control electronics</p><p>89Fiber</p><p>90Faraday Isolator</p><p>91 Polarized beam splitter</p><p>CTarget part</p><p>COCondenser lens</p><p>EXBeam imaging lens</p><p>IFInterference displacement measuring device</p><p>INIntegrated lens</p><p>LALight source</p><p>M₁mark</p><p>M₂mark</p><p>MAmask</p><p>MTThe first object table (mask table)</p><p>M_RReference mark</p><p>Pmark</p><p>P₁mark</p><p>P₂mark</p><p>PBBeam</p><p>PLProjection lens</p><p>PaQuadrant/Grating</p><p>PbQuadrant/Grating</p><p>PcQuadrant/Grating</p><p>PdQuadrant/Grating</p><p>VCVacuum Chamber</p><p>WSubstrate</p><p>WTSecond object table (substrate table/wafer table)</p>