Stage device, charged particle beam device and vacuum device

Abstract

To provide a stage device that can properly position an object.SOLUTION: A stage device 10 is provided with a fixing portion 20 including a top plate 22 containing a magnetic material, a bottom plate 26 facing the top plate 22, and a plurality of coils 28 provided on the upper surface of the bottom plate 26, and a moving portion 100 including a support portion 101 that supports an object 160 to be positioned, a plurality of first magnets 141 mounted on the upper surface of the support portion 101, facing the top plate 22, and generating first thrust FA against the top plate 22, and a plurality of second magnets 105 provided on the lower surface of the support portion 101, facing the coil 28, and generating second thrust FB with the coil 28.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a stage apparatus, a charged particle beam apparatus, and a vacuum apparatus. [Background technology]

[0002] As background art of the technical field, the abstract of the following Patent Document 1 discloses a moving device (701) having a first part with a carrier (714) for use in the semiconductor industry, in which magnet systems (710) are arranged according to a row and column pattern extending parallel to the X and Y directions. The magnets in each row and column are arranged according to a Hallbach array, i.e., the magnetic orientation of successive magnets in each row and each column is rotated 90 degrees counterclockwise. The second part has an electric coil system (712) with two types of electric coils, one type having an angular offset of 45° and the other type having an offset of −45° with respect to the X direction. The first part (714, 710) is movable relative to the stationary second part (712) over a range of the order of centimeters or more. For high-precision positioning of the first part, an interferometer system (731, 730) is provided. The disclosure of this document is incorporated herein by reference. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2008-527964 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned technology, there is a demand for more appropriate positioning of the object. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a stage device, a charged particle beam device, and a vacuum device that are capable of appropriately positioning an object. [Means for solving the problem]

[0005] In order to solve the above problems, the stage device of the present invention includes a fixed section having a top plate including a magnetic body, a bottom plate facing the top plate, and a plurality of coils provided on an upper surface of the bottom plate; a support section supporting an object to be positioned, a movable section having a plurality of first magnets attached to the upper surface of the support section and facing the top plate to generate a first thrust force against the top plate, and a plurality of second magnets provided on the lower surface of the support section and facing the coils to generate a second thrust force between the magnets and the coils; a magnetic shield provided on a lower surface of the support portion around the second magnet and having a width 1.0 times or more the width of the coil; The present invention is characterized by comprising: Effect of the Invention

[0006] According to the present invention, the object can be appropriately positioned. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic cross-sectional view of a magnetic levitation planar stage device according to a first embodiment. [Diagram 2] 4 is a schematic plan view of the movable part as viewed from the Z-axis direction. FIG. [Diagram 3] FIG. 2 is a diagram showing the positional relationship between a movable portion and an electro-optical system device. [Figure 4] 13A and 13B are diagrams illustrating other arrangement relationships between the movable portion and the electro-optical device. [Diagram 5] FIG. 11 is a schematic cross-sectional view of a magnetic levitation planar stage device according to a second embodiment. [Figure 6] FIG. 11 is a schematic cross-sectional view of a semiconductor measuring device according to a third embodiment. [Figure 7] FIG. 1 is a schematic cross-sectional view of a magnetic levitation planar stage device according to a first comparative example. [Figure 8] FIG. 11 is a schematic cross-sectional view of a magnetic levitation planar stage device according to a second comparative example. [Figure 9] 13 is another schematic cross-sectional view of the magnetic levitation planar stage device according to the second comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] [Outline of the embodiment] Conventionally, there has been known technology relating to a magnetically levitated planar stage for accurately positioning and supporting a device stage and a wafer applied to an exposure apparatus or the like. This is a magnetically levitated planar stage mechanism that moves a device relative to a mounting base. This conventional magnetically levitated planar stage mechanism has a coil mounted on the levitating movable table side, and a magnet array with magnets regularly arranged on the fixed base side. To maintain levitation, it is necessary to constantly support the gravity of the movable part, and this force is provided by the Lorentz force obtained by passing a current through the coil.

[0009] In particular, in this method, the coil, which is a heating element, is installed on the levitation side. Therefore, if a chuck for supporting a sample or device such as a wafer with a certain mass is mounted on the movable table, the mass of the movable table increases, and the heat generated by the coil due to gravity support increases. To prevent the coil from burning out due to this, measures such as supplying a coolant to the coil and the parts around the coil are required, and the deterioration of the driving characteristics due to the resistance of the coolant piping becomes a problem. In addition, the leakage magnetic field from the densely packed magnet array is large, making it difficult to install it on charged particle beam equipment.

[0010] On the other hand, by applying the technology of Patent Document 1, it is thought that a magnetically levitated planar stage with a magnet on the movable side and a coil on the fixed side can be realized. In this method, since the coil is the fixed side, no refrigerant piping is required for the movable part, and the problem of deterioration of the driving characteristics is solved. However, even in this case, a large current needs to be continuously passed through the coil array in order to constantly support the gravity of the movable part. Here, if the magnet is in a positional relationship where it cannot cover the energized coil, there is a problem that the leakage magnetic field from the coil reaches the upper side, that is, near the charged particle beam. In addition, in this device, in order to support gravity, a large thrust force is constantly generated in the vertical direction. Therefore, due to the limitation of the dynamic range of the current amplifier that supplies current to the coil, the current noise becomes large, and the noise in the coil current causes minute thrust fluctuations, leading to vibration of the movable part.

[0011] Incidentally, in processes such as manufacturing, measuring, and inspecting semiconductor wafers, stage devices such as those described above are used to accurately position the semiconductor wafers. In such stage devices, there is a demand for improved positioning accuracy of the semiconductor wafers. However, the above-mentioned conventional stage devices have problems such as deterioration of drive characteristics due to water-cooling piping and minute vibrations due to the dynamic range of the current amplifier, making it difficult to improve positioning accuracy.Furthermore, there is a problem of magnetic leakage, making it difficult to apply them to charged particle beam devices. Therefore, the embodiments described below provide a stage device, a charged particle beam device, and a vacuum device that can improve the positioning accuracy and suppress leakage of the magnetic field.

[0012] [First embodiment] Configuration of the First Embodiment FIG. 1 is a schematic cross-sectional view of a magnetic levitation planar stage device 10 (stage device) according to the first embodiment. 1, the magnetic levitation planar stage device 10 includes a fixed part 20, a movable part 100, and a controller 40. The fixed part 20 is formed in a substantially rectangular box shape, and includes a top plate 22, a side wall 24, and a bottom plate 26. The top plate 22 and the bottom plate 26 are formed in a rectangular plate shape, and are disposed opposite each other in the up-down direction, i.e., the Z direction. The side wall 24 is disposed along the periphery of the top plate 22 and the bottom plate 26, and is fixed to the top plate 22 and the bottom plate 26.

[0013] A cylindrically cut-out insertion hole 22a (through hole) is formed in the approximate center of the top plate 22. In the illustrated example, a roughly cylindrical electron optical system device 60 is inserted into the insertion hole 22a. The electron optical system device 60 emits an electron beam EB (charged particle beam).

[0014] A plurality of coils 28 are arranged on the upper surface of the bottom plate 26. The coils 28 are formed in a rectangular plate shape and are arranged two-dimensionally along the X direction and the Y direction. The coils 28 may be those described in the above-mentioned Patent Document 1. The top plate 22 is made of a magnetic material processed into a plate shape. However, the entire top plate 22 does not need to be made of a magnetic material, and it is sufficient that at least a part of the top plate 22 is made of a magnetic material, for example, the lower surface of the top plate 22 is made of a magnetic material.

[0015] The movable part 100 moves in the internal space of the fixed part 20, and includes a top table 101 (support part), a bar mirror 102, an electrostatic chuck 103, a magnet 105 (second magnet), a magnetic shield 125, a magnet support base 140, a magnet 141 (first magnet), and a displacement sensor 143 (position sensor). The top table 101 is formed in a rectangular plate shape (see FIG. 2). The bar mirror 102 and the electrostatic chuck 103 are fixed to the upper surface of the top table 101. Here, the electrostatic chuck 103 is formed in a disk shape, and adsorbs an object 160 such as a sample (see FIG. 2) to the upper surface thereof. In the illustrated example, the object 160 is formed in a disk shape.

[0016] In the illustrated example, the magnet support base 140 is fixed to the upper surface of the four corners of the top table 101. A magnet 141 and a displacement sensor 143 are disposed on the upper surface of the magnet support base 140. The magnet 141 is, for example, a permanent magnet. The magnet 141 generates a thrust force FA (first thrust force) by magnetic attraction force against the top board 22, at least a portion of which is a magnetic body. Here, the dimensions and magnetic field strength of the magnet 141 may be determined so that the thrust force FA and the gravity force FD acting on the movable part 100 are balanced when the movable part 100 is at an appropriate predetermined height.

[0017] A plurality of rectangular plate-shaped magnets 105 are attached to the center of the lower surface of the top table 101 so as to face the coil 28. A magnetic shield 125 is arranged to surround the periphery of these magnets 105. The magnetic shield 125 prevents the leakage magnetic field BL generated by the coil 28 from moving above the top table 101. For example, when the magnetic levitation planar stage device 10 is part of an electron microscope, distortion of the trajectory of the electron beam EB causes out-of-focus and misalignment in the observed image. In this embodiment, the provision of the magnetic shield 125 makes it possible to prevent problems such as out-of-focus and misalignment.

[0018] The coil 28 and the magnet 105 repel each other due to the Lorentz force, generating an upward thrust FB (second thrust) on the movable part 100, and functioning as an elevator that raises and lowers the movable part 100 in the vertical direction (Z direction). Furthermore, the coil 28 and the magnet 105 also function as a two-dimensional linear stepping motor that moves the movable part 100 in the horizontal directions (X direction and Y direction).

[0019] As described above, the dimensions of magnet 141 should be determined so that thrust FA and gravity FD are balanced when movable part 100 is at a predetermined height. In addition, magnet 141 should be shielded with a magnetic material (not shown) or the like. This makes it possible to form a magnetic circuit in which a magnetic field is generated only between magnet 141 and a part of the top plate, thereby suppressing the effect on electron beam EB.

[0020] However, it is difficult to stabilize the height of the movable part 100 using only the magnet 141 and the top plate 22. Therefore, it is advisable to bias the magnet 105 in the Z direction by supplying a current to the coil 28 to adjust the minute imbalance of the gravitational support. In addition, the height of the movable part 100 can be stabilized by compensating for the pitching moment during acceleration and deceleration.

[0021] This makes it possible to extremely reduce the thrust force FB in the Z direction that needs to be generated by the magnet 105 and the coil 28, and eliminates the need to pass a large current for supporting gravity through the coil 28. In other words, it becomes possible to extremely reduce the leakage magnetic field BL that is generated from the coil 28 when current is flowing.

[0022] In addition, since a displacement sensor 143 is mounted near the magnet 141, the relative distance between the magnet 141 and the top plate 22 can be measured, thereby enabling measurement and control of the attitude of the movable part 100. Furthermore, since a magnetic shield 125 is disposed around the multiple magnets 105 on the underside of the top table 101, the weak leakage magnetic field BL generated from the multiple coils 28 can be shielded and its influence can be further suppressed. Note that the width LM of the magnetic shield 125 is preferably 0.5 times or more the width of the coil 28, and more preferably 1.0 times or more the width of the coil 28.

[0023] The controller 40 includes a position command unit 42, a position detection unit 44, a current command unit 46, and a current amplifier 48. The position command unit 42 outputs a command value for the position of the movable part 100, i.e., command values ​​for the coordinates in the X, Y, and Z directions, based on a measurement plan for the target object 160. The position detection unit 44 outputs the measurement results of the actual position of the movable part 100, i.e., the coordinate values ​​in the X, Y, and Z directions. The current command unit 46 outputs a current command value that commands a current to be passed through each coil 28, based on the deviation between the command value for the position of the movable part 100 and the measurement results of the actual position. The current command value is an analog signal. The current amplifier 48 amplifies the current command value and supplies it to each coil 28.

[0024] Here, problems that may arise due to the current amplifier 48 will be described. The current amplifier 48 has a dynamic range that is restricted by the performance limit of the elements (not shown) of the current control circuit mounted thereon. The larger the maximum output current of the current amplifier 48, the larger the noise contained in the output current, and the larger the output current, the larger the noise contained in the output current. When this current noise is input to the coil 28, a minute fluctuation in thrust occurs, which leads to a minute vibration of the movable part 100. For example, when the coil 28 constantly generates a large thrust in the Z direction, minute vibrations in the Z direction are constantly generated in the movable part 100. Such minute vibrations of the movable part 100 deteriorate the positioning resolution and cause deterioration of the positioning accuracy.

[0025] In particular, when independent noise occurs in the Z-direction thrust in each of the multiple coils 28, this leads to vibration in attitude control around the X-axis and the Y-axis, and the positioning accuracy in the XY directions also deteriorates. In this embodiment, the Z-direction thrust that the coils 28 should generate to support the mass of the movable part 100 can be reduced, and therefore the output current of the current amplifier 48 can also be reduced. This makes it possible to suppress the noise components output from the current amplifier 48, and therefore to suppress the micro-vibrations generated in the movable part 100, thereby improving the positioning accuracy of the movable part 100.

[0026] Fig. 2 is a schematic plan view of the movable part 100 as viewed from the Z-axis direction. In order to prevent the drawings from becoming complicated, the magnet support base 140, the displacement sensor 143, etc. are omitted from Figs. 2 to 4. 2, two bar mirrors 102 are arranged on the upper surface of a top table 101. These bar mirrors 102 are provided to measure the position of the movable part 100 by a laser interferometer (not shown). This laser interferometer is included in the position detection unit 44 (see FIG. 1) of the controller 40. The laser interferometer irradiates these bar mirrors 102 with a pair of laser optical axes LA. The laser interferometer is arranged so that the intersection of these laser optical axes LA coincides with the irradiation point of the electron beam EB.

[0027] As described above, it is preferable to place the magnets 141 at the four corners of the top table 101 as shown in the figure so as not to block the laser optical axis LA. Furthermore, when replacing the target object 160, it is convenient if the target object 160 can be taken in and out from the negative side in the Y direction. Therefore, for this reason as well, it is preferable to place the magnets 141 at the four corners of the top table 101.

[0028] FIG. 3 is a diagram showing the positional relationship between the movable portion 100 and the electro-optical system device 60. As shown in FIG. As described above, the electro-optical system device 60 is formed in a substantially cylindrical shape, with its radius being Re (second radius). The target object 160 is formed in a substantially disk shape, with its radius being Rw (first radius). In order not to distort the trajectory of the electron beam EB, it is preferable that the magnets 141 are positioned outside the electro-optical system device 60 in a plan view when the target object 160 is irradiated with the electron beam EB. In other words, it is preferable that the interval L between the magnets 141 satisfies the relationship of the following formula (1). L ≧ √2×(Re+Rw) …Equation (1)

[0029] Therefore, in designing the movable part 100, it is preferable to determine the arrangement of the magnet 141 so as to satisfy the relationship of the above formula (1). Furthermore, depending on the type of electro-optical device 60, there may be cases where minute magnetization by the magnet 141 becomes a problem. Therefore, when moving the movable part 100, the controller 40 may control the movable part 100 so as to adopt a moving trajectory in which the magnet 141 does not overlap the range of the electro-optical device 60 at all times.

[0030] FIG. 4 is a diagram showing another arrangement relationship between the movable portion 100 and the electro-optical device 60. In FIG. In the illustrated state, the magnet 141 for attraction overlaps with the electro-optical device 60 in a plan view. When the electron beam EB is not being irradiated due to reasons such as replacement of the target object 160, it is assumed that the arrangement relationship shown in the figure will be obtained. As shown in FIG. 1, the electro-optical device 60 is inserted into the insertion hole 22a formed in the top plate 22. Therefore, in FIG. 4, the magnet 141 in the upper right corner is located within the range of the insertion hole 22a, that is, in the range where the top plate 22 does not exist. As a result, no thrust force FA (see FIG. 1) is generated between the magnet 141 in the upper right corner of FIG. 4 and the top plate 22.

[0031] In such a case, the controller 40 may increase the current supplied to the coil 28 to generate a large thrust force FB (see FIG. 1) in the Z direction, thereby supporting the gravity FD of the movable part 100. As described above, when the current flowing through the coil 28 is increased, minute vibrations in the Z direction may occur in the movable part 100. However, when the object 160 is not being measured by the electron beam EB, the occurrence of minute vibrations in the movable part 100 often does not pose any particular problem.

[0032] [Second embodiment] 5 is a schematic cross-sectional view of a magnetic levitation planar stage device 12 (stage device) according to the second embodiment. In the following description, the same reference numerals are used to designate parts corresponding to the respective parts of the first embodiment described above, and the description thereof may be omitted. 5, the magnetic levitation planar stage device 12, like that of the first embodiment (see FIG. 1), comprises a fixed part 20, a movable part 100, and a controller 40. Also in this embodiment, the fixed part 20 is formed in a substantially rectangular box shape, and comprises a top plate 22, a side wall 24, and a bottom plate 26.

[0033] However, in the top plate 22 of this embodiment, instead of the insertion hole 22a shown in FIG. 1, an insertion hole 22b (through hole) tapered into an inverted cone shape is formed. In other words, by forming an acute edge on the inner circumference of the insertion hole 22b, the decrease in suction force is made gentle. In this embodiment, too, an electro-optical device 60 (see FIG. 1) is inserted through the insertion hole 22b. In addition, an optical microscope 64 is attached to the top plate 22 at a location away from the insertion hole 22b. The configuration of this embodiment other than that described above is the same as that of the first embodiment (see FIG. 1).

[0034] When the movable part 100 is in the illustrated position, the top plate 22 is not present above the right-side magnet 141, and therefore the gravity on the right side of the movable part 100 is not compensated for by the magnet 141. Therefore, the controller 40 switches the control state so that the Z-direction thrust FB2 of the coil 28 also compensates for the gravity component. Thereafter, when the movable part 100 moves and the magnet 141 is again directly below the magnetic material of the top plate 22, the controller 40 switches the control state so that the gravity compensation component is not added to the Z-direction thrust command value.

[0035] 5, the gravitational force of the movable part 100 is supported by the thrust generated by the coil 28, so that the leakage magnetic field BL2 from the coil 28 at the lower right side of the movable part 100 becomes large. As a result, the leakage magnetic field BL2 wraps around to above the movable part 100. However, in the position of FIG. 5, the electron optical system device 60 (see FIG. 1) is not irradiating the electron beam EB, so this condition is often not a particular problem.

[0036] However, even when the electron beam EB is not irradiated, for example, when the object 160 is observed with the optical microscope 64, there may be cases where the vibration of the movable part 100 needs to be suppressed to some extent. Therefore, in this embodiment, as described above, an acute edge is formed on the inner circumference of the insertion opening 22b. This makes it possible to make the decrease in magnetic attraction force gentle when the magnet 141 enters the area of ​​the insertion opening 22b. This makes it possible to prevent abrupt fluctuations in the Z-direction thrust FB2 by the coil 28, and to suppress the vibration of the movable part 100 even when the controller 40 switches the control of the Z-direction thrust.

[0037] [Third embodiment] 6 is a schematic cross-sectional view of a semiconductor measuring device 900 according to a third embodiment. In the following description, the same reference numerals are used to designate parts corresponding to those in the other embodiments described above, and the description thereof may be omitted. The semiconductor measuring device 900 (stage device, vacuum device, charged particle beam device) is a charged particle beam device in that it irradiates the object 160 with an electron beam, i.e., a charged particle beam, and is a vacuum device in that it maintains a vacuum around the object 160. The semiconductor measuring device 900 is, for example, a length measuring SEM which is an application device of a scanning electron microscope (SEM).

[0038] In FIG. 6, the semiconductor measuring device 900 includes a vacuum chamber 901 (fixed portion), an electron optical system barrel 902 (charged particle beam emitting portion), a vibration control mount 903, a laser interferometer 904, a controller 905, and a stage device 910 (movable portion).

[0039] The vacuum chamber 901, like the fixed part 20 in the first and second embodiments, includes a top plate 22, a side wall 24, a bottom plate 26, and a coil 28. Furthermore, the vacuum chamber 901 includes a vacuum pump 29 that reduces the pressure in the internal space surrounded by the top plate 22, the side wall 24, and the bottom plate 26 to create a vacuum state. Here, the "vacuum state" refers to a state in which the pressure is at least lower than atmospheric pressure.

[0040] The electron optical system barrel 902 is similar to the electron optical system device 60 in the first and second embodiments in that it irradiates an electron beam onto the object 160. Furthermore, the electron optical system barrel 902 has a function of capturing an image of a pattern on the surface of the object 160, measuring the line width of the pattern, and evaluating the shape accuracy. The object 160 is, for example, a semiconductor wafer. The vibration-damping mount 903 supports the vacuum chamber 901 and attenuates vibrations from the floor surface.

[0041] Stage device 910 is configured similarly to movable section 100 (see FIGS. 1 to 5) in the first and second embodiments. Laser interferometer 904 measures the position of bar mirror 102 attached to stage device 910. Controller 905 is configured similarly to controller 40 in the first and second embodiments. In this way, controller 905 positions object 160, such as a semiconductor wafer, held by electrostatic chuck 103 of stage device 910.

[0042] The semiconductor measuring apparatus 900 of this embodiment includes the stage device 910, which can improve the positioning accuracy of the target object 160 such as a semiconductor wafer and can suppress leakage of a magnetic field. Therefore, the measurement accuracy of the semiconductor measuring apparatus 900 as a charged particle beam device can be improved. In addition, since the levitation mechanism of the stage device 910 is a magnetic levitation type, it is easily applied to the semiconductor measuring apparatus 900, which is a vacuum device, and can exhibit excellent effects such as reducing contamination and suppressing heat generation.

[0043] [Comparative Example] First Comparative Example Next, in order to clarify the effects of each of the above-mentioned embodiments, various comparative examples will be described. In the following description, the same reference numerals will be used to designate parts corresponding to the respective parts of the above-mentioned embodiments, and the description thereof may be omitted. FIG. 7 is a schematic cross-sectional view of a magnetic levitation planar stage device 70 according to a first comparative example. The magnetic levitation planar stage device 70, like that of the first embodiment (see FIG. 1), comprises a fixed part 20, a movable part 100, and a controller 40 (see FIG. 1). Also in this comparative example, the fixed part 20 is formed in a substantially rectangular box shape, and comprises a top plate 22 (see FIG. 1), a side wall 24 (see FIG. 1), and a bottom plate 26. However, in FIG. 7, only a part of the bottom plate 26 is illustrated.

[0044] In this comparative example, a plurality of magnets 105 are arranged on the upper surface of the bottom plate 26. The magnets 105 are formed in a rectangular plate shape and are arranged two-dimensionally along the X direction and the Y direction. Meanwhile, a plurality of coils 28 are attached to the lower surface of the top table 101. Thus, in this comparative example, the arrangement of the coils 28 and the magnets 105 is reversed from that in the first embodiment. In this comparative example as well, a thrust force FC due to the Lorentz force is generated between the coils 28 and the magnets 105 by passing a current through the coils 28. However, in this comparative example, there is no magnet corresponding to the magnet 141 (see FIG. 1) in the first embodiment, and this thrust force FC is balanced with the gravity FD of the movable part 100.

[0045] Here, when the mass of movable part 100 is large or when the device is in a vacuum environment and there is no heat transfer to the air, it becomes necessary to prevent the coil 28 from burning due to heat generation from the coil 28 and the top table 101 from thermal deformation due to a rise in temperature. Therefore, in this comparative example, a refrigerant pipe 107 is attached to the movable part 100. A refrigerant is supplied to the coil 28 and the top table 101 through this refrigerant pipe 107 to cool them.

[0046] However, in this comparative example, a problem occurs in that the resistance of the refrigerant pipes 107 deteriorates the driving characteristics of the movable part 100. In particular, in the magnetic levitation planar stage device 70 configured to eliminate other friction disturbances such as rolling guides (not shown), the effect of the resistance of the refrigerant pipes 107 becomes noticeable.

[0047] Furthermore, in this comparative example, there is also a problem that the influence of the leakage magnetic field BM generated by the magnet 105 becomes large. In the configuration of Fig. 7, the magnets 105 are arranged along the entire movable range of the movable part 100, and the magnetic circuit is not closed in the upward direction, so the leakage magnetic field BM becomes large. This leakage magnetic field BM increases the adverse effect on the electron beam EB irradiated from the electro-optical device 60 (see Fig. 1) and the like.

[0048] Furthermore, in this comparative example, there is also a problem that the influence of noise generated by the current amplifier 48 becomes large. As described above, the magnitude of the noise generated by the current amplifier 48 becomes larger as the maximum output current becomes larger and as the output current becomes larger. In this comparative example, in order to balance the thrust FC generated by the coil 28 and the gravity FD of the movable part 100, it becomes necessary to pass a large current through the coil 28, which increases the noise generated by the current amplifier 48. If the movable part 100 vibrates slightly due to this noise, the positioning resolution of the movable part 100 deteriorates, and the positioning accuracy of the movable part 100 also deteriorates.

[0049] Second Comparative Example FIG. 8 is a schematic cross-sectional view of a magnetic levitation planar stage device 80 according to a second comparative example. The magnetic levitation planar stage device 80 includes a fixed part 20, a movable part 100, and a controller 40 (see FIG. 1), similar to that of the first embodiment (see FIG. 1). Also in this comparative example, the fixed part 20 is formed in a substantially rectangular box shape, and includes a top plate 22 (see FIG. 1), a side wall 24 (see FIG. 1), and a bottom plate 26. However, only a part of the bottom plate 26 is illustrated in FIG. 8. Also, the coils 28-1 to 28-4 in the figure are similar to the coils 28 in the first embodiment, and these coils 28-1 to 28-4 may be collectively referred to as "coils 28."

[0050] In this comparative example, the positional relationship between the coil 28 and the magnet 105 is the same as that in the first embodiment (see FIG. 1), and is the opposite of that in the first comparative example (see FIG. 7). FIG. 8 shows a state in which the coils 28-2, 28-3 and the two magnets 105 face each other in a one-to-one relationship. In this comparative example, the gravity FD of the movable part 100 is supported by the thrust force FC generated by the coil 28. Here, since the coil 28, which is a heating element, is provided on the bottom plate 26, it is not necessary to connect the refrigerant pipe 107 (see FIG. 7) to the movable part 100. Therefore, in this comparative example, the problem of the refrigerant pipe 107 acting as a resistance to the movable part 100 does not occur.

[0051] Furthermore, the magnetic circuit formed by magnet 105 and coils 28-2, 28-3 mainly forms a magnetic field below top table 101, so there is less leakage magnetic field BL into the space above top table 101. However, even in this comparative example, in order to support gravity FD, it is necessary to pass a large current through coils 28-2, 28-3 facing magnet 105, which intensifies the leakage magnetic field BL.

[0052] However, in the illustrated state, since the magnet 105 is located above the coils 28-2 and 28-3, the leakage magnetic field BL is unlikely to reach the path of the electron beam EB. This makes it possible to suppress the effect of the leakage magnetic field BL on the electron beam EB. However, since it is necessary to pass a large current through the coils 28-2 and 28-3 to support the gravity FD of the movable part 100 as described above, the problem of micro-vibrations due to the constraints on the dynamic range of the current amplifier 48 is not solved in this comparative example.

[0053] FIG. 9 is another schematic cross-sectional view of the magnetic levitation planar stage device 80 according to the second comparative example. 9 is a state in which the movable part 100 is moved in the X direction by 1 / 2 the width of the coil 28 with respect to the state in FIG. 8. In this arrangement, it becomes necessary to pass a large current through the coils 28-2, 28-3, and 28-4 in order to support the gravity FD of the movable part 100. However, in the illustrated positional relationship, part of the upper surfaces of the coils 28-2 and 28-4 are not covered by the magnet 105.

[0054] Therefore, the leakage magnetic field BL that extends beyond the magnet 105 reaches the vicinity of the electron beam EB above the target object 160, distorting the electron beam EB. As a result, for example, when the magnetic levitation planar stage device 80 is applied to an electron microscope, the observed image will be out of focus or out of position. Also, even in the positional relationship of FIG. 9, it is necessary to increase the thrust FC in the Z direction so that the thrust FA of the movable part 100 can be supported. Therefore, the problem of micro-vibrations caused by the constraints of the dynamic range of the current amplifier 48 is not solved even in the positional relationship of FIG. 9.

[0055] [Effects of the embodiment] As described above, according to the embodiment, the stage device (10, 12, 900) comprises a fixed part (20, 901) having a top plate 22 containing a magnetic material, a bottom plate 26 facing the top plate 22, and a plurality of coils 28 provided on the upper surface of the bottom plate 26, a support part (101) supporting an object 160 to be positioned, and a movable part 100, 910 having a plurality of first magnets (141) attached to the upper surface of the support part (101) facing the top plate 22 and generating a first thrust force (FA) against the top plate 22, and a plurality of second magnets (105) provided on the lower surface of the support part (101), facing the coil 28, and generating a second thrust force (FB) between the coil 28 and the first magnets (141).

[0056] As a result, the movable parts 100, 910 can be supported by the first thrust (FA) and the second thrust (FB), so the second thrust (FB) can be made smaller than when there is no first thrust (FA). This makes it possible to reduce the current flowing through the coil 28, so that the target object 160 can be appropriately positioned.

[0057] Furthermore, when the object 160 is disk-shaped with a predetermined first radius (Rw) and a cylindrical electro-optical device 60 with a second radius (Re) faces the object 160, it is more preferable that the multiple first magnets (141) are spaced apart at intervals that are √2 times or more the sum of the first radius (Rw) and the second radius (Re). This allows the electro-optical device 60 and the first magnet (141) to be sufficiently spaced apart even when the peripheral portion of the object 160 is being measured by the electro-optical device 60.

[0058] It is more preferable to provide a magnetic shield 125 around the second magnet (105) on the lower surface of the support part (101). This makes it possible to shield the weak leakage magnetic field BL generated from the coil .

[0059] It is even more preferable that the width LM of the magnetic shield 125 is at least 0.5 times the width of the coil 28. This makes it possible to more reliably shield the weak leakage magnetic field BL generated from the coil 28.

[0060] Moreover, it is more preferable that the stage device (10, 12, 900) further includes a position sensor (143) that measures the distance between the movable part 100, 910 and the top board 22. This makes it possible to determine an appropriate current value to be supplied to the coil 28 based on the measurement result of the position sensor (143).

[0061] It is further preferable that the top plate 22 has a through hole (22b) having a tapered peripheral surface, which can smooth out fluctuations in the first thrust force (FA) when the first magnet (141) moves to a position facing the through hole (22b).

[0062] Furthermore, when the top plate 22 has the through holes (22a, 22b), it is more preferable to further provide a controller 40 that controls the current supplied to the coil 28 so as to increase the second thrust (FB) when any of the first magnets (141) faces the through holes (22a, 22b). This makes it possible to maintain the posture of the movable parts 100, 910 within an appropriate range even when the first magnet (141) faces the through holes (22a, 22b).

[0063] [Variations] The present invention is not limited to the above-mentioned embodiment, and various modifications are possible. The above-mentioned embodiment is exemplified to explain the present invention in an easy-to-understand manner, and is not necessarily limited to those having all the configurations described. In addition, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. In addition, it is possible to delete a part of the configuration of each embodiment, or to add or replace other configurations. In addition, the control lines and information lines shown in the figure show those that are considered necessary for explanation, and do not necessarily show all the control lines and information lines necessary on the product. In reality, it may be considered that almost all the configurations are connected to each other. Possible modifications of the above-mentioned embodiment are, for example, as follows.

[0064] (1) In the above third embodiment, the semiconductor measuring device 900 is given as an example of a charged particle beam device and a vacuum device. However, various charged particle beam devices and vacuum devices are conceivable other than the semiconductor measuring device 900. For example, the present invention can be applied to a transmission electron microscope (TEM) or an ion microscope as a charged particle beam device. Furthermore, charged particle beam devices are often vacuum devices. The present invention can also be applied to, for example, various microfabrication devices as vacuum devices other than charged particle beam devices. [Explanation of symbols]

[0065] 10,12 Magnetically levitated flat stage device (stage device) 20 Fixed part 22 Tabletop 22a, 22b Insertion hole (through hole) 26 Bottom plate 28 Coil 29 Vacuum Pump 40 Controller 60 Electro-optical equipment 100,910 Moving parts 101 Top table (support part) 105 Magnet (Second Magnet) 125 Magnetic Shield 141 Magnet (First Magnet) 143 Displacement sensor (position sensor) 160 Objects 900 Semiconductor measurement equipment (stage equipment, vacuum equipment, charged particle beam equipment) 901 Vacuum chamber (fixed part) 902 Electron Optical System Column (Charged Particle Beam Emission Section) 910 Stage equipment (moving parts) EB Electron beam (charged particle beam) FA Thrust (First Thrust) FB thrust (second thrust) LM width Rw Radius (first radius) Re radius (second radius)

Claims

1. a fixed portion including a top plate including a magnetic body, a bottom plate facing the top plate, and a plurality of coils provided on an upper surface of the bottom plate; a movable section including a support section for supporting an object to be positioned, a plurality of first magnets attached to an upper surface of the support section, facing the top plate, and generating a first thrust against the top plate, and a plurality of second magnets provided on a lower surface of the support section, facing the coil, and generating a second thrust between the coil and the second magnet; a magnetic shield provided on the lower surface of the support portion around the second magnet and having a width 1.0 times or more the width of the coil; A stage apparatus comprising:

2. the object is disk-shaped having a predetermined first radius, and a cylindrical electron optical device having a second radius faces the object; The first magnets are spaced apart from each other at intervals equal to or greater than √2 times the sum of the first radius and the second radius.

2. The stage apparatus according to claim 1 .

3. The movable portion further includes a position sensor for measuring the distance between the movable portion and the top plate.

2. The stage apparatus according to claim 1 .

4. The top plate has a through hole whose peripheral surface is tapered.

2. The stage apparatus according to claim 1 .

5. The top plate has a through hole, The actuator further includes a controller that controls a current supplied to the coil so as to increase the second thrust when any of the first magnets faces the through hole.

2. The stage apparatus according to claim 1 .

6. a fixed portion including a top plate including a magnetic body, a bottom plate facing the top plate, and a plurality of coils provided on an upper surface of the bottom plate; a movable section including a support section for supporting an object to be positioned, a plurality of first magnets attached to an upper surface of the support section, facing the top plate, and generating a first thrust against the top plate, and a plurality of second magnets provided on a lower surface of the support section, facing the coil, and generating a second thrust between the coil and the second magnet; a magnetic shield provided on a lower surface of the support portion around the second magnet and having a width 1.0 times or more the width of the coil; A charged particle beam emitting unit that irradiates the object with a charged particle beam. A charged particle beam device comprising:

7. a fixed portion including a top plate including a magnetic body, a bottom plate facing the top plate, and a plurality of coils provided on an upper surface of the bottom plate; a movable section including a support section for supporting an object to be positioned, a plurality of first magnets attached to an upper surface of the support section, facing the top plate, and generating a first thrust against the top plate, and a plurality of second magnets provided on a lower surface of the support section, facing the coil, and generating a second thrust between the coil and the second magnet; a magnetic shield provided on a lower surface of the support portion around the second magnet and having a width 1.0 times or more the width of the coil; a vacuum pump that reduces the air pressure in the internal space of the fixing portion to less than atmospheric pressure. A vacuum device comprising:

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