Holding device, method for determining adsorption abnormality of holding device, lithography apparatus, and method for manufacturing article

Abstract

To provide a technique that can accurately determine abnormal adsorption of a mold holding device or a substrate holding device.SOLUTION: A holding device is used for a lithography device that transfers a pattern formed on a mold to a substrate, and adsorbs and holds the mold or the substrate by decompression, and the holding device has: a holding unit that holds the mold or the substrate, the holding unit having a plurality of recesses that forms a plurality of spaces with the mold or the substrate; a first pressure mechanism that decompresses a first space being at least one of the plurality of spaces; a second pressure mechanism that adjusts a pressure in a second space being at least one of the plurality of spaces to be different from the pressure in the first space; a control unit that controls the first and second pressure mechanisms so that the first and second spaces become spaces adjacent to each other; a measurement unit that measures a flow rate of at least one of the first and second pressure mechanisms; and a determination unit that determines an abnormality related to the adsorption and holding of the mold or the substrate on the basis of the measured flow rate.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a holding device, a method for determining adsorption abnormality of the holding device, a lithography apparatus, and a method for manufacturing an article.

Background Art

[0002] An exposure apparatus has a substrate holding device for holding a substrate. Further, an imprint apparatus has, in addition to a substrate holding device, a mold holding device for holding a mold. The mold holding device or the substrate holding device generally includes a vacuum suction type chuck having a suction surface for holding an object to be adsorbed, a suction port formed in the chuck, and a pressure sensor for monitoring the pressure of an exhaust port communicated with the suction port. In this case, after the mold holding device or the substrate holding device sucks and adsorbs the object to be adsorbed, if the measured value of the pressure sensor reaches an arbitrary value (vacuum state), it is determined that the object to be adsorbed is in a state of being adsorbed and held. On the other hand, the mold holding device or the substrate holding device stops sucking the object to be adsorbed and returns the pressure in the exhaust port to approximately atmospheric pressure, thereby determining that the state of holding the object to be adsorbed is released.

[0003] Here, abnormalities such as adhesion of dust or formation of scratches may occur on the back surface of the object to be adsorbed (or the suction surface of the chuck). In order to deal with these abnormalities, Patent Document 1 discloses a substrate holding device capable of measuring a physical quantity related to adsorption during substrate adsorption, determining an adsorption state from the measured physical quantity, and changing holding control.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, although the substrate holding device disclosed in Patent Document 1 measures the physical quantity related to adsorption during adsorption, when the foreign matter or the change in the surface state between the object to be adsorbed and the adsorption surface is minute, the measured value during abnormal adsorption becomes small, so there is a problem that it is difficult to judge adsorption abnormality.

[0006] Therefore, an object of the present invention is to provide a holding device capable of accurately determining adsorption abnormality of a mold holding device or a substrate holding device.

Means for Solving the Problems

[0007] The holding device of the present invention is used in a lithography apparatus that transfers a pattern formed on a mold to a substrate ru and is a holding device, A plurality of concave portions are provided, and the a mold or is the a holding part for holding a substrate and , the mold or the substrate and 、 the plurality of concave portions formed by ru a plurality of spaces contained in a first pressure mechanism for decompressing the first space ru , the plurality of spaces contained in and adjacent to the first space a second pressure mechanism for pressurize the second space 、 the first pressure mechanism of at least gas flowing in one direction of the second pressure mechanism of the measurement unit a measurement unit that measures the flow rate of result , and 、 a determination unit that determines abnormality based on the measurement

Effects of the Invention

[0008] According to the present invention, it is possible to provide a holding device capable of accurately determining adsorption abnormality of a mold holding device or a substrate holding device.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Embodiments for Carrying Out the Invention

[0010] <First Embodiment> The configuration of the substrate holding device according to the first embodiment of the present invention will be described. FIG. 1 is a schematic diagram showing the configuration of the substrate holding device 10. The substrate holding device 10 includes a wafer chuck body (main body part) 1, a vacuum exhaust system (pressure mechanism, first pressure mechanism) 20, a compressed air system (pressure mechanism, second pressure mechanism) 30, and a main control unit (judgment unit) 8. The wafer chuck body (main body part) 1 has a holding surface (holding part) 17 for holding a wafer (substrate) W. The vacuum exhaust system 20 applies a force (negative pressure) for adsorbing the wafer W mounted on the wafer chuck body 1 to the holding surface 17. The compressed air system 30 applies a positive pressure to the space formed between the wafer W and the wafer chuck body (main body part) 1. The main control unit 8 controls the entire device in which the substrate holding device 10 is installed. In this embodiment, the substrate holding device 10 is applied to a stage device that moves the wafer W in an exposure device, and the main control unit 8 controls the entire exposure device.

[0011] FIG. 2 is a schematic diagram showing the structure of the wafer chuck body 1. In particular, FIG. 2(a) is a plan view of the wafer chuck body 1, and FIGS. 2(b) and 2(c) are cross-sectional views showing the M-M' cross-section and the N-N' cross-section in FIG. 2(a), respectively.

[0012] The wafer chuck body 1 has a plurality of grooves (a plurality of recesses) 5 on the holding surface 17 side for holding the wafer W. The number of grooves 5 is, as will be described later, preferably provided at equal intervals in the radial direction in the circular wafer chuck body 1 with about 4 grooves as shown in FIG. 2(a) in relation to measuring the flow rate of the plurality of spaces formed by the grooves 5 of the wafer chuck body 1 and the wafer W. Further, as shown in FIG. 2(b), the grooves 5 are provided with four exhaust ports 6a and three air supply ports 6b that penetrate the lower surface of the wafer chuck body 1. The exhaust ports 6a and the air supply ports 6b are preferably arranged in a row and evenly as shown in the M-M' part in FIG. 2(a). Note that the number of the above-described grooves 5 and the number of the exhaust ports 6a and the air supply ports 6b are not particularly limited, respectively.

[0013] In addition, the surface of the groove 5 has a plurality of convex portions 4 having the same height as the holding surface 17 formed by etching (only shown in Fig. 2(a)). The arrangement of the convex portions 4 can be various methods such as an orthogonal lattice pattern, a staggered lattice pattern, or a concentric circular pattern, and is not particularly limited. Regarding the interval (pitch) between the convex portions 4, when the wafer W is held, it is desirable that the wafer W does not deform due to the suction force of the vacuum exhaust system 20 causing it to sink in the direction of the groove 5.

[0014] Furthermore, the wafer chuck body 1 has three through-holes 7 for lift pins (not shown) that perform a vertical movement to lift the wafer W from the holding surface 17 of the wafer chuck body 1 when placing the wafer W. Generally, the placement of the wafer W onto the wafer chuck body 1 is performed by a substrate transfer device (not shown) placing the wafer W on the lift pins and the lift pins descending.

[0015] The vacuum exhaust system 20 includes a vacuum pump 12. The exhaust port 6a is provided with a solenoid valve 13, a vacuum regulator 14, a flow sensor (measurement unit) 15, and a vacuum exhaust line 16 that connects them to the exhaust port 6a of the wafer chuck body 1. The vacuum pump 12 is an exhaust means used to hold the wafer W by reducing the pressure in the space formed by the wafer W placed on the wafer chuck body 1 and the groove 5. Note that the pressure is adjusted to a predetermined pressure by the vacuum regulator 14 and the main control unit 8, and it is possible (controllable) to reduce the pressure in the space formed by the groove 5 selected by the solenoid valve 13. The vacuum pump 12 and each of the plurality of grooves 5 can be selectively connected by the solenoid valve 13. Also, although the vacuum exhaust line 16 is connected only to the wafer chuck body 1 for convenience in this embodiment, it may be connected to other vacuum exhaust lines. Thus, the substrate holding device 10 of this embodiment includes a decompression unit composed of the wafer chuck body 1, the vacuum exhaust line 16, and the vacuum pump 12.

[0016] Further, the vacuum exhaust system 20 includes flow sensors 15 installed in each of the plurality of vacuum exhaust lines 16. Furthermore, the vacuum exhaust system 20 includes a flow information control unit 11 that manages the measurement results of each flow sensor 15.

[0017] Each flow sensor 15 is a measurement unit that measures the flow rate value of each vacuum exhaust line 16. In this embodiment, one flow sensor 15 is installed in each vacuum exhaust line 16. However, if one flow sensor 15 can measure the flow rate values of a plurality of vacuum exhaust lines 16, the number of installed flow sensors 15 may be less than four.

[0018] The compressed air system 30 includes a pressure pump 21. At the air supply port 6b, there are provided a solenoid valve 22, a regulator 23, and a pressure line 24 that connects them to the air supply port 6b of the wafer chuck body 1. The pressure pump 21 is a pressurizing means that supplies and pressurizes air to the space formed by the wafer W placed on the wafer chuck body 1 and the groove 5. The pressure is adjusted to a predetermined pressure by the regulator 23 and the main control unit 8, and it is possible (controllable) to pressurize the space formed by the groove 5 selected by the solenoid valve 22. The pressure pump 21 and each of the plurality of grooves 5 can be selectively connected by the solenoid valve 22.

[0019] Also, in this embodiment, the pressure line 24 is connected only to the wafer chuck body 1 for convenience, but it may be connected to other pressure lines. Thus, the substrate holding device 10 of this embodiment includes a pressurizing unit composed of the wafer chuck body 1, the pressure line 24, and the pressure pump 21.

[0020] The flow rate information control unit 11 is an information control unit that manages the flow rate information including the measurement results measured by each flow rate sensor 15. Here, "flow rate information" refers to the flow rate or flow velocity measured by the flow rate sensor 15. In addition, the flow rate information control unit 11 sequentially monitors the flow rate information of the flow rate sensor 15 and transmits the flow rate information to the main control unit 8. In this embodiment, the flow rate sensor 15 is configured in each vacuum exhaust line 16 of the vacuum exhaust system 20, but it may also be configured in the pressure supply line 24 of the pressure supply system 30. Further, instead of the flow rate sensor 15, a differential pressure gauge may be configured to calculate the flow rate or flow velocity flowing through each vacuum exhaust line 16 from the differential pressure.

[0021] The main control unit 8 is a control unit that controls the adsorption operation of the substrate holding device 10, the vacuum pump 12, the vacuum regulator 14, the solenoid valve 13, and the flow rate information control unit 11 in the vacuum exhaust system 20, and the pressure supply pump 21, the regulator 23, the solenoid valve 22, etc. in the pressure supply system 30. Further, the main control unit 8 controls the entire device where the substrate holding device 10 is installed. The main control unit 8 is composed of a computer or a sequencer including various operation programs. The main control unit 8 transmits operation commands to the vacuum pump 12, the vacuum regulator 14, the solenoid valve 13, the flow rate information control unit 11, the pressure supply pump 21, the regulator 23, the solenoid valve 22, etc. connected by the LAN cable 9 or the like. Further, the main control unit 8 can store the flow rate information sent from the flow rate information control unit 11 in a storage device (storage unit) such as a memory provided inside, and can appropriately read out past flow rate information (history information). Note that in this embodiment, the flow rate information control unit 11 and the main control unit 8 are described as separate entities, but one control unit may have both functions.

[0022] Next, referring to the flowchart shown in FIG. 3, the overall flow of the maintenance method of the substrate holding device 10 will be described.

[0023] First, the main control unit 8 loads the wafer W and places it on the holding surface 17 of the substrate holding device 10 (step S101). Here, it is preferable to use the wafer W on which no abnormality with respect to the planar state such as warping has been confirmed by prior measurement.

[0024] Next, the main control unit 8 selects the groove 5 to be pressurized from among the plurality of grooves 5 of the substrate holding device 10. The solenoid valve 22 of the compressed air system 30 corresponding to the selected groove 5 is opened, the solenoid valves 22 other than that are closed, and the solenoid valve 13 of the vacuum exhaust system 20 corresponding to the selected groove 5 is closed, while the other solenoid valves 13 are opened (step S102).

[0025] Next, the main control unit 8 drives the vacuum pump 12 and performs vacuum suction until the pressure set by the vacuum regulator 14 is reached, thereby decompressing the space (first space) formed by the groove 5 corresponding to the opened solenoid valve 13 and starting the adsorption of the wafer W (step S103). Here, the suction pressure is set to about -60 kPa, for example.

[0026] Thereafter, the main control unit 8 drives the pressure pump 21 and pressurizes the space (second space) formed by the selected groove 5 until the pressure set by the regulator 23 is reached (step S104). Here, the pressure is set to about 10 kPa, for example.

[0027] In this state, the main control unit 8 causes the flow rate information control unit 11 to acquire the flow rate value from the flow rate sensor 15 at an arbitrary time interval, further causes each flow rate information to be created, and receives the flow rate information from the flow rate information control unit 11 (step S105). Here, the groove 5 for measuring the flow rate value only needs to be the groove 5 adjacent to the pressurized groove 5, but the flow rate values of all the flow rate sensors may be acquired. Also, the acquired flow rate information is stored in the flow rate information control unit 11.

[0028] The flow from step S102 to step S105 is repeated until all the grooves 5 are pressurized and the flow rate value is acquired (step S106).

[0029] Next, the main control unit 8 checks whether the flow rate information obtained from step S102 to step S106 is less than or equal to a specified value. If it is within the specified value, it is determined that there is no abnormality. If it exceeds the specified value, it is determined that an abnormality has occurred between the holding surface 17 and the wafer W (step S107). The specified value here may be the flow rate value obtained when no abnormality occurs between the holding surface 17 and the wafer W, for example, the flow rate value obtained in a state where no foreign matter is caught in an unused wafer chuck body.

[0030] In step S107, if it is determined that there is no abnormality, the main control unit 8 unloads the wafer and ends the maintenance (step S108).

[0031] Also, in step S107, if it is determined that an abnormality has occurred, the cause of the abnormality is determined (step S109).

[0032] Here, two types of causes of abnormality are determined. The first cause of abnormality is the case where a foreign object P is caught between the holding surface 17 and the wafer W (contact surface) (Fig. 4). The second cause of abnormality is the case where wear (aging deterioration) S occurs on the holding surface 17 and an abnormality has occurred (Fig. 5). When these abnormalities occur, when one of the two grooves 5 sandwiching the location where the abnormality occurs (the location where there is a gas flow between the adjacent grooves 5) is sucked and the other is pressurized, a flow is generated due to the pressure difference between the grooves, and the measured flow rate value increases. When the flow rate value exceeds the specified value, it is determined that an abnormality has occurred.

[0033] The main control unit 8 refers to the past flow rate information stored in the flow rate information control unit 11 and compares it with the flow rate information at the time of abnormality. If the flow rate information at the time of abnormality deviates from the temporal change of the past flow rate information, the main control unit 8 determines that the cause of the abnormality is the entrapment of the foreign object P. Also, if the flow rate information at the time of abnormality matches the tendency of the temporal change of the past flow rate information, the main control unit 8 determines that the cause of the abnormality is due to the wear S occurring on the holding surface 17 (step S109).

[0034] When it is determined that the abnormality is due to the entrapment of the foreign object P, the wafer W is unloaded (step S110), the holding surface 17 is cleaned (step S111), and the flow is restarted from step S101.

[0035] When it is determined that the abnormality is due to the wear S of the holding surface 17, the wafer W is unloaded (step S112), the wafer chuck body 1 is replaced (step S113), and the flow is restarted from step S101.

[0036] As described above, according to the present embodiment, when the substrate holding device 10 is maintained, a pressure difference is applied by suction and pressurization of the groove 5, and by referring to the flow rate information of the air flowing through the groove 5, an abnormality between the holding surface 17 and the wafer W can be detected with high accuracy. Further, by performing a recovery process corresponding to each abnormality, it is possible to prevent deterioration of the flatness of the wafer W due to an abnormality between the holding surface 17 and the wafer W. In addition, a large-scale adsorption abnormality detection device is not required, which is advantageous in terms of cost and space.

[0037] (Exposure apparatus) Next, as an example of a lithography apparatus to which the substrate holding device 10 in the first embodiment of the present invention is applied, an embodiment of an exposure apparatus will be described. FIG. 6 is a schematic diagram showing the configuration of the exposure apparatus 40. The exposure apparatus 40 includes an illumination optical system 31, a reticle stage 32 that holds a reticle (master), a projection optical system 33, and a substrate stage 34 that holds a substrate (wafer) W. Note that the exposure apparatus 40 in the present embodiment employs a step-and-repeat method or a step-and-scan method, and is a scanning projection exposure apparatus that transfers a circuit pattern formed on a reticle to a substrate W.

[0038] The illumination optical system 31 includes a light source unit (not shown) and is a device that illuminates a reticle on which a circuit pattern for transfer is formed. In the light source unit, for example, a laser is used as the light source. Available lasers include an ArF excimer laser with a wavelength of approximately 193 nm, a KrF excimer laser with a wavelength of approximately 248 nm, an F2 excimer laser with a wavelength of approximately 157 nm, and the like. Note that the type of laser is not limited to excimer lasers. For example, a YAG laser may be used, and the number of lasers is also not limited.

[0039] When a laser is used in the light source unit, it is preferable to use a beam shaping optical system that shapes the parallel light beam from the laser light source into a desired beam shape and an incoherent optical system that makes the coherent laser incoherent. Furthermore, the light source that can be used in the light source unit is not limited to lasers, and one or more lamps such as mercury lamps and xenon lamps can also be used.

[0040] The illumination optical system 31 includes a lens, a mirror, a light integrator, an aperture, and the like. Generally, the illumination optical system 31 is arranged in the order of a condenser lens, a fly's eye lens, an aperture stop, a condenser lens, a slit, and an imaging optical system. The illumination optical system 31 can be used for both on-axis light and off-axis light. The light integrator includes an integrator formed by stacking a fly's eye lens and two sets of cylindrical lens array plates. Note that the light integrator may be replaced with an optical rod or a diffraction element. The aperture stop is configured as a circular aperture, an annular illumination aperture for deformed illumination, a quadrupole illumination aperture, and the like.

[0041] The reticle is made of, for example, quartz glass and has a circuit pattern to be transferred formed thereon. The reticle stage 32 is a stage that can move in a direction within a plane parallel to the substrate holding surface and is a device that holds the reticle. Note that the reticle stage 32 is held by the reticle stage base plate 35.

[0042] The projection optical system 33 projects the pattern on the reticle illuminated by the exposure light from the illumination optical system 31 onto the substrate W at a predetermined magnification (for example, 1 / 4 or 1 / 5). As the projection optical system 33, an optical system composed only of a plurality of refractive optical elements or an optical system composed of a plurality of refractive optical elements and at least one concave mirror (catadioptric optical system) can be adopted. Alternatively, as the projection optical system 33, an optical system composed of a plurality of refractive optical elements and at least one diffractive optical element such as a kinoform or a full mirror type optical system can also be adopted. Note that the reticle stage surface plate 35 and the projection optical system 33 are supported on the floor surface (base surface) 36 by the lens barrel surface plate 38 via the damper 37.

[0043] The substrate W is a workpiece such as a silicon wafer on which a resist (photosensitive agent) R is applied on its surface. The substrate stage 34 is a stage provided with the substrate holding device 10 of the present invention and movable in a direction in a plane parallel to the substrate holding surface, and is a device for holding the substrate W. The substrate stage 34 is installed on a stage surface plate 39 placed on the floor surface (base surface) 36.

[0044] In the exposure apparatus 40 of the present embodiment, the diffracted light emitted from the reticle passes through the projection optical system 33 and is projected onto the substrate W. The substrate W and the reticle are in a conjugate relationship. In the case of a scanning type projection exposure apparatus, the pattern of the reticle is transferred onto the substrate W by scanning the reticle and the substrate W. Note that in the case of a stepper (exposure apparatus of the step-and-repeat method), exposure is performed with the reticle and the substrate W stationary. Note that the substrate holding device 10 of the present invention is applicable not only to the illustrated exposure apparatus 40 but also to a lithography apparatus that transfers a pattern onto the substrate W.

[0045] <Second Embodiment> The configuration of the mold holding device according to the second embodiment of the present invention will be described. FIG. 7 is a schematic diagram showing the configuration of the mold holding device 50. Note that in FIG. 7, components having the same configuration as those in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted. The mold holding device 50 of the present embodiment is a device for adsorbing and holding a mask (mold) M.

[0046] FIG. 8 is a schematic view showing the structure of the mask chuck body 41 provided in the mold holding device 50. In particular, FIG. 8(a) is a plan view of the mask chuck body 41, and FIG. 8(b) is a cross-sectional view showing the K-K' cross-section in FIG. 8(a).

[0047] The mask chuck body 41 in FIG. 8(a) has a plurality of grooves 5 on the holding surface 17 side for adsorbing the mask M, but the grooves 5 may be provided on the mask M as shown in FIG. 9. The mold holding device 50 of the second embodiment is also applied to an imprint device to be described later, and the mask chuck body 41 has an opening 42 in order to be configured to be able to conduct ultraviolet light for curing the imprint material through the mask M to the imprint material.

[0048] Next, with reference to the flowchart shown in FIG. 10, the overall flow of the method for holding the mask M by the mold holding device 50 will be described.

[0049] First, the main control unit 8 loads the mask M and adsorbs and holds it on the holding surface 17 of the mold holding device 50 (step S201). It is preferable to use the mask M that has no abnormalities such as scratches on the held surface of the mask M confirmed by prior measurement here.

[0050] Next, the main control unit 8 selects the groove 5 to be pressurized from the plurality of grooves 5 of the mold holding device 50. The solenoid valve 22 of the pressure air system 30 corresponding to the selected groove 5 is opened, the solenoid valves 22 other than that and the solenoid valve 13 of the vacuum exhaust system 20 corresponding to the selected groove 5 are closed, and the other solenoid valves 13 are opened (step S202).

[0051] Next, the main control unit 8 drives the vacuum pump 12 and performs vacuum suction to a pressure set by the vacuum regulator 14, thereby decompressing the space (the first space) composed of the groove 5 corresponding to the opened solenoid valve 13 and starting to adsorb the mask M (step S203). Here, the suction pressure is set to about -60 kPa, for example.

[0052] After that, the main control unit 8 drives the pressure pump 21 to pressurize the space (the second space) formed by the selected groove 5 to the pressure set by the regulator 23 (step S204). The pressure setting here is, for example, about 10 kPa.

[0053] In this state, the main control unit 8 causes the flow rate information control unit 11 to acquire the flow rate value from the flow rate sensor 15 at an arbitrary time interval, further create each flow rate information, and receive the flow rate information from the flow rate information control unit 11 (step S205). The groove 5 for measuring the flow rate value here may only be the groove 5 adjacent to the pressurized groove 5, but the flow rate value may be acquired by all the flow rate sensors 15. Also, the acquired flow rate information is stored in the flow rate information control unit 11.

[0054] The flow from step S202 to step S205 is repeated until all the grooves 5 are pressurized and the flow rate value is acquired (step S206).

[0055] Next, the main control unit 8 checks whether the flow rate information obtained from step S202 to step S206 is equal to or less than a specified value. If it is within the specified value, it is determined that there is no abnormality, and if it exceeds the specified value, it is determined that an abnormality has occurred between the holding surface 17 and the mask M (step S207). The specified value here may be the flow rate value obtained when no abnormality has occurred between the holding surface 17 and the mask M, for example, the flow rate value obtained in a state where no foreign matter is sandwiched by the unused mask chuck body 41.

[0056] In step S207, if it is determined that there is no abnormality, it is determined that the mask M is normally adsorbed, and the flow ends.

[0057] Also, in step S207, if it is determined that an abnormality has occurred, the cause of the adsorption abnormality is determined (step S208).

[0058] The abnormal causes here are classified into two types. The first abnormal cause is the case where a foreign object P is sandwiched between the holding surface 17 and the mask M (not shown). The second abnormal cause is the case where wear S occurs on the holding surface 17 over time and an abnormality occurs (not shown). When these abnormalities occur, when one of the two grooves 5 sandwiching the location where the abnormality occurs (the location where there is a gas flow between the adjacent grooves 5) is sucked and the other is pressurized, a flow is generated due to the pressure difference between the grooves 5, and when the measured flow rate value becomes large and exceeds the specified value, it is determined as an abnormality.

[0059] The main control unit 8 refers to the past flow rate information stored in the flow rate information control unit 11 and compares it with the flow rate information at the time of abnormality. When the flow rate information at the time of abnormality deviates from the change over time of the past flow rate information, the main control unit 8 determines that the cause of the abnormality is the sandwiching of a foreign object. Also, when the flow rate information at the time of abnormality matches the tendency of the change over time of the past flow rate information, the main control unit 8 determines that the cause of the abnormality is due to the wear occurring on the holding surface 17 (step S208).

[0060] In the case of an abnormality caused by the sandwiching of a foreign object, the mask M is unloaded (step S209), the holding surface 17 and the adsorbed surface of the mask M are cleaned (step S210), and the flow is executed again from step S201.

[0061] When it is determined that the abnormality is due to the wear S of the holding surface 17, the mask M is unloaded (step S211), the mask chuck body 41 is replaced (step S212), and the flow is executed again from step S201.

[0062] As described above, according to the present embodiment, when the mask M is adsorbed, a pressure difference is applied by suction and pressurization of the groove 5, and by referring to the flow rate information of the air flowing through the groove 5, abnormalities between the holding surface 17 and the mask M can be detected with high precision. Further, by performing recovery processing corresponding to each abnormality, it is possible to prevent changes in the holding posture of the mask M due to abnormalities between the holding surface 17 and the mask M and to prevent the mask M from falling off due to poor adsorption. In addition, a large-scale adsorption abnormality detection device is not required, which is advantageous in terms of cost and space.

[0063] (Imprint apparatus) Next, as an example of a lithography apparatus to which the mold holding device 50 in the second embodiment of the present invention is applied, an embodiment of an imprint apparatus will be described. FIG. 11 shows a cross-sectional view of the imprint apparatus 80 according to the second embodiment. The imprint apparatus 80 includes a mold holding device 50 that holds a mask M. The mask M has a pattern surface Mp on which a pattern is formed. The mold holding device 50 is attached to the structure 78 and can be driven in a direction in which the substrate W and the mask M approach and separate from each other by a drive source and a main control unit (not shown).

[0064] A substrate stage 74 that drives on the stage surface plate 79 holds the wafer W. In order to supply (coat) the resin 82 as an imprint material to the wafer W, a supply mechanism (coating mechanism 92) is provided inside the imprint apparatus 80. The coating mechanism 92 supplies the resin 82. The substrate stage 74 is driven to move the wafer W under the coating mechanism 92 to coat the resin 82. The substrate stage 74 is driven to move the imprinted region coated with the resin 82 under the mask M.

[0065] At this time, the position of the substrate stage 74 is measured using the length measuring device 75, and alignment control of the substrate stage 74 is performed with nanometer accuracy by a main control unit (not shown). As the length measuring device 75, for example, a laser interferometer or an encoder can be used. Further, the imprint apparatus 80 includes an alignment scope 91. The alignment scope 91 images alignment marks formed on the wafer W and calculates the positions by image processing. Based on the positions calculated in this way, imprinting is performed so as to overlap the substrate with high precision.

[0066] After performing alignment as described above, the mold holding device 50 is moved toward the wafer W, so that the pattern surface Mp of the mask M is pressed against the imprint region where the resin 82 is applied on the substrate W. In order to cure the resin 82 in a state where the pattern surface Mp is pressed against the resin 82, the imprint apparatus 80 includes a light source 76. In this embodiment, ultraviolet rays are irradiated from the light source 76 to cure the resin 82. The mask M is made of glass (quartz) so that ultraviolet light for curing the resin 82 can pass through.

[0067] After the resin 82 is cured, the mask M is separated from the resin 82, so that a pattern is formed on the wafer W. After the pattern transfer is performed, next, in order to apply the resin 82 to the imprint region where the pattern is formed, the substrate stage 74 is driven and the wafer W moves under the coating mechanism 92. In this way, a series of operations for molding the imprint material on the imprint region are repeated on the wafer W, so that patterns can be formed in a plurality of imprint regions. Note that the substrate holding device 10 of the first embodiment of the present invention may be applied to the imprint apparatus.

[0068] (Method for manufacturing a device as an article) Next, a method for manufacturing a device (such as a semiconductor device or a liquid crystal display device) as an article according to an embodiment of the present invention will be described.

[0069] A semiconductor device is manufactured through a pre-process of forming integrated circuit chips on a wafer and a post-process of completing the integrated circuit chips on the wafer produced in the pre-process as products. The pre-process includes a process of exposing a wafer coated with a photosensitive agent using the above-described exposure apparatus and a process of developing the wafer. The post-process includes an assembly process (dicing, bonding) and a packaging process (encapsulation). A liquid crystal display device is manufactured through a process of forming a transparent electrode. The process of forming a transparent electrode includes a process of applying a photosensitive agent to a glass substrate on which a transparent conductive film is deposited, a process of exposing the glass substrate coated with the photosensitive agent using the above-described exposure apparatus, and a process of developing the glass substrate.

[0070] A method for manufacturing a device as an article (such as a semiconductor integrated circuit element, a liquid crystal display element, etc.) includes a process of forming a pattern on a substrate (wafer, glass plate, film-like substrate) using the above-described imprint apparatus. Further, the manufacturing method may include a process of etching the substrate on which the pattern is formed. In the case of manufacturing other articles such as a patterned medium (recording medium) or an optical element, the manufacturing method may include other processes of processing the substrate on which the pattern is formed instead of etching. According to the device manufacturing method of the present embodiment, a higher-quality device than before can be manufactured.

[0071] (Other Embodiments) The present invention can also be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or a storage medium and having one or more processors in the computer of the system or device read and execute the program. Further, it can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

[0072] As described above, the preferred embodiments of the present invention have been described. Needless to say, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist thereof.

Description of Reference Numerals

[0073] 8 Main control unit (control unit, determination unit) 10 Substrate holding device (holding device) 15 Flow meter (measurement unit) 20 Vacuum exhaust system (first pressure mechanism) 30 Compressed air system (second pressure mechanism) 50 Mold holding device (holding device) W Wafer (substrate) M Mask (mold)

Claims

1. A holding device used in a lithography apparatus for transferring a pattern formed in a mold onto a substrate, comprising: a holding part provided with a plurality of recesses for holding the mold or the substrate; a first pressure mechanism for reducing the pressure in a first space included in a plurality of spaces formed by the mold or the substrate and the plurality of recesses; a second pressure mechanism for pressurizing a second space included in the plurality of spaces and adjacent to the first space; a measuring part for measuring the flow rate of gas flowing into at least one of the first pressure mechanism and the second pressure mechanism; a determination part for determining an abnormality based on the measurement result of the measuring part; The holding device is characterized by comprising the above.

2. The holding device according to claim 1, wherein the second pressure mechanism includes a pressure pump.

3. The holding device according to claim 1 or 2, characterized by comprising a storage part for storing the flow rate measured by the measuring part.

4. The holding device according to claim 3, wherein the determination part determines the type of the abnormality based on the history of the flow rate measured by the measuring part.

5. The holding device according to claim 4, wherein the determination part determines whether the abnormality is caused by foreign matter on the contact surface between the mold or the substrate and the holding part or by aging deterioration of the holding part based on the history of the flow rate measured by the measuring part.

6. A determination method for determining an abnormality of a holding device used in a lithography apparatus for transferring a pattern formed in a mold onto a substrate, the holding device having a holding part provided with a plurality of recesses for holding the mold or the substrate, the method comprising: a step of reducing the pressure in a first space included in a plurality of spaces formed by the mold or the substrate and the plurality of recesses; a step of pressurizing a second space included in the plurality of spaces and adjacent to the first space; a step of measuring the flow rate of gas related to the pressure change in at least one of the first space and the second space; a step of determining an abnormality based on the measured flow rate; The determination method is characterized by including the above steps.

7. The determination method according to claim 6, further comprising a step of storing the history of the flow rate, wherein the step of determination determines the type of the abnormality based on the stored history of the flow rate.

8. The determining step determines, based on the stored history of the flow rate, whether the abnormality is due to foreign matter on the mold or the contact surface between the substrate and the holding unit, or an abnormality due to the aging deterioration of the holding device. The determination method according to claim 7, characterized in that.

9. A lithography apparatus comprising the holding device according to any one of claims 1 to 5.

10. A method for manufacturing an article using the lithography apparatus according to claim 9, A transfer step of transferring a pattern onto a substrate using the lithography apparatus, A step of processing the substrate on which the pattern is formed in the transfer step, A method for manufacturing an article, characterized by comprising.

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