JP2020123699A - Foreign matter removal device, lithography device and article manufacturing method - Google Patents

Abstract

To provide a foreign matter removal device advantageous in terms of removing performance for small foreign matter of smaller grain size.SOLUTION: A foreign matter removal device which uses a suction device sucking a gas to remove foreign matter (particle 18) has: a substrate stage 2 which holds an object (substrate 1) and moves; a tubular member (piping 16) which has one end and the other end, and has a suction device connected to the one end and a suction port (nozzle 11) formed at the other end; an adjustment part (micromotion Z stage 14) which adjusts the distance between the suction port and object; and a control part which controls the adjustment part and a drive part to change the position where the object faces the suction port while maintaining a state in which the distance between the suction port and object is kept less than a thickness of a tube wall at the suction port.SELECTED DRAWING: Figure 2

Description

The present invention relates to a foreign matter removing apparatus, a lithographic apparatus, and an article manufacturing method.

In a lithography apparatus (pattern forming apparatus) such as an exposure apparatus or an imprint apparatus, foreign matter (particles) attached to a substrate, an original plate, or an optical element has a great influence on a formed pattern. For example, in an imprint apparatus, when particles are present between a mold and a substrate when forming a pattern, a phenomenon may occur in which the mold is sandwiched between the mold and the substrate during the imprint operation and the mold is deformed. As a result, in the portion deformed with the particles sandwiched, a pattern having a shape different from the original pattern is formed on the substrate in the subsequent imprint operation.

Conventionally, when a particle is detected, pattern formation is not performed in a shot area including a portion where the particle is detected, or when the particle is detected, the pattern forming operation is stopped and the substrate is discarded. Was taken. Alternatively, some measures have been taken to remove the particles from the substrate.

However, if a unit for removing particles is mounted on the pattern forming apparatus and the particles can be removed when they are detected, the pattern forming operation can proceed efficiently. Various methods have conventionally been proposed as methods for removing particles attached to the surface of a substrate. In particular, many methods have been proposed for removing particles in a non-contact manner using an air flow. For example, Patent Document 1 discloses a method of blowing particles onto the surface of a substrate to remove particles. Further, Patent Documents 2 and 3 disclose a method of sucking gas to remove particles.

Japanese Patent No. 5088142 JP-A-61-189546 JP, 2000-337377, A

It is difficult to blow off particles having a small particle diameter by the method of blowing gas as in Patent Document 1 to remove particles. Since the gas blown from the nozzle forms an air flow along the substrate surface, a desired air flow is obtained from the substrate surface at a height of, for example, about 0.1 mm. Therefore, the particle size is as large as that. Particles are blown by the air flow. However, since the air flow becomes very small in the vicinity of the substrate surface, for example, at a height of about 0.01 mm or less from the substrate, particles having a particle size of about 0.01 mm or less are generated by the air flow enough to move the particles. It is difficult to obtain the effect. Further, in the method of blowing a gas, particles that have once moved by the air flow may be reattached to the substrate, and thus the process may need to be repeated many times.

In the method of sucking a gas as in Patent Documents 2 and 3, particles can be sucked and removed by being placed on an air flow generated by gas suction, so that there is no fear of re-adhesion to the substrate. However, it is difficult to control the air flow on the surface of the object simply by sucking the gas in the vicinity of the object, and the air flow that can move particles at a height of about 0.01 mm or less from the surface of the object. Is difficult to generate. In Patent Documents 2 and 3, since the target particle size is larger than the groove height or the space between the air guide bearings, particles having a particle size smaller than that cannot be removed. Maybe it's okay.

An object of the present invention is to provide a foreign matter removing device that is advantageous in terms of, for example, the ability to remove foreign matter having a small particle size.

According to one aspect of the present invention, there is provided a foreign matter removing device for removing foreign matter on an object using a suction device for sucking gas, comprising a stage for holding and moving the object, and one end and the other end. A tubular member having the suction device connected to the one end and a suction port formed at the other end, an adjusting unit for adjusting a distance between the suction port and the object, and the distance for the suction port And a control unit that controls the adjusting unit and the stage so as to change the position of the object facing the suction port while maintaining the state in which the thickness is smaller than the thickness of the tube wall in. To be done.

According to the present invention, it is possible to provide a foreign matter removing device which is advantageous in terms of, for example, the performance of removing foreign matter having a small particle size.

The figure which shows the structure of the foreign material removal apparatus in embodiment. The figure which shows the structure of the removal part in embodiment. The figure which shows the structure of the nozzle in embodiment. The figure which shows the structure of the removal part in embodiment. Sectional drawing of the front-end|tip part of the some nozzle in embodiment. The figure which shows the structure of the nozzle in embodiment. The figure which shows the structure of the nozzle in embodiment. The figure which shows the structure of the removal part in embodiment. The figure which shows the structure of the removal part in embodiment. FIG. 3 is a diagram showing how particles are surrounded by droplets. The figure explaining the advantage of embodiment.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. The following embodiments do not limit the invention according to the claims. Although a plurality of features are described in the embodiment, not all of the plurality of features are essential to the invention, and the plurality of features may be arbitrarily combined. Further, in the accompanying drawings, the same or similar components are designated by the same reference numerals, and duplicated description will be omitted.

The present invention relates to a foreign matter removing apparatus for removing foreign matter (particles) on an object, and the target object is a flat surface or a gently curved object such as a substrate, an original plate, or an optical element used in a lithographic apparatus. It is possible. INDUSTRIAL APPLICABILITY The present invention can be applied to the case where the particles attached to the surface of such an object cause a decrease in performance. Note that the lithographic apparatus includes, for example, an exposure apparatus and an imprint apparatus. The exposure device exposes the photoresist supplied onto the substrate through the original plate to form a latent image corresponding to the pattern of the original plate on the photoresist. The imprint apparatus forms a pattern on the substrate by curing the imprint material supplied to the substrate with a mold (original plate) in contact therewith.

In the following, the particle removal on a substrate used in particular in a lithographic apparatus will be described in order to provide an example.

<First Embodiment>
FIG. 1 shows a schematic configuration of the foreign matter removing apparatus according to the embodiment. In this specification and the accompanying drawings, directions are shown in an XYZ coordinate system in which the horizontal plane is the XY plane. The directions parallel to the X axis, the Y axis, and the Z axis in the XYZ coordinate system are defined as the X direction, the Y direction, and the Z direction. In FIG. 1, the stage 2 holds the substrate 1, is guided by the surface plate 7 to move in the XY directions, and can rotate about the Z axis. The movement of the stage 2 is performed by the drive mechanism 9. The detection unit 3 irradiates the surface of the substrate 1 with the light beam 4 to detect particles on the substrate 1. The removing unit 5 removes particles on the substrate. The stage 2, the detection unit 3, the removal unit 5, the surface plate 7, and the drive mechanism 9 are housed inside the chamber 6. A clean space is kept inside the chamber 6 so that particles do not adhere to the substrate 1. The control unit 8 centrally controls each of these units. The control unit 8 can be a computer device including a CPU and a memory.

The substrate 1 is transported via an opening (not shown) or a load lock mechanism provided in the chamber 6 and held on the stage 2. The substrate 1 is moved below the detection unit 3 by the stage 2, and the detection unit 3 inspects the presence or absence of particles on the substrate surface. The particle inspection is performed, for example, by a known method in which the substrate 1 is irradiated with the light beam 4 and the scattered light is detected. Particles on the entire surface of the substrate are inspected by irradiating the stage 1 with the light beam 4 while moving or rotating the substrate 1 to a position where the light beam 4 is irradiated. When particles are detected, the location of particles on the substrate surface is specified from the driving state at that time.

If no particles are detected in such a particle inspection, the substrate is transferred to the lithographic apparatus outside the chamber 6 via an opening or a load lock mechanism (not shown) and advances to the exposure step. When particles are detected in the particle inspection, the substrate 1 is moved below the removing unit 5 by the stage 2 and the removing process of removing particles is performed by the removing unit 5. After the removal process is completed, the substrate 1 is moved below the detection unit 3 by the stage 2 and the detection unit 3 re-inspects the particles in order to confirm whether or not the particles have been removed. The re-inspection of the particles may be performed on the entire surface of the substrate, but may be performed only in the area near the location where the particles are detected. If the particles are not detected as a result of the particle re-inspection, the substrate 1 is carried out of the chamber 6 and proceeds to the lithography process, but if the particles are detected in the re-inspection, the removing process is performed again. In this way, the removal process and the inspection process are repeated until no particles are detected. If the particles are detected even after the removal process and the inspection process are repeated a predetermined number of times, it is determined that the particles cannot be removed, and the substrate is not advanced to the next process.

Hereinafter, the configuration of the removing unit 5 and the method of removing particles in the embodiment will be described. FIG. 2 is a diagram showing the configuration of the removing unit 5. The removing unit 5 has a pipe 16 (a tubular member) through which the fluid flows. A suction device (not shown) for sucking gas is connected to one end of the pipe 16. The nozzle 11 forming a suction port is connected to the other end of the pipe 16. The removing unit 5 includes a distance measuring sensor 12 that measures the distance between the tip surface of the nozzle 11 and the surface of the substrate 1, and a holding unit 13 that holds the nozzle 11 and the distance measuring sensor 12. The removing unit 5 further includes a fine movement Z stage 14 that moves the holding unit 13 in the Z direction. The fine movement Z stage 14 functions as an adjusting unit that adjusts the distance between the suction port and the substrate 1. The removal unit 5 further includes a support unit 15 that supports the fine movement Z stage 14, and a flow rate controller 17 that is installed in the middle of the pipe 16 and controls the flow rate of the gas sucked by the suction device.

FIG. 3 is a diagram showing the configuration of the nozzle 11. 3A is a bottom view (end view) of the tip of the nozzle 11, and FIG. 3B is a cross-sectional view of the nozzle 11 taken along the XZ plane. The nozzle 11 has a cylinder wall 21 (tube wall) and a cavity 22 whose outer periphery is surrounded by the cylinder wall 21 and through which a fluid flows. Here, the thickness of the cylindrical wall 21 is indicated by D, and the distance between the nozzle tip (tip surface of the suction port) and the surface of the substrate 1 is indicated by G. Further, particles 18 are present on the substrate 1.

Hereinafter, the particle removing step will be described. As described above, when particles are detected in the particle inspection on the substrate 1, the control unit 8 controls the stage 2 to move the substrate 1 below the removing unit 5. At this time, the stage 2 is driven so that the detected attachment portion of the verticle is near the removing portion 5. The removing unit 5 stands by at a position (for example, about 5 mm) sufficiently distant from the substrate surface in the Z direction so that the nozzle 11 does not come into contact with the substrate 1. The control unit 8 moves the stage 2 so that the particles 18 on the substrate 1 are located slightly away from the position just below the tip of the nozzle 11 (for example, about 5 to 10 mm), and temporarily stops.

Next, the control unit 8 drives the fine movement Z stage 14 (adjustment unit) of the removal unit 5 to bring the tip of the nozzle 11 closer to the surface of the substrate 1. At this time, the control unit 8 sets the distance G between the tip of the nozzle 11 and the surface of the substrate 1 to be smaller than the thickness D of the tube wall at the tip of the nozzle. The controller 8 adjusts the flow rate of the gas sucked from the nozzle 11 by the flow rate controller 17 to a preset value and starts the gas suction. The gas suction may be started before or after the operation of bringing the nozzle 11 close to the surface of the substrate 1.

After that, the control unit 8 faces the nozzle 11 of the substrate 1 while keeping the distance G between the nozzle 11 and the substrate 1 smaller than the tube wall thickness D at the nozzle tip (suction port). The fine movement Z stage 14 and the stage 2 are controlled so as to change. For example, the control unit 8 scan-moves the stage 2 at a low speed so that the adhesion portion of the particles 18 passes through the facing surface of the cavity 22 of the nozzle 11, that is, the center of the cavity. The control unit 8 stops the stage 2 after the location where the particles 18 adhere has passed the facing surface of the nozzle 11. The reason why the stage 2 is scanned and moved at a low speed is that the distance measuring sensor 12 constantly measures the distance from the substrate surface so that the substrate and the nozzle do not come into contact with each other, and the change is transmitted to the fine movement Z stage 14, and the fine movement Z stage 14 is This is because control is performed by Z drive so that the distance does not change. Further, since the particles 18 scan-move the thickness of the cylindrical wall 21 at a low speed, the time for which the particles 18 are exposed to the gas passing through the gap between the nozzle tip and the substrate surface becomes longer.

The feature of this embodiment is that the tip of the nozzle formed of a thick cylinder wall is brought closer to the substrate as much as possible so that the distance G is smaller than the thickness of the cylinder wall 21, and the tip of the cylinder wall 21 is sucked by sucking gas. The purpose is to increase the flow velocity of the gas passing through the gap between the substrate and the substrate surface. Since the distance G is smaller than the thickness D of the cylindrical wall 21, the flow velocity distribution of the gas passing through the gap exists closer to the substrate surface, so that the air current can be applied to the particles adhering to the substrate surface. .. This can increase the possibility that even small particles move due to the air flow. Further, the particles 18 on the substrate pass twice below the cylindrical wall 21 at the tip of the nozzle (cylindrical wall 21→cavity→cylindrical wall 21 on the opposite side), so that the air flow can be applied twice to the particles. it can. Since the airflows of the two degrees have different directions, it can be expected that the action of moving the particles is further enhanced. As a result, particles having a size that has been difficult to move in the airflow generated by blowing or sucking gas in the related art can be reliably hit by the airflow, and the possibility of suction removal increases.

Here, the advantage of setting the distance G to be smaller than the thickness D of the cylindrical wall 21 will be described. 11A shows an example in which the thickness of the nozzle cylinder wall is large, and FIG. 11B shows an example in which the thickness of the nozzle cylinder wall is small. The arrow in the figure indicates the air flow due to the gas suction, and the length of the arrow indicates the flow velocity of the gas. In either case, when the gas is sucked, the gas outside the cylindrical wall 21 of the nozzle gathers in the nozzle, the gas passes through the gap between the tip of the nozzle and the substrate, and then the gas spreads inside the cylindrical wall 21. .. As shown in the drawing, when the distance from the gap between the tip of the nozzle and the substrate 1 increases, the space expands, and the flow velocity of gas decreases.

Focusing on the air flow in the vicinity of the substrate surface where the particles to be removed exist, as shown in the figure, the gas in the vicinity of the substrate surface has a certain flow velocity in the gap between the tip of the nozzle and the substrate 1. Decreases rapidly. That is, the airflow is obtained near the substrate surface only in the section where the nozzle tip and the substrate face each other. As shown in FIG. 11( b ), when the thickness of the cylindrical wall 21 of the nozzle is small, there are few sections where an air flow is generated near the substrate surface. Therefore, the time for moving the stage 2 to remove the particles and the particles on the substrate passing through the section having the air flow is short, and the time for the air flow to act on the particles is short.

On the other hand, as shown in FIG. 11A, when the thickness of the cylindrical wall 21 of the nozzle is sufficiently large, the time in which the air flow acts on the particles becomes long. Even if the flow velocity of gas is small on the surface of the substrate, the probability that particles move will be increased by prolonging the action time. Even if the cylindrical wall 21 of the nozzle is thin, the same effect can be expected if the nozzle wall 21 stays there for a certain period of time. However, in order to position the place where the particles are present in the interval between the cylinder wall 21 of the nozzle and the substrate, it is necessary to improve the particle position measurement performance and the stage positioning performance. turn into. Further, in order to maintain the rigidity of the tip portion of the nozzle so as not to be deformed due to the pressure difference between the inside and the outside during suction, the cylindrical wall 21 of the nozzle needs to be sufficiently thick.

However, the thicker the cylindrical wall 21 of the nozzle, the better. If the thickness is made extremely large, the conductance of the gap between the nozzle tip and the substrate becomes large, so that the amount of gas that can pass therethrough decreases and, as a result, the flow velocity cannot be sufficiently obtained. From this point, it is appropriate that the tube wall thickness is, for example, 5 times or more and 100 times or less of the distance G between the nozzle tip and the substrate, and the optimum value is determined by design conditions.

A specific configuration example of the removing unit 5 will be described. In order to expect a sufficient air flow in the nozzle, it is necessary to set a low atmospheric pressure in the upstream part of the nozzle. The maximum value of the gas flow rate is determined by the inner diameter and length of the nozzle, that is, the conductance and pressure difference of the nozzle portion. Therefore, the inner diameter of the pipe 16 is as large as possible, and it is desired to shorten the distance to the suction device (pump) not shown. However, since the removing unit 5 has the fine movement Z stage 14 and moves in the Z direction, a thick and heavy pipe cannot be directly connected to the nozzle. It is necessary to use a thick pipe from the suction device to the vicinity of the removing unit 5 and to connect to the nozzle 11 by using a pipe thinner than that in the removing unit 5. A resin tube having an outer diameter of 12 mm and an inner diameter of 9 mm can be used for the thin pipe in the removing unit 5, for example. In one example, it is assumed that the size of the particles is several tens of μm or less, and the position resolution of the particle adhesion portion is about 1 mm. In this assumption, the nozzle 11 is, for example, a tubular body having an outer diameter of 6 mm and an inner diameter of 4 mm, and the tip thereof is preferably made of a resin such as urethane that causes little damage even if it comes into contact with the substrate. In this case, if the thickness D of the cylinder wall at the tip of the nozzle is set to 1 mm and the distance G to the substrate is set to about 0.2 mm or less, the condition of D>G can be satisfied.

A specific setting example of the distance G between the nozzle and the substrate surface will be described. In the embodiment, the detection unit 3 has a function of estimating or measuring the size of the detected particle, and the control unit 8 determines the distance G according to the size of the particle detected by the detection unit 3. You can In one example, the control unit 8 can set the dimension G that is 2 to 3 times the size of the particle as the distance G. Thus, even if there are rare particles having a size exceeding 0.1 mm, it is possible to prevent such particles from colliding with the nozzles and not sucking them, and also scratching the substrate. Particles having a particle diameter of several tens of μm or more tend to be highly likely to be sucked by the air flow even if the distance G is large.

Further, depending on the particle inspection method, it may not be possible to estimate or measure the size of particles. In such a case, the control unit 8 may control the fine movement Z stage 14 and the stage 2 so as to pass the particle existence position under the nozzle in a plurality of times while changing the distance G. For example, the control unit 8 sets the distance G to the first distance (for example, 0.2 mm) at first, and moves the stage 2 in the first direction (for example, +X direction) so that the particle existence position passes under the nozzle. Move to scan. Next, the control unit 8 brings the distance G closer to the second distance (for example, 0.03 mm), and moves the stage 2 in the second direction (the direction opposite to the first direction) so that the particle existing position passes under the nozzle. For example, the scanning movement is performed in the −X direction). In this way, the control unit 8 drives the stage 2 back and forth along the direction parallel to the surface of the substrate. At this time, the distance G is kept at the first distance on the outward path in the reciprocating drive, and the distance G is kept at the second distance smaller than the first distance on the returning path in the reciprocating drive. The reciprocating drive may be repeated while further reducing the distance G.

Once the removal process is completed in this way, the control unit 8 controls the stage 2 to move the substrate 1 to below the detection unit 3, and the detection unit 3 re-inspects. If the particles are detected again as a result of the re-inspection, the substrate 1 is moved below the removing unit 5 again to perform the removing step. In this case, since the size of the particles is often quite small, the distance G starts from the minimum distance set in the previous removal step and is further reduced on the return path in the reciprocating drive. The reciprocating drive may be repeated while gradually reducing the distance. The distance G is determined by an error of the distance measuring sensor 12, an error in the straightness of the fine movement Z stage 14, an error in the tip shape of the nozzle 11, an error in the installation angle of the nozzle 11, and the like. At present, the distance G is set to a limit of about 0.005 mm even if it can be set with high accuracy, and if the distance G is closer than this, the possibility of contact with the substrate increases, so the minimum value of the distance for avoiding contact is Should be set. In the above example, when the thickness D of the cylinder wall at the tip of the nozzle is set to 1 mm, for example, the distance G from the substrate may be set to about 0.2 mm or less. Therefore, the distance G is preferably 0.005 mm or more and 0.2 mm or less.

<Second Embodiment>
Hereinafter, as a second embodiment, an example in which a plurality of suction ports are provided and the plurality of suction ports are arranged so that the distances to the substrate are different when facing the substrate will be described. In the example of FIG. 4, a plurality of nozzles 11a, 11b, 11c are arranged side by side. In FIG. 4, three nozzles are arranged as an example, but the present invention is not limited to a specific number of nozzles. The plurality of nozzles 11a, 11b, 11c are arranged, for example, such that the centers of the respective tip surfaces are arranged linearly along the scan direction (for example, the X direction) of the substrate, and the heights of the nozzle tips are different from each other.

Hereinafter, the particle removing step in this embodiment will be described. FIG. 5 is a cross-sectional view of the tip portions of the plurality of nozzles 11a, 11b, 11c. As described above, when the particles 18 are detected by the detection unit 3, the control unit 8 controls the stage 2 to move the substrate 1 below the removal unit 5. At this time, the removing unit 5 stands by at a position (for example, about 5 mm) sufficiently separated from the substrate surface in the Z direction so that the nozzles 11a, 11b, and 11c do not contact the substrate 1. The control unit 8 controls the stage 2 so that the detected attachment positions of the particles 18 are substantially aligned with the extension of the line passing through the centers of the three linearly aligned nozzles. In FIG. 5, the control unit 8 brings the particles 18 to a position about 5 mm further to the left of the left nozzle 11a, and temporarily stops the stage 2. The control unit 8 drives the fine movement Z stage 14 of the removal unit 5 to bring the tips of the plurality of nozzles closer to the substrate surface. For example, the control unit 8 controls the fine movement Z stage 14 so that the distance between the tip of the nozzle and the substrate is Ga=0.2 mm, Gb=0.03 mm, and Gc=0.015 mm from the left side. In the embodiment, the fine movement Z stage 14 fixes a plurality of nozzles by changing their respective heights. Specifically, with respect to the height of the tip of the left nozzle 11a, the tip of the central nozzle 11b is set near 0.015 mm substrate, and the tip of the right nozzle 11c is set near 0.185 mm substrate. There is. Alternatively, a fine movement Z stage may be provided for each of the plurality of nozzles, and the distance between the nozzle tip and the substrate surface may be set for each nozzle. The control unit 8 adjusts the flow rate of the gas sucked from the plurality of nozzles 11a, 11b, 11c by the flow rate controller 17 to a preset value and starts the gas suction.

After that, the control unit 8 scan-moves the stage 2 at a low speed so that the attachment points of the particles 18 pass through the facing surface of the cavity 22 of the nozzle 11a, that is, the center of the cavity, and the attachment points of the particles 18 face all the nozzles. Pass Stage 2 and stop Stage 2. The reason why the stage 2 is moved at a low scanning speed is that the distance measuring sensor 12 always measures the distance from the substrate surface so that the substrate and the nozzle do not come into contact with each other, and the change is transmitted to the fine movement Z stage 14. This is because control is performed by Z drive so that the distance does not change. The particles 18 first pass under the nozzle 11a having the largest distance to the substrate surface. Most of the particles have a particle diameter of several tens of μm, and almost no particles have a height exceeding 0.2 mm. Therefore, the particles move under the nozzle tip without coming into contact with the nozzle tip due to the movement of the substrate. Due to the air flow at this time, large particles having a particle size of several tens of μm are sucked in here. Since the distance Ga between the first nozzle and the substrate surface is relatively large, an air flow sufficient to move particles having a particle size of about 10 μm or less cannot be obtained here. Since the distance Gb between the tip of the next nozzle 11b and the substrate surface is 0.03 mm, the air flow through this gap becomes faster, and it is possible to affect particles of several μm. Furthermore, since the distance Gc between the tip of the last nozzle 11c and the substrate surface is 0.015 mm, the air flow becomes even faster, and particles having a particle size of around 1 μm or less can be affected.

According to the second embodiment described above, a plurality of nozzles having different distances to the substrate are arranged side by side, and the particle attachment position is scanned in order from the one having the largest distance to the substrate. This makes it possible to efficiently suck and remove particles from large particles to small particles without the nozzle tip contacting the particles.

<Third Embodiment>
FIG. 6 shows the configuration of the nozzle 11 according to the third embodiment. 6A is a perspective view of the nozzle 11, FIG. 6B is a bottom view (end view) of the tip of the nozzle 11, and FIG. 6C is a cross-sectional view of the nozzle 11 taken along the XZ plane.

In the example of FIG. 6, the cavity 22 through which the gas flows is eccentric with respect to the center C on the tip surface of the nozzle. Therefore, the thickness of the cylinder wall forming the nozzle is not uniform. The purpose of this shape is to give different flow rates to the air flow passing through the gap between the nozzle tip and the substrate surface. The suction amount of gas is determined by the nozzle diameter and the pressure difference. The suction device for sucking the gas may be a dedicated suction pump or a vacuum suction device of a factory utility, but in any case, the maximum pressure difference is 1 atm. Due to the conductance of the pipe, the pressure difference at the nozzle is a value smaller than 1 atm, and there is a limit. Therefore, in order to increase the air flow at the tip of the nozzle, it is an object of the present embodiment to provide a difference in conductance due to the gap between the nozzle and the substrate so as to increase the air flow in the gap through which the particles pass.

Since the conductance in the gap between the nozzle and the substrate is small in the direction in which the cylinder wall is thin, a large amount of gas passes through, and the air flow is likely to concentrate. As a result, the air flow easily acts on smaller particles, and the probability that particles can be removed by suction increases.

FIG. 7 shows the configuration of the nozzle 11 according to another example of the third embodiment. 7A is a perspective view of the nozzle 11, FIG. 7B is a bottom view (end view) of the tip of the nozzle 11, and FIG. 7C is a cross-sectional view of the nozzle 11 taken along the XZ plane. In the example of FIG. 7, a step is formed on the tip surface of the nozzle 11 by providing the cutout portion 21 a on the tip surface of the nozzle 11. In this case, the passing gas is concentrated in the cutout portion 21a. The shape of the cutout is not limited to the shape shown in the drawing, and may be, for example, a triangle or a semicircle. The control unit 8 controls the stage 2 so that the particles 18 pass through the cutout portions 21a, so that a stronger airflow can act on the particles.

<Fourth Embodiment>
Hereinafter, as a fourth embodiment, an example in which the foreign matter removing apparatus further includes an injection unit that injects a compressed gas onto the substrate will be described. In FIG. 8, the removing unit 5 has a branch pipe 32 that branches at the branch unit 31 with the pipe 16. An air filter 33, a valve 34, a pressure control unit 35, and a gas supply device 36 (compressor) are connected to the branch pipe 32.

As described in the above third embodiment, in the method of sucking gas, the pressure difference is 1 atm at the maximum, so that there is a limit to the flow rate of gas through the narrow gap between the nozzle 11 and the substrate 1. is there. For this reason, there is a limit to the action of an air flow passing through fine particles having a particle size of about 1 μm or less. Therefore, there is a possibility that the particles cannot be removed by the air flow by the gas suction. Therefore, first, the particle removal by gas suction is tried several times, and when the particles cannot be removed, the method is switched. Once, the controller 8 controls the fine movement Z stage 14 to widen the gap between the nozzle 11 and the substrate 1. Next, the control unit 8 controls the stage 2 so that the particle adhesion portion is located, for example, about 30 mm away from the nozzle 11 while the substrate surface is at the position facing the nozzle 11. Next, the controller 8 controls the flow rate controller 17 to set the suction gas flow rate to zero. As a result, the nozzle 11 stops sucking gas. Next, the controller 8 opens the valve 34. As a result, the nozzle 11 is connected to the gas supply line and the compressed gas is injected from the nozzle 11. Next, the pressure control unit 35 sets the gas pressure to, for example, about 1.5 atm. The control unit 8 drives the stage 2 to move the substrate 1 to a place where the particle adhering place is about 10 mm from the tip of the nozzle. The control unit 8 drives the fine movement Z stage 14 to bring the distance between the tip of the nozzle and the substrate surface close to 0.03 mm, for example. In this state, the control unit 8 slowly moves the stage 2 so that the particle adhesion portion on the substrate passes through a position facing the tip of the nozzle 11. The control unit 8 stops the stage 2 at a position further advanced by about 5 mm after the particles 18 have passed immediately below the center of the tip of the nozzle 11. After that, the control unit 8 drives the fine movement Z stage 14 to retract the nozzle 11 so as to widen the gap between the tip of the nozzle 11 and the substrate 1, and stops the gas supply. In order to confirm whether or not the particles on the surface of the substrate can be removed, and further, whether or not the removed particles are reattached to another place on the substrate, the control unit 8 controls the stage 2 to move the substrate 1 to the substrate 1. It is moved below the detection unit 3. The detection unit 3 reinspects the entire surface of the substrate 1. If the place where the particles 18 are detected by the re-inspection is the same place as in the previous inspection, it is determined that the particles 18 are difficult to remove. If the location where the particles 18 are detected by the reinspection is different from the location at the time of the previous inspection, it is determined that the particles 18 have been blown out by the injection of the compressed gas and reattached to another location, and the particle removing step at that location again. Is done.

In the above example, a configuration is shown in which the nozzle is shared by suction and injection of gas, but a suction nozzle and an injection nozzle may be separately provided.

<Fifth Embodiment>
Many fine particles do not move in the airflow. Therefore, the fifth embodiment provides an example of collecting particles by interposing a liquid, which is a substance having a higher viscosity than gas. For example, the foreign matter removing apparatus of the present embodiment includes a supply unit that supplies droplets to a region containing particles detected by the detecting unit 3, and the suction unit sucks particles together with the droplets from the suction port.

In FIG. 9, the removing unit 5 has a supply unit 40 that supplies liquid droplets. The supply unit 40 includes a droplet supply nozzle 41, a discharge control unit 42, a droplet supply pipe 43, and a liquid storage unit 44. Pure water, for example, is used as the liquid. Alternatively, highly volatile alcohols may be used. When particles are re-detected in the particle inspection, the control unit 8 first positions the particle attachment location below the droplet supply nozzle 41 when moving the substrate 1 below the removal unit 5 by the stage 2. .. The ejection control unit 42 supplies the droplets from the droplet supply nozzle 41 to the particle attachment locations. A few drops may be supplied to ensure that the particles enter the drop. FIG. 10 shows how the particles 18 are surrounded by the droplets 45. After that, the control unit 8 drives the stage 2 to move the substrate 1 so that the position of the droplet is separated from the position facing the nozzle 11 by, for example, about 10 mm. The control unit 8 controls the fine movement Z stage 14 to bring the nozzle 11 close to the substrate 1, set the distance between the nozzle 11 and the substrate 1 to, for example, 0.03 mm, and start gas suction. In this state, the control unit 8 moves the stage 2 at a low speed so that the droplet 45 containing particles on the substrate passes directly under the nozzle tip. When the nozzle 11 sucks the droplet 45, the movement of the liquid acts on the particles to move the particles, and the particles are sucked into the nozzle 11 together with the liquid. There may be a mechanism for applying ultrasonic vibration to the substrate 1 in order to make the particles move more easily.

In the example of FIG. 9, the droplet supply nozzle 41 is arranged close to the nozzle 11, but it need not be close to the nozzle 11. Since it is considered that the frequency of removing particles using droplets is not so high, the droplet supply nozzle 41 may be installed at a place distant from the nozzle 11.

<Other Embodiments>
Although the foreign matter removing device in each of the above-described embodiments is described as a device independent of the lithographic apparatus, the foreign matter removing device may be included in the lithographic apparatus. According to the lithographic apparatus having the foreign matter removing apparatus, when the particles are detected, the particles can be removed in the apparatus, and the lithography process can be efficiently performed.

<Embodiment of article manufacturing method>
The article manufacturing method according to the embodiment of the present invention is suitable for manufacturing articles such as microdevices such as semiconductor devices and elements having a fine structure. The article manufacturing method according to the present embodiment includes a forming step of forming a pattern of an original plate on a substrate using the above-mentioned lithographic apparatus (exposure apparatus, imprint apparatus, etc.), and processing the substrate on which the pattern is formed in the forming step. Processing steps. Furthermore, such an article manufacturing method may include other well-known steps (oxidation, film formation, vapor deposition, doping, planarization, etching, resist stripping, dicing, bonding, packaging, etc.). The article manufacturing method of the present embodiment is advantageous in at least one of the performance, quality, productivity, and production cost of the article as compared with the conventional method.

The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Therefore, the following claims are attached to open the scope of the invention.

1: substrate, 2: substrate stage, 5: removal unit, 11: nozzle, 14: fine movement Z stage, 16: piping

Claims (13)

A foreign matter removing device for removing foreign matter on an object using a suction device for sucking gas,
A stage that holds and moves the object,
A tubular member having one end and the other end, the suction device being connected to the one end, and a suction port being formed at the other end,
An adjusting unit that adjusts the distance between the suction port and the object,
A control unit that controls the adjusting unit and the stage to change the position of the object facing the suction port while maintaining the distance smaller than the thickness of the tube wall at the suction port;
A foreign matter removing device comprising: The controller reciprocally drives the stage along a direction parallel to the surface of the object, keeps the distance at a first distance in a forward path in the reciprocating drive, and keeps the distance in a return path in the reciprocating drive. The foreign matter removing apparatus according to claim 1, wherein the second distance is smaller than the first distance. The foreign matter removing device according to claim 1, wherein a plurality of the suction ports are provided, and the plurality of suction ports are arranged so that distances to the object are different when facing the object. .. The foreign matter removing device according to any one of claims 1 to 3, wherein, in the suction port, a hollow portion through which the gas flows is eccentric with respect to a center of a distal end surface of the tubular member. The foreign matter removing device according to any one of claims 1 to 4, wherein a step is formed on a tip surface of the suction port. Further having a detection unit for detecting foreign matter on the object,
The foreign matter removing device according to claim 1, wherein the control unit determines the distance according to a size of the foreign matter detected by the detecting unit. The foreign matter removing device according to any one of claims 1 to 6, further comprising a spraying unit that sprays a compressed gas onto the object. A detection unit for detecting foreign matter on the object,
And a supply unit that supplies liquid droplets to a region containing the foreign matter detected by the detection unit,
The foreign matter removing device according to any one of claims 1 to 7, wherein the foreign matter is sucked together with the liquid droplets from the suction port by the suction device. The foreign matter removing device according to any one of claims 1 to 8, wherein a thickness of the tube wall is 5 times or more and 100 times or less of the distance. The said distance is 0.005 mm or more and 0.2 mm or less, The foreign material removal apparatus of any one of Claim 1 thru|or 9 characterized by the above-mentioned. The foreign matter removing apparatus according to claim 1, wherein the object is at least one of a substrate, an original plate, and an optical element used in a lithographic apparatus. A lithographic apparatus comprising the foreign matter removing device according to claim 11. Forming a pattern on a substrate using the lithographic apparatus according to claim 12;
A step of processing the substrate on which the pattern is formed,
And manufacturing an article from the processed substrate.

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