Patent ID: 12214529

DESCRIPTION OF THE EMBODIMENTS

Hereinafter, embodiments will be described in detail with reference to the attached drawings. Note, the following embodiments are not intended to limit the scope of the claimed invention. Multiple features are described in the embodiments, but limitation is not made to an invention that requires all such features, and multiple such features may be combined as appropriate. Furthermore, in the attached drawings, the same reference numerals are given to the same or similar configurations, and redundant description thereof is omitted.

First Embodiment

FIG.1is a schematic view of a planarization apparatus100according to an embodiment. In the specification and the drawings, directions will be indicated on an XYZ coordinate system in which a horizontal surface is defined as the X-Y plane. In general, a substrate1serving as an object to be processed is placed on a substrate stage3such that the surface of the substrate1is parallel to the horizontal surface (X-Y plane). Therefore, in the following description, the directions orthogonal to each other in a plane along the surface of the substrate1are the X-axis and the Y-axis, and the direction perpendicular to the X-axis and the Y-axis is the Z-axis. Further, in the following description, directions parallel to the X-axis, the Y-axis, and the Z-axis of the XYZ coordinate system are referred to as the X direction, the Y direction, and the Z direction, respectively, and a rotational direction around the X-axis, a rotational direction around the Y-axis, and a rotational direction around the Z-axis are referred to as the θX direction, the θY direction, and the θZ direction, respectively.

The underlying pattern on the substrate has a concave-convex profile derived from a pattern formed in the previous step. More particularly, a process substrate may have a step of about 100 nm along with a multilayer structure of a recent memory element. The step derived from the moderate undulation of the entire surface of the substrate can be corrected by the focus tracking function of a scan exposure apparatus used in the photo process. However, the fine concave/convex portions having a pitch small enough to fall within the exposure slit area of the exposure apparatus may fall outside the DOF (Depth Of Focus) of the exposure apparatus. As a conventional method of planarizing the underlying pattern of the substrate, a method of forming a planarized layer, such as SOC (Spin On Carbon) or CMP (Chemical Mechanical Polishing), is used. However, the conventional technique undesirably cannot obtain sufficient planarization performance, and the concave/convex difference of the underlayer by multilayer formation tends to increase.

In order to solve this problem, studies have been conducted on a planarization apparatus that planarizes a substrate by using an imprint technique. The planarization apparatus locally performs planarization within a substrate plane by bringing a flat surface of a member or a member (flat template) on which no pattern is formed into contact with an uncured composition supplied to the substrate in advance. Subsequently, the composition is cured while the composition is in contact with the flat template, and the flat template is separated from the cured composition. This forms a planarized layer on the substrate. Since the planarization apparatus using the imprint technique is configured to drop a composition in an amount corresponding to the step of the substrate, it is expected to improve the planarization accuracy as compared with the existing methods.

The planarization apparatus100inFIG.1can be embodied by a forming apparatus that forms a composition on the substrate1using a plate9serving as a pressing member. The planarization apparatus100cures the composition in a state in which the material on the substrate1and the plate9are in contact with each other, and separates the plate9from the cured composition, thereby forming a planarized layer made of the material on the substrate1.

The substrate1can be, for example, a silicon wafer, but is not limited thereto. The substrate1can be formed of a material arbitrarily selected from aluminum, a titanium-tungsten alloy, an aluminum-silicon alloy, an aluminum-copper-silicon alloy, silicon oxide, silicon nitride, and the like. Note that a substrate on which an adhesion layer has been formed by surface treatment such as silane coupling treatment, silazane treatment, film formation of an organic thin film, or the like to improve the adhesiveness to the composition may be used as the substrate1. Note that the substrate1typically has a circular shape with a diameter of 300 mm, but is not limited thereto.

The plate9can be formed of a light transmissive material in consideration of the light irradiation step. Such a material can be, for example, glass, quartz, PMMA (Polymethyl methacrylate), a phototransparent resin such as a polycarbonate resin, a transparent metal vapor deposition film, a flexible film such as polydimethylsiloxane, a photo-curable film, a metal film, or the like. Note that the plate9preferably has a circular shape with a diameter larger than 300 mm and smaller than 500 mm, but is not limited thereto. The thickness of the plate9is preferably 0.25 mm or more and less than 2 mm, but is not limited thereto.

The composition can be a curable composition cured by light irradiation, for example, a UV-curable liquid. As the UV-curable liquid, typically, a monomer such as acrylate or methacrylate can be used. The curable composition may be referred to as a formable material. In the following description, the formable material will be simply referred to as the “material”.

As shown inFIG.1, the planarization apparatus100includes a substrate chuck2, the substrate stage3, a base plate4, support columns5, a top plate6, guide bars7, support columns8, a plate chuck11, a head12, and an alignment shelf13. The planarization apparatus100further includes a pressure regulator15, a supplier17, a substrate conveyer18, an alignment scope19, a light source20, a stage driving device21, a plate conveyer22, a cleaning device23, an input device24, and a controller200. The substrate chuck2and the substrate stage3can hold and move the substrate1. The plate chuck11and the head12can hold and move the plate9.

Note that a conveyer may be provided as each of the plate conveyer22for the plate9and the substrate conveyer18for the substrate1, but may be shared. Further, in this embodiment, the plate conveyer22and the substrate conveyer18are described as a part of the planarization apparatus100. However, a conveyer may be provided as an external apparatus of the planarization apparatus100and convey the plate9and the substrate1to the planarization apparatus100.

The substrate1is loaded from the outside of the planarization apparatus100by the substrate conveyer18including a conveyance hand or the like, and held by the substrate chuck2. The substrate stage3is supported by the base plate4, and driven in the X direction and the Y direction to position the substrate1held by the substrate chuck2at a predetermined position. The stage driving device21includes, for example, a linear motor or an air cylinder, and drives the substrate stage3in at least the X direction and the Y direction. However, the stage driving device21may have a function of driving the substrate stage3in two or more axis directions (for example, six axis directions). Further, the stage driving device21includes a rotation mechanism, and can rotate and drive the substrate chuck2or the substrate stage3in the θZ direction.

The plate9serving as the pressing member is loaded from the outside of the planarization apparatus100by the plate conveyer22(conveyance apparatus) including a conveyance hand or the like, and held by the plate chuck11. The plate9has, for example, a circular or rectangular outer shape, and includes a first surface including a flat surface10to be in contact with the material arranged on the substrate, and a second surface on the opposite side of the first surface. The size of the flat surface10is equal to or larger than that of the substrate1. The plate chuck11is supported by the head12, and has a function of correcting the θZ-direction position (an inclination about the Z-axis) of the plate9. Each of the plate chuck11and the head12includes an opening through which light (ultraviolet light) applied from the light source20via a collimator lens passes. The plate chuck11functions as a holder that mechanically holds the plate9. For example, the plate chuck11holds the plate9by chucking the second surface in a state in which the second surface of the plate9faces upward. The head12mechanically holds the plate chuck11. The plate chuck11and the head12form a forming device50that performs a forming process of a planarized film. The head12forms a driving mechanism (not shown) for positioning the spacing between the substrate1and the plate9upon bringing the plate9into contact with the material on the substrate1and separating the plate9from the material, and moves the plate9in the Z direction. The driving mechanism of the head12can be formed by, for example, an actuator such as a linear motor, an air cylinder, or a voice coli motor. A load cell for measuring the pressing force (imprinting force) of the plate9against the material on the substrate can be arranged in the plate chuck11or the head12. A plate deforming mechanism (plate deforming device) includes a sealing member14that makes a space region A, which is formed by the space existing inside the plate chuck11and the internal space surrounded by the plate9, a sealed space. The plate deforming mechanism also includes the pressure regulator15which is installed outside the plate chuck11and regulates the pressure in the space region A. The sealing member14is formed by a light transmissive flat plate member such as silica glass, and partially includes a connection port (not shown) of a tube16connected to the pressure regulator15. The pressure regulator15can increase the amount of convex deformation of the plate9toward the substrate side by increasing the pressure in the space region A. Further, the pressure regulator15can decrease the amount of convex deformation of the plate9by decreasing the pressure in the space region A. The support columns5for supporting the top plate6are arranged on the base plate4. The guide bars7are suspended from the top plate6, extend through the alignment shelf13, and are fixed to the head12. The alignment shelf13is suspended from the top plate6via the support columns8. The guide bars7extend through the alignment shelf13. Further, the alignment shelf13is arranged with a height measurement system (not shown) which is used to measure the height (flatness) of the substrate1held by the substrate chuck2using, for example, an obliquely incident image shift method.

The alignment scope19includes an optical system and an image capturing system used to observe a reference mark provided on the substrate stage3and an alignment mark provided in the plate9. However, if no alignment mark is provided in the plate9, no alignment scope19may be provided. The alignment scope19is used for alignment in which the relative positions of the reference mark provided on the substrate stage3and the alignment mark provided in the plate9are measured and the positional shift therebetween is corrected.

The supplier17includes a dispenser including discharge ports (nozzles) which discharge a material in an uncured state to the substrate1, and supplies (applies) the material onto the substrate. The supplier17employs, for example, a piezo jet method, a micro solenoid method, or the like, and can supply a material of a small volume such as 1 pL (pico liter) onto a substrate. Note that the number of the discharge ports in the supplier17is not limited. The supplier17may include one nozzle (single nozzle), or may include a plurality of (for example, 100 or more) nozzles. The plurality of nozzles may form a linear nozzle array including one row or a plurality of rows.

The cleaner23cleans the plate9in a state in which the plate9is held by the plate chuck11. In this embodiment, the cleaner23removes the material having adhered to the plate9, particularly, the flat surface10upon separating the plate9from the cured material on the substrate. For example, the cleaner23may wipe off the material adhering to the plate9, or may remove the material adhering to the plate9using UV irradiation, wet cleaning, dry plasma cleaning, or the like.

The controller200is formed by a computer apparatus including a CPU and a memory, and controls the entire planarization apparatus100. The controller200functions as a processor that comprehensively controls the respective units of the planarization apparatus100to perform a planarization process. Here, the planarization process is a process of planarizing a material by bringing the flat surface10of the plate9into contact with the material on the substrate to make the flat surface10follow the surface shape of the substrate1. Note that the planarization process is generally performed on a lot basis, that is, for each of a plurality of substrates included in a single lot.

Next, with reference toFIGS.2A to2C, the planarization process will be described. First, a material IM is supplied by the supplier17onto the substrate1formed with an underlying pattern1a.FIG.2Ashows a state after the material IM is arranged on the substrate and before the plate9is brought into contact thereto. Next, as shown inFIG.2B, the material IM on the substrate1and the flat surface10of the plate9are brought into contact with each other. When the plate9presses the material IM, the material IM spreads over the entire surface of the substrate1.FIG.2Bshows a state in which the entire surface of the flat surface10of the plate9is in contact with the material IM on the substrate1so that the flat surface10of the plate9follows the surface shape of the substrate1. Then, in the state shown inFIG.2B, light is applied from the light source20to the material IM on the substrate1via the plate9, and this cures the material IM. After this, the plate9is separated from the cured material IM on the substrate1. Thus, the layer (planarized layer) of the material IM having a uniform thickness over the entire surface of the substrate1is formed.FIG.2Cshows a state in which a planarized layer made of the material IM is formed on the substrate1. In the following description, bringing the flat surface10of the plate9and the material IM on the substrate into contact (tight contact) with each other or separating them from each other are simply represented as bringing the plate9and the material IM on the substrate into contact (tight contact) with each other or separating them from each other, respectively.

Next, with reference toFIG.3, plate conveyance will be described.FIG.3is a view exemplarily showing the components related to the plate conveyer22(conveyance apparatus). Transfer of the plate between the inside and the outside of the planarization apparatus100is performed via a load port25. The load port25is an interface unit for moving the substrate in an FOUP into and out of the planarization apparatus100. In this embodiment, the plate is stored in the FOUP. Note that the plate9to be replaced after performing the planarization process is also unloaded from the load port25to the outside of the apparatus. A conveyance hand26grasps and conveys the plate9. The conveyance hand26may include an edge clamp and a vacuum suction mechanism using a pad for holding the plate9. The conveyance hand26obtains the plate9loaded from the load port25and conveys it to a determiner27. The determiner27determines whether the upper surface (determination surface) of the plate placed on a predetermined placement surface is the first surface (the surface to be in contact with the substrate1, which is also referred to as the “front surface”) including the flat surface10, or the second surface (the surface to be in contact with the plate chuck11, which is also referred to as the “back surface”) on the opposite side of the first surface (this determination is also referred to as “front/back determination” below). In accordance with the result of the determination by the determiner27, the plate9can be conveyed to a reversing device28by the conveyance hand26. The reversing device28turns over the plate9(reverses the plate9). The reversing device28can include a grasping mechanism for grasping the plate9, and a pivot mechanism that causes the grasping mechanism to pivot 180°. The reversing device28can further include a holding mechanism29for temporarily holding the reversed plate. The plate9normally placed on the holding mechanism29such that the lower direction of the plate becomes the first surface (front surface) and the upper direction of the plate becomes the second surface (back surface) can be obtained by the conveyance hand26and conveyed to an adjuster30. The adjuster30adjusts the prealignment state of the plate9. For example, the adjuster30performs alignment regarding the center position and rotational direction of the plate9such that the feeding position upon conveying the plate9to the plate chuck11is kept constant. Therefore, the adjuster30may be called a prealigner. The adjuster30can include a driving stage, a plate chuck, and a measurement device. The driving stage can include driving mechanisms for the X direction, the Y direction, the Z direction, the θX direction, the θY direction, and the θZ direction, respectively. The plate chuck chucks and holds the plate9by a chuck pad or the like. Note that as the chucking method, vacuum suction, electrostatic attraction, or another chucking method may be used. The alignment (prealignment) of the plate can be performed by obtaining the positional information of the plate outer peripheral portion by the measurement device while rotating the plate. Note that the measurement device can include, for example, an image capturing device such as a CCD camera, and a processing device that processes an image and detects the position of an object on the image.

The conveyance hand26obtains the plate9whose prealignment state has been adjusted by the adjuster30, and conveys it to the plate chuck11in the forming device. After the planarization process is performed in the forming device, the conveyance hand26obtains the plate9form the plate chuck11, and conveys it to the FOUP of the load port25.

Note that it may be configured that the plate9having undergone the planarization process is loaded to the determiner27by the conveyance hand26and the front/back determination of the plate is performed. Alternatively, the front/back determination may not be performed in the procedure of a series of plate conveyance, but the front/back determination of the plate may be performed by the determiner27only during specific conveyance at the time such as when the planarization apparatus is turned on next time after a power failure or power cut-off of the planarization apparatus. A control device31controls the operations of the plate chuck11, the reversing device28, the conveyance hand26, the adjuster30, the load port25, and the determiner27. The control device31may be implemented by the controller200.

With reference toFIGS.4A to4D, a method of performing plate front/back determination by the determiner27will be described.FIG.4Ais a view showing the arrangement of the determiner27. The determiner27can include a driving stage36, a supporter37, a plate chuck38, a camera39(image capturing device), and an image processing device40. The driving stage36includes a driving mechanism for the X and Y directions and a driving mechanism for the θZ direction (both are not shown). The supporter37supports the driving stage36. The plate chuck38holds the plate9. The camera39is arranged at a position where it can capture the outer peripheral portion of the plate9. The plate9placed on the plate chuck38(the predetermined placement surface) by the conveyance hand26is held by the plate chuck38.

As will be described later, a mark for identifying the first surface (front surface) or the second surface (back surface) of the plate9is formed in the outer peripheral portion (the region on the outer periphery side of the flat surface10) of the plate9. The camera39captures the mark. More specifically, the outer peripheral portion of the plate9is captured by the camera39while rotating the driving state36in the θZ direction. The image obtained by the camera39is transferred to the image processing device40. The image processing device40performs the front/back determination by processing the image of the mark extracted from the image obtained by the camera39.

FIG.4Bshows a portion of the plate9. A mark41for identifying the first surface (front surface) or the second surface (back surface) of the plate9is formed in the outer peripheral portion of the plate9. Since the mark41is formed in the region on the outer periphery side of the flat surface10, the mark41does not hinder planarization. The mark41can be, for example, a T7 mark complying with the SEMI standard. This mark is formed by a two-dimensional binary data matrix code symbol having a rectangular outer shape, and can be read by machine. The mark41includes a plurality of code symbols (dots) arranged asymmetrically.FIG.4Cshows an arrangement example of the mark41. The mark41is formed by a plurality of dots42. Each of the plurality of dots42is a local area having a refractive index different from that in the surrounding surface, and written in the plate9by, for example, a laser. A solid border43is a set of the dots arranged in an L-shape in the end portions of the mark41.FIG.4Cshows the mark41in a case in which the upper surface of the plate9placed on the plate chuck38forming a predetermined placement surface is the first surface. In this case, the shape of the solid border43is recognized as an L-shape. On the other hand,FIG.4Dshows the mark41in a case in which the upper surface of the plate9placed on the plate chuck38is the second surface, that is, in a case in which the plate9is placed in the opposite direction to the direction inFIG.4C. In this case, the shape of the solid border43is recognized as an inverted L-shape. Therefore, the front/back determination can be performed by the image processing device40detecting the mark41from the image and recognizing the shape of the solid border43in the detected mark41.

Note that the mode of the mark41is not limited to that shown inFIG.4C, and only required to have a feature that enables the front/back determination of the plate. For example, the mark41may be a directional notch formed in the outer peripheral portion of the plate.

FIG.5is a flowchart illustrating an operation of the planarization apparatus100from plate loading to a planarization process.

In step S701, the control device31controls the conveyance hand26to obtain the plate9placed in the load port25and convey it to the determiner27. The conveyed plate9is placed on the plate chuck38and held by the plate chuck38.

In step S702, the control device31controls the determiner27to measure the mark of the plate9. The measurement is performed by capturing the outer peripheral portion of the plate9by the camera39while rotating the driving stage36in the θZ direction. The image obtained by the camera39is transferred to the image processing device40. The image processing device40extracts the image of the mark from the image obtained by the camera39.

In step S704, for example, by recognizing the orientation of the solid border43in the extracted image of the mark, the image processing device40determines whether the upper surface of the plate9placed on the plate chuck38is the first surface (front surface) or the second surface (back surface). If it is determined that the upper surface of the plate9is the first surface, the control device31controls the conveyance hand26to convey the plate9to the reversing device28in step S705. The reversing device28turns over the plate9(reverses the plate9). With this, the upper surface of the plate9becomes the second surface, and the lower surface becomes the first surface. After this, in step S707, the control device31controls the conveyance hand26to convey the plate9to the adjuster30. If it is determined in step S704that the upper surface of the plate9is the second surface (back surface), the plate9is conveyed to the adjuster30without reversing the plate9by the reversing device28. Note that the next conveyance destination may be set in advance in accordance with the front/back state of the plate9, or the state may be notified to the user and the user may be allowed to select the conveyance destination.

In step S707, the adjuster30adjusts the prealignment state of the conveyed plate9. After this, in step S708, the control device31controls the conveyance hand26to convey the plate9adjusted by the adjuster30to the forming device50(more specifically, immediately below the plate chuck11). Thus, the plate chuck11chucks the second surface in a state in which the second surface of the plate9faces upward, and holds the plate9.

Thereafter, the controller200controls the forming device50to perform the planarization process on the substrate1using the plate9.

Note that the sequence has been described here in which the plate9is finally conveyed to the plate chuck11regardless of the result of the front/back determination of the plate9performed by the determiner27. However, the present invention is not limited to this. For example, the user can make setting such that, if it is determined that the plate9is in a wrong state (the upper surface of the plate9is the first surface), the plate9is immediately unloaded. If such the setting has been made and it is determined in step S704that the upper surface of the plate9is the second surface, this may be determined as an abnormal state and the conveyance hand26may convey the plate9to the load port25. Further, in this case, an alarm notifying the occurrence of the abnormal state may be output.

The adjuster30is not necessarily installed in the planarization apparatus100, and may be provided outside the planarization apparatus100. If the adjuster30is provided outside the planarization apparatus100, the plate is loaded into the planarization apparatus100in a state in which the prealignment state is adjusted in advance. In this case, the processing in step S707is eliminated, and the plate9reversed by the reversing device28is directly conveyed to the forming device50. If it is determined by the determiner27that the upper surface of the plate9is the second surface (NO in step S704), the plate9is conveyed to the forming device50(not to the adjuster30).

The case in which the front/back determination of the plate9is performed before the planarization process (step S709) is illustrated inFIG.5, but the front/back determination of the plate9may be performed after the planarization process as illustrated inFIG.6.FIG.6is a flowchart illustrating the process up to plate unloading after the planarization process.

In step S711, the control device31controls the conveyance hand26to obtain the plate9on the plate chuck11and convey it to the determiner27. The conveyed plate9is placed on the plate chuck38and held by the plate chuck38.

In step S712, the control device31controls the determiner27to measure the mark of the plate9. The measurement is performed by capturing the outer peripheral portion of the plate9by the camera39while rotating the driving stage36in the θZ direction. The image obtained by the camera39is transferred to the image processing device40. The image processing device40extracts the image of the mark from the image obtained by the camera39.

In step S714, for example, by recognizing the orientation of the solid border43in the extracted image of the mark, the image processing device40determines whether the upper surface of the plate9placed on the plate chuck38is the first surface (front surface) or the second surface (back surface). If it is determined that the upper surface of the plate9is the second surface, the control device31controls the conveyance hand26to convey the plate9to the reversing device28in step S715. The reversing device28turns over the plate9(reverses the plate9). With this, the upper surface of the plate9becomes the first surface, and the lower surface becomes the second surface. After this, in step S717, the control device31controls the conveyance hand26to convey the plate9to the load port25(a carrier arranged in the load port25).

The example in which the front/back determination of the plate9is performed after the planarization process has been described above with reference toFIG.6. The front/back determination of the plate and reversing the plate accordingly may be performed before the planarization process, may be performed after the planarization process, or may be performed before and after the planarization process. Note that although the conveyance of the plate9to the adjuster30and the alignment thereof are not described in the procedure ofFIG.6, if the plate9is likely to cause physical interference in the unloading path, the alignment step may be included.

According to the above-described process, it is possible to reduce troubles caused by loading the plate in a wrong state to the planarization apparatus.

Second Embodiment

A front/back determination method of a plate9according to the second embodiment will be described. In the second embodiment, an inclined portion is formed in the outer edge portion of at least the first surface of the plate, and a determiner27performs the front/back determination by detecting the inclined portion. A specific example will be described below.

FIG.7Ais a perspective view showing an example of the shape of the plate9in this embodiment. The plate9can be formed of a light transmissive material in consideration of a light irradiation step, and have a circular shape with a diameter of 300 mm (inclusive) to 500 mm (inclusive). In the plate9, for the purpose of uniform spreading of the material to the outer peripheral portion of the substrate during the planarization process, an inclined portion is formed in the outer peripheral portion on the side of the tight contact surface (first surface) which is to contact a substrate.

FIG.7Bis a top view of the plate9, andFIG.7Cis a side view showing the end face of the plate9. Let T1be the inclination start position from the plate center side in an inclined portion S1connecting an end face32of the plate9and the plane of a first surface9aof the plate9. Further, let T2be the inclination start position from the plate center side in an inclined portion S2connecting the end face32of the plate9and the plane of a second surface9bof the plate9. Note that the inclined portion S2may not be formed. θ1indicates the inclination angle of the inclined portion S1on the side of the tight contact surface (first surface9a) of the plate9which is to contact a substrate. θ2indicates the inclination angle of the inclined portion S2on the side of the second surface9bof the plate9. θ1and θ2are not equal to each other. For example, for the purpose of uniform spreading of the material to the outer peripheral portion of the substrate during the planarization process, θ1is smaller than θ2.

With reference toFIGS.8A to8E, the front/back determination method of the plate9according to this embodiment will be described. As shown in FIG.8A, two displacement sensors33and34as measurement devices are arranged at positions vertically facing each other with respect to the plate9. The two displacement sensors33and34are arranged equidistant from the plate9. The plate9held by a conveyance hand26is conveyed into the measurement range of the two displacement sensors33and34. It is desirable that the two displacement sensors are arranged at identical positions in the horizontal direction (X and Y directions). The determiner27performs the front/back determination by detecting the inclined portion based on the measurement results of the two displacement sensors33and34upon scanning the plate9.FIG.8Bshows a measurement graph in a case of measuring the distance while the plate9is inserted between the two displacement sensors33and34. The abscissa represents the plate movement distance, and the ordinate represents the measured plate distance. The measured value (distance) of the plate outer peripheral portion measured by each of the two displacement sensors33and34changes in accordance with the inclination angle of the inclined portion of the plate9. The smaller the inclination angle θ1, the larger an inclination α of a graph60regarding the plate movement distance and the measured plate distance. To the contrary, the larger the inclination angle θ2, the smaller an inclination β of a graph61. The distances to the plate outer peripheral portion are simultaneously measured using the two displacement sensors33and34and, if α>β, it can be determined that the upper surface of the plate9is the first surface (front surface) and the lower surface is the second surface (back surface). To the contrary, if α<β, it can be determined that the upper surface of the plate is the back surface and the lower surface is the front surface.FIG.5Cshows a case in which the two displacement sensors33and34are arranged at different distances from the plate9. Also in this arrangement, the front surface/back surface can be determined based on the difference in inclination. Each ofFIGS.5D and5Eis a graph showing the plate movement distance and the measured plate distance in a case of moving the plate in the direction away from the two displacement sensors33and34by the conveyance hand26. Also in this case, the front/back determination can be performed based on the inclination between the plate movement distance and the measured plate distance.

Accordingly, the front/back of the plate9can be determined in both cases of loading and unloading the plate9with respect to the two displacement sensors33and34by the conveyance hand26. Note that the positions of the two sensors33and34may not be equidistant from the plate9. For example, by measuring, in advance, the difference between the distances of the both sensors from the plate9and using the difference as a correction value in the determination, the both sensors need not be arranged equidistant from the plate9.

FIG.9Ashows a modification of the arrangement of the measurement devices shown inFIG.8A. InFIG.9A, photoelectric sensors35are arranged at predetermined positions from the upper surface and the lower surface of the plate outer peripheral portion, respectively. The inclined portion in the plate outer peripheral portion is irradiated with light from the photoelectric sensor35. The front/back determination of the plate9is performed based on the refraction angle of the light entering from the inclined portion and transmitted through the plate9. For example, a projector of the photoelectric sensor35is arranged above the plate, and the light transmitted through the plate9enters the receiver-side sensor arranged on the side of the plate lower surface.

FIG.9Bis a view schematically showing the optical path of the light emitted to the inclined surface of the plate upper surface. The light travels with an incident angle α1at the boundary surface between the air and the plate, which becomes a refraction angle α2in the plate. The light having travelled in the plate has an incident angle α3at the boundary surface between the plate9and the air, and is emitted into the air at a refraction angle α4. The light having the refraction angle α4is received by the light receiving side sensor.

FIG.9Cis a view schematically showing the optical path of the photoelectric sensor in a case in which the plate9is turned over in the state in which the photelectric sensors are arranged as inFIG.9B. The light travels with an incident angle β1at the boundary surface between the air and the plate, which becomes a refraction angle β2in the plate. The light having traveled in the plate has an incident angle β3at the boundary surface between the plate9and the air, and is emitted into the air at a refraction angle β4. The light having the refraction angle β4is not received by the light receiving side sensor. Thus, when the measurement is performed with the plate9in the turn-over state, due to the different inclination angles of the inclined portions, the light emitted from the light projecting side cannot be received by the light receiving side sensor. Therefore, the front/back of the plate9can be determined based on whether the light can be received. Note that in the example shown inFIG.9, the light projecting side sensor is arranged above the plate and the light receiving side sensor is arranged below the plate, but the arrangement may be reversed.

Third Embodiment

With reference toFIGS.10A to10C, a plate front/back determination method according to the third embodiment will be described. In the third embodiment, a coating film is formed on the first surface of a plate9, and the intensity distribution of reflected light upon emitting light toward the upper surface of the plate is measured. A determiner27performs the front/back determination based on the measurement result. A specific example will be described below.

FIG.10Ais a view showing the arrangement of the determiner27according to this embodiment. The determiner27is formed by a plate chuck (not shown) and a displacement meter44serving as a measurement device. The plate chuck holds the plate9. The displacement meter44can include, for example, a spectral interferometer (spectacle interference laser displacement meter). Alternatively, the displacement meter44can include a multi-layer film thickness measurement device. The displacement meter44is arranged above the plate9, and is configured to emit light toward the upper surface of the plate9. The plate9is coated with a coating material45for the purpose of protecting the surface from damage and facilitating a separation of the plate9from a cured material. The thickness of the coating material45is sufficiently smaller than the thickness of the plate9. The light emitted from the displacement meter44is reflected by each of a front surface A of the coating material45, a front surface B of the plate9with the coating material45coated thereon, and a back surface C of the plate9, and returns to the displacement meter44. An optical path46indicates the light reflected by the respective surfaces.

FIG.10Bis a graph showing the optical path length and the light intensity measured by the displacement meter44. Each of the positions of the plate9and the surface of the coating material45is indicated by the optical path length and the peak of the light intensity. Since the coating material45is thinner than the plate9, the distance between the front surface B of the plate9and the back surface C of the plate9is larger than the distance between the front surface A of the coating material45and the front surface B.FIG.10Cis a graph showing the optical path length and the light intensity measured by the displacement meter44when the plate9is reversed. The light emitted by the displacement meter44is reflected by each of a back surface A′ of the plate9, a front surface B′ of the plate9, and a front surface C′ of the coating material45and returns to the displacement meter44. With this, the arrangement of the plate9and the coating material45can be determined. In this manner, the front/back of the plate9can be determined based on the respective optical path lengths and the positions of the peaks of the light intensity.

In the above-described embodiment, a planarization apparatus100includes the determiner27that determines whether the upper surface of the plate9placed on a predetermined placement surface is the first surface including a flat surface or the second surface on the opposite side of the first surface. However, the determiner27may be implemented in, for example, an adjuster30.

Embodiment of Article Manufacturing Method

A method of manufacturing an article (a semiconductor IC element, a liquid crystal display element, a color filter, a MEMS, or the like) by using the above-described planarization apparatus will be described next. The manufacturing method includes, by using the above-described planarization apparatus, a step of planarizing a composition by bringing the composition arranged on a substrate (a wafer, a glass substrate, or the like) and a mold into contact with each other, a step of curing the composition, and a step of separating the composition and the mold from each other. With this, a planarized film is formed on the substrate. Then, processing such as pattern formation using a lithography apparatus is performed on the substrate with the planarized film formed thereon, and the processed substrate is processed in other known processing steps to manufacture an article. Other known steps include etching, resist removal, dicing, bonding, packaging, and the like. This manufacturing method can manufacture an article with higher quality than the conventional methods.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

This application claims the benefit of Japanese Patent Application No. 2021-109414, filed Jun. 30, 2021, which is hereby incorporated by reference herein in its entirety.