JP2004158847A - Apparatus and method for forming pattern on thin substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To securely form an exposed pattern without gradation on the processing region of a substrate (a substrate surface, namely the exposed surface of a processing object) in application such as an exposure apparatus, a processing apparatus, a method of exposure, a method of manufacturing thin-film transistors, and a method of manufacturing a display device. <P>SOLUTION: The substrate processing apparatus to be provided includes a holding table 1 for holding the substrate, an undulation or a thickness-unevenness detecting device 2, and a control unit 3 for operating the undulation or the thickness-unevenness detecting device, wherein the holding table 1 is locally deformed based on the detected undulation or the thickness unevenness of the substrate to deform the substrate in the range of the field to be processed. As a consequence the gradation of the image formed on the substrate is prevented. <P>COPYRIGHT: (C)2004,JPO

Description

  The present invention relates to an exposure apparatus, a processing apparatus, an exposure method, and a method for manufacturing a thin film transistor or a display apparatus, particularly for a substrate having a large thickness unevenness represented by a glass substrate used for a liquid crystal display or the like.

A semiconductor substrate or a glass substrate used for a liquid crystal display or the like has a structure in which a plurality of materials such as a semiconductor layer and an insulator layer are patterned and laminated. For this patterning, a photolithography technique is used.
In lithography technology, a photoresist is coated on a material to be processed to form a photoresist layer, an exposure pattern is formed on the resist layer (surface), the resist layer is developed, and then the resist layer in an undeveloped portion is removed. The remaining (obtained) portion is selectively processed by etching, deposition, or the like to form a circuit, a transistor, or the like.
A typical example of this exposure is a projection exposure method such as a lens projection exposure and a mirror projection exposure.
In this exposure method, an image (exposure pattern) of an original (mask) is projected onto the surface of a workpiece to which a resist layer has been applied, and an image corresponding to the exposure pattern is formed on the resist layer (by forming the exposure pattern). Is formed.
In the projection exposure, it is required that an imaging plane formed by the projection exposure, that is, a focal length of the projection apparatus and a distance of the exposure plane (resist plane) from the projection apparatus coincide.
However, the surface of the resist layer, that is, the exposed surface may include microscopic irregularities. The unevenness on the surface of the resist layer is caused by factors such as uneven thickness of the substrate on which the resist layer is formed, bending of the substrate, and flatness of the stage on which the substrate is mounted.
The amount of change in the unevenness of the resist layer surface needs to be within a range in which the depth of focus (DOF) of the imaging optical system (incorporated in the projection device) can maintain a predetermined level. Needless to say, if the exposure surface (and the distance from the projection device) is out of the range of the DOF, the light intensity distribution (aerial image) of the imaging pattern is deformed and the intended resist pattern (planar shape or cross-sectional shape) Can not be obtained. That is, as shown in FIG. 21, the portion A outside the range of the DOF is not resolved.
In general, the relationship between the resolution of an image on a resist layer in exposure and DOF is as follows.
DOF = kR ² / λ
It is assumed that λ: light source wavelength, R: line width (resolution), and k: proportional coefficient (a value of about 1 depending on the process).
At the time of exposure, the exposed surface of the resist layer surface must fall within the DOF at all points of the exposure field. That is, the exposure surface needs to be located at a position satisfying the following expression (1).
DOF>"Uneven thickness of substrate"
+ "Surface unevenness of stage (substrate holding part)"
+ "Focus accuracy (depending on the focal position of the imaging optical system of the projection device)
Allowable deviation from the focal length inherent in the imaging optical system) "
+ "Unevenness due to processed layer"
+ "Effect of imaging system aberration"
+ "Process margin" ... (1)
As shown in FIG. 22, when the thin substrate a is placed on the stage S, the size of the unevenness on the surface of the resist layer of the substrate a, that is, the exposed surface is represented by “(amount of thickness unevenness of the substrate) + (stage (The size of the surface irregularities) ”). These are collectively referred to as “swell T”.
Patent Document 1 describes that such “undulation T” is periodic, and that the “undulation T” causes a problem when exposing a fine pattern.
However, an exposure apparatus (exposure apparatus) capable of forming a predetermined pattern on a glass substrate used for a large-sized liquid crystal display device (for example, larger than 20 inches × 25 inches or a diagonal of 32 inches) It is not easy to satisfy the condition of the expression (1) for the following reasons a) and b).
a) In recent years, high-quality images have been required for displaying digital information. For this reason, a high resolution is required as the resolution (the line width R becomes fine), so that the DOF (the band in which the DOF is allowed) becomes narrow.
b) In particular, in the case of a liquid crystal display, not a silicon wafer having good flatness (used as a substrate of a semiconductor device) but a glass substrate having large thickness unevenness (compared to the flatness of the silicon wafer). In the manufacturing process, the size of the glass substrate is selected so that a plurality of glass substrates for a single display device can be formed (a plurality of glass substrates can be formed). Then, the thickness unevenness of the glass substrate apparently increases.
As a result, the maximum value and the minimum value of the thickness unevenness of the glass substrate deviate from the DOF in order to increase the resolution in order to reduce the line width.
For example, when a (minimum) pattern having a line width R = 1.0 μm is exposed in a 100 mm square exposure field on a liquid crystal display substrate having a size of 550 × 650 mm, the following values are adopted.
λ = 0.365 μm (used wavelength), k = 1.0
At this time, DOF is
DOF = kR ² /λ=2.7 μm
It becomes.
The exposure field needs to have a certain size or more with respect to the substrate size in order to shorten the time required for exposing the entire substrate. In the case of a substrate of about 550 × 650 mm or more generally used for a liquid crystal display, a 100 mm square is used. The degree has been adopted.
The thickness unevenness of a glass substrate used for a liquid crystal display is peak-to-peak, and is generally about 10 μm with a width of 100 mm.
Therefore, DOF <thickness unevenness of the substrate, and even if the other term is “0”, the expression (1) is not satisfied. In other words, where the image forming surface and the exposed surface (resist surface) largely separate due to thickness unevenness, the image formation of the exposed mask image (light intensity distribution on the exposed surface) is blurred. This is also a problem in Patent Document 1 described above.
It is known that the thickness unevenness of the glass substrate for a liquid crystal display is substantially one-dimensional as shown in FIG. That is, in FIG. 23, although there is thickness unevenness in the X direction, it is uniform in the Y direction. Typical methods for producing substrate glass include a fusion method and a float method, both of which result from the characteristics of this production method.
On the other hand, as an exposure method used for manufacturing a thin film transistor (TFT) used for a liquid crystal display or the like, a step-and-repeat method or a step-and-scan method is mainly used. is there. However, in any type of exposure apparatus or the like, only a stage for holding an exposure substrate is provided, and there is no necessity or a countermeasure for a mechanism or an unevenness measuring stage for flattening unevenness on the surface. .
In the step-and-repeat method, before and after exposure, irregularities on the surface of a substrate to be exposed are measured by an auto-focus system on a substrate stage for each exposure (shot), and the optimal exposure surface and the image forming system of the exposure apparatus are measured. Is determined by tilting or lifting, which is movement of the substrate up and down, and then exposure (static exposure) is performed.
When performing a step-and-repeat exposure by adding a mechanism that flattens the surface irregularities to the exposure substrate stage, the exposure is performed before a continuous series of static exposure operations (just an exposure operation). The surface unevenness of the substrate to be exposed placed on the substrate stage is measured. Therefore, the time until the end of the exposure is lengthened, and the throughput is reduced.
In the step-and-scan method, c) the unevenness of the surface of the substrate to be exposed placed on the exposure substrate stage is measured before the scanning exposure, and d) the optimum exposure surface is chilled based on the measurement data at the start of the scanning exposure. Scanning exposure is performed while deciding by lifting and lifting.
At this time, the scanning exposure may be performed while simultaneously adding the focus control. As described above, in the step-and-scan method, the time for measuring the surface unevenness of the substrate to be exposed on the exposure substrate stage is included in the exposure time, and the time until the end of the exposure is increased by that amount. Similarly, the throughput decreases.
In Patent Document 2, before the substrate to be exposed is conveyed onto the exposure stage, the unevenness of the surface of the substrate to be exposed is measured, and the surface unevenness of the substrate to be exposed is flattened by, for example, a plurality of two-dimensionally arranged piezo elements. There is disclosed a method for converting the data. However, precise control means for partially adjusting the height using a large number of piezo elements arranged two-dimensionally is required.
JP 2001-36088 A JP-A-63-260129

The problem to be solved is that where the imaging surface and the exposure surface are largely separated by the thickness unevenness of the glass substrate used in the large-sized liquid crystal display device, the image of the mask is blurred, and the resist is as desired. Is that the pattern cannot be formed.
Further, a problem to be solved is that, when exposure is performed by adding a flattening mechanism, the time required until the exposure is completed becomes longer, and the throughput is reduced.
Further, a problem to be solved is that the flattening mechanism becomes a large-scale apparatus, and the cost of the exposure apparatus further increases.
An object of the present invention is to provide an exposure apparatus, a processing apparatus, an exposure method, a method for manufacturing a thin film transistor, a method for manufacturing a display apparatus, and the like, in which a processing area (substrate surface, that is, an exposure surface) of a substrate (processing object) has no blur. The purpose is to surely form an exposure pattern.

The present invention includes detection means for detecting undulation or uneven thickness on the surface of the substrate to be exposed, and a support mechanism which is long in a direction orthogonal to the direction of undulation or uneven thickness detected by the undulation or uneven thickness detection means. A support mechanism for supporting the substrate to be exposed, wherein a plurality of the support mechanisms are arranged in the direction of the undulation or thickness unevenness and can be independently displaced in a displacement direction orthogonal to the surface of the substrate to be exposed. Holding means, and a plurality of support mechanisms for the holding means are provided along a length direction of the support mechanism, and suction means for sucking and holding the substrate to be exposed. An object of the present invention is to provide an exposure apparatus for exposing an exposure pattern on a substrate to be exposed.
Further, the present invention provides a detecting means for detecting undulation or thickness unevenness on the surface of the object to be processed, and detecting the undulation or thickness unevenness in a direction orthogonal to the direction of the undulation or thickness unevenness on the surface of the object to be processed. A plurality of holding means including suction plates displaceable in a direction orthogonal to the surface of the object to be processed, each of which is arranged along the direction, and provided on each of the suction plates, wherein the object to be processed is provided. An object of the present invention is to provide a processing apparatus for processing an object to be processed, which is provided on a stage, and having a suction unit for performing suction.
In addition, the present invention may be configured such that the substrate to be exposed is positioned on the holding means such that a direction orthogonal to the direction of the undulation or thickness unevenness of the surface of the substrate to be exposed coincides with the long side direction of the suction plate. An exposure method for exposing an exposure pattern to a substrate to be exposed provided at a predetermined position of a holding means in which a plurality of suction plates are arranged, wherein the exposure is performed after being arranged together.
In addition, the present invention provides an adsorption step of adsorbing the substrate to be exposed on the surface of the adsorption plate, a step of detecting undulation or uneven thickness of the surface of the substrate to be exposed, and a step of detecting undulation or uneven thickness. Adjusting the suction plate to adjust according to the undulation or thickness unevenness detected in the undulation or thickness unevenness detection step in the direction orthogonal to the substrate surface to be exposed, the suction plate long in the direction orthogonal to the direction. An exposure method for exposing an exposure pattern to a substrate to be exposed provided at a predetermined position of a holding means in which a plurality of suction plates are arranged.
Further, the present invention provides a suction step of adsorbing the substrate to be exposed on the surface of the suction plate, a detecting step of detecting undulation or uneven thickness of the surface of the substrate to be exposed, and a step orthogonal to the direction of the undulation or uneven thickness. Adjusting the suction plate, which adjusts the suction plate that is long in the direction to be perpendicular to the surface of the substrate to be exposed, in accordance with the waviness or thickness unevenness detected by the waviness or uneven thickness detection step; Exposing a predetermined exposure pattern to a substrate to be exposed on which a semiconductor thin film is formed in advance in a state in which the suction plate is adjusted according to A thin film transistor for manufacturing a thin film transistor by exposing a thin film transistor pattern to a substrate to be exposed provided at a predetermined position of a holding means in which the plates are arranged. It is a method for producing a register.
In addition, the present invention provides an adsorption step of adsorbing the substrate to be exposed on the surface of the adsorption plate, a step of detecting undulation or uneven thickness of the surface of the substrate to be exposed, and a step of detecting undulation or uneven thickness. Adjusting the suction plate to adjust according to the undulation or thickness unevenness detected in the undulation or thickness unevenness detection step in the direction orthogonal to the substrate surface to be exposed, the suction plate long in the direction orthogonal to the direction. Exposing a predetermined exposure pattern by an exposure unit to a substrate to be exposed on which a semiconductor thin film is formed in advance in a state in which the suction plate is adjusted according to undulation or thickness unevenness; Facing the substrates and disposing an electro-optical material having a predetermined thickness between the substrates.

According to the present invention, the suction mechanism that holds the plate-like body as the processing target has a maximum value of the displacement in the surface direction of the processing target region of the plate-like body that is smaller than the allowable capacity of the displacement of the processing apparatus. Since the correction can be performed so as to fall within the predetermined range, the processing for the plate-like body to be processed is made uniform.
Further, according to the present invention, the total processing time required for all the steps, particularly for the end of the exposure, is reduced. The deformation element for deforming the substrate may be prepared linearly or one-dimensionally in accordance with the characteristics of undulation or thickness unevenness, that is, displacement, and the cost of the apparatus is reduced.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram for explaining a configuration of a correction device for correcting the influence of undulation or thickness unevenness on an exposure surface according to the present invention.
An object a, for example, a predetermined area of a plate-like body such as a glass substrate or a silicon wafer, that is, a waviness or thickness unevenness correction device for correcting waviness or thickness unevenness of an exposed surface is a holding means (a substrate deformation mechanism) for holding the substrate a. 1, a waviness or thickness unevenness detecting means 2 for detecting waviness or thickness unevenness of the substrate a placed on the holding means 1, and a control device 3 for controlling the operation of the waviness or thickness unevenness correction device. For the control device 3, for example, a personal computer or the like can be used.
The holding means 1 serves to deform a plurality of suction plates (suction means) 11 for sucking the substrate a and the substrates a sucked by the suction plate 11, and includes, for example, a plurality of substrates including piezoelectric elements (deformation means). It comprises a deformation element 10 having a deformation element 12, and a stage 13 supporting the deformation element 10.
The suction plate 11 is made of a material having appropriate rigidity, flexibility and elasticity, for example, an elastic material such as silicon rubber integrally formed on a surface of a metal plate such as aluminum, as shown in FIG. A plurality of vacuum suction holes b are provided substantially at the center of the length direction along the length direction. Each vacuum suction hole b is schematically described in FIG. 1, but is connected to the vacuum pump 14 via a flow path (a communication pipe not shown) connected to each of the suction holes b, that is, a pipe 14a. I have. The plurality of piezoelectric elements 12 described above are fixed on both left and right sides of the suction hole b on the bottom surface of each suction plate 11. The suction plates 11 are also arranged in parallel with a plurality of suction plates 11 having substantially the same length as the width of the substrate a at a constant interval along a direction in which the thickness unevenness of the substrate a is large. Preferably, the suction plates 11 are arranged at a pitch equal to or less than 基本 of the basic period in the thickness unevenness of the substrate a.
When the exposure surface of the substrate a is horizontal, the holding means 1 can deform the substrate a by independently moving the deformation element 10 in the vertical direction, or by tilting the deformation element 10 simultaneously with the vertical movement. That is, the substrate a is deformed by deforming the holding means 1 based on the undulation or thickness unevenness of the substrate a detected by the undulation or uneven thickness detection device described below, and the exposure surface of the substrate a will be described later. The correction is made so as to substantially coincide with the image plane formed by the image forming optical system of the pattern exposure apparatus.
In addition, as the deforming means, one using magnetism such as a solenoid coil, one using static electricity, an actuator or the like can be used. It is desirable that the substrate a be fixed by a suction means such as a vacuum chuck, an electrostatic chuck, or a mechanical clamper as the holding means 1. Further, it is desirable that the holding means 1 also has a suction means in addition to the deformation means. The electrostatic chuck is formed by integrally sintering a plurality of internal electrodes which are spaced apart and opposed to each other between two upper and lower ceramics, for example, and an electrostatic force generated between the ceramic and a substrate placed on the surface thereof Is used to fix the substrate a.
The piezoelectric element 12 is an element that expands and contracts in proportion to the applied voltage, is capable of high-precision control of minute displacement, has a high response speed, and has a large generated stress. Used for mirror control.
Specifically, as shown in FIG. 3A or 3B, the piezoelectric element 12 has a structure in which a piezoelectric ceramic C is sandwiched between two electrodes A and B, and switches the polarity of a voltage applied to the electrodes A and B. Thereby, the piezoelectric ceramics C can be compressed or expanded in the thickness direction. Further, the amount of expansion and contraction of the piezoelectric ceramics C can be finely adjusted by the magnitude of the voltage applied to the electrodes A and B.
The undulation or uneven thickness detecting means 2 irradiates a laser light L of a light source, for example, a semiconductor laser 21 at a predetermined angle to the surface of the substrate a, captures the specularly reflected light by a lens 22, and outputs the position detection device (PSD). : Position Sensitive Device (hereinafter simply referred to as PSD) 23.
The PSD 23 has two signal extraction electrodes, and can specify the position where the reflected light R is imaged from the ratio of the output currents output from the respective electrodes. The undulation or uneven thickness of the surface of the substrate a, which is the object, is detected by calculating the direction and the amount of displacement based on the output signal output from the PSD 23. In order to improve the accuracy of detecting undulation or thickness unevenness by the PSD 23, several points, for example, five points on the substrate surface are irradiated with the height measuring laser light L, and the reflected light R corresponding to each measuring laser light is irradiated. Preferably, it is detected.
As shown in FIG. 23, it is known that the characteristic of the undulation or uneven thickness of the glass substrate is almost one-dimensional due to the method of manufacturing the glass substrate. Is generated only in one dimension, for example, in one direction of the substrate a, for example, in the length direction, and not in the width direction of the substrate a, for example, in a direction orthogonal to the substrate a.
As a method of detecting undulation or thickness unevenness, in addition to the method of using the reflected light R as described above, there are a method of using light interference shown in FIG. 4A, a method of using a stylus P shown in FIG. 4B, and the like. . Of these methods, the method using light interference and the method using the stylus P need to be detected before loading the substrate a (transferring the substrate to a predetermined position for processing by a substrate processing apparatus such as an exposure apparatus). However, the method using the reflected light R described above can be detected even when the substrate a is placed on the stage 13.
The method using the light interference detects only the thickness unevenness of the substrate a, but the method using the stylus P and the method using the reflected light R can detect the undulation of the exposed surface.
According to the above-described measuring method of scanning and irradiating the exposure surface of the substrate a with the laser beam L and receiving the reflected light R generated as a result and performing signal processing, the thickness and surface displacement of the transparent body are measured. By using a commercially available laser focus displacement meter (easily available), it is possible to detect the direction of the undulation or uneven thickness of the substrate a and the amount of displacement with an accuracy of, for example, 0.1 μm.
In any of the detection methods, the detection means and the detection step, and the other means and the detection step may be separated. In addition, the processing time can be shortened by detecting undulation or thickness unevenness in a region of the substrate to be exposed next in parallel with the exposure.
In the control device (personal computer) 3, the control system of the undulation or thickness unevenness detecting means 2 is connected to the input side, and the control system of the holding means 1 is connected to the output side. The output current of the PSD 23 is A / D converted by an A / D converter (not shown) and input to the control device 3, from which the direction of undulation or uneven thickness of the substrate a and the amount of displacement are calculated.
The control device 3 controls each piezoelectric element 12 according to the direction of undulation or uneven thickness and the amount of displacement and the positional relationship of the piezoelectric element 12 so that all points on the exposure surface of the object, that is, the glass substrate a fall within the range of the DOF. Is calculated, and a voltage having a polarity and magnitude corresponding to the expansion direction and the expansion amount is output to each piezoelectric element 12.
For example, as shown in FIG. 20, a displacement distribution (direction of swell or thickness unevenness and displacement amount) in the exposure field is calculated based on an output from the PSD 23 (after A / D conversion) (S11).
From the displacement distribution in the exposure field obtained in S11, a correction amount z,
z = ax + b
Are determined (S12).
A tilting amount and a leveling amount for locally deforming the glass substrate a held by the holding means 1 are obtained based on the correction amount z (a, b) obtained in S12 (S13).
On the basis of the tilting amount and the leveling amount obtained in S13, the operation direction for each of the piezoelectric elements (deformation means) 12 arranged in a predetermined arrangement on the stage 13, that is, the expansion / compression and the control amount (elongation). Amount / compression amount) (S14).
The operating direction (extension or compression) of each piezoelectric element 12 and the amount (extension / compression amount) of the individual piezoelectric elements 12 determined in this way are determined by the polarity to be supplied to the piezoelectric element 12 by a D / A converter (not shown). And voltage of magnitude.
There are various other approximation methods for the linear approximation algorithm, such as determining the amount of tilting from the maximum value and the minimum value and determining the amount of leveling from the average value.
The correction of the influence of the undulation or the uneven thickness may be performed only in one dimension in the direction in which the undulation or the uneven thickness of the substrate a is large, similarly to the detection of the undulation or the uneven thickness.
In this case, the polarities and magnitudes of the voltages output to the piezoelectric elements 12 arranged in the length direction of the bottom surface of the suction plate 11 are all the same. By performing the detection of the undulation or uneven thickness and the correction thereof only in one dimension, the configuration of the undulation or uneven thickness detecting means 2 and the deforming means becomes simple and the control becomes easy.
As another correction method, the substrate a is deformed by detecting the undulation or thickness unevenness of the substrate a and distributing the vacuum suction force (air pressure) on the back surface of the substrate a in accordance with the undulation or the unevenness of the thickness of the exposure surface. May be corrected so as to match. In this case, an elastic material may be used for the surface in contact with the substrate a so that the deformation of the substrate a can follow a large undulation.
FIG. 5 schematically illustrates a substrate processing apparatus, for example, an exposure apparatus including an exposure surface waviness correction apparatus embodying the present invention, and an image forming optical system between an original (mask) 4 and a substrate a. 5, the surface of the substrate a is divided into a plurality of exposure fields c by a step-and-repeat method, and undulation detection, correction, and exposure are performed for each exposure field.
When the substrate a is set horizontally, the initial voltage applied to the piezoelectric element 12 is first set to 0 V (reference voltage by calibration) so that all the piezoelectric elements 12 are at the same height, and the substrate a is loaded on the stage 13. To be held on the suction plate 11.
Next, the laser beam of the semiconductor laser 21 is scanned in the long side direction of the substrate a to detect one-dimensional undulation or thickness unevenness in the exposure field (see FIG. 1).
Subsequently, the substrate a is deformed by operating (displacing) the piezoelectric element 12 in the exposure field in a direction opposite to the direction of the detected undulation or thickness unevenness, thereby correcting the undulation or thickness unevenness of the exposed surface of the substrate a. I do.
That is, when the direction of the undulation or thickness unevenness is upward (convex in a direction orthogonal to the surface direction of the substrate a), the piezoelectric element 12 is compressed to lower the exposure surface, and the direction of the undulation or thickness unevenness is downward (for the substrate a). When it is concave in the direction perpendicular to the plane direction), the piezoelectric element 12 is extended to push up the exposed surface.
When the suction plate 11 comes into contact with the peak or valley of undulation or uneven thickness, the left and right piezoelectric elements 12 are set at the same height, and the exposure surface is moved in parallel in either of the upper and lower directions.
When the suction plate 11 is in contact between the peaks and valleys of the undulation or uneven thickness, the right and left piezoelectric elements 12 are set at different heights, and the exposure surface is inclined in a direction to cancel the undulation or uneven thickness.
In this manner, when the height of the exposure surface in substantially the entire area of the exposure field of the substrate a coincides with the focal position of the imaging optical system of the exposure apparatus or the processing apparatus, the original 4 is irradiated with illumination light. The exposure field c of the substrate a is exposed.
As a result, in the currently selected (exposed) exposure field, as shown in FIG. 19, the height of the exposure surface is located within the DOF almost over the entire exposure field, and an image without blur on the substrate a is obtained. It is formed.
As another exposure method, scanning exposure for exposing while simultaneously moving the original 4 and the substrate a with respect to the imaging optical system 5 may be adopted. In this case, the substrate a need only be deformed with respect to the exposure field c. Further, the undulation or thickness unevenness may be detected at the same time as the exposure (real time) or during the step operation, and it is not necessary to detect the entire undulation or thickness unevenness in advance. That is, the detection time and the total processing time required until the end of exposure can be reduced. In addition, since the area that must be deformed at a time is reduced, the size of the deformation mechanism is reduced, and the control thereof is facilitated.
Hereinafter, an embodiment using a piezoelectric element as a deformation unit for deforming the substrate a will be described.
A liquid crystal display glass (non-alkali glass) having a size of 550 × 650 mm and a thickness of 0.7 mm was used as the substrate a. The undulation or thickness unevenness of this glass substrate, for example, thickness unevenness was basically only in the long side direction of the substrate, and in the direction of large thickness unevenness, the peak-to-peak peak was 10 μm, and its basic period was about 100 mm.
The piezoelectric element 12 having a stroke of 15 μm was used.
The length of the suction plate 11 is the same as the short side of the substrate a, and the deformation element 10 (see FIG. 2) including the vacuum suction hole b and the piezoelectric element 12 is moved along the long side in the direction of the undulation or thickness of the substrate a. A total of thirteen pieces were arranged at a pitch of 50 mm, which is の of the basic cycle of unevenness, for example, thickness unevenness.
The substrate a is loaded onto the stage 13 provided with the deformable element 10, and the surface of the substrate a is detected for undulation or thickness unevenness in a state of being sucked by the suction plate 11, and corresponding to the piezoelectric elements 12 according to the information. A voltage was applied to correct undulation or thickness unevenness. The height of the deformable element 10 was made non-uniform by changing the amount of displacement of the left and right piezoelectric elements 12 so as to make it easier to adhere to the substrate a.
While maintaining this state, step exposure was performed in a 100 mm square exposure field by lens projection exposure. At this time, the minimum line width is 1 μm, and the depth of focus (DOF) is
λ = 0.365 μm (used wavelength), k = 1.0
At this time, DOF is
DOF = kR ² /Λ=2.7 μm. Therefore, the substrate a having undulations or thickness unevenness with a basic period of 100 mm or 10 μm normally should not partially resolve, but a complete resist pattern was obtained over the entire surface.
As described above, according to the above-described embodiment, the undulation or uneven thickness device that corrects undulation or thickness unevenness existing on the substrate surface, that is, the exposed surface, allows the exposed surface to form an imaging optical system during the exposure time. Undulation or thickness unevenness of the substrate surface can be corrected so as to fall within the depth of focus. Therefore, the divergence between the imaging surface and the exposure surface due to the undulation or uneven thickness of the substrate surface is reduced, and even when the exposure pattern is exposed by the exposure apparatus having a small depth of focus, the exposure pattern formed on the exposure surface is blurred. Is reduced. As a result, ultra-fine pattern processing can be performed even on a substrate having a large undulation or thickness unevenness (processing target or processing target), such as a glass substrate used for a liquid crystal display or the like.
Next, more specific embodiments of the present invention will be described with reference to the drawings.
FIG. 6 is a schematic view of an exposure apparatus embodying the present invention.
As shown in FIG. 6, an exposure apparatus 301 that exposes a pattern on a glass substrate includes an exposure performing unit 30 and a thickness measuring unit 40.
The exposure performing unit 30 includes, for example, an illumination system (illumination device) 31, a mask (original) 32, a mask scan stage 33, a mask holder 34, an imaging optical system 35, a substrate scan stage 36, a substrate deformation unit 37, and the like.
The plate thickness measuring unit 40 includes a loader 41, a robot arm 42, a double-sided plate thickness sensor 43, a back plate thickness sensor 44, a substrate 45 to be exposed, a substrate cassette 46, and the like.
The exposure apparatus 301 shown in FIG. 6 uses a step-and-scan method, but the basic operation is the same in a step-and-repeat method.
The illumination system 31 is a light source, for example, a KrF excimer laser device that emits a wavelength and energy light sufficient for exposing and exposing an object to be exposed, for example, a resist layer. Note that, in this example, the traveling direction of the laser light output from the light source 31 is changed by approximately 90 ° via the reflecting mirror 111.
The laser beam whose traveling direction is changed by 90 ° by the reflecting mirror 111 is given a predetermined cross-sectional beam shape by an optical lens 112 which enlarges or reduces the cross-sectional beam shape to a predetermined shape and size for irradiating the mask 32. Can be
The mask 32 is disposed at the focal position of the optical lens 112 and provides a predetermined exposure pattern (optical image) to a resist layer previously applied to a predetermined surface of the substrate, that is, the glass substrate 42. The optical image, that is, the exposure pattern formed by the mask 32 is a circuit pattern or a MOS-TFT structure pattern.
The mask scan stage 33 moves the mask 32 temporarily fixed to the mask holder 34 in a predetermined direction, for example, an x direction by a predetermined program.
The imaging optical system 35 forms an optical image transmitted through the mask 32 on the surface of the resist layer.
The substrate scan stage 36 is movable at a predetermined timing in the same direction as the mask 32, for example, in a predetermined procedure in the x direction.
The substrate deforming section 37 is a suction mechanism that deforms the substrate in a direction to cancel the waviness on a substrate having waviness or uneven thickness on the surface, for example, a one-dimensional suction plate as described above with reference to FIG. . The suction force of the suction plate can be changed within a predetermined range based on the size of the undulation or thickness unevenness of the substrate 45 to be exposed. In this case, for example, the displacement of the pump 14 (see FIG. 1) may be directly changed, or an adjustment mechanism (not shown), for example, an electromagnetic valve or the like is provided at a predetermined position of the pipe 14a, and the opening thereof is controlled by the controller 3. May be controlled by As the suction plate, a temporary fixing means such as a vacuum suction or an electrostatic chuck in which a large number of suction holes connected to a vacuum pump are arranged is optimal.
The loader 41 is a mechanism for aligning a substrate cassette 46 containing an arbitrary number of substrates 45 so that a substrate to be exposed before exposure processing, for example, a substrate 45 for exposure can be automatically taken out by a robot arm 42. The positioning mechanism can be moved by a drive transmission mechanism (not shown) to a predetermined height (position) for the robot arm 42 to take out the substrate 45 to be exposed next. In addition, as a drive transmission mechanism, for example, a ball screw or the like can be used.
The robot arm 42 has a mechanism for taking out the substrate 45 to be exposed next from the substrate cassette 46 and aligning the substrate 45 with a predetermined position on the substrate scan stage 36 for installation.
It is desirable that the portion of the robot arm 42 that comes into contact with the substrate 45 to be exposed is made of metal, for example, aluminum whose surface is treated with alumina, because it can suppress generation of dust.
The robot arm 42 is supported by an operation shaft that can rotate 360 ° in an arbitrary direction of XYR · θ of the robot. The robot is, for example, a scalar robot.
The double-sided board thickness sensor 43 or the backside board thickness sensor 44 measures the plate thickness of the substrate 45 to be exposed taken out of the substrate cassette 46 from the front surface and the back surface, respectively. Is detected. The double-sided board thickness sensor 43 and the back-side board thickness sensor 44 are connected to a signal processing system (for example, the control device 3 shown in FIG. 1). Although FIG. 6 shows both the double-sided plate thickness sensor 43 and the backside plate thickness sensor 44, at least one of them may be provided for implementation.
The substrate 45 to be exposed is, for example, a substrate in which a base insulating layer, an amorphous semiconductor layer, a resist layer, and the like are sequentially laminated on a glass substrate for a liquid crystal display device.
The substrate cassette 46 accommodates the substrate 45 to be exposed, is mounted on the loader 41, and is arranged at predetermined intervals so that the substrate 45 can be automatically loaded by the robot arm 42. is there.
Next, a transfer process for exposing the substrate 45 to be exposed will be described.
First, any one of the substrates 45 accommodated in the loader 41 is transported by the robot arm 42 to a predetermined position where the sensors 43 and 44 are provided (S101, transport step). That is, as shown in FIG. 8, first, the substrate 45 to be exposed stored in a predetermined position is taken out of the substrate cassette 46 by the robot arm 42.
Next, the sensor 43 and the sensor 44 are stopped at the sensor unit, and the undulation or thickness unevenness inherent to the substrate 45 is measured (S102, a measuring step). The measurement step is a step of measuring the thickness of the substrate 45 to be exposed on the robot arm 42 or the thickness of the glass substrate by the double-sided thickness sensor 43 or the back surface thickness sensor 44, for example. As described above with reference to FIG. 23, the characteristic of the undulation or thickness unevenness of the glass substrate is known to be substantially one-dimensional due to the method of manufacturing the glass substrate. In the case of a glass substrate having a plate thickness that fluctuates in a short cycle, the measurement position may be scanned one-dimensionally by scanning the measurement position in a direction in which the plate thickness fluctuation is large (x direction in FIG. 7).
Therefore, since the thickness variation occurs at a constant cycle, the thickness variation data of the entire surface can be obtained by one scan, and the measurement time of the thickness variation of the substrate 45 to be exposed can be shortened. . This measurement may be performed by scanning the measurement position two-dimensionally over the entire surface at intervals of several mm, but if the unevenness is regular as shown in FIG. 7, it is better to measure it one-dimensionally. The measurement time is shorter. In addition, this is sufficient for a substrate having a large thickness variation in one direction, such as a glass substrate as shown in FIG.
As described above, when measuring the undulation or the thickness unevenness of the substrate 45 to be exposed, it is more preferable that the exposure performing unit 30 performs the alignment and the exposure on the substrate 45 to be exposed placed before the substrate deforming unit 37. Desirably, the exposure process time can be reduced.
Thereafter, the substrate 45 to be exposed is placed from the substrate cassette 46 to the substrate deforming section 37 by the robot arm 42.
Hereinafter, the surface of the substrate 45 to be exposed is flattened in the substrate deforming section 37, and an optical image (MOS-TFT) transmitted through the mask 32 by the imaging optical system 35 on the semiconductor thin film previously formed on the substrate. That is, a pattern for a thin film transistor) is formed on the surface of the resist layer, and the next step is performed as necessary.
When a liquid crystal display panel is formed, the first glass substrate on which the TFT pattern is formed in each of the above-described steps, and a swelling or thickness unevenness corrected in the same step as the first glass substrate for the opposite substrate. After the second glass substrate on which the pattern is formed is opposed at a predetermined interval, an electro-optical material such as a liquid crystal material having a predetermined thickness is disposed between the two substrates, and the driving circuit is hermetically sealed between the two substrates. A liquid crystal panel is formed by adding the above.
Next, the operation of the exposure apparatus described in FIG. 6 will be described in detail with reference to FIGS. 8 and 9, the same parts as those in FIG. 6 are denoted by the same reference numerals, and detailed description thereof will be omitted.
As shown in FIG. 9, in the transporting step (S103), the substrate 45 to be exposed on which the thickness measurement on the robot arm 42 has been completed is transported to a predetermined position of the substrate deforming section 37.
Next, the flattening step (S104) is performed as follows. That is, during this transport operation, the surface of the substrate deforming portion 37 is made uneven (vertical direction) based on the measurement data of the thickness unevenness so that the exposed surface of the substrate 45 to be exposed becomes flat (cancel). Control).
Next, an alignment process and an exposure process for the substrate 45 to be exposed are performed (S105).
When the exposure process is completed, the substrate 45 to be exposed is stored in the substrate cassette 46 for storing another exposed substrate or the same substrate cassette 46 (S106). Alternatively, it may be transferred to the next step, for example, a developing device.
Next, a description will be given of how the above process is performed with reference to a time chart shown in FIG.
10, the substrate 45 to be exposed is taken out (S101), a measurement step of measuring the thickness of at least the exposed area of the substrate 45 to be exposed (S102), and the conveyance of the substrate 45 to be exposed to the substrate deforming section 37 is performed. Step (S103), a flattening step (S104) for making the surface of the substrate deformed portion 37 uneven, an exposure step (S105) for aligning and exposing the substrate 45 to be exposed, and a substrate cassette 46 for exposing the substrate 45 for exposure. The transporting process (S106) for storing the sheets overlaps. Therefore, it can be seen that the time required until the exposure of the substrate is completed is shorter than in the case of using a known exposure apparatus in which the detection of the waviness or thickness unevenness of the substrate and the exposure step are independent.
Next, another embodiment of the exposure apparatus described above with reference to FIG. 6 will be described with reference to FIG.
A feature of the exposure apparatus shown in FIG. 11 is that an unevenness measuring stage 47 and a surface unevenness sensor 48 are provided instead of the double-sided thickness sensor 43 and the back surface thickness sensor 44 of FIG. The same parts as those in FIG. 6 are denoted by the same reference numerals, and a detailed description thereof will be omitted.
The substrate 45 to be exposed is carried into the substrate cassette 46 at a predetermined position.
The substrate 45 to be exposed is transferred from the substrate cassette 46 to the unevenness measuring stage 47 by the robot arm 42.
The unevenness of the surface of the substrate 45 to be exposed on the unevenness measuring stage 47 is measured by the surface unevenness sensor 48.
The output from the surface unevenness sensor 48 is connected to a signal processing system that amplifies an unevenness (undulation) signal on the surface of the substrate 45 to be exposed and outputs a signal for driving the stage so as to cancel the undulation.
The arrangement of the holes and grooves for vacuum suction provided on the surface of the unevenness measuring stage 47 that is in contact with the substrate 45 to be exposed is the same as the arrangement of the substrate deforming section 37.
The substrate 45 for exposure is also deformed by these holes and grooves, so that the substrate 45 for exposure placed on the substrate deforming portion 37 is brought into the same state as at the time of measurement.
Next, an embodiment of handling the substrate 45 to be exposed by the exposure apparatus of FIG. 11 will be described with reference to FIGS.
First, in the unloading step (S201), a predetermined substrate 45 to be exposed for the next exposure processing is taken out of the substrate cassette 46 by the robot arm 42. This removal operation is performed by a program stored in the memory of the control device 101 in advance. That is, the loader 41 is operated to set the storage position of the substrate 45 to be exposed for the next exposure processing to a predetermined position. This position is a position set in advance for the robot arm 42 to move the substrate 45 to be exposed into and out of the substrate cassette 46. The loader 41 rotates the ball screw contained in the loader 41 so as to coincide with the position, thereby aligning the position.
Next, after the robot arm 42 is rotated by the control of the control device 101, the robot arm 42 is inserted between the substrate 45 to be exposed and the substrate 45 to be exposed stored below the substrate 45, and The substrate 45 to be exposed is taken out of the substrate cassette 46 by moving the robot arm 42 upward by a predetermined set amount and performing an operation of returning with the substrate 45 to be exposed placed on the robot arm 42. .
Next, as shown in FIG. 14, in the transporting step (S202), the substrate 45 to be exposed on the robot arm 42 is transported and positioned at a predetermined position on the unevenness measuring stage 47. .
Here, in the surface unevenness measurement step (S203), the surface unevenness sensor 48 measures the unevenness of the surface of the substrate 45 to be exposed.
The unevenness measurement data of the surface of the substrate 45 to be exposed by the surface unevenness sensor 48 is stored at a predetermined position in a memory of the control device 101 and is used for the flattening operation of the surface of the substrate 45 to be exposed. After the controller 101 receives the signal for ending the measurement of the unevenness of the surface of the substrate 45 to be exposed, the controller 101 moves the substrate 45 to be exposed on the unevenness measuring stage 47 by the robot arm 42 as shown in FIG. The transfer to a predetermined position on the substrate deforming section 37 is controlled (a transfer step (S204)).
During this transport operation, the control device 101 reads out the unevenness measurement data of the surface of the substrate 45 to be exposed stored in the memory, and based on the measurement data so that the exposure surface of the substrate 45 to be exposed becomes flat. The surface of the substrate deforming section 37 is controlled so as to be uneven (flattening step (S205)).
That is, as the unevenness control of the surface of the substrate deforming section 37, the surface of the substrate 45 to be exposed placed on the substrate deforming section 37 is controlled to be flat. The flattening operation area on the surface of the substrate 45 to be exposed may be moved for each exposure area, or may be performed all at once.
Next, alignment and exposure of the substrate 45 to be exposed mounted on the substrate deforming section 37 are performed (exposure step (S206)). The positioning is performed by an operation of matching a predetermined reference position of the substrate deforming section 37 with a predetermined positioning position of the substrate 45 to be exposed under the control of the control device 101.
The exposure step is, for example, a step-and-repeat method, and is performed by sequentially moving the substrate deforming section 37 (that is, the substrate 45) in the uniaxial direction (x direction) described above with reference to FIG.
After the exposure step, the substrate 45 to be exposed is stored in another substrate cassette 46 or the same substrate cassette 46 (transport step (S207)). Alternatively, it may be transferred to the developing device as it is.
Next, with reference to a time chart shown in FIG. 12, the above process will be described with reference to a timing chart of FIG. 13 to FIG.
The unloading step (S201) for taking out the substrate 45 to be exposed from the substrate cassette 46, the transporting step (S202) for transporting the substrate 45 for exposure onto the unevenness measuring stage 47, and the unevenness of the surface of the substrate 45 for exposure A measuring step (S203) for measuring the thickness of the substrate 45 for exposure, a transporting step (S204) for transporting the substrate 45 to be exposed to the substrate deforming section 37, and a flattening step for making the surface of the substrate deforming section 37 uneven ( (S205), an exposure step (S206) for aligning and exposing the substrate 45 for exposure, and a transport step (S207) for storing the substrate 45 for exposure in the substrate cassette 46 overlap. Therefore, it can be seen that the time required until the exposure of the substrate is completed is shorter than in the case of using a known exposure apparatus in which the detection of the waviness or thickness unevenness of the substrate and the exposure step are independent.
Next, another specific embodiment of the undulation correction system shown in FIGS. 1 and 2 will be described with reference to FIG.
FIG. 16 shows a specific configuration of a stage for mounting a substrate to be exposed in an exposure apparatus for forming a semiconductor device on a glass substrate for a liquid crystal display device.
On a square base 51 made of steel with a width of 400 mm in the x direction and a depth of 400 mm in the y direction, for example, a rectangular parallelepiped suction plate 52 is provided at predetermined intervals, for example, at 10 mm intervals, for example, in five rows. Are arranged. Each rectangular parallelepiped suction plate 52 is independently movable in the vertical direction (z direction).
In this embodiment, the rectangular parallelepiped suction plates 52 have the same length and the length in the short side direction of the substrate 45 to be exposed. The length of each of the rectangular parallelepiped suction plates 52 may be shortened by one or a plurality of them. The size of the substrate 45 to be exposed is a rectangular glass substrate having a width of, for example, 300 mm and a depth of 320 mm.
In this case, the length of each rectangular parallelepiped suction plate 52 is 320 mm, and the width of the arrangement range is, for example, 300 mm. The means for moving in the up and down direction is a means for adjusting the amount of movement in the up and down direction (z direction) by an electric signal provided between the rectangular base 51 and each rectangular adsorption plate 52, for example, a piezoelectric element, an air pressure Adjustment devices, ball screws, and the like. The moving distance by the means for moving in the vertical direction is a distance determined by the height of the undulation or thickness unevenness generated on the substrate 45 for exposure, and is, for example, ± 10 to 30 μm.
In this embodiment shown in FIG. 16, a groove 53 is formed at a position where the rectangular parallelepiped suction plates 52 of the rectangular base 51 are arranged so that a part of the bottom side of each rectangular parallelepiped suction plate 52 is fitted. ing. In each groove 53, a piezoelectric element 54 is embedded. The piezoelectric element 54 may be installed so as to support each of the rectangular parallelepiped suction plates 52 at a plurality of locations, or may be formed of a single elongated strip.
At least one row of rectangular parallelepiped suction plates 52 is mounted on the piezoelectric element 54.
Each rectangular suction plate 52 is provided with a plurality of suction holes 55 for vacuum suction at intervals for temporarily sucking the substrate 45 to be exposed. Each of the suction holes 55 is connected to a vacuum pump 56 so that suction and desorption operations can be independently controlled for each rectangular parallelepiped suction plate 52.
Thus, the stage 37 for the exposure apparatus is configured. The means for attracting the substrate 45 to be exposed may be an electrostatic chuck.
Next, a method of transferring the substrate 45 to be exposed onto the stage 37 for such an exposure apparatus will be described.
Data obtained by measuring the undulation or thickness unevenness of the substrate 45 to be exposed is output to the control device 101. As a result, it is assumed that the substrate 45 to be exposed has undulations as shown in FIG. 7 in the width direction x.
The control device 101 outputs a command for transporting the substrate for exposure 45 after measurement onto the stage 37.
According to a predetermined procedure, the depth direction of the substrate 45 to be exposed is set to the length direction of each rectangular adsorption plate 52, and the width direction x of the substrate 45 to be exposed is aligned with the arrangement direction of each rectangular adsorption plate 52. . As a result, the length direction of each rectangular adsorption plate 52 coincides with the vertical direction z with respect to the undulation direction x shown in FIG.
At this time, the control device 101 operates the vacuum pump 56 to generate a vacuum suction action, vacuum-adsorbs the substrate 45 to be exposed to the rectangular parallelepiped suction plates 52, and causes the piezoelectric elements 54 to have the above-described undulation or thickness. The drive information in the vertical direction is supplied so that the exposed surface of the surface of the substrate for exposure 45 created from the unevenness information is flattened.
By this operation, the exposed surface of the surface of the substrate 45 to be exposed is flattened at least over a predetermined width section in the y direction (about a 10 mm section in the x direction). If the suction plate 52 and the piezoelectric elements 54 are arranged in five rows, the entire area of the glass, that is, the substrate 45 to be exposed in the y direction and the area of about 50 mm in the x direction are flattened. The expression that the exposure surface of the surface of the substrate 45 to be exposed is flattened means that the exposure surface A located outside the DOF described above with reference to FIG. 21 is moved up and down so as to fit within the DOF as shown in FIG. Adjusting the position).
In the above embodiment, the suction operation of all the rectangular parallelepiped suction plates 52 is performed. However, for example, in the case of the exposure method of the step-and-scan exposure, the suction operation and the vertical movement operation may be performed for each exposure area.
FIG. 17 shows a block diagram of a control system of the substrate deforming section 37 (of the stage 37 of the exposure apparatus capable of eliminating the influence of the undulation shown in FIG. 16). The control system of the board deforming section 37 receives the output signal of the control device 3 via the interface 24 and sends the driving voltage and the column selection signal to the x driver 27 and the y driver 28 via the board deforming section controller 25 and the power supply circuit 26. (Column address), and individually controls the amount of displacement of the piezoelectric element 12 disposed on a predetermined line (adsorption plate 52) of the substrate deforming section 37. A switching element and a capacitive element (not shown) are disposed on each suction plate 52, and the driving voltage of the piezoelectric element 12 is held for a certain time.
The output current of the thickness measuring sensor is A / D converted and input to the control device 3, from which the direction of the undulation or thickness unevenness of the substrate a and the amount of displacement are calculated. Then, as described above, the control device 3 calculates such that the exposure surface A outside the DOF in FIG. 21 enters the DOF as shown in FIG. That is, the expansion and contraction direction and the amount of expansion and contraction of each piezoelectric element 12 are calculated according to the direction of undulation and the amount of displacement and the positional relationship of the piezoelectric element 12 so that all points on the exposure surface fall within the range of the DOF. A voltage having a polarity and a magnitude corresponding to the amount of expansion / contraction is output to each piezoelectric element 12.
Similar to the detection of the undulation, the undulation may be corrected only for one dimension in the direction in which the thickness unevenness of the exposure target substrate 45 is large. In this case, the polarities and magnitudes of the voltages output to the piezoelectric elements 12 arranged in the length direction of the bottom surface of the suction plate 11 are all the same. By performing the detection and correction of the undulation only in one dimension, the configuration of the detecting means and the deforming means of the undulation and the uneven thickness is simplified, and the control becomes easy.
As another correction method, the substrate 45 to be exposed is deformed by detecting the undulation or uneven thickness of the substrate 45 to be exposed and distributing the vacuum suction force (air pressure) on the back surface of the substrate 45 to be exposed according to the detection. Alternatively, the correction may be performed so that the exposure surface substantially matches the image forming surface. In this case, an elastic material may be used for the surface in contact with the substrate 45 to be exposed so that the deformation of the substrate 45 to be exposed can follow a large undulation.
Specifically, as shown in FIG. 18, first, the thickness (normally 0.5 to 1.1 mm) of the substrate 45 to be exposed is measured while scanning the thickness measurement sensor in the x direction of FIG. The thickness measurement value tn (at least a value of 0.1 μm or more) and the position coordinates (xn, yn) output from the sensor scanning system are stored in the memory of the personal computer 3 (step S301). Next, an average value <t> of the plate thickness is obtained, tn is converted into a form of tn = <t> ± Δn, and stored (step S302).
Next, a voltage Vn corresponding to the amount of expansion and contraction of the piezoelectric element 12 of ± Δn is applied to the piezoelectric element 12 at that position (xn, yn) (step S303).
Next, the substrate 45 to be exposed is placed on the substrate deforming section 37 (Step S304).
Next, the substrate 45 to be exposed is vacuum-adsorbed (step S305).
Finally, alignment is performed, and exposure is started (step S306).
As another exposure method, scanning exposure for exposing while simultaneously moving the mask 32 and the substrate 45 to be exposed with respect to the imaging optical system 5 may be adopted. In this case, the deformation of the substrate 45 for exposure may be performed only on the exposure field. Thus, the detection of the undulation may be performed at the same time as the exposure (in real time) or during the step operation, and it is not necessary to detect the entire undulation in advance, so that the detection time can be reduced. In addition, since the area that is deformed at a time is reduced, control is facilitated.
As described above, in the substrate processing (processing) apparatus of the present invention, the plurality of suction plates holding the substrate are vertically moved so that the exposure surface of the substrate to be exposed is flattened, and the exposure is performed. An exposure pattern can be accurately formed within a range of the depth of focus (DOF) of an imaging optical system on a substrate having a large undulation or thickness unevenness, particularly a thickness unevenness such as a glass substrate of a liquid crystal display. That is, in an application such as an exposure apparatus, a processing apparatus, an exposure method, a method for manufacturing a thin film transistor, and a method for manufacturing a display device, an exposure pattern without blur is surely formed on a processing area (substrate surface, that is, an exposure surface) of a substrate (processing target). Can be formed.
As described above, according to the present invention, the maximum value of the displacement in the surface direction of the processing target region of the plate-shaped object is set to the maximum value of the displacement of the processing apparatus. Since the correction can be made so as to fall within a predetermined range smaller than the permissible capacity, the processing for the plate-like object to be processed is made uniform.
In addition, the total processing time required for all the steps, particularly, until the end of the exposure is reduced. The deformation element for deforming the substrate may be prepared linearly or one-dimensionally in accordance with the characteristics of undulation or uneven thickness, that is, displacement, and the cost of the apparatus can be reduced.
Note that the present invention is not limited to the above embodiments, and various modifications or changes can be made at the stage of implementation without departing from the scope of the invention. In addition, the embodiments may be implemented in appropriate combinations as much as possible. In that case, the effects of the combinations are obtained.

1 is a schematic diagram illustrating an example of an exposure surface waviness correction device according to an embodiment of the present invention. FIG. 2 is a schematic diagram illustrating an example of a suction mechanism that can be incorporated in the swell correction device illustrated in FIG. 1. FIG. 2 is a schematic diagram illustrating the operation of a piezoelectric element incorporated in the swell correction device shown in FIG. 1. FIG. 2 is a schematic diagram illustrating the operation of a piezoelectric element incorporated in the swell correction device shown in FIG. 1. FIG. 2 is a schematic diagram illustrating a principle of detecting undulation of the substrate by the undulation correction device illustrated in FIG. 1. FIG. 2 is a schematic diagram illustrating a principle of detecting undulation of the substrate by the undulation correction device illustrated in FIG. 1. FIG. 1 is a schematic diagram illustrating an example of applying the present invention, in which a pattern is exposed on a substrate. FIG. 1 is a schematic diagram illustrating an example in which the present invention is applied to a pattern exposure apparatus. FIG. 4 is a schematic diagram illustrating the relationship between the undulation (uniaxiality) of a substrate and the measurement direction by a one-dimensional thickness measurement sensor. FIG. 7 is a schematic diagram illustrating an example of the operation of the exposure apparatus illustrated in FIG. 6 (extraction of a substrate to be exposed). FIG. 7 is a schematic diagram illustrating an example of the operation of the exposure apparatus shown in FIG. 6 (the substrate to be exposed is placed on a substrate holding unit). 7 is a time chart for explaining a process of measuring a plate thickness and exposing a substrate to light in the exposure apparatus shown in FIG. 6. FIG. 9 is a schematic diagram illustrating another example in which the present invention is applied to a pattern exposure apparatus. 12 is a time chart for explaining a process of measuring a plate thickness and exposing a substrate to light in the exposure apparatus shown in FIG. 11. FIG. 12 is a schematic diagram for explaining an example of the operation of the exposure apparatus shown in FIG. 11 (removal of a substrate to be exposed). FIG. 12 is a schematic diagram for explaining an example of the operation of the exposure apparatus shown in FIG. 11 (the substrate to be exposed is placed on the unevenness measurement stage). FIG. 12 is a schematic diagram for explaining an example of the operation of the exposure apparatus shown in FIG. 11 (a substrate to be exposed is placed on a substrate deforming section). FIG. 9 is a schematic diagram illustrating another embodiment of a substrate waviness correction device usable in the present invention. FIG. 2 is a schematic block diagram illustrating an example of a control system that controls a substrate deformation unit that corrects undulation (uniaxiality) of the substrate illustrated in FIG. 1. 4 is a flowchart illustrating an example of a “undulation correction process” in the undulation correction device that corrects undulation (uniaxiality) of the substrate illustrated in FIG. 1. FIG. 19 is a schematic diagram illustrating the relationship between the substrate deformed by the “undulation correction process” illustrated in FIG. 18 and the defocus of the pattern exposed on the substrate. FIG. 9 is a schematic diagram illustrating an example of a method of setting an operation amount (control amount) of a piezoelectric element in “undulation correction processing”. FIG. 4 is a schematic diagram illustrating the relationship between undulations generated on a substrate and defocus of a pattern exposed on the substrate, that is, a deviation between an exposure surface and an imaging surface. FIG. 4 is a schematic diagram illustrating “undulation” specific to a glass substrate. FIG. 23 is a schematic diagram illustrating the direction (uniaxiality) of the swell shown in FIG. 22.

Explanation of reference numerals

  DESCRIPTION OF SYMBOLS 1 ... Holding | maintenance means (substrate deformation | transformation mechanism), 2 ... undulation or thickness unevenness detection means, 3 ... Control device, 4 ... Original, a ... Substrate, 5 ... Imaging optical system, 10 ... Deformation element, 11 ... Suction plate (Suction) Means), b: Vacuum suction hole of suction plate, 12: piezoelectric element (substrate deformation element), 13: stage, 14: vacuum pump, 14a: pipe, 21: semiconductor laser (light source), 22: lens, 23: PSD (Position detection device)

Claims (20)

Detecting means for detecting undulation or thickness unevenness of the substrate surface to be exposed,
The undulation or thickness unevenness includes a support mechanism that is long in a direction perpendicular to the direction of the undulation or thickness unevenness detected by the undulation or thickness unevenness detection means, and supports the substrate to be exposed, and the support mechanism includes the undulation or thickness unevenness. A plurality of holding units arranged in the direction of unevenness and independently formed so as to be displaceable in a displacement direction orthogonal to the surface of the substrate to be exposed,
A plurality of the support mechanisms of the holding means are provided along a length direction of the support mechanism, and suction means for sucking and holding the substrate to be exposed,
An exposure apparatus for exposing an exposure pattern to a substrate to be exposed, comprising:   2. The exposure pattern according to claim 1, wherein the support mechanism includes one of a piezoelectric element capable of changing a displacement amount in the displacement direction, a displacement mechanism by air pressure, and a motor drive mechanism. Exposure device for exposing.   3. The exposure apparatus according to claim 2, wherein the support mechanism has a linear shape or a one-dimensional shape.   The size of the holding means is the same as the substrate to be exposed, or the length in a direction orthogonal to the direction of the undulation or thickness unevenness of the substrate to be exposed is the same or more. An exposure apparatus for exposing an exposure pattern on a substrate to be exposed according to claim 1.   2. The exposure apparatus according to claim 1, wherein the suction unit includes one of a suction unit, a vacuum suction unit, and an electrostatic chuck.   6. The exposure apparatus according to claim 5, wherein the suction unit is capable of changing a suction force based on a degree of undulation or thickness unevenness of the substrate to be exposed. .   2. The substrate for exposure according to claim 1, wherein the detection means receives reflected light of the light applied to the surface of the substrate for exposure and measures undulation or uneven thickness of the surface of the substrate for exposure. Exposure device that exposes the exposure pattern to the surface.   2. An exposure pattern on a substrate to be exposed according to claim 1, wherein said support mechanism of said holding means is arranged at an interval of 1/2 or less of a fundamental period of undulation or thickness unevenness of said substrate to be exposed. Exposure device for exposing.   2. The exposure apparatus according to claim 1, further comprising: an elastic member provided on a side of the suction unit in contact with the substrate to be exposed. Detecting means for detecting undulation or thickness unevenness on the surface of the processing object,
In the direction orthogonal to the direction of the undulation or thickness unevenness of the surface of the object to be processed, a plurality of pieces are arranged along the direction of the undulation or uneven thickness, and each is orthogonal to the surface of the object to be processed independently. Holding means including a suction plate displaceable in the direction,
Suction means provided on each of the suction plates, for sucking the object to be processed,
A processing apparatus for processing an object to be processed provided on a stage, comprising:   After aligning the substrate for exposure on the holding means such that a direction orthogonal to the direction of undulation or thickness unevenness of the surface of the substrate for exposure coincides with the long side direction of the suction plate, An exposure method for exposing an exposure pattern to a substrate to be exposed, which is provided at a predetermined position of a holding unit in which a plurality of suction plates are arranged, wherein the exposure is performed.   The substrate to be exposed is sucked by all the suction plates opposed to the substrate to be exposed provided on the holding means, and each of the suction plates has an uneven surface of the exposure surface of the substrate to be exposed. 12. The holding device according to claim 11, wherein the exposure pattern is exposed after the substrate is displaced in a direction orthogonal to the surface of the substrate to be exposed so as to fall within a predetermined range. An exposure method for exposing an exposure pattern on a substrate to be exposed provided at a predetermined position of the means.   By operating an arbitrary number of the suction plates corresponding to a predetermined exposure area on the surface of the substrate to be exposed, among the plurality of suction plates facing the substrate to be exposed provided on the holding means, After adsorbing the substrate to be exposed, after displacing each of the suction plates in a direction orthogonal to the surface of the substrate to be exposed so that the unevenness of the exposure surface of the substrate to be exposed falls within a predetermined range, 12. The exposure method according to claim 11, wherein the exposure pattern is exposed to a substrate to be exposed provided at a predetermined position of a holding unit in which a plurality of suction plates are arranged. An adsorption step of adsorbing the substrate to be exposed on the surface of the adsorption plate,
A step of detecting waviness or thickness unevenness to detect waviness or thickness unevenness of the substrate surface to be exposed,
A suction plate that adjusts the suction plate that is long in the direction perpendicular to the direction of the undulation or thickness unevenness in the direction orthogonal to the surface of the substrate to be exposed according to the undulation or the thickness unevenness detected in the undulation or thickness unevenness detection step. Adjusting the
An exposure method for exposing an exposure pattern to a substrate to be exposed, which is provided at a predetermined position of a holding means on which a plurality of suction plates are arranged, characterized by comprising:   15. The step of adjusting the suction plate, wherein the substrate to be exposed is displaced in a direction perpendicular to the surface of the substrate to be exposed so that the unevenness of the surface of the substrate to be exposed falls within a predetermined range. An exposure method for exposing an exposure pattern to a substrate to be exposed provided at a predetermined position of a holding means in which a plurality of suction plates are arranged.   The step of adjusting the suction plate displaces the substrate to be exposed in a direction orthogonal to the surface of the substrate to be exposed so as to be within a predetermined range in a one-dimensional manner along a direction in which the unevenness of the surface of the substrate to be exposed is large. 15. The exposure method according to claim 14, wherein an exposure pattern is exposed on a substrate to be exposed, which is provided at a predetermined position of a holding means on which a plurality of suction plates are arranged. An adsorption step of adsorbing the substrate to be exposed on the surface of the adsorption plate,
A step of detecting undulation or thickness unevenness on the surface of the substrate to be exposed,
A suction plate that adjusts the suction plate that is long in the direction perpendicular to the direction of the undulation or thickness unevenness in the direction orthogonal to the surface of the substrate to be exposed according to the undulation or the thickness unevenness detected in the undulation or thickness unevenness detection step. Adjusting the
In a state where the suction plate is adjusted according to the undulation or thickness unevenness, a step of exposing a predetermined exposure pattern to the substrate to be exposed on which the semiconductor thin film is formed in advance by an exposure unit,
A method for manufacturing a thin film transistor, comprising: exposing a pattern of a thin film transistor to a substrate to be exposed provided at a predetermined position of a holding means on which a plurality of suction plates are arranged, thereby manufacturing a thin film transistor.   18. The pattern of the thin film transistor is exposed in a state in which undulation or thickness unevenness of the surface of the substrate to be exposed is controlled within a range of a depth of focus of an imaging optical system in the adjusting step. A method for manufacturing a thin film transistor, comprising: exposing a pattern of a thin film transistor to a substrate to be exposed provided at a predetermined position of a holding means on which a plurality of suction plates are arranged, thereby manufacturing the thin film transistor.   18. The method according to claim 17, further comprising: exposing a predetermined exposure pattern to the semiconductor thin film formed on the substrate to be exposed in the exposing step to form a thin film transistor. A method for manufacturing a thin film transistor, by exposing a pattern of the thin film transistor to a substrate to be exposed provided at a predetermined position of the holding means. An adsorption step of adsorbing the substrate to be exposed on the surface of the adsorption plate,
A step of detecting waviness or thickness unevenness to detect waviness or thickness unevenness of the substrate surface to be exposed,
A suction plate that adjusts the suction plate that is long in the direction perpendicular to the direction of the undulation or thickness unevenness in the direction orthogonal to the surface of the substrate to be exposed according to the undulation or the thickness unevenness detected in the undulation or thickness unevenness detection step. Adjusting the
In a state where the suction plate is adjusted according to the undulation or thickness unevenness, a step of exposing a predetermined exposure pattern to the substrate to be exposed on which the semiconductor thin film is formed in advance by an exposure unit,
Opposing a pre-formed counter substrate, and arranging an electro-optical material having a predetermined thickness between the substrates,
A method for manufacturing a display device, comprising:

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