JP2018030046A - Film forming apparatus and film forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film forming apparatus capable of suppressing variations in the shapes of films formed.SOLUTION: In a film forming apparatus, a film forming part applies a film material to a substrate 50, thereby forming a film. An image taking device 27 takes an image of the surface of the substrate 50 arranged in the film forming part. A control part 30 controls the film forming part. The control part 30 stores pattern data for defining the planar shape of the film to be formed. Before the film is formed on the basis of the pattern data, the control part 30 causes the film material to be discharged to part of the inside of a region to which the film material is to be applied for forming the film, thereby forming an evaluation pattern. An image of the evaluation pattern is taken by the image taking device 27. On the basis of the image, the control part 30 determines the quality of the surface condition of the substrate 50 and executes different processing on the basis of the result of the determination.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a film forming apparatus and a film forming method.

  A photolithography technique or a screen printing technique is used to form a resist pattern for patterning the transparent conductive film of the touch panel. In the method using the photolithography technique, a high-definition pattern can be formed, but the apparatus cost, the waste liquid processing cost, and the like increase. The method using the screen printing technique is more advantageous than the method using the photolithography technique in terms of apparatus cost and waste liquid treatment cost, but it is difficult to form a high-definition pattern. A technique for forming a resist pattern using an inkjet printing technique has been proposed (Patent Document 1).

International Publication No. 2013/089049

  When films having the same pattern were formed on a plurality of substrates using an ink jet printing technique, it was found that the shapes of the films varied among the substrates. An object of the present invention is to provide a film forming apparatus and a film forming method capable of suppressing variations in the shape of a formed film.

According to one aspect of the invention,
A film forming unit that forms a film by applying a film material to the substrate;
An imaging device for imaging the surface of the substrate disposed in the film forming unit;
A control unit for controlling the film forming unit,
The controller is
Stores pattern data that defines the planar shape of the film to be formed,
Before the film is formed based on the pattern data, an evaluation pattern made of the same material as the film to be formed is formed on the inner part of the region where the film material is applied to form the film. Control and form,
Obtaining an image of the evaluation pattern captured by the imaging device;
There is provided a film forming apparatus that determines the quality of the surface state of the substrate based on the acquired image and performs different processing based on the determination result.

According to another aspect of the invention,
An evaluation pattern is formed by ejecting the film material of the film from the ink jet head inside a region on the surface of the substrate where a film having a pattern is to be formed,
Based on the evaluation pattern formed on the substrate, determine the quality of the surface state of the substrate,
If the determination result is good, forming the film having the pattern on the surface of the substrate,
When the determination result is poor, a film forming method is provided in which the film having the pattern is formed on the surface of the substrate after cleaning the surface of the substrate.

  By forming an evaluation pattern and determining the quality of the surface state of the substrate before forming the film, it is possible to avoid forming the film as it is on the substrate having a defective surface state. Thereby, the dispersion | variation in the shape of the formed film | membrane can be suppressed.

FIG. 1 is a schematic front view of a film forming apparatus according to an embodiment. FIG. 2 is a plan view of a resist film used as an etching mask when patterning the transparent electrode of the touch panel. FIG. 3 is a flowchart of the film forming method according to the embodiment. FIG. 4 is a plan view showing the positional relationship between the film to be formed and the evaluation pattern. 5A is a plan view of a normal dot pattern formed by one droplet, FIG. 5B is a plan view of a dot pattern larger than the normal dot pattern, and FIG. 5C is a plan view of a blurred dot pattern. FIG. 5D is a plan view of a dot pattern having a distorted planar shape. 6A is a cross-sectional view of the substrate in a state where the evaluation pattern is formed on the substrate (step S4), and FIG. 6B is a cross-sectional view of the substrate in a state where the resist film is formed on the substrate (step S7). FIG. 6D is a cross-sectional view of the substrate after etching the transparent conductive film using the resist film as an etching mask, and FIG. 6D is a cross-sectional view of the substrate with the resist film used as the etching mask removed. 7A and 7B are enlarged plan views of a part of the resist film to be formed. 8A is a cross-sectional view of a substrate in a state where an evaluation pattern is formed on the substrate by a method according to another embodiment (step S4), and FIG. 8B is a cross-sectional view of the substrate in a state where a resist film is formed on the substrate (step S7). It is sectional drawing.

  A film forming apparatus and a film forming method according to an embodiment will be described with reference to FIGS.

  FIG. 1 is a schematic front view of a film forming apparatus according to the present embodiment. A stage 23 is supported on the base 20 via a moving mechanism 21. The stage 23 has a function as a support part that supports the substrate 50 on its upper surface (support surface). The moving mechanism 21 can move the substrate 50 in a two-dimensional direction by moving the stage 23 in a two-dimensional direction parallel to the support surface. As the moving mechanism 21 and the stage 23, for example, an XY stage can be used. Usually, the support surface of the stage 23 is kept horizontal.

  A plurality of inkjet heads 26 and a plurality of imaging devices 27 are arranged above the substrate 50 supported by the stage 23. The inkjet head 26 and the imaging device 27 are supported on the base 20 by the portal frame 24. Each of the inkjet heads 26 is provided with a plurality of nozzle holes. A droplet of the film material is discharged from the nozzle hole toward the substrate 50. The inkjet head 26, the stage 23, and the moving mechanism 21 function as a film forming unit that forms a film on the substrate. The imaging device 27 images a part of the substrate 50 supported by the stage 23, and transmits the acquired two-dimensional image data to the control device (control unit) 30.

  A film can be formed by curing the liquid film material attached to the substrate 50. As the film material, a photocurable resin, a thermosetting resin, or the like can be used. A light source or a heat source for curing the film material attached to the substrate 50 is disposed on the side of the inkjet head 26.

  The control device 30 controls the movement of the stage 23 by the moving mechanism 21 and the discharge of the film material from the nozzle holes of the inkjet head 26. The control device 30 includes a storage device 31, and the storage device 31 stores film pattern data to be formed. The pattern data is composed of a plurality of pixels (pixels) arranged in a matrix, for example. The control device 30 controls the moving mechanism 21 and the inkjet head 26 based on the pattern data, so that a film having a desired pattern can be formed on the substrate 50.

  Various commands and data are input from the input device 35 to the control device 30. As the input device 35, for example, a keyboard, a pointing device, a USB port, a communication device, or the like is used. The output device (output unit) 36 outputs various information related to the operation of the film forming apparatus based on a command from the control device 30. As the output device 36, for example, a liquid crystal display, a speaker, a USB port, a communication device, or the like is used.

  FIG. 2 is a plan view of a resist film 53 used as an etching mask when patterning the transparent electrode film of the touch panel. A transparent electrode is formed by etching a transparent conductive film made of ITO or the like using the resist film 53 as an etching mask. In FIG. 2, a dot pattern is added to the region where the resist is applied. The film forming apparatus shown in FIG. 1 forms a resist film 53 on a substrate 50.

  The resist film 53 includes a plurality of pad portions 51 arranged in a matrix and a connection portion 52 that connects the plurality of pad portions 51 in the column direction. An interval G separating two pad portions 51 adjacent in the row direction is the minimum dimension of the pattern.

  A method of forming a film using the film forming apparatus shown in FIG. 1 will be described with reference to FIG.

  FIG. 3 is a flowchart of the film forming method according to this embodiment. First, in step S1, the substrate 50 (FIG. 1) on which a film is to be formed is placed on the support surface of the stage 23, and the substrate 50 is fixed by a vacuum chuck or the like. In step S2, the control device 30 determines whether or not the alignment of the substrate 50 is necessary. Whether or not alignment is necessary is determined depending on the type of the substrate 50, and information on whether or not alignment is necessary is stored in the storage device 31 (FIG. 1).

  For example, when some pattern is already formed on the substrate 50, it is necessary to align the already formed pattern with a newly formed film. In this case, a new film is formed by positioning with respect to the alignment mark formed on the substrate 50. When no pattern is formed on the substrate 50, for example, when a film to be patterned is formed on the entire surface of the substrate 50, alignment is not necessary. In this case, a new film is formed on the basis of the stage coordinates defined for the stage 23.

  If alignment of the substrate 50 is necessary, the position of the substrate 50 within the support surface of the stage 23 is detected in step S3. Specifically, the position of the substrate 50 is detected by imaging the alignment mark provided on the substrate 50 with the imaging device 27 (FIG. 1) and performing image analysis.

  After detecting the position of the substrate 50, in step S4, an evaluation pattern is formed inside the region where the film is to be formed. If it is not necessary to align the substrate 50, step S4 is executed without executing step S3.

  The process of step S4 will be described with reference to FIG. FIG. 4 is a plan view showing the positional relationship between the resist film 53 to be formed and the evaluation pattern 55. The controller 30 determines at least one position where the evaluation pattern 55 is to be formed based on the pattern data of the resist film 53 to be formed. The evaluation pattern 55 is arranged inside a region where a film material is to be applied when the resist film 53 is formed based on the pattern data. For example, one evaluation pattern 55 is composed of a plurality of dot patterns spaced from each other. FIG. 4 shows an example in which the evaluation pattern 55 includes five dot patterns arranged inside one pad portion 51. One dot pattern included in the evaluation pattern 55 has a size formed by droplets ejected from one nozzle hole.

  After determining the position where the evaluation pattern 55 is to be formed, the control device 30 controls the inkjet head 26 and the moving mechanism 21 (FIG. 1) to form the evaluation pattern 55 on the substrate 50.

  After forming the evaluation pattern 55, the control device 30 moves the formed evaluation pattern 55 into the imaging range of the imaging device 27 in step S5 (FIG. 3), and images the evaluation pattern 55. Thereafter, in step S6, the quality of the surface state of the substrate 50 is determined based on the image of the evaluation pattern 55. The control device 30 executes different processes based on the determination result of the surface condition.

  A method for determining the quality of the surface state of the substrate 50 will be described with reference to FIGS. 5A to 5D. The liquid droplets that have landed on the surface of the substrate 50 spread in the in-plane direction according to the surface state, cause bleeding, or be distorted. In this embodiment, the quality of the surface state is determined based on the size, spread width, shape distortion, and the like of the formed evaluation pattern 55. For example, when the size, bleeding width, shape distortion, etc. of the formed evaluation pattern 55 are within a predetermined allowable range, the surface state is determined as “good” and is out of the allowable range. In this case, the surface state is determined as “defective”.

  FIG. 5A shows a plan view of a normal dot pattern 56 formed by one droplet. The planar shape of the normal dot pattern 56 is almost a perfect circle.

  FIG. 5B shows a plan view of an example in which one dot pattern 57 of the evaluation pattern 55 (FIG. 4) is larger than the normal dot pattern 56. When the size of the large dot pattern 57 is out of the allowable range, the control device 30 determines that the surface state of the substrate 50 is defective. The size of the large dot pattern 57 can be represented by, for example, diameters in two directions orthogonal to each other.

  FIG. 5C shows a plan view of an example in which a blur 58b is generated in one dot pattern 58 of the evaluation pattern 55 (FIG. 4). A blur 58b is observed around the main body 58a of the dot pattern 58. For example, when the width (dimension in the radial direction) of the bleeding 58b exceeds the upper limit of the allowable range, the control device 30 determines that the surface state of the substrate 50 is defective.

  FIG. 5D shows a plan view of an example in which the planar shape of one dot pattern 59 of the evaluation pattern 55 (FIG. 4) is distorted. For example, the dot pattern 59 spreads in one direction (left-right direction in FIG. 5D) than the normal dot pattern 56, but shrunk in a direction perpendicular to the dot pattern 59 (up-down direction in FIG. 5D). When the distortion amount of the distorted dot pattern 59 is out of the allowable range, the control device 30 determines that the surface state of the substrate 50 is defective. As an index representing the amount of strain, a ratio between the major axis and the minor axis can be employed.

  The allowable range described above is preferably set so as to satisfy the condition that the resist films 53 on both sides of the gap G corresponding to the minimum dimension of the pattern shown in FIG. As an example, the upper limit value of the protrusion amount of the portion where the formed dot pattern 57 (FIG. 5B), dot pattern 58 (FIG. 5C), and dot pattern 59 (FIG. 5D) protrude from the outer periphery of the normal dot pattern 56. However, the allowable range can be set to be less than 1/2 of the minimum dimension of the pattern.

  In addition, a dot pattern may be formed on a plurality of substrates that are known to have good surface conditions in advance, and an allowable range may be set based on variations in dimensions. For example, a dimension obtained by adding three times the standard deviation to the average value of the dimension of the formed dot pattern may be used as the upper limit value of the allowable range.

  In determining whether the surface condition of the substrate 50 is good or not, the control device 30 determines whether or not the size of the evaluation pattern 55 is within an allowable range, and whether or not the width of bleeding around the evaluation pattern 55 is within the allowable range. The quality is determined based on at least one determination condition as to whether or not the distortion of the planar shape is within an allowable range.

  When determining that the surface state of the substrate 50 is “good”, the control device 30 forms a resist film 53 (FIG. 2) on the substrate 50 based on the pattern data in step S <b> 7. After forming the resist film 53, the substrate 50 is unloaded from the film forming apparatus in step S9.

  When determining that the surface state of the substrate 50 is “defective”, the control device 30 causes the output device 36 to output information indicating that the surface state is defective in step S8. As an output mode of this information, for example, output by sound, output by image, output by light emission, or the like can be adopted.

  Next, a method of forming a film on the substrate 50 and etching the transparent electrode film of the substrate 50 will be described with reference to FIGS. 6A to 6D. 6A to 6D correspond to cross-sectional views at the position of dashed-dotted line 6-6 in FIG.

  6A is a cross-sectional view of the substrate 50 in a state where the evaluation pattern 55 is formed on the substrate 50 (step S4 in FIG. 3). The substrate 50 includes a glass substrate 50a and a transparent conductive film 50b made of ITO formed on the surface thereof. An evaluation pattern 55 made of a resist material is formed on the transparent conductive film 50b. The evaluation pattern 55 is composed of five isolated dot patterns. Each dot pattern is formed by one droplet ejected from one nozzle hole of the inkjet head 26. In FIG. 6A, one arrow is shown corresponding to the ejection of one droplet.

  6B is a cross-sectional view of the substrate 50 in a state where the resist film 53 is formed on the substrate 50 (step S7 in FIG. 3). The control device 30 forms the resist film 53 by controlling the moving mechanism 21 and the inkjet head 26 based on the pattern data defining the shape of the resist film to be formed. In FIG. 6B, one arrow is shown corresponding to the ejection of one droplet. Since droplets are applied in an overlapping manner at positions where each dot pattern of the evaluation pattern 55 is formed, a bulge 54 reflecting the shape of the evaluation pattern 55 is formed on the surface of the resist film 53.

  As shown in FIG. 6C, the transparent conductive film 50b is etched (patterned) using the resist film 53 as an etching mask. The transparent conductive film 50b in the region where the resist film 53 is not formed is removed by etching.

  As shown in FIG. 6D, the resist film 53 used as an etching mask is removed. The transparent conductive film 50b remains in the region where the resist film 53 (FIG. 6C) has been formed.

  Next, with reference to FIG. 7A and FIG. 7B, the excellent effect of the said Example is demonstrated.

  7A and 7B are enlarged plan views of a part of the resist film 53 to be formed. 7A and 7B, the target shape 53a of the resist film 53 to be formed is indicated by a broken line.

  FIG. 7A shows a plan view of the resist film 53 formed when the wettability of the surface of the substrate 50 is higher than a standard value. The formed resist film 53 is wider than the target shape 53a. If the spread of the film material in the in-plane direction exceeds the allowable range, the two pad portions 51 adjacent to each other in the row direction of the formed resist film 53 come into contact with each other.

  FIG. 7B shows a plan view of the resist film 53 formed when the surface of the substrate 50 is in a state where bleeding is likely to occur. A blur 53b is generated around the target shape 53a. Two pad portions 51 adjacent to each other in the row direction are continuous via the bleeding portion 53b.

  When the transparent conductive film 50b (FIG. 6C) is etched in the state shown in FIGS. 7A and 7B, there is a high possibility that a short circuit failure of the transparent conductive film 50b occurs.

  In this embodiment, the surface state of the substrate 50 is inspected before the resist film 53 is formed, and a state in which the wettability is too high, a state in which bleeding is likely to occur, and a state in which the film shape is likely to be distorted are detected. When the surface state of the substrate 50 supported by the stage 23 is bad, the film forming apparatus notifies the operator that the surface state is bad without continuously forming the film (FIG. 3). Step S8). When the operator notices the notification, the operator can carry out the surface modification process by unloading the substrate 50 having a defective surface state from the film forming apparatus and cleaning the surface. Thereby, the fall of the yield of a product can be suppressed.

  In this embodiment, as shown in FIG. 6B, a bulge 54 that reflects the shape of the evaluation pattern 55 (FIG. 6A) is formed on the surface of the resist film 53. However, the resist film 53 is removed after the transparent conductive film 50b is etched. Further, since the evaluation pattern 55 is arranged inside a region where the resist film 53 is to be formed, the evaluation pattern 55 does not affect the planar shape of the resist film 53. Therefore, the evaluation pattern 55 does not affect the shape of the transparent conductive film 50b after etching (FIG. 6D).

  Next, various modifications of the present embodiment will be described.

  In the above embodiment, a plurality of isolated dot patterns are used as the evaluation pattern 55 (FIG. 4), but other patterns may be used. For example, two strip patterns having the same interval as the interval G that is the minimum dimension of the resist film 53 may be used as the evaluation pattern 55. The quality of the surface state of the substrate 50 may be determined based on whether or not the interval between the formed belt-like patterns is within an allowable range.

  In the above embodiment, the evaluation pattern 55 (FIG. 4) is formed in at least one place on the substrate 50. According to the evaluation experiment by the inventors of the present application, it was found that even one substrate 50 has a different surface state depending on the position within the surface. For example, the inside may tend to exhibit higher wettability than the periphery of the substrate 50.

  In consideration of the variation of the surface state in the surface of one substrate 50, the evaluation pattern 55 (FIG. 4) is uniformly distributed in the surface of the substrate 50 in order to improve the accuracy of determining the quality of the surface state. Is preferred. For example, the surface of the substrate 50 may be divided at equal intervals in the row direction and the column direction so that one evaluation pattern 55 is formed in one section.

  In the above embodiment, the resist film 53 is formed by moving the inkjet head 26 with respect to the base 20 and moving the stage 23, but on the contrary, the stage 23 is stopped with respect to the base 20, The inkjet head 26 may be moved. That is, one of the inkjet head 26 and the substrate 50 may be moved with respect to the other.

  Next, a film forming method according to another embodiment will be described with reference to FIGS. 8A and 8B. Hereinafter, differences from the embodiment shown in FIGS. 1 to 7 will be described, and description of common configurations will be omitted.

  FIG. 8A is a cross-sectional view of the substrate 50 in a state where the evaluation pattern 55 is formed on the substrate 50 (step S4 in FIG. 3). This process is the same as the process of the embodiment shown in FIG. 6A.

  8B is a cross-sectional view of the substrate 50 in a state where the resist film 53 is formed on the substrate 50 (step S7 in FIG. 3). The arrows shown in FIG. 8B are displayed corresponding to locations where droplets of the resist film 53 are discharged. In the present embodiment, the control device 30 (FIG. 1) creates correction pattern data by excluding the pixels that define the evaluation pattern from the pattern data pixels of the resist film 53 to be formed from the application target. The resist film 53 is formed by controlling the ink jet head 26 based on the correction pattern data. As indicated by the arrows in FIG. 8B, the droplets are not applied in an overlapping manner on the portion where the dot pattern of the evaluation pattern 55 (FIG. 8A) is formed.

  In the present embodiment, droplets are not overcoated when forming the resist film 53 on the pixels on which the evaluation pattern 55 (FIG. 8A) is formed. For this reason, generation | occurrence | production of the rise 54 which appeared in the Example shown to FIG. 6B can be prevented.

  In the case where the resist film 53 is finally removed as in the embodiment shown in FIGS. 1 to 7, there is no problem even if the bulge 54 is formed, but the film remaining in the final product is formed. It is preferable to apply the embodiment shown in FIGS. 8A and 8B.

  Each of the above-described embodiments is an exemplification, and needless to say, partial replacement or combination of the configurations shown in the different embodiments is possible. About the same effect by the same composition of a plurality of examples, it does not refer to every example one by one. Furthermore, the present invention is not limited to the embodiments described above. It will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like can be made.

20 Base 21 Movement mechanism 23 Stage (support part)
24 Gate frame 26 Inkjet head 27 Imaging device 30 Control device 31 Storage device 35 Input device 36 Output device 50 Substrate 50a Glass substrate 50b Transparent conductive film 51 Pad portion 52 Connection portion 53 Resist film 53a Resist film target shape 53b Bleed 54 Swell 55 Evaluation pattern 56 Normal dot pattern 57 Large dot pattern 58 Blurred dot pattern 58a Blurred dot pattern body 58b Blur 59 Distorted dot pattern

Claims (8)

A film forming unit that forms a film by applying a film material to the substrate;
An imaging device that images the surface of the substrate disposed in the film forming unit;
A control unit for controlling the film forming unit,
The controller is
Stores pattern data that defines the planar shape of the film to be formed,
Before the film is formed based on the pattern data, an evaluation pattern made of the same material as the film to be formed is formed on the inner part of the region where the film material is applied to form the film. To form
Obtaining an image of the evaluation pattern captured by the imaging device;
A film forming apparatus that determines the quality of the surface state of the substrate based on the acquired image and performs different processing based on the determination result. The film forming part
A support for supporting the substrate;
An inkjet head that discharges a film material toward the substrate supported by the support;
A moving mechanism for moving one of the substrate and the inkjet head supported by the support portion with respect to the other;
The film forming apparatus according to claim 1, wherein the control unit controls the inkjet head and the moving mechanism.   In the determination of the quality of the surface state of the substrate, the control unit determines whether the size of the evaluation pattern is within an allowable range, and whether the width of the blur around the evaluation pattern is within the allowable range. The film forming apparatus according to claim 1, wherein the quality is determined based on at least one determination condition as to whether or not the distortion of the planar shape is within an allowable range. Furthermore, it has an output unit that outputs information according to a command from the control unit,
The controller is
If it is determined that the surface state of the substrate is defective, the output unit outputs information notifying that the surface state of the substrate is defective,
The film forming apparatus according to claim 1, wherein when the surface state of the substrate is determined to be good, the film is formed on the substrate based on the pattern data.   5. The film forming apparatus according to claim 1, wherein the control unit applies droplets for forming the film in an overlapping manner at a location where the evaluation pattern is formed. 6.   The control unit, when forming the film based on the pattern data, forming the film based on correction pattern data obtained by removing a portion where the evaluation pattern is formed from the pattern data. 5. The film forming apparatus according to any one of 1 to 4. An evaluation pattern is formed by ejecting the film material of the film from the ink jet head inside a region on the surface of the substrate where a film having a pattern is to be formed,
Based on the evaluation pattern formed on the substrate, determine the quality of the surface state of the substrate,
If the determination result is good, forming the film having the pattern on the surface of the substrate,
A film forming method for forming the film having the pattern on the surface of the substrate after cleaning the surface of the substrate when the determination result is poor.   When determining whether the surface state of the substrate is good or not, whether the size of the evaluation pattern is within an allowable range, whether the width of the blur around the evaluation pattern is within the allowable range, and a plane The film forming method according to claim 7, wherein the quality is determined based on at least one determination condition as to whether or not the shape distortion is within an allowable range.

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