Alignment method, vapor deposition method using the alignment method, and electronic device manufacturing method

Abstract

The present invention provides an alignment method, a vapor deposition method using the alignment method, and an electronic device manufacturing method. The alignment method aligns the positions of a substrate and a mask by performing a first alignment for the first position alignment of the substrate and a mask and a second alignment for the second position alignment of the substrate and the mask. The method is characterized in that the alignment method includes the following steps: as a preliminary alignment stage, the first alignment and the second alignment are performed in sequence, and a first alignment substrate mark set on the substrate when the second alignment is completed is registered as an imaginary first alignment substrate mark; and as a formal alignment stage after the preliminary alignment stage, at least one of the substrate and the mask is relatively moved with the registered position of the imaginary first alignment substrate mark as a reference so that the position of the first alignment substrate mark set on the substrate is contained in a predetermined position range, thereby performing the first alignment.

Description

Technical Field

[0001] The present invention relates to an alignment method, a vapor deposition method using the alignment method, and an electronic device manufacturing method, and more particularly to a method for accurately aligning the positions of a mask and a substrate in a vacuum vapor deposition process of an organic electroluminescent display device. Background Art

[0002] Recently, organic electroluminescent displays have attracted attention as flat panel displays. As self-luminous displays, organic electroluminescent displays have superior characteristics such as response speed, viewing angle, and thinness compared to liquid crystal panel displays. They are rapidly replacing existing liquid crystal panel displays with various portable terminals such as monitors, televisions, and smartphones. In addition, their application areas have also expanded to automotive displays, etc.

[0003] An organic electroluminescent display has a basic structure in which an organic material layer that causes light emission is formed between two electrodes (cathode electrode and anode electrode) facing each other. The organic material layer and the electrode metal layer of the organic electroluminescent display are manufactured by vapor-depositing a vapor-deposited material onto a substrate via a mask formed with a desired pixel pattern in a vacuum chamber. However, in order to vapor-deposit the vapor-deposited material onto a desired position on the substrate in a desired pattern, the position of the mask and the substrate must be precisely aligned before vapor deposition on the substrate.

[0004] In addition, due to the increase in the size of the deposited agent and the miniaturization of the pattern, there is a continuous demand for further improvement in the accuracy of the alignment between the substrate and the mask. Summary of the invention

[0005] An object of the present invention is to provide an alignment method that further improves the accuracy of positional alignment between a substrate and a mask, and a vapor deposition method and an electronic device manufacturing method using the alignment method.

[0006] An alignment method according to a technical solution of the present invention aligns the positions of the substrate and the mask by performing a first alignment for the first position alignment of the substrate and the mask and a second alignment for the second position alignment of the substrate and the mask, and is characterized in that the alignment method includes the following steps: as a preliminary alignment stage, the first alignment and the second alignment are performed in sequence, and a first alignment substrate mark provided on the substrate when the second alignment is completed is registered as an imaginary first alignment substrate mark; and as a formal alignment stage after the preliminary alignment stage, the first alignment is performed by relatively moving at least one of the substrate and the mask with respect to the registered position of the imaginary first alignment substrate mark so that the position of the first alignment substrate mark provided on the substrate is within a predetermined position range.

[0007] Another technical solution of the alignment method of the present invention is to align the positions of the substrate and the mask by performing a first alignment for the first position alignment of the substrate and the mask and a second alignment for the second position alignment of the substrate and the mask, and is characterized in that the alignment method includes the following steps: as a preliminary alignment stage, the first alignment and the second alignment are performed in sequence, and the first alignment mask mark provided on the mask when the second alignment is completed is registered as an imaginary first alignment mask mark; and as a formal alignment stage after the preliminary alignment stage, at least one of the substrate and the mask is relatively moved with respect to the registered position of the imaginary first alignment mask mark so that the position of the first alignment mask mark provided on the mask is within a predetermined position range, thereby performing the first alignment.

[0008] Effects of the Invention

[0009] According to the present invention, the accuracy of the first alignment can be significantly improved, so that the accommodation error between the first alignment for rough position alignment between the substrate and the mask and the second alignment for high-precision position alignment can be minimized, thereby shortening the time required for alignment and the time of the overall film forming process. In addition, the initial contact position accuracy between the substrate and the mask becomes higher, which helps to improve the yield rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a plan view schematically showing a part of the structure of an electronic device manufacturing apparatus.

[0011] Figure 2 It is a cross-sectional view schematically showing the structure of a film forming apparatus.

[0012] Figure 3 It is a perspective view of a substrate holding unit.

[0013] Figure 4 It is a figure which shows the 1st alignment.

[0014] Figure 5 It is a diagram showing the second alignment of the measurement position.

[0015] Figure 6 It is a diagram showing the second alignment of the vapor deposition position.

[0016] Figure 7 is a conceptual diagram of alignment marks provided on a substrate and a mask, respectively.

[0017] Figure 8 This is a diagram for explaining the difference between the first and second alignment storage positions when there is an error in the formation position of the alignment mark.

[0018] Fig. 9It is a diagram for explaining the first alignment of the present invention.

[0019] Fig.10 This is a schematic diagram of the organic EL device of the present invention.

[0020] Description of Reference Numerals

[0021] S: substrate; 10: transport chamber; 20, 30: film forming chamber; 40: transport robot; 120: mask; 160, 161: camera; Psr, Pmr: first alignment mark (substrate, mask); Psf, Pmf: second alignment mark (substrate, mask); P'sr: imaginary first alignment substrate mark; Fr, Ff: storage position. DETAILED DESCRIPTION

[0022] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The present invention can be modified in many ways and can have many embodiments. Although specific embodiments are illustrated based on the accompanying drawings, the present invention is not limited to the specific embodiments and should be understood to include all modifications, equivalents, and even substitutes included in the concept and technical scope of the present invention.

[0023] The present invention relates to a film forming device for forming a thin film on a substrate and a control method thereof, and in particular to a technology for high-precision conveying and position adjustment of a substrate. The present invention can be preferably applied to a device for forming a thin film (material layer) of a desired pattern on the surface of a substrate by vacuum evaporation. As the material of the substrate, any material such as glass, resin, metal, etc. can be selected. In addition, as the evaporation material, any material such as organic material, inorganic material (metal, metal oxide, etc.) can also be selected. The technology of the present invention can be specifically applied to manufacturing devices for organic electronic devices (for example, organic EL display devices, thin-film solar cells), optical components, etc. Among them, due to the large-scale substrate or the high-precision display panel, the alignment accuracy between the substrate and the mask is required to be further improved, so the manufacturing device of the organic EL display device is one of the preferred application examples of the present invention.

[0024] [Manufacturing equipment and manufacturing process]

[0025] Figure 1 It is a plan view schematically showing a part of the structure of an electronic device manufacturing apparatus. Figure 1 The manufacturing device is used, for example, for manufacturing display panels of organic EL display devices for smartphones. In the case of display panels for smartphones, after an organic EL film is formed on a substrate S of about 1800 mm × about 1500 mm, the substrate S is cut to produce a plurality of small-sized panels.

[0026] like Figure 1As shown, the manufacturing apparatus of electronic devices generally has a plurality of film forming chambers 20, 30 and a transfer chamber 10. A transfer robot 40 for holding and transferring a substrate S is provided in the transfer chamber 10. The transfer robot 40 is, for example, a robot having a structure in which a robot hand for holding the substrate S is mounted on a multi-joint arm, and carries the substrate S in and out of each film forming chamber.

[0027] Each film forming chamber 20, 30 is provided with a film forming device (also called a vapor deposition device). The film forming device automatically performs a series of film forming processes such as the transfer of the substrate S to the conveying robot 40, the adjustment (alignment) of the relative position of the substrate S and the mask, the fixing of the substrate S to the mask, and film formation (evaporation). Although the film forming devices of each film forming chamber 20, 30 have different parts in small aspects such as different vapor deposition sources and different masks, the basic structure (especially the structure related to the conveyance and alignment of the substrate) is roughly the same. The common structure of the film forming devices of each film forming chamber 20, 30 is described below.

[0028] [Film forming device]

[0029] Figure 2 : is a cross-sectional view schematically showing the structure of the film forming device. In the following description, an XYZ orthogonal coordinate system is used with the vertical direction as the Z direction. During film forming, the substrate S is fixed in a manner parallel to the horizontal plane (XY plane), and the width direction (direction parallel to the short side) of the substrate S is the X direction, and the length direction (direction parallel to the long side) is the Y direction. In addition, θ represents the rotation angle around the Z axis.

[0030] The film forming apparatus includes a vacuum chamber 100. The interior of the vacuum chamber 100 is maintained in a vacuum atmosphere or an inert gas atmosphere such as nitrogen. A substrate holding unit 110, a mask 120, a mask stage 121, a cooling plate 130, and a vapor deposition source 140 are generally provided inside the vacuum chamber 100. The substrate holding unit 110 is a unit for holding and conveying the substrate S received from the conveying robot 40, and is also called a substrate holder. The mask 120 is a metal mask having an opening pattern corresponding to a thin film pattern formed on the substrate S, and is fixed on a frame-shaped mask stage 121.

[0031] During film formation, a substrate S is placed on the mask 120. Therefore, the mask 120 also serves as a carrier for placing the substrate S. The cooling plate 130 is a component that suppresses the deterioration or degradation of the organic material by being in close contact with the substrate S (the surface on the opposite side of the mask 120) during film formation and suppressing the temperature rise of the substrate S. The cooling plate 130 can also serve as a magnet plate. The magnet plate refers to a component that attracts the mask 120 by magnetic force, thereby improving the adhesion between the substrate S and the mask 120 during film formation. The evaporation source 140 is composed of an evaporation material, a heater, a baffle, a driving mechanism of the evaporation source, an evaporation rate monitor, etc. (none of which are shown in the figure).

[0032] A substrate Z actuator 150, a fixture Z actuator 151, a cooling plate Z actuator 152, an X actuator (not shown), a Y actuator (not shown), and a θ actuator (not shown) are provided above (outside) the vacuum chamber 100. These actuators are composed of, for example, a motor and a ball screw, a motor and a linear guide, etc. The substrate Z actuator 150 is a driving component for lifting and lowering the substrate holding unit 110 as a whole (moving in the Z direction). The fixture Z actuator 151 is a driving component for opening and closing the clamping mechanism of the substrate holding unit 110.

[0033] The cooling plate Z actuator 152 is a driving component for raising and lowering the cooling plate 130. The X actuator, the Y actuator, and the θ actuator (hereinafter collectively referred to as "XYθ actuator") are driving components for aligning the substrate S. The XYθ actuator moves the substrate holding unit 110 and the cooling plate 130 as a whole in the X direction, the Y direction, and the θ rotation. In the present embodiment, although a structure is formed in which a θ actuator for θ rotation is separately provided, θ rotation can also be performed by a combination of an X actuator and a Y actuator. In addition, in the present embodiment, a structure is formed in which the X, Y, and θ of the substrate S are adjusted in a state where the mask 120 is fixed, but the alignment of the substrate S and the mask 120 can also be performed by adjusting the position of the mask 120 or adjusting the positions of both the substrate S and the mask 120.

[0034] Above (outside) the vacuum chamber 100, cameras 160 and 161 are provided to measure the positions of the substrate S and the mask 120, respectively. The cameras 160 and 161 photograph the substrate S and the mask 120 through a window provided in the vacuum chamber 100. By identifying the alignment marks on the substrate S and the alignment marks on the mask 120 based on their images, the respective XY positions and the relative displacement in the XY plane can be measured. In order to achieve high-precision alignment in a short time, it is preferred to implement two stages of alignment, namely, the first alignment (also referred to as "rough alignment") as the first adjustment process for roughly performing position alignment and the second alignment (also referred to as "fine alignment") as the second adjustment process for performing position alignment with high precision. In this case, it is preferred to use two cameras, namely, the first alignment camera 160 with low resolution but wide field of view and the second alignment camera 161 with narrow field of view but high resolution. In this embodiment, two first alignment cameras 160 are used to measure alignment marks at two locations of a pair of opposing sides of the substrate S and the mask 120, respectively, and four second alignment cameras 161 are used to measure alignment marks at four corners of the substrate S and the mask 120. The number of alignment marks and cameras for measuring the alignment marks is not particularly limited, and for example, in the case of fine alignment, two cameras 161 may be used to measure the marks at two corners of the substrate S and the mask 120.

[0035] The film forming device has a control unit 170. In addition to the functions of controlling the substrate Z actuator 150, the clamp Z actuator 151, the cooling plate Z actuator 152, the XYθ actuator and the cameras 160 and 161, the control unit 170 also has functions such as controlling the conveyance and alignment of the substrate S, controlling the evaporation source, and controlling film forming. The control unit 170 can be composed of a computer having, for example, a processor, a memory, a storage device, an I / O, etc. In this case, the functions of the control unit 170 are realized by executing a program stored in the memory or the storage device by the processor. As a computer, a general-purpose personal computer, an embedded computer or a PLC (programmable logic controller) can be used. Alternatively, a part or all of the functions of the control unit 170 can be constituted by a circuit such as an ASIC or an FPGA. In addition, a control unit 170 can be set for each film forming device, or a plurality of film forming devices can be controlled by one control unit 170.

[0036] [Substrate holding unit]

[0037] Reference Figure 3 The structure of the substrate holding unit 110 will be described. Figure 3 1 is a perspective view of the substrate holding unit 110 .

[0038] The substrate holding unit 110 is a component that holds and transports the substrate S by clamping the periphery of the substrate S with a clamping mechanism. Specifically, the substrate holding unit 110 comprises: a support frame 204 having a plurality of support members 203 that respectively support the four sides of the substrate S from below; and a clamp member 206 having a plurality of pressing members 205 that clamp the substrate S between the support members 203. A pair of support members 203 and pressing members 205 constitute a clamping mechanism. Figure 3 In the example of FIG. 1 , three support members 203 are arranged along the short side of the substrate S, and six clamping mechanisms (a pair of support members 203 and pressing members 205) are arranged along the long side, forming a structure for clamping two sides of the long side. However, the structure of the clamping mechanism is not limited to Figure 3 In addition, the number and configuration of the clamping mechanism can be appropriately changed according to the size, shape or film forming conditions of the substrate to be processed. In addition, the support member 203 is also called a "receiving claw" or a "hook claw", and the pressing member 205 is also called a "clamp".

[0039] The transfer of the substrate S from the transport robot 40 to the substrate holding unit 110 is performed, for example, as follows. First, the clamp member 206 is raised by the clamp Z actuator 151, and the pressing member 205 is separated from the support member 203, so that the clamping mechanism is in an open state. After the substrate S is introduced between the support member 203 and the pressing member 205 by the transport robot 40, the clamp member 206 is lowered by the clamp Z actuator 151, and the pressing member 205 is pressed against the support member 203 with a specified pressing force. As a result, the substrate S is clamped between the pressing member 205 and the support member 203. In this state, the substrate holding unit 110 is driven by the substrate Z actuator 150, so that the substrate S can be raised and lowered (moved in the Z direction). In addition, since the clamp Z actuator 151 rises / falls together with the substrate holding unit 110, the state of the clamping mechanism will not change even if the substrate holding unit 110 is raised or lowered.

[0040] [alignment]

[0041] 1. Overview of alignment

[0042] Figure 3 Reference numeral 202 indicates alignment marks for the second alignment provided at the four corners of the substrate S, and reference numeral 201 indicates alignment marks for the first alignment provided at the short side of the substrate S. Figure 3 , the alignment mark 201 for the first alignment is shown as being located near the center of the short side of the substrate S, but the position of the alignment mark 201 for the first alignment is not limited thereto, and may be provided at a position other than the center.

[0043] The alignment is generally performed in two stages. That is, after the alignment marks provided on the substrate S and the mask 120 are detected by the optical components (cameras 160, 161), the relative positions between the detected marks are measured, and based on the result of the measurement process, the substrate S or the mask 120 is moved to adjust the relative position of the substrate S and the mask 120 to perform alignment.

[0044] Figure 4 It is a figure which shows the 1st alignment. Figure 4 (a) shows the state of the substrate S immediately after it is transferred from the transfer robot 40 to the substrate holding unit 110. The center of the substrate S is bent downward due to its own weight. Figure 4 As shown in (b), the clamp member 206 is lowered, and the left and right sides of the substrate S are clamped by the clamping mechanism composed of the pressing member 205 and the supporting member 203. Figure 4 As shown in (c), in a state where the substrate S and the mask 120 are separated, the first alignment based on the above-mentioned measurement process and position alignment process is performed. The first alignment is a first position adjustment process for roughly adjusting the relative position of the substrate S and the mask 120 in the XY plane (a direction parallel to the surface of the mask 120), which is also called "rough alignment". In the first alignment, the camera 160 identifies the substrate alignment mark 201 provided on the substrate S and the mask alignment mark (not shown) provided on the mask 120, measures the respective XY positions and the relative displacement in the XY plane, and performs position alignment. In order to enable rough position alignment, the camera 160 used in the first alignment is a low-resolution but wide-field camera. During the position alignment, the position of the substrate S (substrate holding unit 110) can be adjusted, the position of the mask 120 can be adjusted, and the positions of both the substrate S and the mask 120 can be adjusted.

[0045] After the first alignment process is completed, Figure 5 As shown in (a) and (b), the substrate holding unit 110 is lowered to a position where the center of the substrate S contacts the mask 120 (hereinafter referred to as the "measurement position"). Figure 5 As shown in (c), at this measurement position, the measurement process for the second alignment is performed in a state where the peripheral portion of the substrate S is clamped by the clamping mechanism. The position (measurement position) at which the measurement process for the second alignment is performed is, for example, a position where the support surface (upper surface) of the support member 203 is slightly higher than the placement surface of the mask 120 (for example, a position 2 mm to 3 mm higher).

[0046] The second alignment is a high-precision alignment process, also known as "fine alignment". Figure 5As shown in (c), at the above-mentioned measurement position, the substrate alignment mark 202 provided on the substrate S and the mask alignment mark (not shown) provided on the mask 120 are recognized by the camera 161, and the XY positions and relative offsets in the XY plane of each are measured. In order to enable high-precision position alignment, the camera 161 is a camera with a narrow field of view but high resolution.

[0047] When the measured offset exceeds the threshold, the position alignment process is performed through the following process. Figure 5 As shown in (d), the substrate Z actuator 150 is driven to raise the substrate S and separate it from the mask 120 again. Figure 5 In (e), the XYθ actuator is driven to perform position alignment based on the offset measured by the camera 161. During the position alignment, the position of the substrate S (substrate holding unit 110) or the position of the mask 120 can be adjusted, or the positions of both the substrate S and the mask 120 can be adjusted.

[0048] Afterwards, if Figure 5 As shown in (f), the substrate S is lowered to the above-mentioned measurement position again, and the substrate S is placed on the mask 120. Then, the camera 161 takes pictures of the alignment marks of the substrate S and the mask 120 to measure the offset. When the measured offset exceeds the threshold, the above-mentioned position alignment process is repeated.

[0049] When the offset is within the threshold, such as Figure 6 (a) Figure 6 As shown in (b), the substrate holding unit 110 holding the substrate S is lowered so that the support surface of the substrate holding unit 110 and the mask 120 are aligned at the same height. As a result, the entire substrate S is placed on the mask 120. Figure 6 As shown in (c), at the position where the substrate S is completely placed on the mask 120, the camera 161 once again photographs the alignment marks of the substrate S and the mask 120, and finally measures and verifies whether the positional deviation is within the threshold. The final measurement process at this position is the following process, that is, after performing the measurement at the above-mentioned measurement position ( Figure 5 (c)) and the position alignment process based on the measurement results, Figure 6 (a)~ Figure 6 In the process (b), the possible positional deviation is finally verified while the substrate S is completely placed on the mask 120 .

[0050] Through the above steps, the substrate S is placed on the mask 120. Figure 6As shown in (d), the cooling plate Z actuator 152 is driven to lower the cooling plate 130 and bring it into close contact with the substrate S. Thus, the preparation for the film forming process (evaporation process) by the film forming apparatus is completed.

[0051] 2. Details of the 1st and 2nd alignment operations

[0052] Hereinafter, alignment, particularly, measurement and positioning of relative displacement between alignment marks respectively provided on the substrate S and the mask 120 in the first and second alignments will be described in detail.

[0053] Figure 7 1 is a diagram conceptually showing alignment marks provided on the substrate S and the mask 120, respectively. Figure 7 (a) indicates substrate alignment marks (Psr, Psf), Figure 7 (b) represents mask alignment marks (Pmr, Pmf). The substrate alignment marks include: a first alignment substrate alignment mark Psr provided near the center of the short side of the substrate S for roughly adjusting the relative position of the substrate S and the mask 120; and a second alignment substrate alignment mark Psf provided at the four corners of the substrate S for high-precision position alignment. The mask alignment marks also include a first alignment mask alignment mark Pmr provided approximately in the center of the short side of the mask 120 and a second alignment mask alignment mark Pmf provided at the four corners of the mask 120. The substrate alignment marks (Psr, Psf) are formed in a cross shape, and the mask alignment marks (Pmr, Pmf) are formed in a circular shape, but the shapes of the marks are not limited thereto.

[0054] Substrate alignment marks such as Figure 7 As shown in (a), the centers of the two first alignment marks Psr connected at the centers of the opposing short sides of the substrate coincide with the centers of the second alignment marks Psf connected at the four corners. Figure 7 As shown in (b), in the case of mask alignment marks, the center of the mark Pmr connected to the first alignment and the center of the mark Pmf connected to the second alignment do not coincide with each other. This is because the substrate alignment marks (Psr, Psf) are usually formed by chemical printing methods such as photolithography, so the mark positions on the substrate are controlled and formed with high precision. In contrast, the alignment marks (Pmr, Pmf) formed on the mask are usually formed by physical processing such as opening the mask or laser processing, so the positional accuracy of the formed marks is not high, and errors will also occur in the formation positions of the marks on each mask.

[0055] In this way, if an error occurs in the formation position of the alignment mark (especially the mask alignment mark), when the position is aligned based on the detection result of the mark, problems such as an increase in the number of necessary relative movements between the substrate S and the mask 120 and an increase in the overall time required for alignment may occur.

[0056] Below, refer to Figure 8 The following describes a decrease in the efficiency of the alignment operation when there is an error in the formation position of the alignment mark as described above.

[0057] Figure 8 Indicates Figure 7 In the case where the connection center of the first alignment mark Pmr formed on the mask does not coincide with the connection center of the second alignment mark Pmf, the first and second alignments are performed based on these marks. Figure 8 (a) shows the state after the first alignment is completed. Figure 8 (b) shows a state after the second alignment is performed following the first alignment.

[0058] That is, in Figure 8 During the first alignment of (a), the substrate alignment mark Psr for the first alignment provided at the center of the short side of the substrate and the mask alignment mark Pmr for the first alignment provided at the center of the short side of the mask are photographed and recognized by the camera 160, and based on the recognition result, the substrate or the mask is relatively moved so that the two corresponding marks are accommodated within a predetermined position range. As a result, as shown in the figure, the substrate S and the mask 120 are roughly aligned (roughly aligned) with the accommodation position Fr as the center.

[0059] On the other hand, in the subsequent Figure 8 During the second alignment of step (b), after the substrate alignment marks Psf and the mask alignment marks Pmf for the second alignment provided at the four corners are recognized by the camera 161, the substrate or the mask is relatively moved similarly so that the corresponding marks are accommodated within a predetermined position range. As a result, the substrate S and the mask 120 are finally aligned with high precision (fine alignment) with the accommodation position Ff as the connection center of the alignment marks (Psf, Pmf) for the second alignment as the center.

[0060] As shown in the figure, the first alignment (rough alignment, Figure 8 (a)) and the second alignment (fine alignment, Figure 8(b)) The alignment storage positions (Fr, Ff) in the rough position alignment process are not consistent with each other. That is, the result is that the accuracy of the first alignment is not high. This is because, as described above, the connection centers of the first alignment mark Psr and the second alignment mark Psf of the substrate alignment mark are consistent, but the connection centers of the first alignment mark Pmr and the second alignment mark Pmf of the mask alignment mark are inconsistent with each other due to manufacturing errors during formation.

[0061] Therefore, a method for correcting the result of such a first alignment with low accuracy has been considered, and as one of the methods, the following scheme has been considered, namely, in a preparatory process stage before performing a formal process, the difference between the storage position Fr of the first alignment and the storage position Ff of the second alignment is pre-calculated and saved, and in the formal process, after the first alignment and before entering the second alignment, the substrate (or mask) is pre-moved relative to the difference in the storage positions calculated above.

[0062] By correcting the difference between the storage positions (Fr, Ff) of the first alignment and the second alignment through such so-called offset correction, the alignment accuracy at the initial stage of the second alignment can be improved to a certain extent. However, it requires a new solution that can fundamentally solve the difference between the storage positions (Fr, Ff) of the first alignment and the second alignment, that is, a new solution that can fundamentally improve the accuracy of the first alignment itself.

[0063] The present invention meets such a demand and aims to improve the accuracy of the first alignment and fundamentally eliminate the difference between the storage positions (Fr, Ff) of the first alignment and the second alignment, which will be described in detail below.

[0064] In the present invention, the first alignment is performed mainly by using the alignment mark on the substrate with high position accuracy. The first and second alignments are performed sequentially through the preliminary process, and the position of the first alignment mark provided on the substrate in the state where the final position of the substrate and the mask are aligned is registered as a virtual alignment mark. When the first alignment is performed in the formal process, the substrate or the mask is relatively moved so that the position of the actual first alignment mark on the substrate recognized by the camera is consistent with the position of the registered virtual alignment mark, so as to perform the alignment. That is, unlike the existing first alignment method in which the positions of the first alignment marks provided on the substrate and the mask are compared, so that the mark on one side (for example, the first alignment mark on the substrate) is contained in a predetermined position range relative to the mark on the other side (for example, the first alignment mark on the mask), the first alignment mark on the substrate with high position accuracy is used as a reference, and the alignment is performed so that the mark comes to the position of the pre-registered virtual first alignment substrate mark.

[0065] Hereinafter, registration of a virtual first alignment mark on a substrate and a first alignment method using the same according to an embodiment of the present invention will be described with reference to the drawings.

[0066] First, the first and second alignments are performed in sequence through the preparatory process before entering the actual process. Figure 7 As shown in (b), when the final position alignment of the substrate S and the mask 120 is performed, the position of the first alignment mark Psr on the substrate S in this state is registered as a virtual first alignment mark on the substrate. Fig. 9 (a) again shows the state in which the second alignment is completed through such a preliminary step. As shown in the figure, the position of the first alignment mark Psr on the substrate when the second alignment of the preliminary step is completed is registered as a virtual first alignment substrate mark P'sr.

[0067] Next, when the first alignment is performed in the main process, alignment is performed so that the actual first alignment mark Psr on the substrate recognized by the camera 160 is positioned at the virtual first alignment substrate mark P'sr registered in the above-mentioned preliminary process. Fig. 9 (b) shows the state after the first alignment in the main process is performed in this way.

[0068] As shown in the figure, according to the embodiment of the present invention, the first alignment is performed so that the alignment storage position Fr (refer to Fig. 9 (b)) and the aligned storage position Ff during the second alignment (refer to Fig. 9 (a)) are substantially consistent, and the difference in the storage position is suppressed to the limit. This is because, unlike the existing first alignment method in which the position of the alignment mark Pmr on the mask with relatively low position accuracy is used as a reference to align the position with the alignment mark Psr on the substrate, in the structure based on the embodiment of the present invention, the alignment is performed based on the alignment mark P'sr on the virtual substrate with high position accuracy and pre-adjusted to the storage position to the storage position Ff.

[0069] Thus, according to the structure of the embodiment of the present invention, the difference between the alignment storage position during the first alignment and the second alignment can be suppressed to an ideal value close to zero, and the accuracy of the first alignment can be significantly improved. Therefore, after the first alignment is completed, even if the above-mentioned additional offset correction is not performed, it is possible to immediately transfer to the second alignment, which has the effect of shortening the time required for alignment and the overall film forming process time.

[0070] The first alignment method of the embodiment of the present invention has been described above, but various modifications are possible within the scope of the present invention. For example, when registering the position of the first alignment mark P'sr on the imaginary substrate, as described above, the absolute position (absolute position in the camera shooting area) of the first alignment substrate mark Psr when the second alignment of the preparatory process is completed may be registered as the imaginary alignment mark P'sr, or the position of the imaginary alignment mark P'sr may be registered as the relative position of the first alignment substrate mark Psr relative to the first alignment mask mark Pmr when the second alignment of the preparatory process is completed. In the latter case, even if some errors occur in the camera shooting range due to differences in the accuracy of the camera that shoots the alignment mark, the position of the imaginary alignment mark P'sr can be accurately registered / determined.

[0071] In addition, as described above, according to the present invention, since the difference between the aligned storage positions during the first alignment and the second alignment can be made close to the ideal value of zero, it is not necessary to perform an additional offset correction after the first alignment is completed. However, since the slight storage position deviation that may be caused by actual errors such as differences in camera accuracy is corrected, the storage position deviation that has been minimized by the first alignment of the present invention can be further corrected by the offset correction.

[0072] In addition, in the above-mentioned embodiment, an example is described in which the position of the first alignment mark set on the substrate when the second alignment of the preliminary process is completed is registered as a virtual alignment mark, but depending on the situation, especially when the alignment process is performed in a manner such that the substrate is fixed and the mask is moved relative to the substrate, the position of the first alignment mark set on the mask when the preliminary process is completed may be registered as a virtual alignment mark, and during the first alignment of the formal process, the mask is moved to perform alignment so that the virtual alignment mark on the mask is consistent with the position of the actual first alignment mark on the mask.

[0073] [Embodiment of the method for manufacturing an electronic device]

[0074] Next, an example of a method for manufacturing an electronic device using the film-forming apparatus of this embodiment is described. Hereinafter, as an example of an electronic device, the structure and manufacturing method of an organic EL display device are described.

[0075] First, the organic EL display device to be manufactured will be described. Fig.10 (a) is a general view of an organic EL display device 500. Fig.10 (b) shows the cross-sectional structure of one pixel.

[0076] like Fig.10As shown in (a), a plurality of pixels 520 having a plurality of light-emitting elements are arranged in a matrix in a display area 510 of an organic EL display device 500. As will be described in detail later, each of the light-emitting elements has a structure having an organic layer sandwiched by a pair of electrodes. In addition, the pixel mentioned here refers to the minimum unit that can display a desired color in the display area 510. In the case of the organic EL display device 500 of this embodiment, the pixel 520 is formed by a combination of a first light-emitting element 520R, a second light-emitting element 520G, and a third light-emitting element 520B that display different light. The pixel 520 is mostly formed by a combination of a red light-emitting element, a green light-emitting element, and a blue light-emitting element, but can also be formed by a combination of a yellow light-emitting element, a cyan light-emitting element, and a white light-emitting element, and there is no particular limitation as long as there is at least one color.

[0077] Fig.10 (b) Yes Fig.10 (a) is a partial cross-sectional schematic diagram at the A-B line. The pixel 520 has an organic EL element on a substrate 530, and the organic EL element includes a first electrode (anode) 540, a hole transport layer 550, any one of the light-emitting layers 560R, 560G, and 560B, an electron transport layer 570, and a second electrode (cathode) 580. Among them, the hole transport layer 550, the light-emitting layers 560R, 560G, 560B, and the electron transport layer 570 are equivalent to organic layers. In addition, in this embodiment, the light-emitting layer 560R is an organic EL layer that emits red light, the light-emitting layer 560G is an organic EL layer that emits green light, and the light-emitting layer 560B is an organic EL layer that emits blue light. The light-emitting layers 560R, 560G, and 560B are formed into patterns corresponding to the light-emitting elements (sometimes also described as organic EL elements) that emit red light, green light, and blue light, respectively. In addition, the first electrode 540 is formed separately for each light-emitting element. The hole transport layer 550, the electron transport layer 570, and the second electrode 580 may be formed in common with the plurality of light-emitting elements 520R, 520G, and 520B, or may be formed for each light-emitting element. In addition, in order to prevent the first electrode 540 and the second electrode 580 from being short-circuited due to foreign matter, an insulating layer 590 is provided between the first electrode 540. Furthermore, since the organic EL layer is degraded by moisture and oxygen, a protective layer 600 is provided to protect the organic EL element from moisture and oxygen.

[0078] In order to form the organic EL layer into a light-emitting element unit, a film forming method via a mask is used. In recent years, the high-precision display device has been developed, and a mask with an opening width of several tens of μm is used in the formation of the organic EL layer. In the case of film formation using such a mask, if the mask receives heat from the evaporation source during film formation and is thermally deformed, the position of the mask and the substrate will deviate, and the pattern of the thin film formed on the substrate will be formed deviating from the desired position. Therefore, the film forming device (vacuum evaporation device) of the present invention is preferably used in the film formation of the organic EL layer.

[0079] Next, an example of a method for manufacturing an organic EL display device will be described in detail.

[0080] First, a circuit (not shown) for driving the organic EL display device and the substrate 530 on which the first electrode 540 is formed are prepared.

[0081] Acrylic resin is formed by spin coating on the substrate 530 having the first electrode 540 formed thereon, and the acrylic resin is patterned by photolithography to form an opening in the portion having the first electrode 540 formed thereon to form an insulating layer 590. The opening corresponds to a light emitting region where the light emitting element actually emits light.

[0082] The substrate 530 with the insulating layer 590 patterned thereon is carried into the first film forming device, the substrate is held by the substrate holding unit, and the hole transport layer 550 is formed as a common layer on the first electrode 540 in the display region. The hole transport layer 550 is formed by vacuum evaporation. In practice, since the hole transport layer 550 is formed to a size larger than the display region 510, a high-definition mask is not required.

[0083] Next, the substrate 530 formed with the hole transport layer 550 is carried into the second film forming device and held by the substrate holding unit. The substrate and the mask are aligned, the substrate is placed on the mask, and the light emitting layer 560R emitting red light is formed on the portion of the substrate 530 where the element emitting red light is arranged. According to this example, the mask and the substrate can be well overlapped, and high-precision film formation can be performed.

[0084] Similar to the film formation of the light-emitting layer 560R, the light-emitting layer 560G emitting green light is formed by the third film-forming device, and the light-emitting layer 560B emitting blue light is formed by the fourth film-forming device. After the film formation of the light-emitting layers 560R, 560G, and 560B is completed, the electron transport layer 570 is formed on the entire display area 510 by the fifth film-forming device. The electron transport layer 570 is formed as a common layer for the light-emitting layers 560R, 560G, and 560B of three colors.

[0085] The substrate on which the electron transport layer 570 has been formed is moved to a sputtering device to form a second electrode 580 , and then moved to a plasma CVD device to form a protective layer 600 , thereby completing the organic EL display device 500 .

[0086] If the substrate 530 with the insulating layer 590 patterned thereon is exposed to an atmosphere containing moisture and oxygen from the time when it is carried into the film forming apparatus until the film forming of the protective layer 600 is completed, the light-emitting layer composed of the organic EL material may be degraded by moisture and oxygen. Therefore, in this example, the substrate is carried in and out of the film forming apparatus in a vacuum atmosphere or an inert gas atmosphere.

[0087] The organic EL display device thus obtained has a light-emitting layer formed with high precision for each light-emitting element. Therefore, by using the above-mentioned manufacturing method, it is possible to suppress the occurrence of defects in the organic EL display device caused by positional deviation of the light-emitting layer.

[0088] Above, the mode for implementing the present invention is specifically described, but the gist of the present invention is not limited to these records, and should be interpreted widely based on the records of the claims. In addition, various changes, modifications, etc. based on these records are also naturally included in the gist of the present invention.

Claims

1. An alignment method for aligning the positions of a substrate and a mask by performing a first alignment as a rough alignment for aligning the positions of the substrate and the mask once and performing a second alignment as a fine alignment for aligning the positions of the substrate and the mask twice, characterized in that: The alignment method includes the following steps: As a preliminary alignment stage, the first alignment and the second alignment are sequentially performed based on the position of the mask mark provided on the mask so that the position of the substrate mark provided on the substrate is contained within a predetermined position range, and the first alignment substrate mark provided on the substrate when the second alignment is completed is registered as an imaginary first alignment substrate mark; as well as As a formal alignment stage after the preliminary alignment stage, the first alignment is performed by relatively moving at least one of the substrate and the mask based on the registered position of the imaginary first alignment substrate mark so that the position of the first alignment substrate mark set on the substrate is within a predetermined position range.

2. The alignment method according to claim 1, characterized in that: The first alignment in the preliminary alignment stage is performed by detecting the first alignment substrate mark provided on the substrate and the first alignment mask mark provided on the mask using a first optical component, and relatively moving at least one of the substrate and the mask so that the positions of the two marks are within a predetermined position range. The second alignment in the preliminary alignment stage is performed by using a second optical component to detect a second alignment substrate mark set on the substrate and a second alignment mask mark set on the mask, and by relatively moving at least one of the substrate and the mask so that the positions of the two marks are within a predetermined position range.

3. The alignment method according to claim 2, characterized in that: The registration of the imaginary first alignment substrate mark is to register the absolute position of the first alignment substrate mark within the imaging area of ​​the first optical component as the position of the imaginary first alignment substrate mark when the second alignment as the preliminary alignment stage is completed.

4. The alignment method according to claim 2, characterized in that: The registration of the imaginary first alignment substrate mark is that when the second alignment as the preliminary alignment stage is completed, the relative position of the first alignment substrate mark within the shooting area of ​​the first optical component with respect to the first alignment mask mark is registered as the position of the imaginary first alignment substrate mark.

5. The alignment method according to claim 2, characterized in that: After performing the first alignment as the formal alignment stage, the second alignment as the formal alignment stage is performed by using a second optical component to detect the second alignment substrate mark provided on the substrate and the second alignment mask mark provided on the mask, and by relatively moving at least one of the substrate and the mask so that the positions of the two marks are within a predetermined position range.

6. The alignment method according to claim 5, characterized in that: In the first alignment and the second alignment which are the formal alignment stages, when there is a difference between the storage position of the first alignment based on the imaginary first alignment substrate mark and the first alignment substrate mark and the storage position of the second alignment based on the second alignment substrate mark and the second alignment mask mark, after the first alignment which is the formal alignment stage is completed, at least one of the substrate and the mask is relatively moved by the difference, and then the second alignment which is the formal alignment stage is performed.

7. The alignment method according to any one of claims 2 to 6, characterized in that: The second optical component is an optical component having a higher resolution and a narrower angle of view than the first optical component.

8. The alignment method according to any one of claims 2 to 6, characterized in that: The first alignment substrate mark and the first alignment mask mark are marks provided near the center of the short sides of the substrate and the mask, respectively.

9. The alignment method according to any one of claims 2 to 6, characterized in that: The second alignment substrate mark and the second alignment mask mark are marks provided near four corners of the substrate and the mask, respectively.

10. The alignment method according to any one of claims 2 to 6, characterized in that: The first alignment substrate mark and the second alignment substrate mark are formed on the substrate by a chemical printing method.

11. The alignment method according to any one of claims 2 to 6, characterized in that: The first alignment mask mark and the second alignment mask mark are formed on the mask by physically processing the mask.

12. An alignment method for aligning the positions of the substrate and the mask by performing a first alignment as a rough alignment for aligning the positions of the substrate and the mask once and performing a second alignment as a fine alignment for aligning the positions of the substrate and the mask twice, characterized in that: The alignment method includes the following steps: As a preliminary alignment stage, the first alignment and the second alignment are sequentially performed based on the position of the mask mark provided on the mask so that the position of the substrate mark provided on the substrate is within a predetermined position range, and the first alignment mask mark provided on the mask when the second alignment is completed is registered as an imaginary first alignment mask mark; as well as As a formal alignment stage after the preliminary alignment stage, the first alignment is performed by relatively moving at least one of the substrate and the mask based on the registered position of the imaginary first alignment mask mark so that the position of the first alignment mask mark set on the mask is within a predetermined position range.

13. The alignment method according to claim 12, characterized in that: The first alignment in the preliminary alignment stage is performed by detecting the first alignment substrate mark provided on the substrate and the first alignment mask mark provided on the mask using the first optical component, and relatively moving at least one of the substrate and the mask so that the positions of the two marks are within a predetermined position range. The second alignment in the preliminary alignment stage is performed by using a second optical component to detect a second alignment substrate mark set on the substrate and a second alignment mask mark set on the mask, and by relatively moving at least one of the substrate and the mask so that the positions of the two marks are within a predetermined position range.

14. The alignment method according to claim 13, characterized in that: After performing the first alignment as the formal alignment stage, the second alignment as the formal alignment stage is performed by using a second optical component to detect the second alignment substrate mark provided on the substrate and the second alignment mask mark provided on the mask, and by relatively moving at least one of the substrate and the mask so that the positions of the two marks are within a predetermined position range.

15. The alignment method according to claim 14, characterized in that: In the first alignment and the second alignment which are the formal alignment stages, when there is a difference between the storage position of the first alignment based on the imaginary first alignment mask mark and the first alignment mask mark and the storage position of the second alignment based on the second alignment substrate mark and the second alignment mask mark, after the first alignment which is the formal alignment stage is completed, at least one of the substrate and the mask is relatively moved by the difference, and then the second alignment which is the formal alignment stage is performed.

16. A vapor deposition method, in which a vapor deposition source material from an vapor deposition source is deposited on a substrate via a mask in a processing chamber to form a film, characterized in that: After the substrate and the mask are aligned using the alignment method according to any one of claims 1 to 6 and 12 to 15, vapor deposition is performed using an evaporation source.

17. A method for manufacturing an electronic device having an organic film formed on a substrate, characterized in that: The organic film is formed by the evaporation method according to claim 16.

18. A method for manufacturing an electronic device having a metal film formed on a substrate, characterized in that: The metal film is formed by the vapor deposition method according to claim 16.

19. The method for manufacturing an electronic device according to claim 17, characterized in that: The electronic device is a display panel of an organic EL display apparatus.

20. The method for manufacturing an electronic device according to claim 18, characterized in that: The electronic device is a display panel of an organic EL display apparatus.

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