JP4305476B2 - Device manufacturing method, electro-optical device, and electronic apparatus - Google Patents

Description

  The present invention relates to a device manufacturing method, an electro-optical device, and an electronic apparatus.

  An electro-optical device used as a display, a display light source, or the like, or an electronic device such as a semiconductor device includes a process of arranging a material on a substrate and forming a film on the substrate in the manufacturing process. Material placement technology and film formation technology are closely related to quality and function, and are important for improving the performance of each of the above devices.

  As a technique for arranging a material on a substrate, there is a method of discharging a liquid material as droplets through a nozzle provided in an ejection head (for example, Patent Document 1).

This droplet discharge method is advantageous in that it consumes less liquid material and can easily control the amount and position of the liquid material placed on the substrate, compared to a technique such as spin coating.
Japanese Patent Laid-Open No. 11-274671

  The technique of forming a film on a substrate using the droplet discharge method requires placement accuracy when the liquid material is placed on the substrate, while improving and stabilizing the film shape after drying the liquid film. Desired.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a film forming method capable of accurately and stably forming a film having a desired shape on a substrate. Another object of the present invention is to provide a device manufacturing method, an electro-optical device, and an electronic apparatus capable of improving quality.

The inventor's device manufacturing method includes a first step of disposing droplets containing silica fine particles on a substrate, and after the first step, the droplets are dried to form crystal nuclei. A second step of adjusting the supersaturation degree to a degree of supersaturation that is insufficient to form other crystal nuclei, and forming a dry film having a film thickness at the center equal to or greater than the film thickness of the edge; a third step of placing overlapping the resin onto the dry film, was perforated, the diameter of the droplets after the second step, characterized in that it contracted immediately after the first step. According to this, since the dry film can be stably formed, the quality of the device can be improved.

The inventor's device manufacturing method includes a first step of disposing droplets on a substrate, and after the first step, drying the droplets, and flowing a liquid from a central portion of the droplets toward an edge, Forming a liquid flow from the edge of the droplet toward the center, and increasing the local amount of particles dispersed in the droplet or dissolved solute within the droplet. It is suppressed, possess a second step of the thickness of the central portion to form an edge thickness equal to or greater than the dry film, and a third step of placing overlapping the resin onto the dry film, the droplets Includes salt and colloidal particles, and the salt concentration in the liquid phase is adjusted according to the surface potential of the colloidal particles . According to this, since the dry film can be stably formed, the quality of the device can be improved.

  In the device manufacturing method, the third step is preferably a step of forming a microlens.

  In the device manufacturing method, the dry film is preferably a colloidal crystal film.

  In the device manufacturing method, the dry film is preferably a crystalline thin film.

  In the device manufacturing method, it is preferable that the droplets are disposed on the substrate by a droplet discharge method.

  According to another aspect of the present invention, there is provided an electro-optical device including a device manufactured using the above-described device manufacturing method. As a device, a semiconductor element, an image pick-up element, a liquid crystal display element, an organic electroluminescent element etc. can be illustrated, for example. Examples of the electro-optical device include a liquid crystal display device, an organic electroluminescence display device, and a plasma display device.

According to another aspect of the invention, there is provided an electronic apparatus including the above electro-optical device.
According to these inventions, quality can be improved.

The present invention will be described in detail below.
FIG. 1 is a diagram schematically showing a typical droplet drying process in the film forming method of the present invention.
In the film forming method of the present invention, a liquid material is formed as droplets on a substrate and dried to form a dried film of droplets on the substrate. Although a case where one droplet is arranged on the substrate will be described here, the present invention is not limited to this, and includes, for example, a case where a plurality of droplets are arranged on the substrate and dried. Further, as will be described later, it is also possible to form a linear film pattern on a substrate by continuously arranging dry films of a plurality of droplets.

  In the film forming method of the present invention, in the drying process, the dried film of the droplet is controlled in various shapes using at least one of the solid content concentration of the liquid material and the drying speed of the droplet as a parameter. Specifically, for example, as shown in FIG. 1 (a), the dry film of the droplet has a shape with a thicker film thickness than the center part, or as shown in FIG. 1 (b). Or a contracted shape compared to the droplet after landing.

  In the drying process shown in FIG. 1 (a), the above parameters (solid content concentration of liquid material, droplet drying speed) are set so that the solid content concentration at the edge reaches the saturation concentration faster than the central portion of the droplet. It is determined. In general, the droplets disposed on the substrate are rapidly dried at the edges. In the drying process of the droplet, when the solid content concentration at the edge of the droplet reaches the saturation concentration, the solid content locally precipitates at the edge. Then, the edge of the droplet is pinned by the deposited solid content, and the contraction of the droplet (the contraction of the outer diameter) accompanying the subsequent drying is suppressed. Hereinafter, this phenomenon, that is, a phenomenon in which the shrinkage of the droplet accompanying drying is suppressed by the solid content deposited at the edge is referred to as “pinning”.

  On the other hand, in the drying process shown in FIG. 1B, the above parameters (solid content concentration of liquid material, droplet drying speed) were determined so that the solid concentration of the entire droplet reached the saturation concentration almost simultaneously. Is. In this case, it is difficult for local solids to precipitate at the edge of the droplet, so that the above-described pinning does not occur, and the droplet shrinks with evaporation in the drying process. That is, as the drying progresses, the outer diameter of the droplet decreases. Hereinafter, this phenomenon, that is, a phenomenon in which droplets contract without being pinned during drying is referred to as “depinning”. In addition, the flow of the liquid in the droplet shown by the arrows in FIGS. 1A and 1B is an example and may be different from the actual one.

  Here, among the above parameters, the drying speed of the droplets is the moving speed of the stage on which the substrate is mounted, the interval between the droplets arranged on the substrate (inter-droplet distance), the arrangement of a plurality of droplets, It changes according to the timing of arrangement and the contact angle of the substrate surface with respect to the liquid material.

  For example, when the stage moves, drying of the droplets is promoted due to a decrease in vapor concentration in the gas phase near the droplets. As the moving speed of the stage increases, the moving speed of the droplet relative to the atmosphere increases, and the drying speed of the droplet increases.

  FIG. 2 is a diagram showing an example in which a plurality of (here, two) droplets are arranged on a substrate. As shown in FIG. 2, when the droplets are dried, the vapor that goes out from the liquid phase to the gas phase diffuses three-dimensionally around the droplets. “Vapor diffusion layer” refers to a region where a concentration gradient is formed in the gas phase in the vicinity of a droplet due to the movement of molecules evaporated from the droplet due to diffusion. Here, a vapor layer formed in the gas phase near the droplet surface and having a concentration that affects other droplets is included as a vapor diffusion layer in a broad sense. Further, the distance between the droplets is the center distance between the two adjacent droplets. Note that the thickness of the vapor diffusion layer varies depending on the physical properties, solid content concentration, environmental temperature, and the like of the liquid material.

  When multiple droplets are placed on the substrate, if the droplets exist in the vapor diffusion layer of another droplet or the vapor diffusion layers of both adjacent droplets partially overlap each other, the droplet surface The evaporation rate of the droplet changes due to a change in the vapor concentration of the liquid. Specifically, the shorter the distance between droplets and the longer the overlapping distance of the vapor diffusion layers, the smaller the droplet evaporation rate (drying rate) and the longer the drying time. On the other hand, when the vapor diffusion layers do not overlap, even if the distance between the droplets changes, the evaporation rate and drying time of the droplets hardly change. Accordingly, the drying speed of the droplets can be changed by changing the distance between the droplets within the range affected by the vapor diffusion layer.

  In addition, when a plurality of droplets are arranged on the substrate, the drying time of the droplets varies depending not only on the distance between the droplets described above but also on the timing, number and arrangement of the droplets. For example, the drying (evaporation) state of the previous liquid droplet changes when the next liquid droplet is disposed, depending on the period from when the first liquid droplet is disposed on the substrate to when the next liquid droplet is disposed. Therefore, according to the change, the magnitude of the influence of the vapor diffusion layer between the droplets and the drying rate of the droplets change. That is, the longer the period, the less the influence of the vapor diffusion layer between the plurality of droplets, and the higher the drying rate of the droplets.

  Further, as shown in FIGS. 3A and 3B, the larger the number of droplets B arranged in one droplet A within the overlapping range of the vapor diffusion layers, the more the influence of the vapor diffusion layer is. It appears large and the drying speed of the droplet A becomes small. Further, when one droplet B is arranged on one side of one droplet A within the range where the vapor diffusion layers overlap (FIG. 3A), the droplet B is arranged in the droplet A. The drying speed on the other side is partially reduced. In this case, since a partial deviation occurs in the drying speed, the shape of the dry film of the droplet A becomes anisotropic. On the other hand, when a plurality of droplets B are arranged over the entire circumference of one droplet A (FIG. 3B), the above-described partial unevenness in the drying speed is unlikely to occur, and the droplet A is dried. The shape of the membrane is isotropic.

FIGS. 4A and 4B show the state of droplets when the contact angle (static contact angle) of the substrate surface with respect to the liquid material is different from each other (contact angle θa <θb).
When the same amount of droplets is placed on the substrate, the smaller the contact angle, the larger the outer diameter of the droplets. Since the drying speed tends to increase when the outer diameter of the droplet is large, the drying speed increases as the contact angle of the substrate surface with the liquid material decreases. The contact angle is decreased by, for example, lyophilic treatment of the substrate surface, and is increased by lyophobic treatment of the substrate surface.

  From the above, the moving speed of the stage on which the substrate is mounted, the interval between droplets arranged on the substrate (distance between droplets), the arrangement and arrangement timing of a plurality of droplets, and the substrate surface with respect to the liquid material By controlling the contact angle and the like, the drying speed of the droplets can be changed. As a method of changing the drying speed of the droplets, in addition to the above, environmental factors such as temperature, humidity, and atmospheric pressure may be controlled, or a heating unit or a blowing unit may be used. These control methods can be used in combination as necessary.

  FIG. 5 is a diagram showing the time integration of the evaporation amount of the liquid (solvent, dispersion medium, etc.) from the droplets under a constant drying condition. As shown in FIG. 5, in the initial stage of drying, the amount of evaporation per time is large (part A shown in FIG. 5). This is because in the initial stage of drying immediately after the droplets are placed on the substrate, the vapor concentration around the droplets is low and the drying rate (evaporation rate) of the droplets is high. After that, when the periphery of the droplet (the average free process distance of the liquid molecules) reaches the saturation concentration, the drying rate of the droplet becomes a steady state limited by the diffusion rate of the vapor (part B shown in FIG. 5). Slower compared to the initial drying stage.

  As described above, the droplets disposed on the substrate are rapidly dried at the edges. Therefore, in the initial stage of drying (part A shown in FIG. 5), the liquid rapidly evaporates at the edge of the droplet, and the solid concentration tends to increase. At this time, when the solid content concentration at the edge of the droplet reaches the saturation concentration, the above-described pinning occurs.

[Pinning]
6 to 8 each show the shape of a dry film (pinning thin film) formed through pinning, with the upper part being a plan view and the lower part being a sectional view. As described above, pinning is a phenomenon in which the shrinkage of droplets accompanying drying is suppressed by the solid content deposited at the edges. When pinning occurs, as shown in FIG. 1A, in the droplet, a flow supplementing the liquid lost by evaporation at the edge of the droplet from the central portion, that is, liquid flowing from the central portion toward the edge. Is formed. This liquid flow changes in accordance with the above parameters. The dry films shown in FIGS. 6 to 8 have different parameters in the drying process.

  The dry film shown in FIG. 6 is formed by determining the above parameters so that the liquid flow from the central portion to the edge is strongly formed in the droplet during drying. As shown in FIG. 1A, after a pinning occurs, if a liquid flow from the center to the edge is strongly formed in the droplet, the edge of the droplet is generated along with the liquid flow. A lot of solids are carried in At the edge of the liquid droplet, the liquid flow tends to stay due to an increase in the viscosity accompanying the precipitation of the solid content, and the high concentration state of the solid content is maintained. That is, the liquid flow from the edge toward the center is weaker than the liquid flow from the center toward the edge. As a result, a large amount of solid content is deposited at the edge of the droplet, and the film thickness at the edge of the dry film is increased.

  In this case, among the above parameters, the lower the solid content concentration of the liquid material and the higher the drying speed, the stronger the liquid flow from the central portion toward the edge. Therefore, the film thickness ratio of the edge with respect to the center part of the dry film can be increased by reducing the solid content concentration of the liquid material or increasing the drying speed. That is, a dry film having a thick edge is formed. In addition, when the solid content is fine particles, the smaller the particle size of the fine particles, the easier it is to carry the solid content to the edge by being placed on the liquid flow, so the thickness of the central portion of the dry film tends to be thin. By increasing the film thickness ratio of the edge to the center of the dry film, for example, a ring-shaped dry film is formed as shown in FIG.

  The dry film shown in FIG. 7 has the above parameters determined so that the flow of the liquid from the center to the edge in the droplet is weakened. Among the above parameters, the higher the solid content concentration of the liquid material and the lower the drying speed, the weaker the liquid flow from the center to the edge, and the more difficult the solid content is conveyed to the edge of the droplet. In addition, when the solid content is fine particles, the larger the particle size of the fine particles, the more difficult it is to carry the solid content from the central portion of the droplet to the edge, so the thickness of the central portion of the dry film is less likely to be thin. As a result, as shown in FIG. 7, a dry film having a substantially flat cross-sectional shape with the same thickness at the center and the edge is formed.

  In the dry film shown in FIG. 8, the above parameters are determined so that the flow of liquid from the center to the edge in the droplet is weaker than in FIG. The dry film shown in FIG. 8 has, for example, a higher solid content concentration of the liquid material, a lower drying speed, and a larger particle size of the solid content as compared with the dry films shown in FIGS. In this case, it is difficult to carry the solid content from the central portion of the droplet to the edge, and the thickness of the central portion is thicker than the edge of the dry film as shown in FIG.

  In this way, under the conditions where pinning occurs, changing the above parameters (solid content concentration of liquid material, drying speed of liquid droplets) or the particle size of the fine particles changes the dry film of the liquid droplets into various shapes. Can be controlled.

  In addition, for the ring-shaped dry film having a thick film at the edge portion, it is possible to control the width and the like of the raised portion of the edge by changing the above parameters and the particle diameter of the fine particles. Specifically, the higher the concentration and the larger the particle size of the fine particles, the less the influence of the liquid flow from the center toward the edge, so that the film shape approaches flat and the width of the raised part of the edge becomes narrower. There is a tendency.

FIG. 9 relates to a dry film formed through pinning, and particularly shows how the film shape changes when the solid content concentration of the liquid material and the particle size of the fine particles are changed for a ring-shaped film. Here, the particle size of the fine particles: (a) <(b), and the solid content concentration of the liquid material: (a) <(b). The outer diameter of the dry film of (a) is W ₁ , the thickness of the edge is h ₁ , the width of the raised portion of the edge is L ₁ , the outer diameter of the dry film of (b) is W ₂ , and the thickness of the edge is When h ₂ and the width of the raised portion of the edge are L ₂ , W ₁ <W ₂ , h ₁ <h ₂ , L ₁ > L ₂ were satisfied.

  Note that another droplet may be placed on the droplet being dried by pinning. In this case, increasing the liquid content of the drying droplets maintains the flow of liquid from the center to the edge, further transporting the solid content to the edge. Therefore, the movement of the solid content to the edge is promoted, and the film thickness of the edge tends to be further increased. Further, the affinity of the substrate surface with respect to the liquid material may be controlled, and the boundary portion where the affinity changes may act as an incentive for pinning. In addition, when the liquid material disposed on the substrate is heated or a low boiling point solvent is used as the liquid material, the change in the film shape due to the above parameters becomes significant.

[Diping]
On the other hand, in order to prevent pinning and to cause depinning, it is possible to reduce the drying speed of the liquid droplets or reduce the solid content concentration of the liquid material. It is good to prevent.

  As shown in FIG. 1B, in the drying process by depinning, the droplets shrink with evaporation (for example, shrinkage ratio: 1/2 or less). In the droplet shrinkage process, convection including a liquid flow from the center to the edge and a flow from the edge to the center is continuously formed in the droplet, and the local solid concentration in the droplet Is suppressed, and the solid content concentration in the droplets is made uniform. Then, when the solid content concentration of the entire droplet reaches the saturated concentration, precipitation occurs almost simultaneously in the entire droplet. In this case, solidification occurs while maintaining the shape of the droplet in the contraction process of the droplet, and the dry film (depinning thin film) has a film thickness approximately equal to the center and the edge, or compared to the edge. The film thickness at the center increases.

  In film formation by depinning, droplets are shrunk during the drying process, so that it is possible to form a very small film on the substrate. In addition, using the shrinkage of the droplets during the drying process, for example, forming a film with various characteristics, such as forming a dense structure film (such as colloidal crystals) or forming a crystalline thin film can do.

[Micromembrane]
The size (outer diameter) of the depinning thin film can be controlled by adjusting the solid content concentration of the liquid material. Specifically, for a predetermined amount of droplets, the higher the solid content concentration of the liquid material, the larger the diameter of the dry film. On the contrary, it is possible to form a very small thin film by keeping the solid content concentration of the liquid material low. In this case, even when there is a lower limit to the amount of droplets that can be placed on the substrate, the liquid content shrinkage ratio in the drying process is increased by adjusting the solid content concentration of the liquid material, resulting in extremely fine drying on the substrate. A film can be formed.

  FIG. 10 shows a state where a dry film is formed on a substrate using a liquid material (silica slurry) containing silica fine particles. Here, the solid content concentration of the liquid material is 0.01 wt%, the droplet amount (before drying): 9 pl (picoliter), and the moving speed of the substrate stage: 500 μm / s. In addition, (a) Si substrate (contact angle: 50 °) and (b) glass substrate (contact angle: 9 °) were used as the substrates on which the droplets were placed.

  As a result, depinning occurred during the drying process of the droplet, and a dried film contracted compared to the droplet immediately after placement was formed. Further, in the Si substrate (FIG. 10A), the diameter of the droplets was 45 μm, whereas the diameter of the dry film was 3.0 μm. In the glass substrate (FIG. 10B), the droplet diameter: 84 μm, whereas the dry film diameter: 4.8 μm.

  That is, in the Si substrate, the diameter of the dry film was about 1/15 (shrinkage ratio) compared to the droplet immediately after placement, and in the glass substrate, it was about 1 / 17.5. When the diameter of the 0.01 wt%, 9 pl silica slurry droplet is 3 μm, the solid concentration of the droplet at that time is 50 wt%. This value almost coincides with the literature value that the silica slurry solidifies at a filling rate of 0.5 to 0.6. That is, it is considered that when the silica slurry droplets contracted to a diameter of 3.0 μm, the entire droplets reached the saturation concentration almost simultaneously.

  In addition, in this example, not only liquid-repellent substrates with a high contact angle (Si substrate: contact angle 50 °) but also lyophilic substrates with a low contact angle (glass substrate: contact angle 9 °) can be depinned. occured. That is, regardless of the affinity of the substrate surface for the liquid material, depinning could be caused by keeping the drying speed of the droplets small.

  FIGS. 11A to 11C show changes in the shape of the dried film (depinning thin film) due to depinning when the solid content concentration of the liquid material is changed. Regarding (a) to (c), the amount of droplets when arranged on the substrate is the same. The solid content concentration of the liquid material is (a) <(b) <(c), and (a) is the lowest. At this time, the diameters of the depinning thin film were (a) 0.8 μm, (b) 2.6 μm, and (c) 9.6 μm. That is, the diameter of the dry film changed according to the solid content concentration. In this example, an extremely minute dry film having a diameter of 0.8 μm was formed at the lowest solid content concentration of the liquid material (a).

[Colloidal crystal film]
In film formation by depinning, precipitation of solids at the stage where droplets are contracted is suppressed, and thus a characteristic film structure can be obtained. For example, when a liquid material containing fine particles (colloid particles) is used, a dry film having a dense structure is formed by adjusting the salt concentration of the liquid phase (dispersion medium) according to the surface potential of the fine particles. Is possible.

  That is, when the fine particles in the liquid phase are charged, an electric double layer is formed around the fine particles due to electrostatic interaction between ions. If the salt concentration of the liquid phase containing colloidal particles is set to an appropriate value and the size of the electric double layer on the particle surface is set appropriately, the particle arrangement becomes a close-packed structure (close-packed structure). Is generated. In film formation by depinning, solid content precipitation during the contraction process of droplets is suppressed, so that the arrangement structure of the fine particles in the liquid is not easily broken. As a result, a film having a dense structure (closest-packed structure) is formed.

  FIG. 12 schematically shows an observation image of the structure of the depinning thin film. Here, a dry film of droplets was formed using a liquid material containing polystyrene fine particles. Further, the salt concentration of the liquid material was adjusted according to the surface potential of the fine particles in the liquid. Specifically, the salt concentration of the liquid material was adjusted so that an appropriate electric double layer was formed near the surface of the fine particles. Then, a dry film was formed from the liquid material droplets through depinning. As a result, as shown in FIG. 12, colloidal crystals having a close-packed structure (close-packed structure) were observed in the dry film.

[Crystalline thin film]
In film formation by depinning, solid content aggregates in accordance with the contraction of droplets, so that it is possible to crystallize a low molecular substance contained as a solute in a liquid material. That is, the solute content can be crystallized by creating a supersaturated state and precipitating the solute from the solution during the contraction of the droplet (aggregation method).

  In general, in the crystal formation process, the ease of nucleation changes by adjusting the supersaturation degree of concentration. When the degree of supersaturation is large, stable crystal nuclei are easily generated, and crystals are generated everywhere in the liquid. Conversely, if the degree of supersaturation is low, crystal nuclei are less likely to be generated, and supersaturated molecules are used only for the growth of nuclei generated earlier. That is, when one crystalline particle (thin film) is to be produced, firstly a little supersaturation is formed to form one crystal nucleus, and then the degree of supersaturation is insufficient to form a nucleus. Thus, crystal growth is promoted, and one crystalline particle (thin film) can be formed without generating new nuclei.

  That is, in order to form a crystal film using depinning, it is preferable to appropriately manage the solid content concentration of the liquid material and the drying speed of the droplets. In particular, regarding the drying speed of the droplets, it is preferable to appropriately combine the above-described control elements such as the stage speed, the distance between the droplets, the timing of arrangement and arrangement of a plurality of droplets, and the contact angle of the substrate surface. By appropriately managing the solid content concentration and the drying speed of the liquid material, it is possible to form a good crystalline thin film.

  FIG. 13 shows how the film structure changes when the drying conditions are changed for the purpose of forming a crystalline thin film. Here, a liquid material containing NaCl as a solute was used. In addition, the film was formed under three conditions: (a) 500 μm / s, (b) 100000 μm / s, and (c) 75000 μm / s when the droplets were dried. Actually, other control elements for changing the drying speed were also changed.

  As a result, a favorable crystalline thin film (single crystalline thin film) was formed through depinning under the condition (c). Under the condition (a), crystal nuclei were generated almost simultaneously at various locations in the droplet during the contraction of the droplet in depinning, and a good crystalline thin film was not formed. Under the condition (b), pinning occurred and a crystalline thin film scattered in an annular shape was formed.

  FIG. 14 schematically shows the relationship between the above-described parameters (solid content concentration of liquid material, drying speed of droplets) and the shape of the dry film. As shown in FIG. 14, the depinning thin film is formed under the condition that the solid content concentration is low and the drying speed is low. A pinning thin film is formed under dry conditions where no depinning occurs. When the solid content concentration is high, the pinning thin film becomes thick and approaches a flat film. Further, when the drying speed is high, the rising of the edge increases.

  As described above, according to the film forming method of the present invention, the dry film of the droplet is controlled in various shapes by changing at least one of the solid content concentration of the liquid material and the drying speed of the droplet. can do. As a result, a film having a desired shape can be accurately and stably formed on the substrate. Therefore, it is possible to improve device quality by manufacturing an electronic device using this film forming method.

  Of the pinning thin films, the ring-shaped thin film can be preferably used as a container or base for other materials. That is, when another material is arranged inside the edge of the ring-shaped thin film, the rise of the edge serves as a wall, so that the arrangement accuracy of the material can be improved.

  In addition, the depinning thin film can be applied to various fields because it can be miniaturized and improved in film properties.

  For example, a microfilm formed through dipping can be preferably used for high definition of various electronic devices such as a semiconductor element, a TFT element, and an EL element. When placing droplets on a substrate using the droplet ejection method, there is a lower limit on the amount of droplets that can be ejected. It is possible to easily form a fine film as compared with the liquid droplets. In this case, it is possible to form a minute film equivalent to or more than that of an apparatus capable of discharging femtoliter (fl) droplets using a conventional apparatus.

  In addition, colloidal crystal films and crystalline thin films formed through depinning can be preferably used for thin films in organic EL, electrodes in organic TFTs, and the like because of high conductivity and pure characteristics. In addition, since crystallization of the film facilitates structural analysis, it can be used for structural analysis of proteins and the like in the fields of biotechnology and pharmaceuticals. It can also be used as an optical member. For example, application to a microlens or the like is possible by arranging a curable resin on a crystalline thin film.

  FIG. 15 shows a configuration example of a film forming apparatus suitably used for the film forming method of the present invention. In FIG. 15, the film forming apparatus 10 is provided on a base 112, a substrate stage 22 supporting the substrate 20, and interposed between the base 112 and the substrate stage 22 so that the substrate stage 22 can be moved. A first moving device (moving device) 114 supported by the substrate stage, a liquid ejecting head 21 capable of ejecting the processing liquid to the substrate 20 supported by the substrate stage 22, and a first supporting device movably supporting the liquid ejecting head 21. A two-movement device 116 and a control device 23 for controlling the droplet discharge operation of the liquid discharge head 21. Further, the film forming apparatus 10 includes an electronic balance (not shown) as a weight measuring device provided on the base 112, a capping unit 25, and a cleaning unit 24. The operation of the film forming apparatus 10 including the first moving device 114 and the second moving device 116 is controlled by the control device 23.

  The first moving device 114 is installed on the base 112 and is positioned along the Y direction. The second moving device 116 is mounted upright with respect to the base 112 using the support columns 16A and 16A, and is mounted at the rear portion 12A of the base 112. The X direction (second direction) of the second moving device 116 is a direction orthogonal to the Y direction (first direction) of the first moving device 114. Here, the Y direction is a direction along the front 12B and rear 12A directions of the base 112. On the other hand, the X direction is a direction along the left-right direction of the base 112 and is horizontal. The Z direction is a direction perpendicular to the X direction and the Y direction.

  The first moving device 114 is constituted by, for example, a linear motor, and includes guide rails 140 and 140 and a slider 142 provided to be movable along the guide rail 140. The slider 142 of the first moving device 114 of this linear motor type can be positioned by moving in the Y direction along the guide rail 140.

  Further, the slider 142 includes a motor 144 for rotating around the Z axis (θZ). The motor 144 is, for example, a direct drive motor, and the rotor of the motor 144 is fixed to the substrate stage 22. Thus, by energizing the motor 144, the rotor and the substrate stage 22 can rotate along the θZ direction to index (rotate index) the substrate stage 22. That is, the first moving device 114 can move the substrate stage 22 in the Y direction (first direction) and the θZ direction.

  The substrate stage 22 holds the substrate 20 and positions it at a predetermined position. The substrate stage 22 has a suction holding device (not shown), and the suction holding device operates to suck and hold the substrate 20 on the substrate stage 22 through the hole 46A of the substrate stage 22.

  The second moving device 116 is constituted by a linear motor, and is supported by a column 16B fixed to the columns 16A and 16A, a guide rail 62A supported by the column 16B, and movable along the guide rail 62A in the X direction. The slider 160 is provided. The slider 160 can be positioned by moving in the X direction along the guide rail 62 </ b> A, and the liquid discharge head 21 is attached to the slider 160.

  The liquid discharge head 21 has motors 62, 64, 67, 68 as swing positioning devices. If the motor 62 is operated, the liquid ejection head 21 can be positioned by moving up and down along the Z axis. The Z axis is a direction (vertical direction) orthogonal to the X axis and the Y axis. When the motor 64 is operated, the liquid discharge head 21 can be positioned by swinging along the β direction around the Y axis. When the motor 67 is operated, the liquid discharge head 21 can be positioned by swinging in the γ direction around the X axis. When the motor 68 is operated, the liquid discharge head 21 can be positioned by swinging in the α direction around the Z axis. That is, the second moving device 116 supports the liquid discharge head 21 so as to be movable in the X direction (first direction) and the Z direction, and can move the liquid discharge head 21 in the θX direction, the θY direction, and the θZ direction. To support.

  15 can be positioned by linearly moving in the Z-axis direction in the slider 160, and can be positioned by swinging along α, β, and γ. The droplet discharge surface 11P can be accurately controlled in position or posture with respect to the substrate 20 on the substrate stage 22 side. A plurality of nozzles for discharging droplets are provided on the droplet discharge surface 11P of the liquid discharge head 21.

  The liquid discharge head 21 discharges a liquid material (resist) from a nozzle by a so-called liquid discharge method (droplet discharge method). As the liquid ejection method, various known techniques such as a piezo method that ejects ink using a piezoelectric element as a piezoelectric element, and a method that ejects liquid material using bubbles generated by heating the liquid material are applied. it can. Among these, the piezo method has an advantage that it does not affect the composition of the material because no heat is applied to the liquid material. In this example, the piezo method is used.

  FIG. 16 is a diagram for explaining the discharge principle of the liquid material by the piezo method. In FIG. 16, a piezo element 32 is installed adjacent to a liquid chamber 31 for storing a liquid material. The liquid material is supplied to the liquid chamber 31 via a liquid material supply system 34 including a material tank that stores the liquid material. The piezo element 32 is connected to a drive circuit 33, and a voltage is applied to the piezo element 32 via the drive circuit 33. By deforming the piezo element 32, the liquid chamber 31 is deformed and the liquid material is discharged from the nozzle 30. At this time, the amount of distortion of the piezo element 32 is controlled by changing the value of the applied voltage, and the speed of distortion of the piezo element 32 is controlled by changing the frequency of the applied voltage. That is, in the liquid ejection head 21, the ejection of the liquid material from the nozzle 30 is controlled by controlling the voltage applied to the piezo element 32.

  Returning to FIG. 15, the electronic balance (not shown) measures, for example, 5000 drops from the nozzle of the liquid discharge head 21 in order to measure and manage the weight of one drop discharged from the nozzle of the liquid discharge head 21. Receive a minute drop. The electronic balance can accurately measure the weight of one droplet by dividing the weight of the 5000 droplet by the number of 5000. Based on the measured amount of droplets, the amount of droplets ejected from the liquid ejection head 21 can be optimally controlled.

  The cleaning unit 24 can clean the nozzles and the like of the liquid discharge head 21 periodically or at any time during the device manufacturing process or during standby. The capping unit 25 covers the droplet discharge surface 11P during standby when the device is not manufactured in order to prevent the droplet discharge surface 11P of the liquid discharge head 21 from drying.

  By moving the liquid discharge head 21 in the X direction by the second moving device 116, the liquid discharge head 21 can be selectively positioned above the electronic balance, the cleaning unit 24, or the capping unit 25. That is, even during the device manufacturing operation, the weight of the droplet can be measured by moving the liquid discharge head 21 to the electronic balance side, for example. If the liquid discharge head 21 is moved onto the cleaning unit 24, the liquid discharge head 21 can be cleaned. If the liquid discharge head 21 is moved onto the capping unit 25, a cap is attached to the droplet discharge surface 11P of the liquid discharge head 21 to prevent drying.

  That is, the electronic balance, the cleaning unit 24, and the capping unit 25 are disposed on the rear end side on the base 112 and directly below the movement path of the liquid discharge head 21 and separated from the substrate stage 22. Since the supply work and the discharge work of the substrate 20 with respect to the substrate stage 22 are performed on the front end side of the base 112, the electronic balance, the cleaning unit 24, or the capping unit 25 does not hinder the work.

  As shown in FIG. 15, in the portion of the substrate stage 22 other than the substrate 20 that supports the preliminary ejection area (preliminary ejection) for the liquid ejection head 21 to discard or testly eject droplets (preliminary ejection). (Region) 152 is provided separately from the cleaning unit 24. As shown in FIG. 15, the preliminary discharge area 152 is provided along the X direction on the rear end side of the substrate stage 22. This preliminary discharge area 152 is fixed to the substrate stage 22 and has a concave-shaped receiving member that opens upward, and an absorbent material that is exchangeably installed in the concave portion of the receiving member and absorbs the discharged droplets. It is composed of

  As the substrate 20, various substrates such as a glass substrate, a silicon substrate, a quartz substrate, a ceramic substrate, a metal substrate, a plastic substrate, and a plastic film substrate can be used. Also included are those in which a semiconductor film, a metal film, a dielectric film, an organic film or the like is formed as a base layer on the surface of these various material substrates. Examples of the plastic include polyolefin, polyester, polyacrylate, polycarbonate, polyethersulfone, and polyetherketone.

  In the film forming apparatus, when the droplets ejected from the liquid ejection head are arranged on the substrate, the drying speed of the droplets is controlled by moving the substrate stage or the like. The method for drying the droplets is not limited to this, and for example, the droplets may be dried using a drying means such as lamp annealing.

FIGS. 17A to 17C show an example of the procedure of a method for forming a linear film pattern on a substrate using the above-described film forming apparatus 10 as an example of the film pattern forming method.
In this film pattern forming method, a liquid material is discharged from the discharge head 21 as droplets, and the droplets are arranged on the substrate 21 at regular intervals (pitch). Then, a linear film pattern is formed on the substrate 21 by repeating this droplet placement operation.

  Specifically, first, as shown in FIG. 17A, the droplets L1 ejected from the ejection head 21 are sequentially arranged on the substrate 21 with a certain interval.

  After the droplet L1 is placed on the substrate 21, a drying process is performed in order to remove liquid components (solvent, dispersion medium, etc.). The drying process may be performed by moving a stage on which the substrate 21 is mounted, in addition to a general heating process using heating means such as a hot plate, an electric furnace, a hot air generator, and lamp annealing. In this example, as described above, the shape of the dried film of the droplet is controlled using at least one of the solid content concentration of the liquid material and the drying speed of the droplet as a parameter.

  Next, as shown in FIG. 17B, the above-described droplet placement operation is repeated. That is, as in the previous time shown in FIG. 17A, the liquid material is discharged from the discharge head 21 as droplets L2, and the droplets L2 are arranged on the substrate 21 at regular intervals. At this time, the amount of the droplet L2 (the amount of the liquid material per droplet) and the arrangement pitch P2 thereof are the same as the previous droplet L1. Further, the arrangement position of the droplet L2 is shifted by a predetermined distance S1 from the previous droplet L1. That is, the center position of the previous droplet L1 disposed on the substrate 21 and the center position of the current droplet L2 are in a positional relationship separated by the distance S1. In this example, the shift amount S1 is narrower than the pitches P1 and P2 (S1 <P1 = P2), and the next droplet L2 partially overlaps the droplet L1 previously disposed on the substrate 21. It has been established.

  At this time, the current droplet L2 and the previous droplet L1 are in contact with each other. However, since the liquid component of the previous droplet L1 has already been completely or removed to some extent, they merge and spread on the substrate 21. There is hardly anything. After the droplet L2 is placed on the substrate 21, a drying process is performed in the same manner as the previous time in order to remove the liquid component.

  Thereafter, as shown in FIG. 17C, the above-described droplet placement operation is repeated a plurality of times. At each time, the distance interval (pitch Pn) between the droplets Ln to be arranged is the same as the distance of the first time (pitch Pn = P1), and is always constant. Further, when the droplet placement operation is repeated a plurality of times, the position where the placement of the droplet Ln is started is shifted by a predetermined distance from the position where the previous droplet was placed each time. By repeating this droplet placement operation, the gaps between the droplets placed on the substrate 21 are filled, and a linear continuous pattern is formed. In addition, the film pattern formed on the substrate is always formed by droplet arrangement with the same pitch, and the whole undergoes a substantially equal forming process, so that the structure is uniform.

  In the film pattern forming method of this example, since the shape of the dried film of droplets is controlled, a film pattern having a desired shape can be formed on the substrate with high accuracy and stability.

  In addition, the formation method of a linear pattern is not limited to what was shown to Fig.17 (a)-(c). For example, the arrangement pitch of the droplets and the shift amount at the time of repetition can be arbitrarily set.

  FIG. 18 is a perspective view illustrating the configuration of a liquid crystal display device equipped with a color filter manufactured using the film forming method of the present invention. The liquid crystal display device 400 according to this embodiment is equipped with auxiliary elements such as a liquid crystal driving IC (not shown), wirings (not shown), a light source 470, and a support (not shown). The configuration of the liquid crystal display device 400 will be briefly described. The liquid crystal display device 400 includes a color filter 460 and a glass substrate 414 arranged so as to face each other, a liquid crystal layer (not shown) sandwiched therebetween, and an upper surface side (observer side) of the color filter 460. Are mainly composed of a polarizing plate 416 attached to the lower surface of the glass substrate 414 and a polarizing plate (not shown) attached to the lower surface side of the glass substrate 414. The color filter 460 includes a substrate 461 made of transparent glass and is a substrate provided on the viewer side, and the glass substrate 414 is a transparent substrate provided on the opposite side.

  A partition wall 462 made of a black photosensitive resin film, a colored portion 463, and an overcoat layer 464 are sequentially formed below the substrate 461, and a driving electrode 418 is formed below the overcoat layer 464. ing. Note that in the actual liquid crystal device, an alignment film is provided on the liquid crystal layer side and the electrode 432 described later on the glass substrate 414 side so as to cover the electrode 418, but illustration and description thereof are omitted. The liquid crystal driving electrode 418 formed on the liquid crystal layer side of the color filter 460 is formed by forming a transparent conductive material such as ITO (Indium Tin Oxide) on the entire surface of the overcoat layer 464.

  An insulating layer 425 is formed on the glass substrate 414, and a TFT (Thin Film Transistor) as a switching element and a pixel electrode 432 are formed on the insulating layer 425. A scanning line 451 and a signal line 452 are formed in a matrix over the insulating layer 425 formed over the glass substrate 414, and a pixel electrode 432 is formed for each region surrounded by the scanning line 451 and the signal line 452. Is provided. A TFT is incorporated in a corner portion of each pixel electrode 432 and a portion between the scanning line 451 and the signal line 452, and the TFT is turned on or off by applying a signal to the scanning line 451 and the signal line 452. Thus, energization to the pixel electrode 432 is controlled.

  FIG. 19 is a perspective view illustrating the configuration of a mobile phone as an example of an electronic apparatus using the liquid crystal display device. In the figure, a cellular phone 92 is provided with the above-described liquid crystal display device 400 as well as a plurality of operation buttons 921, an earpiece 922 and a mouthpiece 923.

  The application of the droplet discharge device is not limited to the patterning of the color filter used in the electro-optical device, and can be used to form various film patterns as follows. For example, it can be used for forming thin films such as an organic EL layer and a hole injection layer included in an organic EL (electroluminescence) display panel. When forming an organic EL layer, for example, a droplet containing an organic EL material such as a polythiophene-based conductive polymer is discharged toward a region partitioned by a partition formed on the substrate, and the droplet is discharged. Place in the area. The organic EL layer is formed by drying the liquid material arranged in this way.

  Other uses of the droplet discharge device include the formation of devices such as antennas included in auxiliary wiring for transparent electrodes included in plasma displays and IC (integrated circuit) cards. Specifically, after a solution obtained by mixing conductive fine particles such as silver fine particles in an organic solution such as tetradecane is patterned using a droplet discharge device, a metal thin film layer is formed when the organic solution is dried.

  In addition to the above, the droplet discharge device can be used for various types of materials such as thermosetting resins and ultraviolet curable resins used for three-dimensional modeling, microlens array materials, and biological substances such as DNA (deoxyribonucleic acid) and proteins. It can also be used for arrangement of various materials.

  In addition to mobile phones, electronic devices include computers, projectors, digital cameras, movie cameras, PDAs (Personal Digital Assistants), in-vehicle devices, copying machines, audio devices, and the like.

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but it goes without saying that the present invention is not limited to such examples. Various shapes, combinations, and the like of the constituent members shown in the above-described examples are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

The figure which shows typically the drying process of the typical droplet in the film | membrane formation method of this invention. The figure which shows the example which has arrange | positioned the several droplet on a board | substrate. The figure which shows the example of an arrangement | sequence of a some droplet. The figure which shows the mode of the droplet when the contact angles (static contact angle) of the substrate surface with respect to a liquid material differ from each other. The figure which shows the time integration of the evaporation amount of the liquid (a solvent, a dispersion medium, etc.) from a droplet under fixed dry conditions. The shape of the pinning thin film is shown, the top is a plan view and the bottom is a cross-sectional view. The other shape of a pinning thin film is shown, the upper stage is a top view and the lower stage is sectional drawing. FIG. 4 shows another shape of the pinning thin film, where the upper stage is a plan view and the lower stage is a sectional view. The figure which shows the mode of a film | membrane shape change when the solid content concentration and droplet diameter of a liquid material are changed regarding the dry film | membrane formed through pinning especially about a ring-shaped film | membrane. The figure which shows a mode that the dry film was formed on the board | substrate using the silica slurry. The figure which shows the mode of the change of the shape of a depinning thin film when changing the solid content density | concentration of a liquid material. The figure which shows typically the observation image of the structure of a depinning thin film. The figure which shows the mode of a change of the film | membrane structure at the time of changing dry conditions for the purpose of formation of a crystalline thin film. The figure which shows roughly the relationship between the parameters (solid content concentration of a liquid material, the drying speed of a droplet) and the shape of a dry film. The figure which shows the structural example of the film | membrane formation apparatus used suitably for the film | membrane formation method of this invention. The figure for demonstrating the discharge principle of the liquid material by a piezo system. The figure which shows an example of the procedure of the method of forming a linear film | membrane pattern on a board | substrate. FIG. 5 is a perspective view illustrating the configuration of a liquid crystal display device on which a color filter manufactured using the film forming method of the invention is mounted. FIG. 14 is a perspective view illustrating the configuration of a mobile phone as an example of an electronic apparatus using a liquid crystal display device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Film forming apparatus, 20 ... Substrate, 21 ... Discharge head, 22 ... Substrate stage.

Claims (7)

A first step of disposing droplets containing silica fine particles on a substrate;
After the first step, the droplets are dried to form crystal nuclei, and the supersaturation degree of the concentration of the droplets is adjusted to a degree of supersaturation insufficient to form other crystal nuclei, A second step of forming a dry film having a film thickness at the center equal to or greater than the film thickness at the edge;
Have a, and a third step of placing overlapping the resin on the dry film,
The device manufacturing method , wherein a diameter of the droplet after the second step is contracted immediately after the first step . A first step of placing droplets on a substrate;
After the first step, the liquid droplets are dried to form a liquid flow from the central part to the edge of the liquid droplets and a liquid flow from the edge to the central part of the liquid droplets. Suppressing local increase of the dispersed particles or dissolved solute droplets in the droplets, and forming a dry film with a central film thickness equal to or greater than the edge film thickness A second step of
Have a, and a third step of placing overlapping the resin on the dry film,
The liquid droplet contains salt and colloidal particles, and a liquid phase salt concentration is adjusted according to a surface potential of the colloidal particles . In claim 1 or 2,
A device manufacturing method, wherein the third step is a step of forming a microlens. In any one of Claims 1 thru | or 3 ,
A device manufacturing method, wherein the droplets are disposed on the substrate by a droplet discharge method. Electro-optical device which comprises a device formed in a device manufacturing method according to any one of claims 1 to 4. An electronic apparatus comprising the electro-optical device according to claim 5 . The device manufacturing method according to claim 1, wherein the liquid droplets have a solid content concentration of 0.01% by weight of the silica fine particles.

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