JP2007080765A - Method of forming film pattern, device, and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of forming a film pattern capable of forming a uniform film by improving wettability of ink in the bank. <P>SOLUTION: The method forms the film pattern by arranging a functional liquid on a substrate, and includes a step of forming a bank B on the substrate P and a step of arranging the functional liquid L in the area demarcated by the bank B. The step of forming the bank B includes a step of forming an inorganic material film B1f on the substrate P, a step of forming an organic bank layer B2 containing an organic material component on the surface of the inorganic material film B1f, and a step in which the inorganic material film B1f is patterned using the organic bank layer B2 as a mask and an inorganic bank layer B1 consisting of the inorganic material film is formed between the organic bank layer B2 and the substrate P. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a film pattern forming method, a device, and an electronic apparatus.

  For example, a photolithography method is used for manufacturing a device having wiring such as an electronic circuit or an integrated circuit. In this photolithography method, a thin film wiring pattern is formed by applying a photosensitive material called a resist onto a substrate on which a conductive film has been previously applied, irradiating and developing a circuit pattern, and etching the conductive film according to the resist pattern. Is formed. This photolithography method requires large-scale equipment such as a vacuum apparatus and complicated processes, and the material usage efficiency is about several percent, and most of the material must be discarded, and the manufacturing cost is high.

  On the other hand, there has been proposed a method of forming a wiring pattern on a substrate by using a droplet discharge method in which a liquid material is discharged from a droplet discharge head, that is, a so-called inkjet method. In this method, a wiring pattern forming ink, which is a functional liquid in which conductive fine particles such as metal fine particles are dispersed, is directly applied to a substrate, and then heat treatment or laser irradiation is performed to convert the ink into a thin conductive film pattern. According to this method, there is an advantage that photolithography is not required, the process is greatly simplified, and the amount of raw materials used is reduced.

When a film pattern is formed on a substrate using an inkjet method, a bank structure called a bank is usually formed in order to prevent the ink (functional liquid) from spreading. A bank generally has a two-layer structure of an inorganic bank layer and an organic bank layer. These two types of bank layers are formed one by one from the lower layer side in the order of the inorganic bank layer and the organic bank layer by repeating the formation and patterning of the material film. In addition, in order to dispose ink only inside the bank, the surface of the organic bank layer is subjected to CF ₄ plasma treatment so that the ink has liquid repellency (see Patent Document 1).
WO99 / 48339 pamphlet

However, the bank formed by the above method has the following problems.
(1) When the organic bank layer is patterned, a development residue remains on the substrate, which may affect the wettability of ink in the bank.
(2) When the surface of the organic bank layer is plasma-treated, a part of the organic bank layer may be ashed, and the residue may be deposited in the opening of the organic bank layer. Such a deposit affects the wettability of the ink in the bank as well as the development residue.
(3) In the method of forming the inorganic bank layer and the organic bank layer one by one, there may be a slight misalignment between the inorganic bank layer and the organic bank layer, and this misalignment is the flatness of the film. May be affected.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a film pattern forming method capable of improving the wettability of ink in a bank and forming a uniform film. . Moreover, it aims at providing the device and electronic device which can exhibit the outstanding characteristic by providing such a film | membrane pattern.

In order to solve the above problems, a film pattern forming method of the present invention is a method of forming a film pattern by disposing a functional liquid on a substrate, the step of forming a bank on the substrate, Disposing the functional liquid in a region partitioned by a bank, and forming the bank includes forming an inorganic material film on the substrate and forming an organic material component on a surface of the inorganic material film. Forming an organic bank layer including the organic bank layer, patterning the inorganic material film using the organic bank layer as a mask, and forming an inorganic bank layer made of the inorganic material film between the organic bank layer and the substrate. And a process.
According to this method, when patterning the inorganic bank layer, the development residue of the organic bank layer, which causes uneven coating, deposits generated when the organic bank layer is subjected to liquid repellent treatment (CF ₄ plasma treatment, etc.), etc. Therefore, a film can be uniformly formed in the entire bank as compared with the case where the inorganic bank layer and the organic bank layer are formed one by one as in the prior art. Further, since the inorganic bank layer is formed in a self-aligned manner with respect to the organic bank layer, no positional deviation occurs between them, and the film flatness and film thickness uniformity are excellent. Furthermore, since it is not necessary to form a resist mask for patterning the inorganic bank layer, there is an advantage that the process is simplified.

  “Including organic material component” includes not only the case where the organic bank layer is composed only of the organic material component but also the case where the organic bank layer is composed of a mixed component of the organic material component and the inorganic material component (organic / inorganic hybrid material) Means that.

In the present invention, the inorganic material film can be patterned by wet etching using a hydrofluoric acid solution.
According to this method, since a hydrofluoric acid solution is used as the etching solution, for example, when the base of the inorganic bank layer is an ITO electrode, the work function of the ITO electrode is controlled and formed on the electrode. The efficiency of charge injection into the light emitting layer or the like can be increased.

In the present invention, a groove formed by overetching the inorganic material film may be formed on the side surface of the bank.
According to this method, a uniform film can be formed in the entire bank by wetting and spreading the functional liquid to the groove on the side surface of the bank by capillary action.

In the present invention, the functional liquid can be arranged by a droplet discharge method.
According to this method, by using the droplet discharge method, the consumption of the liquid material is less wasteful than other coating techniques such as a spin coating method, and the amount and position of the liquid material placed on the substrate are controlled. There is an advantage that it is easy to perform.

The device of the present invention includes a film pattern formed by the film pattern forming method of the present invention described above.
According to this configuration, a device having excellent characteristics can be provided by a simple process. Examples of the device of the present invention include an organic electroluminescence device and a color filter substrate. The organic functional layer (light emitting layer, charge transport layer, etc.) and pixel electrode pattern of these organic electroluminescence devices, or the color filter of the color filter substrate. The film pattern forming method of the present invention can be suitably applied to a pattern forming process or the like.

An electronic apparatus according to the present invention includes the above-described device according to the present invention.
According to this configuration, an electronic device having excellent characteristics can be provided.

[First Embodiment]
FIG. 1 is a view conceptually showing the film pattern forming method of the present invention.
In the film pattern forming method of the present invention, first, as shown in FIG. 1A, an inorganic material film B1f is formed on a substrate P, and an organic bank layer containing an organic material component on the surface of the inorganic material film B1f. B2 is formed.

  Examples of the substrate P include various types such as glass, quartz glass, Si wafer, plastic film, and metal plate. Furthermore, a semiconductor film, a metal film, a dielectric film, an organic film, etc. are provided on the surface of these various material substrates. Also includes those formed as an underlayer.

  The inorganic material film B1f forms an inorganic bank layer B1 described later by patterning. As a material for forming the inorganic material film B1f, silicon oxide is suitable. This is because such a material has a high affinity (lyophilicity) for the liquid material, and the liquid material applied on the substrate P can be well wetted and spread along the wall surface of the inorganic bank layer B1. In the present invention, since the inorganic material film B1f is patterned using the organic bank layer B2 as a mask, if the inorganic material film B1f is made of silicon oxide, a high selectivity can be obtained with respect to the organic bank layer B2 made of polyimide or the like. It becomes like this.

  As a material for forming the organic bank layer B2, a polymer material such as an acrylic resin, a polyimide resin, an olefin resin, a melamine resin, an organic / inorganic hybrid material containing polysilazane, polysiloxane, or the like is used. The organic bank layer B2 is obtained by forming a material film containing such an organic material component on the surface of the inorganic material film B1f and patterning it using a photolithography technique or the like. The opening H2 formed in the organic bank layer B2 corresponds to a film pattern formation region.

  The surface of the organic bank layer B2 is subjected to a liquid repellent treatment as necessary. This is because the organic bank layer B2 functions as a partition member that partitions the film pattern formation region, and therefore preferably exhibits non-affinity (liquid repellency) with respect to the functional liquid applied in the organic bank layer B2. .

As the liquid repellent treatment, plasma treatment using a gas having a fluorine component such as CF ₄ , SF ₆ , or CHF ₃ can be used. Instead of the liquid repellent treatment, the material of the organic bank layer B2 itself (for example, the material for forming the organic bank layer B2) may be filled with a liquid repellent component such as a fluorine group in advance. By making the surface of the organic bank layer B2 liquid-repellent, it is possible to form a film only at the opening of the organic bank layer B2 and prevent an unnecessary film from being formed on the upper surface of the organic bank layer B2.

  When the organic bank layer B2 is formed, the inorganic material film B1f is patterned using the organic bank layer B2 as a mask, as shown in FIG. By this step, an inorganic bank layer B1 having an opening H1 communicating with the opening H2 of the organic bank layer B2 is formed between the organic bank layer B2 and the base P. The inorganic bank layer B1 and the organic bank layer B2 constitute a partition member (bank B) for partitioning the film pattern, and the openings H1 and H2 formed in the two bank layers B1 and B2 are formed with the film pattern formation region H. Become.

For patterning the inorganic material film B1f, wet etching using a hydrofluoric acid solution (HF) is preferably employed. By using wet etching, it is possible to remove a development residue when the organic bank layer B2 is patterned, a deposit generated when the organic bank layer B2 is subjected to a liquid repellent treatment (CF ₄ plasma treatment or the like), and the like. In addition, when a hydrofluoric acid solution is used as an etchant, the work function of the ITO electrode formed on the base with the etchant can be adjusted. For example, when the inorganic bank layer B1 is made of an ITO electrode and a hole injection layer or a light emitting layer is formed on the ITO electrode, the surface of the ITO electrode is treated with hydrofluoric acid so that the positive electrode from the ITO electrode to the light emitting layer can be obtained. The hole injection efficiency can be increased.

  In this step, the opening H1 of the inorganic bank layer B1 is formed in a self-aligned manner with respect to the opening H2 of the organic bank layer B2. For this reason, even if the relative positions of the two openings H1 and H2 are not precisely aligned, no positional deviation occurs between them. That is, if the etching conditions are appropriately controlled so that the etching of the inorganic material film B1f is not overetched, it can be formed flush with the wall surface B1c of the inorganic bank layer B1 and the wall surface B2c of the organic bank layer B2. .

  When the bank B is formed, the functional liquid L is disposed in the region H partitioned by the bank B as shown in FIG. The functional liquid L is a liquid material obtained by dissolving or dispersing a material constituting the film pattern in a solvent.

  As a material constituting the film pattern, materials (functional materials) having various functions such as an electrical function and an optical function can be used. For example, when a light emitting layer of an organic EL element is formed, a material having fluorescence or phosphorescence may be used as a functional material, and when a color filter is formed, a fine particle coloring material such as a pigment may be used. . Further, when forming a transparent pixel electrode such as a liquid crystal device, a fine particle conductive material such as indium tin oxide (ITO) may be used.

  The solvent is not particularly limited as long as it can dissolve or disperse the above functional material and does not cause aggregation. For example, water, alcohols, hydrocarbon compounds, and ether compounds are suitable.

  As a method of disposing the functional liquid L in the region partitioned by the bank B, it is preferable to use a droplet discharge method, a so-called ink jet method. By using the droplet discharge method, compared to other coating techniques such as spin coating, there is an advantage that the consumption of the liquid material is less and the amount and position of the functional liquid placed on the substrate can be easily controlled. is there. However, the method of arranging the functional liquid L in the region partitioned by the bank B is not limited to the ink jet method, and may be arranged using a spin coat method or the like if necessary.

  Examples of the discharge technique of the droplet discharge method include a charge control method, a pressure vibration method, an electromechanical conversion method, an electrothermal conversion method, and an electrostatic suction method.

In the charge control method, a charge is applied to a material by a charging electrode, and the flight direction of the material is controlled by a deflection electrode and discharged from a nozzle. In addition, the pressurized vibration method is a method in which an ultra-high pressure of about 30 kg / cm ² is applied to the material and the material is discharged to the nozzle tip side. When no control voltage is applied, the material goes straight and is discharged from the nozzle. When a control voltage is applied, electrostatic repulsion occurs between the materials, and the materials are scattered and are not discharged from the nozzle. The electromechanical conversion method utilizes the property that a piezoelectric element (piezoelectric element) is deformed by receiving a pulse-like electric signal. The piezoelectric element is deformed through a flexible substance in a space where material is stored. Pressure is applied, and the material is extruded from this space and discharged from the nozzle.

  In the electrothermal conversion system, a material is rapidly vaporized by a heater provided in a space in which the material is stored to generate bubbles, and the material in the space is discharged by the pressure of the bubbles. In the electrostatic attraction method, a minute pressure is applied in a space in which the material is stored, a meniscus of the material is formed on the nozzle, and an electrostatic attractive force is applied in this state before the material is drawn out. In addition to this, techniques such as a system that uses a change in the viscosity of a fluid due to an electric field and a system that uses a discharge spark are also applicable. The droplet discharge method has an advantage that the use of the material is less wasteful and a desired amount of the material can be accurately disposed at a desired position. The amount of one drop of the liquid material (fluid) discharged by the droplet discharge method is, for example, 1 to 300 nanograms.

  FIG. 2 is a perspective view showing a schematic configuration of a droplet discharge device (inkjet device) IJ that disposes a liquid material on a substrate by a droplet discharge method.

  The droplet discharge device IJ includes a droplet discharge head 1, an X-axis direction drive shaft 4, a Y-axis direction guide shaft 5, a control device CONT, a stage 7, a cleaning mechanism 8, a base 9, and a heater. 15.

  The stage 7 supports the substrate P on which ink (liquid material) is provided by the droplet discharge device IJ, and includes a fixing mechanism (not shown) that fixes the substrate P at a reference position.

  The droplet discharge head 1 is a multi-nozzle type droplet discharge head including a plurality of discharge nozzles, and the longitudinal direction and the Y-axis direction are made to coincide. The plurality of ejection nozzles are provided on the lower surface of the droplet ejection head 1 at regular intervals along the Y-axis direction. From the discharge nozzle of the droplet discharge head 1, the ink containing the conductive fine particles described above is discharged onto the substrate P supported by the stage 7.

  An X-axis direction drive motor 2 is connected to the X-axis direction drive shaft 4. The X-axis direction drive motor 2 is a stepping motor or the like, and rotates the X-axis direction drive shaft 4 when a drive signal in the X-axis direction is supplied from the control device CONT. When the X-axis direction drive shaft 4 rotates, the droplet discharge head 1 moves in the X-axis direction.

  The Y-axis direction guide shaft 5 is fixed so as not to move with respect to the base 9. The stage 7 includes a Y-axis direction drive motor 3. The Y-axis direction drive motor 3 is a stepping motor or the like, and moves the stage 7 in the Y-axis direction when a drive signal in the Y-axis direction is supplied from the control device CONT.

  The control device CONT supplies the droplet discharge head 1 with a voltage for controlling droplet discharge. In addition, a drive pulse signal for controlling the movement of the droplet discharge head 1 in the X-axis direction is supplied to the X-axis direction drive motor 2, and a drive pulse signal for controlling the movement of the stage 7 in the Y-axis direction is sent to the Y-axis direction drive motor 3. Supply.

  The cleaning mechanism 8 cleans the droplet discharge head 1. The cleaning mechanism 8 is provided with a Y-axis direction drive motor (not shown). The cleaning mechanism 8 moves along the Y-axis direction guide shaft 5 by driving the Y-axis direction drive motor. The movement of the cleaning mechanism 8 is also controlled by the control device CONT.

  Here, the heater 15 is a means for heat-treating the substrate P by lamp annealing, and performs evaporation and drying of the solvent contained in the liquid material applied on the substrate P. The heater 15 is also turned on and off by the control device CONT.

  The droplet discharge device IJ discharges droplets onto the substrate P while relatively scanning the droplet discharge head 1 and the stage 7 that supports the substrate P. Here, in the following description, the X-axis direction is a scanning direction, and the Y-axis direction orthogonal to the X-axis direction is a non-scanning direction. Therefore, the discharge nozzles of the droplet discharge head 1 are provided at regular intervals in the Y-axis direction, which is the non-scanning direction. In FIG. 2, the droplet discharge head 1 is arranged at a right angle to the traveling direction of the substrate P, but the angle of the droplet discharging head 1 is adjusted so as to intersect the traveling direction of the substrate P. It may be. In this way, the pitch between the nozzles can be adjusted by adjusting the angle of the droplet discharge head 1. Moreover, you may enable it to adjust the distance of the base | substrate P and a nozzle surface arbitrarily.

FIG. 3 is a view for explaining the discharge principle of the liquid material by the piezo method.
In FIG. 3, a piezo element 22 is installed adjacent to a liquid chamber 21 for storing a liquid material (ink for wiring pattern, functional liquid). The liquid material is supplied to the liquid chamber 21 via a liquid material supply system 23 including a material tank that stores the liquid material.

  The piezo element 22 is connected to a drive circuit 24, and a voltage is applied to the piezo element 22 via the drive circuit 24 to deform the piezo element 22, whereby the liquid chamber 21 is deformed and the liquid material is discharged from the nozzle 25. Is discharged. In this case, the amount of distortion of the piezo element 22 is controlled by changing the value of the applied voltage. Further, the strain rate of the piezo element 22 is controlled by changing the frequency of the applied voltage.

  Since the droplet discharge by the piezo method does not apply heat to the material, it has an advantage of hardly affecting the composition of the material.

  Returning to FIG. 1, when the functional liquid L is arranged in the region H partitioned by the bank B, the solvent of the functional liquid L is removed by drying as shown in FIG. As a result, a film pattern F made of the functional material is formed in the opening H of the bank B.

  In the film pattern forming method of the present invention, the functional liquid L is disposed in the region partitioned by the bank B, and the functional liquid L is dried or baked to form the film pattern F on the substrate P. In this case, since the shape of the film pattern F is defined by the bank B, the film pattern F can be made finer by appropriately forming the bank B, for example, by narrowing the width between the adjacent banks B and B. Thinning is achieved.

  Further, since the underlying inorganic bank layer B1 is patterned using the organic bank layer B2 as a mask, when the inorganic bank layer is patterned, the development residue of the organic bank layer, the deposit when the organic bank layer is subjected to a liquid repellent treatment, etc. Can be removed. For this reason, the wettability with respect to the functional liquid L is improved as compared with the conventional method, and a uniform film is formed in the entire bank. In addition, since the inorganic bank layer B1 is formed in a self-aligned manner with respect to the organic bank layer B2, there is no positional shift between them, and the flatness of the film is also good. Further, since it is not necessary to form a resist mask for patterning the inorganic bank layer B1, there is an advantage that the process is simplified.

[Second Embodiment]
Next, a second embodiment of the film pattern forming method of the present invention will be described with reference to FIG. 4A is a cross-sectional view showing the structure of the bank B, and FIGS. 4B and 4C are plan views showing a state in which the functional liquid L is discharged to the region H partitioned by the bank B. FIG. FIG.

  The basic structure and manufacturing method of the bank B of the present embodiment are the same as those of the first embodiment, and the only difference is that a groove G formed by over-etching the inorganic material film B1f is provided on the side surface of the bank B. It is. That is, in the first embodiment, the wall surface B1c of the inorganic bank layer B1 is formed to be flush with the wall surface B2c of the organic bank layer B2, but in this embodiment, the inorganic material film B1f is over-etched to form the organic bank layer B2 4 is different in that a reverse tapered groove G as shown in FIG.

  The groove portion G is formed by over-etching the inorganic material film B1f. First, the inorganic bank layer B1 and the organic bank layer B2 are formed flush with each other by dry etching, and then hydrofluoric acid is formed. It is also possible to form the groove G under the organic bank layer B1 by side-etching (overetching) the wall surface B1c of the inorganic bank layer B1 with a solution or the like.

  When the groove portion G is formed on the wall surface of the bank B, the functional liquid L can be uniformly wetted and spread along the groove portion G over the entire opening portion of the bank B. For example, when the functional liquid L is discharged to the opening H of the bank B as shown in FIG. 4B, the functional liquid L spreads isotropically around the discharge position, but when reaching the wall surface of the bank B, FIG. As shown in (c), the functional liquid L enters the groove G due to the capillary phenomenon, and spreads along the groove G as it is to the entire opening H. Since the groove part G is formed in the whole wall surface of the bank B, it is possible to spread the functional liquid L to every corner of the opening part H. Since there is no development residue or the like of the organic bank layer B2 that causes uneven coating in the opening H, the coating film of the functional liquid L is uniformly formed throughout the opening H. The film pattern obtained by drying this also has excellent flatness and film thickness uniformity.

[Third Embodiment]
Next, as an embodiment of the device manufacturing method of the present invention, an example in which the film pattern forming method of the present invention is applied to a method of manufacturing an organic electroluminescence device (organic EL device) will be described. This organic EL device is an organic EL device in which organic EL elements are arranged on a substrate as pixels, and can be suitably used as display means for electronic devices, for example.

  FIG. 5 is a circuit configuration diagram of the organic EL device 70, and FIG. 6 is a diagram illustrating a planar structure of each pixel 71 provided in the organic EL device 70, and FIG. FIG. 4B is a diagram showing a pixel driving portion such as a bank (partition wall member) that partitions pixels. FIG. 7 is a diagram showing a cross-sectional configuration along the line AA in FIG.

  As shown in FIG. 5, the organic EL device 70 includes a plurality of scanning lines (wirings, power conducting portions) 131 and a plurality of signals extending in a direction intersecting with the scanning lines 131 on a substrate made of glass or the like. A line (wiring, power conduction unit) 132 and a plurality of common power supply lines (wiring, power conduction unit) 133 extending in parallel to the signal lines 132 are respectively wired. A pixel (pixel region) 71 is provided for each intersection.

  For the signal line 132, a data side driving circuit 72 including a shift register, a level shifter, a video line, an analog switch, and the like is provided. On the other hand, the scanning line 131 is provided with a scanning side drive circuit 73 including a shift register, a level shifter, and the like. Further, each of the pixel regions 71 is supplied from a switching TFT (thin film transistor) 142 to which a scanning signal is supplied to the gate electrode through the scanning line 131 and from the signal line 132 through the switching TFT (thin film transistor) 142. A storage capacitor cap for holding the image signal (power) to be generated, a driving TFT 143 to which the image signal held by the storage capacitor cap is supplied to the gate electrode, and the common feeding line 133 via the driving TFT 143 A pixel electrode 141 into which a drive current flows from the common power supply line 133 when connected to the light-emitting element, and a light emitting unit 140 sandwiched between the pixel electrode 141 and the common electrode 154 are provided. An element composed of the pixel electrode (first electrode) 141, the common electrode (second electrode) 154, and the light emitting unit 140 made of an organic functional layer is an organic EL element.

  Under such a configuration, when the scanning line 131 is driven and the switching TFT 142 is turned on, the potential of the signal line 132 at that time is held in the holding capacitor cap, and depending on the state of the holding capacitor cap, The on / off state of the driving TFT 143 is determined. Then, a current flows from the common power supply line 133 to the pixel electrode 141 through the channel of the driving TFT 143, and further a current flows to the common electrode 154 through the light emitting unit 140. Will start to emit light.

  Next, when viewing the planar structure of the pixel 71 shown in FIG. 6A, the pixel 71 has four sides of the pixel electrode 141 that is substantially rectangular in plan view, the signal line 132, the common power supply line 133, the scanning line 131, and the illustrated figure. The arrangement is surrounded by scanning lines for other pixel electrodes that are not. Further, in the cross-sectional structure of the pixel 71 shown in FIG. 7, the driving TFT 143 is provided on the base P, and the organic TFT is formed on the base P via a plurality of insulating films formed to cover the driving TFT 143. An EL element 200 is formed. The organic EL element 200 is mainly composed of an organic functional layer 140 provided in a region surrounded by the organic bank layer 150 erected on the base P. The organic functional layer 140 is composed of the pixel electrode 141 and the common electrode. 154 is provided between 154 and 154.

  Here, in the planar structure shown in FIG. 6B, the organic bank layer 150 has an opening 151 having a substantially rectangular shape in plan view corresponding to the region where the pixel electrode 141 is formed. The previous organic functional layer 140 is formed.

  As shown in FIG. 7, the driving TFT 143 includes a channel region 143c via a source region 143a, a drain region 143b and a channel region 143c formed in the semiconductor film 210, and a gate insulating film 220 formed on the surface of the semiconductor layer. And a gate electrode 143A facing the main body. A first interlayer insulating film 230 is formed to cover the semiconductor film 210 and the gate insulating film 220. The drain electrodes 236 are respectively formed in the contact holes 232 and 234 that penetrate the first interlayer insulating film 230 and reach the semiconductor film 210. The source electrode 238 is buried, and each electrode is conductively connected to the drain region 143b and the source region 143a. A second interlayer insulating film 240 is formed on the first interlayer insulating film 230, and a part of the pixel electrode 141 is embedded in a contact hole penetrating through the second interlayer insulating film 240. The pixel electrode 141 and the drain electrode 236 are conductively connected, so that the driving TFT 143 and the pixel electrode 141 (organic EL element 200) are electrically connected. An inorganic bank layer (first partition wall layer) 149 made of an inorganic insulating material is formed so as to partially run on the peripheral edge of the pixel electrode 141. On the inorganic bank layer 149, an organic bank layer (second partition layer) 150 made of an organic material is laminated to form a partition member in the organic EL device.

  In the organic EL element 200, a hole injection layer 140A as a charge transport layer and a light emitting layer 140B are stacked on the pixel electrode 141, and a common electrode 154 covering the light emitting layer 140B and the organic bank layer 150 is formed. It is comprised by doing.

  In the case of a so-called bottom emission type organic EL device, the substrate P is configured to extract light from the substrate P side, and therefore a transparent substrate such as glass is used. On the other hand, in the case of a so-called top emission type organic EL device, light is extracted from the side on which the organic EL element 200 is disposed. Therefore, in addition to a transparent substrate such as glass, an opaque substrate can be used. Examples of opaque substrates include ceramics such as alumina, metal sheets such as stainless steel that have been subjected to insulation treatment such as surface oxidation, thermosetting resins and thermoplastic resins, and films thereof (plastic films). It is done.

  The pixel electrode 141 is formed of a light-transmitting conductive material such as ITO (indium tin oxide) in the case of the bottom emission type that extracts light through the base P, but in the case of the top emission type, the light transmission is performed. It is not necessary to have a property, and it can be formed of an appropriate conductive material such as a metal material.

  The common electrode 154 is formed on the substrate P in a state of covering the upper surfaces of the light emitting layer 140B and the organic bank layer 150 and the wall surfaces forming the side surfaces of the organic bank layer 150. As a material for forming the common electrode 154, in the case of the top emission type, a transparent conductive material is used. ITO is suitable as the transparent conductive material, but other translucent conductive materials may be used. In the case of the bottom emission type, in addition to the transparent conductive material, an opaque or light reflective conductive material such as aluminum can be used.

A cathode protective layer may be formed on the upper layer side of the common electrode 154. By providing such a cathode protective layer, an effect of preventing the common electrode 154 from being corroded during the manufacturing process can be obtained, and an inorganic compound such as silicon oxide, silicon nitride, silicon nitride oxide or the like can be used. Can be formed. By covering the common electrode 154 with a cathode protective layer made of an inorganic compound, intrusion of oxygen or the like into the common electrode 154 made of an inorganic oxide can be satisfactorily prevented.
Such a cathode protective layer is formed to a thickness of about 10 nm to 300 nm on the substrate outside the plane region of the common electrode 154.

[Method for Manufacturing Organic EL Device]
Next, a method for manufacturing the organic EL device 70 will be described with reference to the drawings.
8 to 11 are cross-sectional process diagrams illustrating a method for manufacturing an organic EL device according to an embodiment of the present invention. In the following description, a method of manufacturing the organic EL device having the configuration shown in FIGS. 5 to 7 by using a droplet discharge method (inkjet method) will be described as an example. However, the following procedure and the material configuration of the functional liquid are examples, and the present invention is not limited thereto.

  First, as shown in FIG. 8A, the driving TFT 143, the first interlayer insulating film 230, the second interlayer insulating film 240, and the pixel electrode 141 are formed on the base P. These can be formed by a known method. Note that the pixel electrode 141 is formed of a light-transmitting conductive material such as ITO in the case of the bottom emission type. In the case of the top emission type, in addition to a light-transmitting conductive material, it is formed of an opaque or light-reflective conductive material such as aluminum, silver, gold, or platinum. Moreover, it is good also as a laminated film of ITO / Al.

  Next, as shown in FIG. 8B, a first material film (inorganic material film) 149f made of an inorganic insulating material is formed so as to cover the pixel electrode 141, and subsequently, as shown in FIG. 8C. Then, a second material film 150f containing an organic insulating material component is formed so as to cover the first material film 149f. The first material film 149f and the second material film 150f become the inorganic bank layer 149 and the organic bank layer 150, respectively, by patterning.

The materials of the first material film 149f and the second material film 150f are not particularly limited as long as they are excellent in heat resistance and solvent resistance.
For example, silicon oxide or the like can be used for the first material film 149f. Such a material is excellent in adhesion to the base substrate and has a high dielectric constant, and thus is preferable for reducing the parasitic capacitance between the common electrode 154 and the wirings 131, 132, and 133.
As the second material film 150f, a polymer material such as polyimide or an organic / inorganic hybrid material containing polysilazane or the like can be used. The height of the second material film 150f (that is, the height of the organic bank layer 150) is set to, for example, about 1 to 2 μm in order to ensure a sufficient discharge amount of the functional liquid.

  Next, as shown in FIG. 9A, the second material film 150f is patterned to partially open a region on the pixel electrode 109, thereby forming the organic bank layer 150. As a result, the hole injection layer and the light emitting layer of the organic EL element 200 are formed, that is, the opening 151 having a sufficiently high step between the application position of these forming materials and the surrounding organic bank layer 150. Is formed.

  After the formation of the organic bank layer 150, a surface treatment is applied to the region on the substrate including the organic bank layer 150 as necessary. Since the organic bank layer 150 functions as a partition member that partitions the organic EL element 200, the organic bank layer 150 preferably exhibits non-affinity (liquid repellency) with respect to the liquid material discharged from the droplet discharge head 1. By the surface treatment, non-affinity can be selectively expressed in the organic bank layer 150.

As such surface treatment, for example, a method of performing plasma treatment (liquid repellent treatment) on the surface of the organic bank layer 150 using a gas containing a fluorine compound (fluorine-containing gas) as a treatment gas can be employed. By using a fluorine compound, a fluorine group is introduced on the surface of the organic bank layer 150, thereby allowing the liquid material to be repelled. Examples of the fluorine compound include CF ₄ , SF ₆ , and CHF ₃ . However, instead of such a treatment, the organic bank layer 150 may be filled with a liquid repellent component such as a fluorine group in advance. By making the surface of the organic bank layer 150 liquid-repellent, it is possible to form a film only in the opening 151 of the organic bank layer 150 and prevent an unnecessary film from being formed on the upper surface of the organic bank layer 150.

  Next, as shown in FIG. 9B, the first material film 149 f is patterned using the organic bank layer 150 as a mask, and an opening 149 b is formed on the pixel electrode 141.

The patterning of the inorganic bank layer 149 is preferably performed by wet etching using a hydrofluoric acid solution. By using wet etching, it is possible to remove development residues of the organic bank layer 150 that cause uneven coating, deposits that are generated when the organic bank layer 150 is surface-treated, and the like. When the pixel electrode 141 is made of ITO, the work function (that is, the efficiency of hole injection into the hole injection layer 140A) can be adjusted by treating the surface with a hydrofluoric acid solution. If a hydrofluoric acid solution is used, such surface treatment can be performed simultaneously with the patterning of the inorganic bank layer 149. For example, the work function of ITO before processing was 4.6 eV, whereas the work function of ITO was reduced to 4.9 eV by treating with an aqueous solution of hydrofluoric acid 1 wt% and NH ₄ F 30 wt% for 10 minutes at room temperature. changed.

  However, the patterning method is not limited to wet etching, and patterning may be performed using dry etching if necessary.

  By forming the inorganic bank layer 149, the bank B having a two-layer structure of the inorganic bank layer 149 and the organic bank layer 150 is formed on the base P. The opening 151 of the organic bank layer 150 and the opening 149b of the inorganic bank layer 149 communicate with each other, and the pixel electrode 141 is exposed in these openings.

  In FIG. 9B, the opening 149b of the inorganic bank layer 149 is formed flush with the opening 151 of the organic bank layer 150, but as shown in FIG. 4A of the second embodiment, It is also possible to over-etch the inorganic bank layer 149b and form the wall surface in a reverse taper shape.

  When the bank B is formed, as shown in FIG. 10A, the functional liquid 114 a for forming the hole injection layer is selectively applied to the application position surrounded by the bank B by the droplet discharge head 1. The functional liquid 114a includes a hole injection layer forming material (charge transport layer forming material) and a solvent.

  As the hole injection layer forming material, polyphenylene vinylene whose polymer precursor is polytetrahydrothiophenylphenylene, 1,1-bis- (4-N, N-ditolylaminophenyl) cyclohexane, tris (8-hydroxyquinolinol) Examples thereof include aluminum, polystyrene sulfonic acid, a mixture of polyethylene dioxythiophene and polystyrene sulfonic acid (PEDOT / PSS), and the like. Examples of the solvent include polar solvents such as isopropyl alcohol, N-methylpyrrolidone, and 1,3-dimethyl-imidazolinone.

  When the functional liquid 114a containing the hole injection layer forming material described above is ejected from the droplet ejection head 1 onto the substrate P, it tends to spread in the horizontal direction because of its high fluidity, but surrounds the applied position. Since the organic bank layer 150 is formed, the functional liquid 114a does not spread beyond the organic bank layer 150 to the outside. In addition, since the surface of the pixel electrode 141 and the inorganic bank layer 149 is in a state of maintaining good lyophilicity, the discharged functional liquid 114a spreads over the entire surface of the pixel electrode and forms a uniform coating film. . Further, since the opening 149 b of the inorganic bank layer 149 is formed in a self-aligned manner with respect to the opening 151 of the organic bank layer 150, a positional shift or a step is generated between the inorganic bank layer 149 and the organic bank layer 150. The obtained coating film also has good flatness.

  Subsequently, the solvent of the functional liquid 114a is evaporated by heating or light irradiation to form a solid hole injection layer 140A on the pixel electrode 141. Alternatively, firing may be performed at a predetermined temperature and time (for example, 200 ° C., 10 minutes) in an air environment or a nitrogen gas atmosphere. Or you may make it remove a solvent by arrange | positioning in the pressure environment (under pressure reduction environment) lower than atmospheric pressure. In the present embodiment, since the coating film of the functional liquid 114a is uniformly formed in the entire bank, the obtained hole injection layer 140A is also uniform in film thickness and film quality and excellent in surface flatness. It will be a thing.

  Subsequently, as shown in FIG. 10B, the functional liquid 114 b for forming the hole injection layer is selectively applied onto the hole injection layer 140 </ b> A in the bank B by the droplet discharge head 1. The functional liquid 114b includes a light emitting layer forming material and a solvent.

  As the light emitting layer forming material, polyfluorene derivative (PF), polyparaphenylene vinylene derivative (PPV), polyphenylene derivative (PP), polyparaffin, which are known polymer light emitting materials capable of emitting fluorescence or phosphorescence. Polysilanes such as phenylene derivatives (PPP), polyvinylcarbazole (PVK), polythiophene derivatives, polydialkylfluorene (PDAF), polyfluorenebenzothiadiazole (PFBT), polyalkylthiophene (PAT), polymethylphenylsilane (PMPS), etc. Can be suitably used. In addition, these light-emitting materials include polymer materials such as perylene dyes, coumarin dyes, rhodamine dyes, rubrene, perylene, 9,10-diphenylanthracene, tetraphenylbutadiene, Nile red, coumarin 6, quinacridone, and the like. It is also possible to use a low molecular weight material doped.

  The light emitting layer forming material is preferably dissolved or dispersed in a polar solvent to form a liquid material, and this liquid material is preferably discharged from the droplet discharge head 1. Since the polar solvent can easily dissolve or uniformly disperse the light emitting material or the like, the solid component in the light emitting layer forming material in the nozzle holes of the droplet discharge head 1 may be attached or clogged. Can be prevented.

  Specific examples of such a polar solvent include water, alcohols compatible with water such as methanol and ethanol, N, N-dimethylformamide (DMF), N-methylpyrrolidone (NMP), dimethylimidazoline (DMI), Examples include organic solvents or inorganic solvents such as dimethyl sulfoxide (DMSO), xylene, cyclohexylbenzene, and 2,3-dihydrobenzofuran, and two or more of these solvents may be appropriately mixed.

  The formation of the light emitting layer by discharging the functional liquid 114b from the droplet discharge head 1 is performed by using a functional liquid including a light emitting layer forming material that emits red colored light and a light emitting layer forming material that emits green colored light. The functional liquid containing and the functional liquid containing the light emitting layer forming material that emits blue colored light are ejected and applied to the corresponding pixels 71 (openings 151). The pixels 71 corresponding to the respective colors are determined in advance so that they are regularly arranged.

  When the functional liquid 114b containing the light emitting layer forming material of each color is discharged and applied in this manner, the solvent in the functional liquid 114b is evaporated. By this step, as shown in FIG. 9C, a solid light emitting layer 140B is formed on the hole injection layer 140A, and thereby an organic functional layer 140 composed of the hole injection layer 140A and the light emitting layer 140B is obtained. . Here, regarding the evaporation of the solvent in the functional liquid 114b containing the light emitting layer forming material, treatment such as heating or decompression is performed as necessary. However, the light emitting layer forming material usually has a good drying property and a fast drying property. Therefore, the light emitting layer 140B of each color can be formed in the order of application by sequentially discharging and applying the light emitting layer forming material of each color without performing such a process. Further, as described above, since the surface of the hole injection layer 140A on which the functional liquid 114b is arranged is flattened well, the light emitting layer 140B formed thereon is also formed with good flatness. Thus, the film thickness and film quality are uniform. Therefore, the light emitting layer has uniform and good light emitting characteristics and reliability.

  Thereafter, as shown in FIG. 11, a common electrode 154 made of ITO or the like is formed on the entire surface of the substrate P or in a stripe shape. Thus, the organic EL element 200 can be manufactured.

  In such a method for manufacturing an organic EL element, since the thin film that is a constituent element of the organic EL element such as the hole injection layer 140A and the light emitting layer 140B is manufactured by a droplet discharge device, the hole injection layer 140A and the light emitting layer are formed. There is little loss of the liquid material used as the forming material of 140B, and the hole injection layer 140A and the light emitting layer 140B are formed relatively inexpensively and stably.

  Further, since the inorganic bank layer 150 is patterned using the organic bank layer 149 as a mask, the development residue of the organic bank layer 150 that causes uneven coating, deposits generated when the organic bank layer 150 is subjected to a liquid repellent treatment, etc. It does not remain on P. Further, since the inorganic bank layer 149 is formed in a self-aligned manner with respect to the organic bank layer 150, there is no positional shift between them. Therefore, an organic functional layer having a flat and uniform thickness can be formed in the entire pixel, and an organic EL device having excellent light emission characteristics and reliability is manufactured. Further, since a resist mask for patterning the inorganic bank layer 149 is not required, the process is simplified.

  The organic EL device 70 according to the present embodiment employs a structure in which the pixel electrode 141 is an anode and the common electrode 154 is a cathode. On the contrary, the pixel electrode 141 is a cathode and the common electrode 154 is an anode. It is also possible to adopt a structure that does this. In this case, an electron injection layer is formed as the charge transport layer disposed between the pixel electrode and the light emitting layer. In this embodiment, the organic EL device 70 is an active matrix organic EL display device. However, the organic EL device 70 is used for applications other than a passive matrix organic EL display device or a display device such as a line head. It is also possible to apply the film pattern forming method of the present invention.

[Fourth Embodiment]
Next, as an embodiment of the device manufacturing method of the present invention, an example in which the film pattern forming method of the present invention is applied to a color filter substrate manufacturing method will be described. This color filter substrate can be suitably applied as a color display means of a liquid crystal display panel, for example.

FIG. 12 is a conceptual diagram showing a method for manufacturing a color filter substrate of this embodiment.
In this method for manufacturing a color filter substrate, a plurality of color filters F (F _R , F _G , F _B ) are formed on a substrate P made of glass, plastic, or the like, using the droplet discharge head 20 described above. From the viewpoint of improving productivity, a large-area substrate (large substrate) made of glass, plastic, or the like is used as the base P, and dots are formed inside a plurality of panel regions T formed on the large substrate P. A plurality of arranged color filters F are formed.

  The panel region T is a region where a display color filter F is formed. A bank B is formed in the panel region T, and each region partitioned by the bank B, that is, the opening H of the bank B is a color filter forming region. The color filter F is formed by disposing a functional liquid containing a particulate coloring material such as a pigment in the opening H of the bank B.

Each panel region T can be used as a color filter substrate suitable for a display panel by cutting the large substrate P later. The panel area T, the red color filter F _R containing the red coloring _material, and the green color filter F _G, and a blue color filter F _B containing a blue coloring material provided including green coloring material, these color filters F For example, as shown in FIG. 12B, _{R 1} , F _G , and F _B are obtained during the main scanning while the droplet discharge head 20 is main-scanned a plurality of times in the directions indicated by the arrows A1 and A2. The functional liquid containing the red coloring material, the functional liquid containing the green coloring material, and the functional liquid containing the blue coloring material are selectively discharged from the plurality of nozzles 81 to the predetermined openings H, respectively.

  Here, the color filter substrate is manufactured by arranging color filters of each color of red, green, and blue in a stripe arrangement, a delta arrangement, a mosaic arrangement, or the like. That is, the formation of the color filter F by the droplet discharge head 20 shown in FIG. 12B is performed by changing the droplet discharge head 20 that discharges only one of red, green, and blue into three colors of red, green, and blue. 3 types are prepared in advance, and these droplet discharge heads 20 are used in order corresponding to the three colors, and are arranged in three colors of red, green, and blue on one large substrate P. This is done by forming

FIG. 13 shows a specific manufacturing process.
Figure 13 shows the three regions of blue region green region of the red region the red color filter F _R is formed, a green color filter F _G is formed, and that the blue color filter F _B is formed .

First, as shown in FIG. 13A, a bank B is formed on one surface of a large substrate P.
The bank B functions as a partition member that partitions an area where the color filter F is formed. Bank B has an opening H corresponding to the pixel pattern of the display panel. In the method for manufacturing a color filter substrate of the present invention, a functional liquid containing a coloring material is disposed in a region partitioned by the bank B, and the functional liquid is dried, whereby the color filter (film pattern) F is formed on the large substrate P. Is formed. In this case, since the shape of the color filter F is defined by the bank B, the color filter F can be miniaturized by appropriately forming the bank B, for example, by narrowing the width of the adjacent bank B.

  The method for forming bank B is the same as the method for forming bank B in the first to third embodiments. That is, after forming an inorganic material film on the large substrate P and forming an organic bank layer B2 on the inorganic material film, the inorganic material film is patterned using the organic bank layer B2 as a mask. The inorganic material film is patterned by wet etching using a hydrofluoric acid solution or the like. When a material that does not transmit light (for example, a black resin) is used as the organic bank layer B2, the bank B can function as a black matrix.

  When the bank B is formed, as shown in FIG. 13B, the droplet discharge head 20 selectively discharges the functional liquid L containing the coloring material to the region H partitioned by the bank B. The functional liquid L is obtained by dissolving or dispersing a coloring material such as a pigment in a solvent.

  The functional liquid is discharged by discharging a functional liquid containing a red coloring material, a functional liquid containing a green coloring material, and a functional liquid containing a blue coloring material to the corresponding color filter forming regions H. FIG. 13B shows a step of discharging the functional liquid L to the blue region.

When the functional liquid L is discharged, the solvent in the functional liquid L is evaporated. By this step, as shown in FIG. 13 (c), a color filter F _B of the blue solid in the blue region is formed. At this time, since the bank B has a two-layer structure of the inorganic bank layer B1 and the organic bank layer B2, and no misalignment occurs between the two bank layers B1 and B2, the obtained film is flat. And excellent uniformity of film thickness.

After forming the blue color filter F _B in the blue region, the same procedure, the green color filter F _G is formed in the green region is further formed a blue color filter F _R in the red region. FIG. 13D shows a state in which color filters are formed in all color filter formation regions.

When the color filter F is formed in all the color filter formation regions, a protective film is formed on the surface of the color filter F as necessary.
Thereafter, the large substrate P is cut along a scribe line provided between the panel regions T and T to obtain individual color filter substrates. Thereby, the color filter substrate is completed.

  In the color filter substrate manufacturing method of the present embodiment, since the film pattern forming method of the present invention is applied to the color filter F forming step, the color filter F having a uniform film thickness is formed over the entire panel region. . For this reason, it is possible to provide a color filter substrate with little color unevenness and excellent display characteristics. In addition, since the color filter F can be formed flat, when an electrode is formed on the color filter F, the color filter substrate is excellent in reliability, in which disconnection or the like hardly occurs.

[Electronics]
Next, a specific example of an electronic device including the above-described organic EL device will be described.
FIG. 14 is a perspective configuration diagram illustrating an example of an electronic apparatus.
A video monitor 1200 shown in FIG. 14 includes a display unit 1201 including the organic EL device of the previous embodiment, a housing 1202, a speaker 1203, and the like. The video monitor 1200 can display images with high image quality and uniform brightness using the organic EL device.

  The organic EL device of the above embodiment is not limited to the above mobile phone, but an electronic book, a personal computer, a digital still camera, a viewfinder type or a monitor direct view type video tape recorder, a car navigation device, a pager, an electronic notebook, a calculator, It can be suitably used as an image display means for a word processor, a workstation, a videophone, a POS terminal, a device equipped with a touch panel, etc., and any electronic device can display a high image quality. Furthermore, the above-described organic EL device can be widely applied to electronic devices other than display devices, such as being used as exposure means for line printers.

  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. In the third embodiment or the fourth embodiment, an example in which the film pattern forming method of the present invention is applied to a method of manufacturing an organic EL device or a color filter substrate has been described. Alternatively, it can be widely applied to devices other than the color filter substrate, for example, a method for manufacturing a wiring substrate.

It is a figure which shows notionally the formation method of the film | membrane pattern of this invention. It is a schematic perspective view of a droplet discharge device. It is a figure for demonstrating the discharge principle of the liquid material by a piezo method. It is a figure which shows the other example of the formation method of the film | membrane pattern of this invention. It is a circuit block diagram of the organic electroluminescent apparatus which is an example of the device of this invention. 2 is a plan configuration diagram of the organic EL device. FIG. It is a cross-sectional block diagram which follows the AA line of FIG. It is a section lineblock diagram showing a manufacturing process of an organic EL device. It is a section lineblock diagram showing a manufacturing process of an organic EL device. It is a section lineblock diagram showing a manufacturing process of an organic EL device. It is a section lineblock diagram showing a manufacturing process of an organic EL device. It is a conceptual diagram which shows the manufacturing method of the color filter substrate which is an example of the device of this invention. It is process drawing which shows an example of the manufacturing process of the color filter substrate. It is a perspective lineblock diagram showing an example of electronic equipment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 70 ... Organic EL apparatus (device), 114a, 114b ... Functional liquid, 140 ... Organic functional layer (film pattern), 149 ... Inorganic bank layer, 149b ... Opening of inorganic bank layer, 149f ... First material film (inorganic Material film), 150 ... organic bank layer, 151 ... opening of organic bank layer, 1200 ... video monitor (electronic device), B ... bank, B1 ... inorganic bank layer, B1f ... inorganic material film, B2 ... organic bank layer, F ... Film pattern, L ... Functional liquid, P ... Substrate

Claims (6)

A method of forming a film pattern by disposing a functional liquid on a substrate,
Forming a bank on the substrate;
Arranging the functional liquid in a region partitioned by the bank,
The bank forming step includes:
Forming an inorganic material film on the substrate;
Forming an organic bank layer containing an organic material component on the surface of the inorganic material film;
Patterning the inorganic material film using the organic bank layer as a mask, and forming an inorganic bank layer made of the inorganic material film between the organic bank layer and the substrate. Forming method.   2. The film pattern forming method according to claim 1, wherein the patterning of the inorganic material film is performed by wet etching using a hydrofluoric acid solution.   3. The film pattern forming method according to claim 2, wherein a groove formed by over-etching the inorganic material film is formed on a side surface of the bank.   The film pattern forming method according to claim 1, wherein the functional liquid is disposed by a droplet discharge method.   A device comprising a film pattern formed by the film pattern forming method according to claim 1. An electronic apparatus comprising the device according to claim 5.

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