JP2007035484A - Film pattern forming method and device manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film pattern forming method and a device manufacturing method capable of improving the wettability of ink in a bank and forming a uniform film.
SOLUTION: A step of forming a bank B containing an organic component on a base P, a step of performing a plasma treatment on the surface of the base P on which the bank B is formed, and a functional liquid L is disposed in a region partitioned by the bank B The plasma processing is characterized in that only the plasma processing using a fluorine-containing gas as a processing gas is performed without performing the plasma processing using oxygen as a processing gas.
[Selection] Figure 1

Description

  The present invention relates to a film pattern forming method and a device manufacturing method.

  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, 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 has been proposed (for example, Patent Document 1). reference). 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.
WO99 / 48339 pamphlet

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. The bank generally has a two-layer structure of an inorganic bank made of an inorganic material such as silicon oxide and an organic bank made of an organic material such as polyimide or acrylic. Conventionally, in order to place ink only inside the bank, the surface of the substrate on which the bank is formed is subjected to plasma processing using oxygen as a processing gas (O ₂ plasma processing) and plasma processing using fluorine-containing gas as a processing gas ( was treated successively by a CF ₄ plasma treatment). When such a treatment is performed, the surface of the inorganic bank is activated by the former O ₂ plasma treatment, and exhibits good lyophilicity with respect to the ink. Further, the development residue when the organic bank is patterned can be removed by O ₂ plasma treatment. On the other hand, the surface of the organic bank exhibits strong liquid repellency with respect to the ink because fluorine groups are introduced by the latter CF ₄ plasma treatment or the like. As a result, the ink discharged into the bank wets and spreads along the surface of the inorganic bank, and forms a uniform film throughout the bank. Even if ink is scattered on the surface of the bank, such ink is bounced on the surface of the bank and flows into the inside of the bank, so that no unnecessary film is formed on the upper surface of the bank.

However, such good results are not always obtained in practice. For example, if the surface of an inorganic bank is not supposed to have fluorine groups, the fluorine groups are introduced to the surface by CF ₄ plasma treatment or the like when O ₂ plasma treatment and CF ₄ plasma treatment are performed continuously. And may exhibit liquid repellency. Similarly, when a charge transport layer or the like is formed on the surface of an electrode made of ITO or the like, fluorine groups are introduced to the surface of the electrode by continuous treatment of O ₂ plasma treatment and CF ₄ plasma treatment, and the ink is uniformly wetted and spread. There may not be. Since the problem of ink wettability affects the flatness of the film and the characteristics of the organic EL device as a device, an improvement measure has been demanded.
The present invention has been made in view of such circumstances, and provides a film pattern forming method and a device manufacturing method capable of improving the wettability of ink in a bank and forming a uniform film. For the purpose.

  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 the surface of a substrate whose surface is composed of an inorganic material, Forming a bank containing an organic component on the substrate, plasma treating the surface of the substrate on which the bank is formed, and placing the functional liquid in a region partitioned by the bank, the plasma As a treatment, plasma treatment using a fluorine-containing gas as a treatment gas is performed without performing plasma treatment using oxygen as a treatment gas. Here, the “bank including an organic component” includes not only a bank including only an organic component (the above-described organic bank) but also a bank including a mixed component of an organic component and an inorganic component (organic / inorganic hybrid material). In the present specification, these are collectively referred to as “organic bank or the like”, and are distinguished from a bank made of only an inorganic material (the above-described inorganic bank).

As a cause of non-uniform wettability in the bank, the present inventor has examined the above-mentioned problems. (1) When an O ₂ plasma treatment is performed on the surface of the substrate, a part of the organic bank or the like is ashed. As a result of depositing the residue on the substrate, the inside of the organic bank or the like becomes liquid repellent, and (2) the region (the surface of the inorganic bank or the electrode) in the organic bank is activated by the O ₂ plasma treatment. As a result, it became clear that a fluorine group is easily introduced onto the surface of an inorganic bank or the like by subsequent CF ₄ plasma treatment or the like.

Therefore, in the present invention, as the plasma treatment for the substrate, only the plasma treatment (CF ₄ plasma treatment or the like) using a fluorine-containing gas as a treatment gas is performed without performing the plasma treatment (O ₂ plasma treatment) using oxygen as a treatment gas. It was decided. According to this method, since the region in the organic bank or the like is not activated, the fluorine group is not introduced by the CF ₄ plasma treatment or the like, and the organic bank or the like is not ashed by the O ₂ plasma treatment. Therefore, there is no risk that the inside of the organic bank or the like is made liquid repellent. For this reason, it is possible to arrange the functional liquid while maintaining the region in the organic bank or the like in good lyophilicity, and it is possible to form a uniform film throughout the organic bank or the like.

The conventional O ₂ plasma treatment also has the purpose of removing development residues when patterning an organic bank or the like, but such development residues can also be removed by CF ₄ plasma treatment or the like. Almost no. Rather, there is an advantage that the process can be simplified by omitting the O ₂ plasma treatment.

In the present invention, the organic bank or the like may be formed of a material that exhibits liquid repellency with respect to the functional liquid.
According to this method, it is possible to reliably avoid the formation of an unnecessary film on the surface of an organic bank or the like. In addition, since the plasma energy in CF ₄ plasma treatment or the like can be reduced, it is possible to further avoid introduction of fluorine groups into regions within the organic bank or the like.

In the present invention, an electrode is provided on the surface of the substrate, and the organic bank or the like may be formed with an opening on the electrode. In addition, an inorganic bank made of an inorganic material is provided on the electrode with an opening on the surface of the base, and the organic bank or the like is an opening communicating with the opening provided in the inorganic bank. The wall surface of the opening may be formed to have an opening that recedes outward from the opening of the inorganic bank.
According to this method, a film pattern can be accurately formed on the electrode. In addition, when the bank is formed by a two-layer structure such as an inorganic bank and an organic bank, an inorganic bank having lyophilicity with respect to the functional liquid is formed so as to protrude inside the opening of the organic bank or the like. Good wettability can be obtained even in the vicinity of an organic bank or the like.

In the present invention, the functional liquid may include a charge transport layer forming material for forming a charge transport layer or a light emitting layer forming material for forming a light emitting layer. Here, as the charge transport layer, a hole injection layer can be used when the electrode functions as an anode, and an electron injection layer can be used when the electrode functions as a cathode. The light emitting layer is preferably an organic light emitting layer made of a polymer light emitting material.
According to this method, an electroluminescence element (EL element) having uniform light emission characteristics can be formed.

The device manufacturing method of the present invention is a device manufacturing method including a step of forming a film pattern on a substrate, and the film pattern forming step is performed by the above-described method of forming a film pattern of the present invention. It is characterized by.
According to this method, a film having excellent characteristics can be provided by forming the film pattern uniformly.

The present invention will be described below with reference to the drawings.
FIG. 1 is a view conceptually showing the film pattern forming method of the present invention.
The film pattern forming method of the present invention includes a bank forming step for forming a bank (organic bank or the like) B containing an organic component on a base P, and a plasma processing step for plasma processing the surface of the base P on which the bank B is formed. And a material disposing step for disposing the functional liquid L in the region partitioned by the bank B, and a drying / firing step for drying or firing the functional liquid L disposed on the substrate P.

  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. Note that after the film pattern F is formed, the bank B may be removed from the substrate P or may be left on the substrate P as it is.

In the method for forming a film pattern of the present invention, plasma treatment (CF ₄ ) using a fluorine-containing gas as a treatment gas without performing a plasma treatment (O ₂ plasma treatment) using oxygen as a treatment gas as a surface treatment using plasma. It is characterized in that only plasma processing or the like is performed. The causes of non-uniform wettability in the bank B are as follows: (1) When the surface of the base P is subjected to O ₂ plasma treatment, a part of the bank B is ashed and the residue is deposited on the base P. Then, the inside of the bank B becomes lyophobic, and (2) the region in the bank B is activated by the O ₂ plasma treatment, so that the fluorine group is introduced to the surface of the substrate P by the subsequent CF ₄ plasma treatment or the like. It is thought that it is easy to be done. For this reason, it is possible to prevent the introduction of fluorine groups by activating the region in the bank B by performing only the CF ₄ plasma treatment or the like without performing the O ₂ plasma treatment. Further, since the bank B is not ashed by the O ₂ plasma treatment, there is no possibility that the region in the bank B is made liquid repellent by the residue. For this reason, it is possible to arrange the functional liquid L while maintaining the region in the bank B in good lyophilicity, and thereby it is possible to form a uniform film F in the entire bank B.

The conventional O ₂ plasma treatment also has the purpose of removing the development residue when the bank B is patterned, but such a development residue can also be removed by CF ₄ plasma treatment or the like. Does not occur. Rather, there is an advantage that the process can be simplified by omitting the O ₂ plasma treatment.

  In the present invention, only the plasma treatment using a fluorine-containing gas as the treatment gas is performed as the surface treatment. This means that only the above treatment is performed as the surface treatment using plasma, and ultraviolet rays are used. Processes other than plasma, such as conventional cleaning processes, can be performed in the same manner as before.

Here, examples of the substrate P include various types such as glass, quartz glass, Si wafer, plastic film, and metal plate. Further, a semiconductor film, a metal film, a dielectric film, an organic film are formed on the surface of these various material substrates. It includes those in which a film or the like is formed as a base layer.
At least the surface of the portion where the film pattern F is formed on the substrate P is made of an inorganic material. The substrate P itself may be made of an inorganic material such as glass, or a base insulating film such as silicon oxide or an electrode such as ITO may be formed on the surface of a plastic substrate or the like. As described above, the surface of the substrate P is made of an inorganic material, so that it has good wettability (lyophilicity) with respect to the functional liquid L without performing O ₂ plasma treatment.

  As a forming material of the bank B, 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. As a method for forming the bank B, an arbitrary method such as a lithography method or a printing method can be used. For example, when a lithography method is used, a layer made of the material for forming the bank B is formed on the substrate P by a predetermined method such as spin coating, spray coating, roll coating, die coating, dip coating, and then etching, ashing, etc. By patterning according to the above, a bank having a predetermined pattern shape is obtained. Note that a bank may be formed on an object different from the base P and disposed on the base P.

  The bank B is desirably formed of a material that exhibits liquid repellency with respect to the functional liquid L. Thereby, adhesion of the functional liquid L to the upper surface of the bank B is prevented, and the film pattern F can be accurately formed in a desired shape. The surface of the bank B is given liquid repellency by the plasma treatment process. However, if the bank B is originally formed of a liquid repellant material, the energy of the plasma treatment can be reduced, and the surface of the base P can be further reduced. It is possible to make a structure in which a fluorine group is difficult to be introduced.

  Various functional liquids (inks) L can be used. The functional liquid means a film that can form a film having a predetermined function (functional film) by forming a film component contained in the liquid into a film. Such functions include electrical and electronic functions (conductive, insulating, piezoelectric, pyroelectric, dielectric, etc.), optical functions (light selective absorption, reflectivity, polarization, light selective transmission, nonlinear optics) , Luminescence such as fluorescence or phosphorescence, photochromic, etc.), magnetic function (hard magnetic, soft magnetic, non-magnetic, magnetic permeability, etc.), chemical function (adsorbing, desorbing, catalytic, water absorbing, ion) Conductivity, redox properties, electrochemical properties, electrochromic properties, etc.), mechanical functions (wear resistance, etc.), thermal functions (heat transfer, heat insulation, infrared radiation, etc.), biological functions (biocompatibility, There are various functions such as antithrombotic properties.

  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.

  The dispersion medium of the functional liquid L is not particularly limited as long as it can disperse the above film components and does not cause aggregation. For example, in addition to water, alcohols such as methanol, ethanol, propanol, butanol, n-heptane, n-octane, decane, dodecane, tetradecane, toluene, xylene, cymene, durene, indene, dipentene, tetrahydronaphthalene, decahydro Hydrocarbon compounds such as naphthalene and cyclohexylbenzene, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol methyl ethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, 1,2-dimethoxyethane, bis (2- Methoxyethyl) ether, ether compounds such as p-dioxane, propylene carbonate, γ- Butyrolactone, N- methyl-2-pyrrolidone, dimethylformamide, dimethyl sulfoxide, can be exemplified polar compounds such as cyclohexanone. Of these, water, alcohols, hydrocarbon compounds, and ether compounds are preferred from the viewpoints of fine particle dispersibility and dispersion stability, and ease of application to the droplet discharge method (inkjet method). More preferred dispersion media include water and hydrocarbon compounds.

  The surface tension of the dispersion station in which the film component is dispersed is preferably in the range of 0.02 N / m to 0.07 N / m. When the liquid is discharged by the droplet discharge method, if the surface tension is less than 0.02 N / m, the wettability of the ink composition with respect to the nozzle surface increases, and thus flight bending easily occurs, resulting in 0.07 N / m. If it exceeds the upper limit, the shape of the meniscus at the nozzle tip is unstable, and it becomes difficult to control the discharge amount and the discharge timing. In order to adjust the surface tension, a small amount of a surface tension regulator such as a fluorine-based, silicone-based, or nonionic-based material may be added to the above dispersion within a range that does not significantly reduce the contact angle with the substrate. The nonionic surface tension modifier improves the wettability of the liquid to the substrate, improves the leveling property of the film, and helps prevent the occurrence of fine irregularities on the film. The surface tension modifier may contain an organic compound such as alcohol, ether, ester, or ketone, if necessary.

  The viscosity of the dispersion is preferably 1 mPa · s to 50 mPa · s. When the liquid material is ejected as droplets using the droplet ejection method, if the viscosity is less than 1 mPa · s, the nozzle periphery is easily contaminated by the outflow of ink, and if the viscosity is greater than 50 mPa · s, The frequency of clogging in the nozzle holes increases, and it becomes difficult to smoothly discharge droplets.

  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 apparatus (inkjet apparatus) IJ that arranges a liquid material on a substrate by a droplet discharge method as an example of an apparatus used in the film pattern forming method of the present invention. is there.

  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.

[Example]
Next, examples of the film pattern forming method of the present invention will be described.
FIG. 4 is a view showing a state in which the inkjet droplet L is ejected onto the base P on which the bank B is formed. In FIG. 4, a portion indicated by “E1” indicates a region within 200 μm from the bank B, and a portion indicated by “E2” indicates a region approximately 5 mm away from the bank B.

In this embodiment, as a process for the substrate P, when the O ₂ plasma process and the CF ₄ plasma process are continuously performed (comparative example), and when only the CF ₄ plasma process is performed without performing the O ₂ plasma process, For (Example), the landing diameters of the droplets L are compared. In addition, the board | substrate P which used the board | substrate which formed the ITO electrode on the surface of the glass substrate or the glass substrate is used for the base | substrate P, and SL-1116-4 (brand name, Toray Industries, Inc.) is used for the bank B. Moreover, PEDOT / PSS is used for the droplet L, and the weight of the droplet L is 10 ng / dot.
The measurement results of the impact diameter are as follows.

As shown in Table 1, the landing diameter on the bank B is 30 μm for both the example and the comparative example, and it can be seen that the surface of the bank B exhibits good liquid repellency. However, it can be seen that the comparative example has a smaller landing diameter in the vicinity A of the bank B than the example, and that the O ₂ plasma treatment does not necessarily contribute to the improvement of lyophilicity. In particular, since the landing diameter is smaller in the vicinity E1 of the bank B than in the portion E2 that is away from the bank B, the influence of the residue and the like due to the O ₂ plasma treatment of the bank B is also a factor that reduces the lyophilicity. I understand that

[Organic EL device]
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 150 erected on the base P. The organic functional layer 140 is composed of the pixel electrode 141 and the common electrode 154. The structure sandwiched between the two.

  Here, in the planar structure shown in FIG. 6B, the organic bank 150 has an opening 151 having a substantially rectangular shape in plan view corresponding to the formation region of the pixel electrode 141. 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 in 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 (first partition wall layer) 149 made of an inorganic insulating material is formed so as to partially ride on the peripheral edge of the pixel electrode 141. On the inorganic bank 149, an organic bank (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 150 is formed. It is constituted by. The hole injection layer 140 </ b> A is formed so as to cover the pixel electrode 141, and the peripheral end portion of the inorganic bank 149 provided on the lower layer side of the organic bank 150 extends from the organic bank 150 to the center side of the pixel electrode 141. The protruding portion is also formed so as to cover the portion.

  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 base P so as to cover the light emitting layer 140B and the upper surface of the organic bank 150 and further the wall surface forming the side surface of the organic bank 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. In the present embodiment, a method for manufacturing an 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.
In addition, the procedure shown below and the material structure of a liquid material are examples, and are not limited to this. As the droplet discharge device, the aforementioned one can be used.

  Hereinafter, a method for manufacturing the organic EL element 200 provided in the organic EL device 70 will be described with reference to FIGS. In FIG. 8 and FIG. 9, only a single pixel 71 is shown for simplicity of explanation.

  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, an inorganic bank 149 made of an inorganic insulating material such as silicon oxide is formed so as to partially overlap the peripheral edge of the pixel electrode 141 in a planar manner. Specifically, after a silicon oxide film is formed so as to cover the pixel electrode 141 and the planarization insulating film 240, the silicon oxide film is patterned using a known photolithography technique, and the surface of the pixel electrode 141 is partially covered. It can be formed by opening.

  Next, as shown in FIG. 8C, an organic bank 150 made of an organic insulating material such as acrylic or polyimide is formed on the inorganic bank 149. The height of the organic bank 150 is set to about 1 to 2 μm, for example, and functions as a partition member for the organic EL element 200 on the base P. Under such a configuration, the hole injection layer and the light-emitting layer of the organic EL element 200 are formed at a sufficient height difference between the formation position of the organic EL element 200, that is, the application position of these formation materials and the surrounding organic bank 150. An opening 151 is formed. The opening 151 of the organic bank 150 and the opening 149b of the inorganic bank 149 communicate with each other, and the pixel electrode 141 is exposed in these openings.

  When forming the organic bank 150, it is preferable to form the wall surface of the opening 151 of the organic bank 150 slightly outward from the opening 149 b of the inorganic bank 149. In this way, by partially exposing the inorganic bank 149 in the opening 151 of the organic bank 150, the wet spread of the liquid material in the organic bank 150 can be improved.

  When the organic bank 150 is formed, as shown in FIG. 8D, a surface treatment is performed on a region on the substrate including the organic bank 150 and the pixel electrode 141. Since the organic bank 150 functions as a partition member that partitions the organic EL element 200, the organic bank 150 exhibits non-affinity (liquid repellency) with respect to the liquid material discharged from the droplet discharge head 1 (see FIG. 2). It is preferable that non-affinity can be selectively expressed in the organic bank 150 by the surface treatment.

As such surface treatment, for example, a method in which the surface of the organic bank 150 is subjected to plasma treatment (liquid repellent treatment) using a gas containing a fluorine-based 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 150, thereby enabling the liquid material to be repelled. Examples of the fluorine compound include CF ₄ , SF ₆ , and CHF ₃ .

Usually, before such treatment, lyophilic treatment by O ₂ plasma treatment is performed to make the surface of the pixel electrode 141 and the inorganic bank 149 show affinity (lyophilicity) to the liquid material. However, in this embodiment, the liquid repellent process is performed directly without performing such a lyophilic process.

  In such a process, even if the entire surface of the substrate is processed, the surface of the pixel electrode 141 made of an inorganic material such as an ITO film or a metal film or the surface of an inorganic bank 149 made of an inorganic material such as silicon oxide is Liquid repellency is less likely than the surface of the organic bank 150 made of an organic material. In particular, in the present embodiment, unlike the conventional case, since the O 2 plasma treatment is not performed before the liquid repellent treatment, the surface of the pixel electrode or the like is not activated and has a structure in which a fluorine group is more difficult to be introduced. For this reason, in the above liquid repellent treatment, only the surface of the organic bank 150 is selectively made liquid repellent.

  Next, as shown in FIG. 9A, a liquid material 114a containing a hole injection layer forming material is applied with a liquid droplet ejection head 1 surrounded by an organic bank 150 with the upper surface of the base P facing upward. Selectively apply to position. The liquid material (functional liquid) 114a for forming the hole injection layer 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 liquid material 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 due to its high fluidity, but surrounds the applied position. Since the organic bank 150 is formed, the liquid material 114a does not spread beyond the organic bank 150. In addition, since the surface of the pixel electrode 141 and the inorganic bank 149 is in a state of maintaining good lyophilicity, the discharged liquid material 114a spreads over the entire surface of the pixel electrode and the like, and forms a uniform coating film.

  Subsequently, the solvent of the liquid material 114 a is evaporated by heating or light irradiation to form a solid hole injection layer 140 A 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 this embodiment, since the coating film of the liquid material 114a is uniformly formed in the entire organic bank, the obtained hole injection layer 140A has a uniform film thickness and film quality, and is excellent in surface flatness. It will be.

  Subsequently, as shown in FIG. 9B, a liquid material (functional liquid) 114b containing a light emitting layer forming material and a solvent is supplied from the droplet discharge head 1 with the upper surface of the base P facing upward to the organic bank 150. This is selectively applied on the hole injection layer 140A.

  As this light emitting layer forming material, polyfluorene derivatives (PF), polyparaphenylene vinylene derivatives (PPV), polyphenylene derivatives (PP), polyphenylene derivatives (PF), which are known polymer light emitting materials capable of emitting fluorescence or phosphorescence. Polysilanes such as paraphenylene derivatives (PPP), polyvinylcarbazole (PVK), polythiophene derivatives, polydialkylfluorene (PDAF), polyfluorenebenzothiadiazole (PFBT), polyalkylthiophene (PAT), and polymethylphenylsilane (PMPS) Etc. can be used suitably. 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 liquid material 114b from the droplet discharge head 1 includes a liquid material 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 liquid material containing and the liquid material containing the light emitting layer forming material that emits blue colored light are discharged 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 liquid material 114b containing the light emitting layer forming material of each color is discharged and applied in this manner, the solvent in the liquid material 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 liquid material 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 liquid material 114b is disposed is satisfactorily flattened, 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. 9C, a common electrode 154 made of ITO or the like is formed on the entire surface of the base 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. In addition, as the plasma processing for the substrate, only the plasma processing using the fluorine-containing gas as the processing gas is performed without performing the plasma processing using oxygen as the processing gas, so that the surface of the inorganic bank 149 or the surface of the pixel electrode 141 is used. A state having a higher affinity for the liquid material can be obtained, whereby a flat and uniform film can be formed in the entire pixel.

  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.

[Electronics]
Next, a specific example of an electronic device including the above-described organic EL device will be described.
FIG. 10 is a perspective configuration diagram illustrating an example of an electronic apparatus.
A video monitor 1200 illustrated in FIG. 10 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. Particularly in a large panel, since the pixels are large, it is difficult to uniformly form an organic functional layer that is a light emitting portion. However, in the organic EL device according to the present invention, an organic functional layer of an arbitrary size is uniformly formed. Therefore, the organic EL device is suitable for use in a large panel.

  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 organic EL device of the present invention can be widely applied to electronic devices other than display devices, such as being used as exposure means for line printers.

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 for demonstrating the 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 perspective lineblock diagram showing an example of electronic equipment.

Explanation of symbols

70 ... Organic EL device (device), 114a, 114b ... Liquid material (functional liquid), 140 ... Organic functional layer, 140A ... Hole injection layer (charge transport layer), 140B ... Light emitting layer, 141 ... Pixel electrode, 149 ... Inorganic bank, 149b ... opening of inorganic bank, 150 ... organic bank, 151 ... opening of organic bank (area partitioned by organic bank), B ... bank (organic bank, etc.), F ... film pattern, L ... function Liquid, P ... Substrate

Claims (6)

A method of forming a film pattern by disposing a functional liquid on the surface of a substrate whose surface is composed of an inorganic material,
Forming a bank containing organic components on the substrate;
Plasma treating the surface of the substrate on which the bank is formed;
Arranging the functional liquid in a region partitioned by the bank,
A method for forming a film pattern, characterized in that, as the plasma treatment, only a plasma treatment using a fluorine-containing gas as a treatment gas is performed without performing a plasma treatment using oxygen as a treatment gas.   2. The film pattern forming method according to claim 1, wherein the bank is formed of a material exhibiting liquid repellency with respect to the functional liquid. An electrode is provided on the surface of the substrate,
3. The film pattern forming method according to claim 1, wherein the bank is formed with an opening on the electrode. On the surface of the substrate, an inorganic bank made of an inorganic material is provided with an opening on the electrode,
The bank is an opening that communicates with an opening provided in the inorganic bank, and a wall surface of the opening has an opening that recedes outward from the opening of the inorganic bank. The method for forming a film pattern according to claim 3.   5. The method for forming a film pattern according to claim 4, wherein the functional liquid includes a charge transport layer forming material for forming a charge transport layer or a light emitting layer forming material for forming a light emitting layer. A device manufacturing method including a step of forming a film pattern on a substrate,
A device manufacturing method, wherein the film pattern forming step is performed by the film pattern forming method according to claim 1.

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