JP2006133762A - Manufacturing method of display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display device which can be manufactured while utilization efficiency of materials is improved and the manufacturing process is simplified, to provide its manufacturing technique and to provide a technique with which wiring or the like that constitutes of these display devices is formed with a desired shape and with good controllability. <P>SOLUTION: The surface of a substrate having an electrically conductive layer is selectively reformed by being irradiated with light beams from the back surface and wettability is controlled. An electrically conductive material or an insulating material is adhered onto the reformed surface by discharging (including jetting) or the like to form electrically conductive layers and insulating layers. Moreover, processing efficiency by light beams is improved by light absorption and an energy radiation function of a photocatalyst substance. Furthermore, a mask layer can selectively be formed on the electrically conductive layer and the wettability of the region on the electrically conductive layer, which is a non-irradiated region, can also be controlled. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a display device.

  A thin film transistor (hereinafter also referred to as “TFT”) and an electronic circuit using the thin film transistor are obtained by laminating various thin films such as a semiconductor, an insulator, and a conductor on a substrate and appropriately forming a predetermined pattern by a photolithography technique. It is manufactured. Photolithographic technology is a technology that uses a light to transfer a circuit pattern or other pattern formed on a transparent flat plate called a photomask onto a target substrate. It is widely used in the manufacturing process.

In the manufacturing process using the conventional photolithography technology, a multi-step process such as exposure, development, baking, and peeling is required only for handling a mask pattern formed using a photosensitive organic resin material called a photoresist. Become. Therefore, the manufacturing cost inevitably increases as the number of photolithography processes increases. In order to improve such problems, attempts have been made to manufacture TFTs by reducing the photolithography process (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 11-251259

  The present invention reduces the number of photolithography processes in the manufacturing process of a TFT, an electronic circuit using the TFT, and a display device formed by the TFT, simplifies the manufacturing process, and a large-area substrate whose one side exceeds 1 meter. Another object of the present invention is to provide a technique that can be manufactured at a low cost and with a high yield.

  It is another object of the present invention to provide a technique capable of forming components such as wirings constituting these display devices in a desired shape with good controllability.

    The present invention modifies the irradiated region by light irradiation and controls the wettability of the region. In the irradiated region, a substance that controls the wettability of the surface is formed by light irradiation. A substance that controls wettability is formed on a light-transmitting substance, and light is irradiated from the light-transmitting substance side to the surface of the substance that controls wettability through the light-transmitting substance. The At that time, a non-irradiation region can be formed and a region to be modified can be accurately controlled by forming a conductive layer serving as a mask between the light-transmitting material and the material that controls wettability. Then, a conductive material or an insulating material is deposited on the modified surface by discharging (including jetting or the like) to form a conductive layer and an insulating layer.

    As one of the methods for changing and controlling the wettability of the surface, a photoreactive substance having a characteristic that the wettability is changed by light is formed in the light irradiation region. When the photoreactive substance is irradiated with light, the wettability with respect to the material to be formed changes in the surface of the region. That is, a change in contact angle or surface energy with respect to the material to be formed occurs. By utilizing this characteristic, the wettability of the material to be formed can be controlled by selecting the wavelength of light with which the photoreactive substance reacts.

    As another method for changing and controlling the wettability of the surface, there is a method of changing the wettability by decomposing the surface material and modifying the surface of the region by the energy of light irradiation. In this case, it is preferable to form a substance that increases the processing efficiency by light in the light irradiation region and to form a substance having low wettability with respect to the material to be formed. A photocatalytic substance can be used as a substance that enhances the processing efficiency with light. The photocatalytic substance improves the processing efficiency by light by light absorption and energy radiation action. Due to the photoactive energy of the photocatalytic substance, a substance having low wettability with respect to the layered material to be laminated is decomposed and modified, and the wettability of the substance surface changes. As a substance having low wettability, a substance containing a fluorocarbon chain or a substance containing a silane coupling agent can be used. Since the silane coupling agent can form a monomolecular film, it can be efficiently decomposed and modified, and the wettability can be changed in a short time. A silane coupling agent can be used because it exhibits low wettability by arranging not only one having a fluorocarbon chain but also one having an alkyl group on a substrate.

    In the present invention, before forming a photoreactive substance or a substance with low wettability, a mask layer is formed in a part of a region that becomes a non-irradiated region where light wettability cannot be controlled. Since the photoreactive substance or the substance with low wettability can be selectively formed by the mask layer, the wettability in the formation region of the mask layer can also be controlled.

  The display device of the present invention includes a light-emitting element and a TFT in which a layer containing an organic substance that emits light called electroluminescence (hereinafter also referred to as “EL”) or a mixture of an organic substance and an inorganic substance is interposed between electrodes. And a liquid crystal display device using a liquid crystal element having a liquid crystal material as a display element.

    According to one method for manufacturing a display device of the present invention, a non-light-transmitting first conductive layer is formed over a light-transmitting substrate, an insulating layer is formed over the substrate and the first conductive layer, A mask layer is selectively formed over the insulating layer overlapping with the first conductive layer, a photoreactive substance is formed over the insulating layer and the mask layer, and light is allowed to pass through the substrate to form a photoreactive substance. Irradiation is performed to form a first region and a second region having higher wettability with respect to the composition containing the conductive material than the first region, and a photoreactive substance formed on the mask layer and the mask layer is formed. A third region having higher wettability to the composition containing the conductive material than the first region is formed, and the second region and the third region are formed using the composition containing the conductive material. The conductive layer is formed.

    According to one method for manufacturing a display device of the present invention, a non-light-transmitting first conductive layer including a gate electrode region and a gate wiring region is formed over a light-transmitting substrate, and the substrate and the first conductive layer are formed. An insulating layer is formed over the layer, a semiconductor layer is formed over the insulating layer overlapping with the gate electrode region, a mask layer is selectively formed over the insulating layer overlapping with the gate wiring region, and the semiconductor layer and the mask layer are formed. In addition, the photoreactive substance is formed, the light is allowed to pass through the substrate, and the photoreactive substance is irradiated, so that the wettability to the first region and the composition containing the conductive material is higher than that of the first region. The second region is formed, the photoreactive substance formed on the mask layer and the mask layer is removed, and a third region having higher wettability with respect to the composition containing the conductive material than the first region is formed. Using the composition containing a conductive material in the second region and the third region. To form.

    According to one method for manufacturing a display device of the present invention, a non-light-transmitting first conductive layer is formed over a light-transmitting substrate, an insulating layer is formed over the substrate and the first conductive layer, A photocatalytic substance is formed on the insulating layer, a mask layer is selectively formed on the insulating layer and the photocatalytic substance overlapping with the first conductive layer, and a substance containing a fluorocarbon chain is formed on the photocatalytic substance and the mask layer. Then, light is passed through the substrate, and the photocatalytic substance is irradiated to form the first region and the second region having higher wettability with respect to the composition containing the conductive material than the first region, and the mask layer And a substance containing a fluorocarbon chain formed on the mask layer is removed to form a third region having higher wettability to the composition containing the conductive material than the first region, and the second region and the second region A second conductive layer is formed using a composition containing a conductive material in the region 3.

    According to one method for manufacturing a display device of the present invention, a non-light-transmitting first conductive layer including a gate electrode region and a gate wiring region is formed over a light-transmitting substrate, and the substrate and the first conductive layer are formed. An insulating layer is formed over the layer, a semiconductor layer is formed over the insulating layer overlapping with the gate electrode region, a photocatalytic material is formed over the insulating layer and the semiconductor layer, and selectively formed over the photocatalytic material overlapping with the gate wiring region. A mask layer is formed, a material containing a fluorocarbon chain is formed on the photocatalyst material and the mask layer, light is passed through the substrate, and the photocatalyst material is irradiated to form the first region and the first region The second region having higher wettability to the composition containing the conductive material than the region is formed, the mask layer and the substance containing the fluorocarbon chain formed on the mask layer are removed, and the second region is more conductive than the first region. Forming a third region having high wettability to the composition comprising the material; Using a composition containing a conductive material in the second region and the third region forming a second conductive layer.

    According to one method for manufacturing a display device of the present invention, a non-light-transmitting first conductive layer is formed over a light-transmitting substrate, an insulating layer is formed over the substrate and the first conductive layer, A photocatalytic substance is formed on the insulating layer, a mask layer is selectively formed on the insulating layer and the photocatalytic substance overlapping with the first conductive layer, and a substance containing a silane coupling agent is formed on the photocatalytic substance and the mask layer. Then, light is passed through the substrate, and the photocatalytic substance is irradiated to form the first region and the second region having higher wettability with respect to the composition containing the conductive material than the first region, and the mask layer And a substance containing a silane coupling agent formed on the mask layer is removed to form a third region having higher wettability to the composition containing the conductive material than the first region, and the second region and the second region The second conductive layer is formed using a composition containing a conductive material in the region 3 .

    According to one method for manufacturing a display device of the present invention, a non-light-transmitting first conductive layer including a gate electrode region and a gate wiring region is formed over a light-transmitting substrate, and the substrate and the first conductive layer are formed. An insulating layer is formed over the layer, a semiconductor layer is formed over the insulating layer overlapping with the gate electrode region, a photocatalytic material is formed over the insulating layer and the semiconductor layer, and selectively formed over the photocatalytic material overlapping with the gate wiring region. A mask layer is formed, a photocatalytic material and a material including a silane coupling agent are formed on the mask layer, light is passed through the substrate, and the photocatalytic material is irradiated to form the first region and the first region The second region having higher wettability to the composition containing the conductive material than the region is formed, the mask layer and the substance containing the silane coupling agent formed on the mask layer are removed, and the second region is more conductive than the first region. High wettability for compositions containing materials Forming a region to form the second conductive layer using a composition containing a conductive material to the second region and the third region.

  In the above structure, a substance containing a triphenylmethane derivative, a substance containing an azobenzene derivative, or a substance containing a spiropyran derivative can also be used as the photoreactive substance. In the above structure, the silane coupling agent may be a silane coupling agent having an alkyl group. In the above structure, a titanium oxide film can be formed using titanium oxide having a photocatalytic function as a photocatalytic substance.

  According to the present invention, a desired pattern can be formed with good controllability. In addition, there is little material loss and cost reduction can be achieved. Therefore, a high-performance and highly reliable display device can be manufactured with high yield.

Embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it is easily understood by those skilled in the art that modes and details can be variously changed without departing from the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited to the description of the embodiments below. Note that in structures of the present invention described below, the same portions or portions having similar functions are denoted by the same reference numerals in different drawings, and description thereof is not repeated.
(Embodiment 1)
FIG. 25A is a top view illustrating a structure of a display panel according to the present invention. A pixel portion 2701 in which pixels 2702 are arranged in a matrix over a substrate 2700 having an insulating surface, a scan line side input terminal 2703, a signal A line side input terminal 2704 is formed. The number of pixels may be provided in accordance with various standards. For XGA, 1024 × 768 × 3 (RGB), for UXGA, 1600 × 1200 × 3 (RGB), and for full specification high vision, 1920 × 1080. X3 (RGB) may be used.

  The pixels 2702 are arranged in a matrix by a scan line extending from the scan line side input terminal 2703 and a signal line extending from the signal line side input terminal 2704 intersecting. Each of the pixels 2702 includes a switching element and a pixel electrode connected to the switching element. A typical example of the switching element is a TFT. By connecting the gate electrode side of the TFT to a scanning line and the source or drain side to a signal line, each pixel can be controlled independently by a signal input from the outside. Yes.

    FIG. 25A shows a structure of a display panel in which signals input to the scanning lines and the signal lines are controlled by an external driver circuit. As shown in FIG. The driver IC 2751 may be mounted on the substrate 2700 by the Glass method. As another mounting mode, a TAB (Tape Automated Bonding) method as shown in FIG. 30B may be used. The driver IC may be formed on a single crystal semiconductor substrate or may be a circuit in which a TFT is formed on a glass substrate. In FIG. 30, the driver IC 2751 is connected to the FPC 2750.

    In the case where a TFT provided for a pixel is formed using a polycrystalline (microcrystalline) semiconductor with high crystallinity, a scan line driver circuit 3702 may be formed over the substrate 3700 as illustrated in FIG. it can. In FIG. 30B, reference numeral 3701 denotes a pixel portion, and the signal line side driver circuit is controlled by an external driver circuit as in FIG. In the case where a TFT provided for a pixel is formed using a polycrystalline (microcrystalline) semiconductor, a single crystal semiconductor, or the like with high mobility like the TFT formed in the present invention, FIG. 25C shows a scan line driver circuit 4702. Alternatively, the signal line driver circuit 4704 can be integrally formed over the glass substrate 4700.

    The present invention relates to an object necessary for manufacturing a display panel such as a conductive layer for forming a wiring layer or an electrode or a mask layer for forming a predetermined pattern (all forms such as a film and a layer depending on its purpose and function). The display device is manufactured by forming at least one or more of them in a method that can be selectively formed into a desired shape. The present invention includes all conductive layers such as a gate electrode layer, a source electrode layer, and a drain electrode layer, a semiconductor layer, a mask layer, an insulating layer, and the like that constitute a thin film transistor and a display device. Applicable to components. As a method that can be selectively formed into a desired shape, a conductive layer, an insulating layer, or the like is formed, and droplets of a composition prepared for a specific purpose are selectively ejected (ejected) to form a predetermined pattern A droplet discharge (ejection) method (also called an ink jet method depending on the method) can be used. In addition, a method in which an object can be transferred or drawn in a desired pattern, for example, various printing methods (a method in which a desired pattern such as screen (stencil) printing, offset (lithographic) printing, letterpress printing or gravure (intaglio printing) is formed) Etc. can also be used.

    This embodiment mode uses a method in which a composition containing a material having fluidity is ejected (ejected) as droplets to form a desired pattern. A droplet containing a material to be formed is ejected onto a formation region of the formed product, and fixed by firing, drying, or the like to form an object with a desired pattern. In the present invention, pretreatment is performed on the formation region of the formed product.

    One mode of a droplet discharge apparatus used for the droplet discharge method is shown in FIG. The individual heads 1405 and 1412 of the droplet discharge means 1403 are connected to the control means 1407, which can be drawn in a pre-programmed pattern under the control of the computer 1410. The drawing timing may be performed with reference to a marker 1411 formed on the substrate 1400, for example. Alternatively, the reference point may be determined based on the edge of the substrate 1400. This is detected by the imaging means 1404, converted into a digital signal by the image processing means 1409, is recognized by the computer 1410, a control signal is generated, and sent to the control means 1407. As the imaging unit 1404, a charge coupled device (CCD), an image sensor using a complementary metal oxide semiconductor, or the like can be used. Of course, the information on the pattern to be formed on the substrate 1400 is stored in the storage medium 1408. Based on this information, a control signal is sent to the control means 1407, and each head 1405 of the droplet discharge means 1403 is sent. The heads 1412 can be individually controlled. The material to be discharged is supplied from the material supply source 1413 and the material supply source 1414 to the head 1405 and the head 1412 through piping.

    The inside of the head 1405 has a structure having a space filled with a liquid material as indicated by a dotted line 1406 and a nozzle that is a discharge port. Although not shown, the head 1412 has the same internal structure as the head 1405. When the nozzles of the head 1405 and the head 1412 are provided in different sizes, different materials can be drawn simultaneously with different widths. With one head, conductive material, organic material, inorganic material, etc. can be discharged and drawn respectively. When drawing in a wide area like an interlayer film, the same material is used from multiple nozzles to improve throughput. It is possible to discharge and draw at the same time. In the case of using a large substrate, the head 1405 and the head 1412 can freely scan on the substrate in the direction of the arrow to freely set a drawing area, and a plurality of the same pattern can be drawn on a single substrate. it can.

    In the present invention, irradiation treatment with light is performed as a pretreatment in the vicinity including the formation region of the formed material, and a treatment for selectively modifying the surface is performed. By this modification treatment, at least two or more types of regions having different adhesion to the formed product can be formed in the discharge region of the composition containing the material to be formed. A composition containing a conductive material or an insulating material is attached to the modified surface to form a conductive layer or an insulating layer. A conductive layer or an insulating layer can be formed in a self-aligned manner (self-alignment) by performing light irradiation as an exposure process from the back surface of the substrate. Therefore, by using the present invention, a display device including a thin film transistor can be formed in a self-aligning manner.

    The light used for the modification treatment is not particularly limited, and any one of infrared light, visible light, ultraviolet light, or a combination thereof can be used. For example, light emitted from an ultraviolet lamp, black light, halogen lamp, metal halide lamp, xenon arc lamp, carbon arc lamp, high pressure sodium lamp, or high pressure mercury lamp may be used. In that case, the lamp light source may be lit and irradiated for a necessary time, or may be irradiated multiple times.

Laser light may be used as the light used for the modification treatment, and a laser oscillator that can oscillate ultraviolet light, visible light, or infrared light can be used as the laser oscillator. Examples of laser oscillators include excimer laser oscillators such as ArF, KrF, XeCl, and Xe, gas laser oscillators such as He, He—Cd, Ar, He—Ne, and HF, YAG, GdVO ₄ , YVO ₄ , YLF, and YAlO _3. A solid-state laser oscillator using a crystal doped with Cr, Nd, Er, Ho, Ce, Co, Ti, or Tm, and a semiconductor laser oscillator such as GaN, GaAs, GaAlAs, or InGaAsP can be used. In the solid-state laser oscillator, it is preferable to apply the first to fifth harmonics of the fundamental wave. In order to adjust the shape of the laser light emitted from the laser oscillator and the path of the laser light, an optical system including a reflector such as a shutter, a mirror or a half mirror, a cylindrical lens, or a convex lens may be installed.

  Note that the irradiation method may be to selectively irradiate light by moving the substrate, or to irradiate light by scanning light in the XY axis direction. In this case, it is preferable to use a polygon mirror or a galvanometer mirror for the optical system.

    In addition, light can also be used in combination with light from a lamp light source and laser light, and a region where a relatively wide range of processing is performed is irradiated with a lamp, and only a region where high-definition processing is performed is laser light. Irradiation treatment can also be performed. By performing the light irradiation treatment in this way, it is possible to improve the throughput and to obtain a wiring substrate, a display device, and the like that are processed into a desired shape with high sensitivity.

  An example of forming a conductive layer as a formed product will be described. In the case of forming an insulating layer, a composition containing an insulating material may be used as a material to be discharged. In this embodiment, light is irradiated from the back surface of the substrate, and modification is performed so as to change the wettability of the irradiation region. Therefore, regions having different wettability with respect to the composition containing the conductive material are formed in the vicinity of the region where the conductive layer is formed. This difference in wettability is a relative relationship between the two regions, and there is a difference in the degree of wettability with respect to the composition containing a conductive material between the formed region and the surrounding non-formed region. That's fine. In addition, a region having different wettability is a contact angle of a composition containing a conductive material, and a region having a large contact angle of a composition containing a conductive material is a region having a lower wettability (hereinafter referred to as a low wettability). A region having a small contact angle is a region having high wettability (hereinafter also referred to as a high wettability region). When the contact angle is large, the liquid composition having fluidity does not spread on the surface of the region and repels the composition, so that the surface is not wetted. However, when the contact angle is small, the composition has fluidity on the surface. Because it spreads out and wets the surface well. Therefore, regions having different wettability also have different surface energies. The surface energy of the surface in the region with low wettability is small, and the surface energy at the surface of the region with high wettability is large. In the present invention, the difference in contact angle between the regions having different wettability is 30 degrees or more, preferably 40 degrees or more.

    In this embodiment mode, irradiation treatment with light is performed in order to form regions with different wettability. The formation region is selectively modified by light. As one of the methods for changing and controlling the wettability of the surface, a photoreactive substance having a characteristic that the wettability is changed by light is formed in the light irradiation region. When the photoreactive substance is irradiated with light, the wettability with respect to the material to be formed changes in the surface of the region. That is, a change in contact angle or surface energy with respect to the material to be formed occurs. By utilizing this characteristic, the wettability of the material to be formed can be controlled by selecting the wavelength of light with which the photoreactive substance reacts.

  In the formation region, a photoreactive substance having high wettability with respect to the forming material or wettability as a pretreatment in order to increase the modification process efficiency and increase the wettability difference between the irradiated region and the non-irradiated region. It is preferable to form a photoreactive substance having low properties and to make the wettability of the surface of the formation region relatively large and high or low. These substances are formed in the vicinity of the formation region, and a process for selectively increasing wettability by light and a process for decreasing wettability are performed. In this embodiment mode, a photoreactive substance having low wettability with respect to a composition including a conductive material is formed in a formation region of the conductive layer, and the photoreactive substance is modified (modified). By irradiating light, the wettability of the processing region is improved and a highly wettable region is formed by altering (modifying) (or possibly decomposing or removing) the photoreactive substance in the processing region. The photoreactive substance may be any substance including a material having an effect of changing wettability by light irradiation, and the change in the properties of the photoreactive substance is caused by the light irradiation treatment.

    Embodiment Modes of the present invention will be described with reference to FIGS. More specifically, a method for manufacturing a display device having an inverted staggered thin film transistor to which the present invention is applied will be described. 2A to 6A are top views of the display device pixel portion, FIGS. 2A to 6B are cross-sectional views taken along line A-C in FIGS. 2A to 6A, and FIG. FIG. 6 is a cross-sectional view taken along line BD. FIG. 1 is a cross-sectional view of a display device, and FIG. 7A is a top view. FIG. 7B is a cross-sectional view taken along line LK (including line IJ) in FIG.

  As the light-transmitting substrate 100, a glass substrate made of barium borosilicate glass, alumino borosilicate glass, or the like, a quartz substrate, or a plastic substrate having heat resistance that can withstand the processing temperature in this manufacturing process is used. Further, polishing may be performed by a CMP method or the like so that the surface of the light-transmitting substrate 100 is planarized. Note that an insulating layer may be formed over the light-transmitting substrate 100. The insulating layer is formed as a single layer or a stacked layer using an oxide material or a nitride material containing silicon by a known method such as a CVD method, a plasma CVD method, a sputtering method, or a spin coating method. This insulating layer is not necessarily formed, but has an effect of blocking contaminants from the light-transmitting substrate 100. In the present invention, when the formation region of the formed material is modified, light is irradiated so as to pass through the substrate 100 from the translucent substrate 100 side on which the substance is formed using backside exposure. The surface of the formed substance is modified. Therefore, the light-transmitting substrate 100 needs to be a substance that transmits light that can modify the formation region of the formed material.

    The gate electrode layer 102 and the gate electrode layer 103 are formed over the light-transmitting substrate 100. The gate electrode layer 102 and the gate electrode layer 103 can be formed by a CVD method, a sputtering method, a droplet discharge method, or the like. The gate electrode layer 102 and the gate electrode layer 103 are mainly composed of an element selected from Ag, Au, Ni, Pt, Pd, Ir, Rh, Ta, W, Ti, Mo, Al, and Cu. What is necessary is just to form with an alloy material or a compound material. Alternatively, a semiconductor film typified by a polycrystalline silicon film doped with an impurity element such as phosphorus, or an AgPdCu alloy may be used. Alternatively, a single-layer structure or a multi-layer structure may be used. For example, a two-layer structure of a tungsten nitride (TiN) film and a molybdenum (Mo) film may be used, a 50-nm-thick tungsten film, a 500-nm-thick aluminum film, A three-layer structure in which a silicon alloy (Al—Si) film and a titanium nitride film with a thickness of 30 nm are sequentially stacked may be employed. In the case of a three-layer structure, tungsten nitride may be used instead of tungsten of the first conductive film, or aluminum instead of the aluminum and silicon alloy (Al-Si) film of the second conductive film. A titanium alloy film (Al—Ti) may be used, or a titanium film may be used instead of the titanium nitride film of the third conductive film.

When the gate electrode layer 102 and the gate electrode layer 103 need to be processed, a mask may be formed and processed by dry etching or dry etching. Using an ICP (Inductively Coupled Plasma) etching method, the etching conditions (the amount of power applied to the coil-type electrode, the amount of power applied to the electrode on the substrate side, the electrode temperature on the substrate side, etc.) are appropriately set. By adjusting, the electrode layer can be etched into a tapered shape. As an etching gas, a chlorine-based gas typified by Cl ₂ , BCl ₃ , SiCl _4, CCl _4, etc., a fluorine-based gas typified by CF ₄ , SF _6, NF _3, etc., or O ₂ is appropriately used. be able to.

  A mask for processing can be formed by selectively discharging a composition. When the mask is selectively formed in this way, there is an effect that the processing step is simplified. For the mask, a resin material such as an epoxy resin, a phenol resin, a novolac resin, an acrylic resin, a melamine resin, or a urethane resin is used. Also, using organic materials such as benzocyclobutene, parylene, flare, permeable polyimide, compound materials made by polymerization of siloxane polymers, composition materials containing water-soluble homopolymers and water-soluble copolymers, etc. And formed by a droplet discharge method. Alternatively, a commercially available resist material containing a photosensitizer may be used. For example, a novolak resin that is a typical positive resist and a naphthoquinonediazide compound that is a photosensitizer, a base resin that is a negative resist, diphenylsilanediol, and An acid generator or the like may be used. Whichever material is used, the surface tension and viscosity are appropriately adjusted by adjusting the concentration of the solvent or adding a surfactant or the like.

  In this embodiment mode, when a mask for performing a processing step into a desired shape is formed by a droplet discharge method, a process for forming a region with different wettability is performed in the vicinity of a formation region as a pretreatment. May be. In the present invention, when a pattern is formed by discharging droplets by the droplet discharge method, a low wettability region and a high wettability region can be formed in a pattern formation region, and the shape of the pattern can be controlled. By performing this process on the formation region, there is a difference in wettability in the formation region, so that droplets remain only in the formation region with high wettability, and a pattern can be formed with good controllability. This step can be applied as a pretreatment for forming any pattern when a liquid material is used.

    In this embodiment, the gate electrode layer 102 and the gate electrode layer 103 are formed using a droplet discharge unit. The droplet discharge means is a general term for a device having means for discharging droplets such as a nozzle having a composition discharge port and a head having one or a plurality of nozzles. The diameter of the nozzle provided in the droplet discharge means is set to 0.02 to 100 μm (preferably 30 μm or less), and the discharge amount of the composition discharged from the nozzle is 0.001 pl to 100 pl (preferably 0). .1pl or more and 40pl or less, more preferably 10pl or less). The discharge amount increases in proportion to the size of the nozzle diameter. In addition, the distance between the object to be processed and the nozzle outlet is preferably as close as possible in order to drop it at a desired location, preferably about 0.1 to 3 mm (preferably about 1 mm or less). Set.

  A composition in which a conductive material is dissolved or dispersed in a solvent is used as the composition discharged from the discharge port. The conductive material corresponds to fine particles or dispersible nanoparticles of metals such as Ag, Au, Cu, Ni, Pt, Pd, Ir, Rh, W, and Al, and includes metal sulfides of Cd and Zn, Fe, Ti Further, oxides such as Si, Ge, Zr and Ba, fine particles such as silver halide or dispersible nanoparticles may be mixed. The conductive material may also be used as a mixture. In addition, since the transparent conductive film is translucent, it transmits light during back exposure, but it can be used as a material and a laminate that do not transmit light. As these transparent conductive films, indium tin oxide (ITO), ITSO made of indium tin oxide and silicon oxide, organic indium, organic tin, zinc oxide, titanium nitride, or the like can be used. However, it is preferable to use a composition in which any of gold, silver and copper is dissolved or dispersed in a solvent in consideration of the specific resistance value, more preferably the composition discharged from the discharge port. It is preferable to use low resistance silver or copper. However, when silver or copper is used, a barrier film may be provided as a countermeasure against impurities. As the barrier film, a silicon nitride film or nickel boron (NiB) can be used.

  Alternatively, particles in which a conductive material is coated with another conductive material to form a plurality of layers may be used. For example, particles having a three-layer structure in which nickel boron (NiB) is coated around copper and silver is coated around it may be used. As the solvent, esters such as butyl acetate and ethyl acetate, alcohols such as isopropyl alcohol and ethyl alcohol, organic solvents such as methyl ethyl ketone and acetone, water, and the like are used. The viscosity of the composition is preferably 20 cp or less, in order to prevent the drying from occurring or to smoothly discharge the composition from the discharge port. The surface tension of the composition is preferably 40 mN / m or less. However, the viscosity and the like of the composition may be appropriately adjusted according to the solvent to be used and the application. As an example, the viscosity of a composition in which ITO, organic indium, or organic tin is dissolved or dispersed in a solvent is 5 to 20 mPa · s, the viscosity of a composition in which silver is dissolved or dispersed in a solvent is 5 to 20 mPa · s, The viscosity of the composition in which gold is dissolved or dispersed in a solvent is preferably set to 5 to 20 mPa · s.

  The conductive layer may be a stack of a plurality of conductive materials. Alternatively, first, silver may be used as a conductive material, and a conductive layer may be formed by a droplet discharge method, followed by plating with copper or the like. Plating may be performed by electroplating or chemical (electroless) plating. For plating, the substrate surface may be immersed in a container filled with a solution having a plating material, but the substrate is placed at an angle (or vertically) so that the solution having the material to be plated flows on the substrate surface. It may be applied. When plating is performed so that the solution is applied while standing the substrate, there is an advantage that the process apparatus is reduced in size.

  Although depending on the diameter of each nozzle and the desired pattern shape, the diameter of the conductor particles is preferably as small as possible for preventing nozzle clogging and producing a high-definition pattern. A particle size of 1 μm or less is preferred. The composition is formed by a known method such as an electrolytic method, an atomizing method, or a wet reduction method, and its particle size is generally about 0.01 to 10 μm. However, when formed by a gas evaporation method, the nanomolecules protected by the dispersant are as fine as about 7 nm, and these nanoparticles are aggregated in the solvent when the surface of each particle is covered with a coating agent. And stably disperse at room temperature and shows almost the same behavior as liquid. Therefore, it is preferable to use a coating agent.

  In the present invention, since the wettability difference between the composition of the fluid and the vicinity of the region to be formed is processed into a desired pattern shape, the composition has fluidity even when landing on the object to be processed. However, as long as the fluidity is not lost, the step of discharging the composition may be performed under reduced pressure. Further, it is preferable to perform under reduced pressure because an oxide film or the like is not formed on the surface of the conductor. After discharging the composition, one or both steps of drying and baking are performed. The drying and firing steps are both heat treatment steps. For example, drying is performed at 100 degrees for 3 minutes, and firing is performed at 200 to 350 degrees for 15 minutes to 60 minutes. Time is different. The drying process and the firing process are performed under normal pressure or reduced pressure by laser light irradiation, rapid thermal annealing, a heating furnace, or the like. In addition, the timing which performs this heat processing is not specifically limited. In order to satisfactorily perform the drying and firing steps, the substrate may be heated, and the temperature at that time depends on the material of the substrate or the like, but is generally 100 to 800 degrees (preferably 200). ~ 350 degrees). By this step, the solvent in the composition is volatilized or the dispersant is chemically removed, and the surrounding resin is cured and contracted to bring the nanoparticles into contact with each other, thereby accelerating fusion and fusion.

For the laser light irradiation, a continuous wave or pulsed gas laser or solid-state laser may be used. Examples of the former gas laser include an excimer laser and a YAG laser, and examples of the latter solid-state laser include a laser using a crystal such as YAG, YVO ₄ or GdVO ₄ doped with Cr, Nd, or the like. . Note that it is preferable to use a continuous wave laser because of the absorption rate of the laser light. Further, a laser irradiation method combining pulse oscillation and continuous oscillation may be used. However, depending on the heat resistance of the substrate 100, the heat treatment by laser light irradiation may be performed instantaneously within a few microseconds to several tens of seconds so as not to destroy the substrate 100. Instantaneous thermal annealing (RTA) uses an infrared lamp or a halogen lamp that irradiates ultraviolet light or infrared light in an inert gas atmosphere, and rapidly raises the temperature for several minutes to several microseconds. This is done by applying heat instantaneously. Since this treatment is performed instantaneously, only the outermost thin film can be heated substantially without affecting the lower layer film. That is, it does not affect a substrate having low heat resistance such as a plastic substrate.

  Alternatively, after the gate electrode layer 102 and the gate electrode layer 103 are formed by discharging a composition by a droplet discharge method, the surface may be pressed and flattened by pressure in order to improve the flatness. As a pressing method, unevenness may be reduced by scanning a roller-like object on the surface, or the surface may be pressed vertically with a flat plate-like object. A heating step may be performed when pressing. Alternatively, the surface may be softened or melted with a solvent or the like, and the surface irregularities may be removed with an air knife. Further, polishing may be performed using a CMP method. This step can be applied when the surface is flattened when unevenness is generated by the droplet discharge method.

  Next, the gate insulating layer 101 is formed over the gate electrode layer 102 and the gate electrode layer 103. The gate insulating layer 101 needs to have a light-transmitting property with respect to irradiated light in order to pass light when a material formed thereon is modified by light irradiation. The gate insulating layer 101 may be formed of a known material such as a silicon oxide material or a nitride material, and may be a stacked layer or a single layer. In this embodiment, a stacked layer of a silicon nitride film, a silicon oxide film, and a silicon nitride film is used. Alternatively, a single layer or a double layer of silicon oxynitride film may be used. A silicon nitride film having a dense film quality is preferably used. In addition, when silver or copper is used for a conductive layer formed by a droplet discharge method, if a silicon nitride film or a NiB film is formed thereon as a barrier film, diffusion of impurities can be prevented and the surface can be planarized. is there. Note that in order to form a dense insulating film with low gate leakage current at a low deposition temperature, a rare gas element such as argon is preferably contained in a reaction gas and mixed into the formed insulating film.

Next, a semiconductor layer is formed. A semiconductor layer having one conductivity type may be formed as necessary. Further, an N-type semiconductor layer is formed, and an NMOS structure of an N-channel TFT, a PMOS structure of a P-channel TFT having a P-type semiconductor layer, and a CMOS structure of an N-channel TFT and a P-channel TFT are manufactured. be able to. In order to impart conductivity, an element imparting conductivity is added by doping, and an impurity region is formed in the semiconductor layer, whereby an N-channel TFT or a P-channel TFT can be formed. Instead of forming an N-type semiconductor layer, conductivity may be imparted to the semiconductor layer by performing plasma treatment with a PH ₃ gas.

  As a material for forming the semiconductor layer, an amorphous semiconductor (hereinafter also referred to as “AS”) manufactured by a vapor deposition method or a sputtering method using a semiconductor material gas typified by silane or germane is used. A polycrystalline semiconductor crystallized using energy or thermal energy, a semi-amorphous (also referred to as microcrystal or microcrystal, hereinafter, also referred to as “SAS”) semiconductor, or the like can be used. The semiconductor layer can be formed by a known means (such as sputtering, LPCVD, or plasma CVD).

SAS is a semiconductor having an intermediate structure between amorphous and crystalline structures (including single crystal and polycrystal) and having a third state that is stable in terms of free energy and has a short-range order and a lattice. It includes a crystalline region with strain. A crystal region of 0.5 to 20 nm can be observed in at least a part of the film, and when silicon is the main component, the Raman spectrum shifts to a lower wave number side than 520 cm ^−1. Yes. In X-ray diffraction, diffraction peaks of (111) and (220) that are derived from the silicon crystal lattice are observed. It contains at least 1 atomic% or more of hydrogen or halogen that terminates dangling bonds (dangling bonds). The SAS is formed by glow discharge decomposition (plasma CVD) of a silicide gas. As the silicide gas, SiH ₄ , Si ₂ H ₆ , SiH ₂ Cl ₂ , SiHCl ₃ , SiCl ₄ , SiF _{4, and the} like can be used. Further, F ₂ and GeF ₄ may be mixed. This silicide gas may be diluted with H ₂ , or H ₂ and one or more kinds of rare gas elements selected from He, Ar, Kr, and Ne. The dilution rate is in the range of 2 to 1000 times, the pressure is in the range of approximately 0.1 Pa to 133 Pa, and the power supply frequency is 1 MHz to 120 MHz, preferably 13 MHz to 60 MHz. The substrate heating temperature is preferably 300 ° C. or lower, and can be formed even at a substrate heating temperature of 100 to 200 ° C. Here, as an impurity element mainly taken in at the time of film formation, it is desirable that impurities derived from atmospheric components such as oxygen, nitrogen, and carbon be 1 × 10 ²⁰ cm ⁻³ or less, and in particular, the oxygen concentration is 5 × 10 5. It is preferable to be ¹⁹ cm ⁻³ or less, preferably 1 × 10 ¹⁹ cm ⁻³ or less. Further, by adding a rare gas element such as helium, argon, krypton, or neon to further promote lattice distortion, stability is improved and a favorable SAS can be obtained. In addition, a SAS layer formed of a hydrogen-based gas may be stacked on a SAS layer formed of a fluorine-based gas as a semiconductor layer.

    A typical example of an amorphous semiconductor is hydrogenated amorphous silicon, and a typical example of a crystalline semiconductor is polysilicon. Polysilicon (polycrystalline silicon) is mainly made of so-called high-temperature polysilicon using polysilicon formed through a process temperature of 800 ° C. or higher as a main material, or polysilicon formed at a process temperature of 600 ° C. or lower. And so-called low-temperature polysilicon, and polysilicon crystallized by adding an element that promotes crystallization. Of course, as described above, a semi-amorphous semiconductor or a semiconductor including a crystal phase in a part of the semiconductor layer can also be used.

In the case where a crystalline semiconductor layer is used for the semiconductor layer, a method for manufacturing the crystalline semiconductor layer can be a known method (laser crystallization method, thermal crystallization method, or heat using an element that promotes crystallization such as nickel. A crystallization method or the like may be used. In addition, a microcrystalline semiconductor that is a SAS can be crystallized by laser irradiation to improve crystallinity. In the case where an element for promoting crystallization is not introduced, the amorphous silicon film is heated at 500 ° C. for 1 hour in a nitrogen atmosphere before irradiating the amorphous silicon film with laser light, whereby the concentration of hydrogen contained in the amorphous silicon film is set to 1 ×. Release to 10 ²⁰ atoms / cm ³ or less. This is because the film is destroyed when the amorphous silicon film containing a large amount of hydrogen is irradiated with laser light.

  The method of introducing the metal element into the amorphous semiconductor layer is not particularly limited as long as the metal element can be present on the surface of the amorphous semiconductor layer or inside the amorphous semiconductor layer. For example, sputtering, CVD, A plasma treatment method (including a plasma CVD method), an adsorption method, or a method of applying a metal salt solution can be used. Among these, the method using a solution is simple and useful in that the concentration of the metal element can be easily adjusted. At this time, in order to improve the wettability of the surface of the amorphous semiconductor layer and to spread the aqueous solution over the entire surface of the amorphous semiconductor layer, irradiation with UV light in an oxygen atmosphere, thermal oxidation method, hydroxy radical It is desirable to form an oxide film by treatment with ozone water or hydrogen peroxide.

  The crystallization of the amorphous semiconductor layer may be a combination of heat treatment and crystallization by laser light irradiation, or may be performed multiple times by heat treatment or laser light irradiation alone.

    Alternatively, the crystalline semiconductor layer may be directly formed over the substrate by a plasma method. Alternatively, the crystalline semiconductor layer may be selectively formed over the substrate by a plasma method.

  As a semiconductor, an organic semiconductor material can be used and formed by a printing method, a spray method, a spin coating method, a droplet discharge method, or the like. In this case, the number of processes can be reduced because the etching process is not necessary. As the organic semiconductor, a low molecular material, a polymer material, or the like is used, and materials such as an organic dye or a conductive polymer material can also be used. The organic semiconductor material used in the present invention is preferably a π-electron conjugated polymer material whose skeleton is composed of conjugated double bonds. Typically, a soluble polymer material such as polythiophene, polyfluorene, poly (3-alkylthiophene), a polythiophene derivative, or pentacene can be used.

  In addition, as an organic semiconductor material that can be used in the present invention, there is a material that can form a first semiconductor region by processing after forming a soluble precursor. Examples of such an organic semiconductor material include polythienylene vinylene, poly (2,5-thienylene vinylene), polyacetylene, a polyacetylene derivative, and polyarylene vinylene.

  When converting the precursor into an organic semiconductor, a reaction catalyst such as hydrogen chloride gas is added as well as heat treatment. Typical solvents for dissolving these soluble organic semiconductor materials include toluene, xylene, chlorobenzene, dichlorobenzene, anisole, chloroform, dichloromethane, γ-butyllactone, butyl cellosolve, cyclohexane, NMP (N-methyl-2 -Pyrrolidone), cyclohexanone, 2-butanone, dioxane, dimethylformamide (DMF), THF (tetrahydrofuran), or the like can be applied.

  In this embodiment, the semiconductor layer 104 and the semiconductor layer 105 are formed over the gate insulating layer 101 by a droplet discharge method using pentacene.

A mask made of an insulator such as resist or polyimide is formed by a droplet discharge method, and an opening 125 is formed in part of the gate insulating layer 101 by etching using the mask, and the lower layer side thereof is formed. A part of the arranged gate electrode layer 103 is exposed (see FIG. 3). The etching process may be either plasma etching (dry etching) or wet etching, but plasma etching is suitable for processing a large area substrate. As an etching gas, a fluorine-based gas such as CF ₄ or NF ₃ or a chlorine-based gas such as Cl ₂ or BCl ₃ may be used, and an inert gas such as He or Ar may be appropriately added. Further, if an atmospheric pressure discharge etching process is applied, a local electric discharge process is also possible, and it is not necessary to form a mask layer on the entire surface of the substrate.

    Next, as a pretreatment for forming the source electrode layer or the drain electrode layer with good controllability, the vicinity of the formation region of the electrode layer is compared with the surrounding region and modified. In this embodiment mode, a photoreactive substance with increased wettability is formed with respect to a composition including a conductive material by light irradiation. Therefore, it can be said that the photoreactive substance before light irradiation is a photoreactive substance with low wettability. Then, by photoirradiation treatment, the photoreactive substance in the irradiated region is selectively modified to improve wettability and form a highly wettable region. Since the wettability of the photoreactive substance in the non-irradiated region remains low, it becomes a low wettability region with respect to the high wettability region. Therefore, a high wettability region and a low wettability region are formed. The difference in wettability can be confirmed by the contact angle, and the difference in contact angle is 30 degrees or more, preferably 40 degrees or more.

    The display device in this embodiment mode is an active matrix type, and includes a gate wiring layer formed in the same step as the gate electrode layer, a source wiring layer formed in the same step as the source electrode layer or the drain electrode layer, and a power supply line Is formed so as to partially intersect with the gate insulating layer. In this embodiment mode, the wettability in the vicinity of the formation region is controlled in order to selectively form the source electrode layer and the drain electrode layer in a self-aligning manner. Since light irradiation for controlling wettability is performed from the back side of the substrate using the gate electrode layer as a mask, the wettability formed on the gate electrode layer and the gate wiring layer formed in the same process as the gate electrode layer is low. Since the photoreactive substance is not irradiated with light and is not modified, the photoreactive substance has a relatively low wettability compared to the irradiated region. Therefore, the conductive layer cannot be stably formed over the region with low wettability.

    In this embodiment mode, such a gate electrode layer and a source electrode layer (hereinafter referred to as a “gate electrode layer” including a conductive layer such as a gate wiring layer formed in the same process as the gate electrode layer and the gate electrode layer) , The drain electrode layer, the source electrode layer formed in the same process as the source electrode layer and the drain electrode layer, and the power supply line (also referred to as “source electrode layer or drain electrode layer”)) A mask layer is formed so that no reactive substance is formed.

    A mask layer 106a, a mask layer 106b, and a mask layer 106c are formed over the gate insulating layer 101 in a region where the gate electrode layer and the source electrode layer are formed to overlap with each other later. The mask layer 106c is formed so as to cover the opening 125 formed in the gate insulating layer.

    The mask layer 106a, the mask layer 106b, and the mask layer 106c may be either an inorganic material or an organic material, and only need to function as a mask for preventing a substance having low wettability from physically attaching to the gate insulating layer. May be used. Since the mask layer 106a, the mask layer 106b, and the mask layer 106c are removed in a later step, it is preferable that the mask layer 106a, the mask layer 106b, and the mask layer 106c can be removed without damaging the formation region by a process such as etching.

  Examples of the insulating material include silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, aluminum nitride, aluminum oxynitride and other inorganic insulating materials, acrylic acid, methacrylic acid and derivatives thereof, polyimide, aromatic A heat-resistant polymer such as an aromatic polyamide, polybenzimidazole, or a siloxane resin material can be used. Further, a resin material such as a vinyl resin such as polyvinyl alcohol or polyvinyl butyral, an epoxy resin, a phenol resin, a novolac resin, an acrylic resin, a melamine resin, or a urethane resin is used. Alternatively, an organic material such as benzocyclobutene, parylene, flare, polyimide, a compound material made by polymerization of a siloxane polymer, a composition material containing a water-soluble homopolymer and a water-soluble copolymer, or the like may be used. Alternatively, a commercially available resist material containing a photosensitizer may be used. For example, a novolak resin that is a typical positive resist and a naphthoquinonediazide compound that is a photosensitizer, a base resin that is a negative resist, diphenylsilanediol, and An acid generator or the like may be used. As the conductive material, metals such as Ag, Au, Cu, Ni, Pt, Pd, Ir, Rh, W, and Al can be used. Further, metal sulfides of Cd and Zn, and oxides such as Fe, Ti, Si, Ge, Zr, and Ba may be used.

    The mask layer 106a, the mask layer 106b, and the mask layer 106c can be formed by a CVD method, a plasma CVD method, a sputtering method, a printing method, a spray method, a spin coating method, a droplet discharge method, or the like. In this embodiment, the mask layer 106a, the mask layer 106b, and the mask layer 106c are formed by a droplet discharge method using polyvinyl alcohol (hereinafter also referred to as PVA).

    A photoreactive substance 107 is formed over the gate insulating layer 101, the semiconductor layer 104, the semiconductor layer 105, the mask layer 106a, the mask layer 106b, and the mask layer 106c (see FIG. 3).

    The photoreactive substance can be an organic material, an inorganic material, or a mixture thereof as long as the wettability of the surface changes when irradiated with light. For example, triphenylmethane, azobenzene, spiropyran, triphenylmethane derivatives, azobenzene derivatives, spiropyran derivatives, and the like, which are derivatives of the above materials, can be used. In this embodiment, polystyrene having triphenylmethane leuco hydroxide partially in the side chain, which changes from a low wettability state to a high state by irradiation with light having a wavelength of 300 nm to 400 nm, is used. The photoreactive substance may be a thin film having a thickness of several nanometers, and may not have continuity as a film depending on the formation method. This light with a wavelength of 300 nm to 400 nm can be transmitted through the glass substrate used as the substrate 100 in this embodiment mode and is not transmitted through the gate electrode layer 102 and the gate electrode layer 103; Light can be irradiated. The photoreactive substance is light-transmitting with the substrate, semiconductor layer, gate insulating layer, and gate electrode layer with respect to the wavelength of the light to react, and wettability with respect to the material of the source electrode layer or drain electrode layer that is the formation material, What is necessary is just to select suitably.

    Next, the photoreactive substance 107 is irradiated with light 109a and light 109b from the light-transmitting substrate 100 side through the substrate 100 by the light source 108a and the light source 108b. The light 109a and 109b changes the wettability of the photoreactive substance 107 by the energy, and improves the wettability. Since the gate electrode layer 102 and the gate electrode layer 103 serve as a mask, the surface of the photoreactive substance in the region overlapping with the gate electrode layer 102 and the gate electrode layer 103 is not modified. In addition, since the mask layer used in this embodiment transmits light 109a and light 109b, the photoreactive substance on the mask layer 106a, the mask layer 106b, and the mask layer 106c in a region where light is not blocked by the gate electrode layer is also used. Light is irradiated and the surface is modified. However, the mask layer 106a, the mask layer 106b, and the mask layer 106c may not have a light-transmitting property. In that case, light is blocked by the mask layer, and the photoreactive substance on the mask layer is modified. .

  By the irradiation process of the light 109a and the light 109b, the surface of the photoreactive substance 107 has a high wettability region 110 having relatively high wettability, a low wettability region 111a and a low wettability region 111b having relatively low wettability. Is formed (see FIG. 4). In the present invention, light irradiation (so-called backside exposure) is performed for surface modification with good controllability, so the apparatus and process are simplified, so that cost and time can be reduced and productivity can be improved. it can.

  After the wettability is controlled by light irradiation, the mask layer 106a, the mask layer 106b, the mask layer 106c, and the photoreactive substance formed on these mask layers are removed. In this embodiment mode, the mask layer 106a, the mask layer 106b, and the mask layer 106c are removed by cleaning with water. In the region where the mask layer 106a, the mask layer 106b, and the mask layer 106c are provided, a photoreactive substance that has been controlled to have low wettability is not formed. Similar to the formed region, the wettability is higher than the relatively low wettability region where the photoreactive substance is formed.

    A composition containing a conductive material is discharged from the droplet discharge device 117 a and the droplet discharge device 117 b to the highly wettable region 110, and the source or drain electrode layer 112, the source or drain electrode layer 113, and the source An electrode layer or drain electrode layer 114 and a source electrode layer or drain electrode layer 115 are formed (see FIG. 5). Even when the pattern material ejection method cannot be precisely controlled depending on the size of the ejection port of the nozzle from which the liquid droplets are ejected, the scanning capability of the ejection port, etc., a process for improving wettability is applied to the formation region. As a result, the droplets adhere only to the formation region and are formed in a desired pattern. This is because the wettability is different between the formation region and the surrounding region, so that the droplet is repelled in the low wettability region and remains in the formation region with higher wettability. That is, since the droplets are repelled by the low wettability region, it functions as if there is a partition wall (bank) at the boundary between the high wettability region and the low wettability region. Therefore, even a composition including a conductive material having fluidity remains in the highly wettable region, so that the source electrode layer or the drain electrode layer can be formed in a desired shape.

    A region where a substance having low wettability is not formed by the mask layer 106a, the mask layer 106b, and the mask layer 106c is also a high wettability region; therefore, the composition including a conductive material is stably formed without being repelled. be able to.

  The source or drain electrode layer 112 also functions as a source wiring layer, and the source or drain electrode layer 114 also functions as a power supply line.

  The steps of forming the source or drain electrode layer 112, the source or drain electrode layer 113, the source or drain electrode layer 114, and the source or drain electrode layer 115 also include the gate electrode layer 102 and the gate described above. It can be formed in the same manner as when the electrode layer 103 is formed.

  As a conductive material for forming the source or drain electrode layer 112, the source or drain electrode layer 113, the source or drain electrode layer 114, and the source or drain electrode layer 115, Ag (silver), Au A composition mainly composed of metal particles such as (gold), Cu (copper), W (tungsten), and Al (aluminum) can be used. Further, light-transmitting indium tin oxide (ITO), ITSO made of indium tin oxide and silicon oxide, organic indium, organic tin, zinc oxide, titanium nitride, or the like may be combined.

  In the opening 125 formed in the gate insulating layer 101, the source or drain electrode layer 113 and the gate electrode layer 103 are electrically connected. A part of the source electrode layer or the drain electrode layer forms a capacitor element. Since part of the gate electrode layer 103 is selectively covered with the mask layer 106c, part of the source or drain electrode layer 114 is provided with stability through the gate insulating layer, and a capacitor element is formed. Can do.

    With the present invention, when it is desired to form a fine pattern such as an electrode layer, the droplet does not spread on the formation region even if the droplet discharge port is somewhat large, and the conductive layer is formed only in the formation region. It is possible to prevent defects such as a short circuit due to erroneous formation in a non-formation region. The thickness of the wiring can also be controlled. When the surface of the material is modified by light irradiation from the substrate side as in this embodiment mode, not only can the pattern be formed with high controllability, but also a large area can be processed, so that productivity is improved. Further, by combining the droplet discharge method, material loss can be prevented and costs can be reduced as compared with the entire surface coating formation by spin coating method or the like. According to the present invention, it is possible to form wirings and the like with good controllability even if they are designed to be densely arranged in a complicated manner by downsizing and thinning.

  In addition, in order to improve adhesion to a conductive layer or an insulating layer by a droplet discharge method as a pretreatment, an organic material substance that functions as an adhesive may be formed. In this case, a process for forming regions having different wettability may be performed on this substance. An organic material (organic resin material) (polyimide, acrylic) or a siloxane resin may be used. Note that a siloxane resin corresponds to a resin including a Si—O—Si bond. Siloxane has a skeleton structure formed of a bond of silicon (Si) and oxygen (O). As a substituent, an organic group containing at least hydrogen (for example, an alkyl group or an aromatic hydrocarbon) is used. A fluoro group may be used as a substituent. Alternatively, an organic group containing at least hydrogen and a fluoro group may be used as a substituent.

  After forming the source or drain electrode layer 112, the source or drain electrode layer 113, the source or drain electrode layer 114, and the source or drain electrode layer 115 with good controllability, this time, not from the back surface of the substrate. Then, light is irradiated from the element side, and the photoreactive substance remaining in the low wettability region 111a and the low wettability region 111b is altered and modified. By light irradiation, the low wettability region 111a and the low wettability region 111b are modified into a high wettability region. The photoreactive substance may remain or unnecessary portions may be removed after the electrode layer is formed. The photoreactive substance can be removed using the electrode layer as a mask, and may be removed by ashing with oxygen or the like, wet etching, dry etching, plasma treatment, or the like.

    In addition, the process of improving the wettability is to make the force (also referred to as an adhesion force or a fixing force) for retaining the droplets discharged on the region higher than that in the surrounding region. This also means that the region is modified to improve the adhesion to the droplet. Further, the wettability may be only on the surface that is in contact with the liquid droplet and is retained, and it is not always necessary to have the same property throughout the film thickness direction.

Subsequently, a first electrode layer 119 is formed by selectively discharging a composition containing a conductive material over the gate insulating layer 101 (see FIG. 6). Of course, when the first electrode layer 119 is formed, pretreatment for forming a low wettability region and a high wettability region may be performed. The first electrode layer 119 can be selectively formed with better controllability by discharging a composition containing a conductive material to the highly wettable region. The first electrode layer 119 is formed of indium tin oxide (ITO) or indium tin containing silicon oxide when light is emitted from the light-transmitting substrate 100 side or when a transmissive display panel is manufactured. Oxide (ITSO), indium zinc oxide (IZO) containing zinc oxide (ZnO), zinc oxide (ZnO), ZnO doped with gallium (Ga), tin oxide (SnO ₂ ), etc. A predetermined pattern may be formed with a composition containing, and may be formed by firing.

  Further, it is preferably formed of indium tin oxide (ITO), indium tin oxide containing silicon oxide (ITSO), zinc oxide (ZnO), or the like by a sputtering method. More preferably, indium tin oxide containing silicon oxide is used by a sputtering method using a target containing 2 to 10% by weight of silicon oxide in ITO. In addition, a conductive material obtained by doping ZnO with gallium (Ga), and an oxide conductive material formed using a target in which silicon oxide is included and 2 to 20 wt% zinc oxide (ZnO) is mixed with indium oxide. Indium zinc oxide (IZO) may be used. After the first electrode layer 119 is formed by a sputtering method, a mask layer may be formed by a droplet discharge method and formed into a desired pattern by etching. In this embodiment, the first electrode layer 119 is formed using a light-transmitting conductive material by a droplet discharge method, and specifically includes indium tin oxide, ITO, and silicon oxide. It is formed using ITSO.

  In this embodiment, the gate insulating layer is a stacked layer including a silicon nitride film, a silicon oxynitride film, and a silicon nitride film made of silicon nitride from the gate electrode layer side. As a preferable structure, the first electrode layer 119 formed of indium tin oxide containing silicon oxide is formed in close contact with the insulating layer made of silicon nitride included in the gate insulating layer 101, and thereby emits light in the electroluminescent layer. The effect that the ratio of the emitted light to the outside can be increased can be exhibited. Further, the gate insulating layer is interposed between the gate electrode layer, the gate electrode layer, and the first electrode layer, and can function as a capacitor.

  The first electrode layer 119 can also be selectively formed over the gate insulating layer 101 before the source or drain electrode layer 115 is formed. In this case, in this embodiment mode, the connection structure of the source or drain electrode layer 115 and the first electrode layer 119 is a structure in which the source or drain electrode layer 115 is stacked on the first electrode layer. It becomes. When the first electrode layer 119 is formed before the source electrode layer or the drain electrode layer 115, the first electrode layer 119 can be formed in a flat formation region. Therefore, the first electrode layer 119 can be formed in a flat formation region. .

  Alternatively, an insulating layer serving as an interlayer insulating layer may be formed over the source or drain electrode layer 115 and electrically connected to the first electrode layer 119 with a wiring layer. In this case, the opening (contact hole) is not formed by removing the insulating layer, but a substance having low wettability with respect to the insulating layer is formed over the source or drain electrode layer 115. After that, when a composition including an insulating layer is applied by a coating method or the like, the insulating layer is formed in a region excluding a region where a substance having low wettability is formed.

  After the insulating layer is solidified by heating, drying, or the like, a substance with low wettability is removed to form an opening. A wiring layer is formed so as to fill the opening, and a first electrode layer 119 is formed so as to be in contact with the wiring layer. When this method is used, there is an effect of simplifying the process because it is not necessary to form an opening by etching.

  In the case where a structure in which emitted light is emitted to the side opposite to the light-transmitting substrate 100 side, in the case of manufacturing a reflective EL display panel, Ag (silver), Au (gold), Cu A composition containing metal particles such as (copper), W (tungsten), and Al (aluminum) as a main component can be used. As another method, a transparent conductive film or a light reflective conductive film is formed by a sputtering method, a mask pattern is formed by a droplet discharge method, and a first electrode layer 119 is formed by combining etching processes. Also good.

  The first electrode layer 119 may be wiped with a CMP method or a polyvinyl alcohol-based porous material and polished so that the surface thereof is planarized. Further, after polishing using the CMP method, the surface of the first electrode layer 119 may be irradiated with ultraviolet rays, oxygen plasma treatment, or the like.

  Through the above steps, a TFT substrate for a display panel in which a bottom gate TFT and a pixel electrode are connected to a light-transmitting substrate 100 is completed. The TFT of this embodiment mode is an inverted stagger type. The TFT described in this embodiment can be manufactured in a self-aligned manner in order to use the present invention.

  Next, an insulating layer 121 (also referred to as a partition wall or a bank) is selectively formed. The insulating layer 121 is formed over the first electrode layer 119 so as to have an opening. In this embodiment mode, the insulating layer 121 is formed over the entire surface, and is etched into a desired shape using a mask such as a resist. When the insulating layer 121 is formed using a droplet discharge method, a printing method, or the like that can be directly and selectively formed, etching processing is not necessarily required. The insulating layer 121 can also be formed in a desired shape by the pretreatment of the present invention.

  The insulating layer 121 is formed using silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, aluminum nitride, aluminum oxynitride, or other inorganic insulating materials, or acrylic acid, methacrylic acid, and derivatives thereof, polyimide, aromatic It can be formed of a heat-resistant polymer such as polyamide, polybenzimidazole, or an insulating material of a material having siloxane (inorganic siloxane, organic siloxane). You may form using photosensitive and non-photosensitive materials, such as an acryl and a polyimide. The insulating layer 121 preferably has a shape in which the radius of curvature continuously changes, and the coverage of the electroluminescent layer 122 and the second electrode layer 123 formed thereon is improved.

  Alternatively, after the insulating layer 121 is formed by discharging a composition by a droplet discharge method, the surface may be pressed and flattened by pressure in order to improve the flatness. As a pressing method, unevenness may be reduced by scanning a roller-like object on the surface, or the surface may be pressed vertically with a flat plate-like object. Alternatively, the surface may be softened or melted with a solvent or the like, and the surface irregularities may be removed with an air knife. Further, polishing may be performed using a CMP method. This step can be applied when the surface is flattened when unevenness is generated by the droplet discharge method. When flatness is improved by this step, display unevenness of the display panel can be prevented and a high-definition image can be displayed.

  A light emitting element is formed over a substrate 100 which is a TFT substrate for a display panel (see FIG. 1).

  Before the electroluminescent layer 122 is formed, heat treatment is performed at 200 ° C. under atmospheric pressure to remove moisture adsorbed in the first electrode layer 119 and the insulating layer 121 or on the surface thereof. In addition, it is preferable to perform heat treatment at 200 to 400 ° C., preferably 250 to 350 ° C. under reduced pressure, and to form the electroluminescent layer 122 by vacuum deposition or droplet discharge under reduced pressure without being exposed to the air as it is. .

  As the electroluminescent layer 122, materials that emit red (R), green (G), and blue (B) light are selectively formed by an evaporation method using an evaporation mask or the like. A material that emits red (R), green (G), and blue (B) light can be formed by a droplet discharge method (such as a low-molecular or high-molecular material) in the same manner as a color filter. In this case, a mask is not used. Both are preferable because RGB can be separately applied. A second electrode layer 123 is stacked over the electroluminescent layer 122 to complete a display device having a display function using a light emitting element.

Although not shown, it is effective to provide a passivation film so as to cover the second electrode layer 123. The protective film provided when forming the display device may have a single layer structure or a multilayer structure. As the passivation film, silicon nitride (SiN), silicon oxide (SiO ₂ ), silicon oxynitride (SiON), silicon nitride oxide (SiNO), aluminum nitride (AlN), aluminum oxynitride (AlON), nitrogen content is oxygen It is made of an insulating film containing aluminum nitride oxide (AlNO) or aluminum oxide, diamond-like carbon (DLC), or nitrogen-containing carbon film (CN _X ) that is higher than the content, and a single layer or a combination of the insulating films is used. Can do. For example, a laminate of a nitrogen-containing carbon film (CN _x ) and a silicon nitride (SiN) film, an organic material can be used, and a laminate of polymers such as a styrene polymer may be used. Alternatively, a material having siloxane may be used.

At this time, it is preferable to use a film with good coverage as the passivation film, and it is effective to use a carbon film, particularly a DLC film. Since the DLC film can be formed in the temperature range from room temperature to 100 ° C., it can be easily formed over the electroluminescent layer having low heat resistance. The DLC film is formed by a plasma CVD method (typically, an RF plasma CVD method, a microwave CVD method, an electron cyclotron resonance (ECR) CVD method, a hot filament CVD method, etc.), a combustion flame method, a sputtering method, or an ion beam evaporation method. It can be formed by laser vapor deposition. The reaction gas used for film formation was hydrogen gas and a hydrocarbon-based gas (for example, CH ₄ , C ₂ H ₂ , C ₆ H _6, etc.), ionized by glow discharge, and negative self-bias was applied. Films are formed by accelerated collision of ions with the cathode. The CN film may be formed using C ₂ H ₄ gas and N ₂ gas as the reaction gas. The DLC film has a high blocking effect against oxygen and can suppress oxidation of the electroluminescent layer. Therefore, the problem that the electroluminescent layer is oxidized during the subsequent sealing process can be prevented.

  As shown in FIG. 7B, a sealant 136 is formed and sealed using a sealing substrate 140. After that, a flexible wiring board may be connected to a gate wiring layer formed by being electrically connected to the gate electrode layer 102 to be electrically connected to the outside. The same applies to the source wiring layer formed by being electrically connected to the source electrode layer or drain electrode layer 112 which is also the source wiring layer.

    A filler 135 is sealed between the substrate 100 having elements and the sealing substrate 140 for sealing. A dripping method can be used to enclose the filler as in the case of the liquid crystal material. Instead of the filler 135, an inert gas such as nitrogen may be filled. Further, by installing the desiccant in the display device, the light emitting element can be prevented from being deteriorated by moisture. The desiccant may be placed on the sealing substrate 140 side or on the substrate 100 side having elements, and may be placed in a region where the sealant 136 is formed with a recess formed in the substrate. In addition, when it is installed in a location corresponding to a region that does not contribute to display, such as a drive circuit region or a wiring region of the sealing substrate 140, the aperture ratio is not lowered even if the desiccant is an opaque substance. The filler 135 may be formed so as to include a hygroscopic material and may have a function of a desiccant. Thus, a display device having a display function using a light-emitting element is completed (see FIG. 7).

  Further, an FPC 139 is bonded to a terminal electrode layer 137 for electrically connecting the inside and the outside of the display device with an anisotropic conductive film 138 to be electrically connected to the terminal electrode layer 137.

    FIG. 7A shows a top view of the display device. As shown in FIG. 7A, the pixel region 150, the scanning line driving region 151a, the scanning line driving region 151b, and the connection region 153 are sealed between the substrate 100 and the sealing substrate 140 with a sealant 136. A signal line driver circuit 152 formed by an IC driver is provided on the substrate 100. A thin film transistor 133 and a thin film transistor 134 are provided in the driver circuit region, and a thin film transistor 131, a thin film transistor 130, and a capacitor element 132 are provided in the pixel region, respectively.

  Note that in this embodiment mode, a case where a light-emitting element is sealed with a glass substrate is shown; however, the sealing process is a process for protecting the light-emitting element from moisture and is mechanically sealed with a cover material. Either a method, a method of encapsulating with a thermosetting resin or an ultraviolet light curable resin, or a method of encapsulating with a thin film having a high barrier ability such as a metal oxide or a nitride is used. As the cover material, glass, ceramics, plastic, or metal can be used. However, when light is emitted to the cover material side, it must be translucent. In addition, the cover material and the substrate on which the light emitting element is formed are bonded together using a sealing material such as a thermosetting resin or an ultraviolet light curable resin, and the resin is cured by heat treatment or ultraviolet light irradiation treatment to form a sealed space. Form. It is also effective to provide a hygroscopic material typified by barium oxide in this sealed space. This hygroscopic material may be provided in contact with the sealing material, or may be provided on the partition wall or in the peripheral portion so as not to block light from the light emitting element. Further, the space between the cover material and the substrate on which the light emitting element is formed can be filled with a thermosetting resin or an ultraviolet light curable resin. In this case, it is effective to add a moisture absorbing material typified by barium oxide in the thermosetting resin or the ultraviolet light curable resin.

  In this embodiment mode, the switching TFT has a single gate structure, but a multi-gate structure such as a double gate structure may be used. In the case where a semiconductor is manufactured using a SAS or a crystalline semiconductor, an impurity region can be formed by adding an impurity imparting one conductivity type. In this case, the semiconductor layer may have impurity regions having different concentrations. For example, the vicinity of the channel region of the semiconductor layer and the region stacked with the gate electrode layer may be low-concentration impurity regions, and the outer region may be high-concentration impurity regions.

  As described above, in this embodiment mode, the process can be omitted by not using a light exposure process using a photomask. In addition, by forming various patterns directly on the substrate using the droplet discharge method, a display panel can be easily manufactured even if a glass substrate of 5th generation or later with one side exceeding 1000 mm is used. Can do.

According to the present invention, a desired pattern can be formed with good controllability. In addition, there is little material loss, and cost reduction can be achieved. Thus, a high-performance and highly reliable light-emitting display device can be manufactured with high yield.
(Embodiment 2)
An embodiment of the present invention will be described with reference to FIGS. In more detail, a method for manufacturing a display device having a coplanar thin film transistor with a bottom gate structure to which the present invention is applied will be described. FIG. 8 is a top view of the display device pixel portion, and FIGS. 9 to 10 are cross-sectional views taken along line E-F in each step of forming FIG. FIG. 11A is also a top view of the display device, and FIG. 11B is a cross-sectional view taken along line OP (including line U-W) in FIG. Note that an example of a liquid crystal display device using a liquid crystal material as a display element is shown. Therefore, repetitive description of the same portion or a portion having a similar function is omitted.

      A gate electrode layer 254a, a gate electrode layer 254b, and a gate electrode layer 254c are formed over the light-transmitting substrate 250. The gate electrode layer 254a, the gate electrode layer 254b, and the gate electrode layer 254c can be formed by a CVD method, a sputtering method, a droplet discharge method, or the like. In this embodiment, a composition containing Ag as a conductive material is selectively discharged by the droplet discharge device 255a, the droplet discharge device 255b, and the droplet discharge device 255c, and the gate electrode layer 254a, the gate electrode layer 254b, A gate electrode layer 254c is formed (see FIG. 9A). As shown in FIG. 8, the gate electrode layer 254a, the gate electrode layer 254b, and the gate electrode layer 254c are integrally formed, and are illustrated as the gate electrode layer 254 in FIG. In addition, a capacitor wiring layer 253 is also formed in the same step as the gate electrode layer (see FIG. 8).

    In this embodiment, as another method of changing and controlling the wettability of the surface, a method of decomposing the surface material, modifying the surface of the region, and changing the wettability by the energy of light irradiation is used. In this case, it is preferable to form a substance that increases the processing efficiency by light in the light irradiation region and to form a substance having low wettability with respect to the material to be formed. A photocatalytic substance can be used as a substance that enhances the processing efficiency with light. The photocatalytic substance improves the processing efficiency by light by light absorption and energy radiation action. Due to the photoactive energy of the photocatalytic substance, a substance having low wettability with respect to the layered material to be laminated is decomposed and modified, and the wettability of the substance surface changes. As a substance having low wettability, a substance containing a fluorocarbon chain or a substance containing a silane coupling agent can be used. The silane coupling agent may have an alkyl group.

  Next, the gate insulating layer 256 is formed over the gate electrode layer 254a, the gate electrode layer 254b, and the gate electrode layer 254c. The gate insulating layer 256 needs to have a light-transmitting property in order to allow light to pass through when a substance with low wettability formed thereon is decomposed by light irradiation. The gate insulating layer 256 may be formed of a known material such as a silicon oxide material or a nitride material, and may be a stacked layer or a single layer. In this embodiment, a stacked layer of a silicon nitride film, a silicon oxide film, and a silicon nitride film is used.

  In the present embodiment, in order to form regions with different wettability accurately and with good controllability, light irradiation to the processing object is performed through the substance (substrate) on which the processing object is formed. In this embodiment mode, an electrode layer or a mask layer which serves as a mask is formed in advance over a substrate that transmits light used for processing, and a material with low wettability is formed thereover. Then, by irradiating light from the light-transmitting substrate side, a material with low wettability contained in a substance with low wettability other than the electrode layer formation region is decomposed. Since the substance with low wettability formed on the electrode layer is not irradiated with light, regions with different wettability can be formed with good controllability. In addition, since the low wettability substance formed on the mask layer is removed when the mask layer is removed, a high wettability region can be selectively formed. The wavelength of light needs to be a wavelength at which a substance with low wettability to be used is decomposed and removed. However, depending on the substance, light having a high energy of 200 nm or less, such as ultraviolet light, is required, and the selection range is narrowed. Furthermore, when the wavelength is absorbed by the light-transmitting substance serving as the substrate, the light is absorbed in the light-transmitting substrate, and the processed object is not irradiated with light, making it difficult to modify the surface. Can be.

  Therefore, in this embodiment mode, the photocatalytic substance is formed in contact with the substance to be treated in order to improve the treatment efficiency by light irradiation. The photocatalytic material absorbs and activates light. The active energy acts on the surrounding material, and as a result, changes the physical properties of the material and modifies it. When the present invention is used, the modification treatment capability is improved by the photocatalytic substance, so that the selection range of the wavelength of light is widened. Therefore, it is possible to select a wavelength in a region where the substance to be processed does not absorb much, and to perform light irradiation for performing surface modification with good controllability. In addition, since the light irradiation efficiency can be improved, sufficient processing can be performed even if the light itself has low energy. Therefore, since the apparatus and the process are simplified, cost and time can be reduced and productivity can be improved.

    In addition to the photocatalytic substance, it is also effective to add a light absorber having an absorption region in the wavelength region of the light to the substance to be treated in order to improve the treatment efficiency by light irradiation. A light absorber having an absorption region in the wavelength region of light absorbs irradiated light and radiates (radiates) the surroundings. The radiant energy acts on surrounding materials, and as a result, changes the physical properties of the materials and modifies them. Since the light absorber may be selected in accordance with the light, the range of light selection is widened.

    As the light absorber, an organic material, an inorganic material, an inorganic material, a substance containing an organic material, or the like can be used. A material having an absorption region at the wavelength may be selected depending on the wavelength of the laser light to be used. It may be a conductive material such as metal or an insulating material such as an organic resin. As the inorganic material, iron, gold, copper, silicon or germanium can be used, and as the organic material, plastic or pigment such as polyimide or acrylic can be used. For example, rhodamine B can be used as the pigment corresponding to a laser wavelength of 532 nm. Coumarins (coumarin 6H, coumarin 102, coumarin 152, coumarin 153, etc.) can be used as pigments having a laser wavelength of 405 nm, such as eosin Y, methyl orange, and rose bengal. Further, as the coloring matter, black carbon black or a pigment-based black resin can be used.

A photocatalytic material 258 is formed over the gate insulating layer 256. Photocatalytic materials include titanium oxide (TiO _x ), strontium titanate (SrTiO ₃ ), cadmium selenide (CdSe), potassium tantalate (KTaO ₃ ), cadmium sulfide (CdS), zirconium oxide (ZrO ₂ ), niobium oxide ( Nb ₂ O ₅ ), zinc oxide (ZnO), iron oxide (Fe ₂ O ₃ ), tungsten oxide (WO ₃ ) and the like are preferable. These photocatalytic substances can be irradiated with light in the ultraviolet region (wavelength 400 nm or less, preferably 380 nm or less) to cause photocatalytic activity.

  The photocatalytic substance is a sol-gel dip coating method, spin coating method, droplet discharge method, ion plating method, ion beam method, CVD method, sputtering method, RF magnetron sputtering method, plasma spraying method, plasma spraying method, or anode. It can be formed by an oxidation method. The substance may not have continuity as a film depending on the formation method. In the case of a photocatalytic substance made of an oxide semiconductor containing a plurality of metals, it can be formed by mixing and melting constituent element salts. When the photocatalytic substance is formed by a coating method such as a dip coating method or a spin coating method, it may be fired or dried when it is necessary to remove the solvent. Specifically, heating may be performed at a predetermined temperature (for example, 300 ° C. or higher), and preferably performed in an atmosphere containing oxygen.

  By this heat treatment, the photocatalytic substance can have a predetermined crystal structure. For example, it has an anatase type and a rutile-anatase mixed type. In the low temperature phase, the anatase type is preferentially formed. Therefore, heating may be performed even when the photocatalytic substance does not have a predetermined crystal structure. Moreover, when forming by the apply | coating method, in order to obtain a predetermined film thickness, a photocatalyst substance can also be formed in multiple times.

  Furthermore, the photocatalytic substance can be doped with transition metals (Pd, Pt, Cr, Ni, V, Mn, Fe, Ce, Mo, W, etc.) to improve the photocatalytic activity or visible light region (wavelength 400 nm to 800 nm). Photocatalytic activity can be caused by the light. This is because transition metals can form a new level in the forbidden band of an active photocatalyst having a wide band gap, and can extend the light absorption range to the visible light region. For example, an acceptor type such as Cr or Ni, a donor type such as V or Mn, an amphoteric type such as Fe, and Ce, Mo, W, or the like can be doped. Thus, since the wavelength of light can be determined by the photocatalytic substance, the light irradiation refers to irradiating light having a wavelength for activating the photocatalytic substance of the photocatalytic substance.

Further, when the photocatalytic substance is heated and reduced in vacuum or hydrogen reflux, oxygen defects are generated in the crystal. Thus, oxygen defects play the same role as electron donors even without doping with a transition element. In particular, in the case of forming by the sol-gel method, oxygen defects are present from the beginning, so that reduction is not necessary. Further, oxygen defects can be formed by doping a gas such as N ₂ .

In this embodiment, a titanium oxide layer is formed as a photocatalytic substance. The titanium oxide layer is formed by applying a TiCl ₃ solution by spin coating, adhering it to the substrate, and baking it in an oxygen atmosphere. Alternatively, titania sol may be applied and dried. A binder can also be used for titania sol, and it is preferable to use inorganic binders, such as a silicate type, an inorganic colloid type, and a metal alkoxide type, as a binder. Alternatively, a titanium oxide (TiO _x (typically TiO ₂ )) crystal having a predetermined crystal structure may be formed by a sputtering method. In this case, a metal titanium tube is used as a target, and sputtering is performed using argon gas and oxygen. Further, He gas may be introduced. In order to form a titanium oxide layer with high photocatalytic activity, the atmosphere is rich in oxygen and the formation pressure is increased. Further, it is preferable to form the titanium oxide layer while heating the substrate provided with the film formation chamber or the processed material. The titanium oxide layer thus formed has a photocatalytic function even if it is a very thin film.

    A mask layer 257 is selectively formed on the photocatalytic material 258. The mask layer 257 is selectively formed in a region where the gate electrode layer and the source or drain electrode layer intersect with each other with the gate insulating layer 256 interposed therebetween. In this embodiment mode, the mask layer 257 is formed by a droplet discharge method using PVA.

  A material 259 having low wettability is formed over the mask layer 257 and the photocatalytic material 258 (see FIG. 9B).

As a substance having low wettability, a substance containing a fluorocarbon chain or a substance containing a silane coupling agent can be used. The silane coupling agent is represented by a chemical formula of Rn—Si—X _(4-n) (n = 1, 2, 3). Here, R is a substance containing a relatively inert group such as an alkyl group. X is a hydrolyzable group such as halogen, methoxy group, ethoxy group or acetoxy group, which can be bonded by condensation with a hydroxyl group on the substrate surface or adsorbed water.

Further, as a representative example of the silane coupling agent, wettability can be further reduced by using a fluorine-based silane coupling agent (fluoroalkylsilane (FAS)) having a fluoroalkyl group in R. R of FAS has a structure represented by (CF ₃ ) (CF ₂ ) _x (CH ₂ ) _y (x: an integer of 0 or more and 10 or less, y: an integer of 0 or more and 4 or less), and a plurality of R Alternatively, when X is bonded to Si, R and X may all be the same or different. As typical FAS, fluoroalkylsilanes (hereinafter also referred to as FAS) such as heptadefluorotetrahydrodecyltriethoxysilane, heptadecafluorotetrahydrodecyltrichlorosilane, tridecafluorotetrahydrooctyltrichlorosilane, and trifluoropropyltrimethoxysilane. ).

    As the substance having low wettability, a substance having no fluorocarbon chain and having an alkyl group in R of the silane coupling agent can be used. For example, octadecyltrimethoxysilane or the like can be used as the organic silane.

  Solvents for the solution that forms the low wettability region include n-pentane, n-hexane, n-heptane, n-octane, n-decane, dicyclopentane, benzene, toluene, xylene, durene, indene, tetrahydronaphthalene, deca A hydrocarbon solvent such as hydronaphthalene or squalane, or a solvent that forms a low wettability surface such as tetrahydrofuran is used.

  In addition, as an example of a composition of a solution that forms a low wettability region, a material having a fluorocarbon chain (fluorine-based resin) can be used. Examples of fluorine resins include polytetrafluoroethylene (PTFE; tetrafluoroethylene resin), perfluoroalkoxyalkane (PFA; tetrafluoroethylene perfluoroalkyl vinyl ether copolymer resin), and perfluoroethylene propene copolymer (PFEP; four fluoropolymer). Ethylene-hexafluoropropylene copolymer resin), ethylene-tetrafluoroethylene copolymer (ETFE; tetrafluoroethylene-ethylene copolymer resin), polyvinylidene fluoride (PVDF; vinylidene fluoride resin), polychlorotrifluoroethylene (PCTFE; trifluoroethylene chloride resin), ethylene-chlorotrifluoroethylene copolymer (ECTFE; trifluoroethylene chloride-ethylene copolymer resin), polytetrafluoroethylene-perfluorodioxide Rukoporima (TFE / PDD), polyvinyl fluoride (PVF; a vinyl fluoride resin), or the like can be used.

Alternatively, an organic material that does not exhibit a low wettability region (that is, a high wettability region) may be used, and a treatment with CF ₄ plasma or the like may be performed later to form the low wettability region. For example, a material in which a water-soluble resin such as polyvinyl alcohol (PVA) is mixed with a solvent such as H ₂ O can be used. Moreover, you may use combining PVA and another water-soluble resin. An organic material (organic resin material) (polyimide, acrylic) or a siloxane resin may be used. Furthermore, even with a material having a low wettability surface, wettability can be further reduced by performing plasma treatment or the like.

  In this embodiment mode, FAS is used as the material 259 having low wettability, and the material 259 is formed over a wide region (overall coating or the like) by a spin coating method. This wettability is with respect to a composition containing a conductive material constituting a source electrode layer or a drain electrode layer formed in a later step. Although FAS used in this embodiment is decomposed by light of 200 nm or less, the glass substrate absorbs a wavelength of 300 nm or less and does not transmit. When a glass substrate is used as the substrate, it is difficult to irradiate the FAS with light. Therefore, in this embodiment, a titanium oxide layer exhibiting a photocatalytic effect is formed by light irradiation of 380 nm or less. A metal halide lamp that is an ultraviolet lamp that irradiates light with a wavelength of 200 nm to 450 nm is used as a light source. What is necessary is just to select a photocatalyst substance suitably according to the wavelength of the light to be used.

    Next, as a pretreatment for forming the source electrode layer or the drain electrode layer with good controllability, the vicinity of the formation region of the source electrode layer and the drain electrode layer is compared with the surrounding region and modified. The wettability is selectively changed by using the photoactivity of the photocatalytic substance by the light irradiation treatment to form a high wettability region and a low wettability region. The difference in wettability can be confirmed by the contact angle, and the difference in contact angle is 30 degrees or more, preferably 40 degrees or more. In the present invention, in order to improve the efficiency of light irradiation treatment, a photocatalytic substance that is activated at the wavelength of light to be irradiated is formed in contact with the treatment object.

  The photocatalytic substance 258 is irradiated with light 262 from the light-transmitting substrate 250 side through the substrate 250 through the light source 260. The light 262 activates the photocatalytic substance 258, decomposes the substance 259 having low wettability by its energy, and improves the wettability. Therefore, the concentration of a substance with low wettability contained in the low wettability region (concentration, amount, etc. of a fluorocarbon chain having an effect of reducing wettability) is lower than that of the high wettability region. Since the photocatalytic effect of the photocatalytic substance is used, the processing efficiency is improved. Since the gate electrode layer 254a, the gate electrode layer 254b, and the gate electrode layer 254c serve as a mask, the surface of the substance with low wettability in the region overlapping with the gate electrode layer 254a, the gate electrode layer 254b, and the gate electrode layer 254c is not modified. . By the irradiation treatment with the light 262, the surface of the substance 259 having low wettability is relatively low in wettability region 268a, high wettability region 268b, and high wettability region 268c having relatively high wettability. A wettability region 267a, a low wettability region 267b, and a low wettability region 267c are formed (see FIG. 9C). When the present invention is used, it is only necessary to select a photocatalytic substance in accordance with light, so that the range of light selection is widened. Therefore, it is possible to select a wavelength in a region where a substance to be processed is not so much absorbed, and to perform light irradiation (so-called back exposure) for performing surface modification with good controllability. In addition, since the light irradiation efficiency can be improved, sufficient processing can be performed even if the light itself has low energy. Therefore, since the apparatus and the process are simplified, cost and time can be reduced and productivity can be improved.

  After controlling the wettability by light irradiation, the mask layer 257 is removed together with the substance having low wettability formed on the mask layer 257. In this embodiment mode, the mask layer 257 is removed by washing with water. Since a substance having low wettability is not formed in the region where the mask layer 257 is provided, a substance having relatively low wettability is provided in the same manner as the region in which the wettability is increased by light irradiation. The wettability is higher than the region where the wettability is low.

    A composition containing a conductive material is discharged from the droplet discharge device 269a, the droplet discharge device 269b, and the droplet discharge device 269c into the high wettability region 268a, the high wettability region 268b, and the high wettability region 268c. An electrode or drain electrode layer 263, a source or drain electrode layer 264, and a source or drain electrode layer 266 are formed (see FIG. 9D). In this embodiment, Ag is used as the conductive material. Even when the pattern material ejection method cannot be precisely controlled depending on the size of the ejection port of the nozzle from which the liquid droplets are ejected, the scanning capability of the ejection port, etc., a process for improving wettability is applied to the formation region. As a result, the droplets adhere only to the formation region and are formed in a desired pattern. This is because the wettability is different between the formation region and the surrounding region, so that the droplet is repelled in the low wettability region and remains in the formation region with higher wettability. That is, since the droplets are repelled by the low wettability region, the boundary between the high wettability region and the low wettability region functions as if there is a partition wall (bank). Therefore, even a composition including a conductive material having fluidity remains in the highly wettable region, so that the source electrode layer or the drain electrode layer can be formed in a desired shape. The source or drain electrode layer 263 also functions as a source wiring layer.

    With the present invention, when it is desired to form a fine pattern such as an electrode layer, the droplet does not spread on the formation region even if the droplet discharge port is somewhat large, and the conductive layer is formed only in the formation region. It is possible to prevent defects such as a short circuit due to erroneous formation in a non-formation region. The thickness of the wiring can also be controlled. When the surface of the material is modified by light irradiation from the substrate side as in this embodiment mode, not only can the pattern be formed with high controllability, but also a large area can be processed, so that productivity is improved. Further, by combining the droplet discharge method, material loss can be prevented and costs can be reduced as compared with the entire surface coating formation by spin coating method or the like. According to the present invention, it is possible to form wirings and the like with good controllability even if they are designed to be densely arranged in a complicated manner by downsizing and thinning.

  In this embodiment mode, light irradiation is performed on the low wettability region 267a and the low wettability region 267b to decompose a substance with low wettability, and to improve wettability. Moreover, you may remove the unnecessary part of a photocatalyst substance and a substance with low wettability. The electrode layer can be used as a mask for removal, which may be removed by ashing with oxygen or the like, wet etching, dry etching, plasma treatment, or the like. After that, the semiconductor layer 270 is formed by a droplet discharge method using pentacene to form a coplanar thin film transistor 271 having a bottom gate structure (see FIG. 10A).

    In addition, the process of improving the wettability is to make the force (also referred to as an adhesion force or a fixing force) for retaining the droplets discharged on the region higher than that in the surrounding region. This also means that the region is modified to improve the adhesion to the droplet. Further, the wettability may be only on the surface that is in contact with the liquid droplet and is retained, and it is not always necessary to have the same property throughout the film thickness direction.

Subsequently, a pixel electrode layer 272 is formed by selectively discharging a composition containing a conductive material in contact with the source or drain electrode layer 266 (see FIG. 10B). Of course, when the pixel electrode layer 272 is formed, a pretreatment for forming a low wettability region and a high wettability region may be performed. The pixel electrode layer 272 can be selectively formed with better controllability by discharging a composition containing a conductive material to the highly wettable region. The pixel electrode layer 272 can be formed using a material similar to that of the first electrode layer 119 described above. When a transmissive liquid crystal display panel is manufactured, indium tin oxide (ITO) and indium containing silicon oxide are used. It may be formed in a predetermined pattern with a composition containing tin oxide (ITSO), zinc oxide (ZnO), tin oxide (SnO ₂ ), and the like, and may be formed by firing. Of course, the material may be formed by vapor deposition (PVD, CVD), sputtering, or the like. In this embodiment mode, indium tin oxide (ITO) is used for the pixel electrode layer 272.

  Next, an insulating layer 273 called an alignment film is formed by a printing method or a spin coating method so as to cover the pixel electrode layer 272 and the thin film transistor 271. Note that the insulating layer 273 can be selectively formed by a screen printing method or an offset printing method. Then, rubbing is performed. Subsequently, a sealant 282 is formed in a peripheral region where pixels are formed by a droplet discharge method.

  After that, an insulating substrate 275 functioning as an alignment film, a colored layer 277 functioning as a color filter, a conductor layer 276 functioning as a counter electrode, a counter substrate 280 provided with a polarizing plate 278 and a substrate 250 which is a TFT substrate are separated by spacers. A liquid crystal display panel can be manufactured by bonding through 281 and providing a liquid crystal layer 274 in the gap (see FIGS. 10C and 11). A polarizing plate 279 is also provided on the side opposite to the surface having the elements of the substrate 250. A filler may be mixed in the sealing material, and a shielding film (black matrix) or the like may be formed on the counter substrate 280. Note that as a method for forming the liquid crystal layer, a dispenser type (dropping type) or a dip type (pumping type) in which liquid crystal is injected using a capillary phenomenon after the substrate 250 having an element and the counter substrate 280 are bonded to each other is used. be able to.

  A liquid crystal dropping injection method employing a dispenser method will be described with reference to FIG. In the liquid crystal dropping injection method of FIG. 29, the control device 40, the imaging means 42, the head 43, the liquid crystal 33, the marker 35, and the marker 45 include the barrier layer 34, the sealing material 32, the TFT substrate 30, and the counter substrate 20. A closed loop is formed by the sealing material 32, and the liquid crystal 33 is dropped from the head 43 once or plural times therein. When the viscosity of the liquid crystal material is high, the liquid crystal material is continuously discharged and adhered to the formation region while being connected. On the other hand, when the viscosity of the liquid crystal material is low, the liquid crystal material is intermittently ejected and droplets are dropped as shown in FIG. At that time, a barrier layer 34 is provided to prevent the sealing material 32 and the liquid crystal 33 from reacting. Subsequently, the substrates are bonded together in a vacuum, and thereafter UV curing is performed to fill the liquid crystal. Further, a sealing material may be formed on the TFT substrate side, and the liquid crystal may be dropped.

A connection portion is formed to connect the inside of the display device formed by the above steps and an external wiring board. The insulator layer in the connection portion is removed by ashing using oxygen gas at or near atmospheric pressure. This treatment is performed using oxygen gas and one or more selected from hydrogen, CF ₄ , NF ₃ , H ₂ O, and CHF ₃ . In this step, in order to prevent damage and destruction due to static electricity, ashing is performed after sealing using the counter substrate. However, if there is little influence from static electricity, it may be performed at any timing. .

    Subsequently, an FPC 286 that is a wiring board for connection is provided on the terminal electrode layer 287 electrically connected to the pixel portion with an anisotropic conductive layer 285 interposed therebetween. The FPC 286 plays a role of transmitting an external signal or potential. Through the above steps, a liquid crystal display device having a display function can be manufactured.

    FIG. 11A shows a top view of a liquid crystal display device. As shown in FIG. 11A, the pixel region 290, the scan line drive region 291a, and the scan line drive region 291b are sealed between the substrate 250 and the counter substrate 280 by a sealant 282, and are formed on the substrate 250. A signal line driver circuit 292 formed by an IC driver is provided. A driving circuit including a thin film transistor 283 and a thin film transistor 284 is provided in the driving region.

    In this embodiment mode, the switching TFT has a double gate structure, but may have a single gate structure or a plurality of multi-gate structures. In the case where a semiconductor is manufactured using a SAS or a crystalline semiconductor, an impurity region can be formed by adding an impurity imparting one conductivity type. In this case, the semiconductor layer may have impurity regions having different concentrations. For example, the vicinity of the channel region of the semiconductor layer and the region stacked with the gate electrode layer may be low-concentration impurity regions, and the outer region may be high-concentration impurity regions.

  As described above, in this embodiment, the process can be simplified. In addition, by forming various components (parts) directly on the substrate using the droplet discharge method, a display panel can be easily used even when a glass substrate of 5th generation or later with one side exceeding 1000 mm is used. Can be manufactured.

According to the present invention, a component constituting a display device can be formed in a desired pattern with good controllability. In addition, there is little material loss, and cost reduction can be achieved. Accordingly, a high-performance and highly reliable liquid crystal display device can be manufactured with high yield.
(Embodiment 3)
An embodiment of the present invention will be described with reference to FIGS. In this embodiment mode, a display device is manufactured using an inverse coplanar thin film transistor as a thin film transistor. Note that an example of a liquid crystal display device using a liquid crystal material as a display element is shown. Therefore, repetitive description of the same portion or a portion having a similar function is omitted. 12A to 17A are top views of the display device, and FIGS. 12B to 17B are lines G- in FIGS. 12A to 17A. FIG.

  In this embodiment also, the photoactive effect of the photocatalytic substance is used to modify the wettability of the irradiated region by changing the light irradiation treatment through the substrate.

    A gate electrode layer 301, a gate electrode layer 303, and a capacitor wiring layer 326 are formed over a light-transmitting substrate 300. In the cross-sectional view of FIG. 12B, the gate electrode layer 301 is divided into a gate electrode region 301a and a gate wiring region 301b. The gate electrode layer 301, the gate electrode layer 303, and the capacitor wiring layer 326 can be formed by a CVD method, a sputtering method, a droplet discharge method, or the like. In this embodiment, a composition containing Ag as a conductive material is selectively discharged by a droplet discharge device 302a and a droplet discharge device 302b, so that the gate electrode layer 301a and the gate electrode layer 301b are formed (FIG. See B).

  Next, the gate insulating layer 304 is formed over the gate electrode layer 301, the gate electrode layer 303, and the capacitor wiring layer 326. The gate insulating layer 304 needs to have a light-transmitting property in order to allow light to pass through when a substance with low wettability formed thereon is decomposed by light irradiation. The gate insulating layer 304 may be formed of a known material such as a silicon oxide material or a nitride material, and may be a stacked layer or a single layer. In this embodiment, a stacked layer of a silicon nitride film, a silicon oxide film, and a silicon nitride film is used.

  In this embodiment mode, a photocatalytic substance is selectively formed in contact with the substance to be treated in order to improve the treatment efficiency by light irradiation. The photocatalytic material absorbs and activates light. The active energy acts on the surrounding material, and as a result, changes the physical properties of the material and modifies it. When the present invention is used, the modification treatment capability is improved by the photocatalytic substance, so that the selection range of the wavelength of light is widened. Therefore, it is possible to select a wavelength in a region where the substance to be processed does not absorb much, and to perform light irradiation for performing surface modification with good controllability. In addition, since the light irradiation efficiency can be improved, sufficient processing can be performed even if the light itself has low energy. Therefore, since the apparatus and the process are simplified, cost and time can be reduced and productivity can be improved.

A photocatalytic material 306a, a photocatalytic material 306b, and a photocatalytic material 306c are selectively formed over the gate insulating layer 304 (see FIG. 13). In this embodiment, titanium oxide (TiO _x ) is used as the photocatalytic substance. The photocatalytic substance may be selectively formed by a droplet discharge method, a printing method, or the like, or may be processed into a desired shape after formation using a mask or the like.

    The photocatalyst material 306a, the photocatalyst material 306b, the photocatalyst material 306c, the gate electrode layer 301, the gate electrode layer 303, and the capacitor wiring layer 326 selectively over the mask layer 305a, the mask layer 305b, the mask layer 305c, the mask layer 305d, and the mask layer 305e. Then, a mask layer 305f, a mask layer 305g, a mask layer 305h, and a mask layer 305i are formed (see FIG. 14). The mask layer 305 a, the mask layer 305 b, the mask layer 305 c, the mask layer 305 d, the mask layer 305 e, the mask layer 305 f, the mask layer 305 g, the mask layer 305 h, and the mask layer 305 i are either a gate electrode layer or a capacitor through the gate insulating layer 304. The wiring layer is selectively formed in a region where the source electrode layer or the drain electrode layer intersects. The mask layer is formed in this manner because the display device in this embodiment has an active matrix structure, and a gate line and a source line intersect with each other with an insulating layer interposed therebetween. In this embodiment mode, the mask layer 305a, the mask layer 305b, the mask layer 305c, the mask layer 305d, the mask layer 305e, the mask layer 305f, the mask layer 305g, the mask layer 305h, and the mask layer 305i are formed using a droplet discharge method using PVA. Formed by. Polyimide or the like may be used as the mask layer.

  A material 330 having low wettability is formed on the mask layer and the photocatalytic material. In this embodiment mode, FAS is used as the material 330 with low wettability, and the material 330 is formed over a wide region (overall coating or the like) by a spin coating method. This wettability is with respect to a composition containing a conductive material constituting a source electrode layer or a drain electrode layer formed in a later step. Although FAS used in this embodiment is decomposed by light of 200 nm or less, the glass substrate absorbs a wavelength of 300 nm or less and does not transmit. When a glass substrate is used as the substrate, it is difficult to irradiate the FAS with light. Therefore, in this embodiment, a titanium oxide layer exhibiting a photocatalytic effect is formed by light irradiation of 380 nm or less. A metal halide lamp that is an ultraviolet lamp that irradiates light with a wavelength of 200 nm to 450 nm is used as a light source. What is necessary is just to select a photocatalyst substance suitably according to the wavelength of the light to be used.

    Next, as a pretreatment for forming the source electrode layer or the drain electrode layer with good controllability, the vicinity of the formation region of the source electrode layer and the drain electrode layer is compared with the surrounding region and modified. The wettability is selectively changed by using the photoactivity of the photocatalytic substance by the light irradiation treatment to form a high wettability region and a low wettability region. The difference in wettability can be confirmed by the contact angle, and the difference in contact angle is 30 degrees or more, preferably 40 degrees or more. In the present invention, in order to improve the efficiency of light irradiation treatment, a photocatalytic substance that is activated at the wavelength of light to be irradiated is formed in contact with the treatment object.

  The photocatalytic substance 306a, the photocatalytic substance 306b, and the photocatalytic substance 306c are irradiated with light 331 from the light-transmitting substrate 300 side through the substrate 300 and the light source 307. The light 331 activates the photocatalyst substance 306a, the photocatalyst substance 306b, and the photocatalyst substance 306c, decomposes the substance 330 having low wettability by the energy, and improves the wettability. A material having low wettability over a region where the photocatalytic substance does not exist, and a region where the photocatalytic substance is not irradiated with light even if the gate electrode layer 301, the gate electrode layer 303, and the capacitor wiring layer 326 serve as a mask. The surface of the material having low wettability is not modified. Due to the irradiation treatment of the light 331 and the photoactive effect of the photocatalytic substance, the surface of the substance 330 with low wettability has a relatively high wettability region 309a, high wettability region 309b, high wettability region 309c, and high wettability. Region 309d, high wettability region 309e, high wettability region 309f, high wettability region 311a, high wettability region 311b, high wettability region 311c, high wettability region 311d, high wettability region 311e, high wettability region 311f, and a low wettability region 310 having a relatively low wettability (FIG. 15B is a cross-sectional view, so the low wettability region 310 is divided into a low wettability region 310a, a low wettability region 310b, and a low wettability region 310c. (See FIG. 15). When the present invention is used, it is only necessary to select a photocatalytic substance in accordance with light, so that the range of light selection is widened. Further, by selectively forming a photocatalytic substance and irradiating light having a wavelength that activates the photocatalytic substance, the modified region can be selected more finely and freely. Therefore, since the apparatus and the process are simplified, cost and time can be reduced and productivity can be improved.

  After control of wettability by light irradiation, the mask layer 305a, the mask layer 305b, the mask layer 305c, the mask layer 305d, the mask layer 305e, the mask layer 305f, the mask layer 305g, the mask layer 305h, and the mask layer 305i are formed. Remove all materials with low wettability. In this embodiment mode, the mask layer 305a, the mask layer 305b, the mask layer 305c, the mask layer 305d, the mask layer 305e, the mask layer 305f, the mask layer 305g, the mask layer 305h, and the mask layer 305i are removed by washing with water. A material having low wettability is formed in the region where the mask layer 305a, the mask layer 305b, the mask layer 305c, the mask layer 305d, the mask layer 305e, the mask layer 305f, the mask layer 305g, the mask layer 305h, and the mask layer 305i are provided. Since it is not formed, the wettability is higher than the low wettability region in which a material with relatively low wettability is formed, as in the region where the wettability is increased by light irradiation.

      High wettability region 309a, high wettability region 309b, high wettability region 309c, high wettability region 309d, high wettability region 309e, high wettability region 309f, high wettability region 311a, high wettability region 311b, high wettability The conductive region 311c, the highly wettable region 311d, the highly wettable region 311e, and the highly wettable region 311f are supplied with a composition containing a conductive material from the droplet discharge device 312a, the droplet discharge device 312b, and the droplet discharge device 312c. Discharging, source or drain electrode layer 313a, source or drain electrode layer 313b, source or drain electrode layer 313c, source or drain electrode layer 314a, source or drain electrode layer 314b, source electrode Layer or drain electrode layer 314c, source electrode layer or drain electrode layer 314d, source electrode layer or drain In the electrode layer 314 e, to form the source or drain electrode layer 314f (see FIG. 16.). In this embodiment, Ag is used as the conductive material. Even when the pattern material ejection method cannot be precisely controlled depending on the size of the ejection port of the nozzle from which the liquid droplets are ejected, the scanning capability of the ejection port, etc., a process for improving wettability is applied to the formation region. As a result, the droplets adhere only to the formation region and are formed in a desired pattern. This is because the wettability is different between the formation region and the surrounding region, so that the droplet is repelled in the low wettability region and remains in the formation region with higher wettability. That is, since the droplets are repelled by the low wettability region, it functions as if there is a partition wall (bank) at the boundary between the high wettability region and the low wettability region. Therefore, even a composition including a conductive material having fluidity remains in the highly wettable region, so that the source electrode layer or the drain electrode layer can be formed in a desired shape. The source or drain electrode layer 313a, the source or drain electrode layer 313b, and the source or drain electrode layer 313c also function as a source wiring layer.

    With the present invention, when it is desired to form a fine pattern such as an electrode layer, the droplet does not spread on the formation region even if the droplet discharge port is somewhat large, and the conductive layer is formed only in the formation region. It is possible to prevent defects such as a short circuit due to erroneous formation in a non-formation region. The thickness of the wiring can also be controlled. When the surface of the material is modified by light irradiation from the substrate side as in this embodiment mode, not only can the pattern be formed with high controllability, but also a large area can be processed, so that productivity is improved. Further, by combining the droplet discharge method, material loss can be prevented and costs can be reduced as compared with the entire surface coating formation by spin coating method or the like. According to the present invention, it is possible to form wirings and the like with good controllability even if they are designed to be densely arranged in a complicated manner by downsizing and thinning.

  In this embodiment, light irradiation is performed on the low wettability region 310a, the low wettability region 310b, and the low wettability region 310c to decompose a substance with low wettability and perform processing to increase wettability. After that, the semiconductor layer 315a, the semiconductor layer 315b, the semiconductor layer 315c, the semiconductor layer 315d, the semiconductor layer 315e, and the semiconductor layer 315f are formed by a droplet discharge method using pentacene, so that an inverse coplanar thin film transistor is formed.

Subsequently, the source or drain electrode layer 314a, the source or drain electrode layer 314b, the source or drain electrode layer 314c, the source or drain electrode layer 314d, the source or drain electrode layer 314e, and the source electrode The pixel electrode layer 316a, the pixel electrode layer 316b, the pixel electrode layer 316c, and the pixel electrode layer 316d are formed by selectively discharging a composition containing a conductive material in contact with the layer or drain electrode layer 314f (FIG. 17). reference.). Needless to say, when the pixel electrode layer 316a, the pixel electrode layer 316b, the pixel electrode layer 316c, and the pixel electrode layer 316d are formed, a pretreatment for forming a low wettability region and a high wettability region may be performed. By discharging a composition containing a conductive material into the highly wettable region, the pixel electrode layer 316a, the pixel electrode layer 316b, the pixel electrode layer 316c, and the pixel electrode layer 316d can be selectively formed with better controllability. . The pixel electrode layer 316a, the pixel electrode layer 316b, the pixel electrode layer 316c, and the pixel electrode layer 316d can be formed using a material similar to that of the first electrode layer 119 described above. When a transmissive liquid crystal display panel is manufactured, Is formed in a predetermined pattern from a composition containing indium tin oxide (ITO), indium tin oxide containing silicon oxide (ITSO), zinc oxide (ZnO), tin oxide (SnO ₂ ), etc., and formed by firing. You may do it. Of course, the material may be formed by vapor deposition (PVD, CVD), sputtering, or the like. In this embodiment, indium tin oxide (ITO) is used for the pixel electrode layer 316a, the pixel electrode layer 316b, the pixel electrode layer 316c, and the pixel electrode layer 316d.

  Next, an insulating layer 317 called an alignment film is formed by a printing method or a spin coating method so as to cover the pixel electrode layer 316a, the pixel electrode layer 316b, the pixel electrode layer 316c, the pixel electrode layer 316d, and the thin film transistor. Note that the insulating layer 317 can be selectively formed by a screen printing method or an offset printing method. Then, rubbing is performed. Subsequently, a sealing material is formed in a peripheral region where pixels are formed by a droplet discharge method.

  After that, an insulating layer 319 functioning as an alignment film, a colored layer 321 functioning as a color filter, a conductor layer 320 functioning as a counter electrode, a counter substrate 322 provided with a polarizing plate 323 and a substrate 300 as a TFT substrate are separated from each other by a spacer. And a liquid crystal layer 318 is provided in the gap, so that a liquid crystal display panel can be manufactured (see FIG. 17B). A polarizing plate 324 is also provided on the side opposite to the side having the elements of the substrate 300. A filler may be mixed in the sealing material, and a shielding film (black matrix) or the like may be formed on the counter substrate 322. Note that as a method for forming the liquid crystal layer, a dispenser type (dropping type) or a dip type (pumping type) in which liquid crystal is injected using a capillary phenomenon after the substrate 300 having an element and the counter substrate 322 are bonded to each other is used. be able to.

A connection portion is formed to connect the inside of the display device formed by the above steps and an external wiring board. The insulator layer in the connection portion is removed by ashing using oxygen gas at or near atmospheric pressure. This treatment is performed using oxygen gas and one or more selected from hydrogen, CF ₄ , NF ₃ , H ₂ O, and CHF ₃ . In this step, in order to prevent damage and destruction due to static electricity, ashing is performed after sealing using the counter substrate. However, if there is little influence from static electricity, it may be performed at any timing. .

    Subsequently, an FPC which is a wiring board for connection is provided on the terminal electrode layer electrically connected to the pixel portion through an anisotropic conductive layer. The FPC is responsible for transmitting external signals and potentials. Through the above steps, a liquid crystal display device having a display function can be manufactured.

    In this embodiment mode, the switching TFT has a single gate structure, but may have a double gate structure or a plurality of multi-gate structures. In the case where a semiconductor is manufactured using a SAS or a crystalline semiconductor, an impurity region can be formed by adding an impurity imparting one conductivity type. In this case, the semiconductor layer may have impurity regions having different concentrations. For example, the vicinity of the channel region of the semiconductor layer and the region stacked with the gate electrode layer may be low-concentration impurity regions, and the outer region may be high-concentration impurity regions.

  As described above, in this embodiment, the process can be simplified. In addition, by forming various components (parts) directly on the substrate using the droplet discharge method, a display panel can be easily used even when a glass substrate of 5th generation or later with one side exceeding 1000 mm is used. Can be manufactured.

According to the present invention, a component constituting a display device can be formed in a desired pattern with good controllability. In addition, there is little material loss, and cost reduction can be achieved. Accordingly, a high-performance and highly reliable liquid crystal display device can be manufactured with high yield.
(Embodiment 4)
A thin film transistor is formed by applying the present invention, and a display device can be formed using the thin film transistor. When a light emitting element is used and an N-type transistor is used as a transistor for driving the light emitting element, The light emitted from the light emitting element performs any one of bottom emission, top emission, and dual emission. Here, a stacked structure of light-emitting elements corresponding to any case will be described with reference to FIGS.

In this embodiment mode, channel protective thin film transistors 461, 471, and 481 to which the present invention is applied are used. The thin film transistor 481 is provided over a light-transmitting substrate 480 and includes a gate electrode layer 493, a gate insulating film 497a, a gate insulating film 497b, a gate insulating film 497c, a semiconductor layer 494, an n-type semiconductor layer 495, and a source electrode layer. Alternatively, the drain electrode layer 487 and the channel protective layer 496 are formed. In this embodiment, a crystalline semiconductor layer is used as the semiconductor layer, and an n-type semiconductor layer is used as the one-conductivity-type semiconductor layer. Instead of forming an n-type semiconductor layer, conductivity may be imparted to the semiconductor layer by performing plasma treatment with a PH ₃ gas. The semiconductor layer is not limited to this embodiment mode, and an amorphous semiconductor layer can also be used as shown in Embodiment Mode 1. In the case where a crystalline semiconductor layer such as polysilicon is used as in this embodiment mode, an impurity having one conductivity type is formed by introducing (adding) an impurity into the crystalline semiconductor layer without forming a one conductivity type semiconductor layer. A region may be formed. Alternatively, an organic semiconductor such as pentacene can be used. When the organic semiconductor is selectively formed by a droplet discharge method or the like, the process of processing into a desired shape can be simplified.

  In this embodiment, an amorphous semiconductor layer is crystallized as the semiconductor layer 494 to form a crystalline semiconductor layer. In the crystallization step, an element (also referred to as a catalyst element or a metal element) that promotes crystallization is added to the amorphous semiconductor layer, and crystallization is performed by heat treatment (at 550 ° C. to 650 ° C. for 5 minutes to 24 hours). As elements for promoting crystallization, metal elements for promoting crystallization of silicon include iron (Fe), nickel (Ni), cobalt (Co), ruthenium (Ru), rhodium (Rh), palladium (Pd). One or plural types selected from osmium (Os), iridium (Ir), platinum (Pt), copper (Cu), and gold (Au) can be used. In this embodiment, nickel is used.

  In order to remove or reduce the element that promotes crystallization from the crystalline semiconductor layer, a semiconductor layer containing an impurity element is formed in contact with the crystalline semiconductor layer and functions as a gettering sink. As the impurity element, an impurity element imparting n-type conductivity, an impurity element imparting p-type conductivity, a rare gas element, or the like can be used. For example, phosphorus (P), nitrogen (N), arsenic (As), antimony (Sb ), Bismuth (Bi), boron (B), helium (He), neon (Ne), argon (Ar), Kr (krypton), and Xe (xenon) can be used. In this embodiment, a semiconductor layer including an impurity element functioning as a gettering sink is formed using an n-type semiconductor layer including phosphorus (P) that is an impurity element imparting n-type conductivity. An n-type semiconductor layer is formed over the crystalline semiconductor layer containing an element that promotes crystallization, and heat treatment is performed (at 550 ° C. to 650 ° C. for 5 minutes to 24 hours). The element that promotes crystallization contained in the crystalline semiconductor layer moves into the semiconductor layer having n-type, and the element that promotes crystallization in the crystalline semiconductor layer is removed or reduced. It is formed. On the other hand, the n-type semiconductor layer becomes the n-type semiconductor layer 495 including a metal element which is an element that promotes crystallinity. In this manner, the n-type semiconductor layer 495 functions as a gettering sink of the semiconductor layer 494 and also functions as a source region and a drain region as it is.

  In this embodiment mode, the crystallization step and the gettering step of the semiconductor layer are performed by a plurality of heat treatments; however, the crystallization step and the gettering step can be performed by a single heat treatment. In this case, an amorphous semiconductor layer is formed, an element that promotes crystallization is added, a semiconductor layer serving as a gettering sink is formed, and then heat treatment is performed.

  In this embodiment, the gate insulating layer is formed by stacking a plurality of layers, a silicon nitride oxide film is stacked as the gate insulating film 497a, and a silicon oxynitride film is stacked as the gate insulating film 497b, and then the gate is formed over the silicon oxynitride film. A silicon nitride oxide film with a thickness of 0.3 nm to 5 nm is formed as the insulating film 497c to have a three-layer structure. With such a structure, the gettering efficiency of the metal element in the semiconductor layer is increased, and the adverse effect of the silicon nitride film on the semiconductor layer can be reduced. The insulating layer to be stacked is preferably formed continuously while switching the reaction gas at the same temperature without breaking the vacuum in the same chamber. If formed continuously without breaking the vacuum, it is possible to prevent the interface between the stacked films from being contaminated.

    A photocatalytic substance 499 and a substance 490 with low wettability are formed over the channel protective layer 496 and the n-type semiconductor layer 495. In this embodiment mode, the photocatalytic substance 499 is irradiated with light from the light-transmitting substrate side, and the photocatalytic substance 499 is activated by light that is not blocked by the gate electrode layer 493, so that the surface of the substance 490 with low wettability is used. To reform. As light, light having a wavelength that activates the photocatalytic substance is irradiated. Due to the energy generated by the activation of the photocatalytic substance, the modification treatment ability by light irradiation is improved. By selecting the photocatalyst substance, the selection range of the wavelength of light to be irradiated is widened, so that it is possible to select light that avoids the wavelength absorbed by the light-transmitting substrate.

  In this embodiment mode, the surface of the substance 490 having low wettability with respect to the composition containing a conductive material is higher than that of the surface over which the gate electrode layer 493 overlaps with the channel protective layer 496 serving as a mask by light irradiation. It has been modified to be wettable. Accordingly, a high wettability region 492a, a high wettability region 492b, which are relatively high wettability regions, and a low wettability region 491 which is a relatively low wettability region are formed on the surface of the material 490 having low wettability. . Since the low wettability region 491 on the surface of the channel protective layer has lower wettability than the high wettability region 492a and the high wettability region 492b on the surrounding N-type semiconductor surface, the composition containing a conductive material does not adhere to the surface. The source or drain electrode layer 487 is formed with high controllability in the high wettability region 492a and the high wettability region 492b with high wettability. The substance having low wettability used in this embodiment is FAS, which is a monomolecular ultrathin film, and thus does not insulate the n-type semiconductor layer from the electrode layer. Whether to have conductivity or insulation may be determined as appropriate depending on the structure to be formed, such as material and film thickness.

  In the thin film transistor 481, a substance having low wettability with respect to a composition containing a conductive material is formed over the channel protective layer. In the case where this substance has low wettability with respect to the insulating layer 498 formed so as to cover the thin film transistor 481, there is a possibility that poor formation of the insulating layer 498 such as lower adhesion may occur. It is preferable to remove a low substance or perform irradiation treatment to improve the wettability. This process is not necessarily required when the insulating layer is formed by vapor deposition, CVD, sputtering, or the like. An insulating layer 498 covering the thin film transistor 481 in FIG. 21A is formed by an evaporation method, and an example in which no treatment is performed on a low wettability substance over a channel protective layer is shown. Since the insulating layer 478 covering the thin film transistor 471 in FIG. 21C is formed using a droplet discharge method, light is applied to the low wettability region 491 before the insulating layer 498 is formed, so that wettability is increased. An example of processing is shown.

  For the channel protective layer 496, polyimide, polyvinyl alcohol, or the like may be dropped by a droplet discharge method. As a result, the exposure process can be omitted. As the channel protective layer, inorganic materials (silicon oxide, silicon nitride, silicon oxynitride, silicon nitride oxide, etc.), photosensitive or non-photosensitive organic materials (organic resin materials) (polyimide, acrylic, polyamide, polyimide amide, resist) , Benzocyclobutene, etc.), a low dielectric constant material, or a film made of a plurality of kinds, or a stack of these films can be used. Alternatively, a material having siloxane may be used. As a manufacturing method, a vapor deposition method such as a plasma CVD method or a thermal CVD method, or a sputtering method can be used. Alternatively, a droplet discharge method or a printing method (a method for forming a pattern such as screen printing or offset printing) can be used. A film obtained by a coating method can also be used.

  First, the case where light is emitted to the substrate 480 side, that is, the case where bottom emission is performed will be described with reference to FIG. In this case, the first electrode layer 484, the electroluminescent layer 485, and the second electrode layer 486 are stacked in this order in contact with the source or drain electrode layer 487 so as to be electrically connected to the thin film transistor 481. The substrate 480 through which light is transmitted needs to have a light-transmitting property with respect to at least light in the visible region. Next, the case where radiation is performed on the side opposite to the substrate 460, that is, the case where top surface radiation is performed will be described with reference to FIG. The thin film transistor 461 can be formed in a manner similar to that of the thin film transistor described above.

  A source or drain electrode layer 462 which is electrically connected to the thin film transistor 461 is in contact with and electrically connected to the first electrode layer 463. A first electrode layer 463, an electroluminescent layer 464, and a second electrode layer 465 are stacked in this order. The source or drain electrode layer 462 is a reflective metal layer, and reflects light emitted from the light emitting element to the upper surface of the arrow. Since the source or drain electrode layer 462 is stacked with the first electrode layer 463, a light-transmitting material is used for the first electrode layer 463 even if light is transmitted. Is reflected by the source or drain electrode layer 462 and radiates to the side opposite to the substrate 460. Needless to say, the first electrode layer 463 may be formed using a reflective metal film. Since light emitted from the light-emitting element is emitted through the second electrode layer 465, the second electrode layer 465 is formed using a light-transmitting material at least in the visible region. Finally, the case where light is emitted to the substrate 470 side and the opposite side, that is, the case where dual emission is performed will be described with reference to FIG. The thin film transistor 471 is also a channel protective thin film transistor. The first electrode layer 472 is electrically connected to the source or drain electrode layer 477 which is electrically connected to the semiconductor layer of the thin film transistor 471. A first electrode layer 472, an electroluminescent layer 473, and a second electrode layer 474 are stacked in this order. At this time, when both the first electrode layer 472 and the second electrode layer 474 are formed with a light-transmitting material or a thickness capable of transmitting light at least in the visible region, dual emission is realized. In this case, the insulating layer through which light is transmitted and the substrate 470 also need to have a light-transmitting property with respect to at least light in the visible region.

  A mode of a light-emitting element which can be applied in this embodiment mode is shown in FIG. The light-emitting element has a structure in which an electroluminescent layer 860 is sandwiched between a first electrode layer 870 and a second electrode layer 850. It is necessary to select materials for the first electrode layer and the second electrode layer in consideration of the work function, and the first electrode layer and the second electrode layer are both anodes or cathodes depending on the pixel configuration. sell. In this embodiment mode, since the polarity of the driving TFT is an N-channel type, it is preferable that the first electrode layer be a cathode and the second electrode layer be an anode. In the case where the polarity of the driving TFT is a p-channel type, the first electrode layer may be an anode and the second electrode layer may be a cathode.

  22A and 22B show the case where the first electrode layer 870 is an anode and the second electrode layer 850 is a cathode. The electroluminescent layer 860 is formed from the first electrode layer 870 side. , HIL (hole injection layer) HTL (hole transport layer) 804, EML (light emitting layer) 803, ETL (electron transport layer) EIL (electron injection layer) 802, and second electrode layer 850 are preferably stacked in this order. FIG. 22A illustrates a structure in which light is emitted from the first electrode layer 870. The first electrode layer 870 includes the electrode layer 805 formed using a light-transmitting oxide conductive material, The electrode layer includes an electrode layer 801 containing an alkali metal or alkaline earth metal such as LiF or MgAg and an electrode layer 800 formed of a metal material such as aluminum from the electroluminescent layer 860 side. FIG. 22B illustrates a structure in which light is emitted from the second electrode layer 850. The first electrode layer is formed using a metal such as aluminum or titanium or nitrogen at a concentration equal to or lower than the stoichiometric composition ratio with the metal. An electrode layer 807 formed of a metal material containing silicon, and a second electrode layer 806 formed of an oxide conductive material containing silicon oxide at a concentration of 1 to 15 atomic%. The second electrode layer is composed of an electrode layer 801 containing an alkali metal or alkaline earth metal such as LiF or MgAg and an electrode layer 800 formed of a metal material such as aluminum from the electroluminescent layer 860 side. However, it is possible to emit light from the second electrode layer 850 by setting each layer to a thickness of 100 nm or less so that light can be transmitted.

  22C and 22D show the case where the first electrode layer 870 is a cathode and the second electrode layer 850 is an anode, and the electroluminescent layer 860 has an EIL (electron injection layer) from the cathode side. ) ETL (electron transport layer) 802, EML (light emitting layer) 803, HTL (hole transport layer) HIL (hole injection layer) 804, and second electrode layer 850 which is an anode are preferably stacked in this order. FIG. 22C illustrates a structure in which light is emitted from the first electrode layer 870. The first electrode layer 870 includes an electrode layer containing an alkali metal or an alkaline earth metal such as LiF or MgAg from the electroluminescent layer 860 side. 801 and an electrode layer 800 formed of a metal material such as aluminum, but each layer emits light from the first electrode layer 870 by setting the thickness to 100 nm or less so that light can be transmitted. It becomes possible to do. The second electrode layer includes, from the electroluminescent layer 860 side, a second electrode layer 806 formed of an oxide conductive material containing silicon oxide at a concentration of 1 to 15 atomic%, a metal such as aluminum or titanium, or the The electrode layer 807 is formed of a metal material containing nitrogen at a concentration equal to or lower than the stoichiometric composition ratio of metal. FIG. 22D illustrates a structure in which light is emitted from the second electrode layer 850. The first electrode layer 870 includes an electrode layer containing an alkali metal or an alkaline earth metal such as LiF or MgAg from the electroluminescent layer 860 side. 801 and an electrode layer 800 formed of a metal material such as aluminum. The film thickness is large enough to reflect light emitted from the electroluminescent layer 860. The second electrode layer 850 includes an electrode layer 805 made of an oxide conductive material that transmits at least light in the visible region. The electroluminescent layer can have a single layer structure or a mixed structure in addition to the laminated structure.

  In addition, as the electroluminescent layer, materials that emit red (R), green (G), and blue (B) light are selectively formed by an evaporation method using an evaporation mask, respectively. A material that emits red (R), green (G), and blue (B) light can be formed by a droplet discharge method (such as a low-molecular or high-molecular material) in the same manner as a color filter. In this case, a mask is not used. Both are preferable because RGB can be separately applied.

In the case of a top emission type, when light-transmitting ITO or ITSO is used for the second electrode layer, BzOs—Li in which Li is added to a benzoxazole derivative (BzOs) or the like can be used. Further, for example, EML may be Alq ₃ doped with a dopant corresponding to each emission color of R, G, and B (DCM in the case of R, DMQD in the case of G).

  Note that the electroluminescent layer is not limited to the above materials. For example, instead of CuPc or PEDOT, an oxide such as molybdenum oxide (MoOx: x = 2 to 3) and α-NPD or rubrene can be co-evaporated to improve the hole injection property. The material of the electroluminescent layer can be used as an organic material (including a low molecule or a polymer), or a composite material of an organic material and an inorganic material. Hereinafter, materials for forming the light emitting element will be described in detail.

Among the charge injecting and transporting substances, particularly, a substance having a high electron transporting property includes, for example, tris (8-quinolinolato) aluminum (abbreviation: Alq ₃ ), tris (4-methyl-8-quinolinolato) aluminum (abbreviation: Almq ₃ ), Bis (10-hydroxybenzo [h] -quinolinato) beryllium (abbreviation: BeBq ₂ ), bis (2-methyl-8-quinolinolato) -4-phenylphenolato-aluminum (abbreviation: BAlq), quinoline skeleton or benzoquinoline Examples thereof include metal complexes having a skeleton. As a substance having a high hole-transport property, for example, 4,4′-bis [N- (1-naphthyl) -N-phenyl-amino] -biphenyl (abbreviation: α-NPD), 4,4′-bis [ N- (3-methylphenyl) -N-phenyl-amino] -biphenyl (abbreviation: TPD) or 4,4 ′, 4 ″ -tris (N, N-diphenyl-amino) -triphenylamine (abbreviation: TDATA) ), 4,4 ′, 4 ″ -tris [N- (3-methylphenyl) -N-phenyl-amino] -triphenylamine (abbreviation: MTDATA) (ie, benzene ring-nitrogen) And a compound having a bond of

Among the charge injecting and transporting materials, materials having particularly high electron injecting properties include alkali metals or alkaline earths such as lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF ₂ ) and the like. Metal compounds can be mentioned. In addition, a mixture of a substance having a high electron transport property such as Alq ₃ and an alkaline earth metal such as magnesium (Mg) may be used.

Among the charge injecting and transporting materials, examples of the material having a high hole injecting property include molybdenum oxide (MoOx), vanadium oxide (VOx), ruthenium oxide (RuOx), tungsten oxide (WOx), and manganese oxide. Examples thereof include metal oxides such as (MnOx). In addition, phthalocyanine compounds such as phthalocyanine (abbreviation: H ₂ Pc) and copper phthalocyanine (CuPc) can be given.

  The light emitting layer may be configured to perform color display by forming light emitting layers having different emission wavelength bands for each pixel. Typically, a light emitting layer corresponding to each color of R (red), G (green), and B (blue) is formed. In this case as well, it is possible to improve color purity and prevent mirror reflection (reflection) of the pixel portion by providing a filter that transmits light in the emission wavelength band on the light emission side of the pixel. Can do. By providing the filter, it is possible to omit a circularly polarized plate that has been conventionally required, and it is possible to eliminate the loss of light emitted from the light emitting layer. Furthermore, a change in color tone that occurs when the pixel portion (display screen) is viewed obliquely can be reduced.

There are various kinds of light emitting materials. As the low-molecular organic light-emitting material, 4-dicyanomethylene-2-methyl-6- [2- (1,1,7,7-tetramethyl-9-julolidyl) ethenyl] -4H-pyran (abbreviation: DCJT), 4 -Dicyanomethylene-2-t-butyl-6- [2- (1,1,7,7-tetramethyljulolidin-9-yl) ethenyl] -4H-pyran (abbreviation: DCJTB), perifrantene, 2,5 -Dicyano-1,4-bis [2- (10-methoxy-1,1,7,7-tetramethyljulolidin-9-yl) ethenyl] benzene, N, N'-dimethylquinacridone (abbreviation: DMQd), Coumarin 6, Coumarin 545T, Tris (8-quinolinolato) aluminum (abbreviation: Alq ₃ ), 9,9′-bianthryl, 9,10-diphenylanthracene (abbreviation: DPA) and 9,10-bis (2-naphthyl) anthrace (Abbreviation: DNA) or the like can be used. Other substances may also be used.

  On the other hand, the high molecular organic light emitting material has higher physical strength than the low molecular weight material, and the durability of the device is high. In addition, since the film can be formed by coating, the device can be manufactured relatively easily. The structure of the light emitting element using the high molecular weight organic light emitting material is basically the same as that when the low molecular weight organic light emitting material is used, and sequentially becomes a cathode, an organic light emitting layer, and an anode. However, when forming a light emitting layer using a high molecular weight organic light emitting material, it is difficult to form a laminated structure as in the case of using a low molecular weight organic light emitting material. . Specifically, the structure is a cathode, a light emitting layer, a hole transport layer, and an anode in this order.

  Since the light emission color is determined by the material for forming the light emitting layer, a light emitting element exhibiting desired light emission can be formed by selecting these materials. Examples of the polymer electroluminescent material that can be used for forming the light emitting layer include polyparaphenylene vinylene, polyparaphenylene, polythiophene, and polyfluorene.

  The polyparaphenylene vinylene system includes derivatives of poly (paraphenylene vinylene) [PPV], poly (2,5-dialkoxy-1,4-phenylene vinylene) [RO-PPV], poly (2- (2′- Ethyl-hexoxy) -5-methoxy-1,4-phenylenevinylene) [MEH-PPV], poly (2- (dialkoxyphenyl) -1,4-phenylenevinylene) [ROPh-PPV] and the like. The polyparaphenylene series includes derivatives of polyparaphenylene [PPP], poly (2,5-dialkoxy-1,4-phenylene) [RO-PPP], poly (2,5-dihexoxy-1,4-phenylene). ) And the like. The polythiophene series includes polythiophene [PT] derivatives, poly (3-alkylthiophene) [PAT], poly (3-hexylthiophene) [PHT], poly (3-cyclohexylthiophene) [PCHT], poly (3-cyclohexyl). -4-methylthiophene) [PCHMT], poly (3,4-dicyclohexylthiophene) [PDCHT], poly [3- (4-octylphenyl) -thiophene] [POPT], poly [3- (4-octylphenyl) -2,2 bithiophene] [PTOPT] and the like. Examples of the polyfluorene series include polyfluorene [PF] derivatives, poly (9,9-dialkylfluorene) [PDAF], poly (9,9-dioctylfluorene) [PDOF], and the like.

  Note that when a hole-transporting polymer-based organic light-emitting material is sandwiched between an anode and a light-emitting polymer-based organic light-emitting material, hole injection properties from the anode can be improved. In general, an acceptor material dissolved in water is applied by spin coating or the like. In addition, since it is insoluble in an organic solvent, it can be stacked with the above-described light-emitting organic light-emitting material. Examples of the hole-transporting polymer organic light emitting material include a mixture of PEDOT and camphor sulfonic acid (CSA) as an acceptor material, a mixture of polyaniline [PANI] and polystyrene sulfonic acid [PSS] as an acceptor material, and the like. .

  The light emitting layer can be configured to emit monochromatic or white light. In the case of using a white light emitting material, color display can be made possible by providing a filter (colored layer) that transmits light of a specific wavelength on the light emission side of the pixel.

To form a light emitting layer that emits white light, for _{example, Alq 3, Alq 3, Alq} 3 doped with Nile Red which is partly red light emitting pigment, p-EtTAZ, by TPD (aromatic diamine) evaporation A white color can be obtained by sequentially laminating. Moreover, when forming a light emitting layer by the apply | coating method using spin coating, after apply | coating, it is preferable to bake by vacuum heating. For example, a poly (ethylenedioxythiophene) / poly (styrenesulfonic acid) aqueous solution (PEDOT / PSS) that acts as a hole injection layer is applied and baked on the entire surface, and then a luminescent center dye (1, 1,4,4-tetraphenyl-1,3-butadiene (TPB), 4-dicyanomethylene-2-methyl-6- (p-dimethylamino-styryl) -4H-pyran (DCM1), Nile Red, Coumarin 6 Etc.) A doped polyvinyl carbazole (PVK) solution may be applied to the entire surface and fired.

  The light emitting layer can also be formed as a single layer, and an electron transporting 1,3,4-oxadiazole derivative (PBD) may be dispersed in hole transporting polyvinyl carbazole (PVK). Further, white light emission can be obtained by dispersing 30 wt% PBD as an electron transporting agent and dispersing an appropriate amount of four kinds of dyes (TPB, coumarin 6, DCM1, Nile red). In addition to the light-emitting element that can emit white light as shown here, a light-emitting element that can obtain red light emission, green light emission, or blue light emission can be manufactured by appropriately selecting the material of the light-emitting layer.

  Furthermore, a triplet excitation material containing a metal complex or the like may be used for the light emitting layer in addition to a singlet excitation light emitting material. For example, among red light emitting pixels, green light emitting pixels, and blue light emitting pixels, a red light emitting pixel having a relatively short luminance half time is formed of a triplet excitation light emitting material, and the other A singlet excited light emitting material is used. The triplet excited luminescent material has a feature that the light emission efficiency is good, so that less power is required to obtain the same luminance. That is, when applied to a red pixel, the amount of current flowing through the light emitting element can be reduced, so that reliability can be improved. As a reduction in power consumption, a red light-emitting pixel and a green light-emitting pixel may be formed using a triplet excitation light-emitting material, and a blue light-emitting pixel may be formed using a singlet excitation light-emitting material. By forming a green light-emitting element having high human visibility with a triplet excited light-emitting material, power consumption can be further reduced.

  Examples of triplet excited luminescent materials include those using a metal complex as a dopant, and metal complexes having a third transition series element platinum as the central metal and metal complexes having iridium as the central metal are known. Yes. The triplet excited light-emitting material is not limited to these compounds, and it is also possible to use a compound having the above structure and having an element belonging to Group 8 to 10 of the periodic table as a central metal.

  The substances forming the light-emitting layer listed above are examples, and functionalities such as a hole injection transport layer, a hole transport layer, an electron injection transport layer, an electron transport layer, a light emission layer, an electron block layer, and a hole block layer are included. A light emitting element can be formed by appropriately stacking each layer. Moreover, you may form the mixed layer or mixed junction which combined these each layer. The layer structure of the light-emitting layer can be changed, and instead of having a specific electron injection region or light-emitting region, an electrode layer for this purpose is provided, or a light-emitting material is dispersed. Modifications can be made without departing from the spirit of the present invention.

  A light-emitting element formed using the above materials emits light by being forward-biased. A pixel of a display device formed using a light-emitting element can be driven by a simple matrix method or an active matrix method as described in Embodiment 2. In any case, each pixel emits light by applying a forward bias at a specific timing, but is in a non-light emitting state for a certain period. By applying a reverse bias during this non-light emitting time, the reliability of the light emitting element can be improved. The light emitting element has a degradation mode in which the light emission intensity decreases under a constant driving condition and a degradation mode in which the non-light emitting area is enlarged in the pixel and the luminance is apparently decreased. However, alternating current that applies a bias in the forward and reverse directions. By performing a typical drive, the progress of deterioration can be slowed and the reliability of the light emitting device can be improved. Further, either digital driving or analog driving can be applied.

  Therefore, although not illustrated in FIG. 21, a color filter (colored layer) may be formed over a sealing substrate facing a substrate having elements. The color filter (colored layer) can be selectively formed by a droplet discharge method. When a color filter (colored layer) is used, high-definition display can be performed. This is because the color filter (colored layer) can correct a broad peak to be sharp in the emission spectrum of each RGB.

  As described above, the case where a material that emits light of each RGB is formed has been described. However, full color display can be performed by forming a material that emits light of a single color and combining a color filter and a color conversion layer. The color filter (colored layer) and the color conversion layer may be formed on, for example, a sealing substrate and attached to the substrate. In addition, as described above, any of the material that emits monochromatic light, the color filter (colored layer), and the color conversion layer can be formed by a droplet discharge method.

  Of course, monochromatic light emission may be displayed. For example, an area color type display device may be formed using monochromatic light emission. As the area color type, a passive matrix type display unit is suitable, and characters and symbols can be mainly displayed.

In the above configuration, a material having a low work function can be used as the cathode, and for example, Ca, Al, CaF, MgAg, AlLi, or the like is desirable. The electroluminescent layer may be any of a single layer type, a laminated type, and a mixed type having no layer interface. It is also formed from singlet materials, triplet materials, or combinations thereof, charge injection / transport materials containing organic compounds or inorganic compounds, and light-emitting materials, and low molecular organic compounds and medium molecular organic compounds (sublimation) based on the number of molecules. And an organic compound having a molecular number of 20 or less, or a chained molecule length of 10 μm or less), including one or more layers selected from high molecular organic compounds, and an electron You may combine with the injection | pouring transport property or the hole injection transport property inorganic compound. The first electrode layer 484, the second electrode layer 465, the first electrode layer 472, and the second electrode layer 474 are formed using a transparent conductive film that transmits light. For example, indium oxide in addition to ITO and ITSO A transparent conductive film formed using a target mixed with 2 to 20 wt% zinc oxide (ZnO) is used. Note that plasma treatment in an oxygen atmosphere or heat treatment in a vacuum atmosphere is preferably performed before the first electrode layer 484, the first electrode layer 463, and the first electrode layer 472 are formed. A partition wall (also referred to as a bank) is formed using a material containing silicon, an organic material, and a compound material. A porous film may be used. However, it is preferable to use a photosensitive or non-photosensitive material such as acrylic or polyimide because the side surface has a shape in which the radius of curvature continuously changes and the upper thin film is formed without being cut off. This embodiment mode can be freely combined with the above embodiment modes.
(Embodiment 5)
Next, a mode in which a driver circuit for driving is mounted on the display panel manufactured by Embodiment Modes 4 to 7 will be described.

  First, a display device employing a COG method is described with reference to FIG. A pixel portion 2701 for displaying information such as characters and images is provided over the substrate 2700. A substrate provided with a plurality of driving circuits is divided into rectangular shapes, and a driver IC 2751 which is a divided driving circuit is mounted on the substrate 2700. FIG. 30A shows a mode in which a plurality of driver ICs 2751 and an FPC 2750 are mounted on top of the driver ICs 2751. Further, the size to be divided may be substantially the same as the length of the side of the pixel portion on the signal line side, and a tape may be mounted on the tip of the driver IC on a single driver IC.

  Alternatively, a TAB method may be employed. In that case, a plurality of tapes may be attached and driver ICs may be mounted on the tapes as shown in FIG. As in the case of the COG method, a single driver IC may be mounted on a single tape. In this case, a metal piece or the like for fixing the driver IC may be attached together due to strength problems.

  A plurality of driver ICs mounted on these display panels may be formed on a rectangular substrate having a side of 300 mm to 1000 mm or more from the viewpoint of improving productivity.

  That is, a plurality of circuit patterns having a drive circuit portion and an input / output terminal as one unit may be formed on the substrate, and finally divided and taken out. The long side of the driver IC may be formed in a rectangular shape having a long side of 15 to 80 mm and a short side of 1 to 6 mm in consideration of the length of one side of the pixel portion and the pixel pitch. Or a length obtained by adding one side of the pixel portion and one side of each driver circuit.

  The advantage of the external dimensions of the driver IC over the IC chip lies in the length of the long side. When a driver IC formed with a long side of 15 to 80 mm is used, the number required for mounting corresponding to the pixel portion is as follows. This is less than when an IC chip is used, and the manufacturing yield can be improved. Further, when a driver IC is formed over a glass substrate, the shape of the substrate used as a base is not limited, and thus productivity is not impaired. This is a great advantage compared with the case where the IC chip is taken out from the circular silicon wafer.

  In the case where the scan line driver circuit 3702 is formed over the substrate as shown in FIG. 25B, a driver IC in which a driver circuit driver circuit on the signal line side is formed in a region outside the pixel portion 3701. Is implemented. These driver ICs are drive circuits on the signal line side. In order to form a pixel region corresponding to RGB full color, the number of signal lines in the XGA class is 3072 and the number in the UXGA class is 4800. The signal lines formed in such a number are divided into several blocks at the end of the pixel portion 3701 to form lead lines, and are collected according to the pitch of the output terminals of the driver IC.

  The driver IC is preferably formed of a crystalline semiconductor formed over a substrate, and the crystalline semiconductor is preferably formed by irradiating continuous-emitting laser light. Therefore, a continuous light emitting solid state laser or gas laser is used as an oscillator for generating the laser light. When a continuous light emission laser is used, a transistor can be formed using a polycrystalline semiconductor layer having a large grain size with few crystal defects. In addition, since the mobility and response speed are good, high-speed driving is possible, the operating frequency of the element can be improved as compared with the prior art, and there is less variation in characteristics, so that high reliability can be obtained. Note that for the purpose of further improving the operating frequency, the channel length direction of the transistor and the scanning direction of the laser light are preferably matched. This is because, in the laser crystallization process using a continuous-wave laser, the highest mobility is obtained when the channel length direction of the transistor and the scanning direction of the laser beam with respect to the substrate are substantially parallel (preferably −30 ° to 30 °). Is obtained. Note that the channel length direction corresponds to the direction in which current flows in the channel formation region, in other words, the direction in which charges move. The transistor thus fabricated has an active layer composed of a polycrystalline semiconductor layer in which crystal grains extend in the channel direction, which means that the crystal grain boundaries are formed substantially along the channel direction. means.

  In order to perform laser crystallization, it is preferable to significantly narrow down the laser beam, and the width of the laser beam shape (beam spot) should be about 1 mm to 3 mm, which is the same width of the short side of the driver IC. Is good. In order to ensure a sufficient and efficient energy density for the irradiated object, the laser light irradiation region is preferably linear. However, the line shape here does not mean a line in a strict sense, but means a rectangle or an ellipse having a large aspect ratio. For example, the aspect ratio is 2 or more (preferably 10 or more and 10,000 or less). In this manner, a method for manufacturing a display device with improved productivity can be provided by setting the width of the laser beam shape (beam spot) to the same length as the short side of the driver IC.

  As shown in FIGS. 30A and 30B, driver ICs may be mounted as both the scanning line driver circuit and the signal line driver circuit. In that case, the specifications of the driver ICs used on the scanning line side and the signal line side may be different.

In the pixel region, signal lines and scanning lines intersect to form a matrix, and transistors are arranged corresponding to the respective intersections. The present invention is characterized in that a TFT having an amorphous semiconductor or semi-amorphous semiconductor as a channel portion is used as a transistor arranged in a pixel region. The amorphous semiconductor is formed by a method such as a plasma CVD method or a sputtering method. A semi-amorphous semiconductor can be formed at a temperature of 300 ° C. or less by a plasma CVD method. For example, even a non-alkali glass substrate having an outer dimension of 550 × 650 mm has a film thickness necessary for forming a transistor. Is formed in a short time. Such a feature of the manufacturing technique is effective in manufacturing a large-screen display device. In addition, a semi-amorphous TFT can obtain a field effect mobility of ² to 10 cm ² / V · sec by forming a channel formation region with SAS. In addition, when the present invention is used, a pattern can be formed in a desired shape with good controllability, and such a fine wiring with a short channel width can be stably formed without causing a defect such as a short circuit. . A TFT having electric characteristics necessary for sufficiently functioning a pixel can be formed. Therefore, this TFT can be used as a switching element for a pixel or an element constituting a driving circuit on the scanning line side. Therefore, a display panel that realizes system-on-panel can be manufactured.

  By using TFTs in which the semiconductor layer is formed of SAS, the scanning line side driver circuit can also be integrally formed on the substrate. In the case of using TFTs in which the semiconductor layer is formed of AS, the scanning line side driver circuit and the signal A driver IC may be mounted on both the line side driver circuits.

  In that case, it is preferable that the specifications of the driver ICs used on the scanning line side and the signal line side are different. For example, although a transistor constituting the driver IC on the scanning line side is required to have a withstand voltage of about 30 V, the driving frequency is 100 kHz or less, and a relatively high speed operation is not required. Therefore, it is preferable to set the channel length (L) of the transistors forming the driver on the scanning line side to be sufficiently large. On the other hand, it is sufficient for the transistor of the driver IC on the signal line side to have a withstand voltage of about 12V, but the drive frequency is about 65 MHz at 3V, and high speed operation is required. Therefore, it is preferable to set the channel length and the like of the transistors constituting the driver on the micron rule. When the present invention is used, fine pattern formation can be performed with good controllability, and it is possible to sufficiently cope with such micron rule.

  The method for mounting the driver IC is not particularly limited, and a known COG method, wire bonding method, or TAB method can be used.

  By setting the thickness of the driver IC to be the same as that of the counter substrate, the height between the two becomes substantially the same, which contributes to the reduction in thickness of the entire display device. In addition, since each substrate is made of the same material, thermal stress is not generated even when a temperature change occurs in the display device, and the characteristics of a circuit made of TFTs are not impaired. In addition, the number of driver ICs to be mounted in one pixel region can be reduced by mounting the drive circuit with a driver IC that is longer than the IC chip as shown in this embodiment.

As described above, a driver circuit can be incorporated in the display panel.
(Embodiment 6)
An example of a protection circuit included in the display device of the present invention will be described.

  As shown in FIG. 30, a protection circuit 2713 can be formed between the external circuit and the internal circuit. The protection circuit is composed of one or a plurality of elements selected from a TFT, a diode, a resistance element, a capacitance element, and the like, and the configurations and operations of some protection circuits will be described below. First, a configuration of an equivalent circuit diagram of a protection circuit arranged between an external circuit and an internal circuit and corresponding to one input terminal will be described with reference to FIG. The protection circuit illustrated in FIG. 27A includes p-channel thin film transistors 7220 and 7230, capacitor elements 7210 and 7240, and a resistance element 7250. The resistance element 7250 is a two-terminal resistor, and an input voltage Vin (hereinafter referred to as Vin) is applied to one end, and a low potential voltage VSS (hereinafter referred to as VSS) is applied to the other end.

  The protection circuit illustrated in FIG. 27B is an equivalent circuit diagram in which the p-channel thin film transistors 7220 and 7230 are replaced with rectifying diodes 7260 and 7270. The protection circuit illustrated in FIG. 27C is an equivalent circuit diagram in which the p-channel thin film transistors 7220 and 7230 are substituted with TFTs 7350, 7360, 7370, and 7380. In addition, as a protection circuit having a structure different from the above, the protection circuit illustrated in FIG. 27D includes resistors 7280 and 7290 and an n-channel thin film transistor 7300. A protection circuit illustrated in FIG. 27E includes resistors 7280 and 7290, a p-channel thin film transistor 7310, and an n-channel thin film transistor 7320. By providing the protection circuit, a rapid change in potential can be prevented, and destruction or damage of the element can be prevented, so that reliability is improved. Note that the element forming the protection circuit is preferably formed using an amorphous semiconductor with excellent withstand voltage. This embodiment mode can be freely combined with the above embodiment modes.

This embodiment mode can be used in combination with each of Embodiment Modes 1 to 14.
(Embodiment 7)
A structure of a pixel of the display panel described in this embodiment will be described with reference to an equivalent circuit diagram illustrated in FIG. In this embodiment, an example in which a light-emitting element (EL element) is used as a display element of a pixel is described.

  In the pixel shown in FIG. 28A, a signal line 710, a power supply line 711, a power supply line 712, a power supply line 713 are arranged in the column direction, and a scanning line 714 is arranged in the row direction. The TFT 701 is a switching TFT, the TFT 703 is a driving TFT, the TFT 704 is a current control TFT, and further includes a capacitor 702 and a light emitting element 705.

  The pixel shown in FIG. 28C is different from the pixel shown in FIG. 28A except that the gate electrode of the TFT 703 is connected to the power supply line 715 arranged in the row direction. is there. That is, both pixels shown in FIGS. 28A and 28C show the same equivalent circuit diagram. However, when the power supply line 712 is arranged in the row direction (FIG. 28A) and in the case where the power supply line 715 is arranged in the column direction (FIG. 28C), each power supply line is conductive on a different layer. Formed with body layers. Here, attention is paid to the wiring to which the gate electrode of the TFT 703 is connected, and FIGS. 28A and 28C are shown separately to show that the layers for producing these are different.

As a feature of the pixel shown in FIGS. 28A and 28C, a TFT 703 and a TFT 704 are connected in series within the pixel, and the channel length L ₃ and channel width W _{3 of} the TFT 703 and the channel length L ₄ and channel width of the TFT 704 are obtained. W ₄ may be set to satisfy L ₃ / W ₃ : L ₄ / W ₄ = 5 to 6000: 1. As an example when 6000: 1 is satisfied, there is a case where L ₃ is 500 μm, W ₃ is 3 μm, L ₄ is 3 μm, and W ₄ is 100 μm. Further, when the present invention is used, since fine processing can be performed, such a fine wiring with a short channel width can be stably formed without causing a defect such as a short circuit. Therefore, a TFT having electrical characteristics necessary for sufficiently functioning the pixels as shown in FIGS. 28A and 28C can be formed, and a highly reliable display panel with excellent display capability can be manufactured. .

Note that the TFT 703 operates in a saturation region and has a role of controlling a current value flowing through the light emitting element 705, and the TFT 704 has a role of operating in a linear region and controls supply of current to the light emitting element 705. Both TFTs preferably have the same conductivity type in terms of manufacturing process. The TFT 703 may be a depletion type TFT as well as an enhancement type. In the present invention having the above structure, since the TFT 704 operates in a linear region, a slight change in V _GS of the TFT 704 does not affect the current value of the light emitting element 705. That is, the current value of the light emitting element 705 is determined by the TFT 703 operating in the saturation region. The present invention having the above structure can provide a display device in which luminance unevenness of a light emitting element due to variation in TFT characteristics is improved and image quality is improved.

  In the pixels shown in FIGS. 28A to 28D, a TFT 701 controls input of a video signal to the pixel. When the TFT 701 is turned on and a video signal is input into the pixel, the capacitor 702 The video signal is held in Note that FIGS. 28A and 28C illustrate a structure in which the capacitor 702 is provided; however, the present invention is not limited to this, and the capacity for holding a video signal can be covered by a gate capacity or the like. The capacitor 702 is not necessarily provided explicitly.

  The light-emitting element 705 has a structure in which an electroluminescent layer is sandwiched between two electrodes, and a potential difference is generated between the pixel electrode and the counter electrode (between the anode and the cathode) so that a forward bias voltage is applied. Is provided. The electroluminescent layer is composed of a wide variety of materials such as organic materials and inorganic materials. The luminescence in the electroluminescent layer includes light emission (fluorescence) when returning from a singlet excited state to a ground state, and a triplet excited state. And light emission (phosphorescence) when returning to the ground state.

  The pixel shown in FIG. 28B has the same pixel structure as that shown in FIG. 28A except that a TFT 706 and a scanning line 716 are added. Similarly, the pixel illustrated in FIG. 28D has the same pixel structure as that illustrated in FIG. 28C except that a TFT 706 and a scanning line 716 are added.

  The TFT 706 is controlled to be turned on or off by a newly arranged scanning line 716. When the TFT 706 is turned on, the charge held in the capacitor 702 is discharged, and the TFT 706 is turned off. That is, the arrangement of the TFT 706 can forcibly create a state in which no current flows through the light emitting element 705. 28B and 28D can improve the duty ratio because the lighting period can be started simultaneously with or immediately after the start of the writing period without waiting for signal writing to all the pixels. It becomes possible.

  In the pixel shown in FIG. 28E, a signal line 750, a power supply line 751, a power supply line 752, and a scanning line 753 are arranged in the column direction. Further, the TFT 741 is a switching TFT, the TFT 743 is a driving TFT, and further includes a capacitor element 742 and a light emitting element 744. The pixel illustrated in FIG. 28F has the same pixel structure as that illustrated in FIG. 28E except that a TFT 745 and a scanning line 754 are added. Note that the duty ratio of the structure in FIG. 28F can also be improved by the arrangement of the TFTs 745.

    As described above, when the present invention is used, a pattern such as a wiring can be formed accurately and stably without causing defective formation, so that high electrical characteristics and reliability can be imparted to the TFT. Therefore, it can sufficiently cope with applied technology for improving the display capability of the pixel in accordance with the purpose of use.

This embodiment mode can be used in combination with each of Embodiment Modes 1 to 16.
(Embodiment 8)
This embodiment will be described with reference to FIG. FIG. 18 shows an example in which an EL display module is formed using a TFT substrate 2800 manufactured by applying the present invention. In FIG. 18, a pixel portion including pixels is formed over the TFT substrate 2800.

  In FIG. 18, outside the pixel portion and between the driver circuit and the pixel, the same TFT as that formed in the pixel, or the gate of the TFT and one of the source or drain is connected to be the same as the diode. The protection circuit portion 2801 operated in the above is provided. As the driver circuit 2809, a driver IC formed of a single crystal semiconductor, a stick driver IC formed of a polycrystalline semiconductor film over a glass substrate, a driver circuit formed of SAS, or the like is applied.

  The TFT substrate 2800 is fixed to the sealing substrate 2820 through spacers 2806a and 2806b formed by a droplet discharge method. The spacer is preferably provided to keep the distance between the two substrates constant even when the substrate is thin and the area of the pixel portion is increased. Resin material having light-transmitting property at least in the visible region in the gap between the TFT substrate 2800 and the sealing substrate 2820 on the light-emitting element 2804 and the light-emitting element 2805 connected to the TFT 2802 and the TFT 2803, respectively. May be solidified by filling, or may be filled with anhydrous nitrogen or inert gas.

  FIG. 18 shows a case where the light-emitting element 2804, the light-emitting element 2805, and the light-emitting element 2815 have a top emission type (top emission type) structure, and emits light in the direction of the arrow shown in the drawing. Each pixel can perform multicolor display by changing the emission color of the pixels to red, green, and blue. At this time, by forming the colored layer 2807a, the colored layer 2807b, and the colored layer 2807c corresponding to each color on the sealing substrate 2820 side, the color purity of the emitted light can be increased. Alternatively, the pixel may be combined with a colored layer 2807a, a colored layer 2807b, or a colored layer 2807c as a white light emitting element.

  A driver circuit 2809 which is an external circuit is connected to a scanning line or a signal line connection terminal provided at one end of the TFT substrate 2800 through a wiring substrate 2810. Further, a heat pipe 2813 and a heat radiating plate 2812 may be provided in contact with or in proximity to the TFT substrate 2800 to enhance the heat radiation effect.

  In FIG. 18, the top emission EL module is used. However, the configuration of the light emitting element and the arrangement of the external circuit board may be changed to have a bottom emission structure, of course, a dual emission structure in which light is emitted from both the upper surface and the lower surface. In the case of a top emission type structure, an insulating layer serving as a partition wall may be colored and used as a black matrix. The partition walls can be formed by a droplet discharge method, and may be formed by mixing a resin material such as polyimide with a pigment-based black resin, carbon black, or the like, or may be a laminate thereof.

  Further, the EL display module may be configured to block reflected light of light incident from the outside using a phase difference plate or a polarizing plate. In the case of a top emission type structure, an insulating layer serving as a partition wall may be colored and used as a black matrix. This partition wall can be formed by a droplet discharge method, and may be a pigment-based black resin, a resin material such as polyimide mixed with carbon black or the like, or a laminate thereof. A different material may be discharged to the same region a plurality of times by a droplet discharge method to form a partition wall. As the retardation plate, a λ / 4 plate or a λ / 2 plate may be used and designed so that light can be controlled. As a configuration, in order, a TFT substrate 2800, a light emitting element 2804, a sealing substrate (sealing material) 2820, a first retardation plate, a second retardation plate (λ / 4 plate, λ / 2 plate), a polarizing plate Thus, the light emitted from the light emitting element passes through these and is emitted to the outside from the polarizing plate side. The retardation plate and the polarizing plate may be installed on the side from which light is emitted, and may be installed on both sides as long as the display is a double-sided emission type that emits light on both sides. Further, an antireflection film may be provided outside the polarizing plate. This makes it possible to display a higher-definition and precise image.

  In the TFT substrate 2800, a sealing structure may be formed by attaching a resin film to the side where the pixel portion is formed using a sealing material or an adhesive resin. Although glass sealing using a glass substrate is described in this embodiment mode, various sealing methods such as resin sealing using a resin, plastic sealing using a plastic, and film sealing using a film can be used. A gas barrier film for preventing the permeation of water vapor may be provided on the surface of the resin film. By adopting a film sealing structure, further reduction in thickness and weight can be achieved.

This embodiment mode can be used in combination with each of Embodiment Modes 1 to 17.
(Embodiment 9)
This embodiment will be described with reference to FIGS. 19 and 20 show an example in which a liquid crystal display module is configured using a TFT substrate 2600 manufactured by applying the present invention.

FIG. 19 shows an example of a liquid crystal display module. A TFT substrate 2600 and a counter substrate 2601 are fixed to each other with a sealant 2602, and a pixel portion 2603 and a liquid crystal layer 2604 are provided therebetween to form a display region. The colored layer 2605 is necessary for color display. In the case of the RGB method, a colored layer corresponding to each color of red, green, and blue is provided corresponding to each pixel. Polarizing plates 2606 and 2607 and a lens film 2613 are provided outside the TFT substrate 2600 and the counter substrate 2601. The light source is composed of a cold cathode tube 2610 and a reflection plate 2611. The circuit board 2612 is connected to the TFT substrate 2600 by a flexible wiring board 2609, and an external circuit such as a control circuit or a power supply circuit is incorporated. The liquid crystal display module includes TN (Twisted Nematic) mode, IPS (In-Plane-Switching) mode, MVA (Multi-domain Vertical Alignment) mode, ASM (Axial Symmetric).
An aligned micro-cell) mode, an OCB mode, or the like can be used.

    In particular, a display device manufactured according to the present invention can have higher performance by using an OCB mode capable of high-speed response. FIG. 20 shows an example in which the OCB mode is applied to the liquid crystal display module shown in FIG. 19, which is an FS-LCD (Field sequential-LCD). The FS-LCD emits red light, green light, and blue light in one frame period, and can perform color display by combining images using time division. Further, since each light emission is performed by a light emitting diode or a cold cathode tube, a color filter is unnecessary. Therefore, since it is not necessary to arrange color filters of the three primary colors, 9 times as many pixels can be displayed with the same area. On the other hand, since three colors of light are emitted in one frame period, a high-speed response of the liquid crystal is required. When the FS mode and the OCB mode are applied to the display device of the present invention, a display device or a liquid crystal television device with higher performance and higher image quality can be completed.

    The liquid crystal layer in the OCB mode has a so-called π cell structure. The π cell structure is a structure in which the pretilt angles of liquid crystal molecules are aligned in a plane-symmetric relationship with respect to the center plane between the active matrix substrate and the counter substrate. The alignment state of the π cell structure is splay alignment when no voltage is applied between the substrates, and shifts to bend alignment when a voltage is applied. When a voltage is further applied, the bend-aligned liquid crystal molecules are aligned perpendicularly to both substrates, and light is transmitted. In the OCB mode, high-speed response that is about 10 times faster than the conventional TN mode can be realized.

    Further, as a mode corresponding to the FS mode, HV-FLC, SS-FLC, or the like using a ferroelectric liquid crystal (FLC) capable of high-speed operation can be used. In the OCB mode, nematic liquid crystal having a relatively low viscosity is used, and in HV-FLC and SS-FLC, smectic liquid crystal is used. it can.

    In addition, the high-speed optical response speed of the liquid crystal display module is increased by narrowing the cell gap of the liquid crystal display module. The speed can also be increased by reducing the viscosity of the liquid crystal material. The increase in speed is more effective when the pixel in the pixel region of the TN mode liquid crystal display module or the dot pitch is 30 μm or less.

    The liquid crystal display module in FIG. 20 is a transmissive liquid crystal display module, and a red light source 2910a, a green light source 2910b, and a blue light source 2910c are provided as light sources. A control unit 2912 is installed to control on / off of the red light source 2910a, the green light source 2910b, and the blue light source 2910c. The light emission of each color is controlled by the control unit 2912, light enters the liquid crystal, an image is synthesized using time division, and color display is performed.

    As described above, when the present invention is used, a highly delicate and highly reliable liquid crystal display module can be manufactured.

This embodiment mode can be used in combination with each of Embodiment Modes 1 to 17.
(Embodiment 10)
A television device can be completed using the display module (also referred to as a display panel) manufactured according to the above embodiment mode. In the display panel, only a pixel portion is formed as shown in FIG. 25A, and a scanning line side driver circuit and a signal line side driver circuit are mounted by a TAB method as shown in FIG. And a case where the TFT is formed by SAS as shown in FIG. 25B, and the pixel portion and the scanning line side driver circuit are integrated on the substrate. In some cases, the signal line side driver circuit is separately mounted as a driver IC, and the pixel portion, the signal line side driver circuit, and the scanning line side driver circuit are integrally formed over the substrate as shown in FIG. However, any form is acceptable.

  As other external circuit configurations, on the video signal input side, among the signals received by the tuner, the video signal amplification circuit that amplifies the video signal, and the signal output from it corresponds to each color of red, green, and blue And a control circuit for converting the video signal into the input specification of the driver IC. The control circuit outputs signals to the scanning line side and the signal line side, respectively. In the case of digital driving, a signal dividing circuit may be provided on the signal line side and an input digital signal may be divided into m pieces and supplied.

  Of the signals received by the tuner, the audio signal is sent to the audio signal amplifier circuit, and the output is supplied to the speaker via the audio signal processing circuit. The control circuit receives control information of the receiving station (reception frequency) and volume from the input unit, and sends a signal to the tuner and the audio signal processing circuit.

  These liquid crystal display modules and EL display modules can be assembled in a housing as shown in FIGS. 26A and 26B to complete a television device. When an EL display module as shown in FIG. 18 is used, an EL television device can be completed. When a liquid crystal display module as shown in FIGS. 19 and 20 is used, a liquid crystal television device can be completed. A main screen 2003 is formed by the display module, and a speaker portion 2009, operation switches, and the like are provided as other accessory equipment. Thus, a television device can be completed according to the present invention.

  A display panel 2002 is incorporated in a housing 2001, and general television broadcasting is received by a receiver 2005, and connected to a wired or wireless communication network via a modem 2004 (one direction (from a sender to a receiver)). ) Or bi-directional (between the sender and the receiver, or between the receivers). The television device can be operated by a switch incorporated in the housing or a separate remote control device 2006, and the remote control device 2006 also includes a display unit 2007 for displaying information to be output. good.

  In addition, the television device may have a configuration in which a sub screen 2008 is formed using the second display panel in addition to the main screen 2003 to display channels, volume, and the like. In this configuration, the main screen 2003 may be formed using an EL display panel with an excellent viewing angle, and the sub screen may be formed using a liquid crystal display panel that can display with low power consumption. In order to prioritize the reduction in power consumption, the main screen 2003 may be formed using a liquid crystal display panel, the sub screen may be formed using an EL display panel, and the sub screen may blink. When the present invention is used, a highly reliable display device can be obtained even when such a large substrate is used and a large number of TFTs and electronic components are used.

  FIG. 26B illustrates a television device having a large display portion of 20 to 80 inches, for example, which includes a housing 2010, a display portion 2011, a remote control device 2012 that is an operation portion, a speaker portion 2013, and the like. The present invention is applied to manufacture of the display portion 2011. The television device in FIG. 26B is a wall-hanging type and does not require a large installation space.

Of course, the present invention is not limited to a television device, but can be applied to various uses such as a monitor for a personal computer, an information display board in a railway station or airport, an advertisement display board in a street, etc. can do.
(Embodiment 11)
Various display devices can be manufactured by applying the present invention. That is, the present invention can be applied to various electronic devices in which these display devices are incorporated in a display portion.

  Such electronic devices include video cameras, digital cameras, projectors, head mounted displays (goggles type displays), car navigation systems, car stereos, personal computers, game machines, personal digital assistants (mobile computers, mobile phones, electronic books, etc.) ), An image reproducing apparatus provided with a recording medium (specifically, an apparatus provided with a display capable of reproducing a recording medium such as a digital versatile disc (DVD) and displaying the image). Examples thereof are shown in FIG.

  FIG. 24A illustrates a personal computer, which includes a main body 2101, a housing 2102, a display portion 2103, a keyboard 2104, an external connection port 2105, a pointing mouse 2106, and the like. The present invention is applied to manufacturing the display portion 2103. When the present invention is used, a highly reliable high-quality image can be displayed even if the size is reduced and wiring and the like are refined.

  FIG. 24B shows an image reproducing device (specifically, a DVD reproducing device) provided with a recording medium, which includes a main body 2201, a housing 2202, a display portion A 2203, a display portion B 2204, and a recording medium (DVD etc.) reading portion 2205. , An operation key 2206, a speaker portion 2207, and the like. The display portion A 2203 mainly displays image information, and the display portion B 2204 mainly displays character information. The present invention is applied to the production of the display portions A, B 2203, and 2204. When the present invention is used, a highly reliable high-quality image can be displayed even if the size is reduced and wiring and the like are refined.

  FIG. 24C illustrates a mobile phone, which includes a main body 2301, an audio output portion 2302, an audio input portion 2303, a display portion 2304, operation switches 2305, an antenna 2306, and the like. By applying the display device manufactured according to the present invention to the display portion 2304, a highly reliable and high-quality image can be displayed even in a mobile phone that is downsized and wiring and the like are precise.

  FIG. 24D shows a video camera, which includes a main body 2401, a display portion 2402, a housing 2403, an external connection port 2404, a remote control receiving portion 2405, an image receiving portion 2406, a battery 2407, an audio input portion 2408, operation keys 2409, and the like. . The present invention can be applied to the display portion 2402. By applying the display device manufactured according to the present invention to the display portion 2304, a highly reliable and high-quality image can be displayed even with a video camera that is downsized and wiring and the like are precise. This embodiment mode can be freely combined with the above embodiment modes.

    Further, the present invention can be applied to a semiconductor device, and the use of the semiconductor device to which the present invention is applied is wide. For example, an ID chip which is one form of the semiconductor device of the present invention is a bill, a coin, a securities, Can be used in certificate documents, bearer bonds, packaging containers, books, recording media, personal belongings, vehicles, foods, clothing, health supplies, daily necessities, medicines, electronic devices, etc. it can. The present invention can also be used for a processor chip which is an aggregate having various signal processing functions.

4A to 4D illustrate a method for manufacturing a display device of the present invention. 4A to 4D illustrate a method for manufacturing a display device of the present invention. 4A to 4D illustrate a method for manufacturing a display device of the present invention. 4A to 4D illustrate a method for manufacturing a display device of the present invention. 4A to 4D illustrate a method for manufacturing a display device of the present invention. 4A to 4D illustrate a method for manufacturing a display device of the present invention. 4A to 4D illustrate a method for manufacturing a display device of the present invention. 4A to 4D illustrate a method for manufacturing a display device of the present invention. 4A to 4D illustrate a method for manufacturing a display device of the present invention. 4A to 4D illustrate a method for manufacturing a display device of the present invention. 4A to 4D illustrate a method for manufacturing a display device of the present invention. 4A to 4D illustrate a method for manufacturing a display device of the present invention. 4A to 4D illustrate a method for manufacturing a display device of the present invention. 4A to 4D illustrate a method for manufacturing a display device of the present invention. 4A to 4D illustrate a method for manufacturing a display device of the present invention. 4A to 4D illustrate a method for manufacturing a display device of the present invention. 4A to 4D illustrate a method for manufacturing a display device of the present invention. Sectional drawing explaining the structural example of EL display module of this invention. Sectional drawing explaining the structural example of the liquid crystal display module of this invention. Sectional drawing explaining the structural example of the liquid crystal display module of this invention. Sectional drawing of the display apparatus of this invention. 3A and 3B each illustrate a structure of a light-emitting element that can be applied to the present invention. 2A and 2B illustrate a structure of a droplet discharge device that can be applied to the present invention. FIG. 11 illustrates an electronic device to which the present invention is applied. The top view of the display apparatus of this invention. FIG. 11 illustrates an electronic device to which the present invention is applied. The figure which shows the protection circuit to which this invention is applied. FIG. 10 is a circuit diagram illustrating a structure of a pixel that can be applied to an EL display panel of the present invention. 4A and 4B illustrate a liquid crystal dropping injection method that can be applied to the present invention. The top view of the display apparatus of this invention.

Claims (9)

Forming a first light-transmitting conductive layer on a light-transmitting substrate;
Forming an insulating layer on the substrate and the first conductive layer;
A mask layer is selectively formed on the insulating layer overlapping the first conductive layer;
Forming a photoreactive substance on the insulating layer and the mask layer;
By passing light through the substrate and irradiating the photoreactive substance, a first region and a second region having higher wettability to the composition containing a conductive material than the first region are formed. ,
Removing the mask layer and the photoreactive substance formed on the mask layer, forming a third region having higher wettability to the composition containing the conductive material than the first region;
A method for manufacturing a display device, wherein a second conductive layer is formed using a composition containing the conductive material in the second region and the third region. Forming a light-transmitting first conductive layer including a gate electrode region and a gate wiring region over a light-transmitting substrate;
Forming an insulating layer on the substrate and the first conductive layer;
Forming a semiconductor layer over the insulating layer overlapping the gate electrode region;
A mask layer is selectively formed on the insulating layer overlapping the gate wiring region;
Forming a photoreactive substance on the semiconductor layer and the mask layer;
By passing light through the substrate and irradiating the photoreactive substance, a first region and a second region having higher wettability to the composition containing a conductive material than the first region are formed. ,
Removing the mask layer and the photoreactive substance formed on the mask layer, forming a third region having higher wettability to the composition containing the conductive material than the first region;
A method for manufacturing a display device, wherein a second conductive layer is formed using a composition containing the conductive material in the second region and the third region. 3. The method for manufacturing a display device according to claim 1, wherein a substance containing a triphenylmethane derivative, a substance containing an azobenzene derivative, or a spiropyran derivative is formed as the photoreactive substance. Forming a first light-transmitting conductive layer on a light-transmitting substrate;
Forming an insulating layer on the substrate and the first conductive layer;
Forming a photocatalytic substance on the insulating layer;
A mask layer is selectively formed on the insulating layer and the photocatalytic material overlapping the first conductive layer;
Forming a fluorocarbon chain-containing material on the photocatalytic material and the mask layer;
Passing the light through the substrate and irradiating the photocatalytic substance to form a first region and a second region having higher wettability to the composition containing a conductive material than the first region;
The mask layer and the substance containing the fluorocarbon chain formed on the mask layer are removed, and a third region having higher wettability with respect to the composition containing the conductive material than the first region is formed. ,
A method for manufacturing a display device, wherein a second conductive layer is formed using a composition containing the conductive material in the second region and the third region. Forming a light-transmitting first conductive layer including a gate electrode region and a gate wiring region over a light-transmitting substrate;
Forming an insulating layer on the substrate and the first conductive layer;
Forming a semiconductor layer over the insulating layer overlapping the gate electrode region;
Forming a photocatalytic substance on the insulating layer and the semiconductor layer;
A mask layer is selectively formed on the photocatalytic material overlapping the gate wiring region,
Forming a fluorocarbon chain-containing material on the photocatalytic material and the mask layer;
Passing the light through the substrate and irradiating the photocatalytic substance to form a first region and a second region having higher wettability to the composition containing a conductive material than the first region;
The mask layer and the substance containing the fluorocarbon chain formed on the mask layer are removed, and a third region having higher wettability with respect to the composition containing the conductive material than the first region is formed. ,
A method for manufacturing a display device, wherein a second conductive layer is formed using a composition containing the conductive material in the second region and the third region. Forming a first light-transmitting conductive layer on a light-transmitting substrate;
Forming an insulating layer on the substrate and the first conductive layer;
Forming a photocatalytic substance on the insulating layer;
A mask layer is selectively formed on the insulating layer and the photocatalytic material overlapping the first conductive layer;
Forming a material containing a silane coupling agent on the photocatalytic material and the mask layer;
Passing the light through the substrate and irradiating the photocatalytic substance to form a first region and a second region having higher wettability to the composition containing a conductive material than the first region;
The mask layer and the substance containing the silane coupling agent formed on the mask layer are removed to form a third region having higher wettability with respect to the composition containing the conductive material than the first region. ,
A method for manufacturing a display device, wherein a second conductive layer is formed using a composition containing the conductive material in the second region and the third region. Forming a light-transmitting first conductive layer including a gate electrode region and a gate wiring region over a light-transmitting substrate;
Forming an insulating layer on the substrate and the first conductive layer;
Forming a semiconductor layer on the insulating layer overlapping the gate electrode region;
Forming a photocatalytic substance on the insulating layer and the semiconductor layer;
A mask layer is selectively formed on the photocatalytic material overlapping the gate wiring region,
Forming a material containing a silane coupling agent on the photocatalytic material and the mask layer;
Passing the light through the substrate and irradiating the photocatalytic substance to form a first region and a second region having higher wettability to the composition containing a conductive material than the first region;
The mask layer and the substance containing the silane coupling agent formed on the mask layer are removed to form a third region having higher wettability with respect to the composition containing the conductive material than the first region. ,
A method for manufacturing a display device, wherein a second conductive layer is formed using a composition containing the conductive material in the second region and the third region. The method for manufacturing a display device according to claim 4, wherein the silane coupling agent has an alkyl group. 9. The method for manufacturing a display device according to claim 4, wherein a titanium oxide film is formed as the photocatalytic substance.

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