JP5089027B2 - Semiconductor device - Google Patents

Description

  The present invention relates to a thin film transistor, a manufacturing method thereof, a display device, a manufacturing method thereof, and a television device using the same.

  A thin film transistor (hereinafter referred to as “TFT”) and an electronic circuit using the thin film transistor are manufactured 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. Has been. 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).

  However, the technique described in Patent Document 1 is merely a replacement of a part of the photolithography process performed a plurality of times in the TFT manufacturing process by the printing method, and drastically contributes to the reduction in the number of processes. It is not possible. In addition, an exposure apparatus used for transferring a mask pattern in photolithography technology transfers a pattern of several microns to 1 micron or less by equal-magnification projection exposure or reduced projection exposure. It is technically difficult to expose a large area substrate exceeding 1 meter at a time.

Further, in a thin film transistor formed by laminating various thin films, it is important to improve the flatness of a region where the thin film is formed in order to form each thin film with good adhesion and stability. This is because, in a thin film, if the flatness of the surface to be formed is poor, the covering property is deteriorated and the processing is not uniform. Attempts have been made to eliminate the step formed by the gate electrode by a gate insulating layer formed by stacking two layers and to planarize the gate electrode (see, for example, Patent Document 2).
Japanese Patent Laid-Open No. 11-251259 JP 2000-150906 A

  An object of the present invention is to reduce the number of photolithography processes in a manufacturing process of a TFT, an electronic circuit using the TFT, and a display device formed by the TFT. In addition, the manufacturing process is further simplified. An object of the present invention is to provide a technique that can be manufactured at a low cost and with a high yield even on a large-area substrate having a side exceeding 1 meter.

  It is another object of the present invention to provide a technique that can form a highly reliable display device by forming wirings and the like constituting the display device with good adhesion.

    The present invention adds (mixes) at least one of the substances constituting the thin film transistor, the display device, etc., among the substances forming the surface of the object having high adhesion to those objects. Thus, the adhesion between the component and the object to be formed is improved. In addition, in the insulating layer formed on the structure, the insulating layer includes an organic material so that the uneven shape generated on the surface of the structure can be sufficiently covered and the insulating layer can be densified to be reliable. The first insulating layer and the second insulating layer containing an inorganic material are stacked to form.

  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.

    One thin film transistor of the present invention includes a conductive layer in which at least one of the substances forming the insulating surface is dispersed over the insulating surface.

    One thin film transistor of the present invention includes a first insulating layer containing an organic material over a conductive layer, a second insulating layer containing an inorganic material over the first insulating layer, A semiconductor layer is provided over the insulating layer, and the conductive layer is formed by discharging a composition containing a conductive material.

    One thin film transistor of the present invention has a conductive layer in which at least one of the substances forming the insulating surface is dispersed over the insulating surface, and the first insulating material includes an organic material on the conductive layer. A second insulating layer containing an inorganic material is provided over the first insulating layer, and a semiconductor layer is provided over the second insulating layer.

    One of the thin film transistors of the present invention has a first conductive layer in which at least one of the substances forming the insulating surface is dispersed on the insulating surface, and an organic material is formed on the first conductive layer. A first insulating layer containing, a second insulating layer containing an inorganic material on the first insulating layer, a semiconductor layer on the second insulating layer, and in contact with the semiconductor layer. A second conductive layer in which at least one of the same substances among the substances forming the semiconductor layer is dispersed is provided.

    One of the thin film transistors of the present invention has a first conductive layer in which at least one of the substances forming the insulating surface is dispersed on the insulating surface, and an organic material is formed on the first conductive layer. A first insulating layer containing, a second insulating layer containing an inorganic material on the first insulating layer, a semiconductor layer on the second insulating layer, and in contact with the semiconductor layer. A second conductive layer in which at least one of the substances forming the semiconductor layer is dispersed; a third insulating layer containing an organic material on the second conductive layer; The third insulating layer and the fourth insulating layer have an opening reaching the second conductive layer, and the second insulating layer includes a second insulating layer containing an inorganic material. A third conductive layer in contact with the conductive layer.

    According to one aspect of the display device of the present invention, there is provided a gate electrode layer in which at least one of the substances forming the insulating surface is dispersed on the insulating surface, the insulating layer on the gate electrode layer, and the insulating layer. A semiconductor layer; a source and drain electrode layer in contact with the semiconductor layer; and an electrode layer electrically connected to the source or drain electrode layer.

    One display device of the present invention includes a first insulating layer containing an organic material over a gate electrode layer, a second insulating layer containing an inorganic material over the first insulating layer, 2 having a semiconductor layer on the insulating layer, a source electrode layer and a drain electrode layer in contact with the semiconductor layer, and an electrode layer electrically connected to the source electrode layer or the drain electrode layer, wherein the gate electrode layer is electrically conductive It is formed by discharging a composition containing a functional material.

    One embodiment of the display device of the present invention includes a gate electrode layer in which at least one of the substances forming the insulating surface is dispersed on the insulating surface, and an organic material is included on the gate electrode layer. A first insulating layer, a second insulating layer containing an inorganic material over the first insulating layer, a semiconductor layer over the second insulating layer, a source electrode layer in contact with the semiconductor layer, and A drain electrode layer; and an electrode layer electrically connected to the source electrode layer or the drain electrode layer.

    One embodiment of the display device of the present invention includes a gate electrode layer in which at least one of the substances forming the insulating surface is dispersed on the insulating surface, and an organic material is included on the gate electrode layer. A first insulating layer, a second insulating layer containing an inorganic material over the first insulating layer, a semiconductor layer over the second insulating layer, and a semiconductor layer in contact with the semiconductor layer, A source electrode layer in which at least one of the same substances among the substances to be formed is dispersed, and a drain electrode layer in which at least one of the same substances among the substances that form the semiconductor layer are dispersed. The electrode layer is in contact with the electrode layer.

    One embodiment of the display device of the present invention includes a gate electrode layer in which at least one of the substances forming the insulating surface is dispersed on the insulating surface, and an organic material is included on the gate electrode layer. A first insulating layer, a second insulating layer containing an inorganic material over the first insulating layer, a semiconductor layer over the second insulating layer, and a semiconductor layer in contact with the semiconductor layer, A source electrode layer in which at least one of the same substances among the substances to be formed is dispersed, and a drain electrode layer in which at least one of the same substances among the substances that form the semiconductor layer are dispersed. A third insulating layer containing an organic material is provided on the electrode layer, a fourth insulating layer containing an inorganic material is provided on the third insulating layer, and the third insulating layer and the fourth insulating layer are provided. Has an opening reaching the source or drain electrode layer, and in the opening, Has over source electrode layer or the wiring layer in contact with the drain electrode layer has an electrode layer in contact with the wiring layer.

    A display screen can be formed using the display device having the above structure, and one of the television devices of the present invention can be manufactured.

    According to one method for manufacturing a thin film transistor of the present invention, a conductive layer is formed by discharging a composition containing a conductive material in which at least one of substances forming an insulating surface is dispersed over the insulating surface. .

    According to one method for manufacturing a thin film transistor of the present invention, a conductive layer is formed by discharging a composition containing a conductive material, a first insulating layer containing an organic material is formed over the conductive layer, and a first insulating layer is formed. A second insulating layer containing an inorganic material is formed over the layer, and a semiconductor layer is formed over the second insulating layer.

    In one method for manufacturing a thin film transistor of the present invention, a conductive layer is formed by discharging a composition containing a conductive material in which at least one of the substances forming the insulating surface is dispersed over the insulating surface. A first insulating layer containing an organic material is formed over the conductive layer, a second insulating layer containing an inorganic material is formed over the first insulating layer, and a semiconductor layer is formed over the second insulating layer. Form.

    According to one method for manufacturing a thin film transistor of the present invention, a first conductive layer is formed by discharging a composition containing a conductive material in which at least one of substances forming an insulating surface is dispersed over an insulating surface. A first insulating layer containing an organic material is formed on the first conductive layer, a second insulating layer containing an inorganic material is formed on the first insulating layer, and a second insulating layer is formed. A second conductive layer is formed by forming a semiconductor layer over the layer, discharging a composition containing a conductive material in which at least one of the substances forming the semiconductor layer is dispersed in contact with the semiconductor layer. Form.

    According to one method for manufacturing a thin film transistor of the present invention, a first conductive layer is formed by discharging a composition containing a conductive material in which at least one of substances forming an insulating surface is dispersed over an insulating surface. A first insulating layer containing an organic material is formed on the first conductive layer, a second insulating layer containing an inorganic material is formed on the first insulating layer, and a second insulating layer is formed. A second conductive layer is formed by forming a semiconductor layer over the layer, discharging a composition containing a conductive material in which at least one of the substances forming the semiconductor layer is dispersed in contact with the semiconductor layer. A third insulating layer containing an organic material is formed on the second conductive layer, a fourth insulating layer containing an inorganic material is formed on the third insulating layer, and a third insulating layer is formed. An opening reaching the second conductive layer is formed in the layer and the fourth insulating layer, and the opening is in contact with the second conductive layer. Forming a conductive layer.

    According to one method for manufacturing a display device of the present invention, a gate electrode layer is formed by discharging a composition containing a conductive material in which at least one of the substances forming an insulating surface is dispersed over the insulating surface. And forming an insulating layer over the gate electrode layer, forming a semiconductor layer over the insulating layer, forming a source electrode layer and a drain electrode layer in contact with the semiconductor layer, and electrically connecting the source electrode layer or the drain electrode layer An electrode layer to be connected is formed.

    According to one method for manufacturing a display device of the present invention, a gate electrode layer is formed by discharging a composition containing a conductive material, a first insulating layer containing an organic material is formed over the gate electrode layer, A second insulating layer containing an inorganic material is formed over one insulating layer, a semiconductor layer is formed over the second insulating layer, a source electrode layer and a drain electrode layer in contact with the semiconductor layer are formed, and a source An electrode layer electrically connected to the electrode layer or the drain electrode layer is formed.

    According to one method for manufacturing a display device of the present invention, a gate electrode layer is formed by discharging a composition containing a conductive material in which at least one of the substances forming an insulating surface is dispersed over the insulating surface. And forming a first insulating layer including an organic material over the gate electrode layer, forming a second insulating layer including an inorganic material over the first insulating layer, and over the second insulating layer. Then, a semiconductor layer is formed, a source electrode layer and a drain electrode layer in contact with the semiconductor layer are formed, and an electrode layer electrically connected to the source electrode layer or the drain electrode layer is formed.

    According to one method for manufacturing a display device of the present invention, a gate electrode layer is formed by discharging a composition containing a conductive material in which at least one of the substances forming an insulating surface is dispersed over the insulating surface. And forming a first insulating layer including an organic material over the gate electrode layer, forming a second insulating layer including an inorganic material over the first insulating layer, and over the second insulating layer. The source electrode layer and the drain electrode layer are formed by discharging a composition containing a conductive material in which at least one of the substances forming the semiconductor layer is dispersed in contact with the semiconductor layer. An electrode layer which is formed and electrically connected to the source electrode layer or the drain electrode layer is formed.

    According to one method for manufacturing a display device of the present invention, a gate electrode layer is formed by discharging a composition containing a conductive material in which at least one of the substances forming an insulating surface is dispersed over the insulating surface. And forming a first insulating layer including an organic material over the gate electrode layer, forming a second insulating layer including an inorganic material over the first insulating layer, and over the second insulating layer. The source electrode layer and the drain electrode layer are formed by discharging a composition containing a conductive material in which at least one of the substances forming the semiconductor layer is dispersed in contact with the semiconductor layer. Forming a third insulating layer containing an organic material over the source electrode layer and the drain electrode layer; forming a fourth insulating layer containing an inorganic material over the third insulating layer; Openings reaching the source electrode layer or the drain electrode layer in the insulating layer and the fourth insulating layer It is formed and the opening, to form a wiring layer in contact with the semiconductor layer to form the electrode layer in contact with the wiring layer.

  According to the present invention, components constituting a thin film transistor, a display device, and the like can be formed with a desired pattern and good adhesion. 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)
An embodiment of the present invention will be described with reference to FIG.

    According to the present invention, at least one or more constituents 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 are selectively used. The display device is manufactured by forming the substrate by a method that can be formed into a desired shape. In the present invention, a composition (also referred to as a pattern) refers to a conductive layer 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 constituting a thin film transistor or a display device. It includes all components that are formed with a predetermined shape. As a method capable of selectively forming a desired pattern, 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. It is possible to use a droplet discharge (ejection) method (also called an ink jet method depending on the method). In addition, a method in which the composition can be transferred or drawn in a desired pattern, for example, various printing methods (screen (stencil) printing, offset (flat plate) printing, letterpress printing, gravure (intaglio printing), etc.) ) Etc. can also be used.

    In this embodiment, a method is used in which a composition containing a constituent forming material that is a fluid is ejected (ejected) as droplets to form a desired pattern. A droplet containing a component forming material is discharged onto a region where the component is to be formed, and fixed by firing, drying, or the like to form a component having a desired pattern.

    One mode of a droplet discharge device used for forming a pattern 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. The nozzle sizes of the head 1405 and the head 1412 are different, and 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.

    A thin film transistor manufactured according to an embodiment of the present invention will be described with reference to FIGS.

    In the case of forming a conductive layer or the like by using a droplet discharge method, a conductive layer is formed by discharging a composition containing a conductive material processed into a particulate form and fusing or fusion bonding by baking to solidify. Since it adheres to a formation area by discharge, the composition containing a conductive material is formed including a solvent and conductive particles so as to have a fluid. In the conductive layer formed by discharging and baking the composition containing the conductive material in this manner, the conductive layer is not densely formed and has a defect, and an object to be formed (formable substance) In some cases, the adhesion to the insulating surface is low. In addition, there are irregularities on the surface of the conductive layer, which may deteriorate the flatness. A conductive layer (or insulating layer) formed by sputtering or the like shows a columnar structure, whereas a conductive layer formed by using a droplet discharge method shows a polycrystalline state having many grain boundaries. There are many.

    Such poor adhesion and flatness cause a decrease in the reliability of a thin film transistor, a display device, and the like to be manufactured. As a method for improving the reliability, the present invention shows two methods.

    One of the methods is to form a constituent of a thin film transistor or a display device by adding (mixing) a substance having high adhesion to the constituent, thereby forming the constituent and the constituent. Improve adhesion. As the substance having high adhesion, the same substance as at least one of the substances forming the surface of the object to be formed is used.

    The other method is that the insulating layer is formed on the organic layer so that the insulating layer formed on the component sufficiently covers the uneven shape generated on the surface of the component and can be densified so as to be reliable as the insulating layer. A first insulating layer containing a material and a second insulating layer containing an inorganic material are stacked to form.

  Either one of the above methods may be used, or both may be used. By using either one of the methods, the reliability is improved. Of course, when both methods are used, a higher reliability improvement effect can be obtained. In this embodiment, an example using both of the two methods is shown.

    As shown in FIG. 1, a gate electrode layer 56 is formed on the substrate 50. A composition containing a conductive material in which at least one of the substances forming the substrate 50 is dispersed in a composition 52 containing a conductive material is discharged as droplets 55 from a droplet discharge device 54 ( And is attached to the substrate 50 that is the object to be formed. Thereafter, drying and baking are performed to form the gate electrode layer 56.

    An enlarged view of the gate electrode layer 56 formed over the substrate 50 is shown in FIG. In this embodiment, the substrate 50 is a glass substrate. Therefore, a substance containing silicon oxide is dispersed in the gate electrode layer 56 as at least one of the substances forming the substrate 50. Of the substances containing silicon oxide added to the gate electrode layer, three substances 61 containing silicon oxide are in contact with the substrate 50. The substance 61 containing silicon oxide having good adhesion to the substrate 50 generates an adhesion force as indicated by an arrow 63 at the interface with the substrate. Therefore, the adhesion force between the gate electrode layer 56 and the substrate 50 can be increased by the adhesion force with the substance 61 containing several silicon oxides added to the gate electrode layer 56 and in contact with the substrate 50.

    Of the substances forming the surface of the object to be formed, the shape of the same substance as at least one may be any shape such as granular, columnar, needle-shaped, plate-shaped, etc. The same substance as at least one may aggregate to form an aggregate as a single body. Of the substances forming the surface of the object to be formed, the size of at least one substance may be 100 nm or less, preferably several tens of nm or less. In order to form a nano-order level thin wiring, since conductive nanoparticles are used as the conductive material, at least one of the substances forming the surface of the object is preferably 10 nm or less. Among the substances forming the surface of the object to be formed, the same substance as at least one is effective if mixed in the conductor material, but at least of the substances forming the surface of the object to be formed with respect to the conductive material. The proportion of the same substance as one may be 0.5 to 4.0% by weight, preferably 1.0 to 3.0% by weight. As described above, the adhesiveness can be improved only by mixing at least one of the substances forming the surface of the object to be formed which has the effect of improving the adhesiveness in a small amount in the conductive material. The present invention is a simpler method than performing a base film or pretreatment over the entire region to be formed, and is also beneficial in terms of productivity and cost.

Of the substances that form the surface of the object to be formed, at least one of the same substances may be a conductive material or an insulating material, and is appropriately set according to the substance that forms the surface to be formed, such as silicon, nitrogen, oxide, or nitride. do it. Examples of the oxide include silicon oxide (SiO ₂ ), boric acid (B ₂ O ₃ ), sodium oxide (NaO ₂ ), magnesium oxide (MgO), aluminum oxide (alumina) (Al ₂ O ₃ ), and potassium oxide (K ₂ O), calcium oxide (CaO), arsenic trioxide (arsenous acid) (As ₂ O ₃ ), strontium oxide (SrO), antimony oxide (Sb ₂ O ₃ ), barium oxide (BaO), indium tin oxide (ITO), ITSO composed of indium tin oxide and silicon oxide, zinc oxide (ZnO), and the like may be included, and the mixing ratio may be appropriately set depending on the component ratio (composition ratio) of each formed object. . Further, among the substances forming the surface of the object to be formed contained in the conductive material, the same substance as at least one may not have the same composition ratio, and the size may be distributed over a certain range. Good. In the present invention, at least one of the substances forming the surface of the object to be formed may be contained in the mixed conductive layer or insulating layer, and the dispersed state may be uniform. It may be uneven. Therefore, in the conductive layer, there may be a portion that exists at a high concentration and a portion that exists at a low concentration, and aggregation, decomposition, and the like may occur in the process of forming the conductive layer.

    In this embodiment mode, the gate electrode layer 56 is 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. Examples of the conductive material include metals such as Ag, Au, Cu, Ni, Pt, Pd, Ir, Rh, W, and Al, metal sulfides of Cd and Zn, Fe, Ti, Si, Ge, Zr, and Ba. It corresponds to oxide, silver halide fine particles or dispersible nanoparticles. Further, it corresponds to indium tin oxide (ITO) used as a transparent conductive film, ITSO composed of indium tin oxide and silicon oxide, organic indium, organic tin, zinc oxide, titanium nitride, and the like. As the conductive material, particles of a single element or a plurality of kinds of elements can be mixed and 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, and water are used. The viscosity of the composition is preferably 20 mPa · s (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. 1 μm or less is preferable. 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 in a gas evaporation method, the nanomolecules protected with the dispersant are as fine as about 7 nm. When the surface of each particle is covered with a coating agent, the nanoparticles are aggregated in the solvent. And stably disperse at room temperature and shows almost the same behavior as liquid. Therefore, it is preferable to use a coating agent.

    Of the substances forming the surface of the object to be added added to the composition containing the conductive material for improving the adhesion added to the conductor, the same substance as at least one depends on the shape of the pattern. In order to prevent nozzle clogging and to produce a high-definition pattern, the size is preferably as small as possible, preferably 100 nm or less.

    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 (C) for 3 minutes, and firing is performed at 200 to 550 degrees (C) for 15 minutes to 60 minutes. Its purpose, temperature and time are 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. Note that the timing of performing this heat treatment and the number of heat treatments are not particularly limited. In order to carry out the drying and firing steps satisfactorily, the substrate may be heated, and the temperature at that time depends on the material such as the substrate, but is generally 100 to 800 ° C. (° C.) ( Preferably, it is set to 200 to 550 degrees (° C.). 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. In addition, a so-called hybrid laser irradiation method combining pulse oscillation and continuous oscillation may be used. However, depending on the heat resistance of the substrate, 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. 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, the gate electrode layer or the like may be formed by discharging a composition by a droplet discharge method, and then 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.

    A gate insulating layer is formed over the gate electrode layer 56. In the present invention, a plurality of gate insulating layers are stacked in order to improve the flatness of the surface of the gate insulating layer and increase the density. First, as shown in FIG. 2A, a first insulating layer 57a containing an organic material is formed. Since the first insulating layer 57a is an organic insulating material containing an organic material, a dip coating method, a spin coating method, a droplet discharge method, or a printing method (a method of forming a pattern such as screen printing or offset printing). ) And other wet methods (wet process). The coating method can be formed with good coverage even on a surface having a rugged uneven surface, and has the effect of improving the flatness of the surface.

    Next, a second insulating layer 57b is stacked over the first insulating layer 57a. Since the second insulating layer 57b is an inorganic insulating material containing an inorganic material, a vacuum deposition method, an ion plating method, an ion beam method, a PVD method, a CVD method, a sputtering method, an RF magnetron sputtering method, a plasma spraying method, It can be formed by a dry method such as a plasma spray method. Since the deposition method can form a dense film, the gate insulating layer can be provided with electrical characteristics with excellent pressure resistance. In this embodiment mode, the second insulating layer is formed using silicon nitride (SiN). Note that in order to form a dense insulating layer 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 layer.

    By applying the present invention, a gate insulating layer that can provide both effects of flatness and improved electrical characteristics (strength) can be formed.

    As a forming material of the first insulating layer 57a, resin materials such as epoxy resin, phenol resin, novolac resin, acrylic resin, melamine resin, urethane resin, acrylic acid, methacrylic acid and derivatives thereof, polyimide, aromatic A compound material made by polymerization of a polymer such as an aromatic polyamide, polybenzimidazole, or a siloxane polymer containing a Si—O—Si bond can be used. The film thickness is preferably several tens nm to 500 nm. In this embodiment, the first insulating layer is formed using a composition containing a siloxane polymer.

The second insulating layer 57b includes silicon oxide (SiO ₂ ), silicon nitride (SiN), silicon oxynitride (SiON), silicon nitride oxide (SiNO), aluminum oxide (Al ₂ O ₃ ), aluminum nitride (AlN), Aluminum oxynitride (AlON), aluminum nitride oxide (AlNO), or other inorganic insulating materials can be used. In silicon oxynitride and aluminum oxynitride, oxygen is higher in component ratio than nitrogen, and in silicon nitride oxide and aluminum nitride oxide, nitrogen has a higher component ratio than oxygen. The film thickness is preferably several tens of nm to 300 nm.

  The film thickness ratio between the first insulating layer 57a and the second insulating layer 57b is controlled by the surface shape and film thickness of the gate electrode layer to be covered, the required flatness, and the degree of electrical characteristics. Thus, an optimum gate insulating layer can be formed. Accordingly, the characteristics imparted to the gate insulating layer can be controlled, so that the characteristics required for the thin film transistor and the display device to be applied can be flexibly and widely dealt with. In addition, the first insulating layer 57a containing an organic material and the second insulating layer 57b containing an inorganic material may each be a stacked layer including a plurality of layers, and can be formed with at least good coverage and flatness. It may be a stack of two or more layers of a first insulating layer made of an insulating material and a second insulating layer made of an inorganic insulating material that can be formed with high density.

    A semiconductor layer 58 and an N-type semiconductor layer 59 which is a semiconductor layer having one conductivity type are formed over the gate electrode layer 56, the first insulating layer 57a, and the second insulating layer 57b. A semiconductor layer having one conductivity type may be formed as necessary. In addition, 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. it can. 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.

  A material for forming the semiconductor layer 58 is 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, and the amorphous semiconductor. A polycrystalline semiconductor crystallized using light energy or thermal energy, or a semi-amorphous (also referred to as microcrystal or microcrystal; hereinafter also referred to as “SAS”) semiconductor 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. At least 1 atomic% or more of hydrogen or halogen is contained as a neutralizing agent for 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 linear plasma method. Alternatively, the crystalline semiconductor layer may be selectively formed over the substrate by a linear 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 the organic semiconductor material that passes through such a precursor 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.

  The source or drain electrode layer 60a and the source or drain electrode layer 60b are formed in contact with the N-type semiconductor layer 59 and a droplet 67 is discharged from a droplet discharge device 66 (see FIG. 2D). ). In this embodiment, the source or drain electrode layer 60a and the source or drain electrode layer 60b are formed by a droplet discharge method in which a composition containing a conductive material is discharged. Similarly to the gate electrode layer 56, the source electrode / drain electrode layer 60a and the source electrode layer / drain electrode layer 60b also have high adhesion to the object to be formed in order to increase the adhesion in the region to be formed. A substance 65 containing silicon is added as at least one of the substances forming the surface. The semiconductor layer, the first insulating layer, and the substrate which are formed objects have silicon and have good adhesion to the substance 65 containing silicon. Due to the adhesion increasing effect of the mixed silicon-containing substance 65, the source or drain electrode layer 60a and the source or drain electrode layer 60b can also be stably formed with good adhesion.

    Examples of the conductive material for forming the source or drain electrode layer 60a and the source or drain electrode layer 60b include Ag (silver), Au (gold), Cu (copper), W (tungsten), and Al (aluminum). A composition mainly composed of metal particles such as the above 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.

    By combining the droplet discharge method, material loss can be prevented and costs can be reduced as compared to the entire surface coating formation by spin coating or the like. According to the present invention, even if the wiring or the like is designed to be densely and complicatedly arranged by downsizing and thinning, it can be formed in a good shape with good adhesion and coverage, and reliability is improved. Can do.

    By this invention, a structure can be formed with sufficient adhesiveness with a desired pattern. In addition, there is little material loss, and cost reduction can be achieved. Thus, a high-performance and highly reliable thin film transistor and display device can be manufactured with high yield.

(Embodiment 2)
Embodiments of the present invention will be described with reference to FIGS. 3 to 9, FIG. 14, and FIG. More specifically, a method for manufacturing a display device having a channel-etched thin film transistor to which the present invention is applied will be described. 3A to 7A are top views of the pixel portion of the display device, FIGS. 3 to 7B are cross-sectional views taken along line A-C in FIGS. 3 to 8A, and FIG. FIG. 6 is a cross-sectional view taken along line BD.

    FIG. 14A 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. 14A shows the structure of a display panel in which signals input to the scanning lines and signal lines are controlled by an external driver circuit. As shown in FIG. 15A, a COG (Chip on 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. 15B 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. 15, the driver IC 2751 is connected to an FPC (Flexible printed circuit) 2750.

    In the case where a TFT provided for a pixel is formed using SAS, a scan line driver circuit 3702 can be formed over the substrate 3700 and integrated as shown in FIG. 14B, the pixel portion 3701 is controlled by an external driver circuit as in FIG. 14A connected to the signal line side input terminal 3704. 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, FIG. 14C illustrates a pixel portion 4701, a scan line driver circuit 4702, and a signal line driver circuit. 4704 can be integrally formed on the substrate 4700.

    A TFT includes a semiconductor layer, a gate insulating layer, and a gate electrode layer as main components, and a wiring layer connected to a source region and a drain region formed in the semiconductor layer is attached to the TFT. Structurally, the top gate type in which the semiconductor layer, the gate insulating layer and the gate electrode layer are arranged from the substrate side, and the bottom gate type in which the gate electrode layer, the gate insulating layer and the semiconductor layer are arranged from the substrate side are representative. In the present invention, any of those structures may be used.

  As the substrate 100, a glass substrate made of barium borosilicate glass, alumino borosilicate glass, or the like, a quartz substrate, a silicon substrate, a metal substrate, a stainless steel 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. In this embodiment, a substrate made of glass and containing silicon oxide is used as the substrate 100. Note that an insulating layer containing the substrate 100 and silicon may be formed over the 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. For example, a silicon oxide film, a silicon oxynitride film, a silicon nitride oxide film, a stacked layer thereof, or the like is preferably used. This insulating layer may not be formed, but has an effect of blocking contaminants from the substrate 100. In this case, the gate electrode layer is formed in contact with an insulating layer formed over the base substrate. Therefore, at least one of the substances forming the insulating layer forming the surface to be formed is mixed in the gate electrode layer. Of the substances forming the insulating layer, at least one of the same substances has good adhesion to the surface of the insulating layer, so that the gate electrode layer can be formed with good adhesion.

    The gate electrode layer 103 and the gate electrode layer 104 are formed over the substrate 100 by the droplet discharge device 180a and the droplet discharge device 180b (see FIG. 3). In this embodiment, the gate electrode layer 103 and the gate electrode layer 104 are formed by discharging a conductive material to which at least one of the substances forming the surface of the object is added. As in Embodiment 1, the gate electrode layer 103 and the gate electrode layer 104 can be formed using Ag, Cu, or the like as a conductive material. The adhesion force between the gate electrode layer 103, the gate electrode layer 104, and the substrate 100 can be increased by the adhesion force of at least one of the substances forming the substrate surface having good adhesion with the substrate 100. In this embodiment, a substance containing silicon oxide is used as the same substance as at least one of the substances forming the substrate surface.

  Next, a first insulating layer 105a and a second insulating layer 105b are formed as gate insulating layers over the gate electrode layer 103 and the gate electrode layer 104 (see FIG. 4). In the present invention, a plurality of gate insulating layers are stacked in order to improve the flatness of the surface of the gate insulating layer and increase the density. First, the first insulating layer 105a containing an organic material is formed. Since the first insulating layer 105a is an organic insulating material containing an organic material, a dip coating method, a spin coating method, a droplet discharge method, or a printing method (a method for forming a pattern such as screen printing or offset printing) is used. ) And other wet methods (wet process). The coating method can be formed with good coverage even on a surface having a rugged uneven surface, and has the effect of improving the flatness of the surface.

    Next, the second insulating layer 105b is stacked over the first insulating layer 105a. Since the second insulating layer 105b is an inorganic insulating material containing an inorganic material, a vacuum deposition method, an ion plating method, an ion beam method, a PVD method, a CVD method, a sputtering method, an RF magnetron sputtering method, a plasma spraying method, It can be formed by a dry method such as a plasma spray method. Since the deposition method can form a dense film, the gate insulating layer can be provided with electrical characteristics with excellent pressure resistance. In this embodiment, the second insulating layer 105b is formed using silicon oxide (SiN).

    By applying the present invention, a gate insulating layer that can provide both effects of flatness and improved electrical characteristics (strength) can be formed.

    A semiconductor layer is formed over the first insulating layer 105b, and an N-type semiconductor layer is formed as a semiconductor layer having one conductivity type thereon. Patterning is performed using a mask or the like to form a semiconductor layer 107, a semiconductor layer 108, an N-type semiconductor layer 109, and an N-type semiconductor layer 110 (see FIG. 5). The semiconductor layer 107, the semiconductor layer 108, the N-type semiconductor layer 109, and the N-type semiconductor layer 110 use silicon which is an inorganic material in this embodiment mode; however, an organic semiconductor such as pentacene as described above can also be used. . When the organic semiconductor is selectively formed by a droplet discharge method or the like, the patterning process can be simplified.

A mask made of an insulator such as resist or polyimide is formed by a droplet discharge method, and through holes 145 are formed in part of the first insulating layer 105a and the second insulating layer 105b by etching using the mask. And a part of the gate electrode layer 104 disposed on the lower layer side is exposed. 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 or chlorine-based gas such as CF ₄ , NF ₃ , 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.

  A mask for patterning can be formed by selectively discharging a composition. Such selective mask formation has the effect of simplifying the patterning process. For the mask, a resin material such as an epoxy resin, an acrylic resin, a phenol resin, a novolac 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.

    After the mask is removed, a composition containing a conductive material is discharged from the droplet discharge device 181a and the droplet discharge device 181b, and the source / drain electrode layer 111, the source / drain electrode layer 112, and the source electrode are discharged. A layer or drain electrode layer 113 and a source or drain electrode layer 114 are formed (see FIG. 6). Similar to the gate electrode layer, the source electrode layer or the drain electrode layer has the same adhesion property as the at least one of the substances that form the surface of the object with good adhesion to the object in order to improve the adhesion in the formation region. A substance containing silicon is added as a substance. The semiconductor layer, the first insulating layer, and the substrate which are formed objects have silicon and have good adhesion to a substance containing silicon. Source electrode layer or drain electrode layer 111, source electrode layer or drain electrode layer 112, source electrode layer or drain electrode layer 113, source electrode layer or drain electrode layer 114 are also formed by the effect of increasing the adhesion force of the substance containing silicon mixed therein. It can be formed stably with good adhesion.

    The semiconductor layer 107, the semiconductor layer 108, and the N-type semiconductor with the source or drain electrode layer 111, the source or drain electrode layer 112, the source or drain electrode layer 113, and the source or drain electrode layer 114 as masks The layer 109 and the N-type semiconductor layer 110 are patterned to expose the semiconductor layer 107 and the semiconductor layer 108. The source or drain electrode layer 111 also functions as a source wiring layer, and the source or drain electrode layer 113 also functions as a power supply line.

  As a conductive material for forming the source or drain electrode layer 111, the source or drain electrode layer 112, the source or drain electrode layer 113, and the source or drain electrode layer 114, 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 through-hole 145, the source or drain electrode layer 112 and the gate electrode layer 104 are electrically connected. A part of the source electrode layer or the drain electrode layer forms a capacitor element.

  The step of forming the through hole 145 is performed after the source or drain electrode layer 111, the source or drain electrode layer 112, the source or drain electrode layer 113, and the source or drain electrode layer 114 are formed. Alternatively, the through hole 145 may be formed using the drain electrode layer 111, the source or drain electrode layer 112, the source or drain electrode layer 113, and the source or drain electrode layer 114 as a mask. Then, a conductive layer is formed in the through hole 145, and the source or drain electrode layer 112 and the gate electrode layer 104 are electrically connected. In this case, there is an advantage that the process is simplified.

    In this manner, the channel etch type thin film transistor 170 and the channel etch type thin film transistor 171 according to the present embodiment are formed.

Subsequently, a composition containing a conductive material is selectively discharged over the second insulating layer 105b which is a gate insulating layer, so that the first electrode layer 117 is formed (see FIG. 7). The first electrode layer 117 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 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, indium zinc oxide (IZO (IZO), which is a conductive material obtained by doping ZnO with gallium (Ga), and an oxide conductive material containing silicon oxide and indium oxide mixed with 2 to 20% zinc oxide (ZnO). indium zinc oxide)) may be used. After the first electrode layer 117 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 mode, the first electrode layer 117 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 second insulating layer 105b is made of silicon nitride. As a preferred structure, the first electrode layer 117 formed of indium tin oxide containing silicon oxide is formed in close contact with the second insulating layer made of silicon nitride contained in the gate insulating layer, whereby the electroluminescent layer The effect that the rate at which the light emitted in the step is emitted to the outside can be increased. The gate insulating layers (the first insulating layer 105a and the second insulating layer 105b) are interposed between the gate electrode layer, the source electrode layer or the drain electrode layer, and the first electrode layer, and function as a capacitor element. You can also

    The first electrode layer 117 can be selectively formed over the second insulating layer 105b which is a gate insulating layer before the source or drain electrode layer 114 is formed. In this case, in this embodiment mode, the connection structure of the source or drain electrode layer 114 and the first electrode layer 117 is a structure in which the source or drain electrode layer 114 is stacked on the first electrode layer. It becomes. When the first electrode layer 117 is formed before the source electrode layer or the drain electrode layer 114, the first electrode layer 117 can be formed in a flat formation region. Therefore, the first electrode layer 117 can be formed in a flat region. It can be formed well.

  9A, a third insulating layer 150a and a fourth insulating layer 150b which are interlayer insulating layers are formed over the source or drain electrode layer 114, and the wiring layer 151 can A structure that is electrically connected to one electrode layer 117 may be used. The third insulating layer 150a and the fourth insulating layer 150b which are interlayer insulating layers are also formed using the present invention in the same manner as the first insulating layer 105a and the second insulating layer 105b which are gate insulating layers. Can do. In the display device in FIG. 9A, the wiring layer 151 is also formed by adding at least one of the same substances among the substances forming the source or drain electrode layer 114 in contact with the wiring layer 151. In this embodiment mode, silicon oxide is added to the source or drain electrode layer 114; therefore, the wiring layer 151 is also formed by adding silicon oxide.

    As with the first insulating layer 105a, the third insulating layer 150a is an insulating layer containing an organic material and is formed using a wet method such as a coating method. The third insulating layer containing an organic material can be formed with good coverage so as to fill unevenness and steps, and the surface can be planarized.

    As with the second insulating layer 105b, the fourth insulating layer 150b is an insulating layer containing an inorganic material and is formed using a dry method such as an evaporation method. The fourth insulating layer containing an inorganic material can be formed into a dense structure by a dry method.

    By applying the present invention, it is possible to form an interlayer insulating layer that can provide both effects of flatness and improvement of electrical characteristics (strength). Therefore, the first electrode layer formed over the third insulating layer 150a and the fourth insulating layer 150b can also be formed stably and uniformly with good coverage. Such flatness is important for displaying a high-definition and high-quality image in the first electrode layer 117 functioning as a pixel electrode. When the present invention is used, the first electrode layer 117 can be formed on a surface having excellent flatness, so that the thin-film light-emitting layer formed by stacking can be stably formed in a good shape, A display device capable of displaying a high-quality image can be manufactured.

    In addition, as shown in FIG. 9B, the first insulating layer containing an organic material formed by a coating method or the like is formed relatively thick so as to fill a step due to the gate electrode layer, thereby further improving flatness. You can also In this case, the second insulating layer 105b containing an inorganic material to be stacked does not have a step on the surface to be formed, so that the second insulating layer 105b can be formed more densely, and electrical characteristics such as pressure resistance required for the insulating layer. Will also improve.

  In addition, when a structure in which emitted light is emitted to the side opposite to the substrate 100 side, in the case of manufacturing a reflective EL display panel, Ag (silver), Au (gold), Cu (copper)), A composition composed mainly of metal particles such as W (tungsten) and Al (aluminum) 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 the first electrode layer 117 is formed by combining etching processes. Also good.

  The first electrode layer 117 may be wiped with a CMP method or a polyvinyl alcohol-based porous body and polished so that the surface thereof is planarized. Further, after the polishing using the CMP method, the surface of the first electrode layer 117 may be subjected to ultraviolet irradiation, oxygen plasma treatment, or the like.

  Through the above steps, the substrate 100 having a display panel TFT in which bottom-gate thin film transistors 170 and 171 and a pixel electrode (first electrode layer 117) are connected to the substrate 100 is completed. Further, the thin film transistor of this embodiment is an inverted staggered type.

  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 117 so as to have an opening. In this embodiment mode, the insulating layer 121 is formed over the entire surface, and is etched and patterned with 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, patterning by etching 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 Heat-resistant polymers such as polyamide, polybenzimidazole, or inorganic siloxanes containing Si-O-Si bonds among silicon, oxygen, and hydrogen compounds formed from siloxane-based materials as starting materials It can be formed of an organic siloxane insulating material in which hydrogen is substituted with an organic group such as methyl or phenyl. 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 having a TFT for a display panel (see FIG. 8).

  Before forming the electroluminescent layer 122, heat treatment is performed at 200 ° C. under atmospheric pressure to remove moisture adsorbed in the first electrode layer 117 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 the insulating film is a single layer or a laminated layer (for example, nitrogen A carbon-containing film (CN _x ) and silicon nitride (SiN) or the like) can be used. An organic material can also be used, and a laminate of polymers such as styrene polymer may be used. In addition, a skeleton structure is formed by a bond of silicon (Si) and oxygen (O), and at least one of a material containing at least hydrogen as a substituent, or fluorine, an alkyl group, or an aromatic hydrocarbon as a substituent. You may use the material which has.

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 a 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 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.

  Subsequently, a sealing material is formed and sealed using a sealing substrate. After that, a flexible wiring board may be connected to a gate wiring layer formed by being electrically connected to the gate electrode layer 103 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 the drain electrode layer 111 which is also the source wiring layer.

  A completed view of an EL display panel manufactured using the present invention is shown in FIG. 18A is a top view of the EL display panel, and FIG. 18B is a cross-sectional view taken along line EF in FIG. 18A. In FIG. 18, a pixel portion 3301 formed over an element substrate 3300 includes a pixel 3302, a gate wiring layer 3306a, a gate wiring layer 3306b, and a source wiring layer 3308, which are attached to each other with a sealing substrate 3310 and a sealant 3303. Combined and fixed. In this embodiment mode, a driver IC 3351 is installed on the FPC 3350 and mounted by the TAB method.

  As shown in FIGS. 18A and 18B, a desiccant 3305, a desiccant 3304a, and a desiccant 3304b are provided in the display panel in order to prevent deterioration of the element due to moisture. The desiccant 3305 is formed so as to surround the periphery of the pixel portion, and the desiccant 3304a and the desiccant 3304b are formed in regions corresponding to the gate wiring layers 3306a and 3306b. In the present embodiment, the desiccant is installed in a recess formed in the sealing substrate as shown in FIG. 18B, and has a structure that does not hinder thinning. Since the desiccant is also formed in the region corresponding to the gate wiring layer, the water absorption area can be increased and the water absorption effect is improved. Further, since the desiccant is formed on the gate wiring layer that does not emit light directly, the light extraction efficiency is not lowered. In this embodiment mode, a filler 3307 is filled in the display panel. The filler 3307 can be formed into a liquid composition by a dropping method like the liquid crystal dropping method of FIG. When a hygroscopic substance such as a desiccant is used as the filler, a further water absorption effect can be obtained and deterioration of the element can be prevented.

  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 a low concentration impurity region, and the region outside the channel region may be a high concentration impurity region.

  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.

  By this invention, a structure can be formed with sufficient adhesiveness with a desired pattern. In addition, there is little material loss, and cost reduction can be achieved. Thus, a high-performance and highly reliable thin film transistor and 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 a top-gate (forward staggered) 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. 10 and 11 are cross-sectional views of the display device.

  In this embodiment mode, a conductive layer is formed by adding (mixing) at least one of the substances forming the particulate object surface to the composition containing a conductive material. Of the substances forming the surface of the object to be formed, at least one same substance is in the form of particles and may be 100 nm or less, preferably tens of nm or less. In order to form a nano-order level thin wiring, since conductive nanoparticles are used as the conductive material, at least one of the substances forming the surface of the object is preferably 10 nm or less. Of the substances forming the surface of the object to be formed, the same substance as at least one is effective if mixed in the conductor material, but at least one of the substances forming the surface of the object to be formed with respect to the conductive material is effective. The ratio of the same substance may be 0.5 to 4.0% by weight, preferably 1.0 to 3.0% by weight. As described above, the adhesiveness can be improved only by mixing at least one of the substances forming the surface of the object to be formed which has the effect of improving the adhesiveness in a small amount in the conductive material. The present invention is a simpler method than performing a base film or pretreatment over the entire region to be formed, and is also beneficial in terms of productivity and cost.

    A source or drain electrode layer 330 and a source or drain electrode layer 308 are formed over a substrate 300 (see FIG. 10A). In this embodiment, the substrate 300 uses a glass substrate, and the glass substrate contains silicon oxide. In this embodiment mode, the source electrode layer and the drain electrode layer are formed using silicon oxide as the same substance as at least one of the substances that form the surface of the formation object, which has good adhesion to the substrate 300 that is the formation surface. It is formed to have a containing material. A composition including a conductive material to which a substance containing silicon oxide is added is discharged onto the substrate 300 using a droplet discharge device 380, and dried and baked to form an electrode layer. The electrode layer thus formed is a well-formed source or drain electrode layer 330 formed with good adhesion by the effect of increasing the adhesion of a substance containing silicon oxide present at the interface with the substrate 300, the source electrode It functions as a layer or drain electrode layer 308.

  An N-type semiconductor layer is formed over the source or drain electrode layer 330 and the source or drain electrode layer 308 and etched using a mask made of resist or the like. The resist may be formed using a droplet discharge method. A semiconductor layer is formed on the N-type semiconductor layer and patterned again using a mask or the like. Thus, an N-type semiconductor layer 307 and a semiconductor layer 306 are formed (see FIG. 10B). In this embodiment mode, silicon which is an inorganic material is used for the semiconductor layer 306; however, an organic semiconductor such as pentacene as described above can also be used. When the organic semiconductor is selectively formed by a droplet discharge method or the like, the patterning process can be simplified.

  Next, a gate insulating layer is formed by stacking a first insulating layer 305a containing an organic material and a second insulating layer 305b containing an inorganic material (see FIG. 10C). Since the first insulating layer 305a is an organic insulating material containing an organic material, it is formed by a coating method. Therefore, uneven shapes and steps in the formation region can be formed with sufficient coverage. As in this embodiment, even if the surface of the source or drain electrode layer 330 and the source or drain electrode layer 308 formed by using a droplet discharge method has an uneven shape, a formation defect occurs. And can be formed with good flatness. In this embodiment, the first insulating layer is formed using a composition containing a siloxane polymer.

  Next, a second insulating layer is formed using a plasma CVD method or a sputtering method. Therefore, the second insulating layer can be formed in a dense layer, and electrical characteristics such as voltage resistance against voltage can be improved. In this embodiment mode, the second insulating layer is formed using silicon nitride (SiN). By applying the present invention, a gate insulating layer that can provide both effects of flatness and improved electrical characteristics (strength) can be formed.

  Next, a mask made of a resist or the like is formed, and the first insulating layer 305a and the second insulating layer 305b are etched to form an opening 345. In this embodiment mode, a mask is selectively formed by a droplet discharge method (see FIG. 10D).

  A composition containing a conductive material is discharged as droplets having fluidity over the second insulating layer 305b from the droplet discharge device 381 to form the gate electrode layer 303 (see FIG. 11A). In this embodiment, as in the case of the source electrode layer or the drain electrode layer 330, the gate electrode layer 303 is also formed with a surface with good adhesion to the object to be formed in order to increase adhesion in the formation region. A substance containing silicon is added as at least one of the substances. The gate electrode layer 303 can also be stably formed with good adhesion on the second insulating layer by the effect of increasing the adhesion of the substance containing silicon mixed therein.

A pixel electrode layer 311 is formed by a droplet discharge method. In this embodiment mode, the planarity of the surface is enhanced by the first insulating layer 305a; therefore, the pixel electrode layer 311 can also be formed stably and uniformly without forming defects. The pixel electrode layer 311 and the source or drain electrode layer 308 are electrically connected to each other through the opening 345 formed in advance. The pixel electrode layer 311 can be formed using a material similar to that of the first electrode layer 117 described above. When a transmissive liquid crystal display panel is manufactured, indium tin oxide (ITO) and indium containing silicon oxide are used. A predetermined pattern may be formed by a composition containing tin oxide (ITSO), zinc oxide (ZnO), tin oxide (SnO ₂ ), and the like, and may be formed by baking.

  Next, an insulating layer 312 called an alignment film is formed by a printing method or a spin coating method so as to cover the pixel electrode layer 311. Note that the insulating layer 312 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 (not shown).

  After that, an insulating substrate 321 functioning as an alignment film, a colored layer 322 functioning as a color filter, a conductor layer 323 functioning as a counter electrode, a counter substrate 324 provided with a polarizing plate 325, and a substrate 300 having TFTs are provided with spacers. Then, a liquid crystal display panel can be manufactured by providing the liquid crystal layer 320 in the gap (see FIG. 11B). In the case of a transmissive liquid crystal display device, a polarizing plate is preferably provided on the side opposite to the surface having the TFT of the substrate 300 having TFTs. 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 324. 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 counter substrate 324 is attached can be used.

  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.

A connection portion is formed in order to connect the pixel portion formed in the above steps and an external wiring substrate. 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, a wiring board for connection is provided so that the wiring layer is electrically connected through the anisotropic conductor layer. The wiring board plays a role of transmitting signals and potentials from the outside. Through the above steps, a liquid crystal display panel having a display function can be manufactured.

  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 a low concentration impurity region, and the region outside the channel region may be a high concentration impurity region.

  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.

  By this invention, a structure can be formed with sufficient adhesiveness with a desired pattern. 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 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 each 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 the substrate 480, and includes a gate electrode layer 493, a first insulating layer 497a, a second insulating layer 497b, a semiconductor layer 494, an N-type semiconductor layer 495, a source or drain electrode layer 482, and channel protection. Formed by layer 496. In this embodiment mode, a silicon film having an amorphous structure is used as the semiconductor layer, and an N-type semiconductor layer is used as the one-conductivity-type semiconductor layer. Instead of forming the 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 a crystalline semiconductor layer can also be used as described in Embodiment Mode 2. When a crystalline semiconductor layer such as polysilicon is used, an impurity region having one conductivity type may be formed by introducing (adding) an impurity into the crystalline semiconductor layer without forming the one conductivity type semiconductor layer. . 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 patterning process can be simplified.

  In the thin film transistor 481 to which the present invention is applied, the gate insulating layer includes two layers, which are a stack of a first insulating layer 497 a containing an organic material and a second insulating layer 497 b containing an inorganic material. Since the first insulating layer 497a is formed by a coating method, the gate electrode layer 493 can be covered with good coverage, which is effective in planarizing the surface. In addition, since the second insulating layer 497b can form a dense film, electrical characteristics such as high breakdown voltage can be improved. Therefore, poor coverage due to surface unevenness on the surface to be formed, deterioration of electrical characteristics caused by defects included in the insulating layer, and the like can be prevented, and a highly reliable thin film transistor can be obtained. In the present invention, a glass substrate is used as the substrate 480, and the gate electrode layer 493 includes silicon oxide contained in the glass substrate as at least one of the substances forming the surface of the object to be formed. Substance is added (mixed). Therefore, since the substance containing silicon oxide is in close contact with the interface between the gate electrode layer 493 and the substrate 480, the gate electrode layer 493 can be formed over the substrate 480 with good adhesion without being peeled off by the adhesive force.

  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. Channel protective layers include 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, benzo Cyclobutene, etc.), a resist, a low-k material having a low dielectric constant (preferably a relative dielectric constant of 2.5 or less), or a film made of a plurality of kinds, or a stack of these films can be used. In addition, a skeleton structure is formed by a bond of silicon (Si) and oxygen (O), and at least one of a material containing at least hydrogen as a substituent, or fluorine, an alkyl group, or an aromatic hydrocarbon as a substituent. You may use the material which has. 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 TOF film or an SOG film obtained by a coating method can also be used.

  First, a case where light is emitted to the substrate 480 side, that is, a 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 sequentially stacked so as to be in contact with the source or drain electrode layer 482 so as to be electrically connected to the thin film transistor 481. The first insulating layer 497a, the second insulating layer 497b, and the substrate 480 that transmit light are required to have a light-transmitting property. 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 electrically connected to the thin film transistor 461, a first electrode layer 463, an electroluminescent layer 464, and a second electrode layer 465 are stacked in this order. With the above structure, even when light is transmitted through the first electrode layer 463, the light is reflected by the source or drain electrode layer 462 and emitted to the side opposite to the substrate 460. Note that in this structure, it is not necessary to use a light-transmitting material for the first electrode layer 463. Finally, a case where light is emitted to the substrate 470 side and the opposite side, that is, a case where dual emission is performed will be described with reference to FIG. The thin film transistor 471 is a channel protective thin film transistor similar to the thin film transistor 481. The thin film transistor 481 can be formed in a similar manner. A source or drain electrode layer 477 electrically connected to the thin film transistor 471, a first electrode layer 472, an electroluminescent layer 473, and a second electrode layer 474 are sequentially stacked. At this time, when both the first electrode layer 472 and the second electrode layer 474 are formed using a light-transmitting material or a thickness capable of transmitting light, dual emission is realized. In this case, the insulating layer and the substrate 470 through which light is transmitted need to have a light-transmitting property.

  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.

  FIGS. 13A and 13B 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. In this order, 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 stacked in this order. Is preferred. FIG. 13A illustrates a structure in which light is emitted from the first electrode layer 870. The first electrode layer 870 includes an 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. 13B illustrates a structure in which light is emitted from the second electrode layer 850, and the first electrode layer 870 is formed using a metal such as aluminum or titanium or a concentration equal to or lower than the stoichiometric composition ratio with the metal. The electrode layer 807 is formed of a metal material containing nitrogen and the second electrode layer 806 is 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.

  FIGS. 13C and 13D 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) in order from the cathode side. Layer) / ETL (electron transport layer) 802, EML (light emitting layer) 803, HTL (hole transport layer) / HIL (hole injection layer) 804, and the second electrode layer 850 which is an anode are preferably stacked in this order. FIG. 13C 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. 13D illustrates a structure in which light is emitted from the second electrode layer 850, and 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 a light-transmitting oxide conductive material. 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 materials, materials having a particularly high electron transporting property include, for example, tris (8-quinolinolato) aluminum (abbreviation: Alq ₃ ), tris (5-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. Further, in the case where the EL layer is formed by a coating method using spin coating, it is preferably fired by vacuum heating after coating. 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 luminescent 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 a compound having the above structure and having an element belonging to group 8 to 10 in the periodic table as a central metal can also be used.

  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 shown in FIG. 12, a color filter (colored layer) may be formed over the sealing substrate of the substrate 480. The color filter (colored layer) can be formed by a droplet discharge method. In that case, light irradiation treatment or the like can be applied as the above-described base pretreatment. By using the present invention, a color filter (colored layer) can be formed in a desired pattern with good controllability. 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, for example, on the second substrate (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 small 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 having a length of 10 μm or less), including one or more layers selected from macromolecular organic compounds, You may combine with the injection | pouring transport property or the hole injection transport property inorganic compound. The first electrode layer 484, the first electrode layer 463, and the first electrode layer 472 are formed using a transparent conductive film that transmits light. For example, in addition to ITO and ITSO, indium oxide is oxidized at 2 to 20%. A transparent conductive film mixed with zinc (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)
In the display panel manufactured in Embodiment Modes 2 to 4, the driver circuit on the scanning line side can be formed over the substrate 3700 as described in FIG. 14B by forming the semiconductor layer using SAS. it can.

FIG. 25 shows a block diagram of a scanning line side driving circuit constituted by an n-channel TFT using SAS capable of obtaining a field effect mobility of 1 to 15 cm ² / V · sec.

  In FIG. 25, a block 500 corresponds to a pulse output circuit that outputs a sampling pulse for one stage, and the shift register includes n pulse output circuits. Reference numeral 901 denotes a buffer circuit, to which a pixel 902 is connected.

  FIG. 26 shows a specific configuration of a block 500 corresponding to a pulse output circuit, and a circuit is configured by n-channel TFTs 601 to 613. At this time, the size of the TFT may be determined in consideration of the operating characteristics of the n-channel TFT using SAS. For example, if the channel length is 8 μm, the channel width can be set in the range of 10 to 80 μm.

  A specific configuration of the buffer circuit 901 is shown in FIG. Similarly, the buffer circuit is composed of n-channel TFTs 620 to 635. At this time, the size of the TFT may be determined in consideration of the operating characteristics of the n-channel TFT using SAS. For example, if the channel length is 10 μm, the channel width is set in the range of 10 to 1800 μm. By using the present invention, a pattern can be formed in a desired shape with good controllability, and such a fine wiring having a channel width of 10 μm can be stably formed without defects such as a short circuit. .

  In order to realize such a circuit, the TFTs need to be connected to each other by wiring, and a configuration example of the wiring in that case is shown in FIG. In FIG. 16, as in Embodiment 2, the gate electrode layer 103, the first insulating layer 105a containing an organic material as the gate insulating layer, the second insulating layer 105b containing an inorganic material, the semiconductor layer 107, one conductivity type In this figure, an N-type semiconductor layer 109, a source or drain electrode layer 111, and a source or drain electrode layer 112 are formed as the semiconductor layers. In this embodiment, the gate electrode layer 103 is added with a substance containing silicon oxide which is contained in the substrate 100 which is a formation body. Therefore, the gate electrode layer 103 can also be formed over the substrate 100 with good adhesion using a substance containing silicon oxide that has good adhesion with the substrate 100.

  Further, since the first insulating layer 105a is formed by a coating method, the gate electrode layer 103 can be covered with good coverage, which is effective in planarizing the surface. In addition, since the second insulating layer 105b can form a dense film, electrical characteristics such as high breakdown voltage can be improved. Therefore, poor coverage due to surface unevenness on the surface to be formed, deterioration of electrical characteristics caused by defects included in the insulating layer, and the like can be prevented, and a highly reliable thin film transistor can be obtained.

  A connection wiring layer 160, a connection wiring layer 161, and a connection wiring layer 162 are formed over the substrate 100 in the same process as the gate electrode layer 103. Then, a part of the gate insulating layer is etched so that the connection wiring layer 160, the connection wiring layer 161, and the connection wiring layer 162 are exposed, and the source or drain electrode layer 111, the source or drain electrode layer 112 is etched. Various circuits can be realized by connecting TFTs as appropriate by the connection wiring layer 163 formed in the same process.

(Embodiment 6)
Next, a mode in which a driver circuit for driving is mounted on a display panel manufactured according to Embodiment Modes 4 to 5 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 drive circuits is divided into rectangles, and the divided drive circuit (also referred to as a driver IC) is mounted on the substrate 2700. FIG. 15A illustrates a mode in which a plurality of driver ICs 2751 and an FPC 2750 are mounted on the tip 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 side driver circuit 3702 is formed over the substrate as shown in FIG. 14B, a driver IC in which a signal line side driver circuit is formed is mounted in a region outside the pixel portion 3701. Is done. 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. 15A and 15B, 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, the surface can be formed with good flatness and better adhesion, so that a fine wiring with a short channel width can be stably prevented from causing defects such as a short circuit due to poor coverage or film peeling. Can be formed. 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. In addition, when the present invention is used, the surface can be formed with good flatness and adhesion, so that wiring can be stably formed without causing defects such as a short circuit due to poor coverage or peeling of the film. Therefore, it is possible to sufficiently cope with such a 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 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 the pixel shown in FIG. 17A, a signal line 410, a power supply line 411, a power supply line 412, a power supply line 413, and a scanning line 414 are arranged in the column direction. In addition, the pixel includes a TFT 401 that is a switching TFT, a TFT 403 that is a driving TFT, a TFT 404 that is a current control TFT, a capacitor element 402, and a light emitting element 405.

  The pixel shown in FIG. 17C is different from the pixel shown in FIG. 17A except that the gate electrode of the TFT 403 is connected to the power supply line 415 arranged in the row direction. is there. That is, both pixels shown in FIGS. 17A and 17C show the same equivalent circuit diagram. However, in the case where the power supply line 412 is arranged in the column direction (FIG. 17A) and the power supply line 415 is arranged in the row direction (FIG. 17C), 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 403 is connected, and FIGS. 17A and 17C are shown separately to show that the layers for producing these are different.

As a feature of the pixel shown in FIGS. 17A and 17C, a TFT 403 and a TFT 404 are connected in series in the pixel, and the channel length L ₃ and channel width W _{3 of} the TFT 403 and the channel length L ₄ and channel width of the TFT 404 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. In addition, when the present invention is used, the surface can be formed with good flatness and better adhesion, so that a fine wiring with a short channel width can be stably prevented from causing defects such as a short circuit due to poor coverage or film peeling. Can be formed. Accordingly, a TFT having electric characteristics necessary for sufficiently functioning a pixel as shown in FIGS. 17A and 17C can be formed, and a highly reliable display panel with excellent display capability can be manufactured. .

Note that the TFT 403 operates in a saturation region and has a role of controlling a current value flowing through the light emitting element 405, and the TFT 404 has a role of controlling a current supply to the light emitting element 405 by operating in a linear region. Both TFTs preferably have the same conductivity type in terms of manufacturing process. The TFT 403 may be a depletion type TFT as well as an enhancement type. In the present invention having the above structure, since the TFT 404 operates in a linear region, a slight change in V _GS of the TFT 404 does not affect the current value of the light emitting element 405. That is, the current value of the light emitting element 405 is determined by the TFT 403 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 pixel shown in FIGS. 17A to 17D, a TFT 401 controls input of a video signal to the pixel. When the TFT 401 is turned on and a video signal is input into the pixel, the capacitor 402 The video signal is held in Note that FIGS. 17A and 17C illustrate a structure in which the capacitor 402 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. In this case, the capacitor 402 is not necessarily provided explicitly.

  The light-emitting element 405 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. 17B has the same pixel structure as that shown in FIG. 17A except that a TFT 406 and a scanning line 416 are added. Similarly, the pixel illustrated in FIG. 17D has the same pixel structure as that illustrated in FIG. 17C except that a TFT 406 and a scanning line 416 are added.

  The TFT 406 is controlled to be turned on or off by a newly arranged scanning line 416. When the TFT 406 is turned on, the charge held in the capacitor 402 is discharged and the TFT 404 is turned off. That is, a state in which no current flows through the light emitting element 405 can be created by the arrangement of the TFT 406. Accordingly, the configurations in FIGS. 17B and 17D 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. 17E, a signal line 450, a power supply line 451, a power supply line 452, and a scanning line 453 are arranged in the column direction. Further, the pixel includes a TFT 441 that is a switching TFT, a TFT 443 that is a driving TFT, a capacitor 442, and a light-emitting element 444. The pixel illustrated in FIG. 17F has the same pixel structure as that illustrated in FIG. 17E except that a TFT 445 and a scanning line 454 are added. Note that the duty ratio of the structure in FIG. 17F can also be improved by the arrangement of the TFTs 445.

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

(Embodiment 8)
One mode in which protective diodes are provided in the scanning line side input terminal portion and the signal line side input terminal portion will be described with reference to FIG. In FIG. 24, a pixel 2702 is provided with a TFT 501, a TFT 502, a capacitor 504, and a light emitting element 503. This TFT has a configuration similar to that of the second embodiment.

  A protection diode 561 and a protection diode 562 are provided in the signal line side input terminal portion. This protection diode is manufactured in the same process as the TFT 501 or the TFT 502, and is operated as a diode by connecting the gate and one of the drain or the source. An equivalent circuit diagram of the top view shown in FIG. 24 is shown in FIG.

  The protection diode 561 includes a gate electrode layer, a semiconductor layer, and a wiring layer. The protective diode 562 has a similar structure. The common potential line 554 and the common potential line 555 connected to the protection diode are formed in the same layer as the gate electrode layer. Therefore, in order to be electrically connected to the wiring layer, it is necessary to form a contact hole in the gate insulating layer.

  The contact hole to the gate insulating layer may be etched by forming a mask layer. In this case, 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.

  The signal wiring layer is formed of the same layer as the source and drain wiring layer 505 in the TFT 501, and has a structure in which the signal wiring layer connected thereto and the source or drain side are connected.

  The input terminal portion on the scanning signal line side has the same configuration. The protective diode 563 includes a gate electrode layer, a semiconductor layer, and a wiring layer. The protective diode 564 has a similar structure. The common potential line 556 and the common potential line 557 connected to the protection diode are formed in the same layer as the source and drain wiring layers. A protection diode provided in the input stage can be formed at the same time. Note that the position at which the protective diode is inserted is not limited to this embodiment mode, and can be provided between the driver circuit and the pixel.

  As described above, when the present invention is used, a pattern such as a wiring can be stably formed with good controllability without causing defective formation. Even if it is formed densely, a short circuit or the like due to poor installation during formation will not occur. In addition, since it is not necessary to consider a wide margin, even if the device is reduced in size and thickness, it can sufficiently cope. Therefore, a display device having favorable electrical characteristics and high reliability can be manufactured.

(Embodiment 9)
FIG. 22 shows an example in which an EL display module is formed using a TFT substrate 2800 manufactured by applying the present invention. In FIG. 22, a pixel portion including pixels is formed over a TFT substrate 2800.

  In FIG. 22, 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 and the 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. A space 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 a light-transmitting resin material. Then, it may be filled with dehydrated nitrogen or inert gas.

  FIG. 22 shows a case where the light-emitting element 2804 and the light-emitting element 2805 have a top emission type (top emission type) configuration, in which light is emitted 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 external circuit board 2811 through a wiring board 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. 22, 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 and lower surfaces. 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, 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.

(Embodiment 10)
A television device can be completed with the display device formed according to the present invention. In the display panel, only the pixel portion is formed as shown in FIG. 14A, and the scanning line side driver circuit and the signal line side driver circuit are mounted by the TAB method as shown in FIG. 15B. And a case where the TFT is formed by SAS as shown in FIG. 14B, 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, or the pixel portion, the signal line side driver circuit, and the scanning line side driver circuit are integrally formed on 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.

  FIG. 30 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. A polarizing plate 2606, a polarizing plate 2607, and a lens film 2613 are disposed outside the TFT substrate 2600 and the counter substrate 2601. The light source is composed of a cold cathode tube 2610 and a reflector 2611. The circuit board 2612 is connected to the TFT substrate 2600 by a drive circuit 2608 and a flexible wiring board 2609, and an external circuit such as a control circuit or a power supply circuit is incorporated. .

  As shown in FIGS. 20A and 20B, the display module can be incorporated into a housing to complete the television device. When an EL display module as shown in FIG. 22 is used, a liquid crystal television device can be completed when a liquid crystal display module as shown in FIG. 30 is used for an EL television device. 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.

  In addition, as shown in FIG. 19, reflected light of light incident from the outside may be blocked using a retardation plate or a polarizing plate. FIG. 19 shows a top emission type structure in which an insulating layer 3605 serving as a partition is colored and used as a black matrix. This partition wall can be formed by a droplet discharge method, and carbon black or the like may be mixed with a resin material such as polyimide, or may be 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. In the present embodiment, a pigment-based black resin is used. As the phase difference plate 3603 and the phase difference plate 3604, a λ / 4 plate, a λ / 2 plate, or the like may be used so that light can be controlled. As a structure, a TFT substrate 2800, a light emitting element 2804, a sealing substrate (sealing material) 2820, a retardation plate 3603, a retardation plate 3604 (λ / 4 plate, λ / 2 plate), and a polarizing plate 3602 are sequentially formed. The light emitted from the element passes through them 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 3601 may be provided outside the polarizing plate. This makes it possible to display a higher-definition and precise image.

  As shown in FIG. 20A, a display panel 2002 using a display element is incorporated in a housing 2001, and reception of general television broadcasting is started by a receiver 2005, and a wired or wireless connection is made via a modem 2004. By connecting to a communication network, information communication in one direction (from the sender to the receiver) or in both directions (between the sender and the receiver or between the receivers) can be performed. 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. 20B 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 keyboard portion 2012 that is an operation portion, a speaker portion 2013, and the like. The present invention is applied to manufacture of the keyboard part 2012 which is an operation part. Since the display portion in FIG. 20B uses a bendable substance, the television set has a curved display portion. According to the present invention, since the wiring and the insulating layer constituting the display device are formed with good adhesion, even such a bent shape can be sufficiently dealt with without causing film peeling. Since the shape of the display portion can be freely designed as described above, a television device having a desired shape can be manufactured.

  By using the present invention, the process can be simplified, and a display panel can be easily manufactured even if a glass substrate of the fifth generation or more in which one side exceeds 1000 mm is used.

  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 television device using the present invention can be formed at low cost even if it has a large screen display portion. Further, even if the shape is freely designed, no formation failure occurs. Therefore, a high-performance and highly reliable television device can be manufactured with high yield.

  Of course, the present invention is not limited to a television device, but can be applied to various applications such as personal computer monitors, information display boards at railway stations and airports, and advertisement display boards on streets. 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 cameras such as video cameras and 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 or An electronic book), and an image reproducing apparatus (specifically, an apparatus having 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. 21A illustrates a 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. By using the present invention, a computer that displays a high-quality image with high reliability can be completed even if the device is downsized and wiring and the like are refined.

  FIG. 21B 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 A2203 mainly displays image information, and the display portion B2204 mainly displays character information. By using the present invention, an image reproducing device that displays a high-quality image with high reliability can be completed even if the device is downsized and wiring and the like are refined.

  FIG. 21C 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 using the present invention, a mobile phone that displays a high-quality image with high reliability can be completed even if the mobile phone is downsized and wiring and the like are refined.

  FIG. 21D illustrates a video camera, which includes a main body 2401, a display portion 2402, a housing 2403, an external connection port 2404, a remote control reception portion 2405, an image receiving portion 2406, a battery 2407, an audio input portion 2408, operation keys 2410, and an eyepiece. Part 2409 and the like. By using the present invention, a video camera capable of displaying a high-reliability and high-quality image even if the size is reduced and wiring and the like are made precise can be completed. This embodiment mode can be freely combined with the above embodiment modes.

    In this example, the effect of the present invention will be described based on experimental results.

    As a comparative example, the present invention was not applied, and a composition containing silver as a conductive material was discharged onto a glass substrate and dried and fired to form a silver wiring. FIG. 31 shows the result of silver wiring formed by the droplet discharge method using silver as the conductive material of the comparative example. FIG. 31 (A) shows an atomic force microscope (AFM) photograph of a silver wiring that was fired for 30 seconds after discharging a composition containing particulate silver, and FIG. It is the AFM photograph baked for 2 seconds. The firing temperature is 400 to 450 degrees (° C.). As shown in FIGS. 31A and 31B, the silver wiring surface has irregularities and poor flatness. FIG. 31C shows the result of profiling the surface of the silver wiring in the range of about 500 nm in cross section. The surface of the silver wiring showed an uneven shape, and the silver wiring with a firing time of 120 seconds had an unevenness of 50 nm or more. Thus, it was confirmed that the conductive layer formed by discharging and baking the composition containing the conductive material has irregularities on the surface and the flatness may be deteriorated.

  Next, a sample in which an insulating layer was formed over the first silver electrode and a second silver electrode was formed over the insulating layer was manufactured using the droplet discharge method as described above. Samples were formed by the droplet discharge method using silver as the conductive material in the same manner for the silver electrodes. An insulating layer formed between the first silver electrode and the second silver electrode is formed on Sample A in which a 100 nm-thick silicon nitride film is stacked on a 100 nm-thick siloxane polymer film, and on a 150 nm-thick siloxane polymer film. Three types of samples were prepared by changing the sample B to a sample B in which silicon nitride having a thickness of 100 nm was stacked and the sample C having only a siloxane polymer film having a thickness of 150 nm. An optical micrograph of each sample is shown in FIGS. 32A (sample A), 33 (A) (sample B), and 34 (A) (sample C).

    A voltage was applied between the silver electrodes of Sample A, Sample B, and Sample C, and the withstand voltage of the insulating layer was measured. FIG. 32B (sample A), FIG. 33B (sample B), and FIG. 34B (sample C) show changes in the current value of the insulating layer with respect to the voltage applied to each sample. Applying the present invention, a lamination of a siloxane polymer film formed by a coating method which is a first insulating layer containing an organic material and a silicon nitride film formed by a sputtering method which is a second insulating layer containing an inorganic material In Sample A and Sample B, no current flows even when a large voltage is applied. However, in the insulating layer of one layer of the siloxane polymer film, it was confirmed that the withstand voltage could not be obtained near the voltage of −30V, and the current flowed, the insulating layer was destroyed and it did not have a function as the insulating layer. .

    Therefore, it was confirmed that an insulating layer capable of imparting an effect of improving electrical characteristics (strength) can be formed by using the present invention. By this invention, a structure can be formed with sufficient adhesiveness with a desired pattern. In addition, there is little material loss, and cost reduction can be achieved. Thus, a high-performance and highly reliable thin film transistor and display device can be manufactured with high yield.

    Also in this example, the effect of the present invention will be described based on experimental results.

    Two types of silver wiring formed by discharging a composition containing silver as a conductive material were produced. One is a silver wiring as a comparative example consisting only of the composition, and the other is the same material added to at least one of the materials forming the surface of the object in the composition. A silver wiring containing at least one of the substances forming the surface of the formed product.

A sample (sample X1, sample X2, sample Y1, sample Y2) in which an amorphous silicon film was formed on a glass substrate by a CVD method and silver wiring was formed on the amorphous silicon film was manufactured. A liquid composition containing silver as a conductive material was attached to the surface of each object to be formed, and baked under different conditions to form silver wiring. A substance containing SiO ₂ , B ₂ O ₃ , and R ₂ O was used as the same substance as the substance forming the surface of the object to be formed.

    As a sample, a sample using silver as a conductive material was discharged onto an amorphous silicon film on a glass substrate and baked at 300 ° C. for 1 hour, sample X1 baked at 500 ° C. for 10 minutes in a nitrogen atmosphere X2, on the amorphous silicon film on the glass substrate, a composition obtained by adding at least one of the substances forming the surface of the object in the composition to the composition is discharged and baked at 300 ° C. for 1 hour. Sample Y1 and sample Y2 baked at 500 ° C. for 10 minutes in a nitrogen atmosphere were produced.

    The samples X1, X2, Y1, and Y2 were immersed in a 0.5 wt% hydrofluoric acid diluted solution, and the adhesion of the silver wiring to the material to be formed was evaluated. The results are shown below.

    Sample X1 in which only silver wiring is formed on an amorphous silicon film on a glass substrate is peeled off after 30 seconds after immersion in a hydrofluoric acid solution, and sample X2 is peeled off from the amorphous silicon film in about 1 minute. I have. On the other hand, the sample Y1 in which the silver wiring containing the same material as the material forming the surface of the object to be formed is only about one third of the silver wiring from the amorphous silicon film even after 2 minutes. In the sample Y2, the silver wiring was hardly peeled off from the amorphous silicon film even after 2 minutes.

    The silver wiring containing at least one of the substances that form the surface of the formed object has higher adhesion to the amorphous silicon film that is the formed object. It was confirmed that the adhesion between the silver wiring and the formed object was improved by the effect of at least one of the substances to be formed. Therefore, according to the present invention, the constituent can be formed in a desired pattern with good adhesion. In addition, there is little material loss, and cost reduction can be achieved. Thus, a high-performance and highly reliable thin film transistor and display device can be manufactured with high yield.

The figure explaining this invention. The figure explaining this 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 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. The top view of the display apparatus of this invention. The top view of the display apparatus of this invention. 4A to 4D illustrate a method for manufacturing a display device of the present invention. 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. FIG. 6 is a top view illustrating a display panel of the present invention. Sectional drawing explaining the structural example of EL display module of this invention. FIG. 11 illustrates an electronic device to which the present invention is applied. FIG. 11 illustrates an electronic device to which the present invention is applied. Sectional drawing explaining the structural example of EL display module of this invention. FIG. 25 is an equivalent circuit diagram of an EL display panel described in FIG. FIG. 14 is a top view illustrating an EL display panel of the present invention. 6A and 6B illustrate a circuit structure in the case where a scan line side driver circuit is formed using TFTs in an EL display panel of the present invention. 6A and 6B illustrate a circuit configuration in the case where a scan line side driver circuit is formed using TFTs in an EL display panel of the present invention (shift register circuit). 4A and 4B illustrate a circuit configuration in the case where a scan line side driver circuit is formed using TFTs in an EL display panel of the present invention (buffer circuit). 2A and 2B illustrate a structure of a droplet discharge device that can be applied to the present invention. 4A and 4B illustrate a liquid crystal dropping injection method that can be applied to the present invention. Sectional drawing explaining the structural example of the liquid crystal display module of this invention. AFM measurement data of silver wiring formed by the droplet discharge method. The micrograph of the sample A produced in Example 1, and the data of a pressure | voltage resistant measurement. The micrograph of the sample B produced in Example 1 and the data of a pressure | voltage resistant measurement. The micrograph of the sample C produced in Example 1, and the data of a pressure | voltage resistant measurement.

Claims (3)

Having first and second transistors and a light emitting element;
The gate electrodes of the first and second transistors are formed by discharging a composition containing a solvent and conductive particles,
In the composition, at least one of the substances forming the surface of the gate electrode is dispersed.
The first and second transistors are electrically connected in series between a first wiring for supplying a power supply potential and the light emitting element,
The first transistor has a gate electrically connected to a second wiring for supplying a power supply potential, and has a function of operating in a saturation region and controlling a current value flowing through the light-emitting element;
The second transistor has a gate electrically connected to a third wiring that supplies a potential corresponding to a video signal, and operates in a linear region to control a current supply to the light emitting element. A semiconductor device characterized by the above. Having first and second transistors and a light emitting element;
The source and drain electrodes of the first and second transistors are formed by discharging a composition containing a solvent and conductive particles,
In the composition, at least one of the substances forming the surface of the source electrode and the drain electrode is dispersed.
The first and second transistors are electrically connected in series between a first wiring for supplying a power supply potential and the light emitting element,
The first transistor has a gate electrically connected to a second wiring that supplies a potential corresponding to a power supply potential, and has a function of operating in a saturation region and controlling a current value flowing through the light emitting element. ,
The second transistor is electrically connected to a third wiring for supplying a video signal and has a function of operating in a linear region to control supply of current to the light emitting element. Semiconductor device. In claim 1 or claim 2,
When the channel length of the first transistor is L1, the channel width is W1, the channel length of the second transistor is L2, and the channel width is W2, L1 / W1: L2 / W2 = 5 to 6000: 1 is satisfied. A semiconductor device.