JP4954836B2 - Method for manufacturing semiconductor device - Google Patents

Description

  The present invention relates to a method for manufacturing a semiconductor device. In particular, the present invention relates to a method for forming an opening in a thin film such as a conductive layer or an insulating layer.

  Conventionally, MOS transistors and thin film transistors (hereinafter also referred to as TFTs) and semiconductor devices having them are manufactured by forming a thin film such as an insulating layer and a conductive layer on a substrate and appropriately forming a desired pattern by lithography. Yes. Lithography technology is a technology that uses light to transfer a circuit pattern, etc., formed of a light-shielding material on a transparent flat plate called a photomask to a target object, such as a semiconductor integrated circuit. It is widely used in the manufacturing process.

  However, a manufacturing process using a lithography technique requires a multi-step process such as resist coating using a photosensitive resin called a photoresist, pattern exposure, development, etching using a resist as a mask, and resist stripping. Therefore, as the number of lithography processes increases, the cost increases and the throughput decreases.

  For example, Patent Document 1 describes a method for manufacturing a semiconductor device that eliminates an etching process when forming an opening in an insulating film and simplifies the lithography process. Specifically, a resist film is formed in advance in a region where an opening is to be formed, an insulating film is formed in a region other than the resist film, and the resist film is removed to form an opening in the insulating film.

JP 2001-77194 A

  An object of the present invention is to provide a semiconductor device manufacturing technique that simplifies the lithography process or a semiconductor device manufacturing technique that reduces the number of lithography processes.

  Another object of the present invention is to provide a semiconductor device manufacturing apparatus that can process a thin film without using a photoresist.

  The present invention uses an ablation by irradiation of a laser beam without using a photoresist, or an opening for electrically connecting conductive layers, or for electrically connecting a conductive layer and a semiconductor layer. An opening is formed. A process of forming a pattern using laser ablation as in the present invention is referred to herein as a laser ablation patterning process (LAPP). The present invention forms an opening pattern using laser ablation.

  Note that in this specification, ablation (also referred to as laser ablation) refers to a phenomenon in which part of an irradiation region of an irradiated object is removed by irradiation with a laser beam. Here, the ablation is a sublimation in which a part of the irradiation region of the irradiated object changes from a solid state to a gas state by laser beam irradiation, and evaporation in which the phase of the irradiation region changes from a solid state to a liquid state to a gas state. And both.

  The irradiated body is a stacked body in which a light absorption layer and an insulating layer are stacked on a substrate. Moreover, the to-be-irradiated body may have a conductive layer formed under the light absorption layer. Irradiation is performed so as to superimpose a multimode laser beam and a single mode laser beam from the insulating layer side, and an opening is formed in a part of the irradiated object in the region irradiated so as to be superimposed.

  The multimode laser beam and the single mode laser beam irradiated from the insulating layer side are transmitted through the insulating layer and absorbed by the light absorption layer. In the region irradiated so that the multimode laser beam and the single mode laser beam are superimposed, the energy of both laser beams is synthesized. The light absorption layer absorbs the combined energy in the region irradiated so that the multimode laser beam and the single mode laser beam overlap, and is heated by the energy. As a result, the insulating layer stacked at least on the upper layer of the light absorption layer is destroyed and removed, and an opening is formed in the insulating layer. A part or all of the light absorption layer in the region irradiated with the laser beam may be removed together with the insulating layer.

  The light absorption layer is formed using a material that absorbs a laser beam. The insulating layer is formed using a material that transmits a laser beam.

  The multimode laser beam may be emitted from a laser oscillation apparatus that can obtain a multimode laser beam. The single mode laser beam may be emitted from a laser oscillation device that can obtain a single mode laser beam.

  By utilizing laser ablation, an opening can be formed without using a lithography process using a photoresist.

  In the present invention, a light absorption layer is formed, an insulating layer is formed on the light absorption layer, and a multimode laser beam and a single mode laser beam are irradiated from the insulating layer side so as to overlap each other. The insulating layer in the region irradiated with the beam and the single mode laser beam is removed, and an opening is formed in the insulating layer.

  In another configuration of the present invention, a light absorption layer is formed, an insulating layer is formed on the light absorption layer, and irradiation is performed so as to superimpose a multimode laser beam and a single mode laser beam from the insulating layer side, The light absorption layer and the insulating layer in a region irradiated with the multimode laser beam and the single mode laser beam are removed, and an opening is formed in the light absorption layer and the insulating layer.

  In another structure of the present invention, a light absorption layer is formed on a conductive layer, an insulating layer is formed on the light absorption layer, and a multimode laser beam and a single mode laser beam are superimposed from the insulating layer side. Irradiation is performed to remove the insulating layer in the region irradiated with the multimode laser beam and the single mode laser beam, and an opening is formed in the insulating layer.

  In another structure of the present invention, a light absorption layer is formed on a conductive layer, an insulating layer is formed on the light absorption layer, and a multimode laser beam and a single mode laser beam are superimposed from the insulating layer side. Irradiation is performed to remove the light absorption layer and the insulating layer in the region irradiated with the superposition of the multimode laser beam and the single mode laser beam, and an opening is formed in the light absorption layer and the insulating layer.

The multimode laser beam is preferably a laser beam emitted from a YAG laser, a YVO ₄ laser, or an excimer laser.

  The single mode laser beam is preferably a laser beam emitted from a femtosecond laser or a picosecond laser.

  The light absorption layer is preferably formed using a material that absorbs a multimode laser beam and a single mode laser beam.

  In another configuration of the present invention, the light absorption layer is made of chromium (Cr), molybdenum (Mo), nickel (Ni), titanium (Ti), cobalt (Co), copper (Cu), aluminum (Al), It is preferable to use a material containing at least one element.

  In another configuration of the present invention, the light absorption layer includes silicon, germanium, silicon germanium, molybdenum oxide, tin oxide, bismuth oxide, vanadium oxide, nickel oxide, zinc oxide, gallium arsenide, gallium nitride, indium oxide, and phosphide. It is preferable to use a material containing at least one of indium, indium nitride, cadmium sulfide, cadmium telluride, and strontium titanate.

  The insulating layer is preferably formed using a material that transmits a multimode laser beam and a single mode laser beam.

  In another structure of the present invention, a conductive layer is formed in an opening formed in the insulating layer or the light absorption layer and the insulating layer.

  The present invention also provides a laser processing apparatus that can directly form an opening in an insulating layer.

  A laser processing apparatus of the present invention forms a first laser oscillation apparatus that emits a multimode first laser beam, a first laser beam emitted from the first laser oscillation apparatus, and forms an object to be irradiated. A first optical system for irradiation, a second laser oscillation device for emitting a single-mode second laser beam, and a second optical device for shaping the second laser beam emitted from the second laser oscillation device A system, an optical element that divides the second laser beam that has passed through the second optical system, and irradiates the irradiated body with the second laser beam so as to overlap the first laser beam; Holding and moving the stage to a desired location.

  In addition, a laser processing apparatus having another configuration forms a first laser oscillation apparatus that emits a multimode first laser beam, a first laser beam emitted from the first laser oscillation apparatus, A first optical system for irradiating the irradiation body, a second laser oscillation device for emitting a second laser beam in a single mode, and a second laser beam emitted from the second laser oscillation device. A second optical system that divides the second laser beam, and a second laser beam that divides the second laser beam that has passed through the second optical system and overlaps the first laser beam. A deflector that irradiates the irradiated object, and a stage that holds the irradiated object and moves the irradiated object to a desired location.

The first laser oscillation device is preferably a YAG laser, a YVO ₄ laser, or an excimer laser. The second laser oscillation device is preferably a femtosecond laser or a picosecond laser.

  In another configuration of the present invention, a part of the irradiated object in the region irradiated with the second laser beam is removed so as to overlap with the first laser beam.

  In another configuration of the present invention, the irradiated object is a stacked body in which a light absorption layer and an insulating layer are sequentially stacked on a substrate, and the second laser beam is overlapped with the first laser beam. Irradiation is performed to remove the light absorption layer and the insulating layer or the insulating layer.

  By applying the present invention, an opening can be formed in a thin film such as an insulating layer without using a photoresist.

  The present invention can reduce or simplify a lithography process when forming an opening in a manufacturing process of a semiconductor device. Therefore, it is possible to reduce manufacturing costs and improve throughput.

  Embodiments of the present invention will be described below with reference to the drawings. However, the present invention is not limited to the following description, and it will be 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 the structures of the present invention described below, the same reference numerals may be used in common in different drawings.

(Embodiment 1)
The present invention is characterized in that an opening is formed in a desired region without using a lithography technique using a photoresist. In this embodiment, an opening for electrically connecting the conductive layers is formed in the insulating layer. Hereinafter, one mode of a method for forming an opening in an insulating layer by applying the present invention will be specifically described with reference to FIGS.

  First, the substrate 10 in which the conductive layer 12, the light absorption layer 14, and the insulating layer 16 are sequentially stacked is prepared (see FIG. 1A). The substrate 10 on which the conductive layer 12, the light absorption layer 14, and the insulating layer 16 are sequentially stacked is the irradiated object of this embodiment.

  As the substrate 10, a glass substrate, a quartz substrate, a sapphire substrate, a ceramic substrate, a semiconductor substrate, or the like is used. Note that a base insulating layer can also be formed over the substrate 10. In that case, the base insulating layer may be formed using an insulating material such as silicon oxide, silicon nitride, silicon oxynitride, or silicon nitride oxide.

  The conductive layer 12 is not particularly limited and is formed using a conductive material. For example, silver (Ag), gold (Au), nickel (Ni), platinum (Pt), palladium (Pd), iridium (Ir), rhodium (Rh), tantalum (Ta), tungsten (W), titanium (Ti) ), Molybdenum (Mo), aluminum (Al), copper (Cu), or an alloy material or a compound material containing the element as a main component can be used. As the compound containing the element as a main component, a nitrogen compound, an oxygen compound, a carbon compound, a halogen compound, or the like can be used. Specifically, aluminum nitride, tungsten nitride, tantalum nitride, or the like can be used. The conductive layer 12 can be formed with a single-layer structure or a stacked structure by using these conductive materials by a sputtering method, a CVD method, or the like.

  The light absorption layer 14 is formed using a material capable of absorbing a laser beam. The light absorption layer 14 is preferably formed using a material having a boiling point or sublimation temperature lower than the melting point of the lower conductive layer 12. For example, any element of chromium (Cr), molybdenum (Mo), nickel (Ni), titanium (Ti), cobalt (Co), copper (Cu), aluminum (Al), or the element as a main component Conductive materials such as alloy materials or compounds can be used. As the compound containing the element as a main component, a nitrogen compound, an oxygen compound, a carbon compound, a halogen compound, or the like can be used. For example, aluminum nitride, tungsten nitride, tantalum nitride, or the like can be used. In addition, silicon, germanium, silicon germanium, molybdenum oxide, tin oxide, bismuth oxide, vanadium oxide, nickel oxide, zinc oxide, gallium arsenide, gallium nitride, indium oxide, indium phosphide, indium nitride, cadmium sulfide, cadmium telluride A semiconductor material such as strontium titanate can be used. Further, zinc sulfide, silicon nitride, mercury sulfide, aluminum chloride, or the like can be used. The light absorption layer 14 can be formed with a single-layer structure or a stacked structure by using a material as described above by a vapor deposition method, a sputtering method, a CVD method, or the like. Further, hydrogen or an inert gas (a rare gas such as helium (He), argon (Ar), krypton (Kr), neon (Ne), or xenon (Xe)) can be added to the light absorption layer 14. By adding hydrogen or an inert gas to the light absorption layer 14, it is possible to easily cause gas emission or evaporation in the light absorption layer 14 when the laser beam is irradiated later.

  The insulating layer 16 is formed using a material that can transmit a laser beam. For example, a light-transmitting inorganic insulating material or organic insulating material is used. As the inorganic insulating material, silicon oxide, silicon nitride, silicon oxynitride, silicon nitride oxide, or the like can be used. As the organic insulating material, organic resins such as polyimide, acrylic, polyamide, polyimide amide, benzocyclobutene, and epoxy resin can be used. The insulating layer 16 can be formed with a single layer structure or a stacked structure by using these materials by a sputtering method, a CVD method, a coating method, or the like.

  Next, a laser beam is irradiated from the insulating layer 16 side. The laser beam is irradiated so that the first laser beam 18 and the second laser beam 20 overlap each other. In the light absorption layer 14 and the insulating layer 16, a region irradiated with the first laser beam 18 and the second laser beam 20 is referred to as a superimposed irradiation region 22 (see FIG. 1B).

  As the first laser beam 18, a multi-mode laser beam is irradiated. As the second laser beam 20, a single mode laser beam is irradiated. Here, FIG. 3A shows a waveform of energy distribution in a cross section of a multimode laser beam (corresponding to the first laser beam 18). FIG. 3B shows a waveform of energy distribution in a cross section of a single mode laser beam (corresponding to the second laser beam 20). The waveforms shown in FIGS. 3A and 3B are obtained by looking at the energy distribution in the cross section perpendicular to the traveling direction of the laser beam. In the waveforms shown in FIGS. 3A and 3B, the vertical axis indicates the energy intensity of the laser beam, and the horizontal axis indicates the distance from the center of the laser beam.

The energy distribution in the cross section of the multimode laser beam as shown in FIG. 3A has a wide peak width. A multimode laser beam generally has a high energy of the entire laser beam, and a large output can be obtained. Such a multimode laser beam, that is, the first laser beam 18 in the present embodiment is an excimer laser oscillator such as KrF, ArF, or XeCl, or a gas laser oscillator such as He, He—Cd, Ar, or He—Ne. , Single crystal YAG, YVO ₄ , forsterite (Mg ₂ SiO ₄ ), YAlO ₃ , GdVO ₄ , or polycrystalline (ceramic) YAG, Y ₂ O ₃ , YVO ₄ , YAlO ₃ , GdVO ₄ as dopants A solid laser oscillator using one or more of Nd, Yb, Cr, Ti, Ho, Er, Tm, Ta added as a medium, a semiconductor laser oscillator such as GaN, GaAs, GaAlAs, InGaAsP, or the like is used. Can be obtained. Preferably, as the first laser beam 18, a high output is easily obtained when a YAG laser, a YVO ₄ laser, or an excimer laser is used. In the case of using a solid-state laser oscillator, it is preferable to select and use the fifth harmonic from the fundamental wave as appropriate. A gas laser oscillator and a solid-state laser oscillator can obtain a multimode laser beam by appropriately selecting an excitation method. The first laser beam 18 may be either a continuous wave laser beam or a pulsed laser beam.

On the other hand, the energy distribution in the cross section of the single mode laser beam as shown in FIG. 3B has a sharp peak near the center (near the center of the laser beam). A waveform as shown in FIG. 3B is also called a Gaussian distribution. A single-mode laser beam has a sharp peak and thus has a high light-condensing property. It is also possible to focus the laser beam on a spot with a diameter of several μm. Such a single mode laser beam, that is, the second laser beam 20 in the present embodiment, is a pulsed laser that can obtain a laser beam having a pulse width in the picosecond range or a femtosecond ( ^10-15 seconds) range. Oscillator, gas laser oscillator such as He, He—Cd, Ar, He—Ne, single crystal YAG, YVO ₄ , forsterite (Mg ₂ SiO ₄ ), YAlO ₃ , GdVO ₄ , or polycrystalline (ceramic) YAG , Y ₂ O ₃ , YVO ₄ , YAlO ₃ , GdVO ₄ , a solid containing one or more of Nd, Yb, Cr, Ti, Ho, Er, Tm, and Ta as dopants It can be obtained using a laser oscillator or the like. When using a solid-state laser oscillator, it is preferable to select and use the fifth harmonic from the fundamental wave as appropriate. A gas laser oscillator and a solid-state laser oscillator can obtain a single mode laser beam by appropriately selecting an excitation method.

  The first laser beam 18 and the second laser beam 20 pass through the insulating layer 16 and are absorbed by the light absorption layer 14. The light absorption layer 14 is ablated in the region (superimposed irradiation region 22) irradiated with the first laser beam 18 and the second laser beam 20 superimposed, and is removed together with the upper insulating layer 16. As a result, the opening 24 is formed. The conductive layer 12 is exposed at the bottom surface of the opening 24 (see FIG. 1C).

  Ablation occurs when a laser beam having energy above a certain threshold is irradiated. Hereinafter, in this specification, the threshold value of the energy of the laser beam at which ablation occurs is also referred to as an ablation threshold value. In the present embodiment, the light absorption layer 14 and the insulating layer 16 are ablated when the energy of the laser beam absorbed by the light absorption layer 14 is equal to or greater than the ablation threshold. Therefore, when the energy of the laser beam absorbed by the light absorption layer 14, that is, the irradiated laser beam is less than the ablation threshold, the light absorption layer 14 and the insulating layer 16 are not ablated even when the laser beam is irradiated.

  In the present embodiment, the energy of the first laser beam 18 is less than the ablation threshold. It is assumed that the energy of the second laser beam 20 is equal to or greater than the ablation threshold when combined with the energy of the first laser beam 18.

  For example, the energy of the first laser beam 18 is A, the energy of the second laser beam 20 is B, and the energy of the ablation threshold is C. The present invention satisfies the following formulas (1) and (2).

  In a region to be irradiated with only the first laser beam 18, the first laser beam 18 passes through the insulating layer 16 and is absorbed by the light absorption layer 14. However, ablation is not performed because the energy of the laser beam absorbed by the light absorption layer 14 is less than the ablation threshold. In the region irradiated so that the first laser beam 18 and the second laser beam 20 are superimposed, the energy of the first laser beam 18 and the second laser beam 20 is synthesized. As a result, the energy of the laser beam absorbed by the light absorption layer 14 becomes equal to or higher than the ablation threshold, and ablation is performed. The shape of the opening 24 formed in the irradiated object (the light absorption layer 14 and the insulating layer 16) by the ablation depends on the second laser beam 20. Since the second laser beam 20 can provide energy locally with good light condensing properties, a fine opening having a diameter of several μm can be formed.

  In general, a multi-mode laser beam has an advantage that a large output can be obtained, but it has a poor light condensing property and can only condense up to a diameter of about several hundred μm. On the other hand, a single-mode laser beam can give energy locally, so it has good light-collecting properties and has the advantage of being able to collect light with a diameter of about several μm. was difficult.

  The present inventors do not alter the irradiated object at all even if the irradiated object is irradiated with a laser beam having an energy less than the ablation threshold, and ablation is performed only when irradiated with a laser beam having an energy higher than the ablation threshold. I found out that This will be described in detail with reference to FIG.

  32A and 32B are diagrams showing the relationship between ablation and energy, where the vertical axis indicates energy (E) and the horizontal axis indicates length. Further, an energy distribution waveform 3420 in the cross section of the multimode laser beam and an energy distribution waveform 3422 in the cross section of the single mode laser beam are shown.

  In FIG. 32A, the irradiated object is not altered at all even when irradiated with a laser beam having energy lower than the ablation threshold 3202, that is, energy within the energy range 3200. Waveform 3420 is within energy range 3200, ie below ablation threshold 3202. Therefore, even if the irradiated object is irradiated with a multimode laser beam having an energy distribution showing the waveform 3420, the irradiated object is not altered at all.

  FIG. 32B illustrates an example of irradiation with a single mode laser beam with an energy distribution indicated by a waveform 3422 so as to overlap with a multimode laser beam with an energy distribution indicated by a waveform 3420. In the overlapped irradiation region, the energy of the multimode laser beam having the energy distribution indicated by the waveform 3420 and the energy of the single mode laser beam having the energy distribution indicated by the waveform 3422 are combined, and the waveform 3422 becomes equal to or higher than the ablation threshold 3202. As a result, the irradiated object is ablated only in the region irradiated with the multimode laser beam and the single mode laser beam superimposed. Further, since the ablation of the irradiated object depends on the single mode laser beam, the shape and size of the opening formed by ablating the irradiated object also depends on the single mode laser beam.

  In the present invention, the multimode first laser beam 18 and the single mode second laser beam 20 are superimposed on each other to irradiate the object to be irradiated, thereby giving energy equal to or higher than the ablation threshold. From FIG. 32, it can be seen that the multimode first laser beam 18 can be made as high as possible as long as it is less than the ablation threshold. Therefore, the present invention can obtain a high assist effect with a multi-mode laser beam, so that the energy of the single-mode laser beam can be reduced. That is, the following formula (3) is made possible.

  Therefore, it is possible to use the advantages of both the ability to gain energy with a multimode laser beam and to form a fine aperture with a single mode laser beam. By irradiating the multimode first laser beam 18, it is possible to irradiate a laser beam having a certain size and uniform energy over a wide range. Then, the region where the opening is to be formed by ablation is irradiated with the single-mode second laser beam 20 so as to overlap the multi-mode first laser beam 18. Since the second laser beam 20 can give energy locally, it can be ablated in a fine region to form a fine opening.

  Further, as described above, since the irradiation energy of the single mode second laser beam 20 can be reduced, the second laser beam 20 can be divided into a plurality of laser beams. As a result, a plurality of fine openings can be formed simultaneously.

For example, the multimode first laser beam 18 can easily obtain a large output when a YAG laser, a YVO ₄ laser, or an excimer laser is used. Therefore, it is preferable to use these lasers because high energy can be easily given over a wide range and the assist effect is enhanced. In addition, the single-mode second laser beam can be easily focused on a fine region by using a femtosecond laser or a picosecond laser. Therefore, it is preferable to use these lasers because energy can be easily applied locally and fine processing can be performed.

  Next, a conductive layer 26 is formed in the opening 24. The conductive layer 26 is electrically connected to the conductive layer 12. In the case where the light absorption layer 14 is formed using a conductive material, the conductive layer 26 is also electrically connected to the light absorption layer 14 (see FIG. 1D). Through the above steps, an opening for electrically connecting the conductive layer and the conductive layer can be formed in the insulating layer without using a lithography technique using a photoresist.

  By applying the present invention, an opening can be formed in a desired region without using a lithography process using a photoresist. Therefore, the lithography process can be reduced and simplified, loss of materials such as a resist material and a developer can be prevented, and the number of necessary photomasks can be reduced. As a result, the manufacturing cost of the semiconductor device can be reduced. Further, since the lithography process can be reduced and simplified, throughput can be improved.

(Embodiment 2)
In this embodiment, a structural example of the laser processing apparatus of the present invention will be described.

  FIG. 2 shows a schematic diagram of a laser processing apparatus. In FIG. 2, a laser processing device 200 includes a first laser oscillation device 202, a first optical system 206 that shapes a laser beam, a second laser oscillation device 208, and a second optical that shapes a laser beam. A system 210, a diffractive optical element 214 that divides the laser beam that has passed through the second optical system 210 into a plurality of parts, and a stage 215 are provided.

The first laser oscillation device 202 includes a laser oscillator that can obtain a multimode laser beam. For example, excimer laser oscillators such as KrF, ArF, and XeCl, gas laser oscillators such as He, He—Cd, Ar, and He—Ne, single crystal YAG, YVO ₄ , forsterite (Mg ₂ SiO ₄ ), YAlO ₃ , GdVO ₄ , or polycrystalline (ceramic) YAG, Y ₂ O ₃ , YVO ₄ , YAlO ₃ , GdVO ₄ and one or more of Nd, Yb, Cr, Ti, Ho, Er, Tm, Ta as dopants A solid laser oscillator using a seeded medium as a medium, a semiconductor laser oscillator such as GaN, GaAs, GaAlAs, InGaAsP, or the like can be used. Preferably, when the first laser oscillation device 202 uses a YAG laser oscillator, a YVO ₄ laser oscillator, or an excimer laser oscillator, a large output is easily obtained. When using a solid-state laser oscillator, it is preferable to select and use the fifth harmonic from the fundamental wave as appropriate. Further, either a continuous wave laser beam or a pulsed laser beam may be used.

  The first optical system 206 is an optical system for shaping the laser beam emitted from the first laser oscillation device 202 into a desired shape. Specifically, the cross-sectional shape of the laser beam is formed into a planar shape such as a circle, an ellipse, or a rectangle, or a linear shape (strictly, an elongated rectangular shape). The first optical system 206 may be composed of a plurality of lenses so as to suppress the divergence angle of the laser beam and to focus the laser beam on the irradiation surface. For example, the first optical system 206 can be used in combination with a diffractive optical element, a homogenizer, or the like. By incorporating a homogenizer or the like into the first optical system 206, the energy distribution of the laser beam can be made uniform.

  An optical fiber 204 is preferably provided between the first laser oscillation device 202 and the first optical system 206. The optical fiber 204 can transmit the laser beam from the first laser oscillation device 202 to the first optical system 206. The optical fiber 204 has flexibility and can be moved freely. Therefore, by moving the optical fiber 204, it is possible to irradiate a desired place on the irradiated object 230 with a laser beam. Note that the present invention is not particularly limited, and a device capable of transmitting a laser beam may be provided between the first laser oscillation device 202 and the first optical system 206.

The second laser oscillation device 208 includes a laser oscillator capable of obtaining a single mode laser beam. For example, a pulse oscillation laser oscillator capable of obtaining a laser beam having a pulse width on the order of picoseconds or femtoseconds ( ^10-15 seconds), a gas laser oscillator such as He, He-Cd, Ar, or He-Ne, a single crystal YAG, YVO ₄ , forsterite (Mg ₂ SiO ₄ ), YAlO ₃ , GdVO ₄ , or polycrystalline (ceramic) YAG, Y ₂ O ₃ , YVO ₄ , YAlO ₃ , GdVO ₄ , and Nd, Yb as dopants , Cr, Ti, Ho, Er, Tm, and Ta, a solid laser oscillator or the like using one or more added as a medium can be used.

  The second optical system 210 is an optical system for shaping the laser beam emitted from the second laser oscillation device 208. Specifically, the cross-sectional shape of the laser beam is formed into a surface shape such as a circle, an ellipse, or a rectangle, or a linear shape (strictly, an elongated rectangle). For example, the second optical system 210 can use an expander or the like that adjusts the beam diameter of the laser beam.

  The diffractive optical element 214 is an optical element that divides the laser beam that has passed through the second optical system 210 into a plurality of parts. The diffractive optical element 214 can control the behavior of the laser beam by the diffraction phenomenon of the surface structure of the diffractive optical element 214. Specifically, the diffractive optical element 214 can control the energy distribution of the beam spot formed on the irradiated surface by the laser beam irradiation by the diffraction phenomenon of the surface structure of the diffractive optical element 214. For example, the diffractive optical element 214 can change the energy distribution of the beam spot formed on the irradiated surface into an energy distribution having a number of peaks. As a result, the laser beam can be divided into a plurality on the irradiated surface. By appropriately designing the surface structure of the diffractive optical element 214, it is possible to divide the laser beam into a plurality of parts, and to irradiate the laser beam to a desired place of the irradiated object 230.

  For example, the diffractive optical element 214 can be designed and manufactured by optimizing the phase distribution by an ORA (Optical Rotation Angle) method or the like. The diffractive optical element 214 can also be manufactured by automatically designing with optical design software capable of performing wave optical analysis.

  As a physical shape of the diffractive optical element 214, a binary phase grating, a multilevel phase grating, a continuous phase grating, or the like can be applied. Further, as the diffractive optical element 214, a transmissive diffractive optical element or a reflective diffractive optical element may be used. The diffractive optical element 214 described in this embodiment is a transmissive type.

  In order to control the traveling direction, deflection direction, etc. of the laser beam, it is preferable to provide a mirror or the like as appropriate. As the mirror, a galvanometer mirror or a polygon mirror may be provided. In this embodiment, a mirror 212 is provided between the second optical system 210 and the diffractive optical element 214. The laser beam that has passed through the second optical system 210 is deflected by the mirror 212.

  The stage 215 holds the irradiated object 230 and moves it in a desired direction. In the present embodiment, the stage 215 includes a suction stage 220, a transport stage 216 that operates in the X-axis direction, and a transport stage 218 that operates in the Y-axis direction. The irradiated object 230 is sucked and fixed by the suction stage 220. Further, the irradiated object 230 is moved by the transfer stages 216 and 218 so that a desired region is irradiated with the laser beam. Accordingly, on the irradiated surface of the irradiated object 230, when the irradiation object is processed by irradiating a certain region with the laser beam, the irradiated object 230 is moved by operating the transfer stages 216 and 218, and the new irradiation object 230 is moved. The object to be irradiated can be processed by irradiating a laser beam to a certain region.

  Note that the configuration of the laser processing apparatus shown in FIG. 2 is an example, and the positional relationship between the optical system and the diffractive optical element disposed in the optical path of the laser beam is not particularly limited. In addition, a mirror for controlling the traveling direction, the deflection direction, and the like of the laser beam, a homogenizer that uniformizes the energy distribution of the laser beam, and the like may be provided as appropriate.

  The irradiated object 230 is formed by stacking at least a light absorption layer and an insulating layer on a substrate. A conductive layer, an insulating layer, or the like may be formed below the light absorption layer. The materials of the light absorption layer and the insulating layer are the same as those in Embodiment Mode 1. In the irradiation object 230, the surface side on which the insulating layer is formed becomes the irradiation surface irradiated with the laser beam.

  The laser beam emitted from the first laser oscillation device 202 is transmitted through the optical fiber 204, passes through the first optical system 206, and is shaped. The shaped laser beam that has passed through the first optical system 206 is irradiated onto the irradiated surface of the irradiated object 230 held on the stage 215. At this time, the irradiated surface of the irradiated object 230 is irradiated with the beam spot 232 of the laser beam from the first laser oscillation device 202.

  On the other hand, the laser beam emitted from the second laser oscillation device 208 passes through the second optical system 210 and is shaped. The shaped laser beam that has passed through the second optical system 210 is deflected by the mirror 212, passes through the diffractive optical element 214, and is divided into a plurality of laser beams. The plurality of laser beams that have passed through the diffractive optical element 214 are irradiated onto the irradiated surface of the irradiated object 230 held on the stage 215. The plurality of laser beams irradiated through the diffractive optical element 214 are all irradiated within the range of the beam spot 232 by the first laser oscillation device 202 on the irradiated surface of the irradiated object 230. That is, a plurality of laser beams from the second laser oscillation device 208 are irradiated on the surface to be irradiated of the irradiation object 230 so as to overlap with the laser beams from the first laser oscillation device 202.

  As described above, when the laser beam emitted from the second laser oscillation device 208 and the laser beam emitted from the first laser oscillation device 202 are superimposed and irradiated, the energy of the laser beam is irradiated in the superimposed irradiation region. Is synthesized. In this embodiment mode, the laser beam from the second laser oscillation device 208 is divided into a plurality of parts by the diffractive optical element 214, and each of the divided laser beams is superimposed on the laser beam from the first laser oscillation device 202. Irradiate as you do.

  In the present invention, the energy of the laser beam emitted from the first laser oscillation device 202 is less than the ablation threshold. It is assumed that the energy of the laser beam emitted from the second laser oscillation device 208 is equal to or higher than the ablation threshold when combined with the energy of the laser beam emitted from the first laser oscillation device 202.

  In the irradiated object 230, energy less than the ablation threshold is absorbed in a region where only the laser beam from the first laser oscillation device 202 is irradiated. Therefore, the irradiated object 230 is not ablated.

  On the other hand, in a region where the laser beam from the first laser oscillation device 202 and the laser beam from the second laser oscillation device 208 are superimposed and irradiated, the energy obtained by combining the energy of both laser beams is irradiated. 230 is absorbed. As a result, the irradiated object 230 is ablated and an opening is formed. Specifically, in the irradiated object 230, the light absorption layer in the region irradiated with the laser beam emitted from the first laser oscillation device 202 and the laser beam emitted from the second laser oscillation device 208 is ablated, and the light absorption is performed. The layer and the insulating layer above it or the insulating layer above the light absorbing layer are removed. A desired opening pattern is formed at least in the insulating layer.

  In this embodiment mode, the laser beam emitted from the second laser oscillation device 208 is divided into a plurality of pieces, and the divided laser beams are irradiated so as to overlap with the laser beam emitted from the first laser oscillation device 202, respectively. Is done. That is, in the irradiated object 230, there are a plurality of regions where the laser beam from the first laser oscillation device 202 and the laser beam from the second laser oscillation device 208 are superimposed and irradiated. Therefore, in the irradiated object 230, a plurality of regions can be ablated and a plurality of openings can be formed simultaneously.

  In the present invention, the shape and size of the opening formed in the irradiated object 230 by ablation depends on the laser beam from the second laser oscillation device 208. In this embodiment mode, the second laser oscillation device 208 emits a single-mode laser beam that has good light condensing properties and can provide energy locally. Therefore, it is possible to form a fine opening in the irradiated object 230.

  In this embodiment, as described above, the light absorption layer in the region irradiated with the laser beam emitted from the first laser oscillation device 202 and the laser beam emitted from the second laser oscillation device 208 is ablated. In addition, the energy of the laser beam from the first laser oscillation device 202 and the energy of the laser beam from the second laser oscillation device 208 may be determined as appropriate.

  In addition, since the laser beam from the first laser oscillation device 202 can give the irradiated object 230 high energy up to the ablation threshold energy, the energy of the laser beam from the second laser oscillation device 208 can be reduced. can do. As a result, the laser beam by the second laser oscillation device 208 can be divided into a large number.

  Further, the first laser oscillation device is divided by dividing the laser beam by the second laser oscillation device 208 into a large number and irradiating the divided laser beam so as to overlap the laser beam by the first laser oscillation device 202. It is possible to form a large number of openings in the irradiated object 230 by one-time laser beam irradiation by the second laser oscillation device 202. Accordingly, mass productivity can be easily improved in the manufacturing process of the semiconductor device.

  The laser processing apparatus of the present invention can form an opening in a desired region of an irradiated object without using a photoresist. Therefore, since the number of lithography processes can be reduced and simplified in the manufacturing process of the semiconductor device, the manufacturing cost can be reduced and the throughput can be improved.

  In addition, the laser processing apparatus of the present invention can form a large number of openings in the irradiated object in a single process. Therefore, in the manufacturing process of the semiconductor device, the process time for forming the opening can be shortened, and the mass productivity can be improved.

  Note that this embodiment mode can be freely combined with Embodiment Mode 1 as appropriate.

(Embodiment 3)
In this embodiment, a configuration example of a laser processing apparatus different from that in Embodiment 2 will be described.

  FIG. 4 shows a schematic diagram of a laser processing apparatus. In FIG. 4, a laser processing apparatus 300 includes a first laser oscillation apparatus 302, a first optical system 306 that shapes a laser beam, a second laser oscillation apparatus 308, and a second that divides the laser beam into a plurality of parts. Optical system 310, a first deflector 312 for controlling the traveling direction of the laser beam, a second deflector 314, and a stage 315.

The first laser oscillation device 302 includes a laser oscillator capable of obtaining a multimode laser beam. Specifically, the first laser oscillation device 302 can be the same as the first laser oscillation device 202 described in the second embodiment. Preferably, if the first laser oscillation device 302 includes a YAG laser oscillator, a YVO ₄ laser oscillator, or an excimer laser oscillator, a large output can be easily obtained.

  The first optical system 306 is an optical system for shaping the laser beam emitted from the first laser oscillation device 302 into a desired shape. Specifically, the cross-sectional shape of the laser beam is formed on a surface such as a circle, an ellipse, a rectangle, or a line (strictly speaking, an elongated rectangle). The first optical system 306 may be composed of a plurality of lenses so as to suppress the divergence angle of the laser beam and focus the laser beam on the irradiation surface. Further, the first optical system 306 may incorporate a homogenizer or the like that makes the energy distribution of the laser beam uniform.

  An optical fiber 304 is preferably provided between the first laser oscillation device 302 and the first optical system 306. The optical fiber 304 can transmit the laser beam from the first laser oscillation device 302 to the first optical system 306. The optical fiber 304 has flexibility and can be moved freely. Therefore, by moving the optical fiber 304, it is possible to irradiate a laser beam to a desired place of the irradiated object 330. Note that the present invention is not particularly limited, and a device capable of transmitting a laser beam may be provided between the first laser oscillation device 302 and the first optical system 306.

The second laser oscillation device 308 includes a laser oscillator capable of obtaining a single mode laser beam. For example, a pulse oscillation laser oscillator capable of obtaining a laser beam having a pulse width on the order of picoseconds or femtoseconds ( ^10-15 seconds), a gas laser oscillator such as He, He-Cd, Ar, or He-Ne, a single crystal YAG, YVO ₄ , forsterite (Mg ₂ SiO ₄ ), YAlO ₃ , GdVO ₄ , or polycrystalline (ceramic) YAG, Y ₂ O ₃ , YVO ₄ , YAlO ₃ , GdVO ₄ , and Nd, Yb as dopants , Cr, Ti, Ho, Er, Tm, and Ta, a solid laser oscillator or the like using one or more added as a medium can be used.

  The second optical system 310 is an optical system for shaping the laser beam emitted from the second laser oscillation device 308 and dividing it into a plurality of parts. The second optical system 310 may be configured by appropriately combining a polarizing plate and a polarizer. The second optical system 310 can have a function of branching a laser beam by being configured by combining a polarizing plate and a polarizer. Further, the second optical system 310 may incorporate a half mirror or the like that can branch the laser beam.

  The first deflector 312 deflects the laser beam divided through the second optical system 310 and controls the traveling direction of the laser beam. For example, an AOD (Acousto-Optical Deflector) can be used as the first deflector 312. An AOD is a deflector that deflects a laser beam by an acousto-optic change in an optical medium. The optical medium used for AOD may be appropriately selected according to the wavelength of the laser beam to be deflected, the deflection direction, energy, and the like. For example, when a laser beam in the visible region is deflected using AOD, gallium phosphorus, tellurium dioxide, indium phosphorus, or the like can be used as an optical medium. By deflecting the laser beam using the AOD as the first deflector 312 and controlling the traveling direction of the laser beam, the irradiation of the laser beam can be switched on and off. Here, turning on the laser beam irradiation means that the laser beam is deflected so as to irradiate the irradiated surface. On the other hand, turning off the laser beam irradiation means that the irradiated surface is not irradiated with the laser beam or the irradiated surface is irradiated with the laser beam.

  The second deflector 314 deflects the laser beam that has passed through the first deflector 312 and controls the traveling direction of the laser beam. For example, a galvanometer mirror can be used as the second deflector 314. The galvanometer mirror can arbitrarily set the mirror installation angle. Therefore, by using a galvano mirror as the second deflector 314, it is possible to irradiate a desired position of the irradiated object 330 with a laser beam.

  The stage 315 holds the irradiated object 330 and moves it in a desired direction. In the present embodiment, the stage 315 includes a suction stage 320, a transfer stage 316 that operates in the X-axis direction, and a transfer stage 318 that operates in the Y-axis direction. The irradiated object 330 is sucked and fixed by the suction stage 320. In addition, the irradiated object 330 is moved by the transfer stages 316 and 318 so that a desired region is irradiated with the laser beam. Therefore, on the irradiated surface of the irradiated object 330, when a certain area is irradiated with a laser beam and the irradiated object is processed, the irradiated object is moved by operating the transfer stages 316 and 318, and a new one is moved. The region can be processed by being irradiated with a laser beam.

  Note that the configuration of the laser processing apparatus shown in FIG. 4 is an example, and the positional relationship between the optical system and the deflector disposed in the optical path of the laser beam is not particularly limited. In addition, a mirror for controlling the traveling direction and the deflection direction of the laser beam, a homogenizer for uniformizing the energy distribution of the laser beam, and the like may be provided as appropriate. In this embodiment mode, a configuration in which a plurality of deflectors of the first deflector 312 and the second deflector 314 are provided has been described, but the present invention is not particularly limited. Therefore, a configuration in which only one deflector is provided, or a configuration in which three or more deflectors are provided may be employed.

  The irradiated object 330 is formed by laminating at least a light absorption layer and an insulating layer on a substrate. A conductive layer, an insulating layer, or the like may be formed below the light absorption layer. The materials of the light absorption layer and the insulating layer are the same as those in Embodiment Mode 1. In the irradiated object 330, the surface side on which the insulating layer is formed becomes the irradiated surface irradiated with the laser beam.

  The laser beam emitted from the first laser oscillation device 302 is transmitted through the optical fiber 304, passes through the first optical system 306, and is shaped. The shaped laser beam that has passed through the first optical system 306 is irradiated onto the irradiated surface of the irradiated object 330 held on the stage 315. At this time, the irradiated surface of the irradiated object 330 is irradiated with the beam spot 332 of the laser beam from the first laser oscillation device 302.

  On the other hand, the laser beam emitted from the second laser oscillation device 308 passes through the second optical system 310 and is divided into a plurality of parts. In this embodiment mode, the laser beam from the second laser oscillation device 308 passes through the second optical system 310 and is divided into four laser beams. Of course, the present invention is not particularly limited, and the laser beam can be divided into four or less or four or more.

  The laser beam that has been divided into a plurality of parts through the second optical system 310 is deflected by the first deflector 312 and the traveling direction is controlled. The plurality of laser beams that have passed through the first deflector 312 are further deflected by the second deflector 314, and the traveling direction is controlled. The plurality of laser beams that have passed through the second deflector 314 are irradiated onto the irradiated surface of the irradiated object 330 held on the stage 315. The plurality of laser beams irradiated through the second deflector 314 are all irradiated within the range of the beam spot 332 by the first laser oscillation device 302 on the irradiated surface of the irradiated object 330. That is, a plurality of laser beams from the second laser oscillation device 308 are irradiated on the surface to be irradiated of the irradiation object 330 so as to overlap with the laser beams from the first laser oscillation device 302, respectively.

  As described above, when the laser beam emitted from the second laser oscillation device 308 and the laser beam emitted from the first laser oscillation device 302 are superimposed and irradiated, the energy of the laser beam is emitted in the superimposed irradiation region. Is synthesized. In this embodiment mode, the laser beam from the second laser oscillation device 308 is divided into a plurality of parts by the second optical system 310, and the divided laser beam is converted into a deflector (first deflector 312; Irradiation passes through the second deflector 314) so as to be superimposed on the laser beam by the first laser oscillation device 302.

  In the present invention, the energy of the laser beam emitted from the first laser oscillation device 302 is less than the ablation threshold. The energy of the laser beam emitted from the second laser oscillation device 308 is equal to or higher than the ablation threshold when combined with the energy of the laser beam emitted from the first laser oscillation device 302.

  In the irradiated object 330, energy below the ablation threshold is absorbed in a region irradiated only with the laser beam from the first laser oscillation device 302. Therefore, the irradiated object 330 is not ablated.

  On the other hand, in the region where the laser beam from the first laser oscillation device 302 and the laser beam from the second laser oscillation device 308 are superimposed and irradiated, the energy obtained by combining the energy of both laser beams is irradiated. 330 is absorbed. As a result, the irradiated object 330 is ablated and an opening is formed. Specifically, in the irradiated object 330, the light absorption layer in the region irradiated with the laser beam emitted from the first laser oscillation device 302 and the laser beam emitted from the second laser oscillation device 308 is ablated, and the light absorption is performed. The layer and the insulating layer above it or the insulating layer above the light absorbing layer are removed. A desired opening pattern is formed at least in the insulating layer.

  In this embodiment mode, the laser beam from the second laser oscillation device 308 is divided into a plurality of parts by the second optical system 310, and each of the divided laser beams is a laser from the first laser oscillation device 302. Irradiated so as to overlap the beam. That is, in the irradiated object 330, there are a plurality of regions where the laser beam emitted from the first laser oscillation device 302 and the laser beam emitted from the second laser oscillation device 308 are superimposed and irradiated. Therefore, in the irradiated object 330, it is possible to ablate a plurality of regions and simultaneously form a plurality of openings.

  In the present invention, the shape of the opening formed in the irradiated object 330 by the ablation depends on the laser beam from the second laser oscillation device 308. In this embodiment mode, since the second laser oscillation device 308 emits a single-mode laser beam that has good light condensing properties and can locally give energy, an optical element disposed in the optical path of the laser beam. It is also possible to form a beam spot having a diameter of several μm by appropriately selecting a system, a deflector and the like. Therefore, a fine opening can be formed in the irradiated object 330.

  In this embodiment mode, the first laser oscillation device 302 and the laser beam from the second laser oscillation device 308 are overlapped with each other so that the light absorption layer in the region irradiated with the first laser oscillation device 302 is ablated. The energy of the laser beam emitted from the laser oscillation device 302 and the energy of the laser beam emitted from the second laser oscillation device 308 may be determined as appropriate. The first laser oscillation device 302 can irradiate the irradiated object 330 with a laser beam having a high energy with the upper limit of the energy of the ablation threshold. Therefore, the energy of the laser beam by the second laser oscillation device 308 can be reduced. As a result, the laser beam by the second laser oscillation device 308 can be divided into a large number.

  In addition, the first laser oscillation device is obtained by dividing the laser beam by the second laser oscillation device 308 into a large number and irradiating the divided laser beam so as to overlap the laser beam by the first laser oscillation device 302. 302 and the second laser oscillation device 308 can irradiate the laser beam once to form a large number of fine openings in the irradiated object 330. Accordingly, mass productivity can be easily improved in the manufacturing process of the semiconductor device.

  The laser processing apparatus of the present invention can form an opening in a desired region of an irradiated object without using a photoresist. Therefore, since the number of lithography processes can be reduced and simplified in the manufacturing process of the semiconductor device, the manufacturing cost can be reduced and the throughput can be improved.

  In addition, the laser processing apparatus of the present invention can form a large number of openings in the irradiated object in a single process. Therefore, in the manufacturing process of the semiconductor device, the process time for forming the opening can be shortened, and the mass productivity can be improved.

  This embodiment mode can be freely combined with Embodiment Mode 1 as appropriate.

(Embodiment 4)
In this embodiment, a method for forming a plurality of openings in a desired region without using a lithography technique using a photoresist will be described. Specifically, one mode of a method for forming a plurality of openings in an insulating layer by applying the present invention will be specifically described with reference to FIGS.

  First, the substrate 500 in which the conductive layer 502, the light absorption layer 504, and the insulating layer 506 are sequentially stacked is prepared (see FIG. 5A).

  As the substrate 500, a substrate similar to the substrate 10 described in Embodiment Mode 1 may be used. For example, a glass substrate, a quartz substrate, a sapphire substrate, a ceramic substrate, a semiconductor substrate, or the like can be used. Further, a base insulating layer may be formed over the substrate 500.

  The conductive layer 502, the light absorption layer 504, and the insulating layer 506 may be formed using the same materials as the conductive layer 12, the light absorption layer 14, and the insulating layer 16 described in Embodiment 1, respectively.

  The conductive layer 502 includes, for example, silver (Ag), gold (Au), nickel (Ni), platinum (Pt), palladium (Pd), iridium (Ir), rhodium (Rh), tantalum (Ta), tungsten (W ), Titanium (Ti), molybdenum (Mo), aluminum (Al), and copper (Cu), or an alloy or compound containing the element as a main component.

  The light absorption layer 504 includes, for example, an element selected from chromium (Cr), molybdenum (Mo), nickel (Ni), titanium (Ti), cobalt (Co), copper (Cu), and aluminum (Al), or An alloy or a compound containing an element as a main component can also be formed using a conductive material. In addition, silicon, germanium, silicon germanium, molybdenum oxide, tin oxide, bismuth oxide, vanadium oxide, nickel oxide, zinc oxide, gallium arsenide, gallium nitride, indium oxide, indium phosphide, indium nitride, cadmium sulfide, cadmium telluride It can be formed using a semiconductor material such as strontium titanate.

  The insulating layer 506 is formed using, for example, a light-transmitting inorganic insulating material such as silicon oxide, silicon nitride, silicon oxynitride, or silicon nitride oxide, polyimide, acrylic resin, polyamide, polyimide amide, benzocyclobutene resin, or epoxy resin. It can be formed using a light-transmitting organic insulating material.

  Next, a laser beam is irradiated from the insulating layer 506 side. Irradiation with the laser beam is performed using the first laser beam 510 and the second laser beam 512. The second laser beam 512 is divided into a plurality of pieces, and irradiation is performed so that each overlaps with the first laser beam 510. In the light absorption layer 504 and the insulating layer 506, the regions irradiated with the first laser beam 510 and the second laser beam 512 are overlapped irradiation regions 520, 522, 524, 526, 528, and 530 (FIG. 5 (B)).

  FIG. 6 is a perspective view of FIG. FIG. 5B corresponds to a cross-sectional view of the line segment OP in FIG. In FIG. 6, the first laser beam 510 is omitted, and a beam spot 511 formed by the first laser beam 510 is shown. A part of the second laser beam 512 is also omitted. In FIG. 6, the second laser beam 512 divided into a plurality is irradiated within the range of the beam spot 511 by the first laser beam. That is, a superimposed irradiation region group 518 is formed in which the first laser beam 510 and the second laser beam 512 are superimposed and irradiated in the beam spot 511 of the first laser beam. In FIG. 6, a part of the superimposed irradiation region group 518 surrounded by a broken-line circle is a superimposed irradiation region 520, 522, 524, 526, 528, and 530 in FIG.

As the first laser beam 510, a multimode laser beam is irradiated. For example, the first laser beam 510 includes an excimer laser oscillator such as KrF, ArF, or XeCl, a gas laser oscillator such as He, He—Cd, Ar, or He—Ne, a single crystal YAG, YVO ₄ , forsterite (Mg). ₂ SiO ₄ ), YAlO ₃ , GdVO ₄ , or polycrystalline (ceramic) YAG, Y ₂ O ₃ , YVO ₄ , YAlO ₃ , GdVO ₄ , Nd, Yb, Cr, Ti, Ho, Er, Tm as dopants , Ta, or a semiconductor laser oscillator such as GaN, GaAs, GaAlAs, InGaAsP or the like using one or more of Ta added as a medium. It is preferable to use a YAG laser, YVO ₄ laser, or excimer laser as the first laser beam 510 because a large output can be easily obtained. When using a solid-state laser oscillator, it is preferable to select and use the fifth harmonic from the fundamental wave as appropriate. Further, either a continuous wave laser beam or a pulsed laser beam may be used.

  The energy of the first laser beam 510 is set such that no ablation occurs in the light absorption layer 504. That is, the energy of the first laser beam 510 is less than the ablation threshold.

  In addition, the cross-sectional shape of the first laser beam 510 is appropriately selected from a planar shape such as a circle, an ellipse, and a rectangle, or a linear shape (strictly, an elongated rectangular shape). The first laser beam 510 may be shaped by an optical system so as to have such a cross-sectional shape. In this embodiment mode, the first laser beam 510 is irradiated with the cross-sectional shape formed into a rectangular surface. Therefore, in FIG. 6, a rectangular beam spot 511 of the first laser beam is formed. In the present invention, since a multi-mode laser beam is irradiated as the first laser beam 510, a large output can be obtained, and high energy up to the energy of the ablation threshold can be given to the beam spot 511. .

The second laser beam 512 irradiates a single mode laser beam. For example, the second laser beam 512 is a pulse oscillation laser oscillator that can obtain a laser beam having a pulse width in the picosecond range or femtosecond ( ^10-15 seconds), He, He-Cd, Ar, He-Ne. Gas laser oscillator such as single crystal YAG, YVO ₄ , forsterite (Mg ₂ SiO ₄ ), YAlO ₃ , GdVO ₄ , or polycrystalline (ceramic) YAG, Y ₂ O ₃ , YVO ₄ , YAlO ₃ , GdVO _{3 4} can be obtained by using a solid-state laser oscillator or the like using one or more of Nd, Yb, Cr, Ti, Ho, Er, Tm, and Ta as dopants. When using a solid-state laser oscillator, it is preferable to select and use the fifth harmonic from the fundamental wave as appropriate.

  The energy of the second laser beam 512 is energy at which ablation occurs in the light absorption layer 504 due to energy obtained when combined with the first laser beam 510. That is, the energy of the beam obtained by combining the first laser beam 510 and the second laser beam 512 is set to be equal to or greater than the ablation threshold value.

  In addition, as the cross-sectional shape of the second laser beam 512, a circular shape, an elliptical shape, a planar shape such as a rectangle, or a linear shape (strictly, an elongated rectangular shape) is appropriately selected. The second laser beam 512 may be shaped by an optical system so as to have such a cross-sectional shape. In the present invention, since a single mode laser beam is irradiated as the second laser beam 512, the second laser beam 512 can be condensed to a diameter of about several μm. Therefore, the second laser beam 512 can locally give energy to a minute region having a diameter of about several μm.

  In addition, since the first laser beam 510 having high energy with the upper limit of the ablation threshold is irradiated, the energy of the second laser beam 512 can be reduced. Therefore, the second laser beam 512 can be divided into a larger number. Therefore, according to the present embodiment, energy exceeding the ablation threshold value can be locally applied to the light absorption layer 504 in a large number of fine regions at a time.

  The first laser beam 510 and the second laser beam 512 are transmitted through the insulating layer 506 and absorbed by the light absorption layer 504. The light absorption layer 504 is a region irradiated with the first laser beam 510 and the second laser beam 512 superimposed (superimposed irradiation regions 520, 522, 524, 526, 528, and 530 in FIG. 5B). It is ablated and removed with the upper insulating layer 506. As a result, an opening 532, an opening 534, an opening 536, an opening 538, an opening 540, and an opening 542 are formed. The conductive layer 502 is exposed at the bottom surfaces of the openings 532, 534, 536, 538, 540, and 542 (see FIG. 5C).

  Since the first laser beam 510 has energy less than the ablation threshold, the light absorption layer 504 in which only the first laser beam 510 is absorbed is not ablated. On the other hand, in the regions irradiated so that the first laser beam 510 and the second laser beam 512 are superimposed (superimposed irradiation regions 520, 522, 524, 526, 528, and 530 in FIG. 5B), light absorption is performed. The energy of the laser beam absorbed by the layer 504 is greater than or equal to the ablation threshold. Therefore, the light absorption layer 504 is ablated and removed together with the insulating layer 506 stacked on the upper layer. In this embodiment mode, the overlapping irradiation regions 520, 522, 524, 526, 528, and 530 shown in FIG. 5B are ablated to form openings 532, 534, 536, 538, 540, and 542 (FIG. 5). 5 (C)).

  FIG. 7A shows a perspective view of FIG. FIG. 5C corresponds to a cross-sectional view of the line segment OP in FIG. FIG. 7B shows an enlarged view of the vicinity of the line segment OP in FIG. 7A and 7B, an opening is formed so as to penetrate the insulating layer 506 and the light absorption layer 504, and the conductive layer 502 is exposed on the bottom surface of the opening.

  In the present invention, a single mode laser beam is irradiated as the second laser beam 512, and energy can be applied locally. Therefore, it is possible to locally apply energy equal to or higher than the ablation threshold to a fine region of the light absorption layer 504 to ablate the light absorption layer 504 to form a fine opening.

  In the present invention, the first laser beam and the second laser beam are irradiated so as to overlap each other. In the present invention, the first laser beam can be increased to the limit as long as it is less than the ablation threshold, and has a high assist effect. Therefore, the energy of the second laser beam can be reduced, and the second laser beam 512 can be divided into a large number. Therefore, a large number of fine openings can be formed at the same time, and the process time can be shortened.

  Note that by forming a conductive layer in the opening, the conductive layer 502 can be electrically connected.

  This embodiment mode can be freely combined with any of Embodiment Modes 1 to 3 as appropriate.

(Embodiment 5)
In this embodiment, a method for forming an opening in an insulating layer for electrically connecting conductive layers or between a conductive layer and a semiconductor layer will be described. In Embodiment 1, an example is shown in which an opening is formed so as to penetrate the insulating layer and the light absorption layer stacked on the conductive layer, and the conductive layer is exposed at the bottom surface of the opening. In this embodiment mode, another example of forming an opening reaching the conductive layer is described. An example of forming an opening reaching the semiconductor layer is also shown.

  8A to 8C illustrate a structure in which a conductive layer, a light absorption layer, and an insulating layer are sequentially stacked over a substrate, and an opening reaching the conductive layer or the light absorption layer is formed. In addition, a structure in which a conductive layer is formed in the opening and the conductive layer is electrically connected to the conductive layer formed over the substrate is shown.

  In FIG. 8, at least the opening formed in the insulating layer is formed using ablation by laser beam irradiation as described in the first to fourth embodiments. Specifically, the multimode laser beam and the single mode laser beam are irradiated so as to overlap each other, and the overlapped and irradiated region is ablated and removed. The part to be removed by ablation can be selected by appropriately selecting the energy of the laser beam, the material constituting the light absorption layer, and the like.

  In FIG. 8, the substrate, the conductive layer, and the insulating layer are the same as those in Embodiment Mode 1 and the like. For example, a glass substrate, a quartz substrate, a sapphire substrate, a ceramic substrate, a semiconductor substrate, or the like may be used as the substrate. A conductive material may be used for the conductive layer. For example, the conductive layer is made of silver (Ag), gold (Au), nickel (Ni), platinum (Pt), palladium (Pd), iridium (Ir), rhodium (Rh), tantalum (Ta), tungsten (W). , Titanium (Ti), molybdenum (Mo), aluminum (Al), copper (Cu), or the like, or an alloy material or a compound material containing the element as a main component. The insulating layer may be formed using a light-transmitting inorganic insulating material or organic insulating material. Further, a base insulating layer that functions as a protective layer may be formed between the substrate and the conductive layer or between the substrate and the light absorption layer. The base insulating layer can be formed using an inorganic insulating material such as silicon oxide, silicon nitride, silicon oxynitride, or silicon nitride oxide. By forming the base insulating layer, the influence of the laser beam irradiation on the substrate can be reduced.

  The light absorption layer is formed using a conductive material that can absorb a laser beam. The light absorption layer is preferably formed using a material having a boiling point or sublimation point lower than the melting point of the lower conductive layer. For example, the light absorption layer is mainly composed of an element such as chromium (Cr), molybdenum (Mo), nickel (Ni), titanium (Ti), cobalt (Co), copper (Cu), aluminum (Al), or the like. It is formed using a conductive material such as an alloy material or a compound as a component. Alternatively, indium oxide, zinc oxide, or the like may be used. This will be specifically described below.

  FIG. 8A illustrates an example in which only the insulating layer is removed by ablation in the light absorption layer and the insulating layer which are stacked over the conductive layer. A conductive layer 802, a light absorption layer 804, and an insulating layer 806 are sequentially stacked over the substrate 800. The opening 810 is formed so as to penetrate only the insulating layer 806, and the light absorption layer 804 is exposed at the bottom surface of the opening 810. A conductive layer 808 is formed in the opening 810 and is in contact with the light absorption layer 804. Since the light absorption layer 804 is formed using a conductive material, the conductive layer 808 and the conductive layer 802 are electrically connected.

  FIG. 8B illustrates an example in which the upper layer portion of the light absorption layer and the insulating layer are removed by ablation in the light absorption layer and the insulating layer which are stacked over the conductive layer. A conductive layer 822, a light absorption layer 824, and an insulating layer 826 are sequentially stacked over the substrate 820. The opening 830 is formed in the upper layer portion of the insulating layer 826 and the light absorption layer 824, and the light absorption layer 824 is exposed at the bottom surface of the opening 830. In the light absorption layer 824, the thickness of the region where the opening 830 is formed is thinner than that of other regions. A conductive layer 828 is formed in the opening 830 and is in contact with the light absorption layer 824. Since the light absorption layer 824 is formed using a conductive material, the conductive layer 828 and the conductive layer 822 are electrically connected.

  FIG. 8C illustrates an example in which at least a side surface of an opening formed in the insulating layer has a tapered shape. A conductive layer 842, a light absorption layer 844, and an insulating layer 846 are sequentially stacked over the substrate 840. The opening 850 is tapered, and the side surface of the opening 850 is tapered with respect to the bottom surface. A conductive layer 848 is formed in the opening 850 and is electrically connected to the conductive layer 842.

  Note that FIG. 8C illustrates an example in which the opening 850 is formed so as to penetrate the insulating layer 846 and the light absorption layer 844; however, there is no particular limitation. An opening may be formed so as to penetrate only the insulating layer as shown in FIG. 8 (A), or the insulating layer may penetrate as shown in FIG. 8 (B), and the light absorption layer may be applied to the upper layer portion. An opening may be formed in the surface. At least the conductive layer may be in contact with the light absorption layer.

  Next, an example in which an opening reaching the conductive layer or an opening reaching the semiconductor layer is formed in the insulating layer is described. 9A to 9D illustrate a structure in which a light absorption layer and an insulating layer are sequentially stacked over a substrate, and an opening reaching the light absorption layer is formed. A structure in which a conductive layer is formed in the opening and the conductive layer and the light absorption layer exposed in the opening are electrically connected is shown.

  In FIG. 9, at least the opening formed in the insulating layer is formed using ablation by laser beam irradiation as described in Embodiment Modes 1 to 4. Specifically, the multimode laser beam and the single mode laser beam are irradiated so as to overlap each other, and the overlapped and irradiated region is ablated and removed. The part to be removed by ablation can be selected by appropriately selecting the energy of the laser beam, the material constituting the light absorption layer, and the like.

  The substrate and the insulating layer shown in FIG. 9 can be the same as those in FIG. The light absorption layer is formed using a material capable of absorbing a laser beam. As the light absorption layer, the same material as that in FIG. 8 can be used, and a semiconductor material can be used. For example, as a light absorption layer, silicon, germanium, silicon germanium, molybdenum oxide, tin oxide, bismuth oxide, vanadium oxide, nickel oxide, zinc oxide, gallium arsenide, gallium nitride, indium oxide, indium phosphide, indium nitride, sulfide Semiconductor materials such as cadmium, cadmium telluride, and strontium titanate can also be used. This will be specifically described below.

  FIG. 9A shows an example in which only the insulating layer is removed by ablation in the light absorption layer and the insulating layer which are stacked over the substrate. A light absorption layer 862 and an insulating layer 864 are stacked over the substrate 860. The opening 868 is formed so as to penetrate only the insulating layer 864, and the light absorption layer 862 is exposed at the bottom surface of the opening 868. A conductive layer 866 is formed in the opening 868 and is in contact with the light absorption layer 862. The light absorption layer 862 is formed using a conductive material or a semiconductor material. Through the above, a structure in which the conductive layers or the conductive layer and the semiconductor layer are electrically connected can be obtained.

  FIG. 9B illustrates an example in which the upper layer portion and the insulating layer of the light absorption layer are removed by ablation in the light absorption layer and the insulating layer which are stacked over the substrate. A light absorption layer 872 and an insulating layer 874 are stacked over the substrate 870. The opening 878 is formed in the upper layer portion of the insulating layer 874 and the light absorption layer 872, and the light absorption layer 872 is exposed at the bottom surface of the opening 878. In the light absorption layer 872, the thickness of the region where the opening 878 is formed is smaller than that of other regions. A conductive layer 876 is formed in the opening 878 and is in contact with the light absorption layer 872. The light absorption layer 872 is formed using a conductive material or a semiconductor material. Through the above, a structure in which the conductive layers or the conductive layer and the semiconductor layer are electrically connected can be obtained.

  FIG. 9C illustrates an example in which the light absorption layer and the insulating layer stacked over the substrate are removed so as to penetrate the light absorption layer and the insulating layer by ablation. A light absorption layer 882 and an insulating layer 884 are stacked over the substrate 880. The opening 888 is formed so as to penetrate the insulating layer 884 and the light absorption layer 882, and the light absorption layer 882 is exposed on the side surface of the opening 888. A conductive layer 886 is formed in the opening 888, and the conductive layer 886 and the light absorption layer 882 are in contact with each other on the side surface of the opening 888. The light absorption layer 882 is formed using a conductive material or a semiconductor material. Through the above, a structure in which the conductive layers or the conductive layer and the semiconductor layer are electrically connected can be obtained.

  FIG. 9D illustrates an example in which at least a side surface of an opening formed in the insulating layer has a tapered shape. A light absorption layer 892 and an insulating layer 894 are stacked over the substrate 890. The opening 898 is tapered, and the side surface of the opening 898 is tapered with respect to the bottom surface. A conductive layer 896 is formed in the opening 898, and the conductive layer 896 is in contact with the light absorption layer 892. The light absorption layer 892 is formed using a conductive material or a semiconductor material. Through the above, a structure in which the conductive layers or the conductive layer and the semiconductor layer are electrically connected can be obtained.

  Note that FIG. 9D illustrates an example in which the opening 898 is formed so as to penetrate only the insulating layer 894; however, there is no particular limitation. As shown in FIG. 9B, an opening may be formed so as to cover the upper layer portion of the insulating layer and the light absorption layer, or as shown in FIG. 9C, the opening penetrates the insulating layer and the light absorption layer. An opening may be formed in the surface. At least the conductive layer may be in contact with the light absorption layer.

  By applying the present invention, various openings can be formed. The opening can have various forms by appropriately selecting the energy of the laser beam, the material constituting the light absorption layer, and the like.

  Further, by applying the present invention, an opening can be formed in a desired region without using a lithography process using a photoresist. Therefore, the lithography process can be reduced and simplified, and the manufacturing cost can be reduced and the throughput can be improved.

  This embodiment mode can be freely combined with any of Embodiment Modes 1 to 4 as appropriate.

(Embodiment 6)
In this embodiment, a display device in which the present invention is applied and an opening for connecting a transistor and a pixel electrode is formed will be described with reference to FIGS. Note that in this embodiment, an example of manufacturing an inverted staggered transistor as a transistor is described.

  First, the transistor 720 is formed over the substrate 7000 with the base insulating layer 7002 interposed therebetween. Specifically, the gate electrode layer 704 is formed over the substrate 7000 with the base insulating layer 7002 interposed therebetween. A semiconductor layer is formed over the gate electrode layer 704 with a gate insulating layer 706 interposed therebetween. A conductive layer 712a and a conductive layer 712b functioning as a source electrode or a drain electrode are formed over the semiconductor layer (see FIG. 10A).

  In this embodiment, the semiconductor layer has a stacked structure of the semiconductor layer 708 and semiconductor layers 710a and 710b having one conductivity. Note that the semiconductor layers 710a and 710b having one conductivity may be formed as necessary. The semiconductor layers 710a and 710b having one conductivity are preferably formed in order to improve ohmic contact between the semiconductor layer forming a channel and the conductive layer functioning as a source electrode or a drain electrode.

For example, an n-type semiconductor layer is formed as the semiconductor layers 710a and 710b having one conductivity to form an n-channel transistor NMOS structure, and a p-type semiconductor layer is formed to form a p-channel transistor PMOS structure. Can do. Further, an n-channel transistor or a p-channel transistor can be formed by adding an element imparting conductivity to the semiconductor layer 708 by doping to form an impurity region. Further, conductivity may be imparted to the semiconductor layer 708 by performing plasma treatment with a PH ₃ gas.

  As the substrate 7000, a glass substrate containing barium borosilicate glass, aluminoborosilicate glass, or the like, a quartz substrate, a sapphire substrate, a ceramic 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 substrate 7000 is planarized.

  The base insulating layer 7002 has a single-layer structure or a stacked structure using an insulating material such as silicon oxide, silicon nitride, silicon oxynitride, or silicon nitride oxide by various methods such as a CVD method, a sputtering method, and a spin coating method. Form. The base insulating layer 7002 is not necessarily formed, but has an effect of blocking contaminants from the substrate 7000.

  The gate electrode layer 704 may be formed using a conductive material. For example, an element such as Ag, Au, Ni, Pt, Pd, Ir, Rh, Ta, W, Ti, Mo, Al, or Cu, or the element is used. What is necessary is just to form using the alloy material or compound material etc. which are the main components. Alternatively, a semiconductor material typified by polycrystalline silicon doped with an impurity element such as phosphorus, or an AgPdCu alloy may be used. Alternatively, a single layer structure or a stacked structure may be used, for example, a two-layer structure of a tungsten nitride film and a molybdenum (Mo) film, a tungsten film with a thickness of 50 nm, an alloy film of aluminum and silicon with a thickness of 500 nm, A three-layer structure in which titanium nitride films with a thickness of 30 nm are sequentially stacked may be employed. In the case of a three-layer structure, tungsten nitride may be used instead of tungsten of the first conductive layer, or an alloy film of aluminum and titanium is used instead of the alloy film of aluminum and silicon of the second conductive layer. A titanium film may be used instead of the titanium nitride film of the third conductive layer.

  The gate electrode layer 704 is formed by selectively etching a conductive layer formed by a PVD method (Physical Vapor Deposition) such as a sputtering method or a CVD method (Chemical Vapor Deposition) such as a low pressure CVD method (LPCVD method) or a plasma CVD method. To form.

  The gate electrode layer 704 can be formed by various printing methods (screen (stencil) printing, offset (lithographic) printing, a method of forming a desired pattern such as relief printing or gravure (intaglio printing)), nanoimprinting, and droplet discharge method. Alternatively, a dispenser method, a selective coating method, or the like may be used. When such a method is used, a conductive layer can be selectively formed at a desired place.

  The gate insulating layer 706 is formed using an insulating material such as silicon oxide, silicon nitride, silicon oxynitride, or silicon nitride oxide by a CVD method, a sputtering method, or the like. The gate insulating layer 706 may have a single-layer structure or a stacked structure. For example, the gate insulating layer 706 may have a single-layer structure of a silicon oxynitride layer or a stacked structure of two layers of a silicon nitride layer and a silicon oxide layer. Moreover, it is good also as a laminated structure of three or more layers using these. Preferably, silicon nitride having a dense film quality is used. Further, the gate insulating layer 706 is preferably formed using silicon nitride or NiB when the lower gate electrode layer 704 is formed using silver or copper by a droplet discharge method. These films have the effect of preventing the diffusion of impurities and flattening the surface. Note that a rare gas element such as argon may be included in the reaction gas during the formation of the gate insulating layer 706. By including the rare gas element in the reaction gas, a dense insulating layer with low leakage current can be obtained at a low film formation temperature.

  The semiconductor layers (semiconductor layer 708, semiconductor layers 710a and 710b) are amorphous semiconductors (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. A polycrystalline semiconductor obtained by crystallizing the amorphous semiconductor using light energy or thermal energy, or a crystalline semiconductor such as a semi-amorphous (also referred to as microcrystal or microcrystal; hereinafter also referred to as “SAS”) semiconductor is used. Can be formed. The semiconductor layer can be formed by various means (such as sputtering, LPCVD, or plasma CVD).

SAS is a semiconductor having an intermediate structure between amorphous and crystalline structures (including single crystals and polycrystals) and having a third state that is stable in terms of free energy, and has short-range order and lattice distortion. It includes a crystalline region having. A crystal region of 0.5 nm 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 wavenumber 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. In order to terminate dangling bonds (dangling bonds), hydrogen or halogen is contained at least 1 atomic% or more. SAS is formed by glow discharge decomposition (plasma CVD) of a gas containing silicon. As a gas containing silicon, 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. The gas containing silicon may be diluted with H ₂ or H ₂ and one or more kinds of rare gas elements selected from He, Ar, Kr, or 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 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 ° C. to 200 ° C. Here, as an impurity element mainly taken in at the time of film formation, impurities derived from atmospheric components such as oxygen, nitrogen, and carbon are preferably 1 × 10 ²⁰ cm ⁻³ or less, and in particular, the oxygen concentration is 5 × 10 5. ¹⁹ cm ^-3 or less, preferably set to be 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 (also referred to as polycrystalline silicon) includes so-called high temperature polysilicon using polysilicon formed as a main material after a process temperature of 800 ° C. or higher, or polysilicon formed at a process temperature of 600 ° C. or lower. It includes so-called low-temperature polysilicon used as a main material 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 such as a polycrystalline semiconductor or a semi-amorphous semiconductor is used for the semiconductor layer, various methods (laser crystallization method, thermal crystallization method, or crystallization of nickel, etc. are promoted). For example, a thermal crystallization method using an element to be formed). In addition, a microcrystalline semiconductor that is a SAS can be crystallized by laser irradiation to improve crystallinity. Note that in the case where a semiconductor layer is formed using silicon and without introducing an element that promotes crystallization, the semiconductor layer is heated at 700 ° C. for 1 hour in a nitrogen atmosphere before the amorphous silicon layer is irradiated with a laser beam. Thus, it is preferable to release the hydrogen concentration of the amorphous silicon layer to 1 × 10 ²⁰ atoms / cm ³ or less. This is because the amorphous silicon layer is destroyed when the amorphous silicon layer containing a large amount of hydrogen is irradiated with a laser beam.

  The method for 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, a sputtering method, a CVD method, 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 on the surface of the amorphous semiconductor layer by treatment with ozone-containing water or hydrogen peroxide water.

  For crystallization of the amorphous semiconductor layer, heat treatment and crystallization by laser beam irradiation may be combined, or heat treatment and laser beam irradiation may be performed several times independently.

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

  The semiconductor layer can be formed using an organic semiconductor material. As the organic semiconductor material, a low molecular material, a polymer material, or the like is used, and a material such as a conductive polymer material can also be used. For example, a π-electron conjugated polymer material whose skeleton includes conjugated double bonds can be used. Specifically, soluble materials such as polythiophene, polyfluorene, poly (3-alkylthiophene), polythiophene derivatives, and pentacene can be used. In addition, as an organic semiconductor material, there is a material capable of forming a semiconductor layer by processing after forming a soluble precursor. Examples of such an organic semiconductor material include polythienylene vinylene, poly (2,5-thienylene vinylene), polyacetylene, a polyacetylene derivative, and polyarylene vinylene.

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

  In this embodiment, amorphous semiconductor layers are formed as the semiconductor layer 708 and the semiconductor layers 710a and 710b having one conductivity. As the semiconductor layers 710a and 710b having one conductivity, an n-type semiconductor layer containing phosphorus (P) which is an impurity element imparting n-type conductivity is formed. The semiconductor layers 710a and 710b having one conductivity function as a source region and a drain region, and make ohmic contact between the semiconductor layer 708 and the conductive layer functioning as a source electrode or a drain electrode. Note that the semiconductor layers 710a and 710b having one conductivity may be formed as necessary, and an n-type semiconductor layer including an impurity element imparting n-type (P, As) or an impurity element imparting p-type conductivity. A p-type semiconductor layer having (B) can be formed.

  The semiconductor layer 708 or the semiconductor layers 710a and 710b are formed by selectively etching a semiconductor layer formed by a sputtering method, an LPCVD method, a plasma CVD method, or the like. Note that when the separated semiconductor layers 710 a and 710 b are formed, the semiconductor layer 708 is slightly etched, and a recess may be formed in the semiconductor layer 708.

  Further, the semiconductor layer 708 or the semiconductor layers 710a and 710b can be formed by various printing methods (methods formed in a desired pattern such as screen (stencil) printing, offset (lithographic printing), relief printing or gravure printing (intaglio printing)), and nanoimprinting methods. Alternatively, a droplet discharge method, a dispenser method, a selective coating method, or the like may be used. When such a method is used, a semiconductor layer can be selectively formed at a desired place.

  The semiconductor layer 708 forms a channel of the transistor. In addition, the semiconductor layers 710a and 710b form a source region or a drain region of the transistor.

  The conductive layers 712a and 712b are formed using a conductive material that can absorb a laser beam. For example, an element such as chromium (Cr), molybdenum (Mo), nickel (Ni), titanium (Ti), cobalt (Co), copper (Cu), aluminum (Al), or an alloy material containing the element as a main component Alternatively, a conductive material such as a compound can be used. In addition, light-transmitting indium tin oxide (ITO), indium tin oxide containing silicon oxide (ITSO), organic indium, organic tin, zinc oxide, titanium nitride, or the like may be combined. In addition, the conductive layers 712a and 712b may have a single-layer structure or a stacked structure.

  The conductive layers 712a and 712b are selectively formed by a PVD method (Physical Vapor Deposition) such as a sputtering method, or a CVD method (Chemical Vapor Deposition) such as a low pressure CVD method (LPCVD method) or a plasma CVD method. It is formed by etching.

  In addition, the conductive layers 712a and 712b can be formed by various printing methods (screen (stencil) printing, offset (flat plate) printing, a method of forming a desired pattern such as relief printing or gravure (intaglio printing)), nanoimprinting, and droplet ejection. It may be formed using a method, a dispenser method, a selective coating method, or the like. When such a method is used, a conductive layer can be selectively formed at a desired place.

  Next, an insulating layer 7010 is formed so as to cover the transistor 720 (see FIG. 10A).

  The insulating layer 7010 is formed of a material containing silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, aluminum nitride, aluminum oxynitride, diamond-like carbon (DLC), nitrogen-containing carbon (CN), polysilazane, or other inorganic insulating materials. Using a selected material or the like, a single layer structure or a laminated structure is formed. Alternatively, a material containing siloxane may be used. An organic insulating material may be used, and as the organic material, polyimide, acrylic, polyamide, polyimide amide, resist, or benzocyclobutene can be used. Moreover, it can also form using an oxazole resin, for example, photocurable polybenzoxazole etc. can be used.

  The insulating layer 7010 can be formed by a PVD method (Physical Vapor Deposition) such as a sputtering method, a CVD method (Chemical Vapor Deposition) such as a low pressure CVD method (LPCVD method) or a plasma CVD method, a spin coating method, or the like.

  Next, a laser beam is irradiated from the insulating layer 7010 side (see FIG. 10A), and an opening reaching the conductive layer 712b is formed in the insulating layer 7010 (see FIG. 10C).

  In FIG. 10C, an opening formed in the insulating layer 7010 is formed using ablation by laser beam irradiation as described in Embodiments 1 to 5.

  Specifically, as shown in FIG. 10B, a multimode laser beam 7034 and a single mode laser beam 7032 are irradiated as laser beams. The single-mode laser beam 7032 is irradiated so as to overlap with the multi-mode laser beam 7034. In the conductive layer 712 b and the insulating layer 7010, a region irradiated with the multimode laser beam 7034 and the single mode laser beam 7032 is referred to as a superimposed irradiation region 7036. The irradiated multimode laser beam 7034 and single mode laser beam 7032 are absorbed by the conductive layer 712b.

  The conductive layer 712b is ablated in the region irradiated with the multimode laser beam 7034 and the single mode laser beam 7032 superimposed (superimposed irradiation region 7036), and the upper insulating layer 7010 is removed. As a result, an opening 7038 is formed in the insulating layer 7010 as illustrated in FIG.

  Note that although an example in which only the insulating layer 7010 is removed by ablation to form the opening 7038 is described in this embodiment, the present invention is not particularly limited. For example, a part or all of the conductive layer 712b in the superimposed irradiation region 7036 may be removed by ablation to form an opening.

  Next, a light-emitting element 7020 that is electrically connected to the transistor 720 is formed. As the light-emitting element 7020, a light-emitting element that emits red (R), green (G), or blue (B) light may be formed. Alternatively, a light-emitting element 7020 that emits white (W) light may be formed, and RGB light emission may be obtained in combination with a color filter. A method for forming the light emitting element 7020 is described below.

  First, a first electrode layer 7012 of a light-emitting element that functions as a pixel electrode is formed in the opening 7038 from which the conductive layer 712b is exposed. The conductive layer 712b and the first electrode layer 7012 are electrically connected (see FIG. 11A).

  The first electrode layer 7012 can be formed using a conductive material such as indium tin oxide (ITO), indium tin oxide containing silicon oxide (ITSO), or zinc oxide. For example, indium tin oxide (TISO) containing silicon oxide can be formed by a sputtering method using a target containing 2 wt% to 10 wt% of silicon oxide in ITO. In addition, a conductive material in which ZnO is doped with gallium (Ga), and an oxide conductive material formed using a target in which silicon oxide is included and indium oxide is mixed with 2 wt% to 20 wt% of zinc oxide (ZnO). You may form using indium zinc oxide (IZO (indium zinc oxide)).

  The first electrode layer 7012 is a conductive layer formed by a PVD method (Physical Vapor Deposition) such as a sputtering method, or a CVD method (Chemical Vapor Deposition) such as a low pressure CVD method (LPCVD method) or a plasma CVD method. It is formed by etching.

  The first electrode layer 7012 can be selectively formed at a desired place using a droplet discharge method, a printing method (a method for forming a pattern such as screen printing or offset printing), a dipping method, a dispenser method, or the like. It can also be formed.

  The first electrode layer 7012 may be cleaned by polishing with a CMP method or a polyvinyl alcohol-based porous body so that the surface thereof is planarized. Further, after the polishing using the CMP method, the surface of the first electrode layer 7012 may be subjected to ultraviolet irradiation, oxygen plasma treatment, or the like.

  Next, a partition layer 7014 is formed so as to have an opening over the first electrode layer 7012 (see FIG. 11B). The partition layer 7014 is formed using an inorganic insulating material such as silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, aluminum nitride, or aluminum oxynitride, or acrylic acid ester, methacrylic acid ester and derivatives thereof, polyimide, or aromatic. Heat-resistant polymers such as aromatic polyamides, polybenzimidazoles, or silicon formed using siloxane-based materials as starting materials, inorganic siloxanes containing Si—O—Si bonds, and hydrogen bonded to silicon is a methyl group or phenyl It can be formed of an organosiloxane insulating material substituted with an organic group such as a group. You may form using photosensitive and non-photosensitive materials, such as an acryl and a polyimide.

  The partition layer 7014 can be selectively formed by a droplet discharge method, a printing method, a dispenser method, or the like. Alternatively, the partition layer 7014 having a desired shape may be formed by forming an insulating material over the entire surface, forming a resist mask or the like using a lithography process, and performing etching. In addition, the partition layer 7014 having a desired shape can be formed by forming a photosensitive material on the entire surface and exposing and developing the partition layer made of the photosensitive material. Note that the partition wall layer 7014 preferably has a shape in which the radius of curvature continuously changes. With such a shape of the partition layer, the coverage with the layer 7016 and the second electrode layer 7018 formed above is improved.

  Further, after the composition is discharged by a droplet discharge method to form the partition layer 7014, the surface may be pressed and flattened by pressure in order to improve the flatness. As a pressing method, a roller-shaped object may be scanned over the surface, or the surface may be pressed vertically with a flat plate-shaped 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 device can be prevented and a high-definition image can be displayed.

  Next, a layer 7016 and a second electrode layer 7018 are stacked over the first electrode layer 7012 and the partition layer 7014. Then, a light-emitting element 7020 having a structure in which the layer 7016 is sandwiched between the first electrode layer 7012 and the second electrode layer 7018 is obtained (see FIG. 11C). The layer 7016 includes a layer containing a light-emitting material that can obtain at least a desired light emission wavelength (hereinafter also referred to as a light-emitting layer). Specifically, the layer 7016 is formed of an organic compound, an inorganic compound, or a layer containing both.

  Through the above steps, a display device including the light-emitting element 7020 can be obtained.

  By applying the present invention, an opening can be formed in a desired region without using a lithography process using a photoresist. Accordingly, the lithography process can be reduced and simplified, loss of materials such as a resist material and a developer can be prevented, and the number of photomasks can be reduced. Therefore, in the manufacturing process of the display device, it is possible to reduce costs and improve throughput. In addition, a large number of openings can be formed at the same time, and the mass productivity of the display device can be improved.

  This embodiment mode can be freely combined with any of Embodiment Modes 1 to 5 as appropriate.

(Embodiment 7)
In this embodiment mode, a structure of a display panel according to the present invention will be described.

  FIG. 15A 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 scanning 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 full color display using XGA and RGB, 1024 × 768 × 3 (RGB), and for full color display using UXGA and RGB, 1600 × 1200. If it corresponds to x3 (RGB) and full spec high vision and is full color display using RGB, it may be 1920 x 1080 x 3 (RGB).

  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 a switching element is a transistor, and the gate electrode side of the transistor is connected to a scanning line, and the source electrode or drain electrode side is connected to a signal line, so that each pixel is controlled independently by a signal input from the outside. It is possible.

  FIG. 15A illustrates a structure of a display device in which signals input to the scan lines and the signal lines are controlled by an external driver circuit. As illustrated in FIG. 16A, COG (Chip on The driver IC 2751 may be mounted on the substrate 2700 by a glass method. As another mounting mode, a TAB (Tape Automated Bonding) method as shown in FIG. 16B may be used. The driver IC may be formed on a single crystal semiconductor substrate or may be a circuit in which a transistor is formed on a glass substrate. In FIG. 16, the driver IC 2751 is connected to the FPC 2750.

  In the case where the transistor provided in the pixel is formed using a polycrystalline (or microcrystalline) semiconductor with high crystallinity, the scan line driver circuit 3702 is formed over the substrate 3700 as illustrated in FIG. You can also. In FIG. 15B, reference numeral 3701 denotes a pixel portion, and the signal line side driver circuit is controlled by an external driver circuit as in FIG. In the case where a transistor provided in a pixel is formed using a polycrystalline (or microcrystalline) semiconductor, a single crystal semiconductor, or the like with high mobility, FIG. 15C illustrates a scan line driver circuit 4702 and a signal line driver circuit 4704. Can be integrally formed on the substrate 4700.

  In this embodiment mode, an opening for forming a wiring for connecting a switching element and a pixel electrode, an opening for forming a wiring for connecting a gate electrode of a transistor to a scanning line, and a wiring for connecting a source electrode or a drain electrode to a signal line The present invention using laser ablation as shown in Embodiment Modes 1 to 6 can be applied to the opening to be formed.

  By applying the present invention, the lithography process using a photoresist can be reduced and simplified. Therefore, the manufacturing cost for manufacturing the display panel can be reduced and the throughput can be improved. In addition, a large number of openings can be formed at the same time, and mass productivity can be improved.

  This embodiment mode can be freely combined with Embodiment Mode 6 as appropriate.

(Embodiment 8)
In this embodiment, an example of a display device according to the present invention will be described with reference to FIG.

  FIG. 27A is a schematic view of the top surface of the display device described in this embodiment. FIG. 27B is a cross-sectional view taken along the line QR in FIG.

  A display device 900 illustrated in FIG. 27 includes a pixel portion 902 and a driver circuit portion 904 over a substrate 901. A sealing substrate 908 is provided above the substrate 901 with a sealant 910 interposed therebetween. Further, a terminal portion 906 is provided on the substrate 901. A signal for controlling operations of a plurality of elements included in the pixel portion 902 and a power supply potential are input from the outside through the terminal portion 906.

  In the pixel portion 902, a light-emitting element 930, a driving transistor 924, a switching transistor 922, and a capacitor 920 are provided. In the light-emitting element 930, a layer including at least a light-emitting layer is sandwiched between a pair of electrode layers. The light-emitting element 930 is electrically connected to the driving transistor 924.

  An end portion of an electrode layer (an electrode layer electrically connected to the driving transistor 924) below the light-emitting element 930 is covered with a partition wall layer 918. The partition layer 918 is formed using an inorganic insulating material such as silicon oxide or silicon nitride, an organic insulating material such as acrylic, polyimide, or resist, or a siloxane material. A partition layer 918 can be separated from another light-emitting element provided adjacent to the partition layer 918. Note that, as in this embodiment, the partition wall layer 918 having a rounded end portion whose curvature radius continuously changes so that the coverage of the layer formed by stacking upward is provided. Is preferable.

  The driver circuit portion 904 is provided with a plurality of transistors 926 and forms a driver circuit that controls the operation of the pixel portion 902. The driver circuit portion 904 is provided with, for example, a shift register, a decoder, a buffer, a sampling circuit, or a latch.

  The substrate 901 and the sealing substrate 908 are attached to each other with a sealant 910 so that the pixel portion 902 and the driver circuit portion 904 are sealed. The sealing substrate 908 is provided with a color filter 942 and a light shielding layer 944. Note that the present invention is not particularly limited, and the color filter 942 and the light-blocking layer 944 are not necessarily provided.

  This embodiment is different from Embodiment 6 in that the gate electrode layer of the transistor is located below or above the semiconductor layer. Other configurations are the same as those in the sixth embodiment.

  Next, a specific example of a manufacturing method will be described.

  The substrate 901 is ground-insulated using silicon nitride oxide by a PVD method (Physical Vapor Deposition) such as a sputtering method, or a CVD method (Chemical Vapor Deposition) such as a low pressure CVD method (LPCVD method) or a plasma CVD method. The layer 903a is formed with a thickness of 10 nm to 200 nm (preferably 50 nm to 150 nm), and the base insulating layer 903b is stacked with a thickness of 50 nm to 200 nm (preferably 100 nm to 150 nm) using silicon oxynitride.

  In this embodiment, the base insulating layer 903a and the base insulating layer 903b are formed by a plasma CVD method. As the substrate 901, a glass substrate, a quartz substrate, a silicon substrate, a metal substrate, or a stainless substrate on which an insulating layer is formed may be used. Further, a plastic substrate having heat resistance that can withstand the processing temperature of this embodiment may be used, or a flexible substrate such as a film may be used. As the plastic substrate, a substrate made of PET (polyethylene terephthalate), PEN (polyethylene naphthalate), or PES (polyethersulfone) can be used, and as the flexible substrate, a synthetic resin such as acrylic can be used.

  As the base insulating layer, silicon oxide, silicon nitride, silicon oxynitride, silicon nitride oxide, or the like can be used, and a single-layer structure or a stacked structure of two layers or three layers may be used.

  Next, a semiconductor layer is formed over the base insulating layer. The semiconductor layer may be formed with various thicknesses (sputtering method, LPCVD method, plasma CVD method, or the like) with a thickness of 25 nm to 200 nm (preferably 30 nm to 150 nm). In this embodiment mode, it is preferable to use a crystalline semiconductor layer obtained by crystallizing an amorphous semiconductor layer by laser crystallization.

  In order to control the threshold voltage of the transistor, the semiconductor layer obtained in this manner may be doped with a trace amount of an impurity element (boron or phosphorus). This doping of the impurity element may be performed on the amorphous semiconductor layer before the crystallization step. When an impurity element is doped in the state of the amorphous semiconductor layer, the impurity can be activated by heat treatment for subsequent crystallization. In addition, defects and the like generated during doping can be improved.

  The semiconductor layer may be selectively etched and processed into a desired shape. In addition, the semiconductor layer may be formed by various printing methods (screen (stencil) printing, offset (lithographic) printing, a method of forming a desired pattern such as relief printing or gravure printing (intaglio printing)), nanoimprinting method, droplet discharge method, dispenser. It may be formed using a method, a selective coating method, or the like.

  Note that the lower electrode layer constituting the capacitor is also formed in the same process as the semiconductor layer. The lower electrode layer is formed of the same layer as the semiconductor layer constituting the transistor.

  A gate insulating layer is formed to cover the semiconductor layer. The gate insulating layer is formed of an insulating layer containing silicon with a thickness of 10 nm to 150 nm by using a plasma CVD method, a sputtering method, or the like. The gate insulating layer may be formed of an inorganic insulating material such as silicon nitride, silicon oxide, silicon oxynitride, or silicon nitride oxide, and may have a stacked structure or a single layer structure. Alternatively, the gate insulating layer may have a three-layer structure including a silicon nitride layer, a silicon oxide layer, and a silicon nitride layer, or a single layer or two layers of a silicon oxynitride layer.

  Next, a gate electrode layer is formed over the gate insulating layer. The gate electrode layer can be formed by forming a conductive layer by a technique such as sputtering, vapor deposition, or CVD, and selectively etching the conductive layer. The gate electrode layer is an element selected from tantalum (Ta), tungsten (W), titanium (Ti), molybdenum (Mo), aluminum (Al), copper (Cu), chromium (Cr), neodymium (Nd), or What is necessary is just to form with the alloy material or compound material which has the said element as a main component. Alternatively, a semiconductor layer typified by polycrystalline silicon doped with an impurity element such as phosphorus, or an AgPdCu alloy may be used as the gate electrode layer. The gate electrode layer may have a single layer structure or a stacked structure. At this time, an upper electrode layer of a capacitor element to be completed later is also formed. The upper electrode layer is made of the same material as the gate electrode layer.

  In this embodiment, the side surface of the gate electrode layer is formed to have a tapered shape. The tapered shape of the gate electrode layer can be formed by using a wet etching method in the etching process. Alternatively, after the dry etching method, the wet etching method can be performed. Note that a gate electrode layer having a vertical side surface may be formed. Alternatively, the gate electrode layer may have a two-layer structure, and each layer may have a different taper angle. By making the side surface of the gate electrode layer into a tapered shape, coverage with a layer stacked on the upper layer can be improved.

  In addition, the gate electrode layer may be formed by various printing methods (screen (stencil) printing, offset (lithographic) printing, a method of forming a desired pattern such as relief printing or gravure (intaglio printing)), nanoimprinting method, droplet discharge method, You may form using the dispenser method, the selective application method, etc.

  Note that the gate insulating layer may be slightly etched by the etching for forming the gate electrode layer, and the film thickness may be reduced (so-called film reduction).

  An impurity element is added to the semiconductor layer to form a pair of impurity regions. The impurity region formed in the semiconductor layer functions as a source region or a drain region. As the impurity element to be added, an impurity element imparting n-type conductivity or an impurity element imparting p-type conductivity may be appropriately selected and added. As the impurity element imparting n-type conductivity, phosphorus (P), arsenic (As), or the like can be used. As the impurity element imparting p-type conductivity, boron (B), aluminum (Al), gallium (Ga), or the like can be used. At this time, a channel formation region is formed between the pair of impurity regions.

  Note that in the semiconductor layer, an impurity region called an LDD (Light Doped Drain) region may be formed between an impurity region functioning as a source region or a drain region and a channel formation region. The LDD region is an impurity region having a lower concentration than the source region or the drain region. Further, the LDD region may have a structure overlapping with the gate electrode layer or a structure not overlapping.

  In order to activate the impurity element, heat treatment, intense light irradiation, or laser beam irradiation may be performed. Simultaneously with activation, plasma damage to the gate insulating layer and plasma damage to the interface between the gate insulating layer and the semiconductor layer can be recovered.

  Next, a first interlayer insulating layer is formed to cover the gate electrode layer and the gate insulating layer. In this embodiment, a stacked structure of the insulating layer 913 and the insulating layer 914 is employed. As the insulating layer 913 and the insulating layer 914, a silicon nitride layer, a silicon nitride oxide layer, a silicon oxynitride layer, a silicon oxide layer, or the like formed by a sputtering method or plasma CVD can be used. The layers may be used as a single layer structure or a stacked structure of three or more layers.

  Further, a heat treatment is performed at 300 ° C. to 550 ° C. for 1 hour to 12 hours in a nitrogen atmosphere to perform a step of hydrogenating the semiconductor layer. Preferably, it is performed at 400 ° C to 500 ° C. This step is a step of terminating dangling bonds in the semiconductor layer with hydrogen contained in the insulating layer 913 which is an interlayer insulating layer. In this embodiment, heat treatment is performed at 410 ° C.

  As the insulating layer 913 and the insulating layer 914, aluminum nitride, aluminum oxynitride, aluminum nitride oxide or aluminum oxide whose nitrogen content is higher than oxygen content, diamond-like carbon (DLC), nitrogen-containing carbon (CN), It can be formed of a material selected from substances including polysilazane and other inorganic insulating materials. Further, a material containing siloxane may be used. An organic insulating material may be used, and polyimide, acrylic, polyamide, polyimide amide, resist, or benzocyclobutene can be used. Moreover, an oxazole resin can also be used, for example, photocurable polybenzoxazole or the like can be used.

  Next, an opening reaching the source or drain region formed in the semiconductor layer is formed in the insulating layer 913, the insulating layer 914, and the gate insulating layer.

  The opening can be formed using ablation by irradiation with a laser beam as described in Embodiment Modes 1 to 6. Specifically, irradiation is performed so that a multimode laser beam and a single mode laser beam are superimposed. Since the semiconductor layer can function as a light absorption layer, the region irradiated with the multimode laser beam and the single mode laser beam are ablated, and the insulating layer 913, the insulating layer 914, and the gate over the semiconductor layer are ablated. The insulating layer can be removed to form an opening.

  The opening reaching the semiconductor layer may be formed by forming a mask layer using a photoresist and etching using the mask layer.

  A source electrode layer or a drain electrode layer is formed in an opening reaching the source region or the drain region of the semiconductor layer, and the source region or the drain region of the semiconductor layer and the source electrode layer or the drain electrode layer can be electrically connected.

  The source electrode layer or the drain electrode layer can be formed by forming a conductive layer by a PVD method, a CVD method, an evaporation method, or the like, and selectively etching the conductive layer. The material of the source electrode layer or the drain electrode layer is Ag, Au, Cu, Ni, Pt, Pd, Ir, Rh, W, Al, Ta, Mo, Cd, Zn, Fe, Ti, Si, Ge, Zr, Ba Or an alloy material containing the element as a main component or a metal nitride containing the element as a main component. The source electrode layer or the drain electrode layer may have a single-layer structure or a stacked structure.

  In addition, the source electrode layer or the drain electrode layer may be formed by various printing methods (a method of forming a desired pattern such as screen (stencil printing), offset (lithographic printing), relief printing or gravure printing (intaglio printing)), nanoimprinting method, liquid A droplet discharge method, a dispenser method, a selective coating method, or the like may be used. Furthermore, a reflow method or a damascene method may be used. When such a method is used, a conductive layer can be selectively formed at a desired place. Note that the terminal electrode layer 950 of the terminal portion 906 is also formed when the source electrode layer or the drain electrode layer is formed.

  Through the above steps, an active matrix substrate including the transistor 922 and the transistor 924 in the pixel portion 902 and the plurality of transistors 926 in the driver circuit portion 904 can be manufactured.

  Note that the present invention is not particularly limited, and the transistor may have a single gate structure in which one channel formation region is formed, a double gate structure in which two channel formation regions are formed, or a triple gate structure in which three transistors are formed.

  Next, an insulating layer 916 is formed as a second interlayer insulating layer. As the insulating layer 916, silicon oxide, silicon nitride, silicon oxynitride, silicon nitride oxide, aluminum nitride, aluminum oxide containing nitrogen (also referred to as aluminum oxynitride), aluminum nitride containing oxygen (also referred to as aluminum nitride oxide), aluminum oxide , Diamond-like carbon (DLC), nitrogen-containing carbon (CN), PSG (phosphorus glass), BPSG (phosphorus boron glass), alumina, and other materials including inorganic insulating materials. A siloxane resin may also be used. An organic insulating material may be used. The organic material may be photosensitive or non-photosensitive, and may be polyimide, acrylic, polyamide, polyimide amide, resist or benzocyclobutene, polysilazane, low dielectric constant (Low-k). ) Materials can be used. Moreover, an oxazole resin can also be used, for example, photocurable polybenzoxazole or the like can be used. As an interlayer insulating layer provided for planarization, a layer having high heat resistance and high insulating property and a high planarization rate is required. Therefore, a method for forming the insulating layer 916 is represented by a spin coat method. It is preferable to use a coating method.

  The insulating layer 916 can be formed by other dipping methods, spray coating, doctor knife, roll coater, curtain coater, knife coater, CVD method, vapor deposition method, or the like. The insulating layer 916 may be formed by a droplet discharge method. When the droplet discharge method is used, the material liquid can be saved. Further, a method capable of transferring or drawing a pattern, such as a droplet discharge method, for example, a printing method (a method for forming a pattern such as screen printing or offset printing), a dispenser method, or the like can be used.

  An opening reaching the source or drain electrode layer of the transistor 924 is formed in the insulating layer 916 of the pixel portion 902. The opening may be formed in the same manner as the opening for electrically connecting the source or drain electrode layer and the source or drain region of the semiconductor layer. When ablation by laser beam irradiation is used, the source electrode layer or the drain electrode layer is irradiated with a laser beam. The laser beam is irradiated so as to superimpose a multimode laser beam and a single mode laser beam. In the source electrode layer or the drain electrode layer in the region irradiated so as to overlap, energy obtained by combining the energy of the multimode laser beam and the single mode laser beam is absorbed. The source electrode layer or the drain electrode layer is ablated by the absorbed energy of the laser beam, and the upper insulating layer 916 is removed. As a result, an opening reaching the source or drain electrode layer is formed in the insulating layer 916. Note that in the case where the opening is formed using ablation by laser beam irradiation, it is preferable to use a low-melting point metal (chromium in this embodiment) that is relatively easily evaporated in the source electrode layer or the drain electrode layer.

  A light-emitting element 930 is formed over the insulating layer 916 in the pixel portion 902. The light-emitting element 930 is electrically connected to the transistor 924.

  First, the first electrode layer 932 is formed in the opening provided in the insulating layer 916 and exposing the source electrode layer or the drain electrode layer of the transistor 924.

  Next, a partition layer 918 is formed so as to cover an end portion of the first electrode layer 932 and to have an opening over the first electrode layer 932. As the partition layer 918, silicon oxide, silicon nitride, silicon oxynitride, silicon nitride oxide, or the like can be used, and a single-layer structure or a stacked structure including two layers and three layers may be used. As another material for the partition layer 918, aluminum nitride, aluminum oxynitride with an oxygen content higher than the nitrogen content, aluminum nitride oxide or aluminum oxide with a nitrogen content higher than the oxygen content, diamond like carbon (DLC) ), Nitrogen-containing carbon, polysilazane, and other materials including inorganic insulating materials can be used. A material containing siloxane may be used. An organic insulating material may be used, and the organic material may be either photosensitive or non-photosensitive, and polyimide, acrylic, polyamide, polyimide amide, resist, benzocyclobutene, or polysilazane can be used. Moreover, an oxazole resin can also be used, for example, photocurable polybenzoxazole or the like can be used.

  The partition layer 918 is formed by a droplet discharge method that can selectively form a pattern, a printing method that can transfer or draw a pattern (a method that forms a pattern such as screen printing or offset printing), a dispenser method, and other spin coating methods. It can be formed using a coating method, a dipping method, or the like. Further, a partition layer can be formed on the entire surface using a photosensitive material, and the partition layer can be processed into a desired shape by exposure and development. Further, it is formed on the entire surface using a PVD method (Physical Vapor Deposition) such as a sputtering method, or a CVD method (Chemical Vapor Deposition) such as a low pressure CVD method (LPCVD method) or a plasma CVD method, and a resist using a lithography technique. Etc. may be formed and etched into a desired shape.

As the etching process for processing the partition layer into a desired shape, either a dry etching method or a wet etching method may be employed. Plasma etching (a kind of dry etching method) is suitable for processing a large area substrate. As an etching gas, a fluorine-based gas such as CF ₄ , CHF ₃ , or NF ₃ or a chlorine-based gas such as Cl ₂ or BCl ₃ may be used, and an inert gas such as He or Ar may be added as appropriate. Further, if an atmospheric pressure discharge etching process is applied, a local electric discharge process is possible, and it is not necessary to form a mask such as a resist on the entire surface of the substrate.

  The partition layer 918 preferably has a shape in which the radius of curvature continuously changes. By forming the partition layer in such a shape, the coverage of the layer formed on the upper side is improved.

  Next, a layer 934 and a second electrode layer 936 are stacked over the first electrode layer 932 and the partition wall layer 918. Then, a light-emitting element 930 having a structure in which the layer 934 is sandwiched between the first electrode layer 932 and the second electrode layer 936 is obtained. The layer 934 includes a layer containing a light emitting material that can obtain at least a desired light emission wavelength.

  One of the first electrode layer 932 and the second electrode layer 936 functions as an anode, and the other functions as a cathode. The first electrode layer 932 and the second electrode layer 936 include indium tin oxide (ITO), indium tin oxide containing silicon oxide, indium tin oxide containing 2 wt% to 20 wt% zinc oxide, gold, (Au), platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), palladium (Pd), etc. Can be formed. In addition to aluminum, an alloy of magnesium and silver, an alloy of aluminum and lithium, or the like can also be used.

  Note that in order to extract light emitted from the layer 934 to the outside, one or both of the first electrode layer 932 and the second electrode layer 936 uses indium tin oxide or the like, or silver, aluminum, or the like Is preferably formed so as to allow visible light to pass therethrough.

  The first electrode layer 932 can be formed by selective etching after the above-described material is formed over the entire surface. In addition, the first electrode layer 932 can be formed by various printing methods (screen (stencil) printing, offset (lithographic printing) printing, a method of forming a desired pattern such as letterpress printing or gravure printing (intaglio printing)), nanoimprinting, and droplets. You may form using the discharge method, the dispenser method, the selective application method, etc. Furthermore, a reflow method or a damascene method may be used. When such a method is used, a conductive layer can be selectively formed at a desired place.

  Further, the first electrode layer 932 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 polishing using the CMP method, the surface of the first electrode layer 932 may be subjected to ultraviolet irradiation, oxygen plasma treatment, or the like.

  Heat treatment may be performed after the first electrode layer 932 is formed. By this heat treatment, moisture contained in the first electrode layer 932 is released. Therefore, the first electrode layer 932 does not cause degassing. Therefore, even when a light-emitting material that easily deteriorates due to moisture is formed over the first electrode layer 932, the light-emitting material is not deteriorated and the display has high reliability. A device can be made.

  The second electrode layer 936 can be formed by an evaporation method, a sputtering method, or the like. Further, an insulating layer may be provided as a passivation layer (protective layer) over the second electrode layer 936. In this way, it is effective to provide a passivation layer so as to cover the second electrode layer 936. As the passivation layer, silicon nitride, silicon oxide, silicon oxynitride, silicon nitride oxide, aluminum nitride, aluminum oxynitride, aluminum nitride oxide or aluminum oxide whose nitrogen content is higher than oxygen content, diamond like carbon (DLC), The insulating layer includes a nitrogen-containing carbon film, and a single layer structure of the insulating layer or a laminated structure in combination can be used. Alternatively, a siloxane resin may be used.

At this time, it is preferable to use a film with good coverage as the passivation layer, 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., even when the heat resistance of the layer 934 is low, the DLC film can be easily stacked. The DLC film is formed by a plasma CVD method (typically, an RF plasma CVD method, a microwave CVD method, an electron cyclotron resonance (ECR) CVD method, a hot filament CVD method, etc.), a combustion flame method, a sputtering method, or an ion beam evaporation method. It can be formed by laser vapor deposition. The reaction gas used for film formation was hydrogen gas and a hydrocarbon-based gas (for example, CH ₄ , C ₂ H ₂ , C ₆ H _6, etc.), ionized by glow discharge, and negative self-bias was applied. Films are formed by accelerated collision of ions with the cathode. The CN film may be formed using C ₂ H ₄ gas and N ₂ gas as reaction gases. The DLC film has a high blocking effect against oxygen and can suppress oxidation of the layer 934. Therefore, the problem that the layer 934 is oxidized during the subsequent sealing process can be prevented.

  The layer 934 formed over the first electrode layer 932 is a light-emitting layer containing at least a light-emitting material. The light-emitting layer is formed using an organic compound, an inorganic compound, or a layer containing an organic compound and an inorganic compound. A layer 934 is provided between the first electrode layer 932 and the second electrode layer 936, whereby the light-emitting element 930 can be obtained.

  The substrate 901 over which the light-emitting element 930 is formed in this manner and the sealing substrate 908 are fixed with a sealant 910, and the light-emitting element 930 is sealed. As the sealant 910, typically, a visible light curable resin, an ultraviolet curable resin, or a thermosetting resin is preferably used. For example, bisphenol A type liquid resin, bisphenol A type solid resin, bromine-containing epoxy resin, bisphenol F type resin, bisphenol AD type resin, phenol type resin, cresol type resin, novolac type resin, cyclic aliphatic epoxy resin, epibis type epoxy Epoxy resins such as resins, glycidyl ester resins, glycidylamine resins, heterocyclic epoxy resins, and modified epoxy resins can be used. Note that the region 948 surrounded by the sealant may be filled with a filler, or nitrogen or the like may be sealed by sealing in a nitrogen atmosphere. In the case of a structure in which light is extracted through the filler, the filler needs to have translucency. Typically, a visible light curable, ultraviolet curable, or thermosetting epoxy resin may be used. Through the above steps, a display device having a display function using a light-emitting element is completed. Further, the filler can be dropped in a liquid state and filled in the display device. 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 light-emitting element 930 can be prevented.

  In order to prevent deterioration of the element due to moisture, a desiccant may be provided so as to surround the pixel portion 902. For example, a desiccant may be installed in the recess formed in the sealing substrate. With such a structure, it is possible to achieve a configuration that does not prevent thinning. Moreover, if a desiccant is formed also in the area | region corresponding to a gate wiring layer and a water absorption area is taken widely, the water absorption effect will be high. Further, when a desiccant is formed on the gate wiring layer that does not emit light directly, the light extraction efficiency is not lowered.

  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 extracted 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 or around the partition layer 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.

  Alternatively, the source or drain electrode layer and the first electrode layer 932 may be in direct contact with each other and may not be electrically connected but may be connected through a wiring layer.

  In this embodiment mode, the terminal portion 906 has a structure in which the FPC 954 is connected to the terminal electrode layer 950 through the anisotropic conductive layer 952 and electrically connected to the outside.

  As shown in FIG. 27A, the display device manufactured in this embodiment includes a driver circuit portion 904 over the same substrate as the pixel portion 902. Note that the present invention is not particularly limited, and an IC chip may be mounted as a peripheral driver circuit by the above-described COG method or TAB method.

  In the display device of the present invention, the screen display driving method is not particularly limited. For example, a dot sequential driving method, a line sequential driving method, a surface sequential driving method, or the like may be used. Typically, a line sequential driving method is used, and a time-division gray scale driving method or an area gray scale driving method may be used as appropriate. The video signal input to the source line of the display device may be an analog signal or a digital signal, and a drive circuit or the like may be designed in accordance with the video signal as appropriate.

  By applying the present invention, an opening can be formed in a desired region without using a lithography process using a photoresist. Accordingly, the lithography process can be reduced and simplified, and the manufacturing cost can be reduced and the throughput can be improved in the manufacturing process of the display device. In addition, a large number of openings can be formed at the same time, and the mass productivity of the display device can be improved.

  This embodiment mode can be freely combined with any of Embodiment Modes 1 to 7 as appropriate.

(Embodiment 9)
Various element structures can be applied to a light-emitting element having a display function of a display device. Generally, light-emitting elements are distinguished depending on whether the light-emitting material is an organic compound or an inorganic compound. The former is called an organic EL element, and the latter is called an inorganic EL element. Here, examples of light-emitting elements that can be applied to the present invention will be described with reference to FIGS.

  FIG. 12 shows an organic EL element. In the light-emitting element illustrated in FIG. 12, the layer 8260 is interposed between the first electrode layer 8270 and the second electrode layer 8250. One of the first electrode layer 8270 and the second electrode layer 8250 serves as an anode, and the other serves as a cathode. The anode refers to an electrode that injects holes into the light emitting layer, and the cathode refers to an electrode that injects electrons into the light emitting layer. In this embodiment mode, the first electrode layer 8270 is an anode and the second electrode layer 8250 is a cathode. The layer 8260 has a structure in which a hole injection layer 8262, a hole transport layer 8264, a light-emitting layer 8266, an electron transport layer 8268, and an electron injection layer 8269 are sequentially stacked.

  The first electrode layer 8270 and the second electrode layer 8250 include indium tin oxide (ITO), indium tin oxide containing silicon oxide, indium tin oxide containing 2 wt% to 20 wt% zinc oxide, gold, (Au), platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), palladium (Pd), etc. Can be formed. In addition to aluminum, an alloy of magnesium and silver, an alloy of aluminum and lithium, or the like can be used for forming the first electrode layer 8270. A method for forming the first electrode layer 8270 is the same as that of the first electrode layer 7012 or the first electrode layer 932. There is no particular limitation on the method for forming the second electrode layer 8250, and the second electrode layer 8250 can be formed by, for example, a sputtering method or an evaporation method.

  Note that in order to extract the emitted light to the outside, either one or both of the first electrode layer 8270 and the second electrode layer 8250 uses indium tin oxide or the like, or silver, aluminum, or the like is several nm. It is preferably formed so as to have a thickness of ˜tens of nm so that visible light can be transmitted.

The hole injection layer 8262 is a layer having a function of assisting injection of holes from the first electrode layer 8270 to the hole transport layer 8264. By providing the hole-injecting layer 8262, the difference in ionization potential between the first electrode layer 8270 and the hole-transporting layer 8264 is reduced, and holes are easily injected. The hole-injecting layer 8262 has a lower ionization potential than the substance forming the hole-transporting layer 8264 and has a higher ionization potential than the substance forming the first electrode layer 8270, or the hole-transporting layer It is preferable to use a substance whose energy band bends when it is provided as a thin film having a thickness of 1 nm to 2 nm between 8264 and the first electrode layer 8270. Specific examples of a substance that can be used to form the hole-injecting layer 8262 include phthalocyanine-based compounds such as phthalocyanine (abbreviation: H ₂ Pc) and copper phthalocyanine (CuPC), or poly (ethylenedioxythiophene) / Examples thereof include a polymer such as a poly (styrenesulfonic acid) aqueous solution (PEDOT / PSS). In other words, the hole injection layer 8262 is formed by selecting a substance from which the ionization potential in the hole injection layer 8262 is relatively smaller than the ionization potential in the hole transport layer 8264 from among the hole transport materials. can do. In the case where the hole-injecting layer 8262 is provided, the first electrode layer 8270 is preferably formed using a substance having a high work function such as indium tin oxide. Note that the present invention is not particularly limited, and the hole-injection layer 8262 is not necessarily provided.

The hole-transport layer 8264 is a layer having a function of transporting holes injected from the first electrode layer 8270 to the light-emitting layer 8266. In this manner, by providing the hole-transport layer 8264, the distance between the first electrode layer 8270 and the light-emitting layer 8266 can be increased, and as a result, the metal contained in the first electrode layer 8270 and the like can be reduced. This can prevent the emission of light from disappearing. The hole-transport layer 8264 is preferably formed using a hole-transport substance, and particularly preferably formed using a substance having a hole mobility of 1 × 10 ⁻⁶ cm ² / Vs or higher. Note that the hole-transporting substance has higher hole mobility than electrons, and the ratio of the hole mobility to the electron mobility (= hole mobility / electron mobility) is preferably 100. Larger than the substance. Specific examples of a substance that can be used for forming the hole-transport layer 8264 include 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (abbreviation: NPB), 4, 4′-bis [N- (3-methylphenyl) -N-phenylamino] biphenyl (abbreviation: TPD), 4,4 ′, 4 ″ -tris (N, N-diphenylamino) triphenylamine (abbreviation: TDATA), 4,4 ′, 4 ″ -tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine (abbreviation: MTDATA), 4,4′-bis {N- [4- ( N, N-di-m-tolylamino) phenyl] -N-phenylamino} biphenyl (abbreviation: DNTPD), 1,3,5-tris [N, N-di (m-tolyl) amino] benzene (abbreviation: m -MTDAB), 4, 4 ', 4 " Tris (N- carbazolyl) triphenylamine (abbreviation: TCTA), phthalocyanine _{(abbreviation:} H 2 Pc), copper phthalocyanine (abbreviation: CuPc), or vanadyl phthalocyanine (abbreviation: VOPc), 4,4'-bis [N- ( 4-biphenylyl) -N-phenylamino] biphenyl (abbreviation: BBPB) and the like. Note that the hole-transport layer 8264 may have a single-layer structure or a stacked structure.

  The light-emitting layer 8266 is a layer having a light-emitting function and includes a light-emitting material formed using an organic compound. Moreover, the inorganic compound may be included. The organic compound contained in the light-emitting layer 8266 is not particularly limited as long as it is a light-emitting organic compound, and various low-molecular organic compounds and high-molecular organic compounds can be used. As the light-emitting organic compound, either a fluorescent light-emitting material or a phosphorescent light-emitting material can be used. The light-emitting layer 8266 may be a layer including only a light-emitting organic compound, or may have a structure in which a light-emitting organic compound is dispersed in a host material having an energy gap larger than that of the organic compound. Note that in the case where the light-emitting layer 8266 is a layer in which a plurality of compounds are mixed, such as a layer including a light-emitting material formed using an organic compound and a host material, the light-emitting layer 8266 can be formed by a co-evaporation method. Here, co-evaporation refers to a vapor deposition method in which raw materials are vaporized from a plurality of vapor deposition sources provided in one processing chamber, the vaporized raw materials are mixed in a gas phase state, and deposited on an object to be processed.

The electron-transport layer 8268 is a layer having a function of transporting electrons injected from the second electrode layer 8250 to the light-emitting layer 8266. In this manner, by providing the electron-transport layer 8268, the distance between the second electrode layer 8250 and the light-emitting layer 8266 can be increased, and as a result, the metal is contained in the second electrode layer 8250 and the like. Thus, it is possible to prevent the light emission from disappearing. The electron transporting layer 8268 is preferably formed using an electron transporting substance, and particularly preferably formed using a substance having an electron mobility of 1 × 10 ⁻⁶ cm ² / Vs or higher. Note that the electron transporting substance has higher electron mobility than holes, and the ratio of the electron mobility to the hole mobility (= electron mobility / hole mobility) is preferably from 100. Also refers to a large substance. Specific examples of a substance that can be used for forming the electron-transport layer 8268 include tris (8-quinolinolato) aluminum (abbreviation: Alq ₃ ), tris (4-methyl-8-quinolinolato) aluminum (abbreviation: Almq _3). ), Bis (10-hydroxybenzo [h] -quinolinato) beryllium (abbreviation: BeBq ₂ ), bis (2-methyl-8-quinolinolato) -4-phenylphenolato-aluminum (abbreviation: BAlq), bis [2- In addition to metal complexes such as (2-hydroxyphenyl) benzoxazolate] zinc (abbreviation: Zn (BOX) ₂ ), bis [2- (2-hydroxyphenyl) benzothiazolate] zinc (abbreviation: Zn (BTZ) ₂ ) 2- (4-biphenylyl) -5- (4-tert-butylphenyl) -1,3,4-oxadiazole ( Abbreviation: PBD), 1,3-bis [5- (p-tert-butylphenyl) -1,3,4-oxadiazol-2-yl] benzene (abbreviation: OXD-7), 3- (4- tert-butylphenyl) -4-phenyl-5- (4-biphenylyl) -1,2,4-triazole (abbreviation: TAZ), 3- (4-tert-butylphenyl) -4- (4-ethylphenyl) -5- (4-biphenylyl) -1,2,4-triazole (abbreviation: p-EtTAZ), bathophenanthroline (abbreviation: BPhen), bathocuproin (abbreviation: BCP), 4,4-bis (5-methylbenzoxa) And sol-2-yl) stilbene (abbreviation: BzOs). The electron transport layer 8268 may have a single-layer structure or a stacked structure.

The electron injection layer 8269 has a function of assisting injection of electrons from the second electrode layer 8250 to the electron transport layer 8268. The electron injection layer 8269 has an electron affinity higher than that of a material used for forming the electron transport layer 8268 from among materials which can be used to form the electron transport layer 8268 such as BPhen, BCP, p-EtTAZ, TAZ, and BzOs. It can be formed by selecting and using a substance having a relatively large value. By forming the electron injection layer 8269 in this manner, the difference in electron affinity between the second electrode layer 8250 and the electron transport layer 8268 is alleviated, and electrons are easily injected. The electron injection layer 8269 includes an alkali metal such as lithium (Li) or cesium (Cs), an oxide of alkali metal such as lithium oxide, potassium oxide, or sodium oxide, calcium oxide, or magnesium oxide. Alkali earth metal oxides, fluorides of alkali metals such as lithium fluoride and cesium fluoride, fluorides of alkaline earth metals such as calcium fluoride, or alkalis such as magnesium (Mg) and calcium (Ca) Inorganic materials such as earth metals may be included. Further, the electron injection layer 8269 may include an organic compound such as BPhen, BCP, p-EtTAZ, TAZ, or BzOs, an alkali metal fluoride such as LiF, or an alkaline earth metal such as CaF _2. It may be composed of an inorganic compound such as fluoride. As described above, the electron injection layer 8269 is provided as a thin film having a thickness of 1 to 2 nm using an inorganic compound such as an alkali metal fluoride such as LiF or an alkaline earth metal fluoride such as CaF _2. When the energy band is bent or a tunnel current flows through the electron injection layer 8269, electrons can be easily injected from the second electrode layer 8250 into the electron transport layer 8268.

  Note that a hole generation layer may be provided instead of the hole injection layer 8262, or an electron generation layer may be provided instead of the electron injection layer 8269.

  Here, the hole generation layer is a layer that generates holes. The hole generating layer can be formed by mixing at least one substance selected from the hole transporting substances and a substance that exhibits an electron accepting property with respect to the hole transporting substance. Here, as the hole-transporting substance, a substance similar to the substance that can be used for forming the hole-transport layer 8264 can be used. As the substance exhibiting electron accepting properties, it is preferable to use a metal oxide such as molybdenum oxide, vanadium oxide, ruthenium oxide, or rhenium oxide.

  The electron generating layer is a layer that generates electrons. The electron generating layer can be formed by mixing at least one substance selected from electron transporting substances and a substance exhibiting an electron donating property with respect to the electron transporting substance. Here, as the electron transporting substance, a substance similar to the substance that can be used for forming the electron transporting layer 8268 can be used. Moreover, as the substance exhibiting electron donating property, a substance selected from alkali metals and alkaline earth metals, specifically, lithium (Li), calcium (Ca), sodium (Na), potassium (K), Magnesium (Mg) or the like can be used.

  The hole-injection layer 8262, the hole-transport layer 8264, the light-emitting layer 8266, the electron-transport layer 8268, and the electron-injection layer 8269 may be formed using an evaporation method, a droplet discharge method, a coating method, or the like, respectively. The first electrode layer 8270 or the second electrode layer 8250 may be formed by a sputtering method, an evaporation method, or the like.

  In this embodiment mode, the layer 8260 only needs to include at least the light-emitting layer 8266 and have other functions (a hole injection layer 8262, a hole transport layer 8264, an electron transport layer 8268, an electron injection layer 8269, or the like). ) May be provided as appropriate.

  Alternatively, the first electrode layer 8270 may be a cathode and the second electrode layer 8250 may be an anode. In that case, the layer 8260 has a structure in which an electron injection layer, an electron transport layer, a light-emitting layer, a hole transport layer, and a hole injection layer are sequentially stacked from the first electrode layer 8270 side.

  Next, an inorganic EL element will be described with reference to FIGS. Inorganic EL elements are classified into a dispersion-type inorganic EL element and a thin-film inorganic EL element depending on the element structure. The former has a light-emitting layer in which particles of a light-emitting material are dispersed in a binder, and the latter has a light-emitting layer made of a thin film of the light-emitting material. It is common in the point that requires. Note that the obtained light emission mechanism includes donor-acceptor recombination light emission using a donor level and an acceptor level, and localized light emission using inner-shell electron transition of a metal ion. In general, the dispersion-type inorganic EL often has donor-acceptor recombination light emission, and the thin-film inorganic EL element often has localized light emission.

  A light-emitting material that can be used in the present invention includes a base material and an impurity element. The impurity element functions as a light emission center. By changing the impurity element to be contained, light emission of various colors can be obtained. As a method for manufacturing the light-emitting material, various methods such as a solid phase method and a liquid phase method (coprecipitation method) can be used. Also, spray pyrolysis method, metathesis method, precursor thermal decomposition method, reverse micelle method, method combining these methods with high temperature firing, liquid phase method such as freeze-drying method, etc. can be used.

  The solid phase method is a method in which a base material and an impurity element or a compound containing the impurity element are weighed, mixed in a mortar, heated and fired in an electric furnace, reacted, and the base material contains the impurity element. The firing temperature is preferably 700 ° C to 1500 ° C. This is because the solid phase reaction does not proceed when the temperature is too low, and the base material is decomposed when the temperature is too high. In addition, although baking may be performed in a powder state, it is preferable to perform baking in a pellet state. Although firing at a relatively high temperature is required, it is a simple method, so it has high productivity and is suitable for mass production.

  The liquid phase method (coprecipitation method) is a method in which a base material or a compound containing the base material and an impurity element or a compound containing the impurity element are reacted in a solution, dried, and then fired. The particles of the luminescent material are uniformly distributed, and the reaction can proceed even at a low firing temperature with a small particle size.

As a base material used for the light-emitting material, sulfide, oxide, or nitride can be used. Examples of sulfides that can be used include zinc sulfide, cadmium sulfide, calcium sulfide, yttrium sulfide, gallium sulfide, strontium sulfide, and barium sulfide. As the oxide, for example, zinc oxide, yttrium oxide, or the like can be used. As the nitride, for example, aluminum nitride, gallium nitride, indium nitride, or the like can be used. Furthermore, zinc selenide, zinc telluride, and the like can also be used, such as calcium sulfide-gallium sulfide (CaGa ₂ S ₄ ), strontium sulfide-gallium sulfide (SrGa ₂ S ₄ ), barium sulfide-gallium sulfide (BaGa ₂ S ₄ ), and the like. Or a ternary mixed crystal.

  As impurity elements for localized emission, manganese (Mn), copper (Cu), samarium (Sm), terbium (Tb), erbium (Er), thulium (Tm), europium (Eu), cerium (Ce), praseodymium (Pr) or the like can be used. Note that a halogen element such as fluorine (F) or chlorine (Cl) may be added. The halogen element can also function as charge compensation.

  On the other hand, a light-emitting material containing a first impurity element that forms a donor level and a second impurity element that forms an acceptor level can be used as the impurity element for donor-acceptor recombination light emission. As the first impurity element, for example, fluorine (F), chlorine (Cl), aluminum (Al), or the like can be used. For example, copper (Cu), silver (Ag), or the like can be used as the second impurity element.

  In the case where a light-emitting material for donor-acceptor recombination light emission is synthesized using a solid-phase method, a base material, a first impurity element or a compound containing the first impurity element, a second impurity element, or a second impurity element Each compound containing an impurity element is weighed and mixed in a mortar, and then heated and fired in an electric furnace. As the base material, the above-described base material can be used, and as the first impurity element or the compound containing the first impurity element, for example, fluorine (F), chlorine (Cl), aluminum sulfide, or the like is used. As the second impurity element or the compound containing the second impurity element, for example, copper (Cu), silver (Ag), copper sulfide, silver sulfide, or the like can be used. The firing temperature is preferably 700 ° C to 1500 ° C. This is because the solid phase reaction does not proceed when the temperature is too low, and the base material is decomposed when the temperature is too high. In addition, although baking may be performed in a powder state, it is preferable to perform baking in a pellet state.

  In addition, as an impurity element in the case of using a solid phase reaction, a compound including a first impurity element and a second impurity element may be used in combination. In this case, since the impurity element is easily diffused and the solid-phase reaction easily proceeds, a uniform light emitting material can be obtained. Further, since no extra impurity element is contained, a light-emitting material with high purity can be obtained. As the compound constituted by the first impurity element and the second impurity element, for example, copper chloride, silver chloride, or the like can be used.

  Note that the concentration of these impurity elements may be 0.01 atom% to 10 atom% with respect to the base material, and is preferably in the range of 0.05 atom% to 5 atom%.

In the case of a thin-film inorganic EL, the light emitting layer is a layer containing the above light emitting material, and a physical vapor deposition method (PVD) such as a resistance heating vapor deposition method, a vacuum vapor deposition method such as an electron beam vapor deposition (EB vapor deposition) method, or a sputtering method ), Chemical vapor deposition (CVD) such as organometallic CVD or hydride transport low pressure CVD, atomic layer epitaxy (ALE), or the like.

  FIGS. 13A to 13C illustrate an example of a thin-film inorganic EL element that can be used as a light-emitting element. 13A to 13C, the light-emitting element includes a first electrode layer 50, a layer 51, and a second electrode layer 53. The layer 51 includes at least the light emitting layer 52.

  In the light-emitting element illustrated in FIG. 13A, a layer 51 including only the light-emitting layer 52 is sandwiched between the first electrode layer 50 and the second electrode layer 53. 13B and 13C is the same as the light-emitting element in FIG. 13A between the first electrode layer 50 or the second electrode layer 53 and the light-emitting layer 52. In this structure, an insulating layer is provided. 13B includes an insulating layer 54 between the first electrode layer 50 and the light-emitting layer 52, and the light-emitting element illustrated in FIG. 13C includes the first electrode layer 50 and the light-emitting element. An insulating layer 54 a is provided between the light emitting layer 52 and an insulating layer 54 b is provided between the second electrode layer 53 and the light emitting layer 52. Thus, the insulating layer may be provided only between one of the pair of electrode layers sandwiching the light emitting layer, or may be provided between both. The insulating layer may have a single layer structure or a laminated structure.

  13B, the insulating layer 54 is provided so as to be in contact with the first electrode layer 50. However, the order of the insulating layer and the light emitting layer is reversed so as to be in contact with the second electrode layer 53. An insulating layer 54 may be provided.

  Next, a dispersion-type inorganic EL element will be described. In the case of a dispersion-type inorganic EL element, a particulate light emitting material is dispersed in a binder to form a film light emitting layer. When particles having a desired size cannot be obtained sufficiently by the method for manufacturing a light emitting material, the particles may be processed into particles by pulverization or the like in a mortar or the like. A binder is a substance for fixing a granular light emitting material in a dispersed state and maintaining the shape as a light emitting layer. The light emitting material is uniformly dispersed and fixed in the light emitting layer by the binder.

  In the case of a dispersion-type inorganic EL element, a light emitting layer can be formed by a droplet discharge method capable of selectively forming a light emitting layer, a printing method (screen printing, offset printing, etc.), a coating method such as a spin coating method, or a dipping method. A dispenser method or the like can also be used. The film thickness is not particularly limited, but is preferably in the range of 10 nm to 1000 nm. In the light-emitting layer including the light-emitting material and the binder, the ratio of the light-emitting material may be 50 wt% or more and 80 wt% or less.

  FIGS. 14A to 14C show examples of a dispersion-type inorganic EL element that can be used as a light-emitting element. 14A to 14C, the light-emitting element includes a first electrode layer 60, a layer 65, and a second electrode layer 63. The layer 65 includes at least a light emitting layer.

  14A has a stacked structure of a first electrode layer 60, a light emitting layer 62, and a second electrode layer 63, and includes a light emitting material 61 held in the light emitting layer 62 by a binder.

As a binder that can be used in this embodiment mode, an insulating material can be used. Specifically, an organic material or an inorganic material can be used, and a mixed material of an organic material and an inorganic material may be used. As the organic material, a polymer having a relatively high dielectric constant such as a cyanoethyl cellulose resin, or a resin such as polyethylene, polypropylene, polystyrene resin, silicone resin, epoxy resin, or vinylidene fluoride can be used. Alternatively, a heat-resistant polymer such as aromatic polyamide, polybenzimidazole, or siloxane resin may be used. Note that a siloxane resin corresponds to a resin including a Si—O—Si bond. Siloxane has a skeleton structure formed of a bond of silicon (Si) and oxygen (O). As a substituent, an organic group containing at least hydrogen (for example, an alkyl group or an aromatic hydrocarbon) is used. A fluoro group may be used as a substituent. Alternatively, an organic group containing at least hydrogen and a fluoro group may be used as a substituent. Moreover, resin materials such as vinyl resins such as polyvinyl alcohol and polyvinyl butyral, phenol resins, novolac resins, acrylic resins, melamine resins, urethane resins, and oxazole resins (polybenzoxazole) may be used. The dielectric constant can be adjusted by appropriately mixing fine particles of high dielectric constant such as barium titanate (BaTiO ₃ ) and strontium titanate (SrTiO ₃ ) with these resins.

Examples of the inorganic material contained in the binder include silicon oxide, silicon nitride, silicon containing oxygen and nitrogen, aluminum nitride, aluminum or aluminum oxide containing oxygen and nitrogen, titanium oxide, BaTiO ₃ , SrTiO ₃ , lead titanate, niobic acid It can be formed of a material selected from materials including potassium, lead niobate, tantalum oxide, barium tantalate, lithium tantalate, yttrium oxide, zirconium oxide, and other inorganic materials. By including an inorganic material having a high dielectric constant in the organic material (by addition or the like), the dielectric constant of the light emitting layer made of the light emitting material and the binder can be further controlled, and the dielectric constant can be further increased. When a mixed layer of an inorganic material and an organic material is used for the binder and the dielectric constant is high, a larger charge can be induced in the light emitting material.

  In the manufacturing process, the light-emitting material is dispersed in a solution containing a binder. As a solvent for the solution containing a binder that can be used in this embodiment mode, a method for forming a light-emitting layer by dissolving the binder material (various methods) The wet process) and a solvent capable of producing a solution having a viscosity suitable for a desired film thickness may be selected as appropriate. Specifically, an organic solvent or the like can be used. For example, when a siloxane resin is used as a binder, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate (also referred to as PGMEA), 3-methoxy-3-methyl-1-butanol ( It is also possible to use MMB).

  14B and 14C is the same as the light-emitting element in FIG. 14A between the first electrode layer 60 or the second electrode layer 63 and the light-emitting layer 62. In this structure, an insulating layer is provided. 14B includes an insulating layer 64 between the first electrode layer 60 and the light-emitting layer 62, and the light-emitting element illustrated in FIG. 14C includes the first electrode layer 60 and the light-emitting element. An insulating layer 64 a is provided between the light emitting layer 62 and an insulating layer 64 b is provided between the second electrode layer 63 and the light emitting layer 62. Thus, the insulating layer may be provided only between one of the pair of electrode layers sandwiching the light emitting layer, or may be provided between both. The insulating layer may have a single layer structure or a laminated structure.

  14B, the insulating layer 64 is provided so as to be in contact with the first electrode layer 60, but the order of the insulating layer and the light emitting layer is reversed so as to be in contact with the second electrode layer 63. An insulating layer 64 may be provided.

  The insulating layers such as the insulating layer 54 in FIG. 13 and the insulating layer 64 in FIG. 14 are not particularly limited, but preferably have a high withstand voltage and a dense film quality. Furthermore, it is preferable that the dielectric constant is high. For example, silicon oxide, yttrium oxide, titanium oxide, aluminum oxide, hafnium oxide, tantalum oxide, barium titanate, strontium titanate, lead titanate, silicon nitride, zirconium oxide, etc. Can be used. These insulating layers can be formed by a sputtering method, a vapor deposition method, a CVD method, or the like. The insulating layer may be formed by dispersing particles of these insulating materials in a binder. The binder material may be formed using the same material and method as the binder contained in the light emitting layer. The film thickness is not particularly limited, but is preferably in the range of 10 nm to 1000 nm.

  The inorganic EL elements shown in FIGS. 13 and 14 can emit light by applying a voltage between a pair of electrode layers sandwiching the light emitting layer, but can operate in either DC driving or AC driving.

  The light-emitting element described in this embodiment (FIGS. 12 to 14) can be provided as the display element of the display device described in the above embodiment.

  For example, when the organic EL element illustrated in FIG. 12 is applied to the display device illustrated in FIG. 11, the first electrode layer 7012 or the second electrode layer 7018 is the first electrode layer 8270 or the second electrode layer 8250. It corresponds to. The layer 7016 corresponds to the layer 8260. Similarly, in the display device illustrated in FIG. 27, the first electrode layer 932 or the second electrode layer 936 corresponds to the first electrode layer 8270 or the second electrode layer 8250. The layer 934 corresponds to the layer 8260.

  The same applies to the case where the inorganic EL element shown in FIGS. 13 and 14 is applied to the display device shown in FIG. The first electrode layer 7012 or the second electrode layer 7018 corresponds to the first electrode layer 50 or the second electrode layer 53, or the first electrode layer 60 or the second electrode layer 63. The layer 7016 corresponds to the layer 51 or the layer 65. Similarly, in the case of the display device illustrated in FIG. 27, the first electrode layer 932 or the second electrode layer 936 includes the first electrode layer 50 or the second electrode layer 53, or the first electrode layer 60 or This corresponds to the second electrode layer 63. The layer 934 corresponds to the layer 51 or the layer 65.

  The present invention can be applied to formation of an opening for connecting the light-emitting element of this embodiment mode to a transistor or the like. By applying the present invention, throughput is improved in the manufacturing process of a display device having a light-emitting element. In addition, the mass productivity of the display device can be improved.

  This embodiment mode can be freely combined with any of Embodiment Modes 6 to 8 as appropriate.

(Embodiment 10)
In this embodiment, a liquid crystal display device is described.

  FIG. 29A is a top view of the liquid crystal display device, and FIG. 29B is a cross-sectional view taken along line GH in FIG.

  As shown in FIG. 29A, a pixel region 606, a driving circuit region 608a which is a scanning line driving circuit, and a driving circuit region 608b which is a scanning line driving region are separated from each other with a substrate 600 and a sealing substrate 695 by a sealant 692. A driving circuit region 607 which is a signal line driving circuit which is sealed between and formed on the substrate 600 by an IC driver is provided. A transistor 622 and a capacitor 623 are provided in the pixel region 606, and a driver circuit including a transistor 620 and a transistor 621 is provided in the driver circuit region 608b. As the substrate 600, a substrate similar to that in the above embodiment can be used. When a substrate made of a synthetic resin is used as the substrate 600, there is a concern that the heat-resistant temperature is lower than that of other substrates. However, the substrate 600 is adopted by transposition after a manufacturing process using a substrate with high heat resistance. It becomes possible.

  In the pixel region 606, a transistor 622 serving as a switching element is provided through a base insulating layer 604a and a base insulating layer 604b. In this embodiment, a multi-gate thin film transistor is used as the transistor 622. The transistor 622 includes a semiconductor layer having an impurity region functioning as a source region and a drain region, a gate insulating layer, a gate electrode layer having a two-layer structure, a source electrode layer, and a drain electrode layer. The electrode layer is in contact with and electrically connected to the impurity region of the semiconductor layer and the pixel electrode layer 630.

  The source electrode layer or the drain electrode layer has a stacked structure. The source electrode layer or the drain electrode layer is electrically connected to the impurity region of the semiconductor layer through an opening formed in the gate insulating layer and the insulating layer 611 covering the gate electrode layer.

  The opening reaching the impurity region of the semiconductor layer can be formed using ablation by laser beam irradiation as described in Embodiment Modes 1 to 6. Specifically, irradiation is performed so that a multimode laser beam and a single mode laser beam are superimposed. Since the semiconductor layer can function as a light absorption layer, the regions irradiated with the multimode laser beam and the single mode laser beam are ablated, and the gate insulating layer and the insulating layers 611 and 612 over the semiconductor layer are ablated. Can be removed to form an opening.

  The opening reaching the impurity region of the semiconductor layer may be formed by forming a mask layer using a photoresist and performing etching using the mask layer.

  The source or drain electrode layers 644 a and 644 b are electrically connected to the pixel electrode layer 630 through openings formed in the insulating layer 615. The opening formed in the insulating layer 615 can be formed using ablation by laser beam irradiation as described in Embodiment Modes 1 to 6. In this embodiment, a low-melting point metal (chromium in this embodiment) that is relatively easily evaporated is used for the source electrode layer or the drain electrode layer 644b, and the source electrode layer or the drain electrode is used for the source electrode layer or the drain electrode layer 644a. A refractory metal (tungsten in this embodiment) that is harder to evaporate than the layer 644b is used. Irradiation is performed from the insulating layer 615 side so as to superimpose a multimode laser beam and a single mode laser beam. At this time, irradiation is performed so that the multimode laser beam and the single mode laser beam overlap with each other in the source or drain electrode layers 644a and 644b. In the source or drain electrode layers 644a and 644b in the regions irradiated so as to overlap, energy obtained by combining the energy of the multimode laser beam and the single mode laser beam is absorbed. The source or drain electrode layers 644a and 644b are ablated by the energy of the absorbed laser beam, and the upper source or drain electrode layer 644b and the insulating layer 615 are removed. As a result, an opening reaching the source or drain electrode layer 644a is formed.

  The pixel electrode layer 630 is formed in the opening from which the source or drain electrode layers 644a and 644b are exposed, and the source or drain electrode layers 644a and 644b and the pixel electrode layer 630 can be electrically connected. Note that the pixel electrode layer 630 may be formed without forming an opening in the source or drain electrode layer 644b.

  Thin film transistors can be manufactured by a number of methods. For example, a crystalline semiconductor layer is formed as the semiconductor layer. A gate electrode layer is provided over the crystalline semiconductor layer with a gate insulating layer interposed therebetween. An impurity element can be added to the crystalline semiconductor layer using the gate electrode layer as a mask. Thus, it is not necessary to form a mask layer for adding an impurity element by adding the impurity element using the gate electrode layer. The gate electrode layer can have a single-layer structure or a stacked structure. The impurity region can be a high concentration impurity region and a low concentration impurity region by controlling the concentration thereof. A thin film transistor having such a low concentration impurity region is referred to as an LDD (Light Doped Drain) structure. The low-concentration impurity region can be formed so as to overlap with the gate electrode. Such a thin film transistor is referred to as a GOLD (Gate Overlapped LDD) structure. The polarity of the thin film transistor is n-type by using phosphorus (P) or the like in the impurity region. When p-type is used, boron (B) or the like may be added. After that, an insulating layer 611 and an insulating layer 612 that cover the gate electrode layer and the like are formed. A dangling bond in the crystalline semiconductor layer can be terminated by hydrogen mixed in the insulating layer 611 (and the insulating layer 612).

  In order to further improve the flatness, an insulating layer 615 may be formed as an interlayer insulating layer. The insulating layer 615 can be formed with a single-layer structure or a stacked structure using an organic insulating material or an inorganic insulating material. For example, silicon oxide, silicon nitride, silicon oxynitride, silicon nitride oxide, aluminum nitride, aluminum oxynitride, aluminum nitride oxide or aluminum oxide whose nitrogen content is higher than oxygen content, diamond like carbon (DLC), polysilazane, nitrogen content It can be formed of a material selected from substances including carbon (CN), PSG (phosphorus glass), BPSG (phosphorus boron glass), alumina, and other inorganic insulating materials. An organic insulating material may be used, and the organic material may be either photosensitive or non-photosensitive, and polyimide, acrylic, polyamide, polyimide amide, resist, benzocyclobutene, siloxane resin, or the like can be used. Note that a siloxane resin corresponds to a resin including a Si—O—Si bond. Siloxane has a skeleton structure formed of a bond of silicon (Si) and oxygen (O). As a substituent, an organic group containing at least hydrogen (for example, an alkyl group or an aromatic hydrocarbon) is used. A fluoro group may be used as a substituent. Alternatively, an organic group containing at least hydrogen and a fluoro group may be used as a substituent.

  In addition, by using a crystalline semiconductor layer, the pixel region and the driver circuit region can be formed over the same substrate. In that case, the transistor in the pixel region 606 and the transistor in the driver circuit region 608b are formed at the same time. Transistors used for the driver circuit region 608b constitute a CMOS circuit. Although the thin film transistor included in the CMOS circuit has a GOLD structure, an LDD structure such as the transistor 622 can also be used.

  Without being limited to this embodiment mode, the thin film transistor in the pixel region 606 may have a single gate structure in which one channel formation region is formed, a double gate structure in which two channel formation regions are formed, or a triple gate structure in which three channel formation regions are formed. . The thin film transistor in the peripheral driver circuit region may have a single gate structure, a double gate structure, or a triple gate structure.

  Note that not only the method for manufacturing the thin film transistor described in this embodiment mode, but a top gate type (for example, a forward staggered type), a bottom gate type (for example, an inverted staggered type), or a gate insulating film above and below a channel region is used. The present invention can also be applied to a dual gate type or other structure having two gate electrode layers arranged.

  Next, an insulating layer 631 called an alignment film is formed by a printing method or a droplet discharge method so as to cover the pixel electrode layer 630. Note that the insulating layer 631 can be selectively formed by a screen printing method or an offset printing method. Thereafter, a rubbing process is performed. This rubbing process may not be performed in the liquid crystal mode, for example, the VA mode. The insulating layer 633 functioning as an alignment film is similar to the insulating layer 631. Subsequently, a sealant 692 is formed in a peripheral region where pixels are formed by a droplet discharge method.

  After that, a sealing substrate provided with an insulating layer 633 that functions as an alignment film, a conductive layer 634 that functions as a counter electrode, a colored layer 635 that functions as a color filter, a polarizer 641 (also referred to as a polarizing plate), and a polarizer 642. 695 and a substrate 600 which is a TFT substrate are attached to each other with a spacer 637, and a liquid crystal layer 632 is provided in the gap. Since the liquid crystal display device in this embodiment is a transmissive type, a polarizer (polarizing plate) 643 is provided on the side opposite to the surface of the substrate 600 having elements. The polarizer can be provided on the substrate by an adhesive layer. A filler may be mixed in the sealing material, and a sealing film (black matrix) or the like may be formed on the sealing substrate 695. Note that the color filter or the like may be formed from a material exhibiting red (R), green (G), and blue (B) when the liquid crystal display device is set to full color display. It may be formed of a material that eliminates or exhibits at least one color.

  When a continuous additive color mixing method (field sequential method) in which RGB light emitting diodes (LEDs) are arranged in the backlight and color display is performed in a time-sharing manner, a color filter may not be provided. The black matrix is preferably provided so as to overlap with the transistor or the CMOS circuit in order to reduce reflection of external light due to the wiring of the transistor or the CMOS circuit. Note that the black matrix may be formed so as to overlap with the capacitor. This is because reflection by the metal film constituting the capacitor element can be prevented.

  As a method for forming the liquid crystal layer, a dispenser method (dropping method) or an injection method in which liquid crystal is injected by using a capillary phenomenon after the substrate 600 having an element and the sealing substrate 695 are bonded to each other can be used. The dropping method is preferably applied when handling a large-area substrate to which it is difficult to apply the implantation method.

  The spacer may be provided by spraying particles of several μm, but in this embodiment, a method of forming a resin film on the entire surface of the substrate and then etching it is employed. After applying such a spacer material with a spinner, it is formed into a predetermined pattern by exposure and development processing. Further, it is cured by heating at 150 ° C. to 200 ° C. in a clean oven or the like. The spacers produced in this way can have different shapes depending on the conditions of exposure and development processing, but preferably, the spacers are columnar and the top is flat, so that the opposite substrate is When combined, the mechanical strength of the liquid crystal display device can be ensured. The shape can be a conical shape, a pyramid shape or the like, and there is no particular limitation.

  Subsequently, an FPC 694 which is a wiring board for connection is provided on the terminal electrode layers 678a and 678b electrically connected to the pixel region with an anisotropic conductive layer 696 interposed therebetween. The FPC 694 plays a role of transmitting an external signal or potential. Through the above steps, a liquid crystal display device having a display function can be manufactured.

  Note that a wiring included in the transistor, a gate electrode layer, a pixel electrode layer 630, and a conductive layer 634 which is a counter electrode layer include indium tin oxide (ITO), indium oxide and zinc oxide (ZnO) mixed in IZO (indium zinc oxide). , Conductive material in which silicon oxide is mixed with indium oxide, organic indium, organic tin, indium oxide including tungsten oxide, indium zinc oxide including tungsten oxide, indium oxide including titanium oxide, indium tin oxide including titanium oxide , Tungsten (W), molybdenum (Mo), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), cobalt (Co), nickel (Ni ), Titanium (Ti), platinum (Pt), aluminum It can be selected from metals such as copper (Al), copper (Cu), silver (Ag) or the like, or an alloy or metal nitride containing the metal as a main component.

  You may laminate | stack in the state which had the phase difference plate between the polarizing plate and the liquid-crystal layer.

  Note that although a TN liquid crystal panel is described in this embodiment mode, the above process can be similarly applied to other types of liquid crystal panels. For example, the present embodiment can be applied to a horizontal electric field type liquid crystal panel in which an electric field is applied in parallel with a glass substrate to align liquid crystals. Further, the present embodiment can be applied to a VA (Vertical Alignment) liquid crystal panel.

  17 and 18 show the pixel structure of the VA liquid crystal panel. FIG. 17 is a plan view, and FIG. 18 shows a cross-sectional structure corresponding to the line segment IJ shown in the figure. The following description will be given with reference to both the drawings.

  In this pixel structure, a single pixel has a plurality of pixel electrodes, and a TFT is connected to each pixel electrode. Each TFT is configured to be driven by a different gate signal. In other words, a multi-domain designed pixel has a configuration in which signals applied to individual pixel electrodes are controlled independently.

  The pixel electrode layer 1624 is connected to the TFT 1628 through a wiring layer 1618 through an opening 1623 (contact hole). The pixel electrode layer 1626 is connected to the TFT 1629 through the wiring layer 1619 through an opening 1627 (contact hole). The gate wiring layer 1602 of the TFT 1628 and the gate electrode layer 1603 of the TFT 1629 are separated so that different gate signals can be given. On the other hand, the wiring layer 1616 functioning as a data line is used in common by the TFT 1628 and the TFT 1629.

  The openings 1623 and 1627 can be formed by utilizing ablation by laser beam irradiation as described in Embodiment Modes 1 to 6. Specifically, irradiation is performed from the insulating layer 1622 side so as to superimpose a multimode laser beam and a single mode laser beam. The laser beam is irradiated so as to overlap with the wiring layer 1618 and the wiring layer 1619. In the wiring layers 1618 and 1619 in the regions irradiated so as to overlap, energy obtained by combining the energy of the multimode laser beam and the single mode laser beam is absorbed. The wiring layers 1618 and 1619 are ablated by the absorbed energy of the laser beam, and the upper insulating layer 1620 and insulating layer 1622 are removed. As a result, an opening 1623 reaching the wiring layer 1618 and an opening 1627 reaching the wiring layer 1619 are formed.

  The pixel electrode layer 1624 and the pixel electrode layer 1626 can be formed by being selectively etched after a conductive material is formed over the entire surface. The pixel electrode layer 1624 and the pixel electrode layer 1626 have different shapes and are separated by a slit 1625. A pixel electrode layer 1626 is formed so as to surround the outside of the V-shaped pixel electrode layer 1624. The timing of the voltage applied to the pixel electrode layer 1624 and the pixel electrode layer 1626 is varied depending on the TFT 1628 and the TFT 1629, thereby controlling the alignment of the liquid crystal. A counter substrate 1601 is provided with a light-blocking layer 1632, a coloring layer 1636, and a counter electrode layer 1640. In addition, a planarization layer 1637 is formed between the colored layer 1636 and the counter electrode layer 1640 to prevent alignment disorder of the liquid crystal. FIG. 19 shows a structure on the counter substrate side. The counter electrode layer 1640 is a common electrode between different pixels, but a slit 1641 is formed. By arranging the slits 1641 and the slits 1625 on the pixel electrode layer 1624 side and the pixel electrode layer 1626 side to alternately engage with each other, an oblique electric field can be effectively generated to control the alignment of the liquid crystal. Thereby, the direction in which the liquid crystal is aligned can be varied depending on the location, and the viewing angle is widened.

  By applying the present invention, an opening can be formed in a desired region without using a lithography process using a photoresist. Therefore, the lithography process can be reduced and simplified, loss of materials such as a resist material and a developer can be prevented, and the number of necessary photomasks can be reduced. Therefore, in the manufacturing process of the display device, it is possible to reduce costs and improve throughput. In addition, a large number of openings can be formed at the same time, and the mass productivity of the display device can be improved.

  This embodiment mode can be freely combined with any of Embodiment Modes 1 to 6 as appropriate.

(Embodiment 11)
In this embodiment, a liquid crystal display device using a liquid crystal display element as a display element will be described.

  The display device illustrated in FIG. 30 includes a transistor 420 which is an inverted staggered transistor, a pixel electrode layer 451, an insulating layer 452, an insulating layer 453, a liquid crystal layer 454, a spacer 481, an insulating layer 435, and a pixel region. Electrode layer 456, color filter 458, black matrix 457, counter substrate 410, polarizing plate (polarizer) 431, polarizing plate (polarizer) 433, sealing material 482 in the sealing region, terminal electrode layer 487, anisotropic conductive layer 488 and FPC 486 are provided.

  The gate electrode layer, the semiconductor layer, the source electrode layer, the drain electrode layer, and the pixel electrode layer 451 of the transistor 420 manufactured in this embodiment are formed using conductive materials as described in Embodiments 6, 8, 10, and the like. Alternatively, a material layer made of a semiconductor material can be formed, and the material layer can be selectively etched as appropriate.

  In this embodiment, an amorphous semiconductor layer is used as a semiconductor layer for forming a channel, and a semiconductor layer having one conductivity provided between the source electrode layer or the drain electrode layer and the semiconductor layer is necessary. It may be formed accordingly. In this embodiment mode, an amorphous n-type semiconductor layer is stacked as a semiconductor layer and a semiconductor layer having one conductivity. In addition, an n-type semiconductor layer is formed as a semiconductor layer having one conductivity, an NMOS structure of an n-channel thin film transistor, a PMOS structure of a p-channel thin film transistor in which a p-type semiconductor layer is formed, an n-channel thin film transistor and a p-channel thin film transistor, The CMOS structure can be manufactured.

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 transistor or a P-channel transistor can be formed. Alternatively, conductivity may be imparted to the semiconductor layer by performing plasma treatment with a PH ₃ gas.

  In this embodiment, the transistor 420 is an n-channel inverted staggered thin film transistor. Alternatively, a channel-protective inverted staggered thin film transistor in which a protective layer is provided over the channel region of the semiconductor layer can be used.

  Next, the configuration of the backlight unit 352 will be described. The backlight unit 352 includes a cold cathode tube, a hot cathode tube, a light emitting diode, an inorganic EL, and an organic EL as a light source 361 that emits fluorescence, a lamp reflector 362 that efficiently guides the fluorescence to the light guide plate 365, and total reflection of the fluorescence. However, a light guide plate 365 for guiding light to the entire surface, a diffusion plate 366 for reducing unevenness in brightness, and a reflection plate 364 for reusing light leaked under the light guide plate 365 are provided. .

  A control circuit for adjusting the luminance of the light source 361 is connected to the backlight unit 352. The luminance of the light source 361 can be controlled by supplying a signal from the control circuit.

  A source electrode layer or a drain electrode layer of the transistor 420 is electrically connected to the pixel electrode layer 451 through an opening formed in the insulating layer 452. The opening can be formed using ablation by laser beam irradiation as described in Embodiment Modes 1 to 6. In this embodiment, a low-melting-point metal (chromium in this embodiment) that is relatively easily evaporated is used for the source electrode layer or the drain electrode layer. Irradiation is performed from the insulating layer 452 side so as to superimpose a multimode laser beam and a single mode laser beam. The laser beam is irradiated so as to overlap with the source electrode layer or the drain electrode layer. In the source electrode layer or the drain electrode layer in the region irradiated so as to overlap, energy obtained by combining the energy of the multimode laser beam and the single mode laser beam is absorbed. The source electrode layer or the drain electrode layer is ablated by the energy of the absorbed laser beam and removed together with the upper insulating layer 452. As a result, the semiconductor layer having one conductivity can be formed, and an opening through which the source electrode layer or the drain electrode layer is exposed can be formed.

  A pixel electrode layer 451 is formed in the opening from which the source or drain electrode layer and the semiconductor layer having one conductivity are exposed, and the semiconductor layer having one conductivity, the source or drain electrode layer, and the pixel electrode layer 451 are formed. Can be electrically connected.

  By applying the present invention, an opening can be formed in a desired region without using a lithography process using a photoresist. Therefore, the lithography process can be reduced and simplified, the manufacturing cost can be reduced, and the throughput can be improved. In addition, a large number of openings can be formed at the same time, and the mass productivity of the display device can be improved.

  This embodiment mode can be freely combined with any of Embodiment Modes 1 to 10 as appropriate.

(Embodiment 12)
In this embodiment, an example of a display device which is different from the above embodiment will be described.

  FIG. 20 shows active matrix electronic paper to which the present invention is applied. Although FIG. 20 shows an active matrix type, the present invention can also be applied to a passive matrix type.

  A twist ball display system can be used as the electronic paper. In the twist ball display system, spherical particles that are separately painted in white and black are arranged between the first electrode layer and the second electrode layer, and a potential difference is generated between the first electrode layer and the second electrode layer. In this method, display is performed by controlling the orientation of the spherical particles.

  The transistor 5801 is an inverse coplanar thin film transistor and includes a gate electrode layer 5802, a gate insulating layer 5804, a wiring layer 5805a, a wiring layer 5805b, and a semiconductor layer 5806. The wiring layer 5805a and the wiring layer 5805b function as a source electrode layer or a drain electrode layer. The wiring layer 5805b is in contact with and electrically connected to the first electrode layer 5807 through an opening formed in the insulating layer 5908. Between the first electrode layer 5807 and the second electrode layer 5808, spherical particles 5809 including a cavity 5904 having a black region 5900a and a white region 5900b and being filled with a liquid are provided. The periphery of the spherical particle 5809 is filled with a filler 5905 such as a resin.

  In this embodiment, the gate electrode layer 5802, the semiconductor layer 5806, the wiring layers 5805a, 5805b, and the like included in the transistor 5801 form a material layer formed using a conductive material or a semiconductor material as described in the above embodiment mode. The material layer can be formed by being selectively etched as appropriate.

  The wiring layer 5805b is electrically connected to the first electrode layer 5807 through an opening formed in the insulating layer 5908. The opening can be formed using ablation by laser beam irradiation as described in Embodiment Modes 1 to 6. In this embodiment mode, a low melting point metal (chromium in this embodiment mode) that is relatively easily evaporated is used for the wiring layer 5805b. Irradiation is performed from the insulating layer 5908 side so as to superimpose a multimode laser beam and a single mode laser beam. The laser beam is irradiated so as to overlap with the wiring layer 5805b. In the wiring layer 5805b in the region irradiated so as to overlap, energy obtained by combining the energy of the multimode laser beam and the single mode laser beam is absorbed. The wiring layer 5805b is ablated by the energy of the absorbed laser beam and removed together with the upper insulating layer 5908. As a result, an opening through which the wiring layer 5805b is exposed can be formed on the side surface. Note that the present invention is not particularly limited, and the wiring layer 5805b may remain when an opening is formed by ablation. The wiring layer 5805b can be partially or entirely left by appropriately selecting a conductive material and energy of a laser beam.

  The first electrode layer 5807 is formed in the opening from which the wiring layer 5805b is exposed, and the wiring layer 5805b and the first electrode layer 5807 can be electrically connected.

  By utilizing laser ablation, an opening can be formed in the insulating layer by laser beam irradiation without performing a complicated lithography process.

  Further, instead of the twisting ball, an electrophoretic element can be used. A microcapsule having a diameter of about 10 μm to 200 μm in which transparent liquid, positively charged white microparticles, and negatively charged black microparticles are enclosed is used. In the microcapsule provided between the first electrode layer and the second electrode layer, when an electric field is applied by the first electrode layer and the second electrode layer, the white particles and the black particles are in opposite directions. And can display white or black. A display element using this principle is an electrophoretic display element, and is generally called electronic paper. Since the electrophoretic display element has higher reflectance than the liquid crystal display element, an auxiliary light is unnecessary, power consumption is small, and the display portion can be recognized even in a dim place. In addition, even when power is not supplied to the display unit, it is possible to retain the image once displayed. Therefore, even when the display device with a display function is moved away from the radio wave source, it is displayed. The image can be stored.

  The transistor may have any structure as long as it can function as a switching element. As the semiconductor layer, various semiconductors such as an amorphous semiconductor, a crystalline semiconductor, a polycrystalline semiconductor, and a microcrystalline semiconductor can be used, and an organic transistor may be formed using an organic compound.

  In this embodiment mode, specifically, the case where the structure of the display device is an active matrix type is shown; however, the present invention can also be applied to a passive matrix type display device.

  By applying the present invention, an opening can be formed in a desired region without using a lithography process using a photoresist. Therefore, the lithography process can be reduced and simplified, and the manufacturing cost can be reduced and the throughput can be improved. In addition, a large number of openings can be formed at the same time, and the mass productivity of the display device can be improved.

  This embodiment mode can be freely combined with any of Embodiment Modes 1 to 6 as appropriate.

(Embodiment 13)
Next, a mode in which a driver circuit for driving is mounted on the display panel manufactured according to Embodiments 6 to 12 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 a rectangular shape, and a divided drive circuit (also referred to as a driver IC) 2751 is mounted on the substrate 2700. FIG. 16A illustrates a form in which an FPC 2750 is mounted on the tip of a plurality of driver ICs 2751 and 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 mm to 80 mm and a short side of 1 mm 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 having a long side of 15 mm to 80 mm is used, the number required for mounting corresponding to the pixel portion is as follows. This is less than when an IC chip is used, and the manufacturing yield can be improved. Further, when a driver IC is formed over a glass substrate, the shape of the substrate used as a base is not limited, and thus productivity is not impaired. This is a great advantage compared with the case where the IC chip is taken out from the circular silicon wafer.

  In the case where the scan line driver circuit 3702 is formed over the substrate as shown in FIG. 15B, a driver IC in which a driver circuit driver circuit on the signal line side is formed in a region outside the pixel portion 3701. Is implemented. These driver ICs are drive circuits on the signal line side. In order to form a pixel region corresponding to RGB full color, the number of signal lines in the XGA class is 3072 and the number in the UXGA class is 4800. The signal lines formed in such a number are divided into several blocks at the end of the pixel portion 3701 to form lead lines, and are collected according to the pitch of the output terminals of the driver IC.

  The driver IC is preferably formed using a crystalline semiconductor formed over a substrate, and the crystalline semiconductor is preferably formed by irradiation with a continuous wave laser beam. Therefore, a continuous wave solid laser or gas laser is used as an oscillator for generating the laser beam. When a continuous wave laser beam is used, a transistor can be manufactured 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 beam are preferably matched. This is because, in the laser crystallization process using a continuous wave laser beam, the highest movement occurs 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 between −30 degrees and 30 degrees). This is because the degree 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 manufactured in this manner has a semiconductor 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 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 as 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 beam 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 shape of the laser beam (beam spot) to the same length as the short side of the driver IC.

  As shown in FIGS. 16A and 16B, 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. This embodiment is characterized in that a TFT having an amorphous semiconductor or a 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 mm × 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. Further, a semi-amorphous TFT can obtain field effect mobility of ^{2cm 2 / V · sec~10cm 2 /} V · sec by forming a channel formation region using a SAS. Thus, a display panel that realizes system-on-panel can be manufactured.

  By using a TFT in which the semiconductor layer is formed of SAS, the scanning line side driver circuit can be integrally formed on the substrate. Note that in the case of using a TFT in which a semiconductor layer is formed of SAS, it is preferable to mount a driver IC in both the scanning line side driving circuit and the signal line side driving circuit.

  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.

  The method for mounting the driver IC is not particularly limited, and a COG method, a wire bonding method, or a 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 14)
Examples of display panels (EL display panels and liquid crystal display panels) manufactured according to Embodiments 6 to 13 in which a semiconductor layer is formed using an amorphous semiconductor or SAS and a driver circuit on the scan line side is formed over a substrate. Indicates.

Figure 22 ^shows a block diagram of a scanning line driver circuit including the n-channel TFT using the SAS that field-effect mobility of ^{1cm 2 / V · sec~15cm 2 /} V · sec can be obtained.

  In FIG. 22, a block denoted by reference numeral 8500 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 8501 denotes a buffer circuit to which a pixel 8502 is connected.

  FIG. 23 shows a specific structure of the pulse output circuit 8500, and the circuit is composed of n-channel TFTs 8601 to 8613. 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 structure of the buffer circuit 8501 is shown in FIG. Similarly, the buffer circuit includes n-channel TFTs 8620 to 8635. 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.

  In order to realize such a circuit, it is necessary to connect the TFTs by wiring.

  As described above, a driver circuit can be incorporated in the display panel.

(Embodiment 15)
This embodiment will be described with reference to FIG. FIG. 28 shows an example in which an EL display module is formed using a TFT substrate 2800 manufactured by applying the present invention. In FIG. 28, a pixel portion including pixels is formed over the TFT substrate 2800.

  In FIG. 28, outside the pixel portion and between the driver circuit and the pixel, a TFT similar to that formed in the pixel or a gate electrode layer of the TFT and one of the source electrode layer or the drain electrode layer is provided. A protection circuit portion 2801 that is connected and operated in the same manner as a diode 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 layer over a glass substrate, a driver circuit formed of SAS, or the like is applied.

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

  FIG. 28 shows a case where the light-emitting element 2804 and the light-emitting element 2805 are configured as an upward emission type (top emission type), 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 which are pipe-like high-efficiency heat conduction devices used for transferring heat to the outside of the device in contact with or close to the TFT substrate 2800 are provided to enhance the heat radiation effect. It is good also as a structure.

  In FIG. 28, the top emission type EL display module is used. However, a bottom emission structure or a dual emission structure in which light is emitted from both the upper surface and the lower surface may be changed by changing the configuration of the light emitting element and the arrangement of the external circuit board. . 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.

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

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

  In a display device including a TFT substrate or the like manufactured by applying the present invention, a part of the process is simplified, and the throughput is improved in manufacturing the display device. Therefore, a display module can be manufactured with high productivity.

  This embodiment mode can be freely combined with any of Embodiment Modes 1 to 9 and Embodiments 13 and 14.

(Embodiment 16)
This embodiment will be described with reference to FIGS. 31A and 31B. FIG. 31A and FIG. 31B illustrate an example in which a liquid crystal display module is formed using a TFT substrate 2600 manufactured by applying the present invention.

  FIG. 31A illustrates an example of a liquid crystal display module. A TFT substrate 2600 and a counter substrate 2601 are fixed to each other with a sealant 2602, and a pixel portion 2603 and a liquid crystal layer 2604 are provided therebetween to form a display region. The colored layer 2605 is necessary for color display. In the case of the RGB method, a colored layer corresponding to each color of red, green, and blue is provided corresponding to each pixel. Polarizing plates 2606 and 2607 and a diffusion plate 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 reflection plate 2611. The circuit board 2612 is connected to the TFT substrate 2600 by a flexible wiring board 2609, and an external circuit such as a control circuit or a power supply circuit is incorporated. Moreover, you may laminate | stack in the state which had the phase difference plate between the polarizing plate and the liquid-crystal layer.

  The liquid crystal display module includes a TN (Twisted Nematic) mode, an IPS (In-Plane-Switching) mode, an FFS (Fringe Field Switching) mode, an MVA (Multi-domain Vertical Alignment) mode, and a PVA (Pattern Vertical Alignment) mode. (Axial Symmetrical Aligned Micro-cell) mode, OCB (Optical Compensated Birefringence) mode, FLC (Ferroelectric Liquid Crystal) mode, AFLC (Anti-Ferroelectric Crystal) mode, etc. It is possible to have.

  FIG. 31B is an example in which the OCB mode is applied to the liquid crystal display module of FIG. 31A, and is an FS-LCD (Field sequential-LCD). The FS-LCD emits red light, green light, and blue light in one frame period, and can perform color display by combining images using time division. Further, since each light emission is performed by a light emitting diode or a cold cathode tube, a color filter is unnecessary. Therefore, it is not necessary to arrange the color filters of the three primary colors and limit the display area of each color, and it is possible to display all three colors in any area. On the other hand, since three colors of light are emitted in one frame period, a high-speed response of the liquid crystal is required. By applying the FLC mode using the FS method and the OCB mode to the display device of the present invention, a high-performance and high-quality display device and a liquid crystal television device can be completed.

  The liquid crystal layer in the OCB mode has a so-called π cell structure. The π cell structure is a structure in which the pretilt angles of liquid crystal molecules are aligned in a plane-symmetric relationship with respect to the center plane between the active matrix substrate and the counter substrate. The alignment state of the π cell structure is splay alignment when no voltage is applied between the substrates, and shifts to bend alignment when a voltage is applied. This bend orientation is white. When a voltage is further applied, the bend-aligned liquid crystal molecules are aligned perpendicularly to both substrates, and light is not transmitted. In the OCB mode, high-speed response that is about 10 times faster than the conventional TN mode can be realized.

  Further, as a mode corresponding to the FS method, HV (Half V) -FLC using a ferroelectric liquid crystal (FLC) capable of high-speed operation, SS (Surface Stabilized) -FLC, or the like can be used. . A nematic liquid crystal having a relatively low viscosity is used for the OCB mode, and a smectic liquid crystal having a ferroelectric phase can be used for HV-FLC and SS-FLC.

  In addition, the high-speed optical response speed of the liquid crystal display module is increased by narrowing the cell gap of the liquid crystal display module. The speed can also be increased by reducing the viscosity of the liquid crystal material. The increase in speed is more effective when the pixel pitch of the pixel region of the TN mode liquid crystal display module is 30 μm or less. Further, the speed can be further increased by the overdrive method in which the applied voltage is increased (or decreased) for a moment.

  The liquid crystal display module in FIG. 31B is a transmissive liquid crystal display module, and is provided with a red light source 2910a, a green light source 2910b, and a blue light source 2910c as light sources. The light source is provided with a controller 2912 for controlling on / off of the red light source 2910a, the green light source 2910b, and the blue light source 2910c. The light emission of each color is controlled by the control unit 2912, light enters the liquid crystal, an image is synthesized using time division, and color display is performed.

  In the liquid crystal display module described above, the present invention can be applied to form an opening for connecting a TFT substrate, a pixel portion, and the like. Accordingly, part of the steps can be simplified and the throughput can be improved, so that it can be manufactured with high productivity. In addition, since the number of lithography steps using a photoresist can be reduced, a highly reliable liquid crystal display module can be manufactured.

  This embodiment mode can be freely combined with Embodiment Modes 1 to 7 and 10 to 14 as appropriate.

(Embodiment 17)
With the display device formed according to the present invention, a television device (also simply referred to as a television or a television receiver) can be completed. FIG. 21 is a block diagram illustrating a main configuration of the television device.

  FIG. 15A corresponds to a top view illustrating an example of the structure of the display panel of the television device illustrated in FIG. 21, and includes a pixel portion 2701 in which pixels 2702 are arranged in a matrix on a substrate 2700 having an insulating surface, and scanning. A line side input terminal 2703 and a signal line side input terminal 2704 are formed. The number of pixels may be provided in accordance with various standards. For full color display using XGA and RGB, 1024 × 768 × 3 (RGB), and for full color display using UXGA and RGB, 1600 × 1200. If it corresponds to x3 (RGB) and full spec high vision and is full color display using RGB, it may be 1920 x 1080 x 3 (RGB).

  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 pixel 2702 in the pixel portion 2701 is provided with a switching element and a pixel electrode layer connected to the switching element. A typical example of a switching element is a TFT. By connecting the gate electrode layer 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. It is said.

  FIG. 15A 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. 16A, COG (Chip on The driver IC 2751 may be mounted on the substrate 2700 by a glass method. As another mounting mode, a TAB (Tape Automated Bonding) method as shown in FIG. 16B 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. 16, 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 a crystalline semiconductor, a scan line driver circuit 3702 can be formed over a substrate 3700 as shown in FIG. In FIG. 15B, the pixel portion 3701 is controlled by an external driver circuit as in FIG. 15A 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, as illustrated in FIG. 15C, a pixel portion 4701, a scan line driver circuit 4702, and a signal The line driver circuit 4704 can be formed over the substrate 4700 integrally.

  In the structure of the display panel of the television device illustrated in FIG. 21, only the pixel portion 9011 is formed over the substrate, and the scan line side driver circuit 9013 and the signal line side driver circuit 9012 are as illustrated in FIG. When mounted by the TAB method, when the scanning line side driver circuit 9013 and the signal line side driver circuit 9012 are mounted by the COG method as shown in FIG. 16A, and as shown in FIG. In the case where the pixel portion 9011 and the scanning line side driver circuit 9013 are formed over the substrate by the TFT and the signal line side driver circuit 9012 is separately mounted as a driver IC, and as shown in FIG. There are cases in which the signal line driver circuit 9012, the signal line side driver circuit 9012, and the scanning line side driver circuit 9013 are formed integrally on the substrate, but any form may be employed.

  In FIG. 21, as the configuration of other external circuits, on the video signal input side, among the signals received by the tuner 9014, the video signal amplification circuit 9015 for amplifying the video signal and the signal output therefrom are red, green The video signal processing circuit 9016 converts the color signal into a color signal corresponding to each blue color, and the control circuit 9017 converts the video signal into the input specifications of the driver IC. The control circuit 9017 outputs a signal to each of the scanning line side and the signal line side. In the case of digital driving, a signal dividing circuit 9018 may be provided on the signal line side so that an input digital signal is divided into m pieces and supplied.

  Of the signals received by the tuner 9014, the audio signal is sent to the audio signal amplifier circuit 9019, and the output is supplied to the speaker 9113 through the audio signal processing circuit 9110. The control circuit 9111 receives control information on the receiving station (reception frequency) and volume from the input unit 9112, and sends a signal to the tuner 9014 and the audio signal processing circuit 9110.

  As shown in FIGS. 25A and 25B, these display modules can be incorporated into a housing to complete a television device. If a liquid crystal display module is used as the display module, a liquid crystal television device can be manufactured. If an EL module is used, an EL television device, a plasma television, an electronic paper, or the like can be manufactured. In FIG. 25A, a main screen 2403 is formed by a display module, and a speaker portion 2409, operation switches, and the like are provided as accessory equipment. Thus, a television device can be completed according to the present invention.

  In FIG. 25A, a display panel 2402 is incorporated in a housing 2401, and by receiving a general television broadcast by a receiver 2405, it is connected to a wired or wireless communication network through a modem 2404. Information communication can be performed in the direction (from the sender to the receiver) or in both directions (between the sender and the receiver, or between the receivers). The television device can be operated by a switch incorporated in the housing or a separate remote control device 2406. Even if this remote control device is provided with a display portion 2407 for displaying information to be output. good.

  In addition, the television device may have a configuration in which a sub screen 2408 is formed using the second display panel in addition to the main screen 2403 to display a channel, a volume, and the like. In this structure, the main screen 2403 and the sub screen 2408 can be formed using the liquid crystal display panel of the present invention, the main screen 2403 is formed using an EL display panel with an excellent viewing angle, and the sub screen 2408 has low power consumption. It may be formed of a liquid crystal display panel that can be displayed with In order to prioritize low power consumption, the main screen 2403 may be formed of a liquid crystal display panel, the sub screen may be formed of an EL display panel, and the sub screen may be blinkable. When the present invention is used, a display device can be manufactured with high productivity by using such a large-area substrate and using many TFTs and electronic components.

  FIG. 25B illustrates a television device having a large display portion of 20 inches to 80 inches, for example, which includes a housing 2410, a display portion 2411, a remote control device 2412 that is an operation portion, a speaker portion 2413, and the like. The present invention is applied to manufacturing the display portion 2411. The television device in FIG. 25B is a wall-hanging type and does not require a large installation space.

  Of course, the present invention is not limited to a television device, but can be applied to various uses such as a monitor for a personal computer, an information display board in a railway station or airport, an advertisement display board in a street, etc. can do.

  By applying the present invention, an opening or the like for connecting a TFT and a pixel of a display device can be formed. As a result, since the process can be simplified, a display device can be manufactured with high productivity.

  This embodiment mode can be freely combined with any of Embodiment Modes 1 to 16 as appropriate.

(Embodiment 18)
As an electronic apparatus according to the present invention, a television device (also simply referred to as a television or a television receiver), a camera such as a digital camera or a digital video camera, a mobile phone device (also simply referred to as a mobile phone or a mobile phone), a PDA, or the like Mobile information terminals, portable game machines, computer monitors, computers, sound reproduction apparatuses such as car audio, and image reproduction apparatuses equipped with recording media such as home game machines. A specific example will be described with reference to FIG.

  A portable information terminal device illustrated in FIG. 26A includes a main body 9201, a display portion 9202, and the like. The display device according to the present invention can be applied to the display portion 9202. As a result, since it can be manufactured by a simplified process, a portable information terminal device can be manufactured with high mass productivity.

  A digital video camera shown in FIG. 26B includes a display portion 9701, a display portion 9702, and the like. The display device according to the present invention can be applied to the display portion 9701. As a result, since it can be manufactured by a simplified process, a digital video camera can be manufactured with high mass productivity.

  A cellular phone shown in FIG. 26C includes a main body 9101, a display portion 9102, and the like. The display device according to the present invention can be applied to the display portion 9102. As a result, since it can be manufactured through a simplified process, a mobile phone can be manufactured with high productivity.

  A portable television device illustrated in FIG. 26D includes a main body 9301, a display portion 9302, and the like. The display device according to the present invention can be applied to the display portion 9302. As a result, a television device can be manufactured with high productivity because it can be manufactured through a simplified process. In addition, the present invention can be applied to a wide variety of television devices, from a small one mounted on a portable terminal such as a cellular phone to a medium-sized one that can be carried and a large one (for example, 40 inches or more). A display device according to the above can be applied.

  A portable computer shown in FIG. 26E includes a main body 9401, a display portion 9402, and the like. The display device according to the present invention can be applied to the display portion 9402. As a result, since it can be manufactured by a simplified process, a portable computer can be manufactured with high productivity.

  As described above, the display device according to the present invention can provide an electronic device with high productivity.

  This embodiment mode can be freely combined with any of Embodiment Modes 1 to 17 as appropriate.

The conceptual diagram explaining this invention. The figure explaining the laser processing apparatus of this invention. The conceptual diagram explaining this invention. The figure explaining the laser processing apparatus of this invention. The conceptual diagram explaining this invention. The conceptual diagram explaining this invention. The conceptual diagram explaining this invention. The conceptual diagram explaining this invention. The conceptual diagram explaining this invention. 4A and 4B illustrate an example of a method for manufacturing a display device of the present invention. 4A and 4B illustrate an example of a method for manufacturing a display device of the present invention. FIG. 6 illustrates a structure of a light-emitting element that can be applied to the present invention. FIG. 6 illustrates a structure of a light-emitting element that can be applied to the present invention. FIG. 6 illustrates 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. FIG. 11 illustrates an example of a display device of the present invention. FIG. 11 illustrates an example of a display device of the present invention. FIG. 11 illustrates an example of a display device of the present invention. FIG. 11 illustrates an example of a display device of the present invention. 1 is a block diagram illustrating a main configuration of an electronic device to which the present invention is applied. FIG. 11 illustrates an example of a circuit configuration of a display device of the present invention. FIG. 11 illustrates an example of a circuit configuration of a display device of the present invention. FIG. 11 illustrates an example of a circuit configuration of a display device of the present invention. FIG. 11 illustrates an example of an electronic device to which the present invention is applied. FIG. 11 illustrates an example of an electronic device to which the present invention is applied. FIG. 11 illustrates an example of a display device of the present invention. The figure which shows the structural example of the display module of this invention. FIG. 11 illustrates an example of a display device of the present invention. FIG. 11 illustrates an example of a display device of the present invention. The figure which shows the structural example of the display module of this invention. The conceptual diagram explaining this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Board | substrate 12 Conductive layer 14 Light absorption layer 16 Insulating layer 18 1st laser beam 20 2nd laser beam 22 Overlapping irradiation area | region 24 Opening 26 Conductive layer

Claims (6)

A method for manufacturing a semiconductor device for forming an electrical connection between conductive layers through an opening,
Forming a second conductive layer on the first conductive layer with a material that absorbs the first and second laser beams;
Forming an insulating layer on the second conductive layer with a material that transmits the first and second laser beams;
By irradiating from the insulating layer side so that the first and second laser beams partially overlap in the irradiation region, the insulating layer and the second conductive layer in the irradiation region are removed and the opening is removed. Forming a step;
Electrically connecting the third conductive layer and the first conductive layer by forming a third conductive layer in the opening;
Including
As the first laser beam, a multi-mode laser beam is irradiated,
A method for manufacturing a semiconductor device, wherein the second laser beam is irradiated with a single mode laser beam. A method for manufacturing a semiconductor device for forming an electrical connection between conductive layers through an opening,
Forming a second conductive layer on the first conductive layer with a material that absorbs the first and second laser beams;
Forming an insulating layer on the second conductive layer with a material that transmits the first and second laser beams;
By irradiating from the insulating layer side so that the first and second laser beams partially overlap in the irradiation region, the insulating layer and the second conductive layer in the irradiation region are removed and the opening is removed. Forming a step;
Electrically connecting the third conductive layer and the first conductive layer by forming a third conductive layer in the opening;
Including
The first laser beam is irradiated with a non-divided multimode laser beam,
The second laser beam is irradiated with a single mode laser beam divided into a plurality of parts,
In the irradiation region, a plurality of the openings are formed by irradiating all the second laser beams divided into a plurality on the region irradiated with the first laser beam.
A method for manufacturing a semiconductor device. In claim 1 or claim 2,
When the energy of the first laser beam is A, the energy of the second laser beam is B, and the energy threshold at which ablation occurs in the second conductive layer is C,
The first and second laser beams are:
A <C,
A + B> C and
A> B
A method for manufacturing a semiconductor device, which satisfies the following condition. In any one of Claim 1 thru | or 3 ,
As the multi-mode laser beam , a laser beam emitted from a YAG laser, a YVO ₄ laser, or an excimer laser is irradiated,
The method for manufacturing a semiconductor device as a laser beam, characterized that you irradiated with a laser beam emitted from a femtosecond laser or a picosecond laser of the single mode. In any one of Claims 1 thru | or 4 ,
The second conductive layer contains at least one element of chromium (Cr), molybdenum (Mo), nickel (Ni), titanium (Ti), cobalt (Co), copper (Cu), and aluminum (Al). A manufacturing method of a semiconductor device, characterized by being formed using a material containing the semiconductor device. In any one of Claims 1 thru | or 5,
The method for manufacturing a semiconductor device is characterized in that the second conductive layer is formed using a material having a boiling point or a sublimation temperature lower than the melting point of the first conductive layer.

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