Light-emitting device, method for manufacturing the same, and cellular phone

The invention relates to: a light-emitting device which includes a first flexible substrate having a first electrode, a light-emitting layer over the first electrode, and a second electrode with a projecting portion over the light-emitting layer and a second flexible substrate having a semiconductor circuit and a third electrode electrically connected to the semiconductor circuit, in which the projecting portion of the second electrode and the third electrode are electrically connected to each other; a method for manufacturing the light-emitting device; and a cellular phone which includes a housing incorporating the light-emitting device and having a longitudinal direction and a lateral direction, in which the light-emitting device is disposed on a front side and in an upper portion in the longitudinal direction of the housing.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention disclosed in this specification relates to a light-emitting device, a method for manufacturing the light-emitting device, and a cellular phone.

2. Description of the Related Art

Conventionally, a light-emitting device having a light-emitting element has been formed through the following steps of: 1) forming a semiconductor circuit for driving a light-emitting element over a substrate such as a glass substrate by using a semiconductor process, 2) forming an insulating film (a planarization film) over the semiconductor circuit, and 3) forming a light-emitting element over the insulating film. In other words, a semiconductor circuit for driving a light-emitting element and the light-emitting element are formed by being stacked over a substrate in this order.

Since a light-emitting device manufactured through the conventional manufacturing process has a light-emitting element over a semiconductor circuit for driving the light-emitting element, there is a step (irregularity) or the like resulting from an element, a wiring, or the like that is formed below the light-emitting element (see Reference 1).[Reference 1] Japanese Published Patent Application No. 2003-258211

SUMMARY OF THE INVENTION

As mentioned above, one of problems is that defective coverage may be caused by a step or the like resulting from an element, a wiring, or the like that is formed below a light-emitting element.

Other problems that occur when a semiconductor circuit for driving a light-emitting element is formed and then the light-emitting element is formed thereover are long manufacturing time and high manufacturing cost.

Another problem is that a light-emitting layer in a light-emitting element is sensitive to moisture, so that the entry of moisture into a light-emitting element should be prevented.

In addition, a problem that occurs when a light-emitting element and a semiconductor circuit for driving the light-emitting element are formed over a hard substrate such as a glass substrate is that the light-emitting element and the semiconductor circuit cannot be incorporated into electronic devices of various shapes because such a hard substrate lacks flexibility and the shape cannot be changed.

A problem that occurs when a light-emitting element and a semiconductor circuit for driving the light-emitting element are formed over a flexible substrate is that although the shape of the substrate can be freely changed, stress may damage the light-emitting element and the semiconductor circuit for driving the light-emitting element.

In view of the above problems, in accordance with the invention disclosed in this specification, a semiconductor circuit for driving a light-emitting element and the light-emitting element are disposed over flexible substrates and attached to each other such that the light-emitting element and the semiconductor circuit for driving the light-emitting element are electrically connected to each other. The light-emitting element and the semiconductor circuit for driving the light-emitting element may be formed over different substrates and separated from the respective substrates, and then may be disposed over respective flexible substrates and attached to each other.

Because the light-emitting element and the semiconductor circuit for driving the light-emitting element are disposed over different substrates, the semiconductor circuit is not formed below the light-emitting element.

In addition, a projecting portion is formed in part of the light-emitting element, and the light-emitting element and the semiconductor circuit for driving the light-emitting element are attached to each other such that a space portion is provided therebetween. A desiccant can be disposed in the space portion.

Because the light-emitting element and the semiconductor circuit for driving the light-emitting element can be disposed over flexible substrates, the shape can be changed even after the light-emitting element and the semiconductor circuit are attached to each other.

Furthermore, the light-emitting element and the semiconductor circuit for driving the light-emitting element are disposed over flexible substrates such that a space (a space portion) for relaxing stress is provided between the light-emitting element and the semiconductor circuit for driving the light-emitting element.

The invention disclosed in this specification relates to a light-emitting device which includes a first flexible substrate having a first electrode, a light-emitting layer over the first electrode, and a second electrode with a projecting portion over the light-emitting layer and a second flexible substrate having a semiconductor circuit and a third electrode electrically connected to the semiconductor circuit. The projecting portion of the second electrode and the third electrode are electrically connected to each other.

The invention relates to a light-emitting device in which a desiccant is provided in a space portion that is generated by disposing the first flexible substrate and the second flexible substrate to face each other.

The invention disclosed in this specification also relates to a light-emitting device which includes a first flexible substrate having a first electrode, a light-emitting layer over the first electrode, and a second electrode with a projecting portion over the light-emitting layer and a second flexible substrate having a semiconductor circuit and a third electrode electrically connected to the semiconductor circuit. The projecting portion of the second electrode and the third electrode are electrically connected to each other through an anisotropic conductive film that contains conductive particles.

The invention relates to a light-emitting device which includes a structure body covering the semiconductor circuit and having a fibrous body and an organic resin, and the third electrode penetrating the structure body and formed with a conductive resin.

The invention relates to a method for manufacturing a light-emitting device, which includes the steps of: forming a first separation layer, a first insulating film (a base film), a first electrode, a light-emitting layer, and a second electrode with a projecting portion over a first substrate; separating the first insulating film, the first electrode, the light-emitting layer, and the second electrode from the first substrate by using the first separation layer; forming a first adhesive layer over a first flexible substrate; attaching the first insulating film, the first electrode, the light-emitting layer, and the second electrode to the first flexible substrate with the first adhesive layer; forming a second separation layer, a second insulating film, a semiconductor circuit, and a third electrode electrically connected to the semiconductor circuit over a second substrate; separating the second insulating film, the semiconductor circuit, and the third electrode from the second substrate by using the second separation layer; forming a second adhesive layer over a second flexible substrate; attaching the second insulating film, the semiconductor circuit, and the third electrode to the second flexible substrate with the second adhesive layer; and electrically connecting the projecting portion of the second electrode and the third electrode to each other.

The invention relates to a method for manufacturing a light-emitting device in which a desiccant is provided in a space portion that is generated by disposing the first flexible substrate and the second flexible substrate to face each other.

The invention disclosed in this specification also relates to a method for manufacturing a light-emitting device, which includes the steps of: forming a first separation layer, a first insulating film (a base film), a first electrode, a light-emitting layer, and a second electrode with a projecting portion over a first substrate; separating the first insulating film, the first electrode, the light-emitting layer, and the second electrode from the first substrate by using the first separation layer; forming a first adhesive layer over a first flexible substrate; attaching the first insulating film, the first electrode, the light-emitting layer, and the second electrode to the first flexible substrate with the first adhesive layer; forming a second separation layer, a second insulating film, a semiconductor circuit, and a third electrode electrically connected to the semiconductor circuit over a second substrate; separating the second insulating film, the semiconductor circuit, and the third electrode from the second substrate by using the second separation layer; forming a second adhesive layer over a second flexible substrate; attaching the second insulating film, the semiconductor circuit, and the third electrode to the second flexible substrate with the second adhesive layer; forming an anisotropic conductive film containing conductive particles between the first flexible substrate and the second flexible substrate; and electrically connecting the projecting portion of the second electrode and the third electrode to each other through the anisotropic conductive film.

The invention relates to a method for manufacturing a light-emitting device, which includes the step of forming a structure body having a fibrous body and an organic resin to cover the semiconductor circuit, and the third electrode is formed with a conductive resin to penetrate the structure body.

The invention disclosed in this specification also relates to a cellular phone which includes a light-emitting device including a first flexible substrate having a first electrode, a light-emitting layer over the first electrode, and a second electrode with a projecting portion over the light-emitting layer and a second flexible substrate having a semiconductor circuit and a third electrode electrically connected to the semiconductor circuit and a housing incorporating the light-emitting device and having a longitudinal direction and a lateral direction. In the light-emitting device, the projecting portion of the second electrode and the third electrode are electrically connected to each other. The light-emitting device is disposed on a front side and in an upper portion in the longitudinal direction of the housing.

Accordingly, the semiconductor circuit is not formed below the light-emitting element and thus the generation of defective coverage due to steps can be suppressed.

In addition, because a desiccant can be disposed in the space portion between the light-emitting element and the semiconductor circuit for driving the light-emitting element, the entry of moisture into the light-emitting layer can be prevented.

In addition, because the light-emitting element and the semiconductor circuit for driving the light-emitting element can be disposed over flexible substrates, the shape can be changed even after the light-emitting element and the semiconductor circuit are attached to each other, and the light-emitting element and the semiconductor circuit for driving the light-emitting element can be incorporated into electronic devices of various shapes.

Furthermore, because a space (a space portion) is provided between the light-emitting element and the semiconductor circuit for driving the light-emitting element which are disposed over flexible substrates, stress can be relaxed even when the flexible substrates are bent.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the invention disclosed in this specification will be hereinafter described with reference to the accompanying drawings. Note that the invention disclosed in this specification can be carried out in a variety of different modes, and it is easily understood by those skilled in the art that the modes and details of the invention disclosed in this specification can be changed in various ways without departing from the spirit and scope thereof. Therefore, the invention disclosed in this specification should not be interpreted as being limited to the description in the embodiments. Note that in the accompanying drawings, the same portions or portions having similar functions are denoted by the same reference numerals, and repetitive description thereof is omitted.

Note that in this specification, a semiconductor circuit refers to a circuit which functions by utilizing a semiconductor. Furthermore, a semiconductor device refers to an element or a device in general which functions by utilizing a semiconductor. Electric devices including electronic circuits, liquid crystal display devices, light-emitting devices, and the like and electronic devices on which the electric devices are mounted are included in the category of semiconductor devices.

Note that ordinal numbers such as “first” and “second” in this specification are used simply for convenience and do not restrict the order of stacked layers, the order of manufacturing steps, and the like.

First, a light-emitting element and a method for manufacturing the light-emitting element are described with reference toFIGS. 2A to 2C,FIGS. 3A and 3B,FIGS. 4A and 4B,FIGS. 5A and 5B, andFIGS. 6A to 6C.

First, a separation layer132, a base film102, and an electrode111are formed over a substrate131(seeFIG. 2A). As the substrate131, a glass substrate, a quartz substrate, a semiconductor substrate, a ceramic substrate, or the like may be used.

The base film102may be a silicon oxide film, a silicon nitride film, a silicon oxide film containing nitrogen, or a silicon nitride film containing oxygen or may be a stacked layer of any two or more of these films. The base film102functions to prevent the entry of moisture into a light-emitting layer112which is to be formed later.

As the separation layer132, a single layer or a stacked layer is formed using an element selected from tungsten (W), molybdenum (Mo), titanium (Ti), tantalum (Ta), niobium (Nb), nickel (Ni), cobalt (Co), zirconium (Zr), zinc (Zn), ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), and silicon (Si) or an alloy material or a compound material mainly containing any of the elements, by a plasma CVD method, a sputtering method, or the like. The crystalline structure of a layer containing silicon may be any one of amorphous, microcrystalline, and polycrystalline structures.

When the separation layer132has a single-layer structure, it is preferable to form a layer containing any one of the following: tungsten, molybdenum, a mixture of tungsten and molybdenum, an oxide of tungsten, an oxynitride of tungsten, a nitride oxide of tungsten, an oxide of molybdenum, an oxynitride of molybdenum, a nitride oxide of molybdenum, an oxide of a mixture of tungsten and molybdenum, an oxynitride of a mixture of tungsten and molybdenum, and a nitride oxide of a mixture of tungsten and molybdenum. Note that a mixture of tungsten and molybdenum corresponds to an alloy of tungsten and molybdenum, for example.

When the separation layer132has a stacked structure, it is preferable to form a layer containing tungsten, molybdenum, or a mixture of tungsten and molybdenum as a first layer and to form a layer containing an oxide of tungsten, an oxide of molybdenum, an oxide of a mixture of tungsten and molybdenum, an oxynitride of tungsten, an oxynitride of molybdenum, or an oxynitride of a mixture of tungsten and molybdenum as a second layer. In this manner, when the separation layer132is formed to have a stacked structure, a stacked structure of a metal film and a metal oxide film is preferable. Examples of a method for forming a metal oxide film include a method of forming a metal oxide film directly by a sputtering method, a method of forming a metal oxide film by oxidizing a surface of a metal film formed over the substrate131by heat treatment or by plasma treatment in an oxygen atmosphere, and the like.

As the metal film, a film can be formed using an element selected from titanium (Ti), tantalum (Ta), niobium (Nb), nickel (Ni), cobalt (Co), zirconium (Zr), zinc (Zn), ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), and iridium (Ir), as well as tungsten (W) and molybdenum (Mo) as mentioned above, or an alloy material or a compound material mainly containing any of the elements.

Note that an insulating film such as a silicon oxide film, a silicon nitride film, a silicon oxide film containing nitrogen, or a silicon nitride film containing oxygen may be formed over the substrate131before the separation layer132is formed, and the separation layer132may be formed over the insulating film. By such an insulating film provided between the substrate131and the separation layer132, an impurity contained in the substrate131can be prevented from entering an upper layer. In addition, in a subsequent laser irradiation step, the substrate131can be prevented from being etched. Note that a silicon oxide film containing nitrogen is distinguished from a silicon nitride film containing oxygen in that the former contains more oxygen than nitrogen, whereas the latter contains more nitrogen than oxygen.

The electrode111may be formed using a conductive film having a light-transmitting property. The conductive film having a light-transmitting property can be formed by a sputtering method, a vacuum evaporation method, or the like using a material such as indium oxide (In2O3) or an alloy of indium oxide and tin oxide (In2O3—SnO2) (indium tin oxide (ITO)). Alternatively, an alloy of indium oxide and zinc oxide (In2O3—ZnO) may be used. Furthermore, zinc oxide (ZnO) is also a suitable material, and moreover, zinc oxide to which gallium (Ga) is added (ZnO:Ga) in order to increase conductivity or visible light transmissivity may be used. When the electrode111is formed using such a material, the electrode111serves as an anode.

When the electrode111is used as a cathode, an extremely thin film of a material with a low work function, such as aluminum, can be used. Alternatively, a stacked structure of a thin film of such a material and the above-mentioned conductive film having a light-transmitting property can be employed.

Next, an insulating film121is formed to cover the base film102and the electrode111(seeFIG. 2B). The insulating film121can be formed using an inorganic material or an organic material.

As an inorganic material, for example, silicon oxide, silicon nitride, silicon oxide containing nitrogen, or diamond-like carbon (DLC) or a stacked structure of two or more of these materials can be used. As an organic material, polyimide, acrylic, polyamide, polyimide amide, resist, benzocyclobutene, or siloxane or a stacked structure of two or more of these materials may be used.

Siloxane has a skeleton formed by the bond of silicon (Si) and oxygen (O), and is formed using as a starting material a polymer material including at least hydrogen or at least one of fluorine, an alkyl group, and aromatic hydrocarbon as a substituent. As the substituent, a fluoro group may be used, or both an organic group containing at least hydrogen and a fluoro group may be used as the substituents.

Next, using the insulating film121, a spacer105, a partition104a, and a partition104bare formed (seeFIG. 2C). At this time, the spacer105is formed into a forward tapered shape; in other words, the spacer105is formed such that its cross-sectional shape is a trapezoid whose upper base is shorter than the lower base. The partition104aand the partition104bare each formed into an inverted tapered shape; in other words, the partition104aand the partition104bare each formed such that its cross-sectional shape is a trapezoid whose upper base is longer than the lower base.

The cross-sectional shape of the spacer105may be a trapezoid whose four corners have a curvature radius, in order to improve the coverage of the spacer105with a light-emitting layer112and an electrode113which are to be formed later.

The partition104aand the partition104beach function to separate the light-emitting layer112and the electrode113, which are to be formed later, of each pixel from those of other pixels.

Note that without forming the insulating film121, the spacer105, the partition104a, and the partition104bmay be formed into their respective shapes from the beginning, using an insulator. For example, the partition104aand the partition104bmay be formed into an inverted tapered shape from the beginning by an inkjet method or the like.

Next, an insulating film138is formed using any of the materials mentioned in the description of the insulating film121to cover the base film102, the electrode111, the spacer105, the partition104a, and the partition104b(seeFIG. 3A). Alternatively, the insulating film138may be formed using a material different from that of the insulating film121.

Using the insulating film138, a spacer106is formed over the spacer105(seeFIG. 3B). The spacer106is formed into a forward tapered shape; in other words, the spacer106is formed such that its cross-sectional shape is a trapezoid whose upper base is shorter than the lower base.

Note that without forming the insulating film138, the spacer106may be formed into that shape from the beginning, using an insulator. For example, the spacer106may be formed into a forward tapered shape from the beginning by an inkjet method or the like.

The cross-sectional shape of the spacer106may be a trapezoid whose four corners have a curvature radius, in order to improve the coverage of the spacer106with the light-emitting layer112and the electrode113which are to be formed later.

When the spacer105and the spacer106are provided, the light-emitting layer112and the electrode113which are formed later are raised along the spacer105and the spacer106. In other words, a projecting portion is generated in the light-emitting layer112and the electrode113, and the projecting portion of the electrode113is to be electrically connected to a conductive resin306which is electrically connected to a TFT211as described below. The projecting portion of the electrode113and the conductive resin306are connected to each other at a position apart from the electrode113, the light-emitting layer112, and the TFT211; accordingly, damage to the electrode113, the light-emitting layer112, and the TFT211can be prevented.

Next, the light-emitting layer112and the electrode113are formed in a region over the electrode111, which is surrounded by the partition104aand the partition104b(seeFIG. 4A). Note that an EL material layer107athat is formed from the same material as the light-emitting layer112and a conductive material layer108athat is formed from the same material as the electrode113are formed over the partition104a, and an EL material layer107bthat is formed from the same material as the light-emitting layer112and a conductive material layer108bthat is formed from the same material as the electrode113are formed over the partition104b. However, these layers are each electrically insulated from the electrode111by the partition104aand the partition104bthat are formed from an insulating film; thus, these layers do not emit light.

The light-emitting layer112may be a single layer or may be freely combined with a layer for injection, transport, or recombination of carriers of both electrons and holes, in other words, a carver transport layer, a carrier injection layer, or the like, between the light-emitting layer and the electrode111or between the light-emitting layer and the electrode113. The light-emitting layer112collectively refers to a light-emitting layer alone or a layer having a stacked structure of a light-emitting layer and a carrier transport layer, a carrier injection layer, or the like.

Specific materials used for a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, and an electron injection layer are hereinafter described.

The hole injection layer is a layer that is provided in contact with an anode, either the electrode111or the electrode113, and contains a material with an excellent hole injection property. Molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, manganese oxide, or the like can be used. Alternatively, the hole injection layer can be formed using any of the following materials: phthalocyanine compounds such as phthalocyanine (abbreviation: H2Pc) and copper phthalocyanine (CuPc); aromatic amine compounds such as 4,4′-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB) and 4,4′-bis(N-{4-[N-(3-methylphenyl)-N-phenylamino]phenyl}-N-phenylamino)biphenyl (abbreviation: DNTPD); high molecular compounds such as poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonic acid) (abbreviation: PEDOT/PSS); and the like.

Alternatively, as the hole injection layer, a composite material of a material with an excellent hole transport property which contains an acceptor material can be used. Note that, by using a material with an excellent hole transport property which contains an acceptor material, a material used to form an electrode may be selected regardless of its work function. In other words, besides a material with a high work function, a material with a low work function may be used for the anode. As the acceptor material, 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F4-TCNQ), chloranil, or the like can be used. In addition, a transition metal oxide can be used. Moreover, an oxide of any of the metals belonging to Groups 4 to 8 of the periodic table can be used. Specifically, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide are preferable because they have excellent electron accepting properties. Among them, molybdenum oxide is especially preferable because it is stable in the air and its hygroscopic property is low so that it can be easily handled.

As the material with an excellent hole transport property which is used for the composite material, various compounds such as an aromatic amine compound, a carbazole derivative, aromatic hydrocarbon, and a high molecular compound (such as oligomer, dendrimer, or polymer) can be used. Note that an organic compound used for the composite material preferably has an excellent hole transport property. Specifically, a material having a hole mobility of 10−6cm2/Vs or higher is preferable. However, materials other than these materials can also be used, as long as they have more excellent hole transport properties than electron transport properties. Specific organic compounds which can be used for the composite material are given below.

The carbazole derivative which can be used for the composite material is specifically 3-[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA1), 3,6-bis[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA2), 3-[N-(1-naphthyl)-N-(9-phenylcarbazol-3-yl)amino]-9-phenylcarbazole (abbreviation: PCzPCN1), or the like.

The carbazole derivative which can be used for the composite material is alternatively 4,4′-di(N-carbazolyl)biphenyl (abbreviation: CBP), 1,3,5-tris[4-(N-carbazolyl)phenyl]benzene (abbreviation: TCPB), 9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: CzPA), 1,4-bis[4-(N-carbazolyl)phenyl]-2,3,5,6-tetraphenylbenzene, or the like.

Note that the aromatic hydrocarbon which can be used for the composite material may have a vinyl skeleton. The aromatic hydrocarbon having a vinyl group is, for example, 4,4′-bis(2,2-diphenylvinyl)biphenyl (abbreviation: DPVBi), 9,10-bis[4-(2,2-diphenylvinyl)phenyl]anthracene (abbreviation: DPVPA), or the like.

The hole transport layer is a layer that contains a material with an excellent hole transport property. The material with an excellent hole transport property is, for example, an aromatic amine compound such as 4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB), N,N′-bis(3-methylphenyl)-N,N′-diphenyl-[1,1′-biphenyl]-4,4′-diamine (abbreviation: TPD), 4,4′,4″-tris(N,N-diphenylamino)triphenylamine (abbreviation: TDATA), 4,4′,4″-tris[N-(3-methylphenyl)-N-phenylamino]triphenylamine (abbreviation: MTDATA), or 4,4′-bis[N-(spiro-9,9′-bifluoren-2-yl)-N-phenylamino]biphenyl (abbreviation: BSPB). The materials mentioned here are mainly materials having a hole mobility of 10−6cm2/Vs or higher. However, materials other than these materials can also be used, as long as they have more excellent hole transport properties than electron transport properties. Note that the layer that contains a material with an excellent hole transport property is not limited to a single layer, and two or more layers containing any of the aforementioned materials may be stacked.

Further, a high molecular compound such as poly(N-vinylcarbazole) (abbreviation: PVK) or poly(4-vinyltriphenylamine) (abbreviation: PVTPA) can also be used for the hole transport layer.

The light-emitting layer is a layer that contains a light-emitting material. The light-emitting layer may be either a so-called light-emitting layer of a single film including an emission center material as its main component or a so-called light-emitting layer of a host-guest type in which an emission center material is dispersed in a host material.

The electron transport layer is a layer that contains a material with an excellent electron transport property. For example, the electron transport layer is a layer including a metal complex or the like having a quinoline or benzoquinoline skeleton, such as tris(8-quinolinolato)aluminum (abbreviation: Alq), tris(4-methyl-8-quinolinolato)aluminum (abbreviation: Almq3), bis(10-hydroxybenzo[h]quinolinato)beryllium (abbreviation: BeBq2), or bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum (abbreviation: BAlq). Alternatively, a metal complex having an oxazole-based or thiazole-based ligand, such as bis[2-(2-hydroxyphenyl)benzoxazolato]zinc (abbreviation: Zn(BOX)2) or bis[2-(2-hydroxyphenyl)benzothiazolato]zinc (abbreviation: Zn(BTZ)2), can be used. Besides the metal complexes, 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-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviation: TAZ), bathophenanthroline (abbreviation: BPhen), bathocuproine (abbreviation: BCP), or the like can also be used. The materials mentioned here are mainly materials having an electron mobility of 10−6cm2/Vs or higher. Note that the electron transport layer may be formed using materials other than those mentioned above as long as the materials have more excellent electron transport properties than hole transport properties.

Furthermore, the electron transport layer is not limited to a single layer, and two or more layers which are each formed from the aforementioned material may be stacked.

In addition, a layer for controlling the movement of electron carriers may be provided between the electron transport layer and the light-emitting layer. The layer for controlling the movement of electron carriers is a layer formed by adding a small amount of material with an excellent electron trap property to a material with an excellent electron transport property as mentioned above, and carrier balance can be adjusted by controlling the movement of electron carriers. Such a structure has a great effect on reducing problems (for example, a reduction in element lifetime) which may be caused by electrons passing through the light-emitting layer.

Furthermore, the electron injection layer may be provided in contact with a cathode, the other of the electrode111and the electrode113. The electron injection layer may be formed using an alkali metal, an alkaline earth metal, or a compound thereof, such as lithium fluoride (LiF), cesium fluoride (CsF), or calcium fluoride (CaF2). For example, a layer formed from a material with an electron transport property, which contains an alkali metal, an alkaline earth metal, or a compound thereof, (for example, a layer that contains magnesium (Mg) in Alq), can be used. Note that the electron injection layer is preferably a layer formed from a material with an electron transport property, which contains an alkali metal or an alkaline earth metal, because electrons can be efficiently injected from the cathode.

When the electrode113is used as a cathode, a metal, an alloy, an electrically conductive compound, a mixture thereof, or the like with a low work function (specifically, 3.8 eV or less) can be used. Specific examples of such a cathode material are as follows: an element that belongs to Group 1 or Group 2 of the periodic table, i.e., an alkali metal such as lithium (Li) or cesium (Cs), an alkaline earth metal such as magnesium (Mg), calcium (Ca), or strontium (Sr), an alloy containing these (such as MgAg or AlLi), a rare earth metal such as europium (Eu) or ytterbium (Yb), an alloy containing these, and the like. Note that when an electron injection layer is provided between the cathode and the electron transport layer, the cathode can be formed using any of a variety of conductive materials such as Al, Ag, ITO, or indium oxide-tin oxide containing silicon or silicon oxide, regardless of its work function. Films of these conductive materials can be formed by a sputtering method, an inkjet method, a spin coating method, or the like.

When the electrode113is used as an anode, a metal, an alloy, a conductive compound, a mixture thereof, or the like with a high work function (specifically, 4.0 eV or more) is preferably used. Specific examples are as follows: indium tin oxide (ITO), indium tin oxide containing silicon or silicon oxide, indium zinc oxide (IZO), indium oxide containing tungsten oxide and zinc oxide, and the like. Films of these conductive metal oxides are usually formed by sputtering; however, a sol-gel method or the like may also be used. For example, a film of indium zinc oxide (IZO) can be formed by a sputtering method using a target in which zinc oxide is added to indium oxide at 1 wt % to 20 wt %. A film of indium oxide containing tungsten oxide and zinc oxide can be formed by a sputtering method using a target in which tungsten oxide and zinc oxide are added to indium oxide at 0.5 wt % to 5 wt % and 0.1 wt % to 1 wt %, respectively. Furthermore, gold (Au), platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), palladium (Pd), a nitride of a metal material (such as titanium nitride), or the like can be used. By providing any of the above-mentioned composite materials in contact with the anode, an electrode material can be selected regardless of its work function.

Next, as illustrated inFIG. 4B, by irradiation with a laser beam134, for example, a UV laser beam, an opening135is formed in the separation layer132and the base film102as illustrated inFIG. 5A. In addition, before the irradiation with the laser beam134, a resin for separation may be provided to cover a stacked body that is formed over the substrate131.

Part of the separation layer132is removed by formation of the opening135, which enables a stacked structure body137including the base film102, the electrode111, the spacer105, the spacer106, the partition104a, the partition104b, the light-emitting layer112, and the electrode113to be easily separated from the substrate131. This separation occurs inside the separation layer132or at the interface between the separation layer132and the base film102.

Although a UV laser beam is used as the laser beam134in this embodiment, there is no particular limitation on the kind of the laser beam134as long as the opening135can be formed.

A laser which emits the laser beam134includes a laser medium, an excitation source, and a resonator. Lasers can be classified according to their media into gas lasers, liquid lasers, and solid-state lasers and can be classified according to their oscillation characteristics into free electron lasers, semiconductor lasers, and x-ray lasers. In this embodiment, any of these lasers may be used. Note that a gas laser or a solid-state laser is preferably used, and a solid-state laser is more preferably used.

Examples of gas lasers include a helium-neon laser, a carbon dioxide gas laser, an excimer laser, and an argon ion laser. Examples of an excimer laser include a rare gas excimer laser and a rare gas halide excimer laser. A rare gas excimer laser oscillates with three kinds of excited molecules of argon, krypton, and xenon. Examples of an argon ion laser include a rare gas ion laser and a metal vapor ion laser.

Examples of a liquid laser include an inorganic liquid laser, an organic chelate laser, and a dye laser. In an inorganic liquid laser and an organic chelate laser, rare earth ions of neodymium or the like, which are utilized in a solid-state laser, are used as a laser medium.

A laser medium used in a solid-state laser is a solid base doped with active species functioning as a laser. The solid base is a crystal or glass. A crystal is YAG (yttrium aluminum garnet crystal), YLF, YVO4, YAlO3, sapphire, ruby, or alexandrite. Active species functioning as a laser are, for example, trivalent ions (such as Cr3+, Nd3+, Yb3+, Tm3+, Ho3+, Er3+, and Ti3+).

When ceramic (polycrystal) is used as the laser medium, the medium can be formed into any desired shape in a short amount of time at low cost. In the case of using a single crystal, a columnar medium having a diameter of several millimeters and a length of several tens of millimeters is generally used; in the case of using ceramic (polycrystal), a medium larger than that can be formed. The concentration of a dopant such as Nd or Yb in a medium which directly contributes to light emission cannot be changed largely either in a single crystal or in a polycrystal. Therefore, there is limitation to some extent on improvement of laser output by increasing the concentration. However, in the case of using ceramic as the medium, a drastic improvement of output can be achieved because the size of the medium can be significantly increased compared to that of a single crystal. Furthermore, in the case of using ceramic, a medium having a parallelepiped shape or a rectangular solid shape can be easily formed. When a medium having such a shape is used and emitted light is made to propagate inside the medium in zigzag, the optical path of emitted light can be extended. Therefore, the amplitude is increased and a laser beam can be oscillated with high output. In addition, because a laser beam emitted from a medium having such a shape has a quadrangular cross-sectional shape at the time of emission, it is advantageous over a circular beam in being shaped into a linear beam. By shaping the laser beam emitted as described above through an optical system, a linear beam having a length of 1 mm or less on a shorter side and a length of several millimeters to several meters on a longer side can be easily obtained. Further, by uniformly irradiating the medium with excited light, the linear beam has a uniform energy distribution in a longer-side direction. By irradiating a semiconductor film with this linear beam, the entire surface of the semiconductor film can be annealed uniformly. When uniform annealing with the linear beam from one end to the other end is needed, a device of providing a slit at both of the ends so as to block an energy attenuated portion of the beam is necessary.

Note that a continuous-wave (CW) laser beam or a pulsed laser beam can be used as the laser beam134in this embodiment. The conditions for irradiation with the laser beam134, such as frequency, power density, energy density, or beam profile, are controlled as appropriate in consideration of the thicknesses, the materials, or the like of the base film102and the separation layer132.

Next, the stacked structure body137including the base film102, the electrode111, the spacer105, the spacer106, the partition104a, the partition104b, the light-emitting layer112, and the electrode113is separated from the substrate131(seeFIG. 5B).

In addition, an insulating film142and an adhesive layer143are formed over a substrate141(seeFIG. 6A). Note that the insulating film142may be formed as necessary and does not need to be formed if not necessary.

The substrate141is flexible and has a light-transmitting property. As such a substrate, a plastic substrate which has a light-transmitting property, or the like may be used. For example, a polyester resin such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN), a polyacrylonitrile resin, a polyimide resin, a polymethyl methacrylate resin, a polycarbonate (PC) resin, a polyethersulfone (PES) resin, a polyamide resin, a cycloolefin resin, a polystyrene resin, a polyamide imide resin, a polyvinylchloride resin, or the like can be used as appropriate.

For the insulating film142, any of the materials mentioned in the description of the base film102may be used.

For the adhesive layer143, any of a variety of types of curable adhesives, e.g., a photocurable adhesive such as a UV curable adhesive, a reactive curable adhesive, a thermosetting adhesive, and an anaerobic adhesive, can be used. As examples of materials of such adhesives, an epoxy resin, an acrylic resin, a silicone resin, a phenol resin, and the like can be given.

Next, the base film102included in the stacked structure body137and the adhesive layer143over the substrate141are disposed to face each other and attached to each other (seeFIG. 6B).

In the aforementioned manner, a light-emitting element145is manufactured over a flexible substrate (seeFIG. 6C).

Next, a semiconductor circuit for driving a light-emitting element and a method for manufacturing the semiconductor circuit are hereinafter described with reference toFIGS. 7A to 7D,FIGS. 8A to 8C,FIGS. 9A to 9C,FIGS. 10A and 10B,FIG. 11,FIG. 12,FIGS. 14A and 14B,FIG. 15,FIG. 16,FIGS. 17A and 17B,FIGS. 18A and 18B,FIG. 19,FIG. 20,FIG. 21, andFIGS. 23A and 23B.

First, a separation layer222and a base film204are formed over a substrate221(seeFIG. 7A). The substrate221, the separation layer222, and the base film204may be formed using any of the respective materials mentioned in the description of the substrate131, the separation layer132, and the base film102.

Next, an island-like semiconductor film231is formed over the base film204; a gate insulating film205is formed to cover the base film204and the island-like semiconductor film231; and a gate electrode236is formed over the island-like semiconductor film231with the gate insulating film205interposed therebetween (seeFIG. 7B).

The island-like semiconductor film231can be formed using any of the following materials: an amorphous semiconductor manufactured by a sputtering method or a vapor-phase growth method using a gas including a semiconductor material typified by silicon (Si) or germanium (Ge); a polycrystalline semiconductor formed by crystallizing the amorphous semiconductor with the use of optical energy or thermal energy; a microcrystalline (also referred to as semi-amorphous or microcrystal) semiconductor; a semiconductor containing an organic material as its main component; and the like. The island-like semiconductor film231may be formed by forming a semiconductor film by a sputtering method, an LPCVD method, a plasma CVD method, or the like and then etching the semiconductor film into an island-like shape. In this embodiment, an island-like silicon film is formed as the island-like semiconductor film231.

As a material of the island-like semiconductor film231, as well as an element such as silicon (Si) or germanium (Ge), a compound semiconductor such as GaAs, InP SiC, ZnSe, GaN, or SiGe can be used. Alternatively, an oxide semiconductor such as zinc oxide (ZnO), tin oxide (SnO2), magnesium zinc oxide, gallium oxide, or indium oxide, an oxide semiconductor including two or more of the above oxide semiconductors, or the like can be used. For example, an oxide semiconductor including zinc oxide, indium oxide, and gallium oxide can also be used. In the case of using zinc oxide for the island-like semiconductor film231, the gate insulating film205may be formed using Y2O3, Al2O3, or TiO2, a stacked layer thereof, or the like, and the gate electrode236and an electrode215aand an electrode215bwhich are to be described below may be formed using ITO, Au, Ti, or the like. In addition, In, Ga, or the like can be added to ZnO.

The gate electrode236may be formed by a CVD method, a sputtering method, a droplet discharge method, or the like using an element selected from Ag, Au, Cu, Ni, Pt, Pd, Ir, Rh, W, Al, Ta, Mo, Cd, Zn, Fe, Ti, Si, Ge, Zr, and Ba or an alloy material or a compound material containing any of the elements as its main component. In addition, a semiconductor film typified by a polycrystalline silicon film doped with an impurity element such as phosphorus, or an AgPdCu alloy may be used. Further, either a single layer structure or a stacked structure of a plurality of layers may be employed.

In addition, a channel formation region233, a region234awhich is one of a source region and a drain region, and a region234bwhich is the other of the source region and the drain region are formed in the island-like semiconductor film231(seeFIG. 7C). The region234aand the region234bmay be formed by adding an impurity element having one conductivity type to the island-like semiconductor film231with the gate electrode236used as a mask. As the impurity element having one conductivity type, phosphorus (P) or arsenic (As) which is an impurity element imparting n-type conductivity or boron (B) which is an impurity element imparting p-type conductivity may be used.

A low-concentration impurity region may be formed in each of regions between the channel formation region233and the region234aand between the channel formation region233and the region234b.

Next, an insulating film206and an insulating film207are formed to cover the gate insulating film205and the gate electrode236. Furthermore, an electrode215awhich is electrically connected to the region234aand an electrode215bwhich is electrically connected to the region234bare formed over the insulating film207. In the aforementioned manner, a TFT211which is included in a semiconductor circuit is manufactured (seeFIG. 7D). Note that although a single TFT is illustrated inFIG. 7D, two or more TFTs may be provided. A semiconductor circuit may be formed with a plurality of TFTs that are electrically connected to each other.

The insulating film206and the insulating film207may each be formed using any of the materials mentioned in the description of the base film204. In this embodiment, a silicon nitride film containing oxygen is formed as the insulating film206, and a silicon oxide film containing nitrogen is formed as the insulating film207. This is in order to terminate dangling bonds in the island-like semiconductor film231with hydrogen contained in the silicon nitride film containing oxygen through heat treatment. Alternatively, either the insulating film206or the insulating film207may be formed as necessary.

The electrode215aand the electrode215bmay be formed using any of the materials mentioned in the description of the gate electrode236.

Next, an insulating film208is formed to cover the insulating film207, the electrode215a, and the electrode215b, and an electrode217which is electrically connected to one of the electrode215aand the electrode215bis formed over the insulating film208(seeFIG. 8A).

The insulating film208may be formed using an organic insulating material or an inorganic insulating material.

As an inorganic material, silicon oxide, silicon nitride, silicon oxide containing nitrogen, or diamond-like carbon (DLC) or a stacked structure of two or more of these materials can be used. As an organic material, polyimide, acrylic, polyamide, polyimide amide, resist, benzocyclobutene, or siloxane or a stacked structure of two or more of these materials may be used.

The electrode217may be formed using any of the materials mentioned in the description of the gate electrode236.

A structure body305in which a sheet-like fibrous body302is impregnated with an organic resin301is provided over the insulating film208and the electrode217(seeFIG. 8B). Such a structure body305is also called a prepreg. A prepreg is specifically formed in the following manner: after a sheet-like fibrous body is impregnated with a composition in which a matrix resin is diluted with an organic solvent, drying is performed so that the organic solvent is volatilized and the matrix resin is semi-cured.

In the drawings of this specification, the sheet-like fibrous body302is illustrated as a woven fabric which is plain-woven using yarn bundles with an elliptical cross-sectional shape. Although the size of the TFT211is larger than the width of a yarn bundle of the sheet-like fibrous body302, the size of the TFT211may be smaller than the width of a yarn bundle of the sheet-like fibrous body302in some cases.

The structure body (also called “prepreg”)305including the sheet-like fibrous body302and the organic resin301is hereinafter described in detail with reference toFIGS. 14A and 14B,FIG. 15,FIG. 16, andFIGS. 17A and 17B.

A top view of a woven fabric which is the sheet-like fibrous body302woven using yarn bundles as warp yarns and weft yarns is illustrated inFIGS. 14A and 14B, and a cross-sectional view thereof is illustrated inFIG. 17A. In addition, a cross-sectional view of the structure body305in which the sheet-like fibrous body302is impregnated with the organic resin301is illustrated inFIG. 17B.

The sheet-like fibrous body302is a woven fabric or a nonwoven fabric of an organic compound or an inorganic compound. Alternatively, as the sheet-like fibrous body302, a high-strength fiber of an organic compound or an inorganic compound may be used.

Alternatively, the sheet-like fibrous body302may be a woven fabric which is woven using bundles of fibers (single yarns) (hereinafter, the bundles of fibers are referred to as yarn bundles) for warp yarns and weft yarns, or a nonwoven fabric obtained by stacking yarn bundles of plural kinds of fibers in a random manner or in one direction. In the case of a woven fabric, a plain-woven fabric, a twilled fabric, a satin-woven fabric, or the like can be used as appropriate.

The yarn bundle may have a circular cross-sectional shape or an elliptical cross-sectional shape. As the yarn bundle, a yarn bundle may be used which has been subjected to fiber opening with a high-pressure water stream, high-frequency vibration using liquid as a medium, continuous ultrasonic vibration, pressing with a roller, or the like. A yarn bundle which has been subjected to fabric opening has a larger width, has a smaller number of single yarns in the thickness direction, and has an elliptical cross-sectional shape or a flat cross-sectional shape. Furthermore, by using a loosely twisted yarn as the yarn bundle, the yarn bundle is easily flattened and has an elliptical cross-sectional shape or a flat cross-sectional shape. By using yarn bundles having an elliptical cross-sectional shape or a flat cross-sectional shape as described above, it is possible to reduce the thickness of the sheet-like fibrous body302. Accordingly, the structure body305can be made thin, and thus, a thin semiconductor device can be manufactured.

As illustrated inFIG. 14A, the sheet-like fibrous body302is woven using warp yarns302aspaced at regular intervals and weft yarns302bspaced at regular intervals. Such a fibrous body has regions without the warp yarns302aand the weft yarns302b(referred to as basket holes302c). Such a sheet-like fibrous body302is further impregnated with the organic resin301, whereby adhesiveness of the sheet-like fibrous body302can be further increased. Note that although neither the warp yarns302anor the weft yarns302bexist in the basket holes302cof the structure body305, the basket holes302care filled with the organic resin301.

As illustrated inFIG. 14B, in the sheet-like fibrous body302, the density of the warp yarns302aand the weft yarns302bmay be high and the proportion of the basket holes302cmay be low. Typically, the size of the basket hole302cis preferably smaller than the area of a locally pressed portion. More typically, the basket hole302cpreferably has a rectangular shape having a side with a length of 0.01 mm to 0.2 mm. When the basket hole302cof the sheet-like fibrous body302has such a small area, even when pressure is applied by a member with a sharp tip (typically, a writing instrument such as a pen or a pencil), the pressure can be absorbed by the entire sheet-like fibrous body302.

Furthermore, in order to enhance the permeability of the organic resin301into the inside of the yarn bundles, the yarn bundles may be subjected to surface treatment. For example, as the surface treatment, corona discharge treatment, plasma discharge treatment, or the like for activating a surface of the yarn bundle can be given. Moreover, surface treatment using a silane coupling agent or a titanate coupling agent can be given.

A high-strength fiber is specifically a fiber with a high tensile modulus of elasticity or a fiber with a high Young's modulus. As typical examples of a high-strength fiber, a polyvinyl alcohol fiber, a polyester fiber, a polyamide fiber, a polyethylene fiber, an aramid fiber, a polyparaphenylene benzobisoxazole fiber, a glass fiber, and a carbon fiber can be given. As the glass fiber, a glass fiber using E glass, S glass, D glass, Q glass, or the like can be used. Note that the sheet-like fibrous body302may be formed from one or more kinds of the above-mentioned high-strength fibers.

As the organic resin301with which the sheet-like fibrous body302is impregnated, a thermosetting resin such as an epoxy resin, an unsaturated polyester resin, a polyimide resin, a bismaleimide-triazine resin, or a cyanate resin can be used. Alternatively, a thermoplastic resin such as a polyphenylene oxide resin, a polyetherimide resin, or a fluorine resin may be used. Further alternatively, a plurality of the above-mentioned thermosetting resins and thermoplastic resins may be used. By using the above-mentioned organic resin, the sheet-like fibrous body can be fixed to a semiconductor element layer by heat treatment. The higher the glass transition temperature of the organic resin301is, the less easily the organic resin301is damaged by local pressure; thus, the organic resin301preferably has high glass transition temperature.

Highly thermally conductive filler may be dispersed in the organic resin301or in yarn bundles of a fiber. Examples of the highly thermally conductive filler include aluminum nitride, boron nitride, silicon nitride, alumina, and metal particles of silver, copper, or the like. When the highly thermally conductive filler is included in the organic resin or the yarn bundles, heat generated in an element layer can be easily released to the outside. Accordingly, thermal storage in a semiconductor device can be suppressed, and damage to the semiconductor device can be reduced.

Note thatFIGS. 14A and 14Billustrate a sheet-like fibrous body woven using alternate warp and weft yarns. However, the number of warp yarns and that of weft yarns are not limited to these. The number of warp yarns and that of weft yarns may be determined as needed. For example,FIG. 15is a top view of a sheet-like fibrous body woven using warp yarns and weft yarns each including ten yarns, andFIG. 16illustrates a cross-sectional view thereof. InFIG. 15, the sheet-like fibrous body302is impregnated with the organic resin301to form the structure body305.

Next, a conductive resin306is disposed over the structure body305and over the electrode217(seeFIG. 8C). In this embodiment, a conductive paste including a metal element, for example, silver paste, is used as the conductive resin306. The metal element may be included in the conductive paste as metal particles.

The conductive paste may be any paste that includes copper (Cu), silver (Ag), nickel (Ni), gold (Au), platinum (Pt), palladium (Pd), tantalum (Ta), molybdenum (Mo), or titanium (Ti).

As a method for disposing the conductive resin306over the structure body305, a screen printing method or an inkjet method may be employed.

When the conductive resin306is disposed over the structure body305, the organic resin301in the structure body305reacts with a component of the conductive resin306and, for example, in the case of using a conductive paste, the organic resin301reacts with the paste. Thus, part of the organic resin301is dissolved and metal particles in the conductive resin306pass through interstices in the sheet-like fibrous body302and move to a surface (a second surface) opposite to the surface over which the conductive resin306is disposed first (a first surface). Accordingly, a through electrode is formed in the structure body305(seeFIG. 9A).

Note that the area of the conductive resin306on the second surface of the structure body305may be smaller or larger than the area on the first surface. That is, the conductive resin306may contract or expand while moving in the structure body305.

Because a through hole (also referred to as a contact hole) is not formed in the structure body305, that is, because the sheet-like fibrous body302is not divided, one surface of the structure body305can be electrically connected to the other surface without reducing the strength of the structure body305.

After that, a heating step and a pressure bonding step are performed to cure an undissolved portion of the organic resin301in the structure body305.

A stacked structure from the substrate221to the structure body305and the conductive resin306are herein referred to as a stacked structure body237.

Next, in order to facilitate a later separation step, the stacked structure from the separation layer222to the structure body305may be irradiated with a laser beam225from the structure body305side as illustrated inFIG. 9Bto form a groove227in the stacked structure including the separation layer222, the base film204, the gate insulating film205, the insulating film206, the insulating film207, the insulating film208, and the structure body305as illustrated inFIG. 9C. The laser beam225may be any of the laser beams mentioned in the description of the laser beam134.

Next, using the groove227as a trigger, the substrate221provided with the separation layer222is separated from a stacked structure body232including the base film204, the gate insulating film205, the insulating film206, the insulating film207, the insulating film208, the structure body305, and the TFT211, at the interface between the separation layer222and the base film204by a physical means (seeFIG. 10A).

The physical means refers to a dynamic means or a mechanical means, which applies some dynamical energy (mechanical energy). Typically, the physical means is an action of applying mechanical force (e.g., a peeling process with human hands or with a gripper, or a separation process with a rotating roller). At this time, when an adhesive sheet which can be separated by light or heat is provided over a surface of the structure body305, separation can be performed more easily.

Alternatively, the stacked structure body232may be separated from the separation layer222by dropping a liquid into the groove227to allow the liquid to be infiltrated into the interface between the separation layer222and the base film204. In this case, a liquid may be dropped only into the groove227, or the stacked structure manufactured over the substrate221may be entirely soaked in a liquid so that the liquid is infiltrated from the groove227into the interface between the separation layer222and the base film204.

Alternatively, inFIG. 9C, a method can be employed in which a fluoride gas such as NF3, BrF3, or ClF3is introduced into the groove227and the separation layer222is removed by etching with the use of the fluoride gas so that the stacked structure body232is separated from the substrate221.

In addition, a substrate201provided with an insulating film202and an adhesive layer203is prepared, and then, the base film204included in the stacked structure body232and the adhesive layer203over the substrate201are disposed to face each other and attached to each other. The substrate201, the insulating film202, and the adhesive layer203may be formed using the respective materials mentioned in the description of the substrate141, the insulating film142, and the adhesive layer143. In the manner mentioned above, a semiconductor circuit element235is manufactured (seeFIG. 10B).

Next, the light-emitting element145and the semiconductor circuit element235are disposed to face each other (seeFIG. 1). At this time, these elements are disposed to face each other such that the projecting portion of the electrode113and the conductive resin306overlap each other.

A case where the projecting portion of the electrode113and the conductive resin306are directly bonded to each other is illustrated inFIG. 11. Before the direct bonding, surfaces of the light-emitting element145and the semiconductor circuit element235are preferably subjected to plasma treatment. In addition, when electric current is applied between the electrode113and the conductive resin306, the bonding is strengthened.

In addition, a space241surrounded by the electrode113, the partition104a, and the structure body305is generated, and in the case where a desiccant242is provided in the space241, the entry of moisture into the light-emitting layer112can be prevented.

Furthermore, because the space241exists, stress can be relaxed even when the substrate141and the substrate201are bent.

An example in which the light-emitting element145and the semiconductor circuit element235are attached to each other with an anisotropic conductive resin film331is illustrated inFIG. 12. As the anisotropic conductive resin film331, an anisotropic conductive paste (ACP), an anisotropic conductive film (ACF), and the like can be given as examples. By attaching the light-emitting element145and the semiconductor circuit element235to each other with the anisotropic conductive resin film331, the projecting portion of the electrode113and the conductive resin306are electrically connected to each other through conductive particles332which are contained in the anisotropic conductive resin film331. Because the anisotropic conductive resin film331conducts electricity only in a longitudinal direction, only a portion between the projecting portion of the electrode113and the conductive resin306conducts electricity.

Alternatively, the light-emitting element145and the semiconductor circuit element235may be attached to each other with a non-conductive paste (NCP).

A semiconductor circuit element having a structure different from that inFIG. 10Band a method for manufacturing the semiconductor circuit element, and a light-emitting device and a method for manufacturing the light-emitting device are described with reference toFIGS. 18A and 18B,FIG. 19,FIG. 20, andFIG. 21.

First, based on the manufacturing steps toFIG. 8B, a separation layer222, a base film204, a gate insulating film205, an insulating film206, an insulating film207, an insulating film208, a TFT261including an electrode262and an electrode263, and a structure body305including a sheet-like fibrous body302and an organic resin301are formed over a substrate221.

At this time, the TFT261may be formed in a manner similar to the TFT211, and the electrode262and the electrode263are formed in place of the electrode215aand the electrode215b, respectively. Contact holes are formed in the gate insulating film205, the insulating film206, the insulating film207, and the insulating film208to reach a region234band the separation layer222, and one of the electrodes262and263, which is the electrode263in this embodiment, is formed in contact with the region234band the separation layer222.

Next, based on the manufacturing steps illustrated inFIGS. 9B and 9C, a groove227is formed in a stacked structure including the gate insulating film205, the insulating film206, the insulating film207, the insulating film208, and the structure body305(seeFIG. 18A).

Next, using the groove227as a trigger, the substrate221provided with the separation layer222is separated from a semiconductor circuit element245including the base film204, the gate insulating film205, the insulating film206, the insulating film207, the insulating film208, the structure body305, and the TFT261, at the interface between the separation layer222and the base film204(seeFIG. 18B). Accordingly, the electrode263is exposed at a surface of the base film204.

Next, the base film204of the semiconductor circuit element245and the electrode113of the light-emitting element are disposed to face each other (seeFIG. 19). At this time, the projecting portion of the electrode113and the electrode263exposed at the surface of the base film204are arranged to overlap each other.

A case where the projecting portion of the electrode113and the electrode263are directly bonded to each other is illustrated inFIG. 20. Before the direct bonding, surfaces of the light-emitting element145and the semiconductor circuit element245are preferably subjected to plasma treatment. In addition, when electric current is applied between the electrode113and the electrode263, the bonding is strengthened.

In addition, a space247surrounded by the electrode113, the partition104a, and the base film204is generated, and in the case where a desiccant242is provided in the space247, the entry of moisture into the light-emitting layer112can be prevented.

An example in which the light-emitting element145and the semiconductor circuit element245are attached to each other with an anisotropic conductive resin film331is illustrated inFIG. 21. By attaching the light-emitting element145and the semiconductor circuit element245to each other with the anisotropic conductive resin film331, the projecting portion of the electrode113and the electrode217are electrically connected to each other through conductive particles332which are contained in the anisotropic conductive resin film331. Because the anisotropic conductive resin film331conducts electricity only in a longitudinal direction, only a portion between the projecting portion of the electrode113and the electrode263conducts electricity.

Alternatively, the light-emitting element145and the semiconductor circuit element245may be attached to each other with a non-conductive paste (NCP).

A semiconductor circuit element having a structure different from that inFIG. 10Band a method for manufacturing the semiconductor circuit element, and a light-emitting device and a method for manufacturing the light-emitting device are described with reference toFIGS. 23A and 23BandFIGS. 24A and 24B.

First, based on the manufacturing steps toFIG. 8B, a separation layer222, a base film204, a gate insulating film205, an insulating film206, an insulating film207, an electrode217, an insulating film208, and a TFT211including an electrode215aand an electrode215bare formed over a substrate221.

A resin layer251and a support252are formed over the insulating film208and the electrode217(seeFIG. 23A). In this embodiment, a water-soluble resin is used as the resin layer251, and UV tape is used as the support252. Before the resin layer251and the support252are formed, a groove may be formed by laser beam irradiation in a manner similar to the manufacturing step illustrated inFIG. 9B.

Next, the substrate221provided with the separation layer222is separated from a semiconductor circuit element255including the base film204, the gate insulating film205, the insulating film206, the insulating film207, the insulating film208, the TFT211, and the electrode217, at the interface between the separation layer222and the base film204. Then, the semiconductor circuit element255and a substrate201provided with an insulating film202and an adhesive layer203are attached to each other with the adhesive layer203(seeFIG. 23B).

Next, the resin layer251is dissolved and removed to separate the support252. For the resin layer251, another soluble resin, plastic resin, or the like may be used, and the semiconductor circuit element255and the support252may be chemically or physically separated from each other (seeFIG. 24A).

A light-emitting element145is manufactured based on the manufacturing steps illustrated inFIG. 1,FIGS. 2A to 2C,FIGS. 3A and 3B,FIGS. 4A and 4B,FIGS. 5A and 5B, andFIGS. 6A to 6C, and the projecting portion of the electrode113of the light-emitting element145and the electrode217of the semiconductor circuit element255are directly bonded (connected) to each other (seeFIG. 24B).

Before the projecting portion of the electrode113and the electrode217are directly bonded to each other, surfaces of the light-emitting element145and the semiconductor circuit element255are preferably subjected to plasma treatment. In addition, when electric current is applied between the electrode113and the electrode217, the bonding is strengthened.

In addition, a space241surrounded by the electrode113, the partition104a, and the structure body305is generated, and in the case where a desiccant242is provided in the space241, the entry of moisture into the light-emitting layer112can be prevented.

Furthermore, because the space241exists, stress can be relaxed even when the substrate141and the substrate201are bent.

In a manner similar to the structure illustrated inFIG. 12, the light-emitting element145and the semiconductor circuit element255may be attached to each other with an anisotropic conductive resin film331containing conductive particles332, and the projecting portion of the electrode113and the conductive resin306may be electrically connected to each other.

Alternatively, the light-emitting element145and the semiconductor circuit element255may be attached to each other with a non-conductive paste (NCP).

Through the above steps, a light-emitting device including a light-emitting element and a semiconductor circuit element is manufactured. By manufacturing the light-emitting element and the semiconductor circuit element over different substrates and then attaching the elements to each other, a semiconductor circuit is not formed below the light-emitting element and thus the generation of defective coverage due to steps can be suppressed.

In addition, because the light-emitting element and the semiconductor circuit element for driving the light-emitting element can be disposed over flexible substrates, the shape can be changed and the light-emitting element and the semiconductor circuit element for driving the light-emitting element can be incorporated into electronic devices of various shapes even after the light-emitting element and the semiconductor circuit element are attached to each other.

In this embodiment, a cellular phone incorporating the light-emitting device described in Embodiment 1 is described with reference toFIGS. 13A to 13D,FIGS. 22A and 22B,FIG. 25,FIG. 26,FIGS. 27A to 27D, andFIGS. 28A and 28B. In this embodiment, the same elements are denoted by the same reference numerals.

FIG. 13Cis a front view of the cellular phone;FIG. 13D, a side view;FIG. 13B, a top view; andFIG. 13A, a cross-sectional view of a housing411. The shape of the front of the housing411is a rectangle having longer sides and shorter sides, which may have round corners. In this embodiment, a direction parallel to the longer sides of the rectangle that is the shape of the front is referred to as a longitudinal direction, and a direction parallel to the shorter sides is referred to as a lateral direction.

In addition, the shape of the side of the housing411is also a rectangle having longer sides and shorter sides, which may have round corners. In this embodiment, a direction parallel to the longer sides of the rectangle that is the shape of the side is a longitudinal direction, and a direction parallel to the shorter sides is referred to as a depth direction.

The cellular phone illustrated inFIGS. 13A to 13Dhas the housing411, a housing402, and a display region413, operation buttons404, an EL panel421, a touch panel423, and a support416which are incorporated in the housing411.

The EL panel421and a driver circuit412which is mentioned below may be formed using the light-emitting device including the light-emitting element and the semiconductor circuit element, which is described in Embodiment 1. In the EL panel421, the light-emitting element is used and the semiconductor circuit element is used as a pixel circuit for driving the light-emitting element. The driver circuit412for driving the pixel circuit may be manufactured using a semiconductor circuit element.

Note thatFIG. 28Ais a perspective view of the housing411. A region of the housing411which has the largest area is a front455; a surface opposite to the front455is a back452; regions between the front455and the back452are sides453; and one of regions surrounded by the front455, the back452, and the sides453is a top454.

FIG. 22Ais a back view of the cellular phone illustrated inFIGS. 13A to 13D.

As illustrated inFIG. 22A, the driver circuit412is manufactured so as to be located on the back452of the housing411.

FIG. 22Bis a top view of the cellular phone which is rotated 90° to the side from the orientation inFIG. 13C. Images and letters can be displayed, whether the cellular phone of this embodiment is placed horizontally or vertically for a landscape mode or a portrait mode.

As illustrated inFIG. 13A, the housing411includes the support416, and the EL panel421is disposed on the support416. Here, the EL panel421covers an upper region of the support416.

In this manner, the display region413is present at an upper portion in the longitudinal direction of the cellular phone. In other words, the display region413is present on the top454. Accordingly, when the cellular phone is put in, for example, a breast pocket, the display region413can be seen even if the cellular phone is not taken out of the pocket.

The display region413may be capable of displaying date, phone number, personal name, whether or not there is incoming e-mail or an incoming call, and the like. If necessary, display may be performed only in a region of the display region413which is on the top454and not performed in the other region, in which case energy saving can be achieved.

A cross-sectional view ofFIG. 13Dis illustrated inFIG. 25. As illustrated inFIG. 25, in the housing411, the EL panel421and the touch panel423are disposed along the support416, and the display region413is present on the front455and the top454of the housing411.

A development view of the EL panel421and the driver circuit412is illustrated inFIG. 26. InFIG. 26, the EL panel421is manufactured so as to be located on the top454and the back452, and the driver circuit412is located on the back452. In this manner, the EL panel421is manufactured so as to be located on both the front455and the top454, not manufactured separately on the front455and the top454. Thus, manufacturing cost and manufacturing time can be reduced.

The touch panel423is disposed on the EL panel421, and the display region413displays buttons414for the touch panel. By touching the buttons414with a finger or the like, operations displayed in the display region413can be performed. Further, making a call or composing mail can be performed by touching the buttons414in the display region413with a finger or the like.

The buttons414for the touch panel423may be displayed when needed, and when the buttons414are not needed, images or letters can be displayed in the whole area of the display region413as illustrated inFIG. 22B.

Furthermore, an example of a cellular phone in which a display region433is present also at an upper portion in the longitudinal direction of the cellular phone and an upper longer side in a cross-section of the cellular phone also has a curvature radius is illustrated inFIGS. 27A to 27DandFIG. 28B.

FIG. 27Cis a front view of the cellular phone;FIG. 27Dis a side view;FIG. 27Bis a top view; andFIG. 27Ais a cross-sectional view of a housing431. The shape of the front of the housing431is a rectangle having longer sides and shorter sides, which may have round corners. In this embodiment, a direction parallel to the longer sides of the rectangle is referred to as a longitudinal direction, and a direction parallel to the shorter sides is referred to as a lateral direction.

The cellular phone illustrated inFIGS. 27A to 27Dhas the housing431, a housing402, and the display region433, operation buttons404, an EL panel441, a touch panel443, and a support436which are incorporated in the housing431.

The EL panel441and a driver circuit412may be formed using the light-emitting element and the semiconductor circuit element which are described in Embodiment 1. In the EL panel441, the light-emitting element is used and the semiconductor circuit element is used as a pixel circuit for driving the light-emitting element. The driver circuit412for driving the pixel circuit may be manufactured using a semiconductor circuit element.

Note thatFIG. 28Bis a perspective view of the housing431. In a manner similar toFIG. 28A, a region of the housing431which has the largest area is a front455; a surface opposite to the front455is a back452; regions between the front455and the back452are sides453; and one of regions surrounded by the front455, the back452, and the sides453is a top454.

The back view of the cellular phone illustrated inFIGS. 27A to 27Dis similar toFIG. 22Awhich is the back view of the cellular phone illustrated inFIGS. 13A to 13D.

In a manner similar toFIG. 22A, the driver circuit412is manufactured so as to be located on the back452of the housing431. The back view of the cellular phone illustrated inFIGS. 27A to 27Dcorresponds to a view in which the housing411inFIG. 22Ais replaced with the housing431.

In the cellular phone illustrated inFIGS. 27A to 27D, the support436is formed to have a cross-sectional shape in which an upper longer side has a curvature radius. Accordingly, the EL panel441and the touch panel443each have a cross-sectional shape in which an upper longer side has a curvature radius. In addition, an upper longer side of the housing431is also curved. In other words, the display region433on the front455is curved outwards.

When the upper longer side of the support436has a curvature radius R1, the curvature radius R1is preferably 20 cm to 30 cm.

Because the upper longer side of the support436is curved with the curvature radius R1, the upper longer sides of the EL panel441covering the support436, the touch panel443covering the EL panel441, and the housing431are also curved.

In the cellular phone illustrated inFIGS. 27A to 27D, the display region433is present also at an upper portion in the longitudinal direction of the cellular phone. In other words, the display region433is present also on the top454. Accordingly, when the cellular phone is put in, for example, a breast pocket, the display region433can be seen even if the cellular phone is not taken out of the pocket.

The display region433may be capable of displaying date, phone number, personal name, whether or not there is incoming e-mail or an incoming call, and the like. If necessary, display may be performed only in a region of the display region433which is on the top454and not performed in the other region, in which case energy saving can be achieved.

A development view of the EL panel441and the driver circuit412is similar toFIG. 26, which is the development view of those of the cellular phone illustratedFIGS. 13A to 13D, and corresponds to a view in which the EL panel421inFIG. 26is replaced with the EL panel441. In a manner similar toFIG. 26, the driver circuit412is located on the top454and the back452.

This application is based on Japanese Patent Application serial no. 2008-294661 filed with Japan Patent Office on Nov. 18, 2008, the entire contents of which are hereby incorporated by reference.