JPH08171990A - Thin film electroluminescence device - Google Patents

Abstract

(57) [Structure] A thin film which also serves as a lower electrode and a crystallinity control layer of a light emitting layer is formed on a supporting substrate 101, and a lower insulating layer 103 is formed in contact with this thin film 102 to form a lower insulating layer. In a thin film electroluminescent device in which a light emitting layer 104 is formed by sandwiching 103 and an upper insulating layer 105, and an upper electrode 106 is formed on the upper insulating layer 105, the crystallinity of the lower electrode and the light emitting layer is controlled. The layer 102 which also serves as a thin film electroluminescent element is a silicon thin film formed by the melt recrystallization method in which at least two kinds of crystal orientation planes parallel to the substrate exist. [Effects] Since the EL device according to the present invention does not have a dead layer, it is possible to lower the driving voltage and sustain the emission brightness as compared with an EL device composed of a conventional polycrystalline material. Excellent in. In addition, since this EL element can use a glass substrate as a supporting substrate, it is also advantageous in increasing the area.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film electroluminescent light emitting device having improved light emitting characteristics.

[0002]

2. Description of the Related Art A thin film electroluminescent device (hereinafter referred to as an EL device) is a visible light emitting device which has been drawing attention as a promising candidate for a flat panel display. Especially M
An EL device using a ZnS: Mn thin film with n as an emission center is currently gaining the status of a practical device. FIG. 1 shows a block diagram of a general EL element currently under development.

In this EL device, a transparent electrode (102) is formed on a base substrate (101), and an insulating layer (10) is formed thereon.
3), a light emitting layer (104), an insulating layer (105), and an upper electrode (106) are formed in a double insulating structure, and a polycrystalline material is used for each layer. When the light emitting layer is made of a polycrystalline material, a so-called dead layer having extremely lowered crystallinity is formed at the interface between the insulating layer and the light emitting layer at the initial stage of film formation. Since this dead layer does not contribute to light emission, a means for recovering the crystallinity is required to increase the light emission brightness. However, in the case of the usual method, there is no other method than making the light emitting layer thick and utilizing the high orientation of the thin film.
As a result, the thickness of the light emitting layer is increased and the driving voltage of the EL element is increased. Currently, in order to achieve multi-color, a thin film element using CaS or SrS as a light emitting layer in addition to ZnS is under study. Since these materials are less likely to obtain a highly oriented film than ZnS, the influence on the crystallinity characteristics is further increased.

By the way, the film thickness of the dead layer can be made thin by devising a method of forming a thin film, but it is impossible to completely remove it as long as a polycrystalline material is used. Therefore, JP-A-2-56895 and JP-A-2-60090 are available.
Japanese Patent Application Laid-Open No. 2-90493 proposes a double insulating structure EL element in which a lower insulating layer and a light emitting layer are epitaxially grown on a single crystal Si substrate by a heteroepitaxial growth method to single crystallize the light emitting layer. These proposals are intended to completely remove the dead layer by epitaxially growing the light emitting layer on the single crystal insulating layer. However, since the EL elements according to these proposals can remove the dead layer and thus can be driven at a low voltage, they have drawbacks that the emission luminance and luminous efficiency are not sufficient, and an EL element with a long life cannot be obtained. The reason is as follows.

EL emission occurs when electrons emitted from the interface state between the insulating layer and the light emitting layer are accelerated by an electric field, and the emitted electrons become initial electrons, which causes avalanche multiplication and excites emission centers. It is considered. here,
The interface level at the interface between the insulating layer and the light emitting layer is formed by a defect such as a dangling bond or a dead layer. Therefore, in the EL element composed of a single crystal material in which the interface between the insulating layer and the light emitting layer continuously changes due to the heterojunction, the interface state is extremely reduced as compared with the element made of the polycrystalline material. As a result, the carriers that excite the emission centers are reduced, and the emission brightness is reduced. Also,
As described above, the avalanche breakdown is involved in the light emission of the EL element. When the avalanche breakdown occurs, the voltage applied to the light emitting layer is clamped to a constant value, and the emission brightness is saturated. This clamp voltage varies depending on the crystallinity of the light emitting layer, and in a device in which the light emitting layer is single-crystallized, crystal defects such as grain boundaries are reduced, so that avalanche breakdown is more likely to occur and the clamp voltage is lower than in the case of a polycrystalline material. To do. As a result, high-energy carriers cannot be generated, and the emission brightness is reduced.

As described above, as compared with the polycrystalline EL element, the single crystallized EL element has a low voltage because the dead layer does not exist at the interface or carriers causing scattering such as crystal defects do not exist in the film. Although it can be driven and the reliability is improved, there is a problem that the emission brightness is reduced due to a decrease in carrier generation sources and a decrease in clamp voltage.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above drawbacks of the prior art.
It is an object of the present invention to provide a thin film electroluminescent device which has no dead layer, can be driven at a low voltage, and has improved emission brightness and emission efficiency.

According to the present invention, a thin film layer which also serves as a lower electrode and a crystallinity control layer of the light emitting layer is formed on a supporting substrate, and a lower insulating layer is formed in contact with this thin film layer. In a thin film electroluminescent element formed by forming a light emitting layer with a structure sandwiched by an upper insulating layer and forming an upper electrode on the upper insulating layer, the thin film layer also serving as the control of the crystallinity of the lower electrode and the light emitting layer is Provided is a thin film electroluminescent device characterized by being a silicon thin film formed by a melt recrystallization method in which there are at least two types of crystal orientation planes in the direction parallel to the substrate, and the crystal of the lower electrode and the light emitting layer is provided. The thin-film electroluminescent element is characterized in that the thin-film layer also serving as a property control is a silicon thin film formed by a melt recrystallization method in which a plurality of crystal orientation planes having a twin relationship exist. It is. Further, according to the present invention, a thin film layer which also serves as a lower electrode and a crystallinity control layer of the light emitting layer is formed on a supporting substrate, and a lower insulating layer is formed in contact with this thin film, and the lower insulating layer and the upper insulating layer are formed. In the thin-film electroluminescent element formed by forming a light-emitting layer with a layer and an upper electrode on the upper insulating layer, the thin-film layer also serving as the lower electrode and the crystallinity control layer of the light-emitting layer is a grain. There is provided a thin film electroluminescence device characterized by being a silicon thin film formed by a melt recrystallization method composed of a single crystal orientation in which a field exists, and control of crystallinity of a lower electrode and a light emitting layer. The silicon thin film layer also serving as the thin film electro-luminescent device is characterized in that the generation density of grain boundaries periodically changes in the substrate surface, and a driving element composed of a silicon thin film transistor is formed in the high density generation portion. Nessensu element is provided.

The structure and operation of the EL element according to the present invention will be described below with reference to FIG. The EL device according to the present invention comprises a support substrate (201), a thin film layer (hereinafter also referred to as a melt recrystallized film) (202) which also serves as a lower electrode and a crystallinity control layer of a light emitting layer, and a heteroepitaxial growth layer formed thereon. Single crystal insulating film (203) and single crystal light emitting layer (204), upper insulating layer (205), upper electrode (20)
6). In the present invention, a single crystal silicon thin film formed on the support substrate (201) by the melt recrystallization method is used as the melt recrystallized film (202).

FIG. 3 is an explanatory view (sketch diagram) of an electron micrograph of a surface in which a molten recrystallized film formed on a glass substrate is subjected to etching treatment to highlight various defects. FIG.
It can be seen that the melt recrystallized film of (a) has twin defects (301) and the film of FIG. 3 (b) has subgrain boundaries (302). Such crystal defects are peculiar to the melt recrystallized film, and it is possible to control the type and position of the defects by the recrystallization method. Then, the light emitting layer formed by heteroepitaxial growth on the molten recrystallized film in this state also reflects the crystal information such as twins or sub-grain boundaries. Therefore, by using the melt recrystallized film as a base substrate for forming a single crystal EL device, it is possible to introduce crystal defects such as twins or subgrain boundaries into the light emitting layer, which is not possible with a normal single crystal silicon substrate. become. As a result, the EL of the present invention
The element has the following features. 1. The dead layer does not exist at the insulating layer / light emitting layer interface. 2. Crystal defects (dangling bonds) exist in the thickness direction in the light emitting layer. 3. There is a discontinuous portion (twin zone) of the crystal lattice in the voltage application direction of the EL element.

Next, the operation of the EL device of the present invention having the above structure will be described. Since the EL element according to the present invention does not have a dead layer, the driving voltage can be lowered as in the conventional single crystal element. Further, the crystal defects existing in the light emitting layer serve as a supply source of electrons that excite the emission center. FIG. 4 shows the direction of the twin band (406) formed in the light emitting layer (404) formed on the underlying substrate (401) via the molten recrystallized film (402) and the lower insulating layer (403). Show. As shown in FIG. 4, when the mother crystal (405) is an EL device (408) having an orientation (100),
The twin band is formed in a direction crossing the voltage application direction (407). By forming such a state in the light emitting layer, it is possible to control the voltage at which avalanche breakdown occurs, and it is possible to solve the problem of lowering the clamp voltage, which has been a problem in conventional single crystal devices. As described above, the EL element of the present invention can realize high-luminance light emission by driving at a low voltage.

Next, materials constituting the EL device of the present invention and a method for forming the same will be described with reference to FIG. As the support substrate (201), a transparent or opaque substrate such as quartz glass, glass, or a ceramic material, which can have a large area, can be used. The melt recrystallized film (202) formed on the insulating substrate is the support substrate (201) by a melt recrystallization method such as a strip heater method, a high frequency induction heating method, a lamp heating method or a laser heating method. Formed on. In this case, the single crystal Si is controlled by controlling the melt recrystallization conditions.
Can control the growth state of (100), (111), (1
The plane orientation such as 10) can be formed at an arbitrary position. further,
On the melt recrystallized film (202) formed by the above method, single crystal Si or single crystal Ge is deposited by the LPCVD method, MO-C.
VD method (metalorganic pyrolysis method), MBE method (Molecu
lar-Beam-Epitaxy), ALE method (At
The single crystal semiconductor layer may have a multi-layered structure by epitaxial growth using a thin film growth method such as an electron-layer-epitaxial method, an electron beam evaporation method, a sputtering method, and a plasma CVD method.

In this case, the single-crystal Si or Ge layer grown on the melt-recrystallized film improves the surface property and alleviates lattice mismatch with the single-crystal insulator layer grown on the melt-recrystallized film. Have an effect.

In the present invention, since the melt recrystallized film is also used as an electrode, its resistivity is 10 ⁻⁴ (Ω).
・ Cm) to 10 ² (Ω · cm) is preferable. The melt recrystallized film (20
2) as a single crystal insulator layer (203) on top of which PbTi
O ₃ , PLT, PLZT, BaTiO ₃ , SrTiO ₃ ,
Y ₂ O ₃ , YSZ, Ta ₂ O ₃ , Sm ₂ O ₃ , Al ₂ O ₃ , Mg
O, oxide materials such as MgAl ₂ O ₃ , CaF ₂ , Ba
Fluoride materials such as F ₂ and SrF ₂ are epitaxially grown in a carbon layer or a multilayer structure. As means for epitaxial growth, MO-CVD method (organic metal pyrolysis method),
MBE method (Molecular-Beam-Epita
xy), ALE method (Atomic-Layer-Epi)
Examples of the growth method include a taxy) method, an electron beam evaporation method, a sputtering method, and a plasma CVD method. These methods may be used alone or in combination of two or more kinds.

As the single crystal light emitting layer (204) epitaxially grown on the single crystal insulating layer (203), Zn is used.
A ZnS: Mn-based material in which S, ZnSe, ZnSxSex-1 or the like is used as a base material and Mn is added as an emission center, or a ZnS: Cu-based material in which Cu is added to the base material, or a rare earth fluoride ( TbF ₃ , ErF ₃ , N
dF ₃ , TmF ₃ , PrF ₃ , SmF ₃ , DyF ₃ , HoF ₃
Etc.) is used. Further, SrS is used as a base material, and Ce, Sm, Tb, Dy, Er, T
A material to which m, Pr, Mn or the like is added, or a material in which CaS is a base material and Er or the like is added to the emission center may be used as the light emitting layer.

The light emitting layer material is used as a single crystal insulating layer (20
3) Epitaxially grow a single layer or a multi-layered structure on it. As means for epitaxial growth, MO-C
Growth methods such as the VD method, the MBE method, the ALE method, the EB vapor deposition method, the sputtering method, and the plasma CVD method are used alone or in combination. The single crystal insulating layer (203) and the single crystal light emitting layer (204) heteroepitaxially grown on the melt recrystallized film (202) by the above method have a crystal structure of each layer, a matching of lattice spacing, a difference in thermal expansion coefficient, etc. In consideration of the above, the optimum material is selected, and epitaxial growth is sequentially performed on each layer. As a result, the plane orientations of the single crystal insulating layer (203) and the single crystal light emitting layer (204) are the same as those of the melt recrystallized film layer (2).
02) which reflects the plane orientation.

Next, heteroepitaxy is formed on the melt-recrystallized film.
If the single crystal is grown on the single crystal light emitting layer (204)
Insulator materials such as polycrystalline oxides, fluorides and nitrides
Forming an upper insulating layer (205). Single crystal
As a polycrystalline oxide material, PbTiO 3₃, PL
T, PLZT, BaTiO₃, SrTiO₃, Y₂O₃, Y
SZr, Ta₂O₃, Sm₂O₃, Al ₂O₃, MgO, Mg
Al₂O₃, SiO₂, SiON, ZnO and other materials are used
As a single crystal or polycrystalline fluoride material,
CaF₂, BaF₂Materials such as can be used. Single crystal
Or, as the polycrystalline nitride material, Si₃N_FourEtc.
Can be used. As a method for growing the above-mentioned insulator material, MO-
CVD method, MBE method, ALE method, sputtering method,
Razma CVD method, electron beam evaporation method, etc. are used.
Be done.

Finally, on the upper insulating layer (205),
As the transparent conductive film (206), Au, ITO, i ₂ O ₃ , S
nO ₂ , ZnO: Al, etc. are used for MO-CVD, MBE,
The double-insulation EL device according to the present invention can be obtained by using the ALE method, the sputtering method, the plasma CVD method, the electron beam vapor deposition method, or the like.

[0019]

EXAMPLES Next, the present invention will be specifically described by way of examples.

Example 1 First, the EL device of the present invention shown in FIG. 5 will be described. This EL device comprises a molten recrystallized film (single crystal Si: thin film) (502) formed on a glass substrate (501) by using a laser beam as a heat source, and a CaF ₂ thin film epitaxially grown thereon by the MBE method ( 503), MO-
ZnS: Mn thin film (504) epitaxially grown by CVD method, Si ₃ formed by sputtering method
It is a double insulating structure element composed of an N ₄ thin film (505) and an ITO thin film (506). Here, when a laser beam is used as a heating source for melt recrystallization, an arbitrary temperature profile can be formed by controlling the beam shape.
As a result, the melting and recrystallization process of the single crystal Si thin film changes for each region, and crystals with different orientation states can be formed on the same substrate. FIG. 6 shows the X-ray diffraction results of the melt recrystallized film formed by this method. In the diffraction pattern, peaks due to the (111) orientation (601) and the (100) orientation (602) are observed. This reflects the state of the Si thin film as shown in FIG. In FIG. 7, 702 is a molten recrystallized film, 703 is a (100) oriented portion, and 704 is (11).
1) Oriented portion. A ZnS: Mn thin film (5
04) also has a similar orientation state, and regions having different orientation states are separated by grain boundary. Therefore, FIG.
The EL device of No. 1 has a structure in which no dead layer is present and grain boundary is introduced into the light emitting layer.
FIG. 8 shows the results of comparison of the emission luminance voltage characteristics of the present EL device (801) with the conventional double insulating structure device (802) in which each layer is made of a polycrystalline material. From this result, it can be seen that the EL element according to the present example emits light at a lower voltage than the conventional EL element using the polycrystalline material as the light emitting layer. Further, in the EL device of the present invention, a characteristic different from that of the conventional device is observed in the rise of the luminance after the start of light emission. That is, in the conventional EL element, the light emission brightness sharply increases after the start of light emission, whereas the rise of the brightness in the present EL element shows a gradual characteristic immediately after the start of light emission. This is ZnS: Mn
This is because the light emission threshold voltage and the luminance voltage characteristics differ depending on the orientation surface of the thin film. In this EL device, (100) and (111)
When the orientation plane coexists in the device and a low voltage is applied, (10
0) Light emission occurs only in the alignment portion, and light emission occurs in any of the alignment portions when a high voltage is applied. As a result, unlike the conventional EL element, the emission luminance is excellent in sustainability.

Example 2 Next, a blue light emitting device using the SrS: Ce thin film shown in FIG. 9 as a light emitting layer will be described. This EL element realizes low voltage driving and high brightness light emission. This EL device comprises a melt recrystallized film (90) on a glass substrate (901).
2) SrF ₂ thin film (903) which is a lower insulating layer formed by heteroepitaxial growth method, SrS: Ce thin film (904) which is a light emitting layer, and Si ₃ N ₄ thin film (905 which is formed as an upper insulating layer on it) ), And an ITO thin film (906) used for a transparent electrode. Here, the melt-recrystallized film serving as a substrate for forming each thin film is formed by processing poly-Si before melt-recrystallization into a stripe shape having a width of 100 μm and then recrystallizing. In the molten recrystallized film formed by this method, stress is applied in the direction orthogonal to the stripe in the process of solidification after melting, and twin defects are introduced in the direction parallel to the stripe (FIG. 3). Similar twin defects are introduced into the light emitting layer grown on the melt recrystallized film. FIG. 10 shows an EL device (1001) according to this embodiment.
2 shows the results of comparison of the luminance voltage characteristics of the conventional EL element (1002) having the same structure formed on a single crystal Si substrate. From this result, E according to the present embodiment
It can be seen that the L element has higher emission luminance in the saturated region which appears in the luminance voltage characteristic than the EL element formed on the single crystal Si substrate. As shown in FIG. 4, the twin zone (406) is introduced in the direction transverse to the voltage application direction when the mother crystal (405) has the (100) orientation. As a result, in the present EL element, avalanche breakdown occurs at a higher voltage as compared with the conventional single crystal EL element. That is, when the same voltage as that of the single crystal EL element is applied, the voltage applied to the light emitting layer becomes higher in the case of the present EL element. Therefore, it is presumed that higher saturated brightness can be obtained as shown in the figure.

Example 3 This example describes an EL device in which the driving voltage is lowered. The melt recrystallized film generally has a structure shown in FIG.
There is a sub-grain boundary (subgrain boundary) shown in.
Subgrain boundaries are aggregates of dislocations and have crystal defects such as dangling bonds. Similar defects are formed in the light emitting layer epitaxially grown on the melt recrystallized film. When such a defect is present in the light emitting layer, carriers that contribute to light emission are generated at a lower voltage, and light emission at a lower voltage is possible as compared with the conventional single crystal EL element. FIG. 11 shows the fused recrystallized film (1101) and the single crystal Si substrate (1102).
The results of comparing the luminance-voltage characteristics by forming the same double-insulated structure element in FIG. The element structure formed here is as follows. For the lower insulating layer, C epitaxially grown on Si by the MEB method to a film thickness of 1500 (Å)
An aF ₂ thin film was used. For the light emitting layer, a film thickness of 3000 (Å) and 100 is formed on the CaF ₂ thin film by MO-CVD.
The Si ₂ N ₄ and SiON laminated film formed in (Å) was used. In addition, Au formed on the transparent electrode by a vacuum deposition method
A thin film was used. The element formed on each substrate was driven by a 5 kHz sine wave. From FIG. 11, it was confirmed that the EL element formed on the melt-recrystallized film by the above method has a lower emission start voltage than that of the conventional single crystal element by about 50 (V). The above results indicate that the introduction of sub-grain boundaries into the light emitting layer is effective for lowering the device driving voltage.

Example 4 This example describes an EL element in which an EL element and its driving element are integrated on a single crystal Si thin film formed on a glass substrate by a melt recrystallization method. When forming a display panel using EL elements as light emitting elements, E
The demand for the L element is to reduce the driving voltage, and the demand for the thin film transistor for pixel control is to increase the switching speed. Generally, switching elements include
Amorphous or polycrystalline silicon, which is easy to increase in area, is used. However, these materials have problems of low field effect mobility and low switching speed. On the other hand, the melt-recrystallized film is the most desirable material for the switching element of the display because it has a mobility similar to that of bulk Si and can have a large area. By the way, Example 3 shows that the introduction of sub-grain boundaries into the light emitting layer is effective for a low voltage of the device. However, in an element such as a thin film transistor in which carriers move in a direction parallel to the film surface, this kind of defect sometimes has an adverse effect and causes a defect or variation in device characteristics. Therefore, when forming a high-performance transistor using a melt-recrystallized film, the density of subgrain boundaries in the film must be reduced as much as possible. As described above, when elements having different influences of crystal defects on characteristics are formed on the same substrate, it is possible to cope with the occurrence of crystal defects by controlling them as described below. FIG. 12 is an explanatory diagram (sketch diagram) of an electron micrograph of the surface of the melt recrystallized film in which the position of generation of subgrain boundaries is controlled to a region of a 150 μm cycle. As is clear from FIG. 12, the region (1201) having a large number of sub-grain boundaries is formed in a stripe shape, and the region (1202) between them has almost no sub-grain boundaries. Then, as shown in FIG. 13, the EL device of the present embodiment has a portion (130
An EL element (1304) is formed in 5), and a thin film transistor is formed in a portion (1303) where subgrain boundaries do not exist. This EL element of the present invention is the same as the EL element of Example 3.
As in the L element, the driving voltage of the EL element formed in the sub-grain boundary portion can be lowered, and the field effect mobility of the MOS-TFT (n-ch) formed in the portion where the sub-grain boundary does not exist. (ΜFE) shows 920 (cm ² / V · s), and therefore high mobility can be achieved. As described above, in the EL device of the present embodiment, the light emitting device and the driving device thereof are integrated on the same substrate. In this case, by controlling the generation position of crystal defects (sub-grain boundaries), It is possible to easily form an EL element that can be driven by a voltage and a thin film transistor having a mobility similar to that of bulk Si on the same substrate.

[0024]

【The invention's effect】

(1) Operation and Effect Corresponding to Claim 1 As described in Example 1, the EL device of claim 1 does not have a dead layer, so compared with an EL device composed of a conventional polycrystalline material, The driving voltage can be lowered, and the emission brightness is excellent in sustainability. Also, this E
Since the glass substrate can be used as the support substrate, the L element is also advantageous in increasing the area. (2) Functions and Effects Corresponding to Claim 2 As described in Example 2, the EL element of Claim 2 has a light emitting layer formed of a crystalline material having twin defects. Compared with an EL device composed of a single crystal material, it exhibits enhanced emission brightness. Further, in this EL element, since it is difficult to obtain a highly oriented film and SrS or CaS can be used as the material of the light emitting layer, the degree of freedom in material selection is extremely high. (3) Function and Effect Corresponding to Claim 3 As described in Example 3, in the EL element of Claim 3, since the light emitting layer made of a crystalline material having subgrain boundaries is formed, It is possible to lower the driving voltage compared to an EL element composed of a single crystal material, and the generation density of sub-grain boundaries in the melt recrystallized film is controlled by the melt recrystallization method. Since it is possible, its productivity is also good. (4) Operation and Effect Corresponding to Claim 4 As described in Example 4, in the EL element of claim 4, a low-voltage driven EL element and its driving element capable of high-speed operation are formed on the same support substrate. Therefore, it can be effectively used as a thin film display.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a conventional double-insulation EL device made of a polycrystalline material.

FIG. 2 is a sectional view of a double insulating structure EL element according to the present invention.

FIG. 3 is an explanatory view of an electron micrograph (after etching process for emphasizing defects) of the surface of the melt-recrystallized film. (A) A melt-recrystallized film with sub-grain boundaries formed (b) Twin defects formed Melt recrystallized film

FIG. 4 is a diagram showing a relationship between voltage application directions of directions of twin bands introduced into a light emitting layer.

FIG. 5 is a cross-sectional view of an EL element in Example 1.

FIG. 6 is an explanatory diagram of X-ray diffraction results of a melt recrystallized film.

FIG. 7 is a schematic view of the orientation state of the melt recrystallized film.

FIG. 8 is a diagram showing the relationship between the light emission luminance and the voltage characteristic of the EL element according to Example 1.

FIG. 9 is a sectional view of an EL element disconnection according to Example 2.

FIG. 10 is a relationship diagram between the light emission luminance and the voltage characteristic of the EL element according to the second embodiment.

FIG. 11 is a sectional view of an EL device according to a third embodiment.

FIG. 12 is an explanatory view of an electron micrograph (after etching treatment for emphasizing defects) of the surface of the melt-recrystallized film in which the generation position of subgrain boundaries is controlled.

FIG. 13 is a schematic view of a method of manufacturing a drive element integrated EL element.

[Explanation of symbols]

101 Supporting Substrate 102 Lower Electrode 103 Lower Insulating Layer 104 Light Emitting Layer 105 Upper Insulating Layer 106 Upper Transparent Electrode 201 Supporting Substrate 202 Melt Recrystallization Film Layer 203 Single Crystal Insulating Layer (Lower Insulating Layer) 204 Single Crystal Emitting Layer 205 Upper Insulating Layer 206 Upper Transparent Electrode 301 Subgrain Boundary 302 Twin Defect 401 Supporting Substrate 402 Melt Recrystallized Film 403 Lower Insulating Layer 404 Light Emitting Layer 405 Parent Crystal 406 Twin Band 407 Voltage Application Direction 408 Crystal Axis Direction 501 Glass Substrate 502 Si Thin Film 503 CaF ₂ thin film 504 ZnS: Mn thin film 505 Si ₃ N ₄ thin film 506 ITO thin film 601 (111) Diffraction peak from orientation part 602 (100) Diffraction peak from orientation part 701 Glass substrate 702 Melt recrystallized film 703 (100) ) Oriented portion 704 (111) Oriented portion 8 EL element 802 conventional polycrystalline EL element 901 glass substrate 902 Si thin film 903 SrF ₂ film 904 according to one embodiment SrS: Ce film 905 Si ₃ N ₄ film 906 EL element 1002 conventional single according to the ITO thin film 1001 Example 2 Crystal EL element 1101 EL element according to Example 3 1102 Conventional single crystal EL element 1201 High density generation portion 1202 Low density generation portion 1301 Support substrate 1302 Melt recrystallized film 1303 Driving element formation region 1304 EL element 1305 Sub grain boundary height Density generation area

Claims (4)

[Claims] 1. A thin film layer that also serves as a lower electrode and a crystallinity control layer of a light emitting layer is formed on a supporting substrate, and a lower insulating layer is formed in contact with the thin film layer, and a lower insulating layer and an upper insulating layer are formed. In a thin film electroluminescent device in which a light emitting layer is formed with a structure sandwiched between, and an upper electrode is formed on an upper insulating layer, the thin film layer that also controls the crystallinity of the lower electrode and the light emitting layer is parallel to the substrate. A thin film electroluminescent element, which is a silicon thin film formed by a melt recrystallization method in which at least two kinds of crystal orientation planes of the above exist. 2. The thin film layer which also controls the crystallinity of the lower electrode and the light emitting layer is a silicon thin film formed by a melt recrystallization method in which a plurality of crystal orientation planes having a twin relationship exist. The thin film electroluminescent element according to claim 1. 3. A thin film layer which also serves as a lower electrode and a crystallinity control layer of the light emitting layer is formed on a supporting substrate, and a lower insulating layer is formed in contact with this thin film layer, and a lower insulating layer and an upper insulating layer are formed. In a thin film electroluminescent device in which a light emitting layer is formed with a structure sandwiched between the upper electrode and an upper electrode on an upper insulating layer, the thin film layer that also serves as the crystallinity of the lower electrode and the light emitting layer has a grain boundary. A thin film electroluminescent device, which is a silicon thin film formed by a melt recrystallization method having one crystal orientation. 4. A silicon thin film layer, which also serves as a control of crystallinity of a lower electrode and a light emitting layer, has a generation density of grain boundaries which periodically changes in a substrate surface, and a driving element formed of a silicon thin film transistor in a high density generation portion. The thin film electroluminescent element according to claim 3, wherein the thin film electroluminescent element is formed.