JP2986933B2 - Thin film stacking device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin-film laminated device, and more particularly, to a switching element which can be suitably used for a flat panel display for OA equipment and TV.

[0002]

2. Description of the Related Art In OA equipment terminals and liquid crystal TVs, there is a strong demand for the use of large area liquid crystal panels. Therefore, in the active matrix system, a switch is provided for each pixel to hold a voltage. In recent years, liquid crystal panels have been actively reduced in weight and cost, and the use of plastic for the switching element substrate has been studied. However, when a thin film laminated switching element is formed on plastic, the plastic substrate is deformed or curled, and there is a problem such as film peeling. Also, when fabricating a thin-film laminated switching element, there is a photolithography step of immersing the plastic in a solution of acid, alkali, water, etc.Acid, alkali, water, etc. remain in the plastic, causing the element deterioration. became. When a thin film laminated device is formed into a fine pattern, a pattern shift occurs due to expansion and contraction of a substrate, and it has been difficult to expose a large area at a time.
Further, the anisotropy of the expansion and contraction of the substrate made pattern formation more difficult. In the production of a liquid crystal display device using a plastic film substrate, it is necessary to perform an alignment method specific to plastic at the time of alignment treatment. But SiO ₂
Japanese Patent Publication No. 1-47769 discloses that a layer can be formed on one side of a plastic film so that orientation treatment can be performed in the same manner as a glass substrate. However, when a plastic film is coated with SiO ₂ and a thin-film laminated device is formed thereon, it is often recognized that cracks of SiO ₂ occur in a process involving heat during the production, which impairs the reliability of the thin-film laminated device. It was enough.

[0003]

[Object] The present invention solves the above-mentioned conventional problems, and is lightweight and
It is an object of the present invention to provide a thin film laminated device with low cost, no film peeling, no curl and the like, and excellent reliability.

[0004]

In order to achieve the above object, the present inventors have studied the production of switching elements on lightweight and inexpensive plastics, and as a result of repeated studies, have found that the deformation of the plastic substrate in the element production process has been reduced. It became clear that curling was the biggest problem in the case of plastic films. He also found that the causes of plastic deformation and plastic film curl were internal stress of the laminated thin film, thermal expansion and contraction of the plastic, swelling with acid, alkali, and water. It became clear that it was effective to use plastic substrates formed on both sides, and the present invention was completed. That is, the present invention is characterized in that, in a substrate and a thin film laminated device formed on the substrate, the substrate is a plastic having an amorphous thin film made of an inorganic substance formed on both surfaces thereof.

An amorphous thin film made of an inorganic substance has a wavelength of 400 to 8
The transmittance at 50 nm is preferably 75% or more.
As the inorganic substance, SiO ₂ , Si ₃ N ₄ , Si: N: O, S
It is preferably selected from the group consisting of i: O: H, Si: N: H, Si: O: N: H, and AlN. In addition, as a thin film laminated device, an MIM element using a hard carbon film as an insulating layer can extremely effectively exhibit the features of the present invention. Formation of a thin film of an inorganic substance such as SiO ₂ on a plastic substrate is important for solving problems such as peeling of a thin film laminated device to be formed thereon. If the thin film is formed only on one side of the plastic substrate (film), curl occurs according to the internal stress of the inorganic material thin film,
This causes problems such as handling. Further, it has been found that when the inorganic substance thin film is crystalline, moisture and the like existing in the plastic substrate reach below the thin film laminated device through the crystal grain boundaries, resulting in deterioration of the element. In addition, cracks occurred in the inorganic material thin film with the crystal grain boundaries as nuclei in the heating step in the thin film laminated device manufacturing process. Furthermore, it has also been found that when microfabricating a thin-film laminated device, anisotropic expansion and contraction of the substrate is caused based on the thermal expansion anisotropy of the inorganic substance, making it difficult to form a pattern. To avoid these problems, plastic substrate (film)
It is important to form an amorphous thin film made of an inorganic substance on both sides of the substrate. When the thin film laminated device of the present invention is used for a liquid crystal display driving element, in order to secure display contrast,
It is preferable that the transmittance of the inorganic substance is 75% or more at a wavelength of 400 to 850 nm. In order to manufacture the thin film laminated device of the present invention, first, a plastic such as polyethylene terephthalate, polyarylate, polyether sulfone, polycarbonate, polyethylene, polymethyl methacrylate, polyimide, etc., or SiOx (1 ≦ × ≦ 2) on both surfaces of a plastic film. , Si: O: N, Si:
O: H, Si: N: H, Si: O: N: H, SixNy
(y = 1-x), TiO ₂ , ZnS, ZnO, Al ₂ O ₃ , Al
_{N, MgO, GeO, ZrO 2} , Nb 2 O 5, SiC, Ta 2 O 5
Inorganic substances such as sputtering, vapor deposition, plasma CVD
It is formed in a thickness of 300 to 15000 °, preferably 1000 to 10000 ° by a method or the like. In order to make these inorganic substances amorphous, the substrate temperature is preferably 200 ° C. or lower, more preferably 150 ° C. or lower, and the substrate is preferably formed by a sputtering method or a plasma CVD method. The formed thin film does not necessarily need to have the same inorganic substance on both surfaces, and does not need to have the same thickness. Particularly preferred inorganic substances include SiO ₂ , Si ₃ N ₄ , Si: N: O, and Si: having a large passivation effect.
O: H, Si: N: H, Si: O: N: H, AlN and the like. The thickness of the plastic is from 50 μm to 2 mm, preferably 500 μm or less, particularly preferably 300 μm or less. Further, a thin film laminated device is formed on a plastic coated on both sides with an inorganic substance. Examples of the thin film laminated device include a MIM type element having a metal-insulator-metal layer structure, and an MSI element (Metal-type element) described in JP-A-61-275811.
-Semi-Insulator), an SIS element having a semiconductor-insulator-semiconductor layer configuration, and a metal-insulator-metal-insulator-metal MIMIM element described in JP-A-64-7577.
Among them, an MIM element using a hard carbon film as an insulator is advantageous. When a hard carbon film is used for the insulating layer, the plastic substrate (film) curls greatly. Therefore, it is necessary to form an inorganic material film on both surfaces of the substrate to increase the rigidity of the substrate.

Next, a method for manufacturing the device will be described in detail. First, the inorganic material is coated on both sides (2a, 2a).
b) A transparent electrode material for a pixel electrode is deposited on the plastic substrate 1 by vapor deposition, sputtering, or the like, and is patterned into a predetermined pattern to form a pixel electrode 4. Next, a conductor thin film for a lower electrode is formed by a method such as vapor deposition or sputtering, and is patterned into a predetermined pattern by wet or dry etching to form a first conductor 7 serving as a lower electrode, on which a plasma CVD method and an ion beam After the hard carbon film 2 is coated by a method or the like, it is patterned into a predetermined pattern by dry etching, wet etching or a lift-off method using a resist to form an insulating film, and then a conductor for bus lines is formed thereon by a method such as vapor deposition or sputtering. The thin film is covered and patterned into a predetermined pattern to form a second conductor 6 serving as a bus line. Finally, an unnecessary portion of the lower electrode is removed to expose a transparent electrode pattern,
The pixel electrode 4 is used. In this case, the configuration of the MIM element is not limited to this. After the MIM element is manufactured, a transparent electrode is provided on the uppermost layer, a transparent electrode also serves as an upper or lower electrode, a side surface of the lower electrode. Various modifications are possible, such as the one in which a MIM element is formed. Here, the thicknesses of the lower electrode, the upper electrode, and the transparent electrode are generally in the range of several hundreds to several thousand, several hundreds to several thousand, and several hundreds to several thousand, respectively. The thickness of the hard carbon film is 100 ~ 8000Å, preferably 200 ~ 6000
Å, more preferably in the range of 300-4000Å. In the case of a plastic substrate, it has been extremely difficult to fabricate an active matrix device using an active element because of its heat resistance. However, a hard carbon film can be produced at a substrate temperature of about room temperature, and a high quality film can be produced on a plastic substrate, which is a very effective means for improving image quality.

Next, the material of the MIM element used in the present invention will be described in more detail. As the material of the first conductor 7 serving as the lower electrode, Al, Ta, Cr, W, Mo, Pt, N
i, Ti, Cu, Au, ITO, ZnO: Al, In ₂ O ₃ , S
Various conductors such as nO ₂ are used. Next, as a material of the second conductor 6 to be a bus line, Al, Cr, Ni, Mo,
Pt, Ag, Ti, Cu, Au, W, Ta, ITO, ZnO:
Although various conductors such as Al, In ₂ O ₃ , and SnO ₂ are used, Ni, Pt, and Ag are preferable because the stability and reliability of the IV characteristics are particularly excellent. It can be seen from the MIM element using the hard carbon film 2 as the insulating film that the symmetry does not change even if the type of the electrode is changed, and that it has a Pool-Frenkel conduction from the relationship of lnI∝√v. Also from this, this kind of M
In the case of the IM device, it can be understood that any combination of the upper electrode and the lower electrode may be used. However, the device characteristics (IV characteristics) are degraded and changed due to the adhesion between the hard carbon film and the electrode and the state of the interface. Considering these, Ni, P
It turned out that t and Ag were good. The current-voltage characteristics of the MIM element of the present invention are shown in FIG. 4, and are approximately represented by the following conduction equations.

[0008]

(Equation 1)

I: current V: applied voltage κ: conductivity coefficient β: pool Frenkel coefficient n: carrier density μ: carrier mobility q: electron charge Φ: trap depth ρ: specific resistance d: film thickness of hard carbon ( Å) k: Boltzmann constant T: ambient temperature ε ₁ : dielectric constant of hard carbon ε ₂ : vacuum dielectric constant

Next, a method for manufacturing a liquid crystal display device will be described with reference to FIG. First, on the insulating substrate 1 ', a transparent conductor for the common electrode 4', for example, ITO, ZnO: Al, ZnO: Si, Sn
The O _2, In ₂ O ₃ such as sputtering, is several μm deposited from several hundred Å by vapor deposition or the like, and patterned into a stripe shape and the common electrode 4 '. Substrate 1 'provided with this common electrode 4'
An alignment material 8 such as polyimide is attached to each surface of the substrate 1 on which the MIM elements are provided in a matrix form, a rubbing process is performed, a sealing material is attached, and a gap material 9 is inserted to make the gap constant. 3 to form a liquid crystal display device. Thus, a liquid crystal display device is obtained.

The hard carbon film used for the MIM element of the device of the present invention will be described in detail. An organic compound gas, especially a hydrocarbon gas, is used to form a hard carbon film. The phase state of these raw materials does not necessarily need to be a gaseous phase at normal temperature and normal pressure, but may be used in a liquid phase or a solid phase as long as it can be vaporized through melting, evaporation, sublimation, etc. by heating or decompression. is there. As for the hydrocarbon gas as the raw material gas, for example, CH ₄ , C ₂ H ₆ , C ₃ H ₈ , C ₄
Paraffinic hydrocarbons H _10, etc., olefinic hydrocarbons such as C ₂ H _4, diolefinic hydrocarbons, even at least comprises a gas hydrocarbons Te to base and aromatic hydrocarbons can be used. Further, other than hydrocarbons, for example, alcohols, ketones, ethers, esters, C
Any compound containing at least a carbon element such as O and CO ₂ can be used. As a method for forming a hard carbon film from a source gas in the present invention, a method in which a film forming active species is formed through a plasma state generated by a plasma method using a direct current, a low frequency, a high frequency, or a microwave or the like However, a method utilizing a magnetic field effect is more preferable because deposition is performed under a low pressure for the purpose of increasing the area, improving uniformity, and forming a film at a low temperature. Active species can also be formed by thermal decomposition at high temperatures. In addition, ionization evaporation,
Alternatively, it may be formed through an ion state generated by an ion beam evaporation method or the like, may be formed from neutral particles generated by a vacuum evaporation method, a sputtering method, or the like, and further, a combination thereof. May be formed.

Deposition conditions for the hard carbon film thus produced
Is as follows in the case of the plasma CVD method. RF output: 0.1-50W / cm^Two  Pressure: 1/10^Three~ 10 Torr Deposition temperature: room temperature ~ 350 ° C Due to this plasma state, the source gas becomes radicals and ions.
Is decomposed into and reacts to form carbon atoms C on the substrate
(Amorphous) and fine particles comprising
At least one crystalline material (crystal size is several tens to several micrometers)
A hard carbon film including both sides is deposited. In addition, various types of hard carbon
Table 1 shows the characteristics.

[0013]

[Table 1]

Note) Measuring method; Specific resistance (ρ): Determined from the IV characteristics of a coplanar cell. Optical band gap (Egopt): The absorption coefficient (α) is determined from the spectral characteristics, and is determined from the relationship of Equation (2).

[0015]

(Equation 2) Hydrogen content in film [C (H)]: 2900 from infrared absorption spectrum
/ Cm is integrated and the absorption cross section A is multiplied. That is, [C (H)] = A∫Δα (v) / v ・ dv SP ³ / SP ² ratio: The infrared absorption spectrum is decomposed into Gaussian functions assigned to SP ³ and SP ² respectively. Determined from the area ratio. Pecker hardness (H): Measured by Micro Vickers meter. Refractive index (n): Based on ellipsometer. Defect density: by ESR.

The hard carbon film thus formed was analyzed by Raman spectroscopy and IR absorption. As a result, as shown in FIGS. 6 and 7, the carbon atom has a hybrid orbital of SP ^{3 and} a hybrid orbital of SP ² , respectively. It is clear that the formed interatomic bonds are mixed. The ratio of SP ³ bonds to SP ² bonds is
It can be roughly estimated by separating the IR spectrum into peaks. In the IR spectrum, spectra of many modes are overlapped and measured at 2800 to 3150 / cm. The assignment of peaks corresponding to each wave number is clear, and peak separation is performed by Gaussian distribution as shown in FIG. By calculating the respective peak areas and calculating their ratios, SP ³ / SP ² can be known. According to X-ray and electron diffraction analysis, the amorphous state (a-C: H) and / or about 50 °
It is known that it is in an amorphous state containing fine crystal grains of about several μm. Plasma C generally suitable for mass production
In the case of the VD method, the lower the RF output, the higher the specific resistance and hardness of the film, and the lower the pressure, the longer the lifetime of the active species. Therefore, the substrate temperature can be lowered and the large area can be made uniform. And the specific resistance and hardness tend to increase. Furthermore, since the plasma density decreases at low pressure, the method utilizing the magnetic field confinement effect is particularly effective for increasing the specific resistance. Further, this method has a feature that a high-quality hard carbon film can be similarly formed even at a relatively low temperature condition of about room temperature to about 150 ° C., and is therefore most suitable for lowering the temperature of the MIM element manufacturing process. Therefore, there is a feature that a degree of freedom in selecting a substrate material to be used is widened and a uniform film can be obtained over a large area because the substrate temperature can be easily controlled.
Further, as shown in Table 1, the structure and physical properties of the hard carbon film can be controlled in a wide range, and therefore, there is an advantage that device characteristics can be freely designed. Further, the dielectric constant of the film is 2 to 6, which is Ta ₂ O ₅ , Al ₂ O ₃ , S used in the conventional MIM element.
Since it is smaller than iNx, when an element having the same capacitance is manufactured, the element size can be large, so that fine processing is not so required, and the yield is improved. Capacity ratio is C (LCD)
/ C (MIM) = approximately 10: 1). Further, since the element steepness β∝1 / ∝ε · √d, if the relative permittivity ε is small, the steepness increases, and the ratio between the on-current Ion and the off-current Ioff can be increased. For this reason, the LCD can be driven at a lower duty ratio, and a high-density LCD can be realized. Further, since the hardness of the film is high, the damage due to the rubbing step at the time of enclosing the liquid crystal material is small, and the yield is also improved from this point. Considering the above points, by using a hard carbon film, low cost, gradation (colorization),
A high-density LCD can be realized. Further, this hard carbon film is composed of a group III element, a group IV element, a group V element, an alkali metal element, an alkaline earth metal element, a nitrogen atom, an oxygen element, in addition to carbon atoms and hydrogen atoms. , A chalcogen element or a halogen atom as a constituent element. As one of the constituent elements, those in which Group III element of the periodic table, Group V element, alkali metal element, alkaline earth metal element, nitrogen atom or oxygen atom are introduced are those in which the thickness of the hard carbon film is non-doped The thickness can be increased by about 2 to 3 times as compared with the above, and thereby, the generation of pinholes at the time of manufacturing the device can be prevented, and the mechanical strength of the device can be remarkably improved. Further, in the case of a nitrogen atom or an oxygen atom, the same effect as in the case of a group IV element of the periodic table as described below is obtained. In the same way, the elements incorporating a Group IV element of the periodic table, a chalcogen-based element or a halogen element significantly improve the stability of the hard carbon film and also improve the hardness of the film. Can be produced. These effects are obtained because the group IV element and the chalcogen element reduce the active double bond existing in the hard carbon film, and in the case of the halogen element, 1) abstraction with respect to hydrogen. The reaction promotes the decomposition of the source gas to reduce dangling bonds in the film, and 2) during the film formation process, the halogen element X extracts hydrogen in the CH bond and replaces it.
This is because they enter the film as CX bonds, and the bond energy increases (the bond energy between CH and CX is larger between CX). In order to make these elements the constituent elements of the film, in addition to hydrocarbon gas and hydrogen as the raw material gas, a group III element, a group IV element and a group V element of the periodic table in the film as a dopant are contained in the film. In order to contain an element, an alkali metal element, an alkaline earth metal element, a nitrogen atom, an oxygen atom, a chalcogen element or a halogen element, a compound (or molecule) containing these elements or atoms (hereinafter referred to as `` other Compound (which may be referred to as “compound”). Here, as the compound containing a Group III element of the periodic table, for example, B (OC ₂ H ₅ ) ₃ , B ₂ H ₆ , BCl ₃ , BB
_{r 3, BF 3, Al (} O-i-C 3 H 7) 3, (CH 3) 3 Al, (C
_{2 H 5) 3 Al, (} i-C 4 H 9) 3 Al, AlCl 3, Ga (O-i-C 3 H
₇ ) ₃ , (CH ₃ ) ₃ Ga, (C ₂ H ₅ ) ₃ Ga, GaCl ₃ , GaBr ₃ ,
_{(O-i-C 3 H} 7) 3 In, there is a (C ₂ H _{5) 3} In like. Examples of the compound containing a Group IV element of the periodic table include Si ₂ H ₆ , (C
₂ H ₅ ) ₃ SiH, SiF ₄ , SiH ₂ Cl ₂ , SiCl ₄ , Si (OC
_{H 3) 4, Si (OC} 2 H 5) 4, Si (OC 3 H 7) 4, GeCl 4, G
eH ₄ , Ge (OC ₂ H ₅ ) ₄ , Ge (C ₂ H ₅ ) ₄ , (CH ₃ ) ₄ Sn, (C
₂ H ₅ ) ₄ Sn, SnCl _{4 and the} like. Examples of the compound containing a Group V element of the periodic table include PH ₃ , PF ₃ , PF ₅ , and PCl ₂
F ₃ , PCl ₃ , PCl ₂ F, PBr ₃ , PO (OCH ₃ ) ₃ , P
(C ₂ H ₅ ) ₃ , POCl ₃ , AsH ₃ , AsCl ₃ , AsBr ₃ , As
F ₃ , AsF ₅ , AsCl ₃ , SbH ₃ , SbF ₃ , SbCl ₃ , Sb
(OC ₂ H ₅ ) _{3 and the} like. As the compound containing an alkali metal atom, for example _{LiO-i-C 3 H 7} , NaO-i-C 3 H 7, K
O-i-C ₃ H _{7 and the} like. Examples of the compound containing an alkaline earth metal atom include Ca (OC ₂ H ₅ ) ₃ and Mg (OC
₂ H _{5) 2,} there are (C ₂ H _{5) 2} Mg, or the like. Examples of the compound containing a nitrogen atom include nitrogen gas, inorganic compounds such as ammonia, organic compounds having a functional group such as an amino group and a cyano group, and heterocycles containing nitrogen. Examples of the compound containing an oxygen atom include oxygen gas, ozone, water (steam), hydrogen peroxide, carbon monoxide, carbon dioxide, carbon suboxide, nitric oxide, nitrogen dioxide, nitrous oxide, and nitrous oxide. , Inorganic compounds such as nitric oxide, hydroxyl group, aldehyde group, acyl group, ketone group, nitro group, nitroso group, sulfone group,
Organic compounds having a functional group or a bond such as an ether bond, an ester bond, a peptide bond, and a heterocyclic ring containing oxygen, and a metal alkoxide may be used. As the compound containing a chalcogen element, for example, H ₂ S, (CH ₃ ) (C
H ₂ ) ₄ S (CH ₂ ) ₄ CH ₃ , CH ₂ ＣＨCHCH ₂ SCH ₂ CH
_{= CH 2, C 2 H 5} SC 2 H 5, C 2 H 5 SCH 3, thiophene, H ₂ Se, there are _{(C 2 H 5) 2 Se} , H 2 Te , and the like. Compounds containing a halogen element include, for example, fluorine, chlorine, bromine, iodine, hydrogen fluoride, carbon fluoride, chlorine fluoride, bromine fluoride,
Iodine fluoride, hydrogen chloride, bromine chloride, iodine chloride, hydrogen bromide,
Inorganic compounds such as iodine bromide and hydrogen iodide, and organic compounds such as alkyl halide, aryl halide, styrene halide, polymethylene halide and haloform are used. A hard carbon film suitable as a liquid crystal driving MIM element is:
Depending on the driving conditions, the film thickness is 100 to 8000 mm and the specific resistance is 10 ⁶ to 10 ¹³ Ω
Advantageously in the range of cm. Considering the margin between the driving voltage and the withstand voltage (dielectric breakdown voltage), the film thickness is
The thickness is desirably 200 mm or more, and the film thickness is 6000 mm in order to prevent color unevenness caused by a step (cell gap difference) between the pixel portion and the thin film two-terminal device portion from becoming a practical problem.
It is more preferable that the thickness is 200 to 6000 ° and the specific resistance is 5 × 10 ⁶ to 10 ¹³ Ω · cm. The number of element defects due to pinholes in the hard carbon film increases with decreasing film thickness, and becomes particularly significant below 300 mm (defect rate exceeds 1%), and the uniformity of the in-plane distribution of film thickness. (Thus, the accuracy of film thickness control is limited to about 30 mm, and the variation in film thickness exceeds 10%), so it is more preferable that the film thickness is 300 mm or more. . Further, in order to make it difficult for the hard carbon film to peel off due to stress and to drive at a lower duty ratio (preferably 1/1000 or less), the film thickness is more preferably 4000 ° or less. In consideration of these factors, it is more preferable that the hard carbon film has a thickness of 300 to 4000 ° and a specific resistivity of 10 ⁷ to 10 ¹¹ Ω · cm.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described.
It is not limited to them. Example 1 As shown in FIG. 1, a 100 μm thick polyarylate film
6000 on both sides by sputtering at a substrate temperature of 50 ° C
ＳｉＯ thick SiO_TwoLayers (2a, 2b) were prepared. X-ray
SiO by diffraction_TwoThe film was found to be amorphous.
In addition, it shows a transmittance of 80% or more at a wavelength of 400 to 850 nm.
Was. Next, SiO_TwoITO on top by sputtering method
After depositing to a thickness of about 1000 mm, it is patterned to form pixel electrodes.
Was. Next, a MIM element was provided as follows. First,
Al is deposited to a thickness of about 1000mm by vapor deposition and patterned.
A lower electrode 7 is formed, and a hard electrode is formed thereon as an insulating layer 2.
A carbon film is deposited to a thickness of about 1000 mm by plasma CVD.
After that, patterning was performed by dry etching. this
The conditions for forming the hard carbon film at this time are as follows. Pressure: 0.035 Torr CH_Four Flow rate: 10 SCCM RF power: 0.2W / cm^Two  Further, Ni is deposited on this to a thickness of about 1000 mm by EB evaporation.
After stacking, patterning was performed to form the upper electrode 6.

Example 2 As shown in FIG. 1, a polyether sulfone having a thickness of 250 μm was used.
Film sputtering on both sides at 30 ° C substrate temperature
5000mm thick Si_ThreeN_FourLayers 2a and 2b were produced. X-ray
Si by diffraction_ThreeN_FourThe layer turns out to be amorphous
Was. In addition, at a wavelength of 400 to 850 nm, the transmittance is 80% or more.
Indicated. Next, Si_ThreeN_FourITO on top by sputtering
After deposition to a thickness of about 1000 mm, pattern and form pixel electrodes
Done. Next, a MIM element was provided as follows. Ma
Al is deposited to a thickness of about 1000mm by vapor deposition and patterned.
To form a lower electrode 7, on which an insulating layer 2 is formed.
Hard carbon film deposited about 1000mm thick by plasma CVD
After that, patterning was performed by dry etching.
The conditions for forming the hard carbon film at this time are as follows. Pressure: 0.035 Torr CH_Four Flow rate: 10 SCCM RF power: 0.2W / cm^Two  Further, Ni is deposited on this to a thickness of about 1000 mm by EB evaporation.
After stacking, patterning was performed to form the upper electrode 6. Example 1,
The MIM type element shown in FIG.
No curls or cracks of inorganic substances were observed. Ma
No deterioration was observed even when stored at 80 ° C for 1000 hours.
Was.

[0019]

As described above, the present invention is configured as described above. Therefore, the thin film laminated device of the present invention can achieve low cost and light weight without deformation and curling of the substrate. MIM using hard carbon film for insulating layer
In the case of a mold element, a hard carbon film is manufactured by 1) a gas phase synthesis method such as a plasma CVD method, so that physical properties can be controlled widely by film forming conditions, and therefore, a degree of freedom in device design is large. Because it is hard and can be made thick, it is hard to be damaged by mechanical damage, and it can be expected that pinholes are reduced by thickening.3) A good film can be formed even at low temperature around room temperature, so there are restrictions on the substrate material. No, 4) It is suitable for thin film devices because of its excellent uniformity of film thickness and film quality.5) It has a low dielectric constant, so it does not require advanced microfabrication technology, and therefore can be used for large-area devices. The liquid crystal is particularly advantageous because it has the advantage that the dielectric constant is low, the steepness of the element is high, and the Ion / Ioff ratio can be taken, so that it can be driven at a low duty ratio. Suitable as a display switching element , It is extremely useful on the industry.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a structure of a thin film device of the present invention.

FIG. 2 shows an MIM constituted by the thin film device of the present invention.
FIG. 4 is an explanatory diagram of a main part of an element.

FIG. 3 is a partial sectional perspective view of a liquid crystal display device incorporating the thin film device of the present invention.

FIGS. 4A and 4B are graphs respectively showing an IV characteristic curve and an lnI-√v characteristic curve of the MIM element.

FIG. 5 shows a Gaussian distribution of an IR spectrum of a hard carbon film used for an insulating layer of the MIM element of the present invention.

FIG. 6 is a spectrum diagram showing an analysis result obtained by analyzing a hard carbon film used as an insulating layer of the MIM element of the present invention by a Raman spectrum method.

FIG. 7 is a spectrum diagram showing an analysis result obtained by analyzing a hard carbon film used as an insulating layer of the MIM element of the present invention by an IR absorption method.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 plastic substrate 1 ′ plastic substrate 2 hard carbon film 2 a inorganic material layer 2 b inorganic material layer 3 liquid crystal 4 pixel electrode 4 ′ common electrode 5 active element (MIM element) 6 second conductor (bus line) (upper electrode) 7 first Conductor (lower electrode) 8 Alignment film 9 Gap material

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yuji Kimura 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Masayoshi Takahashi 1-3-6 Nakamagome, Ota-ku, Tokyo Ricoh Co., Ltd. (72) Inventor Kenji Kameyama 1-3-6 Nakamagome, Ota-ku, Tokyo Co., Ltd. (72) Inventor Makoto Tanabe 1-3-6 Nakamagome, Ota-ku, Tokyo Co., Ltd. Ricoh Company (58) Field surveyed (Int.Cl. ⁶ , DB name) H01L 49/02 G02F 1/133 H01L 29/786

Claims (3)

(57) [Claims] 1. A thin film laminated device wherein a thin film composed of an inorganic substance is amorphous in a plastic substrate formed on both sides with a thin film composed of an inorganic substance and a thin film laminated device formed on the substrate. 2. The method according to claim 1, wherein the thin film made of the inorganic substance has a wavelength of 400-8.
2. The thin-film laminated device according to claim 1, wherein the transmittance at 50 nm is 75% or more. 3. The thin-film laminated device according to claim 1, wherein the thin-film laminated device is a MIM type element using a hard carbon film as an insulating layer.