JPH0354527A - Mim element and liquid crystal display device using the same - Google Patents

Abstract

PURPOSE:To form an insulating film at relatively low temperature in a simple process and to design a device over a wide range by using a hard carbon film for the insulating film. CONSTITUTION:On an insulating substrate 1 where transparent picture element electrodes 2' are formed, a metallic thin film for a lower electrode is formed and patterned as specified to form the lower electrode 2, which is coated with a hard carbon film to form the insulating film by specific patterning. A metallic thin film for an upper electrode is formed thereupon by coating and patterned as specified to form the upper electrode 4 and an unnecessary part of the lower electrode 2 is removed to expose a transparent picture element electrode 2' as a picture element electrode. The hard carbon film used as the insulating film of this liquid crystal driving MIM (Metal-Insulator-Metal) element has 100-8000Angstrom film thickness and 10<6>-10<13> OMEGA.cm resistivity.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a metal-insulator-metal (M
etal-Insulator-Metal
, hereinafter sometimes abbreviated as rMIMJ) structure, and a liquid crystal display device using this MIM element as a switching element. [Prior art] MIM! Conventionally, a metal electrode such as Ta, Afl, Ti, etc. is provided as a lower electrode on an insulating substrate such as a glass plate, and an oxide of the metal or SinX is placed on top of the electrode.
, SiNz, etc. is provided, and a metal electrode such as Afl, Cr, etc. is provided thereon as an upper electrode. However, MIM elements using metal oxides as insulation films (Japanese Patent Laid-open Nos. 57-196589, 61-232689,
62-62333), the insulating film is formed by anodic oxidation or thermal oxidation of the lower metal electrode, so the process is complicated and requires high-temperature heat treatment (It! electrode). Even with the oxidation method, high-temperature heat treatment is required to ensure removal of impurities, etc.), film controllability (uniformity and reproducibility of film quality and film thickness) is poor, and the substrate is limited to heat-resistant materials. Also, because the insulating film is made of metal oxides with fixed physical properties, the device material and device characteristics cannot be changed freely, and the degree of freedom in design is limited. This means that it is impossible to design and manufacture devices incorporating MIM elements, such as liquid crystal display devices, that fully meet the specifications.
In addition, if film controllability is poor in this way, the current (I) and voltage (v) characteristics as element characteristics, especially the symmetry of the I-■ characteristics and I-■ characteristics (the current at positive bias and negative bias There is also the problem that the variation in the ratio I-/I+ increases. In addition, MIM elements are used in liquid crystal display devices @ (L
When used for CDs, the liquid crystal capacitance/MIM capacitance ratio is generally required to be 1O or more, so it is desirable that the MIM capacitance is smaller, but in the case of metal oxide films, since the dielectric constant is large, The element capacitance also increases, which requires microfabrication to reduce the element capacitance and therefore the element area. In this case, there is also the problem that the insulating film is mechanically damaged during the rubbing process when filling the liquid crystal material, which, combined with microfabrication, causes a decrease in yield. On the other hand, in the case of MIM cables using SiOz or SiNz for the insulating film (Japanese Unexamined Patent Publication No. 61-275819), the insulating film is formed by a gas phase method such as plasma CVD or sputtering; Normally, a temperature of about 300°C is required. Low-cost substrates cannot be used, and when increasing the area, film thickness and film quality tend to become non-uniform due to substrate temperature distribution. Furthermore, since these insulating films are synthesized in a gas phase, a lot of dust is generated and the film has many pinholes, which reduces the yield of devices. Furthermore, the film stress is large and film peeling occurs, which also reduces device yield. The present inventors previously proposed an MIM device using a hard carbon film (i-type carbon film) as an insulating film, but the thickness of the insulating film was as thin as 20-100λ. In the case of this insulating film (i-C film), the conduction mechanism is tunnel conduction, and it is rather suitable for applications as ultra-thin film devices such as high-speed switches and tunnel light emission. However, when applied to liquid crystal display devices, etc., a thicker film is preferable in terms of breakdown voltage, yield (defect rate), uniformity of device characteristics, and threshold voltage. [Problems to be Solved by the Invention] The present invention solves the defects and problems described above, and its first purpose is to form a film that can be formed at a relatively low temperature and in a simple process. Moreover, by using a low dielectric constant insulating film (hard carbon film) with excellent film controllability and mechanical strength, it is possible to design a wide range of devices, there is little variation in device characteristics, and the threshold voltage is low. This provides an MIM device with excellent voltage resistance and high yield. A second object of the present invention is to provide a liquid crystal display device using such an MIM element as a switching element. [Means for Solving the Problems] An MIM device according to one aspect of the present invention includes a lower electrode, an antiseptic film, and an upper electrode provided on an insulating substrate.
The insulating film is characterized by being made of a hard carbon film with a thickness of 100 to 8,000 people. Another aspect of the present invention is an active matrix liquid crystal display device, which is characterized by using the MIM element according to the present invention as a switching element. In short, the present invention is characterized by an insulating film in an MIM element, and this insulating film has at least one of non-quality and microcrystalline materials with carbon atoms and hydrogen atoms as the main structure-forming elements. hard carbon film (i-C film,
Diamond-like carbon film, amorphous diamond film,
(also called a diamond thin film). One of the features of hard carbon film is that it is a vapor phase or long film.
As will be discussed later, its physical properties can be controlled over a wide range by changing the film forming conditions. Therefore, even though it is called an insulating film, its resistance value covers the region from the semi-M edge to the insulator region, and in this sense, the MIM element of the present invention is
The MSI element (Metal--Se-Peng-I-Insulat) described in Publication No. 75819
or), and SIS elements (an element consisting of a semiconductor, an insulator, and a semiconductor, where the semiconductor is doped with impurities at a high concentration). The current-voltage characteristics of the MIM element of the present invention are expressed as shown in the diagram, and approximately expressed by the conduction equation shown below. ■=κexp(βy1/-)...
(1) Current V: Applied voltage κ: Conductivity coefficient β: Poole-Frenkel coefficient n: Carrier density μ: Carrier mobility q: Electron charge Φ: Trap depth ρ: Specific resistance d: Thickness of hard carbon film Sak: Boltzmann constant T: Ambient temperature ε1:
Liquid crystal display device using dielectric constant MIM element of hard carbon film ['
The equivalent circuit of one pixel (LCD) is shown in Figure 2. Moreover, FIG. 3 schematically shows the drive voltage waveform in the LCD, and (8) is the voltage waveform applied to the selected pixel;
(b) represents the voltage vLc across the liquid crystal. The necessary conditions for a liquid crystal display device to be activated are ■ Operating voltage (Vo
n) is within an appropriate range. The lower limit is approximately 1.5V above the threshold voltage of the liquid crystal, and the upper limit is approximately 25V below the withstand voltage of the circuit system. That is, 1.5V<Von<25V (4).

■Be able to write sufficiently within the selected time. For this purpose, it is necessary to make the time Ton required for writing (charging time) shorter than the selection pulse width T. CLC: Liquid crystal capacity. R
on: ON resistance of MIM element Ion: ON of MIM element
Current Von: Since it is the ON voltage of the MIM element, now CLC=1.6×10−”F(i
Assuming that rJ is 3.5, pixel size is 300 x 300 μL, and cell gap is 7.5 μL, Equation (5) is obtained.

Ion>Von-N XIO-” (A) - (5)
■The write state is maintained for one frame time. Therefore, it is necessary to make the holding time (discharge time) Toff longer than the frame period Tf. Roff: Ioff: Voff: Since Toff=1.6X10-' (sec), the OFF resistance of the MIM element The OFF current of the MIM element The OFF voltage of the MIM element, that is, Ioff<VoffX10-'' (A) - (6
) (CLc=1.6X10-"F) The current-voltage characteristics of the MIM element can be changed arbitrarily by changing the β and κΦ values, but as schematically shown in Figure 4, the current-voltage characteristics of the MIM element When (Von) is maximum (■), the slope (β) of the lnl −(;r line is minimum and the intercept (κ) is maximum. At this time, from equations (2) and (3), The film thickness (d) is the maximum and the specific resistance (ρ) is the minimum.Similarly, V
When on is minimum (■) β is maximum and κ is minimum, that is, film thickness (d) is minimum and resistivity (ρ) is maximum.

As can be seen from the equivalent circuit in Figure 2. When Von is applied, the voltage V applied to the MIM element by capacitance division is expressed as.

Here, in order for most of the voltage to be applied to the MIM element, it is necessary that Cx+x<CLc, and as mentioned earlier, it is usually designed so that CMIN/CLc=1/10 or less. As will be explained later, the hard carbon film has a relatively low dielectric constant of about 3 to 5, so the above constraints can be met without reducing the element area that much.However, from the perspective of panel aperture ratio, the pixel size 300μm
The element size is lOμa+X10 for X 300μa
It is desirable that the thickness be on the order of μm.

Therefore, the element size was set to 10μ×10μ, N=400.
(1/400 duty), find the maximum value of d and the minimum value of ρ (corresponding to the case shown in Figure 4 (■)). If we fix the value of ρ. By giving the value of Von, the limit value of Ion that satisfies Equation (5) can be found, and Equation (1)
By using (2) and (3), the value of d at that time can be found. The relationship between film thickness (d), collective voltage (Van), and dielectric breakdown voltage (vb) when ρ=to'Ω・C is shown in Figure 5. It is desirable that there is a sufficient margin between Von and vb.

Also, since Von<25V, d<8000. Note that when ρ<106Ω·cIl, the current value of the non-lit pixel increases, causing problems such as crosstalk, which is undesirable. Next, find the minimum value of d and the maximum value of ρ (corresponding to the case ◯ in Figure 4). Similarly to the above case, the relationship between d, Von, and Vd when ρ=io13Ω·CIll is shown as ■ in FIG. From Figure 5, when d<100 people, Van<1.5■
Therefore, it is difficult to control the liquid crystal display, and there is no difference between Von and VB, making it virtually impossible to perform dragon motion. Therefore, there arises a need for d) 100 pieces.

As shown in Figure 6, the dielectric strength increases as the resistivity ρ increases, but the rate of increase in the dynamic voltage exceeds this (this tendency is shown in ■ in Figure 5). , ρ
> When io”Ω・cl (at all film thicknesses) Vo
The difference between n and vb disappears, and it becomes virtually impossible to move. From the above study results, the hard carbon film used as the M edge film of MIM elements for liquid crystal disposal has a film thickness of 100 to 8000.
It is desirable that the resistivity is in the range of 10'' to 101:1Ω'cm.In addition, considering the margin between dynamic voltage and withstand voltage (breakdown voltage), the thickness of the hard carbon film is 200λ. It is desirable that the film thickness is 6,000 or more, and in order to prevent color unevenness caused by the step difference (cell gap difference) between the pixel part and the MIM element part from becoming a practical problem, it is desirable that the film thickness be 6,000 or less. Therefore, the thickness of the hard carbon film is 200 to 60
00λ, and the specific resistance is more preferably 5X10' to 10L2Ω·c.

Furthermore, the number of device defects due to bottle holes in the hard carbon film increases as the film thickness decreases, and becomes especially noticeable when the number of users is less than 300 (defect rate exceeds 1%), and Since uniformity of distribution (and therefore uniformity of device characteristics) cannot be ensured (accuracy of film thickness control is limited to around 30 pcs, and variation in film thickness exceeds 10%), the film thickness is 300 pcs or more. It is more desirable that In addition, in order to prevent the hard carbon film from peeling off due to film stress,
In order to drive at a low upstream duty ratio (preferably 1/1000 or less), it is more desirable that the film thickness be 4000 μm or less. Therefore, the thickness of the hard carbon film is 30
0 to 4000 pieces, specific resistance 10' to 10"Ω"cm
It is more preferable that

Here, the hard carbon film in the present invention will be explained in detail. Is there a way to form a hard carbon film? compound gas,
In particular hydrocarbon gases are used.

The phase state of these raw materials does not necessarily have to be a gas phase at normal temperature and pressure; they can be used in either a liquid or solid phase as long as they can be vaporized through melting, evaporation, sublimation, etc. by heating or reduced pressure. be.

Regarding hydrocarbon gas as a raw material gas, for example, CH
4, CzHa - Paraffinic hydrocarbons such as CJz, CaH*, acetylenic hydrocarbons such as C■H4, olefinic hydrocarbons, acetylenic hydrocarbons, diolefinic hydrocarbons, and even aromatic hydrocarbons. Gases containing at least hydrocarbons can be used. Furthermore, other than hydrocarbons, compounds containing at least the carbon element can be used, such as alcohols, ketones, ethers, esters, co, and co2.

In the method of forming a hard carbon film from a raw material gas in the present invention, a certain film active species is formed through a plasma state generated by a plasma method using direct current, low frequency, high frequency, microwave, etc. However, since deposition is performed under low pressure for the purpose of increasing the area, improving uniformity, and forming a low-temperature I1 film, a method that utilizes a magnetic field effect is even more preferred. However, active species can also be formed by thermal decomposition at high temperatures. In addition, a hard carbon film may be formed through the ionic state generated by ionization vapor deposition, ion beam vapor deposition, etc., or a neutral carbon film formed by vacuum vapor deposition, sputtering, etc. It may be formed from particles, or a film may be formed from a combination of these.

Schematic diagrams of typical film forming methods (high-frequency plasma method, microwave plasma method, ionization deposition method, ion beam deposition method, etc.) are shown in Figures 7 to 11. These Figures 7 (high frequency plasma CVD equipment) and Figure 8 (
Microwave excited plasma CVD system! if). Figure 9 (
In FIG. 10 (ion beam device) and FIG. I1 (dual ion beam device),
101 is an upper electrode, 102 is a lower electrode, 103 is a substrate,
10.4 is a high frequency power supply, 105 is a DC power supply (for applying bias). 106 is a magnetic field coil, 107 is a susceptor, IOS is a waveguide, 109 is a matching box, 110 is a power monitor, 111 is a microwave oscillator, 112 is a flanger, 113 is a crucible, 1l4 is a deposition material, 115 is a raw material (carbon ), 116 is an ionization filament, l17 is a spatter electrode, 118 is an anode, 119 is an extraction electrode, 120 is an ion source chamber. 121a and 12
lb indicates the ion source, and l22 indicates the target. An example of the deposition conditions for the hard carbon film produced in this manner is approximately as follows in the case of plasma CVD method.

RF output 7 0.1 ~ 501/cm'' Pressure:
10-3 to 10 Torr Deposition temperature: room temperature to 950°C (such a wide range can be adopted, but preferably room temperature to 3
00°C, more preferably room temperature to 150°C.
) Due to this plasma state, the raw material gas is decomposed into radicals and ions and reacts, resulting in amorphous (non-quality) and microcrystalline (crystal size is several tens of tens of degrees) consisting of carbon atoms C and hydrogen atoms H on the substrate. A hard carbon film is deposited containing at least one of the following: Table 1 shows the properties of the hard carbon film. Table 1D Note) Measurement method: Specific resistance (ρ): Determined from I-■ characteristics using a coplanar cell. Optical bandgap (Egopt): Obtain the absorption coefficient (α) from the spectral characteristics and determine from the relationship (αhνp /l :B (hEgopt).Hydrogenffl(Co) in the film: 29 from the infrared absorption spectrum
00 (integrate the peak near m-' and multiply by the absorption cross section A. c, = ATf a (w)/w・dw S P'/S P" ratio: Infrared absorption spectrum, sp3
, SP2 respectively. It is calculated from the area ratio. Vickers hardness Jfi (11): Based on micro Vickers meter. Refractive index (n): measured by ellipsometer
Depth density: Based on ESR. The hard carbon film formed in this way was analyzed by IR absorption method and Raman spectroscopy, and it was found that the carbon atoms formed SP3 hybrid orbital and SP2 hybrid orbital, as shown in FIGS. 12 and 13, respectively. It has become clear that there are interatomic bonds.

The ratio of SP1 coupling to SP'' coupling can be roughly estimated by peak-separating the TR spectrum.In the IR spectrum, spectra of many modes are overlapped in the range 2800 to 3150Cl-1, but each wave number The attribution of the peak corresponding to is clear, and the SP3/SP'' ratio can be determined by performing peak separation using a Gaussian distribution as shown in FIG. 14, calculating the area of each peak, and finding the ratio.

Moreover, according to X-ray and electron diffraction analysis, it has been found that it is in an amorphous state (a-C: It) or an amorphous state containing microcrystalline grains of several tens of micrometers to several micrometers. In the case of plasma CVD method, which is generally suitable for mass production,
The lower the RF output, the higher the resistivity and hardness of the film, and the lower the pressure, the longer the life of the active species. There is a tendency for the number to increase. Furthermore, since the plasma density decreases at low pressures, methods using magnetic field confinement effects are particularly effective in increasing resistivity. Furthermore, this method has the characteristic that it can form a high-quality hard carbon film even under relatively low temperature conditions of about room temperature to 150°C, so it is ideal for lowering the temperature of the MIMJ child manufacturing process. Therefore, there is greater freedom in selecting the substrate material to be used, and because the substrate temperature can be easily controlled, a uniform film can be obtained over a large area. In addition, the depiction of hard carbon II value, physical properties, etc. are as shown in Table-1.
Since it can be controlled over a wide range, there is also the advantage that device characteristics can be designed freely. Furthermore, the dielectric constant of the film is between 2 and 6, which was conventionally used in MIM. O,,A Q
Since it is smaller than 20,H SiNX, if an element with the same electric capacity is to be manufactured, the element size can be large, so fine processing is not required and the yield is improved.

Therefore, the smaller the permittivity, the greater the steepness,
On electrician. n and off-current engineering. The ratio with ff becomes large. Therefore, L at lower duty ratio
CD rotation becomes possible, and a high-density LCD can be realized. Furthermore, since the hard carbon film has high hardness, there is less damage caused by the rubbing process during encapsulation of the liquid crystal material, which also improves yield.

In view of the above points, by using a hard carbon film, a low-cost, gradation (color), and high-density LCD can be realized. In addition to carbon and hydrogen atoms, this hard carbon film also contains
It may contain as a constituent element an element of group Ⅰ of the periodic table, an element of group ② of the periodic table, an element of group ② of the periodic table, an alkali metal element, an alkaline earth metal element, a nitrogen atom, an oxygen element, a chalcogen element, or a halogen atom. For those in which Group Ⅰ element of the periodic table, an alkali metal element, an alkaline earth metal element, a nitrogen atom, or an acid iA atom is introduced as one of the constituent elements, the thickness of the hard carbon film can be changed to a non-doped layer. Approximately 2
It is possible to increase the thickness by ~3 times, thereby preventing the occurrence of bottle holes during device fabrication, and improving the mechanical strength of the device. Furthermore, in the case of nitrogen atoms or oxygen atoms, there is an effect similar to that of the elements of group Ⅰ of the periodic table, etc., as described below. Similarly, devices that incorporate elements from group Ⅰ of the periodic table, chalcogen elements, or halogen elements dramatically improve the stability of the hard carbon film and also improve the hardness of the film, resulting in highly reliable elements. can be created. These effects can be obtained because, in the case of Group I elements and chalcogen-based elements, active double bonds present in the hard carbon are reduced. In addition, in the case of halogen elements, 1) the decomposition of the raw material gas is promoted by an abstraction reaction against hydrogen, and II! 2) During the film formation process, the halogen element X pulls out hydrogen in the C-11 bond and replaces it, entering the film as a C-X bond and increasing the bond energy. (The bonding energy between C-}1 and between C-x is larger between C-x).

In order to use these elements as the constituent elements of the film, in addition to hydrocarbon gas and hydrogen, the raw material gases include elements from group Ⅰ of the Periodic System Table of Elements, elements of group Ⅰ, elements of group Ⅰ, alkali metal elements,
Compounds (or molecules) containing alkaline earth metal elements, nitrogen atoms, oxygen atoms, chalcogen elements, or halogen elements (
Hereinafter, these gases may also be referred to as "other compounds".

Examples of compounds containing Group I elements of the periodic table include B (OC2 8s )3, B, H, . BCQ,,
BBr3. BF3, AQ (0-i-C, H7)ff,
(CI1, ): + Party A, (C2H, ), . AQ
, (i-C41fq), AQ, AQCQ3, aa (o
-i-cyut)3-(CH3)3Ga,
(C2H.): I Ga, GaCQ3, GaBr3
, (0-i-Cl I{t L . In, (Cz'
s)3In etc. As a compound containing a group IV element of the periodic table, for example, S
iH4, SL, II Si, II (C2 HS
)3 SiH. SiFSi}l, CQ2, Si
(OC}l- )4,S1(QC2}1, )Si
(QC, H7) GeCQ. ．． GeH. , Ge (
OCt H5)4, Ge(CaHs)4- (Cl13
)4Sn, (CJg)4Sn. There are SnCQ4 etc.
As a compound containing an element of group Ⅰ of the periodic table, for example, P
H,,PF,,PF,. PCQ2F,. PCQ2F.
PCQ3, PBr,. PO(OCR3),,P(C
2H,),. POCm,,^sH,,AsC1,,A
qBr,, As F,, AsF5, AsCQ3.
Sb}l. ．． SbF3, sbca,, Sb COC
x HS ) 3 etc.

Examples of compounds containing alkali metal atoms include io
-i-C, H. , NaO-i-C, H,, KO-i
-C,}! , etc. Examples of compounds containing alkaline earth metal atoms include Ca (QC, H, ), M
g(OCzHs)3. (Cills) 2Mg etc. Compounds containing nitrogen atoms include, for example, nitrogen gas, inorganic compounds such as ammonia, organic compounds having functional groups such as amino groups and cyano groups, and complex compounds containing nitrogen. There is a ring q◆.

Examples of compounds containing oxygen atoms include oxygen gas, ozone, water (steam), hydrogen peroxide, carbon monoxide, carbon dioxide, suboxide, nitrogen monoxide, nitrogen dioxide, dinitrogen trioxide, and dinitrogen pentoxide. Inorganic compounds such as il element, nitrogen dioxide, hydroxyl group, aldehyde group, acyl group, ketone group, nitro group,
Examples thereof include organic compounds having functional groups or bonds such as nitroso groups, sulfone groups, ether bonds, ester bonds, peptide bonds, and heterocycles containing tvI elements, as well as metal alkoxides. Examples of compounds containing chalcogen elements include 11■
S, (CH■) (CI1■)4S(C}l,)4C}
+3, (1, H. =CHCH, SC}l2CH=C
1{2, C2It, SC2I+5, C z }I s
S C'H 3, thiophene, H2Se, (Cx H
%)2 Ss. There are H2 Te, etc. Compounds containing halogen elements include, for example, fluorine, chlorine, bromine,
Inorganic compounds such as iodine, hydrogen fluoride, chlorine fluoride, bromine fluoride, iodine fluoride, hydrogen chlorine, bromine chloride, iodine chloride, hydrogen bromide, iodine bromide, hydrogen iodide, alkyl halides, aryl halides Organic compounds such as , halogenated styrene, halogenated polymethylene, and haloform are used.

To make the MIM device of the present invention, for example, as shown in FIG.
As shown in (b), first, a metal thin film for the lower electrode is formed by vapor deposition, sputtering, etc. on the insulating substrate 1 on which the transparent pixel electrode 2' is formed, and then a predetermined metal film is formed by wet or dry etching. A lower electrode 2 is formed by patterning, and a hard carbon film 3 is coated thereon by a plasma CVD method, an ion beam method, etc., and then a predetermined pattern is formed by dry etching, wet etching, or a lift-off method using a resist. The insulating film is formed by patterning, and then a metal m film for the upper electrode is coated on it by a method such as vapor deposition or sputtering, and the upper electrode 4 is formed by patterning into a predetermined pattern.Finally, the lower electrode is formed. Remove unnecessary portions of the transparent pixel electrode 2' and expose the transparent pixel electrode 2'.
Use as pixel electrode. Alternatively, as shown in FIGS. 16(a) and (b), the lower electrode 2 and the insulating film are placed on the substrate 1 in the same manner as in FIGS. 15(a) and (b) except for the shape of the upper electrode 4'. 3 and the upper electrode 4', a transparent electrode thin film is formed by a method such as vapor deposition or sputtering, and then patterned so that a part of it covers the upper electrode 4'.
Il! ii) A transparent electrode 5 serving as an elementary electrode may be formed.

Oh, the MIM elements shown in Figures 15(a) and (b) are LCD! It has a configuration suitable for dynamic use. in this case. MIM! The MIM device is not limited to this structure, but may include a structure in which a transparent electrode is provided on the top layer after production of the MIM device, a structure in which the transparent electrode also serves as an upper or lower electrode,
Various modifications are possible, such as forming an MIM element on the side surface of the lower electrode. Here, the thickness of the lower electrode, upper electrode and transparent electrode is usually 100 to several thousand pieces, 3
00 to several 1000 lambda and 300 to several 1000 people. As mentioned above, the thickness of the hard carbon film is 100 to 8
000 people, preferably 200 to 6000 people, and more preferably 300 to 4000 people. Some modifications of the MrM element described above are as follows.

(i) Providing a metal layer in the contact area between the lower electrode and the insulating film (hard carbon film). According to this example, M. A pixel transparent electrode exists under the metal layer in the IM part, which is effective for protecting the lower electrode when forming a hard carbon film.6 The thickness of this metal layer is about 100 to several thousand amps. As appropriate, this metal layer may be a single layer or two or more layers.

(if) Avoid buttering the insulating film (hard carbon film) and make the upper electrode a transparent electrode.

According to this example, reaction between the transparent electrode and the hard carbon film raw material can be avoided by arranging the MIM element configuration from the plate side to the lower electrode, the hard carbon film, and the transparent upper electrode. Additionally, when the hard carbon film and transparent electrode overlap, the visible transmittance is higher than that of the hard carbon film alone, and the process of removing the hard carbon film from the areas that will become pixels can be omitted, significantly shortening the process. Note that the increase in transmittance when a transparent electrode is layered on a hard carbon film is considered to be due to the antireflection effect.

(iii) disposing a pixel transparent electrode adjacent to the lower electrode;
At least a portion of the upper electrode is bonded to an insulating film (hard carbon film) on the lower electrode, and an ohmic bond is formed with the pixel transparent electrode. According to this example, the lower electrode also serves as a bus line (a narrow long pattern with increased wiring resistance), and the pixel electrode is in direct contact with the upper electrode, so the current flows between the metal layers. Since it flows without passing through the interface, contact resistance and electrical problems at the interface are eliminated, and the upper electrode wiring portion is shortened, so inconveniences such as disconnections and short circuits are no longer observed.

Next, the materials used in the present invention will be explained in more detail.

First, a glass plate, a plastic plate, or a flexible plastic film is used as the insulating substrate.

The materials for the lower electrode are AQ,'l"a, Cr+W
Various conductors such as +Mo, Pt, Ni, and other transparent conductors can be used, but Au and Ni are preferable in view of their particularly excellent nonlinear characteristics. This can be explained graphically as follows. Fig. 17 shows the MIM element of the present invention using AI2 or Ni for the lower electrode, and Fig. 18 shows the MIM element of the present invention using Cr, Mo (the upper electrodes are both made of Ni,
Pt, AI2) current-voltage characteristic diagrams (in each figure, (a) is an IV characteristic diagram, and (b) is a Qn I-v'▼ characteristic diagram). From these figures, good nonlinear characteristics can be obtained when Afl,Ni is used for the lower electrode, but when other metals other than 11,Ni are used. It can be seen that the linearity deteriorates on the high voltage side of the QnI-f7 characteristic, and very good characteristics cannot be obtained.

Next, the materials for the upper electrode are AQ, Cr, Ni,
Various conductors such as Mo, Pt, Ag, and other transparent conductors can be used, but Ni, Pt, and Ag are preferred because they have particularly excellent stability and reliability of IV characteristics. That is, as mentioned above, the symmetry of the MIM element using hard carbon I as the insulating film does not change even if the type of electrode is changed, and the symmetry of +2
From the relationship nIccf7, it can be seen that Pool-Funkel type conduction is occurring.

Also, from this, it can be seen that in the case of this type of MIM element, the combination of the t part electrode and the do part electrode can be made in any manner.

However, on the other hand, the adhesion between the hard carbon film and the upper electrode and the state of the interface cause deterioration and deterioration of the device characteristics (IV characteristics). This can be explained using drawings as follows. FIG. 19 and FIG. 20 show Ni and Ni in the upper electrode, respectively.
M using Pt, Ag, AI2, Mo and Cr
Current-voltage characteristic diagram of an IM element (lower electrode is Ag or Ni) (in each figure, (a) is an IV characteristic diagram, (b) is a Qn
I-(';;- characteristic diagrams. These diagrams show that when the voltage is low, Qn I-f7 has a linear relationship at all electrodes, but as the voltage increases, Cr and Mo deviate from this line, and the current increases. It becomes less.

Also, from the measurement of adhesion strength, Ni, Pt
, A g z MOI Cr J AQ.

Furthermore, when we conducted various reliability tests on the I-V characteristics due to aging, we found that there was almost no aging deterioration for NllPt+Ag, and that the deterioration increased in the order of Mo, Cr, and AQ. Note that not only the deterioration test of the IV characteristic but also the adhesion test serve as a guide for evaluating the stability and reliability of the IV characteristic.

Subsequently, a temperature cycle test @ (-20°C to +60°C, held for 30 minutes, cycled 10 times) revealed that Ni, P
Regarding t,Ag, there was no change in appearance such as film peeling,
Furthermore, Ni and Pt have almost no D-V characteristics, indicating that they have excellent stability (Table 2). Table 2 (Temperature Cycle Test) Note) Ion retention rate: Retention rate when Ion is the initial value of the current when Von is applied. Symmetry conservation rate: R is the initial value of the current ratio at +, - bias.
The conservation rate when defined as o (symmetry). On the other hand, the results of high temperature storage (80°C, low humidity, 1000 hours) and low temperature storage (-20"C, low humidity, 1000 hours) were
It is shown in Figure 1 and Figure 22. The results are also summarized in Table 3. Table 3 (High and low temperature storage stability) From this Table 3, Ni and PL are used as materials for the upper fI bunpoku.
, Ag provides a highly stable element, but Ni is particularly superior from a comprehensive standpoint.

In addition, as shown in Fig. 23, for LC]) rotation,
It is necessary to use a transparent electrode 5, and the material for this transparent electrode is ITO. Examples include tin oxide and zinc oxide.

The structure of the liquid panel incorporating MIM elements is as follows. , J!
Essentially, an alignment layer made of polyimide or the like is provided as an alignment film on each transparent substrate having a common transparent electrode facing the liquid crystal display substrate obtained as described above, and then a rubbing treatment is performed.

Next, a liquid crystal display device is obtained by placing the respective substrates facing each other with the respective pixel electrodes facing inside and pasting them together with a gap material interposed therebetween, and further filling the thus formed cell with a liquid crystal material. In addition, in the liquid crystal display device manufactured in this way. The highest point W of the MIM element (i.e., the top surface of the upper electrode)
When the MIM element is located higher than the top surface of the pixel electrode, an insulating substrate having an MIM element and a transparent substrate having a common electrode are usually placed opposite to each other with a spacer interposed therebetween. However, it is difficult to control the cell gap to a desired value; There is a problem that the display responsiveness and color tone of the obtained liquid crystal display panel vary within the panel or depending on the product.Also, even if a uniform gap is obtained throughout the substrate, the difference between the element part and the display pixel There is a gap difference (optical path difference) between the parts, and when this exceeds a certain value, color unevenness occurs. Taking this into consideration, a transparent border film is provided between the display pixel electrode and the transparent substrate, and the difference in height between the top surface of the display image electrode and the top surface of the nonlinear two-terminal element is set to 0.5 μm or less. ，
It is desirable that the ugliness is preferably 0.3μ or less. Specifically, transparent insulating film J8J. MI
It may be made approximately equal to the thickness of the M element (the sum of the thicknesses of the lower electrode, hard Jf! insulating film, and J bipart electrode), or the display pixel electrode may also serve as the upper electrode.

Although the liquid product display device described above is a monochrome display device, the present invention is not limited to this, and may be a color liquid crystal display device in which a color filter is provided inside or outside the cell.

By the way, in the explanation so far, we have mainly talked about the thickness and specific resistance of the hard carbon 1 model regarding MIM elements, but SP
The amount of J (S P'/(S P2+ S P')) is approximately 0
．． 6 or more is good, preferably 0.66 or more (third
Figure 1).

The hardness of a hard carbon film is related to the amount of SP3 bonding in the film width, and the amount of SP3 (diamond-like bonding amount) decreases and the amount of SP'
As ff (graphitic bond content) increases, hardness decreases. For this reason, it is advantageous to use a hard carbon film whose SP3 amount satisfies the above-mentioned value without causing any practical problems. The dielectric strength voltage of the hard carbon film formed in the present invention is related to the amount of hydrogen in the film, and if it deviates from a certain range, dielectric breakdown is likely to occur (Figure 32). Therefore, the amount of hydrogen in the film is preferably 10 to 50 atomic%, more preferably 20 to 45 atomic%. Note that the deterioration of the element is due to IJ! This is remarkable when the spin density N5 of J is large. That is,
MIM devices using hard carbon films formed under certain conditions often experience deterioration of characteristics over time (reduction in ON current).
occurs. The causes are (1) oxidation of the electrodes, which leads to a reduction in the device area due to peeling of the electrodes, and (2) a decrease in defects in the film, which leads to higher resistance of the film. The above item (■) can be countered by using metals that are difficult to oxidize. However, regarding the above-mentioned item (2), although it seems likely that a film with a large number of defects can be used, there is a high probability that the number of defects will decrease with a film with a large number of defects.
The increase in resistance (deterioration) of the film is significant. However, if the initial number of defects is small, the number of defect reduction agents will be small, and the overall effect will be almost negligible. Therefore, this ■
To deal with this, it is desirable to use a film that originally has a small number of defects. The number of defects can also be replaced by a random spin density Ns, and the spin density Ns and the characteristic deterioration of the MIM element have a relationship as shown in FIG. 33. In the figure, Io is the initial current value of the MIM element, and ■ is the current value of the MIM element after one month. The acceptable range for characteristic deterioration (storage rate) is 0.9
˜1, and therefore, the spin density in the hard carbon film in the MIM device according to the present invention is 5×]01 g or less, preferably 101″ or less.

In addition to this. As a result of further intensive research on the thickness of the hard carbon film of MIM elements, we would like to stress that there is almost no peeling of the hard carbon film (it is known that the adhesion of the hard carbon film varies depending on the underlying material). , for any material to have good adhesion)1)
A good range is from 00 to 900, preferably from 200 to 90.
0, more preferably 300 to 900.

On the other hand, considering that the defect rate of the device due to pinholes, short circuits on the step side, step breaks, etc. is approximately O, and the allowable amount of variation in device characteristics, the film thickness variation is preferably ±3.
If you want to emphasize that it is less than % (because there are almost no bottle holes and there is sufficient coverage on the step side,
Furthermore, the limit value for film thickness control (approximately 30 pieces) is 3% of the previous film thickness.
1,100 to 8,000 people, preferably 1,100 to 6,000 people, and more preferably 1,100 to 4,000 people. Note that the element defects referred to here are not limited to initial defects, but also include cases where the operating life is short. [Example] The present invention will be explained in more detail with reference to Examples.

Example 1 IT was placed on a Vilex glass substrate as one transparent substrate.
After depositing O to a thickness of about 100 ml by sputtering,
A pixel electrode was formed by patterning.

Next, an MIM element was provided as an active element as follows. First, about 1 liter of Aα is deposited on the pixel electrode of the substrate by vapor deposition.
After depositing to a thickness of 0.000 mm, it was patterned to form the lower electrode. On top of that, a hard carbon film is deposited as an insulating film by plasma CVD.
After approximately 900 layers were deposited by the method, it was patterned by dry etching. The coating conditions at this time were as follows.

Pressure: 0,035TorrCH4 Flow rate: 20SCCM RF power: 0.2W/c+*z Further, Ni is deposited on the hard carbon insulating film by vapor deposition to approx.
After depositing it to a certain thickness, it was patterned to form the upper electrode. Next, as the other transparent substrate (counter substrate), ITO was deposited on a Pyrex substrate with a thickness of approximately 100 OA by sputtering.
After depositing it thickly, it was patterned into stripes to form a common pixel electrode. Subsequently, a polyimide film was formed as an alignment film on both substrates, and a rubbing process was performed.

These substrates are placed facing each other with each pixel electrode side facing inside, and are pasted together with a gap material having a diameter of approximately 5 μm interposed therebetween, and a commercially available liquid crystal material is sealed in the cells thus formed. I made a liquid crystal display device like the one shown below. 24th
In the figure, 1a and 1b are transparent substrates. 5 is a pixel electrode, 5' is a common pixel electrode, and 6 is an MIM. +1 child, 7 is common @ pole or common wiring, 8a and 8b are alignment films, 9 is gap material, 1
0 is the liquid crystal material. Example 2 An AQu film with a thickness of about 1000 mm was formed on a glass plate by vapor deposition, and then patterned by etching to form a lower electrode.A hard carbon film with a thickness of about 1200 mm was coated on top of it, and patterned by dry etching. An insulating film is formed on the hard carbon film, and an E. B. Approximately 100 by vapor deposition method
The second layer is coated with a zero-thick ITO film and patterned by etching to form an upper transparent pixel electrode.
An MIM device of the type shown in Figure 5 was made. In FIG. 25, la is a transparent substrate, 2 is a lower electrode, 3 is a hard carbon insulating film, and 5 is a transparent electrode. The conditions for the hard carbon film are as follows.

Pressure: 0.05Torr CH. Flow rate: IOSCCM RF bar'7: 0. 11/c+a" Next, IT○ was deposited to a thickness of about 500λ by sputtering on a plastic film as a counter substrate, and patterned into stripes to form a common pixel electrode. Subsequently, a common pixel electrode was formed on it in the same manner as in Example 1. Polyimide 1 was applied to the substrate and rubbed.After bonding these two substrates together via a gap material in the same manner as in the example, a liquid crystal display device was produced by filling a commercially available liquid crystal material.

Example 3 After forming a hard carbon film (approximately 800 mm thick) as a lower electrode and insulating film on a glass plate in the same manner as in Example 1, a PTLL of approximately 500 mm thick was formed on the hard carbon film by vapor deposition.
! A MIM element of the type shown in FIG. 26 is obtained by forming an auxiliary electrode by forming an auxiliary electrode, and then forming an upper transparent pixel electrode thereon in the same manner as in Example 2. made.

In FIG. 26, 1a is a transparent substrate, 2 is a lower electrode, 3 is a hard carbon insulating film, 5 is a transparent electrode, and 1l is an auxiliary electrode. The conditions for forming the hard carbon film are as follows. pressure
Force: 2 X 10-3TorrCH, COC
H, flow fit: ISCCMRF power: IV/c Next, ITO was deposited on a Pyrex substrate as a counter substrate to a thickness of approximately 800 nm by magnetron sputtering, and then patterned into stripes to form a common pixel electrode. Subsequently, a polyimide film was provided thereon in the same manner as in Example 1, and after rubbing treatment, these two substrates were bonded together via a gap material in the same manner as in Example 1.
A liquid crystal display device was created by encapsulating a commercially available liquid crystal material. Example 4 As shown in FIG. 27(a), a lower electrode 2 is placed on a transparent substrate 1.
, a hard carbon film 3 was laminated. NiCr was used as the material for the lower electrode 2, and the film thickness was about 7000 μm. The conditions for forming the hard carbon film 3 are as follows. Pressure: I XIO””torrCH, O
H flow i: lsecM H, O flow f: 50SCCM Microwave power: 5001 Substrate temperature: 600°C Film thickness was approximately 5000 mm. Next, as shown in FIG. 27(b), hard carbon 11κ3
and the lower electrode 2 were sequentially etched by dry etching to form a predetermined pattern.

The process of sequentially etching the hard carbon film 3 and the lower electrode 2 can be performed continuously in the same chamber by selectively setting the gas type, pressure, discharge power, etc.

Furthermore, as shown in FIG. 27(c), a second hard carbon film 3a was formed to cover the top and side surfaces of the patterned hard carbon film 3 and the side surfaces of the lower electrode 2. The thickness of this second hard carbon film 3a (composition is the same as in Example 1) is approximately 50 mm.
There were 0 people. These hard carbon films 3 and 3a provide insulation of the MIM element, but on the surface of the lower electrode 2 where the hard carbon films 3 and 3a are M-layered, the film thickness becomes erratic due to the sum of both.
At the stepped portion, that is, at the side surface of the lower electrode 2, there is only the hard carbon film 3a, and the film thickness is designed to be thin. Furthermore, as shown in FIG. 27(d), the transparent electrode 5 that will become the pixel electrode is coated with E. B. It was formed by a vapor deposition method and subjected to predetermined patterning. ITO is the material for the transparent electrode 5.
was used, and the lI'J thickness was approximately 900 people. In such a configuration. The lower electrode 2 operates as an MIM element.
This is a thin part of the hard carbon film 3a on the side surface, that is, a part A where the lower electrode 2, the second hard carbon film (M edge layer) 3a, and the transparent electrode 5 are laminated in the horizontal direction. In addition. The area of the MIM element is determined by the stepped portion (film thickness) of the lower electrode 2 and the pattern of the transparent electrode 5. A perspective view of this MIM element is shown in Figure 28. A polyimide film was provided on the substrate of the MIM device thus obtained in the same manner as in Example 1, and subjected to rubbing treatment. Next, ITO was placed on a plastic film as a counter substrate.
A common pixel electrode was formed by depositing ITO to a thickness of about 500 nm by sputtering and patterning it into stripes. Subsequently, a polyimide film was applied on top of it in the same manner as in the example work, and a rubbing treatment was performed. These two substrates were bonded together via a gap material in the same manner as in Example 1, and then a commercially available liquid crystal material was encapsulated to produce a liquid crystal display device.

Embodiment 5 Here, as shown in FIG. 29, the upper electrode 4 for the MIM element is formed independently and connected to the transparent electrode 5 in a 71-way manner.

First, the lower electrode 2 and the hard carbon film 3 are laminated on the substrate L. The conditions for forming the hard carbon film 3 are as follows. Pressure: 3XIO-'TorrCH4
Flow-κ: 2SCCM RF power = 3w/cI12 Magnetic field (near the substrate surface): IK Gauss The lower electrode material is the same as in Example 4, and these It') are sequentially dry etched into a predetermined pattern. Patterned. In this case, when etching the lower electrode 2, the step portion is etched so that it has a tapered cross-sectional shape. By forming such a tapered shape, it becomes easier to control the thickness and uniformity of the second hard carbon film 3a formed in the next step on the stepped portion, that is, the tapered surface. However, the film thickness of hard carbon [3a] was the same as in Example 4. Next, in the same manner as in Example 4, after forming the second hard carbon film 3a, in this example, the hard carbon film 3a is formed.
The upper electrode 4 is formed in a predetermined pattern from a part of the upper part of the upper electrode 4 to the upper part of the substrate 1. This upper electrode 4 was formed using the same material as the lower electrode 2 and had a film thickness of approximately 4000 mm. After this, the transparent electrode 5 that will become the pixel electrode is shaped and patterned so that a part of it overlaps the upper electrode 4. As a result, according to this embodiment, the transparent electrode 5 and the hard carbon film 3a
Since there is no direct contact with the transparent electrode 5, deterioration of the bonding state due to carbon on the surface of the hard carbon film does not occur during the formation of the transparent electrode 5, and the device characteristics are further stabilized. A polyimide film was provided on the MIM element substrate thus obtained in the same manner as in Example 1, and subjected to rubbing treatment. Next, IT◯ was deposited to a thickness of about 500 layers on a glass substrate as a counter substrate by sputtering, and then patterned into stripes to form a common pixel electrode. Subsequently, a polyimide film was provided thereon in the same manner as in the example and subjected to rubbing treatment.

These two planting boards were bonded together via a gap material in the same manner as in Example 1, and then a commercially available liquid crystal material was sealed therein to produce a liquid crystal display device.

Example 6 I1゛○ was deposited on a plastic substrate as one transparent substrate to a thickness of about 1,000 yen by sputtering, and then patterned to form a pixel electrode. AM was deposited thereon to a thickness of about 1,000 layers by vapor deposition, and then patterned to form a lower common electrode. As an insulating film, a hard carbon film with a thickness of about 150 ml was applied thereon by the plasma CVD method in the same manner as in Example 1.
After depositing to a thickness of 0, IT○ is approximately 500 thick by striping.
After being deposited to a thickness of λ, it was patterned by dry etching.
Furthermore, Cr was deposited to a thickness of about 2000λ on top of the Cr layer, and then patterned to form an upper electrode. Subsequently, a polyimide film was provided thereon in the same manner as in Example 1, and rubbed.

Next, IT is placed on the plastic film l1 as a counter substrate.
IT○ was deposited to a thickness of approximately 500 mm by sputtering O, and then patterned into stripes to form a common pixel electrode. Subsequently, a polyimide layer was applied thereon in the same manner as in Example 1, and after a wrapping process, a color filter 12 was patterned in red (R), green (G), and blue (B) with a certain regularity on the opposite side. I installed one. These two substrates were bonded together via a gap material in the same manner as in Example 1, and then a commercially available liquid crystal material was encapsulated to produce a color liquid crystal display device as shown in Figure SO. In this liquid crystal display device, at least one active element TFT, MIM, PIN diode, etc. may be arranged in each display pixel electrode, and a plastic finolem substrate may be used as a color filter instead of a color filter. You may also use it by coloring it in the same way. When color filters are used, it is desirable to have different areas of the MIM elements for each color. Especially in the case of full color, red (R), green (G)
) and blue (B) relative sensitivity of 30:59:11.
It is necessary to mix in p1 ratio, so it is desirable to make the areas of the MIM elements different. The area ratio of the MIM element varies depending on the filter transmittance, driving method, and pixel area. Not limited to 30:59:11, but when the pixel area is constant R: G: B = 20 to 40
:40-80:8-14 is desirable, and within this range, R, G, and B can take any area ratio (for example, R:G:B = 35:65:10, 26 :
ratios such as 60:12, 30:65:8). If the pixel areas are different for R, G, and 13, multicolor display is not limited to this range. Full color here means a color Pff style display that can reproduce natural colors, which is used on displays such as current color TVs. Methods for producing color filters include a phosphor method, a printing method, an electrodeposition method, etc., but are not limited to one method in particular.

Examples of the arrangement of R, G, and H are shown in fJS34 diagrams (a), (b), and (
C), but is not limited to this arrangement.

〔effect〕

The hard carbon film used in the MIM element of the present invention is 1) manufactured by a gas phase deposition method such as plasma CVD, so its physical properties can be controlled over a wide range by changing the film formation conditions, and therefore there is a large degree of freedom in device design. , 2) Since it is hard and can be made into a thick film, it is less susceptible to mechanical damage, and pinholes can be expected to be reduced by thickening the film. 3) A high-quality film can be formed even at low temperatures near room temperature, so it is suitable for substrates. 4) Excellent uniformity in film thickness and film quality, making it suitable for thin film devices; 5) Low dielectric constant, so advanced microfabrication technology is not required; It is advantageous for increasing the area, and since the dielectric constant is low, the steepness of the element is high and f on / I off
Since the ratio can be maintained, it has the following characteristics: it can operate at a low duty ratio, and is therefore particularly suitable as a highly reliable switching element for liquid crystal displays.

[Brief explanation of drawings]

FIG. 1 shows 1. of the MIM device according to the present invention. It is a graph showing −V characteristics. FIG. 2 shows a one-stroke equivalent circuit of a liquid crystal display device using an MIM element according to the present invention. Figure 3 schematically represents the rotating voltage waveform of a liquid crystal display device. FIG. 4, FIG. 5, and FIG. 6 are graphs for explaining the driving voltage of the MIM element. FIG. 7 to FIG. 11 are diagrams showing several forms or means of the hard carbon membrane in the present invention. FIG. 12, FIG. 13, and FIG. 14 are diagrams for explaining the properties of the hard carbon film in the present invention. FIGS. 15 and 16 are diagrams for explaining two examples of the method of manufacturing an MIM element according to the present invention. From Figure 17 to Figure 20,
It is a current-voltage characteristic diagram of MIM elements of the present invention and a comparison. Figure 21 and Figure 2z show MIM when the upper electrode is changed.
This shows the temperature cycle test results of the device. Figure 23 is a diagram showing part of a liquid crystal panel incorporating MIM elements. Figures 24 and 30 are partially cutaway perspective views of two examples of liquid crystal display devices. Figures 25 and 26 are schematic cross-sectional views of two examples of MIM elements. Figure 27 is a diagram for explaining the manufacturing process of another type of MIM element, and Figure 28 is a diagram for explaining the manufacturing process of another type of MIM element.
It is a perspective view of an IM element. FIG. 29 is a perspective view of a type of MIM element in which an upper electrode is formed independently and electrically connected to a transparent electrode. FIG. 31 is a graph showing the relationship between the amount of SP3 in i-Cjl and the hardness of the film. Figure 32 is a graph showing the relationship between the amount of hydrogen in a hard carbon film and the dielectric strength of the film. FIG. 33 is a graph showing the relationship between the spin density (Ns) of a hard carbon film and the characteristic deterioration of a HIM element using the hard carbon film. Figure 34 shows three examples of the arrangement of R, G, and B color filters. 1... Insulating substrate 3... Hard carbon film (#!ll#IJ!J) 5... Transparent VF1 pole (pixel electrode) 7... Common electrode or common wiring 8a, 8b... Alignment film 10...Liquid material l2...Color filter 2...Lower electrodes 4, 4-...Upper electrode 6...M. IM element 9...Gap material 11...Auxiliary electrode

Claims (1)

[Scope of Claims] 1. An MIM device having a lower electrode, an insulating film, and an upper electrode provided on an insulating substrate, wherein the insulating film is made of a hard carbon film with a thickness of 100 to 8000 Å. 2. An active matrix type liquid crystal display device characterized in that an MIM element having a lower electrode, a hard carbon insulating film with a thickness of 100 to 8000 Å, and an upper electrode provided on an insulating substrate is used as a switching element.