JPH02289828A - Mim element - Google Patents

Abstract

PURPOSE:To obtain the MIM element which is high in mechanical strength, is adequate for thin-film devices and can be formed to a larger area by forming an insulating film of a hard carbon film. CONSTITUTION:The insulating film 3 of the MIM element interposed with the insulating film 3 between a lower electrode 2 and an upper electrode 4 is the hard carbon film contg. group III elements, group IV elements and group V elements of the periodic table, alkaline metal elements, alkaline earth metal elements, nitrogen atom, chalcogen element or halogen atom as dopants in addition to a carbon atom and hydrogen atom. This element is advantageous for the formation to the larger area and is adequate as the switching element for a liquid crystal display having high reliability. The mechanical strength of the element is thus greatly improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a switching element, particularly an MIM (metal-insulating film-metal) element useful as a switching element for liquid crystal display. [Prior Art] A typical example of a two-terminal film-based device is an MIM device. Conventional MIM elements use Ta. The insulating film is coated with Ta, O, and the upper part (by anodizing the lower electrode).
(metal) electrode using Cr alone or a single Cr/ITO product (Japanese Unexamined Patent Publication No. 62-62333), or using IT as the lower electrode.
O. SiNx. insulating film by plasma CVD method. and one using Cr for the upper electrode (Japanese Patent Application Laid-Open No. 61-260219
issue, Nikkei Electronics, January 12, 1987 issue). These MIN devices are particularly used as switching devices for active matrix type liquid crystal displays, but in the case of the former HIM device, l) the insulating film is formed by anodizing the lower metal; 2) When used in a liquid crystal display device, rubbing treatment is required to orient the liquid crystal in a certain direction, making it difficult to control the mechanical properties of the film and element. A thick or hard insulating film is required to prevent physical damage, but the anodic oxide film is soft, and due to current-voltage characteristics and damage voltage, the film thickness must be kept to about 600 or less. must be suppressed,
3) In the case of anodic oxide film, 30% to obtain polarity symmetry.
4) When used in a liquid crystal display device, the capacitance of the liquid crystal portion Cr. xD/HIM element capacitance CMIM=1
0:1 is required, so the smaller the dielectric constant of the insulating film is, the more advantageous it is for processing. 0. Since the anodic oxide film has a high dielectric constant (approximately 25 in the case of Ta and OS), it requires advanced microfabrication technology and has drawbacks such as being difficult to manufacture over a large area with good yield.

On the other hand, in the case of the latter HIM element, the above l), 2) and 4
), but since the film forming temperature is as high as approximately 300°C, there are the same drawbacks as in 3) above, and when increasing the area, the film thickness and quality may become non-uniform due to the substrate temperature distribution. Therefore, it is unsuitable for thin film devices. Furthermore, the dust generated in the gas phase during film formation causes a large number of via holes, which reduces device yield, and high film stress tends to cause peeling, which also reduces fM.
There are disadvantages such as causing [Problems to be Solved by the Invention] The first purpose of the present invention is to eliminate the above-mentioned drawbacks of the conventional technology, and by forming the insulating film with a hard carbon film, the degree of freedom in device design is widened. It has high mechanical strength, has no restrictions on substrate materials, is suitable for thin film devices, and can be easily expanded to a large area. An object of the present invention is to provide an HM element.

The second aspect of the present invention is to provide an elbow H element in which film properties such as mechanical strength, hardness, and stability are further improved by adding a specific element (dopant) to the constituent elements of a normal hard carbon film. [Structure and operation of the invention] The HIM element of the present invention is a HIM element in which an insulating film is interposed between a lower electrode and an upper electrode, and the insulating film contains carbon atoms and hydrogen atoms as dopants. periodic table m
Group elements. It is characterized by being a hard carbon film containing a Group III element, an alkali metal element, an alkali metal element, a nitrogen atom, an oxygen atom, a chalcogen element, or a halogen atom as a constituent element. It is something.

As described above, the HIM element of the present invention is characterized by its insulating film.
This insulating film is made of a hard carbon film containing the specific element or atom.

The invention? The hard carbon film itself used in the IIM element is composed of a material containing at least one of non-quality and microcrystalline quality, with carbon atoms and hydrogen atoms as the main constituent elements, and the i-C
Also called diamond-like carbon film, amorphous diamond film, and diamond thin film. In the present invention, the hard carbon film also contains specific elements such as the above-mentioned Group Ⅰ elements. In the present invention, in order to form a hard carbon film, a mixed system of organic compound gas, particularly hydrocarbon gas, and other compound gases as described below is used. The phase state of these raw materials is necessary at room temperature and pressure. Sushi does not necessarily have to be in a gas phase; it can be used in either a liquid phase or the same phase as long as it can be vaporized through melting, evaporation, sublimation, etc. by heating or reduced pressure. Regarding hydrocarbon gas as raw material gas, for example, CH
,,C. H. , C3H. , C. H. ．． All hydrocarbons can be used, including paraffinic hydrocarbons such as, acetylenic hydrocarbons such as C, 84, olefinic hydrocarbons, diolefinic hydrocarbons, and even aromatic hydrocarbons. ? Furthermore, other than hydrocarbons, for example, alcohols, ketones, ethers, esters, co. co. Any compound that can become carbon can be used.

In addition to hydrocarbon gas and hydrogen, raw material gases include elements from group Ⅰ of the periodic table, elements from group Ⅰ, elements from group ①, alkali metal elements, alkaline earth metal elements, nitrogen elements, In order to contain an oxygen atom, a chalcogen element, or a halogen element, a gas of a compound (or molecule) containing these elements or atoms (hereinafter, these may be referred to as "other compounds") is used.

Here, examples of compounds containing Group I elements of the periodic table include B(QC21{,),, B21f,, BCQ,,
BBr,,BF31 An(0-i-CJt)it
(CH3)3AQI (C2HS)3AQl(i-C4
H. )3AQ, AQCQ,, Ga(0-i-C3H
7) 37(CH3), Ga, (C2Hs). Ga, G
aCQ3, GaBr3T (0-i-C3H7)3T
There are nl(czos)■In, etc.

Examples of compounds containing Group Ⅰ elements of the periodic table include Si.
,H,, (C2H,),SiHI SiF4, Si
H,CQ2,? iCQ4, Si(QC}I,)4,
Si(QC,tl,),, Si(QC,tl■)4,
GeCQ4, GeH4, Ge(OCzHs)4+G
e(CzHi)4+(CHi)*Sn+(C2H, )
．． There are Sn, SnCff, etc.

Examples of compounds containing Group V elements of the periodic table include PH
3, PFJ. PF,, PCfl. F. , PC4
,, PCQ. F, PBr,, po(ocl+,),
, P(CzH5)3p POCQ3H A! 3}+3
1AsCQ,, AsBr,, AsF3, AsFs
, AsCQ,, SbH,, SbF,, SbCQ3,
There are Sb(QC,H.)■ etc.

Examples of compounds containing alkali metal atoms include LiO-
i-C,f{,, NaO-i-C,H,, KO-i
-C, H, etc.

Examples of compounds containing alkaline earth metal atoms include Ca
(OCzHsL+ Mg(QC21ts)z. (cz
There are uJzMg etc.

Examples of compounds containing nitrogen atoms include nitrogen gas, inorganic compounds such as ammonia, organic compounds having functional groups such as amino groups and cyano groups, and nitrogen-containing heterocycles. Examples of compounds containing oxygen atoms include oxygen gas, ozone, water (steam), hydrogen peroxide, and monoacid. Inorganic compounds such as carbon, carbon dioxide, nitrous oxide, nitrogen monoxide, nitrogen dioxide, dinitrogen trioxide, dinitrogen pentoxide, nitrogen trioxide, hydroxyl groups,
Examples include organic compounds having functional groups or bonds such as aldehyde groups, acyl groups, ketone groups, nitro groups, nitroso groups, sulfone groups, ether bonds, ester bonds, peptide bonds, and oxygen-containing heterocycles, as well as metal alkoxides. It will be done.

Examples of compounds containing chalcogen elements include H2S,
(C■,) (CH,). S(Cl1■)4CH, ,
CI+, = C}+CIl25CH2Cll =
CIl■, C. 2H,SC,H,, C2H,SCH
,,thiophene, H2Ss, (C,H,). Sa,
There are H, Te, etc. Examples of compounds containing halogen elements include fluorine, chlorine, bromine, iodine, hydrogen fluoride, chlorine fluoride, bromine fluoride, iodine fluoride, hydrogen chloride, bromine chloride, iodine chloride, hydrogen bromide, iodine bromide, Inorganic compounds such as hydrogen iodide, and organic compounds such as alkyl halides, aryl halides, styrene halides, polymethylene halides, and haloform are used. The amount of doband contained as one of the constituent elements in the hard carbon film of the present invention is as shown in Table 1 A below. The amounts of these elements or atoms can be measured by conventional methods of elemental analysis, such as Auger analysis. Moreover, this amount can be adjusted by adjusting the amount of other compounds contained in the source gas, film formation conditions, etc. The amount of elements or atoms contained in the film does not match the flow rate ratio of the compounds in the source gas.

The amount incorporated into the film varies depending on the gas type, film forming conditions, etc., but is approximately 50% or less.

The amount of each compound used in the present invention is as shown in Table 1 B below for carbon-containing compounds. (Left below) In the method of forming a hard carbon film from a raw material gas in the present invention, active species for film formation pass through a plasma state generated by a plasma method using direct current, low frequency, high frequency, microwave, etc. Although the most preferred method is to form the ions, the ions may be formed through an ion state generated by ionization vapor deposition, ion beam evaporation, or the like, or may be formed by vacuum evaporation, sputtering, or the like. It may be formed from neutral particles, or may be formed from a combination of these.

An example of the deposition conditions for the hard carbon film produced in this manner is as follows in the case of the plasma CVD method. RF output: 0
．． 1 to 5011/aJ pressure: 10”” to 1
0 Torr Deposition temperature: room temperature to 950°C The physical properties of the film created under these deposition conditions are shown in Table 2 below. Table 2 Note) Measurement method; Specific resistance (ρ): Determined from the characteristics of a coplanar cell. Optical band gap (Egopt): Obtain the absorption coefficient (α) from the spectral characteristics and determine it from the relationship (αhν)'=B(hγ−Egopt). Amount of hydrogen in the film (CH): 2900 from infrared absorption spectrum
Integrate the peak near cn-1 and multiply by the absorption cross section A. ? ■=Ajfα(I1)lw-dv SP'/SP" ratio: The infrared absorption spectrum is
p'' is decomposed into Gaussian functions assigned to each, and determined from the area ratio. Bibbers hardness (H): by micro-Vickers meter.
Refractive index (b): Based on ellipsometer. Defect density: E
By S.R. In addition, according to xg and electron diffraction analysis, it has been found that it is in an amorphous state (a-C:H) and/or an amorphous state containing microcrystalline grains of about 50 to several μm in size. As a result of analysis by IR absorption method and Raman spectroscopy, the hard carbon film formed in this way shows that carbon atoms form SP1 hybrid orbitals and SP1 hybrid orbitals as shown in FIGS. 2 and 3, respectively. It is clear that there is a mixture of inter-connections. The ratio of sp” bonds to SP1 bonds is I
It can be roughly estimated by separating the peaks of the R spectrum.
In the IR spectrum, the spectra of many modes overlap in the range from 2800 to 3150 cm-'', but the attribution of the peak corresponding to each wave number has been clarified.
Peak separation is performed using Gaussian distribution as shown in Figure 2,
If you calculate each peak area and find the ratio, SP3
/SP" ratio. Also, in film formation,
The smaller the RF output and the lower the pressure, the higher the resistivity and hardness of the film, and the larger the hydrogen mixing ratio, the higher the refractive index and the lower the defect density, that is, the higher the quality of the film. In this way, by forming the Ml film of the MIM element with a hard carbon film, variations in element characteristics are reduced.
It can be used as an MIM element that can withstand mechanical damage. This MIX
When the device is used as an active device for a liquid crystal display, there is less damage caused by the rubbing process during encapsulation of liquid crystal material, and the yield is improved. Also, as mentioned above, the LCD and MI
The capacitance of the M element is CLCD: CMl11=10
: Approximately 1 is required, but it is advantageous for processing if the dielectric constant of the insulating film is small. In the present invention, the dielectric constant t of the hard carbon film is
Since the r-valve is as small as 4, it can be formed with high precision without requiring very fine processing, and from this point of view as well, the yield is improved.

The dielectric constant of the hard carbon film in the present invention is preferably 2 to 6.

This dielectric constant can be controlled by RF power (power applied) during film formation.

Figure 12 shows the relationship between dielectric constant and RF power. Furthermore, as one of the constituent elements of this hard carbon film, an element from group Ⅰ of the periodic table, an element from group Ⅰ, an alkali metal element, an alkaline earth metal element, a nitrogen atom, or an oxygen atom is introduced. The film thickness can be made approximately 2 to 3 times thicker than that of a non-doped film, and this can prevent the occurrence of bottle holes during device fabrication and dramatically improve the mechanical strength of the device. ．． Furthermore, in the case of nitrogen atoms or oxygen atoms, the same effect as in the case of elements of group Ⅰ of the periodic table, etc., as described below, is obtained. Similarly, when nitrogen atoms, oxygen atoms, elements from group Ⅰ of the periodic table, chalcogen elements, or halogen elements are introduced, the stability of the hard carbon film is dramatically improved, and the hardness of the film is also improved. In combination, a highly reliable device can be manufactured.

These effects are obtained because oxygen atoms, group Ⅰ elements, and chalcogen elements reduce the active double bonds present in the hard carbon film. In the case of halogen elements, 1) an abstraction reaction with hydrogen promotes the decomposition of the source gas and reduces dangling bonds in the film; 2) halogen element X abstracts hydrogen from C-H bonds during the film formation process. This is because it replaces this and enters the film as a C-X bond, increasing the bond energy (the bond energy between C-H and C-X is larger for C-X).
This is because nitrogen atoms have a highly excited state and are therefore effective in activating the source gas during gas phase reactions. Next, a liquid crystal display device using the κIM element of the present invention will be explained. The substrate used is a transparent insulating plate such as a glass plate, plastic plate, or flexible plastic film. Two such transparent substrates are prepared, a pixel electrode is provided on each substrate, and at least one IM element and a common electrode wiring are provided on each pixel electrode of at least one substrate. In this case, the pixel electrode is made of ITO, ZnO:i, Z on the substrate.
nO: Si, SnO. : Sputtering, vapor deposition, etc. of transparent electrode material such as sb. It is formed by depositing several hundred layers to a thickness of about 1 μm using a method such as CVD and patterning it. Next, a lower electrode is formed on the transparent electrode as described above. The lower electrode is ^Q, Ni-Cr alloy, No.
Cr, Ni, Tit Zr, Nb, Au, A
Highly conductive materials such as G, Pt, and Cu are deposited to a thickness of several hundred to several thousand layers by sputtering, vapor deposition, CVD, etc., and then patterned into a predetermined pattern using photolithography and etching processes. It is formed by .

Next, using the method described above, a hard carbon film was coated from 100 to 1
The film is deposited to a thickness of μ, and then photolithographically
It is patterned into a predetermined pattern using an etching process. Next, a highly conductive material similar to that used for the lower electrode was used as the upper electrode, and this was applied by sputtering or vapor deposition.
Several hundred to several thousand layers are deposited by CVD, etc., and then patterned by photolithography. As a result, a liquid crystal display substrate using the AIN element of the present invention is obtained.

In this case, the configuration of the HIM element is not limited to this, but after the creation of the κIN element, a transparent electrode is provided on the top layer, a transparent electrode also serves as an upper or lower electrode, a side surface of the lower electrode, etc. Various configurations are possible, such as one in which an Iff element is formed on the top. An alignment layer made of polyimide or the like is provided as an alignment film on each of the transparent substrates having a common transparent electrode facing the liquid crystal display substrate obtained as described above, and then rubbed. Next, place each substrate facing each other with each pixel electrode side facing inside.
A liquid crystal display device can be obtained by bonding them together via a gap material and then sealing a liquid crystal material into the cells thus formed.

Although the liquid crystal display device described above is a black and white display device, the present invention is not limited to this. It is also possible to use a color liquid crystal display device with a color filter provided inside or outside the cell.In general, the current voltage (1-V) characteristics of an MIM element differ depending on the insulating film, but it is currently possible to use a hard carbon film as the insulating film. When used, it exhibits Poole-Frenkel type conduction, and there is a relationship expressed by the following equation.

I: (!8 decreases rapidly with an increase in
The larger β is, the more rapid the change in resistance becomes. Further, α is proportional to the area where the κ element is formed and the reciprocal of the thickness of the M edge film.

FIGS. 3 and 4 show curved I of the MIM device of the present invention, respectively.
-V characteristics and element configuration are shown. In FIG. 4, 1 is a pixel transparent electrode, 2 is a lower electrode, 3 is a hard carbon film, and 4 is an upper and scanning electrode.

The present invention will be explained below by way of examples.

Examples 1 to 9 IT was placed on a Pyrex glass substrate as one transparent substrate.
After O was deposited to a thickness of IOOOA by sputtering, it was patterned to form a pixel electrode.

Next, an elbow M element was provided as an active element as follows.
First, AQ was deposited to a thickness of 1,000 layers on the pixel electrode of the substrate by vapor deposition, and then patterned to form a lower electrode. A hard carbon film was deposited thereon as an insulating film to a thickness of 900 mm by plasma CVD, and then patterned by dry etching. The film forming conditions at this time are as follows.

Pressure: 0.035 Torr Raw material gas composition: As shown in Table 3 Total flow rate: 20 SCCM RF power: 0.2 v/i Table 3 Table 4 shows the physical properties of the carbon film.

Furthermore, 100% Ni was deposited on each hard carbon insulating film by vapor deposition.
After being deposited to a thickness of 0.000 g, it was turned into a batter to form an upper electrode.

Next, ITO was deposited on a Pyrex substrate as the other transparent substrate (counter substrate) to a thickness of 1,000 layers by sputtering, and then patterned into stripes to form a common pixel electrode.

Next, a polyimide film was formed as an alignment film on both substrates, and a rubbing process was performed.

Next, these substrates were placed facing each other with each pixel electrode side facing inward, and then pasted together with a gap material with a diameter of 5 μm interposed therebetween. Furthermore, a liquid crystal display device as shown in FIG. 5 was manufactured by sealing a commercially available liquid crystal material into the cells thus formed. In Fig. 5, 5 is a transparent substrate, 6 is a pixel electrode, 6' is a common pixel electrode, 7 is a MIX element, 8 is a common electrode or common wiring, 9 is an alignment film, 10 is a gap material, and 1l is a liquid crystal material. be. Examples 1O~18 A 1000-layer thick AQ thin film was formed on a glass plate by vapor deposition, and then patterned by etching to form a lower metal electrode, and an 800-layer thick film was formed on it by the same method as in Examples 1-9, respectively. I! is coated with a hard carbon film and patterned by dry etching. E. B. 1000mm thick ITO by vapor deposition method
An MI element of the type shown in FIG. 6 was fabricated by coating and patterning by etching to form an upper transparent pixel electrode. In FIG. 6, 12 is a transparent substrate, 13 is a metal electrode, 14 is a transparent electrode, and 15 is a hard carbon insulating film. Next, sputtering was performed on a plastic film as a counter substrate. After depositing ITO to a thickness of 500 layers, it was 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 rubbed. These two substrates were bonded together via a gap material in the same manner as in Examples 1 to 9, and then a commercially available liquid crystal material was encapsulated to produce a liquid crystal display device. Example 19
~27 After forming a hard carbon film as a lower metal electrode and an insulating film on a glass plate in the same manner as in Examples 1 to 9, a 500-layer thick PT film was formed on each hard carbon film by vapor deposition,
Perform patterning to form auxiliary electrodes. Further, an upper transparent pixel electrode was formed thereon in the same manner as in Examples 10 to 18, thereby producing a κIM element of the type shown in FIG. In Figure 7. 12 is a transparent substrate. 13 is a metal electrode, 14 is a transparent electrode, 15 is a hard carbon insulation film, and l6 is an auxiliary electrode. Next, ITO was deposited on a Pyrex substrate as a counter substrate to a thickness of 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 Examples 1 to 9. After rubbing these two substrates in Example 1
After bonding via a gap material in the same manner as in steps 9 to 9, a liquid crystal display device was made by filling a commercially available liquid crystal material. Examples 28 to 36 As shown in FIG. 8(a), the lower electrode 1 was placed on the transparent substrate 17.
8. Form a layer of hard carbon film 19. NiCr was used as the material for the lower electrode 18, and the film thickness was 7000. The hard carbon $19 was the same material as in Examples 1 to 9, and the film thickness was 5000.

Next, as shown in the same figure (b), a hard carbon film! 9 and the lower electrode 18 are sequentially etched using a dry etching method. Pattern into a predetermined pattern. The process of sequentially etching the hard carbon film 19 and the lower electrode 18 is as follows:
It can be performed continuously by selecting and setting the gas type, pressure, discharge power, etc. in the same chamber. Furthermore, as shown in the same figure (c), patterned hard carbon 7
1I A second hard carbon film 20 is formed to cover the top and side surfaces of the electrode 19 and the side surface of the lower electrode 18. The thickness of this second hard carbon film 20 (composition is the same as in Examples 1 to 9) is 400 mm.
As a person.

These hard carbon films 19 and 20 constitute the insulating film of the AIN element, but on the surface of the lower electrode 18 on which the hard carbon films 19 and 20 are laminated, the film thickness becomes thicker than the sum of both, and the step portion and the In other words, only the hard carbon film 20 is formed on the side surface of the lower electrode 18, and the film thickness is reduced.

Furthermore, as shown in the same figure (d), a transparent electrode w serving as a pixel electrode is
A21 to E. B. It is formed by a vapor deposition method and subjected to predetermined patterning. ITO was used as the material for the transparent electrode 21, and the film thickness was 900 mm.

In such a configuration. The thin part of the hard carbon film 20 on the side surface of the lower electrode 18 operates as an MIM element. This is the location A where the layers are stacked in the direction. Note that the area of the MEN element is determined by the step portion (film thickness) of the lower electrode l8 and the pattern of the transparent electrode 21.

A perspective view of this MIκ element is shown in FIG. A polyimide film was provided on the substrate of the M element thus obtained in the same manner as in Examples 1 to 9, and rubbed. Next, on a plastic film as a counter substrate, a film of 100% was deposited to a thickness of about 100 ml using a sputtering method, and then patterned into stripes to form a common pixel electrode. Subsequently, a polyimide film was provided thereon in the same manner as in Examples 1 to 9. Rubbed. These two substrates were bonded together via a gap material in the same manner as in Examples 1 to 9, and then a commercially available liquid crystal material was encapsulated to produce a liquid crystal display device. Example 37
~45 As shown in FIG. 10, in this embodiment, the upper electrode 122 for the MIX element is formed independently. Transparent electrode 2
It is designed to make an electrical connection with 1. First, a lower electrode 18 and a hard carbon film 19 are laminated on a substrate 17. These materials are the same as in Examples 28 to 36, and these layers are sequentially dry etched to form a predetermined pattern. In this case, the lower electrode 18 is etched so that the stepped portion has a tapered cross-sectional shape. By forming such a tapered shape, the second hard carbon film 2 to be formed in the next step
It becomes easier to control the film thickness and its uniformity on the stepped portion of 0, that is, on the Taber surface. However, the film thickness of hard carbon 11120 is the same as in Examples 28-36. Next, after forming the second hard carbon film 20 in the same manner as in Examples 28 to 36, in this example, the upper electrode 22 is formed in a predetermined pattern over a portion of the hard carbon film 20 onto the substrate l7. Do 9 this upper part? ! The electrode 22 was formed using the same material as the lower electrode 18 and had a film thickness of 400 mm.

Thereafter, a transparent electrode 21 that will become a pixel electrode is formed and patterned so that a portion thereof extends over the upper electrode 22. As a result, according to this embodiment, the transparent electrode 2l and the hard carbon film 20
Since the transparent electrode 21 is not in direct contact with the transparent electrode 21, the bonding state does not deteriorate due to deterioration of the surface of the hard carbon film, and the device characteristics become more stable. Examples 1-
A polyimide film was provided and rubbed in the same manner as in 9. Next, ITO was deposited to a thickness of 500 nm 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 Examples 1 to 9, and Labyrig treatment was performed.

After bonding these two substrates together via a gap material in the same manner as in Examples 1 to 9, a commercially available liquid crystal material was encapsulated to produce a liquid crystal display device.

Examples 46 to 54 ITO was deposited on a plastic substrate as one transparent substrate to a thickness of 1000 nm by sputtering, and then patterned to form pixel electrodes. AI2 was deposited thereon to a thickness of 1,000 layers by vapor deposition, and then patterned to form a lower common electrode. On top of that, a hard carbon film was applied as an insulating film to 600% by plasma CVD method in the same manner as in Examples 1 to 9.
After depositing Cr to a thickness of 2,000 mL, it was patterned by dry etching, and then Cr was deposited to a thickness of 2,000 mL and patterned to form an upper electrode. , rubbed. Next, fTO was deposited to a thickness of 500 nm on a plastic film 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 Examples 1 to 9, and after rubbing treatment, a color filter 23 was applied on the opposite side.
was installed.

These two substrates were bonded together via a gap material in the same manner as in Examples 1 to 9, and then a commercially available liquid crystal material was encapsulated to produce a color liquid crystal display device as shown in FIG. 11.

[Function and effect of the invention]

The hard return element film used in the κ■κ element of the present invention is 1) produced by a gas phase synthesis method such as plasma CVO method, so its physical properties can be controlled over a wide range by changing the film formation conditions, and therefore there is greater freedom in device design. 2) It is hard and can be made into a thick film, so it is less susceptible to mechanical damage, and a thicker film can also be expected to reduce pinholes. 3) A high-quality film can be formed even at low temperatures near room temperature. 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 has the following characteristics: it is advantageous for increasing the area of the display, and is therefore particularly suitable as a highly reliable switching element for liquid crystal displays. Furthermore, a hard carbon film is one in which an element from group Ⅰ of the periodic table, an alkali metal element, an alkaline earth metal element, a nitrogen atom, or an oxygen atom is introduced as one of the constituent elements of the hard carbon film. The film thickness can be made approximately 2 to 3 times thicker than that of a non-doped film, and this makes prevention of pinholes during device fabrication more effective. The mechanical strength of the device can be dramatically improved. Furthermore, in the case of nitrogen atoms or oxygen atoms, the periodic table No.
There is an effect similar to that of group elements. Introducing elements from group Ⅰ of the periodic table, chalcogen elements, or halogen elements dramatically improves the stability of the hard carbon film and improves the hardness of the film, making it possible to create highly reliable devices. can. The reason why the above effects can be obtained is as described above.

[Brief explanation of the drawing]

Figures 1 and 2 are IR and Raman spectra of the hard carbon film used in the MIM cord of the present invention, respectively, and Figure 3 (
a. ) and (b) are curved IV characteristic and QnI-v'v characteristic diagrams of the MIP1 device of the present invention, respectively, FIG. 4 is a curved configuration diagram of the MIM device of the present invention, and FIG. A perspective view of the liquid crystal display device manufactured in Examples 1 to 9, and FIG. 6 is a perspective view of the liquid crystal display device manufactured in Examples 1 to 9.
8 is a cross-sectional view of the MIM element made in Example 19.
8 (a) to (b) are cross-sectional views of the MIM device made in 27.
) is the MI? made in Examples 28 to 36? Figure 9 is a perspective view of the HIM element made in Examples 28 to 36, and Figure 10 is a diagram of the HIM element made in Examples 37 to 45.
A perspective view of the M element, FIG. 11 is a perspective view of the color liquid display device made in Examples 46 to 54, and FIG. 12 shows the RF power (input power) during hard carbon film formation and the hard carbon obtained. It is a graph showing the relationship between dielectric constants of films. 1... Pixel transparent electrode 2, 18... Lower N pole 3,
15...Hard carbon fiber membrane 4...Upper and scanning electrode 5,12.17...Transparent substrate 5''...Plastic film substrate 6...Pixel electrode 6'...Common pixel electrode 7・
・・IM element 8・・Common electrode or common wiring 9・・Alignment film 10・・Gap material 11・
...Liquid crystal material l3...gold if! i pole l4...
- Transparent electrode 16... Auxiliary electrode l9... First hard carbon film 20... Second hard carbon film 2l... Transparent electrode 22... Upper electrode 23... Color filter

Claims (1)

[Claims] 1. An MIM element having an insulating film interposed between a lower electrode and an upper electrode, wherein the insulating film is a hard carbon film containing a dopant.