JP2006301492A - Liquid crystal device, electronic apparatus, film forming method, and method of manufacturing liquid crystal device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal device in which a protection film arranged between a conductive film and an alignment layer has its film hardness controlled to be advantageous in simplifying manufacturing processes while having an ion adsorbing function. <P>SOLUTION: The liquid crystal device is constituted by holding a liquid crystal 50 between a pair of mutually opposite substrates 10 and 20. Conductive films 9 and 21, protective films 41 and 61 containing ion adsorptive particles, and alignment layers 40 and 60 are formed in order on the internal-surface side of at least one of the pair of substrates 10 and 20, and the protective films 41 and 61 are formed in mesoporous structure. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid crystal device, an electronic apparatus, a film forming method, and a method for manufacturing a liquid crystal device.

  A liquid crystal device used as a light modulation means mounted on a liquid crystal projector or the like or a direct-view display device mounted on a mobile phone or the like mainly includes a pair of substrates having electrodes for applying a voltage to a liquid crystal layer. Has been. An alignment film for controlling the initial alignment state of the liquid crystal molecules is formed on each inner surface side of the pair of substrates constituting the liquid crystal device.

  As the alignment film, a film obtained by subjecting the surface of a polymer film such as polyimide to an alignment treatment such as rubbing is generally used. Deterioration of such an alignment film may be accelerated by diffusion of a metal element from a conductive film provided adjacent to the alignment film or diffusion of ionic impurities. The deterioration of the alignment film causes a decrease in the display quality of the liquid crystal device as the liquid crystal alignment ability decreases.

In order to suppress such deterioration of the alignment film or display quality deterioration due to mobile ions in the liquid crystal, there is a technique for disposing a protective film containing fine particles having an ion adsorption function between the conductive film and the alignment film. Yes (for example, see Patent Documents 1 and 2).
JP 2002-229027 A JP 2003-186054 A

  In the technique of disposing a protective film containing ion-adsorbing fine particles between the conductive film and the alignment film, the protective film has a high hardness. Therefore, after the protective film is formed, the conductor is electrically connected to the conductive film in the lower layer. If the connection is attempted, the number of steps is likely to increase, for example, a photolithography step is required to form a contact hole in the protective film.

  The present invention provides a liquid crystal device having a film hardness controlled so as to be advantageous for simplification of a manufacturing process while having an ion adsorption function for a protective film disposed between a conductive film and an alignment film. The purpose is to do.

  The liquid crystal device of the present invention is a liquid crystal device in which a liquid crystal is sandwiched between a pair of substrates facing each other, and a conductive film and an ion adsorption are provided on the inner surface side of at least one of the pair of substrates. A protective film containing conductive fine particles and an alignment film are sequentially formed, and the protective film has a mesoporous structure.

  Further, the liquid crystal device of the present invention is a liquid crystal device in which a liquid crystal is sandwiched between a pair of substrates facing each other, and a conductive film is formed on an inner surface side of at least one of the pair of substrates, A protective film containing ion-adsorbing fine particles and an alignment film are sequentially formed, the protective film has a mesoporous structure, and a conductor that is electrically connected to the conductive film penetrates the protective film. And it protrudes from the surface of this protective film, It is characterized by the above-mentioned.

  The liquid crystal device of the present invention is a liquid crystal device in which liquid crystal is sandwiched between a pair of substrates facing each other, and each inner surface side of the pair of substrates includes a conductive film and ion-adsorbing fine particles. A protective film and an alignment film are sequentially formed, the protective film has a mesoporous structure, and a conductor for electrical conduction between the pair of substrates is the protective film on each of the pair of substrates. It is characterized by being disposed through.

  According to the above-described liquid crystal device of the present invention, since the protective film disposed between the conductive film and the alignment film has an ion adsorption function, deterioration of the alignment film and deterioration of display quality due to movable ions in the liquid crystal are prevented. Is done. Further, since the protective film has a mesoporous structure, it is possible to control the film hardness so as to be advantageous for simplification of the manufacturing process, such as reducing the film hardness.

In the liquid crystal device of the present invention described above, it is preferable that a pore volume of the protective film is controlled so as to have a hardness capable of inserting the conductor.
According to this configuration, by controlling the pore volume, the protective film has a hardness that allows a conductor to be inserted therein, so that a photolithography process for forming a contact hole is not required, and the manufacturing process can be simplified. it can.

Specifically, the mesoporous structure in the protective film can be formed by heat-treating a coating film made of a solution containing a surfactant.
According to this configuration, when forming a protective film having a mesoporous structure, it is only necessary to add a surfactant to the solution, and an increase in the number of steps can be prevented.

Moreover, it is desirable that the thickness of the protective film is 10 nm or more and 300 nm or less.
If the film thickness of the protective film is less than 10 nm, the effect of adsorbing mobile ions may be insufficient, and the display quality of the liquid crystal device may be degraded. If the film thickness of the protective film exceeds 300 nm, the driving voltage is increased. There is a possibility that the display characteristics of the liquid crystal device will be lowered.

An electronic apparatus of the present invention includes the liquid crystal device of the present invention described above.
According to the electronic apparatus of the present invention, display quality can be improved and costs can be reduced.

The film forming method of the present invention is a method for forming a protective film disposed between a conductive film and an alignment film in a liquid crystal device, and comprises a solution containing a matrix component, ion-adsorbing fine particles, and a surfactant. The protective film having a mesoporous structure containing ion-adsorbing fine particles is formed by coating on a substrate and heat-treating the coating film.
Specifically, for example, a method in which the surfactant is chloride or bromide can be employed.

  According to the film forming method of the present invention, the film hardness can be controlled for the protective film having an ion adsorption function.

The liquid crystal device of the present invention is a method of manufacturing a liquid crystal device in which liquid crystal is sandwiched between a pair of substrates facing each other, and includes a conductive film and an alignment film on at least one of the pair of substrates. A step of forming a protective film having a mesoporous structure disposed between and containing ion-adsorbing fine particles, and a step of inserting a conductor into the protective film and electrically connecting the conductor and the conductive film It is characterized by that.
Specifically, a method using the above-described film forming method of the present invention can be employed for forming the protective film.

  According to the manufacturing method of the present invention, the protective film disposed between the conductive film and the alignment film has a film hardness so that it has an ion adsorption function and is advantageous for simplification of the manufacturing process. A controlled liquid crystal device can be manufactured.

(Liquid crystal device)
FIG. 1 is a schematic cross-sectional view conceptually showing a configuration example of a liquid crystal device of the present invention.
As shown in FIG. 1, the liquid crystal device has a configuration in which a liquid crystal 50 (liquid crystal layer) is sandwiched between a pair of substrates 10 and 20 facing each other. On the inner surface side (opposite surface side) of the substrate 10, a translucent conductive film 9 (pixel electrode), a protective film 41 containing ion-adsorbing fine particles, and an alignment film 40 are sequentially formed. On the other hand, a translucent conductive film 21 (common electrode, counter electrode), a protective film 61 containing ion-adsorbing fine particles, and an alignment film 60 are sequentially formed on the inner surface side (opposing surface side) of the substrate 20. Yes.

  The substrate 10 and the substrate 20 are bonded together by a sealing material 52, and the liquid crystal 50 is sealed and held in a region partitioned by the sealing material 52. For example, the sealing material 52 is provided with a liquid crystal injection port for injecting liquid crystal after the substrate 10 and the substrate 20 are bonded together.

  On the outside of the sealing material 52, an inter-substrate conductive material 206 for electrical connection between the substrate 10 and the substrate 20 and a conductive terminal 207 for electrical connection with the outside are disposed. Yes. One end of the inter-substrate conducting material 206 is electrically connected to the conductive film 9 on the substrate 10 and the other end is electrically connected to the conductive film 21 on the substrate 20. The conduction terminal 207 has one end electrically connected to the conductive film 9 on the substrate 10 and the other end electrically connected to an external device (for example, a control device) via the wiring 205 or the like. Yes.

  An inter-substrate conductive material 206 for electrical continuity between the pair of substrates 10 and 20 is disposed through the protective films 41 and 61 and the alignment films 40 and 60 in each of the substrates 10 and 20. The conduction terminal 207 electrically connected to the conductive film 9 in the substrate 10 is disposed so as to penetrate the protective film 41 and the alignment film 60 and protrude from the surface of the protective film 41 and the alignment film 60. The shapes of the inter-substrate conducting material 206 and the conducting terminal 207 are arbitrarily set such as a columnar shape or a spherical shape.

  As the conductive films 9 and 21, for example, an indium oxide film (ITO film) doped with tin is used. In addition, various known conductive films having translucency and conductivity, such as an IZO film and an FTO film, can be applied. In the case where translucency is not required, various known conductive films having excellent conductivity can be applied. The ITO film can be formed by an evaporation method, a sputtering method, a baking method (also referred to as a coating pyrolysis method), or the like.

  In order to form an ITO film by using the sputtering method, an ITO transparent conductive film made of indium oxide and tin oxide is set to a predetermined film thickness (for example, 0.8 mm) by setting the substrate surface temperature to a predetermined temperature (for example, 200 ° C.). A film is formed to a thickness of 05 μm to 10 μm, and heat treatment is performed while maintaining a predetermined temperature (for example, 200 ° C. to 250 ° C.) for a certain time (for example, 60 minutes). Thereafter, patterning is performed in a desired planar shape by photolithography as necessary.

  In order to form the ITO film using the firing method, a liquid material of the ITO film is placed on the substrate, and the film is heat-treated. Formation of a conductive film using a liquid phase method is advantageous in reducing manufacturing costs. As an arrangement technique of the liquid material, an inkjet method, a Cap coating method, a spin coating method, or the like can be used. By using an organic solvent in which an organic compound of indium and an organic compound of tin are dissolved in the presence of an organic amine as the liquid material, firing at a relatively low temperature (for example, 250 ° C. or less) becomes possible. Further, after a fine particle film containing light-transmitting conductive fine particles is formed on a substrate, an organic solvent in which the light-transmitting conductive fine particles are dissolved is infiltrated into the fine particle film, and then the film is subjected to heat treatment (firing). ), A light-transmitting conductive film having excellent conductivity can be obtained even when the firing temperature is relatively low (for example, 250 ° C. or lower).

  The protective films 41 and 61 are formed by applying a solution containing a matrix component, ion-adsorptive fine particles, and a surfactant on the substrate 10 (20), and heat-treating the applied film, and have a mesoporous structure. Become. The mesoporous structure is a porous structure having pores with a diameter of about 2 nm to 50 nm, and is formed using the surfactant molecular aggregate as a template in the heat treatment process of the coating film. The surfactant used for forming the protective films 41 and 61 is decomposed during the heat treatment.

  As a matrix which comprises the protective films 41 and 61, an inorganic oxide, resin, etc. are used, for example. Specifically, those derived from one or more matrix-forming components selected from acetylacetonato chelate compounds, organosilicon compounds, polysilazanes and metal alkoxides are applicable.

  Examples of the ion-adsorbing fine particles include inorganic oxides such as SiO2, Al2O3, ZrO2, TiO2, SnO2, In2O3, Sb2O5, SiO2, Al2O3, SiO2, TiO2, In2O3, SnO2, Sb2O5, SnO2, SnO2, In2O3, SbO5. A composite inorganic oxide or solid solution of the above, zeolite (crystalline aluminum silicate), and the like can be applied, and a mixture of two or more of these can also be applied.

  In addition to the above, known techniques described in JP-A-2002-229027 and JP-A-2003-186054 can be used for the matrix for ion-adsorbing film and ion-adsorptive fine particles.

  As the alignment films 40 and 60, either an organic alignment film or an inorganic alignment film can be applied. The organic alignment film can be formed, for example, by performing an alignment process such as rubbing on the surface of a polymer film such as polyimide. The inorganic alignment film has higher light resistance and heat resistance than the organic alignment film. After forming an inorganic film such as SiO2 by vapor deposition or sputtering, the surface of the inorganic film is irradiated with an ion beam or particle beam. It can be formed by performing an alignment treatment. Alternatively, the inorganic alignment film can be formed by a so-called oblique vapor deposition method in which an inorganic material is incident on the substrate obliquely to form a film having an oblique columnar structure. The alignment films 40 and 60 may be formed after the planarization film is formed on the surfaces of the protective films 41 and 61.

  In the liquid crystal device having the above-described configuration, mobile ions are adsorbed by the protective films 41 and 61 including ion-adsorptive fine particles disposed between the conductive films 9 and 21 and the alignment films 40 and 60, and the conductive film 9. , 21 is prevented from being diffused, and the alignment films 40 and 60 are prevented from being deteriorated and the display quality of the liquid crystal device is prevented from being deteriorated due to movable ions in the liquid crystal.

  The thickness of the protective films 41 and 61 is preferably 10 nm or more and 300 nm or less. If the film thickness of the protective films 41 and 61 is less than 10 nm, the effect of adsorbing impurities and mobile ions may be insufficient, and the display quality of the liquid crystal device may deteriorate, and the film thickness of the protective film exceeds 300 nm. As a result, the drive voltage increases and the display characteristics of the liquid crystal device may deteriorate.

  In order to form the protective films 41 and 61, a solution containing a matrix component, ion-adsorbing fine particles, and a surfactant is applied onto the substrate, and the applied film is heat-treated. For the application of the solution, a spin coating method, a dipping method, an ink jet method, a dispensing method, a spray coating method, or the like can be used. By the heat treatment of the coating film, fine pores are formed using the surfactant molecular aggregate as a template, and protective films 41 and 61 having a mesoporous structure including ion-adsorbing fine particles are formed.

  As the surfactant, for example, chloride or bromide is used.

  Examples of the chloride used for the surfactant include tetradecanyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, octadecanyltrimethylammonium chloride, eicosanyltrimethylammonium chloride, and cetyltrimethylammonium chloride. can give.

  Examples of the bromide used for the surfactant include cetyltrimethylammonium bromide, decyltrimethylammonium bromide, dodecyltrimethylammonium bromide, tetradecyltrimethylammonium bromide, and hexadecyltrimethylammonium bromide.

  The heat treatment temperature of the coating film made of a solution containing a matrix component, ion-adsorptive fine particles, and a surfactant is preferably 200 ° C. to 400 ° C., and is pre-dried for volatilizing the solvent (for example, 80 ° C. to 120 ° C.) is preferably performed in advance.

  For example, butyl cellosolve, hexylene glycol, nitric acid, cetyltrimethylammonium bromide as a surfactant, and pure water are added to ethyl silicate as a matrix component precursor and stirred, and deionized using an ion exchange resin or the like. Then, an inorganic ion-adsorbing fine particle sol in which antimony pentoxide fine particles (Sb2O5 · 2.7H2O) as inorganic oxide fine particles are uniformly dispersed in hexylene glycol is added to the dispersion and stirred. Further, a solvent was added to prepare a solution having a predetermined solid content concentration. The amount of cetyltrimethylammonium bromide added is 0.25 mol with respect to 1 mol of the matrix component. And after apply | coating said solution on a board | substrate and pre-drying the coating film at 80 degreeC, the film | membrane of the mesoporous structure which has ion adsorption property was able to be formed by heat-processing at 250 degreeC.

  Here, the pore volume (porosity) of the protective films 41 and 61 can be controlled by adjusting the type or addition amount of the surfactant. In this example, the pore volume is controlled so that the hardness is such that the inter-substrate conducting material 206 and the conducting terminal 207 can be inserted. The inter-substrate conducting material 206 and the conducting terminal 207 are disposed after the conductive films 9 and 21, the protective films 41 and 61, and the alignment films 40 and 60 are formed. That is, after the conductive film 9 (21), the protective film 41 (61), and the alignment film 40 (60) are formed, the inter-substrate conductive material 206 (conductive terminal 207) is pressed against the surface of the alignment film 40 (60). The film is inserted into the alignment film 40 (60) and the protective film 41 (61). Then, the alignment film 40 (60) and the protective film 41 (61) are pierced to penetrate the inter-substrate conductive material 206 (conductive terminal 207), and the end portion and the conductive film 9 (21) are electrically connected.

  Since the pore volume of the protective films 41 and 61 is controlled so that the inter-substrate conducting material 206 and the conducting terminal 207 can be inserted, the photolithography process for forming the contact hole is unnecessary. Thus, the manufacturing process can be simplified. Further, when forming the protective films 41 and 61, the coating film may be formed on the entire surface of the substrates 10 and 20, so that the process can be simplified as compared with the method of partially forming the coating film.

  The pore volume of the protective films 41 and 61 is preferably 0.01 to 0.6 ml / g, and more preferably 0.2 to 0.5 ml / g. Further, the average pore diameter of the protective films 41 and 61 is preferably 2 to 10 nm, and more preferably 2 to 4 nm. If the pore volume of the protective films 41 and 61 is less than 0.01, the effect of adsorbing mobile ions may be insufficient, and the display quality of the liquid crystal device may be degraded. When the volume exceeds 0.6 ml / g, the quality of the membrane may deteriorate.

  In the example of FIG. 1, the inter-substrate conductive material 206 is disposed so as to penetrate both the protective films 41 and 61 and the alignment films 40 and 60 in each of the substrates 10 and 20. It is not limited. The present invention also includes a configuration in which the inter-substrate conductive material 206 is disposed so as to penetrate only the protective films 41 and 61 in the respective substrates 10 and 20. In the case where the alignment films 40 and 60 are made of an inorganic component, the hardness of the alignment films 40 and 60 tends to increase. Therefore, the formation of the alignment films 40 and 60 in the region where the inter-substrate conductive material 206 is disposed is avoided. Is desirable. Similarly, in the example of FIG. 1, the conduction terminal 207 is disposed through both the protective film 41 and the alignment film 40, but the present invention is not limited to this. The present invention also includes a configuration in which the conductive terminal 207 is disposed so as to penetrate only the protective film 41 in the substrate 10.

Next, a specific configuration example of the liquid crystal device of the present invention will be described.
FIG. 2 is a plan view showing the overall structure of the liquid crystal device of the present embodiment. FIG. 3 is an equivalent circuit diagram showing switching elements, signal lines and the like in a plurality of pixels arranged in a matrix constituting the image display area of the liquid crystal device of this embodiment. FIG. 4 is a plan view showing the structure of a plurality of pixel groups adjacent to each other on a TFT array substrate on which data lines, scanning lines, pixel electrodes and the like are formed. FIG. 5 is a cross-sectional view showing the structure of the liquid crystal device of this embodiment, and is a cross-sectional view taken along the line AA ′ of FIG.

  As shown in FIG. 2, in this liquid crystal device (transmission type liquid crystal device), the TFT array substrate 10 and the counter substrate 20 are bonded together by a sealing material 52, and the liquid crystal 50 is enclosed in a region partitioned by the sealing material 52. Is retained. The sealing material 52 is formed with a liquid crystal injection port 55 for injecting liquid crystal after the TFT array substrate 10 and the counter substrate 20 are bonded together at the time of manufacturing. The liquid crystal injection port 55 is sealed after the liquid crystal injection. It is sealed with a material 54.

  A peripheral part (not shown) made of a light-shielding material is formed in a region inside the sealing material 52, while a data line driving circuit 201 and a mounting terminal 202 are provided in the TFT array substrate in a region outside the sealing material 52. The scanning line driving circuit 204 is formed along two sides adjacent to the one side. On the remaining side of the TFT array substrate 10, a plurality of wirings 205 are provided for connecting between the scanning line driving circuits 204 provided on both sides of the image display area. A part of the mounting terminal 202 is connected to the conduction terminal 207 (see FIG. 1), and is electrically connected between the TFT array substrate 10 and the counter substrate 20 at least at one corner of the counter substrate 20. An inter-substrate conducting material 206 for conducting is provided.

  As shown in FIG. 3, a pixel electrode 9 and a TFT element 30 that is a switching element for controlling the pixel electrode 9 are formed on a plurality of pixels arranged in a matrix that forms an image display area. The data line 6 a to which the image signal is supplied is electrically connected to the source of the TFT element 30. The image signals S1, S2,..., Sn supplied to the data line 6a are supplied line-sequentially in this order, or are supplied for each group to a plurality of adjacent data lines 6a.

  In addition, the scanning line 3a is electrically connected to the gate of the TFT element 30, and scanning signals G1, G2,..., Gm are applied to the plurality of scanning lines 3a in a pulse-sequential manner at predetermined timing. The The pixel electrode 9 is electrically connected to the drain of the TFT element 30. By turning on the TFT element 30 for a certain period, the image signals S1, S2,. Sn is written at a predetermined timing.

  A predetermined level of image signals S1, S2,..., Sn written to the liquid crystal via the pixel electrode 9 is held for a certain period with the common electrode described later. This liquid crystal modulates light by changing the orientation and order of the molecular assembly according to the applied voltage level, thereby enabling gradation display. In order to prevent the held image signal from leaking, a storage capacitor 17 is added in parallel with the liquid crystal capacitor formed between the pixel electrode 9 and the common electrode.

  As shown in FIG. 4, a plurality of rectangular pixel electrodes 9 made of a transparent conductive material such as ITO (Indium Tin Oxide) are provided in a matrix on the TFT array substrate. A data line 6a, a scanning line 3a, and a capacitor line 3b are provided along the vertical and horizontal boundaries of the electrode 9, respectively. Here, the outline of the pixel electrode 9 is indicated by a dotted line 9A. In the present embodiment, each pixel electrode 9 and a region where the data line 6a, the scanning line 3a, the capacitor line 3b, etc., which are arranged so as to surround each pixel electrode 9 are formed are pixels and arranged in a matrix. Thus, the display can be performed for each pixel.

  The data line 6a is electrically connected to a source region (described later) through a contact hole 5 in the semiconductor layer 1a made of, for example, a polysilicon film constituting the TFT element 30, and the pixel electrode 9 is connected to the semiconductor layer 1a. Among these, it is electrically connected to a drain region described later via a contact hole 8. In addition, a scanning line 3a is disposed in the semiconductor layer 1a so as to face a channel region (a region with a slanting line in the left-upward direction in the figure) described later. The scanning line 3a is a gate electrode at a portion facing the channel region. It is configured to function as.

  The capacitor line 3b extends along the data line 6a from the main line portion (first area formed along the scanning line 3a) extending in a substantially straight line along the scanning line 3a and the data line 6a. And a protruding portion (a second region extending along the data line 6a in plan view) protruding to the front side (upward in the drawing). In FIG. 4, a plurality of first light shielding films 11 a are provided in a region indicated by a diagonal line rising to the right.

  More specifically, each of the first light shielding films 11a is provided at a position covering the TFT element 30 including the channel region of the semiconductor layer 1a when viewed from the TFT array substrate side, and further, the main line portion of the capacitor line 3b. And a main line portion that extends linearly along the scanning line 3a, and a protruding portion that protrudes from the portion intersecting the data line 6a to the rear stage side (downward in the figure) adjacent to the data line 6a. The tip of the downward protruding portion in each stage (pixel row) of the first light shielding film 11a overlaps the tip of the upward protruding portion of the capacitor line 3b in the next stage under the data line 6a. A contact hole 13 for electrically connecting the first light-shielding film 11a and the capacitor line 3b to each other is provided at the overlapping portion. In other words, in the present embodiment, the first light shielding film 11a is electrically connected to the upstream or downstream capacitor line 3b through the contact hole 13.

  As shown in FIG. 5, the TFT array substrate 10 includes a substrate body 10A made of a translucent material such as quartz, a pixel electrode 9, a TFT element 30, and an alignment film 40 formed on the surface of the liquid crystal layer 50 side. The counter substrate 20 is composed mainly of a substrate body 20A made of a light-transmitting material such as glass or quartz, and a common electrode 21 and an alignment film 60 formed on the liquid crystal layer 50 side surface. Has been.

  More specifically, in the TFT array substrate 10, a pixel electrode 9 is provided on the surface of the substrate body 10 </ b> A on the liquid crystal layer 50 side, and for pixel switching for switching control of each pixel electrode 9 at a position adjacent to each pixel electrode 9. A TFT element 30 is provided. The pixel switching TFT element 30 has an LDD (Lightly Doped Drain) structure, and includes a scanning line 3a, a channel region 1a ′ of the semiconductor layer 1a in which a channel is formed by an electric field from the scanning line 3a, and the scanning line 3a. A gate insulating film 2 that insulates the semiconductor layer 1a, a data line 6a, a low concentration source region 1b and a low concentration drain region 1c of the semiconductor layer 1a, and a high concentration source region 1d and a high concentration drain region 1e of the semiconductor layer 1a. ing.

  Further, a second contact hole 5 leading to the high concentration source region 1d and a contact hole 8 leading to the high concentration drain region 1e are formed on the substrate main body 10A including the scanning line 3a and the gate insulating film 2. An interlayer insulating film 4 is formed. That is, the data line 6 a is electrically connected to the high concentration source region 1 d through the contact hole 5 that penetrates the second interlayer insulating film 4. Further, on the data line 6a and the second interlayer insulating film 4, a third interlayer insulating film 7 having a contact hole 8 leading to the high concentration drain region 1e is formed. That is, the high concentration drain region 1 e is electrically connected to the pixel electrode 9 through the contact hole 8 that penetrates the second interlayer insulating film 4 and the third interlayer insulating film 7.

  In the present embodiment, the gate insulating film 2 is extended from a position facing the scanning line 3a and used as a dielectric film, the semiconductor layer 1a is extended to form the first storage capacitor electrode 1f, and further opposed thereto. The storage capacitor 17 is configured by using a part of the capacitor line 3b to be a second storage capacitor electrode.

  In addition, the TFT array substrate 10 is transmitted through the region where the pixel switching TFT elements 30 are formed on the surface of the TFT array substrate 10 on the liquid crystal layer 50 side of the substrate body 10A, and the lower surface of the TFT array substrate 10, that is, the TFT Return light reflected at the interface between the array substrate 10 and air and returning to the liquid crystal layer 50 side is incident on at least the channel region 1a ′ and the low concentration source / drain regions (LDD regions) 1b and 1c of the semiconductor layer 1a. The 1st light shielding film 11a for preventing is provided. Further, a first interlayer insulation for electrically insulating the semiconductor layer 1a constituting the pixel switching TFT element 30 from the first light shielding film 11a is provided between the first light shielding film 11a and the pixel switching TFT element 30. A film 12 is formed.

  Further, as shown in FIG. 5, in addition to providing the first light shielding film 11a on the TFT array substrate 10, the first light shielding film 11a is electrically connected to the capacitor line 3b at the front stage or the rear stage through the contact hole 13. Configured to connect to. Further, the liquid crystal when no voltage is applied so as to cover the pixel electrode 9 and the third interlayer insulating film 7 in a region where the pixel electrode 9 is not formed on the outermost surface of the TFT array substrate 10 on the liquid crystal layer 50 side. An alignment film 40 for controlling the alignment of the liquid crystal molecules in the layer 50 is formed.

  In the TFT array substrate 10, a protective film 41 containing ion-adsorbing fine particles is formed immediately below the alignment film 40, that is, between the pixel electrode 9 and the third interlayer insulating film 7 and the alignment film 40. Has been. Due to the presence of the protective film 41, diffusion of ionic impurities caused by decomposition of the alignment film 40 made of an organic polymer and inflow into the liquid crystal layer 50 are prevented. In addition, deterioration of the alignment film 40 due to diffusion of impurities and metal elements from the pixel electrode 9 provided below the alignment film 40 is prevented. A polarizer 15 that transmits only predetermined polarized light is attached to the surface of the TFT array substrate 10 opposite to the liquid crystal layer 50 side.

  On the other hand, the counter substrate 20 has a surface on the liquid crystal layer 50 side of the substrate body 20A, which is a region facing the formation region of the data line 6a, the scanning line 3a, and the pixel switching TFT element 30, that is, an opening of each pixel unit. Second light-shielding film 23 for preventing incident light from entering the channel region 1a ′, the low-concentration source region 1b, and the low-concentration drain region 1c of the semiconductor layer 1a of the pixel switching TFT element 30 in a region other than the region. Is provided. Further, a common electrode 21 made of a transparent electrode material such as ITO is formed on almost the entire surface of the substrate body 20A on which the second light shielding film 23 is formed on the liquid crystal layer 50 side.

  An alignment film 60 for controlling the alignment of liquid crystal molecules in the liquid crystal layer 50 when no voltage is applied is formed on the outermost surface of the counter substrate 20 on the liquid crystal layer 50 side. A protective film 61 containing ion-adsorptive fine particles is formed between the common electrode 21 and the alignment film 60. The alignment film 60 and the protective film 61 have structures equivalent to the alignment film 40 and the protective film 41 of the TFT array substrate 10, respectively. Further, a polarizer 25 that transmits only predetermined polarized light is attached to the surface of the counter substrate 20 opposite to the liquid crystal layer 50 side.

  The film thickness of the protective films 41 and 61 is preferably in the range of 10 to 300 nm, and more preferably in the range of 10 to 100 nm. The reason is that if the protective films 41 and 61 are less than 10 nm in thickness, the adsorption effect of the ionic impurities generated by the decomposition of the alignment films 40 and 60 is insufficient, so that the liquid crystal due to the inflow of impurities into the liquid crystal layer 50 is obtained. There is a possibility that deterioration of the reliability of the device cannot be prevented, and the effect of preventing the diffusion of impurities and metal elements from the electrode (pixel electrode 9 or common electrode 21) is insufficient, and the alignment films 40, 60 This is because there is a possibility that the deterioration cannot be prevented. When the film thickness exceeds 300 nm, the distance between the liquid crystal layer 50 and the electrode (pixel electrode 9 or common electrode 21) increases, the voltage for driving the liquid crystal layer 50 increases, and good display characteristics are obtained. It is because it becomes impossible.

  In the present embodiment, only the TN mode liquid crystal device has been described. However, the present invention is not limited to this, and the present invention is not limited to the vertical alignment mode, the STN (Super Twisted Nematic) mode, and the like. The alignment state of the liquid crystal molecules during heating can be applied to any liquid crystal device. When the present invention is applied to a vertical alignment mode liquid crystal device, the liquid crystal layer has a positive and negative dielectric anisotropy in which the major and minor axis directions of the liquid crystal molecules are more easily polarized than the minor and major axis directions. May be configured. In this case, when no voltage is applied, the liquid crystal molecules in the liquid crystal layer are controlled by the alignment film and are aligned in a predetermined direction, whereas when a voltage is applied, the liquid crystal molecules in the liquid crystal layer have their major axis direction changed. Since it is arranged in a direction substantially perpendicular to the direction of the vertical electric field generated between the pair of substrates, the arrangement of liquid crystal molecules when no voltage is applied and when the voltage is applied can be optically identified and displayed. it can.

  In the present embodiment, only the method for forming the alignment film by the vapor deposition method has been described. However, the present invention may have a configuration in which a protective film including ion-adsorbing fine particles is formed between the electrode and the alignment film. The manufacturing method is not limited to this. For example, the alignment film may be formed by a sputtering method or an ion plating method.

FIG. 6 is a perspective view showing the overall configuration of a passive matrix transmissive liquid crystal device.
This transmissive liquid crystal device is schematically configured to include a pair of substrates 70 and 80 arranged to face each other with a liquid crystal layer (not shown) interposed therebetween.

  More specifically, the substrate 70 includes a plurality of transparent electrodes 72 formed in a stripe shape on the surface of the substrate body 71 on the liquid crystal layer side, a protective film (not shown) and an alignment film containing ion-adsorbing fine particles. (Not shown) are sequentially provided. The substrate 80 includes a large number of transparent electrodes 82 formed in a stripe pattern on the surface of the substrate body 81 on the liquid crystal layer side, a protective film (not shown) containing ion-adsorbing fine particles, and an alignment film (not shown). ) In order.

  As shown in the figure, the transparent electrode 72 of the substrate 70 and the transparent electrode 82 of the substrate 80 are formed in a direction crossing each other. Further, the structure of the liquid crystal layer, the alignment film, and the protective film constituting the transmissive liquid crystal device of this embodiment is the same as that of the liquid crystal device of FIG.

  As described above, the present invention can also be applied to a passive matrix transmissive liquid crystal device, and the same effect as that of an active matrix transmissive liquid crystal device can be obtained.

  In each of the above-described embodiments, only the active matrix type transmissive liquid crystal device and the passive matrix type transmissive liquid crystal device using TFT elements have been described. However, the present invention is not limited to these, and TFD ( The present invention can also be applied to an active matrix liquid crystal device using a two-terminal element typified by a thin-film diode element.

  The present invention is not limited to the above-described embodiments formed on the entire surface of the substrate as long as a protective film containing ion-adsorbing fine particles is formed between the electrode and the alignment film. For example, the protective film may be formed in the same shape as the electrode. In this case, it can be performed simultaneously with the electrode patterning. Further, when formed on the entire surface of the substrate, the protective film may be planarized to improve the alignment characteristics as long as the step formed on the liquid crystal side surface is not large.

  In each of the above embodiments, the transmissive liquid crystal device has been described. However, the present invention may be any configuration as long as a protective film including ion-adsorbing fine particles is formed between the electrode and the alignment film. The invention is not limited to the above embodiments. For example, the present invention can be applied to a reflective liquid crystal device other than a transmissive liquid crystal device and a transflective liquid crystal device, and can be applied to a liquid crystal device having any structure.

(Electronics)
Next, a projector will be described as an example of the electronic apparatus of the invention.
FIG. 7 schematically shows the projector.
This projector PJ1 uses the liquid crystal device of the present invention as a light modulation means (liquid crystal light valve), and includes a transmissive liquid crystal light valve for each of different colors of R (red), G (green), and B (blue). 3 plate type intermittent display type color liquid crystal projector.

  As shown in FIG. 7, the projector PJ1 includes a light source 810, dichroic mirrors 813, 814, reflection mirrors 815, 816, 817, an incident lens 818, a relay lens 819, an exit lens 820, and a liquid crystal light valve 822. , 823, 824, a cross dichroic prism 825, and a projection lens 826.

The light source 810 includes a lamp 811 such as a metal halide and a reflector 812 that reflects the light of the lamp.
The dichroic mirror 813 transmits red light contained in white light from the light source 810 and reflects blue light and green light. The transmitted red light is reflected by the reflection mirror 817 and enters the red light liquid crystal light valve 822. The green light reflected by the dichroic mirror 813 is reflected by the dichroic mirror 814 and enters the liquid crystal light valve 822 for green light. Further, the blue light reflected by the dichroic mirror 813 passes through the dichroic mirror 814. For blue light, in order to prevent light loss due to a long optical path, a light guide means 821 including a relay lens system including an incident lens 818, a relay lens 819, and an exit lens 820 is provided. Blue light is incident on the blue light liquid crystal light valve 824 via the light guiding means 821.

  The three color lights modulated by the liquid crystal light valves 822, 823, and 824 are incident on the cross dichroic prism 825. The cross dichroic prism 825 is formed by bonding four right-angle prisms. A dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light are formed in an X shape at the interface. Yes. These dielectric multilayer films combine the three color lights to form light representing a color image. The synthesized light is projected onto the screen 827 by the projection lens 826 which is a projection optical system, and the image is enlarged and displayed.

  According to the projector PJ1 described above, since the deterioration of the alignment film in the liquid crystal light valves 822, 823, and 824 and the deterioration of the display quality due to the movable ions in the liquid crystal are prevented, the display quality can be improved. In addition, the cost can be reduced by simplifying the manufacturing process of the liquid crystal light valves 822 823 824.

In this example, the liquid crystal device of the present invention is adopted for each of the liquid crystal light valves for red light, green light, and blue light. However, the liquid crystal device is not necessarily applied to all liquid crystal light valves. When applied to at least one of the liquid crystal light valves of R, G, and B, the effect can be obtained. The liquid crystal device of the present invention is particularly effective when applied to a liquid crystal light valve for blue light (B) having high light energy.
Further, although the description has been given by taking a three-plate projection display device (projector) as an example, the present invention can also be applied to a single-plate projection display device or a direct-view display device.

  The liquid crystal device of the present invention can also be applied to electronic devices other than projectors. As a specific example, a mobile phone including the liquid crystal device of the present invention in a display portion can be given. Other electronic devices include, for example, a video camera, a personal computer, a head mounted display, a fax machine with a display function, a digital camera finder, a portable TV, a PDA (Personal Digital Assistant), an electronic notebook, and an electric bulletin board. And advertising announcement displays.

  As described above, the preferred embodiments according to the present invention have been described with reference to the accompanying drawings, but the present invention is not limited to the examples. It is obvious for those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea described in the claims. It is understood that it belongs to.

FIG. 2 is a schematic cross-sectional view conceptually showing a configuration example of a liquid crystal device of the present invention. The top view which shows the whole structure of a liquid crystal device. FIG. 6 is an equivalent circuit diagram illustrating an image display area of the transmissive liquid crystal device. FIG. 3 is a plan view showing the structure of a plurality of pixel groups of a transmissive liquid crystal device. Sectional drawing which shows the structure of a transmissive liquid crystal device. FIG. 6 is a perspective view illustrating a passive matrix transmissive liquid crystal device. FIG. 2 schematically shows an example of a projector.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... TFT array substrate, 20 ... Counter substrate, 30 ... TFT element, 9 ... Pixel electrode (conductive film), 21 ... Common electrode (conductive film), 50 ... Liquid crystal layer, 52 ... Sealing material, 40, 60 ... Alignment film , 41, 61 ... protective film, 70 ... lower substrate, 80 ... upper substrate, 206 ... inter-substrate conductive material (conductor), 207 ... conductive terminal (conductor), 205 ... wiring, PJ1 ... projector.

Claims (11)

A liquid crystal device having a liquid crystal sandwiched between a pair of substrates facing each other,
A conductive film, a protective film containing ion-adsorptive fine particles, and an alignment film are sequentially formed on the inner surface side of at least one of the pair of substrates.
The liquid crystal device, wherein the protective film has a mesoporous structure. A liquid crystal device having a liquid crystal sandwiched between a pair of substrates facing each other,
A conductive film, a protective film containing ion-adsorptive fine particles, and an alignment film are sequentially formed on the inner surface side of at least one of the pair of substrates.
The protective film has a mesoporous structure,
A liquid crystal device, wherein a conductor electrically connected to the conductive film penetrates the protective film and protrudes from a surface of the protective film. A liquid crystal device having a liquid crystal sandwiched between a pair of substrates facing each other,
On each inner surface side of the pair of substrates, a conductive film, a protective film containing ion-adsorbing fine particles, and an alignment film are sequentially formed,
The protective film has a mesoporous structure,
A liquid crystal device, wherein a conductor for electrical conduction between the pair of substrates is disposed through the protective film in each of the pair of substrates.   4. The liquid crystal device according to claim 2, wherein the protective film has a pore volume controlled so as to have a hardness capable of inserting the conductor.   5. The liquid crystal device according to claim 1, wherein the mesoporous structure in the protective film is formed by heat-treating a coating film made of a solution containing a surfactant.   6. The liquid crystal device according to claim 1, wherein the protective film has a thickness of 10 nm to 300 nm.   An electronic apparatus comprising the liquid crystal device according to claim 1. A method of forming a protective film disposed between a conductive film and an alignment film in a liquid crystal device,
A mesoporous structure-containing protective film containing ion-adsorbing fine particles is formed by applying a solution containing a matrix component, ion-adsorbing fine particles and a surfactant on a substrate, and heat-treating the coating film. Film forming method.   9. The film forming method according to claim 8, wherein the surfactant is chloride or bromide. A method of manufacturing a liquid crystal device in which a liquid crystal is sandwiched between a pair of substrates facing each other,
Forming a protective film having a mesoporous structure disposed between the conductive film and the alignment film on at least one of the pair of substrates and including ion-adsorbing fine particles;
A method for manufacturing a liquid crystal device, comprising: inserting a conductor into the protective film and electrically connecting the conductor and the conductive film.   A method for manufacturing a liquid crystal device, wherein the film forming method according to claim 8 or 9 is used for forming the protective film.

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