JPH11249178A - 2-terminal type nonlinear element, manufacture thereof and liquid crystal display panel and electronic equipment using the nonlinear element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain especially uniformity among the steepness, symmetry and uniformity of the voltage/current characteristics of a nonlinear element by supplying temperature distribution based on the difference of the characteristics of a 2-terminal type nonlinear element to a substrate and performing heat treatment. SOLUTION: An insulation film 31 formed on the substrate 30 is turned into a base, a thin film diode(TFD) element 20 is formed on the upper surface and is constituted of first metallic film 22, oxidized film 24 which is an insulator and second metallic film 26 in an order from the side of the insulation film 31 and the sandwich structure of metal - insulator - metal is adopted. Then, in the heat treatment process, a computer stores resistance value change characteristics beforehand and obtains the characteristic distribution of the element from the result of TEG or the like measured beforehand and the result of automatically measuring the characteristics of the TFD element 20 of an element array substrate 30 over plural points. In such a manner, the temperature distribution corresponding to the characteristic distribution of the element is calculated, a heat treatment device is controlled and the temperature distribution is supplied to the element array substrate 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-terminal nonlinear element suitable for use as a switching element for driving a pixel electrode in a liquid crystal display panel, for example, a method of manufacturing the same, and a liquid crystal display panel using the nonlinear element. And electronic equipment.

[0002]

2. Description of the Related Art In general, an active matrix type liquid crystal display panel has an element array substrate in which non-linear (switching) elements are provided in each of pixel electrodes arranged in a matrix, and an opposing array in which color filters and the like are formed. It is composed of a substrate and a liquid crystal filled between the two substrates, and displays predetermined information by driving each nonlinear element and controlling the alignment state of the liquid crystal for each pixel.

Here, as the nonlinear element, mainly, a three-terminal type nonlinear element such as a thin film transistor (TFT) and a thin film diode (TFD: Thin film transistor) are used.
Film Diode) and other two-terminal non-linear elements, but the latter two-terminal non-linear elements do not have short-circuit failures between wiring in principle because there is no intersection of wiring. Further, it is advantageous in that the film formation step and the photolithography step can be shortened.

[0004]

However, in such a two-terminal nonlinear element, a nonlinear characteristic having a definite threshold value such that it turns on when the voltage applied between the terminals is high and turns off when the voltage applied between the terminals is low, Specifically, it is required that the voltage-current characteristics be steep. Further, in order to perform AC driving, it is required that this characteristic is symmetrical in both positive and negative directions. In addition, it is required that the steepness and the symmetry of such characteristics are uniform in all the nonlinear elements provided on the element array substrate. If even one of the steepness, symmetry, and uniformity of these characteristics is impaired, the display becomes non-uniform, and display unevenness, poor gradation display, reduced contrast, etc. occur.
There was a problem.

The present invention has been made in view of such circumstances, and it is an object of the present invention to make the voltage-current characteristics of a nonlinear element particularly uniform among steepness, symmetry, and uniformity. It is an object of the present invention to provide a liquid crystal display panel and an electronic device having a uniform display by using a two-terminal nonlinear element provided therewith, a method of manufacturing the same, and the nonlinear element.

[0006]

According to a first aspect of the present invention, there is provided a method for manufacturing a two-terminal nonlinear element comprising a first metal-insulator-second metal. Forming a metal on a substrate, forming the insulator on the surface of the first metal, and forming the second metal on the surface of the insulator to form a plurality of two-terminal nonlinear elements on the substrate The method is characterized by comprising a step of forming on the substrate and a step of heat-treating the substrate by giving a temperature distribution based on the difference in characteristics of the two-terminal nonlinear element.

According to a second aspect of the present invention, there is provided a semiconductor device comprising: a plurality of second metal layers formed of a first metal-insulator-second metal formed on a substrate;
A terminal-type non-linear element, characterized in that after being formed on a substrate, a temperature distribution based on a difference in characteristics thereof is given.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

<TFD Element> First, as an example of a two-terminal type nonlinear element according to an embodiment of the present invention, a TFD element for driving each pixel of an active matrix liquid crystal display device will be described.

FIG. 1A is a plan view showing a layout for one pixel in a liquid crystal panel substrate to which the TFD element is applied, and FIG. 1B shows the structure of the TFD element in FIG. FIG. 3 is a cross-sectional view taken along line AA in FIG.

As shown in these figures, the TFD element 20
Is based on the insulating film 31 formed on the substrate 30
The first metal film 22, the oxide film 24 serving as an insulator, and the second metal film 22 are sequentially formed from the insulating film 31 side.
It is composed of a metal film 26 and has a metal-insulator-metal sandwich structure. And, with such a structure, TFD
The device will have bidirectional diode switching characteristics.

The first metal film 22 constituting the TFD element 20 becomes the scanning line 12 as one terminal as it is, while the second metal film 26 forms the pixel electrode 34 as the other terminal.
Connected to.

The substrate 30 has insulating properties and transparency, and is made of, for example, glass or plastic. Here, the reason why the insulating film 31 serving as a base is provided is to prevent the first metal film 22 from peeling off from the base by heat treatment after the deposition of the second metal film 26, and This is for preventing impurities from diffusing. Therefore, if this is not a problem, the insulating film 31 can be omitted.

The first metal film 22 is a conductive metal thin film and is made of, for example, tantalum alone or a tantalum alloy. The oxide film 24 is, for example, an insulating film formed by anodizing the surface of the first metal film 22 in a chemical solution. The second metal film 26 is a conductive metal thin film and is made of, for example, chromium alone or a chromium alloy.

The pixel electrode 34 is made of ITO (Indium Tin Oxide) when used for a transmission type liquid crystal display panel.
When it is applied to a reflective liquid crystal display panel, it is made of a metal film having a high reflectance, such as aluminum or silver.

<Another Example of TFD Element>
Another example of the D element will be described.

<Common use of second metal film and pixel electrode> FIG.
In the TFD element 20 shown in FIG. 1, the second metal film 26 and the pixel electrode 34 are formed of different metal films.
As shown in the cross-sectional view of FIG. 2, the second metal film and the pixel electrode may be formed of a transparent conductive film 36 made of the same ITO film or the like. TFD element 20 having such a configuration
Has an advantage that the second metal film and the pixel electrode can be formed by the same process. In FIG. 2, the same components as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.

<Back-to-back structure>
As another example of the D element, a back-to-back (back-t
An o-back) TFD element will be described. FIG.
FIG. 3A is a plan view showing a layout of one pixel on a liquid crystal panel substrate to which the TFD element is applied, and FIG.
(B) is a sectional view showing the structure of the TFD element along the line BB.

The back-to-back structure refers to a structure in which two diodes are connected in series in opposite directions in order to make the nonlinear characteristics symmetric. Therefore, as shown in FIG.
The FD element 40 includes a first TFD element 40a and a second TF element 40a.
And D40b are connected in series with opposite polarities.

More specifically, a substrate 30, an insulating film 31 formed on the surface, a first metal film 42, an oxide film 44 formed on the surface by anodic oxidation, and a The second metal films 46a and 46b are separated from each other.

The second metal film 46a of the first TFD element 40a becomes the scanning line 48 as it is, while the second metal film 46b of the second TFD element 40b is connected to the pixel electrode 45. The oxide film 44 is formed as shown in FIG.
The film thickness is set smaller than the oxide film 24 in the TFD element 20 shown in FIG. The specific configuration of each component such as the first metal film 42, the oxide film 44, and the second metal films 46a and 46b is the same as that of the TFD element 20 described above, and thus the description thereof is omitted. And

In addition, the symmetry of the nonlinear characteristic can be ensured by a ring-shaped element in which two diodes are connected in parallel in opposite directions.

<Manufacturing Process of TFD Element> Next, a manufacturing process of the nonlinear element according to the first embodiment of the present invention will be described with reference to the TFD element 20 shown in FIG. 1 as an example.

(1) First, as shown in FIG.
An insulating film 31 is formed on the upper surface. The insulating film 31 is made of, for example, tantalum oxide, and is formed by a method of thermally oxidizing a tantalum film deposited by a sputtering method, a sputtering method using a target made of tantalum oxide, or a co-sputtering method. This insulating film 31
Is provided for the main purpose of improving the adhesion of the first metal film 22 and preventing diffusion of impurities from the substrate 30 as described above.
About 50 to 200 nm is sufficient.

(2) Next, the first metal film 22 is formed on the upper surface of the insulating film 31. The composition of the first metal film 22 is, for example, tantalum alone or a tantalum alloy. When using a tantalum alloy, for example,
Elements belonging to Groups 6 to 8 in the periodic table, such as tungsten, chromium, molybdenum, rhenium, yttrium, lanthanum, and displorium, may be added. In addition, as an element to be added, tungsten is preferable,
The content ratio is desirably, for example, 0.1 to 6 atomic%.

The first metal film 22 can be formed by a sputtering method, an electron beam evaporation method, or the like. When the first metal film 22 made of a tantalum alloy is formed, the first metal film 22 can be formed by a sputtering method using a mixed target. , Co-sputtering method, electron beam evaporation method and the like are used.

The thickness of the first metal film 22 is selected at a suitable value depending on the use of the TFD element.
It is about nm.

(3) Then, the first metal film 22 is patterned by commonly used photolithography and etching techniques.

(4) Subsequently, the oxide film 24 is formed on the first metal film 2
2 is formed on the surface. Specifically, the surface of the first metal film 22 is formed by oxidation by an anodic oxidation method.
At this time, the surface of the scanning line 12 is simultaneously oxidized to form an insulating film. A preferred value of the thickness of the oxide film 24 is selected depending on its use, and is, for example, about 20 to 70 nm. The chemical conversion solution used for the anodic oxidation is not particularly limited, but for example, a citric acid aqueous solution of 0.01 to 0.1% by weight can be used.

(5) Next, a second metal film 26 is formed. The second metal film 26 is, for example, chromium, aluminum, titanium, molybdenum, or the like, and is formed by depositing by a sputtering method or the like.
The thickness of the second metal film 26 is, for example, about 50 to 300 nm.

(6) Then, as shown in FIG. 5, the second metal film 26 is patterned by commonly used photolithography and etching techniques.

(7) Next, a metal film to be the pixel electrode 34 is formed. The metal film is preferably an ITO film for a transmissive liquid crystal display panel, and an aluminum film or the like for a reflective liquid crystal display panel. The metal film is formed by depositing a film having a thickness of 30 to 200 nm by a sputtering method or the like. Filmed.

(8) The metal film is patterned by a generally used photolithography and etching technique to become the pixel electrode 34.

According to such a process, a plurality of TFD elements 20 are formed in a matrix on the substrate 30 to form an element array substrate. However, in this state, the TFD in the element array substrate 30 may vary due to various factors such as variations in the thickness of each metal / insulating film and etching accuracy.
It is believed that the non-linear characteristics of element 20 are not completely uniform, but have a distribution, as shown in FIG. This figure shows T
The logarithm of the resistance value (on resistance) when a constant voltage (10 V) is applied to the FD element 20 is:
The distribution is shown based on actual measurement values. As shown in this figure, it can be seen that the resistance value is lower toward the center of the substrate and higher toward the outer periphery. Therefore, the same element array substrate 30
In the plurality of TFD elements 20, the uniformity of the non-linear characteristics is not ensured. Therefore, even if the liquid crystal display panel is configured in this state, display unevenness will occur.

On the other hand, the inventors of the present invention heat-treated the substrate on which the TFD element was formed, and measured how the non-linear characteristics changed with the processing time. FIG. 7 shows the measurement results. In this figure, the vertical axis is the logarithmic value of the resistance value when a voltage of 10 V is applied to the TFD element, and the horizontal axis is the heat treatment time. As shown in this figure, the resistance value increases with the passage of time in the initial stage of the heat treatment, but thereafter decreases slowly. Further, the change in the resistance value is sharper as the temperature of the heat treatment is higher.

The inventors of the present application have found that the use of such a resistance change characteristic makes it possible to make the characteristics of the TFD elements on the same element array substrate 30 uniform.

That is, even if the characteristics of the TFD element 20 formed in the above step (8) are different, the TFD element 20 is heat-treated by giving a temperature distribution corresponding to the difference in the characteristics.
The characteristics of the TFD elements on the same element array substrate 30 can be made uniform.

Specifically, with respect to the element array substrate 30,
When the heat treatment is performed for the treatment time A using the characteristics shown in FIG. 7, the higher the temperature of the heat treatment, the more rapidly the resistance value increases. A higher temperature is given to the TFD element 20 having a lower value.

Alternatively, when the element array substrate 30 is heat-treated for the processing time B using the characteristics shown in FIG. 7, after the resistance value once increases, the resistance value gradually decreases as the temperature of the heat treatment decreases. Therefore, a higher temperature is applied to the TFD element 20 having a high resistance value, while a lower temperature is applied to the TFD element 20 having a low resistance value.

Here, the TF on the element array substrate 30
Regarding the characteristics of the D element 20, the resistance value of the TFD element 20 formed in the above step (8) may be measured over a plurality of sites for each substrate, and the distribution of the nonlinear characteristic may be determined by the format, If there is a tendency to depend on glass size, production lot, etc., TEG measured in advance according to these
(Test Element Group) results may be used.

As a method of giving a temperature distribution to the element array substrate 30, first, using a hot plate capable of heating at a different temperature for each of a plurality of blocks, the temperature of each block is set according to the resistance value of the TFD element. There is a method of setting. In addition, a method of locally controlling the laser output according to the resistance value using a laser annealing apparatus is also conceivable.

In the heat treatment step for providing such a temperature distribution, as shown in FIG.
First, the resistance change characteristics (see FIG. 7) are stored in advance, and second, the results of the previously measured TEG and the like and the characteristics of the TFD elements of the element array substrate 30 are automatically measured at a plurality of points. It is desirable to obtain a characteristic distribution of the element from the result, thirdly, calculate a temperature distribution according to the characteristic distribution of the element, and thirdly, control the heat treatment apparatus 810 to give a temperature distribution to the element array substrate 30. .

As described above, according to the manufacturing process of the first embodiment, even if the TFD element formed in the step (8) has a difference in the non-linear characteristic, thereafter, the resistance change characteristic (see FIG. 7) is used. Then, since the heat treatment is performed by giving a temperature distribution based on the difference, the non-linear characteristics of the plurality of TFD elements 20 formed over the entire surface of the element array substrate 30 are made uniform. Therefore, in the liquid crystal display panel using this TFD element, it is possible to provide a uniform and uniform display screen.

<Manufacturing Process of TFD Element> Next, a manufacturing process of the non-linear element according to the second embodiment of the present invention will be described.

The inventors of the present invention have previously formed a nonlinear coefficient (β value) indicating steepness of the voltage-current characteristic by combining the atoms forming oxide film 24 and oxygen atoms in TFD element 20. Can be significantly improved, and by controlling the ratio of bonding with oxygen atoms,
It has been found that a current value when a current flows from the first metal film 22 to the second metal film 26 and a current value when a current flows from the second metal film 26 to the first metal film 22 can be controlled. ing.

Here, in order to bond the atoms forming the oxide film 24 with the oxygen atoms, for example, the above-mentioned step (1)
It is possible by adding the following steps to (8).

That is, the oxide film 2 is formed by the step (4).
A step (4a) of heat-treating the substrate 30 on which the substrate 4 is formed in an atmosphere containing moisture is added.
After that, it is possible to add a step (9) of performing a heat treatment at a temperature of 200 ° C. or more.

If such a step is added, first, oxygen atoms and hydrogen atoms are added to the interface between the surface layer of the oxide film 24 and the first metal film 22 by the heat treatment in the step (4a). In the step (5), some of the atoms forming the second metal film 26 are added to the surface layer of the oxide film 24.

In this state, as shown in FIG. 9, the oxide film 24 has the following first oxide film 24a and second oxide film 24b.
And the third oxide film 24c. That is, the first oxide film 24a in the oxide film 24
Is formed at the interface with the first metal film 22 containing hydrogen atoms and oxygen atoms, and the third oxide film 24c is formed on the second metal film 22 containing hydrogen atoms, oxygen atoms and atoms of the second metal film 26.
An interface with the metal film 26 is formed, and the second oxide film 24b is formed between the first oxide film 24a and the third oxide film c.

At this time, hydrogen atoms and oxygen atoms contained in the first oxide film 24a and the third oxide film 24c are
It is added by the newly added step (4a) and activated by the heat treatment. Therefore, the energy level of the conduction band of the oxide film 24 is lower than that of the second oxide film.

Here, the resistance value R of the TFD element is expressed by the following equation.

R = (1 / α) exp (βp · Vi 1 / ²⁻ Eg
/ Κ · T) + (Vs / λ) exp (q · Vs / κ · T) In this equation, each coefficient is α: conductivity when no voltage is applied to the TFD element at room temperature, βp: coefficient Vi: voltage applied to the oxide film; Eg: activation energy; κ: Boltzmann constant; T: absolute temperature; Vs: voltage applied between the first or third oxide film and the second oxide film , Λ: constant, q: charge.

In the above equation, the first term on the right side relates to the Pool-Frenkel conduction regarding the conduction of the oxide film, and the second term relates to the difference in the energy level of the conduction band in the oxide film. That is, the second term is that the first oxide film 24a and the third oxide film 2
This is a term caused by the forward conduction of the pn junction when 4c is an n-type semiconductor and the second oxide film 24b is a p-type semiconductor.

Now, the oxide film 24 divided into only three layers
(See FIG. 9), the second metal film 26 is formed on the first oxide film 24a.
Is included, the impurity level is generated, and as a result, the contribution of the second term of the above equation is reduced, so that the voltage-current characteristics are not steep. However, when the heat treatment in the above step (9) is performed, atoms forming the second metal film 26 included in the first oxide film 24a are oxidized as shown in FIG. Since the voltage becomes large, the voltage-current characteristics become steep. Further, by controlling the degree of this oxidation, the second metal film 22
The current value when a current flows through the metal film 26 and the second metal film 2
This makes it possible to control the current value when a current flows from 6 to the first metal film 22.

As described above, the manufacturing process according to the second embodiment is different from the manufacturing process according to the first embodiment in that a step (4a) of performing a heat treatment in an atmosphere containing moisture is added after the step (4). And after step (8), at 200 ° C.
The step (9) of heat treatment at the above temperature is added.

However, the heat treatment in the step (9) can be used also as the heat treatment for providing the temperature distribution in the first embodiment.

That is, in the manufacturing process of the second embodiment, in the step (9), the heat treatment for uniformizing the non-linear characteristics and the second metal film 2 included in the oxide film 24 are performed.
Since the heat treatment for oxidizing the forming atoms of No. 6 is also used, the step (4a) is substantially added to the manufacturing process of the first embodiment.

Hereinafter, the manufacturing process of the second embodiment will be described in detail.

First, the insulating film 31 is formed on the upper surface of the substrate 30 in the above step (1), the first metal film 22 is formed on the upper surface of the insulating film 31 in the step (2). Is patterned. Then, in step (4), oxide film 24 is formed on the surface of first metal film 22.

Next, in the step (4a), the oxide film 24 is formed.
Then, heat treatment is performed to divide the layers into three layers as shown in FIG. This heat treatment is, first, an inert gas,
For example, in an atmosphere such as argon, constant temperature treatment is performed at a temperature of 300 ° C. or more, preferably 320 to 380 ° C., for 10 to 120 minutes. Second, the oxide film 24 is formed in an atmosphere containing water vapor. Preferably 220 so as to contain moisture
The temperature is reduced at a temperature of not more than 200 ° C., more preferably at most 200 ° C., for 5 to 300 minutes.

Thereafter, in step (5), the second metal film 2
6 is formed and patterned in step (6). Then, in step (7), a metal film to be the pixel electrode 34 is formed, and in step (8), it is patterned to become the pixel electrode 34.

By such a process, a plurality of TFD elements 20 are formed on the element array substrate 30 in a matrix. However, in this state, as described above, the element array substrate 30 may not be formed due to variations in the thickness of various metals and insulating films and various factors such as etching accuracy.
It is considered that the nonlinear characteristics of the TFD element 20 are not completely uniform. Further, in the second embodiment, in step (4a), the substrate 30 is heat-treated. At this time, if the temperature applied to the substrate 30 is not uniform, the resistance change characteristic as shown in FIG. 7, that is, the characteristic that the resistance change changes when the temperature is different, is affected. Is considered to be more remarkable. Actually, in the constant temperature furnace in which the heat treatment in the step (4a) is performed, a temperature difference occurs depending on the positional relationship in the furnace, particularly, whether or not the heater is close to the heater. As shown in FIG.

Therefore, similarly to the first embodiment, in step (9), the substrate 30 on which the TFD elements 20 are formed is subjected to a heat treatment giving a temperature distribution corresponding to the difference in the characteristics of the TFD elements 20. Is done. In the second embodiment, this heat treatment is also a heat treatment for oxidizing atoms forming the second metal film 26 included in the first oxide film 24a, as shown in FIG.

At this time, when the temperature of the heat treatment is increased, the processing time required for the oxidation becomes shorter. For example, at 200 ° C, 5 ~
20 hours, and at 250 ° C. for 0.5 to 2 hours. The heat treatment temperature and time are such that the material of the second metal film 26 is chromium,
The same was true for aluminum, titanium and molybdenum.

Therefore, in the heat treatment of the step (9), the temperature and the processing time are sufficient to oxidize the atoms forming the second metal film 26 included in the first oxide film 24a, and the resistance value is reduced. The point is to provide a sufficient temperature difference for uniformity.

For this purpose, as shown in FIG. 8 of the first embodiment, a computer 800 storing resistance change characteristics (see FIG. 7) in advance calculates a temperature distribution corresponding to the characteristic distribution of the TFD element. Thus, a configuration in which the heat treatment apparatus 810 is controlled is desirable.

As described above, according to the manufacturing process of the second embodiment, similarly to the above-described first embodiment, even if the TFD elements formed in the step (8) have different nonlinear characteristics,
Since the heat treatment is performed by giving the temperature distribution based on the difference in the step (9), the nonlinear characteristics of the plurality of TFD elements 20 formed over the entire surface of the element array substrate 30 are uniformed. Further, according to the manufacturing process of the second embodiment, the oxide film as an insulator becomes three layers in step (4a), and the second metal film 26 included in the oxide film 24 is formed in step (9). Since the formed atoms are oxidized, the voltage-current characteristics of the TFD element become steep. Therefore, this TF
In a liquid crystal display panel using a D element, a display screen with high uniformity and uniformity can be provided.

<Liquid Crystal Display Panel> Next, the TF formed by the manufacturing process of the first or second embodiment described above.
An example of a liquid crystal display panel to which the D element 20 (40) is applied will be described. FIG. 11 is a block diagram showing an example of the equivalent circuit.

As shown in this figure, the liquid crystal display panel 10
In FIG. 2, a pixel region 16 is formed at each intersection of the scanning line 12 and the data line 14, and each pixel region 16 has a configuration in which a liquid crystal display element (liquid crystal layer) 18 and a TFD element 20 are connected in series. Has become. Here, each scanning line 12 is controlled by the scanning signal driving circuit 100 and each data line 14
Are driven by the data signal drive circuit 110, respectively.

In FIG. 11, the TFD element 20 is connected to the scanning line side and the liquid crystal layer 18 is connected to the data line side. Conversely, the TFD element 20 is connected to the data line side. Alternatively, the liquid crystal layer 18 may be provided on the scanning line side.

Next, the structure of the liquid crystal display panel 10 will be described. FIG. 12 is a partially broken perspective view schematically showing one example.

As shown in this figure, the liquid crystal display panel 10
Includes an element array substrate 30 and an opposing substrate 32 disposed opposite to the element array substrate 30. The counter substrate 32 is made of, for example, a glass substrate.

In the element array substrate 30, the pixel electrodes 3
4 are arranged in a matrix. here,
The pixel electrodes 34 arranged in the same row are connected via the TFD elements 20 to one of the plurality of scanning lines 12 extending in a strip shape in the row direction.

On the other hand, in the counter substrate 32, the plurality of data lines 14 extend in the form of a strip in a column direction orthogonal to the direction in which the scanning lines 12 extend.
Is formed so as to intersect with the pixel electrode 34 of FIG.

Now, the element array substrate 30 and the opposing substrate 32 configured as described above have a certain gap (a gap) between the sealing agent applied along the periphery of one of the substrates and spacers appropriately dispersed. In this closed space, for example, a TN (Twisted Nematic) type liquid crystal is sealed, and a liquid crystal layer 18 (see FIG. 11) is formed.

On the other hand, the scanning signal driving circuit 1 shown in FIG.
00 sequentially supplies a scanning signal of a predetermined voltage to each TFD element 20 via the scanning line 12, and the data signal driving circuit 110 generates a data signal having a pulse width corresponding to the gradation level of the display. Are sequentially supplied via the data line 14.

Then, the current value of the TFD element 20 changes based on the potential difference applied between the scanning line 12 and the data line 14, and the liquid crystal layer 18 is charged and discharged.
Is switched to the display state, the non-display state, or the intermediate state. Thus, the display operation of the liquid crystal layer 18 is controlled.

In addition, the opposing substrate 32 is provided with color filters arranged in, for example, a striped mosaic shape or a triangle shape according to the use of the liquid crystal display panel 10. And a black matrix such as resin black in which carbon or titanium is dispersed in a photoresist. Further, the element array substrate 30 and the counter substrate 3
An alignment film or the like that has been rubbed in a predetermined direction is provided on each of the opposing surfaces, and a polarizing plate according to the alignment direction is provided on each back surface (both are not shown).

However, in the liquid crystal display panel 10,
The use of polymer-dispersed liquid crystal in which liquid crystals are dispersed as fine particles in a polymer eliminates the need for the above-mentioned alignment film, polarizing plate, etc., thereby increasing the light use efficiency and thus increasing the brightness of the liquid crystal display panel. And low power consumption.
Further, when the liquid crystal display panel 10 is of a reflective type, the pixel electrode 34 is made of a metal film having a high reflectivity such as aluminum, and an SH (super homeotropic) type in which liquid crystal molecules are substantially vertically aligned in a state where no voltage is applied. Liquid crystal or the like may be used.

<Electronic Apparatus: Part 1> Next, some examples in which such a liquid crystal display panel 10 is used in an electronic apparatus will be described.

First, a video projector using the liquid crystal display panel as a light valve will be described. FIG. 13 is a plan view showing a configuration example of a video projector.

As shown in this figure, a lamp unit 1102 including a white light source such as a halogen lamp is provided inside a video projector 1100. The projection light emitted from the lamp unit 1102 is transmitted to a plurality of mirrors 1106, 1 arranged in a light guide 1104.
.., And two dichroic mirrors 110
8 are separated into three primary colors of RGB, and liquid crystal panels 1110R and 111 serving as light valves corresponding to the respective primary colors.
OB and 1110G.

The configurations of the liquid crystal panels 1110R, 1110B and 1110G are as described above, and are driven by R, G, and B primary color signals supplied from a video signal processing circuit (not shown). Now, the light modulated by these liquid crystal panels is transmitted to the dichroic prism 111.
2 is incident from three directions. In the dichroic prism 1112, the R and B lights are refracted at 90 degrees, while the G light travels straight. Therefore, as a result of combining the images of each color, a color image is projected on a screen or the like via the projection lens 1114.

When the liquid crystal display panel 10 is applied to a projector as described above, the liquid crystal panel 1110R,
Light corresponding to each of the primary colors R, G, and B is incident on 110B and 1110G by the dichroic mirror 1108, so that it is not necessary to provide a color filter on the opposite substrate 32.

<Electronic Equipment: Part 2> An example in which the liquid crystal display panel is applied to a personal computer will be described. FIG. 14 is a front view showing the configuration of this personal computer. In the figure, a personal computer 1200 has a main body 1 having a keyboard 1202.
204 and a liquid crystal display 1206. The liquid crystal display 1206 is configured by adding a color filter and a backlight to the liquid crystal display panel 10 described above.

<Electronic Equipment: Part 3> Next, an example in which a liquid crystal display panel is applied to a pager will be described. FIG.
FIG. 2 is an exploded perspective view showing the structure of the pager. As shown in this figure, the pager 1300 is a metal frame 1
In 302, the liquid crystal display panel 10 is connected to the light guide 1306 including the backlight 1306 a and the circuit board 13.
08, the first and second shield plates 1310 and 1312 are housed together. The liquid crystal display panel 10 and the circuit board 10 are electrically connected to each other by the two elastic conductors 1314 and 1316 for the counter substrate 32 and by the film tape 1318 for the element array substrate 30. .

Note that, in addition to the electronic devices described with reference to FIGS. 13 to 15, a liquid crystal television, a viewfinder type, a monitor direct-view type video tape recorder, a car navigation device, an electronic notebook, a calculator, a word processor, Workstations, mobile phones, video phones, POS terminals,
A device including a touch panel and the like are examples of the electronic device. It goes without saying that the present invention can be applied to these various electronic devices.

[0088]

As described above, according to the present invention,
Since the voltage-current characteristics of a non-linear element such as a TFD element can be particularly uniform, a liquid crystal display panel using the non-linear element and an electronic device using the non-linear element can display uniformly. In addition, it is possible to eliminate unevenness.

[Brief description of the drawings]

FIG. 1A shows a TFD according to an embodiment of the present invention.
FIG. 2B is a plan view showing a layout for one pixel of a liquid crystal panel substrate to which the element is applied, and FIG.
It is sectional drawing of a line.

FIG. 2 is a sectional view showing a structure of another TFD element.

3A is a plan view showing a layout for one pixel of a liquid crystal panel substrate to which another TFD element is applied, and FIG. 3B is a cross-sectional view taken along the line BB. is there.

FIGS. 4A to 4C are diagrams illustrating a manufacturing process of the TFD element according to the embodiment, respectively.

FIGS. 5 (6) to (8) are diagrams illustrating a manufacturing process of the TFD element according to the embodiment, respectively.

FIG. 6 is a diagram showing how characteristics (resistance values) of a TFD element are distributed on an element array substrate.

FIG. 7 is a diagram showing resistance change characteristics of a TFD element.

FIG. 8 is a diagram illustrating an example of heat treatment control by a computer.

FIG. 9 is a partial cross-sectional view showing a state in which an oxide film in a TFD element is divided into three layers.

FIG. 10 is a partial cross-sectional view showing a state where atoms forming a second metal film included in an oxide film of the TFD element are oxidized.

FIG. 11 is a block diagram illustrating a configuration of a liquid crystal display panel and a driving circuit thereof.

FIG. 12 is a partially cutaway perspective view showing a configuration of a liquid crystal display panel.

FIG. 13 is a cross-sectional view illustrating a configuration of a liquid crystal projector as an example of an electronic apparatus to which the liquid crystal display panel is applied.

FIG. 14 is a front view illustrating a configuration of a personal computer as an example of an electronic apparatus to which a liquid crystal display panel is applied.

FIG. 15 is an exploded perspective view illustrating a configuration of a pager as an example of an electronic apparatus to which the liquid crystal display panel is applied.

[Explanation of symbols]

 10 liquid crystal display panel 12, 48 scanning line 14, data line 18, liquid crystal layer 20, 40 TFD element 22, first metal film (first metal), 24 ... Oxide film (insulator), 26... Second metal film (second metal), 30... (Element array) substrate, 32...

Claims (8)

[Claims] 1. A semiconductor comprising a first metal-insulator-second metal
In the method of manufacturing a terminal type nonlinear element, a step of forming the first metal on a substrate; a step of forming the insulator on a surface of the first metal; and a step of forming the second metal on a surface of the insulator And multiple 2
A step of forming a terminal type nonlinear element on a substrate; and a step of subjecting the substrate to a heat treatment by giving a temperature distribution based on a difference in characteristics of the two terminal type nonlinear element. Manufacturing method. 2. The method for manufacturing a two-terminal nonlinear element according to claim 1, further comprising: a substrate on which the insulator is formed on a surface of the first metal, before the second metal is formed. A method for manufacturing a two-terminal nonlinear element, comprising a step of subjecting a substrate to a heat treatment in an atmosphere containing moisture. 3. The characteristic of the two-terminal nonlinear element is a result obtained by previously measuring the characteristic of the two-terminal nonlinear element on the substrate at a plurality of different portions on the substrate. The method for manufacturing a two-terminal nonlinear element according to claim 1 or 2. 4. The method according to claim 3, wherein the characteristic of the two-terminal nonlinear element is a current-voltage characteristic. 5. A first metal-insulator formed on a substrate.
A two-terminal nonlinear element comprising a plurality of two-terminal nonlinear elements made of a second metal, wherein the two-terminal nonlinear element is formed on a substrate and then given a temperature distribution based on a difference in characteristics thereof. 6. The two-terminal nonlinear element according to claim 5, wherein at least a part of atoms forming the second metal contained in the insulator is bonded to oxygen atoms. 7. A liquid crystal panel substrate having the two-terminal type nonlinear element according to claim 5 or 6, and a counter substrate are arranged at an appropriate distance, and the liquid crystal panel substrate and the counter substrate are A liquid crystal display panel characterized in that liquid crystal is sealed in a gap between the two. 8. An electronic apparatus comprising the liquid crystal display panel according to claim 7.