JP3194291B2 - Switching element of liquid crystal display and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric element used for an integrated circuit, a liquid crystal driving circuit, and the like, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Heretofore, elements using semiconductors, mainly silicon, have been used in electric devices such as integrated circuits. Among them, logic circuits that apply digital technology,
It is a well-known fact that they have been remarkably active in various information processing and communication fields including computers.

Further, in one of the fields to which semiconductors are applied, a liquid crystal display using a so-called thin film transistor, which constitutes a display device in combination with a liquid crystal, has recently attracted attention in various fields. This is a conventional integrated circuit that uses single-crystal silicon, whereas a switching element is configured and used using a thin film of polycrystalline or amorphous silicon. is there.

[0004] However, in the case of a display, if even one defective portion exists in one display area, the value as a product is greatly reduced. However, a liquid crystal display has a very long manufacturing process and has a remarkably large element area in a unit of cutout as compared with an integrated circuit.

Therefore, an attempt has been made to form a switching element without using a semiconductor and to suppress the occurrence of the defect. For example, MIM (Metal Insul)
A representative example is a method using a two-terminal switching element using an Attor Metal).

[0006]

However, a two-terminal switching element using the MIM according to the prior art is:
Although a thin film transistor can form a drive circuit on the same substrate, the circuit cannot be formed. Therefore, all of the drive circuits have to be formed outside the substrate. Therefore, it is necessary to connect hundreds or thousands of connection terminals to an external circuit, and thus the number of steps, the occurrence of defects in the process, and the like have become problems.

[0007]

According to the present invention, there is provided a switching element for a liquid crystal display, comprising: a plurality of conductive regions provided on an insulating substrate; a first insulating film covering the plurality of conductive regions; A charge storage region disposed on the first insulating film in a shape straddling the region, a second insulating film covering the charge storage electrode, and And a control electrode disposed so as to cover the charge storage electrode in a planar manner. In the method for manufacturing a switching element of a liquid crystal display according to the present invention, a plurality of conductive regions are patterned on an insulating substrate by a sputtering method, and a first insulating film is formed on the plurality of conductive regions by anodic oxidation. Forming a charge storage electrode by sputtering using a sputtering method on the first insulating film in a shape that straddles the plurality of conductive regions; and forming a second insulating film on the charge storage electrode. A step of forming a film; and a step of forming a control electrode thin film on the second insulating film by a sputtering method. Thus, the present invention provides a structure of a three-terminal switching element using MIM and a method for manufacturing the same.

[0008]

FIG. 1 is a sectional view showing an example of the structure of an electric element according to an embodiment of the present invention.

On an insulating substrate 101, a first conductive region 102 and a second conductive region 103 made of metal tantalum are patterned and formed. Further, a first insulating film 1 made of tantalum pentoxide and having a shape covering the structure.
A charge storage electrode 106 made of chromium metal is further formed thereon, and a second insulating film 107 made of silicon dioxide is formed on the charge storage electrode 106 so as to cover the structure. An electrode 108 is formed.

FIGS. 2A to 2C are a cross-sectional view and a schematic view showing an example of a manufacturing process of the electric element shown in FIG.

(A) A step of forming metal tantalum thin films 202 and 203 on a glass substrate 201 by sputtering and patterning.

(B) a step of forming insulating films 205 and 206 made of tantalum pentoxide by applying an anodic potential to the structure in an aqueous citric acid solution 204 and anodizing the structure.
Here, reference numeral 207 denotes a cathode electrode made of platinum, and 208 denotes a power source.

(C) A charge storage electrode 209 made of chromium metal is formed on the structure by sputtering using a sputtering method, and is formed in a shape covering the structure by a normal pressure chemical vapor transport method (normal Pressure CVD method-Chemical Vap
a step of forming a silicon dioxide thin film 210 by using our own deposition, and a control electrode thin film 211 made of metallic aluminum by using a sputtering method.

FIG. 3 is a diagram showing an operation when a signal is applied to the electric element according to the embodiment of the present invention shown in FIG.

The potential of the charge storage electrode 106 when the first conductive region 102 is set to the ground level, a constant voltage is applied to the second conductive region 103, and a signal 301 is applied to the control electrode 108. 302, first conductive region 10
2 shows a current value 303 flowing between the second conductive region 103 and the second conductive region 103. The horizontal axis is time.

When a signal is applied to the control electrode 108, the potential of the charge storage electrode 106 becomes a potential intermediate between the potentials of the first conductive region 102 and the second conductive region 103 and a potential intermediate the potential of the control electrode 108. become. When the potential exceeds a certain level, a current flows through the tantalum pentoxide film, and the current continues while the voltage of the control electrode 108 is higher than a certain level.

[0017]

As described above, by using the method according to the embodiment of the present invention, a three-terminal switching element using MIM can be manufactured.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a structure of an electric element according to an embodiment of the present invention.

2A to 2C are a cross-sectional view and a schematic view illustrating an example of a manufacturing process of the electric element illustrated in FIG.

FIG. 3 is a diagram illustrating an operation when a signal is applied to the electric element according to the embodiment of the present invention illustrated in FIG. 1;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 101 Insulating substrate 102 First conductive region made of metal tantalum 103 Second conductive region made of tantalum metal 104, 105 First insulating film made of tantalum pentoxide 106 Charge storage electrode 107 made of chromium metal 107 Second made of silicon dioxide 2 insulating film 108 control electrode made of metal aluminum 201 glass substrate 202, 203 metal tantalum thin film 204 citric acid aqueous solution 205, 206 insulating film made of tantalum pentoxide 207 cathode electrode made of platinum 208 power supply 209 charge storage electrode made of chromium metal Reference Signs List 210 silicon dioxide thin film 211 control electrode thin film made of metallic aluminum 301 voltage applied to control electrode 108 potential of charge storage electrode 106 303 first conductive region 102 and second conductive region 103
Current value flowing between

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G02F 1/1362 H01L 49/02 H01L 29/78 H01L 27/10

Claims (2)

(57) [Claims] A plurality of conductive regions provided on an insulating substrate; a first insulating film covering the plurality of conductive regions; and a first insulating film extending over the plurality of conductive regions. A switching device for a liquid crystal display, comprising: a charge storage region disposed thereon; a second insulating film covering the charge storage electrode; and a control electrode disposed on the second insulating film. element. 2. A method for manufacturing a switching element of a liquid crystal display, comprising: a step of patterning a plurality of conductive regions on an insulating substrate by a sputtering method; and a step of forming a first insulating film on the plurality of conductive regions by anodic oxidation. Forming; forming a charge storage electrode by sputtering using a sputtering method on the first insulating film in a shape that straddles the plurality of conductive regions; and forming a second charge storage electrode on the charge storage electrode. Forming a control electrode thin film on the second insulating film by sputtering using a sputtering method. 2. A method for manufacturing a switching element for a liquid crystal display, comprising the steps of: