JPH0437173A - Non-linear device - Google Patents

Abstract

PURPOSE:To make it possible to eliminate the asymmetry of a device characteristic and obtain a non-linear device whose electric characteristic is stabilized by constituting a non-linear electricity conduction induction layer at least with polydialkyl fumarate. CONSTITUTION:Pyrex glass 11 is used for a substrate. An ITO (indium-tin-oxide) made conductor film is either sputtered or deposited, thereby forming a first conductor 12 and a third conductor 15 based on the application of photoetching. Polydiisopropyl fumarate (PDiPF) used for a non-linear type electric conduction induction layer is refined by resediment and the, it is dissolved in refined chloroform so as to obtain a PDiPF solution where the rotary speed and concentration are controlled so as to obtain a film thickness of some hundreds angstrom, thereby forming a non-linear type electric conduction induction layer 13 by a spin coater. A second conductor 14 is formed on the conduction layer 13 so that a non-linear type device may be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a nonlinear element having nonlinear current-voltage characteristics.

[Prior Art] Conventional nonlinear elements have used semiconductor wafers such as Si, or thin film semiconductors formed on glass, single crystal, or the like. Further, devices having a conductor-insulator-conductor structure (hereinafter referred to as an MIM structure in this specification) have also been put into practical use.

A nonlinear element having an MIM structure is usually manufactured by laminating a metal electrode on tantalum pentoxide, which is formed by anodizing the surface of tantalum metal. However, tantalum pentoxide has a large relative dielectric constant of about 20, and its manufacturing method does not allow for a large film thickness, resulting in the problem that the capacitance of the MIM element becomes too large. In addition, materials with a large dielectric constant do not have large electrical nonlinearity, so
The characteristics of the device were also not very good.

Therefore, it has been proposed that the nonlinear electrical conduction inducing layer between conductors be made of an organic material with a small dielectric constant. Since the dielectric constant can be reduced to about 3 to 4, nonlinear elements have been prototyped that have small capacitance and exhibit large electrical nonlinear characteristics.

[Problems to be solved by the invention] However, in conventional nonlinear elements using organic materials as nonlinear electrical conduction inducing layers, conductors must be formed on the organic thin film so as not to damage the conductor. Characteristics are severely limited. Inevitably, there is a problem that a large difference occurs in the work functions of the conductors, resulting in a large asymmetry in the device characteristics. Therefore, the output with respect to the applied voltage is not stable, making it difficult to use it for driving liquid crystal displays and the like.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a nonlinear element with stable electrical characteristics and no asymmetry in element characteristics.

[Means for Solving the Problems] A nonlinear element of the present invention has a structure in which a nonlinear electrical conduction inducing layer and first and third conductors are arranged symmetrically with respect to a second conductor. The nonlinear electrical conduction inducing layer is characterized in that it is composed of at least polydialkyl fumarate.

[Example] Hereinafter, the details of the present invention will be shown by examples.

(Example 1) FIG. 1 shows a cross-sectional view showing the concept of a nonlinear element in this example.

A Pyrex glass 11 with an optically polished surface was used as the substrate, and a conductive film of Indiu@in Oxide (hereinafter abbreviated as ITO in this specification) was formed by sputtering or vapor deposition, and a pattern was formed by photoetching. The first conductor 12 and the third conductor 15
And so.

Polydiisopropyl fumarate (hereinafter abbreviated as PDiPF) was used as the organic material for the nonlinear electrical conduction inducing layer. It is known that when a polydialkyl fumarate such as PDiPF is used alone, even a very thin film of several hundred angstroms has excellent electrical insulation properties. (Ichihara et al., Polymer Symposium Proceedings Vol.
1.39. N.

[19891P, 2563] After PDiPF was purified by reprecipitation, it was dissolved in purified chloroform to obtain a PDiPF solution. A nonlinear electrical conduction inducing layer 13 was formed on the above-mentioned substrate using a spin coater, controlling the rotation speed and concentration so as to have a film thickness of 200 angstroms. A second conductor 14 was formed thereon by vapor deposition of aluminum to create a nonlinear element.

According to such a manufacturing method, the device configuration includes a nonlinear element made of a first conductor, a second conductor, and a nonlinear electrical conduction inducing layer sandwiched between these two conductors, and It is a nonlinear element made of three conductors and a nonlinear electrical conduction inducing layer, and two nonlinear elements are connected in series.

Hereinafter, this structure will be referred to as MrMIM structure.

In an element with this structure, both the first conductor and the third conductor for wiring from the element to the edge of the substrate can be formed directly on the substrate glass, so it is possible to form conductors with low resistance by heating the substrate etc. It's easy. In addition, in order to avoid damaging the nonlinear electrical conduction inducing layer, the second conductor is formed thinly at a low temperature, so that even if the resistance of the second conductor becomes large,
It also has the advantage of having almost no effect on device characteristics.

When the current-voltage characteristics of the thus obtained nonlinear element between the first and third conductors were measured in a dark place, it was confirmed that the nonlinear element exhibited highly symmetrical nonlinearity as shown in FIG. 2. In addition, the conduction mechanism of this nonlinear element is based on tunnel current, so nonlinearity is large, and when the ON voltage is 9 volts and the OFF voltage is 1 volt, the ON10 FF ratio of the current is 4.
You can get more than 100 digits. Also, from -20°C to 100°C
Almost no change was observed in the current-voltage characteristics in the temperature range of .

(Example 2) In the same manner as in Example 1, first and third conductors of ITO were formed on a substrate. Next, add 0.0% of Bodge tert-butyl fumarate. A 1% tetrahydrofuran solution was spread on the water surface and compressed to form a Langmujr membrane.

While maintaining the surface pressure at 25 mN/m, the substrate was pulled up at a speed of 6 mm/min, the immersion was reversed, and the LBN was reduced to 8 N.
Accumulated. By heating and drying at 120° C. for 1 hour, a nonlinear electrical conduction inducing layer made of Voisy tertiary butyl fumarate was formed on the substrate with a film thickness of 80 angstroms.

A second conductor was formed on this by vapor deposition of indium to create a nonlinear element. When the current-voltage characteristics between the first and third conductors of the nonlinear element thus created were measured, it showed highly symmetrical nonlinearity as in Example 1. Further, this nonlinear element has very large nonlinearity, and when the ON voltage is 9 volts and the OFF voltage is 1 volt, the ON10 FF ratio of the current can be more than 5 digits.

Further, in the temperature range from -20°C to 100°C, almost no change was observed in the current-voltage characteristics.

(Example 3) A chromium conductor film was formed on a substrate by sputtering or vapor deposition, and patterns were formed by photoetching to form a first conductor and a third conductor. Next, polydicyclohexyl fumarate was dissolved in carbon tetrachloride, and a nonlinear electrical conduction inducing layer was formed using a spin coater by controlling the rotation speed and concentration so that the film thickness was 300 angstroms on the substrate. A second conductor was formed thereon by vapor deposition of aluminum to create a nonlinear element.

When II current-voltage characteristics were measured between the first and third conductors of the nonlinear element thus produced, it showed highly symmetrical nonlinearity as in Example 1.

Further, this nonlinear element has large nonlinearity, and when the ON voltage is 12 volts and the OFF voltage is 1 volt, the 0N10FF ratio of the current can be more than 4 digits.

Further, in the temperature range from -20°C to 100°C, almost no change was observed in the current-voltage characteristics.

Although the embodiments have been described above, in the case of the present invention, even if different materials are used for the first and third conductors and the second conductor, the current-voltage characteristics are always symmetrical because the element configuration is symmetrical. becomes. It is possible to use a conductor other than metal as the upper or lower conductor, and methods such as electroplating, electroless plating, and coating can be used as the formation method. Furthermore, various types of polydialkyl fumarates and thin film formation methods can be considered.

The nonlinear element of the present invention can be widely applied to active matrix display devices, electro-optical devices such as optical shutters, and sensors for temperature, humidity, light, gas, solutions, etc., using the same.

[Effects of the Invention] As described above, according to the present invention, in a nonlinear element having a structure in which a nonlinear electrical conduction inducing layer and first and third conductors are arranged symmetrically with respect to a second conductor, Since the nonlinear electrical conduction inducing layer is composed of at least polydialkyl fumarate, there is no asymmetry in device characteristics.
A nonlinear element with stable electrical characteristics could be provided. The nonlinear element of the present invention has a simple element structure and the nonlinear electrical conduction inducing layer can be easily formed, so it is particularly advantageous for manufacturing a large area element.

l......Substrate glass 2...First conductor 3...Nonlinear electrical conduction inducing layer 4...
......Second conductor 5...Third conductor 1...Current-voltage characteristic curve or above Applicant: Seiko Epson Corporation Agent Person Patent attorney Kisanbe Meiki (1 other person)

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the concept of a nonlinear element in Example 1 of the present invention. FIG. 2 is a diagram showing the current-voltage characteristics of the nonlinear element created in Example 1 of the present invention. Figure 2

Claims (1)

[Claims] In a nonlinear element having a structure in which a nonlinear electrical conduction inducing layer and first and third conductors are arranged symmetrically with respect to a second conductor, the nonlinear electrical conduction inducing layer is composed of at least polydialkyl fumarate. A nonlinear element characterized by