JPH08330647A - Manufacture of mim-type nonlinear element and liquid-crystal display device using mim-type nonlinear element - Google Patents

Abstract

PURPOSE: To provide a manufacturing method of an MIN-type nonlinear element which can enhance nonlinear characteristic of the MIN-type nonlinear element. CONSTITUTION: A Ta electrode layer 16 is formed on a transparent substrate 12, the Ta electrode layer 16 is anodized to form a Ta2 O5 anodized film 18. Then, when the transparent substrate 12 on which the Ta electrode layer 16 and the Ta2 O5 anodized film 18 have been formed is heat-treated by using a heat treatment furnace. The heat treatment is executed in an N2 atmosphere, at 450 deg.C and for two hours, the atmosphere is then changed over to a mixed atmosphere of oxygen gas and nitrogen gas at 450 deg.C, the temperature is lowered to 250 deg.C or lower, and the transparent substrate is then taken out to the air from the heat treatment furnace. Then, a Cr electrode layer 20 is formed on the Ta2 O5 anodized film 18 to form an MIM-type nonlinear element 50.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to MIM (Meta).
The present invention relates to a method for manufacturing an l-insulator-metal) type non-linear element and a liquid crystal display device using the MIM type non-linear element.

[0002]

2. Description of the Related Art Generally, in an active matrix type liquid crystal display device, a liquid crystal is provided between a substrate on one side where a switching element is provided for each pixel area to form a matrix array and another substrate on which a color filter is formed. Are filled in, and the alignment state of the liquid crystal is controlled for each pixel region to display predetermined information. Here, a switching element such as a TFT (Thin Film Transistor) is used.
Although a two-terminal element such as a terminal element or a MIM type non-linear element is used, it is more advantageous to use the MIM type non-linear element in order to meet the demand for a larger screen and lower cost of the liquid crystal display device. Further, when the MIM type non-linear element is used, the scanning line can be provided on the substrate on one side where the matrix array is formed and the data line can be provided on the substrate on the other side, so that the scanning line and the data line are crossed. There is also an advantage that an over short circuit does not occur.

An active matrix type liquid crystal display device 100 using such an MIM type non-linear element is shown in FIG.
As shown in, the pixel region 80 is provided in each element of the matrix formed by the plurality of scanning lines 74 connected to the scanning line driving circuit 72 and the plurality of data lines 78 connected to the data driving circuit 76. It is provided. In each pixel region 80, the MIM type non-linear element 50 having one end connected to the data line 78, the MIM type non-linear element 50 and the scanning line 74.
And a liquid crystal display element 60 connected between and. Based on the voltage difference between the signal applied to the scanning line 74 and the signal applied to the data line 78, the liquid crystal display element 60 is switched to the on state or the off state to control the display operation.

FIG. 8 is a sectional view of an active matrix type liquid crystal display device 100 using such an MIM type non-linear element, in which a liquid crystal layer 40 is sandwiched between an electrode substrate 10 and an electrode substrate 30. The electrode substrate 10 includes a transparent substrate 12, an MIM type nonlinear element 50 provided on the transparent substrate 12, and a pixel electrode 22 connected to the MIM type nonlinear element 50. The MIM type nonlinear element 50 is
A Ta electrode layer 16 formed on the transparent substrate 12, a Ta2O5 film 18 provided on the Ta electrode layer 16, and a Ta2O film.
5 and the Cr electrode layer 20 provided on the film 18. The Ta2O5 film is formed on the surface of the Ta electrode layer 16 so that the Ta2O5 film has a uniform film thickness and has no pinhole.
It is formed by anodizing the electrode layer 16 (JP-A-5-297389 and JP-A-5-3132).
No. 07).

A MIM type non-linear element 50 having such a structure
Has been conventionally manufactured as follows. As shown in FIG. 1, a tantalum film is deposited on the transparent substrate 12 by sputtering and then thermally oxidized to about 10
A tantalum oxide film 14 of 00Å is formed. Next, a tantalum film is deposited to a thickness of about 3000 Å by sputtering and then patterned to form a Ta electrode layer 16. Next, the Ta electrode layer 16 is anodized to form a Ta2O5 anodized film 18. After that, a chromium film is deposited by 1500Å sputtering and patterned to form the Cr electrode layer 20, thereby forming the MIM type non-linear element 50.

[0006]

In order to improve the non-linear characteristic of such a MIM type non-linear element, the IEEE Trans
Electron Devices, Vol.ED28, pp.736-739, June 1981
At the Ta electrode layer 1 constituting the MIM type nonlinear element
Means such as doping 6 with nitrogen is introduced. However, this technique requires a high technique at the time of tantalum sputtering, and it is difficult to manufacture the MIM type non-linear element with good reproducibility.

In order to improve the non-linear characteristic of the MIM type non-linear element, it is preferable to subject the tantalum thin film to anodic oxidation and then heat-treat it at 400 to 600 ° C. in a nitrogen atmosphere.
No. 50081 is proposed. However, after simply anodizing the tantalum thin film, the amount of 400 to 6 in a nitrogen atmosphere is increased.
It is difficult to obtain sufficient non-linear characteristics to obtain good image quality only by heat treatment at 00 ° C., and it has been desired to further improve the non-linear characteristics. Further, when the substrate is cooled after the heat treatment is opened to the atmosphere, the characteristics vary depending on the atmosphere of the atmosphere such as the flow of air and humidity, that is, the characteristics vary between heat treatment batches. Further, the in-plane variation of the characteristics was also remarkable.

Therefore, an object of the present invention is to improve the non-linear characteristic of the MIM type non-linear element and further suppress the inter-batch variation and the in-plane variation of the characteristic.
An object of the present invention is to provide a method for manufacturing an M-type non-linear element and a liquid crystal display device using the MIM-type non-linear element having improved non-linear characteristics.

[0009]

[Means for Solving the Problems]

(1) A method of manufacturing a MIM type non-linear element according to the present invention comprises a step of forming a first conductive layer on a substrate, a step of forming an oxide film on the first conductive layer, and at least the final stage thereof. A thermal annealing step of treating the substrate on which the first conductive layer and the oxide film are formed in a gas atmosphere containing oxygen gas, and then a second step on the oxide film.
And a step of forming a conductive layer.

As a result, the non-linear characteristic of the MIM type non-linear element can be improved, and the off-state current can be reduced. As a result, when this MIM type non-linear element is used as a switching element of a liquid crystal display device, a liquid crystal display device with high contrast and good image quality is provided. In addition, the MIM formed in this way
The current value of the non-linear element hardly changes with subsequent thermal history, and the change in current value is small even when the driving voltage for driving the liquid crystal display device is continuously applied. A non-linear element is obtained.

(2) The method for manufacturing a MIM type non-linear element according to the present invention comprises the steps of forming a first conductive layer on a substrate, forming an oxide film on the first conductive layer, and A step of heat-treating the substrate on which the first conductive layer and the oxide film are formed at a predetermined first temperature; and thereafter, lowering the temperature of the substrate from the first temperature to a predetermined second temperature. After that, a step of lowering the temperature of the substrate from the second temperature to a predetermined third temperature in a gas atmosphere containing oxygen gas, and then forming a second conductive layer on the oxide film, It is characterized by having.

As a result, the non-linear characteristic of the MIM type non-linear element can be improved, and the off-state current can be reduced. As a result, when this MIM type non-linear element is used as a switching element of a liquid crystal display device, a liquid crystal display device with high contrast and good image quality is provided. Also, the MI formed in this way
The current value of the M-type non-linear element is unlikely to change with subsequent thermal history, and even if the drive voltage for driving the liquid crystal display device is continuously applied, the change in current value is small and the MIM is highly reliable. Type non-linear element is obtained.

(3) The inert gas is nitrogen gas.

By using nitrogen gas, the nonlinear characteristics can be improved by heat treatment in an inert gas.

(4) The gas containing oxygen gas is preferably a mixed gas of oxygen gas and nitrogen gas.

By lowering the temperature in a gas atmosphere containing oxygen gas, it is possible to further improve the non-linear characteristic and significantly reduce the off-state current.

(5) The flow rate ratio of oxygen gas and nitrogen gas is
It is characterized by being in the range of 1:20 to 20: 1.

If the flow rate ratio is within the range of 1:20 to 20: 1, MI is changed even if the flow rate ratio of oxygen gas and nitrogen gas is changed.
The characteristics of the M-type nonlinear element are hardly changed. The flow rate ratio of oxygen gas and nitrogen gas is more preferably 1:15.
To 15: 1, more preferably 1:10.
It is within the range of 10: 1.

(6) The oxide film is an anodized film of the first conductive layer.

(7) The first conductive layer is made of Ta.

(8) In this case, the gas atmosphere containing the oxygen gas contains water vapor.

The manufacturing method of the present invention is particularly effective when applied to the case where an anodized film is formed on the first conductive layer, and is particularly large when applied to the case where the first conductive layer is made of Ta. The effect is obtained. In this case, the effect is obtained when the gas atmosphere containing the oxygen gas contains water vapor.

(9) The first conductive layer is characterized by comprising Ta as a main component and adding at least one element selected from the group consisting of W, Re and Mo therein. To do.

(10) In this case, the oxygen gas is dry oxygen gas.

It is also large when the first conductive layer is composed of Ta as a main component and at least one element selected from the group consisting of W, Re and Mo added thereto. The effect is obtained. Also in this case, the oxide film on the first conductive layer is preferably formed by anodizing the first conductive layer. Furthermore, a great effect can be obtained by using dry oxygen gas as the oxygen gas.

(11) The second conductive layer is preferably C
r, Ti, Al or indium / tin / oxide (IT
O).

(12) The second conductive layer is more preferably made of Cr.

A larger effect can be obtained by using Cr for the second conductive layer. Further, when ITO is used, the second conductive layer and the pixel electrode can be formed of the same material, so that the process can be simplified.

(13) The average temperature gradient from the first temperature to the third temperature is 0.1 to 60 ° C./min.

By setting the average temperature gradient from the first temperature to the third temperature to 0.1 to 60 ° C./min,
The temperature control during cooling is facilitated, and the MIM type non-linear element with small variations in element characteristics between heat treatment batches can be easily manufactured. In addition, in order to further improve the controllability during the temperature decrease, the temperature decrease rate is 0.5 to 40 ° C./mi.
n is more preferable, and 0.5 is more preferable.
It is preferable to set it to 10 ° C / min. (14) The substrate is a glass substrate and the first temperature is 220
It is characterized by being ~ 600 ° C.

When the substrate is a glass substrate, the first temperature is preferably 220-600 ° C. Although the element characteristics of the MIM type nonlinear element change depending on the temperature of the heat treatment, the first temperature is 22 if the heat resistance of the glass is taken into consideration.
It is preferably in the temperature range of 0 to 600 ° C, more preferably 250 to 500 ° C, and further preferably 270.
It is better to be in the range of to 450 ° C. Although the influence of the heat treatment time on the element characteristics is smaller than that of the heat treatment temperature, the heat treatment time is preferably 30 minutes to 3 hours, more preferably 30 minutes to 2 hours in consideration of the throughput of the process.

(15) The second temperature is 220 to 600 ° C.
Is characterized in that.

By setting the second temperature in the temperature range of 220 to 600 ° C., the non-linear characteristic of the MIM type non-linear element can be greatly improved, and the MIM type non-linear element which is stable to the heat treatment after the formation of the element. Can be manufactured, and the device characteristics can be easily controlled. This temperature range is more preferably 220 to 500 ° C, and further preferably 220 to 450 ° C.

(16) The second temperature may be the same as the first temperature. In this case, the heat treatment is performed at the first temperature in the inert gas atmosphere, and then the inert gas atmosphere is switched to the atmosphere containing the oxygen gas at the time when the temperature decrease starts.

(17) The third temperature is 250 ° C. or lower.

By setting the third temperature to 250 ° C. or lower, it is possible to reduce in-plane and inter-substrate variations in characteristics.

(18) The same heat treatment apparatus is used for the heat treatment at the first temperature, the temperature decrease from the first temperature to the second temperature, and the temperature decrease from the second temperature to the third temperature. It is characterized in that it is continuously performed in the.

As a result, the controllability of the cooling condition of the substrate is remarkably improved, and it is possible to suppress the variation in the element characteristics of the MIM type nonlinear element between the substrates, between the substrates, and between the heat treatment batches.

In this case, if the average temperature gradient from the first temperature to the third temperature is 0.1 to 60 ° C./min, the controllability is remarkably improved.

(19) The substrate on which the first conductive layer and the oxide film are formed is cooled from the second temperature to 250 ° C. or lower in a gas atmosphere containing oxygen gas, and the substrate is taken out of the heat treatment apparatus. Characterize.

By doing so, it is possible to suppress variations in the element characteristics of the MIM type nonlinear element within and between the substrates.

(20) This temperature is more preferably 22
It is 0 ° C or lower.

(21) More preferably, it is 200 ° C. or lower.

As a result, a greater effect can be obtained with respect to variations.

(22) The temperature at which the substrate is taken out of the heat treatment apparatus and the third temperature are the same. This can improve the throughput of the heat treatment process.

(23) In the final stage of the thermal annealing step, the temperature is lowered to 250 ° C. or lower in a heat treatment apparatus in a gas atmosphere containing oxygen gas, and then the substrate is taken out of the heat treatment apparatus. To do.

As a result, the non-linear characteristics of the MIM type non-linear element can be improved, and variations in the element characteristics within and between the substrates can be suppressed.

(24) This temperature is more preferably 22
It is 0 ° C or lower.

(25) More preferably, it is 200 ° C. or lower.

As a result, it is possible to obtain a greater effect on variations without impairing the nonlinear characteristics of the MIM type nonlinear element.

(26) According to the present invention, there is provided a liquid crystal display device characterized in that the MIM type non-linear element manufactured as described above is used as a switching element.

[0052]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings.

Example 1 First, as shown in FIG. 2, a tantalum film is deposited on a transparent substrate 12 made of non-alkali glass by sputtering, and then thermally oxidized to form a tantalum oxide film 14 of about 1000 liters. did. The tantalum oxide film 14 is for improving the adhesion between the transparent substrate 12 made of non-alkali glass and the Ta electrode layer 16. Here, the tantalum oxide film 14 having the same effect can be obtained even if it is deposited by sputtering.

Next, about 2500 Å of a tantalum film containing 0.7% by weight of W was deposited by sputtering and then patterned to form a Ta electrode layer 16. The Ta electrode layer 16 is anodized to form Ta 2 O 5 having a thickness of 600 Å.
The anodic oxide film 18 is formed. An aqueous solution of citric acid having a concentration of 0.01 wt% was used as the anodizing electrolyte. The anodic oxidation voltage was 30 V and the current density was 0.1 mA / cm 2.

Next, the transparent substrate 12 having the Ta electrode layer 16 and the Ta2O5 anodic oxide film 18 formed thereon was heat-treated.

This heat treatment is performed by the vertical heat treatment furnace 2 shown in FIG.
00 was used. As shown in FIG. 3, the heat treatment furnace 20
A boat 206 is installed inside the bell jar 202 of 0,
A plurality of transparent substrates 12 are mounted on the boat 206. The heating is performed by the heater 204, and the gas is made to flow in from the upper portion of the bell jar 202 and flow out from the lower side portion of the bell jar 202.

In this embodiment, 40 transparent substrates 1 are used.
2 was mounted on the boat 206, and the boat 206 was introduced into the bell jar 202 from the bottom of the bell jar 202. N2 gas is introduced from the upper part of the bell jar 202 to
After the inside of 02 was made a nitrogen atmosphere, heat treatment was started. The heat treatment was performed while rotating the boat 206. The flow rate of the N 2 gas is set to 20 l / min, and heating is started by the heater 204 until the temperature of the transparent substrate 12 reaches 450 ° C. 1
The temperature was raised at a rate of 0 ° C./min. Flow rate of N2 gas is 20
The temperature of the transparent substrate 12 was kept at 450 ° C. for 1 hour while keeping it at 1 / min. Then, at 450 ° C., a mixed gas of nitrogen gas and oxygen gas was started to flow from the upper part of the bell jar 202, and the temperature was lowered. Cooling rate is 2 ℃
/ Min. Flow ratio of nitrogen gas and oxygen gas is 9: 1
And the total flow rate was 20 l / min. That is,
In this example, the atmosphere was switched at the stage of entering the substrate cooling stage, and the flow rate of nitrogen gas was 18 l / min and the flow rate of oxygen gas was 2 l / min. The temperature is continuously lowered as it is, and after the temperature of the transparent substrate becomes 200 ° C. or lower, the boat 206 on which the transparent substrate 12 is mounted is attached to the bell jar 202.
The air was taken out from the bottom of the bell jar 202 into the atmosphere outside.

In the present embodiment, the transparent substrate 12 when the temperature is lowered
When the temperature was measured with respect to time, there was almost no difference in the temperatures of the uppermost transparent substrate 12, the central transparent substrate 12 and the lowermost transparent substrate 12, as shown in FIG.

Thereafter, as shown in FIG. 1, a Cr film is formed on the Ta2O5 anodic oxide film 18 by a sputtering method to form 150
The Cr electrode layer 20 was formed by depositing 0 Å and patterning to form the MIM type non-linear element 50 including the Ta electrode layer 16, the Ta2O5 anodic oxide film 18 and the Cr electrode layer 20.

After that, M formed on each transparent substrate 12
The non-linear parameter β of the IM type non-linear element 50 and the off-time current were measured. Here, the non-linear parameter β is a straight line obtained by plotting with the square root of the applied voltage V: √V on the horizontal axis and the logarithm of the quotient of the current I and the applied voltage V: log (I / V) on the vertical axis. Saying the inclination. The current value (A) measured when 4 V was applied to the MIM type non-linear element was taken as the current value at the time of OFF. In this example, β and the current at the time of OFF were measured for each of the 40 transparent substrates 12 and the average value was obtained. β was 3.14, and the off-state current was 7.94 × 10 −12 A. Further, the average values of the in-plane variations of the current values of β and the off state of the transparent substrate 12 are ± 1% and ± 8%, respectively, and the variations between the transparent substrates 12 are ± 3% and ± 10%, respectively. It was a very small value.

After that, each transparent substrate 12 was further heat-treated in a nitrogen atmosphere at 250 ° C. for 2 hours, and then 4 V was applied to the MIM type non-linear element 50 to measure the off-state current value. Forty transparent substrates 12 were obtained. 7.86 × 10− with the average value of
It was 12A.

(Example 2) Under the same conditions as in Example 1, the Ta electrode layer 16 and the Ta2O5 anodic oxide film 18 were formed.
The transparent substrate 12 on which the
Was heat treated. In this embodiment, as in the case of the first embodiment, N 2 gas is caused to flow at 20 l / min and the transparent substrate 1
2 was heat-treated at 450 ° C. for 1 hour and then N 2 gas was added to 20
The substrate temperature was lowered to 400 ° C. at a temperature lowering rate of 2 ° C./min while flowing at 1 / min, and when the temperature reached 400 ° C., a mixed gas of nitrogen gas and oxygen gas was started to flow from the upper part of the bell jar 202, and the same temperature lowering rate 2 The temperature was continuously lowered at ° C / min. The flow rate ratio of nitrogen gas and oxygen gas was 9: 1, and the total flow rate was 20 l / min. That is, in this embodiment, even if the substrate cooling step is started, only nitrogen is allowed to flow until the temperature reaches 400 ° C., and when the temperature reaches 400 ° C., the atmosphere is switched, the nitrogen gas flow rate is 18 l / min, and the oxygen gas flow rate is Was set to 2 l / min. The temperature is continuously lowered as it is, and after the temperature of the transparent substrate becomes 200 ° C. or lower, the transparent substrate 12
The boat 206 carrying the boat was taken out from the bottom of the bell jar 202 into the atmosphere outside the bell jar 202.

Thereafter, the Cr electrode layer 20 was formed in the same manner as in Example 1 to form the MIM type non-linear element 50 including the Ta electrode layer 16, the Ta2O5 anodic oxide film 18 and the Cr electrode layer 20.

Thereafter, in the same manner as in Example 1, the non-linear parameter β of the MIM type non-linear element 50 formed on each transparent substrate 12 and the off-time current are measured, and the average value of the 40 transparent substrates 12 is obtained. It was β was 3.21, and the off-state current was 9.43 × 10 −12 A. Also,
The in-plane variation of the transparent substrate 12 and the variation in the current value at the time of β and OFF, and the variation between the transparent substrates 12 were very small values as in Example 1.

Thereafter, each transparent substrate 12 was further heat-treated in a nitrogen atmosphere at 250 ° C. for 2 hours, and then 4 V was applied to the MIM type non-linear element 50 to measure the current value at the time of OFF. As a result, 40 transparent substrates were obtained. 9.28 × 10 with an average value of 12
It was -12A.

(Example 3) Under the same conditions as in Example 1, the Ta electrode layer 16 and the Ta2O5 anodic oxide film 18 were formed.
The transparent substrate 12 on which the
Was heat treated. In this embodiment, as in the case of the first embodiment, N 2 gas is caused to flow at 20 l / min and the transparent substrate 1
2 was heat-treated at 450 ° C. for 1 hour and then N 2 gas was added to 20
The substrate temperature is lowered to 350 ° C. at a temperature lowering rate of 2 ° C./min while flowing at 1 / min, and when the temperature reaches 350 ° C., a mixed gas of nitrogen gas and oxygen gas is started to flow from the upper part of the bell jar 202, and the same temperature lowering rate 2 The temperature was continuously lowered at ° C / min. The flow rate ratio of nitrogen gas and oxygen gas was 9: 1, and the total flow rate was 20 l / min. That is, in this embodiment, even if the substrate cooling step is started, only nitrogen is allowed to flow until it reaches 350 ° C., and when the temperature reaches 350 ° C., the atmosphere is switched, the flow rate of nitrogen gas is 18 l / min, and the flow rate of oxygen gas is Was set to 2 l / min. The temperature is continuously lowered as it is, and after the temperature of the transparent substrate becomes 200 ° C. or lower, the transparent substrate 12
The boat 206 carrying the boat was taken out from the bottom of the bell jar 202 into the atmosphere outside the bell jar 202.

After that, the Cr electrode layer 20 was formed in the same manner as in Example 1, and the MIM type non-linear element 50 including the Ta electrode layer 16, the Ta2O5 anodic oxide film 18 and the Cr electrode layer 20 was formed.

Thereafter, in the same manner as in Example 1, the non-linear parameter β of the MIM type non-linear element 50 formed on each transparent substrate 12 and the off-time current are measured, and the average value of the 40 transparent substrates 12 is obtained. It was β was 3.32, and the off-state current was 1.12 × 10 −11 A. Also,
The in-plane variation of the transparent substrate 12 and the variation in the current value at the time of β and OFF, and the variation between the transparent substrates 12 were very small values as in Example 1.

Thereafter, each transparent substrate 12 was further heat-treated in a nitrogen atmosphere at 250 ° C. for 2 hours, and then 4 V was applied to the MIM type non-linear element 50 to measure the current value at the time of OFF, and 40 transparent substrates were obtained. 1.10 × 10 on average of 12
It was -11A.

(Example 4) Under the same conditions as in Example 1, the Ta electrode layer 16 and the Ta2O5 anodic oxide film 18 were formed.
The transparent substrate 12 on which the
Was heat treated. In this embodiment, as in the case of the first embodiment, N 2 gas is caused to flow at 20 l / min and the transparent substrate 1
2 was heat-treated at 450 ° C. for 1 hour and then N 2 gas was added to 20
The substrate temperature was lowered to 300 ° C. at a temperature lowering rate of 2 ° C./min while flowing at 1 / min, and when the temperature reached 300 ° C., a mixed gas of nitrogen gas and oxygen gas was started to flow from the upper portion of the bell jar 202, and the same temperature lowering rate was The temperature was continuously lowered at ° C / min. The flow rate ratio of nitrogen gas and oxygen gas was 9: 1, and the total flow rate was 20 l / min. That is, in this embodiment, even when the substrate cooling step is started, only nitrogen is allowed to flow until the temperature reaches 300 ° C., and when the temperature reaches 300 ° C., the atmosphere is switched, the nitrogen gas flow rate is 18 l / min, and the oxygen gas flow rate is Was set to 2 l / min. The temperature is continuously lowered as it is, and after the temperature of the transparent substrate becomes 200 ° C. or lower, the transparent substrate 12
The boat 206 carrying the boat was taken out from the bottom of the bell jar 202 into the atmosphere outside the bell jar 202.

After that, the Cr electrode layer 20 was formed in the same manner as in Example 1, and the MIM type non-linear element 50 including the Ta electrode layer 16, the Ta2O5 anodic oxide film 18 and the Cr electrode layer 20 was formed.

Thereafter, in the same manner as in Example 1, the non-linear parameter β of the MIM type non-linear element 50 formed on each transparent substrate 12 and the off-time current are measured, and the average value of the 40 transparent substrates 12 is obtained. It was β was 3.37, and the off-state current was 2.52 × 10 −11 A. Also,
The in-plane variation of the transparent substrate 12 and the variation in the current value at the time of β and OFF, and the variation between the transparent substrates 12 were very small values as in Example 1.

After that, each transparent substrate 12 was further heat-treated in a nitrogen atmosphere at 250 ° C. for 2 hours, and then 4 V was applied to the MIM type non-linear element 50 to measure the current value when it was off. 2.00 × 10 with an average value of 12
It was -11A.

(Embodiment 5) Under the same conditions as in Embodiment 1, the Ta electrode layer 16 and the Ta2O5 anodic oxide film 18 are formed.
The transparent substrate 12 on which the
Was heat treated. In this embodiment, as in the case of the first embodiment, N 2 gas is caused to flow at 20 l / min and the transparent substrate 1
2 was heat-treated at 450 ° C. for 1 hour and then N 2 gas was added to 20
The substrate temperature is lowered to 250 ° C. at a temperature lowering rate of 2 ° C./min while flowing at 1 / min, and when the temperature reaches 250 ° C., a mixed gas of nitrogen gas and oxygen gas is started to flow from the upper part of the bell jar 202, and the same temperature lowering rate is set to 2 The temperature was continuously lowered at ° C / min. The flow rate ratio of nitrogen gas and oxygen gas was 9: 1, and the total flow rate was 20 l / min. That is, in this embodiment, even if the substrate cooling step is started, only nitrogen is allowed to flow until the temperature reaches 250 ° C., and when the temperature reaches 250 ° C., the atmosphere is switched, the nitrogen gas flow rate is 18 l / min, and the oxygen gas flow rate is set. Was set to 2 l / min. The temperature is continuously lowered as it is, and after the temperature of the transparent substrate becomes 200 ° C. or lower, the transparent substrate 12
The boat 206 carrying the boat was taken out from the bottom of the bell jar 202 into the atmosphere outside the bell jar 202.

Thereafter, the Cr electrode layer 20 was formed in the same manner as in Example 1 to form the MIM type non-linear element 50 including the Ta electrode layer 16, the Ta2O5 anodic oxide film 18 and the Cr electrode layer 20.

Thereafter, in the same manner as in Example 1, the non-linear parameter β and the off-time current of the MIM type non-linear element 50 formed on each transparent substrate 12 are measured, and the average value of the 40 transparent substrates 12 is obtained. It was β was 3.40, and the off-state current was 1.41 × 10 −10 A. Also,
The in-plane variation of the transparent substrate 12 and the variation in the current value at the time of β and OFF, and the variation between the transparent substrates 12 were very small values as in Example 1.

After that, each transparent substrate 12 was further heat-treated at 250 ° C. for 2 hours in a nitrogen atmosphere, and then 4 V was applied to the MIM type non-linear element 50 to measure the current value at the time of OFF. The average value of 12 is 9.43 × 10
It was -11A.

Comparative Example Under the same conditions as in Example 1,
The transparent substrate 12 on which the Ta electrode layer 16 and the Ta 2 O 5 anodic oxide film 18 were formed was prepared, and this transparent substrate 12 was heat-treated. In this comparative example, first, in the same manner as in Example 1, the transparent substrate 12 was heat-treated at 450 ° C. for 1 hour by flowing N 2 gas at 20 l / min. After that, the substrate temperature was kept at 2 ° C./mi while N 2 gas was flown at 20 l / min.
200 ℃ at a temperature decrease rate of n
After that, the boat 206 having the transparent substrate 12 mounted thereon was taken out from the bottom of the bell jar 202 into the atmosphere outside the bell jar 202.

After that, the Cr electrode layer 20 was formed in the same manner as in Example 1, and the MIM type non-linear element 50 including the Ta electrode layer 16, the Ta2O5 anodic oxide film 18 and the Cr electrode layer 20 was formed. Then, in the same manner as in Example 1, the nonlinear parameter β of the MIM type nonlinear element 50 formed on each transparent substrate 12 and the off-time current were measured, and the average value of 40 transparent substrates 12 was obtained. β is 2.99,
The off-time current was 5.96 × 10 −10 A. Further, the average values of the in-plane variations of the β and OFF current values of the transparent substrate 12 are ± 10% and ± 18%, respectively, and the variations between the transparent substrates 12 are ± 15% and ± 21%, respectively. Met.

After that, each transparent substrate 12 was further heat-treated in a nitrogen atmosphere at 250 ° C. for 2 hours, and then 4 V was applied to the MIM type non-linear element 50, and the current value at the time of OFF was measured. As a result, 40 transparent substrates were obtained. 2.24 × 10 with an average value of 12
It was -10A.

FIG. 4 shows β of Examples 1 to 5 and Comparative Example.
It is the figure which plotted the value of. The temperature on the horizontal axis in the figure is the temperature at which the mixed gas of oxygen gas and nitrogen gas starts to flow. Referring to the figure, when the temperature is lowered in a mixed gas atmosphere of oxygen gas and nitrogen gas as in Examples 1 to 5 after heat treatment in nitrogen, as compared with the case of lowering the temperature in an atmosphere of only nitrogen gas. It can be seen that the β value is improved.

FIG. 5 is a plot of off-state current values of Examples 1 to 5 and Comparative Example. The temperature on the horizontal axis in the figure is the temperature at which the mixed gas of oxygen gas and nitrogen gas starts to flow. In the figure, A is the current value at the time of OFF after the formation of the MIM type nonlinear element, and B in the figure is 2 at 250 ° C. in a nitrogen atmosphere thereafter.
It is the current value at the time of OFF after heat treatment for a period of time. Referring to the figure, after the heat treatment in nitrogen, the temperature is lowered in an atmosphere of a mixed gas of oxygen gas and nitrogen gas as in Examples 1 to 5,
It can be seen that the current value at the time of OFF is reduced as compared with the case where the temperature is lowered in the atmosphere of only nitrogen gas. Also, MIM
Even if heat treatment was performed at 250 ° C. after the formation of the non-linear element, the effect on the off-state current value was small, and a highly reliable MIM non-linear element was obtained.

Further, referring to FIGS. 4 and 5, it becomes possible to control β and the current at the time of OFF by the temperature at which the mixed gas of oxygen gas and nitrogen gas starts to flow, and as a result, the required element It can be seen that the characteristics can be easily realized.

(Example 6) Under the same conditions as in Example 1, the Ta electrode layer 16 and the Ta2O5 anodic oxide film 18 were formed.
The transparent substrate 12 on which the
Was heat treated. The heat treatment was performed using the same vertical heat treatment furnace 200 as in Example 1.

In this embodiment, 40 transparent substrates 1 are used.
2 was mounted on the boat 206, and the boat 206 was introduced into the bell jar 202 from the bottom of the bell jar 202. N2 gas is introduced from the upper part of the bell jar 202 to
After the inside of 02 was made a nitrogen atmosphere, heat treatment was started. The heat treatment was performed while rotating the boat 206. The flow rate of the N2 gas is set to 20 l / min and heating is started by the heater 204 until the temperature of the transparent substrate 12 reaches 400 ° C.
The temperature was raised at a rate of 0 ° C./min. Flow rate of N2 gas is 20
The temperature of the transparent substrate 12 was kept at 400 ° C. for 1 hour while keeping it at 1 / min. Then, at 400 ° C., a mixed gas of nitrogen gas and oxygen gas was started to flow from the upper part of the bell jar 202, and the temperature was lowered. Cooling rate is 2 ℃
/ Min. Flow ratio of nitrogen gas and oxygen gas is 9: 1
And the total flow rate was 20 l / min. That is,
In this example, the atmosphere was switched at the stage of entering the substrate cooling stage, and the flow rate of nitrogen gas was 18 l / min and the flow rate of oxygen gas was 2 l / min. The temperature is continuously lowered as it is, and after the temperature of the transparent substrate becomes 200 ° C. or lower, the boat 206 on which the transparent substrate 12 is mounted is attached to the bell jar 202.
The air was taken out from the bottom of the bell jar 202 into the atmosphere outside.

After that, the Cr electrode layer 20 was formed in the same manner as in Example 1, and the MIM type non-linear element 50 including the Ta electrode layer 16, the Ta 2 O 5 anodic oxide film 18 and the Cr electrode layer 20 was formed.

Then, the non-linear parameter β and the off-time current of the MIM type non-linear element 50 formed on each transparent substrate 12 were measured in the same manner as in Example 1, and found to be 45.
It was found that these characteristics were improved as in the case of Examples 1 to 5 in which heat treatment was performed at 0 ° C. in a nitrogen atmosphere.

(Example 7) Under the same conditions as in Example 6, the Ta electrode layer 16 and the Ta2O5 anodic oxide film 18 were formed.
The transparent substrate 12 on which the
Was heat treated. In this example, as in the case of Example 6, N 2 gas was caused to flow at 20 l / min and the transparent substrate 1
2 was heat-treated at 400 ° C. for 1 hour, and then N 2 gas was added to 20
The substrate temperature was lowered to 300 ° C. at a temperature lowering rate of 2 ° C./min while flowing at 1 / min, and when the temperature reached 300 ° C., a mixed gas of nitrogen gas and oxygen gas was started to flow from the upper part of the bell jar 202, and the same temperature lowering rate was set to 2 The temperature was continuously lowered at ° C / min. The flow rate ratio of nitrogen gas and oxygen gas was 9: 1, and the total flow rate was 20 l / min. That is, in this embodiment, even when the substrate cooling step is started, only nitrogen is allowed to flow until the temperature reaches 300 ° C., and when the temperature reaches 300 ° C., the atmosphere is switched, the nitrogen gas flow rate is 18 l / min, and the oxygen gas flow rate is changed. Was set to 2 l / min. The temperature is continuously lowered as it is, and after the temperature of the transparent substrate becomes 200 ° C. or lower, the transparent substrate 12
The boat 206 carrying the boat was taken out from the bottom of the bell jar 202 into the atmosphere outside the bell jar 202.

After that, the Cr electrode layer 20 was formed in the same manner as in Example 1, and the MIM type non-linear element 50 including the Ta electrode layer 16, the Ta2O5 anodic oxide film 18 and the Cr electrode layer 20 was formed.

Thereafter, the non-linear parameter β and the off-time current of the MIM type non-linear element 50 formed on each transparent substrate 12 were measured in the same manner as in Example 1, and found to be 45.
It was found that these characteristics were improved as in the case of Examples 1 to 5 in which heat treatment was performed at 0 ° C. in a nitrogen atmosphere.

(Embodiment 8) Under the same conditions as in Embodiment 1, the Ta electrode layer 16 and the Ta2O5 anodic oxide film 18 are formed.
The transparent substrate 12 on which the
Was heat treated. The heat treatment was performed using the same vertical heat treatment furnace 200 as in Example 1.

In this embodiment, 40 transparent substrates 1 are used.
2 was mounted on the boat 206, and the boat 206 was introduced into the bell jar 202 from the bottom of the bell jar 202. N2 gas is introduced from the upper part of the bell jar 202 to
After the inside of 02 was made a nitrogen atmosphere, heat treatment was started. The heat treatment was performed while rotating the boat 206. The flow rate of the N2 gas is set to 20 l / min and heating is started by the heater 204 until the temperature of the transparent substrate 12 reaches 350 ° C.
The temperature was raised at a rate of 0 ° C./min. Flow rate of N2 gas is 20
The temperature of the transparent substrate 12 was kept at 350 ° C. for 1 hour while keeping it at 1 / min. Then, at 350 ° C., a mixed gas of nitrogen gas and oxygen gas was started to flow from the upper part of the bell jar 202, and the temperature was lowered. Cooling rate is 2 ℃
/ Min. Flow ratio of nitrogen gas and oxygen gas is 9: 1
And the total flow rate was 20 l / min. That is,
In this example, the atmosphere was switched at the stage of entering the substrate cooling stage, and the flow rate of nitrogen gas was 18 l / min and the flow rate of oxygen gas was 2 l / min. The temperature is continuously lowered as it is, and after the temperature of the transparent substrate becomes 200 ° C. or lower, the boat 206 on which the transparent substrate 12 is mounted is attached to the bell jar 202.
The air was taken out from the bottom of the bell jar 202 into the atmosphere outside.

After that, the Cr electrode layer 20 was formed in the same manner as in Example 1, and the MIM type non-linear element 50 including the Ta electrode layer 16, the Ta2O5 anodic oxide film 18 and the Cr electrode layer 20 was formed.

After that, when the non-linear parameter β and the off-time current of the MIM type non-linear element 50 formed on each transparent substrate 12 were measured in the same manner as in Example 1, 45
It was found that these characteristics were improved as in the cases of Examples 1 to 5 which were heat-treated at 0 ° C. in a nitrogen atmosphere and Examples 6 and 7 which were heat-treated at 400 ° C. in a nitrogen atmosphere.

Example 9 The experiment was carried out in 5 batches in the same manner as in Example 1. The batch-to-batch variations in β and OFF current values were ± 3% and ± 8%, respectively, which were very small values.

(Example 10) Under the same conditions as in Example 1, the transparent substrate 12 on which the Ta electrode layer 16 and the Ta2O5 anodic oxide film 18 were formed was prepared, and the transparent substrate 12 of the lake was heat-treated. The heat treatment was performed using the same vertical heat treatment furnace 200 as in Example 1.

In this embodiment, 40 transparent substrates 1 are used.
2 was mounted on the boat 206, and the boat 206 was introduced into the bell jar 202 from the bottom of the bell jar 202. N2 gas is introduced from the upper part of the bell jar 202 to
After the inside of 02 was made a nitrogen atmosphere, heat treatment was started. The heat treatment was performed while rotating the boat 206. The flow rate of the N 2 gas is set to 20 l / min, and heating is started by the heater 204 until the temperature of the transparent substrate 12 reaches 450 ° C. 1
The temperature was raised at a rate of 0 ° C./min. Flow rate of N2 gas is 20
The temperature of the transparent substrate 12 was kept at 450 ° C. for 1 hour while keeping it at 1 / min. Then, at 450 ° C., a mixed gas of nitrogen gas and oxygen gas was started to flow from the upper part of the bell jar 202, and the temperature was lowered. Cooling rate is 2 ℃
/ Min. Flow ratio of nitrogen gas and oxygen gas is 9: 1
And the total flow rate was 20 l / min. That is,
In this example, the atmosphere was switched at the stage of entering the substrate cooling stage, and the flow rate of nitrogen gas was 18 l / min and the flow rate of oxygen gas was 2 l / min. The temperature is continuously lowered as it is, and after the temperature of the transparent substrate becomes 250 ° C. or lower, the boat 206 on which the transparent substrate 12 is mounted is attached to the bell jar 202.
The air was taken out from the bottom of the bell jar 202 into the atmosphere outside.

Thereafter, as shown in FIG. 1, a Cr film is formed on the Ta2O5 anodic oxide film 18 by a sputtering method to a thickness of 150.
The Cr electrode layer 20 was formed by depositing 0 Å and patterning to form the MIM type non-linear element 50 including the Ta electrode layer 16, the Ta2O5 anodic oxide film 18 and the Cr electrode layer 20.

Then, in the same manner as in Example 1, the non-linear parameter β of the MIM type non-linear element 50 formed on each transparent substrate 12 and the off-time current are measured, and the average value of the 40 transparent substrates 12 is obtained. It was β was 3.24, and the off-state current was 7.52 × 10 −12 A. Also, β
The in-plane variation of the current value at the time of off and the in-plane current value of the transparent substrate 12 is ± 4% and ± 11%, respectively.
The variation between 2 was a very small value as in Example 1.

Further, after the temperature of the transparent substrate 12 becomes 220 ° C. or lower, the boat 20 on which the transparent substrate 12 is mounted is mounted.
When 6 is taken out from the bottom of the bell jar 202 into the atmosphere outside the bell jar 202, the non-linear parameter β of the MIM type non-linear element 50 formed on each transparent substrate 12 and the current at the time of OFF of the 40 transparent substrates 12 are measured. The average value of β is 3.20, and the off-state current is 7.68 × 10 −12.
It was A. Further, the in-plane variation of the current values at β and the OFF state of the transparent substrate 12 is ± 3% and ± 9%, respectively, and the variation between the transparent substrates 12 is a very small value as in the first embodiment. .

As described in Examples 1 to 10, after the temperature of the transparent substrate 12 becomes 250 ° C. or lower, the bell jar 2
By taking out the transparent substrate 12 into the atmosphere from No. 02, a large effect can be obtained with respect to a predetermined effect, in particular, in-plane variation of element characteristics of the MIM type nonlinear element 50, variation between transparent substrates 12 and variation between heat treatment batches. be able to.

When the temperature of the transparent substrate 12 is taken out into the atmosphere at a temperature higher than 250 ° C., the above variation is reduced to a level equivalent to that of the comparative example.

(Embodiment 11) First, as shown in FIG.
A tantalum film was deposited on the transparent substrate 12 made of alkali-free glass by sputtering and then thermally oxidized to form a tantalum oxide film 14 of about 1000 liters.
The tantalum oxide film 14 is for improving the adhesion between the transparent substrate 12 made of non-alkali glass and the Ta electrode layer 16. Here, the tantalum oxide film 14 having the same effect can be obtained even if it is deposited by sputtering.

Next, a tantalum film was deposited to a thickness of about 2500 Å by sputtering and then patterned to form a Ta electrode layer 16. The Ta electrode layer 16 is anodized to form a Ta2O5 anodized film 18 having a thickness of 600Å. An aqueous solution of citric acid having a concentration of 0.01 wt% was used as the anodizing electrolyte. The anodic oxidation voltage was 30 V and the current density was 0.1 mA / cm 2.

Next, the transparent substrate 12 having the Ta electrode layer 16 and the Ta2O5 anodic oxide film 18 formed thereon was heat-treated.

This heat treatment is performed by the vertical heat treatment furnace 2 shown in FIG.
00 was used. As shown in FIG. 3, the heat treatment furnace 20
A boat 206 is installed inside the bell jar 202 of 0,
A plurality of transparent substrates 12 are mounted on the boat 206. The heating is performed by the heater 204, and the gas is made to flow in from the upper portion of the bell jar 202 and flow out from the lower side portion of the bell jar 202.

In this embodiment, 40 transparent substrates 1 are used.
2 was mounted on the boat 206, and the boat 206 was introduced into the bell jar 202 from the bottom of the bell jar 202. N2 gas is introduced from the upper part of the bell jar 202 to
After the inside of 02 was made a nitrogen atmosphere, heat treatment was started. The heat treatment was performed while rotating the boat 206. The flow rate of the N 2 gas is set to 20 l / min, and heating is started by the heater 204 until the temperature of the transparent substrate 12 reaches 450 ° C. 1
The temperature was raised at a rate of 0 ° C./min. Flow rate of N2 gas is 20
The temperature of the transparent substrate 12 was kept at 450 ° C. for 1 hour while keeping it at 1 / min. After that, at 450 ° C., a mixed gas of nitrogen gas and oxygen gas containing water vapor was started to flow from the upper part of the bell jar 202, and the temperature was lowered. The rate of temperature decrease was 2 ° C./min. The flow rate ratio of nitrogen gas and oxygen gas was 9: 1, and the total flow rate was 20 l / min. That is, in the present embodiment, the atmosphere is switched at the stage of entering the substrate cooling stage, and the flow rate of nitrogen gas is set at 18.
1 / min, the flow rate of oxygen gas containing water vapor is 2 l / mi
It was set to n. The temperature of the transparent substrate is kept at 20
After the temperature becomes 0 ° C. or lower, the boat 206 on which the transparent substrate 12 is mounted is moved from the bottom of the bell jar 202 to the bell jar 202.
It was taken out to the outside atmosphere.

After that, as shown in FIG. 1, a Cr film is formed on the Ta2O5 anodic oxide film 18 by a sputtering method to a thickness of 150.
The Cr electrode layer 20 was formed by depositing 0 Å and patterning to form the MIM type non-linear element 50 including the Ta electrode layer 16, the Ta2O5 anodic oxide film 18 and the Cr electrode layer 20.

After that, the non-linear parameter β and the off-time current of the MIM type non-linear element 50 formed on each transparent substrate 12 were measured in the same manner as in the first embodiment, and as in the first to eighth embodiments. , It was found that these characteristics were improved.

(Embodiment 12) As in Embodiments 2 to 8,
The MIM type non-linear element 50 is manufactured by changing the heat treatment temperature in Example 11 and the temperature at which the atmosphere is switched when the substrate is cooled, and the MIM type non-linear element formed on each transparent substrate 12 in the same manner as in Example 1. When the non-linear parameter β of 50 and the current at the time of OFF were measured, Example 11
It was found that these characteristics were improved as in the case of.

(Embodiment 13) As in Embodiment 10, the MIM type non-linear element 50 is manufactured by changing the temperature at which the transparent substrate 12 in Embodiment 11 is taken out into the atmosphere, and each transparent substrate is manufactured in the same manner as in Embodiment 1. When the non-linear parameter β and the off-time current of the MIM type non-linear element 50 formed on No. 12 were measured, it was found that these characteristics were improved as in the case of Example 11. Further, the in-plane variation of the element characteristics of the MIM type nonlinear element 50 and the transparent substrate 1
The variation between the two was also at a good level.

(Example 14) MI in the same manner as in Example 1
After manufacturing the M-type non-linear element 50, as shown in FIG.
TO (Indium-Tin-Oxide) film by sputtering 1
000Å deposited and then patterned to form pixel electrode 2
2 to form the transparent substrate 12, the MIM type non-linear element 50 provided on the transparent substrate 12, and the MIM type non-linear element 5
An electrode substrate 10 having a pixel electrode 22 connected to 0 was formed. On the other hand, an electrode film 30 was prepared by depositing an ITO film on a transparent substrate 32 made of non-alkali glass by sputtering and then patterning it to form a counter signal electrode 34. Electrode substrate 10 and electrode substrate 3
The liquid crystal layer 40 was sandwiched between the two.

Next, as shown in FIG. 7, the data line 78 formed of the Ta electrode layer 16 is connected to the data line drive circuit, and the scanning line 74 formed of the counter signal electrode 34 is set to the scanning line drive circuit 72.
And a liquid crystal display device 100 was prepared. When the display characteristics of the liquid crystal display device 100 were examined, the contrast was high and the image quality was good.

Examples 2 to 8 and Examples 10 to 13
When the liquid crystal display device 100 was produced in the same manner as in this example using the MIM type non-linear element 50 produced by the same method as above, the contrast was similarly high and excellent image quality was obtained.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments. For example, in Embodiments 1 to 9, the Ta electrode layer 16 contains Ta as a main component, and It is also possible to use a material to which Re or Mo is added. Further, the concentration is not limited to 0.7% by weight even when the tantalum film to which W is added is used as in the above embodiment.

Further, instead of the Cr electrode layer 20, an electrode layer made of Ti or Al can be used. Furthermore, the Cr electrode layer 20 may be omitted and the pixel electrode 22 may also serve as the Cr electrode layer 20.

Further, in this embodiment, the vertical furnace is used as the heat treatment apparatus, but the same effect can be obtained by performing the heat treatment as in this embodiment using the horizontal furnace having the same specifications. .

When the drive voltage is continuously applied to the element to drive the liquid crystal display device, the current shift occurs even if the same voltage is applied to the initial characteristics. In order to make the burn-in of the liquid crystal display device inconspicuous, this M
It is necessary to suppress the current shift of the IM element within 2%.
Further, in order to drive the liquid crystal, the current value at the time of applying 4V is generally 1 ×, though it depends on the threshold voltage of the liquid crystal used.
It must be 10-10A or less. Furthermore, in order to operate sufficiently even in an environment of 80 ° C., 1 × 10 −1
It should be 1A or less. Therefore, as shown at 91 in FIG. 9, when the heat treatment is performed after the oxide film is formed by using the conventional technique, the current shift becomes large when the operation margin is secured, and the burn-in of the liquid crystal display device becomes conspicuous. Become. The same applies when a MIM type non-linear element is created as in the comparative example.

When the MIM type non-linear element is manufactured by using this embodiment, as shown at 92 in FIG. 9, the operation margin can be secured and the shift can be suppressed within 2%. The liquid crystal display device 100 having

[Brief description of drawings]

FIG. 1 is a cross-sectional view for explaining an embodiment of the present invention and a conventional method for manufacturing a MIM type non-linear element.

FIG. 2 is a cross-sectional view for explaining an example of the present invention and a conventional method for manufacturing a MIM type nonlinear element.

FIG. 3 is a cross-sectional view for explaining a heat treatment furnace used in an example of the present invention.

FIG. 4 is a graph showing β values of MIM type nonlinear elements of the first to fifth embodiments of the present invention and comparative examples.

FIG. 5 is a diagram showing current values when the MIM type nonlinear elements of the first to fifth examples and comparative examples of the present invention are off.

FIG. 6 is a diagram showing a relationship between substrate temperature and time in the first embodiment of the present invention.

FIG. 7 is a diagram for explaining a liquid crystal display device in which the present invention and a conventional MIM type non-linear element are used.

FIG. 8 is a cross-sectional view illustrating a liquid crystal display device using the present invention and a conventional MIM type non-linear element.

FIG. 9 is a diagram showing a relationship between current shifts of the present invention and a conventional MIM type nonlinear element and a current flowing when a voltage of 4V is applied to the MIM type nonlinear element.

[Explanation of symbols]

 10, 30 ... Electrode substrate 12, 32 ... Transparent substrate 14 ... Ta2O5 layer 16 ... Ta electrode layer 18 ... Ta2O5 anodic oxide film 20 ... Cr electrode layer 22 ... Pixel electrode 34 ... Counter signal electrode 40 ... Liquid crystal layer 50 ... MIM type non-linear element 60 ... Liquid crystal display element 72 ... Scan line drive circuit 74 ... Scan line 76 ... Data line drive circuit 78 ... Data line 80 ... Pixel region 100 ... Liquid crystal display device 200 ... Heat treatment furnace 202 ... Bell jar 204 ... Heater 206 ... Boat

Claims (26)

[Claims] 1. A step of forming a first conductive layer on a substrate, a step of forming an oxide film on the first conductive layer, and at least at the final stage thereof, the first conductive layer and the oxidation film. A thermal annealing step of processing the substrate on which the film is formed in a gas atmosphere containing oxygen gas; and a step of forming a second conductive layer on the oxide film after that. A method for manufacturing a MIM type non-linear element. 2. The method of manufacturing a MIM type non-linear element according to claim 1, wherein in the thermal annealing step, the substrate on which the first conductive layer and the oxide film are formed is heated at a predetermined first temperature. A step of performing heat treatment, a step of lowering the temperature of the substrate from the first temperature to a predetermined second temperature, and a step of heating the substrate from the second temperature to a predetermined temperature in a gas atmosphere containing oxygen gas. A step of lowering the temperature to a third temperature,
A method of manufacturing a MIM type non-linear element, comprising: 3. A method of manufacturing a MIM type non-linear element according to claim 2, comprising a step of performing heat treatment at a first temperature and a step of lowering the temperature from the first temperature to the second temperature in a nitrogen gas atmosphere. A method of manufacturing a MIM type non-linear element, characterized in that 4. The MIM according to any one of claims 1 to 3.
A method of manufacturing a MIM type nonlinear element, wherein the gas containing oxygen gas is a mixed gas of oxygen gas and nitrogen gas. 5. The method for manufacturing a MIM type non-linear element according to claim 4, wherein the flow rate ratio of the oxygen gas and the nitrogen gas is 1:20 to 20: 1.
And a method for manufacturing a MIM type non-linear element. 6. The MIM according to any one of claims 1 to 5.
A method of manufacturing a MIM type nonlinear element, wherein the oxide film is an anodized film of a first conductive layer. 7. The MIM according to any one of claims 1 to 6.
In the method for manufacturing a non-linear element, the MI, wherein the first conductive layer is made of Ta.
Method for manufacturing M-type non-linear element. 8. The method of manufacturing an MIM type non-linear element according to claim 7, wherein the gas atmosphere containing the oxygen gas contains water vapor. 9. The MIM according to any one of claims 1 to 6.
In the method for manufacturing a non-linear element, the first conductive layer contains Ta as a main component, and W, R
MIM characterized by comprising at least one element selected from the group consisting of e and Mo
Method of manufacturing type nonlinear element. 10. The method for manufacturing a MIM type non-linear element according to claim 9, wherein the oxygen gas is dry oxygen gas.
IM-type non-linear element manufacturing method. 11. M according to any one of claims 1 to 10.
In the method for manufacturing an IM type non-linear element, the second conductive layer is made of Cr, Ti, Al or indium tin tin oxide (ITO).
Method for manufacturing M-type non-linear element. 12. The method of manufacturing an MIM type non-linear element according to claim 11, wherein the second conductive layer is Cr.
Method of manufacturing type nonlinear element. 13. M according to any one of claims 2 to 12.
In the method for manufacturing an IM-type non-linear element, the average temperature gradient from the first temperature to the third temperature is 0.1 to 60 ° C./min, and the MIM is characterized.
Method of manufacturing type nonlinear element. 14. M according to any one of claims 2 to 13.
In the method for manufacturing an IM-type non-linear element, the substrate is a glass substrate, and the first temperature is 220 ° C.
The manufacturing method of the MIM type | mold nonlinear element characterized by being -600 degreeC. 15. The M according to any one of claims 2 to 14.
The method for manufacturing an IM type non-linear element, wherein the second temperature is 220 ° C. to 600 ° C. 16. M according to any one of claims 2 to 15.
The method for manufacturing an IM-type nonlinear element, wherein the third temperature is 250 ° C. or lower. 17. The M according to any one of claims 2 to 16.
The method for manufacturing an IM-type non-linear element, wherein the second temperature is the same temperature as the first temperature. 18. The M according to any one of claims 2 to 17.
In the method for manufacturing an IM-type non-linear element, a heat treatment step at the first temperature, a temperature reduction step from the first temperature to the second temperature, and a second temperature to the third temperature are performed. A method of manufacturing an MIM type non-linear element, characterized in that the temperature lowering step and the temperature lowering step are continuously performed in the same heat treatment apparatus. 19. M according to any one of claims 2 to 18.
In the method for manufacturing an IM type non-linear element, the substrate on which the first conductive layer and the oxide film are formed is cooled from the second temperature to 250 ° C. or lower in a gas atmosphere containing the oxygen gas, and then the A method of manufacturing a MIM type non-linear element, characterized in that the substrate is taken out of the heat treatment apparatus. 20. M according to any one of claims 2 to 18.
In the method for manufacturing an IM type non-linear element, the substrate on which the first conductive layer and the oxide film are formed is cooled from the second temperature to 220 ° C. or less in a gas atmosphere containing the oxygen gas, and then the A method of manufacturing a MIM type non-linear element, characterized in that the substrate is taken out of the heat treatment apparatus. 21. M according to any one of claims 2 to 18.
In the method for manufacturing an IM nonlinear element, the substrate on which the first conductive layer and the oxide film are formed is cooled from the second temperature to 200 ° C. or lower in a gas atmosphere containing the oxygen gas, and then the A method of manufacturing a MIM type non-linear element, characterized in that the substrate is taken out of the heat treatment apparatus. 22. The M according to any one of claims 2 to 21.
In the method for manufacturing an IM-type nonlinear element, the temperature for taking out the substrate to the outside of the heat treatment apparatus and the third temperature are the same, and the method for manufacturing an MIM-type nonlinear element. 23. The method of manufacturing a MIM type non-linear element according to claim 1, wherein the thermal annealing step is performed in a heat treatment apparatus in a gas atmosphere containing the oxygen gas at a final stage of 25.
A method of manufacturing a MIM type non-linear element, characterized in that the temperature is lowered to 0 ° C. or lower, and then the substrate is taken out of the heat treatment apparatus. 24. The method of manufacturing an MIM type non-linear element according to claim 1, wherein the thermal annealing step is performed in the heat treatment apparatus in a gas atmosphere containing the oxygen gas at the final stage.
A method of manufacturing a MIM type non-linear element, characterized in that the temperature is lowered to 0 ° C. or lower, and then the substrate is taken out of the heat treatment apparatus. 25. The method of manufacturing a MIM type non-linear element according to claim 1, wherein the thermal annealing step is performed in a heat treatment apparatus in a gas atmosphere containing the oxygen gas at the final stage of 20.
A method of manufacturing a MIM type non-linear element, characterized in that the temperature is lowered to 0 ° C. or lower, and then the substrate is taken out of the heat treatment apparatus. 26. An M produced by the method according to claim 1.
A liquid crystal display device using an IM type non-linear element as a switching element of a pixel.