JP2003051384A - Repairing method and manufacturing method of light emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a repairing method of a light emitting device, which performs high quality image display even when a pinhole is formed in forming an organic compound layer, capable of preventing contamination of a device in repairing. SOLUTION: An electric current flowing in an EL element when a reverse bias voltage is applied is made to be reduced by applying a reverse bias voltage at every fixed period of time to an organic luminous element. Furthermore, the contamination of the device when the reverse bias is applied is prevented by preventing from containing an ion with high mobility such as Li, Na contained in a negative electrode as much as possible. Such a negative electrode is preferably AlMG, and MgAg.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for repairing a light emitting device and a method for manufacturing a light emitting device using the repairing method in an intermediate step. More specifically, the present invention relates to a method for repairing a light emitting device that applies a reverse bias to an organic light emitting element, and a method for manufacturing a light emitting device including the repairing method.

A light emitting device is a general term for an organic light emitting display in which an organic light emitting element formed on a substrate is enclosed between the substrate and a cover material, and a module in which an IC is mounted on the organic light emitting display.

[0003]

2. Description of the Related Art An organic light emitting element emits light by itself, so that it has high visibility, is not required to have a backlight required in a liquid crystal display (LCD), is suitable for thinning, and has no limitation in viewing angle. Therefore, in recent years, a light emitting device using an organic light emitting element has been attracting attention as an electro-optical device replacing a CRT or LCD.

The organic light-emitting element is a layer containing an organic compound which can obtain electroluminescence generated by applying an electric field (hereinafter referred to as an organic compound layer).
And an anode layer and a cathode layer. Luminescence includes light emission when returning from a singlet excited state to a ground state (fluorescence) and light emission when returning from a triplet excited state to a ground state (phosphorescence). It is also applicable to a light emitting device using light emission.

In this specification, all layers provided between the anode and the cathode are defined as organic compound layers. The organic compound layer specifically includes a light emitting layer, a hole injection layer, an electron injection layer,
A hole transport layer, an electron transport layer, etc. are included. Basically, an organic light emitting device has a structure in which an anode / a light emitting layer / a cathode are laminated in order, and in addition to this structure, an anode / a hole injection layer / a light emitting layer / a cathode and an anode / a hole injection. It may have a structure in which layers / light emitting layer / electron transporting layer / cathode are laminated in this order.

In this specification, the emission of light from the organic light emitting element is referred to as the driving of the organic light emitting element. Also,
In this specification, a light emitting element formed of an anode, an organic compound layer and a cathode is called an organic light emitting element.

The organic light emitting device has a high rectification characteristic. When the anode is set to have a higher potential than the cathode, a current flows through the organic compound layer, and light is emitted by recombination of carriers. On the contrary, when the potential of the anode is lower than that of the cathode, almost no current flows in the organic compound layer. Due to this diode structure, the organic light emitting device is an organic light emitting diode (organic light emitting diode).
Also called ngDiode: OLED).

[0008]

Generally, in an organic light emitting device, after forming either an anode or a cathode electrode, an organic compound layer is formed so as to be in contact with the electrode, and the organic compound layer is in contact with the organic compound layer. Thus forming either the anode or the remainder of the cathode.

The film formation method of the organic compound layer mainly includes a film formation method by vapor deposition and a film formation method by spin coating. In either method, when depositing the electrode and the organic compound layer, the substrate is cleaned before deposition to prevent dust and the like from adhering to the substrate, and the cleanliness is controlled in a clean room where the deposition is performed. Efforts are being made to ensure that

However, in spite of the above efforts, dust and the like may adhere to electrodes and the like, and holes (pinholes) may be opened in the formed organic compound layer. FIG. 12A is a schematic cross-sectional view of the organic light emitting device 200 when the two electrodes 201 and 202 are short-circuited. When the pinhole is opened in the organic compound layer 203, the electrode 202 is formed on the organic compound layer 203.
When the electrode is formed, the two electrodes 201 and 202 may be connected to each other in a pinhole and may be short-circuited. Note that, hereinafter, a portion in which two layers formed with the light emitting layer sandwiched therebetween are in contact with each other in a pinhole formed in the light emitting layer is referred to as a defect portion 204.

FIG. 13 (A) shows the voltage-current characteristics of the organic light-emitting element having no defect, and FIG. 13 (B) shows the voltage-current characteristics of the organic light-emitting element short-circuited at the defect.

Comparing FIGS. 13A and 13B, the current flowing through the organic light emitting device 200 when a reverse bias voltage is applied to the organic light emitting device 200 is shown in FIG.
The case of (B) is larger.

This is different from FIG. 13 (A) in FIG.
In the case of (B), the two electrodes are short-circuited in the defective portion 204, which suggests that a current is flowing in the defective portion 204.

In the defective portion 204, two electrodes 201,
When 202 is short-circuited, the emission brightness of the organic compound layer decreases. FIG. 12B schematically shows a current flow when a forward bias voltage is applied to the organic light emitting element having a defective portion.

In the defective portion 204, the two electrodes 201,
When 202 is short-circuited, the defective portion 204 has a resistance R
It is considered that the two electrodes of the organic light emitting device 200 are connected to each other with the _SC interposed therebetween. Therefore, when a forward current I _ori is made to flow from one electrode of the organic light emitting element,
The current flowing through the defect portion 204 is I _SC , the organic compound layer 203
_Let I _dio be the current that flows in the current I _ori = I _SC + I
meet _dio .

Therefore, _assuming that I _ori is constant in the above formula I _ori = I _SC + I _dio , the current I actually flowing through the organic compound layer 203 in the organic light emitting device having the defective portion.
_dio becomes smaller. As the resistance R _SC in the defective portion 204 decreases, I _SC increases, and this tendency becomes remarkable, and the rectifying property of the organic light emitting device 200 is further deteriorated.

When the current I _dio flowing through the organic compound layer 203 becomes small, the emission brightness of the organic light emitting device 200 decreases. That is, when the defective portion is short-circuited, the emission luminance of the organic light-emitting element when a forward bias voltage is applied is lower than when the organic light-emitting element is not short-circuited.

Further, even when the organic compound layer is formed by stacking a plurality of layers, when a pinhole is formed in the light emitting layer, the hole injection layer or the hole transport layer is formed through the pinhole. The layers are connected to the electron injection layer or the electron transport layer. Since the reverse bias current flows in the portion where the hole injection layer or the hole transport layer is connected to the electron injection layer or the electron transport layer as well as the defective portion where the electrode is short-circuited. This causes a decrease in the light emission brightness of the organic light emitting element. Note that, hereinafter, all the portions where the two layers formed with the light emitting layer sandwiched therebetween are in contact with each other through the pinhole formed in the light emitting layer are collectively referred to as a defective portion. The defective portion is a portion where the anode and the cathode are electrically short-circuited.

Furthermore, in addition to the reduction of the light emission brightness of the organic light emitting element, if the defective portion is short-circuited, a current always flows through the defective portion, so that the deterioration of the organic compound layer existing around the defective portion is promoted. Will end up.

In view of the above problems, an object of the present invention is to devise a method of repairing a defective portion.

[0021]

The present inventor has found that even if a defect portion is formed in the organic light emitting element, if the resistance in the defect portion is increased, the organic compound layer is formed in the organic compound layer when a forward bias voltage is applied. I thought that it would be possible to prevent the flowing current from becoming small.

Therefore, a method of increasing the resistance R _SC at the defective portion by applying a reverse bias voltage to the organic light emitting element and flowing a reverse bias current I _rev was devised.

When a reverse bias current I _{rev is} passed through the organic light emitting element, most of it does not flow through the organic compound layer but through the short-circuited defective portion. Current I _SC flowing through the defect
If the value is large, the temperature of the defect increases, so the defect burns out, vaporizes and evaporates, or oxidizes or carbonizes to become an insulator, causing some changes in the defect. Therefore, the resistance R _SC becomes large. Note that in this specification, a defective portion in which the resistance R _SC is increased by applying a reverse bias current is referred to as a modified layer.

When the resistance R _SC becomes large, when a forward bias voltage is applied to the organic light emitting element, the current flowing through the modified layer becomes small, and instead the current flowing through the organic compound layer becomes large, and the emission brightness becomes high. Become.

Further, since current always flows in the defective portion, the deterioration of the organic compound layer existing around the defective portion is easily promoted. However, since the resistance R _{SC of the} modified layer is high, it is difficult for current to flow, and it is possible to prevent the deterioration of the organic compound layer existing around the modified layer from being promoted.

Next, the material of the cathode of the organic light emitting device used in the present invention was examined. A material having a low work function is preferable for the cathode because electrons are injected, and materials such as Li and Mg are included. The effects of these materials were investigated.

Using a sample having a MOS (Metal-Oxide-Silicon) structure, C-V (capacitance-voltage) characteristics were examined. MOS
The ratio of the capacitance C of the capacitor and the capacitance C _{OX of the} insulating film is determined depending on the voltage. When using a clean MOS without impurities, C /
It shows an ideal C-V characteristic in which C _ox is uniquely determined according to the voltage. A deviation from this ideal C-V characteristic indicates that the MOS is contaminated with ionic impurities.

The initial characteristics and the characteristics after applying a bias of 1.7 MV / cm to the MOS at 150 ° C. for 1 hour were measured. The process of applying a bias while applying this thermal shock is B
It is called T (bias-temperature) processing. A process in which Si is set to the ground level and a positive bias is applied (+ BT process),
A process of applying a negative bias (-BT process) is performed.

The C-V characteristic is measured by setting Si to the ground level and raising the electrode potential from -10V to + 10V.
Then, the voltage was lowered from + 10V to -10V.

In the MOS structure, a silicon oxide film having a film thickness of 50 nm is formed on a silicon substrate, and AlMg, MgAg, or AlLi is further formed as an electrode on the silicon oxide film. In the measurement, AlM
g is Al: Mg = 95: 5, MgAg is Mg: Ag = 9
The weight ratio of 0:10 and AlLi was Al: Li = 90: 10.

When AlMg is used as an electrode (see FIG.
7) and using MgAg as an electrode (FIG. 18)
Shows an ideal characteristic in which C / C _OX is uniquely determined according to the voltage in both the initial characteristic and the characteristic after the BT treatment. This indicates that the diffusion of Mg was at a level that was negligible even when a thermal shock was applied.

However, when AlLi was used as the electrode (FIG. 19), the CV characteristic was largely deviated from the ideal value. In particular, the characteristic 600 after the BT process (+ BT process) in which a positive bias was applied had a large variation from the ideal value. This is presumably because when AlLi was set to a positive potential, Li ⁺ was eluted from the electrode due to electrical repulsion and diffused. Even in the characteristics after the initial characteristics and the BT processing (-BT processing) with the negative bias, a slight amount of Li ⁺ is eluted by the application of the positive voltage at the time of measurement, and the CV characteristics have a hysteresis.

Therefore, it was concluded that the electrode to which Li having high diffusivity is added is not preferable because of the constitution of the present invention in which the cathode has a positive potential when the reverse bias is applied to the organic light emitting device.

Li ⁺ contained in the cathode by applying a reverse bias
Is dissolved, the device is contaminated while the defect is corrected by applying a reverse bias. Since Li ⁺ eluted from the cathode has high mobility, it penetrates the interlayer insulating film and reaches the TFT to contaminate the channel layer,
It deteriorates the TFT performance.

Of course, not only Li but also highly mobile N
The configuration in which a is included in the cathode is not preferable for the same reason.
If the amount of Li and Na contained in the cathode is small,
The less the better.

It was also found that it is preferable to use an electrode containing Mg having a low diffusivity as the cathode. For example, it is very effective to use AlMg or MgAg.

The organic compound layer included in the light emitting device of the present invention can be formed by using a known organic compound material, but one formed by including an inorganic material as a part thereof is also included. . For example, by using an alkali metal element or an alkaline earth metal element having a low work function and forming a layer containing these elements as part of the organic compound layer, it is possible to improve the electron injectability from the cathode. Alternatively, a light emitting element having excellent characteristics can be formed by including an inorganic material capable of improving the transport property of injected carriers in addition to the above. In the present invention, the types of inorganic materials contained in the organic compound layer and the arrangement of the layers containing these in the organic compound layer are not particularly limited, and known inorganic materials may be used freely. You can

The present invention can be applied not only to an active matrix type light emitting device but also to a passive type light emitting device.

The structure of the present invention is shown below.

According to the present invention, there is provided a method for repairing a light emitting device including an organic light emitting device having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, wherein the cathode contains Li or Na. Each quantity is 1 × 10 ¹⁸ atom
A method for repairing a light-emitting device is provided, which is s / cm ³ or less and a reverse bias voltage is applied between the anode and the cathode.

According to the present invention, there is provided a method for repairing a light emitting device including an organic light emitting device having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, wherein the cathode contains Li or Na. 1 × 10 ¹⁸ atoms
/ Cm ³ or less, and by applying a reverse bias voltage between the anode and the cathode, a current is caused to flow in a portion where the anode and the cathode are electrically short-circuited to generate heat in the short-circuited portion. A method of repairing a light emitting device is provided, which comprises increasing the resistance or insulating the heated portion.

According to the present invention, there is provided a method for repairing a light emitting device including an organic light emitting element having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, wherein the cathode contains Li or Na. Each quantity is 1 × 10 ¹⁸ atom
s / cm ³ or less, the organic compound layer is a hole injection layer,
A hole transport layer, an electron injection layer or an electron transport layer, and a light emitting layer, by applying a reverse bias voltage between the anode and the cathode, a layer above the light emitting layer,
Repairing a light-emitting device characterized in that a current is caused to flow in a portion electrically short-circuited with a layer below the light-emitting layer to cause the short-circuited portion to generate heat, and the heat-generated portion to have high resistance or insulation. A method is provided.

According to the present invention, there is provided a method for repairing a light emitting device including an organic light emitting element having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, wherein the cathode contains Li or Na. Each quantity is 1 × 10 ¹⁸ atom
s / cm ³ or less, and by applying a reverse bias voltage between the anode and the cathode, at least one of the anode or the cathode is recessed into the organic compound layer to form the anode and the cathode. There is provided a method for repairing a light emitting device, characterized in that an electric current is applied to a portion electrically contacted with.

According to the present invention, repairing a light-emitting device characterized in that the current is caused to flow through a portion where the anode and the cathode are in electrical contact to generate heat, and the portion where the heat is generated has high resistance or insulation. A method is provided.

According to the present invention, there is provided a method for repairing a light emitting device including an organic light emitting element having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, wherein the cathode contains Li or Na. Each quantity is 1 × 10 ¹⁸ atom
s / cm ³ or less, the organic compound layer is a hole injection layer,
It has a hole transport layer, an electron injection layer or an electron transport layer, and a light emitting layer, and by applying a reverse bias voltage between the anode and the cathode, a layer above the light emitting layer or the above One of the layers below the light emitting layer is recessed into the light emitting layer, and an electric current is applied to a portion where the layer above the light emitting layer and the layer below the light emitting layer are in electrical contact. A method for repairing a light emitting device is provided.

According to the present invention, the current is applied to a portion where the layer above the light emitting layer and the layer below the light emitting layer are in electrical contact with each other to generate heat, and the heat generated portion has high resistance or insulation. A method of repairing a light emitting device is provided.

According to the present invention, the cathode is Be, Mg,
There is provided a method for repairing a light emitting device, which is an alloy containing at least one of Ca, Sr, and Ba.

According to the present invention, there is provided a method for repairing a light emitting device, wherein the cathode is an alloy containing magnesium.

According to the invention, said cathode is AlMg, M
A method for repairing a light emitting device is characterized by being gAg or MgAgAl.

According to the present invention, there is provided a method for repairing a light emitting device including an organic light emitting element having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, wherein the cathode is at least Al or Ag. There is provided a method for repairing a light emitting device, which is an alloy containing one of Mg and Mg and applying a reverse bias voltage between the anode and the cathode.

According to the present invention, there is provided a method for repairing a light emitting device including an organic light emitting element having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, wherein the cathode is at least Al or Ag. One is an alloy containing Mg, and by applying a reverse bias voltage between the anode and the cathode, a current is caused to flow in a portion where the anode and the cathode are electrically short-circuited, and the short-circuited. There is provided a method for repairing a light emitting device, characterized in that the heated portion is heated, and the heated portion is made higher in resistance or insulated.

According to the present invention, there is provided a method for repairing a light emitting device including an organic light emitting element having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, wherein the cathode is at least Al or Ag. One of them is an alloy containing Mg, and the organic compound layer has a hole injection layer, a hole transport layer, an electron injection layer or an electron transport layer, and a light emitting layer, and the anode and the cathode. By applying a reverse bias voltage between the layers, a current is caused to flow in a portion where the layer above the light emitting layer and the layer below the light emitting layer are electrically short-circuited to generate heat in the short-circuited portion. A method for repairing a light emitting device is provided, which comprises increasing the resistance or insulating the heated portion.

According to the present invention, there is provided a method for repairing a light emitting device including an organic light emitting element having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, wherein the cathode is at least Al or Ag. One is an alloy containing Mg, and by applying a reverse bias voltage between the anode and the cathode, at least one of the anode or the cathode is recessed into the organic compound layer and the anode is A method for repairing a light emitting device is provided, in which a current is applied to a portion that is in electrical contact with the cathode.

According to the present invention, the light emitting device is repaired, characterized in that the current is caused to flow in a portion where the anode and the cathode are electrically in contact with each other to generate heat, and the portion where the heat is generated has high resistance or insulation. A method is provided.

According to the present invention, there is provided a method for repairing a light emitting device including an organic light emitting element having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, wherein the cathode is at least Al or Ag. One of them is an alloy containing Mg, and the organic compound layer has a hole injection layer, a hole transport layer, an electron injection layer or an electron transport layer, and a light emitting layer, and the anode and the cathode. By applying a reverse bias voltage between the light emitting layer, either the layer above the light emitting layer or the layer below the light emitting layer is recessed into the light emitting layer, and the layer above the light emitting layer and the light emitting layer. A method for repairing a light emitting device is provided, in which an electric current is applied to a portion electrically contacting a layer below the layer.

According to the present invention, the current is caused to flow to generate heat in a portion where the layer above the light emitting layer and the layer below the light emitting layer are in electrical contact with each other, so that the heat generated portion has higher resistance or insulation. A method of repairing a light emitting device is provided.

According to the invention, the cathode is Li or N
Provided is a method for repairing a light emitting device, wherein the content of a is 1 × 10 ¹⁸ atoms / cm ³ or less.

According to the present invention, there is provided a method for repairing a light emitting device, wherein the cathode has a Mg content of 1 × 10 ²⁰ atoms / cm ³ or more.

According to the present invention, there is provided a method for repairing a light emitting device, characterized in that the reverse bias voltage is applied at regular intervals.

According to the present invention, when the reverse bias voltage is applied, the avalanche current is gradually increased until it falls within ± 15% of the height at which the avalanche current starts to flow in the organic compound layer. Repair methods are provided.

According to the present invention, there is provided a method for repairing a light emitting device, characterized in that the organic light emitting elements are arranged in a matrix and each of the organic light emitting elements has a thin film transistor connected thereto.

According to the present invention, there is provided a method for producing a light emitting device comprising an organic light emitting element having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, wherein the content of Li or Na is respectively. A method for manufacturing a light emitting device is provided, which comprises applying a reverse bias voltage between the anode and the cathode after forming a cathode having a concentration of 1 × 10 ¹⁸ atoms / cm ³ or less.

According to the present invention, there is provided a method for producing a light emitting device including an organic light emitting element having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, wherein the contents of Li and Na respectively are After forming a cathode having a concentration of 1 × 10 ¹⁸ atoms / cm ³ or less, a reverse bias voltage is applied between the anode and the cathode so that a current flows in a portion where the anode and the cathode are electrically short-circuited. A method for manufacturing a light emitting device is provided, in which the short-circuited portion is caused to generate heat, and the generated heat portion is made to have high resistance or insulation.

According to the present invention, there is provided a method for manufacturing a light emitting device including an organic light emitting element having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, wherein at least one of Al and Ag is provided. A method for manufacturing a light emitting device is provided, which comprises forming a cathode made of an alloy containing Mg and then applying a reverse bias voltage between the anode and the cathode.

According to the present invention, there is provided a method for producing a light emitting device including an organic light emitting element having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, wherein at least one of Al and Ag is included. After forming a cathode made of an alloy containing Mg, by applying a reverse bias voltage between the anode and the cathode, a current is caused to flow in a portion where the anode and the cathode are electrically short-circuited, A method for manufacturing a light-emitting device, characterized in that the short-circuited portion is caused to generate heat, and the heat-generated portion is made to have high resistance or insulation.

[0066]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The repair method of the present invention will be described with reference to FIG. FIG. 1A is a diagram schematically showing a current flow when a reverse bias voltage is applied to an organic light emitting device having a defective portion.

A ground voltage GND and a reverse bias voltage V _rev are alternately applied to the organic light emitting element. Figure 1 (B)
6 shows a timing chart when the ground voltage GND and the reverse bias voltage V _rev are alternately applied. Although the ground voltage GND and the reverse bias voltage V _rev are alternately applied in the present embodiment, the present invention is not limited to this configuration. In the present invention, a reverse bias current may flow in the organic light emitting element. Therefore, the forward bias voltage and the reverse bias voltage V _rev may be alternately applied to the organic light emitting element.

In the present embodiment, a reverse bias voltage is applied to the organic light emitting element at regular intervals, but the present invention is not limited to this. A DC reverse bias voltage may be applied to the organic light emitting element.

In the present embodiment, until the avalanche current occurs in the organic light emitting element due to the avalanche phenomenon,
The reverse bias voltage is gradually increased. In this specification, a voltage at which an avalanche current starts to flow in an organic light emitting device is called an avalanche voltage. However, the present invention is not limited to this configuration, and the height of the voltage applied to the organic light emitting element can be appropriately set by the designer. The voltage applied to the organic light emitting device may be high enough to modify the defective portion and not high enough to damage the organic light emitting device or deteriorate the organic compound layer.

Further, the reverse bias voltage applied by direct current may be gradually increased.

Further, a reverse bias voltage having a constant height may be applied to the organic light emitting element at regular intervals, or may be applied as a direct current.

By applying a reverse bias voltage to the organic light emitting element at regular intervals, it is possible to prevent the organic compound layer around the defect portion from being deteriorated by heat generated by the application of the reverse bias voltage. Is.

Further, by gradually increasing the reverse bias voltage, it becomes easy to find the optimum reverse bias voltage for the organic light emitting device to be repaired.

When a reverse bias voltage V _rev is applied to the organic light emitting element, a reverse bias current I _rev is applied to the organic light emitting element.
Flows. The reverse bias current I _rev is _equal to the organic compound layer 1
_Let I _dio be the current flowing in 03 and I _SC be the current flowing in the defective portion 104, then I _rev = I _dio + I _SC is satisfied. However, since a reverse bias current hardly flows through the organic compound layer, I _rev ≈I _SC holds.

When the current I _rev flows through the defective portion 104, the temperature of the defective portion 104 rises, so that the defective portion may be burned out, vaporized and evaporated, or oxidized or carbonized to become an insulator. Becomes a modified layer. Therefore, the resistance R _SC becomes large.

FIG. 2A shows changes in voltage-current characteristics of the organic light emitting device having the defective portion 104 with time when the repair method of the present invention is used. The graph of the voltage-current characteristic changes in the direction of the arrow with the passage of time. Note that V _av means an avalanche voltage. Since the current flowing through the organic light emitting element decreases when a reverse bias voltage is applied with the passage of time, the resistance R _SC of the defective portion increases, and the current I _SC flowing through the defective portion decreases accordingly.

FIG. 2B schematically shows a current flow when a forward bias voltage is applied to the organic light emitting element. When the current I _SC flowing through the defective portion becomes small, when the forward bias voltage is applied to the organic light emitting element, the current I _dio actually flowing through the organic compound layer becomes large, and the light emission luminance becomes high.

The organic light emitting device has a structure in which an organic compound layer is sandwiched between an anode and a cathode. Known materials may be freely used for the anode and the organic compound layer. However, in the present invention, care must be taken so that highly mobile components such as Na and Li do not mix in the cathode. When the content of Li and Na exceeds 1 × 10 ¹⁸ atoms / cm ³ , the cathode is changed to Li and N.
The problem that the a is diffused and affects the TFT performance to deteriorate or stabilize the TFT characteristics is remarkable. Therefore, the content of each of Na and Li is 1
It is necessary to set it to × 10 ¹⁸ atoms / cm ³ or less.

In the present invention, the cathode uses an alloy containing magnesium having a low work function. For example, AlMg or MgA
It is preferable to use g or the like. The amount of Mg contained in the cathode can be freely determined in consideration of the work function of the cathode. However, the amount of Mg contained is 1 × 10 ²⁰ atom
If it is less than s / cm ² , the work function becomes high and the luminous efficiency is lowered. Therefore, the amount of Mg contained in the cathode is preferably at least 1 × 10 ²⁰ atoms / cm ² or more.

By using the method of the present invention, even if a pinhole is formed due to the influence of dust or the like during the formation of the organic compound layer and two layers formed with the light emitting layer sandwiched therebetween are short-circuited, a short circuit occurs. The defective portion can be changed to a modified portion to increase the resistance, and the current actually flowing in the organic compound layer can be increased when a forward bias voltage is applied to the organic light emitting element. Therefore, according to the repairing method of the present invention, it is possible to increase the light emission luminance when the same voltage is applied even if there is a defective portion.

Further, since current always flows in the defective portion, the deterioration of the organic compound layer existing around the defective portion was easily promoted. However, since the resistance R _{SC of the} modified layer is high, it is difficult for current to flow, and it is possible to prevent the deterioration of the organic compound layer existing around the modified layer from being promoted.

Further, since the cathode of the organic light emitting element is mainly composed of Mg, Al and Ag having low diffusibility, it is possible to prevent the device from being contaminated due to the application of the reverse bias.

[0083]

EXAMPLES Examples of the present invention will be described below.

Example 1 In this example, an active matrix type light emitting device having two thin film transistors (TFTs) in each pixel will be described by using the repairing method of the present invention.

FIG. 3 shows a circuit diagram of a pixel of a light emitting device using the repairing method of the present invention. Each pixel has a source signal line Si (i
Is any one of 1 to x) and the power supply line Vi (i is 1
~ X) and the gate signal line Gj (j is 1 to 1).
any one of y).

Further, each pixel has a switching TFT 3
01, a driving TFT 302, and an organic light emitting element 303
And a capacitor 304.

The gate electrode of the switching TFT 301 is connected to the gate signal line Gi. One of the source region and the drain region of the switching TFT 301 is the source signal line Si, and the other is the driving TFT 302.
Connected to the gate electrode of.

The source region of the driving TFT 302 is connected to the power supply line Vi, and the drain region is connected to either one of the two electrodes of the organic light emitting element 303. Of the two electrodes of the organic light emitting element 303, the one that is not connected to the drain region of the driving TFT 302 is connected to the counter power supply 307.

Of the two electrodes of the organic light emitting element 303, the electrode connected to the drain region of the driving TFT 302 is called a pixel electrode, and the electrode connected to the counter power supply 307 is called a counter electrode.

The capacitor 304 is used for the driving TFT 3
No. 02 gate electrode and the power supply line Vi.

FIG. 4A shows a pixel portion of a light emitting device having a plurality of pixels shown in FIG. The pixel portion 306 has source signal lines S1 to Sx, power supply lines V1 to Vx, and gate signal lines G1 to Gy. A plurality of pixels 305 are formed in a matrix in the pixel portion 306.

FIG. 4B shows the operation of the TFT in each pixel and the height of the voltage input to the power supply line Vi and the counter electrode when the defective portion of the organic light emitting element 303 is repaired. When repairing the defective portion of the organic light emitting element 303, the switching TFT 301 and the driving TFT 30 of each pixel are
Both 2 are turned on. And the power supply line Vi
Voltage is made constant and the voltage of the counter electrode is changed every certain period, so that a predetermined reverse bias current is passed through the organic light emitting element every certain period.

Repair of defects of the organic light emitting device is performed by the pixel unit 30.
All pixels 305 included in 6 may be simultaneously performed, or may be performed for each line or each pixel.

In the present embodiment, the cathode of the two electrodes of the organic light emitting device is formed using an alloy containing magnesium, such as AlMg or MgAg. N for the cathode
A highly mobile component such as a and Li is prevented from being mixed in, and the content of each of these Na and Li is 1 × 10 ¹⁸ at
oms / cm ² or less.

According to the circuit of this embodiment, a reverse bias can be applied to the organic light emitting element by appropriately adjusting the voltage applied to the switching TFT, the driving TFT, the power supply line and the counter power supply. Since the cathode of the organic light emitting element is strictly controlled so that Li and Na are not contained therein, reverse bias can be applied without contaminating the device.

Example 2 In this example, an active matrix type light emitting device having three thin film transistors (TFTs) in each pixel will be described by using the repairing method of the present invention.

FIG. 5 shows a circuit diagram of a pixel of a light emitting device using the repairing method of the present invention. Each pixel has a source signal line Si (i
Is any one of 1 to x) and the power supply line Vi (i is 1
~ X) and the write gate signal line Ga
It has j (j is any one of 1 to y) and erase gate signal line Gej (j is any one of 1 to y).

Further, each pixel has a switching TFT 5
01a, an erasing TFT 501b, and a driving TFT 50
2, an organic light emitting element 503, and a capacitor 504.

The gate electrode of the switching TFT 501a is connected to the writing gate signal line Gaj.
One of the source region and the drain region of the switching TFT 501a is connected to the source signal line Si, and the other is connected to the gate electrode of the driving TFT 502.

The gate electrode of the erasing TFT 501b is connected to the erasing gate signal line Gej. Also, erase T
One of the source region and the drain region of the FT 501b is connected to the power supply line Vi, and the other is connected to the gate electrode of the driving TFT 502.

The source region of the driving TFT 502 is connected to the power supply line Vi, and the drain region is connected to either one of the two electrodes of the organic light emitting element 503. Of the two electrodes of the organic light emitting element 503, the one that is not connected to the drain region of the driving TFT 502 is connected to the counter power supply 507.

Of the two electrodes of the organic light emitting element 503, the electrode connected to the drain region of the driving TFT 502 is called a pixel electrode, and the electrode connected to the counter power supply 507 is called a counter power supply.

The capacitor 504 is the driving TFT 5
No. 02 gate electrode and the power supply line Vi.

FIG. 6A shows a pixel portion of a light emitting device having a plurality of pixels shown in FIG. The pixel portion 506 has source signal lines S1 to Sx, power supply lines V1 to Vx, write gate signal lines Ga1 to Gay, and erase gate signal lines Ge1 to Gey. A plurality of pixels 505 are formed in a matrix in the pixel portion 506.

FIG. 6B shows the operation of the TFT in each pixel and the height of the voltage input to the power supply line Vi and the counter electrode when the defective portion of the organic light emitting element 503 is repaired. When repairing the defective portion of the organic light emitting device 503, the switching TFT 501a and the driving TFT 5 of each pixel are
Both 02 are turned on. Further, the erasing TFT 501b of each pixel is turned off. Then, the voltage of the power supply line Vi is kept constant, and the voltage of the counter electrode is changed at regular intervals, so that the organic light emitting element 5 is made at regular intervals.
A predetermined reverse bias current is passed through 03.

Repair of defects in the organic light emitting device 503 is as follows.
The processing may be performed simultaneously for all the pixels 505 included in the pixel portion 506, or may be performed for each line or each pixel.

The cathode of the organic light emitting element is formed of an alloy containing magnesium, such as AlMg or MgAg, so that the alkali is not eluted when a reverse bias is applied. The cathode is carefully controlled so that highly mobile components such as Na and Li do not mix, and these Na and Li
The content of Li is set to 1 × 10 ¹⁸ atoms / cm ² or less.

Also in the circuit of this embodiment, it is possible to apply a reverse bias to the organic light emitting element.

(Embodiment 3) In this embodiment, an example in which the repairing method of the present invention is applied to an active matrix light emitting device having three thin film transistors (TFTs) in each pixel will be described.

FIG. 7 shows a circuit diagram of a pixel of a light emitting device using the repairing method of the present invention. Each pixel has a source signal line Si (i
Is any one of 1 to x) and the power supply line Vi (i is 1
~ X) and the gate signal line Gj (j is 1 to 1).
any one of y).

Further, each pixel has a switching TFT 4
01, a driving TFT 402, and an organic light emitting element 403
, Capacitor 404, and TFT 40 for reverse bias application
8 and.

The gate electrode of the switching TFT 401 is connected to the gate signal line Gi. One of the source region and the drain region of the switching TFT 401 is the source signal line Si, and the other is the driving TFT 402.
Connected to the gate electrode of.

The source region of the driving TFT 402 is connected to the power supply line Vi, and the drain region is connected to either one of the two electrodes of the organic light emitting element 403. One of the two electrodes of the organic light emitting element 403 that is not connected to the drain region of the driving TFT 402 is connected to the counter power supply 407.

Among the two electrodes of the organic light emitting element 403, the electrode connected to the drain region of the driving TFT 402 is called a pixel electrode, and the electrode connected to the counter power supply 407 is called a counter electrode.

The gate electrode of the reverse bias application TFT 408 is connected to the power supply line Vi. One of the source region and the drain region of the reverse bias application TFT 408 is connected to the power supply line Vi, and the other is connected to the pixel electrode of the organic light emitting element.

The capacitor 404 is used for the driving TFT 4
No. 02 gate electrode and the power supply line Vi.

FIG. 8A shows a pixel portion of a light emitting device having a plurality of pixels shown in FIG. The pixel portion 406 includes source signal lines S1 to Sx, power supply lines V1 to Vx, and gate signal lines G1 to Gy. A plurality of pixels 405 is formed in a matrix in the pixel portion 406.

FIG. 8B shows the operation of the TFT in each pixel and the height of the voltage input to the power supply line Vi and the counter electrode when the defective portion of the organic light emitting element 403 is repaired. When repairing a defective portion of the organic light emitting device 403, the switching TFT 401 and the driving TFT 40 of each pixel are repaired.
Both 2 are turned off. Then, the reverse bias application TFT 408 having a rectifying characteristic is turned on to apply a voltage in the forward direction. Then, a current flows through the reverse bias TFT, and the organic light emitting element is reverse biased. By setting the voltage of the power supply line Vi constant and changing the voltage of the counter electrode at regular intervals, a predetermined reverse bias current is passed through the organic light emitting element at regular intervals.

The repair of defects in the organic light emitting element may be carried out simultaneously for all the pixels or may be carried out for each line.

The cathode of the organic light emitting element is formed of an alloy containing magnesium, such as AlMg or MgAg, so that alkali is not eluted when a reverse bias is applied. The cathode is carefully controlled so that highly mobile components such as Na and Li do not mix, and these Na and Li
The content of Li is set to 1 × 10 ¹⁸ atoms / cm ² or less.

The circuit of this embodiment has the potential of the power supply line,
The reverse bias can be easily applied to the organic light emitting device simply by adjusting the potential of the opposing power source.

(Embodiment 4) In this embodiment, the case where the repairing method of the present invention is applied to an organic light emitting device having a plurality of organic compound layers will be described.

FIG. 9A shows the structure of the organic light emitting device.
First, PEDOT, which is a polythiophene derivative, is formed into a film with a thickness of 30 nm as a hole injection layer on an anode made of a compound (ITO) that is a combination of indium oxide and tin oxide. Next, as a hole transport layer, MTDATA of 20 nm and α-NPD of 10 nm are formed by a vapor deposition method. A singlet compound, Alq ₃ , is formed as a light-emitting material for forming a light-emitting layer thereon by evaporation to have a film thickness of 50 nm. Then, an organic light emitting element is formed by depositing AlMg as a cathode to a film thickness of 100 nm.

When a defect portion due to a pinhole is formed in the light emitting layer of the organic light emitting device having the above structure, AlMg which is the cathode in the defect portion is α as the hole transport layer.
-Contact with NPD.

By applying a reverse bias current to the organic light emitting device having the defective portion at regular intervals, the temperature of the defective portion rises and the defective portion burns out, vaporizes and vaporizes, or oxidizes or carbonizes. As a result, it becomes an insulator, and as a result, the defective portion changes to a modified portion, and the resistance can be increased.
Therefore, it is possible to prevent the deterioration of the organic compound layer existing around the modified layer from being accelerated.

The light emitted from this organic light emitting device utilizes the singlet excitation energy of the singlet compound.

FIG. 9B shows the structure of another organic light emitting device. First, copper phthalocyanine is formed in a thickness of 20 nm as a hole injecting layer by an evaporation method on an anode formed of a compound of indium oxide and tin oxide. next,
As the hole transport layer, α-NPD was formed with a film thickness of 10 nm by a vapor deposition method. Ir (ppy) ₃ and C, which are triplet compounds, are used as a light emitting material for forming a light emitting layer thereon.
BP is deposited to a thickness of 20 nm by vapor deposition. Furthermore, BCP of 10 nm and Alq ₃ of 4 are used as an electron transport layer on the light emitting layer.
The organic light-emitting element is formed by vapor-depositing AlMg as a cathode to a thickness of 100 nm after forming each to 0 nm by the vapor deposition method.

When a defect portion due to a pinhole is formed in the light emitting layer of the organic light emitting device having the above structure, the electron transport layer BCP comes into contact with the hole transport layer α-NPD at the defect portion. .

By applying a reverse bias current to the organic light emitting device having the defective portion at regular intervals, the temperature of the defective portion rises and the defective portion burns out, vaporizes and vaporizes, or oxidizes or carbonizes. As a result, it becomes an insulator, and as a result, the defective portion changes into a modified portion and resistance can be increased. Therefore, it is possible to prevent the deterioration of the organic compound layer existing around the modified layer from being accelerated.

The light emission obtained from this organic light emitting device utilizes the triplet excitation energy of the triplet compound.

FIG. 10A shows the structure of the organic light emitting device. First, as a hole injection layer on the anode made of a compound (ITO) that is a combination of indium oxide and tin oxide,
PEDOT, which is a polythiophene derivative, is formed into a film with a thickness of 30 nm by a spin coating method. Al, which is a singlet compound, is used as a light emitting material for forming a light emitting layer thereon.
q ₃ is formed into a film with a thickness of 50 nm by a vapor deposition method. Then, an organic light emitting element is formed by depositing AlMg as a cathode to a film thickness of 100 nm.

When a defect portion due to a pinhole is formed in the light emitting layer of the organic light emitting device having the above structure, AlMg which is the cathode in the defect portion is P as the hole injection layer.
It comes into contact with EDOT.

By applying a reverse bias current to the organic light-emitting device having the defective portion at regular intervals, the temperature of the defective portion rises and the defective portion burns out, vaporizes and vaporizes, or oxidizes or carbonizes. As a result, it becomes an insulator, and as a result, the defective portion changes to a modified portion, and the resistance can be increased.
Therefore, it is possible to prevent the deterioration of the organic compound layer existing around the modified layer from being accelerated.

The light emitted from this organic light emitting device utilizes the singlet excitation energy of the singlet compound.

FIG. 10B shows the structure of the organic light emitting device. First, AlMg is vapor-deposited to a thickness of 100 nm as a cathode. Alq ₃ which is a singlet compound as a light emitting material for forming a light emitting layer thereon is deposited to a thickness of 50 nm by vapor deposition.
To form a film. Next, as a hole injection layer, PEDOT which is a polythiophene derivative is formed into a film having a thickness of 30 nm by a spin coating method. Then, Au is deposited to a film thickness of 5 nm. Note that Au is provided in order to prevent the surface of the organic compound layer from being deteriorated in a later step. On top of that, a compound that combines indium oxide and tin oxide (IT
The organic light emitting device is formed by forming the anode composed of O).

When a defect portion due to a pinhole is formed in the light emitting layer of the organic light emitting device having the above structure, AlMg which is the cathode in the defect portion is P as the hole injecting layer.
It comes into contact with EDOT.

The light emission obtained by this organic light emitting device utilizes the singlet excitation energy of the singlet compound.

According to the present invention having the above-described structure, pinholes are formed due to the influence of dust or the like during the formation of the organic compound layer, and even if two layers formed with the light emitting layer interposed therebetween are short-circuited, they are short-circuited. By increasing the resistance of the defective portion, the current actually flowing through the organic compound layer can be increased when a forward bias voltage is applied to the organic light emitting element.
Therefore, according to the repairing method of the present invention, it is possible to increase the light emission luminance when the same voltage is applied even if there is a defective portion.

Further, by changing the defective portion to the modified portion to increase the resistance, it is possible to prevent the deterioration of the organic compound layer existing around the modified layer from being promoted.

The carbide formed by carbonizing the material of the light emitting element has a high insulating property and is stable as a substance. Therefore, when an organic compound material is further stacked and formed in the defective portion, for example, a defective portion is generated in the light emitting layer (Alq ₃ ) as shown in FIG. 10B, and the light emitting layer (Alq ₃ ) is directly contacted with the defective portion. The repair method of the present invention is particularly effective when the hole injection layer (PEDOT) is laminated.

This embodiment can be implemented by freely combining with Embodiments 1 to 3.

Example 5 In a light emitting device using the repair method of the present invention, it is possible to use a material for a light emitting element that can utilize phosphorescence from triplet excitons for light emission. A light-emitting device using a material for a light-emitting element that can utilize phosphorescence for light emission can dramatically improve external emission quantum efficiency. As a result, it is possible to reduce the power consumption, extend the life, and reduce the weight of the organic light emitting device.

Here, a report is shown in which triplet excitons are used to improve external emission quantum efficiency. (T.Tsutsui, C.Adachi, S.Saito, Photochemical Proce
sses in Organized Molecular Systems, ed.K.Honda,
(Elsevier Sci.Pub., Tokyo, 1991) p.437.)

The molecular formula of the material (coumarin dye) of the light emitting device reported by the above paper is shown below.

[0145]

[Chemical 1]

(MA Baldo, DFO'Brien, Y.You, A.Shou
stikov, S. Sibley, METhompson, SRForrest, Nature
395 (1998) p.151.)

The molecular formula of the material (Pt complex) of the light emitting device reported by the above paper is shown below.

[0148]

[Chemical 2]

(MA Baldo, S. Lamansky, PEBurrrows,
METhompson, SRForrest, Appl.Phys.Lett., 75 (199
9) p.4.) (T.Tsutsui, M.-J.Yang, M.Yahiro, K.Nakamu
ra, T.Watanabe, T.tsuji, Y.Fukuda, T.Wakimoto, S.Ma
yaguchi, Jpn.Appl.Phys., 38 (12B) (1999) L1502.)

The molecular formula of the material (Ir complex) of the light emitting device reported by the above paper is shown below.

[0151]

[Chemical 3]

As described above, if phosphorescence emission from triplet excitons can be utilized, it is possible in principle to realize external emission quantum efficiency that is 3 to 4 times higher than in the case of using fluorescence emission from singlet excitons. .

The constitution of this embodiment can be freely combined with any constitution of Embodiments 1 to 4.

(Embodiment 6) In this embodiment, a sectional view of a light emitting device using the repairing method of the present invention will be described.

In FIG. 14, the switching TFT 721 provided on the substrate 700 is an n-channel type TFT5.
It is formed using 03.

In this embodiment, the switching TFT is used.
Although 721 has a double gate structure in which two channel forming regions are formed, it may have a single gate structure in which one channel forming region is formed or a triple gate structure in which three channel forming regions are formed.

The driving circuit provided on the substrate 700 has an n-channel TFT 723 and a p-channel TFT 724. In this embodiment, the TFT included in the driving circuit
Although it has a single gate structure, it may have a double gate structure or a triple gate structure.

Further, the wirings 701 and 703 function as a source wiring of the CMOS circuit, and 702 functions as a drain wiring.
The wiring 704 functions as a wiring that electrically connects the source wiring 708 and the source region of the switching TFT, and the wiring 705 functions as a wiring that electrically connects the drain wiring 709 and the drain region of the switching TFT. To do.

The driving TFT 722 is formed using a p-channel TFT. Although the driving TFT 722 has a single gate structure in this embodiment, it may have a double gate structure or a triple gate structure.

The wiring 706 is a source wiring (corresponding to a current supply line) of the driving TFT, and the wiring 707 is superposed on the pixel electrode 710 of the driving TFT to form the pixel electrode 71.
It is an electrode electrically connected to 0.

Reference numeral 710 is a pixel electrode (anode of an organic light emitting element) made of a transparent conductive film. As the transparent conductive film, a compound of indium oxide and tin oxide, a compound of indium oxide and zinc oxide, zinc oxide, tin oxide or indium oxide can be used. Moreover, you may use what added gallium to the said transparent conductive film. The pixel electrode 710 is formed on the flat interlayer insulating film 711 before forming the wiring. In this embodiment, it is very important to flatten the step due to the TFT by using the flattening film 711 made of resin. Since the organic compound layer to be formed later is extremely thin, the presence of the step may cause a light emission failure. Therefore, it is desirable to flatten the organic compound layer before forming the pixel electrode so that the organic compound layer can be formed as flat as possible.

After forming the wirings 701 to 707, a bank 712 is formed as shown in FIG. Bank 712 is 10
It may be formed by patterning an insulating film containing 0 to 400 nm of silicon or an organic resin film.

An organic compound layer 71 is formed on the pixel electrode 710.
3 is formed. Although only one pixel is shown in FIG. 14, in the present embodiment, R (red), G (green), B (blue).
The organic compound layer corresponding to each color is created separately. In this embodiment, the low molecular weight organic compound layer is formed by the vapor deposition method. Specifically, a 20 nm thick copper phthalocyanine (CuPc) film is provided as the hole injection layer 713a,
A 70 nm-thick Tris-8 layer is formed thereon as a light emitting layer 713b.
- it is a quinolinolato aluminum complex layered structure in which a (Alq ₃₎ film. The emission color can be controlled by adding a fluorescent dye such as quinacridone, perylene or DCM1 to Alq ₃ .

However, the above example is an example of the organic compound material that can be used as the organic compound layer, and it is not necessary to limit to this. The light emitting layer, the charge transport layer or the charge injection layer may be freely combined to form an organic compound layer (a layer for causing light emission and carrier movement for that purpose). For example, in this embodiment, an example in which a low molecular weight organic compound material is used as the organic compound layer is shown, but a high molecular weight organic compound material may be used. Further, it is also possible to use an inorganic material such as silicon carbide for the charge transport layer and the charge injection layer. Known materials can be used as these organic materials and inorganic materials.

Next, a cathode 714 made of a conductive film is provided on the organic compound layer 713. In this embodiment, an alloy film of aluminum and magnesium is used as the conductive film. Of course, a known MgAg film (alloy film of magnesium and silver) may be used. As the cathode material, a conductive film made of an element belonging to Group 2 of the periodic table or a conductive film to which those elements are added may be used. For example, Be, M
At least one of g, Ca, Sr, and Ba is added.

When the cathode has a structure in which two layers of films are laminated, magnesium is formed in contact with the organic compound layer, and aluminum is formed on magnesium, the voltage at which the organic light emitting element starts to emit light is reduced. be able to. At this time, magnesium is preferably 10 nm thick and aluminum is preferably 100 nm thick.

When the cathode 714 is formed, the organic light emitting device 719 is completed. Note that the organic light emitting element 719 mentioned here refers to a capacitor formed by the pixel electrode (anode) 710, the organic compound layer 713, and the cathode 714.

It is effective to provide the passivation film 716 so as to completely cover the organic light emitting element 719. The passivation film 716 is made of an insulating film including a carbon film, a silicon nitride film, or a silicon nitride oxide film,
The insulating film is used as a single layer or a combination of layers.

At this time, it is preferable to use a film having good coverage as a passivation film, and a carbon film, especially D
It is effective to use an LC (diamond-like carbon) film. Since the DLC film can be formed in a temperature range from room temperature to 100 ° C. or lower, the organic compound layer 7 having low heat resistance is used.
A film can be easily formed on the upper side of 13. Also, D
The LC film has a high oxygen blocking effect and can suppress oxidation of the organic compound layer 713. Therefore, the organic compound layer 7 is not removed during the subsequent sealing step.
The problem that 13 is oxidized can be prevented.

Further, a sealing material 717 is provided on the passivation film 716, and a cover material 718 is attached. An ultraviolet curable resin may be used as the sealing material 717, and it is effective to provide a substance having a moisture absorption effect or a substance having an antioxidant effect inside. In addition, in this embodiment, the cover material 718 is a glass substrate, a quartz substrate, or a plastic substrate (including a plastic film) on which carbon films (preferably diamond-like carbon films) are formed.

Thus, the light emitting device having the structure shown in FIG. 14 is completed. Note that it is effective to continuously perform the steps from the formation of the bank 712 to the formation of the passivation film 716 using a multi-chamber system (or in-line system) film formation apparatus without exposing to the atmosphere. . Further, it is also possible to further develop and continuously process up to the step of attaching the cover material 718 without exposing to the atmosphere.

Further, the characteristic of the TFT in this embodiment is that
The gate electrode is formed of a two-layer conductive film, and in the low-concentration impurity region provided between the channel formation region and the drain region, there is almost no difference in concentration and there is a gentle concentration gradient. A region that overlaps with the electrode (GOLD region) and a region that does not overlap with the gate electrode (L
DD area). Further, a peripheral portion of the gate insulating film, that is, a region which does not overlap with the gate electrode and a region above the high concentration impurity region is tapered.

In the light emitting device of this embodiment, the light emitting layer 713
When the pinhole is formed in b, a defect portion in which the hole injection layer 713a and the cathode 714 are in contact with each other through the pinhole is formed. According to the repair method of the present invention, the resistance can be increased by changing the defective portion to the modified portion 715. Therefore, the luminance of the portion other than the pinhole of the pixel can be increased, and the deterioration of the organic compound layer around the pinhole can be prevented from being accelerated.

Further, although only the configurations of the pixel portion and the driving circuit are shown in this embodiment, the signal dividing circuit, the D / A converter, the operational amplifier, the γ correction circuit, etc. may also be used according to the manufacturing process of this embodiment. Can be formed on the same insulator, and further, a memory and a microprocessor can be formed.

The constitution of this embodiment is similar to those of the first, second, and third embodiments.
Alternatively, it can be implemented by freely combining with 8. (Embodiment 7) In this embodiment, a sectional view of a light emitting device using the repairing method of the present invention will be described.

In FIG. 15, the p-channel type TFT 200 and the n-channel type TFT of the driving circuit are provided on the same substrate.
201, a pixel-driving TFT 203, a switching TFT 204, and a storage capacitor are formed.

In the p-channel TFT 200 of the driving circuit, the conductive layer 220 having the second taper shape functions as a gate electrode, and the channel formation region 20 is also included.
6. Third that functions as a source region or a drain region
Of the fourth impurity region (A) 207 forming an LDD region which does not overlap with the impurity region 207a of
b, the structure has a fourth impurity region (B) 207c forming an LDD region which partially overlaps with the gate electrode 220.

In the n-channel TFT 201, the conductive layer 221 having the second taper shape functions as a gate electrode, and the channel formation region 208 and the first impurity region functioning as a source region or a drain region. 209a, a second impurity region (A) (A) 209b that forms an LDD region that does not overlap with the gate electrode 221, and a second impurity region that partially forms an LDD region that overlaps with the gate electrode 221.
Of the impurity region (B) 209c. The length of the portion where the second impurity region (B) 209c overlaps the gate electrode 221 is 0.1 to 0.3 μm with respect to the channel length of 2 to 7 μm. The length of Lov is controlled by the thickness of the gate electrode 221 and the angle of the tapered portion. n
By forming such an LDD region in the channel type TFT, the high electric field generated in the vicinity of the drain region can be mitigated, the generation of hot carriers can be prevented, and the deterioration of the TFT can be prevented.

Similarly, in the driving TFT 203, the conductive layer 223 having the second tapered shape functions as a gate electrode, and the third impurity region functions as a channel formation region 212, a source region or a drain region. Two
13a, a fourth impurity region (A) 213b forming an LDD region which does not overlap the gate electrode 223, and a fourth impurity region (B) 213c forming an LDD region partially overlapping the gate electrode 223. ing.

The driver circuit is formed of a logic circuit such as a shift register circuit and a buffer circuit, a sampling circuit formed of analog switches, and the like. In FIG. 15, the TFTs forming these are shown as a single gate structure in which one gate electrode is provided between a pair of source and drain, but as a multi-gate structure in which a plurality of gate electrodes are provided between a pair of source and drain. It doesn't matter.

The drain region of the driving TFT 203 is connected to the pixel electrode 271 via the wiring 231. An organic compound layer 272 made of a known organic compound material is formed in contact with the pixel electrode 271, and a cathode 273 is formed in contact with the organic compound layer 272.

In the switching TFT 204, the conductive layer 224 having the second taper shape functions as a gate electrode, and the channel forming regions 214a and 214a are formed.
4b, first impurity regions 215a and 217 functioning as a source region or a drain region, a second impurity region (A) 215b that forms an LDD region that does not overlap with the gate electrode 224, and an LD that partially overlaps with the gate electrode 224.
The structure has a second impurity region (B) 215c forming a D region. Second impurity region (B) 213
The length of the portion where c overlaps with the gate electrode 224 is 0.1 to
The thickness is 0.3 μm. A semiconductor having a second impurity region (A) 219b, a second impurity region (B) 219c, and a region 218 to which an impurity element which determines the conductivity type is not added, which extends from the first impurity region 217. Layer and third
A storage capacitor is formed from an insulating layer formed in the same layer as the gate insulating film having the above shape and a capacitor wiring 225 formed from a conductive layer having the second tapered shape.

When a pinhole is formed in the organic compound layer 272 in the light emitting device of this embodiment, a defective portion where the pixel electrode 271 and the cathode 273 are in contact with each other through the pinhole is formed. According to the repair method of the present invention, the resistance can be increased by changing the defective portion to the modified portion 274. Therefore, the luminance of the portion other than the pinhole of the pixel can be increased, and the deterioration of the organic compound layer around the pinhole can be prevented from being accelerated.

The constitution of this embodiment is similar to that of the first, second, and third embodiments.
Alternatively, it can be implemented by freely combining with 8.

(Embodiment 8) In this embodiment, a sectional view of a light emitting device using the repairing method of the present invention will be described.

In FIG. 16, reference numeral 811 is a substrate, and 812 is an insulating film serving as a base (hereinafter referred to as a base film). As the substrate 811, a light-transmitting substrate, typically a glass substrate, a quartz substrate, a glass ceramics substrate, or a crystallized glass substrate can be used. However, it must withstand the highest processing temperatures during the fabrication process.

The base film 812 is particularly effective when a substrate containing mobile ions or a substrate having conductivity is used, but it need not be provided on a quartz substrate. Base film 812
For this, an insulating film containing silicon may be used. Note that in this specification, the “insulating film containing silicon” refers to silicon such as a silicon oxide film, a silicon nitride film, or a silicon nitride oxide film (SiOxNy: x, y is an arbitrary integer). On the other hand, it refers to an insulating film containing oxygen or nitrogen at a predetermined ratio.

Reference numeral 8201 denotes a switching TFT, 820
2 is a driving TFT, each of which is an n-channel TF
It is formed of T and p channel type TFTs. When the emission direction of the light generated in the organic compound layer is the lower surface of the substrate (the surface on which the TFT and the organic compound layer are not provided), the above-mentioned configuration is preferable. However, the present invention is not limited to this configuration. The switching TFT and the driving TFT may be either n-channel TFTs or p-channel TFTs.

The switching TFT 8201 comprises a source region 813, a drain region 814 and an LDD region 815a.
˜815d, isolation region 816 and channel forming region 81
An active layer including 7a and 817b, a gate insulating film 818,
The gate electrodes 819a and 819b and the first interlayer insulating film 820
And a source signal line 821 and a drain wiring 822. The gate insulating film 818 or the first interlayer insulating film 820 may be common to all TFTs on the substrate,
It may be different depending on the circuit or element.

Further, the switching TFT shown in FIG.
The gate electrodes 817a and 817b of 8201 are electrically connected to each other and have a so-called double gate structure.
Of course, not only the double gate structure, but also a so-called multi-gate structure such as a triple gate structure (structure including an active layer having two or more channel formation regions connected in series)
May be

The multi-gate structure is extremely effective in reducing the off-state current, and if the off-state current of the switching TFT is sufficiently low, the minimum amount required by the capacitor connected to the gate electrode of the driving TFT 8202 is required. The capacity of can be suppressed. That is, since the area of the capacitor can be reduced, the multi-gate structure is effective in expanding the effective light emitting area of the organic light emitting element.

Further, in the switching TFT 8201, the LDD regions 815a to 815d are provided so as not to overlap the gate electrodes 819a and 819b with the gate insulating film 818 interposed therebetween. Such a structure is very effective in reducing the off current. Also, the LDD region 815a
The length (width) of ˜815d may be 0.5 to 3.5 μm, typically 2.0 to 2.5 μm.

It is more preferable to provide an offset region (a semiconductor layer having the same composition as the channel forming region and having no gate voltage applied) between the channel forming region and the LDD region in order to reduce the off current. . Also,
In the case of a multi-gate structure having two or more gate electrodes, an isolation region 816 provided between channel formation regions
(A region to which the same impurity element is added at the same concentration as the source region or the drain region) is effective for reducing the off current.

Next, the driving TFT 8202 includes a source region 826, a drain region 827 and a channel forming region 8.
29, the active layer, the gate insulating film 818, the gate electrode 830, the first interlayer insulating film 820, and the source signal line 8
31 and the drain wiring 832. In this embodiment, the driving TFT 8202 is a p-channel type T
It is FT.

The drain region 814 of the switching TFT 8201 is the gate 83 of the driving TFT 8202.
It is connected to 0. Although not shown, specifically, the gate electrode 830 of the driving TFT 8202 is electrically connected to the drain region 814 of the switching TFT 8201 via a drain wiring (also referred to as a connection wiring) 822. Although the gate electrode 830 has a single gate structure, it may have a multi-gate structure. Further, the source signal line 831 of the driving TFT 8202
Is connected to a power supply line (not shown).

The driving TFT 8202 is an element for controlling the amount of current injected into the organic light emitting element, and a relatively large amount of current flows. Therefore, it is preferable to design the channel width (W) larger than the channel width of the switching TFT. In addition, it is preferable to design the channel length (L) to be long so that an excessive current does not flow to the driving TFT 8202. Desirably 0.5 to 2 per pixel
μA (preferably 1 to 1.5 μA).

Furthermore, the film thickness of the active layer (particularly the channel formation region) of the driving TFT 8202 is increased (preferably 50 to 100 nm, more preferably 60 to 80 n).
m), deterioration of the TFT may be suppressed. On the contrary, in the case of the switching TFT 8201, from the viewpoint of reducing the off current, the film thickness of the active layer (particularly the channel formation region) is made thin (preferably 20 to 50).
nm, more preferably 25 to 40 nm) is also effective.

The structure of the TFT provided in the pixel has been described above, but at the same time, the drive circuit is also formed. FIG. 16 shows a CM which is a basic unit forming a drive circuit.
The OS circuit is shown.

In FIG. 16, a TFT having a structure for reducing hot carrier injection while keeping the operating speed as low as possible is an n-channel TFT 82 of a CMOS circuit.
Used as 04. Note that the drive circuit here means a source signal side drive circuit and a gate signal side drive circuit. Of course, other logic circuits (level shifter, A / D converter, signal dividing circuit, etc.) can be formed.

CMOS circuit n-channel TFT 820
4 includes a source region 835 and a drain region 83.
6, the LDD region 837 and the channel formation region 838 are included, and the LDD region 837 overlaps with the gate electrode 839 with the gate insulating film 818 interposed therebetween.

The LDD region 8 is provided only on the drain region 836 side.
The reason why 37 is formed is to prevent the operation speed from decreasing. Further, the n-channel TFT 8204 does not need to be so concerned about the off current value, and it is better to give priority to the operation speed than that. Therefore, the LDD region 837
Is completely overlapped with the gate electrode, and it is desirable to reduce the resistance component as much as possible. That is, it is better to eliminate the so-called offset.

Also, a p-channel TFT of a CMOS circuit
In 8205, since deterioration due to hot carrier injection is hardly noticed, it is not necessary to particularly provide the LDD region. Therefore, the active layer includes the source region 840, the drain region 841, and the channel formation region 842, and the gate insulating film 818 and the gate electrode 843 are provided thereover. Of course, n
An LDD region is provided similarly to the channel type TFT 8204,
It is also possible to take measures against hot carriers.

Numerals 861 to 865 are channel forming regions 8
42, 838, 817a, 817b, 829 is a mask.

In addition, the n-channel TFT 8204 and p
The channel type TFT 8205 has a source signal line 84 on the source region via a first interlayer insulating film 820.
It has 4,845. Further, the drain wiring 846 allows the n-channel TFT 8204 and the p-channel TF to be formed.
The drain regions of T8205 are electrically connected to each other.

Next, 847 is a first passivation film having a thickness of 10 nm to 1 μm (preferably 200 to 5).
00 nm). As the material, an insulating film containing silicon (a silicon nitride oxide film or a silicon nitride film is particularly preferable)
Can be used. This passivation film 847
Has a role of protecting the formed TFT from alkali metals and moisture.

Further, 848 is a second interlayer insulating film,
It has a function as a flattening film for flattening a step formed by FT. As the second interlayer insulating film 848, an organic resin film is preferable, and polyimide, polyamide, acrylic, BCB (benzocyclobutene), or the like may be used.
These organic resin films have the advantages of easily forming a good flat surface and having a low relative dielectric constant. Since the organic compound layer is very sensitive to unevenness, it is desirable that the step due to the TFT be almost absorbed by the second interlayer insulating film 848. Further, in order to reduce the parasitic capacitance formed between the gate signal line or the data signal line and the cathode of the organic light emitting element, it is desirable to provide a thick material having a low relative dielectric constant. Therefore,
The film thickness is 0.5-5 μm (preferably 1.5-2.5 μm)
Is preferred.

Reference numeral 849 denotes a pixel electrode (anode of an organic light emitting element) made of a transparent conductive film, and a second interlayer insulating film 848.
Then, after forming a contact hole (opening) in the first passivation film 847, the opening is formed so as to be connected to the drain wiring 832 of the driving TFT 8202.

A third interlayer insulating film 85 made of a silicon oxide film, a silicon nitride oxide film or an organic resin film is formed on the pixel electrode 849.
0 is provided in a thickness of 0.3 to 1 μm. The third interlayer insulating film 850 has an opening formed on the pixel electrode 849 by etching, and the edge of the opening is etched so as to have a tapered shape. The taper angle is 10-60
It is good to set it as ° (preferably 30 to 50 °).

An organic compound layer 851 is provided on the third interlayer insulating film 850. The organic compound layer 851 is used as a single layer or a laminated structure, but the luminous efficiency is better when it is used in a laminated structure. Generally, it is formed on the pixel electrode in the order of hole injection layer / hole transport layer / light emitting layer / electron transport layer. However, hole transport layer / light emitting layer / electron transport layer, or hole injection layer / positive layer. A structure such as a hole transport layer / light emitting layer / electron transport layer / electron injection layer may be used. In the present invention, any known structure may be used, and the organic compound layer may be doped with a fluorescent dye or the like.

The structure of FIG. 16 is an example in the case of using a method of forming three types of organic light emitting elements corresponding to RGB.
Although only one pixel is shown in FIG. 16, pixels having the same structure are formed corresponding to each color of red, green, and blue, whereby color display can be performed.
The present invention can be implemented regardless of the light emitting method.

A cathode 852 of the organic light emitting device is provided on the organic compound layer 851. As the cathode 852, a material containing magnesium (Mg) or calcium (Ca) having a low work function is used. Preferably MgAg
An electrode made of (a material in which Mg and Ag are mixed at a weight ratio of Mg: Ag = 10: 1) or AlMg (Mg and Al are M
An electrode made of a material mixed in a weight ratio of g: Ag = 5: 95) may be used. Another example is a MgAgAl electrode.

The pixel electrode (anode) 849, the organic compound layer 851, and the cathode 852 form the organic light emitting element 820.
6 is formed.

The laminated body including the organic compound layer 851 and the cathode 852 needs to be formed individually in each pixel, but the organic compound layer 851 is extremely weak against moisture, and thus ordinary photolithography technology cannot be used. . Therefore, using a physical mask material such as a metal mask, the vacuum deposition method,
It is preferable to selectively form by a vapor phase method such as a sputtering method or a plasma CVD method.

As a method for selectively forming the organic compound layer, an ink jet method, a screen printing method, a spin coating method, or the like can be used. However, these methods cannot form a continuous cathode at the present time. It can be said that the above method is preferable.

Reference numeral 853 is a protective electrode, and the cathode 85
2 is an electrode for connecting the cathode 852 of each pixel while protecting 2 from the outside moisture and the like. As the protective electrode 853, it is preferable to use a low-resistance material containing aluminum (Al), copper (Cu), or silver (Ag).
The protective electrode 853 can also be expected to have a heat dissipation effect for alleviating the heat generation of the organic compound layer.

Reference numeral 854 is a second passivation film having a thickness of 10 nm to 1 μm (preferably 200 to 5).
00 nm). Second passivation film 85
The purpose of providing No. 4 is mainly to protect the organic compound layer 851 from moisture, but it is also effective to have a heat dissipation effect. However, since the organic compound layer is weak to heat as described above, it is desirable to form the film at a temperature as low as possible (preferably in the temperature range from room temperature to 120 ° C.). Therefore, it can be said that the plasma CVD method, the sputtering method, the vacuum deposition method, the ion plating method, or the solution coating method (spin coating method) is a preferable film forming method.

All the TFTs shown in FIG. 16 are
It goes without saying that the polysilicon film used in the present invention may have an active layer.

When a pinhole is formed in the organic compound layer 860 in the light emitting device of this embodiment, a defective portion where the pixel electrode 849 and the cathode 852 are in contact with each other through the pinhole is formed. According to the repair method of the present invention, the resistance can be increased by changing the defective portion to the modified portion 860. Therefore, the luminance of the portion other than the pinhole of the pixel can be increased, and the deterioration of the organic compound layer around the pinhole can be prevented from being accelerated.

The constitution of this embodiment is similar to those of the first, second, and third embodiments.
Alternatively, it can be implemented by freely combining with 8.

Example 9 Since the light emitting device using the organic light emitting element is a self-luminous type, it has better visibility in a bright place and a wider viewing angle than a liquid crystal display device. Therefore, it can be used for a display unit of various electronic devices.

As electronic equipment using the light emitting device using the repair method of the present invention, there are provided video cameras, digital cameras, goggle type displays (head mounted displays), navigation systems, sound reproduction devices (car audio systems, audio components, etc.), Recording of a notebook type personal computer, a game machine, a portable information terminal (a mobile computer, a mobile phone, a portable game machine, an electronic book, or the like), an image reproducing apparatus (specifically, a digital video disk (DVD)) including a recording medium Play media,
A device including a display device capable of displaying the image) and the like. In particular, for a mobile information terminal that often sees a screen from an oblique direction, since a wide viewing angle is important, it is preferable to use a light emitting device having an organic light emitting element. Specific examples of these electronic devices are shown in FIGS.

FIG. 11A shows a display device, which is a housing 20.
01, support base 2002, display unit 2003, speaker unit 2004, video input terminal 2005 and the like. The light emitting device manufactured using the repair method of the present invention has a display portion 2003.
Can be used for. Since a light emitting device having an organic light emitting element is a self-luminous type, it does not need a backlight and can have a thinner display portion than a liquid crystal display device. The display device includes all display devices for displaying information, such as those for personal computers, those for receiving TV broadcasting, and those for displaying advertisements.

FIG. 11B shows a digital still camera including a main body 2101, a display portion 2102, an image receiving portion 2103,
An operation key 2104, an external connection port 2105, a shutter 2106 and the like are included. The light-emitting device manufactured using the repair method of the present invention can be used for the display portion 2102.

FIG. 11C shows a laptop personal computer, which has a main body 2201, a casing 2202, and a display section 2.
203, keyboard 2204, external connection port 220
5, including a pointing mouse 2206 and the like. The light emitting device using the repairing method of the present invention can be used for the display portion 2203.

FIG. 11D shows a mobile computer, which has a main body 2301, a display portion 2302, and a switch 230.
4, an operation key 2305, an infrared port 2305, and the like. The light emitting device using the repair method of the present invention has a display unit 230.
2 can be used.

FIG. 11E shows a portable image reproducing device (specifically, a DVD reproducing device) provided with a recording medium, which includes a main body 2401, a housing 2402, a display portion A2403, a display portion B2404, and a recording medium ( DVD, etc.) reading unit 240
5, an operation key 2406, a speaker portion 2407, and the like. The display portion A2403 mainly displays image information, and the display portion B2404 mainly displays textual information. However, the light emitting device using the repair method of the present invention has these display portions A and B2.
It can be used for 403 and 2404. Note that the image reproducing device provided with the recording medium includes a home game machine and the like.

FIG. 11F shows a goggle type display (head mounted display), which is a main body 250.
1, a display portion 2502 and an arm portion 2503 are included. The light emitting device using the repairing method of the present invention can be used for the display portion 2502.

FIG. 11G shows a video camera, which includes a main body 2601, a display portion 2602, a housing 2603, an external connection port 2604, a remote control receiving portion 2605, and an image receiving portion 260.
6, a battery 2607, a voice input unit 2608, operation keys 2609, and the like. The light emitting device using the repairing method of the present invention can be used for the display portion 2602.

[0229] Here, FIG. 11H shows a mobile phone, which includes a main body 2701, a housing 2702, a display portion 2703, a voice input portion 2704, a voice output portion 2705, operation keys 2706,
An external connection port 2707, an antenna 2708, and the like are included.
The light emitting device using the repairing method of the present invention can be used for the display portion 2703. Note that the display portion 2703 can suppress power consumption of the mobile phone by displaying white characters on a black background.

If the emission brightness of the organic compound material becomes higher in the future, it becomes possible to magnify and project the output light containing the image information with a lens or the like and use it for a front type or rear type projector.

[0231] Further, the above electronic devices are the Internet or C
Information distributed through electronic communication lines such as ATV (cable television) is often displayed, and in particular, opportunities for displaying moving image information are increasing. Since the response speed of the organic compound material is very high, the light emitting device is suitable for displaying moving images.

Since the light emitting device consumes power in the light emitting portion, it is desirable to display information so that the light emitting portion is as small as possible. Therefore, when a light emitting device is used in a display unit mainly for character information such as a mobile information terminal, a mobile phone or a sound reproducing device, it is driven so that the character information is formed in the light emitting portion with the non-light emitting portion as the background. It is desirable to do.

As described above, the applicable range of the light emitting device using the repairing method of the present invention is extremely wide, and the light emitting device can be used in electronic devices in all fields. Further, the electronic device of this embodiment may use any of the configurations shown in the first to seventh embodiments.

(Embodiment 10) In this embodiment, a case where the repairing method of the present invention is applied to a passive type (simple matrix type) light emitting device will be described.

FIG. 20A shows a structure of a passive type light emitting device. A pixel portion 905 has a plurality of pixels 906. Each pixel is one of a plurality of data lines 903,
And one of the plurality of scan lines 904. Data line 9
03 and the scanning line 904, an organic compound layer is formed, the data line 903 and the scanning line 904 serve as electrodes, and the organic light emitting element 907 is formed.

The signal input to the data line 903 is controlled by the data line driving circuit 901, and the scanning line 90
The signal input to the scanning line 4 is controlled by the scanning line driving circuit 902.

FIG. 20B shows the level of the voltage of a signal input to the scan line 904 and the data line 903 when the repair method of the present invention is used. By keeping the voltage of each scanning line 904 constant and changing the voltage of the data line at regular intervals, a predetermined reverse bias current is passed through the organic light emitting element 907 at regular intervals.

Repair of defects in the organic light emitting device 907 is as follows.
All pixels 906 included in the pixel portion 905 may be simultaneously performed, or may be performed for each line or each pixel.

By using the method of the present invention, pinholes are formed due to the influence of dust during the formation of the organic compound layer, and even if two layers formed with the organic compound layer sandwiched therebetween are short-circuited, The resistance of the short-circuited defective portion can be increased, and the current actually flowing through the organic compound layer can be increased when a forward bias voltage is applied to the organic light emitting element. Therefore, according to the repairing method of the present invention, it is possible to increase the light emission luminance when the same voltage is applied even if there is a defective portion.

Further, since current always flows in the defective portion, the deterioration of the organic compound layer existing around the defective portion was easily promoted. However, since the resistance R _{SC of the} modified layer is high, it is difficult for current to flow, and it is possible to prevent the deterioration of the organic compound layer existing around the modified layer from being promoted.

This embodiment can be implemented by freely combining with Embodiments 4, 5, and 9.

[0242]

EFFECTS OF THE INVENTION With the above structure, the present invention forms pinholes under the influence of dust during the formation of the organic compound layer,
Even if two layers formed with the organic compound layer sandwiched therebetween are short-circuited, the resistance of the short-circuited defective portion can be increased, and when a forward bias voltage is applied to the organic light-emitting element, it is actually The current flowing through the organic compound layer can be increased. Therefore, according to the repair method of the present invention,
Even if there is a defective portion, it is possible to increase the emission brightness when the same voltage is applied.

Further, since current always flows in the defective portion, the deterioration of the organic compound layer existing around the defective portion was easily promoted. However, since the resistance R _{SC of the} modified layer is high, it is difficult for current to flow, and it is possible to prevent the deterioration of the organic compound layer existing around the modified layer from being promoted.

Furthermore, Na and Li are used as the cathode of the organic light emitting device.
By including as little as possible, it is possible to prevent contamination of devices such as the organic light emitting element and the TFT when a reverse bias is applied to the organic light emitting element.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing a current flow in an organic light emitting element when a reverse bias voltage is applied to the organic light emitting element.

FIG. 2 is a diagram schematically showing changes in the voltage-current characteristics of the organic light emitting element during the repair process and the flow of current in the organic light emitting element when a forward bias voltage is applied to the repaired organic light emitting element. .

FIG. 3 is a circuit diagram of a pixel according to the first exemplary embodiment.

4A and 4B are a circuit diagram of a pixel portion of Embodiment 1 and a diagram showing an operation of the pixel portion at the time of repair.

FIG. 5 is a circuit diagram of a pixel according to a second exemplary embodiment.

6A and 6B are a circuit diagram of a pixel portion of Example 2 and a diagram showing an operation of the pixel portion at the time of repair.

7A and 7B are a circuit diagram of a pixel portion of Example 3 and a diagram showing an operation of the pixel portion at the time of repair.

FIG. 8 is a circuit diagram of a pixel of Example 3.

FIG. 9 is a diagram showing a configuration of an organic light emitting device of Example 4.

FIG. 10 is a diagram showing a configuration of an organic light emitting device of Example 4.

FIG. 11 is an electronic apparatus having a light emitting device using the repair method of the invention of Example 10.

FIG. 12 is a cross-sectional view of an organic light emitting device having a defect portion,
The figure which showed typically the flow of the electric current when a forward bias electric current is sent through this organic light emitting element.

FIG. 13 is a diagram showing voltage-current characteristics of an organic light emitting device.

FIG. 14 is a sectional view of a light emitting device of Example 5.

FIG. 15 is a cross-sectional view of a light emitting device of Example 6.

16 is a cross-sectional view of the light emitting device of Example 7. FIG.

FIG. 17 is a diagram showing a MOS structure using AlMg as an electrode and a capacitance-voltage characteristic.

FIG. 18 is a diagram showing a MOS structure using MgAg as an electrode and a capacitance-voltage characteristic.

FIG. 19 is a diagram showing a MOS structure using AlLi as an electrode and a capacitance-voltage characteristic.

FIG. 20 is a view showing a case where the repair method of the present invention is applied to a passive light emitting device.

Claims (26)

[Claims] 1. A method of repairing a light emitting device including an organic light emitting element having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, wherein the cathode is Li or N 2.
A method of repairing a light-emitting device, characterized in that the content of a is 1 × 10 ¹⁸ atoms / cm ³ or less and a reverse bias voltage is applied between the anode and the cathode. 2. A method for repairing a light emitting device including an organic light emitting element having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, wherein the cathode is Li or N 2.
The content of a is 1 × 10 ¹⁸ atoms / cm ³ or less, and by applying a reverse bias voltage between the anode and the cathode, the anode and the cathode are electrically short-circuited. A method for repairing a light-emitting device, comprising applying a current to heat the short-circuited portion and increasing the resistance or insulating the heat-generated portion. 3. A method for repairing a light emitting device including an organic light emitting element having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, wherein the cathode is Li or N 2.
The content of a is 1 × 10 ¹⁸ atoms / cm ³ or less, and the organic compound layer has a hole injection layer, a hole transport layer, an electron injection layer or an electron transport layer, and a light emitting layer. By applying a reverse bias voltage between the anode and the cathode, a current is caused to flow in a portion where the layer above the light emitting layer and the layer below the light emitting layer are electrically short-circuited, A method for repairing a light emitting device, characterized in that the short-circuited portion is made to generate heat, and the generated heat portion is made high in resistance or insulated. 4. A method for repairing a light emitting device including an organic light emitting element having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, wherein the cathode is Li or N 2.
The content of a is 1 × 10 ¹⁸ atoms / cm ³ or less, and when a reverse bias voltage is applied between the anode and the cathode, at least one of the anode and the cathode becomes the organic compound layer. A method for repairing a light-emitting device, which comprises recessing and applying a current to a portion where the anode and the cathode are in electrical contact. 5. The light emission according to claim 4, wherein the current is caused to flow through a portion where the anode and the cathode are in electrical contact to generate heat, and the generated heat portion has a high resistance or is insulated. How to repair the device. 6. A method of repairing a light emitting device including an organic light emitting element having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, wherein the cathode is Li or N 2.
The content of a is 1 × 10 ¹⁸ atoms / cm ³ or less, and the organic compound layer has a hole injection layer, a hole transport layer, an electron injection layer or an electron transport layer, and a light emitting layer. By applying a reverse bias voltage between the anode and the cathode, either the layer above the light emitting layer or the layer below the light emitting layer is recessed into the light emitting layer, and the light emitting layer is A method for repairing a light-emitting device, characterized in that an electric current is applied to a portion where a layer above the light emitting layer and a layer below the light emitting layer make electrical contact. 7. The method according to claim 6, wherein the current is applied to a portion where the layer above the light emitting layer and the layer below the light emitting layer are in electrical contact to generate heat, and the heat generated portion has a high resistance. Alternatively, a method for repairing a light emitting device is characterized by insulating. 8. The method according to any one of claims 1 to 7,
The method for repairing a light emitting device, wherein the cathode is an alloy containing at least one of Be, Mg, Ca, Sr, and Ba. 9. The method according to any one of claims 1 to 7,
The method for repairing a light emitting device, wherein the cathode is an alloy containing magnesium. 10. The cathode according to claim 1, wherein the cathode is AlMg, MgAg, or MgAgAl.
A method of repairing a light emitting device, comprising: 11. A method for repairing a light emitting device including an organic light emitting element having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, wherein the cathode is Al or A.
A repair method for a light-emitting device, which is an alloy containing at least one of g and Mg and applies a reverse bias voltage between the anode and the cathode. 12. A method of repairing a light emitting device including an organic light emitting element having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, wherein the cathode is Al or A.
An alloy containing at least one of g and Mg, and by applying a reverse bias voltage between the anode and the cathode, a current is caused to flow in a portion where the anode and the cathode are electrically short-circuited. A method for repairing a light emitting device, characterized in that the short-circuited portion is made to generate heat, and the generated heat portion is made high in resistance or insulated. 13. A method for repairing a light emitting device including an organic light emitting element having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, wherein the cathode is Al or A.
An alloy containing at least one of g and Mg, wherein the organic compound layer has a hole injection layer, a hole transport layer, an electron injection layer or an electron transport layer, and a light emitting layer. By applying a reverse bias voltage between the cathode and the cathode, a current is caused to flow in a portion where the layer above the light emitting layer and the layer below the light emitting layer are electrically short-circuited, and the shorted portion A method for repairing a light emitting device, characterized in that the light emitting device is made to generate heat, and the heat generating portion is made to have high resistance or insulation. 14. A method of repairing a light emitting device including an organic light emitting element having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, wherein the cathode is Al or A.
An alloy containing at least one of g and Mg, and by applying a reverse bias voltage between the anode and the cathode, at least one of the anode and the cathode is depressed into the organic compound layer. A method for repairing a light-emitting device, comprising applying a current to a portion where the anode and the cathode are in electrical contact. 15. The light emission according to claim 14, wherein the current is caused to flow through a portion where the anode and the cathode are in electrical contact with each other to generate heat, and the heated portion has a high resistance or is insulated. How to repair the device. 16. A method for repairing a light emitting device including an organic light emitting element having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, wherein the cathode is Al or A.
An alloy containing at least one of g and Mg, wherein the organic compound layer has a hole injection layer, a hole transport layer, an electron injection layer or an electron transport layer, and a light emitting layer. By applying a reverse bias voltage between the cathode and the cathode, either the layer above the light emitting layer or the layer below the light emitting layer is recessed into the light emitting layer, and the layer above the light emitting layer. A method of repairing a light emitting device, comprising: applying a current to a portion where the layer under the light emitting layer is in electrical contact with the layer. 17. The resistance according to claim 16, wherein the current is caused to flow through a portion where the layer above the light emitting layer and the layer below the light emitting layer are in electrical contact with each other to generate heat, Alternatively, a method for repairing a light emitting device is characterized by insulating. 18. The cathode according to claim 11, wherein the cathode has a Li or Na content of 1 or less, respectively.
A method for repairing a light emitting device, characterized in that it is not more than × 10 ¹⁸ atoms / cm ³ . 19. The cathode according to claim 11, wherein the cathode has a Mg content of 1 × 10 ²⁰ atoms / cm ^3.
The above is the method for repairing a light-emitting device. 20. The method of repairing a light emitting device according to claim 1, wherein the reverse bias voltage is applied at regular intervals. 21. The height at which an avalanche current starts to flow in the organic compound layer when the voltage of the reverse bias is applied, according to any one of claims 1 to 20.
A method of repairing a light-emitting device, which is characterized by gradually increasing the temperature until it falls within 15%. 22. The repair of a light emitting device according to claim 1, wherein the organic light emitting elements are arranged in a matrix and have thin film transistors connected to each of the organic light emitting elements. Method. 23. A method of manufacturing a light emitting device including an organic light emitting element having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, wherein the content of Li or Na is 1 ×, respectively. 10 ¹⁸ atoms / c
A method for manufacturing a light emitting device, comprising forming a cathode having a size of m ³ or less and then applying a reverse bias voltage between the anode and the cathode. 24. A method for manufacturing a light emitting device including an organic light emitting element having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, wherein the content of Li or Na is 1 ×, respectively. 10 ¹⁸ atoms / c
After forming a cathode that is m ³ or less, by applying a reverse bias voltage between the anode and the cathode, a current is passed to a portion where the anode and the cathode are electrically short-circuited, the short-circuit A method for manufacturing a light-emitting device, characterized in that the heated portion is heated, and the heated portion is made higher in resistance or insulated. 25. A method of manufacturing a light emitting device including an organic light emitting element having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, wherein at least one of Al or Ag and Mg are included. A method for manufacturing a light-emitting device, comprising forming a cathode made of an alloy containing Al and applying a reverse bias voltage between the anode and the cathode. 26. A method of manufacturing a light emitting device including an organic light emitting element having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, wherein at least one of Al or Ag and Mg are included. After forming a cathode made of an alloy containing, by applying a reverse bias voltage between the anode and the cathode, a current is passed to a portion where the anode and the cathode are electrically short-circuited, the short-circuit A method for manufacturing a light-emitting device, characterized in that the heated portion is heated, and the heated portion is made higher in resistance or insulated.