JP2004022400A - Apparatus and method for forming organic film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To supply an organic material being set to be a vapor-phase state onto the entire surface of a substrate whose position is fixed. <P>SOLUTION: The organic material 12 is vaporized or sublimated in a vaporization sublimation chamber 5 to generate a feed gas. A carrier gas is mixed into the feed gas and is transported to a film formation chamber 4 by a feed gas transportation pipe 6. A direction control plate 2 is provided at an injector 18 in the feed gas transportation pipe 6. The direction control plate 2 changes the flow of the feed gas toward the substrate 3 along the surface of the substrate 3, and forms a film by supplying the feed gas to the entire surface of the substrate 3, thus making uniform a film thickness distribution within the substrate 3 and forming an improved organic film. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an organic film forming apparatus and an organic film forming method for forming a thin film by transporting a raw material gas obtained by converting an organic raw material into a gaseous phase onto a substrate using a carrier gas. More specifically, a good organic film can be formed by controlling the flow of the source gas.
[0002]
[Prior art]
2. Description of the Related Art An organic EL (electroluminescence) element is a light-emitting material using an organic material for a light-emitting layer. This organic EL element is used as a light emitting material for various display devices such as a flat panel display used for a computer or a television receiver, a display of a mobile phone, and a display of a mobile terminal called PDA (Personal Digital Assistants). Further, it is used as a light emitting element such as a light emitting diode.
[0003]
FIG. 12 is an explanatory diagram illustrating an example of the structure of the organic EL element. The organic EL element 101 is obtained by sequentially laminating an ITO (Indium-Tin Oxide) transparent electrode 103, an organic film 104, and a back electrode 105 serving as a cathode on a transparent substrate 102 such as glass. The organic film 104 is formed by sequentially stacking a hole injection layer 104a, a hole transport layer 104b, a light emitting layer 104c, an electron transport layer 104d, and an electron injection layer 104e from the side of the ITO transparent electrode 103.
[0004]
When a voltage is applied between the ITO transparent electrode 103 and the back electrode 105, a positive charge (hole) is injected from the ITO transparent electrode 103, and a negative charge (electron) is injected from the back electrode 105. Moving. Then, electrons and holes are recombined with a certain probability in the light emitting layer 104c, and light having a predetermined wavelength is generated at the time of the recombination.
[0005]
Note that the organic film 104 has a structure in which the hole injection layer 104a and the hole transport layer 104b are formed in one layer, a structure in which the electron transport layer 104d and the electron injection layer 104e are formed in one layer, and a structure in which the light emitting layer 104c is formed. For example, the electron transport layer 104d and the electron injection layer 104e are formed as a single layer.
[0006]
FIG. 13 is a plan view showing an outline of an organic EL color display formed using such an organic EL element, and FIG. 14 is a perspective view of a main part of the organic EL color display. In the organic color display 106, an ITO transparent electrode 103 is formed on a transparent substrate 102 in a stripe shape. Further, the organic film 104 is formed in a stripe shape so as to be orthogonal to the ITO transparent electrode 103, and the back electrode 105 is formed on the organic film 104. The ITO transparent electrode 103, the organic film 104, and the back electrode 105 are arranged in a matrix. Deploy. As a result, the organic film 104 at the intersection of the ITO transparent electrode 103 to which the voltage is applied and the back electrode 105 emits light.
[0007]
Then, as the organic film 104, an organic film 104R that emits red (R) light, an organic film 104G that emits green light (G), and an organic film 104B that emits blue light (B) are arranged in order to form a pixel by RGB. Thus, color display becomes possible.
[0008]
Now, the formation of an organic film using a low molecular organic substance has conventionally used a vacuum deposition method. The vacuum evaporation method is a method in which a raw material is heated and evaporated in a high vacuum, and the raw material is adsorbed on a substrate facing an evaporation source to form a thin film.
[0009]
FIG. 15 is an explanatory diagram showing a basic configuration of a vacuum evaporation apparatus that performs such a vacuum evaporation method. The chamber 107 is connected to an exhaust pump (not shown), and the interior of the chamber 107 can be evacuated to a high vacuum. Here, the degree of vacuum in the chamber 107 in the vacuum evaporation method is 10 ^-3 -10 ^-4 It is about Pa (Pascal).
[0010]
The evaporation source 108 is a heating source for evaporating a raw material, here, an organic raw material, and includes resistance heating, electron beam heating, infrared heating, high-frequency induction heating, and the like. Resistance heating is generally used for an organic film. As the resistance heating, the powdery organic raw material 110 is placed in an open container 109 called a boat, and the organic raw material 110 is indirectly heated by indirect heating of the organic raw material 110 due to the resistance heating of the open container 109 by energizing the open container 109. It evaporates or sublimates.
[0011]
A substrate 111 on which an organic film is formed (corresponding to the transparent substrate 102 on which the ITO transparent electrode 103 shown in FIG. 12 and the like is formed) is attached to a substrate holder 112 and arranged to face the evaporation source 108. The substrate holder 112 holds the plurality of substrates 111 inside a dome-shaped jig. Then, the evaporation source 108 is arranged on the central axis of the substrate holder 112 and revolves by a driving mechanism (not shown).
[0012]
When the organic material 110 is vaporized or sublimated by the evaporation source 108 under a high vacuum in the chamber 107, the organic raw material reaches the substrate 111 in a beam form. At this time, by revolving the substrate holder 112, the film thickness distribution and the temperature distribution are made uniform.
[0013]
FIG. 16 is an explanatory diagram showing a film thickness measuring method in a vacuum evaporation apparatus. In the vacuum evaporation apparatus, the position of each substrate 111 during film deposition changes because the substrate holder 112 rotates. Therefore, a monitor glass 112a for thickness measurement is attached to the rotation center where the position does not change by the substrate holder 112, and the organic film formed on the monitor glass 112a is measured by the transmission type optical film thickness meter 113.
[0014]
When a color display shown in FIG. 13 or the like is formed, an organic film is formed using a mask. FIG. 17 is a sectional view showing an example of a film deposition process using a mask. The mask 114 has a stripe-shaped pattern 115. A magnet is used to bring the mask 114 into close contact with the substrate 111. That is, the mask 114 is made of a magnetic material, and a mechanism (not shown) for holding the substrate 111 is provided with a magnetized member 116 made of a permanent magnet or an electromagnet. Then, the substrate 111 is placed on the magnetized member 116, and the mask 114 is placed on the substrate 111, so that the mask 114 comes into close contact with the substrate 111 by the magnetic force of the magnetized member 116.
[0015]
Then, in order to form the R, G, and B organic films, the mask 114 is first mounted at a predetermined position to form the organic film 104R shown in FIG. 14, and then the mounting position of the mask 114 is shifted by ３ pitch. Then, the organic film 104B is formed by shifting the mounting position of the mask 114 by 1/3 pitch. In the vacuum evaporation apparatus shown in FIG. 15, the mask 114 is attached downward.
[0016]
The method for forming an organic film using the vacuum evaporation apparatus described above has the following problems. That is, the vacuum evaporation apparatus needs a mechanism for rotating the substrate holder 112 in order to move the position of the substrate 111, and has a problem of high cost. In addition, since the substrate holder 112 rotates, it is difficult to provide a cooling mechanism for the substrate.
[0017]
Since the organic raw material 110 has a property of being easily decomposed at a high temperature, if the substrate 111 cannot be cooled, the temperature of the substrate 111 rises due to the heat radiation at the time of heating the organic raw material 110 in the evaporation source 108, This leads to a problem of deteriorating the performance of the film.
[0018]
In the vacuum evaporation apparatus, the film formation rate is determined by the heating temperature of the raw material, here, the organic raw material 110. However, the organic raw material 110 is easily decomposed at a high temperature. ₃ The upper limit of the heating temperature of (8-quinolinol aluminum complex) is as low as about 300 ° C. to 400 ° C., and the effect of heat radiation on the substrate 111 must be suppressed, so that the film forming rate cannot be increased. was there.
[0019]
Furthermore, when the RGB pixels are separately applied using the mask 114 shown in FIG. 17, the substrate 111 is rotated, so that the position of the mask 114 may be shifted due to vibration or the like, and there is a problem that the pixel accuracy is low.
[0020]
Further, since the substrate holder 112 has a dome shape and holds the substrate 111 inside, the incident angle of the organic raw material reaching the substrate 111 in a beam shape becomes oblique. Therefore, there is a problem that the edge of the pattern 115 of the mask 114 becomes a shadow, and the edge of the formed organic film is not sharp.
[0021]
Since the substrate 111 rotates, there is a problem that it is difficult to measure the film thickness of each substrate 111 during film formation.
[0022]
On the other hand, as a new organic film forming method different from the vacuum vapor deposition method, a method called organic vapor phase deposition method is disclosed in JP-A-2001-523768.
[0023]
FIG. 18 is an explanatory view of a conventional organic film forming apparatus using an organic vapor deposition method. The outline of the apparatus disclosed in JP-T-2001-523768 will be described below. The chamber 120 is, for example, a substantially cylindrical container that shields the inside from the outside air, and has a substrate holder 121 that holds the substrate 111 therein.
[0024]
Two pipes 122 are provided in the chamber 120. One end of each pipe 122 is open, and a raw material container 123 is provided near the opening. The raw material container 123 is provided with an energizing mechanism (not shown). When an organic raw material is put into the raw material container 123 and energized, the raw material container 123 generates resistance heat, thereby indirectly heating the organic raw material, and evaporating or sublimating to generate a raw material gas. I do.
[0025]
The other end of the pipe 122 is connected to the tank 124. Further, an adjusting valve 125, a pressure adjuster 126a, a flow meter 126b, and a switching valve 126c are provided in the middle of the pipe 122. The tank 124 contains N, which is inert to various organic raw materials. ₂ A gas such as (nitrogen) is charged and supplied to the pipe 122 as a carrier gas whose pressure and flow rate are controlled.
[0026]
Thereby, the source gas generated by vaporizing or sublimating the organic source in the pipe 122 is sent into the chamber 120 using the carrier gas, and is adsorbed on the substrate 111 to form an organic film.
[0027]
The raw material container 123 contains a solid organic material, while the raw material tank 127 contains a liquid organic material 128. A pipe 122 connected to the tank 124 and a pipe 129 connected to the chamber 120 are connected to the raw material tank 127. The pipe 122 includes a pressure regulator 126a, a flow meter 126b, and a switching valve 126c.
[0028]
As a result, the carrier gas supplied from the pipe 122 passes through the organic raw material 128 as air bubbles, and sends the vaporized organic raw material into the chamber 120 via the pipe 129. Further, a temperature control tank 131 for immersing at least the height of the raw material tank 127 in which the organic raw material 128 is put in the liquid 130 is provided, and the temperature of the liquid 130 in the raw material tank 127 is controlled by controlling the temperature of the liquid 130 with a heater (not shown). Control the temperature. A heating / cooling device 132 is provided around the chamber 120. The heating / cooling device 132 controls the temperature inside the chamber 120.
[0029]
An exhaust pipe 133 is provided in the chamber 120, and a trap tank 134, a slot valve 135, and a vacuum pump 136 are attached to the exhaust pipe 133. The vacuum pump 136 exhausts the inside of the chamber 120 to make the inside of the chamber 120 vacuum. The slot valve 135 adjusts the pressure in the chamber 120. The output of a pressure gauge (not shown) attached to the chamber 120 is electrically fed back to the slot valve 135 so that the desired degree of vacuum is maintained in the chamber 120. Controlled. In addition, the organic raw materials and the like which are not adsorbed on the substrate 111 are condensed in the trap tank 134 so as not to reach the slot valve 135 and the vacuum pump 136.
[0030]
An organic vapor deposition method using such an apparatus is an organic film forming method in which a source gas is transported to a substrate under reduced pressure using a carrier gas, and the gas is condensed on the substrate to form a film. As a result, temperature control for vaporizing or sublimating the raw material and flow rate control of the carrier gas for feeding the raw material to the substrate, which cannot be performed by the conventional vacuum deposition method, can be performed independently. When forming a multi-component thin film by simultaneous vapor deposition of raw materials, the amounts of each component can be accurately controlled. Further, since the film is formed under reduced pressure, an organic film having a smooth surface can be formed.
[0031]
[Problems to be solved by the invention]
However, in the organic vapor deposition method, the transport of the source gas is performed using the carrier gas, so that it takes a long time to transport the source gas to the substrate. This means that the time constant for controlling the film forming rate is larger than that of the vacuum deposition method. As a result, the controllability of the deposition rate is very poor. In addition, since the source gas cannot be supplied uniformly to the substrate, the thickness distribution varies.
[0032]
As described above, when the film forming rate is unstable and the film thickness distribution varies, there is a problem that the denseness of the organic film becomes inhomogeneous and a high quality organic film cannot be formed. For example, in a current injection type organic light emitting material, problems such as a decrease in light emission lifetime due to local current concentration and an increase in power consumption due to an increase in electric resistance of the organic film occur. Further, the color purity of light emission is also reduced. In addition, since the amount of the doping gas transported to the substrate varies depending on the film forming rate, there is a problem that the doping concentration in the organic film becomes non-uniform.
[0033]
The present invention has been made to solve such a problem, and an object of the present invention is to provide an organic film forming apparatus and an organic film forming method capable of forming a high-quality organic film.
[0034]
[Means for Solving the Problems]
In order to solve the above-described problems, an organic film forming apparatus according to the present invention includes an organic film forming apparatus for forming a thin film of an organic material on a substrate, wherein a chamber having a holding unit for holding the substrate, Vaporization sublimation means for generating a source gas by changing the source gas, carrier gas introduction means for mixing the source gas and the carrier gas, and a source material for transporting the source gas into the chamber by the carrier gas and releasing the source gas toward the substrate The apparatus includes a gas transport unit, a direction control unit that is provided to face a substrate in a chamber and changes a flow direction of a source gas toward the substrate, and an exhaust unit that exhausts the chamber.
[0035]
In the organic film forming apparatus according to the present invention, the raw material gas is generated by changing the organic raw material into a gas phase by the vaporization sublimation means. A gas which becomes a carrier gas by the carrier gas introducing means, for example, N 2 ₂ , Ar (argon), He (helium), H ₂ (Hydrogen), ammonia, methane, and the like are mixed, and the source gas is transported to the chamber by the source gas transport means using the carrier gas.
[0036]
At this time, by changing the direction in which the source gas flows toward the substrate by the direction control means, the source gas can be supplied to the entire surface of the substrate. As a result, the film thickness distribution in the substrate becomes uniform, and a high-quality organic film can be formed.
[0037]
Further, the organic film forming apparatus according to the present invention is an organic film forming apparatus for forming a thin film of an organic substance on a substrate, wherein a chamber for accommodating the substrate and a vaporization for generating a raw material gas by changing an organic raw material into a gas phase. Sublimation means, carrier gas introduction means for mixing the source gas and the carrier gas, source gas transport means for transporting the source gas into the chamber by the carrier gas, and source gas supplied to the chamber by the source gas transport means A differential pressure generating means for forming a source gas chamber and a film forming chamber in which a substrate is housed, and for generating a pressure difference between the source gas chamber and the film forming chamber where the pressure on the film forming chamber side is reduced; Exhaust means for exhausting the formation chamber.
[0038]
In the organic film forming apparatus according to the present invention, the raw material gas is generated by changing the organic raw material into a gas phase by the vaporization sublimation means. The raw material gas is mixed with a carrier gas by a carrier gas introducing means, and the raw material gas is transported by the raw material gas transporting means by the carrier gas.
[0039]
At this time, a pressure difference is generated between the source gas chamber in which the source gas is supplied by the source gas transport unit and the film forming chamber in which the substrate is stored, and the pressure on the film forming chamber side is reduced by the differential pressure generating unit. Therefore, the transport of the source gas from the source gas chamber to the film forming chamber is promoted. Thus, the source gas is stably supplied to the film forming chamber, so that the film forming rate is stable and a high quality organic film can be formed.
[0040]
The organic film forming method according to the present invention is the organic film forming method of forming an organic thin film on a substrate, wherein a vaporization sublimation step of changing an organic raw material into a gaseous raw material gas, and mixing the raw material gas and a carrier gas A carrier gas introduction step, a source gas transport step of transporting the source gas onto the substrate by the carrier gas, and an organic film deposition step of forming an organic film on the substrate in a chamber under reduced pressure capable of controlling the flow of the source gas. And evacuation of the chamber. In the organic film deposition step, the organic film is formed while changing the flow direction of the source gas toward the substrate at least in one direction along the surface of the substrate. .
[0041]
In the method of forming an organic film according to the present invention, the organic raw material is changed into a gaseous raw material gas, and a gas serving as a carrier gas, for example, N 2 ₂ , Ar, He, H ₂ , Ammonia, methane and the like are mixed and supplied onto the substrate. At this time, since the organic film is formed while changing the flow of the source gas toward the substrate in one direction, the film thickness distribution in the substrate becomes uniform, and a high-quality organic film can be formed.
[0042]
Further, the organic film forming method according to the present invention is the organic film forming method of forming an organic thin film on a substrate, wherein a vaporization sublimation step of changing an organic raw material into a gaseous raw material gas; A source gas transporting step of mixing a carrier gas, a source gas transporting step of transporting the source gas onto the substrate by the carrier gas, an organic film deposition step of forming an organic film on the substrate, and an exhausting step. Is performed between a source gas chamber that fills the source gas and a film formation chamber that houses the substrate, and the pressure of the film formation chamber is reduced from the source gas chamber, so that the source gas flows from the source gas chamber to the film formation chamber. Is to transport.
[0043]
In the method of forming an organic film according to the present invention, the organic raw material is changed to a gaseous raw material gas, and a carrier gas is mixed with the raw material gas and supplied onto the substrate. At this time, the pressure on the film formation chamber side is reduced between the source gas chamber where the source gas is supplied and the film formation chamber in which the substrate is stored, so that the source gas is transported from the source gas chamber to the film formation chamber. Is promoted. Thus, the source gas is stably supplied to the film forming chamber, so that the film forming rate is stable and a high quality organic film can be formed.
[0044]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of an organic film forming apparatus of the present invention will be described with reference to the drawings. FIG. 1 is an overall configuration diagram of the organic film forming apparatus according to the first embodiment. In the organic film forming apparatus 1 of the first embodiment, when transporting a vapor-phase organic raw material using a carrier gas, the direction of the raw material gas is changed by a direction control plate 2 constituting a direction control means. Thus, the organic raw material can be supplied to the entire surface of the fixed substrate 3 to improve the film thickness distribution in the substrate 3. Here, the substrate 3 is a substrate in which an ITO transparent electrode is formed on the transparent glass substrate 102 described in FIG. 12 and the like, or a TFT (Thin Film Transistor) substrate (not shown).
[0045]
The organic film forming apparatus 1 includes a film forming chamber 4 for accommodating a substrate 3, a vaporizing sublimation chamber 5 for vaporizing or sublimating an organic raw material, and a raw material gas transport pipe 6 connecting the vaporizing sublimation chamber 5 and the film forming chamber 4.
[0046]
A substrate holder 7 for holding the substrate 3 is provided in the film forming chamber 4. The substrate holder 7 has a mechanism for circulating, for example, cooling water supplied from a cooling pipe 8 as a cooling means, and cools the held substrate 3 from the back side. Here, the substrate 3 is held vertically in the film forming chamber 4. When manufacturing a light emitting material used for a color display, a mask 114 shown in FIG. 17 is attached to the organic film forming surface of the substrate 3. For this purpose, means for holding the mask 114 on the substrate holder 7, for example, a magnetized member is provided.
[0047]
A pressure gauge 9 and an exhaust pipe 10 are provided in the film forming chamber 4. A vacuum pump (not shown) constituting exhaust means is connected to the exhaust pipe 10, and the output of the pressure gauge 9 is fed back to control the pressure in the film forming chamber 4 to maintain a predetermined low vacuum.
[0048]
Here, although not shown, a heater and a thermometer constituting a heating means are provided in the film forming chamber 4 so that the temperature in the film forming chamber 4 is maintained at such a temperature that the organic raw material before being adsorbed on the substrate 3 is not solidified. May be controlled.
[0049]
In order to allow the substrate 3 to be taken in and out of the film forming chamber 4, the film forming chamber 4 has, for example, a divided structure having an open / close structure, and when closed, the confidentiality is maintained.
[0050]
The vaporization sublimation chamber 5 constitutes vaporization sublimation means and vaporizes or sublimates an organic raw material by, for example, a resistance heating method, and includes a boat-shaped raw material container 11 in a container such as a chamber that can be isolated from outside air. . An unillustrated energizing mechanism for energizing the raw material container 11 is provided.
[0051]
The raw material container 11 is made of a material such as Ta (tantalum) which has a high melting point and does not react with the organic raw material. When power is supplied to the raw material container 11, the raw material container 11 becomes a resistor and generates heat. Thus, when the solid phase (powder) organic raw material 12 is put into the raw material container 11 and energized, the raw material container 11 generates heat, whereby the organic raw material 12 is indirectly heated and vaporized or sublimated. Thereby, H ₂ O or O ₂ The inside of the vaporization sublimation chamber 5, which is completely isolated from substances that alter the organic raw material, such as the organic raw material, is filled with the gas of the organic raw material.
[0052]
A pressure gauge 13 is provided in the vaporization sublimation chamber 5. When the amount of the organic raw material 12 decreases in the vaporization sublimation chamber 5, the pressure in the vaporization sublimation chamber 5 decreases. For this reason, the organic raw material 12 is depleted by providing a pressure gauge 13 in the vaporization sublimation chamber 5, measuring the pressure in the vaporization sublimation chamber 5, and issuing a raw material replenishment instruction when detecting a decrease in pressure. So that they can be refilled before
[0053]
The vaporization sublimation chamber 5 is provided with a thermocouple (not shown) for measuring the temperature of the raw material container 11 in order to control the heating temperature of the organic raw material 12. Further, an ammeter (not shown) for measuring a current value when energizing the raw material container 11 is provided. Thereby, the temperature of the raw material container 11 and the value of the current supplied to the raw material container 11 are monitored, and control is performed so that the temperature at which the organic raw material 12 evaporates or sublimes is maintained. In addition, by measuring the pressure and the temperature of the vaporization sublimation chamber 5, the control is performed such that the vaporization or sublimation amount of the organic raw material 12 is kept constant.
[0054]
Here, in the present embodiment, two independent vaporization sublimation chambers 5 are provided. A supply pipe 14 is connected to each of the vaporization sublimation chambers 5. Each supply pipe 14 is provided with a flow controller 15. Each supply pipe 14 is connected to a tank 16. The tank 16 is used as a carrier gas. ₂ And a gas such as Ar. Then, the flow rate of the carrier gas sent to the vaporization sublimation chamber 5 is independently controlled by the flow rate controller 15. The above-described vaporization sublimation chamber 5 and a mechanism for supplying a carrier gas to the vaporization sublimation chamber 5 constitute a carrier gas introduction unit.
[0055]
Downstream from the flow controller 15 of each supply pipe 14, a heater 17 constituting a heating means is provided. A thermometer (not shown) is provided in each supply pipe 14, and the heater 17 is controlled so that the temperature of the carrier gas sent from the supply pipe 14 to the vaporization sublimation chamber 5 is maintained at a temperature at which the organic raw material does not solidify.
[0056]
A source gas transport pipe 6 constituting source gas transport means is connected to each vaporization sublimation chamber 5. The source gas transport pipe 6 is also connected to the film forming chamber 4, and an injector 18 is provided at an end of the source gas transport pipe 6 inside the film forming chamber 4 at a position facing the substrate 3. Then, the direction control plate 2 is provided on the injector 18.
[0057]
FIG. 2 is a perspective view of the injector 18 showing an example of the direction control plate 2. The injector 18 has, for example, a pipe shape, and a plurality of, for example, three, direction control plates 2 are attached to an open discharge port. Each direction control plate 2 has a plate shape, is rotatable about a shaft 2a, and changes the direction in which the raw material gas discharged from the injector 18 flows. The shaft 2a of each direction control plate 2 is connected to driving means (not shown), and each direction control plate 2 moves by receiving a driving force. Here, the direction control plate 2 shown in FIGS. 1 and 2 has a horizontal axis 2a and swings up and down, but the direction control plate has a vertical axis and swings left and right. May be.
[0058]
Returning to FIG. 1, the source gas transport pipe 6 is provided with a heater 19 constituting a heating means, and heats the direction control plate 2 and the source gas to be transported. The source gas transport pipe 6 is provided with a thermometer (not shown), and a heater is provided so that the temperature of the source gas transported through the source gas transport pipe 6 and the temperature of the direction control plate 2 maintain the temperature at which the organic source does not solidify. 19 is controlled. A thermometer using a thermocouple may be provided on the direction control plate 2 so that the temperature of the direction control plate 2 can be directly measured.
[0059]
Next, an embodiment of the organic film forming method of the present invention will be described as an operation of the above-described organic film forming apparatus 1. The organic film forming method according to the present embodiment includes a vaporization sublimation step of vaporizing or sublimating an organic raw material, a carrier gas introducing step of introducing a carrier gas for transportation, a raw gas transporting step of transporting the raw material gas onto the substrate 3, 3 comprises an organic film deposition step and an exhaust step.
[0060]
The vaporization sublimation step is performed in the vaporization sublimation chamber 5. In the vaporization sublimation step, a current is supplied to the raw material container 11 in which the organic raw material 12 is placed, and the organic raw material 12 is indirectly heated and vaporized or sublimated by the resistance heating of the raw material container 11 to generate a raw material gas.
[0061]
Thereby, H ₂ O or O ₂ The inside of the vaporization sublimation chamber 5, which is completely isolated from substances that alter the organic raw material such as the above, is filled with the raw material gas. In the vaporization sublimation step, the temperature of the raw material container 11 and the value of the current supplied to the raw material container 11 are monitored, and the organic raw material 12 is controlled to keep the amount of vaporization or sublimation constant. Further, the pressure in the vaporization sublimation chamber 5 is monitored by the pressure gauge 13, and when a decrease in pressure is detected, control is performed so as to issue an instruction to replenish the raw material.
[0062]
The carrier gas introduction step is performed in the vaporization sublimation chamber 5. In this carrier gas introduction step, dilution of the source gas and introduction of the carrier gas are performed. That is, the flow rate of the carrier gas in the tank 16 is controlled by the flow rate controller 15 and is sent from the supply pipe 14 into the vaporization sublimation chamber 5. Then, the carrier gas and the source gas sent into the vaporization sublimation chamber 5 are mixed, and the source gas is sent to the source gas transport pipe 6 by the carrier gas.
[0063]
Here, in the carrier gas introducing step, the temperature of the carrier gas and the raw material gas is controlled by heating the supply pipe 14 with the heater 17 in order to avoid the solidification of the organic raw material due to the temperature decrease of the raw material gas in the vaporization sublimation chamber 5. I do. Further, the flow rate controller 15 controls the supply amount of the carrier gas to be constant. As described above, the amount of the carrier gas supplied to the vaporization sublimation chamber 5 is kept constant, and the amount of the organic material 12 vaporized or sublimated in the vaporization sublimation chamber 5 is kept constant. Can be kept constant. Thus, by monitoring the pressure in the vaporization sublimation chamber 5 as described above in the vaporization sublimation step, a decrease in the organic raw material 12 can be detected as a decrease in pressure, and replenishment can be performed before the organic raw material 12 is depleted. .
[0064]
The source gas transport step is performed in the source gas transport pipe 6. In the source gas transport step, the source gas mixed with the carrier gas in the carrier gas introduction step is transported through the source gas transport pipe 6 by the carrier gas. Then, the source gas transported by the carrier gas through the source gas supply pipe 6 is discharged from the injector 18 into the film forming chamber 4.
[0065]
In this source gas transporting step, if the flow rate of the carrier gas is increased in the above-described carrier gas introducing step, the amount of the source gas to be transported can be increased. This makes it possible to increase the amount of the source gas supplied to the substrate 3 and improve the film formation rate on the substrate 3, and to greatly improve the film formation rate as compared with the vacuum evaporation method. it can.
[0066]
In the raw material gas transporting step, the temperature of the raw material gas is controlled by heating the raw material gas transport tube 6 by the heater 19 in order to avoid solidification of the organic raw material due to a decrease in the temperature of the raw material gas in the raw material gas transport tube 6.
[0067]
The organic film deposition step is performed in the film forming chamber 4. In the organic film deposition step, the source gas transported through the source gas transport pipe 6 in the above-described source gas transport step and released from the injector 18 is adsorbed on the substrate 3 to form an organic film.
[0068]
Here, since the injector 18 is provided with the direction control plate 2, the direction in which the raw material gas discharged from the injector 18 flows is controlled by moving the direction control plate 2.
[0069]
FIG. 3 is an explanatory diagram showing an operation example of the direction control plate 2. When three directional control plates 2 are provided in the injector 18, each directional control plate 2 rotates around the shaft 2a. Then, as shown in FIG. 3 (a), when the respective direction control plates 2 operate in the same direction in conjunction with each other, the respective direction control plates 2 receive a driving force from a driving unit (not shown) and move from the position indicated by the solid line. By moving in the same direction to the position indicated by the two-dot chain line, the flow of the source gas discharged from the injector 18 is swung up and down in one direction, here. Thus, even when the position of the substrate 3 is fixed, the source gas can be supplied to the entire surface of the substrate 3 and the film thickness distribution on the substrate 3 can be made uniform.
[0070]
Also, as shown in FIG. 3B, when the respective directional control plates 2 operate independently, the directional control plates 2 at both ends move from the position indicated by the solid line to the position indicated by the two-dot chain line at the center. By moving toward and away from 2, the flow of the source gas discharged from the injector 18 is also swung up and down. Thus, the source gas is supplied to the entire surface of the substrate 3 so that the film thickness distribution can be made uniform.
[0071]
The source gas has a temperature of, for example, about 250 ° C. in order to keep the organic source in a gaseous state. Therefore, the temperature of the substrate 3 to which the source gas is supplied rises. Therefore, in the organic film deposition step, cooling water is supplied to the substrate holder 7 through the cooling pipe 8 so as to control the temperature of the substrate 3 so as to maintain the temperature at about room temperature. In order to efficiently cool the substrate 3, an electrode (not shown) for obtaining a Peltier effect may be provided on the substrate holder 7, and the heat absorbed by the electrode from the substrate 3 may be cooled by the cooling pipe 8. .
[0072]
As described above, since the organic film can be formed while maintaining the temperature of the substrate 3 at around room temperature, the organic raw material adsorbed on the substrate 3 is rapidly cooled from a high-temperature gas state to be amorphous or amorphous. A high quality microcrystalline organic film is formed. Thereby, it is possible to prevent the deterioration of the electric characteristics and the deterioration of the optical characteristics due to the crystallization of a part or all of the organic film deposited on the substrate 3. Further, since the temperature of the substrate 3 can be kept at about room temperature, it is possible to use a heat-sensitive plastic substrate as the substrate 3. Therefore, in the organic film forming apparatus 1 according to the present embodiment, it is possible to manufacture an organic EL light emitting element constituting a flexible display.
[0073]
Here, when manufacturing a light emitting material used for a color display, a mask 114 shown in FIG. 17 is attached to the organic film forming surface of the substrate 3 in an organic film deposition step. In the organic film forming apparatus 1 shown in FIG. 1, the position of the substrate 3 is fixed and does not move during the organic film deposition process. There is no deviation. Further, since the film is formed by changing the flow of the source gas by the direction control plate 2, the incident angle of the source gas with respect to the substrate 3 becomes variable. Therefore, the source gas is also supplied to the vicinity of the edge of the mask 114, so that an organic film having a predetermined size can be formed. Therefore, the film thickness distribution in each pixel becomes uniform.
[0074]
The evacuation step is performed in the film formation chamber 4. In the evacuation process, prior to each of the above-described processes, the film forming chamber 4 in which the substrate 3 is housed can control the flow of the source gas 10. ² -10 ³ Maintain a low vacuum of about Pa. Further, the residual gas generated in the organic film deposition step is exhausted. In this evacuation step, the evacuation speed is controlled to be constant to prevent the pressure in the film formation chamber 4 from changing suddenly.
[0075]
As described above, in the organic film forming apparatus according to the first embodiment, the direction control plate 2 is provided on the injector 18 of the source gas transport pipe 6 to control the direction in which the source gas flows. The source gas can be supplied to the entire surface of the substrate 3 without moving the substrate 3, and the film thickness distribution in the substrate 3 can be made uniform.
[0076]
FIG. 4 is an explanatory view showing a modification of the direction control plate. FIG. 4A is a cross-sectional view of the injector 18, and FIG. 4B is a perspective view of the direction control plate 20. The direction control plate 20 has a plate shape, and one end is rotatably attached to the injector 18 of the source gas transport pipe 6 around the shaft 20a. The other end of the direction control plate 20 is divided into two, and a first direction control plate 21a and a second direction control plate 21b are provided. At least one of the first direction control plate 21a and the second direction control plate 21b is configured to be operable independently of the direction control plate 20 main body. For example, the first direction control plate 21a is configured to be rotatable with respect to the direction control plate 20 around the shaft 20b.
[0077]
With such a configuration, the direction control plate 20 can make the angle of the first direction control plate 21a different from that of the second direction control plate 21b. The shaft 20a of each direction control plate 20 is connected to a drive source (not shown), and each direction control plate 20 receives a driving force and moves in the same direction, for example, in conjunction with each other.
[0078]
In the above configuration, the direction in which the raw material gas discharged from the injector 18 flows is controlled by the direction control plate 20. The direction control plate 20 is provided with the first direction control plate 21a whose angle can be adjusted independently. Therefore, the flow direction of the source gas can be more finely controlled.
[0079]
FIG. 5 is an explanatory view showing another modification of the direction control plate. FIG. 5A is a sectional view of the injector 18, and FIG. 5B is a perspective view of the injector 18. The direction control plate 22 includes a left-right direction control plate 23 and a vertical direction control plate 24. The two left and right direction control plates 23 are arranged to face each other and are connected by a connecting member 25. The two left and right direction control plates 23 are rotatably mounted on the injector 18 of the source gas transport pipe 6 around a shaft 23a and operate integrally.
[0080]
A plurality of, here three, vertical control plates 24 are provided between the two horizontal control plates 23. Each vertical control plate 24 is rotatably mounted between the left and right control plates 23 about a shaft 24a.
[0081]
The shaft 23a of the left-right control plate 23 is connected to a drive source (not shown), and the left-right control plate 23 moves by receiving a driving force. The shaft 24a of each vertical control plate 24 is connected to a drive source (not shown), and each vertical control plate 24 receives a driving force and moves in the same direction, for example, in conjunction with each other.
[0082]
In the above configuration, the direction in which the raw material gas discharged from the injector 18 flows is controlled left and right by operating the left-right direction control plate 23 about the shaft 23a. Further, the vertical direction control plate 24 operates with the shaft 24a as a fulcrum, thereby controlling the direction in which the source gas flows up and down.
[0083]
Thereby, the flowing direction of the raw material gas can be controlled vertically and horizontally. Therefore, even if the size of the substrate 3 becomes large, the source gas can be supplied to the entire surface of the substrate 3 and the film thickness distribution on the substrate 3 can be made uniform.
[0084]
FIG. 6 is an explanatory view showing a modified example of the injector. FIG. 6A is a perspective view of the injector, and FIG. 6B is a sectional view of the injector. In this example, a number of injectors 18 are provided to face one substrate 3, and for example, a plurality of direction control plates 2 are provided in each injector 18. Each direction control plate 2 operates with the shaft 2a as a fulcrum.
[0085]
In the above configuration, the source gas can be supplied to the substrate 3 in a wide range by providing a large number of the injectors 18 and the direction in which the source gas flows can be controlled by providing the direction control plate 2 to each injector 18. Even if the size of the substrate 3 becomes large, the source gas can be supplied to the entire surface of the substrate 3 and the film thickness distribution on the substrate 3 can be made uniform.
[0086]
FIG. 7 is a perspective view showing an example of a film thickness measuring mechanism provided in the organic film forming apparatus 1 according to the first embodiment. In the organic film forming apparatus 1 according to the first embodiment, by providing the direction control plate 2, even when the position of the substrate 3 is fixed, the source gas is supplied to the entire surface of the substrate 3 to reduce the film thickness distribution. Can be improved. For this reason, the substrate 3 is attached to the substrate holder 7 and the position is fixed in the film forming chamber 4.
[0087]
Therefore, a reflection type optical film thickness meter 25 is provided as a film thickness measuring means at a position facing the substrate 3. This enables a so-called IN-SITU monitor in which the thickness of the organic film 3a formed on the substrate 3 during the organic film deposition step can be directly measured.
[0088]
That is, in the organic film deposition step, the source gas discharged from the injector 18 of the source gas transport pipe 6 is supplied to the substrate 3 to form the organic film 3a. Is monitored, and the supply of the source gas is stopped when a predetermined film thickness is obtained, whereby an organic film having a desired film thickness can be obtained. The supply of the source gas is stopped by stopping the supply of the source gas by the flow controller 15 or a valve (not shown).
[0089]
As described above, by performing the organic film deposition step while directly measuring the film thickness of the substrate 3, an organic film having the same thickness can be formed on each substrate 3, so that the film thickness reproducibility between lots is greatly improved.
[0090]
FIG. 8 is an explanatory diagram showing an example of film thickness control. Now, as shown in FIG. 6, by forming an organic film on a single substrate 3 using a plurality of injectors 18, an organic film can be formed on a large-sized substrate. By providing the optical film thickness meter 25 corresponding to each injector 18, the uniformity of the film thickness is improved. Here, in this example, it is assumed that a configuration is provided in which the presence or absence of the supply of the source gas from each injector 18 can be switched independently. For example, the configuration may be such that the vaporization sublimation chamber 5 is connected to each injector 18 and the supply pipe 14 having the flow rate controllers 15-1 to 15-n is connected to each vaporization sublimation chamber 5.
[0091]
The operation will be described below. On the substrate 3, a film thickness in a range where the organic film 3a is mainly formed by the raw material gas discharged from the injector 18-1 is measured by the optical thickness meter 25-1. The thickness of the organic film 3a in the range where the organic film 3a is mainly formed by the source gas released from the injector 18-n is measured by the optical thickness meter 25-n. Although not shown, the film thickness of each of the other injectors 18 is similarly measured by the optical film thickness meter 25.
[0092]
If the measured film thickness by the optical film thickness meter 25 <the design film thickness, the supply of the source gas is continued. On the other hand, if the measured film thickness by the optical film thickness meter 25 = the design film thickness, the supply of the source gas is stopped. By performing this control for each injector, the uniformity of the film thickness is improved even for a very large substrate.
[0093]
In the optical film thickness meter 25, the incident angle of light on the substrate is 90 degrees, but the incident angle of light may be 45 degrees. In this case, the reflected light is separated into p-waves and s-waves by the beam splitter for processing, but the measurement accuracy of the film thickness is improved.
[0094]
FIG. 9 is an overall configuration diagram of an organic film forming apparatus according to the second embodiment. In the organic film forming apparatus 31 according to the second embodiment, the inside of the chamber 32 is partitioned by a perforated plate 33 constituting a pressure difference generating means, and the transport of the raw material gas supplied to the substrate 34 is promoted. Here, the substrate 34 is a substrate obtained by forming an ITO transparent electrode on the transparent glass substrate 102 described with reference to FIG. 12 or the like, or a TFT substrate (not shown).
[0095]
The chamber 32 is, for example, a substantially cylindrical container that shields the inside from the outside air, and is partitioned by a perforated plate 33 to form a film forming chamber 35 and a source gas chamber 36. The film forming chamber 35 is provided with a substrate holder 37 constituting a holding means for the substrate 34.
[0096]
The substrate holder 37 has, for example, a mechanism for circulating cooling water supplied from a cooling pipe 38 as a cooling unit of the held substrate 34, and cools the held substrate 34 from the back side.
[0097]
The source gas chamber 36 is provided with a vaporization sublimation device 40 constituting a vaporization sublimation unit. The vaporization sublimation apparatus 40 vaporizes or sublimates a solid organic material to generate a raw material gas. In the present embodiment, two sets of vaporization sublimation apparatuses 40 are provided. Here, the number of the vaporization sublimation devices 40 is not limited to two.
[0098]
The vaporization sublimation apparatus 40 vaporizes or sublimates a powdery organic raw material by, for example, a resistance heating method. The vaporization sublimation apparatus 40 includes a boat-shaped raw material container 41 and an energizing mechanism (not shown) for energizing the raw material container 41.
[0099]
The raw material container 41 is made of a material such as Ta, which has a high melting point and does not react with the organic raw material. When power is supplied to the raw material container 41, it becomes a resistor and generates heat. Accordingly, when the organic material 42a is put into the material container 41 and energized, the organic material 42a is indirectly heated by the heat generation of the material container 41 and is vaporized or sublimated to generate a material gas.
[0100]
The raw material container 41 is placed in a mixing tube 43 constituting a carrier gas introducing means. The mixing pipe 43 is provided in the source gas chamber 36 and is connected to a gas supply device 44 constituting a carrier gas introduction unit. The gas supply device 44 is, for example, an inert N ₂ , A plurality of supply pipes 46a connecting the tank 45 and one end of each mixing pipe 43, and an adjustment valve provided between each supply pipe 46a and the tank 45. 47, a pressure regulator 48a, a flow meter 48b, and a switching valve 48c provided in each supply pipe 46a.
[0101]
The adjustment valve 47 controls the flow rate of the carrier gas supplied from the tank 45 to each supply pipe 46a. The pressure regulator 48a controls the pressure of the carrier gas flowing through each supply pipe 46a. The flow meter 48b measures the flow rate of the carrier gas flowing through each supply pipe 46a. The switching valve 48c switches the supply of the carrier gas. Here, the output of the flow meter 48b is fed back to the adjustment valve 47, and for example, the flow rate of the carrier gas is controlled so that the inside of the mixing pipe 43 has a predetermined pressure.
[0102]
The other end of the mixing tube 43 is opened to form a discharge port 49. The discharge port 49 is provided in the raw material gas chamber 36, and the raw material gas generated by vaporizing or sublimating the organic raw material 42 a by the vaporization sublimation device 40 is discharged from the discharge port 49 by the carrier gas supplied to the mixing pipe 43. .
[0103]
Then, two sets of the vaporization sublimation devices 40 are provided, and a source gas is generated in an independent atmosphere and transported to the substrate 34. For example, by replacing one organic source with a doping source, the organic source and the doping source are converted. The reaction can be performed on the substrate 34.
[0104]
The vaporization sublimation device 40 using the resistance heating method is used when vaporizing or sublimating a solid organic material. On the other hand, a vaporizer 50 for vaporizing a liquid-phase organic raw material may be added as a vaporization sublimation unit.
[0105]
The vaporizer 50 includes a raw material tank 51 in which a liquid-phase organic raw material 42b is stored. The raw material tank 51 is a container that can be sealed. The supply pipe 46b and the raw material gas transport pipe 52 are connected to the raw material tank 51. The supply pipe 46b is provided with a discharge port 53 at a height reaching the organic raw material 42b in the raw material tank 51. The supply pipe 46b is also provided with a pressure regulator 48a, a flow meter 48b, and a switching valve 48c.
[0106]
The raw material gas transport pipe 52 is provided with a suction port 54 at a height that does not reach the organic raw material 42 b in the raw material tank 51, and a discharge port 55 is provided in the raw material gas chamber 36. Thereby, the carrier gas supplied from the supply pipe 46b passes through the organic raw material 42b as bubbles, and the vaporized organic raw material is transported to the substrate 34 by the raw material gas transport pipe 52. In addition, such a mechanism is called a bubbler. Further, a temperature control tank 57 for immersing at least the height of the raw material tank 51 at which the organic raw material 42b is put in the liquid 56 is provided, and the temperature of the liquid 56 is controlled by a heater (not shown). Control the temperature.
[0107]
A heating / cooling device 58 constituting heating means is provided around the chamber 32. The heating / cooling device 58 is provided corresponding to the film forming chamber 35 and the source gas chamber 36, and controls the temperature of the inside of the film forming chamber 35, the inside of the source gas chamber 36, and the perforated plate 33.
[0108]
Although not shown, a heater may be provided in each of the mixing tubes 43 so that the temperature of the source gas can be individually controlled. Further, a heater may be provided in each of the supply pipes 46a and 46b so that the temperature of the carrier gas can be individually controlled.
[0109]
An exhaust pipe 59 is provided in the film forming chamber 35 of the chamber 32, and a trap tank 60, a slot valve 61 and a vacuum pump 62 are attached to the exhaust pipe 59. The vacuum pump 62 exhausts the inside of the film formation chamber 35 and controls the pressure in the film formation chamber 35.
[0110]
The porous plate 33 that separates the film formation chamber 35 from the source gas chamber 36 has many small holes 33 a that are sufficiently smaller than the diameter of the exhaust pipe 59 and sufficiently larger than the particles of the source gas. When the inside of the formation chamber 35 is exhausted, a difference occurs between the supply amount of the source gas from the source gas chamber 36 to the film formation chamber 35 and the exhaust amount from the film formation chamber 35.
[0111]
Therefore, when the source gas is supplied into the source gas chamber 36 from the mixing pipe 43 or the source gas transport pipe 52, the pressure in the source gas chamber 36 increases, and when the inside of the film formation chamber 35 is evacuated by the vacuum pump 62, The pressure in 35 drops. Accordingly, if the pressure in the source gas chamber 36 is P1 and the pressure in the film forming chamber 35 is P2, the relationship of P1> P2 is established.
[0112]
Then, pressure gauges 63 and 64 are provided in each of the film formation chamber 35 and the source gas chamber 36, and the output of each pressure gauge is fed back to control the flow rate of the carrier gas so that P1> P2. The supply amount of the gas is controlled, and the exhaust amount by the vacuum pump 62 is controlled. The control of the exhaust amount by the vacuum pump 62 is controlled, for example, by opening and closing the slot valve 61. The organic raw materials and the like not adsorbed on the substrate 34 are condensed in the trap tank 60 so as not to reach the slot valve 61 and the vacuum pump 62.
[0113]
Here, in order to allow the substrate 34 to be freely taken in and out of the film formation chamber 35, for example, a divided structure in which an opening and closing part is provided in the chamber 32 is provided so that when this opening and closing part is closed, airtightness can be maintained. , The substrate 34 can be attached and detached.
[0114]
Next, an embodiment of the organic film forming method of the present invention will be described as an operation of the above-described organic film forming apparatus 31. The organic film forming method of the present embodiment includes a vaporization sublimation step of vaporizing or sublimating an organic raw material, a carrier gas introducing step of introducing a carrier gas and mixing with a raw material gas, and a raw material gas of transporting the raw material gas onto the substrate 34. It comprises a transport step, a step of depositing an organic film on the substrate 34, and an exhaust step.
[0115]
In the vaporization sublimation step, the raw material container 41 containing the organic raw material 42a is energized in the vaporization sublimation device 40, and the organic raw material 42a is indirectly heated by the resistance heat of the raw material container 41 to be vaporized or sublimated, thereby converting the raw material gas. Generate. Further, the organic raw material 42b in the raw material tank 51 is heated and evaporated by the vaporizer 50 to generate a raw material gas. In this embodiment, three types of source gas supply sources are provided, but these may be used alone or in combination depending on the type of the organic source and the like.
[0116]
In the vaporization sublimation step, the temperature of the raw material container 41 and the value of the current supplied to the raw material container 41 are monitored, and the current value and the like are controlled so that the temperature at which the organic raw material 42a is vaporized or sublimated is maintained. Further, the temperature of the raw material tank 51 and the like are monitored, and control is performed so that the temperature at which the organic raw material 42b is vaporized is maintained.
[0117]
In the carrier gas introduction step, the carrier gas in the tank 45 is sent to both or one of the mixing tubes 43 as necessary. Each supply pipe 46a is provided with an adjustment valve 47, a pressure regulator 48a, a flow meter 48b, and a switching valve 48c, and controls the pressure and flow rate of the carrier gas sent to the mixing pipe 43.
[0118]
In the mixing pipe 43, the carrier gas and the source gas whose pressure and flow rate are controlled are mixed and discharged from the discharge port 49. As a result, the source gas is discharged from one or both of the mixing tubes 43 depending on whether or not the carrier gas is supplied, and the inside of the source gas chamber 36 is filled.
[0119]
When the carrier gas in the tank 45 is supplied to the raw material tank 51, the carrier gas passes through the organic raw material 42 b as air bubbles, and the organic raw material that has become vapor is supplied from the raw gas transport pipe 52 to the raw gas chamber 36.
[0120]
The raw material gas chamber 36 is heated by the heating / cooling device 58 and is kept at a constant temperature so that the gasified organic raw material does not solidify and does not decompose. The heating temperature of the source gas supplied to the source gas chamber 36 is monitored by a thermometer (not shown) using a thermocouple or the like. Controlled.
[0121]
In the source gas transport step, the source gas in the source gas chamber 36 is transported to the film formation chamber 35. Then, in order to transport the source gas to the film formation chamber 35, the inside of the film formation material 35 is evacuated by a vacuum pump as an evacuation step. When the inside of the film formation chamber 35 is evacuated by the vacuum pump 62, the supply amount of the source gas from the source gas chamber 36 to the film formation chamber 35 is separated from the source gas chamber 36 and the film formation chamber 35 by the porous plate 33. And the amount of exhaust from the film formation chamber 35 can be made different.
[0122]
In other words, the amount of exhaust gas from the film forming chamber 35 through the exhaust pipe 59 is larger than the amount of the source gas supplied from the source gas chamber 36 to the film forming chamber 35 through the fine holes 33a of the porous plate 33. When the pressure is exhausted by the vacuum pump 62, the pressure P1 in the source gas chamber 36> the pressure P2 in the film forming chamber 35. As described above, when P1> P2, the gas moves from the higher pressure to the lower pressure, so that the transport of the source gas from the source gas chamber 36 to the film formation chamber 35 is promoted. Backflow to the source gas chamber 36 does not occur. Therefore, the supply amount of the source gas to the substrate 34 is stabilized.
[0123]
Then, the pressure in the film forming chamber 35 is measured by the pressure gauge 63, and the pressure in the source gas chamber 36 is measured by the pressure gauge 64, so that the film forming chamber 35 and the The pressure of the source gas chamber 36 is controlled.
[0124]
Here, when maintaining the relationship of P1> P2 by increasing the pressure of the source gas chamber 36, the source gas is supplied into the source gas chamber 36 from the mixing pipe 43 or the source gas transport pipe 52. In order to supply the source gas, for example, when the vaporization sublimation device 40 is used, the source container 41 is energized to generate the source gas, and the carrier gas is supplied from the tank 45 to the mixing pipe 43. To supply the source gas into the source gas chamber. Further, when the relationship of P1> P2 is maintained by lowering the pressure of the film formation chamber 35, the amount of exhaust by the vacuum pump 62 is increased.
[0125]
In the organic film deposition step, the source gas transported from the source gas chamber 36 through the porous plate 33 to the film formation chamber 35 in the source gas transport step is adsorbed on the substrate 34 to form an organic film. Now, as the pressure P1 in the source gas chamber 36> the pressure P2 in the film formation chamber 35, the source gas is transported from the source gas chamber 36 to the film formation chamber 35, so that the source gas chamber 36 moves to the film formation chamber 35. Of the source gas is promoted, and the supply amount of the source gas to the substrate 34 is stabilized. Thereby, the film forming speed is improved. Note that a mechanism for cooling the substrate 34 by water cooling is provided in the substrate holder 37 so that the substrate 34 is kept at room temperature. As a result, the organic raw material adsorbed on the substrate 34 is rapidly cooled from a high-temperature gas state, whereby an amorphous or microcrystalline high-quality organic film is formed.
[0126]
In the evacuation step, the film formation chamber 35 is ² As described above, the gas is evacuated by the vacuum pump 62 so as to obtain the relationship of the pressure P1 in the source gas chamber 36> the pressure P2 in the film forming chamber 35 while maintaining a low vacuum of about Pa. In this evacuation step, the residual gas generated in the organic film deposition step is also exhausted.
[0127]
As described above, in the organic film forming apparatus according to the second embodiment, the chamber 32 is partitioned by the perforated plate 33 to form the source gas chamber 36 and the film forming chamber 35, and the pressure P1 in the source gas chamber 36 is set. > Since the pressure P2 in the film formation chamber 35 can be set, the transportation of the source gas from the source gas chamber 36 to the film formation chamber 35 is promoted, and the source gas can be stably supplied to the substrate 34; Is improved.
[0128]
FIG. 10 is an explanatory view showing a modification of the organic film forming apparatus according to the second embodiment. FIG. 10A is a sectional side view of a main part, and FIG. 10B is a partially cutaway perspective view. The chamber 32 is partitioned by a perforated plate 33 to form a film forming chamber 35 and a source gas chamber 36. The film forming chamber 35 is provided with a substrate holder 65 constituting a holding means for the substrate 34.
[0129]
The substrate holder 65 has a disk shape, and a plurality of, in this example, two substrates 34 are mounted in the circumferential direction. The substrate holder 65 is provided with a shaft 66 extending in a horizontal direction perpendicular to the surface of the substrate 34 held. The shaft 66 has a hollow structure, and a gear (not shown) is provided on the outer peripheral surface. Then, a pinion gear 67 connected to a drive mechanism (not shown) meshes with this gear, and the substrate holder 65 rotates about a shaft 66. Here, since the shaft 66 has a structure penetrating from the outside to the inside of the chamber 32, the shaft 66 is rotatably supported by a shield mechanism such as a magnetic shield (not shown), and the shaft 66 is supported at a portion where the shaft 66 is supported. Be airtight.
[0130]
The substrate holder 65 has a configuration for absorbing the heat of the substrate 34 held therein, and the shaft 66 has a configuration for circulating air therein to cool the substrate holder 65. Is configured.
[0131]
Other configurations may be the same as those of the organic film forming apparatus described with reference to FIG. 9, but a source gas discharge port may be provided for each substrate 34 held by the substrate holder 65.
[0132]
That is, two source gas transport pipes 68 are connected to each of the mixing pipes 43 shown in FIG. 9, and the discharge ports of the source gas transport pipes 68 are located at positions facing the respective substrates 34 with the porous plate 33 interposed therebetween. Provide. Further, the raw material gas transport pipe 52 shown in FIG. 9 is branched, and each discharge port is provided at a position facing each substrate 34 with the porous plate 33 interposed therebetween.
[0133]
When the source gas is supplied to each substrate 34, it is preferable that the distance between the discharge port of each source gas transport pipe and the perforated plate 33 and the distance between the substrate 34 and the perforated plate 33 be reduced.
[0134]
In the above-described configuration, the film forming chamber 35 is evacuated by a vacuum pump (not shown) so that the pressure P1 in the source gas chamber 36> the pressure P2 in the film forming chamber 35 is satisfied. The transport of the source gas to the substrate 35 is promoted, and the source gas can be stably supplied to the substrate 34. At this time, by rotating the substrate holder 65, the source gas can be supplied to the entire surface of the substrate 34, and the film thickness distribution is improved. In addition, even when the substrate holder 65 is configured to rotate, by providing a substrate cooling mechanism by air cooling using the shaft 66, the substrate can be cooled in the organic film deposition step.
[0135]
FIG. 11 is an explanatory view showing another modification of the organic film forming apparatus according to the second embodiment. FIG. 11A is a sectional side view of a main part, and FIG. 11B is a partially cutaway perspective view. . The organic film forming apparatus in FIG. 11 has a configuration in which the exhaust pipe 69 is connected to the perforated plate 33 in the configuration described in FIG. That is, an exhaust port 70 is provided at the center of the perforated plate 33, and an exhaust pipe 69 is connected to the exhaust port 70 from the source gas chamber 36 side. By connecting the exhaust pipe 69 to a vacuum pump (not shown), the exhaust of the film formation chamber 35 can be performed from the exhaust pipe 69. The other configuration is the same as the configuration described in FIG.
[0136]
In the above configuration, the film forming chamber 35 is evacuated from the exhaust pipe 59 by the vacuum pump (not shown), and the film forming chamber 35 is also evacuated from the exhaust pipe 69. Since the exhaust port 70 of the exhaust pipe 69 faces the center of the substrate holder 65, it is possible to suppress uneven exhaust in the film formation chamber 35. Accordingly, when a plurality of substrates 34 are held by the substrate holder 65 as shown in FIG. 11, the source gas can be uniformly supplied to each substrate 34. Although not shown, when a film is formed on a large-sized substrate, the source gas can be uniformly supplied to the entire surface of the substrate. Therefore, the film thickness distribution is improved.
[0137]
【The invention's effect】
As described above, the present invention supplies the source gas to the entire surface of the substrate by changing the flow direction of the source gas when the organic source is changed to a gaseous source gas and supplied to the substrate. be able to. As a result, the film thickness distribution in the substrate becomes uniform, and a high-quality organic film can be formed. Therefore, there is no need to use a movable mechanism of the substrate, and an apparatus capable of forming a high-quality organic film can be provided at a reduced cost.
[0138]
Further, the present invention provides a method for forming a film between a source gas chamber in which a source gas is supplied and a film forming chamber in which a substrate is stored, when the organic source is converted into a gaseous source gas and supplied onto a substrate. Since the pressure on the chamber side is reduced, the transport of the source gas from the source gas chamber to the film forming chamber is promoted. As a result, the source gas is stably supplied to the film formation chamber, so that the film formation rate is stabilized and the film formation rate is improved, so that a high-quality organic film can be formed. As described above, when the deposition rate is stable, the uniformity of the organic film and the uniform dispersibility of the doping material are improved, and a light-emitting element having a long light-emitting life can be manufactured. In addition, an organic film having high color purity and improved emission wavelength accuracy of the dopant type material can be formed. Further, since the organic film has few defects, a light-emitting element with low resistance and low power consumption can be manufactured.
[0139]
According to the present invention, an organic EL display having a large screen and less luminance unevenness, a high-definition organic EL display, an organic EL display excellent in color purity, and the like can be manufactured. In addition, a dye-sensitized solar power generation panel, an organic EL laser, an organic EL diode, and the like, which are not limited to the display, can be manufactured.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of an organic film forming apparatus according to a first embodiment.
FIG. 2 is a perspective view of an injector showing an example of a direction control plate.
FIG. 3 is an explanatory diagram showing an operation example of a direction control plate.
FIG. 4 is an explanatory view showing a modification of the direction control plate.
FIG. 5 is an explanatory view showing another modification of the direction control plate.
FIG. 6 is an explanatory diagram showing a modified example of the injector.
FIG. 7 is a perspective view illustrating an example of a film thickness measuring mechanism provided in the organic film forming apparatus according to the first embodiment.
FIG. 8 is an explanatory diagram showing an example of film thickness control.
FIG. 9 is an overall configuration diagram of an organic film forming apparatus according to a second embodiment.
FIG. 10 is an explanatory view showing a modification of the organic film forming apparatus according to the second embodiment.
FIG. 11 is an explanatory view showing another modification of the organic film forming apparatus according to the second embodiment.
FIG. 12 is an explanatory diagram illustrating an example of the structure of an organic EL element.
FIG. 13 is a plan view showing an outline of an organic EL color display.
FIG. 14 is a perspective view of a main part of an organic EL color display.
FIG. 15 is an explanatory diagram showing a basic configuration of a vacuum evaporation apparatus.
FIG. 16 is an explanatory diagram showing a film thickness measuring method in a vacuum evaporation apparatus.
FIG. 17 is a sectional view showing an example of a film deposition step using a mask.
FIG. 18 is an explanatory view of a conventional organic film forming apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Organic film forming apparatus, 2 ... Direction control plate, 2a ... Shaft, 3 ... Substrate, 3a ... Organic film, 4 ... Film forming chamber, 5 ... Vaporization sublimation Chamber, 6: source gas transport pipe, 7: substrate holder, 8: cooling pipe, 9: pressure gauge, 10: exhaust pipe, 11: raw material container, 12 ... Organic raw material, 13 pressure gauge, 14 supply pipe, 15 flow rate controller, 16 tank, 17 heater, 18 injector, 19 heater, 20 ..Direction control plate, 20a ... axis, 20b ... axis, 21a ... first direction control plate, 21b ... second direction control plate, 22 ... direction control plate, 23 ... ..Right and left direction control plate, 23a ... axis, 24 ... vertical direction control plate, 24a ... axis, 25 ... optical film thickness meter, 31 ... Machine film forming apparatus, 32: chamber, 33: perforated plate, 33a: minute hole, 34: substrate, 35: film forming chamber, 36: source gas chamber, 37 ...・ Substrate holder, 38 ・ ・ ・ Cooling tube, 40 ・ ・ ・ Evaporation sublimation device, 41 ・ ・ ・ Material container, 42a ・ ・ ・ Organic material, 42b ・ ・ ・ Organic material, 43 ・ ・ ・ Mixing tube, 44 ・ ・ ・Gas supply device, 45 tank, 46a supply pipe, 46b supply pipe, 47 adjustment valve, 48a pressure regulator, 48b flow meter, 48c Switching valve, 49 discharge port, 50 vaporizer, 51 raw material tank, 52 raw material gas transport pipe, 53 discharge port, 54 suction port, 55 ..Discharge port, 56 ... liquid, 57 ... temperature control tank, 58 ... heating / cooling device, 59 ... exhaust pipe, 0 ... trap tank, 61 ... slot valve, 62 ... vacuum pump, 63 ... pressure gauge, 64 ... pressure gauge, 65 ... substrate holder, 66 ... shaft, 67 ・..Pinion gear, 68 ... source gas transport pipe, 69 ... exhaust pipe, 70 ... exhaust port

Claims (23)

In an organic film forming apparatus for forming an organic thin film on a substrate,
A chamber having holding means for holding the substrate,
Vaporization sublimation means for generating a raw material gas by changing an organic raw material into a gas phase,
Carrier gas introduction means for mixing the source gas and the carrier gas,
A source gas transport unit that transports the source gas into the chamber by the carrier gas, and discharges the source gas toward the substrate;
A direction control unit that is provided to face the substrate in the chamber and changes a direction in which the source gas flows toward the substrate,
An organic film forming apparatus, comprising: an exhaust unit that exhausts the chamber. 2. The organic film forming apparatus according to claim 1, wherein the direction control means changes a flowing direction of the source gas in one direction along a surface of the substrate. 2. The organic film according to claim 1, wherein the direction control unit changes a flowing direction of the source gas into one direction along a surface of the substrate and another direction orthogonal to the one direction. 3. Forming equipment. 2. The organic film forming apparatus according to claim 1, further comprising a heating unit for controlling a temperature of the direction control unit. The source gas transport means includes a source gas discharge port facing the substrate,
2. The organic film forming apparatus according to claim 1, wherein the direction control means has at least one direction control plate variably provided at the emission port. 6. The organic film forming apparatus according to claim 5, further comprising a driving unit for operating the direction control plate. 7. The organic film forming apparatus according to claim 6, wherein the driving unit operates the plurality of direction control plates in conjunction with each other in the same direction. 7. The organic film forming apparatus according to claim 6, wherein the driving unit operates the plurality of direction control plates independently in different directions. 2. The organic film forming apparatus according to claim 1, wherein said holding means includes means for cooling said substrate. 2. The organic film forming apparatus according to claim 1, further comprising a film thickness measuring means for measuring a film thickness of the organic film on the substrate held by the holding means. The source gas transport unit includes a plurality of source gas discharge ports facing the substrate, and includes the film thickness measurement unit corresponding to a supply position of the source gas from each release port on the substrate. The organic film forming apparatus according to claim 10, wherein In an organic film forming apparatus for forming an organic thin film on a substrate,
A chamber in which the substrate is stored,
Vaporization sublimation means for generating a raw material gas by changing an organic raw material into a gas phase,
Carrier gas introduction means for mixing the source gas and the carrier gas,
Source gas transport means for transporting the source gas into the chamber by the carrier gas,
In the chamber, a source gas chamber to which a source gas is supplied by the source gas transport means and a film forming chamber in which the substrate is stored are formed, and the film is formed between the source gas chamber and the film forming chamber. A differential pressure generating means for generating a differential pressure in which the pressure on the forming chamber side is reduced,
An organic film forming apparatus, comprising: an exhaust unit configured to exhaust the film forming chamber. 13. The organic film forming apparatus according to claim 12, further comprising a heating unit for controlling a temperature of the differential pressure generating unit. 13. The organic film forming apparatus according to claim 12, wherein the pressure difference generating means is a perforated plate partitioning the inside of the chamber. The organic film forming apparatus according to claim 14, wherein an exhaust port of the exhaust unit is provided at a center of the perforated plate. In an organic film forming method for forming a thin film of an organic substance on a substrate,
A vaporization sublimation process that changes the organic raw material into a gaseous raw material gas,
A carrier gas introduction step of mixing the source gas and the carrier gas,
A source gas transporting step of transporting the source gas onto the substrate by the carrier gas,
An organic film deposition step of forming an organic film on the substrate in a chamber under reduced pressure capable of controlling the flow of the source gas,
Exhausting the chamber,
In the organic film forming step, an organic film is formed while changing a flow direction of the source gas toward the substrate at least in one direction along a surface of the substrate. . 17. The organic film forming method according to claim 16, wherein the vaporization sublimation step, the carrier gas introduction step, the source gas transport step, and the organic film deposition step perform temperature control for keeping the source gas in a gas phase. 17. The method according to claim 16, wherein in the vaporization sublimation step and the carrier gas introduction step, the pressure is monitored to detect the amount of the organic raw material. 17. The method according to claim 16, wherein a flow rate of the carrier gas in the carrier gas introduction step is controlled to control an amount of the source gas transported in the source gas transport step. In an organic film forming method for forming a thin film of an organic substance on a substrate,
A vaporization sublimation process that changes the organic raw material into a gaseous raw material gas,
A carrier gas introduction step of mixing the source gas and the carrier gas,
A source gas transporting step of transporting the source gas onto the substrate by the carrier gas,
An organic film deposition step of forming an organic film on the substrate,
Having an exhaust process,
The source gas transporting step is performed between a source gas chamber that fills the source gas and a film formation chamber that houses the substrate, and reduces the pressure of the film formation chamber from the source gas chamber to reduce the pressure of the source gas. A method for forming an organic film, comprising transporting a source gas from a gas chamber to the film forming chamber. 21. The organic film forming method according to claim 20, wherein in the evacuation step, control is performed to evacuate the film forming chamber and lower the pressure from the source gas chamber. 21. The organic film forming method according to claim 20, wherein in the carrier gas introducing step, a flow rate of the carrier gas is controlled to increase a pressure of the source gas chamber from that of the film forming chamber. 21. The organic film forming method according to claim 20, wherein the vaporization sublimation step, the carrier gas introduction step, the source gas transporting step, and the organic film deposition step perform temperature control for keeping the source gas in a gas phase.

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