JP4054561B2 - Deposition method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a film forming apparatus and a film forming method used when forming an EL element on a substrate by performing sublimation purification on a film forming material and performing film formation using the purified material.
[0002]
[Prior art]
In recent years, research on a light-emitting device having an EL element as a self-luminous element has been actively conducted, and in particular, a light-emitting device using an organic material as an EL material has attracted attention. This light emitting device is also called an organic EL display (OELD) or an organic light emitting diode (OLED).
[0003]
Note that the EL element includes a layer containing an organic compound (hereinafter, referred to as an EL layer) from which luminescence generated by applying an electric field is obtained, an anode, and a cathode. Luminescence in an organic compound includes light emission (fluorescence) when returning from the singlet excited state to the ground state and light emission (phosphorescence) when returning from the triplet excited state to the ground state. The light-emitting device manufactured by the film formation method can be applied to either light emission.
[0004]
Unlike the liquid crystal display device, the light-emitting device is a self-luminous type and has a feature that there is no problem of viewing angle. That is, as a display used outdoors, it is more suitable than a liquid crystal display, and use in various forms has been proposed.
[0005]
An EL element has a structure in which an EL layer is sandwiched between a pair of electrodes, but the EL layer usually has a laminated structure. A typical example is a “hole transport layer / light emitting layer / electron transport layer” stacked structure proposed by Tang et al. Of Kodak Eastman Company. This structure has very high luminous efficiency, and most of the light emitting devices that are currently under research and development employ this structure.
[0006]
In addition, a hole injection layer / a hole transport layer / a light emitting layer / an electron transport layer, or a hole injection layer / a hole transport layer / a light emitting layer / an electron transport layer / an electron injection layer are sequentially laminated on the anode. Good structure. You may dope a fluorescent pigment | dye etc. with respect to a light emitting layer. These layers may all be formed using a low molecular weight material, or may be formed using a high molecular weight material.
[0007]
Note that in this specification, all layers provided between a cathode and an anode are collectively referred to as an EL layer. Therefore, the above-described hole injection layer, hole transport layer, light emitting layer, electron transport layer, and electron injection layer are all included in the EL layer.
[0008]
In this specification, a light-emitting element formed of a cathode, an EL layer, and an anode is referred to as an EL element. For this purpose, an EL layer is provided between two types of stripe-shaped electrodes provided so as to be orthogonal to each other. There are two types, a formation method (simple matrix method) and a method (active matrix method) in which an EL layer is formed between a pixel electrode connected to a TFT and arranged in a matrix and a counter electrode.
[0009]
The biggest problem in the practical application of EL elements is that the lifetime of the elements is insufficient. In addition, the deterioration of the element appears in the form of light emission for a long time and a non-light emitting region (dark spot) is widened. The cause is deterioration of the EL layer.
[0010]
The EL material forming the EL layer is deteriorated by impurities such as oxygen and water. In addition, it is conceivable that other impurities are included in the EL material to affect the deterioration of the EL layer.
[0011]
Conventionally, when forming a film by the vapor deposition method, the evaporation material is used as it is, but it is considered that impurities are mixed in the evaporation material at the time of vapor deposition. That is, oxygen, water, and other impurities that are one cause of deterioration of the EL element may be mixed.
[0012]
In addition, although the purity can be increased by purifying the evaporation material in advance, there is a possibility that impurities are mixed before the evaporation.
[0013]
[Problems to be solved by the invention]
The present invention has been made in view of the above problems, and by separating and removing impurities contained in an EL material at the time of film formation, film formation is performed using an EL material having a higher purity, thereby a high-purity EL layer. It is an object of the present invention to provide a film forming apparatus capable of forming the film. It is another object of the present invention to provide a film forming method using the film forming apparatus of the present invention.
[0014]
[Means for Solving the Invention]
In the present invention, by sublimation purification of an EL material immediately before film formation by using the sublimation temperature of a pure EL material, a plurality of impurities contained in the EL material can be removed, and the purified EL material A thin film is formed using an evaporation source (hereinafter referred to as a high-purity EL material).
[0015]
FIG. 1 illustrates that when an EL material containing a plurality of impurity substances is vaporized from a solid and a temperature change is applied thereto, the plurality of substances can be separated due to the difference in sublimation temperatures of the respective substances. The vertical axis represents temperature, and the horizontal axis represents total precipitation. In this specification, a substance (impurity) having a higher sublimation temperature than the high-purity EL material is referred to as a high-temperature material, and a substance (impurity) having a lower sublimation temperature is referred to as a low-temperature material. In addition, a high-purity EL material that sublimes at a temperature located between the high temperature and the low temperature is referred to as a medium temperature material. In addition, the sublimation temperature of a pure EL material can be investigated by investigating the material deposited for each temperature in advance by analysis such as mass spectrometry (GC-MS).
[0016]
First, a temperature at which all substances (high-purity EL material and impurities) contained in the EL material are vaporized (hereinafter referred to as complete sublimation temperature) is applied. Thereby, in the complete sublimation region 100, all substances contained in the EL material exist as gas. Thereafter, when the temperature is gradually lowered, a high temperature material having a high sublimation temperature is precipitated as a solid in the high temperature material precipitation region 101 of FIG.
[0017]
Further, when the temperature is lowered, an intermediate temperature material (high purity EL material) as a main product is precipitated in the intermediate temperature material precipitation region 102 of FIG. When the temperature is lowered again, the low temperature material is precipitated in the low temperature material precipitation region 103.
[0018]
In other words, the present invention utilizes the difference in precipitation temperature to separate impurities (high temperature materials) that precipitate at a higher temperature than high purity EL materials (medium temperature materials) or impurities that precipitate at a low temperature (low temperature materials) to achieve high purity. Provided are a film formation apparatus and a film formation method for performing film formation using only an EL material. Further, not only the film forming material but also the film forming apparatus itself has various functions for high purity.
[0019]
In FIG. 2, a method of forming a film by vapor deposition after sublimation purification of the EL material 200 will be described. FIG. 2 is a cross-sectional view. First, low-temperature material (impurities) is separated according to FIG. The system is provided with a temperature control mechanism, and in the system, the EL material undergoes a state change between solid and gas due to temperature, that is, a phenomenon of sublimation occurs. In the plurality of systems shown in FIG. 2, these state changes are performed. Note that a heater is included as a specific example of the temperature adjustment mechanism referred to here. The system (1) 201 is provided with an EL material 200. Further, the system (1) 201 is provided with a temperature adjustment mechanism (a) 203, and the temperature can be controlled to a complete sublimation temperature that vaporizes all the EL material. In addition, the EL material vaporized in the system (1) 201 is referred to as a gas EL material.
[0020]
The gas EL material generated in the system (1) 201 moves to the system (2) 204 provided as shown in FIG. Further, the system (2) 204 is provided with a temperature adjustment mechanism (b) 205, and the system (2) 204 can be maintained at an intermediate temperature. The system (2) 204 is connected so that all the gas generated in the system (1) 201 can move to the system (2) 204 on the lower side when viewed from the cross-sectional view of FIG. The upper portion is provided with an opening 210 that allows the gas inside the system (2) 204 to pass therethrough.
[0021]
Of the gas EL material that has moved to the system (2) 204, a substance that sublimes at a medium temperature or higher is deposited as a solid in the precipitation region (a) 211 inside the system (2) 204. In the present specification, the substance deposited here is referred to as a quasi-EL material. Note that the low-temperature material that sublimates at a temperature equal to or lower than the intermediate temperature remains as a gas, and is thus released from the opening 210 of the system (2) 204 to the outside of the system (2) 204. The low temperature material released here is an impurity contained in the EL material and is collected outside.
[0022]
Next, the system (2) 204 from which the gas has been removed is inverted 180 ° as shown in FIG. Then, the system (2) 204 is maintained at the complete sublimation temperature by the temperature adjustment mechanism (b) 205. Thereby, the quasi-EL material deposited inside the system (2) 204 is vaporized and moves to the system (3) 206.
[0023]
The system (3) 206 is provided with a temperature adjustment mechanism (c) 207. Here, the system (3) 206 is maintained at a high temperature by the temperature adjustment mechanism (c) 207. At this time, of the quasi-EL material, the high temperature material (impurities) is deposited in the region (b) 212 inside the system (3) 206. Thereby, the high temperature material (impurities) can be separated, and only the medium temperature material (high-purity EL material) can be present in the system (3) 206 as a gas.
[0024]
Further, the system (3) 206 has an opening 213 through which gas can pass in the same manner as the system (2) 204 in FIG. 2A, so that a high-purity EL material is provided outside the system (3) 206. (Gas) can be released.
[0025]
Then, by providing the substrate 208 in the direction in which the high-purity EL material (gas) is released, the high-purity EL material obtained by sublimation purification so far can be formed (evaporated).
[0026]
Note that the substrate 208 is preferably subjected to heat treatment immediately before film formation to remove impurities such as oxygen and water on the substrate 208.
[0027]
Furthermore, as materials used in the film formation chamber for performing sublimation purification and film formation of these EL materials, the adsorptivity of impurities such as oxygen and water can be reduced by reducing the surface area. Aluminum or stainless steel (SUS) or the like that has been mirror-polished by polishing is used for the inner wall surface. As a result, the degree of vacuum in the deposition chamber is 10 ^-Five -10 ^-6 Pa can be maintained. Further, a material such as ceramics that has been treated so that the pores are extremely small is used for the internal member. These preferably have surface smoothness with a center line average roughness of 30 mm or less.
[0028]
In addition, when a gas is introduced into each processing chamber in a processing chamber such as a film forming chamber or a transfer chamber included in the film forming apparatus of the present invention, oxygen or water is supplied by a gas purifier provided immediately before the processing chamber. Thus, a highly purified gas from which impurities such as are removed is introduced.
[0029]
Further, all of the processing chambers such as the film forming chamber and the transfer chamber of the film forming apparatus of the present invention are provided with a magnetic levitation type turbo molecular pump, a cryopump, or a dry pump. As a result, the ultimate degree of vacuum in each processing chamber is reduced to 10 ^-Five -10 ^-6 Pa can be set, and the back diffusion of impurities from the pump side and the exhaust system can be controlled.
[0030]
When forming an EL layer using the film forming apparatus of the present invention, surface treatment of the anode or cathode of the EL element formed on the substrate is performed before the formation.
As specific methods, there are methods such as performing heat treatment while irradiating ultraviolet light in oxygen, or performing heat treatment while performing oxygen or hydrogen plasma treatment. In addition, it is preferable that the temperature of a heating is 100 degrees C or less. It is also effective to provide a mechanism for heating the film formation chamber to 100 ° C. or lower in order to remove impurities in the film formation chamber before film formation.
[0031]
Note that the sublimation purification in the present invention can be used not only for the EL material but also for the purification of other materials such as a metal material used for vapor deposition.
[0032]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 3 shows the structure of the film forming chamber provided in the film forming apparatus of the present invention. 3A is a top view of the deposition chamber, and FIGS. 3B and 3C are cross-sectional views. In addition, a common code | symbol shall be used for a common part.
[0033]
In FIG. 3A, reference numeral 301 denotes a film formation chamber, and the substrate 302 is transferred into the film formation chamber 301. When the substrate 302 is transferred, the shutter (2) 306 is opened so that only a necessary evaporation source among the plurality of evaporation sources provided in the film formation chamber 301 can be used. The shutter (2) 306 is provided between the evaporation source and the substrate 302, and serves to block the release of evaporation material from other evaporation sources so that vapor deposition can be performed on the substrate only from the desired evaporation source. Plays. FIG. 3 shows a case where co-evaporation is performed using an evaporation source (1) 303 and an evaporation source (2) 304 among a plurality of evaporation sources.
[0034]
A specific structure will be described with reference to FIGS. 3B and 3C, which are cross-sectional structures obtained by cutting FIG. 3A along a dotted line AA ′ in a direction perpendicular to the paper surface.
[0035]
First, in FIG. 3B, among the impurities contained in the EL material before vapor deposition, the low temperature material is separated and removed. The system (1) 311 is provided with an EL material 312. Further, since the system (1) 311 is provided with a temperature adjusting mechanism (1) 313, the temperature inside the system (1) 311 can be adjusted.
[0036]
The temperature adjustment mechanism (1) 313 maintains the inside of the system (1) 311 at a temperature at which the EL material is vaporized to become a gas EL material (complete sublimation temperature). Then, the gas EL material moves from the system (1) 311 to the system (2) 314.
[0037]
Since the system (2) 314 is provided with a temperature adjustment mechanism (2) 315, the temperature inside the system (2) 314 can be adjusted.
[0038]
The temperature adjustment mechanism (2) 315 maintains the temperature (medium temperature) at which the EL material containing the medium temperature material and the high temperature material out of the gas EL material inside the system (2) 314 is precipitated as a solid. At this time, the low-temperature material remains in a gas state and is discharged from the opening 316 of the system (2) 314 to the outside of the system (2) 314. At this time, the inside of the film forming chamber is shut off from the system (1) 311 and the system (2) 314 by the shutter (1) 317 and the system (3) 318 provided in the upper part.
[0039]
Although not shown here, the low temperature material (gas) released from the opening 316 of the system (2) 314 is released to the outside of the apparatus by the exhaust system. The exhaust here is performed by a cryopump.
[0040]
When the low temperature material is removed, as shown in FIG. 3C, the shutter (1) 317 is opened and the system (2) 314 is inverted by 180 °. And it is connected with the system (3) 318.
[0041]
In the system (2) 314, there is an EL material containing the medium temperature material and the high temperature material deposited in FIG. 3B. The temperature adjustment mechanism (2) 315 causes the interior of the system (2) 314 to be completely sublimated. It can be vaporized again. Then, the vaporized EL material moves from the system (2) 314 to the system (3) 318. The system (3) 318 is provided with a temperature adjustment mechanism (3) 321, and the temperature inside the system (3) 318 is maintained at a high temperature by the temperature adjustment mechanism (3) 321. At this time, the high-temperature material contained in the vaporized EL material is precipitated in the system (3) 318 by sublimation. As described above, the gas present in the system (3) 318 is only a high-purity EL material (medium temperature material).
[0042]
Further, a shutter (2) 306 is provided above the system (3) 318 of each evaporation source so that only the shutter of the necessary evaporation source is opened. In the present embodiment, only the shutters of the evaporation source (1) 303 and the evaporation source (2) 304 are open.
[0043]
That is, when the shutter (2) 306 is opened, the EL material is released from the opening 322 of the system (3) 318 of each of the evaporation source (1) 303 and the evaporation source (2) 304, and the system (3) 318 is released. Deposition is performed on a substrate provided on top. In addition, when there are a plurality of evaporation sources, co-evaporation is performed.
[0044]
In the case where a plurality of EL materials are separately applied on the substrate, a shadow mask having an opening between the shutter (2) 306 and the substrate may be provided. As the shadow mask, a mask made of a metal plate or a glass plate can be used.
[0045]
In addition, the inner wall surfaces of these film forming chambers are usually formed of a metal material such as aluminum or stainless steel (SUS), but these materials have a problem of releasing impurities such as oxygen and water. Therefore, the surface of these metal materials is mirror-finished by electropolishing. Furthermore, it is preferable to use a material having an extremely small number of pores and a small surface area on the internal surface as a member used in the film formation chamber as compared with a normal ceramic. This is because by reducing the internal surface area, desorption characteristics of impurities such as water and oxygen are improved, and impurity contamination in the film formation chamber is prevented. These surfaces have a smoothness with a center line average roughness of 1 to 30 mm.
[0046]
Next, a case will be described in which the EL material is sublimated and purified before vapor deposition by a slightly different method from that described above.
[0047]
In FIG. 4, reference numeral 401 denotes a separation tube in which an inert gas such as nitrogen or a rare gas flows as a carrier gas. In the film forming apparatus of the present invention, those gases introduced into the apparatus are those purified by a gas purifier before being introduced into the apparatus. Therefore, it is necessary to provide a gas purifier so that the gas is introduced into the film forming apparatus after being highly purified. Thereby, oxygen, water, and other impurities contained in the gas can be removed in advance, so that these impurities can be prevented from being introduced into the apparatus.
[0048]
The material chamber 402 is provided with an EL material 403, and the material chamber 402 is provided with a heating mechanism 404 for vaporizing the EL material 403. Note that impurities such as water can be removed by heating the EL material 403 in advance before the EL material 403 is vaporized by the heating mechanism 404. Moreover, it is preferable that the heating temperature at this time is 200 degrees C or less.
[0049]
Further, although not shown here, the material chamber 402 is connected to the material exchange chamber via a gate. Note that a heater for heating the replaced EL material is provided in the material exchange chamber. Impurities such as water can be removed by heating the material in advance. The temperature applied at this time is desirably 200 ° C. or lower. Further, the material exchange chamber is provided with an exhaust pump capable of bringing the inside into a reduced pressure state. After the EL material is introduced from the outside, the inside is brought into a reduced pressure state. The gate is opened when the pressure is the same as that in the material chamber 402, and the EL material can be provided in the material chamber 402.
[0050]
The gas EL material vaporized in the material chamber 402 moves in the direction of arrow a in the separation tube 401 together with the carrier gas. The separation tube 401 is provided with a temperature adjustment mechanism 405 (specifically, a heater is included) for adjusting the temperature inside.
[0051]
The temperature adjustment mechanism 405 is set so that the temperature gradually decreases from the direction in which the gas EL material flows. Note that the temperature of the high temperature portion of the temperature adjustment mechanism 405 is adjusted to be lower than that of the heating mechanism 404.
[0052]
When the gas EL material moves inside the separation tube having a temperature control mechanism, an impurity having a higher sublimation temperature (high temperature material) or an impurity having a lower sublimation temperature than the high purity EL material (low temperature) due to the difference in sublimation temperature. Material) and high-purity EL material (medium temperature material) can be separated and deposited in different temperature ranges.
[0053]
If the temperature at which the pure EL material is deposited is measured in advance, the temperature and position can be easily adjusted. Usually, the precipitation temperature is around ± 10 ° C. from the melting point of the pure EL material. Then, a region 406 in which the separation tube 401 is provided can be separated by the gate (a) 407 and the gate (b) 408, and the temperature may be adjusted so that pure EL material is deposited in this region. The separation tube 401 is separated by the gate (a) 407 and the gate (b) 408, whereby the evaporation source separation chamber 409 can be formed.
[0054]
Although not shown here, the separation tube 401 is connected to the film formation chamber via the gate (c) 410. Therefore, the structure of the film formation chamber connected to the separation tube 401 will be described with reference to FIG.
[0055]
In FIG. 5A, the gas EL material inside the separation tube 501 is separated and precipitated by the temperature adjustment mechanism 502, and only the high-purity EL material (high-purity EL material) 509 is gated (a) 503 inside the separation tube 501. Deposited inside the evaporation source separation chamber 506 blocked by the gate (b) 504 and the gate (c) 505. The evaporation source separation chamber 506 is connected to the film formation chamber 507 through a gate (c) 505. That is, when the gate (c) 505 is opened, the high-purity EL material can be deposited in the region (a) 508.
[0056]
FIG. 5B is an enlarged view of the region (a) 508. The substrate 511 passes through the gate (d) 512 and is carried into the film formation chamber 507. The substrate 511 is vapor-deposited by being fixed on the fixing table 513 with the film formation surface facing downward.
[0057]
Here, in order to form the EL layer, a pixel electrode 514 (anode or cathode) is formed in advance on the substrate.
[0058]
【Example】
[Example 1]
The film forming apparatus of the present invention will be described with reference to FIG. In FIG. 6, reference numeral 601 denotes a transfer chamber. The transfer chamber 601 is provided with a transfer mechanism (A) 602, and the substrate 603 is transferred. The transfer chamber 601 is in a reduced-pressure atmosphere, and is connected to each processing chamber by a gate. The transfer of the substrate to each processing chamber is performed by the transfer mechanism (A) 602 when the gate is opened. In order to depressurize the transfer chamber 601, it is possible to use an exhaust pump such as a dry pump, a mechanical booster pump, a turbo molecular pump (magnetic levitation type), or a cryopump. In order to obtain, a magnetic levitation type turbo molecular pump is preferable.
[0059]
Hereinafter, each processing chamber will be described. Since the transfer chamber 601 is in a reduced pressure atmosphere, all the processing chambers directly connected to the transfer chamber 601 are provided with an exhaust pump (not shown). As the exhaust pump, the above-described dry pump, mechanical booster pump, turbo molecular pump (magnetic levitation type) or cryopump is used, and here, the magnetic levitation type turbo molecular pump is preferable.
[0060]
First, reference numeral 604 denotes a load chamber for substrate setting (installation), which also serves as an unload chamber. The load chamber 604 is connected to the transfer chamber 601 by a gate 600a, and a carrier (not shown) on which a substrate 603 is set is disposed. It should be noted that the load chamber 604 may be distinguished for substrate loading and unloading. The load chamber 604 includes the above-described exhaust pump and a purge line for introducing high-purity nitrogen gas or rare gas. As the exhaust pump, a turbo molecular pump is desirable. Further, the purge line is provided with a gas purifier, and impurities (oxygen and water) of gas introduced into the apparatus are previously removed.
[0061]
Note that in this embodiment, as the substrate 603, a substrate formed up to a transparent conductive film to be an anode of an EL element is used. In this embodiment, the substrate 603 is set on the carrier with the deposition surface facing downward. This is for facilitating the face-down method (also referred to as a deposit-up method) when a film is formed by an evaporation method later. The face-down method refers to a method in which a film is formed with the deposition surface of the substrate facing down. According to this method, adhesion of dust and the like can be suppressed.
[0062]
Reference numeral 605 denotes a processing chamber (hereinafter referred to as a preprocessing chamber) for processing the surface of the anode or cathode (anode in this embodiment) of the EL element. The preprocessing chamber 605 is a transfer chamber by a gate 600b. 601 is connected. The pretreatment chamber 605 can be variously changed depending on the manufacturing process of the EL element. In this embodiment, the surface of the anode made of the transparent conductive film can be heated at 100 to 120 ° C. while irradiating ultraviolet light in oxygen. To do. Such pretreatment is effective when the anode surface of the EL element is treated.
[0063]
As another pretreatment method, a method of heating at 200 to 400 ° C. while irradiating plasma in oxygen or hydrogen is also effective. In this case, a mechanism capable of plasma treatment and heat treatment is provided in the pretreatment chamber. You should prepare for.
[0064]
Next, reference numeral 606 denotes a film formation chamber for forming an organic EL material by vapor deposition, and is referred to as a film formation chamber (A). The film formation chamber (A) 606 is connected to the transfer chamber 601 through a gate 600c. In this embodiment, a film formation chamber having the structure shown in FIG.
[0065]
In this embodiment, a light emitting layer that develops red color is formed in a film formation portion 607 in the film formation chamber (A) 606. Therefore, the shutter above the evaporation source provided with the organic EL material that becomes the light emitting layer that emits red light among the plurality of evaporation sources provided in the film formation chamber (A) 606 is opened. In addition, a shadow mask is set to form a light emitting layer that selectively develops red color. In addition, as a light emitting layer which develops red color, Alq _Three It can be formed using a material doped with DCM. Other Eu complexes (Eu (DCM) _Three (Phen), aluminum quinolinato complex (Alq _Three ) Using DCM-1 as a dopant can be used, but other known materials can also be used.
[0066]
The film formation chamber (A) 606 is connected to the material exchange chamber 614 through a gate 600g. Note that the material exchange chamber 614 is provided with a heater for heating the exchanged material. Impurities such as water can be removed by heating the material in advance. The temperature applied at this time is desirably 200 ° C. or lower. In addition, since the material exchange chamber 614 is provided with an exhaust pump capable of reducing the inside of the material exchange chamber 614, after the evaporation material is added or exchanged from the outside and heat-treated, the inside is reduced. The gate 600g is opened when the pressure is the same as in the film formation chamber, and an evaporation material can be provided in the evaporation source in the film formation chamber. Note that the evaporation material is provided in an evaporation source in the film formation chamber by a transport mechanism or the like.
[0067]
Note that the description of FIG. 3 may be referred to for the film formation process in the film formation chamber (A) 606.
[0068]
Next, reference numeral 608 denotes a film formation chamber for forming an organic EL material by vapor deposition, and is referred to as a film formation chamber (B). The film formation chamber (B) 608 is connected to the transfer chamber 601 through a gate 600d. In this embodiment, a film formation chamber having the structure shown in FIG. 3 is provided as the film formation chamber (B) 608. In this embodiment, a green light emitting layer is formed in a film formation portion 609 in the film formation chamber (B) 608. Note that the light-emitting layer that develops a green color can be formed by co-evaporation of CBP and Ir (ppy) 3. In addition to this, an aluminum quinolinato complex (Alq _Three ), A benzoquinolinolatoberyllium complex (BeBq) can be used. Furthermore, an aluminum quinolinato complex (Alq _Three ) Using a material such as coumarin 6 or quinacridone as a dopant is also possible, but other known materials can also be used.
[0069]
The film formation chamber (B) 608 is connected to the material exchange chamber 615 through a gate 600h. Note that the material exchange chamber 615 is provided with a heater for heating the exchanged material. Impurities such as water can be removed by heating the material in advance. The temperature applied at this time is desirably 200 ° C. or lower. In addition, since the material exchange chamber 615 is provided with an exhaust pump capable of reducing the inside of the material exchange chamber 615, after the evaporation material is introduced from the outside, the inside is reduced. The gate 600h is opened when the pressure is the same as that in the film formation chamber, and an evaporation material can be provided in the evaporation source in the film formation chamber. Note that the evaporation material is provided in an evaporation source in the film formation chamber by a transport mechanism or the like.
[0070]
Note that the description of FIG. 3 may be referred to for the film formation process in the film formation chamber (B) 608.
[0071]
Next, reference numeral 610 denotes a film formation chamber for forming an organic EL material by vapor deposition, and is referred to as a film formation chamber (C). The film formation chamber (C) 610 is connected to the transfer chamber 601 through the gate 600e. In this embodiment, a film formation chamber having the structure shown in FIG. 3 is provided as the film formation chamber (C) 610. In this embodiment, a light emitting layer that develops blue color is formed in a film formation portion 611 in the film formation chamber (C) 610. In addition, as a light emitting layer which develops blue color, DPVBi which is a distyryl derivative, a zinc complex having an azomethine compound as a ligand, and DPVBi doped with perylene can be used, but other known materials are used. May be.
[0072]
The film formation chamber (C) 610 is connected to the material exchange chamber 616 through the gate 600i. Note that the material exchange chamber 616 is provided with a heater for heating the exchanged material. Impurities such as water can be removed by heating the material in advance. The temperature applied at this time is desirably 200 ° C. or lower. Further, since the material exchange chamber 616 is provided with an exhaust pump capable of bringing the inside into a reduced pressure state, the inside is put into a reduced pressure state after the evaporation material is introduced from the outside. Then, when the pressure is the same as in the film formation chamber, the gate 600i is opened, and an evaporation material can be provided in the evaporation source in the film formation chamber. Note that the evaporation material is provided in an evaporation source in the film formation chamber by a transport mechanism or the like.
[0073]
Note that the description of FIG. 3 may be referred to for the film formation process in the film formation chamber (C) 610.
[0074]
In this embodiment, the example in which the light emitting layer is directly formed on the anode or the cathode of the EL element has been described. However, the hole injection layer or the hole transport layer may be formed before the light emitting layer is formed. . In addition, copper phthalocyanine or polythiophene derivative PEDOT can be used as the hole injection layer, and MTDATA (4,4 ′, 4 ″ -tris (3-methylphenylphenylamino) triphenylamine) can be used as the hole transport layer. Or α-NPD can be used. Note that in the case of forming a layer made of a polymer material, a film formation chamber capable of spin coating may be provided instead of the film formation chamber.
[0075]
Further, after the light emitting layer is formed, an electron transport layer or an electron injection layer may be formed. Note that a material such as a 1,3,4-oxadiazole derivative or a 1,2,4-triazole derivative (TAZ) can be used for the electron transport layer. Furthermore, lithium fluoride (LiF), aluminum oxide (Al ₂ O _Three ), A layer using a material such as lithium acetylacetonate (Liacac) may be formed.
[0076]
Next, reference numeral 612 denotes a film formation chamber for forming a conductive film (a metal film to be a cathode in this embodiment) that becomes an anode or a cathode of an EL element by an evaporation method, and is called a film formation chamber (D). The film formation chamber (D) 612 is connected to the transfer chamber 601 through the gate 600f. In this embodiment, an Al—Li alloy film (an alloy film of aluminum and lithium) is formed as a conductive film to be a cathode of the EL element in the film formation portion 613 in the film formation chamber (D) 612. Note that it is also possible to co-evaporate an element belonging to Group 1 or Group 2 of the periodic table (element periodic rule) and aluminum. Co-evaporation refers to an evaporation method in which an evaporation cell is heated at the same time and different substances are mixed in a film formation stage.
[0077]
The film formation chamber (D) 612 is connected to a material exchange chamber 617 through a gate 600j. Note that the material exchange chamber 617 is provided with a heater for heating the exchanged material. Impurities such as water can be removed by heating the material in advance. The temperature applied at this time is desirably 200 ° C. or lower. In addition, since the material exchange chamber 617 is provided with an exhaust pump capable of reducing the inside of the material exchange chamber 617, after the evaporation material is introduced from the outside, the inside is reduced. Then, when the pressure is the same as in the film formation chamber, the gate 600j is opened, and an evaporation material can be provided in the evaporation source in the film formation chamber.
[0078]
Note that a film formation chamber (A) 606, a film formation chamber (B) 608, a film formation chamber (C) 610, and a film formation chamber (D) 612 include a CCD (Charge) known as an image sensor in the film formation chamber. By providing a coupled device, it is possible to accurately align the substrate and the metal mask when the film is formed using the metal mask.
[0079]
The film formation chamber (A) 606, the film formation chamber (B) 608, the film formation chamber (C) 610, and the film formation chamber (D) 612 are each provided with a mechanism for heating each film formation chamber. Thus, part of the impurities in the deposition chamber can be removed.
[0080]
Further, as an exhaust pump provided in these film forming chambers, a dry pump, a mechanical booster pump, a turbo molecular pump (magnetic levitation type), a cryopump, or the like can be used. In this embodiment, the cryopump and the dry pump are used. Is desirable.
[0081]
The deposition chamber (A) 606, the deposition chamber (B) 608, the deposition chamber (C) 610, and the deposition chamber (D) 612 are depressurized by an exhaust pump. The ultimate vacuum at this time is 10 ^-6 For example, the exhaust speed is preferably 10,000 l / s (H ₂ The surface area inside the film formation chamber is 10 m using the cryopump of O). ² When the inside of the film forming chamber is made of aluminum, the amount of leakage inside the film forming chamber is 4.1 × 10 in 20 hours. ^-7 Pa · m ^Three ・ S ^-1 Must be: In order to obtain such a degree of vacuum, it is effective to reduce the surface area of the inside of the film formation chamber by electropolishing.
[0082]
Next, reference numeral 618 denotes a sealing chamber (also referred to as a sealing chamber or a glove box), which is connected to the load chamber 604 via a gate 600k. In the sealing chamber 618, a process for finally sealing the EL element in the sealed space is performed. This treatment is a treatment for protecting the formed EL element from oxygen and moisture, and means such as mechanically encapsulating with a cover material or encapsulating with a thermosetting resin or an ultraviolet light curable resin is used.
[0083]
As the cover material, glass, ceramics, plastic, or metal can be used. However, when light is emitted to the cover material side, it must be translucent. Further, the cover material and the substrate on which the EL element is formed are bonded together using a sealing material such as a thermosetting resin or an ultraviolet light curable resin, and the resin is cured by a heat treatment or an ultraviolet light irradiation treatment to thereby form a sealed space. Form. It is also effective to provide a hygroscopic material typified by barium oxide in this sealed space.
[0084]
In addition, the space between the cover material and the substrate on which the EL element is formed can be filled with a thermosetting resin or an ultraviolet light curable resin. In this case, it is effective to add a moisture absorbing material typified by barium oxide in the thermosetting resin or the ultraviolet light curable resin.
[0085]
In the film forming apparatus shown in FIG. 6, a mechanism (hereinafter referred to as an ultraviolet light irradiation mechanism) 619 for irradiating ultraviolet light is provided inside the sealing chamber 618, and the ultraviolet light irradiation mechanism 619 emits the light. An ultraviolet light curable resin is cured by ultraviolet light. Further, the inside of the sealing chamber 618 can be decompressed by attaching an exhaust pump. In the case where the sealing step is mechanically performed by robot operation, mixing of oxygen and moisture can be prevented by performing it under reduced pressure. Specifically, it is desirable that the oxygen and water concentrations be 0.3 ppm or less. Conversely, the inside of the sealing chamber 618 can be pressurized. In this case, the pressure is increased while purging with high-purity nitrogen gas or rare gas to prevent oxygen or the like from entering from the outside air.
[0086]
Next, a delivery chamber (pass box) 620 is connected to the sealing chamber 618. A delivery mechanism (B) 621 is provided in the delivery chamber 620, and the substrate in which the EL element is completely sealed in the sealing chamber 618 is delivered to the delivery chamber 620. The delivery chamber 620 can also be decompressed by attaching an exhaust pump. The delivery chamber 620 is a facility for preventing the sealing chamber 618 from being directly exposed to the outside air, from which the substrate is taken out. In addition, it is possible to provide a member supply chamber for supplying a member used in the sealing chamber.
[0087]
Although not shown in the present embodiment, after the EL element is formed, a compound containing silicon such as silicon nitride or silicon oxide, or a DLC (Diamond Like Carbon) film containing carbon is laminated on these compounds. A film may be formed on the EL element. DLC (Diamond Like Carbon) film is a diamond bond (sp ^Three Bond) and graphite bond (SP) ² It is an amorphous film in which (bonding) is mixed. In this case, a film forming chamber provided with a CVD (chemical vapor deposition) apparatus for generating a plasma by applying a self-bias and forming a thin film by plasma discharge decomposition of the source gas may be provided.
[0088]
In a film formation chamber equipped with a CVD (chemical vapor deposition) apparatus, oxygen (O ₂ ), Hydrogen (H ₂ ), Methane (CH _Four ), Ammonia (NH _Three ), Silane (SiH) _Four ) Can be used. As the CVD apparatus, a parallel plate type electrode having an RF power source of 13.56 MHz can be used.
[0089]
Further, a film formation chamber in which a film is formed by a sputtering method (also referred to as a sputtering method) can be provided. This is because sputtering is effective in forming the anode after the EL layer is formed on the cathode of the EL element. That is, it is effective when the pixel electrode is a cathode. Note that the oxygen concentration in the formed film can be controlled by forming an atmosphere in which oxygen is added to argon in the film formation chamber at the time of film formation, so that a low-resistance film with high transmittance can be formed. it can. Further, like the other deposition chambers, it is desirable that the deposition chamber be separated from the transfer chamber by a gate.
[0090]
Further, a mechanism for controlling the temperature of the deposition substrate may be provided in the deposition chamber in which sputtering is performed. Note that the deposition substrate is preferably maintained at 20 to 150 ° C. Further, as an exhaust pump provided in the film forming chamber, a dry pump, a mechanical booster pump, a turbo molecular pump (magnetic levitation type), a cryopump, or the like can be used. In this embodiment, a turbo molecular pump (magnetic levitation) is used. Type) and dry pumps are preferred.
[0091]
As described above, by using the film formation apparatus illustrated in FIGS. 6A and 6B, it is not necessary to expose the EL element to the air until the EL element is completely enclosed in a sealed space; thus, a highly reliable light-emitting device can be manufactured. .
[0092]
A film forming apparatus having a shape different from that shown in this embodiment is shown in FIG. In addition to the load chamber and the pretreatment chamber, the deposition apparatus shown in FIG. 6 has three deposition chambers for depositing EL material, one deposition chamber for depositing metal material, a sealing chamber, and a delivery chamber. The film formation apparatus shown in FIG. 11 has a structure including a transfer chamber (1101, 1103) including a transfer mechanism (1102, 1104), a load chamber 1105, a pretreatment chamber 1106, and an EL material. A film forming chamber (A) 1107 for forming a film, a film forming chamber (B) 1108 for forming a metal material, a film forming chamber (C) 1109 for performing a sputtering process, a transfer chamber 1110, and a film forming chamber (D) 1115 for performing a CVD process. , Gates (1100a to 1100i), a sealing chamber 1111 and a delivery chamber 1112. Note that a material exchange chamber (1113, 1114) is connected to a deposition chamber (A) 1107 for depositing an EL material and a deposition chamber (B) 1108 for depositing a metal material through a gate. Alternatively, the structure may be such that it overlaps with the film formation chamber, and the sample is exchanged by pulling out the material exchange chamber (1113, 1114) when the sample is exchanged. Note that these processing chambers provided in the film formation apparatus illustrated in FIG. 11 have the functions described in this embodiment and can perform the processing described in this embodiment.
[0093]
[Example 2]
A case where the film formation apparatus of the present invention is a multi-chamber system (also referred to as a cluster tool system) will be described with reference to FIG. In FIG. 7, reference numeral 701 denotes a transfer chamber. The transfer chamber 701 is provided with a transfer mechanism (A) 702 to transfer the substrate 703. The transfer chamber 701 is in a reduced-pressure atmosphere, and is connected to each processing chamber by a gate. The transfer of the substrate to each processing chamber is performed by the transfer mechanism (A) 702 when the gate is opened. In order to depressurize the transfer chamber 701, an exhaust pump such as a dry pump, a mechanical booster pump, a turbo molecular pump (magnetic levitation type), or a cryopump can be used. In order to obtain, a magnetic levitation type turbo molecular pump is preferable.
[0094]
Hereinafter, each processing chamber will be described. Since the transfer chamber 701 is in a reduced pressure atmosphere, all the processing chambers directly connected to the transfer chamber 701 are provided with an exhaust pump (not shown). As the exhaust pump, the above-described dry pump, mechanical booster pump, turbo molecular pump or cryopump is used, and a magnetic levitation type turbo molecular pump is preferable as described above.
[0095]
Further, the gate is improved in hermeticity by using an O-ring or the like in order to make each processing chamber and transfer chamber completely sealed. In order to prevent impurity contamination in the apparatus, it is preferable to use an O-ring with less degassing.
[0096]
First, reference numeral 704 denotes a load chamber for substrate setting (installation), which is also called a load lock chamber. The load chamber 704 is connected to the transfer chamber 701 by a gate 700a, and a carrier (not shown) on which a substrate 703 is set is disposed. It should be noted that the load chamber 704 may be distinguished for substrate loading and substrate unloading. The load chamber 704 includes the above-described exhaust pump and a purge line for introducing highly purified nitrogen gas or rare gas.
[0097]
Reference numeral 705 denotes a pretreatment chamber for treating the surface of the EL element anode or cathode (in this embodiment, the anode). The pretreatment chamber 705 is connected to the transfer chamber 701 by a gate 700b. The pretreatment chamber can be variously changed depending on the manufacturing process of the EL element. In this embodiment, the surface of the anode made of the transparent conductive film can be heated at 100 to 120 ° C. while irradiating ultraviolet light in oxygen. . Such pretreatment is effective when the anode surface of the EL element is treated.
[0098]
Next, reference numeral 706 denotes a coating chamber for depositing an organic EL material by a vapor deposition method, and is called a coating chamber. Note that the coating chamber 706 is provided with a vacuum evacuation processing chamber 714 between the coating chamber 701 and the coating chamber 706 can be processed at normal pressure (atmospheric pressure).
[0099]
In Example 1, the inside of the thin film forming apparatus is all in a reduced pressure state, and EL layers such as a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer are formed under reduced pressure. However, when an EL layer is formed using a polymer material, since it is performed at normal pressure filled with an inert gas such as nitrogen or a rare gas, in order to transport the substrate to the coating chamber 706, The pressure difference between the coating chamber 706 and other film forming apparatuses must be overcome.
[0100]
Therefore, in this embodiment, first, the vacuum evacuation processing chamber 714 is depressurized to the same pressure as the transfer chamber 701, and in that state, the gate 700c is opened to transfer the substrate. After the gate 700c is closed, the inside of the evacuation processing chamber 714 is purged with an inert gas. When the pressure returns to normal pressure, the gate 700g is opened and the substrate is transferred to the coating chamber 706. Here, the entire stage may be transported together with the substrate, or may be performed by a dedicated transport means.
[0101]
In this embodiment, a case where a polymer material is formed as the hole injection layer will be described. As the polymer material used here, PEDOT (polyethylenedioxy thiophene) which is a polythiophene derivative is preferable, but other known polymer EL materials can be used.
[0102]
Then, a hole injection layer is formed in the coating chamber 706 by spin coating. Note that the coating chamber 706 may include a heating mechanism and a function of performing drying after coating.
[0103]
When the formation of the hole injection layer is completed as described above, the gate 700g is opened, the substrate is transferred to the processing chamber 714 for evacuation, and evacuation is performed with the gate 700g and the gate 700c closed. When the vacuum evacuation processing chamber 714 reaches the same decompressed state as the transfer chamber 701, the gate 700c is opened and the substrate is transferred to the transfer chamber 701.
[0104]
Next, reference numeral 708 denotes a film formation chamber for forming an organic EL material by vapor deposition, and is referred to as a film formation chamber (A). The film formation chamber (A) 708 is connected to the transfer chamber 701 through a gate 700d. In this embodiment, a film formation chamber having the structure shown in FIG. 5 is provided as the film formation chamber (A) 708. In this embodiment, in the film formation portion 709 in the film formation chamber (A) 708, red, green and blue light emitting layers are formed. As the light emitting layer that develops red, green, and blue colors, a known material may be used in addition to the materials described in the first embodiment. In addition, these materials are provided in different evaporation sources, and film formation is performed at a desired position using a shadow mask for each color.
[0105]
Further, the plurality of evaporation materials provided in the film formation chamber (A) 708 are sublimated and purified by the separation tube 715 and then deposited. Further, these evaporation materials are added or exchanged in a material exchange chamber 716 connected to the separation pipe 715 via the gate 700h. Note that the material exchange chamber 716 is provided with a heater for heating the exchanged material. Impurities such as water can be removed by heating the material in advance. The temperature applied at this time is desirably 200 ° C. or lower. In addition, since the material exchange chamber 716 is provided with an exhaust pump capable of reducing the inside of the material exchange chamber 716, the inside of the material exchange chamber 716 is reduced in pressure after the evaporation material is introduced from the outside. Then, when the pressure is the same as that in the film formation chamber, the gate 700h is opened, and an evaporation material can be provided in the evaporation source in the film formation chamber.
[0106]
Next, reference numeral 710 denotes a film formation chamber for forming an organic EL material by vapor deposition, and is referred to as a film formation chamber (B). The film formation chamber (B) 710 is connected to the transfer chamber 701 through a gate 700e. In this embodiment, a film formation chamber having the structure shown in FIG. 5 is provided as the film formation chamber (B) 710. In this embodiment, an electron transport layer or an electron injection layer is formed in the film formation portion 711 in the film formation chamber (B) 710. A known material may be used for the electron transport layer or the electron injection layer.
[0107]
Further, the plurality of evaporation materials provided in the film formation chamber (B) 710 are sublimated and purified by the separation tube 717 and then deposited. Further, these evaporation materials are added or exchanged in a material exchange chamber 718 connected to the separation pipe 717 via the gate 700i. Note that the material exchange chamber 718 is provided with a heater for heating the exchanged material. Impurities such as water can be removed by heating the material in advance. The temperature applied at this time is desirably 200 ° C. or lower. Further, since the material exchange chamber 718 is provided with an exhaust pump capable of bringing the inside into a reduced pressure state, the inside is put into a reduced pressure state after the evaporation material is introduced from the outside. Then, when the pressure is the same as in the film formation chamber, the gate 700i is opened, and an evaporation material can be provided in the evaporation source in the film formation chamber.
[0108]
Next, reference numeral 712 denotes a film formation chamber for forming a conductive film (a metal film to be a cathode in this embodiment) that becomes an anode or a cathode of an EL element by an evaporation method, and is called a film formation chamber (C). The film formation chamber (C) 712 is connected to the transfer chamber 701 through a gate 700f. In this embodiment, a film formation chamber having the structure shown in FIG. 5 is provided as the film formation chamber (C) 712. In this embodiment, an Al—Li alloy film (an alloy film of aluminum and lithium) is formed as a conductive film to be a cathode of an EL element in a film formation portion 713 in the film formation chamber (C) 712. Note that it is possible to co-evaporate an element belonging to Group 1 or Group 2 of the periodic table and aluminum.
[0109]
Further, the plurality of evaporation materials provided in the film formation chamber (C) 712 are sublimated and purified by the separation tube 719 and then deposited. These evaporating materials are added or exchanged in a material exchange chamber 720 connected to the separation pipe 719 via the gate 700j. Note that the material exchange chamber 720 is provided with a heater for heating the exchanged material. Impurities such as water can be removed by heating the material in advance. The temperature applied at this time is desirably 200 ° C. or lower. Further, since the material exchange chamber 720 is provided with an exhaust pump capable of bringing the inside into a reduced pressure state, the inside is put into a reduced pressure state after the evaporation material is introduced from the outside. Then, when the pressure is the same as in the film formation chamber, the gate 700j is opened, and an evaporation material can be provided in the evaporation source in the film formation chamber.
[0110]
Next, reference numeral 721 denotes a sealing chamber, which is connected to the load chamber 704 through a gate 700k. The description of the sealing chamber 721 may refer to the first embodiment. As in the first embodiment, an ultraviolet light irradiation mechanism 722 is provided inside the sealing chamber 721. Further, a delivery chamber 723 is connected to the sealing chamber 721. A delivery mechanism (B) 724 is provided in the delivery chamber 723, and the substrate in which the EL element is sealed in the sealing chamber 721 is delivered to the delivery chamber 723. The description of the delivery chamber 723 may also refer to the first embodiment.
[0111]
As described above, by using the film formation apparatus illustrated in FIG. 7, it is not necessary to expose to the outside air until the EL element is completely enclosed in a sealed space, so that a highly reliable EL display device can be manufactured. Become. Note that the configuration of this embodiment can be implemented in combination with any of the configurations shown in Embodiment 1.
[0112]
Example 3
A case where the film forming apparatus of the present invention is an in-line method will be described with reference to FIG. In FIG. 8, reference numeral 801 denotes a load chamber from which the substrate is transferred. The load chamber 801 is provided with an exhaust system 800a, and the exhaust system 800a includes a first valve 81, a turbo molecular pump 82, a second valve 83, a third valve 84, and a dry pump 85.
[0113]
Also, in this embodiment, as a material used in each processing chamber such as a load chamber, a preprocessing chamber, a film forming chamber, a sealing chamber, and an unloading chamber blocked by a gate, the surface area can be reduced. Since the adsorptivity of impurities such as oxygen and water can be reduced, materials such as aluminum and stainless steel (SUS) that are mirror-polished by electrolytic polishing are used for the inner wall surface, and the pores are extremely reduced. An internal member made of a processed material such as ceramics is used. These materials have surface smoothness with a center average roughness of 30 mm or less.
[0114]
The first valve 81 is a main valve having a gate valve, but a butterfly valve may also be used as a conductance valve. The second valve 83 and the third valve 84 are fore valves. First, the second valve 83 is opened, the load chamber 801 is roughly decompressed by the dry pump 84, and then the first valve 81 and the third valve 84 are opened to make a turbo. The load chamber 801 is depressurized to a high vacuum by the molecular pump 82. A mechanical booster pump may be used instead of the turbo molecular pump, or the turbo molecular pump may be used after increasing the degree of vacuum with the mechanical booster pump.
[0115]
Reference numeral 802 denotes a pretreatment chamber for treating the surface of the anode or cathode (an anode in this embodiment) of the EL element, and the pretreatment chamber 802 includes an exhaust system 800b. The load chamber 801 is hermetically shut off by a gate (not shown). The pretreatment chamber 802 can be variously changed depending on the manufacturing process of the EL element. In this embodiment, the surface of the anode made of the transparent conductive film can be heated at 100 to 120 ° C. while being irradiated with ultraviolet light in oxygen. To do. In addition, a method of performing heat treatment at 200 to 400 ° C. while plasma irradiation in oxygen or hydrogen may be used.
[0116]
Next, reference numeral 803 denotes a film formation chamber for forming an organic EL material by vapor deposition, and is referred to as a film formation chamber (A). The film formation chamber (A) 803 is provided with an exhaust system 800c. The pretreatment chamber 802 is hermetically sealed with a gate (not shown). In this embodiment, a film formation chamber having the structure shown in FIG. 3 is provided as the film formation chamber (A) 803.
[0117]
The substrate 804 transferred to the film formation chamber (A) 803 is an evaporation source (in this embodiment, an evaporation source (a)) whose shutter is opened among the plurality of evaporation sources 805 provided in the film formation chamber (A) 803. 805) is used for film formation. Note that the detailed operation of the film formation chamber (A) 803 may be referred to the description of FIG. In this embodiment, in the film formation chamber (A) 803, a hole injection layer, a hole transport layer, or both a hole injection layer and a hole transport layer are formed. A known material may be used as a material for forming the hole injection layer and the hole transport layer.
[0118]
Next, reference numeral 806 denotes a film formation chamber for forming an organic EL material by vapor deposition, and is referred to as a film formation chamber (B). The film formation chamber (B) 806 includes an exhaust system 800d. The film formation chamber (A) 803 is hermetically shut off by a gate (not shown). In this embodiment, a film formation chamber having the structure shown in FIG. 3 is provided as the film formation chamber (B) 806. Accordingly, the detailed operation of the film formation chamber (B) 806 may be referred to the description of FIG. In this embodiment, a light emitting layer that develops red color is formed in the film formation chamber (B) 806. A known material may be used for the light emitting layer that develops red color.
[0119]
Next, reference numeral 807 denotes a film formation chamber for forming an organic EL material by vapor deposition, and is referred to as a film formation chamber (C). The film formation chamber (C) 807 includes an exhaust system 800e. The film formation chamber (B) 806 is hermetically shut off by a gate (not shown). In this embodiment, a film formation chamber having the structure shown in FIG. 3 is provided as the film formation chamber (C) 807. Therefore, the detailed operation of the film formation chamber (C) 807 may be referred to the description of FIG. In this embodiment, a light emitting layer that emits green light is formed in the film formation chamber (C) 807. A known material may be used for the light emitting layer that develops a green color.
[0120]
Next, reference numeral 808 denotes a film formation chamber for forming an organic EL material by vapor deposition, and is referred to as a film formation chamber (D). The film formation chamber (D) 808 includes an exhaust system 800f. The film formation chamber (C) 807 is hermetically sealed with a gate (not shown). In this embodiment, a film formation chamber having the structure shown in FIG. 3 is provided as the film formation chamber (D) 808. Accordingly, the detailed operation of the film formation chamber (D) 808 may be referred to the description of FIG. In this embodiment, a light emitting layer that develops blue color is formed in the film formation chamber (D) 808. A known material may be used for the light emitting layer that develops a blue color.
[0121]
Next, reference numeral 809 denotes a film formation chamber for forming an organic EL material by vapor deposition, and is referred to as a film formation chamber (E). The film formation chamber (E) 809 includes an exhaust system 800 g. The film formation chamber (D) 808 is hermetically shut off by a gate (not shown). In this embodiment, a film formation chamber having the structure shown in FIG. 3 is provided as the film formation chamber (E) 809. Accordingly, the detailed operation of the film formation chamber (E) 809 may be referred to the description of FIG. In this embodiment, an electron transport layer or an electron injection layer is formed in the film formation chamber (E) 809. Note that a known material may be used as a material for forming the electron transport layer or the electron injection layer.
[0122]
Next, reference numeral 810 denotes a film formation chamber for forming a conductive film (a metal film to be a cathode in this embodiment) which becomes an anode or a cathode of an EL element by an evaporation method, and is called a film formation chamber (F). The film formation chamber (F) 810 includes an exhaust system 800h. The film formation chamber (E) 809 is hermetically sealed with a gate (not shown). In this embodiment, a film formation chamber having the structure shown in FIG. 3 is provided as the film formation chamber (F) 810. Therefore, the detailed operation of the film formation chamber (F) 810 may be referred to the description of FIG.
[0123]
In this embodiment, in the film formation chamber (F) 810, an Al—Li alloy film (an alloy film of aluminum and lithium) is formed as a conductive film to be a cathode of the EL element. Note that it is possible to co-evaporate an element belonging to Group 1 or Group 2 of the periodic table and aluminum.
[0124]
Here, a CVD chamber may be provided in the same manner as described in the first embodiment, and an insulating film such as a silicon nitride film, a silicon oxide film, and a DLC film may be formed as a protective film (passivation film) for the EL element. Good.
[0125]
In the case where a CVD chamber is provided, a gas purifier for purifying a material gas used in the CVD chamber in advance is preferably provided.
[0126]
Next, reference numeral 811 denotes a sealing chamber, which includes an exhaust system 800i. The film formation chamber (F) 810 is hermetically sealed by a gate (not shown). The description of the sealing chamber 811 may refer to the first embodiment. Further, as in the first embodiment, an ultraviolet light irradiation mechanism (not shown) is provided inside the sealing chamber 811.
[0127]
Finally, reference numeral 812 denotes an unload chamber, which includes an exhaust system 800j. The substrate on which the EL element is formed is taken out from here.
[0128]
As described above, by using the film formation apparatus illustrated in FIG. 8, it is not necessary to expose the EL element to the outside until the EL element is completely enclosed in a sealed space; thus, a highly reliable light-emitting device can be manufactured. . In addition, a light-emitting device can be manufactured with high throughput by an in-line method. Note that the configuration of this embodiment can be implemented in combination with any of the configurations shown in Embodiment 1.
[0129]
Example 4
In this embodiment, a light-emitting device that has been processed up to a sealing (or sealing) process for protecting an EL element using the film formation apparatus of the present invention is shown. A method for preventing this will also be described.
[0130]
FIG. 9A is a cross-sectional view of the state where the EL element is sealed. A pixel portion 901 and a driving circuit 902 are formed above the glass substrate 900. The pixel portion 901 is formed by a plurality of pixels including a current control TFT 903 and a pixel electrode 904 electrically connected to the drain thereof. . The driver circuit 902 is formed using a CMOS circuit in which an n-channel transistor 905 and a p-channel transistor 906 are combined. Note that on the glass substrate 900, as a protective film, a silicon-containing compound such as silicon nitride, silicon oxide, or silicon oxynitride, or a carbon film (specifically, a diamond-like carbon film) 916 is provided to a thickness of 2 to 30 nm. good. Thereby, intrusion of impurities from the substrate side can be prevented.
[0131]
The pixel electrode 904 functions as an anode of the EL element. In addition, banks 907 are formed at both ends of the pixel electrode 904, and an EL layer 908 and an EL element cathode 909 are formed on the pixel electrode 904. The cathode 909 also functions as a wiring common to all pixels, and is electrically connected to an FPC (flexible printed circuit) 911 via a connection wiring 910. Although only the FPC is shown here, a printed wiring board (PWB) may be attached to the FPC. Further, all elements included in the pixel portion 901 and the driver circuit 902 are covered with a passivation film 912.
[0132]
Note that treatment performed in a portion 917 in order to prevent impurities such as oxygen and water from entering the EL element will be described with reference to FIGS. 9B and 9C.
[0133]
In FIG. 9B, reference numerals 91a and 91b denote interlayer insulating films, and 91a is formed of an organic resin film such as polyimide or polyamide, and an insulating film such as a silicon nitride film, a silicon oxide film, or a DLC film is formed thereon. A film is formed. Then, a connection wiring 93 from the pixel electrode 92 and the current control TFT is formed, and a bank 94 is formed so as to fill a gap between the pixel electrodes.
[0134]
At this time, the bank 94 is formed of an organic resin film such as polyimide or polyamide. Therefore, in this embodiment, the surface of the bank 94 is densified by performing plasma treatment in a rare gas such as Ar. Thereby, impurities contained in the bank surface can be removed and impurities can be prevented from entering from the outside.
[0135]
9C is the same as FIG. 9B until the bank 94 is formed, but a passivation film 95 such as a silicon nitride film, a silicon oxide film, and a DLC film is formed on the bank 94 with a film thickness of 2 to 30 nm. Form with thickness. In this case, since the bank 94 is completely sealed by the passivation film 95, impurities such as oxygen and water contained in the bank 94 are not released to the outside, and the EL element deteriorates. Can be prevented.
[0136]
Next, as illustrated in FIG. 9A, a cover material 914 is bonded with a seal material 913. Note that a spacer may be provided in order to ensure a space between the cover material 914 and the EL element. A gap 915 is formed inside the sealing material 913. Note that the sealant 913 is preferably a material that does not transmit moisture or oxygen. Furthermore, it is effective to provide a substance having a hygroscopic effect or a substance having an antioxidant effect inside the gap 915.
[0137]
Note that carbon films (specifically, diamond-like carbon films) 916a and 916b may be provided on the front and back surfaces of the cover material 914 in thicknesses of 2 to 30 nm as protective films. Such a carbon film has a role of preventing oxygen and water from entering and mechanically protecting the surface of the cover material 914.
[0138]
By encapsulating the EL element with the structure as described above, the EL element can be completely shut off from the outside, and a substance that promotes deterioration due to oxidation of the EL layer such as moisture and oxygen can be prevented from entering from the outside. Can do. Therefore, a highly reliable light emitting device can be obtained. In addition, the structure of a present Example can be implemented in combination freely with any structure shown in Example 1-3.
[0139]
Example 5
In this embodiment, a metal mask used for film formation in order to realize colorization of an EL layer by using the film formation apparatus of the present invention will be described with reference to FIG.
[0140]
FIG. 10A is a top view of the metal mask. Reference numeral 1001 denotes a mask portion of a metal mask, which serves to cover a portion where no film is formed.
[0141]
A plurality 1002 formed in 1001 is an opening a, and the EL material that has passed through the opening a1002 during vapor deposition is formed on the substrate.
[0142]
In this embodiment, the metal mask shown in FIG. 10A is formed by depositing an EL material in one color and then moving it in the direction of the arrow x to deposit different colors on adjacent pixels. By repeating this, it is possible to form a multi-color EL material.
[0143]
In addition, regarding the shape of the opening a1002 of the metal mask, the distance (p) between the openings a adjacent in the horizontal direction (direction in which different color pixel columns are formed) is preferably 10 to 200 μm, and the vertical direction (same color) The distance (q) between the openings a1002 adjacent in the direction in which the pixel columns are formed is preferably 10 to 40 μm. Further, the short side (r) of the opening a1002 is preferably 20 to 200 μm.
[0144]
Note that the mask portion 1001 of the metal mask is formed from a mask member having a two-layer structure, but a metal mask having higher strength is formed by attaching the mask portion 1001 to the mask frame 1003 to form a three-layer structure. be able to. A cross-sectional view taken along line AA ′ of FIG. 10A is shown in FIG. Note that a member such as hollow aluminum or alumina can be used for the mask frame 1003 used in this embodiment. Moreover, it is preferable that a film thickness is 1-15 mm. Further, the mask frame 1003 is provided with an opening b1011 slightly smaller than the metal mask (the first mask 1001a and the second mask 1001b), and the mask part 1001 is overlapped with the opening b1011 so that a part thereof overlaps. A metal mask can be completed by bonding to the mask frame 1003.
[0145]
Next, a method for forming a metal mask will be described with reference to FIG. However, although the metal mask formed in FIG. 10C has a part of the structure different from that shown in FIG. 10B, either structure of the metal mask is used in the present invention. Can do.
[0146]
First, the first mask layer 1101a is formed. 1101a is preferably formed of a metal material such as iron, copper, nickel, cobalt, aluminum, silver, tantalum, or tungsten, or an alloy made of these metals and a material that can be attracted to a magnet such as stainless steel (SUS316). Note that the thickness of the first mask layer 1101a formed here is preferably 50 to 200 μm.
[0147]
Next, a second mask layer 1101b is stacked on the first mask layer 1101a. The second mask layer 1101b at this time may be formed using a known film formation method such as an evaporation method, a sputtering method, or a CVD method. Note that the thickness of the second mask layer 1101b formed here is preferably 0.5 to 20 μm. In addition, the second mask layer 1101b formed here must be made of a material that has a sufficient etching selectivity when etching is performed simultaneously using the same etching solution as the first mask layer 1101a. Don't be.
[0148]
Note that the thickness ratio of the second mask layer 1101b to the first mask layer 1101a is preferably 0.1 to 0.01. Further, the ratio of the etching rate of the material forming the second mask layer 1101b to the etching rate of the material forming the first mask layer 1101a when using the same etching solution is such that the film thickness ratio of the two is 0. If it is 01 or less, it is preferably 0.001 or less.
[0149]
In this manner, the metal mask in which the first mask layer 1101a and the second mask layer 1101b are stacked is etched at a time after covering both surfaces with a resist material (1004a and 1004b), so that FIG. ) 1201a and 1201b can be formed. Although the case where the metal mask is formed using two kinds of materials has been described here, the metal mask can be formed by etching using one kind of material.
[0150]
After forming the metal masks (1201a, 1201b), the resists (1004a, 1004b) are removed and bonded to the mask frame 1003, whereby a metal mask with higher strength can be formed. Further, by using the mask frame 1003, a large-sized metal mask such as 400 × 500 mm or 620 × 720 mm can be formed.
[0151]
Next, a partial cross section of a method for forming a film by using the metal mask formed in FIG. 10C on a substrate having a TFT (not shown) in which the pixel electrode 1006, the wiring 1007, and the bank 1008 are formed. This will be described with reference to FIG. At this time, by providing the magnet 1009 on the opposite side of the metal mask of the substrate, the first mask 1201a is attracted by magnetic force, so the distance (s) between the substrate and the metal mask is reduced (s ≧ 0), The adhesion between the substrate and the metal mask can be further improved. As described above, it is possible to prevent a defect in a pattern to be manufactured due to bending, floating, or misalignment of the metal mask, and it is possible to deposit the EL material with high accuracy.
[0152]
In addition, the configuration of this embodiment can be implemented by freely combining with any of the configurations of Embodiments 1 to 4.
[0153]
【The invention's effect】
By using the film forming apparatus of the present invention, it is possible to form a thin film using a material that has been further sublimated and purified, and further, the film forming apparatus is provided with a function to prevent impurity contamination so that it is not affected by impurities during film formation. Can be formed. As described above, the element characteristics of the EL element can be improved more than ever.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of the present invention.
FIG. 2 is a diagram showing a configuration of the present invention.
FIG. 3 shows a structure of a film formation chamber.
FIG. 4 shows a structure of a film formation chamber.
FIG. 5 is a diagram showing a structure of a vapor deposition chamber.
FIG. 6 shows a structure of a film forming apparatus.
FIG. 7 shows a structure of a film forming apparatus.
FIG. 8 shows a structure of a film forming apparatus.
FIG 9 illustrates a cross-sectional structure of a light-emitting device.
10A and 10B illustrate a metal mask.
FIG. 11 shows a structure of a film forming apparatus.

Claims (5)

The system 1 is controlled to the first temperature by the first temperature adjusting mechanism, and the evaporation material provided in the system 1 is vaporized.
The vaporized evaporation material is moved to a system 2 connected to the system 1 and provided with an opening, and the system 2 is brought to a second temperature lower than the first temperature by a second temperature adjusting mechanism. Controlling and separating the vaporized evaporation material into a first gas and a first solid state;
Removing the first gas from the opening of the system 2;
Invert the system 2 and connect with the system 3 provided with an opening,
The system 2 is controlled to the first temperature by the second temperature adjusting mechanism, and after the first solid is vaporized, moved to the system 3;
The system 3 is controlled to a third temperature lower than the first temperature and higher than the second temperature by a third temperature adjustment mechanism, and the vaporized first solid is mixed with the second gas and the second temperature. Separated into two solid states,
A film forming method comprising forming a film on a substrate using the second gas released from the opening of the system 3. The system 1 is controlled to the first temperature by the first temperature adjusting mechanism, and the evaporation material provided in the system 1 is vaporized.
The vaporized evaporation material is moved to a system 2 connected to the system 1 and provided with an opening, and the system 2 is brought to a second temperature lower than the first temperature by a second temperature adjusting mechanism. Controlling and separating the vaporized evaporation material into a first gas and a first solid state;
Removing the first gas from the opening of the system 2;
Open the first shutter provided at the top of the system 2 to connect the system 2 to the system 3,
The system 2 is controlled to the first temperature by the second temperature adjusting mechanism, and after the first solid is vaporized, moved to the system 3;
The system 3 is controlled to a third temperature lower than the first temperature and higher than the second temperature by a third temperature adjusting mechanism, and the vaporized first solid is added to the second gas and the second temperature. Separated into a solid state,
A film forming method comprising: opening a second shutter provided on an upper part of the system 3 to form a film on a substrate using the second gas released from an opening of the system 3.   3. The film forming method according to claim 1, wherein in the system 1, the system 2, and the system 3, a state change between solid and gas of the evaporation material is performed. In any one of claims 1 to 3, the film forming method, wherein the evaporating material is an EL material. In any one of claims 1 to 4, the film formation method of wherein said evaporation material is a metal material.

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