US20120312698A1

US20120312698A1 - Method for initializing or removing contaminants from a deposition chamber and method of manufacturing the chamber

Info

Publication number: US20120312698A1
Application number: US13/355,786
Authority: US
Inventors: Jong-Woo Lee; Young-Soo Cho
Original assignee: Samsung Mobile Display Co Ltd
Current assignee: Samsung Display Co Ltd
Priority date: 2011-06-13
Filing date: 2012-01-23
Publication date: 2012-12-13
Also published as: KR20120137650A

Abstract

The present disclosure relates to a method for initializing a deposition chamber, a method for removing contaminants in a deposition chamber, and a method of manufacturing a deposition chamber. In the method for initializing a deposition chamber, light is irradiated in the chamber, and then minute contaminants remaining in the chamber are removed. The newly manufactured chamber is thereby initialized so that it can be used for deposition.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Korean Patent Application No. 10-2011-0056620, filed on Jun. 13, 2011 with the Korean Intellectual Property Office, which is hereby incorporated by reference in its entirety herein.

BACKGROUND

1. Field
The present disclosure relates generally to the field of deposition chambers, and more particularly to a method for initializing a deposition chamber, a method for removing contaminants in the chamber and a method of manufacturing the chamber from which the contaminants therein have been removed.
2. Description of the Related Technology
As a method for forming an electrode, a deposition method is applied to a light emitting layer, or the like, on a substrate of a display device. In the manufacture of an Organic Light Emitting Device (OLED), which is a type of display device, a Chemical Vapor Deposition (CVD) method is used as a method for depositing an organic material to the substrate. In the CVD method, a chemical source (or precursor) material is converted to a gaseous state, so that the gaseous chemical source material can reach a predetermined location of a substrate. Then, it chemically reacts and forms a deposition layer on the substrate.
In the deposition process as described above, the deposition is mainly performed in a closed chamber in order to prevent contaminants and the like from being introduced into the deposition layer. The chamber used for the deposition is called a deposition chamber. For deposition efficiency, contamination prevention and the like, it is usual that the deposition is performed after a vacuum state having a pressure of several mTorr is formed in the chamber.
A clean state must always be maintained in the deposition chamber. This is because when contaminants such as reaction residues or impurities, which may have been introduced from the outside, exist in the chamber, these contaminants contaminate the deposition layer. The contaminants may cause poor quality of the deposition, and the poor quality of the deposition may lead to poor quality of products. Particularly, following the recent trend where displays are becoming larger and thus circuits in the displays are becoming highly integrated, the deposition layer must also be formed minutely and precisely. In order to form such a minute and precise deposition layer, it is very important to maintain a clean state in the chamber in which the deposition process proceeds.
In order to use a newly manufactured chamber for deposition, it is also necessary to remove contaminants in the chamber. When a chamber has been newly manufactured by machining and mechanical assembling, not only assembling by-products but also minute contaminants invisible to the human eye exist in the chamber. Therefore, only after these contaminants are all removed, can the chamber be used for deposition. The process which enables the use of the newly manufactured chamber for deposition is called the initialization of a chamber. The initialization of the chamber is performed once or continuously until the chamber is set up in a production line for manufacturing products after the chamber is manufactured.
After the chamber is manufactured, a cleaning process for removing contaminants in the chamber is important in the process of initializing the chamber so that the chamber can be used for deposition.
The process for cleaning the deposition chamber typically includes using an electrolyte, using water, and drying. Nevertheless, residues, which are not removed even by the cleaning as described above, exist in the chamber. Namely, although the electrolytic cleaning and the cleaning using water are performed, residues such as moisture, oxygen, and other chemical materials exist in the chamber. The above residues can contaminate the deposition layer even with a very small amount of existence, and thus often cause the efficiency degradation or poor quality of a deposited product. With the efficiency degradation or poor quality in a display device, there is degradation of light emitting efficiency, a rapid increase in a brightness reduction rate, etc.
A newly manufactured chamber has, as important contaminants, a contamination source at the time of manufacture of the chamber and residues after cleaning the chamber. Therefore, before a chamber, which has been newly manufactured, is used for deposition, it is necessary to remove the contaminants in the chamber as much as possible.
Various cleaning processes obtained by improving a simple cleaning method using water are applied to the removal of the residual contaminants in the chamber as described above. The various cleaning processes include methods such as pure water shower using distilled water, high-pressure cleaning using water gushing under high pressure, chemical cleaning using detergent, etc.
A very small amount of contaminants still exist in the chamber even after the above cleaning. A very small amount of the contaminants often exist especially at an inner wall of the chamber, a connection portion between structures in the chamber, etc. Therefore, it is not easy to remove them. Even the existence of a very small amount of the contaminants as described above causes contamination of a deposition layer in a subsequent deposition process. Therefore, the contaminants must be all removed from the chamber.
As an example of a deposition chamber, FIG. 1 shows a partly cut-out perspective view illustrating an internal structure of a chamber 700, which is configured in such a manner that a substrate is erected and then deposition is performed on the substrate.
As illustrated in FIG. 1, internal structures such as a substrate support portion 300, a substrate fixing portion 400, a mask fixing portion 500, a deposition source holder 600, or the like, are installed in the chamber 700. A very small amount of residual contaminants existing in the chamber may remain at an edge, a connection portion or the like of each internal structure. Also, they may exist on an inner wall 710 of the chamber.
FIG. 2 is an enlarged view of the inner wall 710 of the chamber 700. The inner wall of the chamber is often made of stainless steel (i.e. SUS) material. Although the stainless steel is processed by micromachining, a minute crack or an uneven surface may be generated on the surface of the processed stainless steel. A very small amount of contaminants 810 may remain in the minute crack or on the uneven surface existing on the inner wall 710 of the chamber.
The conventional cleaning process cannot remove a very small amount of the contaminants as described above. When deposition is performed by using the chamber which has been subjected to only the conventional cleaning process, the residual contaminants in the chamber are not properly removed and thus a problem of poor quality in the deposited products occurs for the first few days, weeks or months of using newly manufactured chamber.
In order to remove a very small amount of the contaminants existing in the chamber, a method of applying ultrasonic waves to the chamber may be considered. However, the size of the deposition chamber is so large that it may be difficult to clean the deposition chamber by applying ultrasonic waves to the chamber.
An outgassing method may be used to convert the contaminant to a gaseous state and then discharge the gaseous contaminant, by heating a wall of the chamber with a linear heater introduced to the chamber. Such an outgassing method is also called a “high temperature baking process.” In the high temperature baking process, the gas generated in the chamber is continuously discharged by operating a vacuum pump while heating the chamber with the linear heater, and thus contaminants are removed.
Since various elements such as a door, a substrate arrangement means, a mask arrangement means, deposition source holder, etc., exist in the chamber, there is a limit on the location at which the heater can be arranged, so that a dense arrangement of the heater is limited. Therefore, the heater is partially arranged in the chamber, and then the entire inside of the chamber is forced to be heated by thermal conduction through material of the chamber. However, when the inside of the chamber is forced to be heated by the thermal conduction through the material of the chamber, it is difficult to uniformly heat the inside of the chamber. Moreover, while the temperature of the inner wall of the chamber rises, the temperatures of other precision instrument portions unnecessarily also rise, so that the precision instrument portions may be damaged. Therefore, the high temperature baking process of heating the inside of the chamber by using the heater has a limited temperature rise in the chamber, and also has a limit because the inside of the chamber cannot be selectively heated.
The high temperature baking process using the heater also has poor contaminant removal efficiency. Therefore, although deposition is performed by using a chamber which has been subjected to the high temperature baking process for several days, it is impossible to prevent the occurrence of poor quality of deposited products at an early stage of the deposition. In this regard, in order to remove the contaminants in the chamber up to a satisfactory level and to thus prevent a deposition layer from being damaged by the contaminants, the high temperature baking process must be performed for dozens of days to several months. Only when deposition is performed after gas generated in the chamber is continuously discharged out of the chamber by operating a vacuum pump while heating the chamber by using the heater for dozens of days to several months, it is possible to obtain a product having a deposition layer which has not been damaged by the contaminants. However, when deposition is performed by using a chamber which has not been subjected to the high temperature baking process for several months, it is impossible to prevent the occurrence of quality degradation of products manufactured at an early stage of using the chamber. In other words, the high temperature baking process has such a poor cleaning efficiency that the chamber must be subjected to an initialization process for as long a period of time as several months in order to obtain a satisfactory deposition layer.
In the conventional cleaning processes described above, it is not easy to remove contaminants, particularly, minute residues, existing in a newly manufactured chamber to a negligible level, and also, a long period of time may be required to remove them. Moreover, when deposition is performed by using a chamber which has been subjected to only the conventional cleaning process, it is impossible to prevent the occurrence of poor quality of deposited products manufactured at an early stage of the deposition chamber.

SUMMARY OF CERTAIN INVENTIVE ASPECTS

Accordingly, embodiments of the present invention aim to solve the above-mentioned problems, and provide a method for initializing or removing contaminants from a deposition chamber, by which an excellent effect can be obtained in a simple manner whereas a large amount of time is not required.
Further, embodiments of the present invention provide a method of manufacturing a chamber for depositing an organic material, from which the contaminants have been removed as described above.
According to one aspect, there is provided a method for initializing a chamber, or removing contaminants from the chamber, in order to use the chamber for deposition, wherein the chamber has been newly manufactured by mechanical assembly. The method may include: electrolytically cleaning the newly manufactured chamber; cleaning the electrolytically cleaned chamber with a solvent; arranging a light source in the cleaned chamber; irradiating light in the chamber from the light source; and discharging gas in the chamber.
The solvent may be at least one of water and alcohol.
Irradiating the light in the chamber and discharging the gas in the chamber out of the chamber may be simultaneously performed.
After the light source is arranged in the chamber, while gas in the chamber is discharged out of the chamber by using a vacuum pump, the light may be irradiated in the chamber by the light source. In addition, after the vacuum pump is first operated and then a vacuum of a predetermined level is formed in the chamber, the light source may be turned on and then the light may be irradiated.
As described above, either light may be irradiated after a vacuum is formed in the chamber, a vacuum may be formed in the chamber by operating the vacuum pump simultaneously with the irradiation of light, or the vacuum pump may be operated in a predetermined time period from the time point of starting the irradiation of light.
Irradiating the light in the chamber may be performed for about 1 to about 120 hours.
While irradiating the light in the chamber is performed, the vacuum pump may be continuously operated and the gas in the chamber may be continuously discharged out of the chamber.
The vacuum pump may be intermittently operated during the irradiation of the light. For example, the vacuum pump may be periodically operated only for a predetermined period of time, and gas, which is generated while the vacuum pump is not operated, may be discharged at once when it is operated.
A vacuum pump capable of forming a pressure equal to or smaller than about 10 Pa in the chamber may be used. The forming of a vacuum in the chamber implies that a pressure equal to or smaller than 10 Pa is formed in the chamber.
For higher vacuum efficiency, a vacuum pump which can form a pressure equal to or smaller than 10⁻²Pa in the chamber may be used. For much higher vacuum efficiency, a vacuum pump which can form a pressure equal to or smaller than 10⁻⁵Pa in the chamber may be used.
The light generated by the light source may include at least one of visible light and infrared light.
A light source for illumination may be used as a light source. For example, a halogen lamp may be used as it. The halogen lamp has an excellent efficiency of radiant heat generation, so that it can efficiently heat the inside of the chamber. Therefore, the halogen lamp can be easily applied.
The light source may be arranged at one or more of corner parts and a space in the chamber. An area, onto which the light is irradiated by the light source, may include at least one of an inner wall of the chamber and structures in the chamber.
The light source may be arranged at a corner part in the chamber, or may be arranged at any part of an empty space in the chamber. The light source may be arranged in a space in the chamber in such a manner that light is irradiated onto a wall. Otherwise, the light source may be arranged at a corner part in the chamber in such a manner that light is irradiated onto a structure in the chamber.
A temperature of a surface, onto which the light is irradiated, may rise up to about 70 to about 200° C.
The gas in the chamber, which is discharged out of the chamber by the vacuum pump, may include at least one of HNO₃and H₂SO₄.
A light blocking cover may be arranged at a part of structures in the chamber, onto which light does not have to be irradiated, in such a manner that light is not irradiated onto the relevant part.
The chamber corresponds to a deposition chamber applied to a process for depositing an organic material during manufacture of an organic light emitting device (OLED).
In the process of removing the contaminants in the chamber, the gas in the chamber, may be discharged out of the chamber by operating a vacuum pump.
According to another aspect, there is provided a method of manufacturing a chamber for depositing an organic material of an organic light emitting device (OLED), the method including: forming a chamber through mechanical assembling; and removing contaminants in the chamber by the method above.
In a method for initializing a deposition chamber according to embodiments of the present invention, contaminants in a chamber are converted to a gaseous state and then the gaseous contaminants are discharged out of the chamber, by arranging a light source and then irradiating the light in the chamber. Therefore, it is possible to remove the contaminants in the chamber and then initialize the chamber in a relatively short period of time.
By applying a relatively simple method including the arrangement of the light source and the irradiation of the light, it is possible to easily remove even the minute residual contaminants in the chamber which are seldom easily removed. Therefore, chamber cleaning efficiency can be improved, and the amount of time required to initialize the chamber can be reduced. As a result, it is possible to significantly reduce the error rate of products manufactured by using the chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, features and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a partly cut-out perspective view illustrating an internal structure of an example deposition chamber;

FIG. 2 is an enlarged view of an inner wall of the deposition chamber of FIG. 1;

FIG. 3A is a flowchart illustrating an embodiment of a method for initializing the chamber and removing contaminants in the chamber;

FIG. 3B is a flowchart illustrating another embodiment of a method for initializing the chamber and removing contaminants in the chamber;

FIG. 4 is a partly cut-out perspective view illustrating an internal structure of an embodiment of a chamber, with an arrangement of light sources;

FIG. 5 is a schematic front view of the chamber shown in FIG. 4;

FIG. 6 is a partly cut-out perspective view illustrating an internal structure of another embodiment of a chamber;

FIG. 7 is an illustrative view showing an embodiment of a light source;

FIG. 8 is a photograph showing a halogen lamp as an embodiment of a light source;

FIG. 9 is a partly cut-out front view of an embodiment of a deposition chamber;

FIG. 10 is a partly cut-out front view of another embodiment of a deposition chamber.

DETAILED DESCRIPTION OF CERTAIN INVENTIVE EMBODIMENTS

Hereinafter, exemplary embodiments will be described in more detail with reference to the accompanying drawings.
The present invention is not limited to the following embodiments, and may be modified in various forms. The following embodiments are mere illustrations of the present invention.
FIG. 3A is a flowchart illustrating an embodiment of a process for initializing a chamber after assembling the chamber. Referring to FIG. 3A, a method for initializing a chamber after assembling the chamber (S110) includes: cleaning the assembled chamber by using an electrolyte (S120), cleaning the chamber by using a solvent and then drying it (S130), arranging a light source in the chamber (S140), irradiating light in the chamber by using the light source (S150), and discharging gas generated in the chamber out of the chamber by irradiating the light (S160).
In the present disclosure, the term “initialization of a chamber” refers to a process which enables the use of a newly manufactured chamber for deposition. After manufacturing a chamber and mounting internal structures in the chamber, a process for setting the chamber in a product production line of a deposition process before performing the deposition process is called the “initialization of a chamber.”
In the process of initializing the chamber in order to enable the use of the chamber for deposition after manufacturing the chamber, the chamber is subjected to a cleaning process for removing contaminants therein.
A method for removing contaminants in the chamber, similar to the method for initializing the chamber, includes: cleaning the chamber by using an electrolyte, cleaning the chamber by using a solvent, arranging a light source in the chamber, irradiating light in the chamber, and discharging gas in the chamber out of the chamber.
Electrolytic cleaning (S120) includes cleaning the chamber by using an electrolyte solution, after the assembling of the chamber has been completed (S110). In the electrolytic cleaning, an acid or base solution may be used. The electrolytic cleaning is sometimes called “electrolytic polishing” because of the use of an electrolyte. After the electrolytic cleaning, residues of acid or base may remain. The residues of acid or base, may include for example, H₂SO₄, HNO₃, and the like.
Solvent cleaning (S130), which is cleaning using a solvent, may be considered a process for re-cleaning the chamber after it is subjected to electrolytic cleaning.
There is no limitation on a method for the solvent cleaning. In some embodiments, water or alcohol may be used as a solvent, or mixed water and alcohol may be used. In other embodiments, another solvent may be used. The cleaning methods using water as a solvent may include such methods as pure water shower using distilled water, high-pressure cleaning using water gushing under high pressure, steam cleaning using steam, and the like. In some embodiments, re-cleaning the chamber may include using distilled water after cleaning it by using ordinary water.
After the chamber is subjected to the solvent cleaning, it is dried.
After the chamber is subjected to the solvent cleaning (S130), a light source is arranged in the dried chamber (S140). At least one light source may be arranged.
The light source may be arranged at an appropriate location in various embodiments in such a manner that the light can be irradiated onto a necessary part in the chamber.
FIG. 4 illustrates light sources 100 which are arranged at corner parts in a chamber 700, respectively. FIG. 5 is a schematic front view of the chamber shown in FIG. 4. A light source can be additionally arranged at locations other than the corner parts in the chamber in various embodiments. In some embodiments, a light source may also be arranged at a location such that light can be better irradiated onto a part, such as for example. a connection portion or a part including complex structures in the chamber, at which it is determined that more minute residual contaminants exist than at other parts. In some embodiments, an additional light source can be arranged at a location capable of irradiating light better onto a connection portion between a substrate support portion 300 and a substrate fixing portion 400, a lower end part of a mask fixing portion 500, or the like.
FIG. 6 is a partly cut-out perspective view illustrating an internal structure of another embodiment of a chamber 700, in which light sources 100 are arranged at the inner space of the chamber. As illustrated in FIG. 6, the light sources 100 may be arranged in a space other than the corner parts in the chamber, and may be easily arranged at any other parts in the chamber. In some embodiments, the chamber may include a separate holder for arranging the light sources 100 in the chamber.
The light sources 100 are removed before a deposition process proceeds after the initialization process is completed. Therefore, it is desirable that the light sources 100 should be mounted in the chamber in consideration of the convenience of removing the light sources 100. FIG. 6 illustrates a structure such that the light sources are arranged by using a separate holder extended from an inner wall of the chamber. The separate holder and the light sources are removed before the deposition process proceeds.
In order to pass a wire for supplying electricity to each light source, an existing through hole formed in a wall of the chamber may be used. In other embodiments, a new through hole can be formed in the wall of the chamber for the passage of the wire. After the wire is passed through the through hole, the through hole may be blocked by using a plunge, a gasket and the like, so that a vacuum state can be formed in the chamber.
Light generated by the light source 100 may include at least one of visible light and infrared light. In some embodiments, a light source for illumination capable of generating visible light may be used, or a light source capable of generating infrared light other than visible light may be used.
A lamp type light source may be used as the light source 100. In some embodiments, a halogen lamp may be used as the lamp type light source. The halogen lamp has an excellent efficiency of radiant heat generation, so that it can efficiently heat the inside of the chamber. When the halogen lamp is used to irradiate light, it makes it possible to increase the temperature of an irradiated surface up to about 200° C. or more. Therefore, the halogen lamp may be used to heat the inside of the chamber.
The halogen lamp is easily and conveniently operated and used, and is simply and easily mounted, so that it can be arranged at any location in the chamber according to the user's need. When the halogen lamp is used as a light source, it is possible to initialize the chamber without any great additional special effort or any additional special loss, so that the initialization process becomes very simple.
FIG. 7 is an illustrative view showing an embodiment of the light source 100. The light source 100 shown in FIG. 7 has a cylindrical shape, which can often be seen in a light source generally called a “fluorescent lamp.” The light source 100 may have a spherical shape in other embodiments. In yet other embodiments, the size and/or shape of the light source may be different. In some embodiments, a light source 100 of a small spherical shape may be used to irradiate light onto a small area in the chamber.
The light source 100 shown in FIG. 7 includes a light emitting unit 110 and a reflection plate 120. In some embodiments, the light emitting unit 110 may be implemented by using a halogen lamp. The reflection plate 120 may sometimes be referred to as a “lampshade.”
FIG. 8 is a photograph showing a halogen lamp as an embodiment of a light source.
Referring back to FIG. 3A, after the light source 100 is arranged in the chamber 700, light is irradiated in the chamber by using the light source (S150). When the irradiation of the light increases a temperature in the chamber and as a result, contaminants in the chamber are evaporated, gas is generated in the chamber. The irradiation of the light evaporates the residual contaminants existing both on the inner wall 710 and at the internal structures of the chamber 700, and the gaseous residual contaminants are gathered in the chamber 700. After the irradiation of the light, a vacuum pump may be operated to discharge gas generated in the chamber out of the chamber (S160). When the contaminants in the chamber are removed by discharging the gas as described above, the chamber is initialized to the extent that it can be used for deposition.
In some embodiments, a vacuum may be first formed in the chamber before light is irradiated (S260), and then light may be irradiated (see S250 shown in FIG. 3B).
FIG. 3B is a flowchart showing another example of a method for initializing a chamber according to the present invention.
Referring to FIG. 3B, after assembling the chamber (S210), the method for initializing a chamber includes: cleaning the assembled chamber by using an electrolyte (S220), re-cleaning the chamber by using a solvent and then drying it (S230), arranging a light source in the chamber (S240), discharging gas in the chamber out of the chamber by using a vacuum pump to form a vacuum in the chamber (S250), irradiating light in the chamber by using the light source (S260), and discharging gas generated in the chamber by the irradiation of the light out of the chamber to remove the generated gas (S270).
The embodiment of the method for initializing the chamber shown in FIG. 3B is different from the embodiment shown in FIG. 3A, only in that, after the light source 100 is arranged in the chamber 700, gas in the chamber is discharged out of the chamber by using a vacuum pump to form a vacuum in the chamber (S250), and then light is irradiated in the chamber. Other steps shown in FIG. 3B are identical to those shown in FIG. 3A.
By operating the vacuum pump simultaneously with irradiating the light (S150), gas may be discharged while a vacuum is formed in the chamber (S160). Otherwise, by operating the vacuum pump in a predetermined time period from the time point of starting the irradiation of the light (S150), gas generated for the predetermined time period may be discharged (S160) when the vacuum pump operates.
The vacuum pump for forming a vacuum in the chamber may be implemented by using a commercially available vacuum pump. The vacuum pump may be mounted at an appropriate location on the chamber according to a person of ordinary skill in the art. The vacuum pump is not illustrated in the drawings.
In some embodiments, the vacuum pump may have a capacity to form a pressure equal to or smaller than about 10 Pa in the chamber. When gas generated by the evaporation of the contaminants is discharged, the higher the capacity of the vacuum, the higher the efficiency of gas discharging. Therefore, for more efficient gas discharging, a vacuum pump which has a capacity of forming a pressure equal to or smaller than about 10⁻²Pa in the chamber may be used. For even more efficient gas discharging, a vacuum pump which has a capacity of forming a pressure equal to or smaller than about 10⁻⁵Pa in the chamber may be used. The vacuum pump may be appropriately selected according to the use thereof by those skilled in the art.
Residual contaminants, which are not removed by the electrolytic cleaning and the conventional solvent cleaning, are mainly minute contaminants existing at a part such as a minute groove on the inner wall of the chamber, a connection portion between structures in the chamber, or the like. Typical examples of these contaminants include HNO₃and H₂SO₄. These contaminants are materials which have strong acidity, so that even the existence of a small amount of these contaminants may cause contamination of a deposition layer.
Even if the above materials exist in the chamber with a very small amount, because they are reactive materials having relatively low molecular weights, they may seriously damage a deposition layer of a product manufactured in the chamber. These materials may be evaporated at a temperature of about 70° C. to about 200° C.
Therefore, in some embodiments, the temperature of a surface, onto which the light is irradiated, may rise up to between about 70° C. to about 200° C.
The existence of the minute reactive materials having low molecular weights, and a temperature, at which they may be removed, have been revealed by the research conducted by the present inventors. When the light source is used to heat the surface of the inner wall of the chamber or that of a chamber structure to a temperature of about 70° C. to about 200° C., the irradiation of the light may evaporate these contaminant materials, but does not damage other structures in the chamber.
In various embodiments, a lamp such as a halogen lamp is used as a light source to remove the contaminants. By using a lamp type light source such as a halogen lamp, an apparatus for cleaning the chamber can be easily configured.
When light is irradiated in the chamber by using the light source as described above, the contaminants existing in the chamber are evaporated, and then gas is generated. Therefore, the generated gas must be discharged out of the chamber. To this end, during or after the irradiation of the light, the gas, which is generated by the irradiation of the light, is discharged out of the chamber by operating the vacuum pump (S160). The gas discharging is performed by using the vacuum pump, and thus is also called “vacuum pumping.”
An experiment was conducted by the present inventors as follows. A chamber was subjected to electrolytic cleaning and solvent cleaning using distilled water, and a vacuum was formed in the chamber to a level of about 10⁻⁵Pa, and then light was irradiated therein by using a halogen lamp. As a result, it was verified that the pressure in the chamber rose up to a level of about 10⁻³Pa within several minutes after the irradiation of the light using the halogen lamp. The pressure rise in the chamber as described above indicates that gas was generated in the chamber after the irradiation of the light using the halogen lamp.
The generation of the gas indicates that contaminants exist to some degree even in the chamber which was considered to be made very clean by the electrolytic cleaning and the solvent cleaning using distilled water, and implies that the contaminants were evaporated by the irradiation of the light using the halogen lamp.
In the discharging of the gas generated by the irradiation of the light out of the chamber by using the vacuum pump (S160), the vacuum pump may be continuously operated during the irradiation of the light, or it may be intermittently operated. In some embodiments, the vacuum pump may be periodically operated only for a predetermined period of time, and gas, which is generated while the vacuum pump is not operated, may be discharged at once when the vacuum pump is operated.
In some embodiments, when a period of time for which light is irradiated is 1 hour, the vacuum pump may be operated and stopped repeatedly at a regular interval of 10 minutes. When a period of time for which light is irradiated is 120 hours, the vacuum pump may be operated and stopped repeatedly at a regular interval of 1 to 2 hours. The regular interval may be appropriately selected by those skilled in the art.
In some embodiments, light may be irradiated for about 1 to about 120 hours. When light is irradiated in the chamber for about 1 to about 120 hours and then gas, which is generated during the irradiation of the light, is discharged out of the chamber, the contaminants in the chamber may be removed to a satisfactory extent and as a result, the chamber may be initialized so that the chamber can be used for deposition.
The above contrasts sharply with the case where a chamber is subjected to the conventional high temperature baking process using a heater. When the chamber is subjected to the conventional high temperature baking process using the heater, the high temperature baking process must be performed for dozens of days to several months so that the residual contaminants in the chamber may not damage a deposition layer at an early stage of the use of the chamber. Where the chamber is subjected to the conventional high temperature baking process, a deposition layer having satisfactory quality can be stably obtained, only when the high temperature baking process is performed for about 4 months after manufacturing and cleaning the chamber.
In some embodiments, only with about 1 hour to about 24 hours of the irradiation of light and gas discharging (or vacuum pumping), the contaminants in the chamber can be removed to the extent that a satisfactory deposition layer can be obtained.
In some embodiments, before or after a light source is arranged in the chamber, a light blocking cover may be arranged in order to prevent light from being irradiated onto a part of structures in the chamber, onto which light does not have to be irradiated. The light blocking cover may be mounted at the part of the structures in such a manner that it can block out light emitted from the light source and then block out radiant heat. In some embodiments, the light blocking cover may be easily mounted on the part of the structures by using an aluminum foil or a light reflective film.
The part, at which the light blocking cover is arranged, is not exposed to light, and thus is shielded from radiant heat, so that the temperature of it does not significantly rise. Therefore, a heat-sensitive element (such as for example an electronic device, a sensor or the like) among the structures in the chamber may be wrapped in an aluminum foil or the like, and then is shielded from light, so that it is possible to suppress the temperature rise of the wrapped heat-sensitive element.
According to the experiment by the present inventors, it was verified that even when the temperature of a part, onto which light was irradiated, rose to about 200° C., the temperature of another part, at which an aluminum foil was used to block out the light, was maintained at about 30° C.
According to some embodiments, the irradiation of light is selectively prevented in a relatively simple method, so that temperature rise can be selectively suppressed.
Embodiments of the cleaning method may be usefully applied particularly to a deposition chamber for manufacturing an Organic Light Emitting Device (OLED). The deposition chamber has a large size, and includes various structures therein. Therefore, a conventionally known method has a limit on cleaning minute contaminants in the deposition chamber. Embodiments of the method for irradiating light described herein can be applied to a large sized chamber. Even though contaminants remain in a deposition chamber that has a large size and a complex structure, contaminants may be easily removed by using embodiments of the method, so that the initialization of the deposition chamber can be easily achieved.
FIG. 9 is a partly cut-out front view of an embodiment of a deposition chamber, which is configured in such a manner that a substrate is horizontally arranged at an upper part in the deposition chamber and deposition is performed on the substrate.
FIG. 10 is a partly cut-out front view of another embodiment of a deposition chamber, which is configured in such a manner that a substrate is horizontally arranged at a lower part in the deposition chamber and deposition is performed on the substrate.
As described above, embodiments of the method for removing contaminants in a chamber may be applied to deposition chambers of various types and sizes.
Embodiments of the present invention also provide a method for removing contaminants in a newly manufactured chamber in order to use the chamber for deposition. A method for removing contaminants in a chamber includes: cleaning the chamber by using an electrolyte, cleaning the chamber by using a solvent, arranging a light source in the chamber, irradiating light in the chamber, and discharging gas in the chamber out of the chamber. The method is identical to the method for initializing the chamber. Therefore, a detailed description will be omitted.
Embodiments also provide a method of manufacturing a chamber for depositing an organic material of an organic light emitting device (OLED). A method of manufacturing a chamber for depositing an organic material of an organic light emitting device includes: forming a chamber through mechanical assembling, and removing contaminants in the chamber by the method for removing the contaminants in the chamber as described above.
Embodiments also provide a chamber for depositing an organic material of an organic light emitting device manufactured by the above method.
Although the invention has been shown and described in detail with reference to certain embodiments thereof, the present invention is not limited to the embodiments thereof, and it will be apparent to a person having ordinary knowledge in the technical field of the present invention that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the principles of the present invention. More particularly, various variations and modifications are possible in the elements, which are specifically described in the embodiments of the present invention, within the scope of the present invention.

Claims

1. A method of initializing a chamber, or removing contaminants from the chamber, in order to use the chamber for deposition, wherein the chamber has been newly manufactured by mechanical assembly, the method comprising:

electrolytically cleaning the newly manufactured chamber;

cleaning the electrolytically cleaned chamber with a solvent;

arranging a light source in the cleaned chamber;

irradiating light in the chamber from the light source; and

discharging gas in the chamber out of the chamber.

2. The method as claimed in claim 1, wherein the solvent comprises at least one of water and alcohol.

3. The method as claimed in claim 1, wherein irradiating the light in the chamber and discharging the gas in the chamber out of the chamber are simultaneously performed.

4. The method as claimed in claim 1, wherein, discharging the gas in the chamber out of the chamber is performed before irradiating the light in the chamber.

5. The method as claimed in claim 1, wherein light is irradiated in the chamber for about 1 to about 120 hours.

6. The method as claimed in claim 1, wherein, while irradiating the light in the chamber, the gas in the chamber is continuously discharged out of the chamber.

7. The method as claimed in claim 1, wherein the light generated by the light source comprises at least one of visible light and infrared light.

8. The method as claimed in claim 1, wherein the light source comprises a halogen lamp.

9. The method as claimed in claim 1, wherein the light source is arranged at one or more of corner parts and a space in the chamber.

10. The method as claimed in claim 1, wherein an area, onto which the light is irradiated by the light source, comprises at least one of an inner wall of the chamber and structures in the chamber.

11. The method as claimed in claim 1, wherein a temperature of a surface, onto which the light is irradiated, rises up to about 70 to about 200° C.

12. The method as claimed in claim 1, wherein the gas in the chamber, which is discharged out of the chamber by the vacuum pump, comprises at least one of HNO3 and H2SO4.

13. The method as claimed in claim 1, which further comprises arranging a light blocking cover at a part of structures in the chamber in order to prevent the light from being irradiated onto the part.

14. The method as claimed in claim 1, wherein the chamber is a chamber applied to a process for depositing an organic material during manufacture of an organic light emitting device (OLED).

15. The method as claimed in claim 1, wherein the gas in the chamber is discharged by operating a vacuum pump.

16. The method as claimed in claim 15, wherein the vacuum pump has a capacity with which a pressure equal to or smaller than about 10 Pa is formed in the chamber.

17. A method of manufacturing a chamber for depositing an organic material of an organic light emitting device (OLED), the method comprising:

forming a chamber through mechanical assembling; and

removing contaminants in the chamber by the method as claimed in claim 1.