KR102519521B1 - Reactor for organic vapor transport deposition - Google Patents

Abstract

Embodiments of the present invention relate to organic vapor transfer deposition reactors. According to one embodiment of the present invention, an organic vapor transfer deposition reactor includes a gas supply unit having a plurality of dispersion openings for supplying an organic vapor phase precursor; and a susceptor spaced apart from the gas supply unit by a predetermined distance and facing the gas supply unit for surface-to-surface deposition of an organic thin film, on which a substrate is placed, wherein the temperature of the organic vapor precursor and the temperature of the substrate In order to suppress vapor condensation due to the difference, a cooling means for reducing the temperature of the organic vapor precursor on a delivery path of the organic vapor precursor from the gas supply unit to the substrate to a critical temperature range may be included. The ratio (ΔT/h) of the difference between the temperature of the organic vapor phase precursor and the temperature of the substrate (ΔT) and the distance (h) between the gas supply unit and the substrate may be in the range of 0.5 to 30.

Description

Reactor for organic vapor transport deposition}

The present invention relates to vapor deposition techniques and, more particularly, to organic vapor transfer deposition reactors.

OLED (Organic Light-Emitting Diode) is a solid-state light-emitting device that not only emits light with high efficiency but also emits light in a wide spectrum unlike inorganic LEDs, so it is attracting attention as a light source for low-power flat-type self-luminous display devices or lighting devices. In addition, unlike inorganic thin films, OLED can be synthesized at a low temperature, so not only glass substrates but also polymer substrates can be used, so flexible designs are possible, and transparent or translucent states can be maintained in the off state, so a wide range of designs different from conventional light emitting devices. It has the advantage of being able to implement changes and uses.

Such an OLED device emits light while positive and negative charges respectively injected from an anode and a cathode form excitons inside an emission layer. The light emitting layer is generally composed of a plurality of organic thin film layers. OLEDs can be classified as polymer OLEDs or low molecular weight OLEDs depending on the type of organic thin film layer applied. In order to form the organic thin film layer, wet coating techniques such as spin coating, inkjet printing, or stamping have conventionally been applied, but these techniques have difficulties in forming multilayer thin films. , Compared to low molecular weight OLEDs having a complex stacked structure, it is limitedly applied only to the polymer OLED having a simple stacked structure. In the case of low molecular weight OLEDs, evaporation-based thin film deposition technology that can control the thickness of each thin film and secure good adhesion between layers in order to form a complex stacked structure has been commercialized.

However, since the evaporation method uses a linear evaporation source that scans a substrate to form a uniform thin film, the species evaporated from the evaporation source have an angular distribution, and the line-of-site (line of Since a shadow effect occurs according to the movement of sight, it is difficult to form a thin film with uniform distribution evenly controlled between fine pixel units as well as across the entire substrate. In addition, since the evaporation method requires an operating mechanism for scan-driving the linear evaporation source to secure uniformity in the chamber, the problem of inevitably occurring particles as a contaminant in the chamber while the linear evaporation source is scan-driven is solved. have

In addition, the evaporation method is a limitation of the bottom-up deposition structure in which the substrate must be placed on top of the evaporation source. It has limitations in high resolution. In addition, in the bottom-up structure of the vapor phase evaporation method, there is a problem of particle contamination due to homogeneous nucleation in which condensed particles of undesirable organic vapor phase precursors having a size of nanometer to micrometer are formed in the gas phase during formation of the organic thin film layer. Occurs frequently, and since the formed particles cause physical defects such as pinholes or short circuits in the organic light emitting thin film, it is absolutely required to overcome this for the manufacture of reliable OLED devices.

The technical problem to be solved by the present invention is to overcome the above-mentioned limitations of the evaporation method, induce the formation of a uniform and dense organic thin film on a substrate, and suppress unwanted particle formation during the process to deposit a reliable organic thin film. In addition, when a mask is used, it is to provide an organic vapor transfer deposition reactor capable of manufacturing a high-resolution and/or large-area display device by suppressing the shadow effect as well as suppressing mask warpage.

In addition, another technical problem to be solved by the present invention is to provide a method of forming an organic light emitting thin film having the above-mentioned advantages.

An organic vapor transfer deposition reactor according to an embodiment of the present invention for solving the above problems includes a gas supply unit having a plurality of dispersion openings for supplying an organic vapor precursor; and a susceptor spaced apart from the gas supply unit by a predetermined distance, disposed facing the gas supply unit for surface-to-surface deposition of an organic thin film, and on which a substrate is placed. and a cooling means for reducing the temperature of the organic vapor phase precursor on a delivery path of the organic vapor phase precursor from the gas supply unit to the substrate to suppress condensation of the gas phase due to a temperature difference between the temperature of the organic vapor phase precursor and the substrate. can do. The cooling unit may include a cooling gas passage for supplying a cooling gas into the gas supply unit, and the cooling gas may be mixed with the organic vapor phase precursor.

In one embodiment, the cooling gas may include an inert gas. The cooling means may be provided by injecting a cooling gas into a supply passage of the organic vapor phase precursor gas. The cooling means may include a refrigerant passage coupled to the gas supply unit to cool the organic precursor gas.

In one embodiment, the cooling means may further include a cooling plate coupled to the gas supply unit and extending toward the susceptor. The cooling plate may include a body including any one of copper, tungsten, aluminum, stainless steel, an alloy thereof, or a combination thereof, and a refrigerant passage coupled to a surface or inside of the body.

An end of the cooling plate on the substrate side may secure a gap with the substrate. The susceptor-side end of the plate defines a gap between the susceptor and the mass transfer boundary layer of the organic vapor precursor flow flowing over the substrate during the deposition process by the size of the gap as the susceptor moves. The thickness of can be controlled.

The distance between the gas supply unit and the substrate may be in the range of 10 mm to 450 mm. The ratio (ΔT/h ) of the difference value ΔT between the temperature of the organic vapor phase precursor and the temperature of the substrate and the distance (h) between the gas supply unit and the substrate may be in the range of 0.5 to 30.

The gas supply unit may be disposed in a horizontal manner with the susceptor, and may be disposed in a top-down or bottom-up manner. Alternatively, the gas supply unit and the susceptor may be disposed side by side in a vertical manner.

According to an embodiment of the present invention, it relates to an organic vapor transfer deposition reactor capable of face-to-face deposition by transferring an organic precursor gas into a chamber using a carrier gas, which cools the temperature of a high-temperature vapor precursor gas to reach a substrate. By delivering the vapor phase precursor, condensation of the vapor phase precursor due to homogeneous nucleation on the path can be suppressed, thereby suppressing unwanted particle formation, thereby depositing a reliable organic thin film. In addition, according to the embodiment of the present invention, unlike the conventional evaporation method, since the gaseous precursor gas can be delivered by the carrier gas in a top-down or horizontal manner, the mask bending problem is solved and there is no shadow effect, so a large-area high-resolution display device can be manufactured.

In addition, according to an embodiment of the present invention, since vapor phase condensation, which increases as the path in the reactor increases to uniformly deliver the precursor gas to the substrate for large-area deposition, can be suppressed, it is possible to deposit a high-quality organic thin film. An organic vapor transfer deposition reactor that can be used may be provided.

Figure 1a is a graph for explaining the temperature profile of the organic vapor transfer deposition reactor according to an embodiment of the present invention, Figure 1b is a nucleus according to the temperature of the Alq3-based green light-emitting organic precursor according to an embodiment of the present invention It shows the condensation result according to the generation.
2 shows an organic vapor transfer deposition reactor according to one embodiment of the present invention.
3 shows an organic vapor transfer deposition reactor according to another embodiment of the present invention.
4 is a cross-sectional view showing an organic vapor transfer deposition reactor according to another embodiment of the present invention.
5 shows an organic vapor transfer deposition reactor according to another embodiment of the present invention.
6 and 7 are cross-sectional views illustrating a top-down organic vapor transfer vapor deposition reactor and a horizontal vapor deposition reactor according to other embodiments of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art, and the following examples may be modified in many different forms, and the scope of the present invention is as follows It is not limited to the examples. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the spirit of the invention to those skilled in the art.

In addition, in the following drawings, the thickness or size of each layer is exaggerated for convenience and clarity of explanation, and the same reference numerals refer to the same elements in the drawings. As used herein, the term "and/or" includes any one and all combinations of one or more of the listed items. Terms used in this specification are used to describe specific embodiments and are not intended to limit the present invention. As used herein, the singular form may include the plural form unless the context clearly indicates otherwise. Also, when used herein, "comprise" and/or "comprising" specifies the presence of the recited shapes, numbers, steps, operations, elements, elements, and/or groups thereof. and does not exclude the presence or addition of one or more other shapes, numbers, operations, elements, elements and/or groups.

In this specification, terms such as first and second are used to describe various members, components, regions, layers and/or portions, but these members, components, regions, layers and/or portions are limited by these terms. It is self-evident that no These terms are only used to distinguish one element, component, region, layer or section from another region, layer or section. Thus, a first member, component, region, layer or section described in detail below may refer to a second member, component, region, layer or section without departing from the teachings of the present invention.

In order to solve various problems occurring in the conventional evaporation method, the present invention provides organic vapor transmission in which a gas supply unit for supplying an organic vapor precursor and a substrate opposite to the gas supply unit are arranged in a plane-to-plane deposition method. A deposition reactor is provided. In particular, in order to form a reliable organic thin film for the realization of high-resolution display pixels, the generation of polluting particles must be suppressed and reduced. It was confirmed that condensation caused by homogeneous nucleation in the gas phase was the main cause. In addition, in such homogeneous nucleation, as the distance between the gas supply unit and the substrate decreases, the organic vapor precursors supplied from the gas supply unit undergo a rapid temperature drop while reaching the substrate, resulting in the rapid formation of particles by homogeneous nucleation near the substrate. Therefore, suppression of it is very important.

The face-to-face deposition method is a top-down method defined according to the relative position of the gas supply unit and the substrate (ie, a method in which the gas supply unit is provided above the substrate to transfer the organic vapor precursor downward) or a bottom-up method. (that is, a substrate is provided above the gas supply unit, so that the organic vapor phase precursor is transferred upward) or a vertical manner (that is, a substrate is provided on one side of the gas supply unit, so that the organic vapor phase precursor is transferred in parallel). direction) may all be provided. The top-down method and the vertical method are advantageous compared to the bottom-up deposition method because there is no problem related to mask bending. However, since the particle issue formed before the vapor phase precursor reaches the substrate can cause serious defects in the top-down method and the vertical method compared to the bottom-up method, a technique for suppressing particle formation in the top-down method is very important.

Figure 1a is a graph for explaining the temperature profile of the organic vapor transfer deposition reactor according to an embodiment of the present invention, Figure 1b is a nucleus according to the temperature of the Alq3-based green light-emitting organic precursor according to an embodiment of the present invention It shows the condensation result according to the generation.

를 나타낸다.Referring to FIG. 1A , an organic thin film experiences a temperature change while a vapor phase precursor supplied from a gas supply unit reaches the substrate. Line L is a temperature profile experienced by a vapor phase precursor in a conventional organic thin film device without a cooling means, and line L' is a temperature profile experienced by a vapor phase precursor in an organic vapor phase transfer deposition reactor according to an embodiment of the present invention having a cooling means. . Typically, the susceptor in which a substrate is placed for substrate deposition by condensation of an organic vapor precursor may be maintained at, for example, 50 °C or less, preferably 30 °C or less. Since the vapor phase precursor evaporates from the source container and reaches the gas supply unit, the temperature of the substrate is considerably low compared to the high temperature of 300 ° C. or more, so that the gas phase precursor experiences an extreme temperature drop while reaching the substrate from the gas supply unit. do. Equation 1 below is a thermal reaction equation when the vapor phase precursor is condensed in the gas phase and solidified. Equation 2 is the Gibbs free energy change ΔG upon condensation of the gaseous precursor

indicates

[Equation 1]

는 응축시 엔탈피 변화량으로서 양의 값을 갖는다.Referring to Equation 1, the vapor phase precursor undergoes an exothermic reaction while being condensed. The condensation process is an exothermic reaction,

is the amount of enthalpy change upon condensation and has a positive value.

[Equation 2]

)(

)

Referring to Equation 2, since the temperature of the vapor precursor (T) is greater than the substrate temperature (Tsub), the temperature difference ΔT has a negative value. Therefore, the Gibbs free energy change ΔG at the time of condensation of the gaseous precursor has a negative value, and since the temperature of the gaseous precursor on the path from the gas supply unit to before reaching the substrate is higher than the substrate temperature, the gaseous phase on the path Condensation of precursors is a spontaneous process. As the absolute value of the difference value ΔT between the substrate temperature and the temperature of the vapor phase precursor increases, the absolute value of ΔG increases, so condensation of the vapor phase precursor occurs more easily. If the temperature drop is large until the gaseous precursor leaves the gas supply unit and reaches the substrate, condensation on the path before reaching the substrate, that is, phase change by homogeneous nucleation in the gaseous phase may occur before reaching the substrate.

This condensation can lead to contaminating particle formation within the chamber. In order to suppress the particle formation, the absolute value of ΔG needs to be reduced, and it is preferable that the gaseous precursor reaches the substrate in a supercooled state without being condensed in the reactor space before reaching the substrate.

In actual OLED device production, organic thin film deposition equipment is preferable as the distance between the gas supply unit and the substrate is small for high organic thin film deposition rate, low shadow effect, and large-area uniform organic thin film deposition. In one embodiment, the organic vapor transfer deposition reactor wherein the distance between the gas supply unit and the substrate is in a range of 10 mm to 450 mm.

However, the smaller the gap between the gas supply unit and the substrate, the higher the possibility that the organic vapor precursor undergoes a rapid temperature drop in the gas phase before reaching the substrate (with an excessively large absolute value of ΔT) and condensation occurs before reaching the substrate. , In the embodiments of the present invention, it is preferable that the vapor phase precursor leaving the gas supply unit is not granulated even if it maintains a supercooled state before reaching the substrate, and the higher the deposition rate for the large-area production of the display device, the higher the resolution Since the spacing can be further reduced to reduce the shadow effect in order to realize a pixel of , the cooling means is important to ensure that the vapor phase precursor does not undergo particle formation before reaching the substrate.

Referring back to FIG. 1A , when the temperature T of the gaseous precursor is reduced by T ₁ 'from T ₁ by the cooling means, the difference value ΔT between the substrate temperature and the gas precursor temperature is as large as ΔT' in absolute value. is reduced, and as a result, the absolute value of ΔG for the condensation reaction of the source precursor gas (SP) on the path from the gas supply unit to the substrate is reduced, so that the possibility of condensation by homogeneous nucleation of the vapor phase precursor before reaching the substrate this is reduced Accordingly, even if the vapor precursor is cooled, it may reach the substrate in a supercooled state without being condensed on the path. 2 to 7, various embodiments of the present invention having a cooling means capable of reducing the absolute value of ΔG related to the condensation reaction of the source precursor gas (SP) on the path from the gas supply unit to the substrate. Organic vapor transfer deposition reactors according to examples are described in detail. In an embodiment, the vapor phase precursor may include a plurality of vapor phase precursors each including a component constituting a main composition of the organic thin film and a dopant component. In this case, the temperature T ₁ ′ of the cooled vapor phase precursor may be lower than the lowest temperature among evaporation temperatures of each source container among the plurality of vapor phase precursors.

Referring to FIG. 1B, the lowest temperature at which the Alq3 green-emitting organic precursor is evaporated and condensed is shown. The Alq3 evaporation temperature in the source container is 320 ° C, the pressure in the reactor is 1.2 Torr, and in order to determine condensation, a glass substrate is placed on the path between the gas supply unit and the susceptor in the reactor, and the thin film The forming process was conducted to observe whether the organic precursor was condensed on the glass substrate. At this time, the temperature of the glass substrate was measured in real time, and the temperature of the glass substrate corresponds to the temperature on the path.

When the organic precursor is condensed on the glass substrate, since a photoluminescent effect can be obtained from the condensed film, the glass substrate was irradiated with ultraviolet light having an excitation wavelength of 254 nm using a photoluminescent lamp. As a result, it can be seen that condensation of the gaseous precursor occurs at a temperature below about 190 ° C., and no condensation occurs at a temperature above about 190 ° C. in the reaction path.

In the present specification, the minimum temperature of the vapor phase precursor (SP) at which the vapor phase precursor (SP) is vapor condensed before reaching the substrate (SUB) and is not granulated is referred to as a critical temperature, and is about 190 ° C. in the case of Alq ₃ exemplified, which is organic It may change according to the type of precursor, the pressure of the reaction furnace, and the like. For example, the critical temperature may decrease as the sublimation temperature of the organic precursor decreases, and the critical temperature may decrease as the pressure of the reaction furnace decreases. In one embodiment, the critical temperature range may be in the range of 180 °C to 250 °C.

In an embodiment of the present invention, a cooling means is actively used to maintain the critical temperature of the vapor phase precursor (SP) within the delivery path of the vapor phase precursor (SP) to the substrate. In one embodiment, the difference value between the temperature of the substrate (T _SUB ) and the temperature of the substrate (T') of the gas precursor dropped by the cooling means and the size of the path (h, eg, between the discharge surface of the gas supply unit and the substrate The ratio of ), ΔT'/h (° C./mm), may be in the range of 0.5 to 30. When ΔT / h (℃ / mm) is less than 0.5, the possibility of condensation by homogeneous nucleation before the vapor phase precursor reaches the substrate is small, but the deposition rate of the organic thin film is reduced by h increased than ΔT, and the shadow effect This is undesirable as it becomes large. When ΔT/h (° C./mm) exceeds 30, the possibility of condensation by homogeneous nucleation is increased by the increased ΔT compared to h, so that the vapor phase precursor is condensed on the path before reaching the substrate to form particles. is formed Accordingly, ΔT′/h (° C./mm) is within the range of 0.5 to 30, more preferably within the range of 1 to 20, and the organic thin film can be formed at a reasonable speed without particle problems.

2 shows an organic vapor transfer deposition reactor 100A according to one embodiment of the present invention.

Referring to FIG. 2 , the organic vapor transfer deposition reactor 100A includes a gas supply unit 10 having a plurality of dispersion openings OH for supplying an organic vapor precursor SP and an organic thin film OL. It may include the susceptor 20 on which the substrate SB to be is seated. Vapor phase precursors can be obtained through vaporization of organic molecules, conjugated polymers, organometallic complexes, or inorganic source materials that are liquid or solid materials. The source material may be, for example, C ₂₇ H ₁₈ AlN ₃ O ₃ (AlQ3) and N, N'-Bis(naphthalene-1-yl)-N, N'-bis(phenyl)benzidine (NPB). It may be a known organic material, and the present invention is not limited thereto. For example, any organic source material for the manufacture of organic light emitting devices, electrochemical cells, photoconductive cells, photoresistors, photoswitches, phototransistors and phototubes can be used.

As shown in FIG. 2 , the gas supply unit 10 may have a perforated dispersion plate 11 in which a plurality of dispersion openings OH are defined. The gas supply unit 10 may be referred to as a shower head, and the plurality of dispersing openings OH are exemplary, and the plurality of dispersing openings may have a plurality of individually formed arrangements, nozzles, or combinations thereof. may, and the present invention is not limited thereto. In any case, the dispersing openings OH of the gas supply unit 10 according to the embodiment of the present invention are uniform organic on the substrate SB through plane to plane deposition without a driving mechanism such as scanning. It may have a shape, arrangement and/or pattern suitable for substantially uniformly providing gaseous fluid over the entire area of the substrate SB, so as to form a thin film.

The susceptor 20 on which the substrate SB is seated may be fixed or may be driven in a vertical direction (y direction) to adjust a distance between the gas supply unit 10 and the substrate SB. Optionally, the susceptor 20 may be coupled to a suitable transport system so that it can be driven in the horizontal direction (x direction) so that continuous organic thin film formation can be performed on different substrates. Also, the susceptor 20 may rotate during a deposition process to improve deposition uniformity of the organic thin film OL.

The substrate SB on which the organic thin film OL is deposited may be a general glass substrate or a polymer substrate for realizing a flexible display device. The polymer substrate, for example, various cellulose-based resin; polyester resins such as polyethyleneterephthalate (PET) and polyethylene naphthalate (PEN); polyethylene resin; polyvinyl chloride resin; polycarbonate (PC); polyetherisulfone (PES); polyether etherketone (PEEK); And it may be any one or a combination of polyphenylene sulfide (PPS) and polyimide (PI). These materials are only illustrative, and the present invention is not limited thereto.

In some embodiments, the organic vapor transfer deposition reactor 100A may include a chamber (not shown) defining a reaction space, in which the gas supply unit 10 and the susceptor 20 are accommodated. can In addition, the chamber may maintain a reduced pressure atmosphere, and for this purpose, a vacuum system such as a cryo pump, a turbo pump, or a dry pump may be installed. This will be described later in more detail with reference to FIGS. 5 and 6 .

The gas supply unit 10 of the organic vapor transfer deposition reactor 100A may include a cooling gas passage 12 to supply a cooling gas CG into the gas supply unit 10 . The cooling gas (CG) may be an inert gas such as argon, nitrogen and helium. The temperature (Tx) of the cooling gas (CG) introduced through the cooling gas passage 12 is lower than the temperature (T ₁ ) of the source precursor gas (SP), and the cooling gas (CG) in the gas supply unit 10 and the source precursor gas (SP) are mixed with each other, so that the source precursor gas (SP) has a temperature (T ₁ ') that is more positively lowered than the temperature (T ₁ ) at the time of its introduction. The temperature Tx of the cooling gas CG may have a temperature for effectively lowering the temperature of all vapor phase precursor gases in the gas supply unit 10 . As a result, the temperature T1 ′ of the organic vapor precursor SP has a value within a critical temperature range so that the vapor phase precursor SP is not condensed into particles before reaching the substrate SUB.

As described with reference to FIG. 1, the source precursor gas (SP) having a temperature (T ₁ ′) lowered by the cooling gas (CG) has a path (P) from the gas supply unit 10 to the substrate (SB). The absolute value of ΔG related to the condensation reaction of the source precursor gas (SP) is reduced to minimize homogeneous nucleation before reaching the substrate (SB), so that particles are not formed on the path (P) and on the surface of the substrate (SB) As a result, a high-quality organic thin film OL can be deposited on the substrate SB.

3 shows an organic vapor transfer deposition reactor 100B according to another embodiment of the present invention. Among the components disclosed in FIG. 3 , reference numerals disclosed in FIG. 2 may be referred to components having the same reference numerals as those of the components disclosed in FIG. 2 unless contradictory.

Referring to FIG. 3 , the gas supply units 10 of the organic vapor transfer deposition reactor 100C are disposed to face each other so as to deposit the organic thin film OL on the substrate SB face-to-face. Before at least one source precursor gas (SP) is drawn into the organic virtual transfer deposition reactor 100B from a source container, a cooling gas (CG) is injected into the supply passage, and the source precursor gas (SP) and the cooling gas (CG) may be supplied to the gas supply unit 10 in a mixed state.

The temperature T of the vapor phase precursor SP is reduced from T ₁ to the critical temperature T ₁ 'by the cooling gas CG. In addition, the difference value ΔT between the substrate temperature and the gas precursor temperature is reduced in absolute value by ΔT′, whereby the amount of the source precursor gas SP on the path from the gas supply unit 10 to the substrate SUB is reduced. The absolute value of ΔG for the condensation reaction is reduced so that condensation due to homogeneous nucleation of the vapor phase precursor before reaching the substrate can be suppressed.

4 is a cross-sectional view showing an organic vapor transfer deposition reactor 100C according to another embodiment of the present invention. Among the elements disclosed in FIG. 4 , reference numerals disclosed in FIG. 2 may be referred to components having the same reference numerals as those of the elements disclosed in FIGS. 2 and 3 unless contradictory.

Referring to FIG. 4 , in order to reduce the absolute value of ΔG related to the condensation reaction of the source precursor gas (SP), the temperature (T1) of the organic vapor phase precursor gas (SP) introduced into the gas supply unit (10') is set. As a cooling means for lowering the temperature T ₁ ′, a refrigerant passage 12 coupled to the gas supply unit 10 ′ may be provided. The refrigerant passage 12 may be provided by a cooling jacket or a cooling block CJ surrounding the outside of the gas supply unit 10 . In addition, the refrigerant passage 12 may be provided inside the gas supply unit 10 as well as outside the gas supply unit 10 .

The refrigerant passage 12 is physically separated from the organic vapor precursor SP in the gas supply unit 10', so that the organic vapor precursor and the refrigerant do not mix. The temperature of the organic hypothetical precursor (SP) drawn into the gas supply unit 10' is lowered by the cooled gas supply unit 10, and is provided as a path P for forming the organic thin film OL. .

5 shows an organic vapor transfer deposition reactor 100D according to another embodiment of the present invention. Among the components disclosed in FIG. 5 , the components disclosed in these drawings may be referred to unless contradictory with respect to components having the same reference numerals as those of the components disclosed in FIGS. 2 to 4 .

Referring to FIG. 5 , the organic vapor transfer deposition reactor 100D may further include a cooling plate PL coupled to the gas supply unit 10 and extending toward the susceptor SB. In one embodiment, the gas supply unit-side end PLa of the cooling plate PL may be fixed to the gas supply unit 10 . Although the cooling plate PL shown is illustrated with respect to its cross section, the cooling plate PL is an organic vapor precursor (SP) from the gas supply unit 10 to the substrate SB along the edge of the gas supply unit 10. ) may be extended to surround the delivery path (P). In some embodiments, the other end PLb of the cooling plate PL is a free end and secures a gap between it and the susceptor 20 so that gas inside the reactor can be pumped and discharged.

The cooling plate (PL) lowers the temperature of the source precursor gas (SP) having a temperature of T ₁ when it is introduced on the path (P) from the gas supply unit 10 to the substrate (SB), thereby ΔG for the condensation reaction. The absolute value of can be reduced, and the possibility of condensation before reaching the substrate (SB) is minimized, so that the source precursor gas (SP) is not granulated by condensation on the path (P), and a high-quality organic thin film on the substrate (SB) (OL) can be deposited.

The cooling plate PL may include, for example, any one of copper, tungsten aluminum, and stainless steel, an alloy thereof, or a combination thereof, but the present invention is not limited thereto. The cooling plate PL may have an appropriate height considering the size of the path. The height of the cooling plate PL may be 50 mm to 1500 mm, preferably 80 mm to 1,000 mm, and may increase as the size of the substrate increases.

Refrigerants flowing through the cooling plate PL may have different temperatures in the longitudinal direction of the cooling plate PL. For example, the temperature of the cooling plate PL may be lowered toward the susceptor 20 from the gas supply unit 10 . Accordingly, in the organic vapor transfer deposition reactor 100D according to the embodiment of the present invention, the temperature profile experienced by the organic vapor precursor SP while reaching the substrate SB can be actively controlled.

6 and 7 are cross-sectional views illustrating a top-down organic vapor transfer vapor deposition reactor 100E and a vertical vapor deposition reactor 100F according to other embodiments of the present invention. In a Cartesian coordinate system for describing the arrangement direction of the reactors 100E and 100F, the x direction is a direction parallel to the ground, and the y direction is a direction perpendicular to the ground, that is, a direction parallel to the direction of gravity.

Referring to FIG. 6 , the reactor 100E for vapor deposition may include a chamber CH for maintaining a reduced-pressure atmosphere. To this end, a discharge pump EP may be attached to the chamber CH. The discharge pump (EP) is a vacuum system such as a cooling pump (cryo), turbo pump or dry pump, and may be any other pump suitable for maintaining a process pressure between 10 ⁻⁸ Torr and 1000 Torr. For pressure control of the chamber CH, the discharge pump EP may be connected to the chamber CH by a pressure valve PV.

The organic vapor phase precursor supplied into the chamber CH is generated in the source container SC. The organic source loaded into the source container SC is solid or liquid, and the organic source is sublimated and/or vaporized by a suitable heating means. The organic source may be an organic molecule suitable for vapor deposition, a conjugated polymer, an organometallic complex, or an inorganic source material, for example, C27H18AlN3O3(AlQ3) and N, N'-Bis(naphthalene-1-yl)-N, A known substance such as N'-bis(phenyl)benzidine (NPB) can be used. The present invention is not limited thereto.

The organic vapor phase precursor is delivered to the gas supply unit 10 along the gas line GL. The organic virtual precursor may be delivered using a high-temperature carrier gas to maintain an appropriate process pressure in the chamber CH and prevent the organic vapor phase precursor from condensing while passing through a delivery system such as the gas line GL. In this case, a port through which the carrier gas is introduced may be further installed inside the source container SC, and the carrier gas and the organic vapor precursor are mixed and delivered to the chamber CH in the source container SC. As is well known in the art for controlling the flow of the organic vapor phase precursor, a flow controller MF and a source valve SV are provided in the gas line GL between each source container CH and the gas supply unit 10. can be combined

The organic vapor precursor transferred into the chamber CH moves toward the substrate SB. In the top-down deposition method, the flow direction P of the organic vapor precursor is parallel to the direction of gravity. The discharge hole EO of the chamber CH to which the discharge pump EP is connected is disposed at a lower height than the susceptor SC, so that the flow of the organic vapor precursor in the flow direction P may be induced.

In some embodiments, the susceptor SC may have a configuration capable of moving in the y direction to control the thickness of the mass transfer boundary layer. The susceptor SC may move toward the gas supply unit 10 .

The cooling method described in the top-down structure can also be applied to a bottom-up structure.

Referring to FIG. 7 , the vapor deposition reactors 100F are similar to the above-described vapor deposition reactors 100A to 100E except that the flow direction P of the organic vapor precursor is perpendicular to the direction of gravity. The susceptor SC is movable in the horizontal direction x.

The discharge hole EO may be disposed on an axis connecting the centers of the gas supply unit SD and the susceptor SC so that the discharge pump EP applies a symmetrical pressure in the chamber CH. However, this is exemplary, and the discharge pump EV is a plurality of discharge pumps symmetrically coupled to the chamber CB at the rear of the susceptor SC for the delivery path P or a plurality of symmetric discharge balls. It may be formed and a single discharge pump may be coupled thereto.

It is common in the technical field to which the present invention belongs that the present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible within a range that does not depart from the technical spirit of the present invention. It will be clear to those who have knowledge of

Claims (13)

a gas supply unit having a plurality of dispersion openings for supplying an organic vapor phase precursor; and
A susceptor spaced apart from the gas supply unit by a predetermined distance, disposed opposite to the gas supply unit for surface-to-surface deposition of an organic thin film, and having a substrate placed thereon;
and a cooling means for reducing the temperature of the organic vapor phase precursor on a delivery path of the organic vapor phase precursor from the gas supply unit to the substrate to suppress condensation of the gas phase due to a temperature difference between the temperature of the organic vapor phase precursor and the substrate. do,
The ratio (ΔT/h) of the difference value (ΔT) between the temperature of the organic vapor phase precursor and the temperature of the substrate and the distance (h) between the gas supply unit and the substrate is organic vapor transmission within the range of 0.5 to 30 deposition reaction. According to claim 1,
The cooling means includes a cooling gas passage for supplying a cooling gas having a temperature lower than that of the organic vapor phase precursor into the gas supply unit,
wherein the cooling gas is mixed with the organic vapor phase precursor. According to claim 2,
wherein the cooling gas having a lower temperature than the organic vapor phase precursor comprises an inert gas. According to claim 1,
The cooling means is provided by injecting a cooling gas into the supply passage of the organic vapor phase precursor gas,
The organic vapor transfer deposition reactor of claim 1 , wherein the cooling gas has a lower temperature than the organic vapor phase precursor. According to claim 1,
The organic vapor transfer deposition reactor of claim 1 , wherein the cooling means comprises a refrigerant passage coupled to the gas supply unit for cooling an organic precursor gas. According to claim 1,
The cooling means further includes a cooling plate coupled to the gas supply unit and extending toward the susceptor, and the cooling plate includes a refrigerant passage for cooling the organic vapor precursor therein. as. According to claim 6,
The cooling plate is an organic vapor transfer deposition reactor comprising any one of copper, tungsten, aluminum, stainless steel, an alloy thereof, or a combination thereof. According to claim 6,
The substrate-side end of the cooling plate secures a gap with the substrate. According to claim 6,
The susceptor-side end of the cooling plate defines a gap between the susceptor and the mass transfer of the organic vapor precursor flow over the substrate during the deposition process by the size of the gap as the susceptor moves. An organic vapor transfer deposition reactor characterized in that the thickness of the boundary layer is controlled. According to claim 1,
The organic vapor transfer deposition reactor of claim 1 , wherein a distance between the gas supply unit and the substrate is in a range of 10 mm to 450 mm. delete According to claim 1,
The gas supply unit and the susceptor are disposed in a horizontal manner. According to claim 1,
The gas supply unit and the susceptor are disposed in a vertical manner.

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