KR20210114347A - Deposition source unit, deposition source and nozzle for deposition source - Google Patents

Abstract

Provided are a deposition source unit, a deposition source, and a nozzle for a deposition source, for maintaining high deposition rate while securing directivity of evaporated deposition materials. The deposition source unit (1), as a deposition source unit which deposits the deposition materials on a surface of a substrate, comprises a nozzle (20) with an outlet (21) discharging heated deposition materials. The nozzle (20) has a plurality of holes (20a) extended in the same direction with the extension direction of the nozzle (20). The plurality of holes (20a) have one end part open to the outlet (21), have aspect ratio of equal to or more than 2, and have length of equal to or less than one-fifth of a mean free path of a molecule.

Description

Evaporation source unit, evaporation source and nozzle for evaporation source

The present invention relates to an evaporation source unit, an evaporation source, and a nozzle for an evaporation source used when forming a thin film on a substrate.

As an apparatus for forming a thin film on the surface of a substrate, there is a film forming apparatus that heats and evaporates a vapor deposition material in a vacuum environment, and deposits the vaporized deposition material on the substrate surface to form a thin film. Such a thin film formation technique by vacuum deposition is, for example, as shown in Patent Document 1, by depositing an organic material to form an organic thin film, and OLED (Organic Light Emitting Display: hereinafter referred to as "organic EL display") It is also used for manufacturing. To deposit a vapor deposition material on a large substrate such as an organic EL display, it is necessary to achieve a uniform film thickness distribution, and in the vacuum film formation apparatus disclosed in Patent Document 1, a vapor deposition process is performed using a nozzle with high directivity.

Japanese Patent Application Laid-Open No. 2005-330551

In the film-forming source disclosed in patent document 1, the vapor deposition material heated by the heating means passes through the nozzle called the rectification|straightening part provided with the flow path divided by the fine opening, and is injected from the opening of a nozzle.

If the aspect ratio of one flow path (pipe) forming the rectifying part in Examples 1 and 2 of Patent Document 1 is calculated, 200 in Example 1 and 50 in Example 2 are required. Since the aspect ratio of the flow path in Patent Document 1 is large, it is necessary to lower the pressure inside the film formation source when the vapor deposition material is sprayed from the rectifying unit, and the film formation rate is significantly lowered. In addition, since the inner diameter of the opening of the flow path is small, a phenomenon in which the vapor deposition material is clogged in the minute opening occurs. The aspect ratio is a value obtained from l/2r (l is the nozzle length, r is the nozzle radius).

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an evaporation source unit, an evaporation source, and a nozzle for an evaporation source that can maintain a high film formation rate while ensuring the directivity of the evaporated evaporation material.

An evaporation source unit according to a first aspect of the present invention,

A deposition source unit for depositing a deposition material on the surface of a substrate, comprising:

A nozzle having a jet port for spraying the heated deposition material is provided,

A plurality of holes extending in the same direction as the extension direction of the nozzle are formed in the nozzle, and one end of the plurality of holes is opened to the jet port,

The aspect ratio of the pores is greater than or equal to 2, and the length of the pores is less than or equal to 1/5 of the mean free path of the molecule.

The plurality of holes may be arranged in a first direction parallel to an imaginary line drawn on the diameter of the nozzle when the nozzle is viewed from the jet port, and the centers of the holes in adjacent rows may be shifted from each other.

An evaporation source according to a second aspect of the present invention,

A plurality of evaporation source units according to the first aspect are provided,

The plurality of nozzles corresponding to the plurality of evaporation source units are arranged in the second direction with a predetermined pitch therebetween.

A limiting plate may be disposed between the nozzles adjacent to each other in the plurality of nozzles for limiting the direction in which the vapor deposition material is injected from the jet port.

In the limiting plate, the second direction in which the plurality of nozzles are arranged and the plate surface thereof may be vertically arranged.

The nozzle may be arranged so that the first direction in which the plurality of holes are arranged and the direction in which the limiting plate is arranged have a predetermined angle.

A nozzle for an evaporation source according to a third aspect of the present invention,

It is a nozzle for an evaporation source used for an evaporation source that deposits a deposition material on the surface of a substrate,

The aspect ratio is greater than or equal to 2, and the length of the nozzle is less than or equal to one-fifth the average free stroke of the molecule.

ADVANTAGE OF THE INVENTION According to this invention, the vapor deposition source unit, vapor deposition source, and the nozzle for vapor deposition sources can be provided which can maintain a high film-forming rate while ensuring the directivity of the vapor deposition material which evaporated.

1A is a top view of a conceptual diagram of an evaporation source unit according to an embodiment.
1B is a cross-sectional view taken along line X-X' of FIG. 1A.
Fig. 2 is a diagram schematically showing the movement of molecules in a hole.
3 is a graph showing the relationship between the number of molecules passing through the hole and the angle of the molecules ejected from the hole.
4 is a graph showing the relationship between the maximum injection angle of molecules that are injected after colliding with the wall surface of the hole and the aspect ratio.
5 is a graph showing the relationship between the half-value angle and the aspect ratio.
6A is a graph showing the distribution state of molecules due to a change in pressure.
6B is a graph showing the relationship between the probability of molecules passing directly through the nozzle and the film formation rate.
It is a graph which shows the relationship between the half-value angle of a single hole nozzle and a porous nozzle, and a film-forming rate.
8 is a conceptual diagram of a film forming apparatus including an evaporation source unit according to the present embodiment.
It is a schematic diagram which shows the state when vapor deposition material is sprayed toward a board|substrate from a some vapor deposition source unit.
Fig. 10 is a graph showing a film formation rate when a vapor deposition material is sprayed from a plurality of vapor deposition source units toward a substrate.
11 is a schematic diagram illustrating a state in which a limiting plate is installed in an evaporation source including a plurality of evaporation source units.
12 is a diagram illustrating a film formation rate with and without a limiting plate.
FIG. 13A is a diagram showing the range of a mask shadow when an evaporation source is used using a limiting plate, and shows the result when the thickness of the deposited film on the metal mask is 0 μm.
13B is a diagram showing the range of a mask shadow when an evaporation source is used using a limiting plate, and shows the result when the thickness of the deposited film on the metal mask is 2 μm.
13C is a diagram showing the mask shadow range when an evaporation source is used using a limiting plate, and shows the results when the thickness of the deposited film on the metal mask is 4 μm.
14A is a view showing the relationship between the row in which the nozzle holes are arranged and the angle between the limiting plate.
14B is a view showing the positional relationship between the limiting plate and the hole of the nozzle.
14C is a diagram showing a film formation rate and an evaporation distribution of an evaporation source using the nozzles shown in FIGS. 14A and 14B.
Fig. 15A is a view showing another example of the relationship between the row in which the nozzle holes are arranged and the angle between the limiting plate.
15B is a diagram showing a film formation rate and evaporation distribution of an evaporation source using the nozzle shown in FIG. 15A.
Fig. 16A is a view showing another example of the relationship between the row in which the nozzle holes are arranged and the angle between the limiting plate.
FIG. 16B is a diagram showing a film formation rate and evaporation distribution of an evaporation source using the nozzle shown in FIG. 16A.
17 is a view showing a modified example of the evaporation source unit.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of an evaporation source unit, an evaporation source, and a nozzle for an evaporation source according to the present invention will be described in detail with reference to the accompanying drawings. In addition, the embodiments described below are for illustration only, and do not limit the scope of the present invention. Therefore, those skilled in the art can employ embodiments in which each element or all elements are substituted with equivalents thereof, but such an embodiment is also included in the scope of the present invention.

(embodiment)

An overall structure of an evaporation source unit according to an embodiment of the present invention will be described with reference to FIG. 1 . Although the vertical and horizontal directions are defined in the drawings, these terms are used to describe the present embodiment, and do not limit the direction when the embodiment of the present invention is actually used. In addition, the technical scope described in the claims should not be construed as being limited by these terms.

(Structure of vapor deposition source unit)

Fig. 1 is a view schematically showing an evaporation source unit 1 according to the present embodiment, in which Fig. 1A is a top view and Fig. 1B is a view schematically showing a cross section taken along line X-X' in Fig. 1A. .

The vapor deposition source unit 1 according to the present embodiment is used, for example, in manufacturing an organic EL display. The organic EL display is formed by sandwiching an electron transport layer, a light emitting layer, and a hole transport layer between two electrodes, an anode and a cathode. The vapor deposition source unit 1 according to the present embodiment is used, for example, to deposit an electron transporting layer, a light emitting layer, a hole transporting layer or an electrode of an organic EL display on a TFT (Thin Film Transistor) substrate.

As shown in FIG. 1B, the vapor deposition source unit 1 evaporates by heating the crucible 10 containing the vapor deposition material 10a and the vapor deposition material 10a in the crucible 10 by a heating means (not shown). A nozzle 20 for spraying one deposition material is provided. The nozzle 20 is arranged to extend upward of the crucible 10 , and the ejection port 21 is formed to open above the evaporation source unit 1 . The nozzle 20 has a cylindrical shape, and the jet port 21 for spraying the vapor deposition material is opened on the side opposite to the side where the crucible 10 is arranged. A plurality of holes 20a extending in the same direction as the extending direction of the nozzle 20 are formed in the nozzle 20 . The length of each diameter of the plurality of holes 20a is the same. One opening 20ab of each hole 20a is opened to the jet port 21, and the other opening 20aa is opened to the crucible 10. As shown in FIG. As the vapor deposition material 10a, Alq3 or the like which forms a light emitting layer is used. The vapor deposition material 10a heated in the crucible 10 evaporates to become a gas, passes through the plurality of holes 20a of the nozzle 20 extending upward in the crucible 10, and is ejected from the jet port 21 . The extending direction of the nozzle 20 and the rising direction of the vapor deposition material 10a are the same direction, and the vapor deposition material 10a which evaporated is ejected quickly.

As shown in Fig. 1A, when the nozzle 20 is viewed from the upper surface, that is, the jet port 21, the plurality of holes 20a are arranged parallel to an imaginary line segment 20b drawn on the diameter of the nozzle 20. . In the present embodiment, seven holes 20a are arranged in a line on the line segment 20b above the diameter of the nozzle 20 . And the holes 20a are arranged side by side along three rows of rows arranged in parallel with the line segment 20b toward both sides of the line segment 20b, and 6, 5, and 4 holes are arranged in each row toward the outside. (20a) is arranged. A total of 37 holes 20a are formed in the nozzle 20 .

The holes 20a arranged parallel to the imaginary line segments 20b drawn on the diameter are arranged so that the centers of the holes 20a in adjacent rows are displaced. By arranging the plurality of holes 20a in this way, the distribution of molecules of the vapor deposition material ejected from the nozzle 20 can be made equal.

Next, the characteristic of the hole 20a is demonstrated. It is necessary to design the hole 20a so that the evaporation material ejected from the nozzle 20 can reach the substrate while maintaining a sufficient film formation rate while ensuring directivity.

The distribution of the vapor deposition material ejected from the hole 20a is considered from the viewpoint of maintaining a sufficient film-forming rate while ensuring directivity. When the average free path of the vapor deposition material molecules is very long and there is no collision between the molecules, as shown in FIG. 2 , the vapor deposition material molecules injected from the hole 20a have an opening on the crucible 10 side. Molecules that are incident from 20aa and directly pass through the hole 20a up to the opening 20ab on the side of the injection port 21 of the nozzle 20 and are ejected after colliding with the wall surface of the hole 20a; There are molecules that return into the hole 20a after colliding with the wall surface of the hole 20a. Molecules ejected after colliding with the wall surface of the hole 20a enter from the opening 20aa and collide once or multiple times on the wall surface of the hole 20a, pass through the opening 20ab and eject from the hole 20a toward the substrate. do. Molecules returning into the hole 20a are incident from the opening 20aa, collide once or plural times on the wall surface of the hole 20a, and pass through the opening 20aa again to return into the crucible 10. In Fig. 2, the movement of molecules passing directly through the hole 20a is a straight line, the movement of molecules passing through the hole 20a after colliding with the wall is a dotted line, and the movement of molecules passing through the hole 20a is a dotted line, and returning into the hole 20a after colliding with the wall surface. Molecular motion is indicated by a dotted dashed line. Among these molecules, if the number of molecules passing directly and passing after colliding with the wall surface increases, a sufficient film formation rate can be secured. In addition, in this embodiment, although the some hole 20a formed in the nozzle 20 is taken as an example and demonstrated, the characteristic of the hole 20a mentioned above and the characteristic of the hole 20a demonstrated below are short hole (單孔). ) nozzles, that is, the present embodiment can also be applied to an evaporation source nozzle having a single hole nozzle corresponding to one hole 20a constituting the evaporation source unit 1 .

The distribution of molecules ejected from the hole 20a is shown in FIG. 3 . In this distribution, when there is no collision between molecules in the nozzle 20 and only the wall surface collides, the distribution of the injected molecules is determined by the aspect ratio of the nozzle 20 , and the nozzle 20 ) does not depend on the diameter or length of the nozzle 20 , and corresponds to a distribution at a sufficiently distant distance compared to the size of the nozzle 20 . In Fig. 3, the horizontal axis represents the injection angle of molecules emitted from the opening 20ab of the hole 20a, and the vertical axis indicates the number of molecules emitted from the opening 20ab of the hole 20a. As a type of distribution of molecules to be injected, the distribution of molecules emitted from the opening 20ab by passing directly through the hole 20a is indicated by a white circle, and the distribution of molecules ejected from the opening 20ab after colliding with the wall surface is indicated by a white circle. A white circle is indicated by an X, and the sum distribution of both molecules passing directly through the hole 20a and molecules passing through the hole 20a after colliding with the wall surface is indicated by double circles. In addition, in FIG. 3 , the distribution of all molecules passing through the opening 20aa including the molecules returning to the hole 20a after colliding with the wall surface is indicated by a black circle. The aspect ratio is 2. The distribution of molecules passing through the hole 20a becomes narrower as the aspect ratio increases. In addition, it can be seen that the directivity of all passing molecules is mainly formed by direct passing molecules.

Fig. 4 shows the relationship between the aspect ratio and the angle at which the molecules emitted after colliding with the wall surface are maximized. The horizontal axis of the graph of FIG. 4 represents the aspect ratio of the hole 20a, and the vertical axis represents the peak injection angle in the injection angle distribution of molecules after collision with the wall surface as the maximum angle. The smaller the angle at which the molecules ejected after colliding with the wall are, the higher the directivity is and preferably. As shown in FIG. 4 , when the aspect ratio is less than 2, it can be seen that the maximum angle increases rapidly. If the aspect ratio is 2 or more, the maximum angle of the molecules injected after collision with the wall surface is small, so that the directivity of the total injection amount from the nozzle 20 can be effectively increased. When the aspect ratio is small, the number of molecules colliding with the wall surface is small, but the degree of irregular dispersion of the spray angle distribution of the evaporating particles becomes large.

Moreover, the relationship between an aspect-ratio and a half-value angle is shown in the graph of FIG. The horizontal axis of the graph is the aspect ratio of the hole 20a, and the vertical axis is the half-value angle. A half-value angle is the value which displayed the half-value width as an angle. The half width is the width of the distribution in which the evaporation distribution from the nozzle becomes half the peak value, and is a value indicating how spread the evaporation distribution is. The smaller the half angle, the higher the directivity, and in particular, when the aspect ratio is 2 or less as shown in Fig. 5, the half angle becomes very large, so it can be seen that the aspect ratio is preferably 2 or more.

On the other hand, since the number of molecules passing directly through the inside of the nozzle 20 decreases as the aspect ratio becomes large, it is necessary to improve the directivity of the vapor deposition material without reducing the number of molecules passing directly through it. In addition, since the conductivity (conductance) of the nozzle 20 decreases and the film formation rate tends to decrease as the aspect ratio becomes larger, it is necessary to improve the directivity without lowering the film formation rate. In addition, when the number of molecules that directly pass through the nozzle 20 increases, the number of molecules passing directly decreases and the directivity decreases. Applicants have found a suitable relationship to increase the number of molecules passing directly through the orifice 20a from the relationship between the mean free stroke and the nozzle length.

The average free path (λ) of a molecule is generally obtained from the following equation (1).

λ = 3.108 × 10 ^-24 × T / d ² P (Equation 1)

T is the temperature in the nozzle, d is the molecular diameter, and P is the pressure in the nozzle.

In the case of the mean free path (λ), if the probability (P(x)) of molecules entering the nozzle in the axial direction remaining without collision is regarded as a probability distribution function of the free path x of the molecules, P(x) can be calculated by Equation 2 below.

P(x) = N / N ₀ = exp (-x / λ) (Equation 2)

6A is a graph calculated using Equations 1 and 2 to calculate the change in the distribution of the injected molecules as the molecules passing directly through it are attenuated when the pressure is changed. Using a porous nozzle with a length of 9 mm, a diameter of 3 mm, and 37 holes, the passage probability is integrated and calculated|required with respect to the pressure gradient in a nozzle. It is assumed that the distribution of molecules ejected after colliding with the wall does not change. It can be seen that as the pressure increases and the number of molecules passing directly through decreases, the peak at the center decreases and the directivity decreases. Therefore, according to Equation 2, when the nozzle length is 1/5 or less of the average free stroke (λ) in designing the nozzle length, the collision-free rate of molecules is 80% or more. Preferably, when the nozzle length is 1/10 or less of the mean free stroke (λ), the collision-free rate of molecules is 90% or more. Accordingly, the directivity of the hole 20a is improved by designing the hole 20a having such a nozzle length. Specifically, the nozzle length is set to 1/5 or less of the average free stroke (λ), and the pressure and temperature are determined from Equation 1.

In calculating the above-described average free stroke (λ), the pressure in the nozzle that can be used in Equation 1 is considered. 6B is a graph in which the probability of molecules passing directly through a porous nozzle having a length of 9 mm, a diameter of 3 mm, and 37 holes was calculated in relation to the film formation rate. In the graph, the triangle is the same condition as in FIG. 6A, and the passage probability is calculated as there is a pressure gradient in the nozzle, but the square indicates that the pressure in the nozzle is constant and the passage probability is calculated using the average pressure. The average pressure is the average of the nozzle inlet pressure and the nozzle outlet pressure, and is equal to the pressure in the nozzle at half the nozzle length. Since the result of integrating the passage probability with respect to the pressure gradient (triangle) and the result of calculating the passage probability from the average pressure (square) coincide, the average free stroke λ may be calculated from the average pressure. In addition, the passage probability in the case of using the pressure in the crucible 10 as the nozzle inlet 20aa is indicated by a circle. Since the result of integrating the passage probability with respect to the pressure gradient (triangle) and the result of calculating the passage probability from the nozzle inlet pressure (circle) are approximate, the average free stroke λ may be obtained using the nozzle inlet pressure.

In this embodiment, the film-forming rate is improved using the porous nozzle provided with the plurality of holes 20a. Fig. 7 shows a graph showing the evaporation distribution when the nozzle 20 which is a porous nozzle is used and the evaporation distribution of the single hole nozzle in relation to the film formation rate. In the graph of FIG. 7 , the vertical axis is the half-value angle, and the horizontal axis is the film formation rate.

In the graph of FIG. 7, the circle represents the measured values of a single hole nozzle having a length of 60 mm and a diameter of 20 mm, a square is a porous nozzle having a length of 6 mm, a diameter of 2 mm, and 61 holes, and a triangle is a porous nozzle having a length of 9 mm, a diameter of 3 mm, and a diameter of 37 holes. represents a value. The white color represents the evaporation distribution at a distance of 200 mm from the nozzle opening, and the black color represents the evaporation distribution at a position of 300 mm from the nozzle opening, respectively. For both the single hole nozzle and the porous nozzle, a nozzle having an aspect ratio of 3 was used. In addition, the line in the figure shows the calculated value of the half-value angle of the distribution changed as the number of molecules passing directly shown in FIG. 6A decreases, the solid line is the distance of the porous nozzle with a diameter of 3 mm, the distance of 300 mm, and the dashed-dotted line is the diameter The distance of 2 mm perforated nozzle is 300 mm, the double-dotted line is the distance of the hole nozzle with a diameter of 2 mm is 200 mm, the fine dotted line is the distance of the single hole nozzle 300 mm, and the thick dotted line is the value at the distance of the single hole nozzle 200 mm. The measured values and the calculated values agree well, indicating that the half-value angle increases as the number of molecules passing directly in the nozzle decreases. In both the single hole nozzle and the porous nozzle, the half value angle is constant in the region where the film formation rate is low, but as the rate increases, the half value angle increases from a certain rate. The rate at which the half-value angle starts to increase is lower in the single-hole nozzle than in the perforated nozzle, and a small half-angle in the perforated nozzle is obtained at a higher rate. Even at the same rate when a porous nozzle is used, the half-value angle is smaller than that of a single pore nozzle, and directivity is good.

(film forming device)

Next, the film-forming apparatus using the above-mentioned vapor deposition source unit 1 is demonstrated. As shown in FIG. 8 , the film forming apparatus 100 includes an evaporation source 120 and a metal mask 130 in a vacuum chamber 110 . The vacuum chamber 110 opens and closes the valve 111 so that the pressure inside is reduced by a vacuum pump (not shown).

The deposition source 120 includes a plurality of deposition source units 1 . The plurality of evaporation source units 1 are arranged in a line in a predetermined direction (also referred to as a second direction) with a predetermined pitch therebetween. Each evaporation source unit 1 is arranged with the jet port 21 of the nozzle 20 facing upward. The metal mask 130 and the substrate 140 are disposed above the deposition source 120 , and the metal mask 130 is disposed between the deposition source 120 and the substrate 140 . The metal mask 130 is used to form a predetermined pattern on the substrate 140 . The substrate 140 is conveyed in a predetermined conveying direction (rear or front direction in the drawing), that is, in a direction perpendicular to the direction in which the deposition source units 1 are arranged. As the substrate 140 is transported, a deposition film is deposited on the surface of the substrate 140 by the deposition source 120 .

9 shows a process of depositing the deposition layer 140a on the surface of the substrate 140 through the metal mask 130 . The deposition material injected from each nozzle 20 is diffused in the vacuum chamber 110 so as to spread outward from the central position of the nozzle 20 . The deposition material sprayed from the nozzle 20 passes through the opening of the metal mask 130 to reach the substrate 140 , and a deposition film 140a is formed on the substrate 140 .

When such a deposition source 120 is used, the deposition material injected into the vacuum chamber 110 has a region that prevents deposition on the substrate 140 due to the presence of the metal mask 130 . That is, the deposition material does not sufficiently reach the outer portion of the pattern of the deposition film 140a formed on the substrate 140, so-called mask shadow occurs. For example, as shown in FIG. 9, when the distance h between the substrate 140 and the nozzle 20 is 300 mm, the deposition distribution of the deposition material sprayed from the nozzle 20 is the distribution shown in FIG. becomes Also, in FIG. 9 , t _m is the thickness of the metal mask 130 , and t _f is the thickness of the deposition layer 130a deposited on the metal mask 130 .

In FIG. 10 , the horizontal axis indicates the position in the deposited film 140a when the center of the deposited film 140a is 0, and the vertical axis indicates the deposition rate. As can be seen from the drawing, a mask shadow in which the deposition material is not sufficiently deposited is formed on the outer portion of the deposition layer 140a. In the example of the figure, the mask shadow occurs with a width of about 5 μm (0.005 mm).

In order to minimize the area where the mask shadow occurs as much as possible, the applicant has found that it is effective to dispose the limiting plate 121 shown in FIG. 11 between the nozzle 20 and the nozzle 20 . In this embodiment, the distance between the center position of the nozzle 20 and the center position of this nozzle 20 and the adjacent nozzle 20 is defined as 1 pitch P. As shown in FIG. In the drawing, h _s is the height of the limiting plate 121 , t _s is the thickness of the limiting plate 121 , w is the opening width _{of the metal mask 130 , t m} is the thickness of the metal mask 130 , t _f is The thickness, h, of the deposition layer 130a deposited on the metal mask 300 represents a distance between the substrate and the nozzle.

The limiting plate 121 is disposed at a position P/2 between the nozzles 20 arranged in a row. The plate surface of the limiting plate 121 is disposed perpendicular to the direction (second direction) in which the plurality of nozzles 20 are arranged. Since the limiting plate 121 is disposed between the adjacent nozzles 20 , the deposition material injected from the nozzle 20 comes into contact with the limiting plate 121 to narrow the distribution of the deposition material, thereby reducing the area where the mask shadow occurs. can be narrowed down The results of the specific deposition distribution are shown in FIG. 12 .

12 shows the vapor deposition distribution of the vapor deposition material of the nozzle 20 alone when the limiting plate 121 is disposed between the nozzles 20 . The graph shown in FIG. 12 shows the film-forming rate at the time of using the nozzle 20 in which the diameter 3mm and length 9mm were formed with 37 holes in relation to the position of the nozzle 20. As shown in FIG. The horizontal axis represents the position on the substrate 140 when the position immediately above the center of the nozzle 20 is 0, and the vertical axis represents the film formation rate. A case in which the limiting plate 121 is not present is indicated by a solid line, and a case in which the limiting plate 121 is present is indicated by a white circle. In the case where the limiting plate 121 is present, compared to the case in which the limiting plate 121 is not present, the deposition material having a large spraying angle among the deposition materials sprayed from the jet port 21 of the nozzle 20 is shielded by the limiting plate 121 and thus the substrate It can be seen that the direction is not reached.

13A to 13C show the deposition rate of the deposited film 140a formed on the substrate 140 when the limiting plate 121 is disposed between the nozzles 20 . The horizontal axis indicates the position in the deposited film 140a when the center of the deposited film 140a is 0, and the vertical axis indicates the deposition rate. The deposition source 120 is configured by arranging nine nozzles 20 at a pitch P of 80 mm. As the limiting plate 121 , a plate having a height (h): 90 mm and a thickness (t _s ): 1.5 mm was used. 13A shows the deposition rate when the deposition film thickness t _f on the metal mask 130 is 0 μm, FIG. 13B shows the deposition film thickness t _f is 2 μm, and FIG. 13C shows the deposition rate when the _{deposition film thickness t f is 4 μm.} 13A and 13B , if the deposited film thickness t _f on the metal mask 130 is 2 μm or less, the range of the mask shadow can be suppressed to 2 μm or less.

By disposing the limiting plate 121 between the nozzles 20, the range of the mask shadow can be reduced, but there is a difference in the distribution of the deposition material depending on the arrangement method of the plurality of holes 20a formed in the nozzle 20. found out that 14A is a diagram showing the arrangement of a plurality of holes 20a in the nozzle 20 . In the nozzle 20, 37 holes 20a having a diameter of 3 mm and a length of 9 mm are formed. The outline of the nozzle 20 is not shown in FIG. 14A . Similarly, the outline of the nozzle 20 is not shown in the following FIGS. 15A and 16A as well.

The plurality of holes 20a are arranged parallel to an imaginary line segment 20b on the diameter of the nozzle 20 . The direction a in which the line segment 20b extends (hereinafter, the arrangement direction of the holes 20a is also referred to as a direction a) and the direction b in which the limiting plate 121 extends are the same. That is, as shown in FIG. 14B , the direction in which the limiting plate 121 and the hole 20a are arranged is the same. In addition, the limiting plate 121 is arranged so that the arrangement direction c of the nozzles 20 and the plate surface of the limiting plate 121 are perpendicular to each other. The direction a is also referred to as a first direction.

The deposition distribution and deposition rate using the deposition source 120 in which nine such nozzles 20 are arranged in a line with a pitch P of 65 mm are shown in FIG. 14C . In FIG. 14C , white circles indicate deposition distribution, and black circles indicate deposition rates. The graphs in FIGS. 15B and 16B are also the same. _{The length h s} of the limiting plate 121 is 75 mm, the thickness t _s is 1.5 mm, and the distance h from the tip of the nozzle 20 to the substrate surface is 300 mm. The holes 20a are arranged as shown in Fig. 14A, and when the deposition material collides with the limiting plate 121, it becomes a step-shaped deposition distribution as shown in Fig. 14C. The distribution of the deposition material in this arrangement is 2.9%.

In order to smooth the distribution of the step shape, if the angle formed by the arrangement direction a of the holes 20a of the nozzle 20 and the direction b of the limiting plate 121 is changed, the distribution of the step shape can be improved. I found out that I can. 15 and 16 show examples thereof.

The nozzle 20 used in Fig. 15A is a nozzle in which 37 holes having a diameter of 3 mm and a length of 9 mm were formed, similarly to the nozzle 20 used in Fig. 14A. The arrangement direction a of the holes 20a of the nozzle 20 is not parallel to the extension direction b of the limiting plate 121, but an arrangement of the holes 20a inclined by 30 degrees as shown in FIG. 15A.

The deposition distribution and the deposition rate in the case of using the deposition source 120 in which nine such nozzles 20 are arranged in a line with a pitch P of 65 mm are shown in FIG. 15B . _{The length h s} of the limiting plate 121 is 75 mm, the thickness t _s is 1.5 mm, and the distance h from the tip of the nozzle 20 to the substrate surface is 300 mm. The distribution of the deposition material in this arrangement was 2.1%.

The nozzle 20 used in Fig. 16A is a nozzle in which 37 holes having a diameter of 3 mm and a length of 9 mm were formed, similarly to the nozzle 20 used in Fig. 14A. The arrangement direction a of the holes 20a of the nozzle 20 is not parallel to the extension direction b of the limiting plate 121, but an arrangement of the holes 20a inclined by 25 degrees as shown in Fig. 16A.

The deposition distribution and deposition rate using the deposition source 120 in which nine such nozzles 20 are arranged in a line with a pitch P of 65 mm are shown in FIG. 16B . _{The length h s} of the limiting plate 121 is 75 mm, the thickness t _s is 1.5 mm, and the distance h from the tip of the nozzle 20 to the substrate surface is 300 mm. The distribution rate of the vapor deposition material in this arrangement was 1.1%. As described above, it can be seen that when the arrangement direction a of the holes 20a of the nozzle 20 is inclined with respect to the extension direction b of the limiting plate 121, the distribution of the deposition material is improved.

According to this embodiment, since the aspect ratio of the hole 20a is 2 or more and the nozzle length is 1/5 or less of the average free stroke, the directivity of the nozzle 20 can be improved and the film formation rate can also be maintained well.

According to this embodiment, the surface of large-sized substrates, such as an organic electroluminescent display, can be formed into a film uniformly by the vapor deposition source 120 which arrange|positioned the some nozzle 20 in a predetermined direction (2nd direction).

According to the present embodiment, since the limiting plate 121 is disposed between the plurality of nozzles 20 , the range in which the mask shadow is generated on the substrate 140 can be reduced.

According to the present embodiment, since the limiting plate 121 is arranged so that the direction in which the plurality of nozzles 20 are arranged (the second direction) and the plate surface are perpendicular to each other, the deposition material sprayed on the substrate 140 is evenly spread. can do.

According to this embodiment, since the nozzle 20 is arranged so that the arrangement direction a (first direction) in which the plurality of holes 20a are arranged and the direction b in which the limiting plate 121 is arranged have a predetermined angle, vapor deposition It is possible to reduce the irregular dispersion of the material distribution.

(variant example)

In the present embodiment, it has been described that the nozzles 20 extending upward from the crucible 10 are arranged in the evaporation source unit 1, but the arrangement of the nozzles 20 may be different. For example, as shown in FIG. 17 , in the deposition source unit 30 , the nozzle 300 may be disposed on the side of the crucible 200 , for example, in a left direction. The nozzle 300 extends in the left direction, and the jet port 301 of the nozzle 300 opens to the side of the evaporation source unit 30 . A plurality of holes 300a extending in the same direction as the extending direction of the nozzle 300 are formed in the nozzle 300 . After the deposition material 200a heated in the crucible 200 rises, the direction is changed in the deposition source unit 30 and is ejected from the nozzle 300 extending perpendicular to the rising direction. Since the vapor deposition material 200a evaporated by arranging the nozzle 300 at such a position is sufficiently diffused in the vapor deposition source unit 30 and ejected from the nozzle 300, the vapor deposition material 200a is ejected from the ejection port 301 equally. In addition, it is possible to increase the degree of freedom in the design of the evaporation source unit 1 .

In the present embodiment, the nozzle 20 has been described as being a porous nozzle having a plurality of holes 20a extending in the same direction as the extending direction of the nozzle 20 . Instead of forming the hole 20a in the nozzle 20, a plurality of thin tube-shaped tubes may be bundled to form the nozzle 20 instead of the hole 20a.

In the present embodiment, the deposition source 120 has been described as being formed by arranging the deposition source units 1 in a row, but the deposition source 120 is formed by arranging the deposition source units 1 in a plurality of rows. also good

In this embodiment, it has been described that the plurality of holes 20a formed in the nozzle 20 are arranged parallel to the imaginary line segment 20b drawn on the diameter. good.

In the present embodiment, the moving direction of the substrate 140 is described as being perpendicular to the direction in which the plurality of evaporation source units 1 of the evaporation source 120 are arranged. good.

In the present embodiment, the number of holes 20a formed in the nozzle 20 was described as 37, but other numbers may be used.

In this embodiment, the pitch of the nozzle 20, the height of the limiting plate 121, the thickness of the limiting plate 121, and the distance from the tip of the nozzle 20 to the substrate in FIGS. 14 to 16 were described under the same conditions. . These values can be appropriately changed to smooth the deposition distribution.

In the present embodiment, an organic EL display is taken as an example as the substrate using the vapor deposition source unit 1, but it can be used for all other substrates and can also be used for generating a light absorption film used in a solar cell.

In addition, the present invention is not limited to the above-described embodiment, and various modifications are possible within the scope indicated in each claim. That is, embodiments obtained by combining technical means appropriately changed within the scope shown in the claims are also included in the technical scope of the present invention.

This application is based on Japanese Patent Application Japanese Patent Application No. 2020-041256 for which it applied on March 10, 2020. In the present specification, the entire specification, claims, and drawings of Japanese Patent Application No. 2020-041256 are incorporated by reference.

INDUSTRIAL APPLICABILITY The present invention can be applied to a deposition source unit, a deposition source, and a deposition source nozzle for depositing a deposition material on the surface of a substrate.

1 Evaporator unit
10 crucible
10a deposition material
20 nozzles
20a hole
20b line segment
20aa, 20ab opening
21 vent
30 Evaporator Unit
100 film forming device
110 vacuum chamber
111 valve
120 vapor source
121 limited edition
130 metal mask
130a deposited film
140 board
140a deposited film
200 crucible
200a deposition material
300 nozzles
301 vent
300a hole

Claims (7)

A deposition source unit for depositing a deposition material on the surface of a substrate, comprising:
and a nozzle having a jet port for spraying the heated deposition material,
A plurality of holes extending in the same direction as the extension direction of the nozzle are formed in the nozzle, and one end of the plurality of holes is opened to the jet port;
An aspect ratio of the holes is 2 or more, and a length of the holes is 1/5 or less of an average free path of molecules. The method according to claim 1,
The plurality of holes are arranged in a first direction parallel to an imaginary line drawn on the diameter of the nozzle when the nozzle is viewed from the jet port, and centers of holes in adjacent rows are shifted from each other. An evaporation source comprising a plurality of evaporation source units according to claim 1 or 2,
A plurality of the nozzles corresponding to the plurality of evaporation source units are arranged in a second direction with a predetermined pitch therebetween. 4. The method according to claim 3,
An evaporation source having a limiting plate disposed between adjacent nozzles in the plurality of nozzles, each limiting plate restricting a direction of spraying of the deposition material sprayed from the jetting port. 5. The method according to claim 4,
The limiting plate is an evaporation source in which the second direction in which the plurality of nozzles are arranged and the plate surface are perpendicular to each other. 6. The method of claim 5,
and the nozzle is disposed such that the first direction in which the plurality of holes are arranged and the direction in which the limiting plate is arranged have a predetermined angle. A nozzle for an evaporation source used in an evaporation source for depositing a deposition material on a substrate surface, comprising:
A nozzle for an evaporation source having an aspect ratio of 2 or more and a nozzle length of 1/5 or less of the average free path of molecules.

Images