WO2011155661A1

WO2011155661A1 - Linear effusion cell, method of manufacturing the same and evaporator using the same

Info

Publication number: WO2011155661A1
Application number: PCT/KR2010/005031
Authority: WO
Inventors: Deok Ha Woo; Sun Ho Kim; Seok Lee; Young Tae Byun; Young Min Jhon; Jae Hun Kim; Min Chul Park; Shin Geun Kim; Yong Woo Jung
Original assignee: Korea Institute Of Science And Technology
Priority date: 2010-06-10
Filing date: 2010-07-30
Publication date: 2011-12-15
Also published as: JP2013529258A; KR20110135138A; JP5732531B2; KR101265067B1

Abstract

Disclosed herein is a linear effusion cell, which is used in a vacuum deposition system, including: a crucible made of pyrolytic boron nitride (PBN), having an open upper portion and containing a raw material; a first heat generating unit formed on an outer surface of the crucible and having a pattern suitable for heating; an array of orifices formed through the lateral sides of the crucible and the first heat generating unit.

Description

LINEAR EFFUSION CELL, METHOD OF MANUFACTURING THE SAME AND EVAPORATOR USING THE SAME

The present invention relates to a linear effusion cell including a crucible and a heat generating unit, which is used in an evaporation system such as an organic light emitting diode deposition apparatus, and which is used to deposit a material emitted from the crucible by heating on a substrate, a method of manufacturing the same, and a linear evaporator using the same. More particularly, the present invention relates to a linear effusion cell including a heat generating unit formed by depositing a heat generating material on the outer surface of an effusing unit and then patterning the deposited heat generating material, an array of orifices formed at the lateral side of the effusing unit, wherein the raw material is emitted from the crucible through the array of orifices formed at the lateral side of the effusing unit directly adjacent to the heat generating unit by applying voltage to the heat generating unit, and to a method of manufacturing the same and a linear evaporator using the same.

General methods of forming a thin film on a substrate include physical vapor deposition (PVD) methods, such as a vacuum evaporation method, an ion plating method and a sputtering, and chemical vapor deposition (CVD) methods using gas reactions. An organic light emitting diode thin film is formed by depositing an organic material constituting an organic light emitting diode on a substrate using a vacuum evaporation method. Further, in an organic light emitting diode, an electrode is formed by depositing a metal, such as aluminum, using a vacuum evaporation method.

A general deposition apparatus for forming an organic film or a metal film includes a deposition chamber whose upper portion is provided with a substrate and whose lower portion is provided with an effusion cell. The effusion cell includes a crucible containing a depositing material and a heat generating unit disposed on the outer surface of the crucible and acting as a heat source for evaporating the depositing material. When power is applied to the heat generating unit of the effusion cell, the crucible and the depositing material contained therein are heated to evaporate the depositing material, and the evaporated material is deposited on the substrate provided in the upper portion of the deposition chamber through openings formed in the upper portion of the crucible, thus forming an organic film or a metal film on the substrate. In relation to the effusion cell, Korean Patent Application No. 10-2009-114068, filed by the present applicant, discloses “a molecular beam effusion cell integrated with a heat generating unit, a method of manufacturing the same, and an evaporator using the same". The molecular beam effusion cell integrated with a heat generating unit disclosed in Korean Patent Application No. 10-2009-114068 includes a crucible which is made of pyrolytic boron nitride (PBN) and contains a depositing material used in a deposition system for forming an organic film in vacuum, and a heat generating unit which is formed on the outer surface of the crucible made of pyrolytic boron nitride (PBN). In this molecular beam effusion cell integrated with a heat generating unit, the heat generating unit formed on the outer surface of the crucible is directly heated, so that the crucible is heated by heat conduction, thereby increasing a thermal efficiency and simplifying a structure.

However, a large-size OLED substrate is problematic in that when it is provided in the upper portion of a deposition chamber, it is extremely warped, and thus a deposition material is not uniformly deposited thereon, and in that it cannot be easily handled. Therefore, if a large-size substrate is disposed vertically or at an angle of 20 degrees or less from the vertical direction in the lateral side portion inside a deposition chamber or is disposed in the lower portion thereof, it is not warped and is easy to handle. Meanwhile, the effusion cell is problematic in that a depositing material cannot be deposited on a substrate disposed vertically in the lateral side portion inside a deposition chamber or disposed in the lower portion thereof because the depositing material is emitted through the openings formed in the upper portion of the conventional crucible.

Therefore, it is required to develop a linear effusion cell which can efficiently supply a depositing material to a substrate disposed vertically in the lateral side portion inside a deposition chamber or disposed in the lower portion thereof.

Accordingly, the present invention has been devised to solve the above-mentioned problems, and an object of the present invention is to provide a linear effusion cell for laterally emitting a raw material, which can be used in a deposition system for forming a thin film in line by vertically disposing a substrate, a method of manufacturing the same, and an evaporator using the same.

In order to accomplish the above object, a first aspect of the present invention provides a linear effusion cell, which is used in a vacuum deposition system, including: a crucible made of pyrolytic boron nitride (PBN), having an open upper portion and containing a raw material; a first heat generating unit formed on an outer surface of the crucible and having a pattern suitable for heating; and an array of orifices formed through the lateral sides of the crucible and the first heat generating unit.

A second aspect of the present invention provides a linear effusion cell, which is used in a vacuum deposition system for depositing a raw material such as organic material or the like on a sample in vacuum, including: a crucible made of pyrolytic boron nitride (PBN) and containing the raw material; a first heat generating unit made of pyrolytic graphite (PG), deposited on the outer surface thereof and having a pattern suitable for heating; a first protective film made of pyrolytic graphite (PG) and formed on an inner surface of the crucible to protect the crucible from a material, such as aluminum, which easily adheres to pyrolytic boron nitride (PBN); an isolating unit for electrically isolating the first heat generating unit and the first protective film; and an array of orifices formed through the lateral sides of the crucible and the first heat generating unit. Since a specific material, such as aluminum, easily adheres to the crucible made of pyrolytic boron nitride (PBN) while it changes from liquid to solid during the cooling process, there is a problem in that the crucible is damaged due to the difference in the thermal expansion coefficient between the material and the crucible. In this case, since the material does not easily adhere to pyrolytic graphite (PG), the problem of damage to the crucible can be solved by forming a protective film made of pyrolytic graphite (PG) on the inner surface of the crucible.

A third aspect of the present invention, in the first aspect of the present invention, provides a linear effusion cell further including: a cover made of pyrolytic boron nitride (PBN) and covering the open upper portion of the crucible; and a second heat generating unit made of pyrolytic graphite (PG), formed on an outer surface of the cover and having a pattern suitable for heating.

A fourth aspect of the present invention, in the second aspect of the present invention, provides a linear effusion cell further including: a cover made of pyrolytic boron nitride (PBN) and covering the open upper portion of the crucible; a second heat generating unit made of pyrolytic graphite (PG), formed on an outer surface of the cover and having a pattern suitable for heating; a second protective film made of pyrolytic graphite (PG) and formed on an inner surface of the cover to protect the crucible from a material, such as aluminum, which easily adheres to pyrolytic boron nitride (PBN); and an isolating unit for electrically isolating the second heat generating unit and the second protective film.

A fifth aspect of the present invention provides a linear effusion cell, which is used in a vacuum deposition system, including: an evaporation unit including a crucible made of pyrolytic boron nitride (PBN) and a first heat generating unit formed on an outer surface of the crucible and having a pattern suitable for heating; an effusing unit made of pyrolytic boron nitride (PBN); a second heat generating unit formed on an outer surface of the effusing unit and having a pattern suitable for heating; and an array of orifices formed through the lateral side of the effusing unit and the second heat generating unit.

A sixth aspect of the present invention, in the fifth aspect of the present invention, provides a linear effusion cell further including: protective films made of pyrolytic graphite (PG) and formed on the inner surfaces of the crucible and the effusing unit to protect the crucible from a material, such as aluminum, which easily adheres to pyrolytic boron nitride (PBN).

A seventh aspect of the present invention provides a method of the linear effusion cell of any one of aspects 1 to 6.

An eighth aspect of the present invention provides an evaporator including electrodes for power supply, which is used as a support when the linear effusion cell is mounted on a vacuum flange.

A ninth aspect of the present invention provides a linear evaporator further including: spacers designed such that the contact area between the spacers and the linear effusion cell in order to prevent the linear effusion cell from being moved or damaged at the time of mounting the linear effusion cell on the vacuum flange.

A tenth aspect of the present invention further including: spreaders for uniformly supplying electric current to heat generating units by dispersing force and electric current at the time of fixing the linear effusion cell on the electrodes for supplying electrical power.

According to the linear effusion cell of the present invention, in a deposition system for vertically disposing a substrate and forming a thin film in line on the substrate, a raw material can be easily and uniformly deposited even on a large-size substrate because the raw material is efficiently and laterally emitted.

The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a schematic sectional view showing a linear effusion cell according to a first embodiment of the present invention;

FIG. 2 is a schematic sectional view showing a linear effusion cell according to a second embodiment of the present invention;

FIG. 3 is a schematic sectional view showing a linear effusion cell according to a third embodiment of the present invention;

FIG. 4 is a schematic sectional view showing a linear effusion cell according to a fourth embodiment of the present invention;

FIG. 5 is a perspective view showing a conventional evaporator;

FIG. 6 is a schematic sectional view showing a linear evaporator using the linear effusion cell according to an embodiment of the present invention;

FIG. 7 is a schematic sectional view showing a linear evaporator using the linear effusion cell while disposing a vacuum flange according to another embodiment of the present invention;

FIG. 8 is a flowchart showing a method of manufacturing a linear effusion cell according to a first embodiment of the present invention;

FIG. 9 is a flowchart showing a method of manufacturing a linear effusion cell according to a second embodiment of the present invention;

FIG. 10 is a flowchart showing a method of manufacturing a linear effusion cell according to a third embodiment of the present invention; and

FIG. 11 is a flowchart showing a method of manufacturing a linear effusion cell according to a fourth embodiment of the present invention.

[Description of the elements in the drawings]

10: crucible

20: first heat generating unit

30: raw material (sample)

40, 240: orifice

50: cover

60, 220: second heat generating unit

70: first protective film

90, 270: second protective film

80, 100, 110: isolating unit

300: thermocouple

500a, 500b: spacer

600: electrode for power supply

700a, 700b: spreader

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

For reference, FIG. 5 is a perspective view showing a conventional evaporator. As shown in FIG. 5, the conventional evaporator includes a crucible 1, a heat shielding 2, a heater 3 disposed between the crucible 1 and the heat shielding 2, a thermocouple 4, a lower heat shielding 5, a vacuum flange 6, an electrode 7 for power supply, and a power connector 8. In this conventional evaporator, since the lateral side of the crucible 1 is surrounded by a heat generating unit with the heat generating unit spaced apart from the crucible, orifices cannot be formed in the lateral side of the crucible 1, and thus a raw material is emitted through openings formed on the upper portion of the crucible 1.

FIG. 1 is a schematic sectional view showing a linear effusion cell according to a first embodiment of the present invention.

As shown in FIG. 1A, in a deposition system for depositing a raw material, such as organic material, a metal or the like, on a sample in vacuum, the linear effusion cell according to a first embodiment of the present invention includes: a crucible 10 made of pyrolytic boron nitride (PBN) and containing a raw material 30; a first heat generating unit 20 made of pyrolytic graphite (PG), deposited on the outer surface thereof and having a pattern suitable for heating; a array of orifices 40 formed through the lateral side of the crucible 10 and the lateral side of the first heat generating unit 20; a cover 50 made of pyrolytic boron nitride (PBN) and covering the opening of the crucible 10; a second heat generating unit 60 made of pyrolytic graphite (PG), deposited on the outer surface thereof and having a pattern (for example, a symmetrical pattern) suitable for heating.

When voltage is applied to the first heat generating unit 20 and the second heat generating unit 60, the ratio of the thickness of the second heat generating unit 60 formed on the cover 50 and the thickness of the first heat generating unit 20 formed on the crucible 10 and the patterns of the first and second

heat generating units

20 and 60 may be controlled such that the temperature of the cover 50 is higher than or equal to the temperature of the crucible 10.

FIG. 1B is a schematic sectional view showing the linear effusion cell taken along the line A-A’ in FIG. 1A. As shown in FIG. 1B, an example of the structure of the first heat generating unit may be formed by partially removing a heat generating material (PG) deposited on the lateral surface of the crucible to a width of about 0.5 mm ranging from the bottom of the crucible to the top thereof in a direction perpendicular to the orifices formed in the lateral side of the crucible. In the first heat generating unit having such a structure, resistances are increased around the orifices, so that the temperatures of the vicinity of the orifices become high compared to other portions, thereby easily obtaining preferable temperature distribution in a simple symmetrical pattern.

As described above, in the linear effusion cell according to the first embodiment of the present invention, pyrolytic graphite (PG) is directly deposited on the outer surface of the crucible 10 made of pyrolytic boron nitride (PBN), so that an integrated linear effusion cell in which the first heat generating unit 20 and the crucible 10 are attached to each other can be realized, with the result that the array of orifices 40 can be easily formed in the lateral side of the linear effusion cell.

Since the pressure in the crucible is decreased from the lower portion thereof to the upper portion thereof, the thickness of a material deposited on a substrate can be made uniform by decreasing the intervals between the orifices formed in the upper portion thereof or increasing the sizes of the orifices formed in the upper portion thereof.

The height of the crucible formed in the lateral side thereof with the orifices may be slightly higher than the height of a substrate such that a large-area substrate can be deposited with a raw material over the entire area thereof.

FIG. 2 is a schematic sectional view showing a linear effusion cell according to a second embodiment of the present invention. As shown in FIG. 2, the linear effusion cell according to a second embodiment of the present invention further includes protective films formed by depositing pyrolytic graphite (PG) on the inner surfaces of the crucible 10 and the cover 50 and the surfaces of the orifices 40 of the first embodiment of the present invention. That is, the linear effusion cell according to the second embodiment of the present invention includes: a first protective film 70 made of pyrolytic graphite (PG) and formed on the inner surface of the crucible 10 and the surfaces of the orifices 40 in order to protect the crucible 10 from a sample which is easily adhered to pyrolytic boron nitride (PBN); a first isolating unit 80 formed by removing the pyrolytic graphite (PG) in order to electrically isolat the first heat generating unit 20 and the first protective film 70 in the vicinity of the orifices 40; a second isolating unit 100 formed by removing the pyrolytic graphite (PG) in order to electrically isolat the first heat generating unit 20 and the first protective film 70 at the upper end of the crucible 10; a second protective film 90 made of pyrolytic graphite (PG) and formed on the inner surface of the cover 50; and a third isolating unit 110 formed by removing the pyrolytic graphite (PG) in order to electrically isolat the second heat generating unit 60 and the second protective film 90.

The first isolating unit 80 and the second isolating unit 100 may be formed by forming the orifices 40 in the lateral side of the crucible 10, depositing pyrolytic graphite (PG) on the inner and outer surfaces of the crucible 10 and then partially removing the deposited pyrolytic graphite (PG) in order to electrically isolat the first heat generating unit 20 and the first protective film 70. Meanwhile, the protective films made of pyrolytic graphite (PG) may be formed on the inner surface of the crucible 10 by forming the heat generating unit 20 on outer surface of the crucible 10 as described in the first embodiment and then entirely depositing the crucible with pyrolytic boron nitride (PBN).

The third isolating unit 110 may be formed by depositing pyrolytic graphite (PG) on the inner and outer surfaces of the cover 50 and then partially removing the deposited pyrolytic graphite (PG) in order to electrically isolat the second heat generating unit 60 and the second protective film 90.

According to the linear effusion cell of the second embodiment of the present invention, when a material 30, such as aluminum, which easily adheres to pyrolytic boron nitride (PBN), is to be cooled, it is possible to prevent the crucible 10 made of pyrolytic boron nitride (PBN) from being damaged by the difference in the thermal expansion coefficient between the material 30 and the pyrolytic boron nitride (PBN), and thus the material 30 can be rapidly cooled. For example, when a crucible having a volume of 500 cc or more is not provided with a protective film, it takes 8 hours or more to cool the material 30 from higher than 660℃ which is a melting point of aluminum to 100℃. However, when the crucible is provided with the protective film, the material 30 can be cooled for a short period time of 1 hour or less.

FIG. 3 is a schematic sectional view showing a linear effusion cell according to a third embodiment of the present invention.

As shown in FIG. 3, in a deposition system for depositing a raw material, such as organic matter, a metal or the like, on a sample in vacuum, the linear effusion cell according to a third embodiment of the present invention includes: a crucible 10 made of pyrolytic boron nitride (PBN) and containing a raw material 30; a first heat generating unit 20 made of pyrolytic graphite (PG), patterned suitable for heating the outer surface of the crucible 10 and deposited on the outer surface thereof; an effusing unit 200 made of pyrolytic boron nitride (PBN) and covering the opening of the crucible 10; a second heat generating unit 220 made of pyrolytic graphite (PG), patterned suitable for heating the outer surface of the effusing unit 200 (for example, symmetrically patterned) and deposited on the outer surface thereof; and an array of orifices 240 formed through the lateral side of the effusing unit 200 and the lateral side of the second heat generating unit 220.

When voltage is applied to the first heat generating unit 20 and the second heat generating unit 220, the ratio of the thickness of the second heat generating unit 220 formed on the effusing unit 200 and the thickness of the first heat generating unit 20 formed on the crucible 10 and the patterns of the first and second

heat generating units

20 and 220 may be controlled such that the temperature of the effusing unit 200 is higher than or equal to the temperature of the crucible 10.

Since the pressure in the effusing unit is decreased from the lower portion thereof to the upper portion thereof, the thickness of a material deposited on a substrate can be made uniform by decreasing the intervals between the orifices formed in the upper portion thereof or increasing the sizes of the orifices formed in the upper portion thereof.

The height of the effusing unit formed in the lateral side thereof with the orifices may be a few higher than the height of a substrate such that a large-area substrate can be deposited with a raw material over the entire area thereof.

FIG. 4 is a schematic sectional view showing a linear effusion cell according to a fourth embodiment of the present invention.

As shown in FIG. 4, the linear effusion cell according to a fourth embodiment of the present invention further includes

protective films

70 and 270 formed by depositing pyrolytic graphite (PG) on the inner surfaces of the crucible 10 and the effusing unit 200 and the surfaces of the orifices 240 of the third embodiment of the present invention in the same manner as in the second embodiment of the present invention.

FIG. 6 is a schematic sectional view showing a linear evaporator using the linear effusion cell disclosed in the fourth embodiment of the present invention according to a fifth embodiment of the present invention. As shown in FIG. 6(A), in the linear evaporator according to the fifth embodiment of the present invention, the linear effusion cell of the present invention may be mounted in a vacuum flange 400 provided with electrodes 600 for power supply and an electrode for a thermocouple (T/C). In this case, the electrodes 600 for power supply are connected to the first heat generating unit 20 and the second heat generating unit 220 to supply electrical power thereto, and the electrode 300 for a thermocouple is disposed to measure the temperature of the linear effusion cell. The structure of the linear evaporator can be simplified by using the electrodes 600 for power supply as supports. The electrodes 600 for power supply are disposed such that orifices 240 are far away from the two electrodes 600 for power supply in order not to allow the electrodes 600 for power supply to interfere with the orifices 240.

The linear evaporator includes: spacers 500a and 500b disposed at the upper and lower portions of the linear effusion cell of the present invention; an electrode 300 for a thermocouple (T/C) disposed such that it comes into contact with the bottom surface of the first heat generating unit 20 located at the lower portion of the linear effusion cell; a vacuum flange 400 disposed at a position spaced apart from the bottom side of the linear effusion cell by a predetermined distance; a pair of electrodes 600 for power supply disposed such that they penetrate the

spacers

500a and 500b and come into contact with the first heat generating unit 20 and the second heat generating unit 220 with the orifices 240 disposed therebetween; and a spreader 700a disposed over the electrode contact portion of the second heat generating unit 220 and a spreader 700b disposed under the electrode contact portion of the first heat generating unit 20.

FIG. 6(B) is a schematic sectional view of each of the spacers 500a and 500b of FIG. 6(A).

The

spacers

500a and 500b serve to fix the linear effusion cell such that the linear effusion cell does not move. Each of the spacers 500a and 500b includes contact portions 520 having a structure for minimizing the contact between the spacer and the linear effusion cell, and through-holes 511 to 514 through which the electrodes 600 for power supply are passed.

FIG. 6(C) is a schematic sectional view of each of the

spreaders

700a and 700b of FIG. 6(A).

The

spreaders

700a and 700b serve to prevent the weight of the linear effusion cell from being concentrated on the electrode contact portions to disperse force. Further, the

spreaders

700a and 700b serve to prevent electric current from being concentrated on one place to allow heat to be uniformly generated from the heat generating units. As shown in FIG. 6(C), each of the

spreaders

700a and 700b includes through-holes 711 to 714 through which the electrodes 600 for power supply are passed.

The

spreaders

700a and 700b may be made of graphite, and, preferably, may be made of a metal, such as molybdenum or the like, having excellent high-temperature characteristics.

FIG. 7 is a schematic sectional view showing a linear evaporator using the linear effusion cell disclosed in the fourth embodiment of the present invention according to a sixth embodiment of the present invention.

As shown in FIG. 7(A), the linear evaporator according to the sixth embodiment of the present invention, unlike the linear evaporator according to the fifth embodiment of the present invention, is configured such that a vacuum flange is mounted over the linear effusion cell. Therefore, as shown in FIG. 7(B), each of the spacers 500a and 500b includes a through-hole 530 through which the electrode 300 for a thermocouple (T/C) is passed, through-holes 511 to 514 through which the electrodes 600 for power supply are passed, and contact portions 520 having a structure for minimizing the contact between the spacer and the linear effusion cell.

FIG. 7(C) is a schematic sectional view of each of the

spreaders

700a and 700b of FIG. 7(A). As shown in FIG. 7(C), each of the

spreaders

700a and 700b includes a through-hole 730 through which the electrode 300 for a thermocouple (T/C) is passed, and through-holes 711 to 714 through which the electrodes 600 for power supply are passed.

FIG. 8 is a flowchart showing a method of manufacturing a linear effusion cell according to a first embodiment of the present invention. As shown in FIG. 8, the method of manufacturing a linear effusion cell, which is used in a vacuum deposition system, according to a first embodiment of the present invention includes the steps of: providing a crucible made of pyrolytic boron nitride (PBN) (S100); depositing pyrolytic graphite (PG) on the outer surface of the crucible to form a first heat generating layer (S110); forming an array of orifices having a predetermined size at the lateral side of the crucible in the longitudinal direction of the crucible (S120); and forming a pattern (for example, a symmetrical pattern) suitable for heating on the first heat generating layer formed on the outer surface of the crucible (S130).

Further, the method of manufacturing a linear effusion cell according to this embodiment may further include the steps of: providing a cover made of pyrolytic boron nitride (PBN) and covering the opening of the crucible (S140); depositing pyrolytic graphite (PG) on the outer surface of the cover to form a second heat generating layer (S150); and forming a pattern (for example, a symmetrical pattern) suitable for heating on the second heat generating layer formed on the outer surface of the cover (S160). Here, it is preferred that the second heat generating layer has a thickness of 1000 μm or less.

FIG. 9 is a flowchart showing a method of manufacturing a linear effusion cell according to a second embodiment of the present invention. As shown in FIG. 9, the method of manufacturing a linear effusion cell according to the second embodiment of the present invention is characterized in that, in the method of manufacturing a linear effusion cell for a vacuum deposition system according to the first embodiment of the present invention, pyrolytic graphite (PG) is deposited on the inner surface of the crucible and the lower surface of the cover to form protective films.

The method of manufacturing a linear effusion cell, which is used in a vacuum deposition system, according to the second embodiment of the present invention includes the steps of: providing a crucible made of pyrolytic boron nitride (PBN) (S200); forming an array of orifices having a predetermined size at the lateral side of the crucible in the longitudinal direction of the crucible (S210); depositing pyrolytic graphite (PG) on the outer surface of the crucible to form a first heat generating layer and depositing the pyrolytic graphite (PG) on the inner surface thereof to form a first protective film (S220); forming a pattern (for example, a symmetrical pattern) suitable for heating on the first heat generating layer formed on the outer surface of the crucible (S230); and forming an isolating unit for electrically isolating the first heat generating layer and the first protective film (S240).

Further, the method of manufacturing a linear effusion cell according to this embodiment may further include the steps of: providing a cover made of pyrolytic boron nitride (PBN), and covering the opening of crucible (S250); depositing pyrolytic graphite (PG) on the outer surface of the cover to form a second heat generating layer and depositing the pyrolytic graphite (PG) on the inner surface thereof to form a second protective film (S260); forming a pattern (for example, a symmetrical pattern) suitable for heating on the second heat generating layer formed on the outer surface of the cover (S270); and forming an isolating unit for electrically isolating the second heat generating layer and the second protective film (S280).

FIG. 10 is a flowchart showing a method of manufacturing a linear effusion cell according to a third embodiment of the present invention. As shown in FIG. 10, the method of manufacturing a linear effusion cell according to the third embodiment of the present invention includes the steps of: providing a crucible made of pyrolytic boron nitride (PBN) (S300); depositing pyrolytic graphite (PG) on the outer surface of the crucible to form a first heat generating layer (S310); forming a pattern suitable for heating on the first heat generating layer formed on the outer surface of the crucible (S320); providing an effusing unit made of pyrolytic boron nitride (PBN) (S330); depositing pyrolytic graphite (PG) on the outer surface of the effusing unit to form a second heat generating layer (S340); forming a pattern suitable for heating on the second heat generating layer formed on the outer surface of the effusing unit (S350); and forming an array of orifices having a predetermined size at the lateral side of the effusing unit (S360).

FIG. 11 is a flowchart showing a method of manufacturing a linear effusion cell according to a fourth embodiment of the present invention. As shown in FIG. 11, the method of manufacturing a linear effusion cell according to the fourth embodiment of the present invention includes the steps of: providing a crucible made of pyrolytic boron nitride (PBN) (S400); depositing pyrolytic graphite (PG) on the outer surface of the crucible to form a first heat generating layer and depositing the pyrolytic graphite (PG) on the inner surface thereof to form a first protective film (S410); forming a pattern suitable for heating on the first heat generating layer formed on the outer surface of the crucible (S420); forming an isolating unit for electrically isolating the first heat generating layer and the first protective film (S430); providing an effusing unit made of pyrolytic boron nitride (PBN) and covering the crucible (S440); forming an array of orifices having a predetermined size at the lateral side of the effusing unit (S450); depositing pyrolytic graphite (PG) on the outer surface of the effusing unit to form a second heat generating layer and depositing the pyrolytic graphite (PG) on the inner surface thereof to form a second protective film (S460); forming a pattern suitable for heating on the second heat generating layer formed on the outer surface of the effusing unit (S470); and forming an isolating unit for electrically isolating the second heat generating layer and the second protective film (S480).

The technical scope of the present invention related to the above-mentioned linear effusion cell and manufacturing method thereof is not limited to the above-mentioned embodiments. That is, the technical scope of the present invention may include predictable various modifications, additions and substitutions belonging to the technical idea of the present invention. For example, in order to protect the heat generating units, the first and second heat generating units may be additionally deposited with pyrolytic boron nitride (PBN). In this case, the portions for connecting the first and second heat generating units with the electrodes for power supply must not be deposited with the pyrolytic boron nitride (PBN). Further, the first and second heat generating units may be made of tungsten (W), molybdenum (Mo), titanium (Ti) or the like, which can generate heat at high temperature, instead of pyrolytic graphite (PG). Further, in order to minimize the emission of heat to a vacuum deposition system, the linear evaporator may be mounted with a heat shielding.

Claims

A linear effusion cell, which is used in a vacuum deposition system, comprising:

a crucible made of pyrolytic boron nitride (PBN), having an open upper portion and containing a raw material;

a first heat generating unit formed on an outer surface of the crucible and having a pattern suitable for heating; and

an array of orifices formed through the lateral sides of the crucible and the first heat generating unit.
The linear effusion cell according to claim 1, further comprising: a first protective film formed on an inner surface of the crucible and surfaces of the array of orifices; and an isolating unit for electrically isolating the first heat generating unit and the first protective film.
The linear effusion cell according to claim 1, further comprising: a cover made of pyrolytic boron nitride (PBN) and covering the open upper portion of the crucible; and a second heat generating unit formed on an outer surface of the cover and having a pattern suitable for heating.
The linear effusion cell according to claim 3, further comprising: a first protective film formed on an inner surface of the crucible and surfaces of the array of orifices and electrically isolated from the first heat generating unit; and a second protective film formed on a lower surface of the cover and electrically isolated from the second heat generating unit.
A linear effusion cell, which is used in a vacuum deposition system, comprising:

a crucible made of pyrolytic boron nitride (PBN) and containing a raw material;

a first heat generating unit formed on an outer surface of the crucible and having a pattern suitable for heating;

an effusing unit made of pyrolytic boron nitride (PBN);

a second heat generating unit formed on an outer surface of the effusing unit and having a pattern suitable for heating; and

an array of orifices formed through the lateral sides of the effusing unit and the second heat generating unit.
The linear effusion cell according to claim 5, further comprising: a first protective film formed on an inner surface of the crucible and electrically isolated from the first heat generating unit; and a second protective film formed on an inner surface of the effusing unit and surfaces of the array of orifices and electrically isolated from the second heat generating unit.
The linear effusion cell according to any one of claims 3 to 6, wherein the temperature of the second heat generating unit is higher than the temperature of the first heat generating unit when voltage is applied to the first heat generating unit and the second heat generating unit.
The linear effusion cell according to any one of claims 1 to 6, wherein the first and second heat generating units and the first and second protective films are made of pyrolytic graphite and have a thickness of 1000 μm or less.
The linear effusion cell according to any one of claims 1 to 6, wherein the first and second heat generating units have a symmetrical pattern.
The linear effusion cell according to claim 1 or 5, wherein the intervals between the upper orifices are narrower than the intervals between the lower orifices such that the deposition rate of the upper portion of the linear effusion cell is equal to the deposition rate of the lower portion thereof.
The linear effusion cell according to claim 1 or 5, wherein the intervals between the orifices are maintained constant, and the sizes of the upper orifices are larger than the sizes of the lower orifices, such that the deposition rate of the upper portion of the linear effusion cell is equal to the deposition rate of the lower portion thereof.
A method of manufacturing a linear effusion cell, which is used in a vacuum deposition system, comprising the steps of:

providing a crucible made of pyrolytic boron nitride (PBN);

depositing pyrolytic graphite (PG) on an outer surface of the crucible to form a first heat generating layer;

forming an array of orifices having a predetermined size at a lateral side of the crucible; and

forming a pattern suitable for heating on the first heat generating layer formed on the outer surface of the crucible.
The method according to claim 12, further comprising the steps of:

providing a cover made of pyrolytic boron nitride (PBN) and covering an upper opening of the crucible;

depositing pyrolytic graphite (PG) on the outer surface of the cover to form a second heat generating layer; and

forming a pattern suitable for heating on the second heat generating layer formed on the outer surface of the cover.
A method of manufacturing a linear effusion cell, which is used in a vacuum deposition system, comprising the steps of:

providing a crucible made of pyrolytic boron nitride (PBN);

forming an array of orifices having a predetermined size at a lateral side of the crucible;

depositing pyrolytic graphite (PG) on an outer surface of the crucible to form a first heat generating layer and depositing the pyrolytic graphite (PG) on an inner surface thereof to form a first protective film;

forming a pattern suitable for heating on the first heat generating layer formed on the outer surface of the crucible; and

forming an isolating unit for electrically isolating the first heat generating layer and the first protective film.
The method according to claim 14, further comprising the steps of:

providing a cover made of pyrolytic boron nitride (PBN), and, covering the upper opening of the crucible;

depositing pyrolytic graphite (PG) on an outer surface of the cover to form a second heat generating layer and depositing the pyrolytic graphite (PG) on an inner surface thereof to form a second protective film;

forming a pattern suitable for heating on the second heat generating layer formed on the outer surface of the cover; and

forming an isolating unit for electrically isolating the second heat generating layer and the second protective film.
A method of manufacturing a linear effusion cell, which is used in a vacuum deposition system, comprising the steps of:

providing a crucible made of pyrolytic boron nitride (PBN);

depositing pyrolytic graphite (PG) on an outer surface of the crucible to form a first heat generating layer;

forming a pattern suitable for heating on the first heat generating layer formed on the outer surface of the crucible;

providing an effusing unit made of pyrolytic boron nitride (PBN);

depositing pyrolytic graphite (PG) on an outer surface of the effusing unit to form a second heat generating layer;

forming a pattern suitable for heating on the second heat generating layer formed on the outer surface of the effusing unit; and

forming an array of orifices having a predetermined size at a lateral side of the effusing unit.
The method according to claim 16, further comprising the steps of:

depositing pyrolytic graphite (PG) on an outer surface of the effusing unit to form a second heat generating layer and depositing the pyrolytic graphite (PG) on an inner surface thereof to form a second protective film;

forming a pattern suitable for heating on the second heat generating layer formed on the outer surface of the effusing unit; and

forming an isolating unit for electrically isolating the second heat generating layer and the second protective film.
A linear evaporator comprising the linear effusion cell of any one of claims 1 to 11.
The linear evaporator according to claim 18, further comprising: a vacuum flange; and electrodes for power supply,

wherein the linear effusion cell is mounted on the vacuum flange using the electrodes for power supply as a support.
The linear evaporator according to claim 19, wherein the electrodes for power supply are disposed at positions spaced apart from the orifices formed on a lateral side of the crucible.