WO2008130205A1

WO2008130205A1 - Twin target sputter system for thin film passivation and method of forming film using the same

Info

Publication number: WO2008130205A1
Application number: PCT/KR2008/002337
Authority: WO
Inventors: Sang-Hyun Lee; Do-Hyun Ryu
Original assignee: Top Engineering Co., Ltd
Priority date: 2007-04-24
Filing date: 2008-04-24
Publication date: 2008-10-30
Also published as: TW200848536A; KR20080095413A; CN101681816B; CN101681816A

Abstract

Provided are a twin target sputter system for thin film passivation, which generates high density plasma between the same-shaped targets opposite to each other to thereby form a film at a high speed, and a method of forming the film using the same. The twin target sputter system for thin film passivation includes: a vacuum chamber; a substrate supporter which supports a substrate in the vacuum chamber; a pair of sputter guns each of which faces the substrate, and comprises a yoke plate opened to one side or opposite sides and a plurality of magnets disposed on the yoke plate at regular intervals; targets which are mounted on the pair of yoke plates, respectively; a gun supporter which supports the pair of sputter guns; and a power supply which supplies electric current to the targets, wherein the plurality of magnets each comprises upper and lower parts, the upper and lower parts are formed as a single body and different in magnetic polarity from each other, and the plurality of magnets are aligned in a line, and wherein the gun supporter or the substrate supporter is movable in the chamber. Using the twin target sputter system for thin film passivation and the method of forming a film using the same, an organic light emitting diode (OLED) and an organic thin film transistor (OTFT) can be fabricated by a simple thin film process without an encapsulation process using the existing metal can or glass substrate, thereby simplifying the process and lowering initial investment costs for fabricating the OLED.

Description

TWIN TARGET SPUTTER SYSTEM FOR THIN FILM PASSIVATION AND METHOD OF FORMING FILM USING THE

SAME

Technical Field

[1] The present invention relates to a twin target sputter system for thin film passivation and a method of forming a film using the same, in which high density plasma is generated between the targets facing each other and having the same shape to form the film at a high speed.

[2]

Background Art

[3] In general, sputtering, also known as physical vapor deposition (PVD), is widely used as a method for depositing a layer of metal or like material when fabricating an integrated circuit. Such sputtering deposits a surface layer of a target material on a test piece, and as schematically shown in FIG.l it can be seen that a magnetron 10 placed behind a sputtering target 12 can be used in enhancing a sputtering speed. The magnetron 10 applies a magnetic field 14 across a surface of the target 12 in order to capture electrons and increase plasma density. Typically, the magnetron 10 includes two magnets 16 and 18 having non-parallel magnetic poles perpendicular to the surface of the target 12, and a magnetic yoke 20 supporting and magnetically connecting the two magnets 16 and 18.

[4] Meanwhile, an example of a facing-target sputter including a box-shaped facing- target sputtering assembly as shown in FIG. 2 has been disclosed in US Patent No. 6156172.

[5] Referring to FIG. 2, the box-shaped facing-target sputtering assembly 70 has a structure in which target units 100a and 100b are mounted on opposite sides 71a and 71b among four sides 71a ~ 7 Id adjacent to an open side 7 If serving as an opening of a rectangular frame 71 (among five sides 71a ~ 7 Ie except the open side 7 If of the rectangular frame 71), and three sides 71c ~ 7 Ie are closed with closing plates 72c ~ 72e, respectively. The target unit 100a includes a target 110a and a magnetic field generator employing a permanent magnet provided around the target 110a, and the target unit 100b includes a target 110b and a magnetic field generator employing a permanent magnet provided around the target 110b. In the box-shaped facing-target type sputtering assembly 70, the open side 7 If faces and connects with a vacuum chamber, and a substrate to be formed with a thin film is put in the vacuum chamber while facing the open side 7 If. [6] Further, an example of a method for fabricating an organic light emitting diode

(OLED) using a facing-target sputter has been disclosed in Korean Patent Laid-Open Publication No. 2006-0064702 (June 13, 2006).

[7] As shown in FIG. 3, the facing-target sputter disclosed in Korean Patent Laid-Open

Publication No. 2006-0064702 includes a chamber 100, a reaction gas supplier 130 to supply reaction gas such as argon and oxygen into the chamber 100, a pump 120 to lower the pressure of the chamber 100 and vacuum, and mirror shaped targets 200 and 210 provided in the chamber 100 and facing each other, in which negative (-) electric power is supplied to the targets 200 and 210 independently or in parallel.

[8] Referring to FIG. 3, magnetic fields of the same direction are uniformly formed between the targets 200 and 210. Further, a region where positive voltage is constant but weak is formed in the middle between the targets 200 and 210. Also, plate magnets 220 and 230 are placed behind the targets 200 and 210, respectively, and face each other with different polarity so as to form the uniform magnetic field between the targets 220 and 230. Here, the magnets 220 and 230 are configured by arranging a plurality of pellet magnets 220 and 230, using bar-shaped magnets 220 and 230, or using electromagnets 220 and 230 capable of adjusting the magnetic field.

[9] In case that a sputtering source including the two targets 200 and 210 is movable, the sputtering source moves to form an electrode film by scanning on the entire surface of a large-sized substrate 110 formed with an organic film including a light emitting layer. Further, if a shield 240 is installed around the targets 200 and 210, a material of the targets 200 and 210 is prevented from being emitted in other directions than a direction toward the substrate 110, i.e., a stacking material is emitted in only one direction, thereby forming a kind of sputtering gun.

[10] To fabricate an organic light emitting diode (OLED) or an organic thin film transistor

(OTFT), an encapsulation process is necessary for protecting the diode or transistor in order to prevent oxygen or moisture of the atmosphere from infiltrating into an organic thin film.

[11] Generally, the organic thin film used for the OLED or the OTFT reacts with moisture or oxygen gas in air, so that the material thereof deteriorates. To prevent such deterioration, the encapsulation process is performed using a metal can or a thin glass substrate.

[12] However, in the case that the encapsulation process is performed using the metal can or the thin glass substrate, the process of fabricating the diode not only becomes complicated but also takes much time. Further, a problem arises in that there has not been developed an encapsulation process or an encapsulation apparatus capable of fabricating a large-sized OLED or OTFT. To solve this problem, instead of the metal can or the glass substrate, an inorganic thin film having transparent ceramic properties like the glass substrate is formed on the OLED or the OTFT as shown in FIG. 4. Thus, thin film passivation is in the limelight as a new encapsulation method substituting for the existing encapsulation process.

[13] To perform such a thin film passivation, research has been conducted on enhancing properties by depositing the inorganic thin film such as SiO_x, SiN_x, SiON_x, A12O₃, etc. on the OLED through a chemical vapor deposition (CVD) such as a plasma enhanced chemical vapor deposition (PECVD), an inductively coupled plasma chemical vapor deposition (ICP-CVD), a plasma enhanced atomic layer deposition (PEALD), etc. and a physical vapor deposition (PVD) such as a radio frequency (RF)/ direct current (DC) sputter. However, since most of the methods employ plasma, the OLED is damaged by exposure to the plasma.

[14] Particularly, as the mostly used thin film passivation, Barix Multilayer Coater of

Vitex Corporation in U.S.A. employs a DC sputter mounted with an Al target to perform an Al₂O₃ thin film coating through a reactive sputtering method. In this method, as shown in FIG. 5, the plasma is generated and Ar ions in the plasma collide with the Al target, thereby sputtering Al particles. The sputtered Al particles react with the oxygen gas, so that the Al₂O₃ thin film can be formed on the OLED. At this time, particles that exist in the plasma have high energy and the sputtered Al particles also have high energy, thereby having an effect on the properties of the OLED.

[15] Such a particle having the high energy collides with the substrate and transfers the energy to the substrate, so that the temperature of the substrate can increase up to 200⁰C, thereby damaging the properties of the organic thin film. In particular, if the particles having the high energy of 10OeV or more collide with the organic thin film, the structural, optical and electrical properties of the organic thin film are deteriorated. Moreover, if DC power increases to grow the film at a high speed, the plasma exposure becomes more effective and thus the deterioration of the organic thin film is accelerated, so that it is difficult for a general DC/RF sputter to grow the film at a high speed.

[16] To solve this problem, as shown in FIG. 6, Phillips Corporation proposed a SiN/SiO_x

/SiN/SiO_x/SiN (NONON) structure using the PECVD as a multiple thin film passivation structure. In this case, a nitride thin film and an oxide thin film are alternately deposited to thickly form the thin film, but the density of the thin film is lowered because the thin films are deposited at low RF power and mass production thereof is difficult because the process is complicated.

[17] Also, Korean electronics and telecommunications research institutes (ETRI) proposed a method of forming an Al₂O₃-thin film through a plasma enhanced atomic layer deposition (PEALD) method as a thin film passivation method. However, in this case, since the thin film is formed by alternately jetting an Al precursor and an O precursor in a unit of atomic layer, the speed of growing the film is so slow that mass production thereof is difficult. [18]

Disclosure of Invention

Technical Problem

[19] Accordingly, a physical vapor deposition (PVD) like sputtering has to be used in growing a film in order to accomplish thin film passivation of high density, but an organic thin film is vulnerable to plasma exposure. However, there has not been proposed yet a new sputtering method for thin film passivation, capable of sputtering without the plasma exposure, and thus development thereof is required.

[20]

Technical Solution

[21] The present invention is conceived to solve the problems as described above, and provides a twin target sputter system for thin film passivation and a method of forming a film using the same, in which magnets are disposed at the center in the form of a ladder to increase central plasma density unlike a general facing target sputter gun, thereby not only enabling a plasma damage-free sputtering process but also growing the film at a high speed.

[22] The present invention further provides a twin target sputter system for thin film passivation and a method of forming a film using the same, in which a sputtering process is possible without plasma exposure.

[23] Additional aspects of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention.

[24] The present invention discloses a twin target sputter system for thin film passivation, including: a vacuum chamber; a substrate supporter which supports a substrate in the vacuum chamber; a pair of sputter guns each of which faces the substrate, and includes a yoke plate opened to one side or opposite sides and a plurality of magnets disposed on the yoke plate at regular intervals; targets which are mounted on the pair of yoke plates, respectively; a gun supporter which supports the pair of sputter guns; and a power supply which supplies electric current to the targets, wherein the plurality of magnets each includes upper and lower parts, the upper and lower parts are formed as a single body and different in magnetic polarity from each other, and the plurality of magnets are aligned in a line, and wherein the gun supporter or the substrate supporter is movable in the chamber.

[25] The pair of sputter guns may be opposite to each other.

[26] The targets may be mounted on opposite sides of the pair of sputter guns, re- spectively.

[27] The substrate may include a large-sized substrate for an organic light emitting diode.

[28] The gun supporter or the substrate supporter may move at a speed adjustable depending on a distance between the targets, distances between the targets and the substrate, a ratio of reaction gas injected into the chamber, or power supplied from the power supply.

[29] The speed of forming a thin film on the substrate may be adjustable depending on a distance between the targets, distances between the targets and the substrate, a ratio of reaction gas injected into the chamber, or power supplied from the power supply.

[30] The present invention further discloses a twin target sputter system for thin film passivation, including: a vacuum chamber; a plurality of substrate supporters which support a plurality of substrates in the vacuum chamber, respectively; a pair of sputter guns each of which faces each substrate, and includes a yoke plate opened to one side or opposite sides and a plurality of magnets disposed on the yoke plate at regular intervals; targets which are mounted on the pair of yoke plates, respectively; a gun supporter which supports the pair of sputter guns; and a power supply which supplies electric current to the targets, wherein the plurality of magnets each includes upper and lower parts, the upper and lower parts are formed as a single body and different in magnetic polarity from each other, and the plurality of magnets are aligned in a line, and wherein the sputter gun moves in the chamber to perform the thin film passivation to each of the substrates.

[31] The moving speed of the sputter gun may be adjustable depending on a forming speed and uniformity of a thin film on the substrate, a distance between the targets, distances between the targets and the substrate, a ratio of reaction gas injected into the chamber, or power supplied from the power supply.

[32] The present invention also discloses a twin target sputter system for thin film passivation at an ultra high speed, including: a vacuum chamber; a substrate supporter which supports a substrate in the vacuum chamber; a plurality of sputter guns each of which faces the substrate, and includes a yoke plate opened to one side or opposite sides and a plurality of magnets disposed on the yoke plate at regular intervals; targets which are mounted on the pair of yoke plates, respectively; a plurality of gun supporters which support the plurality of sputter guns, respectively; and a power supply which supplies electric current to the targets, wherein the plurality of magnets each includes upper and lower parts, the upper and lower parts are formed as a single body and different in magnetic polarity from each other, and the plurality of magnets are aligned in a line, and wherein the substrate moves in the chamber to undergo the thin film passivation by each of the sputter guns.

[33] The moving speed of the substrate may be adjustable depending on the number of sputter guns, a forming speed and uniformity of a thin film on the substrate, a distance between the targets, distances between the targets and the substrate, a ratio of reaction gas injected into the chamber, or power supplied from the power supply.

[34] The plurality of sputter guns may be mounted with the same materials, respectively.

[35] The plurality of sputter guns may be mounted with different materials, respectively.

[36] The thin film passivation of the substrate may include multi-layers.

[37] The multi-layers may include SiN/SiO/SiN/SiO thin films.

[38] The multi-layers may include Al₂O₃, SiN_x, SiON, SiO₂, MgO, TaO and A1₂O₃:N thin films each having a thickness of IOnm or more.

[39] The multi-layers may include a structure in which a transparent inorganic thin film and a monomer coating film are repeatedly formed.

[40] The multi-layers may include a multilayer hybrid thin film of an organic thin film and one or more inorganic thin films selected from Al₂O₃, SiN_x, SiON, SiO₂, MgO, TaO and A1₂O₃:N.

[41] The present invention also discloses a method of forming a film using a twin target sputter system for thin film passivation, the twin target sputter system including a vacuum chamber; a substrate supporter which supports a substrate in the vacuum chamber; a sputter gun which faces the substrate and includes a yoke plate opened to one side or opposite sides, and a plurality of magnets disposed on the yoke plate at regular intervals; targets which are mounted on the yoke plates, respectively; a gun supporter which supports the sputter gun; and a power supply which supplies electric current to the targets, the method including: mounting a substrate on the substrate supporter; adjusting the number of sputter guns, the number of magnets and an interval between magnets according to the size and the number of the substrate(s); applying an electric current to the targets; generating plasma in the center of the targets by the targets and the sputter gun; and moving the substrate or the sputter gun according to conditions of the substrate and the sputter gun.

[42] An idea of the present invention is as follows.

[43] In a twin target sputter system for thin film passivation according to an embodiment of the present invention and a method of forming a film using the same, magnets are disposed in the form of a ladder, and a yoke plate is formed in upper and lower parts, so that not only magnetic flux can be formed in one direction between the targets but also magnetic flux density can be maximized, thereby performing a thin film passivation process at a high speed which is hardly achieved by a general facing target sputter. As shown in FIG. 7, if the magnets are disposed in the form of the ladder, the center, which is empty in case of the general facing target sputter, is filled with the magnets and thus the magnetic flux density can increase at the center.

[44] According to an embodiment of the present invention a new sputter system is provided, in which particles generated in the thin film passivation process using the sputter and having high energy are constrained between the targets, so that the plasma damage-free process can be performed. Further, the ladder type magnets are added to the center to maximize the central magnetic flux density unlike a general facing target sputter gun, thereby growing the film at a high speed.

[45] Unlike the general facing target sputter (FTS), the twin target sputter (TTS) according to an embodiment of the present invention is a new system for thin film passivation, in which the ladder type magnets are disposed to increase the magnetic flux density at the center of the targets, thereby increasing the plasma density and the thin film growth speed. Further, charged particles generated in the sputtering process and having the high energy are constrained by a high density magnetic field formed between the targets, thereby performing the thin film passivation without having an effect on the organic thin film. Also, the twin target sputter gun is modularized so that the process for a large-sized thin film passivation is enabled by moving the substrate or moving the modularized twin target sputter gun.

[46] According to an embodiment of the present invention, in case that a transparent thin film of A12O₃, SiN_x, SiON_x, MgO and SiO_x is formed with a thickness of lOOnm or more on the OLED or the OTFT through the twin target sputter, thin film passivation is processed to have high quality without damage due to the plasma exposure. Then, the OLED or the OTFT encapsulated by the thin film through the foregoing method is protected from infiltration of moisture or air from the outside, and thus the existing glass substrate or metal can for the encapsulation is removed, thereby making the OLED or the OTFT very thin. Also, the film is formed at a high speed, so that the thin film passivation process can be performed more quickly than the existing thin film passivation process, thereby reducing a production cost and a processing time taken in fabricating the diode.

[47] Using the twin target sputter with this configuration, the OLED and the OTFT are encapsulated by the thin film at a high speed without damage due to the plasma exposure, reducing the time taken in fabricating the OLED and the OTFT with high quality, and accelerating size-enlargement of the OLED.

[48] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

[49]

[50]

Brief Description of the Drawings

[51] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the invention, and together with the description serve to explain the aspects of the invention.

[52] FIG. 1 illustrates a principle of a magnetron device.

[53] FIG. 2 is a perspective view a conventional box-shaped facing-target sputtering assembly.

[54] FIG. 3 is a cross-sectional view showing a configuration of a conventional facing- target sputter.

[55] FIG. 4 shows an inorganic thin film having ceramic properties being conventionally formed on an organic light emitting diode (OLED) or an organic thin film transistor (OTFT) instead of a metal can or a glass substrate.

[56] FIG. 5 shows a coating layer formed by a conventional thin film passivation method.

[57] FIG. 6 shows a coating layer formed by a conventional multilayer thin film passivation method.

[58] FIG. 7 shows a plasma damage-free sputter gun having a magnet array in the form of a ladder according to an embodiment of the present invention.

[59] FIG. 8 is a graph showing a distribution of magnetic flux density in the center of targets.

[60] FIG. 9 illustrates a configuration of a twin target sputter system for thin film passivation according to an embodiment of the present invention.

[61] FIG. 10 illustrates a configuration of the twin target sputter system in which scanning is performed by a gun module according to an embodiment of the present invention.

[62] FIG. 11 illustrates a plurality of modularized twin target guns mounted on the inside of the system according to an embodiment of the present invention.

[63] FIG. 12 illustrates the twin target sputter system that enables the thin film passivation using multi-layers.

[64] FIG. 13 illustrates a twin target sputter being used in hybrid thin film passivation according to an embodiment of the present invention.

[65] FIG. 14 is a graph showing life span comparison results between a reference sampling OLED and an OLED that underwent the thin film passivation through the twin target sputter according to an embodiment of the present invention.

[66]

Best Mode for Carrying Out the Invention

[67] The invention is described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. Rather, these exemplary em- bodiments are provided so that this disclosure is thorough, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the size and relative sizes of layers and regions may be exaggerated for clarity.

[68] Like reference numerals in the drawings denote like elements.

[69] FIG. 7 shows a plasma damage-free sputter gun having a magnet array in the form of a ladder according to an embodiment of the present invention, and FIG. 8 shows a distribution of magnetic flux density in the center of targets.

[70] Here, when a thin yoke plate of cast iron is attached to upper and lower parts of the magnet array for uniform distribution of magnetic flux, the magnetic flux of high density is uniformly formed between targets. According to an embodiment of the present invention, the sputter gun includes the yoke plate opened to one side or opposite sides, and a plurality of magnets disposed on the yoke plate at regular intervals. The plurality of magnets each include upper and lower parts, and the upper and lower parts are formed as a single body but different in magnetic polarity from each other.

[71] The plurality of magnets are aligned in a line.

[72] At this time, when DC or RF power is supplied to the twin targets at the same time, high density plasma is formed in the center of the targets and thus high speed sputtering occurs depending on the high density plasma. In particular, since the targets are sputtered by the high density plasma formed in the center, the use efficiency of the targets increases. Further, because the magnetic flux is centralized, charged particles are more efficiently constrained than in a general facing target sputter while forming a film at a high speed. Accordingly, a problem of low-speed film growth in the existing facing target sputter can be solved.

[73] FIG. 9 illustrates a configuration of a twin target sputter system for thin film passivation according to an embodiment of the present invention, which includes a twin target sputter gun 300 enabling high-speed film growth, and FIG. 10 illustrates a configuration of the twin target sputter system in which scanning is performed by a gun module according to an embodiment of the present invention.

[74] In the configurations shown in FIGS. 9 and 10, the gun module has a structure in which the targets 310 are mounted on the twin target sputter guns 300 of FIG. 7.

[75] Referring to FIGS. 9 and 10, the twin target sputter system for thin film passivation includes a vacuum chamber 400 filled with reaction gas; a substrate supporter 402 supporting a substrate 401 in the vacuum chamber 400; the sputter gun 300 facing the substrate 401 and opened to one side or opposite sides; targets 310 mounted on a pair of yoke plates, respectively; a gun supporter (not shown) supporting the sputter gun 300, and a power supply 500 to supply electric current to the targets 310.

[76] As shown in FIGS. 9 and 10, the targets 310 are mounted on opposite sides of the pair of sputter guns 300, respectively.

[77] After such a gun module is internally mounted with a material (Si, Al, Ta, SiO₂, Al₂O

₃, MgO and TaO) of the targets 310 needed for thin film passivation and process gas (Ar, 02, N2, N2O, He and H2) is injected into the chamber 400, when the RF or DC power is applied to the twin targets 310 at the same time, the high density plasma is generated between the targets. The generated plasma causes sputtering to occur in the targets, and the sputtered particles react with the process gas on the substrate, thereby forming the thin film passivation on the substrate 401, i.e., on an organic light emitting diode (OLED).

[78] Here, the thin film growth speed is adjusted depending on a distance between the targets, distances between the targets and the substrate, a ratio of reaction gas injected into the chamber 400, or power supplied from the power supply. Inert gas (Ar, Ne, Xe, Kr and He) is jetted through a gas nozzle installed between the targets and sends the sputtered particles to the substrate 401, thereby forming the film at a high speed. The substrate 401 or the gun module moves rectilinearly by a transport unit (not shown), thereby securing a large-sized uniform thin film.

[79] As shown in FIG. 10, if the modularized twin target gun performs scanning, the thin film passivation is performed at once with regard to a large-sized OLED or a plurality of OLEDs. Here, a scanning speed is a factor for controlling the thin film growth speed and the uniformity of the thin film.

[80] If it is needed to form the thin film at an ultra high speed, a plurality of modularized twin target guns may be provided in the system as shown in FIG. 11. FIG. 11 illustrates the plurality of modularized twin target guns mounted on the inside of the system according to an embodiment of the present invention.

[81] Under the condition that the number of twin target guns having the same material is determined in consideration of the required film growth speed, when the OLED mounted onto the substrate supporter 402 moves rectilinearly, the thin film can be thickly formed for a short time because every gun performs the high speed sputtering process. At this time, since the twin target sputter gun constrains the plasma, there is nothing to increase temperature of the substrate and the OLED does not have deterioration based on plasma exposure.

[82] Also, the twin target sputter according to an embodiment of the present invention may be applied to multi-coating using various materials.

[83] For example, as shown in FIG. 12 which illustrates the twin target sputter system for thin film passivation using multi-layers, the modularized guns for thin film passivation are respectively mounted with different materials for employing SiO and SiN thin films as the multi-layers (SiN/SiO/SiN/SiO), and scan the OLED, so that the thin film passivation using the multi-layers can be accomplished without using a plurality of chambers.

[84] FIG. 13 illustrates a twin target sputter being used in hybrid thin film passivation according to an embodiment of the present invention.

[85] First, a transparent inorganic thin film is formed by the twin target sputter according to an embodiment of the present invention, and then the diode is transported to a monomer chamber, thereby coating the device with a monomer. The diode coated with the monomer is cured in a curing chamber, and returns back to the twin target sputter, thereby being coated with the transparent inorganic thin film. These processes are repeated so that the hybrid thin film passivation can be achieved. At this time, the twin target sputter performs the coating process with the transparent inorganic thin film at a high speed, so that the high-speed hybrid thin film passivation can be accomplished.

[86] With reference to FIG. 14, an OLED encapsulated with the thin film passivation through the foregoing twin target sputter according to an embodiment of the present invention will be compared with an OLED having no thin film passivation with regard to a life span.

[87] FIG. 14 is a graph showing life span comparison results between a reference sampling OLED and an OLED that underwent the thin film passivation through the twin target sputter according to an embodiment of the present invention.

[88] As shown in FIG. 14, in the case that the high-quality transparent inorganic thin film is deposited on the OLED or the OTFT through the twin target sputter according to an embodiment of the present invention, it has a life span longer than that of the reference sampling OLED or OTFT.

[89] The above-mentioned method according to the present embodiment of the invention may be stored in any form of recording media, such as CD-ROM, RAM, ROM, floppy disk, hard disk, or magneto-optical disk, or in any computer-readable form, such as computer code organized into executable programs. A description of a method of storing an exemplary embodiment of the present invention is well known in the art and will be omitted.

[90]

Industrial Applicability

[91] As apparent from the above description, the present invention provides a twin target sputter system for thin film passivation and a method of forming a film using the same, in which the OLED and the OTFT can be fabricated by a simple thin film process without an encapsulation process using the existing metal can or glass substrate, thereby simplifying the process and lowering initial investment costs for fabricating the OLED.

[92] Further, in the case that the sputter system according to an embodiment of the present invention is employed in the thin film passivation process, the time taken in forming the film can be shortened through the high-speed film growth. Since the twin target sputter uses the plasma density higher than that of the general facing target sputter and forms the film based on the jet of the gas nozzle, the high-speed thin film passivation is enabled, thereby not only shortening the time of forming the film but also forming a high-density transparent inorganic thin film.

[93] Also, the sputter system according to an embodiment of the present invention more effectively constrains the charged particles having high energy, thereby eliminating the plasma damage occurring in the thin film passivation process of the general DC/RC sputter. For example, the ladder-type magnet array increases the central magnetic flux density and concentrates the magnetic flux density on the center, so that the charged particles having the high energy are constrained between the targets. Thus, the plasma damage-free sputtering process can be achieved even though the DC/RF power is high.

[94] Further, in the case that the sputter system according to an embodiment of the present invention is used in depositing the high-quality transparent inorganic thin film on the OLED and the OTFT, the OLED and the OTFT can be fabricated to have a long life span. Also, the inorganic thin film deposited by the high density plasma has such high density that moisture and oxygen from the outside are prevented from infiltration, thereby increasing the life span of the diode.

[95] Meanwhile, the thin film passivation using the sputter system according to an embodiment of the present invention can be applied to a fabrication process for a large- sized organic light emitting diode display device. The encapsulation process using the existing metal can or glass substrate can hardly be applied to a substrate beyond 4^th generation because there is no apparatus and the process is difficult. On the other hand, the sputter system according to an embodiment of the present invention is applicable to the thin film passivation for fabricating the large-sized OLED since the size of the gun module is freely changeable according to the magnet array.

[96] Further, according to an embodiment of the present invention, it is possible to fabricate the large-sized OLED display by moving the sputter gun or the substrate left and right.

[97] In addition, if the plurality of sputter gun modules is provided in the twin target sputter system, the large-sized thin film can be formed at an ultra high speed, thereby performing the thin film passivation process at an ultra high speed.

[98] Besides, in the case that the plurality of sputter gun modules are provided in the twin target sputter system, if various materials for the targets and corresponding process gas are used, the process of growing the multilayer thin film of various materials can be performed in one chamber.

[99] It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

Claims

[1] A twin target sputter system for thin film passivation, comprising: a vacuum chamber; a substrate supporter which supports a substrate in the vacuum chamber; a pair of sputter guns each of which faces the substrate, and comprises a yoke plate opened to one side or opposite sides and a plurality of magnets disposed on the yoke plate at regular intervals; targets which are mounted on the pair of yoke plates, respectively; a gun supporter which supports the pair of sputter guns; and a power supply which supplies electric current to the targets, wherein the plurality of magnets each comprises upper and lower parts, the upper and lower parts are formed as a single body and different in magnetic polarity from each other, and the plurality of magnets are aligned in a line, and wherein the gun supporter or the substrate supporter is movable in the chamber.

[2] The twin target sputter system according to claim 1, wherein the pair of sputter guns are opposite to each other.

[3] The twin target sputter system according to claim 2, wherein the targets are mounted on opposite sides of the pair of sputter guns, respectively.

[4] The twin target sputter system according to claim 3, wherein the substrate comprises a large-sized substrate for an organic light emitting diode.

[5] The twin target sputter system according to claim 4, wherein the gun supporter or the substrate supporter moves at a speed adjustable depending on a distance between the targets, distances between the targets and the substrate, a ratio of reaction gas injected into the chamber, or power supplied from the power supply.

[6] The twin target sputter system according to claim 4, wherein a speed of forming a thin film on the substrate is adjustable depending on a distance between the targets, distances between the targets and the substrate, a ratio of reaction gas injected into the chamber, or power supplied from the power supply.

[7] A twin target sputter system for thin film passivation, comprising: a vacuum chamber; a plurality of substrate supporters which support a plurality of substrates in the vacuum chamber, respectively; a pair of sputter guns each of which faces each substrate, and comprises a yoke plate opened to one side or opposite sides and a plurality of magnets disposed on the yoke plate at regular intervals; targets which are mounted on the pair of yoke plates, respectively; a gun supporter which supports the pair of sputter guns; and a power supply which supplies electric current to the targets, wherein the plurality of magnets each comprises upper and lower parts, the upper and lower parts are formed as a single body and different in magnetic polarity from each other, and the plurality of magnets are aligned in a line, and wherein the sputter gun moves in the chamber to perform the thin film passivation to each of the substrates.

[8] The twin target sputter system according to claim 7, wherein the pair of sputter guns are opposite to each other.

[9] The twin target sputter system according to claim 8, wherein the targets are mounted on opposite sides of the pair of sputter guns, respectively.

[10] The twin target sputter system according to claim 9, wherein the substrate comprises a substrate for an organic light emitting diode.

[11] The twin target sputter system according to claim 10, wherein a moving speed of the sputter gun is adjustable depending on a forming speed and uniformity of a thin film on the substrate, a distance between the targets, distances between the targets and the substrate, a ratio of reaction gas injected into the chamber, or power supplied from the power supply.

[12] A twin target sputter system for thin film passivation at an ultra high speed, comprising: a vacuum chamber; a substrate supporter which supports a substrate in the vacuum chamber; a plurality of sputter guns each of which faces the substrate, and comprises a yoke plate opened to one side or opposite sides and a plurality of magnets disposed on the yoke plate at regular intervals; targets which are mounted on the pair of yoke plates, respectively; a plurality of gun supporters which support the plurality of sputter guns, respectively; and a power supply which supplies electric current to the targets, wherein the plurality of magnets each comprises upper and lower parts, the upper and lower parts are formed as a single body and different in magnetic polarity from each other, and the plurality of magnets are aligned in a line, and wherein the substrate moves in the chamber to undergo the thin film passivation by each of the sputter guns.

[13] The twin target sputter system according to claim 12, wherein the pair of sputter guns are opposite to each other.

[14] The twin target sputter system according to claim 13, wherein the targets are mounted on opposite sides of the pair of sputter guns, respectively.

[15] The twin target sputter system according to claim 14, wherein the substrate comprises a large-sized substrate for an organic light emitting diode.

[16] The twin target sputter system according to claim 15, wherein a moving speed of the substrate is adjustable depending on the number of sputter guns, a forming speed and uniformity of a thin film on the substrate, a distance between the targets, distances between the targets and the substrate, a ratio of reaction gas injected into the chamber, or power supplied from the power supply.

[17] The twin target sputter system according to claim 16, wherein the plurality of sputter guns are mounted with the same materials, respectively.

[18] The twin target sputter system according to claim 17, wherein the plurality of sputter guns are mounted with different materials, respectively.

[19] The twin target sputter system according to claim 18, wherein the thin film passivation of the substrate comprises multi-layers.

[20] The twin target sputter system according to claim 19, wherein the multi-layers comprise SiN/SiO/SiN/SiO thin films.

[21] The twin target sputter system according to claim 19, wherein the multi-layers comprise Al₂O₃, SiN_x, SiON, SiO₂, MgO, TaO and A1₂O₃:N thin films each having a thickness of IOnm or more.

[22] The twin target sputter system according to claim 19, wherein the multi-layers comprise a structure in which a transparent inorganic thin film and a monomer coating film are repeatedly formed.

[23] The twin target sputter system according to claim 19, wherein the multi-layers comprise a hybrid thin film of an organic thin film and one or more inorganic thin films selected from Al₂O₃, SiN_x, SiON, SiO₂, MgO, TaO and A1₂O₃:N thin films each having a thickness of IOnm or more.

[24] A method of forming a film using a twin target sputter system for thin film passivation, the twin target sputter system including a vacuum chamber; a substrate supporter which supports a substrate in the vacuum chamber; a sputter gun which faces the substrate and comprises a yoke plate opened to one side or opposite sides, and a plurality of magnets disposed on the yoke plate at regular intervals; targets which are mounted on the yoke plates, respectively; a gun supporter which supports the sputter gun; and a power supply which supplies electric current to the targets, the method comprising: mounting a substrate on the substrate supporter; adjusting the number of sputter guns, the number of magnets and an interval between magnets according to the size and the number of the substrate(s); applying an electric current to the targets; generating plasma in the center of the targets by the targets and the sputter gun; and moving the substrate or the sputter gun according to conditions of the substrate and the sputter gun.

[25] The method according to claim 24, wherein the substrate comprises a large-sized substrate for an organic light emitting display.

[26] The method according to claim 24, wherein the substrate or the sputter gun is movable.

[27] The method according to claim 26, wherein the number of sputter guns increases or decreases according to a forming speed or uniformity of the film on the substrate.

[28] The method according to claim 27, wherein the sputter guns are provided in plural, and the plurality of sputter guns are mounted with the same materials, respectively.

[29] The method according to claim 27, wherein the sputter guns are provided in plural, and the plurality of sputter guns are mounted with different materials, respectively.