JP4317150B2 - Sputtering method and sputtering apparatus - Google Patents

Description

  The present invention relates to a method and an apparatus for forming a thin film on an organic film on a substrate, and more particularly to a method and an apparatus for forming a thin film on an organic film by sputtering.

  2. Description of the Related Art In recent years, an organic electroluminescent display (OELD) attracting attention as a next-generation flat display device is a display device provided with an organic light emitting diode (OLED). The OLED has excellent characteristics such as self-light emission, light viewing angle, and high-speed response characteristics. The basic structure and light emission principle of an organic light emitting display device are generally well known.

  Such an organic light emitting display basically includes a first electrode corresponding to an anode (anode) for each pixel on a substrate, an organic film composed of a light emitting layer and the like, and a second electrode corresponding to a cathode (cathode). The organic electroluminescence device provided for is arranged.

  In the organic electroluminescence device, when a voltage of about several volts (V) is applied between the anode and the cathode, holes are generated at the anode and separated electrons are generated at the cathode. The generated holes and electrons are combined with each other in the light-emitting layer via the hole transport layer or the electron transport layer, so that excitons in a high energy state are generated. While the excitons return to the ground state, light having energy corresponding to the energy difference between the two states is generated.

  In the organic film, an electron or hole generation and transport layer can be formed separately, the transport layer is not formed separately, and only the electroluminescent layer exists between both electrodes. The specific configuration of the organic light emitting device in the apparatus can be various.

  After forming an organic film including a lower anode electrode and an organic light emitting layer on a substrate, the use of sputtering, which is one of the common thin film forming methods, can be considered when forming a cathode electrode and a protective film. In a sputtering apparatus, particles such as Ar ionized in a vacuum vessel collide with a target by being attracted by an electric field or by free movement.

  At that time, the material particles falling from the target are accumulated on the substrate in the process of vapor deposition to form a thin film. In order to improve the properties of the thin film and to ionize process gas such as argon, plasma is usually formed in the process space. At that time, a method of applying a high-frequency electric field to the process space can be used as a plasma formation method.

  However, when conventional DC / RF sputtering is used to form a conductor pattern such as a cathode electrode on the organic film, there is a problem that the organic film is easily damaged.

  In order not to damage the organic film, it is necessary to prevent damage caused by collision of high energy particles. In the OLED, in order to prevent damage to the substrate and the organic film, the process of forming the film on the organic film is preferably a low-temperature process that does not require a high reaction temperature.

More specifically, the conventional sputtering method generates a large number of particles having a high energy of 100 eV or more by applying a voltage of 150 V or more to the target. If high energy particles collide with the substrate to form a film, the structure of the organic film is partially destroyed in the process to change the characteristics of the organic film. For example, in the case of Alq ₃ (Tris 8-Hydroxyquinolinato aluminum) which is the main organic substance constituting OLED, collision between O ⁻ , neutral Ar, and Ar ⁺ in which N—Al and C—O—Al bonds have energy of 100 eV or more. Decompose.

Liao announced in the Journal of Applied Physics Letters (Vol 75, p1619) that Ar ⁺ collisions change Alq ₃ properties to metallic during the sputtering process. Further, the energy of the particles can increase the temperature of the substrate to about 200 ° C., for example, by collision, and the organic film characteristics of the substrate can be changed by heat.

  FIG. 1 is a current-voltage curve measured after Al and ITO electrodes are formed on an organic film of a full emission OLED using existing DC sputtering. It can be seen that when an Al or ITO electrode film is formed on an organic film of an OLED using a DC sputtering (sputtering) apparatus, a leak current is generated from the negative voltage region. As described above, such a leak current is generated by organic film damage due to high energy particles during the film forming process.

  On the other hand, with the recent increase in display size, the screen tends to increase in the OELD field. Since sputtering is performed in a vacuum space where equipment costs are high, it is gradually important to form a thin film economically and efficiently on a large substrate through sputtering. It is also an important problem to uniformly form a good quality thin film on a wide substrate by sputtering.

  The present invention provides a method capable of solving problems such as damage to a conventional organic film when a thin film is formed on the organic film by sputtering, as in the case of an OLED, and an apparatus adapted thereto. 1 purpose.

  It is a second object of the present invention to provide a thin film forming method and apparatus capable of reducing current leakage through the organic film without damaging the lower organic film by forming plasma for sputtering. Objective.

  A third object of the present invention is to provide a thin film forming method and apparatus capable of efficiently forming a thin film having a uniform quality on a wide substrate on which an organic film is formed by sputtering.

In order to achieve the above object, a sputtering method according to the present invention applies a voltage of the same polarity to two opposing targets, and forms a magnetic field substantially orthogonal to the target surface in the space between the two targets. , While generating plasma by introducing a plasma forming process gas between the two targets, the film formation target portion of the substrate on which the organic film is formed is separated from the space between the two targets, And provided so as to face the space between the two targets, and the two targets can be rotated by 90 ° so that the angle formed by the normal directions of the surfaces facing each other is 180 ° to 0 °. In addition, the distance between the targets is provided so as to be movable in the direction of approaching and separating .

  In the method of the present invention, sputtering is preferably performed in a state where the direction other than the direction in which the substrate is provided is blocked by the shield. In that case, for example, the space between the two targets is limited by two targets in both directions. Further, another direction other than the direction toward the substrate is limited by a shield formed so as to be substantially perpendicular to the target surface, in which the peripheral portions of the two targets are coupled while rotating around the periphery of the two targets.

  In the method of the present invention, the magnetic field may be a uniform magnetic field or a magnetic field that becomes stronger as it goes outward from the target surface. The vertical magnetic field may be a method in which a flat permanent magnet or an electromagnet is arranged on the back side of two opposing targets so that the magnets have different polarities. The magnet can be composed of a single magnet or a combination of a plurality of magnets. In this case, the vertical magnetic field is considered to be a magnetic field having a magnetic field line connecting the two target surfaces while being substantially perpendicular to the two opposing target surfaces, rather than being perpendicular to the target surface in the entire space between the targets.

  In the magnetic field forming process, ohmic heat due to current and conduction heat due to plasma particles colliding with the target are generated, and the process of cooling the magnetic field generator and the periphery of the target can be simultaneously performed in the sputtering process.

  In the method of the present invention, a target device including two opposing targets can be formed in a movable manner. In order to prevent the target material from being released in the direction outside the substrate by providing shields around the two targets of the target device, it is more effective to form the target device in a movable type. At this time, providing the target device in a movable manner can widely include a case where the relative position between the portion opened with respect to the substrate in the target device and the substrate portion opposed thereto is changed.

  That is, at least one of the target device or the substrate can be moved in parallel to the substrate surface. In addition, the elastic substrate is bent so as to form a part of the circumference when viewed from above the substrate surface, and the target device is placed at the center of the circle corresponding to the circumference and relatively rotated. A method is also conceivable. At that time, it is possible to move the shield of the target device, rotate the open part, rotate the target device itself, and move the substrate along the circumference. When forming a thin film using a movable target device, a uniform thin film can be formed on the entire surface of a large substrate on which an organic film is formed.

  In the present invention, the materials and characteristics of the electrode film formed on the substrate can be adjusted by adjusting the voltage and effective area applied to each of the two target positions by using different materials for the two targets. For example, in sputtering for forming a conductive wire pattern, when all the targets are usually made of an aluminum alloy material, one target can be made of aluminum and the other target can be made of a material that forms an alloy with aluminum. Further, one target can be formed of ITO, the other target can be formed of indium zinc oxide (IZO), and the sputtered film to be stacked can be formed of ITZO. By the same method, the metal target and the transparent electrode target can be combined to form a transparent electrode film with good electron injection efficiency. The conductive film can also be formed of a multilayer thin film of a metal electrode layer and a transparent electrode layer.

  Since the present invention can be performed at a low temperature of 100 ° C. or lower, it is suitable for forming an organic light-emitting element of a flexible organic light-emitting display device that employs a heat-sensitive synthetic resin substrate. The electrode film formation efficiency of the substrate can be increased by bending the surface to have a curved surface.

  The thin film formed by the method of the present invention can be made amorphous or fine polycrystalline on the organic film. That is, since no impact is generated by the high energy target material particles, there is no energy supply required for crystal growth, and the thin film does not grow in a crystalline structure. For example, an organic electroluminescent device (OLED) has a structure in which a first electrode, an organic film including a light emitting layer, and a second electrode are sequentially provided on a substrate, and an electrode of an electrode formed after the organic film is formed in both electrodes. The film can be formed with a particle size of 30 nm or less with reference to the case where an aluminum film having a thickness of 1000 mm is formed on a glass substrate.

  In order to achieve the above object, another invention of the present application provides a target apparatus for supplying a thin film forming material onto a substrate on which an organic film is formed, and a sputtering apparatus including the target apparatus.

  A sputtering apparatus according to the present invention includes an attachment portion to which a substrate on which an organic film is formed is attached, a target device that supplies target material particles that form a thin film on the substrate, a power supply portion that applies an electric field to the target device, And a chamber portion including a mounting portion and a target device. In addition to the chamber (chamber wall), the chamber portion may include a transfer device to which the target device is attached so as to be able to translate and rotate in the chamber.

  In addition, the target device of the present invention includes two opposing target portions to which a voltage having the same polarity is applied, and a gas supply unit that supplies a process gas such as argon to the space between the two target portions. The target device may further include a wall body portion that covers the space between the two target portions and has an open portion that faces the outside, for example, the substrate mounting portion, from the space between the two target portions. The two target parts can themselves form a part of the entire wall part, in which case the wall part excluding the target part is considered a shield.

  The target portion basically includes a target, and the target is usually a circular or polygonal plate. In the target portion, the target is accommodated in a case having an opening on one side. At that time, the opposing surface of the target is exposed through the opening. In order to stably attach the target to the case, a target body that supports the back surface of the target is further provided in the case. The target unit is provided with a magnetic field generator for forming a magnetic field orthogonal to the target surface in a space between two opposing target units. The magnetic field generator is generally provided behind the target, and is provided so that different magnetic poles are opposed to each other between two opposing target surfaces.

  The magnetic field generator can be incorporated in the target body. A cooling device capable of removing heat generated by driving the magnetic field generator or collision of process gas ions or other plasma particles with the target may be provided around the magnetic field generator and on the rear side of the target. A separate support plate may be provided between the target body and the target to easily attach the target or to apply a voltage to the non-conductive target.

  According to the present invention, a thin film can be formed at a low temperature on the upper side of the organic film without plasma damage to the organic film. Accordingly, in the case of an OLED, the light emission efficiency, electrical and optical characteristics of the light emitting layer organic film can be improved, and the lifetime of the OLED can be extended. In particular, since a good quality ITO can be formed on the organic film, a full surface light emitting OLED having excellent characteristics can be manufactured.

  Moreover, since the method of the present invention uses two targets and forms high-density plasma between them to shorten the electrode film deposition time, the process efficiency can be improved.

  In particular, according to the present invention, since the film can be formed at a low temperature, it is possible to avoid the problem that the substrate is heated when a flexible type OELD using a substrate that is weak against heat is manufactured.

  Hereinafter, a sputtering apparatus and a target apparatus of the present invention will be described in more detail through embodiments with reference to the accompanying drawings.

  2 and 3 are a conceptual cross-sectional view and a schematic perspective view for explaining the sputtering apparatus according to the embodiment of the present invention, and FIGS. 4 to 6 show the target apparatus attached to the sputtering apparatus. It is drawing for demonstrating.

  2 and 3, a sputtering apparatus according to an embodiment of the present invention is an opposed target sputtering apparatus, which includes a chamber unit 100, a target device 200 provided in the chamber unit 100, Power supply device 300.

  The chamber unit 100 includes a chamber 110 that forms a body of the sputtering apparatus, a substrate attachment unit 120 to which a substrate (S) is attached, and a target transfer device 130 for transferring the target device 200. The chamber 110 may be a vacuum chamber, and the inside of the chamber 110 may be maintained at a vacuum between 0.1 mTorr and 100 mTorr.

  The substrate attachment unit 120 attaches a substrate (S), and the substrate (S) is disposed to face the target device 200. Depending on the configuration example, the substrate (S) can be rotated at a predetermined speed. The target transfer device 130 is a device for transferring the target device 200. By transferring the target device 200, uniform sputtering can be performed even when sputtering is performed on a large substrate. In addition, the chamber unit 100 may further include a deposition plate 140 along the inner wall of the chamber 110 in order to prevent the interior of the chamber 110 from being contaminated by the sputtering material during the sputtering process.

  As shown in FIGS. 4-6, the target apparatus 200 is provided with the 1st target part 200a and the 2nd target part 200b which mutually oppose. The first target unit 200a and the second target unit 200b include cases 220a and 220b, targets 210a and 210b, target bodies 230a and 230b, magnetic field generation blocks 240a and 240b, and cooling paths 250a and 250b, respectively.

  The cases 220a and 220b are formed in a box shape in which opposite side portions are opened, and ground shields 222a and 222b are coupled to the side surfaces on the open side. The ground shields 222a and 222b have a hollow ring shape, and end portions 224a and 224b extend toward the center. Such ground shields 222a and 222b play a role of ground in the initial discharge and must be processed so that the surface is not damaged by plasma particles while maintaining a distance of about 1 to 5 mm from the targets 210a and 210b. I must.

  The cases 210a and 220b accommodate the targets 210a and 210b and the target body 230a and 230b. The targets 210a and 210b are accommodated so that one surface is exposed through the openings, and the target bodies 230a and 230b support the back surfaces of the targets 210a and 210b. Support plates 232a and 232b are further interposed between the target bodies 230a and 230b and the targets 210a and 210b, and magnetic field generation blocks 240a and 240b are accommodated in the target bodies 230a and 230b. Cooling paths 250a and 250b are formed between the target bodies 230a and 230b and the magnetic field generation blocks 240a and 240b.

  The targets 210a and 210b are arranged so as to face each other in the first target portion 200a and the second target portion 200b. The targets 210a and 210b are made of a thin film component material to be formed on the substrate (S), and the first target portion 200a and the second target portion 200b are formed depending on the type of the material to be formed on the substrate (S). The targets 210a and 210b may be made of the same material or different materials.

  For example, the targets 210a and 210b can be aluminum (Al), an aluminum alloy, and their equivalents. Alternatively, the targets 210a and 210b may be ITO (Indium-Tin Oxide), IZO (Indium-Zinc Oxide), IO (Indium Oxide), ZnO, TZO (Tin-Zinc Oxide), AZO, GZO, or an equivalent thereof. Can consist of

  In addition, a thin film composed of a compound composed of two or more kinds of substances can be formed on the substrate (S) such that the targets 210a and 210b are made of different substances. For example, one of the targets 210a and 210b is made of ITO, and the other is made of IZO, and a thin film made of ITZO can be formed on the substrate (S). That is, by using various materials as the targets 210a and 210b, the materials formed on the substrate (S) can be variously adjusted.

  The target body 230a, 230b is formed of an insulator and has a box shape with one side open. The support plates 232a and 232b are portions to which the targets 210a and 210b are attached so as to support the rear surfaces of the targets 210a and 210b (back surfaces opposite to each other), and are coupled to the open portions of the target bodies 230a and 230b. is doing.

  The magnetic field generation blocks 240a and 240b are means for generating a magnetic field in the space between the targets 210a and 210b facing each other of the first target unit 200a and the second target unit 200b, and the first target unit 200a and the second target unit 200b. The magnetic field generation blocks 240a and 240b of the unit 200b are arranged so that different polarities face each other. In the embodiment of the present invention, the magnetic field generation blocks 240a and 240b are composed of block bodies 242a and 242b, magnets 244a and 244b, and yokes 246a and 246b.

  The block main bodies 240a and 240b are formed so that at least one of the bar-shaped magnets 244a and 244b can be attached, and are formed of an insulator. The magnets 244a and 244b are formed longer than the length of the magnetic field generating means used in the conventional sputtering apparatus. The length of the magnetic field generating means used in the conventional sputtering apparatus is generally 1.5 cm to 2 cm, but the length of the magnets 244a and 244b of the present invention is preferably 3 to 5 times. That is, the length of the magnets 244a and 244b is preferably 4.5 cm or more, and more preferably 5 to 12 cm.

  This is because as the lengths of the magnets 244a and 244b are longer, the magnetic field formed by the magnetic field generation block is closer to the target surface and is more strongly focused on the space between the target portions. That is, when the magnet length is increased, the magnetic flux component deviating from the space between the first target part 200a and the second target part 200b can be reduced. The surfaces of the magnets 244a and 244b preferably have a magnetic flux density of at least 5000 gauss.

  The yokes 246a and 246b allow the magnetic field intensity generated from the magnetic field generation blocks 240a and 240b to be more uniformly distributed over the entire surface facing the target. Due to this action, the yokes 246a and 246b are preferably made of a material that can be magnetized by the magnets 244a and 244b. That is, the yokes 246a and 246b are preferably formed of a ferromagnetic material and more preferably a paramagnetic material. When the yokes 246a and 246b are made of a ferromagnetic material, the yokes 246a and 246b can be made of any one of iron, cobalt, nickel, and alloys thereof.

  As the yoke, an Fe series plate having a thickness of 2 to 10 mm can be used, and the overall size of the first target portion 200a and the second target portion 200b takes into consideration the uniformity of the formed thin film and the film forming speed. Thus, the size of the substrate is 130 to 200%.

  The cooling paths 250a and 250b cool the magnetic field generation blocks 240a and 240b of the first target unit 200a and the second target unit 200b through the refrigerant flow. The cooling paths 250a and 250b may be formed with predetermined paths on the inner surfaces of the target bodies 230a and 230b and the support plate. In the illustrated example, the refrigerant is arranged so that the refrigerant flows along the gap between the magnetic field generation blocks 240a and 240b and the target body. The refrigerant flowing into the cooling paths 250a and 250b flows in and out along the inflow pipes 252a and 252b and the outflow pipes 254a and 254b formed in the cases 220a and 220b and the target bodies 230a and 230b.

  On the other hand, arbitrarily shaped flow paths 234a and 234b can be formed on the surfaces of the support plates 232a and 232b toward the magnetic field generation blocks 240a and 240b. The flow paths 234a and 234b communicate with the cooling paths 250a and 250b so that the cooling water can flow between the support plates 232a and 232b and the magnetic field generation blocks 240a and 240b.

  Gas supply means 260a and 260b are provided on the upper side and / or the lower side of the cases 220a and 220b. The gas supply means 260a and 260b may be individually injected by the lower or upper gas supply means depending on the process, or may be simultaneously injected by the upper and lower parts, and the process pressure is increased in the entire atmosphere of the chamber 110. Can be adjusted.

  The gas supply means 260a and 260b usually include gas supply pipes 262a and 262b and gas injection nozzles 264a and 264b. As shown in FIGS. 5 and 6, the gas injection nozzles 264a and 264b are formed such that a plurality of holes are formed in a thin pipe extending in the width direction of the cases 220a and 220b so that gas can be injected. At this time, the diameter of the hole is about 1 to 5 mm, the interval is 5 to 100 mm, and the interval can be adjusted depending on the gas flow and the plasma form.

  On the other hand, correction bars 266a and 266b may be further provided between the case 220a and 220b and the gas injection nozzles 264a and 264b. During the actual film formation, the thickness distribution of the thin film can be a Gaussian distribution in which the substrate portion corresponding to the central portion of the target device is thick. With the correction bars 266a and 266b, the film formation distribution in the central portion can be made more uniform.

  The cases 220a and 220b of the first target part 200a and the second target part 200b are provided on the base plate 270 so as to be horizontally movable and rotatable. That is, horizontal moving portions 272a and 272b are provided on the base plate 270 so as to be close to or separated from each other, and the first target portion 200a and the second target portion 200b are disposed on the horizontal moving portions 272a and 272b via the rotating portions 274a and 274b. Cases 220a and 220b are provided.

  The horizontal moving parts 272a and 272b use a rail form or a bolt fixing method so that the first target part 200a and the second target part 200b can maintain an interval of about 30 to 150 mm. The rotating parts 274a and 274b can be hinge means, whereby the first target part 200a and the second target part 200b have the opposing surfaces of the targets 210a and 210b centered on the horizontal moving parts 272a and 272b. As shown in FIG. 6, it can be turned upward.

  The rotating parts 274a and 274b are arranged so that the targets 210a and 210b of the first target part 200a and the second target part 200b face upward when the targets 210a and 210b are exchanged. So that it can be exchanged easily.

  Further, the target device 200 can be connected to an external suction pump (not shown) to discharge foreign substances to the outside. A foreign material removing means (not shown) is further provided on the surface of the base plate 270. The foreign matter removing means can be provided in a replaceable manner. The extraneous matter removing means prevents extraneous matter that can be generated during the sputtering process from being accumulated on the bottom surface of the base plate 270 of the target device 200 or flowing into the substrate (S). Accordingly, material particles and the like emitted from the target including foreign substances are accumulated on the bottom surface around the target, causing a discharge and a short circuit between the target and the wall of the process chamber, thereby affecting the targets 210a and 210b. Can be prevented.

  In FIG. 2, the power supply apparatus 300 connects a (−) electrode to the pair of opposed targets 210a and 210b so that the pair of opposed targets 210a and 210b become cathode electrodes, and the chamber 110 is an anode electrode. Connect the (+) electrode to operate. Hereinafter, the operation of the facing target sputtering apparatus according to the embodiment of the apparatus of the present invention will be described.

A substrate (S) is attached to the substrate attachment portion 120 of the chamber portion 100, and a process gas such as argon (Ar) gas is supplied between the first target portion 200a and the second target portion 200b via gas supply means 260a and 260b. Supply to the space. At that time, when the thin film formed on the substrate (S) is a substance containing oxygen, that is, an oxide, oxygen (O ₂ ) can be injected into the chamber 110 in addition to the argon (Ar) gas. . At this time, the pressure inside the chamber 110, particularly the gas pressure between the first target part 200a and the second target part 200b, is preferably 0.1 mTorr to 100 mTorr.

  The reason is that when the process gas pressure is higher than 100 mTorr, the content of process gas components such as argon (Ar) increases in the thin film formed on the substrate (S) through the sputtering method. When the process gas pressure is lower than 0.1 mTorr, it becomes difficult to form plasma in the space between the first target part 200a and the second target part 200b. Because it will fall.

  4 and FIG. 2, (−) power is simultaneously applied to the targets 210a and 210b of the first target unit 200a and the second target unit 200b facing each other through the power supply device 300. The plasma formed in the space between the first target part 200a and the second target part 200b is restrained by the magnetic field generated by the magnetic field generation blocks 240a and 240b.

  At that time, the electrons in the plasma rotate around the magnetic force line direction as a central axis by the action of a magnetic field in the space between the targets 210a and 210b of the first target portion 200a and the second target portion 200b facing each other. At the same time, the reciprocating motion is performed using the two targets as reflection electrodes by the (−) voltage applied to the targets 210a and 210b. Thus, the electrons are constrained by the space between the targets and maintain a high density plasma.

  Ions formed in the plasma or formed by the applied power supply also rotate around the magnetic field lines and are accelerated by the applied voltage of the target. Due to acceleration and collision of positive ions, particles having high energy of 100 eV or more in the target material particles jumping out from any one of the targets 210a and 210b generally move to the opposite target.

  Therefore, the particles having high energy reciprocate in the space between the two target portions, and the substrate attached to the substrate attachment portion so as to be separated from the target portion and substantially perpendicular to the target surface This high energy particle will not reach and will have no effect on the substrate (S). Further, the neutral substance particles having relatively low energy adhere to the substrate (S) by diffusion and form a thin film.

  In the sputtering apparatus of such an embodiment, damage to the substrate due to plasma, that is, damage to the substrate (S) due to collision of particles having high energy is prevented compared with the case where a conventional sputtering apparatus is used. A thin film can be formed on the organic film without modification of S).

  Moreover, since there is no collision of high energy particles, the temperature after the sputtering process of the substrate (S) is lower than the conventional temperature of about 200 ° C. According to experiments, even when no separate substrate (S) cooling system was installed, the temperature of the substrate (S) could be maintained at 40 ° C. or lower. Therefore, damage and modification of the substrate organic film due to high temperature can be avoided.

  In the apparatus as in the present embodiment, the substrate (S) is disposed in the upper part of the chamber 110, and the targets 210a and 210b of the first target unit 200a and the second target unit 200b are in relation to the substrate (S). Then, the sputtering process is performed in a state of being provided vertically. Therefore, as in the conventional vertical facing target type sputtering apparatus, foreign substances and sputtered materials are accumulated in the lower part, and it is possible to prevent the occurrence of arc discharge from the lower target in the target. Damage to 210b can be prevented. In addition, when the extraneous matter removing means is separately provided, the extraneous matter and the sputtering substance can be removed by exchanging the extraneous matter removing means provided on the bottom surface inside the base plate 270.

  In the illustrated embodiment, the cases 220a and 220b of the first target unit 200a and the second target unit 200b are connected to the horizontal moving units 272a and 272b via the rotating units 274a and 274b. , 210b can be replaced with a new one so that the targets 210a, 210b can face upward, and the replacement of the targets 210a, 210b can be performed smoothly. Therefore, the work time required for replacing the targets 210a and 210b can be shortened.

  The target device 200 according to the present embodiment can be formed in a separate wall portion in the chamber as shown in FIGS. The wall portion includes another element constituting the target device, the first target portion, the second target portion, and the base plate of FIGS. 4 to 6, and covers the space between the opposed target surfaces, and A part of the space is open so that the space between them faces the substrate of the substrate mounting portion. Each target part is connected with a wall part through a base plate. More specifically, each target unit is coupled to the base plate via a rotating unit and a parallel moving unit, and the base plate is attached to the wall body unit. The case of each target part and the base plate itself can form a part of the wall part. In that case, the remaining part of the wall is considered as a shield having one open part.

  In the target device according to the present embodiment, in a state where the wall body portion is provided, a part of the wall body portion is connected to the transfer device of the chamber portion. Even in the absence of a wall portion, it can be operated by being connected to the transfer device of the chamber portion through the base plate. The transfer device serves as means for changing the relative position of the space between the opposing target surfaces of the target device and the thin film formation target portion of the substrate.

  In the present embodiment, in the target device, a wall body part that covers the space between the two target surfaces in general is provided, and target material particles are released by sputtering in a direction other than the substrate direction in which the open part is provided. To prevent that. Since the target material particles can be released in only one direction, the target device is considered as a “sputtering gun” as a kind of “gun”. Of course, the opening of the shield from which the target material is released or the size of the slit can be adjusted in a certain range.

  In that case, a target device including two opposing targets can be formed as a movable type by various methods including the transfer device of the present embodiment. In other words, providing the target device as a movable type is effective when the relative position between the portion opened with respect to the substrate and the substrate portion facing the target device is changed.

  For example, at least one of the target device and the substrate can be moved parallel to the substrate surface. In addition, a substrate having elasticity is arranged by being bent so as to form a part of the circumference when viewed from above the substrate surface, and the target device is arranged at the center of the circle corresponding to this circumference. It is also possible to rotate it. At that time, the wall portion (shield) of the target device can be operated to rotate the open portion, or the target device itself can be rotated. It is also possible to operate the substrate along the circumference.

  When forming a thin film using a movable target device, even if the width of the open portion is narrow, the length of the open portion is made longer than the width in one direction of the substrate, and the target device having the open portion in the vertical direction is translated. By doing so, the entire substrate can be scanned. Therefore, a uniform thin film can be formed on the entire surface of a large substrate on which an organic film is formed.

  On the other hand, FIG. 7 is a schematic view for explaining an opposed target sputtering apparatus according to another embodiment of the present invention.

  Referring to FIG. 7, an opposed target sputtering apparatus according to another embodiment of the present invention is structurally similar to the opposed target sputtering apparatus as shown in FIGS. However, the structure in which a plurality of target devices 400 and 500 are provided in one chamber unit 100 is different. Even if it is a large sized substrate (S), it can sputter | spatter at a time by providing two or more target apparatuses 400 and 500 in the one chamber part 100, and arrange | positioning at an appropriate space | interval.

  By providing a large number of target devices 400 and 500 in one chamber part 100, a highly uniform thin film can be formed on a large substrate (S) through sputtering. Such a sputtering apparatus can be used in various film forming processes, and is particularly applicable to a method for manufacturing an organic thin film transistor and an organic light emitting display.

  FIG. 8 is a cross-sectional view showing an example of an organic thin film transistor manufactured by the sputtering apparatus of the present invention.

  An organic semiconductor layer 12 is formed on the substrate 11, a source / drain electrode 13 is formed on the organic semiconductor layer 12, a gate insulating film 14 is formed so as to cover them, and a gate electrode is formed on the gate insulating film 14. 15 is formed.

  In this case, the organic semiconductor layer 12 includes pentacene, tetracene, anthracene, naphthalene, α-6-thiophene, α-4-thiophene, perylene and its derivatives, Rubrene and its derivatives, coronene and its derivatives, perylene tetracarboxylic diimide and its derivatives, perylene tetracarboxylic dianhydride and its derivatives, naphthalene oligoacene and These derivatives, oligothiophenes of α-5-thiophene and their derivatives, phthalocyanine with and without metal and their derivatives, naphthalene tetracarboxylic diimide and its derivatives Derivatives, naphthalene tetracarboxylic dianhydride and derivatives thereof, pyromellitic dianhydride and derivatives thereof, pyromellitic diimide and derivatives thereof, liquid-feed polymer and derivatives thereof containing thiophene, and fluorene. Including polymers and derivatives thereof can be used.

  The source / drain electrode 13 can be made of a high-grade metal such as Au, Pt, or Ag and a metal such as Al, Cu, Ni, or Fe. This source / drain electrode 13 can be formed by sputtering using the sputtering apparatus of the present invention.

  According to the present invention, even when the source / drain electrode 13 is sputtered on the organic semiconductor layer 12 as described above, damage to the organic semiconductor layer 12 can be reduced. Sputtering of the gate electrode 15 can also utilize the sputtering apparatus of the present invention.

  FIG. 9 shows another example of the organic thin film transistor manufactured by the sputtering apparatus of the present invention, in which the gate electrode 15 is formed on the substrate 11 and the gate insulating film 14 is formed so as to cover the gate electrode 15. The organic semiconductor layer 12 is formed on the gate insulating film 14, and the source / drain electrodes 13 are formed on the organic semiconductor layer 12.

  Also in this case, if the source / drain electrode 13 is formed by sputtering using the sputtering apparatus according to the present invention, damage to the lower organic semiconductor layer 12 can be minimized. Of course, the gate electrode 15 can also be formed using the sputtering apparatus.

  FIG. 10 shows still another example of the organic thin film transistor manufactured by the sputtering apparatus of the present invention. The source / drain electrode 13 is formed on the substrate 11 and the organic semiconductor layer 12 is formed so as to cover the source / drain electrode 13. After the formation, a gate insulating film 14 is formed so as to cover the organic semiconductor layer 12, and a gate electrode 15 is formed thereon.

  In this case, when the gate electrode 15 is formed by sputtering using the sputtering apparatus according to the present invention, damage to the lower organic semiconductor layer 12 can be minimized. Of course, the source / drain electrodes 13 can also be formed using the sputtering apparatus.

  The sputtering apparatus of the present invention can be applied to thin film transistor manufacturing processes having various structures.

  FIG. 11 shows an example of an organic light emitting display device manufactured by the sputtering apparatus of the present invention.

  As described above, after the planarization film 26 is formed on the substrate on which the TFT is formed, the first electrode 28 connected to the drain electrode of the TFT is formed on the planarization film 26. Then, after the planarization film 26 is formed so that the first electrode 28 is exposed, an organic light emitting film 29 is formed on the exposed first electrode 28. Then, the second electrode 30 is formed so as to cover the organic light emitting film 29.

In this case, the organic light emitting film may be a low molecular or high molecular organic film. When a low molecular organic film is used, a hole injection layer (HIL), a hole transport layer (HTL; Hole) are used. A transport layer (EML), an electron emission layer (EML), an electron transport layer (ETL), an electron injection layer (EIL), and the like are laminated in a single or composite structure. Organic materials that can be used are copper phthalocyanine (CuPc), N, N-di (naphthalene-1-yl) -N, N′-diphenyl-benzidine N, N′-di (naphthalene-1). -Yl) -N, N′-diphenyl-benzidine (NPB), tris-8-hydroxyquinoline aluminum (Alq ₃ ), and the like, can be applied in various ways.

  These low molecular organic films are formed by a vacuum deposition method. In the case of a polymer organic film, it may have a structure generally including a hole transport layer (HTL) and a light-emitting layer (EML). At this time, PEDOT is used for the hole transport layer, and PPV ( A polymer organic material such as a Poly-Phenylenevinylene system and a Polyfluorene system can be used, and this can be formed by screen printing or an inkjet printing method.

  The second electrode 30 formed on the organic light emitting film 29 is sputtered with a metal material having a low work function. At this time, the second electrode 30 is formed using the sputtering apparatus according to the present invention. Can do. Then, damage to the lower organic light emitting film 29 can be minimized. Of course, this is not limited to the active matrix type organic electroluminescent display device shown in FIG. 11, but can also be applied to the manufacturing process of the passive matrix type organic electroluminescent display device. It is.

  FIG. 12 is a characteristic diagram for explaining a leakage current of an organic light emitting display manufactured using the sputtering apparatus of the present invention.

  On the organic film of the whole surface light emitting organic light emitting display device having the same structure as that obtained from the experimental results shown in FIG. 1, ITO is used as an upper electrode, and an opposed target sputtering device as shown in FIGS. An ITO film having a thickness of 1000 mm was formed on an organic electroluminescent element composed of Glass / ITO (anode) / HIL / HTL / EML / ETL / EIL.

At the time of film formation, the base pressure is in the 10 ⁻⁷ Torr region, the pressure inside the chamber 110 is 5 mTorr (the pressure during the process can be varied from 0.1 to 50 mTorr level), the process gas As, Ar and O ₂ were used in a ratio of 9: 1 (variable depending on the process, and the O ₂ / Ar ratio can be adjusted within 0.1% to 10%). As the targets 210a and 210b, rectangular ITO was used, and a film was formed in a DC power source 100 W to 5 kW region.

  As shown in the characteristic diagrams of FIGS. 1 and 12, when compared with an organic light emitting display device manufactured by using existing DC sputtering, a leakage current is reduced in the reverse bias region, and is almost generated. I understand that it is not. This is because high energy particles are constrained in the magnetic field to minimize particle collisions toward the substrate.

  Here, in the embodiment of the present invention, the substrate (S) is located in the upper part of the internal space of the chamber, and the target devices 200, 400, 500 are located in the lower part and are sputtered from the lower part to the upper part. Although the sputtering apparatus has been described as an example, the substrate is raised in a state substantially orthogonal to the paper surface, the target apparatus is arranged so that the target surface faces the horizontal direction, and the target particles move in the horizontal direction and are supplied to the substrate. It is also possible to adopt a configuration.

It is a characteristic view which shows the leakage current of the organic electroluminescent display apparatus formed using the conventional sputtering device. It is a schematic fragmentary sectional view for demonstrating the counter target type sputtering device which concerns on embodiment of this invention. It is a schematic perspective view for demonstrating the opposing target type sputtering apparatus which concerns on embodiment of this invention. It is sectional drawing which shows the sputtering target apparatus which concerns on embodiment of this invention. FIG. 5 is a perspective view of the sputtering target device shown in FIG. 4. It is a perspective view which shows the state which the 1st target part and the 2nd target part rotated by the action | operation of the rotation part of the sputtering target apparatus shown in FIG. It is a schematic fragmentary sectional view for demonstrating the opposing target type | mold sputtering apparatus which concerns on another embodiment of this invention. It is sectional drawing which shows an example of the organic thin-film transistor created with the sputtering device of this invention. It is sectional drawing which shows another example of the organic thin-film transistor created with the sputtering device of this invention. It is sectional drawing which shows another example of the organic thin-film transistor created with the sputtering device of this invention. It is sectional drawing which shows an example of the organic electroluminescent display apparatus produced with the sputtering device of this invention. It is a characteristic view which shows the leakage current of the organic electroluminescent display apparatus produced using the facing target type | mold sputtering apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Chamber part 110 Chamber 120 Substrate attachment part 130 Target part transfer apparatus 140 Depositing plate 200,400,500 Sputtering target apparatus 200a First target part 200b Second target part 210a, 210b Sputtering target 220a, 220b Case 230a, 230b Target Body 232a, 232b Support plate 240a, 240b Magnetic field generation block 244a, 244b Magnet 246a, 246b Yoke 250a, 250b Cooling path 260a, 260b Gas supply means 272a, 272b Horizontal moving part 274a, 274b Rotating part 300 Power supply device

Claims (11)

Apply the same polarity voltage to two opposing targets,
Forming a magnetic field substantially perpendicular to the target surface in the space between the two targets;
While a plasma forming process gas is introduced between the two targets to generate plasma, the film formation target portion of the substrate on which the organic film is formed is located at a part separated from the space between the two targets, and Provided to face the space between the two targets,
The two targets can be rotated by 90 ° so that the angle between the normal directions of the faces facing each other is 180 ° to 0 °, and can be translated in the direction in which the distance between the targets approaches and is separated. A sputtering method comprising:   The space between the two targets is subjected to sputtering in a state in which an open surface is limited through a shield that is open only at a portion facing the film formation target portion of the substrate. Sputtering method.   The sputtering method according to claim 2, wherein sputtering is performed while changing a relative position between the opened portion and a deposition target portion of the substrate.   The sputtering method according to claim 1, wherein in the sputtering process, cooling is performed on a portion to which each of the targets is attached.   The sputtering method according to claim 1, wherein sputtering is performed by using different materials for the two targets facing each other. A mounting portion on which a substrate on which an organic film is formed is installed;
A target device for supplying material particles for forming a thin film on the substrate;
A power supply for applying an electric field to the target device;
A chamber portion including the attachment portion and the target device;
The target device includes two target portions each including one of two opposed targets and facing each other.
Each target part has a case having an opening that exposes the opposing surface of the target;
A support plate for supporting the target in the case;
Magnetic field forming means provided behind the support plate ,
In the target device, each of the two target portions is coupled to the outside of the case, and an angle formed by each normal direction of the surfaces of the two targets provided in each target portion facing each other is 180 ° to 0 °. And a horizontal moving part that adjusts a distance between the two target parts by horizontally moving the case. Sputtering equipment.   The sputtering apparatus according to claim 6, wherein the target unit further includes a cooling unit.   The sputtering apparatus according to claim 6, wherein the magnetic field forming unit includes at least one magnet provided at a rear side of the support plate and a ferromagnetic yoke provided at a front side and a rear side of the magnet. . The target unit has a built-in pre-Symbol field forming means, and, the sputtering apparatus of claim 6, wherein the support plate is provided with a target body to be disposed in the opening. The sputtering apparatus according to claim 6, wherein the magnetic field forming unit forms a magnetic field substantially orthogonal to the two target surfaces .   The sputtering apparatus according to claim 6, wherein a gas supply device including a gas supply pipe and an injection nozzle is provided outside the case.

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