KR101960194B1 - Film forming apparatus, film forming method and manufacturing method of organic el display device - Google Patents

Abstract

A film forming device of the present invention comprises: a substrate holding unit including a support part for supporting a periphery part of a substrate; an electrostatic chuck installed on the upper side of the support part for adsorbing the substrate; a magnet installed on the upper side of the electrostatic chuck for applying magnetic force to a mask to bring the substrate and the mask into close contact with each other; and a control part controlling a voltage applied to the electrostatic chuck. The control part controls a first voltage to be applied to the electrostatic chuck as the voltage when the substrate is adsorbed to the electrostatic chuck; and controls a second voltage lower than the first voltage to be applied to the electrostatic chuck as the voltage before starting a process of separating the substrate from the electrostatic chuck after the substrate is adsorbed on the electrostatic chuck.

Description

TECHNICAL FIELD [0001] The present invention relates to a film forming apparatus, a film forming method, and a manufacturing method of an organic EL display device. BACKGROUND OF THE INVENTION 1. Field of the Invention [0002]

The present invention relates to a film forming apparatus, and more particularly, to a film forming apparatus capable of shortening the time required for separating a substrate from an electrostatic chuck and improving film forming accuracy.

Recently, an organic EL display device has been spotlighted as a flat panel display device. The organic EL display device is a self-luminous display, and its characteristics such as response speed, viewing angle, and thinness are superior to those of a liquid crystal panel display, and thus various types of portable terminals represented by monitors, televisions, and smart phones are rapidly replacing existing liquid crystal panel displays . In addition, automotive displays are expanding their applications.

The element of the organic EL display device has a basic structure in which an organic material layer causing light emission is formed between two opposing electrodes (cathode electrode, anode electrode). The organic material layer and the electrode layer of the organic EL display device are formed by depositing the evaporated evaporation material on the lower surface of the substrate placed on the upper part of the vacuum chamber through the mask having the pixel pattern by heating the evaporation source provided at the lower part of the vacuum chamber .

The substrate is held and supported by the substrate holder in the vacuum chamber of the deposition apparatus of the upward deposition type. In order to prevent damage to the organic layer / electrode layer formed on the substrate (lower surface), the periphery of the lower surface of the substrate . In this case, as the size of the substrate increases, the central portion of the substrate, which is not supported by the support portion of the substrate holder, is sagged by the weight of the substrate, which causes a decrease in the deposition accuracy.

A technique of using an electrostatic chuck as a method for reducing deflection due to the weight of the substrate has been studied. That is, an electrostatic chuck is provided on the upper part of the substrate, the upper surface of the substrate supported by the supporting part of the substrate holder is attracted to the electrostatic chuck, and the central part of the substrate is pulled by the electrostatic attraction of the electrostatic chuck, have.

However, even when a separation voltage is applied to the electrostatic chuck to separate the substrate from the electrostatic chuck after the substrate is attracted to the electrostatic chuck by applying an adsorption voltage to the electrostatic chuck, when the charges induced by the adsorption voltage applied to the substrate are discharged It takes a considerable amount of time from when the separation voltage is applied to the electrostatic chuck to when the substrate is actually separated from the electrostatic chuck. This increases the process time (Tact) and decreases the productivity.

In addition, in order to increase film forming precision, the substrate whose position is adjusted with respect to the mask must be adhered in a flat shape to the mask during the film forming process. If the attraction force to the substrate by the electrostatic chuck is weak, the flatness of the substrate is deteriorated, . This lowers the precision of film formation and may cause damage to the film formation surface of the substrate by the mask.

The present invention relates to a film forming apparatus, a film forming method, and a manufacturing method of an organic EL display apparatus which can shorten the time taken to separate a substrate attracted to an electrostatic chuck and can maintain film forming accuracy and prevent damage to a film formation surface The main purpose is to provide.

A film forming apparatus according to an embodiment of the present invention includes a substrate holding unit including a support for supporting a peripheral portion of a substrate, an electrostatic chuck provided above the support for attracting a substrate, A magnet for applying a magnetic force to the mask to bring the substrate and the mask into close contact with each other, and a control unit for controlling a voltage applied to the electrostatic chuck, wherein when the substrate is attracted to the electrostatic chuck, A second voltage lower than the first voltage is applied as the voltage before the substrate is separated from the electrostatic chuck after the substrate is attracted to the electrostatic chuck by controlling the first voltage to be applied to the electrostatic chuck So as to be applied to the electrostatic chuck.

A film forming method according to another aspect of the present invention includes the steps of bringing a substrate into a vacuum chamber of a film forming apparatus, placing the loaded substrate on a supporting portion of the substrate holding unit, adsorbing the substrate on the supporting portion to the electrostatic chuck An alignment step of positioning the substrate attracted to the electrostatic chuck with respect to the mask, a step of placing the aligned substrate on the mask, a step of bringing the mask and the substrate on the mask into close contact with each other by the magnet, Comprising the steps of: depositing a material on a substrate through a mask; and separating the substrate from the electrostatic chuck, wherein the step of adsorbing the substrate to an electrostatic chuck comprises: After the start of the step of depositing the evaporation material on the substrate, the voltage applied to the electrostatic chuck It lowers as a second voltage lower than the first voltage from the first voltage group.

An organic EL display device manufacturing method according to another aspect of the present invention uses the film forming method according to another aspect of the present invention to manufacture an organic EL display device.

According to the present invention, after a first voltage (adsorption start voltage) is applied to the electrostatic chuck to adsorb the substrate and before the separation voltage is applied to separate the substrate from the electrostatic chuck (before starting the separation process from the electrostatic chuck of the substrate) , It is possible to shorten the time taken to separate the substrate from the electrostatic chuck by lowering the voltage applied to the electrostatic chuck to the second voltage (the adsorption holding voltage) lower than the first voltage in advance. As a result, it is possible to prevent an increase in the entire process time and to improve the productivity. In addition, since the time point at which the voltage applied to the electrostatic chuck is lowered to the second voltage is set after the start of the film forming process, the attraction force of the substrate by the electrostatic chuck can be maintained during the film forming process, It is possible to prevent damage to the semiconductor device.

1 is a schematic view of a part of a manufacturing line of an organic EL display device
2 is a schematic view of a film forming apparatus of the present invention.
3 is a block diagram of an electrostatic chuck of the present invention.
4 is a schematic view of the electrostatic chuck and the substrate holding unit of the present invention.
5 is a diagram for explaining a voltage control method for the electrostatic chuck of the present invention.
6 is a view for explaining the film forming method of the present invention.
7 is a schematic diagram showing a structure of an organic EL display device.

Hereinafter, preferred embodiments and examples of the present invention will be described with reference to the drawings. However, the following embodiments and examples are merely illustrative of preferred configurations of the present invention, and the scope of the present invention is not limited to these configurations. In the following description, the hardware configuration, the software configuration, the process flow, the manufacturing conditions, the size, the material, the shape, and the like of the apparatus are intended to limit the scope of the present invention unless otherwise specified no.

The present invention can be suitably applied to an apparatus for forming a thin film (material layer) of a desired pattern by vacuum evaporation on the surface of a substrate. As the material of the substrate, any material such as glass, a film of a polymer material, or a metal can be selected, and as the evaporation material, an arbitrary material such as an organic material, a metallic material (metal, metal oxide, etc.) can be selected. Specifically, the technique of the present invention is applicable to an organic electronic device (for example, an organic EL display, a thin film solar cell), an optical member, and the like. In particular, in an apparatus for manufacturing an organic EL display device, an evaporation material is vaporized and deposited on a substrate through a mask to form an organic EL display device, which is one of preferred applications of the present invention.

<Electronic Device Manufacturing Line>

1 is a plan view schematically showing a part of the configuration of a manufacturing line of an electronic device. The manufacturing line of Fig. 1 is used, for example, in manufacturing a display panel of an organic EL display device for a smart phone. In the case of a display panel for a smart phone, for example, organic EL is formed on a substrate having a size of about 1800 mm x about 1500 mm, and then the substrate is cut out to produce a plurality of small-sized panels.

The manufacturing line of the electronic device generally includes a plurality of film forming chambers 11 and 12 and a transport chamber 13 as shown in Fig. In the transfer chamber 13, a transfer robot 14 for holding and transferring the substrate 10 is provided. The carrying robot 14 is, for example, a robot having a structure in which a robot hand for holding a substrate 10 is mounted on a multi-joint arm, and performs carrying in / out of the substrate 10 into each of the film forming chambers.

Each of the deposition chambers 11 and 12 is provided with a deposition apparatus (also referred to as a deposition apparatus). A series of film formation processes such as the transfer of the substrate 10 to the transfer robot 14, the alignment of the relative position of the substrate 10 and the mask, the fixing of the substrate 10 onto the mask, Is automatically performed by the film forming apparatus.

Hereinafter, the structure of the film forming apparatus of the film forming chamber will be described.

&Lt;

2 is a cross-sectional view schematically showing the structure of the film forming apparatus 2. As shown in Fig. In the following description, an XYZ orthogonal coordinate system in which the vertical direction is the Z direction is used. Assuming that the substrate is fixed parallel to the horizontal plane (XY plane) at the time of film formation, the direction parallel to the short side of the substrate is defined as X direction, and the direction parallel to the long side is defined as Y direction. Also, the rotation angle around the Z axis is denoted by?.

The film forming apparatus 2 has a vacuum chamber 20 defining a space in which a film forming process is performed. The inside of the vacuum chamber 20 is maintained in a vacuum atmosphere or an inert gas atmosphere such as nitrogen gas.

A substrate holding unit 21 for holding and holding a substrate, a mask table 22 for holding a mask, an electrostatic chuck (not shown) for attracting the substrate by an electrostatic attracting force are provided in an upper portion of the vacuum chamber 20 of the film forming apparatus 2 A magnet 24 for applying a magnetic force to a mask made of metal and the like are provided in the vacuum chamber 20 of the film forming apparatus 2. An evaporation source 25 for accommodating the evaporation material is installed in the lower part of the vacuum chamber 20 of the film forming apparatus 2,

The substrate holding unit 21 receives the substrate 10 from the transfer robot 14 of the transfer chamber 13, holds it, and transfers it. The substrate holding unit 21 is also referred to as a substrate holder. The substrate holding unit 21 includes supports 211 and 212 for supporting the peripheral edge of the lower surface of the substrate.

The support portions 211 and 212 are disposed so as to support a plurality of first support members 211 arranged to support one of two opposing sides of the substrate (for example, long sides) And includes a plurality of second support members 212.

Each support member includes a substrate supporting surface portion 213 for supporting the periphery of the lower surface of the substrate and an elastic body portion 214 for elastically supporting the substrate supporting surface portion 213. A fluorine-coated pad (not shown) is provided on the substrate supporting surface portion 213 to prevent damage to the substrate. The elastic body 214 of the supporting member includes an elastic body such as a coil spring, a leaf spring, or a silicone rubber. When the substrate is attracted to the electrostatic chuck, the elastic body is elastically displaced by a pressing force from the electrostatic chuck, Thereby preventing breakage.

The substrate supporting surface portion 213 of the first supporting member 211 may be installed so as to be higher than the substrate supporting surface portion 213 of the second supporting member 212 so as to entirely flatly adhere the substrate to the electrostatic chuck. The elastic modulus of the elastic body 214 of the first supporting member 211 is made larger than the elastic modulus of the elastic body 214 of the second supporting member 212 or the length of the elastic body 214 is made longer, The supporting force by which the supporting member 211 supports the substrate can be made larger than the supporting force by which the second supporting member 212 supports the substrate.

A mask 221 having a frame shape is provided under the substrate holding unit 21 and a mask 221 having an opening pattern corresponding to the thin film pattern to be formed on the substrate 10 . Particularly, a mask used for manufacturing an organic EL device for a smart phone is also called a fine metal mask (FMM) as a metal mask having a fine opening pattern.

An electrostatic chuck 23 is provided above the supporting portions 211 and 212 of the substrate holding unit 21 for attracting and fixing the substrate by electrostatic attraction. The electrostatic chuck has a structure in which an electric circuit such as a metal electrode is buried in a dielectric (e.g., a ceramic material) matrix. When positive (+) and negative (-) voltages are applied to the metal electrode, a polarized charge having a polarity opposite to that of the metal electrode is induced on the substrate through the dielectric matrix, and the electrostatic chuck 23, As shown in Fig. The electrostatic chuck 23 may be formed of a single plate or a plurality of sub-plates. Further, even in the case of a single plate, the electrostatic attraction can be controlled differently in one plate by including a plurality of electric circuits therein.

In the present invention, as described later, the same voltage is not continuously applied to the electrostatic chuck while the electrostatic chuck 23 is adsorbing the substrate, but a voltage lower than the voltage applied at the start of adsorption Thereby shortening the time required for separating the substrate.

 A magnet 24 for applying a magnetic force to the metal mask 221 to prevent sagging of the mask and to closely contact the mask 221 and the substrate 10 is provided on the electrostatic chuck 23. The magnet 24 may be made of a permanent magnet or an electromagnet, and may be divided into a plurality of modules.

Although not shown in FIG. 2, a cooling plate for cooling the substrate is provided between the electrostatic chuck 23 and the magnet 24. The cooling plate may be integrally formed with the electrostatic chuck 23 or the magnet 24.

The evaporation source 25 includes a crucible (not shown) in which an evaporation material to be formed on the substrate is housed, a heater (not shown) for heating the crucible, and evaporation materials scattered to the substrate until the evaporation rate from the evaporation source becomes constant. And a shutter (not shown) for blocking the shutter. The evaporation source 25 may have various configurations depending on the application such as a point evaporation source, a linear evaporation source, and a revolver evaporation source.

Although not shown in FIG. 2, the film forming apparatus 2 includes a film thickness monitor (not shown) and a film thickness calculating unit (not shown) for measuring the film thickness deposited on the substrate.

A driving mechanism for moving the substrate holding unit 21, the electrostatic chuck 23, the magnet 24, and the like in the vertical direction (Z direction) is formed on the outer upper surface of the vacuum chamber 20 of the film forming apparatus 2, And a driving mechanism for moving the electrostatic chuck 23, the substrate holding unit 21, and the like in parallel to the horizontal plane (X direction, Y direction, and? Direction) for alignment of the mask. An alignment camera (not shown) is also provided for taking an alignment mark formed on the substrate and the mask through a window provided in the vacuum chamber 20 for aligning the mask and the substrate.

The film forming apparatus is provided with a control section (26). The control unit 26 has functions such as conveyance and alignment of the substrate 10, control of an evaporation source, and control of film formation. The control unit 26 can be configured by a computer having a processor, memory, storage, I / O, and the like. In this case, the function of the control section 26 is realized by the processor executing the program stored in the memory or storage. As the computer, a general-purpose personal computer may be used, or an embedded type computer or a PLC (programmable logic controller) may be used. Alternatively, some or all of the functions of the control unit 27 may be configured by a circuit such as an ASIC or an FPGA. Further, the control unit 26 may be provided for each deposition apparatus, or one control unit 26 may control a plurality of deposition apparatuses.

<Voltage Control of Electrostatic Chuck>

Hereinafter, the control of the voltage applied to the electrostatic chuck in the configuration of the electrostatic chuck 23 of the present invention and the adsorption and desorption process of the substrate will be described with reference to Figs. 3 to 5. Fig.

The electrostatic chuck 23 of the present invention includes a dielectric portion 30, an electrode portion 31, a voltage control portion 32, and a power source portion 33, as shown in FIG. The power supply unit 33 applies positive (+) voltage and negative (-) voltage to the electrode unit 31 of the electrostatic chuck 23. The voltage control unit 32 controls the magnitude of the voltage applied to the electrode unit 31 from the power supply unit 33 in accordance with the progress of the film forming process of the film forming apparatus 2. [ The voltage control unit 32 may be incorporated in the control unit 26 of the film forming apparatus 2 and the voltage control of the electrostatic chuck 23 may be performed by the control unit 26 of the film forming apparatus 2. [

The electrode unit 31 may include a plurality of sub-electrode units. For example, the electrode unit 31 of the present invention may be divided into a first sub-electrode unit 311 and a second sub-electrode unit 312, as shown in FIG. 4 (a). The first sub-electrode portion 311 and the second sub-electrode portion 312 may be provided on the two long sides opposite to each other with respect to the short-side center of the electrostatic chuck 23. 4 (b), the first sub-electrode portion 311 is provided so as to correspond to the first support member 211 side of the substrate holding unit 21, and the second sub-electrode portion 311 312 are provided so as to correspond to the second support member 212 side of the substrate holding unit 21.

5, the voltage control in the step of attracting the substrate 10 to the electrostatic chuck 23 will be described.

The substrate is carried into the vacuum chamber 20 of the film forming apparatus 2 and placed on the supporting portions 211 and 212 of the substrate holding unit 21 (see Fig. 5 (a)).

Subsequently, the electrostatic chuck 23 descends to move close to the substrate placed on the supports 211 and 212 of the substrate holding unit 21. The electrostatic chuck 23 is brought into contact with the substrate 10 sufficiently close to or brought into contact with the substrate 10 by the power supply unit 33 of the electrostatic chuck 23 as shown in Fig. (V1) is applied. The first voltage V1 is set to a voltage of a sufficient magnitude to firmly attract the substrate 10 to the electrostatic chuck 23. The time when the first voltage V1 is applied to the electrostatic chuck is referred to as t1.

A polarized electric charge of an opposite polarity proportional to the magnitude of the first voltage V1 is induced on the upper surface of the substrate by the first voltage V1 applied to the electrode portion 31 of the electrostatic chuck 23. The substrate is flatly adsorbed on the electrostatic chuck by the electrostatic attraction between the polarized charge induced on the substrate and the electrode portion 31 of the electrostatic chuck 23. [ In the present embodiment, the first voltage V1 is applied in a state in which the electrostatic chuck 23 is in close proximity to or in contact with the substrate 10. However, before the electrostatic chuck 23 starts to fall toward the substrate, The first voltage V1 may be applied during the descent.

The voltage control unit 32 of the electrostatic chuck 23 changes the voltage applied to the electrode unit 31 of the electrostatic chuck 23 from the first voltage V1 to the first voltage V1 at a predetermined time t2 To a second voltage (V2) of a smaller size. The second voltage V2 is a suction holding voltage for holding the substrate 10 once adsorbed on the electrostatic chuck 23 in the state of being attracted to the electrostatic chuck 23 and the substrate 10 is held on the electrostatic chuck 23 Is a voltage having a magnitude lower than the first voltage (V1) at the time of adsorption. When the voltage applied to the electrostatic chuck 23 is lowered to the second voltage V2, the amount of the polarization charge induced in the substrate 10 corresponding to the second voltage V2 also becomes equal to the first voltage V1, However, even if the substrate 10 is once attracted to the electrostatic chuck 23 by the first voltage V1, even if a second voltage V2 lower than the first voltage V1 is applied to the substrate 10, Can be maintained.

The second voltage V2 is preferably determined in consideration of the magnitude of the first voltage V1 and may be a zero voltage or a reverse polarity voltage in consideration of the time taken to detach the substrate. That is, if the first voltage V1 is sufficiently large, it takes time to discharge the polarized electric charge induced in the substrate even if the second voltage is a zero voltage or a reverse polarity voltage. Therefore, 10) can be kept adsorbed.

The timing for lowering the voltage applied to the electrostatic chuck 23 from the first voltage V1 to the second voltage V2 is a period for lowering the voltage applied to the electrostatic chuck 23 from the third voltage V3 ) (T = t3) (i.e., before the start of the substrate separation process from the electrostatic chuck). This is for securing a time for electrostatic attraction between the substrate and the electrostatic chuck to be low enough to separate the substrate 10 from the electrostatic chuck 23. That is, when the substrate 10 is to be separated from the electrostatic chuck 23, the voltage applied to the electrode portion 31 of the electrostatic chuck 23 is set to a third voltage (for example, zero or reverse polarity) The electrostatic attraction between the electrostatic chuck 23 and the substrate 10 does not disappear but the electric charge induced at the interface between the electrostatic chuck 23 and the substrate 10 is lost for a considerable time ). Particularly, when the substrate 10 is attracted to the electrostatic chuck 23, the electrostatic chuck 23 is normally attracted to the electrostatic chuck 23 so that the electrostatic attraction force, which is sufficiently larger than the minimum electrostatic attraction force Fth necessary to attract the substrate to the electrostatic chuck 23, (See Fig. 5 (f)), it takes a considerable time until the substrate can be separated from the first voltage.

In the present invention, in order to prevent the overall process time Tact from increasing due to the time taken to detach and detach the substrate 10 from the electrostatic chuck 23, the electrostatic chuck 23 is supplied with the third voltage V3 The voltage applied to the electrostatic chuck 23 is lowered to the second voltage in advance.

Particularly, the time required for the magnitude of the electrostatic attractive force between the substrate and the electrostatic chuck 23 to decrease from the electrostatic attraction due to the first voltage to the minimum electrostatic attraction Fth for maintaining the attraction between the substrate and the electrostatic chuck 23, (Refer to FIG. 5 (e) and FIG. 5 (f)) in consideration of the balance of the time during which the electrostatic attraction is reduced to such an extent that the electrostatic chuck can be separated from the electrostatic attraction due to the two voltages It is preferable to lower the voltage of the electrostatic chuck 23 to the second voltage at a time when the time required for substrate removal can be sufficiently secured.

A specific point in time for lowering the voltage applied to the electrostatic chuck 23 to the second voltage V2 will be described later with reference to Fig.

The electrode unit 31 of the electrostatic chuck 23 is formed so as to include the first sub-electrode unit 311 and the second sub-electrode unit 312, and the voltage applied to each sub-electrode unit is The time point of lowering the voltage from the first voltage to the second voltage may be different from each other or the magnitudes of the second voltages may be different from each other.

For example, as shown in Figs. 4 (b) and 4 (c), the voltage applied to the first sub-electrode portion 311 formed on the side where the substrate is supported by the first support member 211, Electrode unit 312 from the first voltage to the second voltage after lowering the first sub-electrode unit 312 from the first voltage to the second voltage. Since the peripheral portion of the substrate supported by the first supporting member 211 is first attracted to the electrostatic chuck 23, the amount of the induced polarization charge is larger than the peripheral portion of the substrate supported by the second supporting member 212, The time required for the substrate separation (the time required for discharge of the polarized electric charge) becomes longer. The voltage of the first sub-electrode unit 311, which is held on the periphery of the substrate supported by the first support member 211, is first lowered to the second voltage, Sufficient time can be ensured.

The second voltage applied to the first sub-electrode portion 311 is set to be greater than the second voltage applied to the second sub-electrode portion 312 in order to reduce the charge discharge time on the periphery of the substrate supported by the first support member 211 You can also lower it. That is, by lowering the second voltage applied to the side of the first sub-electrode unit 311 in which a relatively large amount of polarization charge is induced, more induced charges are discharged in advance than the side of the second sub-electrode unit 312, It is possible to balance the time necessary for finally removing the substrate by balancing the discharge time of the polarized electric charges induced on the substrate on the electrode 312 side.

The time point at which the voltage applied to the first sub-electrode portion 311 and the second sub-electrode portion 312 is lowered from the first voltage to the second voltage and the magnitude of the second voltage are the charges In consideration of the balance of time required for discharging the discharge gas.

<Film formation process>

Hereinafter, a film forming method employing the electrostatic chuck voltage control of the present invention will be described with reference to FIG.

The substrate is brought into the vacuum chamber 20 of the film forming apparatus 2 by the transfer robot 14 of the transfer chamber 13 in a state in which the mask 221 is placed on the mask table 22 in the vacuum chamber 20 (Fig. 6 (a)).

The substrate 10 is placed on the support portions 211 and 212 of the substrate holding unit 21 while the hand of the transfer robot 14 that has entered the vacuum chamber 20 is lowered (FIG. 6 (b)).

Subsequently, after the electrostatic chuck 23 descends toward the substrate 10 and comes close enough to or contacts the substrate 10, a first voltage V1 is applied to the electrostatic chuck 23 to adsorb the substrate 10 (Fig. 6 (c)).

The substrate 10 is lowered toward the mask 221 in order to measure the relative positional displacement of the substrate with respect to the mask while the substrate 10 is attracted to the electrostatic chuck 23 (Fig. 6 (d)).

When the substrate 10 is lowered to the measurement position, alignment marks formed on the substrate 10 and the mask 221 are photographed with an alignment camera, and the relative positional displacement between the substrate and the mask is measured (see Fig. 6 (e)).

When the relative positional deviation of the substrate with respect to the mask is found to exceed the threshold value as a result of the measurement, the substrate 10 in the state of being attracted to the electrostatic chuck 23 is moved in the horizontal direction (XY &amp;thetas; (Refer to Fig. 6 (f)).

After the alignment process, the substrate 10 attracted to the electrostatic chuck 23 is placed on the mask 221, the magnet 24 is lowered, and the substrate and the mask are closely contacted by the magnetic force of the magnet 24 on the mask (Fig. 6 (g)).

Then, the shutter of the evaporation source 25 is opened, and the evaporation material is deposited on the substrate 10 through the mask (Fig. 6 (h)).

In one embodiment of the present invention, the voltage applied to the electrostatic chuck 23 is lowered from the first voltage to a second voltage lower than the first voltage after the film forming process is started. This makes it possible to maintain a substantial portion of the attraction force on the substrate by the electrostatic chuck 23 during the film forming process, while securing sufficient time for separating the substrate 10 from the electrostatic chuck 23. That is, even if the voltage applied to the electrostatic chuck 23 is lowered from the first voltage to the second voltage immediately after the film forming process, as shown in Fig. 5 (f), the attraction force of the electrostatic chuck 23 is lowered So that sufficient attraction force can be maintained during the film forming process. As a result, the degree of adhesion with the mask can be maintained in a state where the flatness of the substrate is good, and the deposition precision can be maintained.

When a film having a desired thickness is formed on the substrate, the shutter of the evaporation source 25 is closed, and the film formation process is terminated.

In another embodiment of the present invention, the voltage applied to the electrostatic chuck 23 is lowered from the first voltage (V1) to the second voltage (V2) after the film forming process is completed. This makes it possible to more reliably attract the substrate to the electrostatic chuck 23 during the film forming process, thereby further preventing the film forming precision from being lowered.

When the film forming process is completed, the magnet 24 rises and the close contact between the mask and the substrate is released (Fig. 6 (i)). The voltage applied to the electrostatic chuck 23 is lowered from the first voltage V1 to the second voltage V2 after the magnet 24 rises and the adhesion between the mask and the substrate is released . This makes it possible to prevent the film formation surface of the substrate from being damaged by the mask. That is, when the attracting force of the electrostatic chuck 23 is weakened while the mask is in close contact with the film formation surface of the substrate by the magnet 24, a slight gap is formed between the substrate and the mask. And the mask is relatively shifted, the film formation surface of the substrate can be damaged. Accordingly, the voltage applied to the electrostatic chuck 23 is maintained at the first voltage V1 until the magnet 24 is lifted to release the adhesion between the substrate and the mask, thereby preventing relative displacement between the substrate and the mask, The voltage applied to the electrostatic chuck 23 is lowered to the second voltage V2 after the adhesion between the mask and the mask is released.

Subsequently, the substrate is separated from the mask and raised by the rise of the electrostatic chuck 23 and the substrate holding unit 21 (Fig. 6 (j)).

In another embodiment of the present invention, the voltage applied to the electrostatic chuck 23 after the substrate 10 is separated from the mask is lowered from the first voltage to the second voltage. Since the attraction force of the electrostatic chuck 23 is lowered after the substrate is separated from the mask, the deposition surface of the substrate is not damaged even if disturbance such as vibration of the deposition apparatus occurs.

Subsequently, a hand of the carrying robot enters the vacuum chamber of the film forming apparatus and a third voltage (zero (0) or reverse polarity voltage) as a separation voltage is applied to the electrostatic chuck 23 (t = t3) 23 is sufficiently weakened, the electrostatic chuck 23 separates from the substrate and rises (Fig. 6 (k)). Thereafter, the substrate on which the deposition is completed is taken out.

As described above, in the present invention, the time point at which the voltage applied to the electrostatic chuck 23 is lowered from the first voltage to the second voltage is set before the start of the step of separating the substrate from the electrostatic chuck (Fig. 6 (k) (Before the application of the third voltage), if necessary, after the start of the film forming step, after completion of the film forming step, the substrate is brought into close contact with the mask due to the rise of the magnet 24, After the mask is removed, it can be done.

&Lt; Method of manufacturing electronic device &

Next, an example of a method of manufacturing an electronic device using the film forming apparatus of the present embodiment will be described. Hereinafter, the configuration and manufacturing method of the organic EL display device will be exemplified as an example of the electronic device.

First, an organic EL display device to be manufactured will be described. Fig. 7 (a) is an overall view of the organic EL display device 60, and Fig. 7 (b) shows a cross-sectional structure of one pixel.

As shown in Fig. 7 (a), in the display area 61 of the organic EL display device 60, a plurality of pixels 62 each having a plurality of light emitting elements are arranged in a matrix form. Each of the light emitting devices has a structure including an organic layer sandwiched between a pair of electrodes. The term &quot; pixel &quot; as used herein refers to a minimum unit capable of displaying a desired color in the display region 61. [ In the case of the organic EL display device according to the present embodiment, the pixel 62 is constituted by a combination of the first light emitting element 62R, the second light emitting element 62G, and the third light emitting element 62B, . The pixel 62 is often formed of a combination of a red light emitting element, a green light emitting element, and a blue light emitting element, but may be a combination of a yellow light emitting element, a cyan light emitting element, and a white light emitting element. no.

Fig. 7 (b) is a partial sectional schematic view taken along the line A-B in Fig. 6 (a). The pixel 62 includes a first electrode (anode) 64, a hole transport layer 65, light emitting layers 66R, 66G and 66B, an electron transport layer 67, a second electrode (cathode) 68 The organic EL device according to claim 1, Of these, the hole transport layer 65, the light emitting layers 66R, 66G, and 66B, and the electron transport layer 67 correspond to organic layers. In the present embodiment, the light emitting layer 66R is an organic EL layer emitting red, the light emitting layer 66G is an organic EL layer emitting green, and the light emitting layer 66B is an organic EL layer emitting blue. The light emitting layers 66R, 66G, and 66B are formed in patterns corresponding to the light emitting elements (sometimes referred to as organic EL elements) emitting red, green, and blue, respectively. The first electrode 64 is formed separately for each light emitting device. The hole transport layer 65, the electron transport layer 67 and the second electrode 68 may be formed in common with the plurality of light emitting elements 62R, 62G, and 62B, or may be formed separately for each light emitting element. An insulating layer 69 is provided between the first electrodes 64 to prevent the first electrode 64 and the second electrode 68 from being short-circuited by foreign matter. Further, since the organic EL layer is deteriorated by moisture or oxygen, a protective layer 70 for protecting the organic EL element from moisture or oxygen is provided.

Although the hole transport layer 65 and the electron transport layer 67 are shown as one layer in FIG. 7B, the hole transport layer 65 and the electron transport layer 67 may be formed of a plurality of layers including a hole blocking layer and an electron blocking layer, It is possible. A hole injection layer having an energy band structure capable of smoothly injecting holes from the first electrode 64 into the hole transport layer 65 is formed between the first electrode 64 and the hole transport layer 65 . Similarly, an electron injection layer may be formed between the second electrode 68 and the electron transport layer 67 as well.

Next, an example of a manufacturing method of the organic EL display device will be described in detail.

First, a circuit (not shown) for driving the organic EL display device and a substrate 63 on which the first electrode 64 is formed are prepared.

An acrylic resin is formed on the substrate 63 on which the first electrode 64 is formed by spin coating and the acrylic resin is patterned by lithography so as to form an opening in a portion where the first electrode 64 is formed, . This opening corresponds to a light emitting region where the light emitting element actually emits light.

The substrate 63 on which the insulating layer 69 is patterned is brought into the first organic material film forming apparatus to hold the substrate by the substrate holding unit and the electrostatic chuck and the hole transport layer 65 is transported to the first electrode 64 As a common layer. The hole transport layer 65 is formed by vacuum evaporation. In practice, since the hole transport layer 65 is formed in a size larger than the display area 61, a high-precision mask is not required.

Next, the substrate 63 formed up to the hole transporting layer 65 is brought into the second organic film forming apparatus, and held by the substrate holding unit and the electrostatic chuck. Alignment of the substrate and the mask is performed and the substrate is placed on the mask to form a light emitting layer 66R that emits red light on the portion where the red emitting element of the substrate 63 is disposed.

The light emitting layer 66G that emits green light is formed by the third organic film forming apparatus similarly to the film formation of the light emitting layer 66R and further the light emitting layer 66B that emits blue light by the fourth organic film forming apparatus is formed. After the film formation of the light emitting layers 66R, 66G, and 66B is completed, the electron transport layer 67 is formed on the entire display region 61 by the fifth organic material film forming apparatus. The electron transporting layer 67 is formed as a common layer to the three color light emitting layers 66R, 66G, and 66B.

The substrate formed up to the electron transporting layer 67 is moved to the metallic deposition material film forming apparatus to form the second electrode 68. [

According to the present invention, in depositing various organic materials and metallic materials on a substrate for the production of an organic EL display device, after the substrate is adsorbed on the electrostatic chuck 23 at a predetermined time (for example, By lowering the voltage applied to the electrostatic chuck 23 in advance, the substrate can be stably held by the electrostatic chuck 23, thereby preventing the substrate from being damaged and preventing the substrate from separating from the electrostatic chuck 23 It is possible to shorten the time taken and shorten the process time.

Thereafter, the protective layer 70 is formed by moving to a plasma CVD apparatus to complete the organic EL display device 60.

When the substrate 63 having the insulating layer 69 is exposed to an atmosphere containing moisture or oxygen from the time when the substrate 63 having been patterned is transferred to the film forming apparatus to the completion of film formation of the protective layer 70, There is a possibility of deterioration due to moisture or oxygen. Therefore, in this example, the carrying-in and carrying-out of the substrate between the film forming apparatuses is performed in a vacuum atmosphere or an inert gas atmosphere.

The above embodiment shows an example of the present invention, and the present invention is not limited to the configuration of the above embodiment, but may be appropriately modified within the scope of the technical idea.

21: substrate holding unit
22: Mask band
23: Electrostatic Chuck
24: Magnet
30:
31:
32:
33:
211: first supporting member
212: second supporting member
311: a first sub-
312: second sub-electrode portion

Claims (20)

A film forming apparatus for forming a film on a substrate through a mask,
A substrate holding unit including a support for supporting a periphery of the substrate,
A magnet disposed above the electrostatic chuck for applying a magnetic force to the mask to closely contact the substrate and the mask,
And a control unit for controlling a voltage applied to the electrostatic chuck,
Wherein the control unit controls the first voltage to be applied to the electrostatic chuck when the substrate is attracted to the electrostatic chuck, and the process of separating the substrate from the electrostatic chuck after the substrate is attracted to the electrostatic chuck is started The second voltage lower than the first voltage is applied to the electrostatic chuck in advance as the voltage. The film forming apparatus according to claim 1, wherein the controller controls the second voltage to be applied to the electrostatic chuck after the start of a film forming process for depositing an evaporation material on a substrate through a mask. The film forming apparatus according to claim 1, wherein the controller controls the second voltage to be applied to the electrostatic chuck after completion of a film forming process for depositing an evaporation material on a substrate through a mask. The method according to claim 1,
Wherein the controller controls the second voltage to be applied to the electrostatic chuck after the adhesion of the substrate to the mask by the magnet is released. The film forming apparatus according to claim 1, wherein the control unit controls the second voltage to be applied to the electrostatic chuck after the substrate attracted to the electrostatic chuck is separated from the mask. The apparatus according to claim 1, wherein the control unit controls the third voltage to be applied to the electrostatic chuck at a time when the separation process is started. The film forming apparatus according to claim 1, wherein the second voltage is a zero voltage or a reverse polarity voltage. The apparatus according to claim 1, wherein the electrostatic chuck has an electrode section including a plurality of sub-electrode sections, and the control section controls the magnitudes of the second voltages applied to the plurality of sub-electrode sections to be different from each other. The substrate holder according to claim 8, wherein the support portion includes a first support member arranged to support a peripheral edge of one of two opposing sides of the substrate, and a second support member arranged to support a peripheral edge of the other of the two opposite sides of the substrate And a second support member,
Wherein the substrate support surface of the first support member is higher than the substrate support surface of the second support member,
A second voltage applied to a sub-electrode portion provided at a position corresponding to the first support member among the plurality of sub-electrode portions is lower than a second voltage applied to a sub-electrode portion provided at a position corresponding to the second support member Film deposition apparatus. The electrostatic chuck according to claim 1, wherein the electrostatic chuck has an electrode portion including a plurality of sub-electrode portions,
Wherein the control unit controls each of the plurality of sub-electrode units so that a time point at which the second voltage is applied is different. 11. The apparatus according to claim 10, wherein the support portion includes a first support member arranged to support a peripheral edge of one of two opposite sides of the substrate, and a second support member arranged to support a peripheral edge of the other of the two opposite sides of the substrate Wherein the substrate support surface of the first support member is higher than the substrate support surface of the second support member,
Wherein a time point at which the second voltage is applied to a sub-electrode portion provided at a position corresponding to the first support member among the plurality of sub-electrode portions is set to a sub-electrode portion provided at a position corresponding to the second support member, Film deposition apparatus. A film forming method for forming a film on a substrate through a mask,
Bringing the substrate into a vacuum chamber of a film forming apparatus,
Placing the loaded substrate on the support of the substrate holding unit,
Adsorbing the substrate on the support to an electrostatic chuck,
An alignment step of adjusting the position of the substrate attracted to the electrostatic chuck with respect to the mask,
Placing the positioned substrate on a mask,
Adhering the mask and the substrate on the mask by a magnet,
Depositing an evaporated material evaporated from an evaporation source on a substrate through a mask, and
Separating the substrate from the electrostatic chuck,
Wherein said step of adsorbing a substrate to an electrostatic chuck comprises the step of applying a first voltage to generate an electrostatic attraction on said electrostatic chuck,
Wherein the voltage applied to the electrostatic chuck is lowered from the first voltage to a second voltage lower than the first voltage after the start of the step of forming the evaporation material on the substrate. The film forming method according to claim 12, wherein the voltage applied to the electrostatic chuck after the completion of the film forming step is lowered to the second voltage. 13. The method according to claim 12, further comprising the step of releasing an adhesion state between the mask and the substrate by the magnet between the step of forming the film and the step of separating,
Wherein the voltage applied to the electrostatic chuck is lowered to the second voltage after the step of releasing the contact state. The method according to claim 12, further comprising, between the step of forming a film and the step of separating,
Releasing the adhesion state between the mask and the substrate by the magnet,
And separating the substrate from which the adhered state is released from the mask,
Wherein the voltage applied to the electrostatic chuck is lowered to the second voltage after the step of separating. 13. The method of claim 12,
Wherein a zero voltage or a third voltage which is a reverse polarity voltage is applied to the electrostatic chuck in the step of separating the substrate after the second voltage is applied to the electrostatic chuck. 13. The method of claim 12, wherein the second voltage is a zero voltage or a reverse polarity voltage. The method according to claim 12, wherein a magnitude of a second voltage applied to each of a plurality of sub-electrode portions included in the electrostatic chuck are different from each other. The method according to claim 12, wherein a time point at which the second voltage is applied to each of the plurality of sub-electrode portions included in the electrostatic chuck is different from each other. A manufacturing method of an organic EL display device,
A manufacturing method for manufacturing an organic EL display device using the film forming method according to any one of claims 12 to 19.

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