JP2019099913A - Film deposition device, film deposition method and production method of organic el display device - Google Patents

Abstract

To provide a film deposition device which reduces time taken for separating a substrate absorbed to an electrostatic chuck.SOLUTION: The film deposition device for depositing a film on a substrate through a mask includes a substrate holding unit including support part for supporting a peripheral part of the substrate, and an electrostatic chuck for absorbing the substrate, and the electrostatic chuck includes a power supply part 33 for generating voltage, an electrode part 31 to which the voltage is applied, and a voltage control part 32 for controlling the voltage applied on the electrode part 31. The voltage control part 32 controls that a first voltage as the first voltage is applied on the electrode part 31, when the substrate is absorbed to the electrostatic chuck, and the second voltage lower than the first voltage as the voltage is applied on the electrode part 31, after the substrate is absorbed to the electrostatic chuck and before starting the vapor deposition process.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a film forming apparatus, and more particularly, to voltage control for easily desorbing a substrate from an electrostatic chuck after applying a voltage to the electrostatic chuck in the film forming apparatus and adsorbing the substrate.

  Recently, an organic EL display device has been in the limelight 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 thinning are superior to those of liquid crystal panel displays, and existing liquid crystal panel displays such as monitors, televisions and various portable terminals represented by smartphones. Are being replaced at a high speed. In addition, the field of application is being expanded to displays for automobiles and the like.

  The element of the organic EL display device has a basic structure in which an organic substance layer which emits light is formed between two opposing electrodes (a cathode electrode and an anode electrode). The organic material layer and the electrode layer of the organic EL display element are formed on the upper part of the vacuum chamber through the mask on which the pixel pattern is formed by evaporating the evaporation material evaporated by heating the evaporation source provided under the vacuum chamber of the film forming apparatus. It is formed by vapor deposition on (the lower surface of) the substrate placed.

  The substrate is held by the substrate holder in the vacuum chamber of the film deposition apparatus of the upward deposition type, but the lower surface of the substrate is provided so as not to damage the organic layer / electrode layer formed on (the lower surface of) the substrate. The periphery of the substrate is supported by the support of the substrate holder. 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 bent by its own weight, which causes the deposition accuracy to be lowered.

  As a method for reducing the deflection of the substrate due to its own weight, a technique using an electrostatic chuck has been considered. That is, an electrostatic chuck is provided on the upper side of the substrate, and the upper surface of the substrate supported by the support portion of the substrate holder is attracted to the electrostatic chuck so that the central portion of the substrate is pulled by the electrostatic attractive force of the electrostatic chuck. By doing this, the deflection of the substrate can be reduced.

  However, after the substrate is attracted to the electrostatic chuck by the electrostatic attraction between the electrostatic chuck and the substrate, when the substrate is separated from the electrostatic chuck, the charge induced by the voltage applied at the time of substrate adsorption is discharged There is a problem that it takes time and it takes time to separate the substrate from the electrostatic chuck. If it takes time to separate the substrate from the electrostatic chuck, there is a problem that time (Tact) increases in the whole process and productivity is lowered.

  An object of the present invention is to provide a voltage control method of an electrostatic chuck for reducing the time taken to separate a substrate attracted to the electrostatic chuck.

A film forming apparatus according to an aspect of the present invention is a film forming apparatus for forming a film on a substrate through a mask, the substrate holding unit including a support portion for supporting a peripheral portion of the substrate, and the support The electrostatic chuck is provided above the unit and includes an electrostatic chuck for chucking the substrate, the electrostatic chuck includes a power supply unit that generates a voltage, an electrode unit to which the voltage is applied, and the electrode unit that is applied to the electrode unit. A voltage control unit for controlling a voltage, wherein the voltage control unit controls a first voltage as the voltage to be applied to the electrode unit when the substrate is attracted to the electrostatic chuck; A second voltage lower than the first voltage is controlled to be applied to the electrode portion as the voltage after being attracted to the electrostatic chuck and before a deposition process is started.

  A film forming method according to an aspect of the present invention is a film forming method for forming a film on a substrate through a mask, wherein the substrate is carried into a vacuum chamber of a film forming apparatus, and the carried-in substrate is a substrate holding unit Placing the substrate on the support on an electrostatic chuck, aligning the substrate attracted to the electrostatic chuck with respect to a mask, aligning the substrate Is placed on the mask, the mask is brought into close contact with the substrate on the mask, the deposition material evaporated from the deposition source is deposited on the substrate through the mask, the deposition material is deposited The step of carrying the substrate out of the vacuum chamber of the film forming apparatus, wherein the step of causing the substrate to be attracted to the electrostatic chuck comprises the step of applying a first voltage to the electrostatic chuck to generate electrostatic attraction. Before the start of the step of depositing a deposition material on a substrate, the voltage applied to the electrostatic chuck is lowered from the first voltage to a second voltage lower than the first voltage. .

  According to the present invention, after the substrate is attracted to the electrostatic chuck, the voltage applied to the electrostatic chuck is electrostatically applied to the electrostatic chuck before the substrate is separated from the electrostatic chuck (in particular, before the start of the film forming process). By lowering the voltage (adsorption maintenance voltage) lower than the voltage (adsorption start voltage) applied to cause the chuck to adsorb, the time taken to separate the substrate from the electrostatic chuck can be shortened. This can reduce the process time and improve the overall productivity.

FIG. 1 is a schematic view of a part of a manufacturing line of an organic EL display device. FIG. 2 is a schematic view of a film forming apparatus of the present invention. FIG. 3 is a block diagram of the electrostatic chuck of the present invention. FIG. 4 is a schematic view of the electrostatic chuck and the substrate holding unit of the present invention. FIG. 5 is a diagram for explaining a voltage control method for the electrostatic chuck of the present invention. FIG. 6 is a view for explaining the film forming method of the present invention. FIG. 7 is a schematic view showing the structure of the 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 merely illustrate preferred configurations of the present invention, and the scope of the present invention is not limited to those configurations. In the following description, the hardware configuration and software configuration of the device, the process flow, the manufacturing conditions, the dimensions, the materials, the shape, etc. limit the scope of the present invention to only those unless otherwise specified. It is not for the purpose.

  The present invention can be desirably applied to an apparatus for forming a thin film (material layer) of a pattern on a surface of a substrate by vacuum evaporation. As a material of the substrate, any material such as glass, film of polymer material, metal and the like can be selected, and as a vapor deposition material, organic material, metallic material (metal, metal oxide, etc.), etc. Any material can be selected. Specifically, the technology of the present invention is applicable to manufacturing apparatuses such as organic electronic devices (for example, organic EL display devices, thin film solar cells), optical members and the like. Among them, in a manufacturing apparatus of an organic EL display device, an organic EL display element is formed by evaporating a deposition material and depositing it on a substrate through a mask, which is one of the preferable applications of the present invention. .

<Electronic Device Production Line>
FIG. 1 is a top view schematically showing a part of a configuration of a manufacturing line of an electronic device. The manufacturing line of FIG. 1 is used, for example, for manufacturing a display panel of an organic EL display device for a smartphone. In the case of a display panel for a smartphone, for example, after forming a film of an organic EL on a substrate having a size of about 1800 mm × about 1500 mm, the substrate is cut out to produce a plurality of small size panels.

  Generally, as shown in FIG. 1, a production line of an electronic device has a plurality of film forming chambers 11 and 12 and a transfer chamber 13. In the transfer chamber 13, a transfer robot 14 for holding and transferring the substrate 10 is provided. The transport robot 14 is, for example, a robot having a structure in which a robot hand holding a substrate is attached to an articulated arm, and carries in / out the substrate 10 to / from each film forming chamber.

  A film forming apparatus (also referred to as a vapor deposition apparatus) is provided in each of the film forming chambers 11 and 12. A series of film forming processes such as delivery of the substrate 10 with the transport robot 14, adjustment (alignment) of the relative position between the substrate 10 and the mask, fixing of the substrate 10 on the mask, film formation (deposition) It is done automatically.

Hereinafter, the configuration of the film forming apparatus in the film forming chamber will be described.
<Deposition apparatus>
FIG. 2 is a cross-sectional view schematically showing the configuration of the film forming apparatus 2. In the following description, an XYZ orthogonal coordinate system in which the vertical direction is the Z direction is used. When 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 taken as the X direction, and the direction parallel to the long side is taken as the Y direction. Also, the rotation angle around the Z axis is indicated by θ.

  The film forming apparatus 2 includes a vacuum chamber 20 which defines a space in which a film forming process is established. 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 a substrate, a mask base 22 for holding a mask, an electrostatic chuck 23 for adsorbing the substrate by electrostatic attraction, and a metal mask are provided on the upper portion in the vacuum chamber 20 of the film forming apparatus 2. A magnet 24 or the like for applying a voltage is provided, and a vapor deposition source 25 or the like in which a vapor deposition material is accommodated is provided under the vacuum chamber 20 of the film forming apparatus.

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

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

  Each support member includes a substrate support surface portion 213 that supports the peripheral portion of the lower surface of the substrate, and an elastic body portion 214 that elastically supports the substrate support surface portion 213. A fluorine-coated pad (not shown) is provided on the substrate support surface 213 to prevent damage to the substrate. The elastic body portion 214 of the support member includes an elastic body such as a coil spring, a plate spring, silicone rubber, etc., and when the substrate is adsorbed to the electrostatic chuck, the substrate is made static by being elastically displaced by pressure from the electrostatic chuck. It prevents damage between the electric chuck and the support member.

The substrate support surface portion 213 of the first support member 211 may be installed at a height higher than the substrate support surface portion 213 of the second support member 212 in order to attach the substrate to the electrostatic chuck as a whole. . Further, by making the elastic coefficient of the elastic body portion 214 of the first support member 211 larger than the elastic coefficient of the elastic body portion 214 of the second support member 212 or making the length of the elastic body portion 214 longer, The support force with which the first support member 211 supports the substrate can be made larger than the support force with which the second support member 212 supports the substrate.

  A frame-like mask table 22 is placed under the substrate holding unit 21, and a mask 221 having an opening pattern corresponding to a thin film pattern formed on the substrate 10 is placed on the mask table. In particular, a mask used to manufacture an organic EL element for a smartphone is a metal mask on which a minute opening pattern is formed, and is also called FMM (Fine Metal Mask).

  Above the support portions 211 and 212 of the substrate holding unit 21, an electrostatic chuck 23 for adsorbing and fixing the substrate by electrostatic attraction is provided. The electrostatic chuck has a structure in which an electric circuit such as a metal electrode is embedded in a dielectric (for example, ceramic material) matrix. When positive (+) and negative (-) voltages are applied to the metal electrode, polarization charges of the opposite polarity to the metal electrode are induced in the substrate through the dielectric matrix, and electrostatic attraction between them causes the substrate to be electrostatic chucked. It can be fixed to 23 by adsorption. The electrostatic chuck 23 can be formed of one plate or can be formed to have a plurality of subplates. In addition, even in the case of being formed by one plate, a plurality of electric circuits therein can be included, and electrostatic attraction can be controlled differently depending on the position in one plate.

  In the present invention, as described later, the same voltage is not applied and maintained all the time to the electrostatic chuck while the electrostatic chuck 23 adsorbs the substrate, but after the start of adsorption, the voltage applied at the start of adsorption A lower voltage is applied to reduce the time taken for substrate separation.

  A magnet 24 is provided on the top of the electrostatic chuck 23 to apply a magnetic force to the metal mask 221 to prevent the mask from bending and to bring the mask 221 and the substrate 10 into close contact. The magnet 24 may be 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 can also be integrally formed with the magnet 24.

The deposition source 25 is a crucible (not shown) in which the deposition material to be deposited on the substrate is stored, a heater (not shown) for heating the crucible, the deposition material is a substrate until the evaporation rate from the deposition source becomes constant. Shutter (not shown) etc. which prevent scattering. The deposition source 25 may have various configurations depending on applications such as a point deposition source, a linear deposition source, and a revolver deposition source.
Although not shown in FIG. 2, the film forming apparatus 2 includes a film thickness monitor (not shown) and a film thickness calculation unit (not shown) for measuring the thickness of the film 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) on the outer upper surface of the vacuum chamber 20 of the film forming apparatus 2, and for alignment of the substrate and the mask A drive mechanism or the like for moving the electrostatic chuck 23, the substrate holding unit 21 and the like in parallel to the horizontal plane (in the X direction, the Y direction, and the θ direction) is provided. In addition, an alignment camera (not shown) is also provided which captures an alignment mark formed on the substrate and the mask through a window provided on the ceiling of the vacuum chamber 20 for alignment between the mask and the substrate.

The film forming apparatus includes a control unit 26. The control unit 26 has functions such as transport and alignment of the substrate 10, control of a deposition source, and control of film formation. The control unit 26 can be configured by, for example, a computer having a processor, a memory, a storage, an I / O, and the like. In this case, the function of the control unit 26 is realized by the processor executing a program stored in the memory or the storage. As a computer, a general purpose personal computer may be used, or an embedded computer or programmable logic controller (PLC) may be used. Alternatively, some or all of the functions of the control unit 26 may be configured by a circuit such as an ASIC or an FPGA. Moreover, the control part 26 may be installed for every film-forming apparatus, and one control part 26 is good also as what controls several film-forming apparatuses.

In the film forming process performed in the film forming apparatus, first, the substrate is carried into the vacuum chamber 20 and placed on the substrate holding unit 21 by the transfer robot 14 of the transfer chamber 13. Subsequently, an alignment step of measuring and adjusting the relative position of the substrate 10 and the mask 221 is performed. When the alignment process is completed, the substrate holding unit 21 is lowered by the driving mechanism to place the substrate 10 on the mask 221, and then the magnet 24 is lowered to bring the substrate 10 and the mask 221 into close contact. The substrate is fixed by the support portions 211 and 212 of the substrate holding unit 21 and the electrostatic chuck 23 in such an alignment process, a descending process for placing the substrate on the mask, and a process of adhering the substrate and the mask by magnets.
In this state, the shutter of the deposition source 25 is opened, and the deposition material evaporated from the crucible of the deposition source 25 is deposited on the substrate through the fine pattern opening of the mask.

  When the film thickness of the deposition material deposited on the substrate reaches a predetermined thickness, the shutter of the deposition source 25 is closed, and then the transfer robot 14 unloads the substrate from the vacuum chamber 20 to the transfer chamber 13.

<Voltage control of electrostatic chuck>
The configuration of the electrostatic chuck 23 according to the present invention and the control of the voltage applied to the electrostatic chuck in the substrate adsorption and desorption processes will be described below with reference to FIGS. 3 to 5.

  As shown in FIG. 3, 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. The power supply unit 33 applies a positive (+) voltage and a negative (−) voltage to the electrode unit 31 of the electrostatic chuck 23. The voltage control unit 32 controls, for example, the magnitude of the voltage applied from the power supply unit 33 to the electrode unit 31 according to the progress of the film forming process of the film forming apparatus 2. The voltage control unit 32 may be integrated with 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 can include a plurality of sub electrode units. For example, as shown in FIG. 4A, the electrode unit 31 of the present invention can be separately installed in the first sub electrode unit 311 and the second sub electrode unit 312. The first sub electrode unit 311 and the second sub electrode unit 312 may be disposed on two long sides facing each other with reference to the center of the short side of the electrostatic chuck 23. For example, as shown in FIG. 4B, the first sub electrode portion 311 is provided to correspond to the first support member 211 side of the substrate holding unit 21, and the second sub electrode portion 312 is a substrate holding unit. 21 is provided to correspond to the second support member 212 side.

Hereinafter, voltage control in the step of adsorbing the substrate 10 to the electrostatic chuck 23 will be described with reference to FIG.
The substrate is carried into the vacuum chamber 20 of the film forming apparatus 2 and placed on the support portions 211 and 212 of the substrate holding unit 21 (see FIG. 5A).

Subsequently, the electrostatic chuck 23 descends and moves so as to approach the substrate placed on the support portions 211 and 212 of the substrate holding unit 21. When the electrostatic chuck 23 approaches or contacts the substrate 10 sufficiently, as shown in FIG. 5B, the power source 33 of the electrostatic chuck 23 applies a first voltage (V1) to the electrode 31. The first voltage (V1) is set to a voltage of a sufficient magnitude to ensure that the substrate 10 is attracted to the electrostatic chuck 23. The time when the first voltage (V1) is applied to the electrostatic chuck 23 is t1.

  The first voltage (V1) applied to the electrode portion 31 of the electrostatic chuck 23 induces polarization charges of the opposite polarity proportional to the magnitude of the first voltage (V1) on the upper surface of the substrate. The substrate is flatly attracted to the electrostatic chuck by the electrostatic attraction between the polarization charge induced on the substrate and the electrode portion 31 of the electrostatic chuck 23. In the present embodiment, it has been described that the first voltage (V1) is applied while the electrostatic chuck 23 approaches or contacts the substrate 10, but before the electrostatic chuck 23 starts to descend toward the substrate 10, or The first voltage (V1) may be applied during the descent.

  At a predetermined time thereafter (t = t2), the voltage control unit 32 of the electrostatic chuck 23 causes the voltage applied to the electrode unit 31 of the electrostatic chuck 23 to be higher than the first voltage from the first voltage (V1). Reduce to a small second voltage (V2). The second voltage (V2) is an adsorption maintaining voltage for maintaining the substrate 10 once adsorbed by the electrostatic chuck 23 in a state of being adsorbed by the electrostatic chuck 23, and causes the substrate 10 to be adsorbed by the electrostatic chuck 23. Voltage lower than the first voltage (V1). When the voltage applied to the electrostatic chuck 23 decreases to the second voltage (V2), the amount of polarization charge induced on the substrate 10 corresponding to this is also shown in FIG. 5C, the first voltage (V1). ), But after the substrate 10 is once attracted to the electrostatic chuck 23 by the first voltage (V1), the second voltage (V2) is lower than the first voltage (V1). Can be maintained even if the substrate is applied.

  The second voltage (V2) is preferably determined in consideration of the magnitude of the first voltage (V1), and in consideration of the time taken to desorb the substrate, the voltage should be zero (0) or a reverse voltage. You can also. That is, if the first voltage (V1) is sufficiently large, it takes time for the polarization charge induced in the substrate to be discharged even if the second voltage is a zero voltage or a voltage of the reverse polarity. A state in which the substrate 10 is adsorbed to the electrostatic chuck 23 can be maintained.

  It is desirable that the time to reduce the voltage applied to the electrostatic chuck 23 from the first voltage (V1) to the second voltage (V2) is before the start of deposition on the substrate. This is to ensure the time taken for the 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, even if the voltage applied to the electrode portion 31 of the electrostatic chuck 23 is zero (0), the static potential between the electrostatic chuck 23 and the substrate 10 is immediately reduced. It takes a considerable time (in some cases, several minutes) for the charge induced at the interface between the electrostatic chuck 23 and the substrate 10 to disappear, rather than the elimination of the attractive force. In particular, when the substrate 10 is attracted to the electrostatic chuck 23, usually, in order to ensure the adsorption, the electrostatic chuck 23 is sufficiently larger than the minimum electrostatic attractive force (Fth) required to adsorb the substrate. Although the first voltage is set so that electrostatic attraction acts (see FIG. 5 (f)), it takes a considerable amount of time until the substrate can be separated from such a first voltage.

  In the present invention, in order to prevent an increase in the overall process time (Tact) due to the time taken to separate and desorb the substrate 10 from the electrostatic chuck 23 as described above, it is necessary to The voltage applied to the electric chuck 23 is lowered to the second voltage.

In particular, the magnitude of the electrostatic attraction between the substrate and the electrostatic chuck 23 is from the electrostatic attraction due to the first voltage to the minimum electrostatic attraction (Fth) for maintaining the adsorption between the substrate and the electrostatic chuck 23 In consideration of the balance between the time to decrease and the time to reduce the electrostatic attraction to such an extent that the substrate and the electrostatic chuck can be separated from the electrostatic attraction due to the second voltage (see FIGS. 5 (e) and 5 (f)) It is preferable to lower the voltage of the electrostatic chuck 23 to the second voltage at a time when the time taken to desorb the substrate can be sufficiently secured while stably maintaining the adsorption state of the substrate.
The specific time to reduce the voltage applied to the electrostatic chuck 23 to the second voltage (V2) will be described later with reference to FIG.

  In another embodiment of the present invention, the electrode portion 31 of the electrostatic chuck 23 is formed to include the first sub electrode portion 311 and the second sub electrode portion 312, and a voltage applied to each sub electrode portion is generated from the first voltage. The timings of lowering to the second voltage may be different from one another, or the magnitudes of the second voltages may be different from one another.

  For example, as shown in FIGS. 4B and 4C, the voltage applied to the first sub electrode portion 311 formed on the side where the substrate is supported by the high first support member 211 of the substrate support surface is After reducing the voltage from the first voltage to the second voltage, the voltage applied to the second sub electrode portion 312 is reduced from the first voltage to the second voltage. Since the peripheral portion of the substrate supported by the first support member 211 is first attracted to the electrostatic chuck 23, the induced polarization charge amount is larger than the peripheral portion side of the substrate supported by the second support member 212. Thus, the time taken to separate the substrates (the time taken to discharge the polarization charge) is also longer. The voltage of the first sub-electrode portion 311 adsorbed by the substrate peripheral portion side supported by the first support member 211, which takes a relatively long time to separate the substrates, is first lowered to the second voltage to apply to the substrate separation A sufficient time can be secured.

  The second voltage applied to the first sub-electrode portion 311 is lower than the second voltage applied to the second sub-electrode portion 312 in order to reduce the charge discharge time on the substrate peripheral portion side supported by the first support member 211 You can also That is, by lowering the second voltage applied to the side of the first sub-electrode portion 311 where relatively more polarization charges are induced, more induced charges are discharged in advance than the side of the second sub-electrode portion 312. By balancing the discharge time of the polarization charge induced on the substrate on the side of the second sub electrode portion 312, it is possible to finally balance the time required for substrate desorption.

  When 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 is induced on the substrate in contact with both the sub electrode portions The various combinations can be selected in consideration of the balance of time required to discharge the charge.

<Film formation process>
Hereinafter, a film forming method adopting the electrostatic chuck voltage control of the present invention will be described with reference to FIG.

  While the mask 221 is placed on the mask table 22 in the vacuum chamber 20, the substrate is carried into the vacuum chamber 20 of the film forming apparatus 2 by the transfer robot 14 of the transfer chamber 13 (FIG. 6A).

  The hand of the transfer robot 14 which has entered the vacuum chamber 20 is lowered, and the substrate 10 is mounted on the support portions 211 and 212 of the substrate holding unit 21 (FIG. 6B).

Subsequently, after the electrostatic chuck 23 descends toward the substrate 10 and approaches or contacts the substrate 10 sufficiently, a first voltage (V1) is applied to the electrostatic chuck 23 to adsorb the substrate 10 (FIG. 6 (FIG. c)).

In one embodiment of the present invention, to ensure that the time required to desorb the substrate from the electrostatic chuck 23 is maximized, immediately after the adsorption of the substrate onto the electrostatic chuck 23 is completed, the electrostatic chuck 23 is used. The applied voltage is lowered from the first voltage (V2) to the second voltage (V2). Even if the voltage applied to the electrostatic chuck 23 is lowered to the second voltage (V2) immediately after the adsorption of the substrate is completed, it takes time until the polarization charge induced on the substrate by the first voltage (V1) is discharged. Because of this, it is possible to maintain the adsorption power to the substrate by the electrostatic chuck 23 in the subsequent steps.

  In a state where the substrate 10 is adsorbed to the electrostatic chuck 23, the substrate (10) is lowered toward the mask (221) to measure the relative positional deviation of the substrate relative to the mask (FIG. 6 (d)). In another embodiment of the present invention, after the process of lowering the substrate is completed in order to reliably prevent the substrate from falling off the electrostatic chuck 23 in the process of lowering the substrate adsorbed by the electrostatic chuck 23 The voltage applied to the electrostatic chuck 23 is lowered to the second voltage (V2) (ie, before the alignment process described later is started).

  When the substrate 10 is lowered to the measurement position, the alignment camera captures an alignment mark formed on the substrate (10) and the mask (221) to measure the relative positional deviation between the substrate and the mask (FIG. 6 (e )reference). In another embodiment of the present invention, the electrostatic chuck 23 is added after the measurement process for alignment is completed (during the alignment process) in order to further ensure the accuracy of the measurement process of the relative position between the substrate and the mask. Voltage to a second voltage. That is, by photographing the alignment mark between the substrate and the mask in a state where the substrate is strongly attracted to the electrostatic chuck 23 by the first voltage (V1) (a state where the substrate is kept flat), the space between the substrate and the mask A distance can be secured, and a clearer photographed image of the alignment mark can be obtained.

  As a result of measurement, when it is found that the relative positional deviation of the substrate with respect to the mask exceeds the threshold, the substrate 10 in a state of being adsorbed by the electrostatic chuck 23 is moved in the horizontal direction (XYθ direction) to use the substrate as a mask. On the other hand, position adjustment (alignment) is performed (see FIG. 6F). In another embodiment of the present invention, the voltage applied to the electrostatic chuck 23 is lowered to the second voltage (V2) after such a position adjustment process is completed. This can further increase the accuracy over the entire alignment process (relative position measurement and position adjustment).

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 brought into close contact (FIG. 6 (g)). In another embodiment of the present invention, with the substrate 10 placed on the mask 221, the voltage applied to the electrostatic chuck 23 is lowered to the second voltage (V2). By this, the degree of bending of the substrate can be matched to the degree of bending of the mask, and the adhesion between the substrate and the mask in the subsequent steps is improved. According to another embodiment of the present invention, the voltage applied to the electrostatic chuck 23 is lowered to the second voltage (V2) after the step of bringing the substrate and the mask into close contact by the magnet 24. By this, the substrate can be maintained flat by the time of adhesion by the magnet of the substrate and the mask, and the adhesion between the substrate and the mask can be further improved.
Subsequently, the shutter of the vapor deposition source 25 is opened, and the vapor deposition material is vapor deposited on the substrate 10 through the mask (FIG. 6 (h)).

  After the film of the desired thickness is deposited on the substrate 10, the shutter of the deposition source 25 is closed, and then the magnet 24 is lifted, and the substrate is lifted by the electrostatic chuck and the substrate holding unit (FIG. 6 (i)) ).

  Subsequently, the hand of the transfer robot enters the vacuum chamber of the film forming apparatus, and a voltage of zero (0) or reverse polarity is applied to the electrostatic chuck 23 (t = t3), and the electrostatic chuck 23 separates from the substrate To rise (Fig. 6 (j)). Thereafter, the substrate on which the deposition has been completed is unloaded.

  The present invention is not limited to this, and for example, the substrate is separated from the electrostatic chuck 23 at the time of FIG. 6 (h) to be in a state along the mask 221, and in this state, the shutter of the vapor deposition source 25 is opened. The deposition material may be deposited on the substrate 10 through a mask. As described above, in the present invention, the time when the voltage applied to the electrostatic chuck 23 is lowered from the first voltage to the second voltage is before the start of the deposition process, and the substrate to the electrostatic chuck 23 is After completion of the adsorption process, before the start of the alignment process (after completion of the substrate descent process), during the alignment process (after completion of the measurement process), after completion of the alignment process, after completion of the process of placing the substrate on the mask It can be done after completion of the step of bonding the substrate and the mask.

<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 illustrated 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. 7A, in the display area 61 of the organic EL display device 60, a plurality of pixels 62 including a plurality of light emitting elements are arranged in a matrix. Although details will be described later, each of the light emitting elements has a structure including an organic layer sandwiched between a pair of electrodes. The term “pixel” as used herein refers to the minimum unit capable of displaying a desired color in the display area 61. In the case of the organic EL display device according to the present example, the pixel 62 is configured by a combination of the first light emitting element 62R, the second light emitting element 62G, and the third light emitting element 62B that emit light different from each other. The pixel 62 is often composed 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 It is not limited.

  FIG.7 (b) is a fragmentary-section schematic diagram in the AB line of FIG. 7 (a). The pixel 62 includes a first electrode (anode) 64, a hole transport layer 65, one of light emitting layers 66R, 66G, and 66B, an electron transport layer 67, and a second electrode (cathode) 68 on a substrate 63. , And an organic EL element comprising Among these, the hole transport layer 65, the light emitting layers 66R, 66G, 66B, and the electron transport layer 67 correspond to the organic layer. Further, in the present embodiment, the light emitting layer 66R is an organic EL layer that emits red, the light emitting layer 66G is an organic EL layer that emits green, and the light emitting layer 66B is an organic EL layer that emits blue. The light emitting layers 66R, 66G, 66B are formed in patterns corresponding to light emitting elements (sometimes described as organic EL elements) that emit red, green and blue, respectively. In addition, the first electrode 64 is formed separately for each light emitting element. 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 for each light emitting element. An insulating layer 69 is provided between the first electrodes 64 in order to prevent the first electrodes 64 and the second electrodes 68 from being short-circuited by foreign matter. Furthermore, since the organic EL layer is degraded by moisture and oxygen, a protective layer 70 is provided to protect the organic EL element from moisture and oxygen.

  Although the hole transport layer 65 and the electron transport layer 67 are shown in one layer in FIG. 7B, they are formed of a plurality of layers including the hole block layer and the electron block layer depending on the structure of the organic EL display element. It may be done. In addition, the positive electrode has an energy band structure which can facilitate the injection of holes from the first electrode 64 to the hole transport layer 65 between the first electrode 64 and the hole transport layer 65. A hole injection layer can also be formed. Similarly, an electron injection layer can be formed between the second electrode 68 and the electron transport layer 67 as well.

Next, an example of a method of manufacturing an organic EL display device will be specifically described.
First, a circuit 63 (not shown) for driving the organic EL display device and the substrate 63 on which the first electrode 64 is formed are prepared.
An acrylic resin is formed by spin coating on the substrate 63 on which the first electrode 64 is formed, and the acrylic resin is patterned by lithography so that an opening is formed in the portion where the first electrode 64 is formed. Form 69 The opening corresponds to a light emitting region in which the light emitting element actually emits light.

  The substrate 63 on which the insulating layer 69 is patterned is carried into the first organic material film forming apparatus, the substrate is held by the substrate holding unit and the electrostatic chuck, and the hole transport layer 65 is used as the first electrode 64 in the display area. As a common layer on top of the The hole transport layer 65 is deposited by vacuum evaporation. In practice, the hole transport layer 65 is formed to have a size larger than that of the display area 61, so a high definition mask is not necessary.

Next, the substrate 63 having the hole transport layer 65 formed thereon is carried into the second organic material film forming apparatus, and is held by the substrate holding unit and the electrostatic chuck. Alignment between the substrate and the mask is performed, the substrate is placed on the mask, and the light emitting layer 66R emitting red is formed on the portion of the substrate 63 where the element emitting red is disposed.
Similar to the film formation of the light emitting layer 66R, the light emitting layer 66G emitting green is formed by the third organic material film forming apparatus, and the light emitting layer 66B emitting blue is formed by the fourth organic material film forming apparatus. . After 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 film forming apparatus. The electron transport layer 67 is formed as a layer common to the three color light emitting layers 66R, 66G, and 66B.
The substrate formed up to the electron transport layer 67 is moved to a metallic vapor deposition material deposition apparatus to deposit a second electrode 68.

According to the present invention, in vapor-depositing various organic materials and metallic materials on a substrate for manufacturing an organic EL display element, the electrostatic chuck 23 is attracted to the electrostatic chuck 23 at a predetermined time after the substrate is absorbed by the electrostatic chuck 23. By lowering the voltage to be applied in advance, it is possible to shorten the time taken to separate the substrate from the electrostatic chuck 23 and to reduce the process time.
Thereafter, it moves to a plasma CVD apparatus to form a protective layer 70, and the organic EL display device 60 is completed.

After the substrate 63 on which the insulating layer 69 is patterned is carried into a film forming apparatus and the film is exposed to an atmosphere containing moisture or oxygen until the film formation of the protective layer 70 is completed, the light emitting layer made of the organic EL material It may be degraded by moisture or oxygen. Therefore, in the present embodiment, the loading and unloading of the substrate between the film forming apparatuses is performed under a vacuum atmosphere or an inert gas atmosphere.
The above embodiment is 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 thereof.

21: substrate holding unit 22: mask base 23: electrostatic chuck 24: magnet 30: dielectric portion 31: electrode portion 32: voltage control portion 33: power source portion 211: first support member 212: second support member 311: second 1 sub electrode portion 312: second sub electrode portion

Claims (17)

A film forming apparatus for forming a film on a substrate through a mask,
A substrate holding unit including a support portion for supporting a peripheral portion of the substrate; and an electrostatic chuck provided above the support portion and for adsorbing the substrate,
The electrostatic chuck includes a power supply unit that generates a voltage, an electrode unit to which the voltage is applied, and a voltage control unit that controls the voltage applied to the electrode unit.
The voltage control unit controls the first voltage as the voltage to be applied to the electrode unit when adsorbing the substrate to the electrostatic chuck, and after the substrate is attracted to the electrostatic chuck, a deposition process is performed. The film-forming apparatus which controls so that the 2nd voltage lower than the said 1st voltage as said voltage is applied to the said electrode part, is started.   The voltage control unit may be configured to apply the second voltage to the electrode unit during an alignment process for adjusting the position between the mask and the substrate after the first voltage is applied to the electrostatic chuck. The film-forming apparatus of Claim 1 which controls.   The voltage control unit applies the second voltage to the electrode unit after the first voltage is applied to the electrostatic chuck and before an alignment process for adjusting the position between the mask and the substrate is started. The film forming apparatus according to claim 1, which is controlled to be controlled.   The voltage control unit controls the zero voltage or the reverse polarity voltage to be applied to the electrode unit at a predetermined time after the second voltage is applied to the electrode unit. The film-forming apparatus of any one of Claim 3.   The film forming apparatus according to any one of claims 1 to 4, wherein the second voltage is a zero (0) voltage or a voltage of reverse polarity.   The electrode unit includes a plurality of sub electrode units, and the voltage control unit controls the magnitudes of the second voltages applied to the plurality of sub electrode units to be different from each other. The film-forming apparatus of any one of 5. The support portion is a first support member disposed to support a peripheral edge on one side of two opposing sides of the substrate, and a peripheral edge on the other side of the opposing two sides of the substrate. A second support member arranged to support, wherein the substrate support surface of the first support member is higher in height 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 provided at a sub electrode portion provided at a position corresponding to the second support member. The film forming apparatus according to claim 6, wherein the film forming apparatus is lower than the applied second voltage.   8. The device according to claim 1, wherein the electrode unit includes a plurality of sub-electrode units, and the voltage control unit controls different points in time when the second voltage is applied to each of the plurality of sub-electrode units. The film-forming apparatus of any one. The support portion is a first support member disposed to support a peripheral edge on one side of two opposing sides of the substrate, and a peripheral edge on the other side of the opposing two sides of the substrate. A second support member arranged to support, wherein the substrate support surface of the first support member is higher in height than the substrate support surface of the second support member,
Of the plurality of sub electrode portions, the sub electrode portion provided at the position corresponding to the first support member The point at which the second voltage is applied is provided at the position corresponding to the second support member The film forming apparatus according to claim 8, which is earlier than the time when the second voltage is applied to the electrode unit. A film forming method for forming a film on a substrate through a mask,
Loading the substrate into the vacuum chamber of the 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 a mask;
Placing the aligned substrate on the mask;
Contacting the mask and the substrate on the mask with a magnet,
Forming a deposition material evaporated from a deposition source on a substrate through a mask;
Carrying out the substrate on which the deposition material has been deposited from the vacuum chamber of the deposition apparatus;
The step of attracting the substrate to the electrostatic chuck includes applying a first voltage to the electrostatic chuck to generate an electrostatic attraction.
The film-forming method which reduces the voltage applied to the said electrostatic chuck from the said 1st voltage to the 2nd voltage lower than the said 1st voltage before the start of the said process of forming the vapor deposition material into a film on a board | substrate.   The film forming method according to claim 10, wherein the voltage applied to the electrostatic chuck is lowered to the second voltage during the progress of the alignment step.   The film forming method according to claim 10, wherein the voltage applied to the electrostatic chuck is lowered to the second voltage before the start of the alignment step.   After the second voltage is applied to the electrostatic chuck, a zero (0) voltage or a reverse polarity voltage is applied to the electrostatic chuck before the completion of the step of unloading the substrate. The film-forming method of any one of 12.   The film forming method according to any one of claims 10 to 13, wherein the second voltage is a zero (0) voltage or a voltage of reverse polarity.   The film forming method according to any one of claims 10 to 14, wherein magnitudes of second voltages applied to the plurality of sub electrode portions included in the electrostatic chuck are made different from each other.   The film forming method according to any one of claims 10 to 15, wherein a point in time when the second voltage is applied to each of the plurality of sub electrode parts included in the electrostatic chuck is made different from each other. A method of manufacturing an organic EL display device
The manufacturing method which manufactures an organic electroluminescence display using the film-forming method of any one of Claims 10-16.