Electrostatic chuck unit

Abstract

An electrostatic chuck unit is provided. The electrostatic chuck unit includes a first wiring portion configured to generate a relatively weak electrostatic force and a second wiring portion configured to generate a relatively strong electrostatic force.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2018-0077892 filed on July 4, 2018, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] One or more embodiments relate to a thin film deposition apparatus for generating vapor of a deposition source and for forming a thin film on a substrate through a mask, and also to a thin film deposition apparatus including an improved electrostatic chuck unit for bringing the mask and the substrate into close contact with each other and for supporting the mask and the substrate. Background Art

[0004] In general, an organic light-emitting display device generates an image by emitting light according to the recombination of holes and electrons injected into the anode and cathode, respectively, in the emission layer. The organic light-emitting display device has a stacked structure in which the emission layer is inserted between the anode and the cathode. However, since it is difficult to obtain efficient light emission using the above structure, an electron injection layer, an electron transport layer, a hole transport layer, and a hole injection layer are selectively added to the emission layer as an intermediate layer between the two electrodes (i.e., between the anode and the cathode).

[0005] The electrodes and the intermediate layers of the organic light-emitting display device can be formed by various methods. The deposition method is one of the various methods. When the organic light-emitting display device is manufactured by using the deposition method, a mask having pattern holes corresponding to the thin film pattern to be formed is aligned on a substrate, and a raw material of the thin film is deposited on the substrate through the pattern holes of the mask, thereby forming a thin film having a desired pattern.

[0006] In this case, the electrostatic chuck unit is used to bring the mask and the substrate into close contact with each other and firmly support the mask and the substrate. In other words, the electrostatic chuck unit is positioned opposite to the mask with the substrate therebetween, and pulls the substrate and the mask using electrostatic force so that the mask and the substrate are firmly adhered to each other when deposition is performed. Summary of the invention

[0007] Due to the step difference in the periphery of the mask, repulsion rather than attraction occurs at the end portion of the cell, where the cell is the area in the mask where the pattern holes are formed. Therefore, the adhesion between the substrate and the mask is relatively reduced. In this case, a gap is formed between the substrate and the mask, and deposition may not be accurately performed at the desired position. Therefore, there is a high possibility that the product manufactured in this way may be defective.

[0008] One or more embodiments include an electrostatic chuck unit and a thin film deposition apparatus including the electrostatic chuck unit, wherein the electrostatic chuck unit improves adhesion at an end portion of a cell.

[0009] Additional aspects will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the presented embodiments.

[0010] According to one or more embodiments, the electrostatic chuck unit includes an electrostatic chuck body, the electrostatic chuck body includes a first wiring portion and a second wiring portion, the first wiring portion and the second wiring portion each include a plurality of wirings configured to generate an electrostatic force to generate an attractive force between a substrate and a mask through the electrostatic force, wherein the first wiring portion is configured to generate an electrostatic force weaker than that of the second wiring portion.

[0011] An interval between wirings in the second wiring portion may be smaller than an interval between wirings in the first wiring portion.

[0012] A width of each of the wirings in the second wiring portion may be greater than a width of each of the wirings in the first wiring portion.

[0013] The thickness of each of the wirings in the second wiring portion may be greater than the thickness of each of the wirings in the first wiring portion.

[0014] The electrostatic chuck unit may further include a plurality of pressing protrusions on a surface of the electrostatic chuck body facing the substrate and the mask.

[0015] A plurality of pressing protrusions may be located at positions corresponding to the second wiring portion.

[0016] Multiple pressing protrusions may be located at positions corresponding to the first wiring portion and at positions corresponding to the second wiring portion, and the pressing protrusions located at positions corresponding to the second wiring portion may be more densely distributed than the pressing protrusions located at positions corresponding to the first wiring portion.

[0017] The electrostatic chuck body may also include a cooler.

[0018] The electrostatic chuck unit may further include a magnet for generating a magnetic force to attract the mask.

[0019] The mask may include a unit cell in which a plurality of pattern holes are distributed and a step difference portion is formed in an end portion of the unit cell, wherein the second wiring portion is positioned to correspond to the step difference portion.

[0020] According to one or more embodiments, a thin film deposition apparatus includes a chamber, a deposition source supplier, a mask, and an electrostatic chuck unit, wherein the deposition source supplier is configured to supply a deposition source to a substrate as a deposition target in the chamber; the mask has a unit cell having a plurality of pattern holes formed therein, the plurality of pattern holes being used for patterned deposition on the substrate; the electrostatic chuck unit is configured to support the mask and the substrate to generate an attractive force between the mask and the substrate and includes an electrostatic chuck body, the electrostatic chuck body is configured to generate an electrostatic force to generate an attractive force between the substrate and the mask through the electrostatic force, and the electrostatic chuck body includes a first wiring portion and a second wiring portion, each of which includes a plurality of wirings to generate an electrostatic force, wherein the first wiring portion is configured to generate an electrostatic force weaker than the second wiring portion.

[0021] An interval between wirings in the second wiring portion may be smaller than an interval between wirings in the first wiring portion.

[0022] A width of each of the wirings in the second wiring portion may be greater than a width of each of the wirings in the first wiring portion.

[0023] The thickness of each of the wirings in the second wiring portion may be greater than the thickness of each of the wirings in the first wiring portion.

[0024] The thin film deposition apparatus may further include a plurality of pressing protrusions on a surface of the electrostatic chuck body facing the substrate and the mask.

[0025] A plurality of pressing protrusions may be located at positions corresponding to the second wiring portion.

[0026] Multiple pressing protrusions may be located at positions corresponding to the first wiring portion and at positions corresponding to the second wiring portion, wherein the pressing protrusions located at positions corresponding to the second wiring portion are more densely distributed than the pressing protrusions located at positions corresponding to the first wiring portion.

[0027] The electrostatic chuck body may also include a cooler.

[0028] The thin film deposition apparatus may further include a magnet for attracting the mask using a magnetic force.

[0029] A step difference portion may be formed in an end portion of the unit cell, wherein the second wiring portion is positioned to correspond to the step difference portion in the mask.

[0030] Aspects and features other than those described above may be more readily understood by reference to the following detailed description of the embodiments, the accompanying drawings, and the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] These and / or other aspects will become apparent and more readily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0032] Figure 1 is a cross-sectional view of a thin film deposition apparatus including an electrostatic chuck unit according to an embodiment;

[0033] Figure 2 yes Figure 1 A perspective view of the mask frame assembly shown in ;

[0034] Figure 3 is along Figure 2 A cross-sectional view taken along line III-III;

[0035] Figure 4 yes Figure 1 A plan view of an electrostatic chuck unit shown in ;

[0036] Figure 5 is a plan view of an electrostatic chuck unit according to another embodiment;

[0037] Figures 6 to 10 is a cross-sectional view of an electrostatic chuck unit according to another embodiment; and

[0038] Fig.11 As Figure 1 FIG. 1 is a cross-sectional view of a structure of an organic light-emitting display device of an example of a substrate shown in FIG. DETAILED DESCRIPTION

[0039] Since the present disclosure allows various changes and many embodiments, specific embodiments will be shown in the drawings and described in detail in the written description. The features and effects of the present disclosure and the methods for implementing the present disclosure can be more easily understood by referring to the drawings and the following detailed description of the preferred embodiments. However, the present invention can be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein.

[0040] Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein the same or corresponding components are given the same reference numerals regardless of the drawing numbers and redundant description is omitted.

[0041] Throughout the specification, terms such as “first”, “second”, etc. may not be used for the purpose of limitation but may be used to distinguish one component from another.

[0042] Throughout the specification, a singular form may include a plural form unless there is a specific description contrary thereto.

[0043] Throughout the specification, it will also be understood that the terms "comprise", "include" and / or "having" when used in the specification specify the presence of stated features and / or components, but do not preclude the presence or addition of one or more other features and / or components.

[0044] In the drawings, the thickness of layers and regions are exaggerated for clarity. For example, for ease of description, the thickness and size of elements in the drawings are arbitrarily shown, and the spirit and scope of the present disclosure are not necessarily limited by the drawings.

[0045] In addition, it should be noted that, in some alternative implementations, the steps of all methods described herein may not occur in order. For example, two steps shown in succession may actually be performed substantially simultaneously, or the two steps may sometimes be performed in reverse order.

[0046] Throughout the specification, it will also be understood that when a layer, region, element, etc. is referred to as being connected to or coupled to another layer, region, or element, it may be directly connected to or coupled to the other layer, region, or element, or it may be indirectly connected to or coupled to the other layer, region, or element by inserting an intermediate layer, region, or element between the layer, region, element and the other layer, region, or element. For example, throughout the specification, when a layer, region, element, etc. is referred to as being electrically connected to or coupled to another layer, region, or element, it may be electrically connected to or coupled to the other layer, region, or element in a direct manner, or it may be electrically connected to or coupled to the other layer, region, or element in an indirect manner by inserting an intermediate layer, region, or element between the layer, region, element and the other layer, region, or element.

[0047] Figure 1 is a cross-sectional view of a thin film deposition apparatus including an electrostatic chuck unit 100 according to an embodiment. Figure 2 yes Figure 1 A perspective view of the mask frame assembly 200 is shown in FIG. Figure 3 is along Figure 2 A cross-sectional view taken along line III-III. Figure 4 yes Figure 1 A plan view of an electrostatic chuck unit 100 is shown in FIG.

[0048] like Figure 1As shown in , the thin film deposition device according to the present embodiment includes a deposition source unit / deposition source supplier 300, a mask 210 and an electrostatic chuck unit 100, wherein the deposition source unit / deposition source supplier 300 is used to spray a deposition source in a chamber 400, the mask 210 is in close contact with the surface of a substrate 10 as a deposition target, and the electrostatic chuck unit 100 is positioned on a surface of the substrate 10 opposite to the surface and attracts the substrate 10 and the mask 210 by electrostatic force so that the substrate 10 and the mask 210 are in close contact with each other.

[0049] Therefore, when the deposition source supplier 300 sprays the deposition source in the chamber 400, the deposition source passes through the pattern holes 211a (see FIG. Figure 2 ) is deposited on the substrate 10, and thus, a thin film having a pattern is formed.

[0050] In this case, power is supplied from the power supply 120 of the electrostatic chuck unit 100 to the first wiring portion 111 and the second wiring portion 112 of the electrostatic chuck body 110 (see Figure 4 The first wiring portion 111 and the second wiring portion 112 in the mask 210 are connected to each other to generate an electrostatic force, and the mask 210 and the substrate 10 are firmly and closely contacted with each other by the electrostatic force.

[0051] The mask 210 is used in the form of a mask frame assembly 200 in which an edge portion of the mask 210 is supported by a frame 220, and has a Figure 2 The structure shown in .

[0052] like Figure 2 As shown in FIG. 1 , a frame 220 having an opening 221 at the center thereof is provided, and a plurality of strip-shaped masks (e.g., relatively long and thin masks) 210 are supported on the frame 220 (e.g., by the ends of the frame 220). Each of the masks 210 has two ends fixed to the frame 220, and a plurality of cells 211 located between the two ends of each of the masks 210 are arranged in the opening 221 (e.g., aligned with or corresponding to the opening 221). Each of the cells 211 is a region where a plurality of pattern holes 211a are formed, and when a deposition source passes through the plurality of pattern holes 211a of the cells 211, a thin film is formed on the substrate 10. Typically, the mask 210 includes a metal material.

[0053] The unit cell 211 has a step difference portion 210a formed in the end portions A1 and A2 near the corresponding end of each mask 210, wherein the thickness of the step difference portion 210a changes relatively abruptly. Figure 3As shown in FIG. 1 , a step difference portion 210a whose thickness suddenly changes (for example, located at a position where the thickness of the mask 210 suddenly increases) is formed in the end portions A1 and A2. In the region where the step difference portion 210a is formed, a repulsive force occurs when an electrostatic force occurs, and therefore, the adhesion between the mask 210 and the substrate 10 is lower than that in other regions.

[0054] Therefore, in the present embodiment, the first wiring portion 111 and the second wiring portion 112 are arranged in a differential manner in the electrostatic chuck main body 110 (for example, see Figure 4 ) to suppress the above-mentioned repulsive force problem. The detailed structure will be described later. First, refer to Fig.11 The structure of an organic light emitting display device is briefly described as an example of the substrate 10 on which deposition is performed by the thin film deposition apparatus according to the present embodiment.

[0055] Fig.11 As Figure 1 FIG. 1 is a cross-sectional view of a structure of an organic light-emitting display device of an example of a substrate 10 shown in FIG.

[0056] like Fig.11 As shown in , the organic light emitting display device includes a thin film transistor TFT and an organic light emitting device EL.

[0057] The active layer 14 is formed on the buffer layer 10a located on the substrate 10. The active layer 14 includes a source and a drain heavily doped with N-type or P-type impurities. The active layer 14 may include an oxide semiconductor. For example, the oxide semiconductor may include an oxide of a material selected from Group 12, Group 13, and Group 14 metal elements and combinations thereof, wherein the Group 12, Group 13, and Group 14 metal elements are such as zinc (Zn), indium (In), gallium (Ga), tin (Sn), cadmium (Cd), and germanium (Ge). For example, the active layer 14 including an oxide semiconductor may include GIZO [(In 2 O 3 ) a (Ga 2 O 3 ) b (ZnO) c ] (wherein a, b and c are real numbers satisfying the conditions a≥0, b≥0 and c>0, respectively). The gate electrode 15 is formed on the active layer 14, and the gate insulating layer 10b is located between the gate electrode 15 and the active layer 14. The gate electrode 15 includes two layers, that is, the gate electrode 15 includes a gate lower layer 15a and a gate upper layer 15b.

[0058] A source electrode 16 and a drain electrode 17 are formed on the gate electrode 15. An interlayer insulating layer 10c is provided between the gate electrode 15 and the source electrode 16 and between the gate electrode 15 and the drain electrode 17, and a passivation layer 10d is positioned between the pixel electrode 11 of the organic light emitting device EL and the source electrode 16 and the drain electrode 17.

[0059] A pixel defining layer 10e is formed over the pixel electrode 11. An opening is formed in the pixel defining layer 10e to expose the pixel electrode 11, and then an emission layer 12 is formed on the pixel electrode 11 by deposition.

[0060] The organic light emitting device EL emits red light, green light and blue light according to the current, thereby displaying image information. The organic light emitting device EL includes a pixel electrode 11 connected to a drain electrode 17 of a thin film transistor TFT, a counter electrode 13 facing the pixel electrode 11, and an emission layer 12 for emitting light positioned between the pixel electrode 11 and the counter electrode 13.

[0061] For example, a hole injection layer (HIL), a hole transport layer (HTL), an electron transport layer (ETL), and an electron injection layer (EIL) may be stacked to be adjacent to the emission layer 12 .

[0062] Various thin films may be formed on the substrate 10 by deposition through a thin film deposition apparatus.

[0063] In this case, when there is a portion where the adhesion of the substrate 10 is reduced due to the step difference of the mask 210, deposition failure may occur. Therefore, in order to compensate for the reduced adhesion in this portion, as shown in FIG. Figure 4 As shown in FIG. 1 , the electrostatic chuck unit 100 according to the present embodiment has a differential arrangement structure of the first wiring portion 111 and the second wiring portion 112 .

[0064] In other words, the first wiring portion 111 having a relatively large interval between wirings is formed at a position corresponding to the central portion of the mask 210 having no step difference portion, and the second wiring portion 112 having a relatively small interval between wirings is formed at a position corresponding to the end portions A1 and A2 having the corresponding step difference portion 210a of the corresponding unit cell 211. The relatively small wiring interval in the second wiring portion 112 means that more wirings are arranged in a unit area when compared with the first wiring portion 111. Therefore, a larger electrostatic force can be generated in the second wiring portion 112 having a relatively small wiring interval than in the first wiring portion 111 having a relatively large wiring interval.

[0065] In summary, the second wiring portion 112 having a small wiring interval is disposed at a position corresponding to the end portions A1 and A2 of the unit cell 211 (otherwise it may have relatively low adhesion due to the step difference portion 210a), and the first wiring portion 111 having a large wiring interval is disposed at a position other than the position corresponding to the end portions A1 and A2, and therefore, the difference in adhesion caused by the structure of the mask 210 is compensated by the differential action of electrostatic force.

[0066] In this case, deposition failure due to reduced adhesion can be effectively prevented, thereby improving the performance and reliability of the product. The second wiring portion 112 is formed on an area larger than the area of ​​the end portions A1 and A2 where the step difference portion 210a is formed to increase the range of use of the product. Therefore, even in the case where the size of the unit cell 211 changes and the positions of the end portions A1 and A2 change slightly, deposition failure can be effectively prevented. In addition to the above structure, the amount of power supplied from the power supply 120 to the first wiring portion 111 and the second wiring portion 112 can be controlled differently, so that the difference in electrostatic force can be adjusted more accurately.

[0067] Therefore, when thin film deposition is performed using the electrostatic chuck unit 100 having the above structure, stable deposition can be performed in a state where the substrate 10 and the mask 210 are firmly in close contact with each other, that is, in a state where the substrate 10 and the mask 210 are firmly adhered to each other.

[0068] Variations are described in which components may be modified and additionally implemented within the spirit and scope of the above-described embodiments.

[0069] Figure 5 is a plan view of an electrostatic chuck unit according to another embodiment.

[0070] Reference Figure 5 ,like Figure 4 As in the electrostatic chuck unit 100 of the present invention, the electrostatic chuck body 110 is provided with a first wiring portion 111 for generating a relatively weak electrostatic force and a second wiring portion 112a for generating a relatively strong electrostatic force. Figure 4 In the electrostatic chuck unit 100 of FIG. 1 , the intervals between the wirings of the second wiring portion 112 are reduced when compared with the wirings of the first wiring portion 111 to increase the electrostatic force. Figure 5 In the electrostatic chuck unit, the width W of each of the wirings in the second wiring portion 112a is greater than the width of each of the wirings in the first wiring portion 111 to increase the electrostatic force.

[0071] Accordingly, in Figure 5In the electrostatic chuck unit, the second wiring portion 112a having a wide wiring is arranged in a manner similar to the unit cell 211 (see Figure 2 ) at positions corresponding to the end portions A1 and A2 of the mask 210 (which otherwise may have relatively low adhesion due to the step difference portion 210a), thereby compensating the difference in electrostatic force due to the mask 210 (see Figure 2 )'s structure causes differences in adhesion.

[0072] Figures 6 to 10 is a cross-sectional view of an electrostatic chuck unit according to another embodiment.

[0073] Figure 6 An example is shown in which the thickness T of each of the wirings in the second wiring portion 112 b is greater than the thickness of each of the wirings in the first wiring portion 111 to increase the electrostatic force.

[0074] Accordingly, the second wiring portion 112b having thick wiring is arranged in the same direction as the unit cell 211 (see Figure 2 ) at the positions corresponding to the end portions A1 and A2 of the mask 210 (see Figure 2 )'s structure causes the difference in adhesion.

[0075] Figure 7 In addition to the reference Figures 4 to 6 In addition to the described differential wiring structure, an example in which a pressing protrusion 113 is further formed on the surface of the electrostatic chuck body 110 facing the substrate 10. The pressing protrusion 113 increases the adhesion by applying physical pressure to the substrate 10. This embodiment shows a structure in which the pressing protrusion 113 is located only in the end portions A1 and A2 having the second wiring portions 112, 112a, and 112b.

[0076] Figure 8 Shown as Figure 7 The pressing protrusions 113 shown in FIG. 1 are formed on the entire surface of the electrostatic chuck body 110. The pressing protrusions 113 are sparsely arranged (e.g., relatively spaced apart) in the central portion having the first wiring portion 111, and are more densely arranged in the end portions A1 and A2 having the second wiring portion 112, and therefore, the reduction in adhesion is also compensated by the differential arrangement of the pressing protrusions 113.

[0077] Fig. 9 An example is shown in which the electrostatic chuck body 110 is provided with a cooler 130 while having the above-mentioned electrostatic force difference structure. Figure 1 ) is in a high temperature environment, if a refrigerant pipe 131 and a refrigerant pump 132 are installed to circulate the refrigerant, the risk of deformation due to high temperature can be prevented.

[0078] Fig.10 A structure having the above-mentioned electrostatic force difference structure and further including a magnet unit 140 is shown. That is, the magnet unit 140 including the yoke plate 142 and the magnet 141 is added to the first wiring portion 111 of the electrostatic chuck body 110 so that the substrate 10 and the mask 210 are in close contact with each other not only by the electrostatic force but also by the magnetic force. In particular, when the substrate 10 is large, when deposition is performed after the substrate 10 and the mask 210 are installed, the center of the substrate 10 and the mask 210 may sag due to their weight; and in this case, the mask 210 including the metal material is attracted by the magnetic force of the magnet 141 to prevent sagging.

[0079] Therefore, such various modifications are possible.

[0080] As described above, according to the electrostatic chuck unit and the thin film deposition device based on the described embodiment, the electrostatic force can be enhanced in the end portion of the unit cell (otherwise there is poor adhesion between the substrate and the mask), and therefore, deposition failure due to reduced adhesion can be effectively prevented, and thus the performance and reliability of the product can be improved (for example, the deposition source can be made to deposit more consistently across the substrate).

[0081] It should be understood that the embodiments described herein should be understood in a descriptive sense only and not for purposes of limitation. The description of features or aspects in each embodiment should generally be understood to be applicable to other similar features or aspects in other embodiments.

[0082] Although one or more embodiments have been described with reference to the drawings, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope as defined by the following claims and their functional equivalents thereto.

Claims

1. Electrostatic chuck unit, including: an electrostatic chuck body including a first wiring portion and a second wiring portion, each of the first wiring portion and the second wiring portion including a plurality of wirings, the plurality of wirings being configured to generate an electrostatic force to generate an attractive force between a substrate and a mask by the electrostatic force, in, the first wiring portion is configured to generate a weaker electrostatic force than the second wiring portion, The mask includes a unit cell, a plurality of pattern holes are distributed in the unit cell, and a step difference portion is formed in an end portion of the unit cell. The second wiring portion is positioned to correspond to the step difference portion.

2. The electrostatic chuck unit according to claim 1, wherein: An interval between wirings in the second wiring portion is smaller than an interval between wirings in the first wiring portion.

3. The electrostatic chuck unit according to claim 1, wherein: A width of each of the wirings in the second wiring portion is greater than a width of each of the wirings in the first wiring portion.

4. The electrostatic chuck unit according to claim 1, wherein: The thickness of each of the wirings in the second wiring portion is greater than the thickness of each of the wirings in the first wiring portion.

5. The electrostatic chuck unit according to claim 1, further comprising: A plurality of pressing protrusions are located on a surface of the electrostatic chuck body facing the substrate and the mask.

6. The electrostatic chuck unit according to claim 5, wherein: The plurality of pressing protrusions are located at positions corresponding to the second wiring portion.

7. The electrostatic chuck unit according to claim 5, in, The plurality of pressing protrusions are located at positions corresponding to the first wiring portion and at positions corresponding to the second wiring portion, and Among the pressing protrusions, the pressing protrusions located at the position corresponding to the second wiring portion are distributed more densely than the pressing protrusions located at the position corresponding to the first wiring portion.

8. The electrostatic chuck unit according to claim 1, wherein: The electrostatic chuck body also includes a cooler.

9. The electrostatic chuck unit according to claim 1, further comprising: A magnet is used to generate a magnetic force to attract the mask.

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