Substrate with purge gas flow path

Abstract

The invention relates to a susceptor having a purge gas flow path for supplying a purge gas. Provided is a susceptor comprising a plate in which a heat-generating body layer is embedded, the plate having a purge gas flow path layer disposed on a plane different from that of the heat-generating body layer, and a hollow shaft joined to the lower end of the plate. The purge gas flow path layer includes an internal flow path and a plurality of radial branch flow paths extending outward from the internal flow path.

Description

Technical Field

[0001] The present invention relates to a pedestal, and more particularly to a pedestal having a purge gas flow path for supplying a purge gas. Background Art

[0002] Generally, a semiconductor device or a display device is manufactured through a semiconductor process in which a plurality of thin film layers including a dielectric layer and a metal layer are sequentially stacked on a glass substrate, a flexible substrate, or a semiconductor wafer substrate and then patterned. These thin film layers are sequentially deposited on the substrate through a Chemical Vapor Deposition (CVD) process or a Physical Vapor Deposition (PVD) process. The CVD process includes a Low Pressure CVD (LPCVD) process, a Plasma Enhanced CVD (PECVD) process, a Metal Organic CVD (MOCVD) process, and the like. A pedestal is provided in such a CVD apparatus and a PVD apparatus, and the pedestal is used to support a glass substrate, a flexible substrate, a semiconductor wafer substrate, etc. and process a semiconductor process. Such a pedestal is provided in a CVD apparatus and a PVD apparatus, and may have a heating plate with a heating element built therein for heating the substrate while supporting the substrate. In addition, the pedestal may form a plasma during an etching process or the like for a thin film layer formed on the substrate by providing a high frequency (RF) electrode instead of the heating element or additionally providing a high frequency (RF) electrode on the basis of the heating element.

[0003] In addition, in order to prevent uneven deposition of a local thin film at an end of a wafer during a thin film deposition process or the like in which the pedestal is applied, a purge gas flow path for supplying a purge gas to the end of the wafer needs to be provided.

[0004] In addition, the purge gas flow path formed inside the pedestal may have a radially structured flow path to ensure symmetry with respect to the center of the plate.

[0005] However, in a radially branched flow path, the lengths of the axial flow paths into which the purge gas flows are different, and thus there is a problem that it is difficult to supply a uniform purge gas to the circumference of the wafer, or a plurality of radially branched flow paths branch at a specific fulcrum where they are joined to the shaft, and thus there is a problem that cracks are likely to occur at the branch points due to the large pressure applied when the plate and the shaft are press-fitted. Summary of the Invention

[0006] Problems to be Solved by the Invention

[0007] The present invention is proposed to solve the above problems, and the object of the present invention is to provide a susceptor having a purge gas flow path structure capable of supplying a uniform purge gas to the vicinity of the edge of a wafer.

[0008] In addition, the object of the present invention is to provide a susceptor having a purge gas flow path structure suitable for suppressing cracks generated when a plate and a shaft are press-fitted.

[0009] In addition, the object of the present invention is to provide a susceptor structure capable of suppressing heat transfer from a plate to a shaft.

[0010] Means for Solving the Problem

[0011] To solve the above-mentioned technical problems, the present invention provides a ceramic susceptor, which includes a plate embedded with a heating element layer and a hollow shaft joined to the lower end of the plate. The plate has a purge gas flow path layer disposed on a plane different from the heating element layer. The purge gas flow path layer includes: an internal flow path; and a plurality of radially branched flow paths extending outward from the internal flow path.

[0012] In the present invention, the hollow shaft has a side wall extending in the length direction and a connecting portion forming a joining portion with the plate at the end of the side wall, and the internal flow path can be formed in a shape matching the connecting portion of the shaft.

[0013] In the present invention, the internal flow path and the connecting portion can be circular. At this time, preferably, when projected onto the plane of the plate, the internal flow path is restricted inside the contour of the connecting portion.

[0014] In the present invention, the internal flow path is disposed closer to the center of the plate within the contour of the connecting portion.

[0015] In addition, in the present invention, the ratio of the width of the internal flow path to the width of the connecting portion is preferably 0.1 to 0.7.

[0016] In the present invention, preferably, the shaft has a side wall flow path extending along the length direction of the side wall inside the side wall, and the end of the side wall flow path is aligned with the internal flow path.

[0017] At this time, it may further include a mounting member joined to the end of the shaft and a purge line formed along the circumference of the side wall at the end of the shaft. The purge line can be connected to the side wall flow path.

[0018] In the present invention, preferably, the end of the side wall flow path is located at an intermediate position between the adjacent radially branched flow paths on the internal flow path.

[0019] In the present invention, preferably, the shaft has a plurality of sidewall flow paths which are formed by extending along the length direction of the sidewall inside the sidewall, and each end of each sidewall flow path among the plurality of sidewall flow paths is aligned with the internal flow path.

[0020] In the present invention, the plurality of radially branched flow paths are preferably symmetric with respect to the center of the plate. In addition, the number of the plurality of radially branched flow paths in the present invention can be 4 to 10.

[0021] Advantages of the Invention

[0022] According to the pedestal of the present invention, by providing a purge gas flow path symmetric with respect to the center of the plate, it is possible to supply a uniform purge gas to the vicinity of the edge of the wafer.

[0023] In addition, according to the pedestal of the present invention, by dispersing the flow path branch points of the purge gas, it is possible to provide a purge gas flow path pattern that can suppress cracks generated when the plate and the shaft are press-fitted.

[0024] Furthermore, according to the pedestal of the present invention, it is possible to provide a pedestal structure that can suppress heat loss from the heating element of the plate to the shaft. Description of the Drawings

[0025] Figure 1A and Figure 1B are diagrams schematically showing the purge gas flow path structure of a pedestal according to an embodiment of the present invention.

[0026] Figure 2A and Figure 2B are Figure 1B cross-sectional views of the pedestal in

[0027] Figure 3A and Figure 3B are diagrams for explaining the flow path structure of a pedestal according to an embodiment of the present invention.

[0028] Figure 4 is a photograph for explaining the temperature change based on the shaft position in a conventional pedestal.

[0029] Description of Reference Numerals

[0030] 110: Plate

[0031] 112: Heating element layer

[0032] 114: Internal flow path

[0033] 115: Communication hole

[0034] 116: Branch flow path

[0035] 120: Shaft

[0036] 122: Side wall

[0037] 124: Connecting portion

[0038] 128: Side wall flow path

[0039] 130: Mounting member Detailed implementation manner

[0040] Hereinafter, with reference to the accompanying drawings, the present invention will be described in detail. At this time, the same constituent elements in each drawing are denoted by the same reference numerals as much as possible. In addition, the description of known functions and / or configurations will be omitted. The following disclosure will mainly describe the parts required to understand the operations of various embodiments, and the description of elements that may obscure the gist of the description will be omitted. In addition, some constituent elements in the drawings may be enlarged, omitted, or shown schematically. The size of each constituent element does not fully reflect the actual size. Therefore, the content described herein is not limited by the relative size or spacing of the constituent elements shown in each drawing.

[0041] When describing the embodiments of the present invention, if it is determined that the detailed description of the known technology related to the present invention unnecessarily obscures the gist of the present invention, the detailed description thereof will be omitted. In addition, the following terms are terms defined in consideration of the functions of the present invention, and may vary depending on the intention of the user, operator, or precedent. Therefore, the definition should be based on the content of the entire specification. The terms used in this specification are only used to describe the embodiments of the present invention and are not used for limitation. Unless otherwise specified, singular expressions shall include plural expressions. Expressions such as "including" or "having" in this specification are used to refer to any feature, number, step, action, component, or combination thereof, and should not be construed as excluding the existence or additional possibility of one or more other features, numbers, steps, actions, components, or combinations thereof.

[0042] In addition, although terms such as first, second, etc. can be used to describe various constituent elements, the constituent elements are not limited to the terms, and the terms are only used to distinguish one constituent element from another.

[0043] Figure 1A It is a diagram schematically showing a purge gas flow path structure formed on a plate of a base according to an embodiment of the present invention. Figure 1B It is a diagram schematically showing a state in which a shaft is coupled to the plate.

[0044] Refer to Figure 1A , Exemplarily, inside the plate 110, there are provided purge gas flow paths 114, 116 for supplying purge gas from the center of the plate to the outside.

[0045] As shown in the figure, the purge gas flow paths 114, 116 may include: an internal flow path 114; and radial branch flow paths 116 extending from the internal flow path 114 to the outside of the plate 110. In the present invention, the internal flow path 114 may follow the shape of the plate. As shown in the figure, according to the shape of the circular plate, a circular internal flow path 114 may be formed. However, in the present invention, it is natural that the shape of the internal flow path 114 is not necessarily limited by the shape of the plate.

[0046] In the present invention, the internal flow path 114 may be formed in a manner matching the circumferential direction of the shaft 110, or in a manner corresponding to the joint portion of the shaft 110.

[0047] In the present invention, the plate 110 may be made of plate-shaped ceramics. For example, the ceramic material may include at least one substance or its compound selected from the group consisting of Al 2 O 3 、Y 2 O 3 、ZrO 2 、TiN, AlN, TiC, MgO, CaO, CeO 2 、TiO 2 、BxCy, BN, SiO 2 、SiC, YAG, YAP and YAM, preferably aluminum nitride (AlN). Additionally, when the ceramic material is AlN, the components of the plate 110 may further include at least one metal compound (preferably a metal oxide) selected from the group consisting of Y, Mg, Al, and Ti.

[0048] In addition, a plurality of radial branch flow paths 116 branch out at a predetermined interval or a predetermined angle along the circumference of the internal flow path 114. In the present invention, although the number of the radial branch flow paths or the interval between the flow paths is not particularly limited, the plurality of radial branch flow paths 116 are preferably symmetrically distributed at a predetermined angular interval with respect to the center of the plate 110 to supply a uniform purge gas along the outer periphery of the plate 110. In addition, in the present invention, for example, four, six, eight, ten, twelve or more radial branch flow paths may be provided.

[0049] In addition, in the present invention, it is natural that the flow path widths of the internal flow path 114 and the radial branch flow paths 116 may be designed to be the same or different from each other.

[0050] Figure 1BFIG. is a diagram schematically showing the state in which the plate 110 and the shaft 120 are combined. Referring to the accompanying drawings, when the plane of the plate 110 is projected, the position of the internal flow path 114 of the plate 110 overlaps with the position of the joint portion of the shaft 120. Preferably, the position of the internal flow path 114 is defined within the joint portion of the shaft 120.

[0051] Figure 2A and Figure 2B are diagrams respectively exemplarily showing cross-sections taken along the A-A' direction and the B-B' direction in Figure 1B .

[0052] Referring to Figure 2A , a heating element layer 112 may be embedded inside the plate 110. The heating element layer 112 may be composed of a coil or a plate-shaped metal heating element, and a predetermined pattern may be formed on the plane. In addition, the heating element layer 112 may be formed in a multi-layer structure or multiple zones for precise temperature control. In the present invention, the heating element forming the heating element layer 112 is made of at least one metal or an alloy selected from the group consisting of tungsten (W), molybdenum (Mo), silver (Ag), gold (Au), niobium (Nb), and titanium (Ti), and preferably may be made of molybdenum (Mo). The heating element layer 112 may be connected to a power supply terminal through a power supply rod (not shown). The power supply rod may pass through the internal space of the shaft 120 and extend to the outside through a mount.

[0053] In addition, a purge gas flow path layer may be provided inside the plate 110 at the lower end of the heating element layer 112. The purge gas flow path layer includes: an internal flow path 114; and radial branch flow paths 116 branched from the internal flow path 114.

[0054] The purge gas flow path layer is provided on a plane different from that of the heating element layer 112. In the present invention, although the case where the purge gas flow path layer is provided at the lower end of the heating element layer 112 is shown, it is natural that the purge gas flow path layer may be provided at the upper end of the heating element layer 112.

[0055] In addition, a hollow shaft 120 may be provided at the lower end of the plate 110. The hollow shaft 120 has: a side wall 122 extending in the axial direction; and a connection portion 124 forming a joint portion with the plate 110 at one end of the side wall 122. In the present invention, the connection portion 124 may be a flange, but is not limited thereto. The other end 126 of the side wall 122 may be combined with a structure such as a mount (not shown).

[0056] The shaft 120 may be made of a ceramic material. For example, the ceramic material may include from Al2 O 3 、 Y 2 O 3 、 ZrO 2 、 TiN, AlN, TiC, MgO, CaO, CeO 2 、 TiO 2 、 BxCy, BN, SiO 2 、 SiC, YAG, YAP and YAM, or a compound thereof, preferably aluminum nitride (AlN). Additionally, when the ceramic material is AlN, the components of the plate 110 may further include at least one metal compound (preferably a metal oxide) selected from the group consisting of Y, Mg, Al, and Ti. The shaft 120 is preferably made of a ceramic material with low thermal conductivity. For example, the shaft 120 may be an AlN sintered body containing 2 wt% or less of yttrium oxide as a sintering aid, and the thermal conductivity can be controlled by the content of the sintering aid such as yttrium oxide. For example, by artificially introducing impurities into AlN or by keeping the content of metal elements in the sintered body below 1000 ppm, a shaft with extremely low thermal conductivity can be achieved. 2 O 3 As in the case of adding Al

[0057] Refer to Figure 2B , a side wall flow path 128 for allowing purge gas to flow is provided on the side wall 122 of the shaft 120. The side wall flow path 128 extends axially along the side wall 122 of the shaft 120 and communicates with the internal flow path 114 of the plate 110. To this end, a communication hole 115 may be provided at the lower end of the internal flow path 114 of the plate 110. In the present invention, the side wall flow path 128 may be separated from the inner wall and the outer wall of the shaft 120 by at least 3 mm or more.

[0058] In the present invention, the communication hole 115 is aligned with the internal flow path 114 and the side wall flow path 128. At this time, preferably, the communication hole 115 is formed at a position on the internal flow path 114 away from the branch point of the radial branch flow path 116, that is, at a non-crossing point between the internal flow path 114 and the radial branch flow path 116. This prevents the gas flowing in from the communication hole 115 from being discharged too much to a specific radial branch flow path 116. Preferably, the communication hole 115 is located at an intermediate position between the branch points of the adjacent radial branch flow paths 116 on the internal flow path 114. In the present invention, the lengths of the plurality of radial branch flow paths 116 may be set to be the same.

[0059] Although two sidewall flow paths 128 are shown in the drawings, it is understood that the present invention is not limited thereto. One sidewall flow path 128 or two or more sidewall flow paths 128 may be provided, and an appropriate number of communication holes may be provided in order to introduce uniform purge gas.

[0060] In addition, in the present invention, the sidewall flow path 128 is shown as a one-dimensional flow path extending along the axial direction of the shaft 120 and having a predetermined length, but the present invention is not limited thereto, and it is understood that it may also be a two-dimensional cylindrical flow path extending along the circumference of the sidewall 122 of the shaft 120.

[0061] The shaft 120 may be joined to the plate 110. At this time, a ceramic adhesive or a ceramic paste may be used as the joining agent. In the present invention, the ceramic adhesive or the ceramic paste may have aluminum nitride as the main raw material, but is not limited thereto.

[0062] Referring to Figure 1A 、 Figure 1B 、 Figure 2A and Figure 2B The flow path structure of the present invention described and explained can have the advantage of dispersing structural weak parts inside the plate by distributing branch points to multiple positions of the internal flow path. As described above, by dispersing the flow path branch points of the purge gas, a purge gas flow path pattern capable of suppressing the generation of cracks during the press-fitting of the plate and the shaft can be provided.

[0063] In addition, at the same time, the branch structure can uniformly eject purge gas at the end of the plate by realizing a radial structure symmetric with respect to the center of the plate.

[0064] And, the flow path structure of the present invention can provide a heat insulation mechanism for suppressing heat transfer to the shaft. In this regard, reference will be made to Figure 4 for explanation.

[0065] Figure 3A and Figure 3B show internal flow paths 114 having different areas on the projection plane of the plate. In Figure 3A and Figure 3B the internal flow path 114 is located inside the contour of the connecting portion 122, but the width w1 of the internal flow path 114 can be adjusted.

[0066] As Figures 3A to 3BAs shown, if the width w1 of the internal flow path 114 increases, the flow path area between the connection part 124 of the heating element layer 112 and the shaft 120 increases. In the present invention, since the heat transfer through the flow path is carried out by radiation or convection, it can act as a heat blocking or heat insulating element compared with a plate body having a high thermal conductivity. In particular, since the heat loss of the shaft 120 occurs through the joint part (i.e., the shaft connection part) of the shaft 120 and the plate 110, the heat loss from the heating element layer 112 can be suppressed by aligning the internal flow path 114 with the connection part 124 of the shaft 120.

[0067] In the present invention, the width w1 of the internal flow path 114 can be designed to be smaller than the width w2 of the connection part 124 of the shaft 120. In the present invention, the ratio of the width w1 of the internal flow path 114 to the width w2 of the connection part 124 can be 0.1 or more, 0.2 or more, 0.3 or more, 0.4 or more, or 0.5 or more. In addition, the ratio of the width w1 of the internal flow path 114 to the width w2 of the connection part 124 can be 1 or less, 0.9 or less, 0.8 or less, 0.7 or less, 0.6 or less, 0.5 or less, or 0.4 or less. The ratio is preferably 0.1 to 0.7. In addition, according to the present invention, by adjusting the width w2 of the internal flow path 114, heat loss through the shaft 120 can be prevented or the generation of cracks can be suppressed. For example, if the ratio of the width w1 of the internal flow path 114 to the width w2 of the connection part 124 does not reach 0.1, it is difficult to prevent heat loss, and if the ratio exceeds 0.7, cracks will occur.

[0068] In addition, although the internal flow path 114 is shown in the drawings as being arranged at the contour center of the connection part 124, the present invention is not limited thereto. In the present invention, the internal flow path 114 can be arranged closer to the center of the plate 110 inside (on the inner side) the contour of the connection part 124, or conversely, it can be arranged in a manner biased toward the outer side of the plate 110.

[0069] Figure 4 is a photograph for explaining the temperature change based on the shaft position in a conventional base. After operating the base at a temperature of 650°C, the temperatures measured at each fulcrum ①, ②, ③, ④, ⑤ are shown in Table 1 below. Figure 4 After operating the base at a temperature of 650°C, the temperatures measured at each fulcrum ①, ②, ③, ④, ⑤ are shown in Table 1 below.

[0070]

Table 1

[0071] fulcrum temperature ① 609.7℃ ② 529.0℃ ③ 468.0℃ ④ 404.5℃ ⑤ 327.9℃

[0072] As can be seen from Table 1, the area near the mounting member is exposed to a high-temperature environment above 300°C. The heat generated in the heating plate is transmitted through the shaft, and the temperature reaches above 300°C up to the lower end region ⑤ for mounting the mounting member 130. As a result, there is a problem that the O-ring for sealing the mounting member 130 melts, and in serious cases, there is a problem that the chamber vacuum is released. Therefore, the purge gas flowing through the sidewall flow path 128 of the sidewall 122 of the shaft 120 can be used as a cooling gas. That is, by forming a purge line along the circumference of the sidewall 122 at the lower end of the shaft 120, the heat transferred to the mounting member 130 can be reduced.

[0073] As described above, in the present invention, specific matters such as specific components and limited embodiments and drawings have been described, but these are only provided to assist in the overall understanding of the present invention, and the present invention is not limited to the described embodiments. Those of ordinary skill in the art to which the present invention pertains can make various modifications and changes without departing from the essential features of the present invention. Therefore, the spirit of the present invention should not be limited to and determined by the described embodiments, and all technical ideas equivalent or equivalent to the appended claims should be construed as being included within the scope of the present invention.

Claims

1. A base, comprising a plate in which a heating element layer is embedded and a hollow shaft connected to the lower end of the plate, characterized in that: The plate has a purge gas flow path layer arranged on a plane different from that of the heat generating body layer. The purge gas flow path layer comprises: internal flow paths; and A plurality of radial branch flow paths extend outward from the inner flow path.

2. The base according to claim 1, characterized in that: The shaft has: a side wall extending along the length of the shaft; and The connecting portion forms a joint portion with the plate at an end portion of the side wall.

3. The base according to claim 2, characterized in that: The internal flow path is formed in a shape matching the connecting portion of the shaft.

4. The base according to claim 3, characterized in that: The internal flow path and the connecting portion are formed in a circular shape.

5. The base according to claim 3, characterized in that: The internal flow path is arranged inside the contour of the connecting portion on a plane projected onto the plate.

6. The base according to claim 5, characterized in that The internal flow path is arranged inside the contour of the connecting portion at a position closer to the center of the plate.

7. The base according to claim 5, characterized in that A ratio of a width of the internal flow path to a width of the connecting portion is 0.1 to 0.

7.

8. The base according to claim 5, characterized in that The shaft has a side wall flow path, and the side wall flow path extends inside the side wall along the length direction of the side wall. An end of the sidewall flow path is aligned with the interior flow path.

9. The base according to claim 8, characterized in that The end of the side wall flow path is located at a middle position between adjacent radial branch flow paths on the internal flow path.

10. The base according to claim 8, characterized in that Also includes: a mounting member coupled to an end of the shaft; and A purge line is formed along the circumference of the side wall of the end of the shaft, The purge line is connected to the side wall flow channel.

11. The base according to claim 5, characterized in that The shaft has a plurality of side wall flow paths, and the plurality of side wall flow paths extend inside the side wall along the length direction of the side wall. Each end of each of the plurality of side wall flow paths is aligned with the internal flow path.

12. The base according to claim 1, characterized in that The plurality of radial branch flow paths are formed symmetrically with respect to the center of the plate.

13. The base according to claim 11, characterized in that The number of the plurality of radial branch flow paths is 4 to 10.

Images