Ceramic base

Abstract

There is provided a ceramic susceptor including a ceramic plate on which an electrode layer is formed, in which the ceramic plate includes a plurality of ceramic layers including a first ceramic layer and a second ceramic layer adjacent to the first ceramic layer, a via pad disposed between the first ceramic layer and the second ceramic layer and including an internal space, the plurality of first through holes penetrate through the first ceramic layer and are connected to different positions on the through hole bonding pad; and the electrode layer is embedded in the plurality of ceramic layers and is electrically connected with the through hole bonding pad.

Description

Technical Field

[0001] The present invention relates to a ceramic board and a base including the same, and more particularly to a ceramic board and a base including the same for preventing via pads from peeling off and improving the bonding strength of via pad regions. Background Art

[0002] Typically, semiconductor devices or display devices are manufactured by sequentially stacking multiple thin film layers, including dielectric layers and electrode layers, on a glass substrate, a flexible substrate, or a semiconductor wafer substrate, followed by patterning. The semiconductor process equipment described above is provided with an electrostatic chuck or a ceramic base, such as a ceramic heater, to support the glass substrate, flexible substrate, semiconductor wafer substrate, etc. and to perform semiconductor processing. The electrostatic chuck is primarily used in the process of dry etching the thin film layers formed on the substrate. In dry etching processes such as polysilicon etching, a base with a multilayer ceramic (MLC) structure is used.

[0003] Figure 1 and Figure 2 This is a diagram for explaining a base having the conventional MLC structure as described above.

[0004] first, Figure 1 The electrode rod ( Figure 2 40) Cross-sectional views of a base connected to an MLC structure before and after processing.

[0005] like Figure 1 As shown in part (a) of FIG, the ceramic board 10 may include a stacked structure of multiple ceramic layers 12, a circuit layer 14, electrode layers 16, 18, and through-hole pads 20, 22. In addition, the ceramic board 10 may be provided with one or more through holes to connect the through-hole pads 20, 22 or to connect the through-hole pads and a conductive layer such as the circuit layer. For example, in Figure 1 In part (a), the via pads 20 and 22 are connected by a plurality of upper vias 24 , and a lower via 26 electrically connects the via pad 20 and the circuit layer 14 .

[0006] In addition, as shown in the figure, the upper surface of the ceramic plate is provided with an electrode rod processing groove 28, and the electrode rod processing groove 28 is used to electrically connect the electrode rod to the through-hole pad 20 or the upper through-hole 24. Figure 1 As shown in part (b), the electrode rod connecting groove 30 is formed by processing the electrode rod processing groove 28 to expose the plurality of upper through holes 24.

[0007] Figure 2 is a cross-sectional view showing the connection of the electrode rod to a conventional ceramic base, Figure 3 yes Figure 2 BB cross-sectional view.

[0008] The electrode rod 40 is brazed to the ceramic plate 10 and electrically connected to the upper through-hole 24. Reference numeral 50 denotes a conductive bonding layer. The ceramic layer 12 forming the electrode rod connection groove 30 is reduced in thickness through the aforementioned processing, with the thickness a of the ceramic layer 12-1 between the electrode rod 40 and the through-hole pad 20 being reduced to approximately 100 to 200 μm.

[0009] Generally, the metal via pad 20 and the ceramic layer 12-1 have a low bonding strength. Therefore, when the ceramic layer 12-1 formed on the circular via pad 20 is thin, the via pad 20 and the ceramic layer 12-1 may be peeled off even by a small external force. Summary of the Invention

[0010] Problems to be solved by the invention

[0011] An object of the present invention is to provide a base structure that suppresses peeling of ceramic layers disposed between metal layers disposed on a ceramic plate having a multilayer structure.

[0012] Another object of the present invention is to provide a base structure that improves the mechanical bonding strength of a ceramic layer disposed on a layer where a via pad is formed.

[0013] Means used to solve problems

[0014] An embodiment of the present invention provides a ceramic base, which includes a ceramic plate formed with an electrode layer, wherein the ceramic plate includes: multiple ceramic layers, including a first ceramic layer and a second ceramic layer adjacent to the first ceramic layer, a through-hole pad, arranged between the first ceramic layer and the second ceramic layer, including an internal space, and multiple first through holes, passing through the first ceramic layer and connected to different positions on the through-hole pad; the electrode layer is embedded in the multiple ceramic layers and electrically connected to the through-hole pad.

[0015] An embodiment of the present invention provides a ceramic base, comprising electrode rod connecting grooves formed on a surface of the ceramic plate to expose the plurality of first through holes, and electrode rods electrically connected to the plurality of first through holes through the electrode rod connecting grooves.

[0016] An embodiment of the present invention provides a ceramic base, wherein the electrode rods are engaged with the plurality of first through holes.

[0017] An embodiment of the present invention provides a ceramic base, wherein the through-hole pad includes a first surface adjacent to the first ceramic layer and a second surface adjacent to the second ceramic layer, and the first surface and the second surface are ring-shaped with a predetermined width.

[0018] An embodiment of the present invention provides a ceramic base, wherein the ceramic plate includes a first through hole and a second through hole, the first through hole is connected to the first side of the through hole pad, and the second through hole is connected to the second side of the through hole pad, and the second through hole electrically connects the through hole pad and the electrode layer.

[0019] An embodiment of the present invention provides a ceramic base, wherein the first ceramic layer is the outermost layer.

[0020] An embodiment of the present invention provides a ceramic base, wherein the through-hole pad includes a first surface adjacent to the first ceramic layer and a second surface adjacent to the second ceramic layer, the first surface and the second surface are ring-shaped with a predetermined width, and the ceramic plate includes the first through hole and the second through hole, the first through hole is connected to the first surface, and the second through hole is connected to the second surface.

[0021] An embodiment of the present invention provides a ceramic base, wherein the annular through-hole pad has a predetermined width and an inner space, and the first ceramic layer or the second ceramic layer fills the inner space of the through-hole pad.

[0022] An embodiment of the present invention provides a ceramic base, wherein the thickness of the first ceramic layer penetrated by the first through hole is 100-200 μm.

[0023] An embodiment of the present invention provides a ceramic base, wherein the first through hole penetrates the first ceramic layer, and the second through hole penetrates the second ceramic layer.

[0024] An embodiment of the present invention provides a ceramic base, wherein a width w of the through-hole pad is greater than or equal to a diameter d1 of the first through-hole and a diameter d2 of the second through-hole.

[0025] Effects of the Invention

[0026] According to the embodiment of the present invention, the interlayer bonding force of the layers forming the via pad is increased by changing the shape of the via pad, so that the electrode rod and the ceramic plate can be stably bonded. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Shown are cross-sectional views before and after machining of a base for connecting an electrode rod to a conventional MLC structure.

[0028] Figure 2 The electrode rod is shown in FIG. Figure 1 A partial enlarged view of part A.

[0029] Figure 3 yes Figure 2 BB cross-sectional view.

[0030] Figure 4 is a schematic cross-sectional view of a ceramic susceptor according to an embodiment of the present invention.

[0031] Figure 5 is a cross-sectional view of a ceramic plate according to an embodiment of the present invention.

[0032] Figure 6 yes Figure 5 A partial enlarged view of part C.

[0033] Figure 7 yes Figure 5 A partial enlarged view of part D.

[0034] Figure 8 yes Figure 7 EE cross-sectional view.

[0035] Description of Reference Signs

[0036] 110: Ceramic plate

[0037] 122: Circuit layer

[0038] 124: Heating element layer

[0039] 126: High-frequency electrode layer

[0040] 136: Outermost ceramic layer

[0041] 150, 152: Through hole

[0042] 154: Through-hole pad

[0043] 240: Electrode rod DETAILED DESCRIPTION

[0044] Hereinafter, the embodiments disclosed in this specification will be described in detail with reference to the accompanying drawings. Regardless of the figure numbers of the drawings, the same or similar components are given the same figure numbers, and repeated descriptions thereof are omitted. Hereinafter, in the description of the embodiments of the present invention, when it is recorded that each layer (film), region, pattern or structure is formed "on" or "under" of a substrate, each layer (film), region, pad or pattern, "on" and "under" both include the case where they are formed "directly" or "indirectly through other layers". In addition, the standards of the upper / above or lower / under of each layer are described in accordance with the drawings. In the drawings, for the convenience and clarity of the description, the thickness or size of each layer is exaggerated, omitted or schematically shown. In addition, the size of each component does not fully reflect the actual size.

[0045] In this specification, expressions such as "including", "having" or "comprising" are used to refer to features, numbers, steps, actions, elements, parts thereof or combinations thereof, and should not be interpreted as excluding the existence or possibility of one or more other features, numbers, steps, actions, elements, parts thereof or combinations thereof other than those stated.

[0046] In addition, terms such as first and second may be used to describe various components, but the components are not limited by the terms, and the terms are only used to distinguish one component from another.

[0047] In addition, when describing the embodiments disclosed in this specification, if it is determined that a detailed description of related known technologies may obscure the gist of the embodiments disclosed in this specification, the detailed description will be omitted.

[0048] The attached drawings are only used to help facilitate understanding of the embodiments disclosed in this specification. The technical ideas disclosed in this specification are not limited to the attached drawings and should be understood to include all modifications, equivalents or substitutes within the ideas and technical scope of the present invention.

[0049] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0050] Figure 4 is a schematic cross-sectional view of a ceramic susceptor according to an embodiment of the present invention.

[0051] The ceramic base 100 according to an embodiment of the present invention is provided in an apparatus for performing semiconductor processes, and can be used as an electrostatic chuck for supporting substrates serving as various processing objects such as glass substrates, flexible substrates, and semiconductor wafer substrates in processes such as plasma enhanced chemical vapor deposition, or as a heater for precise temperature control and heat treatment requirements in plasma deposition processes, etc., for precision processes such as miniaturization of wiring of semiconductor devices.

[0052] The electrostatic chuck function is used to fix the substrate being processed using electrostatic force. The electrostatic chuck function is used to perform chucking and de-chucking for adsorbing, fixing, or releasing the substrate in ion implantation processes or other semiconductor process equipment. At this time, chucking can be achieved by providing sufficient clamping force. The attraction electrode layer of the ceramic base is driven by an AC voltage to increase the attraction and desorption time of the substrate while maintaining this clamping pressure. Alternatively, the attraction electrode layer can be driven by a radio frequency electrode layer used to form plasma.

[0053] The heater function can be driven by supplying current to the heating element layer of the ceramic base to heat the substrate while supporting the substrate during an etching process of a thin film layer formed on the substrate or a firing process of a photoresist.

[0054] The electrode layer 120 embedded in the ceramic plate 110 according to an embodiment of the present invention may include all of the pull-in electrode layer, the high-frequency electrode layer, and the heating element layer, or may include one or two of the pull-in electrode layer, the high-frequency electrode layer, and the heating element layer. The electrode layer 120 may be formed by chemical vapor deposition (CVD), PVC, spraying, or screen printing.

[0055] The ceramic base 100 according to an embodiment of the present invention includes a ceramic plate including an electrode layer; a support portion supporting the ceramic plate; and a rod disposed in the support portion and electrically connected to the electrode layer.

[0056] The ceramic plate 110 is a disc-shaped plate formed of an insulator or dielectric ceramic material, and can be made of Al2O3, Y2O3, Al2O3 / Y2O3, ZrO2, AlC, TiN, AlN, TiC, MgO, CaO, CeO2, TiO2, B x C y, BN, SiO2, SiC, YAG, Mullite, AlF3, or a combination of two or more. Ceramic plate 110 includes a flat mounting surface 111, on which the substrate to be processed is mounted, and a lower surface 112, to which a support portion is attached. Electrode layer 120 embedded in ceramic plate 110 receives current via electrode rods 240 located in the support portion.

[0057] The support portion attached to the lower surface 112 of the ceramic board 110 may be a base portion 200 .

[0058] The base portion 200 may be formed of a multi-layer structure composed of a plurality of metal layers, and the metal layers may be joined by brazing, welding, or bonding.

[0059] The ceramic plate 110 can be fixed to the base portion 200 by a predetermined fixing method or bonding method. The base portion 200 and the ceramic plate 110 can also be manufactured separately and joined together, or the structure of the ceramic plate 110 can be directly formed on the upper surface of the base portion 200. The base portion 200 accommodates an electrode rod 240 that supplies current to the electrode layer 120.

[0060] Figure 5 is a cross-sectional view of a ceramic plate according to an embodiment of the present invention, Figure 6 yes Figure 5 A partial enlarged view of part C, Figure 7 yes Figure 5 A partial enlarged view of part D, Figure 8 yes Figure 7 EE cross-sectional view.

[0061] Reference Figures 5 to 8 , the ceramic board 110 according to the embodiment of the present invention is described.

[0062] The ceramic plate 110 is configured to stably support a substrate to be processed and to enable various semiconductor processes, such as heating using the heating element layer 124 and / or plasma-enhanced chemical vapor deposition using the high-frequency electrode layer 126. The high-frequency electrode layer 126 also functions as a chucking electrode layer for chucking and dechucking the substrate to be processed.

[0063] The ceramic board 110 is formed such that a circuit layer 122 and an electrode layer 120 are disposed between a plurality of ceramic layers 134. The electrode layer 120 may include a heating element layer 124 and a high-frequency (RF) electrode layer 126. Specifically, the high-frequency electrode layer 126, the heating element layer 124, the circuit layer 122, and the through-hole pad 154 may be sequentially disposed between the plurality of ceramic layers 134. The high-frequency electrode layer 126, the heating element layer 124, the circuit layer 122, and the through-hole pad 154 are separated by the ceramic layer 134.

[0064] The high-frequency electrode layer 126 can be made of tungsten (W), molybdenum (Mo), silver (Ag), gold (Au), niobium (Nb), titanium (Ti) or alloys thereof and can be electrically connected to a power source or ground via separate electrode rods.

[0065] The heating element layer 124 can be formed into a plate-shaped coil composed of a heating wire or a resistance wire or a flat plate. The heating element layer 124 can also be formed into a multi-layer structure to accurately control the temperature. In addition, the heating element layer 124 can be formed into a multi-zone structure divided into multiple areas on the plane of the ceramic plate 110. The heating element layer 124 is electrically connected to the power supply unit through the electrode rod 240 and performs the function of heating the processing object substrate on the ceramic plate 110 at a predetermined specified temperature, so as to heat the substrate in the semiconductor process or perform a deposition process and an etching process, etc.

[0066] The heating element layer 124 is electrically connected to the electrode rod 240 through the conductive circuit layer 122, the first through hole 150, the through hole pad 154 and the second through hole 152. The current supplied by the electrode rod 240 is distributed to the heating element layer 124 divided into multiple areas through the circuit layer 122.

[0067] The through-hole pad 154 is formed to be arranged between the outermost ceramic layer (first ceramic layer) 136 and the ceramic layer (second ceramic layer) 135 adjacent to the outermost ceramic layer. The outermost ceramic layer 136 is a ceramic layer forming the lower surface 112 of the ceramic board 110, and can be composed of one or more ceramic layers. The through-hole pad 154 can be formed by CVD, PVC, spraying process or screen printing process, etc. The through-hole pad 154 can be made of tungsten (W), molybdenum (Mo), silver (Ag), gold (Au), niobium (Nb), titanium (Ti), nickel (Ni) or their alloys, preferably, it can be made of tungsten (W) and molybdenum (Mo).

[0068] The through-hole pad 154 is a circular ring shape (ring shape) and has a disk-shaped ring shape with an empty internal space 160. Specifically, the through-hole pad 154 is formed into a ring shape with an empty internal space 160 including the center of the circle. The internal space 160 can be a circle with a predetermined radius. Therefore, the through-hole pad 154 can be formed into a ring shape with a specified width w (w1 or w2). The annular through-hole pad 154 according to an embodiment of the present invention is not limited to a disk shape, but can also be formed into a polygonal plate shape such as an ellipse, a quadrilateral or a hexagon. In addition, the internal space 160 can be formed not only into a circle, but also into shapes such as an ellipse or a polygon.

[0069] Via pad 154 has a predetermined thickness (eg, 10 μm) and first and second surfaces 155 and 156 connected to vias 150 and 152. First and second surfaces 155 and 156 are formed in circular, ie, ring-shaped shapes with a region corresponding to inner space 160 being empty.

[0070] Since the through-hole pad 154 is disposed between the outermost ceramic layer 136 and the ceramic layer 135 adjacent to the outermost ceramic layer, the first side 155 of the through-hole pad 154 is adjacent to the outermost ceramic layer 136, and the second side 156 is adjacent to the ceramic layer 135 adjacent to the outermost ceramic layer. In addition, since the internal space 160 of the through-hole pad 154 is empty, the outermost ceramic layer 136 and the ceramic layer 135 adjacent to the outermost ceramic layer fill the internal space 160 and are stacked in a state of direct contact. When the sintering process of the ceramic board 110 is completed, the ceramic layers 135 and 136 are sintered to fill the internal space 160. Figure 8 , the inner space 160 is shown to be filled with the outermost ceramic layer 136 and / or the ceramic layer 135 adjacent to the outermost ceramic layer.

[0071] The through holes 150 and 152 are connected to the through hole pad 154, extend from the through hole pad 154, and are formed to penetrate the outermost ceramic layer 136 and the ceramic layer 135 adjacent to the outermost ceramic layer. Specifically, the first through hole 150 extends from the first side 155 of the through hole pad and is connected to the first side 155 of the through hole pad. Figure 8 Three first through holes 150 are shown in FIG, but the number of the first through holes is not limited thereto and may be changed as required.

[0072] Second vias 152 extend from and connect to second side 156 of the via pad. Second vias 152 may be formed in the number required to electrically connect to circuit layer 122. Vias 150, 152 are filled with a conductive substance and may be formed of the same substance as via pad 154.

[0073] First through-hole 150 extends through outermost ceramic layer 136, with one end 151 of the first through-hole exposed to the outside of ceramic plate 110. One end 151 of the first through-hole is connected to electrode rod 240. Specifically, first through-hole 150 is exposed to the outside through electrode rod connection slot 140 and is electrically connected to electrode rod 240 by brazing. Electrode rod connection slot 140 is formed on lower surface 112 of the ceramic plate to which electrode rod 240 is attached.

[0074] The electrode rod connecting groove 140 can be formed to Figure 1 The same description as for conventional ceramic plates is given in [ 15]. After the processing used to form electrode rod connection grooves 140, the thickness b of the outermost ceramic layer 133 between the electrode rod 240 and the through-hole pad 154 can be, for example, 100 to 200 μm. If the thickness exceeds 200 μm, the thickness of the ceramic plate 110 can be increased. The second through-hole 152 penetrates the ceramic layer 135 adjacent to the outermost ceramic layer and connects to the circuit layer 122.

[0075] To facilitate the connection between the through-holes 150, 152 and the through-hole pad 154, the width w (w1 or w2) of the through-hole pad 154 can be formed to be the same as or larger than the diameter of the through-holes 150, 152. Specifically, the width w1 of the through-hole pad first side 155 is greater than or equal to the diameter d1 of the first through-hole 150, and the width w2 of the through-hole pad second side 156 can be greater than or equal to the diameter d2 of the second through-hole 152. In this case, w1 and w2 can have substantially the same value.

[0076] The electrode rod 240 is brazed to the ceramic plate 10 at the electrode rod connection groove 140 and is electrically connected to the first through hole 150. Reference numeral 242 denotes a conductive bonding layer. The electrode rod 240 may be formed of a metal such as kovar.

[0077] When there are a plurality of first through holes 150, the size of the through-hole pad 154 increases, so that the plurality of first through holes 150 are connected to mutually different positions on the through-hole pad 154. Therefore, in a conventional ceramic board, the area in which the through-hole pad and the ceramic layer are in contact increases, and there is a problem of reduced bonding strength between the through-hole pad and the ceramic layer formed of different materials.

[0078] According to the embodiment of the present invention, the contact area between via pad 154 and ceramic layers 135 and 136, which are formed of different materials, is reduced. Furthermore, because the ceramic layer (first ceramic layer) above the via pad and the ceramic layer (second ceramic layer) below the via pad are in direct contact and sintered within via pad interior space 160, delamination between via pad 154 and ceramic layers 135 and 136 can be prevented. Therefore, even if the thickness of ceramic layer 133 is reduced by machining electrode rod connection groove 140, the problem of delamination of via pad 154 can be solved.

[0079] Table 1 shows the measurement results of the joining forces of the electrode rods of the conventional ceramic plate and the ceramic plate according to the embodiment of the present invention.

[0080] Table 1

[0081] Number of experiments Comparative Example (N·m) Example (N·m) first 0.7 0.9 Second time 0.8 1.1 The third time 0.8 1.1 average 0.77 1.03

[0082] After joining the electrode rods to the conventional ceramic plate and the ceramic plate according to the embodiment of the present invention by brazing, the joining strength (torque) was measured using a torque wrench.

[0083] The results of three experiments and calculation of the average value showed that the average joint strength of the conventional ceramic plate was 0.77 N·m, while the average joint strength of the embodiment of the present invention was 1.03 N·m. Therefore, the joint strength increased by about 34% compared to the conventional ceramic plate.

[0084] As described above, the present invention is described through specific matters such as specific constituent elements, limited embodiments and drawings, but it is only used to help more fully understand the present invention. The present invention is not limited to the above-mentioned embodiments. Ordinary technicians in the field to which the present invention belongs can make various modifications and variations without departing from the essential characteristics of the present invention. Therefore, the idea of ​​the present invention is not limited to the described embodiments, and it should be interpreted that the scope of the present invention includes not only the scope of the attached claims, but also all technical ideas that are equivalent to the scope of the claims or have equivalent variations. In addition, each of the embodiments can be combined with each other and operate as needed.

Claims

1. A ceramic base comprising a ceramic plate having an electrode layer formed thereon, characterized in that: The ceramic plate comprises: a plurality of ceramic layers, including a first ceramic layer and a second ceramic layer adjacent to the first ceramic layer, a through-hole pad disposed between the first ceramic layer and the second ceramic layer, including an internal space, and a plurality of first through holes, penetrating the first ceramic layer and connected to different positions on the through hole pad; The electrode layer is embedded in the plurality of ceramic layers and is electrically connected to the through-hole pad.

2. The ceramic base according to claim 1, characterized in that Also includes: an electrode rod connecting groove formed on a surface of the ceramic plate to expose the plurality of first through holes; as well as The electrode rod is electrically connected to the plurality of first through holes through the electrode rod connecting groove.

3. The ceramic base according to claim 2, characterized in that The electrode rods are engaged with the plurality of first through holes.

4. The ceramic base according to claim 1, characterized in that The through-hole pad includes a first side adjacent to the first ceramic layer and a second side adjacent to the second ceramic layer, The first surface and the second surface are annular.

5. The ceramic base according to claim 4, characterized in that The ceramic plate further includes a second through hole, The first through-hole is connected to the first side of the through-hole pad, and the second through-hole is connected to the second side of the through-hole pad. The second through hole electrically connects the through hole pad and the electrode layer.

6. The ceramic base according to claim 1, characterized in that The first ceramic layer is the outermost layer.

7. The ceramic base according to claim 6, characterized in that The through-hole pad includes a first surface adjacent to the first ceramic layer and a second surface adjacent to the second ceramic layer, the first surface and the second surface are annular, The ceramic board further includes a second through-hole, the first through-hole being connected to the first side, and the second through-hole being connected to the second side.

8. The ceramic base according to claim 1, characterized in that The first ceramic layer or the second ceramic layer fills the inner space of the via pad.

9. The ceramic base according to claim 1, characterized in that The thickness of the first ceramic layer penetrated by the first through hole is 100-200 μm.

10. The ceramic base according to claim 5, characterized in that The first through hole penetrates the first ceramic layer, The second through hole penetrates the second ceramic layer.

11. The ceramic base according to claim 5, characterized in that A width (w) of the via pad is greater than or equal to a diameter (d1) of the first via and a diameter (d2) of the second via.

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