Method for robust electrical termination of embedded circuits within a ceramic pedestal heater

Abstract

An electrical terminal assembly includes: a first disk having a central recess; a second disk separate from the first disk, the second disk having a central hole; a plurality of connector pins electrically contacting the first disk and the second disk and extending between the first disk and the second disk; and a terminal pin extending through the central hole of the second disk and into the central recess of the first disk. The terminal pin is electrically connected to the first disk and the second disk.

Description

Technical Field

[0001] This application claims priority and interest in U.S. Provisional Application No. 63 / 622,280, filed January 18, 2024. The disclosures of the aforementioned application are incorporated herein by reference in their entirety.

[0002] This disclosure relates to electrical terminals, and more particularly to electrical terminals for connecting components embedded in a ceramic substrate, such as, for example, radio frequency (RF) antennas embedded in a ceramic pedestal for semiconductor processing. Prior Technology

[0003] The descriptions in this section provide only background information on this disclosure and do not constitute prior art.

[0004] Ceramic mounts used in semiconductor processing typically include numerous embedded electrical components, such as, for example, a clamping electrode, an RF antenna, and heater circuitry. Because ceramic materials are inherently brittle and have a relatively low coefficient of thermal expansion, embedding conductive terminals with higher coefficients of thermal expansion is challenging and can lead to breakage of these ceramic materials. More specifically, because these electrical components are made of heat-resistant metals or conductive ceramics with very low coefficients of thermal expansion, it is difficult to connect metal electrodes to these embedded electrical components.

[0005] These electrical components are typically multi-layered and usually thin, surrounded by the ceramic material. Ignoring the different coefficients of thermal expansion of the materials, directly bonding metal electrodes, usually nickel or nickel alloys, to these thin electrical components via soldering can cause stress and damage in that area and / or an adjacent conductive layer. Furthermore, any embedded electrical component must be sealed relative to the environment surrounding the ceramic pedestal, i.e., sealed within the semiconductor processing chamber. However, embedded electrical components suffer from poor oxidation resistance at high temperatures, which limits their lifespan and / or reduces reliability.

[0006] This disclosure addresses these and other integration issues related to electrical terminals within ceramic substrates / bases. Summary of the Invention

[0007] This part provides a general overview of this disclosure rather than a complete disclosure of its full scope or all of its features.

[0008] In one embodiment of this disclosure, an electrical terminal assembly includes: a first disk having a central recess; a second disk separate from the first disk, the second disk having a central hole; a plurality of connector pins electrically contacting the first disk and the second disk and extending between the first disk and the second disk; and a terminal pin extending through the central hole of the second disk and into the central recess of the first disk, wherein the terminal pin is electrically connected to the first disk and the second disk.

[0009] In a variation of this electrical terminal assembly, which can be implemented individually or in any combination: the first disk and the second disk are composite materials of AlN and Mo; each connector pin of the plurality of connector pins is a composite material of AlN and Mo; the terminal pin is hard-soldered to the first disk and the second disk; each of the first disk and the second disk defines an arcuate geometry; each of the first disk and the second disk defines an outer perimeter, and the plurality of connector pins are radially inwardly disposed from the outer perimeters of each of the first disk and the second disk; the plurality of connector pins are configured to be perpendicular to the opposing inner surfaces of each of the first disk and the second disk; and the terminal pin is made of an iron-nickel-cobalt alloy material.

[0010] In one embodiment of this disclosure, a ceramic assembly includes: a ceramic body including at least one recess; at least one electrical component embedded in the ceramic body; and an electrical terminal assembly disposed within the recess, the electrical terminal assembly including: a first disk having a central recess; a second disk separate from the first disk, the second disk having a central hole; a plurality of connector pins electrically contacting the first disk and the second disk and extending between the first disk and the second disk; and a terminal pin extending through the central hole of the second disk and into the central recess of the first disk, wherein the terminal pin is electrically connected to the first disk and the second disk, and the first disk electrically contacts the electrical component.

[0011] In a variation of this electrical terminal assembly, which can be implemented individually or in any combination: the first disk is hard-soldered to the electrical component; the electrical component is a heating circuit; the electrical component is an RF antenna; the ceramic body is made of AlN material; the first disk and the second disk are composite materials comprising AlN and Mo; each connector pin of the plurality of connector pins is a composite material comprising AlN and Mo; each of the first disk and the second disk defines an arcuate geometry; each of the first disk and the second disk defines an outer periphery, and the plurality of connector pins are radially inwardly disposed from the outer periphery of each of the first disk and the second disk; and the plurality of connector pins are configured to be perpendicular to the opposing inner surfaces of each of the first disk and the second disk; the terminal pin is made of an iron-nickel-cobalt alloy material.

[0012] In one embodiment of this disclosure, a ceramic assembly includes: a ceramic body including at least one recess; at least one electrical component embedded in the ceramic body; and an electrical terminal assembly disposed within the recess, the electrical terminal assembly including: a first disk having a central recess and an outer periphery, the first disk defining a composite material comprising AlN and Mo; a second disk separate from the first disk, the second disk having a central hole and an outer periphery, and the second disk defining a composite material comprising AlN and Mo; and a plurality of connectors. The connector pins are electrically contacting the first disk and the second disk and extending between the first disk and the second disk. The plurality of connector pins are radially disposed from the outer periphery of each of the first disk and the second disk, and the plurality of connector pins define a composite material comprising AlN and Mo. A terminal pin extends through the central hole of the second disk and into the central recess of the first disk, wherein the terminal pin is electrically connected to the first disk and the second disk, and the first disk is electrically in contact with the electrical component.

[0013] Other application areas can be understood from the descriptions provided herein. It should be understood that the descriptions and specific examples are for illustrative purposes only and are not intended to limit the scope of this disclosure. Simple Explanation of the Diagram

[0014] To facilitate a good understanding of this disclosure, the following description illustrates various forms provided by way of example and with reference to the accompanying drawings, wherein:

[0015] Figure 1 is a side view schematic diagram of a ceramic assembly with embedded electrical components according to the teachings of this disclosure;

[0016] Figure 2 is a side cross-sectional view of part 2-2 of an electrical terminal assembly according to the teachings of this disclosure;

[0017] Figure 3 is a perspective view of the electrical terminal assembly in Figure 2; and

[0018] Figure 4 is an exploded perspective view of the electrical terminal assembly in Figure 3.

[0019] The figures described herein are for illustrative purposes only and are in no way intended to limit the scope of this disclosure. Implementation

[0020] The following description is illustrative in nature and is not intended to limit the disclosure, application, or purpose of this work. It should be understood that throughout the drawings, corresponding symbols denote similar or corresponding parts and shapes.

[0021] Please refer to Figures 1 and 2, which show, and generally denote as 20, a ceramic pedestal assembly according to the teachings of this disclosure. In this embodiment, the ceramic pedestal assembly 20 includes a ceramic pedestal 22, which comprises a ceramic body 24 and a shaft 26 fixed to the ceramic body 24. The ceramic body 24 comprises a ceramic material, such as, for example, aluminum nitride (AlN) or beryllium oxide (BeO). Similarly, in one embodiment of this disclosure, the shaft 26 also comprises a ceramic material. Further details regarding the materials and construction of the ceramic pedestal are disclosed in WO 2023 / 220681 entitled "HYBRID SHAFT ASSEMBLY FOR THERMAL CONTROL IN HEATED SEMICONDUCTOR PEDESTALS" and WO 2023 / 158675 entitled "SOLID-STATE BONDING METHOD FOR THE MANUFACTURE OF SEMICONDUCTOR CHUCKS AND HEATERS", which are jointly owned with this application and whose contents are incorporated herein by reference in their entirety.

[0022] As further shown, a radio frequency (RF) antenna 28 is embedded within the ceramic pedestal 22, and more specifically within the ceramic body 24. In this configuration, a heating circuit 30 is also embedded within the ceramic pedestal 22 (and more specifically the ceramic body 24). The heating circuit 30 is, in one configuration, a resistance heater, for example, including but not limited to a metal foil heater or a thermal spray heater. It should be understood that various electrical components other than the RF antenna 28 and / or the heating circuit 30 may be embedded in or operatively incorporated into the ceramic pedestal assembly 20 and remain within the scope of this disclosure. The ceramic pedestal assembly 20 further includes at least one recess 32 (FIG. 2) and, more specifically below, an innovative electrical terminal assembly 40 embedded within the ceramic body 24.

[0023] Referring to Figures 2 to 4, the electrical terminal assembly 40 includes: a first disk 42; a second disk 44 separate from the first disk 42; and a plurality of connector pins 46 electrically contacting the first disk 42 and the second disk 44 and extending between the first disk 42 and the second disk 44. A terminal pin 48 (also referred to as a terminal pin) is electrically connected to the first disk 42 and the second disk 44, and the first disk 42 electrically contacts the RF antenna 28 (or any other electrical component, such as the heating circuit 30). Therefore, the power supplied through the terminal pin 48 is transmitted to the RF antenna 28 through the first disk 42, the second disk 44, and each of the connector pins 46 and the connector pins. While the first disk 42 and the second disk 44 provide the primary electrical path from the terminal pin 48 to the RF antenna 28, the connector pins 46 provide an auxiliary electrical path to increase the reliability of the overall electrical connection between the terminal pin 48 and the RF antenna 28. The connector pins 46 are spaced apart from the recess 32 and fully embedded within the ceramic body 24, and are therefore not exposed to any oxygen present in the recess 32, thereby increasing the reliability of the electrical connection.

[0024] As further shown, the first disk 42 includes a central recess 50, and the second disk 44 has a central hole 52 (best shown in Figures 2 and 4). The terminal pin 48 extends through the central hole 52 of the second disk 44 and into the central recess 50 of the first disk 42. In one embodiment, the terminal pin 48 is soldered to the first disk 42 and the second disk 44 using a suitable soldering material, as described in more detail below.

[0025] In one embodiment of the electrical terminal assembly 40, the first disk 42, the second disk 44, and the connector pins 46 are composite materials comprising AlN (alumina) and Mo (molybdenum), the ceramic body 24 is AlN, and the terminal pins 48 are nickel alloys with a high nickel content, such as nickel 200 / 201. Alternatively, the terminal pins 48 may be an iron-nickel-cobalt alloy. Typically, the materials used for the first disk 42, the second disk 44, the connector pins 46, and the terminal pins 48 are selected to meet application requirements, and in the case of a ceramic base assembly 20, to achieve the desired conductivity, oxidation resistance, and coefficient of thermal expansion (CTE) close to and close to the coefficient of thermal expansion of the ceramic body 24 for a robust electrical connection. In the case of an AlN and Mo composite material and a nickel terminal pin 48, the solder material may be, for example, a gold-nickel alloy. It should be understood that various soldering materials may be used depending on the different materials used in the components of the electrical terminal assembly 40, and therefore the examples provided herein are merely illustrative and should not be construed as limiting the scope of this disclosure.

[0026] Each of the first disk 42 and the second disk 44 defines an arcuate geometry as shown in the figure; however, it should be understood that various geometries other than arcuate can be used within the scope of this disclosure. As further shown, each of the first disk 42 and the second disk 44 defines an outer perimeter 54, and the connector pins 46 are radially disposed inward from the outer perimeter 54 of each of the first disk 42 and the second disk 44. In this position, the connector pins 46 are sufficiently distanced from the recess 32 to avoid exposure to any oxygen, and the connector pins 46 are also sufficiently distanced from the outer perimeter 54 to prevent any arcing. Furthermore, in this configuration, the connector pins 46 are arranged perpendicular to the opposing inner surfaces 56 of each of the first disk 42 and the second disk 44, providing a more direct electrical path.

[0027] To manufacture the ceramic base assembly 20, in one configuration, the first disk 42, the second disk 44, and the connector pins 46 are placed within the ceramic material of the ceramic body 24 and sintered into a single piece. After the sintering process, the recess 32 is formed (or drilled) within the ceramic body 24, thereby exposing the first disk 42 and the second disk 44. The terminal pins 48 are then inserted into the recess 32 and hard-soldered to each of the first disk 42 and the second disk 44 using a solder layer 58.

[0028] Therefore, the teachings of this disclosure provide a ceramic assembly 20, wherein the ceramic body 24 has one or more recesses 32 to provide an electrical connection between an embedded component (e.g., an RF antenna 28), a heating circuit 30, and a power source (not shown) via the innovative electrical terminal assembly 40. In addition to using the first and second discs 42 / 44 as a primary electrical path, the electrical terminal assembly 40 also uses connector pins 46 as an auxiliary electrical path to provide a more robust electrical connection with one of the embedded components. Furthermore, a composite material is used for certain components of the electrical terminal assembly 40 to provide desired electrical properties, corrosion resistance, and CTE properties to achieve a more robust electrical connection with the embedded components within the ceramic assembly 20.

[0029] Unless expressly stated herein, all numerical values ​​representing mechanical / thermal properties, percentages of composition, dimensions and / or tolerances or other characteristics shall be understood to be modified by the terms "approximately" or "probably" in describing the scope of this disclosure. This modification is necessary for various reasons, including industrial practice; material, manufacturing and assembly tolerances; and testing capabilities.

[0030] The phrase “at least one of A, B and C” as used herein should be interpreted as using a non-exclusive logical “OR” to represent a logic (A or B or C), and should not be interpreted as meaning “at least one A, at least one B and at least one C”.

[0031] The descriptions in this disclosure are merely illustrative in nature, and therefore variations that do not depart from the essence of this disclosure should be considered within its scope. Such variations should not be regarded as deviations from the spirit and scope of this disclosure.

[0032] 20: Ceramic base assembly; Ceramic assembly 22:Ceramic pedestal 24: Ceramic body 26: Shaft 28: RF antenna 30: Heating circuit 32: concave part 40: Electrical terminal assembly 42: First disk 44: Second disk 46: Connector pins 48: Terminal pins 50: Center recess 52: Center Hole 54: Peripheral edge 56: Relative inner surface 58: Hard solder layer

Claims

1. An electrical terminal assembly comprising: a first disk having a central recess; a second disk separate from the first disk, the second disk having a central hole; a plurality of connector pins electrically contacting the first disk and the second disk and extending between the first disk and the second disk; and a terminal pin extending through the central hole of the second disk and into the central recess of the first disk, wherein the terminal pin is electrically connected to the first disk and the second disk.

2. The electrical terminal assembly of claim 1, wherein the first disk and the second disk are composite materials comprising either AlN or Mo.

3. The electrical terminal assembly of claim 1, wherein each connector pin of the plurality of connector pins comprises a composite material of AlN and Mo.

4. The electrical terminal assembly of claim 1, wherein the terminal pins are hard-soldered on the first disk and the second disk.

5. The electrical terminal assembly of claim 1, wherein each of the first disk and the second disk defines an arcuate geometry.

6. The electrical terminal assembly of claim 1, wherein the first disk and the second disk each define an outer periphery, and the plurality of connector pins are disposed radially inward from the outer periphery of each of the first disk and the second disk.

7. The electrical terminal assembly of claim 1, wherein the plurality of connector pins are configured to be perpendicular to the opposing inner surfaces of each of the first disk and the second disk.

8. The electrical terminal assembly as requested in item 1, wherein the terminal pins are made of an iron-nickel-cobalt alloy material.

9. A ceramic assembly comprising: a ceramic body including at least one recess; at least one electrical component embedded in the ceramic body; and an electrical terminal assembly disposed within the recess, the electrical terminal assembly comprising: a first disk having a central recess; a second disk separate from the first disk having a central hole; a plurality of connector pins electrically contacting the first disk and the second disk and extending between the first disk and the second disk; and a terminal pin extending through the central hole of the second disk and into the central recess of the first disk, wherein the terminal pin is electrically connected to the first disk and the second disk, and the first disk electrically contacts the electrical component.

10. The ceramic assembly of claim 9, wherein the first disk is hard-soldered to the electrical component.

11. The ceramic assembly of claim 9, wherein the electrical component is a heating circuit.

12. The ceramic assembly of claim 9, wherein the electrical component is an RF antenna.

13. The ceramic assembly of claim 9, wherein the ceramic body is an AlN material.

14. The ceramic assembly of claim 9, wherein the first disk and the second disk are composite materials comprising either AlN or Mo.

15. The ceramic assembly of claim 9, wherein each connector pin of the plurality of connector pins comprises a composite material of AlN and Mo.

16. The ceramic assembly of claim 9, wherein each of the first disk and the second disk defines an arcuate geometry.

17. The ceramic assembly of claim 9, wherein the first disk and the second disk each define an outer periphery, and the plurality of connector pins are disposed radially inward from the outer periphery of each of the first disk and the second disk.

18. The ceramic assembly of claim 9, wherein the plurality of connector pins are configured to be perpendicular to the opposing inner surfaces of each of the first disk and the second disk.

19. The ceramic assembly of claim 9, wherein the terminal pin is made of an iron-nickel-cobalt alloy material.

20. A ceramic assembly comprising: a ceramic body including at least one recess; at least one electrical component embedded in the ceramic body; and an electrical terminal assembly disposed within the recess, the electrical terminal assembly comprising: a first disk having a central recess and an outer periphery, the first disk defining a composite material comprising AlN and Mo; a second disk separate from the first disk, the second disk having a central aperture and an outer periphery, and the second disk defining a composite material comprising AlN and Mo; a plurality of connector pins electrically contacting and extending between the first disk and the second disk, the plurality of connector pins being radially disposed inward from the outer peripheries of each of the first disk and the second disk, and the plurality of connector pins defining a composite material comprising AlN and Mo; and a terminal pin extending through the central aperture of the second disk and into the central recess of the first disk. The terminal pin is electrically connected to the first disk and the second disk, and the first disk is in electrical contact with the electrical component.

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