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

Abstract

An electrical termination assembly includes a first disk having a central recess, a second disk spaced apart from the first disk, the second disk having a central opening, a plurality of connector pins in electrical contact with and extending between the first disk and the second disk, and a termination pin extending through the central opening of the second disk and into the central recess of the first disk. The termination pin is electrically connected to the first disk and the second disk.

Description

METHOD FOR ROBUST ELECTRICAL TERMINATION OF EMBEDDED CIRCUITSWITHIN A CERAMIC PEDESTAL HEATERCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and the benefit of U.S. provisional application number 63 / 622,280 filed January 18, 2024. The disclosure of the above application is incorporated herein by reference in its entirety.FIELD

[0002] The present disclosure relates to electrical terminations, and more specifically to electrical terminations to components embedded within ceramic substrates, such as by way of example a radio frequency (RF) antenna embedded within a ceramic pedestal for semiconductor processing.BACKGROUND

[0003] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

[0004] Ceramic pedestals for use in semiconductor processing typically include a number of embedded electrical components, such as by way of example, a clamping electrode, an RF antenna, and heater circuits, among others. Because ceramic materials are inherently brittle and have relatively low coefficients of thermal expansion, embedding electrically conductive terminations having higher coefficients of thermal expansion is challenging and can lead to cracking of the ceramic materials. More specifically, it is difficult to connect metal electrodes to the embedded electrical components because the electrical components are made from refractory metals or conductive ceramics which have very low coefficients of thermal expansion.

[0005] The electrical components are generally formed in layers and are typically thin and are surrounded by the ceramic material. Bonding metal electrodes, which are typically nickel or nickel alloys, directly to the thin electrical component, usually by brazing, may result in stress and damage to the ceramic in that area and / or an adjacent electrically conductive layer if coefficients of thermal expansion of the different materials are not accounted for. Additionally, any embedded electrical component must be sealed from the atmosphere surrounding the ceramic pedestal, i.e., within the semiconductor processing chamber. However, embedded electricalcomponents suffer from poor oxidation resistance at elevated temperatures, which limits their life and / or reduces reliability.

[0006] The present disclosure addresses these issues, among other integration issues, related to electrical terminations within ceramic substrates / pedestals.SUMMARY

[0007] This section provides a general summary of the disclosure and is not a comprehensive disclosure of its full scope or all of its features.

[0008] In one form of the present disclosure, an electrical termination assembly includes: a first disk having a central recess; a second disk spaced apart from the first disk, the second disk having a central opening; a plurality of connector pins in electrical contact with and extending between the first disk and the second disk; and a termination pin extending through the central opening of the second disk and into the central recess of the first disk, wherein the termination pin is electrically connected to the first disk and the second disk.

[0009] In variations of this electrical termination assembly, which may be implemented individually or in any combination: the first disk and the second disk are a composite material including AIN and Mo; each of the plurality of connector pins are a composite material including AIN and Mo; the termination pin is brazed to the first disk and the second disk; each of the first disk and the second disk define an arcuate geometry; 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 peripheries of each of the first disk and the second disk; the plurality of connector pins are arranged perpendicular to opposed interior faces of each of the first disk and the second disk; and the termination pin is an iron-nickel-cobalt alloy material.

[0010] In one form of the present disclosure, a ceramic assembly includes: a ceramic body including at least one recess; at least one electrical component embedded within the ceramic body; and an electrical termination assembly disposed within the recess, the electrical termination assembly including: a first disk having a central recess; a second disk spaced apart from the first disk, the second disk having a central opening; a plurality of connector pins in electrical contact with and extending between the first disk and the second disk; and a termination pin extending through the central opening of the second disk and into the central recessof the first disk, wherein the termination pin is electrically connected to the first disk and the second disk, and the first disk is in electrical contact with the electrical component

[0011] In variations of this ceramic assembly, which may be implemented individually or in any combination: the first disk is brazed to the electrical component; the electrical component is a heating circuit; the electrical component is an RF antenna; the ceramic body is an AIN material; the first disk and the second disk are a composite material including AIN and Mo; each of the plurality of connector pins are a composite material including AIN and Mo; each of the first disk and the second disk define an arcuate geometry; 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 peripheries of each of the first disk and the second disk; and the plurality of connector pins are arranged perpendicular to opposed interior faces of each of the first disk and the second disk; the termination pin is an iron-nickel-cobalt alloy material.

[0012] In one form of the present disclosure, a ceramic assembly includes: a ceramic body including at least one recess; at least one electrical component embedded within the ceramic body; and an electrical termination assembly disposed within the recess, the electrical termination assembly including: a first disk having a central recess and an outer periphery, the first disk defining a composite material including AIN and Mo; a second disk spaced apart from the first disk, the second disk having a central opening and an outer periphery, and the second disk defining a composite material including AIN and Mo; a plurality of connector pins in electrical contact with and extending between the first disk and the second disk, the plurality of connector pins disposed radially 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 including AIN and Mo; and a termination pin extending through the central opening of the second disk and into the central recess of the first disk, wherein the termination pin is electrically connected to the first disk and the second disk, and the first disk is in electrical contact with the electrical component.

[0013] Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.DRAWINGS

[0014] In order that the disclosure may be well understood, there will now be described various forms thereof, given by way of example, reference being made to the accompanying drawings, in which:

[0015] FIG. 1 is a side schematic view of a ceramic assembly having embedded electrical components and terminations according to the teachings of the present disclosure;

[0016] FIG. 2 is a side cross-sectional view within detail 2-2 of FIG. 1 , of an electrical termination assembly according to the teachings of the present disclosure;

[0017] FIG. 3 is a perspective view of the electrical termination assembly of FIG. 2; and

[0018] FIG. 4 is an exploded perspective view of the electrical termination assembly of FIG. 3.

[0019] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.DETAILED DESCRIPTION

[0020] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.

[0021] Referring to FIGS. 1 - 2, a ceramic pedestal assembly according to the teachings of the present disclosure is illustrated and generally indicated by reference numeral 20. The ceramic pedestal assembly 20 in this form comprises a ceramic pedestal 22 that includes a ceramic body 24 and a shaft 26 secured to the ceramic body 24. The ceramic body 24 comprises a ceramic material, such as by way of example, aluminum nitride (AIN) or beryllium oxide (BeO), among others. Similarly, the shaft 26 also comprises a ceramic material in one form of the present disclosure. Further details of the materials and construction of exemplary ceramic pedestals are disclosed in published applications WO 2023 / 220681 titled "HYBRID SHAFTASSEMBLY FOR THERMAL CONTROL IN HEATED SEMICONDUCTOR PEDESTALS" and WO 2023 / 158675 titled "SOLID-STATE BONDING METHOD FOR THE MANUFACTURE OF SEMICONDUCTOR CHUCKS AND HEATERS," which are commonly owned with the present application and the contents of which 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 ceramic body 24. In this form, a heating circuit 30 is also embedded within the ceramic pedestal 22 (and more specifically the ceramic body 24). The heating circuit 30 in one form is a resistive heater by way of example, including but not limited to a foil heater or a thermally sprayed heater, among others. It should be understood that a variety of electrical components other than the RF antenna 28 and / or the heating circuit 30 may be embedded within or operatively engaged with the ceramic pedestal assembly 20 while remaining within the scope of the present disclosure. The ceramic pedestal assembly 20 further comprises at least one recess 32 (FIG. 2), and an innovative electrical termination assembly 40 embedded within the ceramic body 24, which is now described in greater detail.

[0023] Referring to FIGS. 2 - 4, the electrical termination assembly 40 comprises a first disk 42, a second disk 44 spaced apart from the first disk 42, and a plurality of connector pins 46 in electrical contact with and extending between the first disk 42 and the second disk 44. A termination 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 is in electrical contact with the RF antenna 28 (or any other electrical component such as by way of example, the heating circuit 30). Accordingly, power supplied through the termination pin 48 is carried through each of the first disk 42, the second disk 44, and the connector pins 46 to the RF antenna 28. While the first disk 42 and the second disk 44 provide the primary electrical pathway from the termination pin 48 to the RF antenna 28, the connector pins 46 provide a secondary electrical pathway to improve the reliability of the overall electrical connection between the termination pin 48 and the RF antenna 28. The connector pins 46 are spaced a distance away from the recess 32 and are completely embedded within the ceramic body 24, and thus are not exposed to any oxygen that may be present within the recess 32, thereby improving 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 opening 52 (best shown in FIGS. 2 and 4). The termination pin 48 extends through the central opening 52 of the second disk 44 and into the central recess 50 of the first disk 42. In one form, the termination pin 48 is brazed to the first disk 42 and the second disk 44 using a suitable brazing material as set forth in greater detail below.

[0025] In one form of the electrical termination assembly 40, the first disk 42, second disk 44, and the connector pins 46 are a composite material comprising AIN (Aluminum Nitride) and Mo (Molybdenum), the ceramic body 24 is AIN, and the termination pin 48 is a nickel alloy material having a high nickel content such as nickel 200 / 201. Alternately, the termination pin 48 may be an iron-nickel-cobalt alloy. Generally, the materials for the first disk 42, second disk 44, the connector pins 46, and the termination pin 48 are selected to meet application requirements, and in the case of a ceramic pedestal assembly 20, the desired electrical conductivity for a robust electrical connection, oxidation resistance, and coefficients of thermal expansion (CTE) that are close to one another and that of the ceramic body 24. With the composite material of AIN and Mo and a termination pin 48 of nickel, the brazing material may be for example a gold-nickel alloy. It should be understood that a variety of different brazing materials may be employed as a function of the different materials for the components of the electrical termination assembly 40, and thus the examples provided herein are merely exemplary and should not be construed as limiting the scope of the present disclosure.

[0026] Each of the first disk 42 and the second disk 44 define an arcuate geometry as shown, however, it should be understood that a variety of geometries other than arcuate may be employed while remaining within the scope of the present disclosure. As further shown, each of the first disk 42 and the second disk 44 define an outer periphery 54, and the connector pins 46 are disposed radially inward from the outer peripheries 54 of each of the first disk 42 and the second disk 44. In this position, the connector pins 46 are a sufficient distance away from the recess 32 so as to avoid exposure to any oxygen, and the connector pins 46 are also a sufficient distance from the outer peripheries 54 in order to inhibit any electrical arcing. Further, in this form, the connector pins 46 are arranged perpendicular to opposed interior faces 56 of each of the first disk 42 and the second disk 44, which provides a more direct electrical path.

[0027] To manufacture the ceramic pedestal assembly 20, in one form,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 as one piece. After the sintering process, the recess 32 is formed (i.e., drilled) within the ceramic body 24, exposing the first disk 42 and the second disk 44. The termination pin 48 is then inserted within the recess 32 and brazed to each of the first disk 42 and the second disk 44 with braze layers 58.

[0028] Accordingly, a ceramic assembly 20 is provided by the teachings of the present disclosure, in which the ceramic body 24 has one or more recesses 32 to provide an electrical connection between embedded components (e.g., RF antenna 28, heating circuit 30 and a power supply (not shown) via the innovative electrical termination assembly 40. The electrical termination assembly 40 provides a more robust electrical connection to the embedded components using the connector pins 46 as a secondary electrical pathway, in addition to the first and second disks 42 / 44 as a primary electrical pathway. Additionally, the use of a composite material for certain components of the electrical termination assembly 40 provides the desired electrical properties, corrosion resistance, and CTE properties for a more robust electrical connection to embedded components within the ceramic assembly 20.

[0029] Unless otherwise expressly indicated herein, all numerical values indicating mechanical / thermal properties, compositional percentages, dimensions and / or tolerances, or other characteristics are to be understood as modified by the word “about” or "approximately" in describing the scope of the present disclosure. This modification is desired for various reasons including industrial practice, material, manufacturing, and assembly tolerances, and testing capability.

[0030] As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean “at least one of A, at least one of B, and at least one of C.”

[0031] The description of the disclosure is merely exemplary in nature and, thus, variations that do not depart from the substance of the disclosure are intended to be within the scope of the disclosure. Such variations are not to be regarded as a departure from the spirit and scope of the disclosure.

Claims

CLAIMSWhat is claimed is:1 . An electrical termination assembly comprising: a first disk having a central recess; a second disk spaced apart from the first disk, the second disk having a central opening; a plurality of connector pins in electrical contact with and extending between the first disk and the second disk; and a termination pin extending through the central opening of the second disk and into the central recess of the first disk, wherein the termination pin is electrically connected to the first disk and the second disk.

2. The electrical termination assembly according to Claim 1 , wherein the first disk and the second disk are a composite material comprising AIN and Mo.

3. The electrical termination assembly according to Claim 1 , wherein each of the plurality of connector pins are a composite material comprising AIN and Mo.

4. The electrical termination assembly according to Claim 1 , wherein the termination pin is brazed to the first disk and the second disk.

5. The electrical termination assembly according to Claim 1 , wherein each of the first disk and the second disk define an arcuate geometry.

6. The electrical termination assembly according to 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 peripheries of each of the first disk and the second disk.

7. The electrical termination assembly according to Claim 1 , wherein the plurality of connector pins are arranged perpendicular to opposed interior faces of each of the first disk and the second disk.

8. The electrical termination assembly according to Claim 1, wherein the termination pin is an iron-nickel-cobalt alloy material.

9. A ceramic assembly comprising: a ceramic body comprising at least one recess; at least one electrical component embedded within the ceramic body; and an electrical termination assembly disposed within the recess, the electrical termination assembly comprising: a first disk having a central recess; a second disk spaced apart from the first disk, the second disk having a central opening; a plurality of connector pins in electrical contact with and extending between the first disk and the second disk; and a termination pin extending through the central opening of the second disk and into the central recess of the first disk, wherein the termination pin is electrically connected to the first disk and the second disk, and the first disk is in electrical contact with the electrical component.

10. The ceramic assembly according to Claim 9, wherein the first disk is brazed to the electrical component.

11. The ceramic assembly according to Claim 9, wherein the electrical component is a heating circuit.

12. The ceramic assembly according to Claim 9, wherein the electrical component is an RF antenna.

13. The ceramic assembly according to Claim 9, wherein the ceramic body is an AIN material.

14. The ceramic assembly according to Claim 9, wherein the first disk and the second disk are a composite material comprising AIN and Mo.

15. The ceramic assembly according to Claim 9, wherein each of the plurality of connector pins are a composite material comprising AIN and Mo.

16. The ceramic assembly according to Claim 9, wherein each of the first disk and the second disk define an arcuate geometry.

17. The ceramic assembly according to 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 peripheries of each of the first disk and the second disk.

18. The ceramic assembly according to Claim 9, wherein the plurality of connector pins are arranged perpendicular to opposed interior faces of each of the first disk and the second disk.

19. The ceramic assembly according to Claim 9, wherein the termination pin is an iron-nickel-cobalt alloy material.

20. A ceramic assembly comprising: a ceramic body comprising at least one recess; at least one electrical component embedded within the ceramic body; and an electrical termination assembly disposed within the recess, the electrical termination assembly comprising: a first disk having a central recess and an outer periphery, the first disk defining a composite material comprising AIN and Mo; a second disk spaced apart from the first disk, the second disk having a central opening and an outer periphery, and the second disk defining a composite material comprising AIN and Mo; a plurality of connector pins in electrical contact with and extending between the first disk and the second disk, the plurality of connector pins disposed radially inward from the outer peripheries of each of the first disk and the second disk, and the plurality of connector pins defining a composite materialcomprising AIN and Mo; and a termination pin extending through the central opening of the second disk and into the central recess of the first disk, wherein the termination 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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