Electric termination for a ceramic base equipped with built-in electrical components

Abstract

An electrical termination assembly comprises a ceramic insert defining a plurality of holes and a plurality of liners disposed within each of the plurality of holes. Each liner comprises a closed hole and a distal end, the distal end being exposed through the corresponding hole of the ceramic insert. A plurality of termination pins are fixed within each of the closed holes of the plurality of liners, and the plurality of liners are made of a ceramic material having a coefficient of thermal expansion between the coefficient of thermal expansion (CTE) of the ceramic insert and the coefficient of thermal expansion of the termination pins.

Description

Technology Field

[0001] Cross-reference for related applications

[0002] This application claims priority to U.S. Provisional Application No. 63 / 622,275 filed on January 18, 2024. The entire contents of said application are incorporated herein by reference.

[0003] Technology field

[0004] The present invention relates to electrical termination, and more specifically, to electrical termination of components embedded in a ceramic substrate, such as a radio frequency (RF) antenna embedded in a ceramic base for a semiconductor process. Background Technology

[0005] The description in this section provides only background information related to the present disclosure and may not constitute prior art.

[0006] Ceramic bases used in semiconductor processes typically contain various embedded electrical components, such as clamping electrodes, RF antennas, and heater circuits. Because ceramic materials are inherently brittle and have a relatively low coefficient of thermal expansion, it is difficult to embed electrically conductive terminations with higher coefficients of thermal expansion, which can cause cracking in the ceramic material. More specifically, since the embedded electrical components are made of refractory metals or conductive ceramics with very low coefficients of thermal expansion, it is difficult to connect metal electrodes to the embedded electrical components.

[0007] Electrical components are typically formed in layers and are usually surrounded by thin ceramic materials. Directly bonding metal electrodes, typically nickel or nickel alloys, to thin electrical components, usually by brazing, can result in stress and damage to the ceramic and / or adjacent electrically conductive layers at that location if the coefficients of thermal expansion of the different materials are not taken into account. Additionally, all embedded electrical components must be sealed from the atmosphere surrounding the ceramic base, i.e., the inside of the semiconductor processing chamber. However, as the temperature increases, the oxidation resistance of embedded electrical components decreases, leading to a shortened lifespan and / or reduced reliability. The problem to be solved

[0008] The present invention focuses on these problems related to electrical termination within a ceramic substrate / support, among other integration problems. means of solving the problem

[0009] This section provides a general summary of the disclosure and is not a comprehensive disclosure of the full scope or all features.

[0010] In one embodiment of the present invention, an electrical termination assembly comprises a ceramic insert defining a plurality of holes, a plurality of liners disposed within each of the plurality of holes—each liner comprising a closed hole and a distal end, said distal end being exposed through the corresponding hole of the ceramic insert—and a plurality of termination pins fixed within each of the closed holes of the plurality of liners. The plurality of liners comprises a ceramic material having a coefficient of thermal expansion (CTE) between the coefficient of thermal expansion (CTE) of the ceramic insert and the CTE of the termination pins.

[0011] Variations of such electrical termination assemblies may be implemented individually or in any combination: the ceramic insert is made of aluminum nitride (AlN), and the plurality of liners comprise a composite material having molybdenum (Mo) and tungsten (W); the ceramic insert comprises a lower flange portion; the ceramic insert comprises an upper flange portion; a plurality of bonding layers are disposed between the plurality of termination pins and the plurality of liners; the bonding layer is selected from the group consisting of a braze layer, a solid-state bonding layer, and a transient liquid bonding layer; and a sheath is disposed around the proximal end of the termination pins.

[0012] In another embodiment, the ceramic assembly comprises 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 comprises a ceramic insert disposed within the ceramic body—the ceramic insert defines a plurality of holes—a plurality of liners disposed within each of the plurality of holes—each liner comprises a closed hole and a distal end face, said distal end face being exposed through the corresponding hole of the ceramic insert—and a plurality of termination pins fixed within each of the closed holes of the plurality of liners. The plurality of liners comprises a ceramic material having a coefficient of thermal expansion between the coefficient of thermal expansion (CTE) of the ceramic insert and the coefficient of thermal expansion of the termination pins.

[0013] Variations of such ceramic assemblies may be implemented individually or in any combination: the electrical termination assembly is bonded to the ceramic body; a bonding layer is disposed between the distal end of a plurality of liners and the electrical component; the bonding layer is selected from a group consisting of a braze layer, a solid-state bonding layer, and a transient liquid bonding layer; a sealing layer is disposed between the outer surface of the ceramic insert and the ceramic body; the ceramic insert includes a lower flange portion; the sealing layer is disposed between the outer surface of the ceramic insert and the upper surface of the lower flange portion; the sealing layer includes a glass material; the ceramic insert includes an upper flange portion; and a sheath is disposed around the proximal end of the termination pins.

[0014] In another embodiment of the present invention, a ceramic base assembly comprises a ceramic base including at least one recess, a radio frequency (RF) antenna embedded within the ceramic base, and an electrical termination assembly disposed within the recess. The electrical termination assembly comprises a ceramic insert disposed within the ceramic base—the ceramic insert defining a plurality of holes—a plurality of liners disposed within each of the plurality of holes—each liner comprising a closed hole and a distal end face, said distal end face exposed through the corresponding hole of the ceramic insert—and a plurality of termination pins fixed within each of the closed holes of the plurality of liners. The plurality of liners comprises a ceramic material having a coefficient of thermal expansion between the coefficient of thermal expansion (CTE) of the ceramic insert and the coefficient of thermal expansion of the termination pins, and a bonding layer disposed between the distal end face of the plurality of liners and the RF antenna.

[0015] Variations of this ceramic base assembly can be implemented individually or in any combination: a resistive heater is embedded inside the ceramic base; and an outer shell is placed around the proximal end of the termination pins.

[0016] In another embodiment of the present invention, an electrical termination assembly comprises a ceramic insert defining a plurality of holes, a plurality of liners disposed within each of the plurality of holes—each liner comprising a closed hole and a distal end, said distal end being exposed through the corresponding hole of the ceramic insert—a plurality of termination pins fixed within each of the closed holes of the plurality of liners, an intermediate conductive layer electrically in contact with the plurality of liners, and at least one conductive via electrically in contact with the intermediate conductive layer and extending through the upper surface of the ceramic insert. The plurality of liners comprises a ceramic material having a coefficient of thermal expansion (CTE) between the coefficient of thermal expansion (CTE) of the ceramic insert and the CTE of the termination pins.

[0017] Additional areas of applicability will become apparent from the description provided herein. It should be understood that the foregoing description and specific examples are for illustrative purposes only and are not intended to limit the scope of the present disclosure. Brief explanation of the drawing

[0018] In order to facilitate a better understanding of the present disclosure, various aspects of the present disclosure provided as examples with reference to the accompanying drawings will now be described. FIG. 1 is a side schematic view of a ceramic assembly having an embedded electrical component and termination according to the teaching of the present disclosure. FIG. 2 is a side cross-sectional view in detail 2-2 of FIG. 1 of an electric termination assembly according to the teaching of the present disclosure. FIG. 3a is a perspective view of the electrical termination assembly of FIG. 2. Figure 3b is an exploded view of the electrical termination assembly of Figure 2. FIG. 4a is a perspective view of one form of an electrical termination assembly constructed in accordance with the teachings of the present disclosure. FIG. 4b is another perspective view of the electrical termination assembly of FIG. 4a. Fig. 4c is a lower view of the electrical termination assembly of Fig. 4a. Figure 5 is another perspective view of the electrical termination assembly of Figure 4a. FIG. 6a is a side view of an electric termination assembly having a protective sheath fixed around termination pins and constructed in accordance with the teachings of the present disclosure. FIG. 6b is a lower perspective view of the electrical termination assembly of FIG. 6a. FIG. 7 is a perspective view of a ceramic assembly constructed in accordance with the teachings of the present disclosure. FIG. 8 is a side cross-sectional view of another electrical termination assembly constructed in accordance with the teachings of the present disclosure. And FIG. 9 is a side cross-sectional view of another electrical termination assembly constructed in accordance with the teachings of the present disclosure. The drawings described herein are for illustrative purposes only and are not intended to limit the scope of the disclosure in any way. Specific details for implementing the invention

[0019] The following description is by nature illustrative and is not intended to limit the disclosure, application, or use thereof. Corresponding reference numbers throughout the drawings should be understood as representing similar or corresponding parts and features.

[0020] Referring to FIGS. 1 and 2, a ceramic base assembly according to the teaching of the present disclosure is illustrated and is generally denoted by reference numeral 20. A ceramic base assembly 20 of this form comprises a ceramic base 22, said ceramic base 22 comprising a ceramic body (in this form, a plate member 24) and a shaft 26 fixed to the plate member 24. The plate member 24 comprises a ceramic material such as, for example, aluminum nitride (AlN) or beryllium oxide (BeO). Similarly, the shaft 26 also comprises a ceramic material in one form of the present disclosure. Further details regarding the materials and structure of an exemplary ceramic pedestal are disclosed in U.S. patent application 63 / 341,163, titled “HYBRID SHAFT ASSEMBLY FOR THERMAL CONTROL IN HEATED SEMICONDUCTOR PEDESTALS” and 63 / 310,448, titled “SOLID-STATE BONDING METHOD FOR THE MANUFACTURE OF SEMICONDUCTOR CHUCKS AND HEATERS”, which are co-owned with this application, the contents of which are incorporated herein by reference in their entirety.

[0021] Additionally, as further shown, a radio frequency (RF) antenna 28 is embedded within the ceramic base 22, more specifically within the plate member 24. In this configuration, a resistive heater 30 is embedded within the ceramic base 22 (more specifically within the plate member 24). It should be understood that various electrical components other than the RF antenna 28 and / or the resistive heater 30 may be embedded within or operablely coupled to the ceramic base assembly 20 while being within the scope of this disclosure. The ceramic base assembly 20 further comprises at least one recess 32 (Fig. 2) and an innovative electrical termination assembly 40 disposed within the recess 32, which will now be described in more detail.

[0022] Referring to FIG. 2 and FIG. 3a and FIG. 3b, the electrical termination assembly 40 comprises a ceramic insert 42 that is generally disposed within a plate member 24 of a ceramic base 22 or at least partially embedded therein. More specifically, the ceramic insert 42 is disposed within a recess 32 as shown. The ceramic insert 42 comprises a plurality of holes 44 that penetrate the entire length of the ceramic insert 42 as shown. A plurality of corresponding liners 46 are disposed within each hole 44, and each liner 46 has a closed hole 48. The distal end 49 of each liner 46 is exposed through each hole 44 of the ceramic insert 42 and is configured to communicate electrically with an RF antenna 28 or other electrical component (e.g., a resistive heater 30) embedded within the plate member 24.

[0023] Corresponding multiple termination pins 50 are secured inside each of the blind holes 48 of the liners 46, which is described in more detail below. To reduce adverse effects due to thermal expansion during manufacturing and operation (i.e., cracking of the plate member 42), the liners 46 comprise a ceramic material having a coefficient of thermal expansion (CTE) between that of the ceramic insert 42 and the coefficient of thermal expansion of the termination pins 50. In one embodiment, the ceramic insert 42 is made of aluminum nitride (AlN) and the liner 46 is a composite material comprising molybdenum (Mo) and tungsten (W). In one embodiment, the ratio of molybdenum to tungsten by volume fraction is between about 20% and about 95%. In this variant, the termination pins 50 are Kovar ®It includes nickel-cobalt iron alloys such as brand alloys. It should be understood that various materials may be used for each of the liners 46, ceramic inserts 42, and termination pins 50, provided that the coefficient of thermal expansion (CTE) of the ceramic insert 42 is within the scope of the present disclosure and is between the CTEs of the liners 46 and the termination pins 50. For example, the liner 46 may include other materials within the scope of the present disclosure, such as, for example, TiN (titanium nitride), TiC (titanium carbide), WC (tungsten carbide), B4C (boron carbide), or tantalum.

[0024] As shown, the termination pin 50 is secured inside the liner 46 through a bonding layer 52 surrounding the termination pin 50. The bonding layer 52 can be a braze layer (brazing), a solid-state bonding layer (solid-state / diffusion bonding), or a transient liquid phase (TLP) bonding layer (TLP bonding). Additionally, the bonding layer 52 can be various materials, such as titanium-rich braze alloys like BTi-5, for example. It should be understood that the various materials can be used for the bonding layer 52 only if the coefficient of thermal expansion (CTE) of the various materials is close to the CTE of the termination pin 50 and the liner 46. And although a plurality of termination pins 50 and corresponding closed holes 48 have been illustrated and described, it should be understood that the teachings of the present disclosure may also apply to an electrical termination assembly 40 comprising only a single termination pin 50 within a single closed hole 48, provided that such assembly is within the scope of the present disclosure. (Note that FIGS. 8 and 9 relate to exemplary single termination pin variations, but are not limited to the specific design of the ceramic insert as shown.)

[0025] Additionally, as shown, another bonding layer 60 is placed between the distal end 49 of each liner 46 and the RF antenna 28, and between the top 43 of the ceramic insert 42 and the RF antenna 28. This bonding layer 60 may be various materials having a coefficient of thermal expansion substantially equal to or between that of the liner 46 and the plate member 24. Generally, the bonding layer 60 is a material such as the material presented above for the bonding layer 52, for example, a titanium-rich brazed alloy. Additionally, the distal end 49 of the liner 46 and the top 43 of the ceramic insert 42 may be secured to the RF antenna 28 via the bonding layer 60 using brazing, solid-state / diffusion bonding, or transient liquid-phase (TLP) bonding.

[0026] The ceramic insert 42 of this form includes a lower flange portion 70. The lower flange portion 70 includes an upper surface 72 and a lower surface 74. The upper surface 72 is configured to abut the outer surface 25 of the plate member 24, thereby placing the ceramic insert 42 within the recess 32. For example, in certain applications such as a ceramic base assembly 20 for semiconductor processes, the interface between the ceramic insert 42 and the plate member 24 is sealed. As such, in this form, a sealing layer 76 is placed between the upper surface 72 of the ceramic insert 42 and the outer surface 25 of the plate member 24. In one form, the sealing layer 76 is made of glass. However, it should be understood that various materials for the sealing layer 76 may be used within the scope of this disclosure.

[0027] Now, referring to FIGS. 4a-4c and FIG. 5, an exemplary electrical termination assembly 40 is illustrated in more detail. In this configuration, a total of five (5) liners 46 and termination pins 50 are secured within a ceramic insert 42. The flange portion 70 is illustrated as having an upper surface 72 and a lower surface 74 together with the distal end surface 49 of the liner 46.

[0028] Returning to FIGS. 6a and 6b, in one embodiment, the electric termination assembly 40 comprises a sheath 80 positioned around the proximal end 51 of the termination pins 50. In one embodiment, the sheath 80 is brazed to the termination pins 50, but other forms of fixing or joining methods may be used as long as they remain within the scope of the present disclosure. The sheath 80 further comprises an electrical connection 82, which is adapted to accommodate a power lead 84 to supply power to the electric termination assembly 40. Although not illustrated, when the application of the electric termination assembly 40 is a ceramic base assembly 20, both the termination pins 50 and the sheath 80 extend through a shaft 26 (Fig. 1).

[0029] Referring to FIG. 7, an exemplary ceramic assembly is illustrated and is generally denoted by reference numeral 90. The ceramic assembly 90 comprises at least one ceramic body 92 comprising at least one recess 94 (in this assembly, three recesses 94 are used). The ceramic assembly 90 comprises at least one electrical component embedded therein (e.g., RF antenna 28, resistive heater 30) as previously described and illustrated (not illustrated). The electrical termination assembly 40 described above is disposed within each recess 94 as illustrated, and more specifically, is bonded to the ceramic body 92 as described herein. Two electrical termination assemblies 40 on the outer surface of the ceramic body 92 comprise ceramic inserts 42 having flange portions 70 as previously presented, and a central electrical termination assembly 40' comprises a ceramic insert 42' without flange portions. The ceramic insert 42' of this type is generally in the shape of a cylindrical plug and is recessed inside the ceramic body 92 as illustrated. Accordingly, various shapes, sizes, and installation configurations for the electrical termination assembly 40 / 40' are considered by the teachings of the present invention.

[0030] Now, referring to FIG. 8, another form of the electrical termination assembly is illustrated and is generally denoted by reference number 100. Similar elements and features presented above, as well as variations and materials thereof, are not repeated here for clarity. As illustrated, this form of the ceramic insert 102 includes an upper flange portion 104 (contrasting with the lower flange portion 70 shown and described above). A bonding layer 110 is placed between the upper surface of the upper flange portion and an electrical component such as an RF antenna 28, and between the distal end 49 of the liner 48 and the RF antenna 28. The bonding layer 110 is similar to the bonding layer 60 presented above. A sealing layer 112 (similar to the sealing layer 76 presented above) is placed between the upper flange portion 104 of the ceramic insert 102 and the surface of the plate member 24. In one form, the sealing layer 112 is made of glass. However, it should be understood that various materials for the sealing layer 112 may be used within the scope of the present disclosure. And it should be understood that although only one termination pin 50 is illustrated, any number of termination pins 50 may be used within a single ceramic insert 102 as long as they remain within the scope of the present disclosure.

[0031] Referring to FIG. 9, another form of the electrical termination assembly is illustrated and is generally denoted by reference numeral 200. In this form, the electrical termination assembly 200 comprises a ceramic insert 202 having two sets of termination pins 50, liners 46, and bond layers 52. However, it should be understood that only one set may be used or more than two sets may be used as long as they remain within the scope of the invention. Unlike the liner 46 which contacts the RF antenna 28 directly as previously described and illustrated, the electrical termination assembly 200 of this form comprises an intermediate conductive layer 204 and a conductive via 206 to provide an electrical path from the termination pin 50 to the RF antenna 28. The conductive via 206 extends through the upper surface 208 of the ceramic insert 202 and is thus exposed to the RF antenna 28 for electrical contact. Accordingly, thermal stress between the RF antenna 28 and the electrical termination assembly 200 is further separated by using an intermediate conductive layer 204 and conductive vias 206. The intermediate conductive layer 204 may be a material such as, for example, W, Mo, a Mo-AlN composite, or a W-AlN composite. The conductive vias 206 may be a material such as, for example, a Mo-AlN composite or a W-AlN composite. Additionally, while two conductive vias 206 are illustrated, it should be understood that only one conductive via 206 or two or more conductive vias 206 may be used while remaining within the scope of this disclosure. Similar elements and features of the electrical termination assembly previously illustrated and described, and variations and materials thereof presented above, are not repeated in this disclosure for the sake of clarity.

[0032] Unless otherwise expressly indicated herein, all figures representing mechanical / thermal properties, compositional percentages, dimensions and / or tolerances, or other properties should be understood as modified by the words “about” or “approximately” in describing the scope of this disclosure. Such modifications are necessary for various reasons, including industrial practice, materials, manufacturing and assembly tolerances, and testing capabilities.

[0033] As used in this specification, the phrase “at least one of A, B, and C” should be interpreted to mean logic (A OR B OR C) using a non-exclusive logical OR, and should not be interpreted to mean “at least one of A, at least one of B, and at least one of C.”

[0034] The description of the present invention is by nature illustrative only, and thus variations that do not depart from the essence of the invention are intended to be within the scope of the invention. Such variations should not be construed as departing from the spirit and scope of the present disclosure.

Claims

Claim 1 An electric termination assembly, wherein the electric termination assembly comprises: a ceramic insert defining a plurality of holes; a plurality of liners disposed within each of the plurality of holes, each liner comprising a closed hole and a distal end, said distal end being exposed through the corresponding hole of the ceramic insert; and a plurality of termination pins fixed within each of the closed holes of the plurality of liners, said liners comprising a ceramic material having a coefficient of thermal expansion between the coefficient of thermal expansion (CTE) of the ceramic insert and the coefficient of thermal expansion of the termination pins. Claim 2 An electrical termination assembly according to claim 1, wherein the ceramic insert is made of aluminum nitride (AlN) and the plurality of liners comprise a composite material having molybdenum (Mo) and tungsten (W). Claim 3 An electrical termination assembly according to claim 1, wherein the ceramic insert includes a lower flange portion. Claim 4 An electrical termination assembly according to claim 1, wherein the ceramic insert includes an upper flange portion. Claim 5 An electric termination assembly according to claim 1, further comprising a plurality of bonding layers disposed between the plurality of termination pins and the plurality of liners. Claim 6 In paragraph 5, the electrical termination assembly, wherein the bonding layer is selected from the group consisting of a braze layer, a solid-state bonding layer, and a transient liquid-phase bonding layer. Claim 7 An electric termination assembly according to claim 1, further comprising an outer sheath disposed around the proximal end of the termination pins. Claim 8 A ceramic assembly, wherein the ceramic assembly comprises: 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, wherein the electrical termination assembly comprises: A ceramic insert disposed inside the ceramic body above - the ceramic insert defines a plurality of holes -; A plurality of liners disposed within each of the plurality of holes above—each liner comprises a closed hole and a distal end, said distal end being exposed through the corresponding hole of the ceramic insert—; and A ceramic assembly comprising a plurality of termination pins fixed inside each of the closed holes of the plurality of liners, wherein the plurality of liners comprise a ceramic material having a coefficient of thermal expansion between the coefficient of thermal expansion (CTE) of the ceramic insert and the coefficient of thermal expansion of the termination pins. Claim 9 In paragraph 8, the electric termination assembly is a ceramic assembly bonded to the ceramic body. Claim 10 A ceramic assembly according to claim 8, further comprising a bonding layer disposed between the distal cross-sections of a plurality of liners and the electrical component. Claim 11 In claim 10, the above bonding layer is selected from the group consisting of a braze layer, a solid-state bonding layer, and a transient liquid-phase bonding layer, in a ceramic assembly. Claim 12 A ceramic assembly according to claim 8, further comprising a sealing layer disposed between the outer surface of the ceramic insert and the ceramic body. Claim 13 In Clause 12, the ceramic assembly comprises a lower flange portion, wherein the ceramic insert comprises a lower flange portion. Claim 14 In paragraph 13, the sealing layer is disposed between the outer surface of the ceramic insert and the upper surface of the lower flange portion, in a ceramic assembly. Claim 15 In Clause 12, the sealing layer comprises a glass material, in a ceramic assembly. Claim 16 In claim 8, the ceramic assembly comprises a ceramic insert including an upper flange portion. Claim 17 A ceramic assembly according to claim 8, further comprising an outer shell disposed around the proximal end of the termination pins. Claim 18 A ceramic base assembly, wherein the ceramic base assembly comprises: a ceramic base including at least one recess; a radio frequency (RF) antenna embedded within the ceramic base; and an electrical termination assembly disposed within the recess, wherein the electrical termination assembly comprises: A ceramic insert disposed inside the ceramic base above - the ceramic insert defines a plurality of holes -; A plurality of liners disposed within each of the plurality of holes above—each liner comprises a closed hole and a distal end, said distal end being exposed through the corresponding hole of the ceramic insert—; and It includes a plurality of termination pins fixed inside each of the blocked holes of the plurality of liners, and The plurality of liners comprises a ceramic material having a coefficient of thermal expansion between the coefficient of thermal expansion (CTE) of the ceramic insert and the coefficient of thermal expansion of the termination pins; and a ceramic base assembly comprising a bonding layer disposed between the distal end of the plurality of liners and the RF antenna. Claim 19 A ceramic base assembly according to claim 18, further comprising a resistive heater embedded inside the ceramic base. Claim 20 A ceramic base assembly according to claim 18, further comprising an outer shell disposed around the proximal end of the termination pins. Claim 21 An electric termination assembly, wherein the electric termination assembly comprises: a ceramic insert defining a plurality of holes; a plurality of liners disposed within each of the plurality of holes, each liner comprising a closed hole and a distal end, said distal end being exposed through the corresponding hole of the ceramic insert; a plurality of termination pins fixed within each of the closed holes of the plurality of liners; an intermediate conductive layer electrically in contact with the plurality of liners; and at least one conductive via electrically in contact with the intermediate conductive layer and extending through the upper surface of the ceramic insert, wherein the plurality of liners comprise a ceramic material having a coefficient of thermal expansion (CTE) between the coefficient of thermal expansion (CTE) of the ceramic insert and the CTE of the termination pins.

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