Solid-state bonding method for the fabrication of semiconductor chucks and heaters

Abstract

A layered assembly for use in a controlled atmosphere chamber includes a plurality of substrates and an electrical functional layer embedded between two adjacent substrates of the plurality of substrates, the electrical functional layer being a material configured to secure the two adjacent substrates together using a solid-state bonding process. An electrical termination region is integral with the electrical functional layer, and a peripheral sealing band is embedded between and extends around the periphery of the inner surfaces of the two adjacent substrates, the peripheral sealing band being a material configured to secure and seal the two adjacent substrates together using a solid-state bonding process. A dielectric region exists between the two adjacent substrates and between edge boundaries of the electrical functional layer, the dielectric region being sealed between the two adjacent substrates by the peripheral sealing band.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and the benefit of U.S. Provisional Application No. 63 / 310,448, filed February 15, 2022. The disclosure of the above application is incorporated herein by reference in its entirety. [Technical field]

[0002] The present invention relates to pedestals and chucks used in semiconductor manufacturing equipment, and more particularly to a method for manufacturing a pedestal and chuck having embedded heaters, RF antennas, and clamping electrodes. [Background technology]

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

[0004] In semiconductor wafer processing, a pedestal is placed within a processing chamber to support the semiconductor substrate. The pedestal is often made of a ceramic material and typically includes a heater plate and a shaft secured to the bottom of the heater plate. The shaft is hollow and configured to accept various electrical connections for powering the heater plate and monitoring various system parameters throughout the manufacturing process.

[0005] Some pedestals also contain embedded clamping electrodes, which electrostatically secure the semiconductor substrate to the upper surface of the pedestal during processing. These types of pedestals are called electrostatic chucks, or ESCs, and operate at potentials ranging from about 300 volts to several thousand volts. Other pedestals contain embedded RF antennas, which couple an RF power source between the chamber wall and the pedestal or chucking electrode.

[0006] The environment within the processing chamber can be corrosive due to the types of gases used and the elevated temperatures during deposition, etching, doping, and annealing processes. Thus, the pedestal must be able to withstand these harsh processing environments, as well as the cleaning steps within the chamber after the wafer is removed, and maintain the integrity of the working components embedded or located within it, i.e., heaters, clamping electrodes, and RF antennas.

[0007] The present disclosure addresses challenges associated with manufacturing pedestals and other ceramic assemblies that operate in harsh chemical environments. Summary of the Invention

[0008] This section provides a general overview of the disclosure and is not a comprehensive disclosure of its entire scope or all features.

[0009] In one aspect of the disclosure, a layered assembly for use in a controlled atmosphere chamber comprises a plurality of substrates, at least one electrical functional layer embedded between two adjacent substrates of the plurality of substrates, the electrical functional layer comprising a material configured to secure the two adjacent substrates together using a solid-state bonding process, at least one electrical termination region integral with the at least one electrical functional layer, and at least one peripheral sealing band embedded between and extending around a periphery of an inner surface of the two adjacent substrates, the at least one peripheral sealing band comprising a material configured to secure and seal the two adjacent substrates together using a solid-state bonding process, and a plurality of dielectric regions present between the two adjacent substrates and between edge boundaries of the at least one electrical functional layer, the plurality of dielectric regions being sealed between the two adjacent substrates by the at least one peripheral sealing band.

[0010] Variations of this layered assembly can be implemented individually or in any combination, the material of the electrical functional layer comprises nickel, and in one embodiment the amount of nickel is greater than 50 at.%, and in another embodiment greater than 99 at.%, the material of the peripheral sealing band comprises nickel, and in one embodiment the amount of nickel is greater than 50 at.%, and in another embodiment greater than 99 at.%, the material of the electrical functional layer and the material of the peripheral sealing band are the same material, and the material of the electrical functional layer and the material of the peripheral sealing band comprise nickel. and in one embodiment the amount of nickel is greater than 50 at.%, and in another embodiment the amount is greater than 99 at.%, the material of the electrical functional layer is graded and has a variable material property along at least one dimension, the electrical functional layer is selected from the group consisting of a resistive heater, an RF antenna, and a clamping electrode, the electrical functional layer is a resistive heater and a temperature sensor, each of the plurality of substrates comprises a ceramic material, the two adjacent substrates comprise the same ceramic material, and the layered assembly includes an upper substrate disposed on one of the two adjacent substrates. The layered assembly further comprises a substrate, the upper substrate comprising a ceramic material different from the ceramic material of the two adjacent substrates, the two adjacent substrates being aluminum nitride (AlN) material, the upper substrate being a high quality AlN material, the substrates comprising a Beryllium Oxide (BeO) material, the two adjacent substrates comprising a plurality of apertures formed therethrough, and the layered assembly comprising a local sealing band disposed around each of the plurality of apertures between the two adjacent substrates. a material of the local sealing band comprises nickel, in one embodiment in an amount greater than 50 atomic %, and in another embodiment in an amount greater than 99 atomic %, the material of the electrical functional layer, the material of the peripheral sealing band, and the material of the local sealing band are the same material, and further comprising an adhesive layer disposed between at least one of the two adjacent substrates and the at least one electrical functional layer, the adhesive layer being further disposed between at least one of the two adjacent substrates and the at least one peripheral sealing band, the layered assembly comprising:the layered assembly further comprising two electrical functional layers embedded between two adjacent substrates of the plurality of substrates, each electrical functional layer being applied to each of the two adjacent substrates prior to the solid-state bonding process, each electrical functional layer comprising a trace, the trace of one electrical functional layer being wider than the trace of the other electrical functional layer; the layered assembly further comprising two peripheral sealing bands embedded between two adjacent substrates of the plurality of substrates, each peripheral sealing band being applied to each of the two adjacent substrates prior to the solid-state bonding process, the band width of one peripheral sealing band being wider than the band width of the other peripheral sealing band; and a plurality of material islands disposed within the dielectric region, wherein the material islands are not electrically live, the at least one electrical functional layer is sputtered onto at least one of the two adjacent substrates, the at least one electrical functional layer is a foil material, a shaft is secured to an underside of one of the two adjacent substrates, a bonding layer is disposed between the shaft and the underside of the adjacent substrate, the bonding layer material comprises nickel, in one form the amount of nickel is greater than 50 atomic % and in another form the amount of nickel is greater than 99 atomic %, the seal is hermetic, the at least one electrical functional layer comprises a resistive heater having multiple zones, and the multiple zones of the resistive heater are disposed in different layers within the multiple substrates.

[0011] In another aspect of the disclosure, a heater assembly for use in a semiconductor processing chamber includes an upper substrate, at least two adjacent substrates secured to a lower surface of the upper substrate, at least one resistive heater embedded between the two adjacent substrates, the at least one resistive heater comprising a nickel material configured to secure the two adjacent substrates using a solid-state bonding process, at least one electrical termination region integral with the at least one resistive heater, and at least one peripheral sealing band embedded between and extending around an inner surface of the two adjacent substrates, the at least one peripheral sealing band comprising a nickel material configured to secure and seal the two adjacent substrates using a solid-state bonding process. A plurality of dielectric regions are present between the two adjacent substrates and between edge boundaries of the resistive heater, the plurality of dielectric regions being sealed between the two adjacent substrates by the at least one peripheral sealing band. A shaft is secured to an underside of one of the two adjacent substrates by a bonding layer comprising a nickel material.

[0012] In a variation of this heater assembly, an RF antenna is embedded between the top substrate and one of the two adjacent substrates, the RF antenna comprising a nickel material configured to secure the top substrate to the adjacent substrate using a solid state bonding process.

[0013] In yet another form, a layered assembly for use in a controlled atmosphere chamber comprises at least two adjacent substrates and at least one peripheral sealing band embedded between and extending around an inner surface of the two adjacent substrates, the at least one peripheral sealing band comprising a nickel material configured to secure and seal the two adjacent substrates using a solid state bonding process.

[0014] In yet another form, a heater assembly for use in a semiconductor processing chamber comprises a heater plate, a shaft secured to an underside of the heater plate, and at least one peripheral sealing band embedded between a periphery of an inner surface of the heater plate and the shaft and extending around the periphery, the at least one peripheral sealing band comprising a nickel material configured to secure and seal the heater plate and the shaft using a solid state bonding process.

[0015] According to another aspect of the present disclosure, a method of forming a layered assembly comprising a plurality of substrates for use in a controlled atmosphere chamber includes applying a material to at least one surface of two adjacent substrates of the plurality of substrates, the material being patterned as an electrical functional layer and integrated with electrical termination regions and a peripheral sealing band disposed around at least one surface of the two adjacent substrates, and bonding the plurality of substrates with heat and pressure in a controlled environment such that the two adjacent substrates are secured together to form the layered assembly and the layered assembly is hermetically sealed, a plurality of dielectric regions are present between the two adjacent substrates in the electrical functional layer, and the plurality of dielectric regions are hermetically sealed within the electrical functional layer by a peripheral sealing element.

[0016] Variations of this method, which may be performed individually or in any combination, include: the peripheral sealing band is patterned in a separate step from the patterning of the electrical functional layer; the material is patterned with a laser; the material is patterned with a mask; the material is patterned with an additive manufacturing process; the material is patterned with an etching process; the material is patterned with a water jet; the material is patterned with a hybrid laser-water jet; the material is nickel and is applied with a sputtering process; the nickel material is at least 50 at.%; the nickel material is at least 99 at.%; the material is applied to both sides of the two adjacent substrates; the pressure is controlled to adjust the size of the dielectric regions; and an adhesion layer is applied to at least one side of the adjacent substrates before applying the material.

[0017] In yet another aspect of the present disclosure, a layered assembly for use in a controlled atmosphere chamber comprises a plurality of substrates, at least one electrical functional layer embedded between two adjacent substrates of the plurality of substrates, the electrical functional layer comprising a material configured to secure the two adjacent substrates together using a solid state bonding process, and at least one electrical termination region integral with the at least one electrical functional layer, wherein a plurality of dielectric regions are present between the two adjacent substrates and between edge boundaries of the at least one electrical functional layer.

[0018] A variation of this layered assembly includes at least one peripheral sealing band embedded between and extending around the perimeter of the inner surfaces of two adjacent substrates, said at least one peripheral sealing band comprising a material configured to secure and seal said two adjacent substrates using a solid state bonding process, and said plurality of dielectric regions being sealed between said two adjacent substrates by said at least one peripheral sealing band.

[0019] In another aspect, a method of forming a layered assembly for use in a controlled atmosphere chamber, the layered assembly comprising a plurality of substrates, applying a material to at least one surface of two adjacent substrates of the plurality of substrates, the material being patterned as an electrical functional layer integrated with electrical termination regions, and bonding the plurality of substrates with heat and pressure in a controlled environment such that the material is solidly bonded to the two adjacent substrates, clamping the two adjacent substrates together to form the layered assembly, and sealing the layered assembly, wherein a plurality of dielectric regions are present between the two adjacent substrates in the electrical functional layer.

[0020] In variations of this method, which may be performed individually or in any combination, the material is applied to at least one surface of the two adjacent substrates and patterned into a peripheral sealing band and disposed around the periphery of at least one surface of the adjacent substrates, and the plurality of dielectric regions are sealed within the electrical functional layer by the peripheral sealing element, the material is applied to each opposing surface of the two adjacent substrates, and the pattern of the electrical functional layer on one opposing face is different from the pattern of the electrical functional layer on the other opposing face, and the electrical functional layer is a resistive heater, and the pattern of one opposing face comprises an unheated region.

[0021] 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. [Brief description of the drawings]

[0022] In order that the present disclosure may be more fully understood, reference will now be made by way of example to the accompanying drawings, in which:

[0023] [Figure 1]FIG. 1 is a perspective view of a pedestal used in a semiconductor processing chamber constructed in accordance with the teachings of the present disclosure.

[0024] [Diagram 2] FIG. 2 is a side view of the base of FIG.

[0025] [Diagram 3] 3 is an exploded view of the base of FIG.

[0026] [Figure 4] FIG. 4 is a perspective view of the resistive heater layer of FIG. 3 and constructed in accordance with the teachings of the present disclosure.

[0027] [Diagram 5] FIG. 5 is a top view of the resistive heater layer of FIG.

[0028] [Figure 6] FIG. 6 is a perspective view of the RF antenna layer of FIG. 3 and constructed in accordance with the teachings of the present disclosure.

[0029] [Figure 7] FIG. 7 is a top view of the RF antenna layer of FIG.

[0030] [Figure 8A] FIG. 8A is a cross-sectional view taken along line 8A-8A of FIG.

[0031] [Figure 8B] FIG. 8B is a detailed view taken from FIG. 8A showing the openings through the pedestal substrate and the various layers constructed in accordance with the teachings of the present disclosure.

[0032] [Figure 9] FIG. 9 is a flow diagram of a manufacturing method in accordance with the teachings of the present disclosure.

[0033] [Figure 10A]FIG. 10A is a top view of a resistive heater layer having a trace pattern constructed in accordance with the teachings of the present disclosure.

[0034] [Figure 10B] FIG. 10B is a top view of another resistive heater layer constructed in accordance with the teachings of the present disclosure and having a different trace pattern formed together with the resistive heater layer of FIG. 10A.

[0035] The drawings described herein are for illustrative purposes only, are not necessarily to scale, and are not intended to limit the scope of the disclosure in any way. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] The following description is merely illustrative and is not intended to limit the present disclosure, its application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.

[0037] 1-2, a heater assembly for use in a semiconductor processing chamber is shown and generally designated by the reference numeral 20. In this embodiment, the heater assembly 20 is also referred to as a "pedestal." The heater assembly 20 comprises an upper substrate 22, at least two adjacent substrates 24 and 26 secured to the underside of the upper substrate 22, and a shaft 28 secured to the underside of one of the two adjacent substrates 26. The upper substrate 22 and each of the two adjacent substrates 24 and 26 in one embodiment are ceramic materials. The ceramic materials may be the same for each substrate or may be different depending on the specific application requirements. For example, in one embodiment, each of the substrates (22, 24, 26) and the shaft 28 are aluminum nitride (AlN) materials. In another embodiment, the upper substrate 22 is a high-grade aluminum nitride (AlN) material having different material properties such as high volume resistivity, and each of the two adjacent substrates 24 and 26 and the shaft 28 are aluminum nitride (AlN) materials. In another embodiment, the lower adjacent substrate 26 is a material having a lower thermal conductivity than the other / upper adjacent substrate 24, for example an aluminum oxide (Al2O3) material. In another embodiment, the top substrate 22, the two adjacent substrates 24 and 26, and the shaft 28 are each a beryllium oxide (BeO) material. These and other variations in the materials of each substrate (22, 24, 26) and shaft 28 should be construed as falling within the scope of the present disclosure.

[0038] With reference to FIG. 3, at least one electrical functional layer is embedded between the substrates (e.g., 22 / 24 / 26), and the electrical functional layer is configured to secure the substrates using a solid-state bonding process, which will be described in more detail below. Advantageously, in one form of the present disclosure, the electrical functional layer serves the dual function of securing the substrates and providing electrical functionality within the heater assembly 20. This electrical functionality may include, by way of example, a resistive heater, an antenna (e.g., an RF antenna), or a clamping electrode, among others. Moreover, in a more general sense, the teachings of the present disclosure may be applied within the scope of the present disclosure to any layered assembly for use within a controlled atmosphere chamber (i.e., not limited to the heater assembly 20 shown and described herein).

[0039] In one form, the electrical functional layer is a resistive heater 30. This form of resistive heater 30 is shown as two layers 30' and 30'' and comprises a nickel material. The two layers 30' and 30'' are applied separately to the inner surfaces 25 and 27 of the two adjacent substrates 24 and 26 in a manufacturing process described in more detail below. However, it should be understood that the resistive heater 30 may be applied in a single layer to either the inner surfaces 25 or 27 within the scope of this disclosure. As shown, the resistive heater 30 is generally in the form of a trace or traces, which are individual continuous tracks of conductive / resistive material (e.g., nickel) that provide a predetermined resistance per unit length. The particular design (material and dimensions) of the traces allows for custom watt density for a particular input power. These traces may also be provided in multiple zones, as described in more detail below.

[0040] As further shown, another electrically functional layer in this configuration is an RF antenna 40. Similar to the resistive heater 30, the RF antenna 40 is two layers 40' and 40'' and comprises a nickel material. The two layers 40' and 40'' are applied separately to the top surface 29 of one of the two adjacent substrates 24 and the bottom surface 23 of the upper substrate 22 in a manufacturing process that will be described in more detail below. However, it should be understood that the RF antenna 40 may be applied in a single layer to either the top surface 29 or the bottom surface 23 within the scope of the present disclosure.

[0041] 4 and 5, at least one electrical termination region 50 is integral with the resistive heater 30 (only one resistive heater layer 30' is shown for clarity). The term "integral" as used herein should be interpreted to mean that the termination region is part of the resistive heater 30 and is electrically continuous with the resistive heater 30. In one form, the integral structure includes a termination region that is the same material as the resistive heater 30, however, different materials may be used within the scope of this disclosure. The electrical termination region 50 in this form is located within a central region of the resistive heater 30 layer and is configured to electrically connect the resistive heater 30 to a power lead (not shown) that extends through a central portion of the shaft 28. In another form, the electrical termination region 50 is not located in the central portion of the shaft 28, but instead is located in other regions of the resistive heater 30, particularly in multiple heater zones. In this exemplary form, the electrical termination region includes a total of four terminations for a two-zone heater, as shown in the figures. However, it should be understood that a single zone or multiple zones may be used within the scope of this disclosure. Additionally, the heater assembly 20 may include additional substrates (not shown) such that multiple heater zones are disposed at different layers within multiple substrates. Such a structure is shown in co-pending application Ser. No. 16 / 196,820, which is commonly assigned with the present application and the contents of which are incorporated herein by reference in their entirety.

[0042] As further shown, at least one peripheral sealing band 60 is embedded between and extends around the perimeter of the resistive heater 30. The peripheral sealing band 60 is configured to secure and seal the two adjacent substrates 24 and 26 together using a solid state bonding process. Thus, the peripheral sealing band 60 also serves two purposes, namely, to secure the two adjacent substrates 24 and 26 and also seal the interface therebetween. In one embodiment, the seal is sealed to meet application requirements within the processing chamber. The hermeticity, or leak rate, in one embodiment is approximately 1x10 -6 atmcc / sec (standard cubic centimeters per second) He. In other forms, the leak rate is about 1x10 -7 atmcc / secHe and in yet another form, the leak rate is about 1x10 -9 atmcc / secHe. Similar to the resistive heater 30 and the RF antenna 40, the peripheral sealing band 60 is two layers 60' and 60'' (FIG. 3) and comprises a nickel material. The two layers 60' and 60'' are applied separately to each of the inner surfaces 25 and 27 of the two adjacent substrates 24 and 26, as described in more detail below. However, it should be understood that within the scope of the present invention, the peripheral sealing band 60 may be applied in a single layer to either the inner surfaces 25 or 27.

[0043] 6 and 7, the layer 40' of the RF antenna 40 is shown in more detail, which also includes a peripheral sealing band 60. The peripheral sealing band 60 is applied to the layer of the RF antenna 40 and functions similarly to the peripheral sealing band 60 described above with respect to the resistive heater 30. The RF antenna 40 is generally a continuous layer of material as shown, but may take other patterns within the scope of this disclosure. For example, other patterns may include a mesh pattern of the RF antenna. Additionally, the RF antenna 40 layer may include two or more electrically independent / separated sections or zones (not shown), or other patterns such as a grid, within the scope of this disclosure. In this form having two or more zones, the electrically functional layer may be a chucking electrode. Additionally, as shown in both the resistive heater 30 and RF antenna 40 layers, a local sealing band 70 is provided, which is disposed around an opening extending through the substrate.

[0044] More specifically, with reference to Figures 8A and 8B, a plurality of openings 90 extend through the substrates (22, 24, 26) that are configured to accommodate lift pins (not shown). A local sealing band 70 on each layer (resistive heater 30 layer and RF antenna 40 layer) functions to seal the interface between the substrates (22, 24, 26) local to each opening 90. The local sealing band 70, in one form, is the same material as the layer in which it is located, and also functions to secure the substrates (22, 24, 26) to each other locally at the opening 90, thereby providing a dual function. Various methods of application and patterning of the local sealing bands 70, peripheral sealing bands 60, resistive heater 30, and RF antenna 40 are described in more detail below.

[0045] As further shown in Figures 8A and 8B, a number of dielectric regions 100 are present between the two adjacent substrates 24 and 26 and between the edge boundaries 31 of the resistive heater 30. In another form, a dielectric region 100 is also present between the top substrate 22 and one of the two adjacent substrates 24. The dielectric regions 100 are sealed between the substrates (22, 24, 26) by the peripheral sealing band 60 and in some areas also by the local sealing band 70. The dielectric regions 100 generally serve to dielectrically isolate the traces of the resistive heater 30 from each other (to prevent arcing and shorting) and to dielectrically isolate the openings 90 in the layers, the peripheral seal element 60 and any other features that should not be electrically "live" when the resistive heater 30 is electrically "live". Similarly, for the RF antenna 40 layer, the dielectric region 100 dielectrically isolates the opening 90 and the peripheral sealing element 60 such that the opening 90 and the peripheral sealing element 60 are not electrically “live” when the RF antenna 40 is electrically “live”, and also isolates electrically independent / separate sections of the RF antenna 40 in the form of multiple sections / zones (not shown).

[0046] In a variation of the present disclosure, a plurality of material islands 102 are provided within the dielectric region 100 and therefore contribute to the bonding of the substrates 22 , 24 , and 26 .

[0047] Due to the dielectric region 100 and various electrical functional layers (e.g., resistive heater 30, RF antenna 40), the present disclosure also provides, in one form of the disclosure, a layered assembly in which the substrates (e.g., 22, 24, 26) are not in physical contact with each other.

[0048] 3, the shaft 28 is secured to the underside of one of the two adjacent substrates 26 by a bonding layer 110. In one form, the bonding layer 110 is also a nickel material, although it should be understood that other materials may be used within the scope of the present disclosure.

[0049] As mentioned above, in one embodiment of the present disclosure, each of the resistive heater 30, RF antenna 40, peripheral seal element 60, local sealing band 70, material island 102, and bonding layer 110 for shaft 28 are nickel materials. Nickel is used in this embodiment because its material properties are compatible with the particular design of heater assembly 20 and manufacturing process described in detail below, as well as its ability to function electrically for resistive heater 30 and RF antenna 40 in a controlled atmosphere chamber. More specifically, nickel has electrical conductivity that provides the electrically functioning elements (resistive heater 30, RF antenna 40, etc.) with a relatively low profile and can be easily integrated into the pedestal design. Nickel also has a relatively high TCR (temperature coefficient of resistance), so that the electrically functioning elements (resistive heater 30, RF antenna 40, etc.) also function as temperature sensors (described in more detail below). Additionally, nickel can operate at relatively high temperatures, i.e., up to about 1,400°C, and in other embodiments, can operate at operating temperature targets such as 650°C, 800°C, or 900°C. Nickel is also a material that is compatible with atmosphere controlled chambers such as semiconductor processing chambers. Nickel has a relatively compatible CTE (coefficient of thermal expansion) compared to ceramic substrates in a controlled chamber environment, and more specifically, can accommodate CTE mismatches and thermal cycling while maintaining material properties. Furthermore, nickel is also compatible with the manufacturing processes of the present invention used to apply nickel materials, which are described in more detail below. One form of nickel material is an alloy composition having a nickel content of greater than about 50 at.%. In another form, the amount of nickel is greater than about 99 at.%, and more specifically, between 99 at.% and 99.999 at.%, and carbon is less than 0.1 at.%. Although nickel is used in each of the elements described herein, it should be understood that other materials and combinations of materials can be used within the scope of the present disclosure. Additionally, graded materials can be used, which have material properties (e.g., resistivity) that vary along at least one dimension, such as thickness, width, or length, by way of example.These variable material properties may be built into the material or may be the result of a manufacturing process such as hot pressing. For example, resistive layer 30 may be a nickel material, while RF antenna 40 is an aluminum material, and further, edge sealing band 60 and / or local sealing band 70 may be the same or different materials, such as titanium. These and other material combinations should be construed as falling within the scope of the present disclosure.

[0050] In yet another form, the nickel material (or other material of the electrical functional layer) acts as a sensor and provides temperature information. Typically, the change in resistance of the material is monitored, and the temperature is calculated (or determined from a look-up table) based on the change in resistance. Exemplary methods, systems, and controllers for such dual function electrical functional layers are described in detail in U.S. Patent No. 7,196,295, which is co-owned with this application and is incorporated herein by reference in its entirety.

[0051] 9 and 3, a method of manufacturing the heater assembly 20 is shown and generally designated by reference numeral 200. In a first step 210, the substrates 22, 24, and 26 are prepared. More specifically, the substrates 22, 24, and 26 are polished or finished to a predetermined flatness and parallel dimension, which is on the order of about 0.0004 inches (0.01 mm). Next, in step 230, layers for the resistive heater 30, RF electrode 40, and bonding layer 110 of the shaft 28 are applied to the surfaces of the substrates (22, 24, 26) and shaft 28. In an optional step shown at 220, an adhesion layer (not shown) may be applied to the surfaces of the substrates / surfaces as a matter of specific material and process requirements. For example, an adhesion layer is used if the surface roughness of the adjacent substrates 24 / 26 is low, or if BeO is used as the material of the substrates (22, 24, 26) and nickel does not adhere as readily as other substrate materials (e.g., AlN). In the specific example of a BeO substrate, a titanium (Ti) adhesion layer would be used between the nickel and the BeO. Thus, if the bonding surface of the substrate is too mechanically smooth or if the substrate material does not easily bond with the joining / adhesive material, an adhesion layer would be used. Examples of adhesion layer materials include nickel (Ni), aluminum (Al), zirconium (Zr), titanium (Ti), and hafnium (Hf), etc.

[0052] In one form, a continuous layer of material (e.g., nickel) is applied to each of the inner surfaces 25 and 27 of the adjacent substrates 24 and 26, and also to the upper surface 29 of one of the two adjacent substrates 24, and to the lower surface 23 of the upper substrate 22. As mentioned above, in one form, the two layers 30' and 30'' forming the resistive heater 30 are applied separately to the inner surfaces 25 and 27 of the two adjacent substrates 24 and 26, respectively, in mirror images. Similarly, the two layers 40' and 40'' forming the RF antenna 40 are applied separately to the upper surface 29 of one of the two adjacent substrates 24, and to the lower surface 23 of the upper substrate 22. This application approach is also referred to as a "double-sided" or "two-sided" application. As mentioned above, single-sided application to the entire layer is within the teachings of the present disclosure. Preliminary testing has shown that the "double-sided" application improves the hermeticity of the entire heater assembly 20. In one form of the present disclosure, bonding layer 110 is applied as a single layer to the upper surface of shaft 28 as a continuous, unpatterned layer.

[0053] Advantageously, the material is applied using a sputtering process, although it should be understood that other application methods, such as chemical vapor deposition (CVD), physical vapor deposition (PVD), thick film, thin film, sol-gel, thermal spray, continuous foil, patterned foil, and combinations thereof, are also considered to be within the scope of the present disclosure.

[0054] In one form, each material layer is applied as a continuous layer and then patterned (step 240) to form the various elements of the layer, namely, the resistive heater 30, the RF antenna 40, the peripheral sealing band 60 and / or local sealing band 70, and the material islands 102. In one form, this patterning is accomplished by laser ablation, i.e., laser removal. Other forms of material removal, such as, by way of example, chemical etching, water jet, hybrid water jet (water jet and laser), mechanical grinding, among others, should be construed as being within the scope of this disclosure. In another form of the present disclosure, a mask may be used for one or more layers, and material is applied over the mask to form one or more elements. In one variation of the present disclosure, the traces of one resistive heater layer 30' are wider than the traces of the other resistive heater layer 30", improving registration or matching of the traces when adjacent substrates 24 and 26 are assembled together. This approach may also be employed for the peripheral sealing band 60 and local sealing band 70, among other elements, and would also be used for "two-sided" application of material.

[0055] After each layer is applied and patterned, the substrates (22, 24, 26) are assembled in step 250 and held together in a fixture tool (not shown). The assembled substrates 22, 24, and 26 are bonded (step 260) by heat and pressure in a controlled environment for a predetermined time to solid-state bond the materials of each layer and secure the substrates (22, 24, 26). For example, a vacuum hot press furnace is used at about 1,000° C. and about 1,000 psi for about two hours to solid-state bond the substrates (22, 24, 26). As used herein, "solid-state" bonding (or bonding) should be understood to mean that the temperature of the materials (e.g., nickel) remains below their liquidus temperature during the application of heat and pressure during the bonding process. This process should be distinguished from other methods, such as brazing, in which the temperature of the materials exceeds their liquidus temperature. Although solid state bonding is also referred to as diffusion bonding, the teachings of the present disclosure do not necessarily require that the material (e.g., nickel) of each electrical functional layer diffuse into the other electrical functional layer (in the case of double-sided application) or into the substrate material. Additionally, it should be understood that "liquidus" as used herein should be interpreted to include transient liquid phase bonding (TLP).

[0056] The shaft 28 may be bonded to the assembled substrates (22, 24, 26) using the same process as described above, although in one form the shaft 28 is bonded to the substrates (22, 24, 26) in a separate process after the substrates (22, 24, 26) are solid-state bonded. In one form the shaft 28 is also solid-state bonded to the substrates (22, 24, 26) using a process similar to that described above, resulting in a complete heater assembly 20 / pedestal in a two-stage solid-state bonding process. For example, at least one peripheral sealing band is embedded between and extends around the perimeter of the inner surface of the adjacent substrate 26 (or more generally, the heater plate) and the shaft 28. One form of the peripheral sealing band comprises a nickel material that is configured to secure and seal the heater plate and shaft 28 together using a solid-state bonding process as described above. However, it should be understood that other bonding / adhesive techniques for bonding the shaft 28 may be employed within the scope of the present disclosure. Additionally, shaft 28 may be integral with one of the adjacent substrates 26 within the scope of the present disclosure.

[0057] In one variation of the present disclosure, the pressure applied during solid-state bonding is further controlled to adjust the size of the dielectric region 100. Generally, in the solid-state bonding process, for nickel materials, the temperature is between about 600° C. and about 1,455° C., the pressure is between about 10 psi and about 10,000 psi, while the total time at the bonding temperature ("soak time") is between about 0.25 hours and about 24 hours. The vacuum level is about 1-1E. -7 The atmosphere may include inert gases such as N2 (nitrogen), He (helium), and Ar (argon) at Torr. Additionally, reducing atmospheres may be used to reduce oxides such as hydrogen and carbon monoxide, for example. It should be understood that these process parameters will vary depending on the size and structure of the layered assembly and therefore should not be construed as limiting the scope of the present disclosure.

[0058] In yet another aspect of the present disclosure, a method for repair is provided, where a layered assembly comprises at least two adjacent substrates (24 / 26) and at least one peripheral sealing band 60 embedded between and extending around the perimeter of the inner surfaces of the two adjacent substrates (24 / 26), similar to the peripheral sealing band 60 described above. In one aspect, the peripheral sealing band 60 comprises a nickel material configured to secure and seal the two adjacent substrates (24 / 26) using the solid state bonding process described above. Additionally, the peripheral sealing band 60 may take on different geometric configurations in this repair application, for example, a continuous monolithic layer, or multiple sealing bands positioned throughout the entire layer, which may or may not be "peripheral."

[0059] Typically, the pedestal in need of refurbishment is resurfaced or polished to a specified flatness and surface roughness. In one example, the resurfaced substrate would represent the adjacent substrate 24, as shown and described above. A peripheral sealing band 60 (or other sealing configuration) would then be applied to one or both interior surfaces of the resurfaced substrate and the new top substrate (i.e., the adjacent substrate 22, as shown and described above), and the assembly would then be solid-bonded as described herein. In this variation, the material used for the peripheral sealing band 60 is nickel, although it will be appreciated that other materials, such as aluminum, silicon, and their alloys, among others, may also be used within the scope of this disclosure. Additionally, the resurfacing process may be performed further down the assembly, for example to the adjacent substrate 26 or shaft 28, within the scope of this disclosure.

[0060] 10A and 10B, in conjunction with FIG. 3, there is shown another embodiment of the present disclosure in which a region of a resistive heater layer 30''' on one adjacent substrate 26 is thermally isolated from a region of the other resistive heater layer 30' on the other adjacent substrate 24. More specifically, the first resistive heater layer 30' applied to the bottom surface of the adjacent substrate 24 is unchanged in this example. The second resistive heater layer 30''' applied to the top surface of the adjacent substrate 26 defines a different trace pattern as shown, in which traces near the electrical termination regions 50 (also referred to as "circuitry") are omitted, resulting in an unheated region 300 near the top of the shaft 28. Thus, heat conduction from the central region 310 of the resistive heater layer 30' to the unheated region 300 is inhibited, thereby providing a further means of locally controlling the temperature near the shaft 28 and reducing heat loss. As with the other electrical functional layers that are not mirror images of one another as described above, these and other variations of alternative trace patterns for the resistive heater layer should be construed as being within the scope of the present disclosure. For example, rather than omitting traces in certain areas, the traces may be reduced in thickness, thereby creating gaps between adjacent traces (in the case of double-sided applications described above), thereby thermally isolating the adjacent traces from one another.

[0061] Unless otherwise stated herein, all numerical values ​​expressing mechanical / thermal properties, compositional percentages, dimensions and / or tolerances, or other characteristics are understood to be modified by the word "about" or "approximately" in describing the scope of the present disclosure. This variation may be desired for a variety of reasons, including industry practices, materials, manufacturing, assembly tolerances, and testing capabilities.

[0062] As used herein, the phrase "at least one of A, B, and C" should be interpreted to mean (A or B or C) using a non-exclusive logical OR, and not to mean "at least one of A, at least one of B, and at least one of C."

[0063] The description of the disclosure is merely exemplary in nature, and thus, variations that do not depart from the gist of the disclosure are intended to be within the scope of the disclosure. Such variations are not to be regarded as departures from the spirit and scope of the disclosure.

Claims

1. 1. A layered assembly for use in a controlled atmosphere chamber, comprising: Multiple substrates, at least one electrical functional layer embedded between two adjacent substrates of the plurality of substrates, the electrical functional layer comprising a material configured to secure the two adjacent substrates together using a solid state bonding process; at least one electrical termination region integral with said at least one electrical functional layer; and at least one peripheral sealing band embedded between and extending around the peripheries of the inner surfaces of two adjacent substrates, said at least one peripheral sealing band comprising a material configured to secure and seal said two adjacent substrates together using a solid state bonding process; Equipped with wherein a plurality of dielectric regions are present between the two adjacent substrates and between edge boundaries of the at least one electrical functional layer, the plurality of dielectric regions being sealed between the two adjacent substrates by the at least one peripheral sealing band.

2. The layered assembly of claim 1 , wherein the material of at least one of the electrical functional layer and the peripheral sealing band comprises nickel.

3. The layered assembly of claim 1 , wherein the material of the electrical functional layer is graded and has material properties that vary along at least one dimension.

4. 10. The layered assembly of claim 1, wherein the electrically functional layer is selected from the group consisting of a resistive heater, an RF antenna, and a clamping electrode.

5. The layered assembly of claim 1 , wherein the electrical functional layer is a resistive heater and a temperature sensor.

6. The layered assembly of claim 1 , wherein each of the plurality of substrates comprises a ceramic material.

7. 7. The layered assembly of claim 6, further comprising a top substrate disposed on one of the two adjacent substrates, the top substrate comprising a ceramic material different from the ceramic material of the two adjacent substrates.

8. 8. The layered assembly of claim 7, wherein the two adjacent substrates are aluminum (AlN) materials and the top substrate is a high quality AlN material.

9. The layered assembly of claim 6 , wherein the substrates comprise a beryllium oxide (BeO) material.

10. 2. The layered assembly of claim 1, wherein the two adjacent substrates have a plurality of openings formed therethrough, and the layered assembly further comprises a local sealing band disposed around a periphery of each of the plurality of openings between the two adjacent substrates.

11. The layered assembly of claim 10 , wherein the material of the local sealing band comprises nickel.

12. The layered assembly of claim 1 , further comprising an adhesive layer disposed between at least one of the two adjacent substrates and the at least one electrical functional layer.

13. 13. The layered assembly of claim 12, wherein the adhesive layer is further disposed between at least one of the two adjacent substrates and the at least one peripheral sealing band.

14. 2. The layered assembly of claim 1, further comprising two electrical functional layers embedded between two adjacent substrates of the plurality of substrates, each electrical functional layer being applied to each of the two adjacent substrates prior to the solid-state bonding process.

15. 15. The layered assembly of claim 14, wherein each electrical functional layer comprises a trace, and the traces of one electrical functional layer are wider than the traces of the other electrical functional layer.

16. 15. The layered assembly of claim 14, further comprising two peripheral sealing bands embedded between two adjacent substrates of the plurality of substrates, each peripheral sealing band being applied to each of the two adjacent substrates prior to the solid bonding process.

17. 17. The layered assembly of claim 16, wherein the bandwidth of one peripheral sealing band is greater than the bandwidth of the other peripheral sealing band.

18. The layered assembly of claim 1 further comprising a plurality of material islands disposed within said dielectric region, said material islands being electrically non-live.

19. The layered assembly of claim 1 , further comprising a shaft secured to an underside of one of the two adjacent substrates.

20. The layered assembly of claim 1 , wherein the seal is airtight.

21. The layered assembly of claim 1 , wherein the at least one electrically functional layer comprises a resistive heater having multiple zones.

22. 10. The layered assembly of claim 1, further comprising a plurality of resistive heater zones disposed at different layers within the plurality of substrates.

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