Friction Stir Welding in Semiconductor Manufacturing Applications

Abstract

To provide a showerhead pedestal assembly for a substrate processing chamber that uses friction stir welding of a heater coil to avoid warping of a pedestal and its premature failure, and improves thermal manufacturing of the pedestal through the use of thermal posts or columns and cascaded circular baffles.SOLUTION: A showerhead pedestal assembly 100 includes a faceplate 102 and a platen 104, which includes a heater element 106 disposed within the faceplate and extending through at least one groove (channel or recess) 124 in the faceplate. The at least one groove is profiled to receive at least a portion of the heater element. The periphery of the platen is joined to the inner surface of the faceplate at a zone 120 by a friction stir welded joint.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] [Priority Claim] This application claims the benefit of priority to U.S. Patent Application No. 62 / 819,215, filed March 15, 2019, which is incorporated herein by reference in its entirety.

[0002] The present disclosure relates generally to friction stir welding in semiconductor manufacturing applications, and more particularly to the formation of friction stir welded components that enable efficient heat transfer during the manufacture of semiconductor devices. In certain exemplary aspects, the present disclosure relates to the use of friction stir welding in joining components together in pedestals for processing chambers, and more particularly showerhead pedestals. [Background technology]

[0003] The background description provided herein is intended to present the contents of the present disclosure generally. Work by the presently named inventors within the scope of what is described in this Background section, as well as aspects of the description that may not otherwise be considered prior art at the time of filing, are not admitted, expressly or impliedly, as prior art against the present disclosure.

[0004] In some conventional semiconductor manufacturing applications, heater coils are embedded into pedestal platen channels and filled with e-beam (electron beam) welded or vacuum brazed metal plugs. In such cases, the interfacial bond strength between the heater coil and pedestal components has proven inconsistent and insufficient, resulting in ineffective heat transfer between the heater coil and pedestal plate, potentially causing pedestal warpage and premature pedestal failure. Summary of the Invention

[0005] In some embodiments, friction stir welding of the heater coil is used to address the limitations of conventional welding techniques and avoid warping of the pedestal and its premature failure. In some embodiments, the use of thermal posts or columns and cascaded circular baffles is also sought to provide improved thermal performance of the pedestal.

[0006] In some examples, a showerhead pedestal assembly for a substrate processing chamber is provided. The exemplary showerhead pedestal assembly includes a faceplate, a platen disposed within the faceplate, the platen including a heater element extending through at least one groove in the faceplate, the at least one groove being profiled to receive at least a portion of the heater element extending through the groove, and a power source for the heater element, wherein a periphery of the platen is joined to an inner surface of the faceplate by a friction stir weld joint.

[0007] In some examples, the faceplate includes a plurality of openings that allow gases to pass through the showerhead pedestal assembly to the underside of a substrate supported by the showerhead pedestal assembly.

[0008] In some examples, the showerhead pedestal assembly further comprises a plurality of heat transfer posts extending between the faceplate and the opposing surface of the platen, the plurality of heat transfer posts comprising friction stir welding material.

[0009] In some instances, the friction stir welding material is different from the material of the faceplate or platen, allowing for the formation of a friction stir weld joint between the faceplate and the platen.

[0010] In some examples, the material of the plurality of heat transfer posts is selected to enhance or retard heat transfer between the faceplate and the platen.

[0011] In some examples, the material of the plurality of heat transfer posts is the same as the material of the heater element.

[0012] In some examples, the showerhead pedestal assembly further comprises a filler cap including at least one baffle sized and configured to reside in the at least one groove in the faceplate.

[0013] In some examples, at least one baffle of the filler cap secures at least a portion of the heater element in a respective groove in the faceplate.

[0014] In some examples, at least one baffle includes a curved feature that matches the profile of a respective groove in the faceplate.

[0015] In some examples, at least one baffle comprises a friction stir welding material.

[0016] In some examples, at least one baffle is provided along the top surface of the filler cap.

[0017] In some examples, a portion of the filler cap includes a heat sink that provides a body of material that is relatively cooler than the material of the platen during operation of the showerhead pedestal assembly.

[0018] In some examples, the at least one baffle includes at least one opening that allows gas to pass through.

[0019] In some examples, the at least one baffle is provided in a series of baffles arranged in a spaced apart arrangement extending along the profile of the heater element, the spaced apart arrangement of baffles including one or more gaps between successive baffles to allow gas to pass therethrough.

[0020] In some examples, the friction stir weld material of the at least one baffle is different from the material of the faceplate or heater element, allowing for the formation of a friction stir weld joint between the heater element and the faceplate.

[0021] In some examples, the at least one baffle is included in multiple concentric rings of baffles.

[0022] In some examples, at least one ring of the plurality of concentric rings of baffles includes spaced baffles.

[0023] In some examples, each of the spaced baffles includes one or more openings formed therein to allow a specific or controlled flow of gas through the one or more openings.

[0024] In some examples, the gap between a pair of spaced-apart baffles in at least one concentric ring of baffles is sized to allow a specific or controlled flow of gas to pass therethrough.

[0025] In some examples, the heater element is energized by a power source during formation of the friction stir welded joint. [Brief explanation of the drawings]

[0026] Several embodiments are illustrated in the figures of the accompanying drawings, which are presented by way of example and not by way of limitation.

[0027] [Figure 1] FIG. 1 is a cross-sectional view of a showerhead pedestal according to an example embodiment.

[0028] [Figure 2] FIG. 2 is a diagram illustrating an arrangement for friction stir welding, according to an exemplary embodiment.

[0029] [Figure 3]FIG. 3 is a pictorial diagram of a heater element in accordance with an exemplary embodiment.

[0030] [Figure 4] FIG. 4 is a cross-sectional view of a showerhead pedestal according to an example embodiment.

[0031] [Figure 5] FIG. 5 is a pictorial illustration of a filler cap in accordance with an exemplary embodiment.

[0032] [Figure 6] FIG. 6 is a cross-sectional view of a showerhead pedestal according to an example embodiment.

[0033] [Figure 7] FIG. 7 is a partial cross-sectional pictorial view of a showerhead pedestal according to an example embodiment.

[0034] [Figure 8] FIG. 8 is a cross-sectional view of a showerhead pedestal according to an example embodiment.

[0035] [Figure 9] FIG. 9 is a block diagram illustrating an example of a machine that may control one or more exemplary embodiments.

[0036] [Figure 10] FIG. 10 illustrates an aspect of an arrangement for friction stir welding, according to an exemplary embodiment.

[0037] [Figure 11] FIG. 11 is a flowchart including operations in an exemplary method, according to an exemplary embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0038] The following description includes systems, methods, techniques, instruction sequences, and computing machine program products that embody exemplary embodiments of the present disclosure. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the exemplary embodiments. However, it will be apparent to those skilled in the art that the present embodiments may be practiced without these specific details.

[0039] A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the patent document or patent disclosure being reproduced by anyone solely as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights. The following notice applies to all data described below or illustrated and forming a part of this document: copyright Lam Research Corporation, 2019-2020, all rights reserved.

[0040] Many semiconductor manufacturing applications involve the use of substrate processing chambers. The processing chambers may include a pedestal or track to which a substrate (e.g., a wafer) is secured during processing. As previously mentioned, the heater coils used in such pedestals are typically fabricated by conventional techniques such as vacuum brazing or electron beam welding. The interfacial bond strength between the heater coil and the pedestal components has proven inconsistent and insufficient, resulting in ineffective heat transfer between the heater and pedestal plate, potentially causing pedestal warpage and premature pedestal failure.

[0041] In some present examples, friction stir welding (FSW) is employed to fabricate or join pedestal components, such as heater elements, faceplates, and pedestal stems. Fabrication or joining of other components is also possible. The methods and manufactured articles described herein may exhibit improved thermal and mechanical properties compared to articles made using conventional techniques, such as vacuum brazing and electron beam welding. FSW addresses some of the limitations of conventional techniques. Such limitations may include weld cracking and porosity, which can result in reduced heat transfer within the pedestal components and reduced efficiency of the processing chamber to which such pedestals are attached.

[0042] 1, an exemplary showerhead pedestal assembly 100 includes a faceplate 102 and a platen 104 disposed within the faceplate 102. In some examples, the faceplate 102 includes openings that allow gases to pass through the showerhead pedestal assembly 100 to the underside of a substrate (such as a wafer) supported by the showerhead pedestal assembly 100 during use, as shown.

[0043] The platen 104 distributes heat within the showerhead pedestal assembly 100. The platen 104 includes a heater element 106. The profile and general configuration of an exemplary heater element 106 can be more clearly reviewed pictorially, as shown in example 300 in FIG. 3 or in FIG. 7. The heater element 106 includes several heater coils 108 that lie in a common plane within a channel (recess, or groove) 124 formed in the platen 104, as shown. Other coil arrangements are also possible. The heater coils 108 are secured within the grooves by the material of a filler cap 110. The groove is continuous and can be shaped to accommodate the profile and configuration of a given heater element 106. The material of the filler cap 110 may or may not include the same material as the material of the platen 104 or the material of the heater coils 108. The material of the filler cap 110 can be selected to improve or facilitate heat transfer through the platen 104 to the faceplate 102 or other areas of the showerhead pedestal assembly 100. In some examples, the deep or increased weld depth enabled by friction stir welding within the channel 124 allows for the introduction of a heat sink. The heat sink provides a body of material that is relatively cooler than the platen 104, and this cooler mass can help prevent warping of the platen 104. The relative thermal conductivity of the material of the filler cap 110 within the channel 124 may also be selected to assist in this regard.

[0044] Power to the heater coils 108 of the heater elements 106 may be supplied by power lines 118. Gas distribution channels 114 distribute gas to the aperture faceplate 102 and other components of the showerhead pedestal assembly 100. The power lines 118 and gas distribution channels 114 may pass through a stem 116 of the showerhead pedestal assembly 100, as shown.

[0045] In some examples, friction stir welding is used to assemble or form components of showerhead pedestal assembly 100. For example, in zone 120 (FIG. 1), friction stir welding is employed to join the periphery of platen 104 to the inner surface of faceplate 102. In a further example, in zone 122 (FIG. 1), friction stir welding is employed to form filler cap 110 over heater coil 108 and secure heater coil 108 within the body of platen 104, as shown. Other pedestal components can be joined or formed in a similar manner. Other friction stir welding zones are also possible.

[0046] Referring to FIG. 2 , an arrangement 200 for friction stir welding is shown. One component 202 of the showerhead pedestal assembly 100 can be joined to another component 204 in the manner shown. The illustrated component 202 can include, for example, an edge portion of the faceplate 102 located in zone 120. The other illustrated component 204 can include, for example, an edge portion of the platen 104 located in the same zone 120. As shown, a downward force 206 is applied to a rotating friction stir welding (FSW) tool 208 that is advanced in a welding direction 210 between the edge portions of the two components 202 and 204. The FSW tool 208 includes a shoulder 212 and a pin 214. As the spinning FSW tool 208 advances through the material of the components 202 and 204 to be joined together, it forms a friction stir weld region 216. The friction stir weld region 216 so formed includes a weld nugget 218 that joins the components 202 and 204 together. The nugget 218 has an advancing side 220 and a retreating side 222 that correspond to the spin rotation direction 224 of the tool.

[0047] In some examples, thermal non-uniformity in the pedestal or showerhead can degrade "on-wafer" (substrate) processing performance. In this situation, processing heat is lost or not properly directed to the desired area. Referring to Figures 3-4, components of further examples of the present disclosure are illustrated.

[0048] The heater element 300 shown in FIG. 3 has features for controlling or enhancing heat transfer within the showerhead pedestal. The heater element 300 includes a heater coil 306 powered by one or more power lines 304. In some configurations of the showerhead pedestal, heat transfer between the faceplate 102 and the platen 104 (or backplate) occurs primarily by conduction at their joined edges, for example, in or near zone 120 of FIG. 1 . In the illustrated example of FIG. 3 , auxiliary heat transfer columns or posts 302 are provided. The posts 302 can be separately fabricated or formed by friction stir welding and extend between the faceplate 102 and the platen 104, for example, as shown at 402 in FIG. 4 . Other elements of the showerhead pedestal 400 can be the same or similar to those described above with respect to the showerhead pedestal assembly 100 of FIG. 1 .

[0049] The posts 302 (402 in FIG. 4) manufactured by friction stir welding can, for example, assist in conducting heat between the faceplate 102 and the platen 104 in the showerhead pedestal assembly 100. In some examples, the heat transfer posts 302 can enhance the structural rigidity of the showerhead pedestal assembly 100, the security of the location of the heater element 106 in the platen 104, or the rigidity of the faceplate 102 or the platen 104. In some examples, the heat transfer posts 302 can conduct heat from the faceplate 102 to the platen 104 or by radiation, reducing the temperature of the faceplate 102 during wafer processing and minimizing or avoiding deflection or warping of the faceplate. Other configurations and arrangements of the heat transfer posts 302 are also possible. The material of the heat transfer posts 302 can be selected to enhance or retard heat transfer between the faceplate 102 and the platen 104. The material selected for the post 302 may or may not be the same as the material of the heater coil 108 .

[0050] 5 illustrates an exemplary filler cap 500 that includes a series of curved or arcuate baffles 502 formed along its top surface, as shown. Other configurations are also possible. The illustrated filler cap 500 can secure the coil 108 of the heater element 106 within the channel 124 of the platen 104, as described above with reference to FIG. 1.

[0051] Referring to FIG. 6 , in some examples of showerhead pedestal 600, various combinations of friction stir welded posts 302 (e.g., shown in FIG. 3 and not visible in FIG. 6 ) and curved baffles 502 can be inserted between the platen 604 and faceplate 602 to control heat transfer and improve thermal uniformity. Other arrangements and configurations of baffles 502 are also possible. Due to the ability of friction stir welding to weld dissimilar metals, optimized material combinations, thicknesses, and spacing patterns of a series of baffles can be adopted and configured accordingly. Other elements of showerhead pedestal 600 can be the same or similar to those described above with respect to the showerhead pedestal assembly 100 of FIG. 1 .

[0052] 7-8 , some exemplary embodiments may provide more specific control of heat and gas flow 708 within a showerhead pedestal 700. In some examples, concentric rings 702, 704, and 706 of spaced-apart baffles 710 are provided extending between a faceplate 802 and a platen 804 ( FIG. 8 ) within the showerhead pedestal 700 (or 100, 400, 600). In some examples, the baffles 710 include openings 712 and are spaced apart as shown (or in other manners) to allow specific or controlled flow of gas through the openings 712 or through the baffles 710 within spaced gaps therebetween.

[0053] FIG. 10 illustrates an embodiment of an exemplary arrangement 1000 for friction stir welding. In some examples, a heater coil 1002 (e.g., one of the heater coils 108, FIG. 1 ) is activated during friction stir welding of a base component with an FSW tool 1004 to control the cooling behavior and grain growth or size around the FSW weld. The FSW tool 1004 may include a shoulder 1006 and a pin 1008, as previously described. Traditionally, FSW joints remain cooled by natural convection, and in current situations, process control for the weld zone typically does not exist. In some examples of the present disclosure, activation of the heater coil 1002 during the FSW process can control (e.g., slow) the cooling rate of the FSW weld, define or provide a specific heat-affected zone, and improve weld quality and material properties, for example, by controlling grain growth during weld solidification.

[0054] 11 , an exemplary method 1100 of forming a showerhead pedestal assembly for a substrate processing chamber includes: providing a faceplate in operation 1102; providing a platen disposed within the faceplate in operation 1104, the platen including a heater element extending through at least one groove in the faceplate, the at least one groove being profiled to receive at least a portion of the heater element extending through the groove; providing a power source for the heater element in operation 1106; and joining a periphery of the platen to an inner surface of the faceplate by friction stir welding in operation 1108.

[0055] In some examples, the method 1100 further includes forming a plurality of openings in the faceplate to allow gas to pass through the showerhead pedestal assembly to an underside of a substrate supported by the showerhead pedestal assembly.

[0056] In some examples, the method 1100 further includes forming, by friction stir welding, a plurality of heat transfer posts extending between the faceplate and opposing surfaces of the platen.

[0057] In some instances, the friction stir weld includes a material that is different from the material of the faceplate or platen, allowing for the formation of a friction stir weld joint between the faceplate and the platen.

[0058] In some examples, the method 1100 further includes selecting a material for the plurality of heat transfer posts to enhance or retard heat transfer between the faceplate and the platen.

[0059] In some examples, the material of the plurality of heat transfer posts is the same as the material of the heater coil.

[0060] In some examples, the method 1100 further includes providing a filler cap for the showerhead pedestal assembly, the filler cap including at least one baffle sized and configured to reside in the at least one groove in the faceplate.

[0061] In some examples, at least one baffle of the filler cap secures at least a portion of the heater coil in a respective groove in the faceplate.

[0062] In some examples, at least one baffle includes a curved feature that matches the profile of a respective groove in the faceplate.

[0063] In some examples, the method 1100 further includes forming the at least one baffle by friction stir welding.

[0064] In some examples, the method 1100 further includes providing at least one baffle along a top surface of the filler cap.

[0065] In some examples, a portion of the filler cap includes a heat sink that provides a body of material that is relatively cooler than the material of the platen during operation of the showerhead pedestal assembly.

[0066] In some examples, the at least one baffle includes at least one opening that allows gas to pass through.

[0067] In some examples, the at least one baffle is provided in a series of baffles arranged in a spaced apart arrangement extending along the profile of the heater element, the spaced apart arrangement of baffles including one or more gaps between successive baffles to allow gas to pass therethrough.

[0068] In some examples, the material involved in the friction stir weld of at least one baffle is different from the material of the faceplate or heater element, enabling the formation of a friction stir weld joint between the heater element and the faceplate.

[0069] In some examples, the at least one baffle is included in multiple concentric rings of baffles.

[0070] In some examples, at least one ring of the plurality of concentric rings of baffles includes spaced baffles.

[0071] In some examples, each of the spaced baffles includes one or more openings formed therein to allow a specific or controlled flow of gas through the one or more openings.

[0072] In some examples, the gap between a pair of spaced-apart baffles in at least one concentric ring of baffles is sized to allow a specific or controlled flow of gas to pass therethrough.

[0073] In some examples, the method 1100 further includes energizing the heater element with a power source during friction stir welding to form the friction stir welded joint.

[0074] FIG. 9 is a block diagram illustrating an example of a machine 900 capable of implementing one or more exemplary process embodiments described herein or capable of controlling one or more exemplary process embodiments described herein. In alternative embodiments, the machine 900 may operate as a standalone device or may be connected (e.g., networked) to other machines. In a network deployment, the machine 900 may operate in the capacity of a server machine, a client machine, or both in a server-client network environment. In one example, the machine 900 may operate as a peer machine in a peer-to-peer (P2P) (or other distributed) network environment. Furthermore, while only a single machine 900 is shown, the term “machine” should also be interpreted to include any collection of machines individually or collectively executing a set (or sets) of instructions 924 to implement any one or more of the methodologies discussed herein, such as via cloud computing, software as a service (SaaS), or other computer cluster configuration.

[0075] The examples described herein may include or operate by logic and / or several components or mechanisms. A circuit set is a collection of circuits implemented in a tangible entity including hardware (e.g., simple circuits, gates, logic, etc.). The membership of a circuit set can flexibly accommodate the passage of time and variability of the underlying hardware. A circuit set includes members that, alone or in combination, can perform a specific operation when in operation. In one example, the hardware of a circuit set may be invariably designed (e.g., hardwired) to perform a specific operation. In one example, the hardware of a circuit set may include variably connected physical components (e.g., execution units, transistors, simple circuits, etc.) including computer-readable media that have been physically modified (e.g., magnetically, electrically, by a movable arrangement of invariant mass particles, etc.) to encode instructions 924 for a specific operation. When connecting the physical components, the underlying electrical properties of the hardware components are changed (e.g., from an insulator to a conductor or vice versa). The instructions 924 enable embedded hardware (e.g., an execution unit or loading mechanism) to create members of the circuit set within the hardware via variable connections and perform some of the specific operations during operation. Thus, the computer-readable medium is communicatively coupled to other components of the circuit set when the device is operating. In one example, any of the physical components may be used by multiple members of multiple circuit sets. For example, during operation, an execution unit may be used by a first circuit of a first circuit set at one time and reused by a second circuit in the first circuit set or a third circuit in the second circuit set at another time.

[0076] The machine (e.g., a computer system) 900 may include a hardware processor 902 (e.g., a central processing unit (CPU), a hardware processor core, or any combination thereof), a graphics processing unit (GPU) 903, a main memory 904, and a static memory 906, some or all of which may communicate with each other via an interlink (e.g., a bus) 908. The machine 900 may further include a display device 910, an alphanumeric input device 912 (e.g., a keyboard), and a user interface (UI) navigation device 914 (e.g., a mouse). In one example, the display device 910, the alphanumeric input device 912, and the UI navigation device 914 may be touchscreen displays. The machine 900 may further include a mass storage device (e.g., a drive unit) 916, a signal generating device 918 (e.g., a speaker), a network interface device 920, and one or more sensors 921 (such as a global positioning system (GPS) sensor, a compass, an accelerometer, or another sensor). The machine 900 may include an output controller 928, such as a serial (e.g., Universal Serial Bus (USB)), parallel, or other wired or wireless (e.g., infrared (IR), near field communication (NFC), etc.) connection, for communicating with or controlling one or more peripheral devices (e.g., printer, card reader, etc.).

[0077] The mass storage device 916 may include a machine-readable medium 922. The machine-readable medium 922 stores one or more sets of data structures or instructions 924 (e.g., software) that embody or are utilized by any one or more of the techniques or functions described herein. The instructions 924 may also reside, completely or at least partially, within the main memory 904, static memory 906, hardware processor 902, or GPU 903 during execution by the machine 900. In one example, the machine-readable medium 922 may be constituted by any one or combination of the hardware processor 902, GPU 903, main memory 904, static memory 906, or mass storage device 916.

[0078] Although the machine-readable medium 922 is shown as a single medium, the term “machine-readable medium” may include a single medium or multiple media (e.g., a centralized or distributed database, and / or associated caches and servers) configured to store one or more instructions 924.

[0079] The term “machine-readable medium” may include any medium capable of storing, encoding, or carrying instructions 924 for execution by machine 900 and causing machine 900 to perform any one or more of the techniques of this disclosure, or any medium capable of storing, encoding, or carrying data structures used by or related to such instructions 924. Non-limiting examples of machine-readable media include solid-state memory, optical media, and magnetic media. In one example, a high-capacity machine-readable medium includes a machine-readable medium 922 having a plurality of particles with an unchanging (e.g., stationary) mass. Thus, a high-capacity machine-readable medium is not a transiently propagating signal. Specific examples of high-capacity machine-readable media include non-volatile memory such as semiconductor memory devices (e.g., electrically programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM)) and flash memory devices, magnetic disks such as internal hard disks and removable disks, magneto-optical disks, and CD-ROM and DVD-ROM disks. Additionally, the instructions 924 may be transmitted or received over a communications network 926 via the network interface device 920 using a transmission medium.

[0080] While the embodiments have been described with reference to certain exemplary embodiments, it will be apparent that various modifications and changes can be made to these embodiments without departing from the broader scope of the present disclosure. Accordingly, the specification and drawings are to be considered in an illustrative and not a restrictive sense. The accompanying drawings, which form a part of this specification, show, by way of example, and not by way of limitation, specific embodiments in which the subject matter may be practiced. The illustrated embodiments are described in sufficient detail to enable those skilled in the art to practice the teachings disclosed herein. Other embodiments may be utilized and derived from the teachings disclosed herein, such that structural and logical substitutions and changes can be made without departing from the scope of the present disclosure. Therefore, this detailed description is not to be construed in a limiting sense, and the scope of various embodiments is defined only by the appended claims, along with the full range of equivalents to which such claims are entitled.

[0081] Although such embodiments of the inventive subject matter may be individually and / or collectively referred to herein by the term "invention," this is merely a matter of convenience and is not intended to voluntarily limit the scope of this application to any single invention or inventive concept (if in fact multiple are disclosed). Accordingly, although specific embodiments have been illustrated and described herein, it should be understood that any configurations calculated to achieve the same purpose may be substituted for the specific embodiment shown. The present disclosure is intended to cover all adaptations or variations of various embodiments. Combinations of the above embodiments with other embodiments not specifically described herein will be apparent to those of skill in the art upon reviewing the above description. The present disclosure can also be realized in the following forms. [Form 1] 1. A showerhead pedestal assembly for a substrate processing chamber, comprising: A face plate and a platen disposed within the faceplate, the platen including a heater element extending through at least one groove in the faceplate, the at least one groove being profiled to receive at least a portion of the heater element extending through the groove; a power source for said heater element; Including, the periphery of the platen is joined to the inner surface of the faceplate by a friction stir welded joint; Shower head pedestal assembly. [Form 2] 10. The showerhead base assembly of claim 1, a showerhead pedestal assembly, wherein the faceplate includes a plurality of openings that allow gases to pass through the showerhead pedestal assembly to an underside of a substrate supported by the showerhead pedestal assembly. [Form 3] 10. The showerhead base assembly of claim 1, The showerhead pedestal assembly further comprises a plurality of heat transfer posts extending between the faceplate and opposing surfaces of the platen, the plurality of heat transfer posts comprising friction stir welding material. [Form 4] 4. The showerhead base assembly of claim 3, A showerhead pedestal assembly, wherein the friction stir welding material is different from the material of the faceplate or the platen, enabling the formation of a friction stir welded joint between the faceplate and the platen. [Form 5] 4. The showerhead base assembly of claim 3, A showerhead pedestal assembly, wherein a material of the plurality of heat transfer posts is selected to enhance or retard heat transfer between the faceplate and the platen. [Form 6] 4. The showerhead base assembly of claim 3, The showerhead pedestal assembly, wherein the material of the plurality of heat transfer posts is the same as the material of the heater element. [Form 7] 10. The showerhead base assembly of claim 1, The showerhead pedestal assembly further comprising a filler cap including at least one baffle sized and configured to reside in the at least one groove in the faceplate. [Form 8] 8. The showerhead base assembly of claim 7, the at least one baffle of the filler cap secures the at least a portion of the heater element in a respective groove in the faceplate. [Form 9] 9. The showerhead base assembly of claim 8, The showerhead pedestal assembly, wherein the at least one baffle includes a curved formation that matches a profile of the respective groove in the faceplate. [Form 10] 8. The showerhead base assembly of claim 7, The showerhead pedestal assembly, wherein the at least one baffle comprises a friction stir welded material. [Form 11] 8. The showerhead base assembly of claim 7, The showerhead pedestal assembly, wherein the at least one baffle is disposed along an upper surface of the filler cap. [Form 12] 8. The showerhead base assembly of claim 7, A showerhead pedestal assembly, wherein a portion of the filler cap includes a heat sink, the heat sink providing a body of material that is relatively cooler than a material of the platen during operation of the showerhead pedestal assembly. [Form 13] 8. The showerhead base assembly of claim 7, the at least one baffle includes at least one opening that allows gas to pass therethrough. [Form 14] 8. The showerhead base assembly of claim 7, the at least one baffle is provided by a series of baffles arranged in a spaced-apart relationship extending along a profile of the heater element, the spaced-apart arrangement of baffles including one or more gaps between successive baffles to allow gases to pass therethrough. [Form 15] 11. The showerhead pedestal assembly of claim 10, a friction stir welded joint between the heater element and the faceplate; [Form 16] 8. The showerhead base assembly of claim 7, The showerhead pedestal assembly, wherein the at least one baffle is included in a plurality of concentric rings of baffles. [Form 17] 17. The showerhead pedestal assembly of claim 16, A showerhead pedestal assembly, wherein at least one ring of the plurality of concentric rings of baffles includes spaced apart baffles. [Form 18] 18. The showerhead pedestal assembly of claim 17, A showerhead pedestal assembly, wherein each of the spaced baffles includes one or more openings formed therein to allow a specific or controlled flow of gas through the one or more openings. [Form 19] 18. The showerhead pedestal assembly of claim 17, A showerhead pedestal assembly, wherein a gap between a pair of spaced-apart baffles in said at least one concentric ring of baffles is sized to allow a specific or controlled flow of gas to pass therethrough. [Form 20] 10. The showerhead base assembly of claim 1, The heater element is energized by the power source during formation of the friction stir welded joint. [Form 21] 1. A method of forming a showerhead pedestal assembly for a substrate processing chamber, comprising: providing a faceplate; providing a platen disposed within the faceplate, the platen including a heater element extending through at least one groove in the faceplate, the at least one groove being profiled to receive at least a portion of the heater element extending through the groove; Providing a power supply for the heater element; Including, the periphery of the platen is joined to the inner surface of the faceplate by friction stir welding; method. [Form 22] 22. The method of claim 21, forming a plurality of openings in the faceplate to allow gas to pass through the showerhead pedestal assembly to an underside of a substrate supported by the showerhead pedestal assembly. [Form 23] 22. The method of claim 21, The method further includes forming, by friction stir welding, a plurality of heat transfer posts extending between the faceplate and opposing surfaces of the platen. [Form 24] 24. The method of claim 23, The method wherein the friction stir weld includes a material different from a material of the faceplate or the platen, allowing for the formation of a friction stir weld joint between the faceplate and the platen. [Form 25] 24. The method of claim 23, The method further includes selecting a material for the plurality of heat transfer posts to enhance or retard heat transfer between the faceplate and the platen. [Form 26] 24. The method of claim 23, The method, wherein the material of the plurality of heat transfer posts is the same as the material of the heater element. [Form 27] 22. The method of claim 21, The method further includes providing a filler cap for the showerhead pedestal assembly, the filler cap including at least one baffle sized and configured to reside in the at least one groove in the faceplate. [Form 28] 28. The method of claim 27, The at least one baffle of the filler cap secures at least a portion of the heater element in a respective groove in the faceplate. [Form 29] 29. The method of claim 28, The method, wherein the at least one baffle includes a curved feature, the curved feature matching a profile of the respective groove in the faceplate. [Form 30] 28. The method of claim 27, The method further comprising forming the at least one baffle by friction stir welding. [Form 31] 28. The method of claim 27, The method further comprising providing the at least one baffle along a top surface of the filler cap. [Form 32] 28. The method of claim 27, A portion of the filler cap includes a heat sink, the heat sink providing a body of material that is relatively cooler than a material of the platen during operation of the showerhead pedestal assembly. [Form 33] 28. The method of claim 27, The method wherein the at least one baffle includes at least one opening that allows gas to pass therethrough. [Form 34] 28. The method of claim 27, wherein the at least one baffle is provided by a series of baffles extending in a spaced arrangement along a profile of the heater element, the spaced arrangement of baffles including one or more gaps between successive baffles to allow gas to pass therethrough. [Form 35] 31. The method of claim 30, wherein a material involved in the friction stir weld of the at least one baffle is different from a material of the face plate or the heater element, enabling formation of a friction stir welded joint between the heater element and the face plate. [Form 36] 28. The method of claim 27, The method, wherein the at least one baffle is included in a plurality of concentric rings of baffles. [Form 37] 37. The method of claim 36, The method wherein at least one ring of the plurality of concentric rings of baffles includes spaced baffles. [Form 38] 38. The method of claim 37, wherein each of the spaced baffles includes one or more openings formed therein to allow a specific or controlled flow of gas through the one or more openings. [Form 39] 38. The method of claim 37, A method wherein a gap between a pair of spaced apart baffles in said at least one concentric ring of baffles is sized to allow a specific or controlled flow of gas to pass therethrough. [Form 40] 22. The method of claim 21, The method further includes energizing the heater element with the power source during the friction stir welding to form a friction stir welded joint.

Claims

1. 1. A showerhead pedestal assembly for a substrate processing chamber, comprising: A face plate and a platen connected to the faceplate, the platen including at least one groove, a heater element at least partially disposed within the at least one groove, and a filler cap at least partially disposed within the at least one groove to secure the heater element within the at least one groove, the at least one groove being profiled to receive at least a portion of the heater element, the filler cap being secured to the platen by a friction stir welded joint, the filler cap including at least one baffle protruding from the platen; A shower head base assembly comprising:

2. 10. The showerhead pedestal assembly of claim 1, the faceplate includes a plurality of openings distributed across a surface of the faceplate facing away from the platen, the plurality of openings configured to allow gas flow through the showerhead pedestal assembly and away from the surface of the faceplate facing away from the platen.

3. 10. The showerhead pedestal assembly of claim 1, the heater elements follow curvilinear paths distributed across the platen; At least a portion of the filler cap follows the curved path.

4. 4. The showerhead pedestal assembly of claim 3, The showerhead pedestal assembly, wherein the curved path is a serpentine path.

5. 5. The showerhead pedestal assembly of claim 3 or 4, the heater element includes at least a first segment following a first arcuate path, a second segment following a second arcuate path, and a third segment following a third arcuate path, the first arcuate path, the second arcuate path, and the third arcuate path being concentric with one another and each having a different radius.

6. 6. The showerhead pedestal assembly of claim 5, the heater element further includes a fourth segment following a fourth arcuate path and a fifth segment following a fifth arcuate path, the fourth arcuate path and the fifth arcuate path being concentric with one another, the fourth arcuate path and the second arcuate path having the same radius, and the fifth arcuate path and the third arcuate path having the same radius.

7. 10. The showerhead pedestal assembly of claim 1, the at least one baffle includes a curved formation, the curved formation matching a profile of a respective portion of the at least one groove in the platen.

8. 10. The showerhead pedestal assembly of claim 1, The showerhead pedestal assembly, wherein the at least one baffle comprises a friction stir welded material.

9. 10. The showerhead pedestal assembly of claim 1, the at least one baffle is disposed along an upper surface of the filler cap.

10. 10. The showerhead pedestal assembly of claim 1, A showerhead pedestal assembly, wherein a portion of the filler cap includes a heat sink.

11. 10. The showerhead pedestal assembly of claim 1, the at least one baffle includes at least one opening that allows gas to pass therethrough.

12. 10. The showerhead pedestal assembly of claim 1, the at least one baffle is provided by a series of baffles arranged in spaced relation extending along a path followed by the heater element, the spaced arrangement of baffles including one or more gaps between successive baffles to allow gases to pass therethrough.

13. 9. The showerhead pedestal assembly of claim 8, the friction stir weld material of the at least one baffle is different from a material of the faceplate or the heater element, enabling formation of a friction stir weld joint between the heater element and the faceplate.

14. 10. The showerhead pedestal assembly of claim 1, The showerhead pedestal assembly, wherein the at least one baffle comprises a plurality of concentric rings of baffles.

15. 15. The showerhead pedestal assembly of claim 14, At least one of the plurality of concentric rings of baffles includes spaced apart baffles.

16. 16. The showerhead pedestal assembly of claim 15, a showerhead pedestal assembly, wherein each of the spaced baffles includes one or more openings formed therein to allow a specific or controlled flow of gas through the one or more openings.

17. 16. The showerhead pedestal assembly of claim 15, a gap between a pair of the spaced-apart baffles in at least one ring of the baffles is sized to allow a specific or controlled flow of gas to pass therethrough.

18. 10. The showerhead pedestal assembly of claim 1, a power source connected to the heater element; The heater element is energized by the power source during formation of the friction stir welded joint.

19. 1. A method of forming a showerhead pedestal assembly for a substrate processing chamber, comprising: providing a faceplate; connecting a platen with the faceplate, the platen including a heater element extending through at least one groove in the platen, the at least one groove being profiled to receive at least a portion of the heater element extending through the groove; attaching a filler cap to the at least one groove to secure the heater element in the at least one groove, the filler cap including at least one baffle that protrudes from the platen after the filler cap is attached; forming a friction stir welded joint between the filler cap and the platen; A method comprising:

20. 20. The method of claim 19, further comprising: The method further includes forming a plurality of openings in the faceplate to allow gas to pass through the showerhead pedestal assembly to an underside of a substrate supported by the showerhead pedestal assembly.

21. 20. The method of claim 19, the heater elements follow curvilinear paths distributed across the platen; At least a portion of the filler cap follows the curved path.

22. 22. The method of claim 21, The method wherein the curved path is a serpentine path.

23. 22. The method of claim 21, the heater element includes at least a first segment following a first arcuate path, a second segment following a second arcuate path, and a third segment following a third arcuate path, the first arcuate path, the second arcuate path, and the third arcuate path being concentric with one another and each having a different radius.

24. 24. The method of claim 23, the heater element further includes a fourth segment following a fourth arcuate path and a fifth segment following a fifth arcuate path, the fourth arcuate path and the fifth arcuate path being concentric with one another, the fourth arcuate path and the second arcuate path having the same radius, and the fifth arcuate path and the third arcuate path having the same radius.

25. 20. The method of claim 19, The method, wherein the at least one baffle includes a curved formation, the curved formation matching a profile of a respective portion of the at least one groove in the platen.

26. 20. The method of claim 19, The method further comprising forming the at least one baffle by friction stir welding.

27. 27. The method of claim 26, wherein a material involved in the friction stir weld of the at least one baffle is different from a material of the face plate or the heater element, enabling formation of a friction stir weld joint between the heater element and the face plate.

28. 20. The method of claim 19, The method further comprising providing the at least one baffle along a top surface of the filler cap.

29. 20. The method of claim 19, A method, wherein a portion of the filler cap includes a heat sink.

30. 20. The method of claim 19, The method wherein the at least one baffle includes at least one opening that allows gas to pass therethrough.

31. 20. The method of claim 19, wherein the at least one baffle is provided in a series of baffles extending in a spaced arrangement along a path followed by the heater element, the spaced arrangement of baffles including one or more gaps between successive baffles to allow gas to pass therethrough.

32. 20. The method of claim 19, The method, wherein the at least one baffle comprises a plurality of concentric rings of baffles.

33. 33. The method of claim 32, The method wherein at least one ring of the plurality of concentric rings of baffles includes spaced baffles.

34. 34. The method of claim 33, wherein each of said spaced apart baffles includes one or more openings formed therein to allow a specific or controlled flow of gas through said one or more openings.

35. 34. The method of claim 33, A method wherein a gap between a pair of said spaced apart baffles in at least one ring of said baffles is sized to allow a specific or controlled flow of gas to pass therethrough.

36. 20. The method of claim 19, The method further includes providing a power source for the heater element and energizing the heater element with the power source during formation of the friction stir welded joint.

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