Patent Publication Number: US-2023135935-A1

Title: Monolithic modular microwave source with integrated temperature control

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a Continuation of U.S. patent application Ser. No. 16/586,548, filed on Sep. 27, 2019, the entire contents of which are hereby incorporated by reference herein. 
    
    
     BACKGROUND 
     1) Field 
     Embodiments relate to the field of semiconductor manufacturing and, in particular, to monolithic source arrays with integrated temperature control for high-frequency sources. 
     2) Description of Related Art 
     Some high-frequency plasma sources include applicators that pass through an opening in a dielectric plate. The opening through the dielectric plate allows for the applicator (e.g., a dielectric cavity resonator) to be exposed to the plasma environment. However, it has been shown that plasma is also generated in the opening in the dielectric plate in the space surrounding the applicator. This has the potential of generating plasma non-uniformities within the processing chamber. Furthermore, exposing the applicator to the plasma environment may lead to a more rapid degradation of the applicator. 
     In some embodiments, the applicators are positioned over the dielectric plate or within a cavity into (but not through) the dielectric plate. Such configurations have reduced coupling with the interior of the chamber and, therefore, does not provide an optimum plasma generation. The coupling of the high-frequency electromagnetic radiation with the interior of the chamber is diminished in part due to the additional interface between the dielectric plate and the applicator across which the high-frequency electromagnetic radiation needs to propagate. Additionally, variations of the interface (e.g., positioning of the applicator, surface roughness of the applicator and/or the dielectric plate, angle of the applicator relative to the dielectric plate, etc.) at each applicator and across different processing tools may result in plasma non-uniformities. 
     Particularly, when the applicators are discrete components from the dielectric plate, plasma non-uniformity (within a single processing chamber and/or across different processing chambers (e.g., chamber matching)) is more likely to occur. For example, with discrete components, small variations (e.g., variations in assembly, machining tolerances, etc.) can result in plasma non-uniformities that negatively affect processing conditions within the chamber. 
     SUMMARY 
     Embodiments disclosed herein include a housing for a source assembly. In an embodiment, the housing comprises a conductive body with a first surface and a second surface opposite from the first surface, and a plurality of openings through a thickness of the conductive body between the first surface and the second surface. In an embodiment, the housing further comprises a channel into the first surface of the conductive body, and a cover over the channel. In an embodiment, a first stem over the cover extends away from the first surface, and a second stem over the cover extends away from the first surface. In an embodiment, the first stem and the second stem open into the channel. 
     Embodiments may also include an assembly for a processing tool. In an embodiment, the assembly comprises a monolithic source array and a housing. In an embodiment, the monolithic source array comprises a dielectric plate having a first surface and a second surface, and a plurality of protrusions extending out from the first surface of the dielectric plate. In an embodiment, the housing comprises a conductive body having a third surface and a fourth surface, and a plurality of openings through the conductive body. In an embodiment, each of the protrusions is within a different one of the openings. The housing may also comprise a channel into the third surface, and a cover over the channel, the cover comprising a first stem and a second stem. 
     Embodiments disclosed herein may also comprise a processing tool. In an embodiment, the processing tool comprises a chamber and an assembly interfacing with the chamber. In an embodiment, the assembly comprises a monolithic source array, a housing over and around the monolithic source array. In an embodiment, the housing comprises a channel that is sealed by a cover. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic illustration of a processing tool that comprises a modular high-frequency emission source with a monolithic source array that comprises a plurality of applicators, in accordance with an embodiment. 
         FIG.  2    is a block diagram of a modular high-frequency emission module, in accordance with an embodiment. 
         FIG.  3    is an exploded perspective view illustration of an assembly, in accordance with an embodiment. 
         FIG.  4 A  is a plan view illustration of a lid plate with embedded heating elements, in accordance with an embodiment. 
         FIG.  4 B  is a cross-sectional illustration of the lid plate in  FIG.  4 A  along line B-B′, in accordance with an embodiment. 
         FIG.  5 A  is an exploded perspective view illustration of a housing, in accordance with an embodiment. 
         FIG.  5 B  is a perspective view illustration of a portion of an assembly, in accordance with an embodiment. 
         FIG.  5 C  is a cross-sectional illustration of the assembly in  FIG.  5 B  along line C-C′, in accordance with an embodiment. 
         FIG.  6    is a cross-sectional illustration of an assembly, in accordance with an embodiment. 
         FIG.  7    is a cross-sectional illustration of a processing tool with an assembly that comprises integrated temperature control, in accordance with an embodiment. 
         FIG.  8    illustrates a block diagram of an exemplary computer system that may be used in conjunction with a high-frequency plasma tool, in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Systems described herein include monolithic source arrays with integrated temperature control for high-frequency sources. In the following description, numerous specific details are set forth in order to provide a thorough understanding of embodiments. It will be apparent to one skilled in the art that embodiments may be practiced without these specific details. In other instances, well-known aspects are not described in detail in order to not unnecessarily obscure embodiments. Furthermore, it is to be understood that the various embodiments shown in the accompanying drawings are illustrative representations and are not necessarily drawn to scale. 
     As noted above, high-frequency plasma sources with discrete applicators may result in plasma non-uniformities within a chamber and in non-optimum injection of the high-frequency electromagnetic radiation into the chamber. The non-uniformities in the plasma may arise for different reasons, such as assembly issues, manufacturing tolerances, degradation, and the like. The non-optimum injection of the high-frequency electromagnetic radiation into the chamber may result (in part) from the interface between the applicator and the dielectric plate. 
     Accordingly, embodiments disclosed herein include a monolithic source array. In an embodiment, the monolithic source array comprises a dielectric plate and a plurality of protrusions that extend up from a surface of the dielectric plate. Particularly, the protrusions and the dielectric plate form a monolithic part. That is, the protrusions and the dielectric plate are fabricated from a single block of material. The protrusions have dimensions suitable for being used as the applicators. For example, holes into the protrusions may be fabricated that accommodate a monopole antenna. The protrusions may, therefore, function as a dielectric cavity resonator. 
     Implementing the source array as a monolithic part has several advantages. One benefit is that tight machining tolerances may be maintained in order to provide a high degree of uniformity between parts. Whereas discrete applicators need assembly, the monolithic source array avoids possible assembly variations. Additionally, the use of a monolithic source array provides improved injection of high-frequency electromagnetic radiation into the chamber, because there is no longer a physical interface between the applicator and the dielectric plate. 
     Monolithic source arrays also provide improved plasma uniformity in the chamber. Particularly, the surface of the dielectric plate that is exposed to the plasma does not include any gaps to accommodate the applicators. Furthermore, the lack of a physical interface between the protrusions and the dielectric plate improves lateral electric field spreading in the dielectric plate. 
     For many applications, temperature uniformity of the workpiece is another requirement in addition to plasma uniformities. Without adequate temperature control, processing outcomes may not be able to meet specifications. For some applications, the surface of the plasma source is directly over the workpiece with only a small gap (e.g., approximately 5 cm or less) separating the two surfaces. Such small gaps facilitate heat transfer (i.e., radiation and convection) from the workpiece to the source, or from the source to the workpiece. The ability to provide a uniform temperature at the surface of the source is therefore very beneficial. Temperature uniformity is particularly critical for certain processing operations, such as atomic layer deposition (ALD), chemical vapor deposition (CVD), and plasma treatments, to name a few. 
     Accordingly, embodiments disclosed herein include a monolithic source array with integrated temperature control. In some embodiments, a housing that surrounds protrusions of the monolithic source array comprises a plurality of channels for routing thermal fluid through the conductive body of the housing. Embodiments may also include an embedded heater. As such, the temperature of the monolithic source array may be increased or decreased. 
     Referring now to  FIG.  1   , a cross-sectional illustration of a plasma processing tool  100  is shown, according to an embodiment. In some embodiments, the processing tool  100  may be a processing tool suitable for any type of processing operation that utilizes a plasma. For example, the processing tool  100  may be a processing tool used for plasma enhanced chemical vapor deposition (PECVD), plasma enhanced atomic layer deposition (PEALD), etch and selective removal processes, and plasma cleaning. Additional embodiments may include a processing tool  100  that utilizes high-frequency electromagnetic radiation without the generation of a plasma (e.g., microwave heating, etc.). As used herein, “high-frequency” electromagnetic radiation includes radio frequency radiation, very-high-frequency radiation, ultra-high-frequency radiation, and microwave radiation. “High-frequency” may refer to frequencies between 0.1 MHz and 300 GHz. 
     Generally, embodiments include a processing tool  100  that includes a chamber  178 . In processing tools  100 , the chamber  178  may be a vacuum chamber. A vacuum chamber may include a pump (not shown) for removing gases from the chamber to provide the desired vacuum. Additional embodiments may include a chamber  178  that includes one or more gas lines  170  for providing processing gasses into the chamber  178  and exhaust lines  172  for removing byproducts from the chamber  178 . While not shown, it is to be appreciated that gas may also be injected into the chamber  178  through a monolithic source array  150  (e.g., as a showerhead) for evenly distributing the processing gases over a substrate  174 . 
     In an embodiment, the substrate  174  may be supported on a chuck  176 . For example, the chuck  176  may be any suitable chuck, such as an electrostatic chuck. The chuck  176  may also include cooling lines and/or a heater to provide temperature control to the substrate  174  during processing. Due to the modular configuration of the high-frequency emission modules described herein, embodiments allow for the processing tool  100  to accommodate any sized substrate  174 . For example, the substrate  174  may be a semiconductor wafer (e.g., 200 mm, 300 mm, 450 mm, or larger). Alternative embodiments also include substrates  174  other than semiconductor wafers. For example, embodiments may include a processing tool  100  configured for processing glass substrates, (e.g., for display technologies). 
     According to an embodiment, the processing tool  100  includes a modular high-frequency emission source  104 . The modular high-frequency emission source  104  may comprise an array of high-frequency emission modules  105 . In an embodiment, each high-frequency emission module  105  may include an oscillator module  106 , an amplification module  130 , and an applicator  142 . As shown, the applicators  142  are schematically shown as being integrated into the monolithic source array  150 . However, it is to be appreciated that the monolithic source array  150  may be a monolithic structure that comprises one or more portions of the applicator  142  (e.g., a dielectric resonating body) and a dielectric plate that faces the interior of the chamber  178 . 
     In an embodiment, the oscillator module  106  and the amplification module  130  may comprise electrical components that are solid state electrical components. In an embodiment, each of the plurality of oscillator modules  106  may be communicatively coupled to different amplification modules  130 . In some embodiments, there may be a 1:1 ratio between oscillator modules  106  and amplification modules  130 . For example, each oscillator module  106  may be electrically coupled to a single amplification module  130 . In an embodiment, the plurality of oscillator modules  106  may generate incoherent electromagnetic radiation. Accordingly, the electromagnetic radiation induced in the chamber  178  will not interact in a manner that results in an undesirable interference pattern. 
     In an embodiment, each oscillator module  106  generates high-frequency electromagnetic radiation that is transmitted to the amplification module  130 . After processing by the amplification module  130 , the electromagnetic radiation is transmitted to the applicator  142 . In an embodiment, the applicators  142  each emit electromagnetic radiation into the chamber  178 . In some embodiments, the applicators  142  couple the electromagnetic radiation to the processing gasses in the chamber  178  to produce a plasma. 
     Referring now to  FIG.  2   , a schematic of a solid state high-frequency emission module  105  is shown, in accordance with an embodiment. In an embodiment, the high-frequency emission module  105  comprises an oscillator module  106 . The oscillator module  106  may include a voltage control circuit  210  for providing an input voltage to a voltage controlled oscillator  220  in order to produce high-frequency electromagnetic radiation at a desired frequency. Embodiments may include an input voltage between approximately 1V and 10V DC. The voltage controlled oscillator  220  is an electronic oscillator whose oscillation frequency is controlled by the input voltage. According to an embodiment, the input voltage from the voltage control circuit  210  results in the voltage controlled oscillator  220  oscillating at a desired frequency. In an embodiment, the high-frequency electromagnetic radiation may have a frequency between approximately 0.1 MHz and 30 MHz. In an embodiment, the high-frequency electromagnetic radiation may have a frequency between approximately 30 MHz and 300 MHz. In an embodiment, the high-frequency electromagnetic radiation may have a frequency between approximately 300 MHz and 1 GHz. In an embodiment, the high-frequency electromagnetic radiation may have a frequency between approximately 1 GHz and 300 GHz. 
     According to an embodiment, the electromagnetic radiation is transmitted from the voltage controlled oscillator  220  to an amplification module  130 . The amplification module  130  may include a driver/pre-amplifier  234 , and a main power amplifier  236  that are each coupled to a power supply  239 . According to an embodiment, the amplification module  130  may operate in a pulse mode. For example, the amplification module  130  may have a duty cycle between 1% and 99%. In a more particular embodiment, the amplification module  130  may have a duty cycle between approximately 15% and 50%. 
     In an embodiment, the electromagnetic radiation may be transmitted to the thermal break  249  and the applicator  142  after being processed by the amplification module  130 . However, part of the power transmitted to the thermal break  249  may be reflected back due to the mismatch in the output impedance. Accordingly, some embodiments include a detector module  281  that allows for the level of forward power  283  and reflected power  282  to be sensed and fed back to the control circuit module  221 . It is to be appreciated that the detector module  281  may be located at one or more different locations in the system (e.g., between the circulator  238  and the thermal break  249 ). In an embodiment, the control circuit module  221  interprets the forward power  283  and the reflected power  282 , and determines the level for the control signal  285  that is communicatively coupled to the oscillator module  106  and the level for the control signal  286  that is communicatively coupled to the amplification module  130 . In an embodiment, control signal  285  adjusts the oscillator module  106  to optimize the high-frequency radiation coupled to the amplification module  130 . In an embodiment, control signal  286  adjusts the amplification module  130  to optimize the output power coupled to the applicator  142  through the thermal break  249 . In an embodiment, the feedback control of the oscillator module  106  and the amplification module  130 , in addition to the tailoring of the impedance matching in the thermal break  249  may allow for the level of the reflected power to be less than approximately 5% of the forward power. In some embodiments, the feedback control of the oscillator module  106  and the amplification module  130  may allow for the level of the reflected power to be less than approximately 2% of the forward power. 
     Accordingly, embodiments allow for an increased percentage of the forward power to be coupled into the processing chamber  178 , and increases the available power coupled to the plasma. Furthermore, impedance tuning using a feedback control is superior to impedance tuning in typical slot-plate antennas. In slot-plate antennas, the impedance tuning involves moving two dielectric slugs formed in the applicator. This involves mechanical motion of two separate components in the applicator, which increases the complexity of the applicator. Furthermore, the mechanical motion may not be as precise as the change in frequency that may be provided by a voltage controlled oscillator  220 . 
     Referring now to  FIG.  3   , an exploded perspective view illustration of an assembly  370  is shown, in accordance with an embodiment. In an embodiment, the assembly  370  comprises a monolithic source array  350 , a housing  372 , and a lid plate  376 . As indicated by the arrows, the housing  372  fits over and around the monolithic source array  350 , and the lid plate  376  covers the housing  372 . In the illustrated embodiment, the assembly  370  is shown as having a substantially circular shape. However, it is to be appreciated that the assembly  370  may have any desired shape (e.g., polygonal, elliptical, wedge shaped, or the like). 
     In an embodiment, the monolithic source array  350  may comprise a dielectric plate  360  and a plurality of protrusions  366  that extend up from the dielectric plate  360 . In an embodiment, the dielectric plate  360  and the plurality of protrusions  366  are a monolithic structure. That is, there is no physical interface between a bottom of the protrusions  366  and the dielectric plate  360 . As used herein, a “physical interface” refers to a first surface of a first discrete body contacting a second surface of a second discrete body. 
     Each of the protrusions  366  are a portion of the applicator  142  used to inject high-frequency electromagnetic radiation into a processing chamber  178 . Particularly, the protrusions  366  function as the dielectric cavity resonator of the applicator  142 . In an embodiment, the monolithic source array  350  comprises a dielectric material. For example, the monolithic source array  350  may be a ceramic material. In an embodiment, one suitable ceramic material that may be used for the monolithic source array  350  is Al 2 O 3 . The monolithic structure may be fabricated from a single block of material. In other embodiments, a rough shape of the monolithic source array  350  may be formed with a molding process, and subsequently machined to provide the final structure with the desired dimensions. For example, green state machining and firing may be used to provide the desired shape of the monolithic source array  350 . In the illustrated embodiment, the protrusions  366  are shown as having a circular cross-section (when viewed along a plane parallel to the dielectric plate  360 ). However, it is to be appreciated that the protrusions  366  may comprise many different cross-sections. For example, the cross-section of the protrusions  366  may have any shape that is centrally symmetric. 
     In an embodiment, the housing  372  comprises a conductive body  373 . For example, the conductive body  373  may be aluminum or the like. The housing comprises a plurality of openings  374 . The openings  374  may pass entirely through a thickness of the conductive body  373 . The openings  374  may be sized to receive the protrusions  366 . For example, as the housing  372  is displaced towards the monolithic source array  350  (as indicated by the arrow) the protrusions  366  will be inserted into the openings  374 . In an embodiment, the openings  374  may have a diameter that is approximately 15 mm or greater. 
     In the illustrated embodiment, the housing  372  is shown as a single conductive body  373 . However, it is to be appreciated that the housing  372  may comprise one or more discrete conductive components. The discrete components may be individually grounded, or the discrete components may be joined mechanically or by any form of metallic bonding, to form a single electrically conductive body  373 . 
     In an embodiment, the lid plate  376  may comprise a conductive body  379 . In an embodiment, the conductive body  379  is formed from the same material as the conductive body  373  of the housing  372 . For example, the lid plate  376  may comprise aluminum. In an embodiment, the lid plate  376  may be secured to the housing  372  using any suitable fastening mechanism. For example, the lid plate  376  may be secured to the housing  372  with bolts or the like. In some embodiments, the lid plate  376  and the housing  372  may also be implemented as a single monolithic structure. In an embodiment, the lid plate  376  and the housing are both electrically grounded during operation of the processing tool. 
     Referring now to  FIGS.  4 A and  4 B , more detailed plan view and cross-sectional view illustrations of the lid plate  476  are shown, respectively, in accordance with an embodiment. In an embodiment, the lid plate  476  comprises a conductive body  479 . The conductive body  479  may comprise one or more trenches  416  to accommodate heating elements  419 . For example, the heating elements  419  may be resistive heating elements. The heating elements  419  may be covered by a cover  417 . In an embodiment, the cover  417  may comprise any suitable material. For example, the cover  717  may be a rigid material. In an embodiment, the cover  717  may be an epoxy or glue that is dispensed over the heating elements  417 . 
     In the illustrated embodiment, a pair of heating elements  419  are shown. A first heating element  419  covered by cover  417   A  is proximate to a perimeter of the lid plate  476 , and a second heating element  419  covered by cover  417   B  is proximate to an axial center of the lid plate  476 . The pair of heating elements  419  provide temperature control for an outer region and an inner region of the assembly. Accordingly, more precise temperature control to correct non-uniformities across the surface of the workpiece is possible. While a pair or ring shaped heating elements are shown, it is to be appreciated that embodiments include any number of heating elements  419  (e.g., one or more) and in any configuration. For example, the heating elements  419  may be arranged in a serpentine pattern, a spiral pattern, or any other suitable pattern. 
     In an embodiment, the lid plate  476  may comprise one or more holes  418 . The holes  418  may pass through an entire thickness of the conductive body  479 . In an embodiment, the holes  418  are positioned to accommodate stems (not shown) extending up from a thermal fluid channel in the housing. The stems and the thermal fluid channel are described in greater detail below. In an embodiment, six holes  418  are shown. The six holes  418  may accommodate three separate thermal fluid channels (i.e., to provide an inlet and an outlet for each channel). However, it is to be appreciated that any number of holes  418  may be used to accommodate different numbers of thermal fluid channel loops. 
     Referring now to  FIG.  5 A , an exploded perspective view illustration of the housing  572  is shown, in accordance with an embodiment. The illustrated embodiment depicts a first surface  534  of the housing  572 . The first surface  534  is the surface that faces towards the lid plate  476 , and a second surface  533  faces towards the monolithic source array. As shown, the housing  572  comprises a conductive body  573  with a plurality of openings  574 . In the illustration, the conductive body  573  is shown as one part and a plurality of covers  531  are raised up off the first surface  534  in order to illustrate the thermal fluid channels  530  (also referred to as simply “channels”) into the first surface  534 . The channels  530  extend into the conductive body  573  but do not pass entirely through the thickness of the conductive body  573 . Furthermore, it is to be appreciated that the openings  574  and the channels  530  are not fluidically coupled to each other. That is, during operation thermal fluid that is flown through the channels  530 , and thermal fluid may not pass through the openings  574 . 
     As shown, the channels  530  have a first end  535   A  and a second end  535   B . The length of the channel  530  between the first end  535   A  and the second end  535   B  may be routed between the openings  574  through the conductive body  573 . For example, each of the channels  530  may encircle one or more of the openings  574 . In the illustrated embodiment, the channels  530  encircle a pair of openings  574 . In an embodiment, each of the channels  530  may have substantially the same shape. For example, each of the three channels  530  in  FIG.  5 A  are substantially uniform in shape. However, other embodiments may include channels  530  that have non-uniform shapes. 
     In an embodiment, the covers  531  may include a first stem  537   A  and a second stem  537   B . The first stem  537   A  is positioned over the first end  535   A  of the channel  530 , and the second stem  537   B  is positioned over the second end  535   B  of the channel  530 . The stems  535  provide an inlet and an outlet into/out of the channel  530 . Accordingly, thermal fluid (e.g., coolant, etc.) may be flown through the channel  530  in order to regulate the temperature of the housing  572 . In an embodiment, the stems  535  pass through the holes  418  in the lid plate  476 . 
     Referring now to  FIG.  5 B , a perspective view illustration of a portion of the assembly  570  is shown, in accordance with an embodiment. The illustrated assembly  570  comprises a monolithic source array  550  and a housing  572  over and around the monolithic source array  550 . The dielectric plate  560  is below the housing  572  and the protrusions  566  extend up through the housing  572 . The protrusions  566  include holes  565  at their axial center. The holes  565  are sized to accommodate a monopole antenna (not shown). In  FIG.  5 B  the covers  531  have been placed over the channels  530 . In an embodiment, the covers  531  are welded to the housing  572 . The stems  537  extend up from the cover  531  away from the first surface  534 . 
     Referring now to  FIG.  5 C , a cross-sectional illustration of the assembly  570  in  FIG.  5 B  along line C-C′ is shown, in accordance with an embodiment. The cross-sectional illustration more clearly depicts the channels  530  and the covers  531 . The channels  530  extend into and out of the plane of the cross-section in order to connect together and form a loop around the protrusions  566 . In an embodiment, the channels  530  are formed into the first surface  534 , but do not extend entirely through a thickness of the conductive body  573 . 
     In an embodiment, the housing  572  may be supported by the first surface  561  of the dielectric plate  560 . In some embodiments, a thermal interface material  592  may be provided at the interface of the first surface  561  of the dielectric plate  560  and the second surface  533  of the housing  572 . For example, the thermal interface material  592  may be a thermal gasket or the like. The use of a thermal interface material  592  improves the heat transfer between the housing  572  and the monolithic source array  550 . In an embodiment, the thermal interface material  592  may be a single continuous layer, or the thermal interface material  592  may comprise a plurality of discrete pads across the interface. 
     Referring now to  FIG.  6   , a cross-sectional illustration of an assembly  670  is shown in accordance with an embodiment. The illustrated embodiment depicts the monolithic source array  650 , the housing  672 , and the lid plate  676 . In an embodiment, the housing  676  is supported by the dielectric plate  660  and wraps around the protrusions  666 . The conductive body  673  of the housing  672  comprises a channel  630  that is sealed by a cover  631 . The lid plate  676  rests over the housing  672  and the protrusions  666 . In an embodiment, a monopole antenna  668  may pass through the lid plate  676  and fit into a hole  665  into the protrusion  666  below the lid plate  676 . 
     In an embodiment, a stem  637  passes through the conductive body  679  of the lid plate  676 . The stem  637  may be fluidically coupled to a source of thermal fluid (not shown). A second stem  637  (out of the plane of  FIG.  6   ) may be an outlet for the thermal fluid. In an embodiment, the lid plate  676  may comprise one or more heating elements  619 . For example, an outer heating element  619   A  and an inner heating element  619   B  are shown in trenches into conductive body  679 . The heating elements  619  may be covered by covers  617   A ,  617   B . 
     Referring now to  FIG.  7   , a cross-sectional illustration of a processing tool  700  that includes an assembly  770  is shown, in accordance with an embodiment. In an embodiment, the processing tool comprises a chamber  778  that is sealed by an assembly  770 . For example, the assembly  770  may rest against one or more O-rings  781  to provide a vacuum seal to an interior volume  783  of the chamber  778 . In other embodiments, the assembly  770  may interface with the chamber  778 . That is, the assembly  770  may be part of a lid that seals the chamber  778 . In an embodiment, the processing tool  700  may comprise a plurality of processing volumes (which may be fluidically coupled together), with each processing volume having a different assembly  770 . In an embodiment, a chuck  779  or the like may support a workpiece  774  (e.g., wafer, substrate, etc.). In an embodiment, the chamber volume  783  may be suitable for striking a plasma  782 . That is, the chamber  778  may be a vacuum chamber. 
     In an embodiment, the assembly  770  may be substantially similar to the assemblies  670  described above. For example, the assembly  770  comprises a monolithic source array  750 , a housing  772 , and a lid plate  776 . The monolithic source array  750  may comprise a dielectric plate  760  and a plurality of protrusions  766  extending up from the dielectric plate  760 . The housing  772  may having openings sized to receive the protrusions  766 . In an embodiment, monopole antennas  768  may extend into holes in the protrusions  766 . The monopole antennas  768  may pass through a lid plate  776  over the housing  772  and the protrusions  766 . The monopole antennas  768  are each electrically coupled to power sources (e.g., high-frequency emission modules  105 ). 
     In an embodiment, the assembly  770  may comprise an integrated temperature control system. In some embodiments, the assembly  770  includes a cooling system and/or a heating system. Particularly, the temperature of the surface of the dielectric plate  760  that faces the workpiece may be controlled by the assembly. One way to control the temperature of the dielectric plate  760  is to flow a thermal fluid through channels  730  in the housing  772 . The channels  730  may be have an input stem  737   A  and an output stem  737   B . The stems  737  may pass through a thickness of the lid plate  776 . In an embodiment, the channels  730  may be sealed by a cover  731 . 
     In an embodiment, a second avenue for temperature control is with a heating element  719 . In an embodiment, one or more heating elements  719  may be embedded in the lid plate  776 . The heating elements  719  may be covered by a cover  717 . In the illustrated embodiment, a pair or ring heating elements  719  are shown, though any number and configuration of heating elements  719  may be used. 
     Referring now to  FIG.  8   , a block diagram of an exemplary computer system  860  of a processing tool is illustrated in accordance with an embodiment. In an embodiment, computer system  860  is coupled to and controls processing in the processing tool. Computer system  860  may be connected (e.g., networked) to other machines in a Local Area Network (LAN), an intranet, an extranet, or the Internet. Computer system  860  may operate in the capacity of a server or a client machine in a client-server network environment, or as a peer machine in a peer-to-peer (or distributed) network environment. Computer system  860  may be a personal computer (PC), a tablet PC, a set-top box (STB), a Personal Digital Assistant (PDA), a cellular telephone, a web appliance, a server, a network router, switch or bridge, or any machine capable of executing a set of instructions (sequential or otherwise) that specify actions to be taken by that machine. Further, while only a single machine is illustrated for computer system  860 , the term “machine” shall also be taken to include any collection of machines (e.g., computers) that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies described herein. 
     Computer system  860  may include a computer program product, or software  822 , having a non-transitory machine-readable medium having stored thereon instructions, which may be used to program computer system  860  (or other electronic devices) to perform a process according to embodiments. A machine-readable medium includes any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computer). For example, a machine-readable (e.g., computer-readable) medium includes a machine (e.g., a computer) readable storage medium (e.g., read only memory (“ROM”), random access memory (“RAM”), magnetic disk storage media, optical storage media, flash memory devices, etc.), a machine (e.g., computer) readable transmission medium (electrical, optical, acoustical or other form of propagated signals (e.g., infrared signals, digital signals, etc.)), etc. 
     In an embodiment, computer system  860  includes a system processor  802 , a main memory  804  (e.g., read-only memory (ROM), flash memory, dynamic random access memory (DRAM) such as synchronous DRAM (SDRAM) or Rambus DRAM (RDRAM), etc.), a static memory  806  (e.g., flash memory, static random access memory (SRAM), etc.), and a secondary memory  818  (e.g., a data storage device), which communicate with each other via a bus  830 . 
     System processor  802  represents one or more general-purpose processing devices such as a microsystem processor, central processing unit, or the like. More particularly, the system processor may be a complex instruction set computing (CISC) microsystem processor, reduced instruction set computing (RISC) microsystem processor, very long instruction word (VLIW) microsystem processor, a system processor implementing other instruction sets, or system processors implementing a combination of instruction sets. System processor  802  may also be one or more special-purpose processing devices such as an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a digital signal system processor (DSP), network system processor, or the like. System processor  802  is configured to execute the processing logic  826  for performing the operations described herein. 
     The computer system  860  may further include a system network interface device  808  for communicating with other devices or machines. The computer system  860  may also include a video display unit  810  (e.g., a liquid crystal display (LCD), a light emitting diode display (LED), or a cathode ray tube (CRT)), an alphanumeric input device  812  (e.g., a keyboard), a cursor control device  814  (e.g., a mouse), and a signal generation device  816  (e.g., a speaker). 
     The secondary memory  818  may include a machine-accessible storage medium  831  (or more specifically a computer-readable storage medium) on which is stored one or more sets of instructions (e.g., software  822 ) embodying any one or more of the methodologies or functions described herein. The software  822  may also reside, completely or at least partially, within the main memory  804  and/or within the system processor  802  during execution thereof by the computer system  860 , the main memory  804  and the system processor  802  also constituting machine-readable storage media. The software  822  may further be transmitted or received over a network  820  via the system network interface device  808 . In an embodiment, the network interface device  808  may operate using RF coupling, optical coupling, acoustic coupling, or inductive coupling. 
     While the machine-accessible storage medium  831  is shown in an exemplary embodiment to be a single medium, the term “machine-readable storage medium” should be taken to include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) that store the one or more sets of instructions. The term “machine-readable storage medium” shall also be taken to include any medium that is capable of storing or encoding a set of instructions for execution by the machine and that cause the machine to perform any one or more of the methodologies. The term “machine-readable storage medium” shall accordingly be taken to include, but not be limited to, solid-state memories, and optical and magnetic media. 
     In the foregoing specification, specific exemplary embodiments have been described. It will be evident that various modifications may be made thereto without departing from the scope of the following claims. The specification and drawings are, accordingly, to be regarded in an illustrative sense rather than a restrictive sense.