Patent Publication Number: US-2021175108-A1

Title: Multi-polar chuck for processing of microelectronic workpieces

Description:
CROSS REFERENCE TO RELATED PATENTS AND APPLICATIONS 
     This application claims priority to and the benefit of the filing date of U.S. Provisional Patent Application No. 62/944,078, filed Dec. 5, 2019, which application is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND 
     The present disclosure relates to systems and methods for the manufacture of microelectronic workpieces. 
     Device formation within microelectronic workpieces typically involves a series of manufacturing techniques related to the formation, patterning, and removal of a number of layers of material on a substrate. To meet the physical and electrical specifications of current and next generation semiconductor devices, process flows are being requested to reduce feature size while maintaining structure integrity for various patterning processes. 
     For many processes, it is important for a microelectronic workpiece, such as a semiconductor wafer, to remain clamped in place within processing equipment. Bowing of the wafer, however, can cause significant problems in maintaining this clamped state. For example, a large amount of bow (e.g., greater than 0.5 millimeter) can occur in wafers during processes to form vertical NAND (V-NAND) devices for FLASH memories. This bowing can cause conventional monopolar electrostatic chucks and bipolar electrostatic chucks to be unable to adequately clamp the wafer. In particular, large bows can create sufficient distance between the wafer surface and the chuck surface such that electrostatic forces generated by these conventional techniques are not sufficient to overcome the distance caused by the bowing. This failure in the clamping provided by the monopolar or bipolar electrostatic chuck leads to device failures in the resulting microelectronic workpieces after manufacture. 
       FIG. 1A  (Prior Art) is a cross-section diagram of an example embodiment  100  where a bipolar electrostatic chuck (ESC)  110  operates to clamp a microelectronic workpiece  112 , such as a semiconductor wafer. The bipolar ESC  110  includes a dielectric body  102  within which is embedded two concentric electrodes  104  and  106 . For the example embodiment shown, it is assumed that the microelectronic workpiece  112  is a disc. The first electrode  104  is circular and is positioned within the middle of bipolar ESC  110 . The second electrode  106  is a ring positioned concentrically around the first electrode  104 . To generate an electric field  115  between the electrodes  104 / 106 , a positive voltage (V+)  105  is applied to the first electrode  104 , and a negative voltage (V−)  107  is applied to the second electrode  106 . These polarities can be reversed and alternating current (AC) signals can also be applied to form an electric field. The electric field  115  causes charge to build up on the bottom surface of the microelectronic workpiece  112 . This charge combined with the electric field  115  causes an electrostatic force  108  to be asserted on the microelectronic workpiece  112 . This electrostatic force  108  is dependent in part on the distance between the bipolar ESC  110  and the microelectronic workpiece  112 . Where the microelectronic workpiece  112  is significantly bowed, the distance  114  between the bottom surface of the microelectronic workpiece  112  and the top surface of the bipolar ESC  110  can become large enough to reduce the electrostatic force  108  such that the bipolar ESC  110  is not able to clamp the microelectronic workpiece  112 . 
       FIG. 1B  (Prior Art) is a cross-section diagram of an example embodiment  150  where a monopolar electrostatic chuck (ESC)  160  operates to clamp a microelectronic workpiece  112 , such as a semiconductor wafer. The monopolar ESC  160  includes a dielectric body  152  within which is embedded an electrode  154 . For the example embodiment shown, it is assumed that the microelectronic workpiece  112  is a disc. The electrode  154  is circular and is positioned within the middle of monopolar ESC  160 . To generate an electric field  165  between the electrode  154  and the microelectronic workpiece  112 , a positive voltage (V+)  105  is applied to the electrode  154 . This polarity can be reversed. The applied voltage causes an opposite charge to build up on the bottom surface of the microelectronic workpiece  112 . This opposite charge forms the electric field  165  and causes an electrostatic force  158  to be asserted on the microelectronic workpiece  112 . This electrostatic force  158  is dependent in part on the distance between the monopolar ESC  160  and the microelectronic workpiece  112 . Where the microelectronic workpiece  112  is significantly bowed, the distance  114  between the bottom surface of the microelectronic workpiece  112  and the top surface of the monopolar ESC  160  can become large enough to reduce the force  158  such that the monopolar ESC  160  is not able to clamp the microelectronic workpiece  112 . 
     SUMMARY 
     Embodiments are described herein for multipolar electrostatic chucks (ESCs) that facilitate the manufacture of microelectronic workpieces within processing equipment. Different or additional features, variations, and embodiments can also be implemented, and related systems and methods can be utilized as well. 
     For one embodiment, a system is disclosed including a multipolar ESC and a voltage generator. The multipolar ESC includes a dielectric body and multiple sets of electrodes formed within the dielectric body. The voltage generator is coupled to the multiple sets of electrodes for the multipolar ESC, and the voltage generator is configured to apply voltages to the multiple sets of electrodes to generate multiple electric fields between the multiple sets of electrodes. 
     In additional embodiments, the multiple electric fields are configured to migrate charge to edges of a microelectronic workpiece. In further embodiments, the multiple electric fields are configured to facilitate clamping of a microelectronic workpiece. In further embodiments, the multiple electric fields are configured to reduce bow in a microelectronic workpiece. In still further embodiments, the multiple sets of electrodes include at least three sets of electrodes. 
     In additional embodiments, the multiple electric fields are sequentially pulsed from a center of the dielectric body to outer edges of the dielectric body. In further embodiments, pulsing for the multiple electric fields overlap with each other. In further additional embodiments, one or more varying voltages are applied to the multiple sets of electrodes. 
     In additional embodiments, the system also includes one or more sensors associated with a microelectronic workpiece. In further embodiments, the voltage generator is further configured to adjust voltages applied to the multiple sets of electrodes based upon one or more parameters detected by the one or more sensors. In still further embodiments, the one or more parameters includes a bow in the microelectronic workpiece. 
     For one embodiment, a method is disclosed including positioning a microelectronic workpiece on a multipolar ESC, where the multipolar ESC includes a dielectric body and multiple sets of electrodes formed within the dielectric body, and generating multiple electric fields between the multiple sets of electrodes by applying voltages to the multiple sets of electrodes. 
     In additional embodiments, the method includes using the multiple electric fields to migrate charge to edges of the microelectronic workpiece. In further embodiments, the method includes using the multiple electric fields to facilitate clamping of the microelectronic workpiece. In still further embodiments, the method includes using the multiple electric fields to reduce bow in the microelectronic workpiece. 
     In additional embodiments, the generating includes sequentially pulsing the multiple electric fields from a center of the dielectric body to outer edges of the dielectric body. In further embodiments, the generating also includes overlapping the pulsing for the multiple electric fields. 
     In additional embodiments, the generating includes applying one or more varying voltages to the multiple sets of electrodes. In further embodiments, the method also includes adjusting voltages applied to the multiple sets of electrodes based upon one or more parameters detected by the one or more sensors associated with the microelectronic workpiece. In still further embodiments, the one or more parameters includes a bow in the microelectronic workpiece. 
     Different or additional features, variations, and embodiments can also be implemented, and related systems and methods can be utilized as well. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more complete understanding of the present inventions and advantages thereof may be acquired by referring to the following description taken in conjunction with the accompanying drawings, in which like reference numbers indicate like features. It is to be noted, however, that the accompanying drawings illustrate only exemplary embodiments of the disclosed concepts and are therefore not to be considered limiting of the scope, for the disclosed concepts may admit to other equally effective embodiments. 
         FIG. 1A  (Prior Art) is a cross-section diagram of an example embodiment where a bipolar electrostatic chuck (ESC) operates to clamp a microelectronic workpiece, such as a semiconductor wafer. 
         FIG. 1B  (Prior Art) is a cross-section diagram of an example embodiment where a monopolar electrostatic chuck (ESC) operates to clamp a microelectronic workpiece, such as a semiconductor wafer. 
         FIG. 2A  is a cross-section view of an example embodiment where a multipolar electrostatic chuck (ESC) according to the disclosed embodiments includes multiple sets of electrodes and where multiple electric fields generated between these electrodes facilitate the processing of a microelectronic workpiece  112 , such as a semiconductor wafer. 
         FIG. 2B  is a top view for the electrodes formed in the multipolar ESC of  FIG. 2A . 
         FIG. 2C  is a process flow diagram of an example embodiment where multiple electric fields generated between electrodes in a multipolar ESC are used to facilitate processing of a microelectronic workpiece. 
         FIG. 3A  is a timing diagram of an example embodiment where one or more algorithms are applied to generate electric fields sequentially with respect to the electrodes formed in the multipolar ESC of  FIGS. 2A-2B . 
         FIG. 3B  is a diagram of an embodiment where charge accumulated on a microelectronic workpiece has migrated to the edge of the microelectronic workpiece based upon the sequential pulsing of the electric fields in  FIG. 3A . 
         FIG. 4  provides one example embodiment for a plasma processing system that can use the disclosed multipolar ESC embodiments and is provided only for illustrative purposes. 
     
    
    
     DETAILED DESCRIPTION 
     Methods and system are disclosed for multipolar ESCs that facilitate processing of microelectronic workpieces and provide improved clamping for microelectronic workpieces within processing equipment. The disclosed multipolar ESCs effectively clamp microelectronic workpieces, such as semiconductor wafers, including those with significant bows, such as bows greater than 0.5 millimeters. A variety of advantages and implementations can be achieved while taking advantage of the process techniques described herein. 
     For one embodiment, multiple different sets of electrodes are included within a dielectric body for a multipolar ESC. Voltages applied to these sets of electrodes are controlled to form multiple different electric fields. For one embodiment, the different electric fields are generated to migrate charge within the multipolar ESC thereby improving the clamp of microelectronic workpiece. Further, sensors can be used to detect bow conditions and/or other conditions, and one or more voltage control algorithms can be applied to facilitate the clamping of the microelectronic workpiece. Although concentric ring embodiments are shown and described below for the different sets of electrodes, the disclosed techniques can also be applied to other electrode configurations. Further, the disclosed multipolar ESCs can be used in a variety of different processes for the manufacture of microelectronic workpieces including etch processes, lithography processes, deposition processes, high-temperature deposition processes (e.g., aluminum nitride deposition), and/or other processes. Further, the multipolar ESCs can be used in a variety of different processing equipment for the manufacture of microelectronic workpieces. For example, the multipolar ESCs can be used in multi-stage heaters, front-end wafer processing equipment, processing equipment used to manufacture V-NAND memories, and/or other processing equipment used in the manufacture of microelectronic workpieces. Other applications can also be implemented while still taking advantage of the techniques described herein. 
       FIG. 2A  is a cross-section view of an example embodiment  200  for a multipolar electrostatic chuck (ESC)  209  according to the disclosed embodiments that includes multiple sets of electrodes where multiple electric fields generated between these electrodes facilitate processing of a microelectronic workpiece  112 , such as a semiconductor wafer. The multipolar ESC  210  includes a dielectric body  202 , and multiple sets of electrodes are formed or embedded within the dielectric body  202 . For the example embodiment shown, a first set of electrodes includes electrodes  204  and  210 ; a second set of electrodes includes electrodes  206  and  212 ; a third set of electrodes includes electrodes  208  and  214 ; and a fourth set of electrodes includes electrodes  210  and  216 . For this example embodiment, it is assumed that the microelectronic workpiece  112  is a disc. The electrode  204  is circular and is positioned within the middle of multipolar ESC  209 . The other electrodes  206 ,  208 ,  210 ,  212 ,  214 , and  216  are rings positioned concentrically around the electrode  204 . Although concentric rings are used for this embodiment, it is again noted that additional and/or different configurations could also be used. 
     To generate an electric field between the different sets of electrodes, differential voltages are applied between the electrodes. For example, a positive voltage (V+) can be applied to one electrode with the set of electrodes, and a negative voltage (V−) can be applied to a second electrode within the set of electrodes. These polarities can also be reversed, and alternating current (AC) signals and/or other varying voltage signals can also be applied to the electrodes to generate the electric field. For one example embodiment, an electric field is generated between electrodes  204  and  210  by applying a voltage (V 1A )  224  with a first polarity to electrode  204  and a voltage (V 1B )  230  with an opposite polarity to electrode  210 . An electric field is generated between electrodes  210  and  216  by applying a voltage (V 1B )  220  with a first polarity to electrode  210  and a voltage (V 1C )  236  with an opposite polarity to electrode  216 . An electric field is generated between electrodes  206  and  212  by applying a voltage (V 2A )  226  with a first polarity to electrode  206  and a voltage (V 2B )  232  with an opposite polarity to electrode  212 . An electric field is generated between electrodes  208  and  214  by applying a voltage (V 3A )  228  with a first polarity to electrode  208  and a voltage (V 3B )  234  with an opposite polarity to electrode  214 . 
     Once generated, the electric fields cause charge to build up on the bottom surface of the microelectronic workpiece  112 . This charge combined with the electric field causes forces to be asserted on the microelectronic workpiece  112 . These forces are dependent in part on the distance between the multipolar ESC  209  and the microelectronic workpiece  112 . Where the microelectronic workpiece  112  is significantly bowed, the distance  114  between the bottom surface of the microelectronic workpiece  112  and the top surface of the multipolar ESC  209  can become large. In contrast with prior monopolar ESC and bipolar ESC solutions, however, the multipolar ESC embodiments described herein can still effectively clamp a microelectronic workpiece that has a large amount of bow (e.g., greater than 0.5 millimeter). This result is achieved in part by controlling the timing and size of the multiple different electric fields for the multipolar ESC  209 . As such, the electrostatic force  240  formed at the edge of the microelectronic workpiece  112  can be made stronger as compared, for example, to the electrostatic force  242  formed closer to the center of the microelectronic workpiece  112 . This increased force at the edges of the microelectronic workpiece  112  facilitates the clamping of the microelectronic workpiece  112  to the multipolar ESC  209 . Further, this increased force can help to reduce the bow in the microelectronic workpiece  112 . Other advantages can also be achieved. 
       FIG. 2B  is a top view of the electrodes  204 ,  206 ,  208 ,  210 ,  212 ,  214 , and  216  formed within the multipolar ESC  209  of  FIG. 2A . It is noted that a portion of the dielectric body is positioned between each of the electrodes  204 ,  206 ,  208 ,  210 ,  212 ,  214 , and  216  as shown in more detail in the cross-section view of  FIG. 2A . 
     During operation of the multipolar ESC  209  in  FIGS. 2A-2B , the voltages applied to the electrodes  204 ,  206 ,  208 ,  210 ,  212 ,  214 , and  216  are controlled to improve clamping, to reduce bow, and/or to achieve other results. For one example embodiment, one or more algorithms are used to apply voltages to the electrodes  204 ,  206 ,  208 ,  210 ,  212 ,  214 , and  216  so that different electric fields are generated in an order and strength to facilitate the clamping provided by the multipolar ESC  209 . For one example embodiment, the electric fields are generated and applied to reduce the bow in the microelectronic workpiece  112 . For each of these example embodiments, electrostatic forces between the microelectronic workpiece and the multipolar ESC  209  can be shifted from the middle portion of the multipolar ESC  209  to the outer edge of the multipolar ESC  209  to facilitate the clamping and/or flattening of the microelectronic workpiece  112 . 
     For further embodiments, one or more sensors can be used to detect bowing in the microelectronic workpiece  112 , currents supplied to the electrodes within the multipolar ESC  209 , and/or other conditions with respect to the multipolar ESC  209  and/or the microelectronic workpiece  112 . The voltage supply algorithms can then be applied and/or adjusted based upon the parameters detected by these sensors. Other variations could also be implemented. 
       FIG. 2C  is a process flow diagram of an example embodiment  270  where multiple electric fields generated between electrodes in a multipolar ESC are used to facilitate processing of a microelectronic workpiece. In block  272 , a microelectronic workpiece is positioned on a multipolar electrostatic chuck (ESC). As described above, the multipolar ESC can include a dielectric body and multiple sets of electrodes formed within the dielectric body. In block  274 , voltages are applied to the multiple sets of electrodes within the multipolar ESC to generate multiple electric fields between the multiple sets of electrodes. In block  276 , the multiple electric fields are used to facilitate processing of the microelectronic workpiece. As described herein, for example, the multiple electric fields can migrate charge to edges of the microelectronic workpiece, can facilitate clamping of the microelectronic workpiece, can reduce bow in the microelectronic workpiece, and/or achieve other advantages. It is also noted that additional or different process steps could also be used while still taking advantage of the techniques described herein. 
       FIG. 3A  is a timing diagram of an example embodiment  300  where one or more algorithms are applied to generate electric fields sequentially with respect to the electrodes  204 ,  206 ,  208 ,  210 ,  212 ,  214 , and  216  in  FIGS. 2A-2B . This sequential timing effectively migrates charge formed on the bottom surface of the microelectronic workpiece  112  to the edges of the microelectronic workpiece  112 . This migration may be useful, for example, where bowing has occurred or has been detected to have occurred in the microelectronic workpiece  112 . 
     For the example embodiment shown, a first electric field  302  is generated and maintained between electrodes  204  and  210  by applying a voltage differential between electrodes  204  and  210  using voltage (V 1A )  224  and voltage (V 1B )  230 . This first electric field  302  causes charge to accumulate on the bottom, middle surface of the microelectronic workpiece  112 . Next, a second electric field  304  is pulsed on and off between electrodes  206  and  212  by applying a varying voltage differential between electrodes  206  and  212  using voltage (V 2A )  226  and voltage (V 2B )  232 . Next, a third electric field  306  is pulsed on and off between electrodes  208  and  214  by applying a varying voltage differential between electrodes  208  and  214  using voltage (V 3A )  228  and voltage (V 3B )  234 . Next, a fourth electric field  308  is pulsed on and off between electrodes  210  and  216  by applying a varying voltage differential between electrodes  210  and  216  using voltage (V 1B )  220  and voltage (V 1C )  236 . Further, for the example embodiment shown, the pulsed electric fields  304 ,  306 , and  308  overlap each other. For example, the third electric field  306  starts while the second electric field  304  is on and turns off after the second electric field  304  has already been turned off. Similarly, the fourth electric field  308  starts while the third electric field  306  is on and turns off after the third electric field  306  has already been turned off. This sequential pulsing of electric fields  304 ,  306 , and  308  progressively towards the edge of the microelectronic workpiece  112  causes charge accumulated on the bottom surface of the microelectronic workpiece  112  to migrate toward the edges of the microelectronic workpiece  112 . 
       FIG. 3B  is a diagram of an embodiment  350  where charge accumulated on the microelectronic workpiece  112  has migrated to the edge of the microelectronic workpiece based upon the sequential pulsing of electric fields  304 ,  306 , and  308  as shown in  FIG. 3A . As indicated by arrows  352 , this sequential pulsing of electric fields  304 ,  306 , and  308  progressively towards the edges of the microelectronic workpiece  112  causes accumulated charge to migrate toward the edges of the microelectronic workpiece  112 . As such, the electrostatic force  240  generated at the edge of the microelectronic workpiece  112  is stronger as compared, for example, to the electrostatic force  242  generated closer to the center of the microelectronic workpiece  112 . This increased force at the edges facilitates the clamping of the microelectronic workpiece  112  to the multipolar ESC  209 , particularly where the microelectronic workpiece  112  is bowed. Further, this increased force at the edges helps to reduce the bow in the microelectronic workpiece  112 . Other advantages can also be achieved. 
     It is noted that the multipolar ESC embodiments described herein may be utilized within a wide range of processing equipment including plasma processing systems. For example, the techniques may be utilized with plasma etch processing systems, plasma deposition processing systems, other plasma processing systems, and/or other types of processing systems. 
       FIG. 4  provides one example embodiment for a plasma processing system  400  that can use the disclosed multipolar ESC embodiments and is provided only for illustrative purposes. The plasma processing system  400  may be a capacitively coupled plasma processing apparatus, inductively coupled plasma processing apparatus, microwave plasma processing apparatus, Radial Line Slot Antenna (RLSA™) microwave plasma processing apparatus, electron cyclotron resonance (ECR) plasma processing apparatus, or other type of processing system or combination of systems. Thus, it will be recognized by those skilled in the art that the techniques described herein may be utilized with any of a wide variety of plasma processing systems. The plasma processing system  400  can be used for a wide variety of operations including, but not limited to, etching, deposition, cleaning, plasma polymerization, plasma-enhanced chemical vapor deposition (PECVD), atomic layer deposition (ALD), atomic layer etch (ALE), and so forth. It will be recognized that different and/or additional plasma processing systems may be implemented while still taking advantage of the techniques described herein. 
     Looking in more detail to  FIG. 4 , the plasma processing system  400  may include a process chamber  405 , and the process chamber  405  may be a pressure-controlled chamber. An upper electrode  420  and a lower electrode  425  may be provided as shown. The upper electrode  420  may be electrically coupled to an upper radio frequency (RF) source  430  through an upper matching network  455 . The upper RF source  430  may provide an upper frequency voltage  435  at an upper frequency (f U ). The lower electrode  425  may be electrically coupled to a lower RF source  440  through a lower matching network  457 . The lower RF source  440  may provide a lower frequency voltage  445  at a lower frequency (f L ). 
     As described above, a microelectronic workpiece  112  (in one example a semiconductor wafer) may be clamped in place by a multipolar ESC  209 . As further described herein, voltages are applied to different sets of electrodes within the multipolar ESC  209  to generate different electric fields that clamp the microelectronic workpiece  112 . For example, a voltage generator  450  can be configured using one or more algorithms to apply varying voltages to the electrodes within the multipolar ESC  209 . The voltage generator  450  can include control circuits that implement the one or more algorithms, and a storage medium can also be used to store the one or more algorithms. Still further, one or more sensors  452  can also be associated with the microelectronic workpiece  112  and/or the multipolar ESC  209 . The sensors  452  detect one or more parameters associated with the microelectronic workpiece  112  and/or the multipolar ESC  209 , and the sensors  452  output these parameters to the voltage generator  450  and/or the controller  470 . Other variations can also be implemented. 
     It is noted that the controller  470  can be coupled to various components of the plasma processing system  400  to receive inputs from and provide outputs to the components. As such, components of the plasma processing system  400  including the voltage generator  450 , the multipolar ESC  209 , and the sensors  452  can be connected to and controlled by the controller  470 . The controller  470  can in turn can be connected to a corresponding memory storage unit and user interface (not shown). Various processing operations can be executed via the user interface, and various plasma processing recipes and operations can be stored in a storage unit. Accordingly, a given microelectronic workpiece can be processed within the plasma-processing chamber with various microfabrication techniques. 
     The controller  470  and/or the control circuits within the voltage generator  450  can be implemented in a wide variety of manners. For example, the controller  470  and voltage generator  450  can include one or more programmable integrated circuits that are programmed to provide the functionality described herein. For example, one or more processors (e.g., microprocessor, microcontroller, central processing unit, etc.), programmable logic devices (e.g., complex programmable logic device (CPLD)), field programmable gate array (FPGA), etc.), and/or other programmable integrated circuits can be programmed with software or other programming instructions to implement the functionality of a proscribed plasma process recipe. It is further noted that the software or other programming instructions can be stored in one or more non-transitory computer-readable mediums (e.g., memory storage devices, FLASH memory, DRAM memory, reprogrammable storage devices, hard drives, floppy disks, DVDs, CD-ROMs, etc.), and the software or other programming instructions when executed by the programmable integrated circuits cause the programmable integrated circuits to perform the processes, functions, and/or capabilities described herein. Other variations could also be implemented. 
     In operation, the plasma processing apparatus uses the upper and lower electrodes to generate a plasma  460  in the process chamber  405  when applying power to the system from the upper RF source  430  and the lower RF source  440 . Further, ions generated in the plasma  460  may be attracted to a substrate for the microelectronic workpiece  112 . The generated plasma can be used for processing a target substrate (or any material to be processed) in various types of treatments such as, but not limited to, plasma etching, chemical vapor deposition, treatment of semiconductor material, glass material and large panels such as thin-film solar cells, other photovoltaic cells, organic/inorganic plates for flat panel displays, and/or other applications, devices, or systems. 
     Application of power results in a high-frequency electric field being generated between the upper electrode  420  and the lower electrode  425 . Processing gas delivered to process chamber  405  can then be dissociated and converted into a plasma. As shown in  FIG. 4 , the exemplary system described utilizes both upper and lower RF sources. Other variations can also be implemented. In one example system, the sources may be switched (higher frequencies at the lower electrode and lower frequencies at the upper electrode). Further, a dual source system is shown merely as an example system and it will be recognized that the techniques described herein may be utilized with other systems in which a frequency power source is only provided to one electrode, direct current (DC) bias sources are utilized, or other system components are utilized. 
     It is noted that reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, material, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention, but do not denote that they are present in every embodiment. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily referring to the same embodiment of the invention. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments. Various additional layers and/or structures may be included and/or described features may be omitted in other embodiments. 
     “Microelectronic workpiece” as used herein generically refers to the object being processed in accordance with the invention. The microelectronic workpiece may include any material portion or structure of a device, particularly a semiconductor or other electronics device, and may, for example, be a base substrate structure, such as a semiconductor substrate or a layer on or overlying a base substrate structure such as a thin film. Thus, workpiece is not intended to be limited to any particular base structure, underlying layer or overlying layer, patterned or unpatterned, but rather, is contemplated to include any such layer or base structure, and any combination of layers and/or base structures. The description below may reference particular types of substrates, but this is for illustrative purposes only and not limitation. 
     The term “substrate” as used herein means and includes a base material or construction upon which materials are formed. It will be appreciated that the substrate may include a single material, a plurality of layers of different materials, a layer or layers having regions of different materials or different structures in them, etc. These materials may include semiconductors, insulators, conductors, or combinations thereof. For example, the substrate may be a semiconductor substrate; a base semiconductor layer on a supporting structure, a metal electrode or a semiconductor substrate having one or more layers, structures or regions formed thereon. The substrate may be a conventional silicon substrate or other bulk substrate comprising a layer of semi-conductive material. As used herein, the term “bulk substrate” means and includes not only silicon wafers, but also silicon-on-insulator (“SOI”) substrates, such as silicon-on-sapphire (“SOS”) substrates and silicon-on-glass (“SOG”) substrates, epitaxial layers of silicon on a base semiconductor foundation, and other semiconductor or optoelectronic materials, such as silicon-germanium, germanium, gallium arsenide, gallium nitride, and indium phosphide. The substrate may be doped or undoped. 
     Systems and methods for processing a microelectronic workpiece are described in various embodiments. One skilled in the relevant art will recognize that the various embodiments may be practiced without one or more of the specific details, or with other replacement and/or additional methods, materials, or components. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of various embodiments of the invention. Similarly, for purposes of explanation, specific numbers, materials, and configurations are set forth in order to provide a thorough understanding of the invention. Nevertheless, the invention may be practiced without specific details. Furthermore, it is understood that the various embodiments shown in the figures are illustrative representations and are not necessarily drawn to scale. 
     Further modifications and alternative embodiments of the described systems and methods will be apparent to those skilled in the art in view of this description. It will be recognized, therefore, that the described systems and methods are not limited by these example arrangements. It is to be understood that the forms of the systems and methods herein shown and described are to be taken as example embodiments. Various changes may be made in the implementations. Thus, although the inventions are described herein with reference to specific embodiments, various modifications and changes can be made without departing from the scope of the present inventions. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and such modifications are intended to be included within the scope of the present inventions. Further, any benefits, advantages, or solutions to problems that are described herein with regard to specific embodiments are not intended to be construed as a critical, required, or essential feature or element of any or all the claims.