Abstract:
A technique for using an improved shield ring in plasma-based ion implantation is disclosed. In one particular exemplary embodiment, the technique may be realized as an apparatus and method for plasma-based ion implantation, such as radio frequency plasma doping (RF-PLAD). The apparatus and method may comprise a shield ring positioned on a same plane as and around a periphery of a target wafer, wherein the shield ring comprises an aperture-defining device for defining an area of at least one aperture, a Faraday cup positioned under the at least one aperture, and dose count electronics connected the Faraday cup for calculating ion dose rate. The at least one aperture may comprise at least one of a circular, arc-shaped, slit-shaped, ring-shaped, rectangular, triangular, and elliptical shape. The aperture-defining device may comprise at least one of silicon, silicon carbide, carbon, and graphite.

Description:
FIELD OF THE DISCLOSURE 
       [0001]    The present disclosure relates generally to plasma-based ion implantation and, more particularly, to a technique for using an improved shield ring in plasma-based ion implantation. 
       BACKGROUND OF THE DISCLOSURE 
       [0002]    Ion implantation is a process of depositing chemical species into a substrate by direct bombardment of the substrate with energized ions. In semiconductor fabrication, ion implanters are used primarily for doping processes that alter the type and level of conductivity of target materials. A precise doping profile in an integrated circuit (IC) substrate and its thin-film structure is often crucial for proper IC performance. To achieve a desired doping profile, one or more ion species may be implanted in different doses and at different energy levels. A specification of the ion species, doses, and energies is referred to as an ion implantation recipe. 
         [0003]    In conventional ion implantation, ions are extracted from a plasma source and are typically filtered (e.g., for mass, charge, energy, etc.), accelerated and/or decelerated, and collimated through several electro-static/dynamic lenses before being directed to a substrate. By contrast, in plasma-based ion implantation, a substrate is immersed in plasma. A negative voltage is applied to the substrate and ions are extracted through a subsequent sheath between the substrate and plasma. 
         [0004]    Several types of plasma sources exist, such as capacitively-coupled plasmas (CCPs), inductively-coupled plasmas (ICPs), glow discharges (GD), and hollow cathode (HC), to name a few. Of these examples, ICPs are typically better suited for ion implantation because of lower electron temperature and higher electron density when compared to CCPs. An example of an ICP is radio frequency (RF) plasma. 
         [0005]    A cross-sectional view of a typical radio frequency plasma doping system (RF-PLAD)  100  is depicted in  FIG. 1 . The plasma doping system  100  includes a plasma chamber  102  and a chamber top  104 . The chamber top  104  includes a conductive top section  116 , a first section  106 , and second section  108 . The top section  116  has a gas entry port  118  for a process gas to enter. Once the process gas enters the gas entry port  118  of the top section  116 , it flows on top of a baffle  126  before being evenly distributed in the chamber  102 . The first section  106  of the chamber top  104  extends generally in a horizontal direction. The second section  108  of the chamber top  104  extends from the first section  106  in generally a vertical direction. A helical coil antenna  112  having a plurality of turns wraps around the second section  108 . A planar coil antenna  114  having a plurality of turns typically sits on the first section  106  and surrounds the second section  108 . The first and second sections  106 ,  108  are typically formed of a dielectric material  110  for transferring RF power to the plasma inside the chamber  102 . 
         [0006]    An RF source  130 , e.g., an RF power supply, may be electrically connected to at least one of the helical coil antenna  112  and the planar coil antenna  114  by an impedance matching network  132  that maximizes power transferred from the RF source  130  to the RF antennas  112 ,  114 . When the RF source  130  resonates RF currents in the RF antennas  112 ,  114 , the RF antennas  112 ,  114  induce RF current into the chamber  102  to excite and ionize process gas for generating a plasma in the chamber  102 . 
         [0007]    The geometry of the first and second sections  106 ,  108  of the chamber top  104  and the configuration of the RF antennas  112 ,  114  are chosen so that a uniform plasma is generated. In addition, electromagnetic coupling may be adjusted with a coil adjuster  134  to improve uniformity of generated plasma. 
         [0008]    A platen (or E-clamp)  124  is positioned in the chamber  102  below the baffle  126 . The baffle  126  may be grounded or floating. A target wafer  120  is positioned on a surface of the platen  124 , which may be biased by a voltage power supply  128 , so that ions in generated plasma are attracted to the target wafer  120 . 
         [0009]    A shield ring  144 , which may be in the shape of an annulus, is positioned on a same plane as and around a periphery of the target wafer  120 . The shield ring  144  is typically formed of a solid material, i.e., aluminum, and may have one or more apertures  146  that define an area. One or more Faraday cups  140  may be positioned on a plane below the target wafer  120 , under the one or more apertures  146  of the shield ring  144  and adjacent to the platen  124 . 
         [0010]    Measurement of ion dose rate in the plasma doping system  100  may be accomplished using the one or more Faraday cups  140 . Incident ion flux may be measured by the one or more Faraday cups  140  as an electrical current. The ion dose rate of the target wafer  120  may be calculated by dose count electronics (DCE)  142  by taking the measured electrical current and dividing by the area of shield ring apertures  146  above the one or more Faraday cups  140 . As a result, the area of shield ring apertures  146  is a critical parameter in calculating ion dose rate. 
         [0011]    However, the area of shield ring apertures  146  is subject to change over time. One reason for such a change, for example, may be attributed to deterioration (or etching) by NF 3  plasma exposure during plasma doping (PLAD) operation. An NF 3  cleaning process is periodically used to maintain satisfactory process control conditions within the chamber  102 . However, this often results in an undesired effect of etching the material of the shield ring  144  and, consequently, enlarging the area of the one or more shield ring apertures  146 . 
         [0012]    When the one or more shield ring apertures  146  reach a certain enlarged size, e.g., where the area of the one or more shield ring apertures  146  is larger than an opening area of the one or more Faraday cups  140 , the one or more Faraday cups  140  may become saturated with too much signal (or current), causing the dose count electronics (DCE)  142  to calculate an inaccurate ion dose rate. 
         [0013]    Frequently replacing the shield ring  144  in order to maintain a well-defined area for the one or more shield ring apertures  146  may provide a temporary solution. However, the process for replacing shield rings is often expensive, inconvenient, and tedious. 
         [0014]    In view of the foregoing, it would be desirable to provide a technique for using an improved shield ring in plasma-based ion implantation to overcome the above-described inadequacies and shortcomings. 
       SUMMARY OF THE DISCLOSURE 
       [0015]    A technique for using an improved shield ring in plasma-based ion implantation is disclosed. In accordance with one particular exemplary embodiment, the technique may be realized as an apparatus for plasma-based ion implantation. The apparatus may comprise a shield ring positioned on a same plane as and around a periphery of a target wafer, wherein the shield ring comprises an aperture-defining device for defining an area of at least one aperture, a Faraday cup positioned under the at least one aperture, and dose count electronics connected the Faraday cup for calculating ion dose rate. 
         [0016]    In accordance with other aspects of this particular exemplary embodiment, the apparatus is for ion implantation in radio frequency plasma doping (RF-PLAD). 
         [0017]    In accordance with further aspects of this particular exemplary embodiment, the aperture-defining device comprises an insert placed under the aperture of the shield ring and above the Faraday cup, wherein the insert is made of a low-etch material. 
         [0018]    In accordance with additional aspects of this particular exemplary embodiment, the aperture-defining device comprises a lens cover placed and fitted over the aperture of the shield ring, wherein the lens cover is made of low-etch material. 
         [0019]    In accordance with further aspects of this particular exemplary embodiment, the aperture-defining device comprises a spring-loaded device placed under the aperture of the shield ring and above the Faraday cup, wherein the spring-loaded device is made of a low-etch material. 
         [0020]    In accordance with other aspects of this particular exemplary embodiment, the shape of the area of at least one aperture comprises at least one of a circular, arc-shaped, slit-shaped, ring-shaped, rectangular, triangular, and elliptical shape. 
         [0021]    In accordance with additional aspects of this particular exemplary embodiment, the aperture-defining device comprises at least one of silicon, silicon carbide, carbon, and graphite. 
         [0022]    In accordance with another exemplary embodiment, the apparatus may comprise a shield ring positioned on a same plane as and around a periphery of a target wafer, wherein the shield ring comprises a bulk material and has at least one aperture defining an area, a Faraday cup positioned under the at least one aperture, and dose count electronics connected the Faraday cup for calculating ion dose rate. 
         [0023]    In accordance with another exemplary embodiment, the apparatus may comprise a shield ring positioned on a same plane as and around a periphery of a target wafer, wherein the shield ring comprises at least one aperture defining an area, a Faraday cup positioned under the at least one aperture, and dose count electronics connected the Faraday cup, wherein the dose count electronics comprise a calculation module for calculating ion dose rate based on correcting for aperture area changes. 
         [0024]    The present disclosure will now be described in more detail with reference to exemplary embodiments thereof as shown in the accompanying drawings. While the present disclosure is described below with reference to exemplary embodiments, it should be understood that the present disclosure is not limited thereto. Those of ordinary skill in the art having access to the teachings herein will recognize additional implementations, modifications, and embodiments, as well as other fields of use, which are within the scope of the present disclosure as described herein, and with respect to which the present disclosure may be of significant utility. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]    In order to facilitate a fuller understanding of the present disclosure, reference is now made to the accompanying drawings, in which like elements are referenced with like numerals. These drawings should not be construed as limiting the present disclosure, but are intended to be exemplary only. 
           [0026]      FIG. 1  depicts a conventional RF-PLAD ion implantation system. 
           [0027]      FIGS. 2A-2B  depict a shield ring configuration according to an embodiment of the present disclosure. 
           [0028]      FIGS. 3A-3B  depict a shield ring configuration according to an embodiment of the present disclosure. 
           [0029]      FIGS. 4A-4C  depict a shield ring configuration according to an embodiment of the present disclosure. 
           [0030]      FIGS. 5A-5C  depict a shield ring configuration according to an embodiment of the present disclosure. 
           [0031]      FIGS. 6A-6D  depict a shield ring configuration according to an embodiment of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0032]    Referring to  FIG. 2A , a side view of a shield ring  244  is shown in accordance with an embodiment of the present disclosure. The shield ring  244  may be in the shape of an annulus and may be positioned on a same plane as and around a periphery of the target wafer  120 . The shield ring  244  may have one or more shield ring apertures  246  that define an area. One or more Faraday cups  140  may be positioned on a plane below the target wafer  120 , under the one or more shield ring apertures  246  and adjacent to the platen (or E-clamp)  124 .  FIG. 2B  depicts a top view of the shield ring  244 . 
         [0033]    In this embodiment, the area of one or more shield ring apertures  246  is smaller than the opening area of the one or more Faraday cups  140  below the ring  244 . In one embodiment, the shield ring  244  may be formed of a thermally and electrically conductive material with a low etch rate, such as aluminum, and coated with silicon (Si), silicon carbide (SiC), carbon (C), graphite, or other similar low-etch coats. In another embodiment, the shield ring  244  may be formed of a bulk (solid) material, such as silicon (Si), silicon carbide (SiC), carbon (C), or graphite. Various types of silicon carbide (SiC) may also be used, e.g., a single crystal silicon, a polycrystalline silicon, etc. In yet another embodiment, the shield ring  244  made of bulk material may be doped for improved resistivity to etching. Coatings and dopings may include a variety of thicknesses depending on the material of the shield ring  244 . The process for forming the shield ring  244  from a bulk material may include sintering (heating), chemical vapor deposition (CVD) (layering), and other similar techniques. 
         [0034]    An advantage of utilizing a coated shield ring or a shield ring made of bulk material, as described above, may include the ability to create an effective plasma sheath that uniformly extends beyond the wafer edge to maintain normal ion incident angles to the edge of the wafer  120 . Another advantage of utilizing a coated shield ring or a shield ring made of bulk material may include the ability to provide and maintain a dimensionally well-defined aperture to allow ion flux to impinge the one or more magnetically suppressed Faraday Cups  140  for accurate measurement of ion flux to the wafer  120 . Ultimately, this may provide more precise process control, minimized contamination levels, and reduced consumables cost (e.g., resulting from tedious replacements of expensive shield rings) associated with high volume manufacturing of plasma doping (PLAD) systems. 
         [0035]    Referring to  FIG. 3A , a side view of a shield ring  344  is shown in accordance with an embodiment of the present disclosure. The shield ring  344  may be a conventional shield ring  144  or a shield ring  244  made of low-etch material, as depicted in  FIG. 2A-2B .  FIG. 3B  depicts a top view of the shield ring  144 . 
         [0036]    In this embodiment, the area of the one or more shield ring apertures  346  may be larger than the opening area of the one or more Faraday cups  140  below the shield ring  344 . As discussed above, one reason for an enlarged area of the one or more shield ring apertures  346  may be the result of deterioration (or etching), for example, by NF 3  plasma exposure during plasma doping (PLAD) operation. When the area of the shield ring apertures  146  is larger than the opening area of the one or more Faraday cups  140 , dose count electronics (DCE)  142  may inaccurately calculate ion dose rate. 
         [0037]    Therefore, a low-etch insert  300  with a small insert aperture  310  may be placed under the one or more enlarged shield ring apertures  346  and above the one or more Faraday cups  140 . The small insert aperture  310  of the insert  300  may provide a dimensionally well-defined area for dose count electronics (DCE)  142  to accurately calculate ion dose rate on the target wafer  120 . As a result, the replacement interval of the shield ring  344  having the one or more enlarged shield ring apertures  346  may be reduced since the insert  300  includes the defining aperture  310  for ion dose rate measurement. Ultimately, this may provide more precise process control, minimized contamination levels, and reduced consumables cost associated with frequent shield ring replacement during high volume manufacturing of plasma doping (PLAD) systems. 
         [0038]    The insert  300  may be formed of a thermally and electrically conductive material with a low etch rate, such as aluminum, and coated with silicon (Si), silicon carbide (SiC), carbon (C), graphite, or other similar low-etch coats. In another embodiment, the low-etch insert  300  may be formed of a bulk (solid) material, such as silicon (Si), silicon carbide (SiC), carbon (C), or graphite. Various types of silicon carbide (SiC) may be used, e.g., a single crystal silicon, a polycrystalline silicon, etc. In yet another embodiment, the insert  300  formed of bulk material may be doped for improved resistivity to etching. Coatings and dopings may include a variety of thicknesses depending on the material of the insert  300 . The process for forming the insert  300  from a bulk material may include sintering (heating), chemical vapor deposition (CVD) (layering), and other similar techniques. 
         [0039]    Referring to  FIG. 4A , a side view of a shield ring  444  is shown in accordance with an embodiment of the present disclosure.  FIG. 4B  depicts a top view of the shield ring  444 . 
         [0040]    In this embodiment, the area of the shield ring apertures  446  may be larger than the opening area of the one or more Faraday cups  140  for similar reasons discussed above. As a result, in this embodiment, a lens cover  400  with a small lens aperture  410  may be placed over the one or more enlarged shield ring apertures  446 . The lens cover  400  may have tapered sides that fit against the deteriorated (or etched) portions of the one or more enlarged shield ring apertures  146 , which may also be tapered, as depicted in  FIG. 4A . The small lens aperture  410  of the lens cover  400  may provide a dimensionally well-defined area for dose count electronics (DCE)  142  to accurately calculate ion dose rate on the target wafer  120 . 
         [0041]    The lens cover  400  may be formed of a thermally and electrically conductive material with a low etch rate, such as aluminum, and coated with silicon (Si), silicon carbide (SiC), carbon (C), graphite, or other similar low-etch coats. In another embodiment, the lens cover  400  may be formed of a bulk (solid) material, such as silicon (Si), silicon carbide (SiC), carbon (C), or graphite. Various types of silicon carbide (SiC) may be used, e.g., a single crystal silicon, a polycrystalline silicon, etc. In yet another embodiment, the lens cover  400  formed of bulk material may be doped for improved resistivity to etching. Coatings and dopings may include a variety of thicknesses depending on the material of the lens cover  400 . The process for forming the lens cover  400  from a bulk material may include sintering (heating), chemical vapor deposition (CVD) (layering), and other similar techniques. 
         [0042]    Referring to  FIG. 4C , another embodiment of the present disclosure may provide one or more stepped lens covers  400   a  to be fitted against one or more stepped shield ring apertures  446   a . The one or more stepped lens cover  400   a  are, in most respects, similar to the one or more tapered lens covers  400  as discussed above. However, rather than waiting for the shield ring apertures  446  to be etched and enlarged (to form a tapered portion), the shield ring  444  may include one or more stepped apertures  446  to be fitted with one or more stepped lens covers  400   a . This may provide another way to reduce shield ring replacement and associated consumables cost. Other various fitting mechanisms may also be provided. 
         [0043]    In another embodiment, a lens cover  400  without a small lens aperture may also be provided. In this example, the lens cover may be used to protect the aperture  146  from etching. Such a lens cover may not be directly used to maintain a well-defined aperture. Instead, the lens cover may preserve unused shield ring apertures on a shield ring having multiple shield ring apertures. This may be useful for indirectly calculating area changes in covered shield ring apertures versus area changes in uncovered shield ring apertures. This process is discussed in further detail below. 
         [0044]    Referring to  FIG. 5A , a side view of a shield ring  544  is shown in accordance with an embodiment of the present disclosure.  FIG. 5B  depicts a top view of the shield ring  544 .  FIG. 5B  depicts a bottom view of the shield ring  544 . 
         [0045]    In this embodiment, the area of the one or more shield ring apertures  546  may be larger than the area of the one or more Faraday cups  140  for similar reasons discussed above. In one embodiment of the present disclosure, a spring-loaded mechanism  500  with a spring-adjusted aperture  510  may be placed under the one or more enlarged apertures  546  of the shield ring  544  and above the one or more Faraday cups  140 . The spring-loaded mechanism  500  may include aperture defining portions  500   a ,  500   b , fixed portions  502   a ,  502   b , springs  504 , and aperture bars  506   a ,  506   b , as depicted in  FIG. 5C . By placing the spring-loaded mechanism  500  under the one or more shield ring apertures  546 , the aperture-defining portions  500   a ,  500   b  may define the area of the one or more shield ring apertures  546  during deterioration and/or etching. The aperture bars  506   a ,  506   b  may be formed of low-etch, highly resistive material, which serve to define the spring-adjusted aperture  510  dimensions. 
         [0046]    The aperture-defining portions  500   a ,  500   b  may be formed of a thermally and electrically conductive material with a low etch rate, such as aluminum, and coated with silicon (Si), silicon carbide (SiC), carbon (C), graphite, or other similar low-etch coats. In another embodiment, the aperture-defining portions  500   a ,  500   b  may be formed of a bulk (solid) material, such as silicon (Si), silicon carbide (SiC), carbon (C), or graphite. Various types of silicon carbide (SiC) may be used, e.g., a single crystal silicon, a polycrystalline silicon, etc. In yet another embodiment, the lens cover  400  formed of bulk material may be doped for improved resistivity to etching. Coatings and dopings may include a variety of thicknesses depending on the material of the aperture-defining portions  500   a ,  500   b . The process for forming the aperture-defining portions  500   a ,  500   b  from a bulk material may include sintering (heating), chemical vapor deposition (CVD) (layering), and other similar techniques. 
         [0047]    As the one or more shield ring apertures  546  are etched, the aperture-defining portions  500   a ,  500   b  of the spring-loaded mechanism  500  may become exposed to etching as well. Even as the aperture-defining portions  500   a ,  500   b  are exposed and etched, the springs  504 , which are attached to the fixed portions  502   a ,  502   b , may push the aperture-defining portions  500   a ,  500   b  towards the aperture bars  506   a ,  506   b  to maintain the size (area) of the one or more shield ring apertures  546 . As a result, the spring-loaded aperture  510  may provide a dynamically-dimensioned, well-defined area for dose count electronics (DCE)  142  to accurately calculate ion dose rate on the target wafer  120 . Therefore, replacement intervals of shield rings having one or more enlarged apertures may be reduced since the spring-loaded mechanism  500  provides the defining apertures  510  for accurate ion dose rate measurement. 
         [0048]    It should be appreciated that while each shield ring, as illustrated above in the embodiments of the present disclosure, is shown with two shield ring apertures each having a rectangular cross section, other numbers, shapes, and sizes of apertures may also be considered. For example, as depicted in  FIG. 6A , a shield ring  644  may have one or more apertures  646   a , e.g., four apertures. In one embodiment, each aperture  646   a  may also correspond to one or more separate Faraday cups  140   a.    
         [0049]    In addition, as depicted in  FIGS. 6B and 6D , a shield ring  644  may include one or more shield ring apertures  646  having different shapes, e.g., circular  646   b  or arc-shaped  646   d . Other shapes, such as triangular, elliptical, slit-shaped, etc., may also be provided. Similarly, the one or more Faraday cups  640  may also include different shapes to correspond to the one or more shield ring apertures  646 . For example, the one or more Faraday cups  640   b  may be circular to correspond to the one or more circular apertures  146   b  or the one or more Faraday cups  640   d  may be arc-shaped to correspond to the one or more arc-shaped apertures  646   d . In another embodiment, a shield ring may include one or more shield ring apertures having a plurality of different shapes. Other variations may also be provided. 
         [0050]    Referring to  FIG. 6C , the shield ring  644  may include an outer shield ring  644   a  and an inner shield ring  644   b  that are separated by a continuous, ring-shaped aperture  646   c . In one embodiment, the Faraday cup  640   c  may also be ring-shaped to correspond to the aperture  646   c . A ring-shaped aperture  646   c  may provide greater accuracy in measuring ion dose rate since incident flux may be averaged over the entire shield ring  644 . Other various embodiments may also be provided. 
         [0051]    In addition to maintaining a well-defined aperture to improve ion dose rate measurements, embodiments of the present disclosure may also provide processes to correct changes in an area of an aperture caused by etching. 
         [0052]    For example, in one embodiment, a process for calculating and correcting for changes in the area of shield ring apertures due to etching may be provided by calculating etch rate. Since etch rate for a given material is predictable in a given set of clean conditions (e.g., power, pressure, flow, DC bias, pulse width frequency, etc.), the etch rate may be inserted into a clean recipe of a calculation module within dose count electronics (DCE)  142  to automatically adjust the area of the aperture during ion dose measurements. 
         [0053]    In another embodiment, a process for calculating and correcting for changes in aperture area due to etching may be provided by in-situ optical measurement. In this example, changes in aperture changes may be optically measured and automatically corrected for in the dose count electronics (DCE)  142  during ion dose rate measurements. 
         [0054]    In yet another embodiment, a process for calculating and correcting for changes in aperture area due to etching may be provided by using a separate ion source or by using a primary plasma generating source, e.g., a RF source, that is substantially stable. In this example, the known ion source may be used to produce a response in the Faraday counting circuit from which the aperture area could be back-calculated. Calibration using this process may be inserted into the calculation module of the dose count electronics (DCE)  142  and may be done frequently and/or periodically. 
         [0055]    In a further embodiment of the disclosure, another process may be provided in the event a primary plasma-generating source is not sufficiently stable to perform the calibration. In this example, a dual-channel dosimetry process may be provided. In one embodiment, a first channel may be used for real-time dosimetry while a second channel may be connected to an aperture that is covered, e.g., by a lens cover, to maintain a constant area only to be removed to perform the calibration. As a result, the value received by the second channel during calibration may be compared to the first channel so that the difference and changes in area may be calculated. 
         [0056]    In another embodiment, a first channel may be connected to an aperture (or a set of apertures) having a particular physical geometry, e.g., circular. A second channel may be connected to another aperture (or set of apertures) having a different physical geometry, e.g., slit-shaped. As the apertures etch in response to plasma exposure, the ratio of perimeter to area may change differently for apertures connected to the first channel when compared to apertures connected to the second channel. As a result, the difference in ratio may be inserted into the dose count electronics (DCE)  142 , for example, and used to calculate the actual area of each etched aperture for improved ion dose rate measurement. 
         [0057]    It should be appreciated that while embodiments of the present disclosure are directed to confining secondary electrons in RF-PLAD, other implementations may be provided as well. For example, a technique for confining of secondary electrons may apply to plasma-based ion implantation systems, such as glow discharge plasma doping (GD-PLAD) system. In this example, an additional source of plasma, such as a hollow cathode, may also be provided. 
         [0058]    The present disclosure is not to be limited in scope by the specific embodiments described herein. Indeed, other various embodiments of and modifications to the present disclosure, in addition to those described herein, will be apparent to those of ordinary skill in the art from the foregoing description and accompanying drawings. Thus, such other embodiments and modifications are intended to fall within the scope of the present disclosure. Further, although the present disclosure has been described herein in the context of a particular implementation in a particular environment for a particular purpose, those of ordinary skill in the art will recognize that its usefulness is not limited thereto and that the present disclosure can be beneficially implemented in any number of environments for any number of purposes. Accordingly, the claims set forth below should be construed in view of the full breadth and spirit of the present disclosure as described herein.