Patent Publication Number: US-11387124-B2

Title: Wafer container and method for holding wafer

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation application of and claims the priority benefit of a prior application Ser. No. 15/884,343, filed on Jan. 30, 2018, now allowed. The prior application claims the priority benefit of U.S. provisional application Ser. No. 62/582,963, filed on Nov. 8, 2017. The entirety of each of the above-mentioned patent applications is hereby incorporated by reference herein and made a part of this specification. 
    
    
     BACKGROUND 
     Robotics are commonly used in the semiconductor manufacturing industry to transfer semiconductor wafers, also known as substrates, throughout the fabrication area. Conventional wafer cassettes are typically used to retain a group of wafers that are commonly referred to collectively as a lot. Many times throughout the manufacturing process, the individual semiconductor wafers must be loaded into or out of the wafer cassettes. Semiconductor integrated circuit fabrication facilities (“fabs”) are automated. Movement of semiconductor wafers between various process tools is accomplished by an automated material handling system (AMHS). 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Aspects of the present disclosure are best understood from the following detailed description when read with the accompanying figures. It is noted that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion. 
         FIG. 1  is a schematic view of a wafer container in accordance with some embodiments of the present disclosure. 
         FIG. 2  is a top view of a pair of stents of the wafer container of  FIG. 1 . 
         FIGS. 3A to 3C  are schematic views of a pair of stents in accordance various embodiments of the present disclosure. 
         FIGS. 4A to 4D  are schematic views of a portion of the stents in accordance various embodiments of the present disclosure. 
         FIGS. 5A to 5B  are schematic views of a portion of the stents in accordance some other embodiments of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     The following disclosure provides many different embodiments, or examples, for implementing different features of the provided subject matter. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. For example, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed between the first and second features, such that the first and second features may not be in direct contact. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. 
     Further, spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper” and the like, may be used herein for ease of description to describe one element or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The apparatus may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may likewise be interpreted accordingly. 
       FIG. 1  is a schematic view of a wafer container in accordance with some embodiments of the present disclosure.  FIG. 2  is a top view of a pair of stents of the wafer container of  FIG. 1 . 
     Referring to  FIG. 1 , a wafer container  10  is fitted into a box  400  according to some embodiments of the present disclosure. The box  400  may be utilized for shipping at least one wafer  300 . There may be some features (not shown) in the box  400  for fixing the wafer container  10  or moving the wafer container  10 , such as slides. In some embodiments of the present disclosure, the box  400  may not be fully sealed since the door  410  of the box  400  leaves an air gap at the edge of the door  410  when the door  410  is closed. As a result, in some embodiments, the inner space IS may be in fluid communication with the outer space OS. 
     As shown in  FIG. 1 , the wafer container  10  includes at least a pair of the stents  100  and a frame  200 . In some embodiments of the present disclosure, the pair of the stents  100  and the frame  200  are made of, for example, plastic, barrier material, Carbon-filled PC or a combination thereof. In one or more embodiments, the pair of the stents  100  and the frame  200  may be made of the same or different materials. In some embodiments of the present disclosure, the pair of the stents  100  is capable of holding the wafer  300 . The frame  200  carries the pair of the stents  100  and allows access to the pair of the stents  100 . Although the wafer container  10  illustrated in  FIG. 1  is a front opening unified pod (FOUP), it should not limit various embodiments of the present disclosure. In some alternative embodiments of the present disclosure, the wafer container  10  may include a front opening shipping box (FOSB), a wafer standardized mechanical interface (SMIF) pod, a sorter, or a combination thereof. In some other embodiments of the present disclosure, the wafer container  10  may be a wafer cassette. 
     As shown in  FIG. 1 , in some embodiments of the present disclosure, the frame  200  has at least a pair of sidewalls  210   a  and  210   b  opposite to each other, and the pair of the stents  100  is respectively disposed on the sidewalls  210   a  and  210   b  of the frame  200 . That is, the pair of the stents  100  is respectively stationary with respect to the sidewalls  210   a  and  210   b  of the frame  200 . The pair of the stents  100  may be substantially horizontally aligned, so that the wafer  300  is substantially level. In some embodiments of the present disclosure, there may be plural pairs of the stents  100  respectively present on the sidewalls  210   a  and  210   b  of the frame  200 . The pairs of the stents  100  are respectively stationary with respect to the sidewalls  210   a  and  210   b  of the frame  200  and vertically spaced apart to define at least one slot for the wafer  300 . That is, in some embodiments of the present disclosure, a gap  102  between two adjacent stents  100  in a Z direction is greater than the thickness  300 T of the wafer  300 , so that the wafer  300  may be easily accommodated into the wafer container  10 . Through the configuration of the pairs of the stents  100 , the stents  100  support the edges of the wafers  300 , and the wafers  300  may be temporarily stored in the wafer container  10 . In some embodiments of the present disclosure, the pairs of the stents  100  are arranged alternately in the Z direction. 
     As shown in  FIG. 1  and  FIG. 2 , in some embodiments of the present disclosure, the pair of the stents  100  comprises a first stent  110  and a second stent  120  opposite to each other. As shown in  FIG. 2 , the first stent  110  is separated from the second stent  120  by a distance D in an X direction (e.g., a first direction). The distance D may be less than a diameter  300   d  of the wafer  300 . In some embodiments of the present disclosure, the distance D may be in a range of 180 mm to 300 mm. The first stent  110  and the second stent  120  may be substantially horizontally aligned, so that the wafer  300  is substantially level. 
     In detail, the first stent  110  includes a first connection portion  112  and a plurality of first comb portions  114 . The plurality of first comb portions  114  are connected to the first connection portion  112  to form a first comb structure. The first connection portion  112  extends along a Y direction (e.g., a second direction) and is fixed on the sidewall  210   a . In some embodiments, a length L of the first connection portion  112  in the Y direction is greater than the diameter  300   d  of the wafer  300 . In some embodiments of the present disclosure, the length L of the first connection portion  112  in the Y direction may be in a range of 300 mm to 355 mm. The plurality of first comb portions  114  are arranged along the Y direction. In some embodiments of the present disclosure, one of the plurality of first comb portions  114  may be a continuous structure extending in an X direction perpendicular to the sidewall  210   a . In some alternative embodiments of the present disclosure, all of the plurality of first comb portions  114  may be continuous structures extending in the X direction perpendicular to the sidewall  210   a . As shown in  FIG. 2 , one of the plurality of first comb portions  114  has a length  114 L and a width  114 W. In some embodiments of the present disclosure, the length  114 L of one of the plurality of first comb portions  114  may be in a range of 63 mm to 123 mm; the width  114 W of one of the plurality of first comb portions  114  may be in a range of 1 mm to 150 mm. In some embodiments of the present disclosure, the X direction, the Y direction, and the Z direction are substantially perpendicular to each other. In some embodiments of the present disclosure, the length  114 L of one of the first comb portions  114  and the length  114 L of another of the first comb portions  114  are the same as or different from each other; the width  114 W of one of the first comb portions  114  and the width  114 W of another of the first comb portions  114  are the same as or different from each other. 
     In some embodiments of the present disclosure, the second stent  120  includes a second connection portion  122  and a plurality of second comb portions  124 . The plurality of second comb portions  124  are connected to the second connection portion  122  to form a second comb structure. The second connection portion  122  extends along the Y direction and is fixed on the sidewall  210   b . The plurality of second comb portions  124  are arranged along the Y direction. In some embodiments of the present disclosure, one of the plurality of second comb portions  124  may be the continuous structure extending in the X direction perpendicular to the sidewall  210   b . In some alternative embodiments of the present disclosure, all of the plurality of second comb portions  124  may be continuous structures extending in the X direction perpendicular to the sidewall  210   b . As shown in  FIG. 2 , one of the plurality of second comb portions  124  has a length  124 L and a width  124 W. In some embodiments of the present disclosure, the length  124 L of one of the second comb portions  124  and the length  124 L of another of the second comb portions  124  are the same as or different from each other; the width  124 W of one of the second comb portions  124  and the width  124 W of another of the second comb portions  124  are the same as or different from each other. In some embodiments of the present disclosure, the length  124 L of one of the second comb portions  124  and the length  114 L of one of the first comb portions  114  are the same as or different from each other; the width  124 W of one of the second comb portions  124  and the width  114 W of one of the first comb portions  114  are the same. 
     Although the sum of the plurality of first comb portions  114  and the plurality of second comb portions  124  illustrated in  FIG. 2  is five comb portions, it should not limit various embodiments of the present disclosure. In some alternative embodiments of the present disclosure, the sum of the plurality of first comb portions  114  and the plurality of second comb portions  124  may be at least three comb portions that are able to form a triangle to hold the wafer  300 . As shown in  FIG. 2 , the pair of the stents  100  is configured to provide at least three supporting points SP 1 , SP 2 , and SP 3  to support the wafer  300 . That is to say, the wafer  300  is in contact with the stents  100  (i.e., the first stent  110  and the second stent  120 ) at the three supporting points SP 1 , SP 2 , and SP 3 . A centroid C of a triangle formed by the three supporting points SP 1 , SP 2 , and SP 3  overlaps a center  300 C of the wafer  300 . Therefore, the wafer  300  is able to be balanced by the three supporting points SP 1 , SP 2 , and SP 3 . Although the number of the supporting points SP 1 , SP 2 , and SP 3  illustrated in  FIG. 2  is three, it should not limit various embodiments of the present disclosure. In some alternative embodiments of the present disclosure, the number of the supporting points (where the wafer  300  is in direct contact with the stents  100 ) is more than three, such as 4 points, 5 points, 6 points or more points. 
     In some embodiments of the present disclosure, the plurality of first comb portions and the plurality of second comb portions are arranged in a completely interleaving, partially interleaving, completely aligned, or partially aligned configuration. The configurations will be described in detail in the following paragraphs. 
     It should be noted that, in some embodiments of the present disclosure, a contact area between the wafer  300  and the stents  100  (i.e., the first stent  110  and the second stent  120 ) may be decreased significantly. Therefore, the particles and/or moisture is hardly adhered to the stents  100 . On the other hands, the stents  100  having the plurality of first comb portions  114  and the plurality of second comb portions  124  may be cleaned easily by utilizing gas (e.g., N 2 ) purge. As a result, the defects formed at the wafer edge may decrease significantly. The reliability of the semiconductor device formed over the wafer is therefore reinforced. 
       FIGS. 3A to 3C  are schematic views of a pair of stents in accordance various embodiments of the present disclosure. 
     Referring to  FIG. 3A , the pair of stents  100   a  comprise a first stent  110   a  and a second stent  120   a  opposite to each other. The first stent  110   a  includes a first connection portion  112   a  and a plurality of first comb portions  114   a  connected to the first connection portion  112   a . The second stent  120   a  includes a second connection portion  122   a  and a plurality of second comb portions  124   a  connected to the second connection portion  122   a . As shown in  FIG. 3A , the plurality of first comb portions  114   a  are arranged along the Y direction with equal spacing. In some embodiments of the present disclosure, a spacing S between the plurality of first comb portions  114   a  is in a range of 1 mm to 240 mm. In some alternative embodiments of the present disclosure, the plurality of first comb portions  114   a  are arranged along the Y direction with non-equal spacing. As shown in  FIG. 3A , in some alternative embodiments of the present disclosure, the plurality of second comb portions  124   a  are arranged along the Y direction with equal spacing. In some alternative embodiments of the present disclosure, the plurality of second comb portions  124   a  are arranged along the Y direction with non-equal spacing. 
     In some embodiments of the present disclosure, at least one of the plurality of first comb portions  114   a  is arranged to correspond to at least one of the plurality of second comb portions  124   a . That is to say, a projection of one of the plurality of first comb portions  114   a  on a YZ plane may overlap with another projection of one of the plurality of second comb portions  124   a  on the YZ plane. In some alternative embodiments of the present disclosure, a projection of all of the plurality of first comb portions  114   a  on the YZ plane may overlap with another projection of all of the plurality of second comb portions  124   a  on the YZ plane. In some embodiments of the present disclosure, the number of the plurality of first comb portions  114   a  and the number of the plurality of second comb portions  124   a  may be the same. 
     It should be noted that, as shown in  FIG. 3A , the wafer  300  is in direct and/or physical contact with the plurality of first comb portions  114   a  to form first contact regions  118   a ,  118   b  and  118   c . In some embodiments of the present disclosure, the first contact regions  118   a ,  118   b  and  118   c  are non-continuous in the Y direction (e.g., a second direction). That is to say, the first contact regions  118   a ,  118   b  and  118   c  are spaced from each other by a distance S and not connect to each other. Similarly, the wafer  300  is in direct and/or physical contact with the plurality of second comb portions  124   a  to form the second contact regions  128   a ,  128   b  and  128   c . In some embodiments of the present disclosure, the second contact regions  128   a ,  128   b  and  128   c  between the wafer  300  and the plurality of second comb portions  124   a  are non-continuous in the Y direction. In other words, the area of the first contact regions  118   a ,  118   b  and  118   c  and/or the second contact regions  128   a ,  128   b  and  128   c  is less than the strip-shaped and/or continuous area. Accordingly, the contact area between the wafer  300  and the stents  100   a  is able to be decreased significantly. 
     Referring to  FIG. 3B , the pair of stents  100   b  comprises a first stent  110   b  and a second stent  120   b  opposite to each other. The first stent  110   b  includes a first connection portion  112   b  and a plurality of first comb portions  114   b  connected to the first connection portion  112   b . The second stent  120   b  includes a second connection portion  122   b  and a plurality of second comb portions  124   b  connected to the second connection portion  122   b . As shown in  FIG. 3B , the plurality of first comb portions  114   b  are arranged interleavingly with the plurality of second comb portions  124   b . To be specific, a projection of one of the plurality of first comb portions  114   b  on the YZ plane may overlap with another projection of one space between the adjacent two second comb portions  124   b  on the YZ plane. In some alternative embodiments of the present disclosure, a projection of all of the plurality of first comb portions  114   b  on the YZ plane may overlap with another projection of all spaces between the plurality of second comb portions  124   b  on the YZ plane. As shown in  FIG. 3B , although the plurality of first comb portions  114   b  and the plurality of second comb portions  124   b  are arranged in a completely interleaving configuration, it should not limit various embodiments of the present disclosure. In some alternative embodiments of the present disclosure, the plurality of first comb portions  114   b  and the plurality of second comb portions  124   b  may be arranged in a partially interleaving configuration or in a partially overlapped configuration. 
     In some embodiments of the present disclosure, the number of the plurality of first comb portions  114   b  and the number of the plurality of second comb portions  124   b  may be different from each other. In some alternative embodiments of the present disclosure, the number of the plurality of first comb portions  114   b  and the number of the plurality of second comb portions  124   b  may be the same, while the plurality of first comb portions  114   b  are configured to be interlaced with the plurality of second comb portions  124   b.    
     Referring to  FIG. 3C , the pair of stents  100   c  comprises a first stent  110   c  and a second stent  120   c  opposite to each other. The first stent  110   c  includes a first connection portion  112   c , a plurality of first comb portions  114   c , and a first case  116 . In detail, first sides  113  of the plurality of first comb portions  114   c  are connected to the first connection portion  112   c , while second sides  115  of the plurality of first comb portions  114   c  are connected to the first case  116 . The first case  116  is extended and connected from a first terminal E 1  of the first connection portion  112   c  to a second terminal E 2  of the first connection portion  112   c  and surrounds the plurality of first comb portions  114   c  to strengthen the mechanical strength of the first stent  110   c . Therefore, the first stent  110   c  may not be easily damaged or collapsed during the operation for holding the wafer  300  or during the cleaning by utilizing gas (e.g., N 2 ) purge. As shown in  FIG. 3C , in some embodiments of the present disclosure, a gap G exists between two adjacent first comb portions  114   c , so that the plurality of first comb portions  114   c  do not contact the wafer  300  at the gaps G. 
     Similarly, the second stent  120   c  includes a second connection portion  122   c , a plurality of second comb portions  124   c , and a second case  126 . The plurality of second comb portions  124   c  are connected to the second connection portion  122   c . The second case  126  is connected to opposite sides of the second connection portion  122   c  and surrounds the plurality of second comb portions  124   c  to strengthen the mechanical strength of the second stent  120   c . Although the plurality of first comb portions  114   c  illustrated in  FIG. 3C  are arranged to correspond to the plurality of second comb portions  124   c , it should not limit various embodiments of the present disclosure. In some alternative embodiments of the present disclosure, the plurality of first comb portions  114   c  may be arranged interleavingly with the plurality of second comb portions  124   c . In some embodiments of the present disclosure, materials of the first connection portion  112   c , the plurality of first comb portions  114   c , and the first case  116  may be the same. In some alternative embodiments of the present disclosure, the materials of the first connection portion  112   c , the plurality of first comb portions  114   c , and the first case  116  may be different from each other. 
       FIGS. 4A to 4D  are schematic views of a portion of the stents in accordance various embodiments of the present disclosure. 
     Referring back to  FIG. 1 , one of the plurality of comb portions may be a continuous structure extending in the X direction perpendicular to the pair of sidewalls  210   a  and  210   b  of the frame  200 . In some embodiments of the present disclosure, the continuous structure may be a pillar structure, such as a rectangular pillar structure  214   a  (as shown in  FIG. 4A ), a triangular pillar structure  214   b  (as shown in  FIG. 4B ), a polygonal pillar structure  314   a  (as shown in  FIG. 4C ), a circular pillar structure  314   b  (as shown in  FIG. 4D ), or a combination thereof. Specifically, as shown in  FIG. 4A , the rectangular pillar structure  214   a  is in contact with the wafer  300  (as shown in  FIG. 1 ) by a plane (or a top surface)  214 T. As shown in  FIG. 4B , the triangular pillar structure  214   b  is in contact with the wafer  300  (as shown in  FIG. 1 ) by a line  214 L. As shown in  FIG. 4C , the polygonal pillar structure  314   a  is in contact with the wafer  300  (as shown in  FIG. 1 ) by a plane (or a top surface)  314 T. As shown in  FIG. 4D , the circular pillar structure  314   b  is in contact with the wafer  300  (as shown in  FIG. 1 ) by a line  314 L. 
       FIGS. 5A to 5B  are schematic views of a portion of the stents in accordance others embodiments of the present disclosure. 
     Although the plurality of comb portions illustrated in  FIG. 1  are continuous structures, it should not limit various embodiments of the present disclosure. Herein, the term “continuous structure” indicates that the contact region or contact area between the wafer and one of the comb portions is continuous. For example, as shown in  FIG. 3A , the first contact region  118   a  between the wafer  300  and one of the first comb portions  114   a  is continuous in the X direction. In some alternative embodiments of the present disclosure, one of the plurality of comb portions may be a non-continuous structure, as shown in  FIG. 5A  and  FIG. 5B . In detail, referring to  FIG. 5A , a comb portion  514  includes a main portion  514   a  and a plurality of island structures  514   b  disposed over the main portion  514   a . The plurality of island structures  514   b  are separated from each other and disposed alternately along the X direction. In some embodiments of the present disclosure, one of the plurality of island structures  514   b  may be a cuboid structure. In some alternative embodiments of the present disclosure, the profile of one of the plurality of island structures  514   b  and the profile of another of the plurality of island structures  514   b  may be the same or different from each other. At least one portion (e.g., the plane or the top surface  514 T in  FIG. 5A ) of the plurality of island structures  514   b  is in contact with the wafer  300  (as shown in  FIG. 1 ). Compared with the continuous structure, the contact area between the wafer and the island structures  514   b  is further decreased. In some embodiments of the present disclosure, the number of the plurality of island structures  514   b  is not limited thereto. 
     Referring to  FIG. 5B , a comb portion  614  includes a main portion  614   a  and a plurality of island structures  614   b  disposed over the main portion  614   a . The plurality of island structures  614   b  are separated from each other and disposed alternately along the X direction. In some embodiments of the present disclosure, one of the plurality of island structures  614   b  may be a pyramid structure. The pyramid structure has sidewalls that taper from a bottom surface of the pyramid structure to a vertex of the pyramid structure. In some alternative embodiments of the present disclosure, the profile of one of the plurality of island structures  614   b  and the profile of another of the plurality of island structures  614   b  may be the same or different from each other. At least one portion (e.g., the point  614 P in  FIG. 5B ) of the plurality of island structures  614   b  is in contact with the wafer  300  (as shown in  FIG. 1 ). Compared with the continuous structure, the contact area between the wafer and the island structures  614   b  further decreases. In some embodiments of the present disclosure, the number of the plurality of island structures  614   b  is not limited thereto. 
     Referring to  FIG. 1 , in some embodiments of the present disclosure, a method for holding the wafer  300  is illustrated herein, in which the wafer container  10  of  FIG. 1  may hold the wafer  300  with a limited number of defects formed. It is noted that in addition to the following steps described, other steps may also be included in the method. 
     The wafer  300  is first inserted into the frame  200  carrying the plural stents  100 . Often, for preventing the features (such as the metal layer or the passivation layer) formed on the top surface of the wafer  300  from being scratched, the wafer  300  may be disposed on the stents  100  so that the top surface of the wafer  300  where the features are formed faces up, and the bottom surface of the wafer  300  may face down and be in contact with the top of the stents  100 . As shown in  FIG. 2 , the stents  100  are configured to provide at least three supporting points SP 1 , SP 2 , and SP 3  to support the wafer  300 , and the centroid C of a triangle formed by the three supporting points SP 1 , SP 2 , and SP 3  overlaps with the center  300 C of the wafer  300 , thereby balancing the wafer  300  to prevent from tipping. 
     In accordance with some embodiments of the present disclosure, a wafer container includes a frame and at least a pair of the support structures. The frame has opposite sidewalls. The at least a pair of support structures are respectively disposed on the opposite sidewalls of the frame. The at least a pair of support structures include a first support structure and a second support structure. The first support structure has a first connection portion and a plurality of first comb portions connected to the first connection portion, wherein one of the plurality of first comb portions includes a first main portion and a plurality of first island structures disposed over the first main portion, and the plurality of first island structures are separated from each other. The second support structure has a second connection portion and a plurality of second comb portions connected to the second connection portion, wherein one of the plurality of second comb portions includes a second main portion and a plurality of second island structures disposed over the second main portion and the plurality of second island structures are separated from each other. 
     In accordance with alternative embodiments of the present disclosure, a wafer container includes a frame, a plurality of first support structures, and a plurality of second support structures. The frame has a first sidewall and a second sidewall extending along a YZ plane, wherein the entire first sidewall is parallel with the entire second side wall. The plurality of first support structures are disposed on the first sidewall and arranged along a Z direction. The plurality of second support structures are disposed on the second sidewall and arranged along the Z direction. One of the plurality of first support structures is horizontally aligned with a corresponding second support structure to constitute a wafer holder. The wafer holder includes a plurality of island structures to hold a wafer in a XY plane, and the plurality of island structures are separated to each other along a X direction. 
     In accordance with yet alternative embodiments of the present disclosure, a method for holding at least one wafer includes: providing a wafer container including a frame having opposite sidewalls and at least a pair of support structures respectively disposed on the sidewalls of the frame, wherein the at least a pair of support structures include a first supporting structure and a second supporting structure opposite to each other, the first support structure has a first connection portion and a plurality of first comb portions connected to the first connection portion, wherein one of the plurality of first comb portions includes a first main portion and a plurality of first island structures disposed over the first main portion, and the plurality of first island structures are separated from each other, the second support structure has a second connection portion and a plurality of second comb portions connected to the second connection portion, wherein one of the plurality of second comb portions includes a second main portion and a plurality of second island structures disposed over the second main portion and the plurality of second island structures are separated from each other; and inserting the wafer into the wafer container, so that the at least a pair of support structures are configured to provide at least three supporting points to support the wafer in a XY plane. 
     The foregoing outlines features of several embodiments so that those skilled in the art may better understand the aspects of the present disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions, and alterations herein without departing from the spirit and scope of the present disclosure.