BUFFING PAD REGENERATION DEVICE, CHEMICAL MECHANICAL POLISHING DEVICE INCLUDING THE SAME, AND METHOD FOR REGENERATING BUFFING PAD

[0001] This application claims priority to Korean Patent Application No. 10-2025-0006927, filed in the Korean Intellectual Property Office on January 16, 2025, the entire contents of which are hereby incorporated by reference.

[0002] The present disclosure relates to a buffing pad regeneration device, a chemical mechanical polishing device including the same, and a method for regenerating a buffing pad.

[0003] A chemical mechanical polishing (CMP) process is widely used as a process technology for planarizing a semiconductor surface. A wafer polished by a chemical mechanical polishing process may undergo a post-process of being cleaned by a buffing pad. In this process of cleaning the wafer, particularly across multiple cleaning cycles, the surface of the buffing pad may become worn or otherwise degraded such that its useful lifetime may be incrementally reduced with each cleaning cycle to a point that the buffing pad may need to be periodically replaced or reconditioned.

[0004] To extend the life of the buffing pad, a conditioning process may be performed by cutting the surface of the buffing pad for refreshing. That conditioning process may, however, undesirably cause the buffing pad to generate cut debris that may, in turn, scratch the wafer due during subsequent processes. Also, when the buffing pad is periodically replaced, semiconductor production cost may increase and productivity may decrease due to labor cost, replacement cost for consumables, and replacement time required for replacing the buffing pad.

[0005] The present disclosure relates to a buffing pad regeneration device, a chemical mechanical polishing device including the same, and a method for regenerating a buffing pad.

[0006] Problems that may be solved by the present disclosure are not limited to those described above, and other problems not mentioned may be clearly understood by those skilled in the art from the following description.

[0007] In some embodiments, a buffing pad regeneration device may include a receiving container configured to receive a polymer precursor liquid, a driving device configured to insert or withdraw at least a portion of a buffing pad so that at least one surface of the buffing pad is immersed in the polymer precursor liquid, a curing device configured to induce curing of the polymer precursor liquid form a buffing layer on the at least one surface of the buffing pad immersed in the polymer precursor liquid; and a controller configured to control the driving device and the curing device.

[0008] In some embodiments, a chemical mechanical polishing device may include a stage configured to support a wafer, a buffing pad configured to process the wafer placed on the stage, and a buffing pad regeneration device configured to regenerate the buffing pad worn during processing of the wafer. The buffing pad regeneration device may include a receiving container configured to receive a polymer precursor liquid, a liquid supply device configured to supply the polymer precursor liquid into the receiving container, a foaming agent injection device configured to inject a foaming agent into the polymer precursor liquid, a driving device configured to insert or withdraw at least a portion of the buffing pad into the receiving container so that at least one surface of the buffing pad is immersed in the polymer precursor liquid, a curing device configured to induce curing of the polymer precursor liquid to form a buffing layer on the at least one surface of the buffing pad immersed in the polymer precursor liquid, and a controller configured to control the driving device and the curing device.

[0009] In some embodiments, a buffing pad regeneration method may include supplying a polymer precursor liquid into a receiving container, inserting at least a portion of a buffing pad into the receiving container by a driving device so that at least one surface of the buffing pad is immersed in the polymer precursor liquid, and inducing curing of the polymer precursor liquid to form a buffing layer on the at least one surface of the buffing pad by a curing device.

[0010] According to various embodiments of the disclosed technologies, by regenerating a buffing pad worn in the wafer processing using a buffing pad regeneration device, repeated use of the buffing pad may bepossible. Accordingly, the time and cost required for conditioning of the buffing pad and/or replacing the buffing pad may be saved.

[0011] According to various embodiments of the disclosed technologies, the amount of light and/or heat delivered respectively to a plurality of regions of the buffing pad may be predetermined based on the amount of thickness change of each of the plurality of regions, so that the surface of the buffing pad may be uniformly regenerated, and the time taken for regenerating the buffing pad may be shortened.

[0012] The effects that may be obtained through the disclosed technologies are not limited to those described above. Other technical effects not mentioned may be clearly understood by those skilled in the art from the following description.

[0028] Hereinafter, various embodiments of the present disclosure will be described with reference to FIGS. 1-15. Throughout the entire specification, the same reference numerals may denote the same components.

[0029] FIGS. 1 and 2 schematically show a chemical mechanical polishing device 10 according to an embodiment of the present disclosure. FIG. 1 is a schematic view illustrating the chemical mechanical polishing device 10 as viewed from above (e.g., in a +Z direction), and FIG. 2 is a schematic cross-sectional view illustrating the chemical mechanical polishing device 10 as viewed from a side direction (e.g., in a +Y direction).

[0030] Referring to FIGS. 1 and 2, the chemical mechanical polishing device 10 may include a stage 100 configured to support a wafer (shown in crosshatch), a buffing pad 200 configured to process the wafer placed on the stage 100, e.g., the buffing pad 200 may be controlled to perform chemical mechanical polishing (CMP) processing on the wafer, and a buffing pad regeneration device 300 configured to regenerate the buffing pad 200 worn during processing of the wafer. The buffing pad regeneration device 300 may include a receiving container 310, a driving device 320, and a curing device 330. In addition, the buffing pad regeneration device 300 may include a controller 340 configured to control the driving device 320 and the curing device 330.

[0031] The receiving container 310 of the buffing pad regeneration device 300 may receive a polymer precursor liquid. The polymer precursor liquid may refer to a precursor solution of a material constituting the buffing pad 200 before curing by light and/or heat. The polymer precursor liquid may include a photo-curable resin and/or a thermosetting resin that can be cured by light and/or heat. By way of example, the polymer precursor liquid may be a polyurethane precursor solution or other suitable solution and/or material. The curing of the polymer precursor liquid as described herein may form a polymer material; e.g., to form a buffing layer 200P of the same polymer material as the buffing pad 200.

[0032] The driving device 320 of the buffing pad regeneration device 300 may move the buffing pad 200. The driving device 320 may insert and/or withdraw at least a portion of the buffing pad 200 into and out of the receiving container 310 such that, when inserted, at least one surface of the buffing pad 200, for example a lower portion, is immersed in the polymer precursor liquid. The at least one surface of the buffing pad 200 corresponds with portions, surfaces, sides, etc. of the buffing pad 200 that may typically be worn during processing of a wafer. The at least one surface, in other words, includes portions of the buffing pad 200 interacting with the wafer during processing, and, as such, need not necessarily comprise only an lowermost portion or extremity of the buffing pad 200, and is, instead, understood to comprise all portions, surfaces, sides, etc. of the buffing pad 200 interacting with the wafer or elements associated therewith for which regeneration may be desired to prolong use of the buffing pad 200.

[0033] In an embodiment, the driving device 320 may include a support arm 322 connected to the buffing pad 200. The buffing pad 200 may be connected to one end of the support arm 322. The support arm 322 may move the buffing pad 200 back and forth between the stage 100 and the receiving container 310. For example, the driving device 320 in cooperation with the support arm 322 may move the buffing pad 200 worn during processing of a wafer while placed on the stage 100 to the receiving container 310 of the buffing pad regeneration device 300 to be regenerated. Further, the regenerated buffing pad 200 may likewise be moved back from the buffing pad regeneration device 300 to the stage 100 and again used for processing the wafer. In FIG. 1, the buffing pad 200 connected to one end of the support arm 322 is shown to rotate around the other end of the support arm 322, however, the present disclosure is not necessarily limited by the manner in which the buffing pad 200 connected to the support arm 322 is moved.

[0034] The curing device 330 of the buffing pad regeneration device 300 may induce curing of the polymer precursor liquid adjacent to one surface or portion of the buffing pad 200 that is immersed in the polymer precursor liquid while the one surface or portion of the buffing pad 200 is immersed in the receiving container 310, i.e., the polymer precursor liquid may be cured upon the lower portion of the buffing pad 200 to facilitate regenerating the portions thereof. For example, the curing device 330 may be disposed below the receiving container 310 and may irradiate light toward one surface of the buffing pad 200 or heat one surface of the buffing pad 200. Accordingly, the polymer precursor liquid adjacent to one surface of the buffing pad 200 may be cured, thus regenerating the buffing pad 200.

[0035] Although not shown in FIGS. 1 and 2, the chemical mechanical polishing device may further include components such as a platen and a polishing pad for polishing a wafer.

[0036] FIG. 3 is a diagram showing a buffing pad regeneration device according to an embodiment of the present disclosure. The buffing pad regeneration device shown in FIG. 3 may be substantially the same as the buffing pad regeneration device shown in FIGS. 1 and 2 (e.g., the buffing pad regeneration device 300 of FIGS. 1 and 2). A first example 30ais a schematic cross-sectional view of part of the buffing pad regeneration device as viewed from a side direction (e.g., +Y direction), and a second example 30b is a schematic plan view of part of the buffing pad regeneration device as viewed from above (e.g., +Z direction).

[0037] Referring to the first example 30a and the second example 30b, the buffing pad regeneration device may include a receiving container 310 for receiving a polymer precursor liquid and a curing device 330 disposed below the receiving container 310 to induce curing of the polymer precursor liquid contained in the receiving container 310.

[0038] The buffing pad regeneration device may further include a liquid supply device 350 configured to supply the polymer precursor liquid into the receiving container 310. The liquid supply device 350 may include a liquid injection device 350_1 disposed at a first side of the receiving container 310 to inject the polymer precursor liquid into the receiving container 310, and a liquid discharge device 350_2 disposed at a second side of the receiving container 310 to discharge the polymer precursor liquid contained in the receiving container 310. For example, the liquid injection device 350_1 and the liquid discharge device 350_2 may include flow paths communicating with the inside of the receiving container 310, and the polymer precursor liquid may be supplied into or discharged from the receiving container 310 through these flow paths.

[0039] In an embodiment, the liquid supply device 350 may further include a foaming agent injection device 350_3. The foaming agent injection device 350_3 may be configured to inject a foaming agent into the polymer precursor liquid supplied into the receiving container 310. By way of example, the foaming agent injection device 350_3 may be disposed in the liquid injection device 350_1 or inside a tank (e.g., a tank that stores the polymer precursor liquid) connected to the liquid injection device 350_1, thereby injecting or generating bubbles into the polymer precursor liquid supplied through the liquid injection device 350_1. In another example, the foaming agent injection device 350_3 may be disposed at a third side of the receiving container 310 so as to inject/generate bubbles into the polymer precursor liquid contained in the receiving container 310. A controller may adjust the concentration of the foaming agent injected into the polymer precursor liquid, thereby adjusting the porosity of the polymer precursor liquid. Accordingly, the porosity of a polymer portion of the buffing pad being regenerated may be controlled.

[0040] In an embodiment, the liquid supply device 350 may further include a liquid circulation device 350_4 connected to the liquid injection device 350_1 and the liquid discharge device 350_2 to circulate the polymer precursor liquid. The liquid circulation device 350_4 may circulate the polymer precursor liquid so that the polymer precursor liquid discharged through the liquid discharge device 350_2 is supplied back into the receiving container through the liquid injection device 350_1.

[0041] In FIG. 1, the liquid injection device 350_1 and the liquid discharge device 350_2 are shown forming separate flow paths at different positions of the receiving container 310. However, the present disclosure is not limited thereto. For example, the liquid injection device 350_1 and the liquid discharge device 350_2 may form a single flow path, and both supply and discharge of the polymer precursor liquid may be performed through the single flow path. In addition, when the amount of the polymer precursor liquid supplied into the receiving container 310 is pre-controlled, and the entire polymer precursor liquid inside the receiving container 310 is used up for regenerating the buffing pad, the liquid discharge device 350_2 may be omitted.

[0042] FIG. 4 is a diagram schematically showing a chemical mechanical polishing device 10 according to an embodiment of the present disclosure. The chemical mechanical polishing device 10 may include a stage 100, a buffing pad 200, and a buffing pad regeneration device 300. The buffing pad regeneration device 300 may include a receiving container 310, a driving device 320, a curing device 330, a controller 340, and a scanner 360. In FIG. 4, redundant descriptions of components corresponding with FIGS. 1 and 2 are omitted.

[0043] The scanner 360 of the buffing pad regeneration device 300 may measure thickness changes caused by wear on one surface or portion of the buffing pad 200. For example, the scanner 360 may be disposed between the stage 100 and the receiving container 310. Accordingly, as the buffing pad 200 moves to the receiving container 310 by the driving device 320, the thickness changes of one surface or portion of the worn buffing pad 200 may be measured by the scanner 360. By way of example, the scanner 360 may measure the distance in the z-direction from the scanner 360 to each position on one surface or portion of the buffing pad 200, and thereby measure a thickness change amount at each position of the buffing pad 200 due to wear. The scanner 360 may include a camera or other suitable sensor configured to scan an entire surface area of the buffing pad 200 such that the scanner 360 is capable of determining the metes and bounds of the buffing pad 200 in the y-direction and the x-direction and depth changes, trenches, or other elevational variances in the z-direction.

[0044] The controller 340 may receive data related to the thickness changes of one surface or portion of the buffing pad 200 from the scanner 360. Further, based on the received data related to the thickness change, the controller 340 may control the curing device 330. For example, the controller 340 may, based on the data related to the thickness change, adjust the amount of light and/or the amount of heat delivered by the curing device 330 to one surface or portion of the buffing pad 200 through the receiving container 310. For instance, the receiving container 310 may include a bottom surface 312 that faces one surface or portion of the buffing pad 200. The bottom surface 312 may be divided into a plurality of zones. Based on the data related to the thickness change, the controller 340 may individually adjust and control the amount of light and/or heat delivered to each of the plurality of zones of the bottom surface 312 by the curing device 330.

[0045] In an embodiment, the scanner 360 may transmit data related to the thickness changes of one surface or portion of the buffing pad to the controller 340, and the controller 340 may generate feedback information on the amount of light and/or the amount of heat delivered to each of the plurality of zones based on the data related to the thickness changes of the plurality of buffing pads. The generated feedback information may be used to set the amount of light, the amount of heat, the light irradiation time, the heat irradiation time, and the like for use in subsequently regenerating the buffing pad 200.

[0046] An example in which the amount of light and/or heat delivered from the curing device 330 is adjusted based on the data related to the thickness changes is described in detail below with reference to FIGS. 5-10.

[0047] FIG. 5 is a diagram showing a buffing pad regeneration device according to an embodiment of the present disclosure. The buffing pad regeneration device shown in FIG. 5 may be an example of the buffing pad regeneration device 300 shown in FIG. 4. A first example 50a is a schematic cross-sectional view of part of the buffing pad regeneration device as viewed from a side direction (e.g., +Y direction), and a second example 50b is a schematic plan view of part of the buffing pad regeneration device as viewed from above (e.g., +Z direction).

[0048] Referring to the first example 50a and the second example 50b, the buffing pad regeneration device may include a receiving container 310 for receiving a polymer precursor liquid, a liquid supply device 350 for supplying the polymer precursor liquid into the receiving container 310, and a curing device 330 disposed below the receiving container 310 to induce curing of the polymer precursor liquid contained in the receiving container 310. In FIG. 5, redundant descriptions of components corresponding with FIGS. 1-4 are omitted.

[0049] The receiving container 310 may include a bottom surface 312 divided into a plurality of zones Z (e.g., Z1, Z2…Zn). In FIG. 5, the plurality of zones Z of the bottom surface 312 is shown as being divided in a grid pattern, however, the shape and number of each zone Z are not limited to those shown and may vary, e.g., the shape and/or size of each zone may be the same and/or different and may varying according the size and shape of the buffing pad 200.

[0050] The curing device 330 may individually adjust the amount of light and/or heat delivered to each of the plurality of zones Z. For example, the amount of light and/or heat delivered to a first zone Z1 of the bottom surface 312 through the curing device 330 and the amount of light and/or heat delivered to a second zone Z2 may be different from each other. The curing device 330 may include a plurality of sub-curing devices corresponding to the plurality of zones Z, i.e., one sub-curing device may be utilized within each zone, but the present disclosure is not necessarily limited thereto.

[0051] A controller (e.g., the controller 340 of FIG. 4) may receive data related to the thickness changes of the lower portion of a buffing pad from a scanner (e.g., the scanner 360 of FIG. 4), and may control the curing device 330 based on the data related to the thickness changes. For example, the controller may receive data related to a thickness change of a first region of the buffing pad corresponding to a first zone Z1 of the bottom surface 312 (and similar data for each of the regions corresponding with the other zones). In this manner, based on the data related to the thickness change of the first region of the buffing pad, the controller may control the curing device 330 so that the amount of light and/or heat delivered to the first region of the buffing pad through the first zone Z1 of the bottom surface 312 is adjusted. For example, the controller may control the curing device 330 so that, the larger the thickness change in the first region of the buffing pad, the greater the amount of light and/or heat delivered to the first region of the buffing pad. By doing the same for each of the other regions and zones, the amount of light and/or heat delivered to each of the plurality of regions of the buffing pad through the plurality of zones Z of the bottom surface 312 may be individually determined and assessed based on the thickness change amount of each of the plurality of regions of the buffing pad.

[0052] In an embodiment, the curing device 330 disposed below the receiving container 310 may irradiate light onto one surface or portion of the buffing pad facing the bottom surface 312 of the receiving container 310. In this case, the bottom surface 312 of the receiving container 310 may include a light-transmissible material through which light irradiated from the curing device 330 passes. For example, the bottom surface 312 of the receiving container 310 may be formed of a transparent material. The curing device 330 may adjust the amount of light and/or heat delivered to each of the plurality of zones Z by controlling the intensity of the light and/or the light irradiation time for each of the plurality of zones Z of the bottom surface 312.

[0053] In another embodiment, the curing device 330 disposed below the receiving container 310 may heat one surface or portion of the buffing pad facing the bottom surface 312 of the receiving container 310. In this case, the bottom surface 312 of the receiving container 310 may include a thermally conductive material for delivering heat from the curing device 330 to one surface or portion of the buffing pad. The curing device 330 may adjust the amount of heat delivered to each of the plurality of zones Z by controlling the intensity of the heat and/or the heating time for each of the plurality of zones Z of the bottom surface 312.

[0054] With this configuration, by determining and controlling in advance the amount of light and/or heat delivered respectively to the plurality of regions of the buffing pad based on the thickness change amount of each of the plurality of regions, the time required to regenerate the buffing pad may be tailored individually for each region depending on the wear thereat, which may be useful in shortening or minimizing process time. For example, applying stronger (more) heat to a region of the buffing pad having a larger thickness change, and applying relatively weaker (less) heat to a region having a smaller thickness change, may allow the buffing pad to be cured uniformly, i.e., the varying amounts of heat results in each of the regions completing the curing process at approximately the same time. Also, since there is no need to extend the time for heating the region with the larger thickness change, the time required for regenerating the buffing pad may be shortened or minimized compared to equally heating the regions according to a lesser amount of heat needed for the regions having the smaller thickness change.

[0055] FIG. 6 is a diagram showing a buffing pad regeneration device according to an embodiment of the present disclosure. The buffing pad regeneration device shown in FIG. 6 may be another example of the buffing pad regeneration device 300 shown in FIG. 4. FIG. 6 is a schematic cross-sectional view of part of the buffing pad regeneration device as viewed from a side direction (e.g., +Y direction).

[0056] Referring to FIG. 6, the receiving container 310 may include a plurality of height adjustment devices M configured to adjust the height of each of the plurality of zones Z in a bottom surface divided into the plurality of zones Z. By way of example, the plurality of height adjustment devices M (e.g., M1, M2,…Mn) may be linear motors for moving the plurality of zones Z in an up-down direction (e.g., the Z direction), but is not limited thereto as the motors may be operable for moving the zones in other directions.

[0057] In FIG. 6, it is shown that one height adjustment device corresponds to each zone of the receiving container 310, but the present disclosure is not limited thereto, optionally one height adjustment device M may correspond to more than one of the plurality of zones Z.

[0058] A controller (e.g., the controller 340 of FIG. 4) may receive data related to the thickness changes of one surface or portion of the buffing pad from a scanner (e.g., the scanner 360 of FIG. 4), and may control the height adjustment devices M based on the received data related to the thickness changes. For example, the controller may receive data related to a thickness change of a first region of the buffing pad corresponding to a first zone Z1 of the bottom surface. In addition, based on the data related to the thickness change of the first region of the buffing pad, the controller may control a first height adjustment device M1 corresponding to the first zone Z1 so that a distance between the first zone Z1 of the bottom surface and the first region of the buffing pad is adjusted. For instance, the controller may control the first height adjustment device M1 so that, the larger the thickness change in the first region of the buffing pad, the closer the distance between the first region of the buffing pad and the first zone Z1 of the bottom surface becomes. In other words, the distance between the plurality of zones Z of the bottom surface and the plurality of regions of the buffing pad corresponding to the plurality of zones Z may be determined/controlled based on the thickness change amount of each of the plurality of regions.

[0059] The curing device 330 disposed below the receiving container 310 may irradiate light onto one surface or portion of the buffing pad facing the bottom surface of the receiving container 310 and/or may heat one surface or portion of the buffing pad. By controlling the plurality of height adjustment devices M so that the height of each of the plurality of zones Z of the bottom surface is adjusted, the controller may control the amount of light and/or heat delivered to one surface or portion of the buffing pad through each of the plurality of zones Z.

[0060] In FIG. 6, the bottom surface of the receiving container 310 is illustrated as being divided into a plurality of rod-shaped zones extending in a vertical direction (e.g., Z-direction), and it is also shown that the lengths of the rods forming the plurality of zones Z differ from each other. However, the present disclosure is not limited thereto. For example, the lengths of the rods forming the plurality of zones Z may be set to be the same, to the extent that the plurality of height adjustment devices M do not interfere with each other.

[0061] FIG. 7 is a diagram showing an example operation in which a buffing pad regeneration device according to an embodiment of the present disclosure regenerates a buffing pad 200. An operation of the buffing pad regeneration device (e.g., the buffing pad regeneration device 300 of FIG. 4) regenerating the buffing pad 200 may be controlled by a controller (e.g., the controller 340 of FIG. 4). Here, the buffing pad 200 may be a buffing pad that has been worn in wafer processing and thus may require regeneration.

[0062] The buffing pad regeneration device may include a receiving container 310 that receives a polymer precursor liquid, a driving device 320 that moves the buffing pad 200 to the receiving container 310, and a curing device 330 that induces curing of the polymer precursor liquid adjacent to one surface or portion of the buffing pad 200. The receiving container 310 of the buffing pad regeneration device may include a bottom surface divided into a plurality of zones Z and a plurality of height adjustment devices M configured to adjust the height of each of the plurality of zones.

[0063] A first example 70a shows an example in which the buffing pad 200 is inserted into the receiving container 310 holding the polymer precursor liquid. By controlling the driving device 320, the controller may insert at least a portion of the buffing pad 200 connected to the driving device 320 into the receiving container 310. By way of example, the receiving container 310 may be in the form of a container with an open top surface and an internal space for holding the polymer precursor liquid. The driving device 320 may lower the buffing pad 200 into the inside of the receiving container 310 through the open top surface of the receiving container 310, thereby inserting at least a portion of the buffing pad 200 into the receiving container 310.

[0064] As the buffing pad 200 is inserted into the receiving container 310, one surface or portion of the buffing pad 200 may be immersed in the polymer precursor liquid inside the receiving container 310. While one surface or portion of the buffing pad 200 is immersed in the polymer precursor liquid, the curing device 330 may induce curing of the polymer precursor liquid adjacent to and upon one surface or portion of the buffing pad 200. The controller may control the curing device 330 and/or the height adjustment devices M to adjust the amount of light and/or heat delivered to one surface or portion of the buffing pad 200.

[0065] A second example 70b shows an example in which the buffing pad 200 is withdrawn from the receiving container 310. By controlling the driving device 320, the controller may pull out the buffing pad 200 connected to the driving device 320 from the receiving container 310. The driving device 320 may raise the buffing pad 200 through the open top surface of the receiving container 310, thereby pulling out the buffing pad 200 from the receiving container 310, e.g., the driving device 320 lifts and returns the buffing pad 200 to the stage 100.

[0066] A buffing layer 200P may be formed on one surface or portion of the buffing pad 200 pulled out from the receiving container 310, where the polymer precursor liquid has been cured or at least partially cured upon the buffing pad 200 while in the receiving container 310. If the buffing layer 200P is incompletely cured, the controller may place the buffing pad 200 at a specific position for a predetermined period so that the buffing layer 200P may naturally cure, but the present disclosure is not limited thereto. The buffing layer 200P may have the same or similar material and internal porosity as those of the buffing pad 200.

[0067] A third example 70c shows an example of the buffing pad 200 whose worn surface has been fully regenerated, i.e., the buffing layer 200P has been added to the buffing pad 200 to smooth or otherwise compensation for the wear incurred while processing the wafer. As the buffing layer 200P formed by the polymer precursor liquid is cured, the buffing pad 200 may be regenerated or extended. The regenerated buffing pad 200 may then be moved back to the stage (e.g., the stage 100 of FIG. 4) by the driving device 320. The buffing pad 200 moved to the stage may be reused to process the wafer placed on the stage. Further, the buffing pad 200 worn in the wafer processing may repeatedly undergo the process of regeneration according to the first through the third examples 70a, 70b, and 70c described above.

[0068] With this configuration, the present disclosure, by regenerating the buffing pad 200 worn in the wafer processing using the buffing pad regeneration device, may allow for repeated use of the buffing pad 200. Accordingly, the time and cost required for conditioning of the buffing pad 200 and/or replacing the buffing pad 200 may be reduced.

[0069] FIG. 8 is a diagram for explaining an example in which a polymer precursor liquid PL is cured to regenerate the buffing pad 200 according to an embodiment of the present disclosure. FIG. 8 is a schematic enlarged view of the X region in FIG. 7.

[0070] A controller (e.g., the controller 340 of FIG. 4) may receive data related to thickness changes of one surface or portion of the buffing pad 200 from a scanner (e.g., the scanner 360 of FIG. 4). Further, based on the received data related to the thickness changes, the controller may control the curing device (e.g., the curing device 330 of FIG. 7) and/or the receiving container 310 so that the amount of light and/or heat delivered to one surface or portion of the buffing pad 200 through each of a plurality of zones of a bottom surface of the receiving container 310 is adjusted.

[0071] Referring to a first example X1, as the buffing pad 200 is worn during the wafer processing, thickness changes may occur in the buffing pad 200. At this time, the thickness changes caused by wear of the buffing pad 200 may vary depending on the position on one surface or portion of the buffing pad 200, i.e., worn patterns may vary in depth, size, and shape across the expanse of the buffing pad 200. For example, a thickness W1 may correspond with wear at a first region A1 of one surface or portion of the buffing pad 200, a thickness W2 may correspond with wear at a second region A2 of one surface or portion of the buffing pad 200, and a thickness W3 may correspond with wear at a third region A3 of one surface or portion of the buffing pad 200 may differ from each other.

[0072] Based on the thickness change at each region on one surface or portion of the buffing pad 200, the controller may control the height adjustment devices so that the heights of a plurality of zones Z1-Z3 of the receiving container 310 corresponding to a plurality of regions A1-A3 of the buffing pad 200 are adjusted. For example, the controller may individually adjust the height of a first zone Z1 of the receiving container 310 corresponding to the first region A1 of one surface or portion of the buffing pad 200, the height of a second zone Z2 of the receiving container 310 corresponding to the second region A2 of one surface or portion of the buffing pad 200, and the height of a third zone Z3 of the receiving container 310 corresponding to the third region A3 of one surface or portion of the buffing pad 200. In doing so, the controller may control the height adjustment devices so that, the larger the thickness change in a specific region of the buffing pad 200, the closer the distance between that specific region and the specific zone of the receiving container 310 corresponding to that specific region becomes.

[0073] As the distance between each of the plurality of regions A1-A3 of the buffing pad 200 and each of the plurality of zones Z1-Z3 of the receiving container 310 corresponding to the plurality of regions A1-A3 is adjusted by the height adjustment devices, the amount of light and/or heat delivered to the plurality of regions A1-A3 of the buffing pad 200 may be adjusted. For example, by adjusting the distances differently between the first region A1 of the buffing pad 200 and the first zone Z1 of the receiving container 310 and between the second region A2 of the buffing pad 200 and the second zone Z2 of the receiving container 310, the amount of light and/or heat delivered to the first region A1 and the second region A2 of the buffing pad 200 may be differently controlled.

[0074] The curing device may induce curing of the polymer precursor liquid PL adjacent to one surface of the buffing pad. For example, the curing device may adjust the amount of light and/or heat delivered to the first region A1 through the first zone Z1, thereby inducing curing of the polymer precursor liquid present between the first zone Z1 and the first region A1.

[0075] By controlling the amount of light and/or heat delivered differently to the plurality of regions of the buffing pad 200, the degree of curing of the polymer precursor liquid PL present between one surface or portion of the buffing pad 200 and the bottom surface of the receiving container 310 may be controlled. For example, the smaller the distance between a specific region of one surface or portion of the buffing pad 200 and the zone corresponding to that specific region, the greater the amount of light and/or heat delivered to that specific region, and the more curing progresses in the polymer precursor liquid present between that specific region and that zone.

[0076] A second example X2 is an example in which the polymer precursor liquid PL present between one surface or portion of the buffing pad 200 and the bottom surface of the receiving container 310 is cured to form a buffing layer 200P. In an embodiment, after the controller induces curing of the polymer precursor liquid PL adjacent to one surface or portion of the buffing pad 200 by using the curing device, the controller may control the plurality of height adjustment devices so that the bottom surface of the receiving container 310 is leveled. Because the bottom surfaces of the plurality of zones Z1-Z3 of the receiving container 310 become flush before the polymer precursor liquid PL is fully cured (i.e., the height adjustment device M adjust the heights of each zone Z while curing), the buffing layer 200P formed by curing of the polymer precursor liquid PL may have a planar surface when the curing process is completed.

[0077] In FIG. 8, for convenience of explanation, the plurality of regions A1-A3 of the buffing pad 200 corresponding to the plurality of zones Z1-Z3 of the receiving container 310 are shown each having a uniform height within that region, but it is not limited thereto. For example, if each of the regions A1-A3 does not have a uniform height within that region, the distance between each of the regions A1-A3 and each of the zones Z1-Z3 may be determined by using, for instance, an average height of each region.

[0078] FIG. 9 is a diagram showing a buffing pad regeneration device according to an embodiment of the present disclosure. The buffing pad regeneration device shown in FIG. 9 may be yet another example of the buffing pad regeneration device 300 shown in FIG. 4. FIG. 9 is a schematic cross-sectional view of part of the buffing pad regeneration device as viewed from a side direction (e.g., +Y-direction).

[0079] Referring to FIG. 9, the receiving container 310 may include a bottom surface divided into a plurality of zones Z and a plurality of height adjustment devices M configured to adjust the height of each of the plurality of zones Z. The curing device 330 may include a plurality of sub-curing devices 330_1-330_ncorresponding to the plurality of zones Z, e.g., one per zone Z. The plurality of sub-curing devices 330_1-330_nmay be disposed below the plurality of zones Z. A specific height adjustment device (e.g., a first height adjustment device M1) among the plurality of height adjustment devices M may adjust the height of a specific zone (e.g., a first zone Z1) of the bottom surface and the height of a specific sub-curing device (e.g., a first sub-curing device 330_1) corresponding to that zone. For example, the one zone of the bottom surface and the sub-curing device corresponding to that zone may be formed integrally and may move together by the height adjustment device.

[0080] A controller (e.g., the controller 340 of FIG. 4) may receive data related to the thickness changes of the lower portion of the buffing pad from a scanner (e.g., the scanner 360 of FIG. 4), and may control the height adjustment devices M based on the received data. For example, the controller may receive data related to the thickness change of a first region of the buffing pad corresponding to the first zone Z1 of the bottom surface. Further, based on the received data related to the thickness change, the controller may control a first height adjustment device M1 corresponding to the first zone Z1 so that the distance between the first zone Z1 (the first sub-curing device 330_1) and the first region of the buffing pad is adjusted.

[0081] In an embodiment, the controller may control the first height adjustment device M1 so that, the larger the thickness change in the first region of the buffing pad, the closer the distance becomes between the first region of the buffing pad and the first zone Z1 of the bottom surface. As the distance between the first region of the buffing pad and the first zone Z1 of the bottom surface becomes smaller, the distance between the first region of the buffing pad and the first sub-curing device 330_1 may also become smaller. Accordingly, the amount of light and/or heat delivered by each of the plurality of sub-curing devices 330_1-330_nto the plurality of regions of the buffing pad may be adjusted as a function of the thickness changes.

[0082] In FIG. 9, the bottom surface of the receiving container 310 is illustrated as being divided into a plurality of rod-shaped zones extending in a vertical direction (e.g., Z-direction), and it is shown that the distance between the bottom surface of the receiving container 310 and the plurality of sub-curing devices 330_1-330_ndiffers depending on the zone. However, the present disclosure is not limited thereto. The distance between the plurality of zones Z and the plurality of sub-curing devices 330_1-330_n corresponding to the plurality of zones Z may be set to be the same within a range in which the plurality of height adjustment devices M do not interfere with each other. In addition, when the bottom surface of the receiving container 310 is divided into a plurality of rod-shaped zones of different lengths in order to avoid interference among the plurality of height adjustment devices M, the amount of light and/or heat delivered through the sub-curing devices corresponding to each zone may be pre-adjusted to be constant.

[0083] FIG. 10 is a diagram showing a buffing pad regeneration device according to an embodiment of the present disclosure. The buffing pad regeneration device shown in FIG. 10 may be yet another example of the buffing pad regeneration device 300 shown in FIG. 4. A first example is a schematic cross-sectional view of part of the buffing pad regeneration device as viewed from a side direction (e.g., +Y-direction).

[0084] Referring to FIG. 10, the receiving container 310 may include a bottom surface divided into a plurality of zones Z and a plurality of height adjustment devices M configured to adjust the height of the plurality of zones Z. The curing device 330 may be disposed on a lower side of the receiving container 310. By way of example, a ring-shaped curing device 330 may be disposed so as to surround the lower side of the receiving container 310 as a whole. In another example, a plurality of curing devices 330 may be symmetrically arranged on the lower side of the receiving container 310.

[0085] FIG. 11 is a diagram showing examples of the receiving container 310 according to various embodiments of the present disclosure. FIG. 11 illustrates various examples 110a-110e of the receiving container 310 of the buffing pad regeneration device (e.g., the buffing pad regeneration device 300 of FIGS. 1 and 2).

[0086] A regenerated buffing pad may have a shape corresponding to the shape of the bottom surface 312 of the receiving container 310. For example, the polymer precursor liquid contained in the receiving container 310 may be cured on the buffing pad in a shape corresponding to the shape of the bottom surface 312 of the receiving container 310.

[0087] By way of example, when a specific position of the buffing pad is cured in a protruding shape, the contact area between that position and a wafer may increase, thereby increasing cleaning power at that position. In other words, the bottom surface 312 of the receiving container 310 may have various shapes depending on the shape of the buffing pad to be regenerated and/or the intended use of the buffing pad. Various shapes of the receiving container 310 may be replaced and used within the buffing pad replacement device depending on the intended use of the buffing pad to be regenerated i.e., the shape of the buffing layer 200P may be changed to accommodate another use of the buffing pad.

[0088] FIG. 12 is a diagram schematically showing a chemical mechanical polishing device 10 according to an embodiment of the present disclosure. The chemical mechanical polishing device 10 may include a stage 100, a buffing pad 200, and a buffing pad regeneration device 300. The buffing pad regeneration device 300 may include a receiving container 310, a driving device 320, a curing device 330, and a controller 340. In FIG. 12, redundant descriptions of components corresponding with FIGS. 1-4 are omitted.

[0089] In an embodiment, a polymer precursor liquid used for regenerating the buffing pad 200 may include a foaming agent. The foaming agent may be injected by a foaming agent injection device. Accordingly, the buffing pad 200 regenerated by the buffing pad regeneration device 300 may have a porous structure. Due to the porous structure of the buffing pad 200, the buffing pad 200 may uniformly distribute pressure on the wafer and may remove foreign substances more effectively during wafer processing.

[0090] In another embodiment, a laser irradiation device 370 may form an etching pattern on one surface or portion of the buffing pad 200. The etching pattern formed by the laser irradiation device 370 may replace the porous structure of the buffing pad 200 or be used in combination with the porous structure. For example, the laser irradiation device 370 may physically form an etching pattern by irradiating a laser onto at least part of one surface or portion of the buffing pad 200 in which the polymer precursor liquid is cured.

[0091] In yet another embodiment, the buffing pad regeneration device 300 may form an etching pattern on one surface or portion of the buffing pad 200 by means of a fluid jet device. For example, the fluid jet device may physically form an etching pattern by jetting a fluid onto at least part of one surface or portion of the buffing pad 200 in which the polymer precursor liquid is cured. An example in which an etching pattern is physically formed on one surface or portion of the buffing pad 200 by the laser irradiation device 370 or by a fluid jet device is described below with reference to FIG. 13.

[0092] In yet another embodiment, the buffing pad regeneration device 300 may form an etching pattern on one surface or portion of the buffing pad 200 by means of a polymer removal device. For example, the curing device 330 may induce curing of the polymer precursor liquid adjacent to one surface or portion of the buffing pad 200 according to a specific pattern. The polymer removal device may form an etching pattern by removing incompletely cured polymer from the buffing pad 200 in accordance with the specific pattern. For example, the polymer removal device may remove incompletely cured polymer by chemical reaction. An example in which an etching pattern is formed on one surface or portion of the buffing pad 200 by the polymer removal device is described below with reference to FIG. 14.

[0093] In an embodiment, the buffing pad regeneration device 300 may further include a cleaning nozzle 380. The cleaning nozzle 380 may clean the buffing pad 200 worn during processing of the wafer. The controller 340 may control the cleaning nozzle 380 so that the one surface or portion of the buffing pad 200 is cleaned before the buffing pad 200 is immersed in the polymer precursor liquid (for example, before the buffing pad 200 undergoes a regeneration process).

[0094] FIG. 13 is a diagram for explaining an example in which an etching pattern is formed on one surface or portion of the buffing pad 200 according to an embodiment of the present disclosure. An operation in which the buffing pad regeneration device (the buffing pad regeneration device 300 of FIG. 12) forms an etching pattern on the buffing pad 200 may be controlled by a controller (e.g., the controller 340 of FIG. 12).

[0095] The buffing pad regeneration device may include a receiving container for holding the polymer precursor liquid, a driving device 320 for inserting or withdrawing the buffing pad 200 with respect to the receiving container, a curing device for inducing curing of the buffing pad 200, and a laser irradiation device 370 for forming an etching pattern on one surface or portion of the buffing pad 200 in which the polymer precursor liquid is cured. The buffing pad 200 may be connected to one end of a support arm 322 included in the driving device 320, and may move according to the operation of the support arm 322.

[0096] A first example 130a may show a state in which the buffing pad 200 is pulled out from the receiving container. Here, the buffing pad 200 may be a regenerated/formulated buffing pad in which a buffing layer 200P has been formed by curing of the polymer precursor liquid in accordance with embodiments described herein.

[0097] A second example 130b shows an example in which a laser is irradiated onto the buffing layer 200P of the buffing pad 200. The support arm 322 may move the buffing pad so that the buffing layer 200P of the buffing pad 200 is positioned over the laser irradiation device 370. The laser irradiation device 370 may etch the buffing layer 200P by irradiating a laser onto at least part of the buffing layer 200P.

[0098] A third example 130c shows an example in which an etching pattern is formed on the buffing layer 200P of the buffing pad 200. The etching pattern of the buffing layer 200P may impart elasticity and flexibility so that the buffing pad 200 delivers uniform pressure to the wafer.

[0099] In FIG. 13, an example is shown in which the etching pattern is formed on the buffing pad 200 by the laser irradiation device 370, but the present disclosure is not limited thereto. For example, an etching pattern may be formed on the buffing pad 200 by a fluid jet device. For example, the support arm 322 may move the buffing pad so that the buffing layer 200P of the buffing pad 200 is positioned over the fluid jet device, and the fluid jet device may physically form an etching pattern on the buffing layer 200P by jetting a fluid onto at least part of the buffing layer 200P.

[0100] FIG. 14 is a diagram for explaining an example in which an etching pattern is formed on one surface or portion of the buffing pad 200 according to an embodiment of the present disclosure. An operation in which the buffing pad regeneration device (the buffing pad regeneration device 300 of FIG. 12) forms an etching pattern on the buffing pad 200 may be controlled by a controller (e.g., the controller 340 of FIG. 12).

[0101] The buffing pad regeneration device may include a receiving container 310 for receiving the polymer precursor liquid, a driving device 320 for inserting or withdrawing the buffing pad 200 with respect to the receiving container 310, a curing device 330 for inducing curing of the buffing pad 200, and a polymer removal device 390 for forming an etching pattern on one surface or portion of the buffing pad 200 in which the polymer precursor liquid is cured. The buffing pad 200 may be connected to one end of a support arm 322 included in the driving device 320, and may move according to the operation of the support arm 322.

[0102] A first example 140a may show a state in which one surface or portion of the buffing pad 200 is immersed in the polymer precursor liquid contained in the receiving container 310. Here, the buffing pad 200 may be a buffing pad that has been worn in the wafer processing and requires regeneration.

[0103] The curing device 330 may irradiate light onto one surface or portion of the buffing pad 200 immersed in the polymer precursor liquid or heat one surface or portion of the buffing pad 200. In this case, the curing device 330 may control the degree of curing of one surface or portion of the buffing pad 200 according to a specific pattern by irradiating light or applying heat to one surface or portion of the buffing pad 200 according to the specific pattern. For example, a photomask with a specific pattern may be disposed between the curing device 330 and the receiving container 310.

[0104] A second example 140b may show a state in which the buffing pad 200 is pulled out from the receiving container. As the degree of curing of one surface or portion of the buffing pad 200 is controlled by the curing device 330, the buffing layer 200P may include incompletely cured polymer. As a specific example, a first pattern region of one surface or portion of the buffing pad 200 may be irradiated with light of a first amount, and a second pattern region of one surface or portion of the buffing pad 200 may be irradiated with light of a second amount lower than the first amount or may not be irradiated with light. Here, the first pattern region may be an area where light is irradiated, and the second pattern region may be an area where light is blocked by the photomask. Accordingly, curing in the first pattern region may proceed further than in the second pattern region, and polymer in the second pattern region may remain incompletely cured.

[0105] A third example 140c shows an example in which incompletely cured polymer in the buffing layer 200P of the buffing pad 200 is removed. The support arm 322 may move the buffing pad so that the buffing layer 200P of the buffing pad 200 is positioned over the polymer removal device 390. The polymer removal device 390 may form an etching pattern by jetting fluid or irradiating a laser onto the incompletely cured polymer region of the buffing layer 200P.

[0106] In an embodiment, the fluid jetted by the polymer removal device 390 may include a substance for melting or chemically reacting with the polymer to remove the polymer. The polymer removal device 390 may remove the polymer of the incompletely cured polymer region of the buffing layer 200P by targeting that region with jetted fluid.

[0107] A fourth example 140d shows an example in which an etching pattern is formed on the buffing layer 200P of the buffing pad 200.

[0108] FIG. 15 is a flowchart illustrating a buffing pad regeneration method 150 according to an embodiment of the present disclosure. The buffing pad regeneration method 150 may be performed by a buffing pad regeneration device included in a chemical mechanical polishing device. The buffing pad regeneration device may include a receiving container, a driving device, a curing device, and a controller.

[0109] The buffing pad regeneration method 150 may begin by supplying a polymer precursor liquid into the receiving container of the buffing pad regeneration device in a supply process S151. In an embodiment, the buffing pad regeneration device may include a liquid supply device configured to supply the polymer precursor liquid into the receiving container. The liquid supply device may supply the polymer precursor liquid into the receiving container.

[0110] In an embodiment, the liquid supply device may include a liquid injection device disposed at a first side of the receiving container to inject the polymer precursor liquid into the receiving container, a liquid discharge device disposed at a second side of the receiving container to discharge the polymer precursor liquid contained in the receiving container, and a liquid circulation device connected to the liquid injection device and the liquid discharge device for circulating the polymer precursor liquid. Additionally, the liquid supply device may further include a foaming agent injection device configured to inject a foaming agent into the polymer precursor liquid.

[0111] In an embodiment, the buffing pad regeneration device may further include a cleaning nozzle for cleaning a buffing pad worn in the wafer processing. Accordingly, before the buffing pad is immersed in the polymer precursor liquid, the controller may control the cleaning nozzle to clean one surface or portion of the buffing pad.

[0112] Then, the driving device of the buffing pad regeneration device may insert at least a portion of the buffing pad into the receiving container so that one surface or portion of the buffing pad is immersed in the polymer precursor liquid in an immersion process S152. In an embodiment, the driving device may include a support arm connected to the buffing pad. The controller may control the support arm so that the buffing pad worn during processing of the wafer on the stage is moved to the receiving container.

[0113] Then, the curing device of the buffing pad regeneration device may induce curing of the polymer precursor liquid adjacent to one surface or portion of the buffing pad in a curing process S153. By way of example, the curing device disposed below the receiving container may irradiate light onto one surface or portion of the buffing pad. In this case, the bottom surface of the receiving container may include a light-transmitting material for transmitting the light irradiated from the curing device therethrough. In another example, the curing device disposed below the receiving container may heat one surface or portion of the buffing pad through the bottom surface of the receiving container. In this case, the bottom surface of the receiving container may include a thermally conductive material.

[0114] In an embodiment, the controller of the buffing pad regeneration device may control the curing device and/or the receiving container based on the thickness change amount caused by wear of one surface or portion of the buffing pad. In this case, the buffing pad regeneration device may further include a scanner that measures thickness changes caused by wear on one surface or portion of the buffing pad. Also, the receiving container may include a bottom surface that faces one surface or portion of the buffing pad. The bottom surface may be divided into a plurality of zones. One surface or portion of the buffing pad may include a plurality of regions corresponding to the plurality of zones. Accordingly, the controller may receive data related to the thickness changes from the scanner and, based on the received data, control the curing device to adjust the amount of light or heat delivered from the curing device to each of the plurality of zones and/or each of the plurality of regions.

[0115] In another example, the receiving container may further include a plurality of height adjustment devices configured to adjust the height of each of the plurality of zones. In this case, based on the data related to the thickness changes, the controller may control the plurality of height adjustment devices so that the distance between each of the plurality of zones and one surface or portion of the buffing pad is adjusted. Also, after inducing curing of the polymer precursor liquid adjacent to one surface or portion of the buffing pad by using the curing device, the controller may control the plurality of height adjustment devices so that the bottom surface of the receiving container is leveled.

[0116] In yet another example, one surface or portion of the buffing pad may include a plurality of regions, and the curing device may include a plurality of sub-curing devices corresponding to the plurality of zones. The plurality of sub-curing devices may be disposed below the plurality of zones, and the plurality of height adjustment devices may adjust the height of the plurality of zones and the plurality of sub-curing devices. In this case, the controller may control the plurality of height adjustment devices such that the larger the thickness change caused by wear measured at a specific region among the plurality of regions, the smaller the distance becomes between that specific region and the specific sub-curing device corresponding to that specific region.

[0117] Then, the driving device of the buffing pad regeneration device may pull out the buffing pad from the receiving container after the polymer precursor liquid is cured. At this time, if the polymer precursor liquid is incompletely cured, the controller may control the driving device so that the buffing pad pulled out from the receiving container may be naturally cured for a predetermined period.

[0118] Subsequently, the buffing pad regeneration device may form an etching pattern on one surface or portion of the buffing pad in which the polymer precursor liquid is cured. For example, if the buffing pad regeneration device includes a laser irradiation device, the laser irradiation device may form an etching pattern by irradiating a laser onto at least part of one surface or portion of the buffing pad.

[0119] In another example, if the buffing pad regeneration device includes a fluid jet device, the fluid jet device may form an etching pattern by jetting a fluid onto at least part of one surface or portion of the buffing pad.

[0120] In yet another example, if the buffing pad regeneration device includes a polymer removal device, the curing device may induce curing of the polymer precursor liquid adjacent to one surface or portion of the buffing pad according to a specific pattern, and the polymer removal device may remove incompletely cured polymer from the buffing pad in accordance with the specific pattern. The step of forming an etching pattern may be omitted when the polymer precursor liquid containing a foaming agent is used, but the present disclosure is not necessarily limited thereto.

[0121] It will be understood that, although the terms "first", "second", "third", and so on may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section described below could be termed a second element, component, region, layer or section, without departing from the spirit and scope of the present disclosure.

[0122] It will be understood that spatially relative terms such as “above,” “upper,” “upper portion,” “upper surface,” “below,” “lower,” “lower portion,” “lower surface,” “side surface,” and the like may be denoted by reference numerals and refer to the drawings, except where otherwise indicated. It will be understood that such 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. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein may be interpreted accordingly.

[0123] The terms “comprises,” “comprising,” “includes” and/or “including,” when used herein, specify the presence of stated elements, but do not preclude the presence of additional elements. The term “and/or” includes any and all combinations of one or more of the associated listed items. The term “connected” may be used herein to refer to a physical and/or electrical connection. The term “surrounding” or “covering” or “filling” as may be used herein may not require completely surrounding or covering or filling the described elements or layers, but may, for example, refer to partially surrounding or covering or filling the described elements or layers, for example, with voids, spaces, or other discontinuities throughout.

[0124] While example embodiments of the inventive concept have been particularly shown and described, it will be understood by one of ordinary skill in the art that variations in form and detail may be made therein without departing from the spirit and scope of the attached claims.