Chiller make-break connector for substrate processing system

Abstract

To provide a substrate processing system for connecting a chiller to a processing chamber.SOLUTION: A substrate processing station 400 includes a slide and pivot assembly 402 which allows a process module bias assembly 406 to slide and pivot relative to remaining components of a processing chamber 404, and which allows the process module bias assembly 406 to be pulled out away from the processing chamber 404 and pivoted up to a predetermined angle relative to a front face of the processing chamber 404. The process module bias assembly 406 includes a housing 408, and a portion 410 of a process module including a process bias bowl 412, and may include, in addition to the process bias bowl 412, an electrostatic chuck and / or other substrate support, and a top plate assembly.SELECTED DRAWING: Figure 4A

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 62 / 984,081, filed March 2, 2020. The disclosures of the above-referenced applications are hereby incorporated by reference in their entireties.

[0002] Technical Field The present disclosure relates to substrate processing systems, and more particularly to a system for connecting a chiller to a processing chamber. [Background technology]

[0003] The "Background" section provided herein is intended to provide a general background to the present disclosure. To the extent described in the "Background" section of the present disclosure, the work of the inventors named herein, as well as aspects of the present disclosure that may not be considered prior art at the time of filing, are not admitted, expressly or impliedly, as prior art to the present disclosure.

[0004] A substrate processing system may be used to treat a substrate, such as a semiconductor wafer. Examples of processes that may be performed on the substrate include, but are not limited to, chemical vapor deposition (CVD), atomic layer deposition (ALD), conductor etching, and / or other etching, deposition, or cleaning processes. The substrate may be placed on a substrate support, such as a pedestal, electrostatic chuck (ESC), or the like, in a processing chamber of the substrate processing system. During etching, a gas mixture including one or more precursors may be introduced into the processing chamber, and a plasma may be used to initiate a chemical reaction. Summary of the Invention

[0005] A substrate processing system includes a hinge assembly configured to allow a substrate support and an RF bias assembly of a processing chamber to slide from a docked position to an undocked position relative to other components of the processing chamber. An opening and closing connector is configured to provide a fluid to at least one of the substrate support and the RF bias assembly. The opening and closing connector includes a first portion including a first fluid passage connected to a first conduit. A second portion includes a second fluid passage connected to a second conduit. The first fluid passage in the first portion is in fluid communication with the second fluid passage in the second portion. A fastener removably connects the first portion to the second portion. The first portion is configured to slide with the substrate support and the RF bias assembly relative to the second portion and other portions of the processing chamber. The first portion is located inwardly from the second portion relative to a direction of sliding from the docked position to the undocked position.

[0006] In other features, when the opening and closing connector is in the docked position, the first portion is connected to the second portion. When the opening and closing connector is in the undocked position, the first portion is disconnected from the second portion. The hinge assembly is configured so that the substrate support and the RF bias assembly slide from the docked position to the undocked position and then pivot through a predetermined angle greater than 90 degrees.

[0007] In another feature, the openable connector is disposed inside the housing. The housing is connected to a gas source and is purged during operation. The gas source is molecular nitrogen or clean dry air.

[0008] In other features, the first portion includes a third fluid passage connected to a third conduit, the second portion includes a fourth fluid passage connected to a fourth conduit, and the third fluid passage in the first portion is in fluid communication with the fourth fluid passage in the second portion.

[0009] The tool includes an equipment front-end module (EFEM), a substrate transfer module, a load lock disposed between the EFEM and the substrate transfer module, and 2N substrate processing systems as claimed in claim 1, where N is an integer between 1 and 5. Half of the 2N substrate processing systems are disposed on one side of the substrate transfer module, and the other half of the 2N substrate processing systems are disposed on the opposite side of the substrate transfer module.

[0010] In other features, a first portion of the opening and closing connector includes a plurality of holes and a second portion of the opening and closing connector includes a plurality of alignment pins that respectively mate with the plurality of holes when the first portion is connected to the second portion.

[0011] Further areas of applicability of the present disclosure will become apparent from the detailed description, claims, and drawings. The detailed description and specific examples are for illustrative purposes only and are not intended to limit the scope of the disclosure.

[0012] The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein: [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a perspective view of a portion of two tools including an exemplary slide and pivot assembly.

[0014] [Diagram 2] FIG. 2 is a top view of a portion of one of the tools of FIG.

[0015] [Diagram 3] FIG. 3 is a side view of a portion of one of the tools of FIG.

[0016] [Figure 4A] FIG. 4A is a top view of an embodiment of a substrate processing station including a slide and pivot assembly.

[0017] [Figure 4B] FIG. 4B is a simplified cross-sectional view of an embodiment of a substrate support.

[0018] [Diagram 5] FIG. 5 is a side view of one embodiment of a processing station including a housing for an opening and closing fluid connector according to the present disclosure.

[0019] [Figure 6] FIG. 6 is a perspective view of an embodiment of a housing for a closing connector for cooling fluid delivered to a processing station according to the present disclosure.

[0020] [Figure 7] FIG. 7 is a perspective view of an embodiment of a housing with the cover removed in accordance with the present disclosure.

[0021] [Figure 8] FIG. 8 is a side view of an embodiment of a switchable connector in a connected position according to the present disclosure. [Figure 9] FIG. 9 is a side view of an embodiment of a switchable connector in a disconnected position according to the present disclosure.

[0022] [Figure 10] FIG. 10 is a side cross-sectional view of an embodiment of a switchable connector in a disconnected position according to the present disclosure.

[0023] [Figure 11] FIG. 11 shows various views of the alignment pins of the opening and closing connector. [Figure 12] FIG. 12 shows various views of the alignment pins of the opening and closing connector. [Figure 13] FIG. 13 shows various views of the alignment pins of the opening and closing connector. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] In the drawings, reference numbers may be reused to identify similar and / or identical elements.

[0025] A semiconductor manufacturing (fab) room may include multiple tools, each of which may include multiple substrate processing stations (hereafter referred to as "stations"). Each of the stations may be configured to perform a conductor etch process, a dielectric etch process, or other substrate processing. Space within a fab room is limited, thus limiting the amount of space available to access each of the tools to perform maintenance and / or servicing on the stations. The tool stations may be arranged in a star pattern or a linear pattern.

[0026] In a star pattern, the stations are arranged around a centrally located substrate transport module that contains a robot that moves substrates from the load lock chamber to each of the substrate processing stations and back to the load lock. This arrangement of stations provides some access space between the stations, but the density of the stations is less than if they were arranged in a linear pattern.

[0027] In a linear pattern, the stations are configured side-by-side to form two rows of stations. The rows are located on either side of a substrate transport module that may operate at atmospheric pressure or vacuum. The linear configuration allows more stations to be placed within a dedicated footprint, but the linear configuration limits access to the sides of the stations.

[0028] To improve serviceability, the processing station may include a sliding and pivoting assembly such that the lower portion of the processing chamber (including the front or passage-facing wall of the processing chamber, the substrate support, and the RF bias assembly) can slide out and then pivot between adjacent tools. In some embodiments, the substrate support includes a base plate having coolant channels through which fluid can flow to control the temperature of the substrate support and a substrate disposed thereon. The top plate assembly can be removed for servicing, maintenance, or replacement. The remainder of the processing chamber remains in the same position.

[0029] Before the sliding and pivoting assembly is moved to the maintenance position, the connections to the substrate support and the RF biasing assembly need to be disconnected. In some embodiments, the substrate support and / or the RF biasing assembly may be cooled by a fluid. Thus, before the sliding and pivoting assembly is moved to the maintenance position, the fluid connections need to be disconnected. In some embodiments, a combination of rigid and flexible conduits is used. Some parts of the fluid delivery components remain in place with the rest of the processing chamber, while other parts of the fluid delivery components move with the sliding and pivoting assembly. As can be seen, it is difficult to provide reliable open and closed fluid connections in the relatively limited space below the biasing assembly.

[0030] 1 and 2 show a portion of two tools 100, 102 (one solid line indicated at 100, the other dashed line indicated at 102) arranged side-by-side in a fab room. Each of the tools includes two rows of stations (one row is shown for each of the tools). The stations are located adjacent to a substrate transfer module (not shown in FIG. 1 for clarity). The space between the tools 100, 102 is limited. The width of the passage between the tools 100, 102 is indicated as W. The width W provides a minimum amount of space between the tools 100, 102 to open the processing chambers of the stations and access the interior of the process modules and the corresponding processing chambers.

[0031] The embodiments described herein include slide and pivot assemblies that can be withdrawn from and pivoted away from the corresponding processing chambers to allow for maintenance or servicing to be performed in the passageway. The slide and pivot assemblies are configured to be repeatedly moved from a fully docked state to a fully undocked state and back to the same fully docked location. As an example, the slide and pivot assemblies are configured to return the process module bias assembly to within ±25 micrometers (μm, referred to as microns) of the fully docked state. The slide and pivot assemblies are configured to handle and compensate for the heavy load of the process module bias assembly. An example of the total weight of the process module bias assembly and the corresponding slide and pivot assemblies is about 300 kilograms (kg).

[0032] The tools 100, 102 include a front opening integrated pod (FOUP) 104, an equipment front end module (EFEM) and load lock 106, a station having a radio frequency generator 107 and a gas box 108, and a power lockout and tagout panel 110. The station further includes a process module bias assembly 112, which includes respective slide and pivot assemblies (shown in FIG. 4).

[0033] Each of the stations, alone or in combination, may be referred to as a substrate processing system. Each of the stations may be used to etch a substrate, for example, using radio frequency (RF) plasma. Each station includes a processing chamber, such as an inductively coupled plasma (ICP) chamber or a conductively coupled plasma (CCP) chamber. The stations may perform, for example, a conductor etch process or a dielectric etch process, or other substrate processing.

[0034] 2 shows a top view of the tool 100. The tool 100 includes a FOUP 104, an EFEM and load lock 106, a station 109, and a power lockout and tagout panel 110. The tool has an overall footprint 220. The tool further includes a substrate transfer module 222 for transferring substrates to and from the station 109. The substrate transfer module 222 may include robots 224, 226 and a buffer 228 for temporary storage of substrates. The robots 224, 226 transfer substrates to and from the station 109 and the buffer 228. In some embodiments, the substrate transfer module 222 operates at vacuum or atmospheric pressure.

[0035] 3 shows a side view of tool 100. Tool 100 includes a FOUP 104, an EFEM and load lock 106, a station 109, and a power lockout and tagout system 110. The station includes a process module bias assembly having an RF generator and gas box (collectively referred to as 300), and a slide and pivot assembly 112. The RF generator may provide RF power to an electrode on the station's substrate support. The gas box provides gas to the station's processing chamber. A substrate transfer module 222 is also shown.

[0036] Substrates to be loaded and processed are stored in the FOUP 104. Substrates are transferred by robots 224, 226 from the FOUP 104 through the EFEM and load lock 106 to the station 109 through the respective load port 302. In some embodiments, an RF generator and gas box 300 is located above the station 109 to provide RF power and process gases to the process modules of the station 109.

[0037] 4A shows a substrate processing station 400 that includes a slide and pivot assembly 402. The slide and pivot assembly 402 allows a process module bias assembly 406 to slide and pivot relative to the remaining components of a processing chamber 404. The slide and pivot assembly 402 allows the process module bias assembly 406 to be withdrawn from the processing chamber 404 and pivoted to a predetermined angle relative to the front surface of the processing chamber 404. The process module bias assembly 406 includes a housing 408, a portion 410 of a process module that includes a process bias bowl 412. In addition to the process bias bowl 412, the process module bias assembly 406 may include an electrostatic chuck and / or other substrate support, as shown in FIG. 4B, and a top plate assembly.

[0038] An exemplary width W of the passageway between station 400 and the opposing station is shown to indicate that the process module bias assembly 406 can slide and pivot into the passageway. This provides an open space 414 to the right of the slide and pivot assembly 402 for a technician to access the process bias bowl 412 and the interior of the processing chamber 404 for maintenance and servicing purposes, including wet cleaning. The process bias bowl 412 and the interior of the processing chamber 404 are accessed from the right side of the process module bias assembly 406 without interference. For example, no slides, rails, and / or other components are located in the open space 414 so that they do not interfere with a technician accessing the interior of the processing chamber. Although the process module bias assembly 406 is shown to pivot to the left, the slide and pivot assembly may be configured and mounted to the right side of the processing chamber such that the process module and bias assembly are extended and pivoted to the right relative to the processing chamber.

[0039] 4B shows the substrate support 460 including a heating layer 470 that includes an electrostatic electrode 472 and / or an RF bias electrode 474. The heating layer 470 may be made of ceramic or other material and is bonded to a base plate 482 by a bonding layer. The base plate 482 is typically made of aluminum and includes coolant channels 480 and fluid passages 484 and 486 to supply coolant to and receive coolant from the base plate 482. The coolant helps to control the temperature of the substrate support and the substrate during processing.

[0040] 5, one of the stations is shown looking inward from the passageway. The station includes an upper portion 510 and a lower portion 514. The upper portion 510 includes a process module bias assembly and a substrate support with a slide and pivot assembly 112. The slide and pivot assembly 112 of the upper portion 510 allows the process module to slide outward into the passageway and then pivot to allow access for cleaning, servicing, or other maintenance. In some embodiments, the slide and pivot assembly of the upper portion 510 pivots outward 90° or more to allow greater access to the processing chamber. The lower portion 514 remains in the same position and includes an enclosure 520 with a removable cover 524. Other components 518 of the processing module (e.g., other fluid and / or electrical components and / or enclosure) are located between the enclosure of the lower portion 514 and the lower edge of the upper portion 510. In some embodiments, the walls of the enclosure and / or conduits within or outside the enclosure may be insulated to prevent condensation.

[0041] As will be further explained below, the inner portion of the open / close connector (see FIG. 7 ), housed within the housing 520, slides outward with the slide and pivot assembly 112 into the passageway. Before sliding or pivoting, the outer portion of the open / close fluid connector is pulled outward and downward to allow the inner portion to move unobstructed. Using this configuration (where the second portion is located outward relative to the first portion), alignment and connection of the second portion to the first portion is easier (compared to when the second portion is located inside the first portion). Furthermore, the partial use of flexible lines avoids tolerance stack-up that would occur with fluid delivery using only rigid lines.

[0042] 6, an enclosure 520 for the open / close connector for cooling fluid delivered to a station is shown in further detail. The enclosure 520 includes a vertical housing section 610 and a horizontal housing section 612 that connects to the vertical housing section 610. The vertical housing section 610 and the horizontal housing section 612 of the enclosure 520 define an interior volume that houses the open / close connector (see FIG. 7) and other components.

[0043] The cover 524 is connected to the side walls 616, 618, 620, 622 and the top surface 624 of the housing 520 by fasteners 614. In some embodiments, the cover 524 includes a vertical surface 626 facing the passageway and a top surface 630 extending inwardly at an angle, such as 90°, relative to the surface 626 facing the passageway. The top surface 630 includes an opening 634 to allow a fluid conduit 638 and a connector 640 to pass through. A flexible sealing material 641 is disposed between the top surface 630 and an upper surface of the side walls 616 to form a seal around the fluid conduit 638. In some embodiments, the flexible sealing material 641 includes a foam material having holes and / or slits extending from the holes to one end of the flexible sealing material 641 to allow attachment of the fluid conduit 638.

[0044] The horizontal housing section 612 includes a cover 650, a sidewall 652, and a bottom 654. An opening 656 in the sidewall 652 and a flexible sealing material 658 (a foam with holes and slits, as described above) can be used to provide a flexible seal for a connector 660, which can include fluid and / or electrical connectors.

[0045] 7, the housing 520 is shown with the cover 524 (see FIG. 6) removed. A closure connector 720 is located within the housing 520 and includes a first portion 722 connected to a second portion 726 by one or more fasteners 724. In some embodiments, the fasteners 724 include threaded bolts. As shown and described below with reference to FIGS. 11-13, the second portion 726 includes two (or more) alignment pins 728, 732. The alignment pins pass through corresponding holes 736, 738 in the first portion 722 to facilitate mounting the first portion 722 onto the second portion 726.

[0046] The first portion 722 is located adjacent to the passageway, and the second portion 726 is disposed inwardly relative to the first portion 722 toward the substrate transport module. The ends of the conduits 730 and 744 are connected to the first portion 722. The ends of the conduits 734 and 746 are connected to the opposite ends of the conduits 730 and 744. In some embodiments, the conduits 730 and 744 are rigid lines and the conduits 734 and 746 are flexible lines. By way of example only, the conduits 730 and 744 are joined to the conduits 734 and 746, respectively, by miter joints, as shown. Alternatively, the conduits 730 and 734 may be joined by a tube having a rounded bend. Additionally, if the height of the housing 520 allows, the conduits 744 and 746 may also be joined by a tube having a rounded bend.

[0047] A conduit 760 is connected to second portion 726. In some embodiments, conduit 760 comprises a rigid line and / or a flexible line. Housing 520 includes a flange 750 extending inwardly from a side thereof. Flange 750 includes holes for receiving fasteners to attach cover 524 to housing 520. When cover 524 is attached, tabs 770 on the top edge of housing 520 can be used to mate with protrusions on the top and inner end of cover 524.

[0048] 8-10, the openable connector 720 is shown in a connected position (see FIG. 8) and a disconnected position (see FIGS. 9 and 10). In these figures, the alignment pins 728, 732 and the holes 736, 738 have been omitted in order to illustrate other features of the openable connector 720. The first portion 722 includes openings that are fluidly connected to the channels 810 and 812 on its side 822. The channels 810 and 812 are aligned with the ends of the conduits 730 and 744 (see FIG. 7). The channels 810 and 812 extend into the first portion 722 and then turn 90 degrees toward the side 826 of the first portion 722 that abuts the second portion 726 (see channels 870 and 872, respectively). The channels 874 and 876 in the second portion 726 are in fluid communication with the channels 870 and 872. A seal (e.g., O-ring 860 disposed in groove 862) may be disposed on the abutting surface between first portion 722 and second portion 726 around the fluid connection between channels 870 and 872 and channels 874 and 876. Channel 874 turns 90° upward and exits the top surface of second portion 726. One end of channel 874 connects to conduit 760. Channel 876 extends horizontally through the back wall of second portion 726 and includes one end in fluid communication with conduit 830.

[0049] A hole 840 in the first portion 722 and a threaded hole 842 in the second portion 726 receive a threaded fastener to connect the first portion 722 and the second portion 726 together. When it is necessary to move the slide and pivot assembly from the closed position to the maintenance position, the first portion 722 and the second portion 726 of the opening and closing connector are pulled apart and the first portion 722 is pulled forward and downward as shown in Figure 9. As can be seen, the conduits 734 and 746 are flexible and capable of bending.

[0050] In other words, the fastener 724 (see FIG. 7) is removed and the first portion 722 is pulled outward toward the passageway and in a downward direction as indicated by arrow 890. The second portion 726, located behind the first portion 722, remains with the slide and pivot assembly and moves in the direction indicated by arrow 892.

[0051] 10, the enclosure 520 can be purged by a gas source 1010 connected to the enclosure 520 by a conduit and optional valve 1014. The enclosure 520 can be connected to an exhaust system 1022 by a conduit and optional valve 1020. In some embodiments, the gas source provides an inert gas, such as molecular nitrogen (N2). In other embodiments, clean dry air (CDA) is used. The use of a purged enclosure reduces condensation in the enclosure 520.

[0052] 11-13 show various views of the alignment pins 728, 732 of the openable connector 720. FIG. 11 shows a cross-sectional view of the openable connector 720. In this view, only the alignment pin 732 on the second portion 726 of the openable connector 720 and the corresponding hole 738 on the first portion 722 of the openable connector 720 are visible. In this view, the first and second portions 720, 726 of the openable connector 720 are shown mated. Thus, the alignment pins 728, 732 of the second portion 726 are shown inserted (i.e., mated) into the corresponding holes 736, 738 in the first portion 722. When the first portion 720 is mounted onto the second portion 726, the alignment pins 728, 732 guide the mounting and facilitate the insertion and fastening of fasteners into the corresponding holes 840.

[0053] 12 shows a top view of the openable connector 720. In this view, the alignment pins 728, 732 of the second portion 726 and the corresponding holes 736, 738 in the first portion 722 are visible. In this view, the first and second portions 720, 726 are again shown mated. Thus, the alignment pins 728, 732 of the second portion 726 are shown inserted (i.e., mated) within the corresponding holes 736, 738 in the first portion 722.

[0054] 13 shows a top view of the second portion 726, with the alignment pins 728, 732 visible. Note that the alignment pins 728, 732 and corresponding holes 736, 738 are shown with a rounded shape by way of example only. Alternatively, the alignment pins 728, 732 and corresponding holes 736, 738 could be any other shape (e.g., square, hexagonal, etc.).

[0055] The foregoing description is merely exemplary in nature and is not intended to limit the disclosure, its application, or uses in any way. The broad teachings of the disclosure can be embodied in various forms. Thus, while the disclosure includes specific examples, other modifications will become apparent upon study of the drawings, the specification, and the following claims, and the true scope of the disclosure should not be so limited. It should be understood that one or more steps in a method may be performed in a different order (or simultaneously) without altering the principles of the disclosure. Furthermore, although each of the embodiments is described above as having certain features, any one or more of these features described with respect to any embodiment of the disclosure may be implemented in any of the other embodiments and / or combined with features of any of the other embodiments, even if the combinations are not explicitly described. In other words, the described embodiments are not mutually exclusive, and permutations of one or more of the embodiments with one another remain within the scope of the disclosure.

[0056] Spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.) are described using various terms including "connected," "engaged," "coupled," "adjacent," "next to," "on," "above," "below," and "disposed." Unless expressly described as "direct," when a relationship between a first element and a second element is described in the disclosure above, the relationship may be a direct relationship where there are no other intervening elements between the first element and the second element, but it may also be an indirect relationship where one or more intervening elements (either spatially or functionally) exist between the first element and the second element. As used herein, the phrase at least one of A, B, and C should be interpreted to mean a logical non-exclusive OR (A OR B OR C), and not to mean "at least one of A, at least one of B, and at least one of C."

Claims

1. 1. A substrate processing system, comprising: a hinge assembly configured to allow a substrate support and an RF bias assembly of a processing chamber to slide relative to other components of the processing chamber from a docked position to an undocked position; a switchable connector configured to supply a fluid to at least one of the substrate support and the RF bias assembly, a first portion including a first fluid passageway connected to a first conduit; a second portion including a second fluid passage connected to the second conduit; a fastener for releasably connecting the first portion to the second portion; the first fluid passage in the first portion is in fluid communication with the second fluid passage in the second portion; the first portion is configured to slide together with the substrate support and the RF bias assembly relative to the second portion and other portions of the processing chamber; the first portion is located inward from the second portion in a sliding direction from the docked position to the undocked position; Substrate processing system.

2. 2. The substrate processing system according to claim 1, wherein the first portion is connected to the second portion when the openable connector is in the docking position.

3. 2. The substrate processing system of claim 1, wherein the first portion is disconnected from the second portion when the openable connector is in the undocked position.

4. 2. The substrate processing system of claim 1 , wherein the hinge assembly is configured to allow the substrate support and the RF bias assembly to slide from the docked position to the undocked position and then pivot through a predetermined angle greater than 90°.

5. The substrate processing system according to claim 1 , further comprising a housing, the opening and closing connector being disposed inside the housing.

6. 6. The substrate processing system of claim 5, wherein the enclosure is connected to a gas supply and is purged during operation.

7. 7. The substrate processing system of claim 6, wherein the gas supply is purged with molecular nitrogen.

8. 7. The substrate processing system of claim 6, wherein the gas supply is purged with clean dry air.

9. 2. The substrate processing system of claim 1, the first portion includes a third fluid passage connected to a third conduit; the second portion includes a fourth fluid passage connected to a fourth conduit; The third fluid passage in the first portion is in fluid communication with the fourth fluid passage in the second portion.

10. A tool, An equipment front-end module (EFEM); A substrate transfer module; a load lock disposed between the EFEM and the substrate transfer module; and 2N substrate processing systems according to claim 1, where N is an integer between 1 and 5; The tool, wherein half of the 2N substrate processing systems are disposed on one side of the substrate transfer module and the other half of the 2N substrate processing systems are disposed on an opposite side of the substrate transfer module.

11. 2. The substrate processing system of claim 1, The first portion of the openable connector includes a plurality of holes; A substrate processing system, wherein the second portion of the opening and closing connector includes a plurality of alignment pins that respectively mate with the plurality of holes when the first portion is connected to the second portion.

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