Cooling plate with aperiodic organic reticulated cooling passage pattern

Abstract

Cooling plates are described that include aperiodic organic reticulated patterns of cooling passage segments that provide more even and more effective cooling performance than in cooling plates that feature more regular geometric patterns of cooling passage segments.

Description

COOLING PLATE WITH APERIODIC ORGANIC RETICULATED COOLING PASSAGE PATTERNINCORPORATION BY REFERENCE

[0000] A PCT Request Form is filed concurrently with this specification as part of the present application. Each application that the present application claims benefit of or priority to as identified in the concurrently filed PCT Request Form is incorporated by reference herein in its entirety and for all purposes.

[0001] Semiconductor manufacturing processes often occur within a chamber in which a semiconductor wafer or semiconductor wafers are supported on pedestals during wafer processing operations. Such a pedestal may be positioned underneath a corresponding gas distribution system, e.g., a showerhead, that may be used to distribute process gases across the exposed side of a semiconductor wafer supported by the pedestal. Such components may, in some cases, require active cooling, e.g., via a cooling plate that may be attached to such a component and used to conduct heat away from the component. Disclosed herein are new cooling plate designs that offer more effective and efficient cooling performance as compared to more conventional designs.SUMMARY

[0002] Details of one or more implementations of the subject matter described in this specification are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages will become apparent from the description, the drawings, and the claims.

[0003] In some implementations, an apparatus may be provided that includes a cooling plate having an inlet, an outlet, a first side, a second side opposite the first side, and a plurality of first passage segments located in between the first side and the second side and internal to the cooling plate. Each first passage segment may fluidically connect with at least two of the other first passage segments at a corresponding first end of that first passage segment and with at least another two of the other first passage segments at a corresponding second end of that first passage segment opposite the first end. The first passage segments may form an aperiodic organic reticulated pattern that provides a plurality of fluid flow paths that are distributedthroughout a cooling region of the cooling plate, located within the cooling plate, and fluidically connect the inlet to the outlet within the cooling plate.

[0004] In some implementations, the cooling plate may further include one or more second passage segments, each second passage segment having a first end that fluidically connects with one or more of the first passage segments and a second end that does not connect to any other passage segment.

[0005] In some implementations, most of the first passage segments may be located within a first annular zone having a first plurality of irregularly shaped columns distributed throughout, each irregularly shaped column in the first plurality of irregularly shaped columns may extend between a first interior surface of the cooling plate and a second interior surface of the cooling plate, and each first passage segment may be bounded by the first interior surface and the second interior surface and may be positioned between two of the irregularly shaped columns in the first plurality of irregularly shaped columns.

[0006] In some such implementations, at least some of the irregularly shaped columns in the first plurality of irregularly shaped columns may be only partially within the first annular zone.

[0007] In some implementations, the portion of the cooling plate within the first annular zone and bounded by the first interior surface and the second interior surface may have an average porosity of between 40% and 70%.

[0008] In some implementations, the inlet and the outlet may be positioned within a common quadrant of the first annular zone, a separator wall may be interposed between the inlet and the outlet, and the separator wall may provide a contiguous barrier to fluid flow and may extend between an inner perimeter of the first annular zone and an outer perimeter of the first annular zone.

[0009] In some such implementations, the inlet may be positioned proximate the inner perimeter of the first annular zone and the outlet may be positioned proximate the outer perimeter of the first annular zone.

[0010] In some implementations, the separator wall may extend in a radial direction relative to a center axis of the first annular zone.

[0011] In some such implementations, the plurality of first passage segments may include a first set of the first passage segments, and the first passage segments in the first set of the firstpassage segments may be arranged along a radial direction, may extend from the inlet to the outer perimeter of the first annular zone, and may be in close proximity to the separator wall.

[0012] In some such implementations, the plurality of first passage segments may include a second set of the first passage segments, the first passage segments in the second set of the first passage segments may be arranged along one or more paths that extend at least 50% or more around a region defined by the inner perimeter of the first annular zone, and the first passage segments in the second set of the first passage segments may have average cross- sectional widths that are at least 50% greater than the average cross-sectional widths of the first passage segments positioned between the outer perimeter of the first annular zone and outermost ones of the first passage segments in the second set of the first passage segments.

[0013] In some such implementations, the cooling plate may include a plurality of first holes that extend from the first side, through the cooling plate, and to the second side, and each first hole may extend through one of the irregularly shaped columns in the first plurality of irregularly shaped columns.

[0014] In some further such implementations, the cooling plate may have a cylindrical interior surface that encircles, and is larger in diameter than, the first annular zone; a second annular zone may be defined by the cylindrical interior surface and the outer perimeter of the first annular zone, the cylindrical interior surface further may define an outer perimeter of a third annular zone, an inner perimeter of the third annular zone may be offset radially inwards from the outer perimeter of the third annular zone by a distance of X, at least 70% of the inner perimeter of the third annular zone, in total, may not intersect with any irregularly shaped columns, and X may be greater than 0.25".

[0015] In some additional such implementations, the second annular zone may include a second plurality of irregularly shaped columns, the cooling plate may include a plurality of second holes that extend from the first side, through the cooling plate, and to the second side, and each second hole may be located within one of the irregularly shaped columns in the second plurality of irregularly shaped columns.

[0016] In some implementations, the cooling plate may have an aperture extending from the first side, through the cooling plate, and to the second side.

[0017] In some such implementations, the apparatus may further include a semiconductor processing chamber, a wafer support positioned within an interior volume of thesemiconductor processing chamber, and a showerhead positioned within the interior volume of the semiconductor processing chamber and configured to flow one or more process gases supplied thereto towards the wafer support. In such an implementation, the cooling plate may be in contact with a surface of the showerhead, and the showerhead may include one or more process gas inlets positioned within the aperture.

[0018] In some implementations, the apparatus may further include a semiconductor processing chamber, a wafer support positioned within an interior volume of the semiconductor processing chamber, a showerhead configured to flow one or more process gases supplied thereto towards the wafer support, and a support column connected with the wafer support and supporting the wafer support within the interior volume of the semiconductor processing chamber. In such implementations, the support column may passthrough the aperture and the cooling plate may be in contact with the wafer support.

[0019] In some implementations, the cooling plate may be circular and may have a diameter of at least 30 cm.

[0020] In some implementations, the cooling plate may be a contiguous part manufactured via additive manufacturing.

[0021] In some implementations, the cooling plate may be assembled from at least two separate layers that are joined together, with at least one of the layers having a plurality of open channels that, when the cooling plate is assembled together, are capped by one of the other layers to form the first passage segments.

[0022] In some implementations, the aperiodic organic reticulated pattern may be generatively defined.BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Reference to the following Figures is made in the discussion below; the Figures are not intended to be limiting in scope and are simply provided to facilitate the discussion below.

[0024] FIG. 1 depicts an example cooling plate according to the present disclosure.

[0025] FIG. 2 depicts the example cooling plate of FIG. 1 with the top surface removed to allow the internal configuration to be seen.

[0026] FIG. 3 depicts a plan view of the cutaway shown in FIG. 2.

[0027] FIG. 4 depicts a side section view of the example cooling plate of FIG. 1.

[0028] FIG. 5 depicts a detail view of the region marked "DETAIL 5" in FIG. 3.

[0029] FIG. 6 depicts a detail view of the region marked "DETAIL 6" in FIG. 3.

[0030] FIG. 7 depicts the plan view of FIG. 3 but with various annular zones marked.

[0031] FIG. 8 depicts a schematic of a semiconductor processing tool incorporating a cooling plate for showerhead cooling.

[0032] FIG. 9 depicts a schematic of a semiconductor processing tool incorporating a cooling plate for wafer support cooling.

[0033] The above-described Figures are provided to facilitate understanding of the concepts discussed in this disclosure and are intended to be illustrative of some implementations that fall within the scope of this disclosure but are not intended to be limiting— implementations consistent with this disclosure and which are not depicted in the Figures are still considered to be within the scope of this disclosure.DETAILED DESCRIPTION

[0034] As discussed above, semiconductor wafer processing operations are often performed on semiconductor wafers while such wafers are supported within a processing chamber on a pedestal, e.g., a structure typically designed to support a semiconductor wafer from below in an evenly distributed manner. Process gases are usually flowed through a showerhead and then distributed across a semiconductor wafer supported on the wafer support via gas distribution ports distributed across an underside of the showerhead.

[0035] Variations in gas flow rates, temperatures, densities, etc. across the surface of a semiconductor wafer during processing operations may result in a corresponding variation in process uniformity across the surface of the semiconductor wafer. For example, reduced or increased gas flow rate across different regions of the showerhead may result in decreased or increased rates of deposition or etching. In another example, variations in temperature of the process gas(es) flowed across the surface of a semiconductor wafer may also result in variations in deposition film thickness or etch depth, depending on the process.

[0036] Moreover, in some semiconductor processing tools, various components may experience elevated temperatures during wafer processing operations due to process conditions. For example, in some semiconductor processing tools, the process conditions may be performed at elevated temperatures and / or may generate heat, thereby causing theshowerhead and / or wafer support to heat up. In order to maintain the temperature(s) of such components at a desired level, some showerheads and / or wafer supports may be connected with a cooling plate (or include an integrated cooling plate) that may be configured to cool the showerhead or wafer support that is connected thereto (or into which it is integrated).

[0037] A typical cooling plate design may have a single passage that is arranged in a spiral or serpentine pattern such that all of the coolant flowed through such a cooling plate is caused to traverse along a single path that traverses across the region to be cooled. Such cooling plates, however, may not cool the component needing cooling in an even manner. For example, the component being cooled may be hotter in regions of the component that are in between adjacent segments of the passage as compared with portions of the component that are directly beneath the passages. Such variations in cooling effectiveness may cause the component being cooled to have a non-uniform temperature that, in turn, causes undesirable variability in process conditions and consequent wafer non-uniformity.

[0038] To address such concerns, the present inventors designed a new type of cooling plate that departs from traditional cooling plate designs. Instead of having a single coolant passage that follows a relatively recognizable path, like a spiral or a switchback pattern, such cooling plates instead feature a large number of first passage segments that are arranged in an aperiodic organic reticulated pattern. Each such first passage segment may have a first end and a second end opposite the first end, each of which may fluidically connect with the first end or the second end of another passage segment.

[0039] Such patterns may, as is intimated from the use of "organic" above, have an appearance that is suggestive of natural reticulated structures or patterns, such as the vein patterns in leaves, the pattern of lighter-color fur on a giraffe pelt, the patterns of lighter-color scales on some species of pythons, etc. Reticulated patterns are patterns that are in the form of a net or network, e.g., having elements that branch and may then reconverge. Such patterns, as with many naturally occurring patterns, tend to have an irregular, aperiodic, or non-repeating aspect to them. For example, unlike rectangular, circular, or other regular geometric patterns which feature repeated instances of the same pattern unit and which support either rotational or translational tiling, aperiodic patterns cannot form a repeating pattern.

[0040] By avoiding the use of a cooling passage or passages that have regular geometric shapes or are arranged in regular geometric patterns and adopting a more organic approach to the arrangement of cooling passages, cooling plates such as those discussed herein are able toprovide temperatures that are much more uniform across the surface of the cooling plate that is in contact with the component being cooled as compared with such temperatures in cooling plates having more traditional coolant passage designs, e.g., spiral or serpentine passages. For example, finite element analyses of a cooling plate similar to that depicted in the accompanying Figures were compared to similar analyses for a cooling plate with a more geometrically regular coolant passage arrangement, e.g., a single coolant passage arranged along four concentric circular paths (with the path angling outward at the end of each circular path to connect with the start of the next larger circular path). The coolant passages in both cooling plates extended throughout the same region of the cooling plate, and the cooling plates were otherwise similar in thickness, diameter, and mounting configuration. The region of the cooling plate in which the coolant passages were located, e.g., the cooling region, was sized to correspond with the area of the component-to-be-cooled that was to receive cooling.

[0041] Such analyses revealed that the cooling plate in which the coolant passages were arranged in an organic, aperiodic reticulated pattern exhibited a maximum temperature variation across the cooling region and on the surface that was in contact with the component- to-be-cooled of about 8°C, whereas the cooling plate with the concentric circular cooling passages exhibited a temperature variation in the same region of about 15°C. Thus, the cooling plate with the organic approach to coolant passage arrangement offered temperature uniformity that was approximately 45% better than that of the cooling plate with the coolant passage following the more regular, geometric pattern.

[0042] Moreover, such organic approaches to the coolant passages in a cooling plate may also significantly reduce the pressure drop experienced by coolant being flowed through the coolant passage(s). For example, the organic coolant passage pattern cooling plate exhibited a pressure drop in the coolant (water) that was more than 73% lower than the pressure drop exhibited by the nested circular coolant passage pattern. Such dramatic improvements in pressure drop allow for significant reductions in the amount of power required to pump coolant through cooling plates having such organically arranged coolant passages as compared with more traditional designs. The organic layout of cooling passages in the example cooling plate also resulted in a much lower peak temperature in the cooling plate as compared with the cooling plate having the more conventional, nested circular coolant path design. For example, the newer cooling plate design with the organically arranged coolant passages exhibited a peak temperature that was nearly 44% lower than that of the conventional coolant path design.

[0043] Cooling plates such as those discussed herein may be designed generatively, e.g., using a combination of human guidance and design coupled with artificial intelligence that, based on the human guidance, iterates through a number of potential designs that build on a core design / design constraints defined by the human designer(s) and optimize such designs to arrive at a solution that meets (or comes closest to) the requirements established by the human designer. In the context of the cooling plates discussed herein, certain characteristic features of such designs are discussed below with reference to the accompanying Figures, but it will be understood that the specific details of the depicted design, e.g., the specific shapes of individual coolant passages or the exact arrangement of the various islands or columns in between such passages, may vary from design to design— even when the boundary conditions and constraints for two such cooling plate designs are very similar.

[0044] FIG. 1 depicts an isometric view of an example cooling plate 212 according to the present disclosure. FIG. 2 depicts the example cooling plate 212 with one face of the cooling plate removed to allow the interior features, including a large number of irregularly shaped columns and the coolant passage segments formed therebetween, to be visible. FIG. 3 depicts a plan view of the example cooling plate 212 (with the face of the cooling plate removed as in FIG. 3), while FIG. 4 depicts a side section view of the cooling plate of FIG. 2. FIGS. 5 and 6 depict detail views of the corresponding regions of the cooling plate 212 indicated in FIG. 3.

[0045] As shown in FIGS. 1 and 2, the cooling plate 212 may have an overall shape in the form of a large disk and may have a first side 214 and a second side 216 opposite the first side 214. The first side 214 and the second side 216 may define a main body of the cooling plate. The cooling plate 212 may have an interior volume 202 within it that is located between the first side 214 and the second side 216 and bounded, at least in part, by a first interior surface 218 and a second interior surface 220 (See FIG. 4). The interior volume 202 may be further defined by a cylindrical interior surface 222 that is provided by an outer wall 224, as well, in some cases, by another cylindrical interior surface provided by an inner wall 226 (in some implementations, the cooling plate 212 may be circular and non-annular, in which case the cooling plate 212 may not have an inner wall 226). Coolant may be supplied to the interior volume 202 of the cooling plate 212 via an inlet 228, and flowed out of the interior volume 202 via an outlet 230.

[0046] As can be best seen in FIGS. 5 and 6, the interior volume of the cooling plate 212 may have a large number of irregularly shaped columns 254 distributed throughout. Each irregularly shaped column 254 may extend between a first interior surface 218 and a second interiorsurface 220 of the cooling plate 212. In FIGS. 5 and 6, the irregularly shaped columns 254 are indicated by regions with medium grey dot shading enclosed by solid black line boundaries.

[0047] Some of the irregularly shaped columns 254 may have one or more holes passing therethrough, e.g., holes that extend from one side of the cooling plate 212 to an opposing side of the cooling plate 212. The gaps between adjacent irregularly shaped columns 254 may define a large number of first passage segments 232. Each first passage segment may be bounded by the first interior surface and the second interior surface and may be positioned between two of the irregularly shaped columns 254.

[0048] Each first passage segment 232 may have a first end 232a and a second end 232b opposite the first end. In FIGS. 5 and 6, the first passage segments 232 are indicated by lighter grey dotted regions bounded by dotted black line boundaries. The first ends 232a and the second ends 232b for two of the many first passage segments 232 that are shown in each of FIGS. 5 and 6 are referenced with callouts. However, in the interest of avoiding undue clutter, the first ends 232a and the second ends 232b of the remaining first passage segments 232 in each of FIGS. 5 and 6 are not separately called out. It will be understood, however, that such first passage segments 232 may nonetheless each similarly include a respective first end 232a and a respective second end 232b.

[0049] Some first passage segments 232 may be quite short, e.g., those bounded on one or both sides by a smaller irregularly shaped column 254 or irregularly shaped columns 254, whereas others may be much longer in length, e.g., those bounded on both sides by larger irregularly shaped columns. The first end 232a of each first passage segment 232 may be fluidically connected with at least two other first passage segments 232, and the second end 232b may be similarly fluidically connected with at least two other first passage segments 232. As can be seen, the size the irregularly shaped columns 254 may vary considerably throughout the interior of the cooling plate 212. Additionally, the size of the gaps between adjacent irregularly shaped columns 254 may also vary significantly— in some cases, as much as 200% or 300%.

[0050] As can be seen, the first passage segments 232 may form an aperiodic organic reticulated pattern of interconnected first passage segments 232 that are distributed throughout a cooling region 248 (see FIG. 4) of the cooling plate 212. The pattern of first passage segments 232, as is evident, does not repeat, and has a distinctly organic appearance, e.g., resembling how roots might grow or how blood vessels might be routed or the boundaries between skin cells. The network of first passage segments 232 may form a plurality of fluidflow paths that fluidically connect an inlet 228 of the cooling plate 212 with an outlet 230 of the cooling plate 212. Coolant, e.g., water, a perfluorinated, inert polyether fluid, or other suitable heat transfer medium, may be flowed into the cooling plate 212 via the inlet 228 and from the inlet 228 to the first passage segments 232 that are in the vicinity of the inlet 228. Different portions of the coolant may then proceed to flow through the remaining first passage segments 232, travelling from one first passage segment 232 to the next first passage segments 232, as the coolant flows through the cooling plate 212 and to the outlet 230 of the cooling plate 212.

[0051] In some implementations, there may also be one or more second passage segments 234 that may similarly each have a first end 234a and a second end 234b. The first end 234a of each second passage segment 234 may be fluidically connected with one or more of the first passage segments 232. The second end 234b of each second passage segment 234, however, does not connect with any other passage segment. Thus, each second passage segment 234 is effectively a dead-end passage. Such second passage segments 234 may serve as smaller, localized recirculation zones— there may be no net fluid transport through such second passage segments 234, but there may nonetheless still be localized turbulent mixing in such second passage segments 234 that results in increased heat transfer from the cooling plate 212 to the cooling fluid. In FIGS. 5 and 6, the second passage segments 234 are indicated by darker grey dotted regions bounded by dotted black line boundaries. The first end 234a and the second end 234b for one of the second passage segments 234 that are shown in each of FIGS. 5 and 6 are referenced with callouts. However, as with the first passage segments 232, the first ends 234a and the second ends 234b of the remaining second passage segments 234 in each of FIGS.5 and 6 are not separately called out. It will be understood, however, that such second passage segments 234 may nonetheless each similarly include a respective first end 234a and respective second end 234b.

[0052] The discussion below discusses particular regions or zones of the cooling plate. FIG. 7 replicates FIG. 3 but depicts a plurality of annular zones that are referenced in discussions below. As can be seen in FIG. 7, a first annular zone 240 may be defined that includes a first plurality of irregularly shaped columns 254. The first annular zone may be defined by an inner perimeter 240a and an outer perimeter 240b.

[0053] The first annular zone 240 may include most of the cooling region of the cooling plate 212 and, consequently, the first plurality of irregularly shaped columns 254 may include most of the irregularly shaped columns 254. Moreover, most of the first passage segments 232 may also lie within the first annular zone 240. It will be understood that some of the irregularlyshaped columns 254 in the first annular zone 240 may be only partially within the first annular zone 240.

[0054] The bulk of the fluid flow through the cooling plate 212 may occur within the first annular zone 240. Accordingly, various characteristics of the first passage segments 232 in the first annular zone 240 may serve to influence most of the fluid flow through the cooling plate 212. Various aspects of such features are discussed below.

[0055] As can be seen, the cooling plate 212 may exhibit a relatively porous structure, e.g., having a large number of small passages or flow paths therethrough. Accordingly, the portion of the cooling plate in between the first interior surface 218 and the second interior surface 220 and within the first annular zone 240 may have an average porosity, in some implementations, that is between 40% and 70%. Such porosity may, in some implementations, be relatively uniformly distributed throughout the cooling region of the cooling plate 212, e.g., each cubic inch of the cooling plate 212 may exhibit an average porosity in such a range.

[0056] The first annular zone 240 may also include (referring back to FIG. 3) a separator wall 256 (see, for example, FIGS. 2, 3, and 6) that is located in a quadrant 250 of the first annular zone 240 that also includes the inlet 228 and the outlet 230. The separator wall 256 may be interposed between the inlet 228 and the outlet 230 and may provide a contiguous barrier to fluid flow within the first annular zone 240. For example, the separator wall 256 may extend between an inner perimeter 240a and an outer perimeter 240b of the first annular zone 240. In some implementations, such as that depicted, the separator wall 256 may extend in a radial direction relative to a center axis 252 of the first annular zone 240.

[0057] In some implementations, the inlet 228, as shown in FIG. 3, may be proximate to the inner perimeter 240a of the first annular zone 240 and the outlet 230 may be proximate to the outer perimeter 240b of the first annular zone 240. Such positioning, in combination with the separator wall 256, may serve to cause the coolant flowed in through the inlet 228 to travel circumferentially through the cooling plate 212 while also, at least partially, flowing radially outward, thereby distributing coolant throughout the entire interior volume 202 of the cooling plate 212.

[0058] In some implementations, the first passage segments 232 may include a first set 236 of the first passage segments 232 that are arranged along a radial direction, extend from the inlet 228 to the outer perimeter 240b of the first annular zone 240, and are in close proximity to the separator wall 256. A shaded region with dashed black borders in FIG. 3 indicates the region where the first set 236 of the first passage segments 232 is located in the examplecooling plate 212. The first passage segments 232 are not shown in FIG. 3, but a portion of the first set 236 of the first passage segments 232 is shown in FIG. 6 with the first passage segments 232 therein being individually indicated. The first passage segments 232 in the first set 236 of the first passage segments 232 may, for example, have widths that are larger than most, if not all, of the first passage segments 232 within the first annular zone 240, and may serve to provide a radial channel that allows a portion of the coolant flowed in from the inlet 228 to easily flow radially outward to reach first passage segments 232 that are close to the outer perimeter 240b of the first annular zone 240.

[0059] In some such implementations, there may also be a second set 238 of the first passage segments 232. A shaded region with dotted black borders in FIG. 3 indicates the region where the second set 238 of the first passage segments 232 is located in the example cooling plate 212. As noted earlier, the first passage segments 232 are not shown in FIG. 3, but a portion of the second set 238 of the first passage segments 232 is shown in FIG. 6 with the first passage segments 232 therein being individually indicated.

[0060] The first passage segments 232 in the second set 238 of the first passage segments 232 may be arranged along one or more paths that extend at least 50% or more around a region defined by the inner perimeter 240a of the first annular zone 240. As can be seen in FIG. 3, the first passage segments 232 in the second set 238 of first passage segments 232 follow a somewhat irregular, but generally arc-shaped, path that starts at the inlet 228, extends around the center of the first annular zone 240, and sometimes splits (and, on occasion, reconverges) about the inner perimeter 240a of the first annular zone 240. The first passage segments 232 in the second set 238 of the first passage segments 232 may have average cross-sectional widths that are at least ~50% greater than the average cross-sectional widths of the first passage segments 232 positioned between the outer perimeter 240b of the first annular zone 240 and outermost ones of the first passage segments 232 in the second set 238 of the first passage segments 232. The first passage segments 232 in the second set 238 of the first passage segments 232 may serve to provide a main conduit that may, similar to the function of the first passage segments 232 in the first set 236 of the first passage segments 232 with respect to radial flow, provide a reduced-flow-resistance flow path that may allow a portion of the coolant introduced into the inlet 228 to flow circumferentially around the interior of the first annular zone 240 for some distance before eventually flowing radially inward or outward to flow into first passage segments 232 that are not in the second set 238 of the first passage segments 232.

[0061] As mentioned earlier, some of the irregularly shaped columns 254 may, in some implementations, have through-holes in them. Threaded fasteners, e.g., socket-head cap screws, may be inserted through such through-holes and may, for example, be used to clamp the cooling plate 212 to, for example, a showerhead or a wafer support, in order to maintain good thermal contact with the showerhead or wafer support and maximize heat transport from such a component and into the cooling plate 212.

[0062] For example, the first annular zone 240 may have a plurality of first holes 260 that extend from the first side 214, through the cooling plate 212, and to the second side 216. Each first hole 260 may extend through one of the irregularly shaped columns 254 in the first plurality of the irregularly shaped columns 254. The first holes 260 may, for example, be arranged in a circular hole pattern, e.g., 8, 10, 12 (as shown), 14, 16, etc. holes. There may, in some cases, be multiple circular hole patterns of first holes 260. For example, there may be a first circular pattern of first holes 260 located approximately in the middle of the first annular zone 240 and a second plurality of first holes 260 located proximate to the inner perimeter 240a of the first annular zone 240. Such implementations may provide for a large number of attachment points for the cooling plate 212 to the component to be cooled, thereby helping ensure more uniform heat transfer between the component to be cooled and the cooling plate 212.

[0063] As shown in FIG. 7, the cooling plate 212 may also have a second annular zone 242 that has an inner perimeter 242a defined by the outer perimeter 240b of the first annular zone 240. The second annular zone 242 may also have an outer perimeter 242b that is defined by a cylindrical interior surface 258 of the cooling plate 212. The cylindrical interior surface 258 may encircle the first annular zone 240 and may generally define an outermost interior wall of the interior volume 202.

[0064] The cylindrical interior surface 258 may further define an outer perimeter 244b of a third annular zone 244. The third annular zone 244 may have an inner perimeter 244a that is offset radially inwards from the outer perimeter 244b of the third annular zone 244 by a distance of X, which may be greater than 0.25". In some implementations, at least 70% of the inner perimeter 244a of the third annular zone 244, in total, does not intersect with any irregularly shaped columns 254. For example, the third annular zone 244 may at least include portions of a plurality of irregularly shaped columns 254 from a second plurality of the irregularly shaped columns 254. The cooling plate 212 may further include a plurality of secondholes 262 that each extend from the first side 214, through the cooling plate 212, and to the second side 216. Each such second hole 262 may pass through one of the irregularly shaped columns in the second plurality of irregularly shaped columns 254. However, the gaps in the third annular zone 244 in between the irregularly shaped columns 254 with the second holes 262 passing therethrough may otherwise be free of irregularly shaped columns 254, thereby creating a flow path along the perimeter of the interior volume 202 that has a lower flow resistance than may be found in most of the first passage segments 232. Such a flow path may further aid in distributing coolant throughout the interior volume 202 of the cooling plate and may further contribute to providing greater temperature uniformity and / or lower pressure drop within the cooling plate 212.

[0065] There is also a fourth annular zone 246 that is depicted in FIG. 7. The fourth annular zone has an inner perimeter 244a that is defined by the inner wall 226 and an outer perimeter 244b that is defined by the inner perimeter 240a of the first annular zone 240. In this particular example, the fourth annular zone includes a small gap that extends around the circumference of the inner wall 226, thereby providing first passage segments that allow for there to be at least a small amount of fluid flow around the aperture 266, including past the separator wall 256. Such gaps may help ensure that there is at least some fluid flow even near the end of the separator wall 256, thereby avoiding potential flow stagnation near that end of the separator wall 256. However, such gaps may be quite small and have a relatively high flow resistance such that the bulk of the coolant that is circulated through the interior volume 202 instead flows through the network of first passage segments 232 that are distributed throughout the interior volume 202.

[0066] In some implementations, the cooling plate 212 may include an aperture 266 that passes from the first side 214, through the cooling plate 212, and to the second side 216. The aperture 266 may, for example, be used to provide a passageway through which process gas inlets on a showerhead may be accessible or the support column of a wafer support may pass.

[0067] In some embodiments, at least a portion of one or more flow paths in a cooling plate are dendritic, meaning that the flow paths are branched. In some cases, downstream branches have smaller cross-sectional areas than upstream branches. The conductance of a portion of a flow path in a dendritic structure may decrease as the flow path branches. In some cases, a dendritic flow path has a single upstream portion of the flow path that branches into multiple downstream branches: e.g., three or more downstream branches. A dendritic portion of a flowpath sometimes branches in the manner of a tree. The branches of a dendritic flow path may sometimes be flow passage segments described herein.

[0068] In some embodiments, the flow paths in a cooling plate have islands. For example, a flow path may initially (upstream) branch into multiple passages and then (downstream) converge. A flow exclusion region between an upstream branch point and a downstream convergence point may be considered an island.

[0069] In some embodiments, the collection of all flow paths in a cooling plate cause the cooling fluid to flow in a generally spiral trajectory. For example, the fluid in a cooling plate may flow generally in a spiral direction, sometimes originating near the center of the cooling plate and spirally passing outward toward the edge of the cooling plate.

[0070] In some embodiments, a cooling plate has a single inlet for all cooling fluid flowing through the plate. In some embodiments, the cooling plate also has a single outlet, where the fluid leaves the plate. Between the inlet and the outlet, the flow channels may branch and recombine in an arrangement that may be dendritic and / or comprise one or more islands.

[0071] In some embodiments, a cooling plate comprises one or more structural elements where cooling fluid cannot flow. For example, a cooling plate comprise a baffle in the form of a substantially radially directed barrier. As another example, a cooling plate may include one or more bolt holes. In some implementations, a cooling plate has an outer exclusion region (at the cooling plate perimeter) where cooling fluid cannot flow. In some cases, the outer exclusion region is about 0.1 to 0.4 inches wide (in the radial direction).

[0072] The cooling plates discussed herein may typically be made of any suitable material, although corrosion-resistant materials with good thermal conductivity, e.g., stainless steel or aluminum alloys, may be preferable in order to promote effective heat transfer and cooling via the cooling plate while resisting potential corrosion effects that may arise with the use of some liquid coolants. Such cooling plates may be made via any suitable process, although their structure and the arrangement of the irregularly shaped columns and the first passage segments (and second passage segments, if present) contained within the cooling plates may make them particularly well suited for manufacture via additive manufacturing processes. For example, such cooling plates may be manufactured using selective laser melting (SLM) or direct metal laser melting (DMLM), either of which may be used to produce metal components.

[0073] In most additive manufacturing processes, a part is manufactured by adding material to the part one horizontal layer at a time; such layers may be extremely thin, e.g., 0.02mm at atime is possible for DMLM parts. In DMLM, for example, a platen supporting a part is gradually lowered relative to a reference plane. The platen forms the "floor" of a cavity that is used to contain the part being manufactured. Each time the platen is lowered, powdered material is added to the cavity and then leveled so as to be level with the reference plane. A laser then scans across the reference plane and applies heat to the uppermost layer of powdered material in the regions where structure is desired, melting the powder granules to each other and to any underlying, previously fused structure. Once a particular layer is done, the platen may be lowered slightly, a new layer of powdered material may be applied, and the laser melting process repeated. This process is repeated until the part is complete, at which point the cavity of the DMLM device will be filled with unmelted powdered material having buried within it the additively manufactured component.

[0074] The use of such additive manufacturing techniques permits the adoption of cooling plate geometries that would be difficult to achieve using only conventional machining (subtractive machining) techniques such as milling, drilling, or turning. For example, the cooling plates discussed above could be milled into a plate of material using conventional, subtractive machining operations and the resulting part then bonded to another plate in order to "cap" the open channels that were machined into the first plate. However, milling such channels may be time-consuming and challenging, as some of the channels might be quite thin and be many times deeper than they are wide, thereby requiring the use of very small-diameter, e.g., submillimeter, end mills that would be prone to breakage and / or would necessitate the very low feed rates (thus increasing the cost of manufacturing the part).

[0075] If additively manufactured, the cooling plates may simply be printed as a single, contiguous part, thereby allowing such small-sized features to be made without needing to resort to easily broken small-diameter end mills. In such implementations, the entire cooling plate may be manufactured using additive manufacturing, or, alternatively, part of the cooling plate, such as one side of the plate and the irregularly shaped columns and first passage segments, may be made via additive manufacturing. In the latter case, the resulting additively manufactured part may be subjected to a post-additive manufacturing subtractive machining process, e.g., face milling, to plane off the top few thousandths of the surface into which the channels that define the irregularly shaped columns and the first passage segments are formed. This surface may then be bonded to a plate to cap such features off and form the first passage segments, similar to the assembly process for a subtractively-manufactured cooling plate. In an additively manufactured cooling plate, the metal powder that is trapped within the coolingplate once additive manufacturing is complete may be removed from the cooling plate using various techniques, e.g., vibrating the cooling plate to cause most of the powder to drain from the cooling plate via the inlet and outlet. Compressed air may flowed through the cooling plate (from inlet to outlet and / or vice-versa) in order to flush powder that may remain in the cooling plate out of the cooling plate. In the event that the cooling plate includes second passage segments (that are dead ends), holes may be drilled into the cooling plate at locations that correspond with the dead ends of such second passage segments so that the powder in such second passage segments is flushed out of the second passage segments via the drilled holes. The drilled holes may then be filled with plugs, e.g., welded or brazed plugs in order to re-seal the second passage segments.

[0076] As discussed above, the cooling plates discussed herein may be designed using a combination of human guidance and computer-guided generative design. For example, various features of such cooling plates may be selected and defined by human designers, e.g., the locations of through-holes, the overall size of the cooling plate and the cooling region located within it, the locations of the i n let / out let, the presence or absence of an aperture in the center of the cooling plate, etc. Various parameters may be defined by human designers, such as the expected heat flux into a surface or region of the cooling plate, the expected flow rate of coolant, the material properties of the coolant (such as density, viscosity, thermal conductivity, and specific heat), the material properties of the cooling plate itself (e.g., thermal conductivity, specific heat, etc.), the cross-sectional area of the inlet and / or the outlet, etc.

[0077] For example, the cooling plate shown in FIGS. 2 through 7 was specified to be made of stainless steel and was defined to have a cooling region that was approximately 21 cm in diameter. The cooling region was defined to have heat flux of approximately 1400 W / square meter into it, and a flow rate of 2 gallons per minute was specified for the coolant flow rate. The locations of the through-holes, inlet, and outlet were also specified by human designers, as well as the overall shape of the cooling plate (an annular plate of a particular thickness, e.g., a plate over 30 cm in diameter, e.g., approximately 40 cm in diameter, approximately 1.25 cm to 2" cm thick, and having a center aperture approximately 7.5 cm to 10 cm in diameter).

[0078] After defining parameters such as the above, the human designer may use a generative design algorithm to iterate through a large number of design variants, with each iteration being subjected, for example, to a coupled flow-thermal computational fluid dynamics (CFD) analysis. The results of such coupled flow-thermal CFD analyses may then be analyzed to identify design variants that provide, for example, better temperature uniformity and / or lowerpeak temperatures and / or reduced or minimized pressure drop for the given set of input conditions than other variants. Such algorithms may then iterate through further design variants that are based on earlier design variants that offered superior temperature uniformity and / or lower peak temperatures. Such further design variants may similarly be evaluated using CFD analysis and design variants that offer even more improvement to such parameters may be identified. The generative design algorithm may continue to iterate in this manner until one or more design variants are identified that meet (or that come closest to) the goals that are established for the design in question, e.g., a temperature uniformity across the cooling region that is within a predefined range and / or a peak temperature that is below a specified target threshold and / or a pressure drop in the coolant that is below a specified threshold or otherwise minimized. The process of modifying each design variant, analyzing it, and then comparing the analysis results against analysis results for other design variants and identifying which design variants offer the best performance with respect to the goals defined for the generative design algorithm, and then repeating such actions to explore further design variants may be completely automated, thereby allowing the human designer to explore a much larger pool of potential designs than such designers could, as a practical matter, previously explore.

[0079] It will also be understood that cooling plates such as those discussed herein may also be used for heating components. For example, a showerhead that is coupled to such a cooling plate may be heated to a target temperature by directing heating fluid into the inlet and through the first passage segments to the outlet. The temperature uniformity that is achieved during cooling operations with such a cooling plate may similarly be evident in heating operations that are performed with such a cooling plate. For example, for a cooling plate that is attached to a showerhead, heating fluid that is introduced into the inlet at an elevated temperature may be flowed through the first passage segments in order to heat the cooling plate (and showerhead) to a specified temperature that may be needed in order to initiate an exothermic semiconductor processing operation, but may then be replaced with a lower- temperature coolant once the processing operation has started and the heat from the processing operation is more than sufficient to maintain the showerhead at the elevated temperature. In such a situation, the heat generated by the exothermic reaction may, if left unchecked, eventually cause the showerhead temperature to exceed a temperature range specified for the process. However, such temperatures may be managed by switching the flow of heating fluid through the cooling plate to flow of lower-temperature coolant through the cooling plate.

[0080] As discussed above, the cooling plates discussed herein may be used to cool and / or heat another component, such as a showerhead or a wafer support. FIGS. 8 and 9 depict schematic diagrams of semiconductor processing tools that utilize cooling plates such as those discussed herein to cool different components of such tools.

[0081] FIG. 8 depicts a schematic of a semiconductor processing tool incorporating a cooling plate for showerhead cooling. As can be seen, the semiconductor processing tool may include a semiconductor processing chamber 200 that may be interfaced with a showerhead 204. The showerhead 204, in this case, is a flush-mount showerhead and has one or more plenums inside that are each f I uidica I ly connected with a plurality of gas distribution ports 203. Process gas for semiconductor processing operations may be flowed into the showerhead 204 plenum(s) via a valve manifold 205, which may, in turn, be fluid ica lly connected with one or more process gas sources (not shown). The semiconductor processing chamber 200 may also include within it a wafer support 208 that may be supported within the semiconductor processing chamber 200 by way of a support column 210. The wafer support 208 may support a semiconductor wafer 201 during wafer processing operations.

[0082] In the implementation of FIG. 8, the showerhead 204 has a top surface that is coupled to the cooling plate 212. For example, the showerhead 204 may have a plurality of threaded holes in the top surface that may receive threaded fasteners that may be inserted through the first holes 260 and the second holes 262 and used to clamp the cooling plate 212 to the showerhead 204. The inlet 228 and the outlet 230 of the cooling plate 212 may be coupled with a cooling fluid (and / or heating fluid) source that may be configured to circulate a heat exchange fluid at a particular temperature through the cooling plate 212 in order to adjust the temperature of the cooling plate 212 to a desired level.

[0083] FIG. 9 depicts a schematic of a semiconductor processing tool incorporating a cooling plate for wafer support cooling. The semiconductor processing tool of FIG. 9 is similar to that of FIG. 8, and the descriptions of the elements shown in FIG. 8 are equally applicable to the implementation of FIG. 9, except that, as can be seen, wafer support 208 has a bottom surface that is coupled to the cooling plate 212. For example, the wafer support 208 may have a plurality of threaded holes in the bottom surface that may receive threaded fasteners that may be inserted through the first holes 260 and the second holes 262 and used to clamp the cooling plate 212 to the wafer support 208.

[0084] It will also be understood that the cooling plates discussed herein may also be made integral to the components that they cool (or heat). For example, the interior volume 202 ofthe cooling plate 212 (and all of the features located therein) may be integrated into a showerhead or wafer support, thereby improving heat conduction into (or out of) the cooling plate 212 by removing a thermal contact interface.

[0085] Such semiconductor processing tools may also include, or be connected with, a controller that may be configured to control various functionalities associated with such semiconductor processing tools. The controller, depending on the processing requirements and / or the type of system, may be programmed to control any of the processes disclosed herein, such as processes for controlling the flow of coolant (or heating fluid) through the cooling plate, as well as other processes or parameters not discussed herein, such as the delivery of processing gases, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid delivery settings, positional and operation settings, wafer transfers into and out of a chamber and other transfer tools and / or load locks connected to or interfaced with a specific system.

[0086] Broadly speaking, the controller may be defined as electronics having various integrated circuits, logic, memory, and / or software that receive instructions, issue instructions, control operation, enable cleaning operations, enable endpoint measurements, and the like. The integrated circuits may include chips in the form of firmware that store program instructions, digital signal processors (DSPs), chips defined as application-specific integrated circuits (ASICs), and / or one or more microprocessors or microcontrollers that execute program instructions (e.g., software). Program instructions may be instructions communicated to the controller in the form of various individual settings (or program files), defining operational parameters for carrying out a particular process on or for a semiconductor wafer or to a system. The operational parameters may, in some examples, be part of a recipe defined by process engineers to accomplish one or more processing steps during the fabrication of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or dies of a wafer.

[0087] The controller, in some implementations, may be a part of or coupled to a computer that is integrated with, coupled to the system, otherwise networked to the system, or a combination thereof. For example, the controller may be in the "cloud" or all or a part of a fab host computer system, which can allow for remote access of the wafer processing. The computer may enable remote access to the system to monitor current progress of fabrication operations, examine a history of past fabrication operations, examine trends or performancemetrics from a plurality of fabrication operations, to change parameters of current processing, to set processing steps to follow a current processing, or to start a new process. In some examples, a remote computer (e.g. a server) can provide process recipes to a system over a network, which may include a local network or the Internet. The remote computer may include a user interface that enables entry or programming of parameters and / or settings, which are then communicated to the system from the remote computer. In some examples, the controller receives instructions in the form of data, which specify parameters for each of the processing steps to be performed during one or more operations. It should be understood that the parameters may be specific to the type of process to be performed and the type of tool that the controller is configured to interface with or control. Thus, as described above, the controller may be distributed, such as by comprising one or more discrete controllers that are networked together and working towards a common purpose, such as the processes and controls described herein. An example of a distributed controller for such purposes would be one or more integrated circuits on a chamber in communication with one or more integrated circuits located remotely (such as at the platform level or as part of a remote computer) that combine to control a process on the chamber.

[0088] Without limitation, example cooling plates according to the present disclosure may be mounted in or part of semiconductor processing tools with a plasma etch chamber or module, a deposition chamber or module, a spin-rinse chamber or module, a metal plating chamber or module, a clean chamber or module, a bevel edge etch chamber or module, a physical vapor deposition (PVD) chamber or module, a chemical vapor deposition (CVD) chamber or module, an atomic layer deposition (ALD) chamber or module, an atomic layer etch (ALE) chamber or module, an ion implantation chamber or module, a track chamber or module, and any other semiconductor processing systems that may be associated or used in the fabrication and / or manufacturing of semiconductor wafers.

[0089] As noted above, depending on the process step or steps to be performed by the tool, the controller might communicate with one or more of other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, neighboring tools, tools located throughout a factory, a main computer, another controller, or tools used in material transport that bring containers of wafers to and from tool locations and / or load ports in a semiconductor manufacturing factory.

[0090] The use, if any, of ordinal indicators, e.g., (a), (b), (c)... or (1), (2), (3)... or the like, in this disclosure and claims is to be understood as not conveying any particular order orsequence, except to the extent that such an order or sequence is explicitly indicated. For example, if there are three steps labeled (i), (ii), and (iii), it is to be understood that these steps may be performed in any order (or even concurrently, if not otherwise contraindicated) unless indicated otherwise. For example, if step (ii) involves the handling of an element that is created in step (i), then step (ii) may be viewed as happening at some point after step (i). Similarly, if step (i) involves the handling of an element that is created in step (ii), the reverse is to be understood. It is also to be understood that use of the ordinal indicator "first" herein, e.g., "a first item," should not be read as suggesting, implicitly or inherently, that there is necessarily a "second" instance, e.g., "a second item."

[0091] It is to be understood that the phrases "for each <item> of the one or more <items>," "each <item> of the one or more <items>," or the like, if used herein, are inclusive of both a single-item group and multiple-item groups, i.e., the phrase "for ... each" is used in the sense that it is used in programming languages to refer to each item of whatever population of items is referenced. For example, if the population of items referenced is a single item, then "each" would refer to only that single item (despite the fact that dictionary definitions of "each" frequently define the term to refer to "every one of two or more things") and would not imply that there must be at least two of those items. Similarly, the term "set" or "subset" should not be viewed, in itself, as necessarily encompassing a plurality of items— it will be understood that a set or a subset can encompass only one member or multiple members (unless the context indicates otherwise).

[0092] The term "between," as used herein and when used with a range of values, is to be understood, unless otherwise indicated, as being inclusive of the start and end values of that range. For example, between 1 and 5 is to be understood to be inclusive of the numbers 1, 2, 3, 4, and 5, not just the numbers 2, 3, and 4.

[0093] The term "operatively connected" is to be understood to refer to a state in which two components and / or systems are connected, either directly or indirectly, such that, for example, at least one component or system can control the other. For example, a controller may be described as being operatively connected with a resistive heating unit, which is inclusive of the controller being connected with a sub-controller of the resistive heating unit that is electrically connected with a relay that is configured to controllably connect or disconnect the resistive heating unit with a power source that is capable of providing an amount of power that is able to power the resistive heating unit so as to generate a desired degree of heating. The controller itself likely cannot supply such power directly to the resistive heating unit due to thecurrents involved, but it will be understood that the controller is nonetheless operatively connected with the resistive heating unit.

[0094] For the purposes of this disclosure, the term "fluidically connected" is used with respect to volumes, plenums, holes, etc., that may be connected with one another, either directly or via one or more intervening components or volumes, in order to form a fluidic connection, similar to how the term "electrically connected" is used with respect to components that are connected together to form an electric connection. In the context of the first and second passage segments discussed in this application, however, it will be understood that when reference is made to such a passage segment fluidically connecting with other passage segments, such fluidic connections are to be understood to be direct couplings between such passage segments, e.g., the end of such a passage segment is directly connected to the ends of the other passage segments (as opposed to being connected with such other passage segments via one or more other intervening passage segments). The term "fluidically interposed," if used, may be used to refer to a component, volume, plenum, or hole that is fluidically connected with at least two other components, volumes, plenums, or holes such that fluid flowing from one of those other components, volumes, plenums, or holes to the other or another of those components, volumes, plenums, or holes would first flow through the "fluidically interposed" component before reaching that other or another of those components, volumes, plenums, or holes. For example, if a pump is fluidically interposed between a reservoir and an outlet, fluid that flowed from the reservoir to the outlet would first flow through the pump before reaching the outlet. The term "fluidically adjacent," if used, refers to placement of a fluidic element relative to another fluidic element such that there are no potential structures fluidically interposed between the two elements that might potentially interrupt fluid flow between the two fluidic elements. For example, in a flow path having a first valve, a second valve, and a third valve placed sequentially therealong, the first valve would be fluidically adjacent to the second valve, the second valve fluidically adjacent to both the first and third valves, and the third valve fluidically adjacent to the second valve.

[0095] It is understood that the examples and implementations described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art. Although various details have been omitted for clarity's sake, various design alternatives may be implemented. Therefore, the present examples are tobe considered as illustrative and not restrictive, and the disclosure is not to be limited to the details given herein but may be modified within the scope of the disclosure.

[0096] It is to be understood that the above disclosure, while focusing on a particular example implementation or implementations, is not limited to only the discussed example, but may also apply to similar variants and mechanisms as well, and such similar variants and mechanisms are also considered to be within the scope of this disclosure.

Claims

CLAIMSWhat is claimed is:

1. An apparatus comprising: a cooling plate having an inlet, an outlet, a first side, a second side opposite the first side, and a plurality of first passage segments located in between the first side and the second side and internal to the cooling plate, wherein: each first passage segment fluidical ly connects with at least two of the other first passage segments at a corresponding first end of that first passage segment and with at least another two of the other first passage segments at a corresponding second end of that first passage segment opposite the first end, and the first passage segments form an aperiodic organic reticulated pattern that provides a plurality of fluid flow paths that are distributed throughout a cooling region of the cooling plate, located within the cooling plate, and fluidical ly connect the inlet to the outlet within the cooling plate.

2. The apparatus of claim 1, wherein the cooling plate further includes one or more second passage segments, each second passage segment has a first end that fluidically connects with one or more of the first passage segments and a second end that does not connect to any other passage segment.

3. The apparatus of either of claims 1 or 2, wherein: most of the first passage segments are located within a first annular zone having a first plurality of irregularly shaped columns distributed throughout, each irregularly shaped column in the first plurality of irregularly shaped columns extends between a first interior surface of the cooling plate and a second interior surface of the cooling plate, andeach first passage segment is bounded by the first interior surface and the second interior surface and is positioned between two of the irregularly shaped columns in the first plurality of irregularly shaped columns.

4. The apparatus of claim 3, wherein at least some of the irregularly shaped columns in the first plurality of irregularly shaped columns are only partially within the first annular zone.

5. The apparatus of either of claims 3 or 4, wherein the portion of the cooling plate within the first annular zone and bounded by the first interior surface and the second interior surface has an average porosity of between 40% and 70%.

6. The apparatus of any one of claims 3 through 5, wherein: the inlet and the outlet are positioned within a common quadrant of the first annular zone, a separator wall is interposed between the inlet and the outlet, and the separator wall provides a contiguous barrier to fluid flow and extends between an inner perimeter of the first annular zone and an outer perimeter of the first annular zone.

7. The apparatus of claim 6, wherein the inlet is positioned proximate the inner perimeter of the first annular zone and the outlet is positioned proximate the outer perimeter of the first annular zone.

8. The apparatus of either of claims 6 or 7, wherein the separator wall extends in a radial direction relative to a center axis of the first annular zone.

9. The apparatus of claim 8, wherein: the plurality of first passage segments includes a first set of the first passage segments, and the first passage segments in the first set of the first passage segments are arranged along a radial direction, extend from the inlet to the outer perimeter of the first annular zone, and are in close proximity to the separator wall.

10. The apparatus of claim 9, wherein: the plurality of first passage segments includes a second set of the first passage segments, the first passage segments in the second set of the first passage segments are arranged along one or more paths that extend at least 50% or more around a region defined by the inner perimeter of the first annular zone, and the first passage segments in the second set of the first passage segments have average cross-sectional widths that are at least 50% greater than the average cross-sectional widths of the first passage segments positioned between the outer perimeter of the first annular zone and outermost ones of the first passage segments in the second set of the first passage segments.

11. The apparatus of claim 10, wherein: the cooling plate includes a plurality of first holes that extend from the first side, through the cooling plate, and to the second side, and each first hole extends through one of the irregularly shaped columns in the first plurality of irregularly shaped columns.

12. The apparatus of claim 11, wherein: the cooling plate has a cylindrical interior surface that encircles, and is larger in diameter than, the first annular zone, a second annular zone is defined by the cylindrical interior surface and the outer perimeter of the first annular zone, the cylindrical interior surface further defines an outer perimeter of a third annular zone, an inner perimeter of the third annular zone is offset radially inwards from the outer perimeter of the third annular zone by a distance of X, at least 70% of the inner perimeter of the third annular zone, in total, does not intersect with any irregularly shaped columns, andX is greater than 0.25".

13. The apparatus of claim 12, wherein: the second annular zone includes a second plurality of irregularly shaped columns, the cooling plate includes a plurality of second holes that extend from the first side, through the cooling plate, and to the second side, and each second hole is located within one of the irregularly shaped columns in the second plurality of irregularly shaped columns.

14. The apparatus of any one of claims 1 through 13, wherein the cooling plate has an aperture extending from the first side, through the cooling plate, and to the second side.

15. The apparatus of claim 14, further comprising: a semiconductor processing chamber;a wafer support positioned within an interior volume of the semiconductor processing chamber; and a showerhead positioned within the interior volume of the semiconductor processing chamber and configured to flow one or more process gases supplied thereto towards the wafer support, wherein: the cooling plate is in contact with a surface of the showerhead, and the showerhead includes one or more process gas inlets positioned within the aperture.

16. The apparatus of claim 14, further comprising: a semiconductor processing chamber; a wafer support positioned within an interior volume of the semiconductor processing chamber; a showerhead configured to flow one or more process gases supplied thereto towards the wafer support; and a support column connected with the wafer support and supporting the wafer support within the interior volume of the semiconductor processing chamber, wherein the support column passes through the aperture and the cooling plate is in contact with the wafer support.

17. The apparatus of either claim 15 or claim 16, wherein the cooling plate is circular and has a diameter of at least 30 cm.

18. The apparatus of any one of claims 1 through 17, wherein the cooling plate is a contiguous part manufactured via additive manufacturing.

19. The apparatus of any one of claims 1 through 17, wherein the cooling plate is assembled from at least two separate layers that are joined together, with at least one of the layers having a plurality of open channels that, when the cooling plate is assembled together, are capped by one of the other layers to form the first passage segments.

20. The apparatus of any one of claims 1 through 19, wherein the aperiodic organic reticulated pattern is generatively defined.

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