Showerhead with a reduced internal volume

Abstract

Showerheads for semiconductor processing operations, manufactured by additive manufacturing methods, are disclosed, which can have a variety of features made possible by the use of such manufacturing techniques. In some implementations, such showerheads can have multiple independent flow paths characterized by lateral passages arranged to form a diamond lattice pattern, with gas distribution ports and / or riser passages located at various intersections between such lateral passages. Such showerheads can also include features that improve their manufacturability while providing desired gas flow performance. For example, the cross-sections of the lateral passages can be designed to be generally triangular or pentagonal in shape, thereby allowing for more efficient use of the volume of material available within the showerhead for the purpose of providing gas flow paths, while also providing geometries that take into account the limitations of typical additive manufacturing processes that can be used.

Description

Background Art

[0001] [Related Applications] As part of this application, a PCT application is filed simultaneously with this specification. Each application for which this application claims benefit or priority, as identified in the PCT application filed simultaneously, is hereby incorporated by reference in its entirety for all purposes.

[0002] Semiconductor processing tools generally use a "showerhead" to distribute semiconductor processing gas over a substrate or wafer supported by a pedestal or chuck within a semiconductor processing chamber. A showerhead typically features a number of gas distribution ports distributed across the entire lower surface of the showerhead, through which the processing gas flows during semiconductor processing operations. There are two general classes of showerheads used in semiconductor processing tools, namely, "chandelier" type showerheads and "flush mount" showerheads. A chandelier type showerhead typically includes a disk-shaped structure that houses the gas distribution ports, one or more internal plenums for distributing the processing gas to those gas distribution ports, and a stem that connects to the upper surface of the disk-shaped structure or extends from the upper surface through or to the ceiling of the processing chamber in which the chandelier type showerhead is located. The stem supports the disk-shaped structure within the processing chamber and further functions to send the processing gas within the disk-shaped structure to the plenum. A flush mount showerhead, instead of having a stem or equivalent structure, is simply attached, for example, to the wall of a semiconductor processing chamber and often serves substantially as a lid for the semiconductor processing chamber.

[0003] Presented herein is a design for a semiconductor processing showerhead manufactured by an additive manufacturing method.

Summary of the Invention

[0004] 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, drawings, and claims of this specification.

[0005] The inventors of the present invention have devised a showerhead manufactured by an additive manufacturing method. Such a showerhead can be manufactured, for example, using any suitable additive manufacturing technique, such as selective laser melting (SLM) (which can be used to produce its ceramic or silicon version), or direct metal laser melting (DMLM) (which can be used to produce its metal version).

[0006] In most additive manufacturing processes, parts are manufactured by adding material to the part in a single horizontal layer at a time. Such layers can be extremely thin; for example, for DMLM parts, 0.02 mm at a time is possible. For example, in DMLM, the platen that supports the part is gradually lowered relative to a reference plane. The platen forms the "floor" of a cavity used to contain the part being manufactured. Each time the platen is lowered, a powdered material is added to the cavity and then leveled so as to be at the same height as the reference plane. Then, a laser scans across the entire reference plane, applying heat to the uppermost layer of the powdered material in the regions where the structure is required, melting the powdered granules together and to any underlying layers that have previously been fused. Once a particular layer is complete, the platen may be lowered slightly, a new layer of powdered material applied, and the laser melting process repeated. This process is repeated until the part is complete, at which point the cavity of the DMLM apparatus will be filled with the unfused powdered material in which the component manufactured by the additive manufacturing method is embedded.

[0007] Components manufactured by such additive manufacturing methods typically have a very fine grain microstructure, i.e., a structure formed by the fusion of small grains of solid material by selective heating supplied by a laser, compared to components manufactured from bulk (e.g., components manufactured by casting where the molten material is generally fabricated into the desired component in a single operation, as opposed to when a small number of grains are fused at once over many successive operations as in SLM or DMLM). Components manufactured by such additive manufacturing methods also often tend to have a microstructure with significant directionality, where the micrograins have a more rounded, larger profile in the XY plane (corresponding to the horizontal plane with respect to the component positioned during the additive manufacturing process and the Z direction corresponding to the vertical direction) than the profile of such fine grains in a plane parallel to the Z direction. FIG. 1 shows, for example, a depiction of grain boundaries as viewed in a vertical plane (left side) and a horizontal plane (right side) in an exemplary component fabricated using one exemplary DMLM process. As can be seen from the figure, the grain size in the vertical plane shows a high degree of asymmetry with respect to the size in the Z direction compared to the size in either the X or Y direction. The micrograins tend to be much longer in the X and / or Y directions compared to the thickness in the Z direction. This micrograined structure may be referred to herein as an anisotropic micrograined structure, which is understood to be distinguished from a micrograined structure where the micrograins exhibit variations in size and shape but generally do not exhibit dimensional variations related to a specific axis. It will be understood that at least some of the showerheads manufactured by the additive manufacturing methods discussed herein may exhibit such an anisotropic micrograined structure.

[0008] By using such additive manufacturing techniques, it becomes possible to adopt a showerhead shape that is extremely difficult or impossible to achieve when using only conventional machining (subtractive machining) techniques such as milling, drilling, or turning. Such a showerhead shape allows, for example, the showerhead to have a smaller internal volume (thus reducing the amount of gas required to supply a desired gas flow through the showerhead and reducing the time required for the showerhead to reach a steady-state flow), and in some cases, to have more different fluidically separated flow paths (or at least a higher density of such flow paths) within the showerhead.

[0009] A typical semiconductor showerhead generally has a circular shape and one or more fluid inlets located near the center of the showerhead. The fluid inlets typically supply gas into a large, flat, cylindrical plenum volume within the showerhead, and then the gas flows out of the showerhead through a plurality of gas distribution ports that are in fluid communication with the plenum volume. When gas flow is initiated in such a showerhead, there may be some delay before a desired level of gas flow is achieved through the gas distribution ports. This is because the plenum volume is very large compared to the gas distribution port volume, for example, several orders of magnitude larger in some cases.

[0010] In contrast, a showerhead manufactured by the additive manufacturing method disclosed herein replaces a large, generally cylindrical plenum volume typical of conventional showerheads with a network of lateral passages that function to distribute gas delivered through a fluid inlet to a plurality of gas distribution ports located on the lower surface of the showerhead. Because additive manufacturing techniques enable the easy creation of true double-blind passages or holes, such a showerhead can have a number of such lateral passages that are fully contained within the showerhead body without incurring additional manufacturing costs (in fact, the manufacturing costs of such a showerhead may somewhat counter-intuitively decrease, because the number of lateral passages in a showerhead manufactured by an additive manufacturing method increases due to an increase in the amount of "empty volume" within the part compared to the "solid volume"). For clarity, a double-blind hole or passage is a hole or passage that does not extend along the hole or passage axis to an opening on the outer surface of the component that contains it (in contrast, a blind hole is a hole that extends from a single opening on the outer surface of a part into the part, and a through-hole is a hole that extends between two openings on the outer surface of a part). While double-blind holes can be created using conventional machining techniques such as drilling, such double-blind holes would first have to be made into blind holes by drilling and then converted into double-blind holes by fixing a plug in place, for example by welding, brazing, or other means, to fill the upper part of the hole. However, such multi-step double-blind hole techniques are costly and increase the potential for leakage at the plug / hole interface. Another technique that can be used to create double-blind holes or passages in a part is to create bonded parts, in which case double-blind holes are milled into the mating surfaces of one or two mating layers, which are then joined, for example brazed, together. However, such techniques can be difficult to implement for thin layers, may require additional (costly) manufacturing steps, and may have issues regarding potential leak paths at the location of the interface between the bonded layers.

[0011] The inventors of the present invention have realized that by constructing a shower head using an additive manufacturing method, it becomes possible to adopt a complex double-blind lateral passage arrangement within the shower head body. The inventors of the present invention have further realized that by utilizing such an arrangement, it is possible to provide a plurality of independent flow paths through the shower head, all having generally the same flow characteristics. Using such technology, it is possible to provide a shower head that supports, in particular, two, three, four, or even more independent flow paths.

[0012] In addition to such advantages, the inventors of the present invention have further determined that by using a specific cross-sectional shape with such lateral passages, it is possible to improve the manufacturability of such lateral passages using additive manufacturing techniques while still providing a sufficiently efficient use of the material volume available within the shower head.

[0013] For example, if there is no previously melted underlying structure in a particular area that is melted during layer construction, the newly melted layer may be supported only by unmelted powder material and may collapse or cause other defects, which degrades the quality in that area. To avoid such defects, it is common for DMLM parts to also include a temporary support structure. Using a temporary support structure, it is possible to reduce the size of unsupported areas (and thus reduce or eliminate such defects), but it can be easily broken off or removed in other ways after the part is completed. However, the use of a temporary support is not feasible in the context of the internal double-blind passages discussed herein because there is no way to remove such a support from within the part after it is fabricated.

[0014] Instead, the inventors of the present invention have determined that by using a lateral passage having a substantially flat bottom and an angled or beveled top, the above-described manufacturing challenges can be avoided while still providing an efficient use of the volume available for such lateral passages.

[0015] While various implementations of a showerhead manufactured by an additive manufacturing method will become apparent from the above and following discussions, the present disclosure includes at least the following specific implementations, which are provided for clarity and are not intended to be limiting.

[0016] In some implementations, an apparatus may be provided that includes a showerhead body, the showerhead body having one or more sets of first lateral passages extending along a path that may be substantially parallel to a first plane, a set of first gas distribution ports extending along a path that may be substantially perpendicular to the first plane and having a first end terminating within the showerhead body and a second end terminating at a first outer surface of the showerhead body, and one or more first fluid inlets. In such implementations, the one or more sets of first lateral passages may include a first set of first lateral passages, the first set of first lateral passages may be fluidly sandwiched within the showerhead body between the set of first gas distribution ports and the one or more first fluid inlets, and the first set of first lateral passages may include at least one first lateral passage having a cross-section such as a nominally triangular cross-section or a nominally pentagonal cross-section.

[0017] In some such implementations, the showerhead body may be manufactured by an additive manufacturing method and may have an anisotropic micro-grain structure resulting from the additive manufacturing process.

[0018] In some implementations, there may be two or more sets of first lateral passages, the two or more sets of first lateral passages may further include a second set of first lateral passages, the showerhead body may further include one or more sets of first riser passages extending along a path that may be substantially perpendicular to the first plane, each set of first riser passages may be fluidly sandwiched between two of the sets of first lateral passages, and the one or more sets of first riser passages may include a first set of first riser passages fluidly sandwiched between the first set and the second set of first lateral passages.

[0019] In some implementations, each first riser passage in the first set of first riser passages may be an extension of a corresponding one of the first gas distribution ports.

[0020] In some implementations, at least one first lateral passage in the first set of first lateral passages may have a nominal triangular cross-section. In some such implementations, the nominal triangular cross-section may have a first side substantially parallel to the first plane, and second and third sides, each of the second and third sides forming an angle of 45° or more with respect to the first side.

[0021] In some other implementations, at least one first lateral passage in the first set of first lateral passages may have a nominal pentagonal cross-section. In some such implementations, the nominal pentagonal cross-section may have a first side substantially parallel to the first plane; second and third sides, each of these sides being adjacent to the first side and substantially perpendicular to the first plane; and fourth and fifth sides, each of these sides being adjacent to the second and third sides and forming an angle of 45° or more with respect to the first side.

[0022] In some implementations, the first gas distribution ports may be arranged in a non-orthogonal rhombic lattice pattern.

[0023] In some implementations, the non-orthogonal rhombic lattice pattern may have a maximum pitch along a first axis and a minimum pitch along a second axis perpendicular to the first axis, and the maximum pitch may be approximately twice the minimum pitch.

[0024] In some implementations, the first lateral passages in the first set of first lateral passages are disposed in two first linear arrays, each first linear array may include a plurality of different first lateral passages in the first set of first lateral passages, the first lateral passages in each first linear array may be substantially parallel to each other, and each intersection between the first lateral passages in the first set of first lateral passages may be aligned with a corresponding one of the first gas distribution ports.

[0025] In some implementations, the showerhead body may further include one or more sets of second lateral passages extending along a path that may be substantially parallel to the first plane, and a set of second gas distribution ports extending along a path that may be substantially perpendicular to the first plane and having a first end terminating within the showerhead body and a second end terminating at a first outer surface of the showerhead body, and one or more second fluid inlets. In such implementations, the one or more sets of second lateral passages may include a first set of second lateral passages, and the first set of second lateral passages may be fluidly sandwiched between the set of second gas distribution ports and the one or more second fluid inlets within the showerhead body.

[0026] In some further such implementations, the showerhead body may further include one or more sets of third lateral passages extending along a path that may be substantially parallel to the first plane, and a set of third gas distribution ports extending along a path that may be substantially perpendicular to the first plane and having a first end terminating within the showerhead body and a third end terminating at a first outer surface of the showerhead body, and one or more third fluid inlets. In such implementations, the one or more sets of third lateral passages may include a first set of third lateral passages, and the first set of third lateral passages may be fluidly sandwiched between the set of third gas distribution ports and the one or more third fluid inlets within the showerhead body.

[0027] In some such implementations, the showerhead body may include one or more sets of fourth lateral passages extending along a path that may be substantially parallel to a first plane, and a set of fourth gas distribution ports extending along a path that may be substantially perpendicular to the first plane, having a first end that terminates within the showerhead body and a fourth end that terminates at a first outer surface of the showerhead body, and one or more fourth fluid inlets. In such implementations, the one or more sets of fourth lateral passages may include a first set of fourth lateral passages, and the first set of fourth lateral passages may be fluidly sandwiched between the set of fourth gas distribution ports and the one or more fourth fluid inlets within the showerhead body.

[0028] In some such implementations, the first, second, third, and fourth gas distribution ports may be arranged in corresponding first, second, third, and fourth non - orthogonal rhombic lattice patterns, each of the first, second, third, and fourth non - orthogonal rhombic lattice patterns may have a maximum pitch along a corresponding first axis and a minimum pitch along a second axis, and the first, second, and third non - orthogonal rhombic lattice patterns may each be offset from the second, third, and fourth non - orthogonal rhombic lattice patterns by a distance equal to one - quarter of the maximum pitch along the first axis.

[0029] In some implementations, the apparatus may further include a stem portion. In such implementations, the stem portion may extend from a side of the showerhead body opposite the first outer surface and may include one or more first fluid inlet passages fluidly connected to one or more first fluid inlets, one or more second fluid inlet passages fluidly connected to one or more second fluid inlets, one or more third fluid inlet passages fluidly connected to one or more third fluid inlets, and one or more fourth fluid inlet passages fluidly connected to one or more fourth fluid inlets.

[0030] In some such embodiments, one or more first fluid inlet passages may surround one or more second fluid inlet passages, one or more second fluid inlet passages may surround one or more third fluid inlet passages, and one or more third fluid inlet passages may surround one or more fourth fluid inlet passages.

[0031] In some additional or alternative such embodiments, the stem portion may further include a first fluid inlet port, one or more first fluid inlet passages may include a first annular fluid inlet passage, the first annular fluid inlet passage may extend along a first axis and may have a generally annular cross-section, the first annular fluid inlet passage may be fluidly sandwiched between the first fluid inlet port and one or more fluid inlets, a diverter structure may be disposed within the first annular fluid inlet passage, and in that case, a first plane is in the same plane as the first axis and is adapted to pass through the first fluid inlet port and through the diverter.

[0032] In some such embodiments, the diverter structure may have a cross-section having a teardrop shape and a triangular shape when viewed along an axis perpendicular to the first axis.

[0033] In some other or alternative such embodiments, all of the surfaces of the diverter structure facing the showerhead body may be angled from the first plane by an angle of 45° or more, or may be angled such that the planes in contact with these surfaces are at 45° or more.

Brief Description of the Drawings

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[0064] It will be understood that the figures discussed herein are for the purpose of providing references for discussion only and are not intended to limit the present disclosure. Other implementations, although not specifically shown herein, are intended to be within the scope of the present disclosure as will be apparent from the entire disclosure.

DETAILED DESCRIPTION OF THE INVENTION

[0065] The specific showerhead shapes and features discussed herein were devised in the context of showerheads manufactured by additive manufacturing methods, for example, showerheads fabricated using selective laser melting or direct metal laser melting. However, it will be understood that showerheads having such shapes and features, but fabricated using other techniques including the use of conventional subtractive machining techniques, are also considered to be within the scope of the present disclosure.

[0066] FIG. 2 depicts a perspective view of an exemplary showerhead for use in a semiconductor processing system. As shown in FIG. 2, the showerhead 201 may include a showerhead body 202, a stem portion 203, and a manifold 204. The showerhead 201 is a chandelier type showerhead, although other implementations may be flash mount showerheads, the size of the stem portion 203 may be reduced, or the stem portion may be omitted entirely.

[0067] The showerhead body 202 shown in FIG. 2 and in other figures herein has a reduced diameter / dimension relative to the other features shown, such that some other features that are typically very small in relation to the showerhead body 202 are more visible in relation to the showerhead body 202 within the constraints of the drawing page size. It will be further understood that the showerhead body 202 may in fact be significantly larger in diameter than shown in FIG. 2, for example, two or three times larger or more. It will be further understood that the internal features of the showerhead body 202 may be replicated as necessary or desired to scale with any increase in the dimensions of the showerhead body 202.

[0068] In this embodiment, the manifold 204 of the shower head 201 includes four separate gas inlets that extend from (and into) the manifold body 205. For example, the first gas inlet 206, the second gas inlet 207, and the third gas inlet 208 may be provided with gas flow paths that are substantially (or somewhat) in the radial direction, as shown, and the fourth gas inlet 209 may be provided with a flow path that is substantially in the axial direction, for example, flowing mainly in a direction parallel to the central axis of the stem portion 203. Each of the first, second, third, and fourth gas inlets 206 - 209 (where the second gas inlet 207 is not visible here, see FIG. 3) may have a fixture 210 at one end to facilitate connecting them to an appropriate gas supply line. It will be understood that other implementations may feature other arrangements of the gas inlets and / or fixtures.

[0069] The manifold body 205 may be connected to the stem portion 203 by any of a variety of mechanisms and, in some cases, may simply be an extension of the stem portion 203 or the shower head body 202. In the illustrated arrangement, both the manifold body 205 and the stem portion 203 may have tapered flanges along the circumferential direction that can be captured by a clamp 211. The clamp 211 may be, for example, a split collar clamp that can be fastened by a fastening mechanism 212.

[0070] The manifold body 205 may be characterized by a threaded portion and a fixing nut 213 that can be screwed into it, as shown in FIG. 2. Such features may be used, for example, to fix the shower head 201 to a fixture or other hardware that can support the shower head with respect to the processing chamber in which the shower head is installed. For example, the support hardware may have a hole sized large enough for the threaded portion of the manifold body 205 to pass through, and then the fixing nut 213 is screwed onto and tightened against the portion of the manifold body 205 that extends through the support hardware, whereby the support hardware may be clamped between the fixing nut 213 and the manifold body 205.

[0071] The shower head body 202 also has a first outer surface 214, for example, the lower surface of the shower head body 202 when the shower head 201 is in the installed and in-use configuration, as shown in FIG. 2. The first outer surface has a plurality of gas distribution ports 215 extending therethrough. Each gas distribution port may have a first end terminating somewhere within the shower head body 202, for example, in a corresponding lateral passage, and a second end terminating at the first outer surface, for example, in a hole in the first outer surface.

[0072] FIG. 3 represents an exploded perspective view of the exemplary shower head of FIG. 2. In FIG. 3, it can be seen how the fixing nut 213 can be removed from the manifold body 205. In FIG. 3, the second gas inlet 207, as well as the tapered flanges 217a and 217b, and the first, second, third, and fourth fluid inlet ports 218 - 221 of the stem portion 203 are visible.

[0073] While any suitable manifold 204 may be used, the manifold 204 shown in FIGS. 2 and 3 can provide a relatively small system for supplying a plurality of gas flows to the shower head 201. FIG. 4 represents a perspective view of the exemplary manifold of the exemplary shower head of FIG. 2, while FIG. 5 represents a cutaway perspective view of the exemplary manifold of FIG. 4.

[0074] As can be seen from FIG. 4, when the showerhead 201 is fully assembled, the four gas inlets 206-209 may each terminate in a different hole in the lower surface of the manifold body 205, i.e., in the surface of the manifold body 205 that abuts the stem portion 203. Such holes may each be aligned with corresponding fluid inlet ports 218-221 on the upper surface of the stem portion 203 (or, when used with a flush mount showerhead, on the upper surface of the showerhead body 202) and may be used to supply gas to the fluid inlet ports. An O-ring 216 may be used to provide a seal between each fluid inlet port 218-221 and each gas inlet 206-209.

[0075] As shown in FIG. 5, the manifold body 205 may have a hole drilled vertically upward along the vertical axis to form part of the third gas inlet 208, and a tube stub, sometimes also referred to in the art as a ground, may be inserted into this hole along with one of the fixtures 210 and welded or brazed. For clarity, references to "vertical" and "horizontal" in this disclosure, unless otherwise indicated by the context, are made with the showerhead in the configuration during use, for example, when the first outer surface 214 faces downward toward the semiconductor substrate undergoing the processing operation, with reference to the horizontal and vertical directions. The remaining first, second, and fourth gas inlets 206, 207, and 209 may be provided by holes drilled horizontally at different circumferential positions around the manifold body 205. A tube stub with a fixture 210 may similarly be inserted into these holes and fixed in place without leakage by brazing, welding, or other means. Each of the first, second, and fourth gas inlets 206, 207, and 209 may extend horizontally into the manifold body 205 until they reach corresponding vertical holes that reach the lower surface of the manifold body 205. In the provided embodiment, these fluid inlet ports are arranged in a "Y" shape, although other arrangements are equally possible (e.g., a Y shape with arms of equal length and equal angles between the arms, or a horizontal four-arm intersection arrangement where the third fluid inlet 208 is like the first, second, and fourth gas inlets 206, 207, and 209 passing through the third gas inlet). The third fluid inlet port 208 in this embodiment follows a somewhat more complex path. This is because while most of the third fluid inlet 208 is provided by a vertical hole centered on the central axis of the manifold body 205, the hole on the lower surface of the manifold body 205 that is fluidly connected to the vertical hole is radially offset from the central axis of the manifold body 205, similar to the three holes on the lower surface of the manifold body 205. To provide this offset, a radial hole 226 is drilled outside the manifold body so as to intersect both vertical holes for the third fluid inlet port 208.Next, a plug 227 is inserted into a portion of the radial holes that extends between the outer surface of the manifold body 205 and the radially outermost hole, and welded or brazed in place to prevent leakage through the plug. The manifold body 205 can also be manufactured using additive manufacturing techniques, if desired, in which case the flow paths can take other shapes and the use of plugs to construct double blind passages can be avoided.

[0076] The showerhead 201 may generally appear similar to existing showerheads, possibly excluding the manifold 204 in some cases. However, due to the internal arrangement of the flow paths that may be incorporated within such a showerhead, the arrangement of the gas distribution ports 215 on the first outer surface 214 can be very different from that typically provided. For example, in FIG. 6, which represents a bottom view of an exemplary showerhead of FIG. 2, it can be seen that the gas distribution ports 215 include four different subsets of gas distribution ports, namely, a first gas distribution port 222, a second gas distribution port 223, a third gas distribution port 224, and a fourth gas distribution port 225. As further apparent from FIG. 6, the gas distribution ports 215 of each subset of the gas distribution ports 215 are arranged, for example, at the intersection points in a diamond lattice pattern and are arranged in a diamond lattice pattern. The diamond lattice pattern is a pattern in which the pattern instances are generally located at the intersection points between a first set of parallel lines and a second set of parallel lines. The lines in both the first set and the second set of lines are spaced apart from each other by the same distance, and the lines in the first set of lines are not parallel to the lines in the second set of lines. In this embodiment, the diamond lattice pattern is a non-orthogonal lattice pattern. That is, the lines in the first set of lines are not orthogonal to the lines in the second set of lines (an orthogonal lattice pattern would be a square lattice or a square array). FIG. 6 includes four diamond depictions schematically showing the diamond arrangement of each of the four sets of gas distribution ports 215.

[0077] The smallest rhombus that can be drawn by vertices that match different pattern instances in a rhombic lattice pattern can generally be characterized as the unit rhombus with respect to the rhombic lattice pattern. The unit rhombus can generally be defined as having a maximum pitch along a first axis and a minimum pitch along a second axis perpendicular to the first axis (in an orthogonal rhombic lattice pattern, the maximum pitch and the minimum pitch may be equal). The maximum pitch refers to the maximum distance between the vertices of the unit rhombus, and the minimum pitch refers to the minimum distance between the vertices of the unit rhombus. In some implementations discussed herein, the maximum pitch may be twice the minimum pitch. As will be apparent from the considerations described below, the rhombic lattice patterns used for each flow path in the various implementations discussed herein may be arranged alternately along an axis perpendicular to the plane in which the rhombic lattice patterns are arranged. For example, in a dual flow path showerhead, two sets of rhombic lattice patterns may be staggered along the first axis by a distance equal to half of the maximum pitch. Similarly, in a triple or quadruple flow path showerhead, the sets of rhombic lattice patterns may be staggered from each other by a distance equal to one-third or one-fourth of the maximum pitch, respectively.

[0078] Note from FIG. 6 that the gas distribution ports for the four flow paths in this particular embodiment are arranged in a square pattern that is itself repeated in an offset manner. For example, there may be four gas distribution ports, one from each flow path, that define a square. Each set of such four gas distribution ports may be offset along one axis by a length of one of the sides of the square (aligned with each respective side of the square), such that the square patterns may be offset from each other.

[0079] FIG. 7 represents a side cross-sectional view of the exemplary showerhead of FIG. 2. As can be seen in FIG. 7, the stem portion 203 may have a plurality of fluid inlet passages extending from one end thereof to the other end, such as first, second, third, and fourth fluid inlet passages 228-231. In this embodiment, each of the fluid inlet passages 228-31 is substantially annular, for example, defined (or delimited by one) between two substantially annular walls, with the second fluid inlet passage 229 surrounding the first fluid inlet passage 228, the third fluid inlet passage 230 surrounding the second fluid inlet passage 229, and the fourth fluid inlet passage 231 surrounding the third fluid inlet passage 230. In other implementations, other arrangements of fluid inlet passages may be used, such as concentric rings of non-annular fluid inlet passages arranged in a circular array, or even non-concentrically arranged fluid inlet passages, such as four fluid inlet passages arranged in a square pattern similar to the bottom surface of the manifold 204.

[0080] Regardless of the particular arrangement of the fluid inlet passages, each of the fluid inlet passages 228-231 may be fluidly connected to a corresponding one of the fluid inlet ports 218-221. In embodiments where the manifold 204 is incorporated within the stem portion 203, it will be understood that the fluid inlet ports 218-221 and the gas inlets 206-209 may be provided by the same feature. Similarly, in a flush-mounted embodiment without the stem portion 203, the fluid inlet passages 228-231 may be provided by any fluid conduit existing between the gas inlets 206-209 and a feature within the showerhead body 202.

[0081] In FIG. 7, the first fluid inlet port 218 is shown to be fluidly connected to the first fluid inlet passage 228, which extends downward to the showerhead body 202 and is fluidly connected to the first fluid inlet 237. In this embodiment, the first fluid inlet 237 is a portion of the first fluid inlet passage 228 that extends outward from the stem portion 203 and enters the showerhead body 202. Similarly, the second fluid inlet port 219 is shown to be fluidly connected to the second fluid inlet passage 229, which extends downward to the showerhead body 202 and is fluidly connected to the second fluid inlet 238. In this embodiment, the second fluid inlet 238 is likewise a portion of the second fluid inlet passage 229 that extends outward from the stem portion 203 and enters the showerhead body 202, but is not deeper than the first fluid inlet 237. The third and fourth fluid inlet passages 230 and 231 may similarly be fluidly sandwiched between the third and fourth fluid inlet ports 220 and 221 and the third and fourth fluid inlets 239 and 240, respectively.

[0082] Thereby, each of the first through fourth fluid inlets 237 - 240 may be fluidly connected to one or more corresponding sets of a set of lateral passages, such as the first through fourth lateral passages 233 - 236. The lateral passages may extend along a path generally parallel to a first plane, e.g., a plane that is horizontal when the showerhead is installed and in its in - use configuration. In contrast, the gas distribution ports may extend along a direction perpendicular to the first plane (in some implementations, the gas distribution ports may be angled with respect to the first plane).

[0083] In the illustrated embodiment, for example, the first fluid inlet 237 is fluidly connected to two corresponding sets of the first lateral passage 233, one set being disposed at a height generally corresponding to the bottom of the first fluid inlet 237, and the other set being disposed at a position adjacent to the first outer surface 214 that is lower within the shower head body 202. Similarly, the second fluid inlet 238 is fluidly connected to two corresponding sets of the second lateral passage 234, one set being disposed at a height generally corresponding to the bottom of the second fluid inlet 238, and the other set being disposed slightly above the lower set of the first lateral passage 233.

[0084] The third fluid inlet 239 may similarly be fluidly connected to two corresponding sets of the third lateral passage 235, one set being disposed at a height generally corresponding to the bottom of the third fluid inlet 239, and the other set being disposed slightly above the lower set of the second lateral passage 234. The fourth fluid inlet 2340 may similarly be fluidly connected to two corresponding sets of the fourth lateral passage 236, one set being disposed at a height generally corresponding to the bottom of the fourth fluid inlet 240, and the other set being disposed slightly above the lower set of the third lateral passage 235.

[0085] FIG. 8 represents a top view of the flow paths within the exemplary shower head of FIG. 2. As can be seen from the figure, the lateral passages 233-236 form a series of offset diamond grid pattern shapes. Gas distribution ports may be located below each intersection point 241 between the two lateral gas passages 233-236.

[0086] The complex configuration of the lateral passages shown in FIG. 8 is more apparent in FIGS. 9 and 10, which represent perspective views and perspective cross-sectional views of the flow paths within the exemplary shower head of FIG. 2. In these figures, the concentric and annular nature of the first to fourth fluid inlet passages 228-231 is apparent.

[0087] In FIGS. 9 and 10, a portion of the fourth fluid inlet passage 231 corresponding to the location of the diverter structure 246 is also visible. The diverter structure 246 is, for example, a triangular or teardrop-shaped feature located within the fourth fluid inlet passage 231 and disposed below the fourth fluid inlet 221, whereby the fluid, such as gas, exiting the fourth fluid inlet port 221 and flowing into the fourth fluid inlet passage 231 is caused to change direction (in an inclined direction having both an axial component and a circumferential component, as opposed to a purely axial flow) and to be split into two separate flows, thereby causing such fluid to be more uniformly dispersed within the fourth fluid inlet passage 231. The teardrop-shaped feature is, for example, a feature having the shape of a teardrop. In such a case, the rounded portion of the teardrop may face towards the bottom and the pointed end of the teardrop may point towards the fourth fluid inlet port 221. Although not visible in FIG. 9, a similar diverter structure may be included in one or more of the other fluid inlet passages 228 - 230. In FIG. 9, what appears as a triangular notch in the fourth fluid inlet passage 231 represents a triangular-shaped diverter structure extending between the walls of the stem portion 203 that surrounds the fourth fluid inlet passage 231 and occupies a triangular-shaped notch area.

[0088] Figures 11 and 12 represent simplified schematic views of two diverter configurations. Both figures show a fluid inlet port and a portion of the annular inlet passage, which is "flared" and flat on the left side of each figure. Each figure also shows, on the right side, a radial cross-section of such a structure. In Figure 11, a first fluid inlet port 1118 supplies a gas flow to a first fluid inlet passage 1128. A diverter structure 1146 (which is triangular in cross-section in this embodiment) is disposed within the first fluid inlet passage 1128 such that a plane that is in the same plane as the stem central axis (not shown; see other figures) passes through both the first fluid inlet port 1118 and the diverter structure 1146. Alternatively, the diverter structure 1146 can be described as being disposed below the first fluid inlet port 1118, such that the fluid flowing out of the first fluid inlet port 1118, e.g., gas, is split into two flows with changed directions having increased directional components to the left and right sides of the diverter structure 1146. As can be seen from the cross-sectional view on the right side of Figure 11, the diverter structure 1146 may have an inclined bottom surface, e.g., a surface having an angle of 45° or more from the horizontal. This can provide a more reliably manufacturable diverter structure compared to a similar diverter structure having a horizontal bottom surface, as will be described later in this specification with respect to the cross-sectional shape of the lateral passage. Figure 12 shows a similar configuration having a first fluid inlet port 1218 that supplies gas to a first fluid inlet passage 1228, but instead of the triangular diverter structure 1146, a teardrop-shaped diverter structure 1246 is used. The bottom surface of the diverter structure 1246 may similarly be inclined, as is apparent from the cross-sectional view on the right side in Figure 12 (although it does not have a flat bottom surface, it may still be desirable in some cases to design the bottom surface of the diverter structure 1246 to have a contact surface that is inclined at 45° or more from the horizontal at any given point).

[0089] In some implementations, as described above, each flow path through the showerhead may include multiple sets of lateral passages. In such implementations, each set of lateral passages may be fluidly connected to other sets of lateral passages by corresponding riser passages. For example, a first flow path through the showerhead body 202 features two sets of first lateral passages 233 at different heights. The lower set of the first lateral passages 233 is fluidly connected to the upper set of the first lateral passages 233 by a first riser passage 242. The first riser passage may extend vertically from the lower set of the first lateral passages 233 and fluidly connect the lower set of the first lateral passages 233 to the upper set of the first lateral passages 233. The lower set of the first lateral passages 233 may be fluidly connected to a first gas distribution port 222.

[0090] Similarly, there may be an upper set of second lateral passages 234 fluidly connected to a lower set of second lateral passages 234 by a second riser passage 243, an upper set of third lateral passages 235 fluidly connected to a lower set of third lateral passages 235 by a third riser passage 244, and an upper set of fourth lateral passages 236 fluidly connected to a lower set of fourth lateral passages 236 by a fourth riser passage 245. The lower sets of the second lateral passages 234, the third lateral passages 235, and the fourth lateral passages 236 may also be fluidly connected to a second gas distribution port 223, a third gas distribution port 224, and a fourth gas distribution port 225, respectively. In implementations where two or more sets of lateral passages are used for each flow path, additional sets of riser passages may be fluidly sandwiched between each additional set of lateral passages and the set adjacent thereto near the lateral passages for that flow path.

[0091] Generally speaking, it will be understood that each set of lateral passages may be fluidly sandwiched between two other fluid flow features (or sets thereof). For example, each upper set of lateral passages may be fluidly sandwiched between a corresponding set of riser passages and one or more corresponding fluid inlets. Similarly, each lower set of lateral passages may be fluidly sandwiched between a corresponding set of riser passages and a corresponding set of gas distribution ports. Similarly, each set of riser passages may be fluidly sandwiched between two sets of lateral passages.

[0092] The illustrated embodiments feature a riser passage that is coaxial with a corresponding gas distribution port for a related flow path, e.g., generally centered at a location where a lateral passage intersects. In other implementations, the riser passage may be differently positioned, e.g., at an intermediate position between intersections of the lateral passages and / or at different intervals, e.g., every other one, or intermediate a pair of every other intersection of the lateral passages. Similarly, the gas distribution ports located at each intersection point between the lateral passages may instead be positioned elsewhere, e.g., shifted from that location such that each gas distribution port is intermediate between two such intersection points (or may be positioned at a location spaced such a distance from the nearest intersection point, e.g., for a gas distribution port at the periphery of a grid pattern, there may be no other intersection point “outside” the gas distribution port). It will be further understood that there may be portions of the showerhead body 202 where the riser passage may be omitted. For example, if a corresponding lateral passage is not disposed above a portion of another lateral passage for the same flow path, a riser passage will not be provided at that location. For example, the upper set of the fourth lateral passages 236 in FIGS. 9 and 10 terminate at the outer boundary of the fourth fluid inlet 240. Thus, a fourth riser passage 245 will not be provided at locations within the inner boundary of the fourth fluid inlet 240 (when viewed along the central axis 248) because there is no upper fourth lateral passage 236 to which such a riser would connect at those locations. Similar adjustments may be made for other sets of lateral passages.

[0093] Figures 13 - 16 each represent perspective cross-sectional views of the first, second, third, and fourth flow paths among the flow paths within the exemplary showerhead of FIG. 2. As shown in FIGS. 13 - 16, each flow path generally features a similar pattern of repeating lateral passages arranged in a diamond lattice configuration. In the illustrated embodiment, each riser passage is generally aligned with the corresponding gas distribution port, which may enable, for example, more precise control of the feature size / tolerances of the riser passage and the distribution port. For example, while additive manufacturing techniques are constantly being refined and improved, constructing parts manufactured by additive manufacturing methods with a smooth surface is often very difficult due to the aliasing effects inherent in most or all additive manufacturing techniques, which result from the use of XY stepper motors that drive the print head of the additive manufacturing system, as well as the layer-by-layer technique used to "stack" the parts manufactured by the additive manufacturing system. As a result, it may be desirable to perform post-additive manufacturing subtractive machining operations on the showerhead manufactured by additive manufacturing to ensure that features such as gas distribution ports, and in some cases riser passages, have a uniform and consistent cross-sectional shape. For example, it may be desirable to drill the gas distribution ports (and, in some cases, riser passages) using a drill, thereby ensuring a truly round (and consistent size) cross-section for these features and providing a consistent surface finish. However, such drilling operations can be achieved relatively quickly. This is because the gas distribution ports (and, in some cases, riser passages) manufactured by additive manufacturing methods function as roughly drilled holes with a full depth, and this hole guides the finishing drilling operation and most of the material to be removed is already absent as a result. Thus, the finishing drilling operation may function, for example, like a honing operation that removes only a few thousandths of an inch of material from a given gas distribution port (and optional riser passage). Of course, if the quality of the components manufactured by additive manufacturing methods is sufficiently high and such operations may be omitted, performing such post-additive manufacturing finishing operations may be unnecessary.

[0094] In the exemplary showerhead described above, all of the lateral passages are designed to be chords of a common outer boundary circle (as can be seen in FIG. 8, the ends of the lateral passages form a complete circle, and thus the ends of each lateral passage are exactly on that circle). As a result, the lateral passages of this exemplary showerhead often have dead legs 247. That is, it is a fluid dead end in that there is no way for the fluid that has entered such a portion to exit that portion other than to flow back through the aperture through which it entered when it entered that portion. Such dead legs are often undesirable in semiconductor gas systems. This is because such systems often need to flow different, mutually reactive gases through a common flow path. To prevent undesirable reactions (which may damage the flow path or generally undesirable particulate matter) between such gases in those flow paths, such systems typically purge the flow path between the flows of each reactant. This takes time and tends to waste the gas that is purged and removed from the flow path. In particular, when there are dead legs in such a system, it is very difficult and in some cases impossible to completely purge such a system because process gas can be trapped in the dead legs 247. The purge gas cannot enter the dead legs due to the lack of an exit path, and thus the process gas that enters the dead legs tends to remain (although over time, diffusion of gas into / out of the dead legs will occur, but during semiconductor processing operations, such diffusion of the purge gas will typically take much longer than an acceptable time to properly purge the process gas from the dead legs).

[0095] In a multi-channel showerhead as discussed above, the showerhead may include a greater number of channels within a given volume (the showerhead body) than may generally be achievable in other showerheads where the volume available for the channels is the same. As a result, such a showerhead can avoid the need to reuse channels for different gases, thereby avoiding the need to purge such channels. In view of this, the presence of dead legs 247 in a showerhead as discussed herein may not have the same adverse effects as would generally result from the presence of dead legs in a showerhead that reuses channels for different gases. Furthermore, there may actually be advantages to including such dead legs 247 in a showerhead as in the embodiments discussed above. The material that would normally be used to "fill" such dead legs may simply be reused directly in an additive manufacturing system, for example, in subsequent additive manufacturing operations for other components. In other words, the increased free space within the showerhead resulting from including such dead legs means that less material is required to manufacture the showerhead body 202. Since the "waste" material from selective laser melting or similar processes can simply be reused in subsequent additive manufacturing operations, the material savings resulting from including dead legs can actually make such showerheads less expensive. The use of such dead legs can avoid the time normally spent "filling" the dead legs, thus reducing the manufacturing time and realizing additional cost savings.

[0096] However, a multi-path showerhead having dead legs may still be undesirable in some cases. For example, the surface finish resulting from an additive manufacturing process may be too rough in some situations to produce the desired fluid flow profile, or there may be powdery particles that are not completely dissolved but are only stuck or fused to the surrounding structure and may flake off during use, thereby contaminating the wafer being processed using such a showerhead. As described above, subtractive machining operations after additive manufacturing, such as drilling, performed on the gas distribution ports (and, optionally, the riser passages) can help provide a more uniform surface finish in those areas of the showerhead, but this can also be a concern within the lateral passages of the showerhead (or in any other part of the showerhead that is not easily accessible by a machine or toolhead capable of smoothing its surface finish). In such cases, other types of liquid-based smoothing or polishing operations, such as electropolishing, slurry polishing, etc., can be performed, whereby an abrasive mixed with or supplied by a liquid is allowed to flow into the showerhead and used to polish the inner surface of the showerhead. However, in such cases, it may be difficult for the abrasive to polish the surface of the dead leg due to the generally stagnant flow condition within the dead leg. In such situations, it may be desirable to avoid using dead legs within the showerhead, even if it results in an increase in the manufacturing cost of the part due to increased material usage.

[0097] FIG. 17 represents a perspective view of another exemplary showerhead having various features disclosed herein. This exemplary showerhead omits the upper portion of the stem portion (including the fluid inlet port) for simplicity (it may be assumed to have features similar to those in the previously provided embodiments), and also completely omits the use of dead legs. The showerhead 1701 shown in FIG. 17 includes a stem portion 1703 connected to the showerhead body 1702. In the stem portion 1703, a first fluid inlet passage 1728, a second fluid inlet passage 1729, a third fluid inlet passage 1730, and a fourth fluid inlet passage 1731 can be seen.

[0098] FIG. 18 represents a perspective cross-sectional view of the exemplary showerhead of FIG. 17. As can be seen from the figure, the cross-section is very similar to that shown in FIG. 7, but a slight portion of the dead leg 247 can be seen on the outer periphery of the showerhead body 202 in FIG. 7, which is not visible in the showerhead body 1702. In addition to the features discussed above with respect to FIG. 17, a portion of a first lateral passage 1733, a second lateral passage 1734, a third lateral passage 1735, and a fourth lateral passage 1736 can be seen. Similar to the showerhead 201, there are two sets each of the first lateral passage 1733, the second lateral passage 1734, the third lateral passage 1735, and the fourth lateral passage 1736, namely a lower set and an upper set.

[0099] FIG. 19 shows a perspective view of the flow paths within the exemplary showerhead of FIG. 18. As can be seen from the figure, each flow path includes a lateral passage that does not extend beyond (or minimally extends, e.g., by half the difference between the width of the lateral passage and the diameter of the gas distribution port and / or riser passage) the outermost gas distribution port and / or riser passage of the showerhead body 1702. Thus, the first flow path may include a first fluid inlet passage 1728, which may flow gas to an upper set of first lateral passages 1733, which may then flow that gas to a first riser passage 1742, and from there to a lower set of first lateral passages 1733 and into a first gas distribution port 1722. Similarly, the second flow path may include a second fluid inlet passage 1729, which may flow gas to an upper set of second lateral passages 1734, which may then flow that gas to a second riser passage 1743, and from there to a lower set of second lateral passages 1734 and into a second gas distribution port 1723. The third flow path may include a third fluid inlet passage 1730, which may flow gas to an upper set of third lateral passages 1735, which may then flow that gas to a third riser passage 1744, and from there to a lower set of third lateral passages 1735 and into a third gas distribution port 1724. Similarly, the fourth flow path may include a fourth fluid inlet passage 1731, which may flow gas to an upper set of fourth lateral passages 1736, which may then flow that gas to a fourth riser passage 1745, and from there to a lower set of fourth lateral passages 1736 and into a fourth gas distribution port 1725.

[0100] FIGS. 20-23 each show perspective cross-sectional views of the first, second, third, and fourth flow paths, respectively, within the exemplary showerhead of FIG. 18.

[0101] For example, FIG. 20 shows a perspective view of a first flow path including an upper set and a lower set of the first lateral passage 1733. Also visible are the first riser passage 1742 and the first gas distribution port 1722 (in the exemplary showerhead 201, the first gas distribution port 222 is somewhat obscured by the dead leg of the first lateral passage 1733 in most of the figures). As can be seen from the figure, the first lateral passage 1733 is arranged in a non-orthogonal rhombic lattice, and the first gas distribution port 1722 is arranged in a non-orthogonal rhombic lattice pattern similar to that of the showerhead 201.

[0102] Similarly, FIG. 21 shows a perspective view of a second flow path including an upper set and a lower set of the second lateral passage 1734. Also visible are the second riser passage 1743 and the second gas distribution port 1723. Similarly, FIG. 22 shows a perspective view of a third flow path including an upper set and a lower set of the third lateral passage 1735. Also visible are the third riser passage 1744 and the third gas distribution port 1724. Finally, FIG. 23 shows a perspective view of a fourth flow path including an upper set and a lower set of the fourth lateral passage 1736, as well as the fourth riser passage 1745 and the fourth gas distribution port 1725.

[0103] In the above embodiments, for each flow path, there are two rhombic lattice patterns of the lateral passages, and the riser passages connecting the lateral passages of each rhombic lattice pattern are arranged such that they are directly above the corresponding gas distribution ports that flow gas from the lower lateral passage and exit from the showerhead. However, it will be understood that other arrangements of the lateral passages and / or gas distribution ports and / or riser passages may be implemented as well.

[0104] FIG. 24 represents a projection view of a plurality of flow paths for an exemplary showerhead. The flow paths shown in FIG. 24 reflect the flow paths of a showerhead in which each flow path includes two diamond lattice patterns of lateral passages, similar to the aforementioned showerhead discussed herein. However, the diamond lattice patterns of the flow paths represented in FIG. 24 are somewhat differently arranged. The most immediately apparent difference is that, as can be more clearly seen in FIGS. 24-A through 24-D, the riser passage spanning between each diamond lattice pattern of the lateral passages fluidly connects to the upper diamond lattice pattern of the lateral passages at the location where it coincides with the intersection of the two lateral passages, while at the location between adjacent intersections of the lateral passages, for example, near the middle of each lateral passage segment located between two adjacent lateral passages and where the adjacent lateral passages have a certain angle with respect to that segment, it connects to the lower diamond lattice pattern of the lateral passage. Such an arrangement forces the gas flowing through the riser passage to flow horizontally again before flowing out of the gas distribution passage, thus providing more uniform gas distribution.

[0105] For example, in FIG. 24-A, a fourth fluid inlet 2440 may supply gas to a set of fourth lateral passages 2436 that supply gas through a fourth riser passage 2445 to a set of fourth lateral passages 2436'. The gas may then change direction by 90° and flow along the lower set of fourth lateral passages 2436' and then flow out from a fourth gas distribution port 2425. The other flow paths shown in FIGS. 24-B through 24-D may be constructed similarly.

[0106] Another difference between the shower head flow path shown in FIG. 24 and the one described above is that the diamond lattice pattern of the lateral passages in FIG. 24 is not evenly spaced from each other. For example, in some of the above-described embodiments, where there are four flow paths, each having a diamond lattice pattern with a maximum pitch of 30 units and the major axes of the diamonds in the pattern are arranged in alignment, each diamond lattice pattern may be shifted along the major axis of the diamonds in the pattern by an amount equal to the value obtained by dividing the maximum pitch by the number of diamond lattice patterns. However, in the embodiment shown in FIG. 24, the diamond lattice patterns for each flow path are shifted from each other along the major axis of the diamonds in the pattern by an even multiple of the value obtained by dividing the maximum pitch by the value obtained by adding 1 to the number N of diamond lattice patterns. Thus, in effect, the N diamond lattice patterns are positioned at spaced locations along an axis as if N + 1 diamond lattice patterns were equally spaced within the same distance (maximum pitch). For example, if the maximum pitch is 30 units and there are four flow paths, each having a corresponding lattice pattern, the lattice patterns will be offset from each other by a distance that is a multiple of 5 units along their major axes. However, since the spacing between the diamond lattice patterns is based on the assumption that there is one more diamond lattice pattern than actually exists, the result is that there are gaps or voids in the evenly spaced diamond lattice pattern, for example, as if there were extra diamond lattice patterns that were removed leaving voids in the set of diamond lattice patterns.

[0107] FIG. 25 provides a more detailed overview thereof. In FIG. 25, a set of four diamond lattice patterns of the lateral passages 2533-2536 is shown (the outer boundaries of the diamond lattice patterns are arbitrarily defined. This is a detailed view of an exemplary set of diamond lattice patterns. The diamond lattice patterns have a major axis parallel to the major axis shown. The maximum pitch of the lattice patterns (which is the same for all of the diamond lattice patterns) is represented as shown. For example, the interval / offset along the major axis between the lattice pattern of the fourth lateral passage 2536 and the lattice pattern of the second lateral passage 2534 may be, for example, one-fifth of the maximum pitch. Similarly, for example, the interval along the major axis between the lattice pattern of the first lateral passage 2533 and the lattice pattern of the third lateral passage 2535 may also be, for example, one-fifth of the maximum pitch. However, for example, the interval along the major axis between the lattice pattern of the second lateral passage 2534 and the lattice pattern of the third lateral passage 2535 may be, for example, two-fifths of the maximum pitch. As a result, the gap in the lattice pattern is large enough for the fifth lattice pattern (represented by the dotted line) to fit in. However, instead of providing the fifth lattice pattern, the lattice patterns for each flow set may instead be offset from each other along an axis aligned with one of the lateral passage directions such that the riser passages (represented by circles) extending downward from the lateral passage intersection points shown in FIG. 25 intersect the lower set of lateral passages at a location that is at the mid-span, near the mid-span, or not directly above at least the gas distribution ports for each respective flow path. The gap allows such an offset between the sets of lateral passages, for example, between the upper set of lateral passages (as shown in FIG. 24) and the lower set of lateral passages.

[0108] Also shown at the top of FIG. 25 is a side cross-sectional view of a portion of the lateral passages in each set of lateral passages. The pentagonal cross-section is taken at an angle with respect to the centerlines of the lateral passages 2533-2536, and thus, in this embodiment, along the top of each of the lateral passages 2533-2536, it appears to have a "roof angle" greater than the 90° actually used. Each cross-sectional view includes the riser passages 2542-2545, as well as both the upper lateral passages for each set and the lower lateral passages for each set (however, in the detailed plan view described above, the lower lateral passages are not shown). For example, the cross-sectional view is taken along the thick dashed line immediately below the cross-sectional view in the larger portion of FIG. 25. As can be seen from the figure, the grid pattern of the lateral passages is not arranged in a "descending" or "ascending" order within the showerhead body 2502. That is, the rhombic grid pattern closest along the major axis is not the closest in the direction parallel to the axis along which the riser passages extend. Instead, the rhombic grid patterns are arranged such that the rhombic grid pattern of the second lateral passage is offset horizontally by three-fifths of the maximum pitch from the rhombic grid pattern of the first lateral passage, the rhombic grid pattern of the fourth lateral passage is offset horizontally by three-fifths of the maximum pitch from the rhombic grid pattern of the third lateral passage, and the rhombic grid pattern of the second lateral passage is offset horizontally by two-fifths of the maximum pitch from the rhombic grid pattern of the third lateral passage. Such an arrangement allows the riser passages extending from the intersection points of the lateral passages in the upper rhombic grid pattern to intersect the lateral passages in the lower rhombic grid pattern at locations near the midpoints of each lateral passage segment, thereby providing a more uniform distribution of the gas flow. Other arrangements of the rhombic grid pattern may be used, but there may be a result that the intersection points between the riser passages and the lower lateral passages approach the intersections between the lateral passages.

[0109] FIG. 26 provides a detailed plan view of the lateral passages for a single flow path, regarding the implementation form of FIG. 25. As can be seen in FIG. 26, only the fourth lateral passages 2536 and 2536' are shown. The other three sets of lateral passages that are apparent in FIG. 25 are omitted. Furthermore, both the upper fourth lateral passage 2536 and the lower fourth lateral passage 2536' are shown, but in FIG. 25, only the upper fourth lateral passage 2536 (and the other upper lateral passages) are shown. FIG. 26 shows how the two diamond lattice patterns used for each set of the fourth lateral passages 2536 and 2536' can be offset from each other or staggered, for example, along one of the lattice directions. In this case, the offset is along the axis passing through the centers of two adjacent fourth riser passages 2545 to which a segment of a single fourth lateral passage 2536 connects, and the amount of the offset is two-fifths (2y) of the distance (5y) between two adjacent fourth riser passages 2545 to which a segment of a single fourth lateral passage 2536 connects. Such an offset enables the fourth gas distribution port 2525 to be similarly offset from the fourth riser passage 2545, whereby the gas flowing through the flow path is forced to travel horizontally (and thus be more evenly distributed) in order to reach the fourth gas distribution port 2525 from the fourth riser passage 2545. It will be understood that a similar effect can be obtained by not offsetting the diamond lattice pattern of the lateral passages, but instead offsetting the location of the gas distribution ports in a similar manner. For example, if the fourth gas distribution port 2545 is located at the position shown in FIG. 26 and the diamond lattice pattern of the fourth lateral passage 2536' is aligned with the diamond lattice pattern of the fourth lateral passage 2536 (thus, in this drawing, if the upper fourth lateral passage 2536 completely obscures the lower fourth lateral passage 2536'), as a result, the fourth gas distribution port 2525 that is fluidly connected to the lower fourth lateral passage 2536' does not exist at the intersection point between the lower fourth lateral passages 2536', but instead exists near the middle of each segment of the lower fourth lateral passage 2536', and a similar effect will be brought about.Similarly, the fourth riser passage 2545 may also be shifted in location with respect to the fourth gas distribution port 2525 such that, for example, instead, the fourth riser passage connects to the fourth lateral passages 2536 and 2536’ at locations other than where the fourth lateral passages 2536 and 2536’ intersect within each diamond lattice pattern.

[0110] The set of lateral passages for the other flow paths may similarly be staggered with respect to each of such flow paths. In other implementations, other offsets between the upper and lower diamond lattice patterns (or riser passages and / or gas distribution ports) may be used, and it will be understood that this is merely an example of such an offset.

[0111] The above examples are merely examples of how a gas distribution port for a given flow path may be positioned such that it is not directly below the riser passage for that flow path. Other similar examples are also considered to be within the scope of the present disclosure.

[0112] As described above, the above examples include four separate flow paths through the showerhead, but may include fewer or more such flow paths. FIG. 27 depicts an example of a diamond lattice pattern that may be used for a dual flow path showerhead. In FIG. 27, a set of first lateral passages 2733 may be arranged in a grid pattern and supply gas to a first gas distribution port 2722. Similarly, a set of second lateral passages 2734 may be arranged in a similar grid pattern and supply gas to a second gas distribution port 2723. In this example, both grid patterns are orthogonal diamond lattices, and the first and second gas distribution ports 2722, 2723 are arranged in an orthogonal diamond lattice pattern.

[0113] FIG. 28 depicts an embodiment of a diamond lattice pattern that may be used for a triple flow path showerhead. In FIG. 28, a set of first lateral passages 2833 may be arranged in a non - orthogonal diamond lattice and may supply gas to a first gas distribution port 2822. Similarly, a set of second lateral passages 2834 and a set of third lateral passages 2835 may be arranged in a similar non - orthogonal lattice pattern and may supply gas to a second gas distribution port 2823 and a third gas distribution port 2824, respectively. In this embodiment, all three lateral passage patterns are non - orthogonal diamond lattices, and the first, second, and third gas distribution ports 2822, 2823, and 2824 are arranged in a non - orthogonal diamond lattice pattern.

[0114] It will be appreciated that in a given flow path, two or more sets of lateral passages may be used. The use of one or more additional sets of lateral passages, e.g., three or more sets of lateral passages, may in some cases facilitate more even gas distribution and more uniform gas delivery. FIG. 29 depicts an exemplary schematic side view of a flow path arrangement characterized by two or more sets of lateral passages per flow path. For example, in FIG. 29, a first fluid inlet 2937 can supply process gas to an upper set of first lateral passages 2933, which then flows from the upper set of first lateral passages 2933 through an upper set of first riser passages 2942, then through an intermediate set of first lateral passages 2933, then through a lower set of first riser passages 2942, reaches a lower set of first lateral passages 2933, and can then flow out from a first gas distribution port 2922. Similarly, a second fluid inlet 2938 can supply process gas to an upper set of second lateral passages 2934, which then flows from the upper set of second lateral passages 2934 through an upper set of second riser passages 2943, then through an intermediate set of second lateral passages 2934, then through a lower set of second riser passages 2943, reaches a lower set of second lateral passages 2934, and can then flow out from a second gas distribution port 2923.

[0115] In addition to the above parameters, of course, the number of gas distribution holes, lateral channels, and riser channels may be more or less than those shown in the drawings discussed in this specification. For example, there may be thousands of gas distribution ports, for example, in some showerheads, there may be about 2000 - 3000 gas distribution ports (much more than the 120 gas distribution ports shown in FIG. 6, for example), and there may be dozens or hundreds of lateral channels. The gas distribution ports and lateral channels may also vary in size. For example, the gas distribution ports may have a nominal cross-sectional size of 0.25 mm to 2 mm in diameter. Furthermore, due to the density at which the lateral channels, riser channels, and gas distribution ports can be printed, it may be possible to achieve a very close packing of features within the showerhead body. For example, in some implementations, a set of lateral channels may be separated from each other by only 0.5 mm of material.

[0116] FIG. 30 shows a cross-section of the flow channels for a showerhead similar to the above-described embodiments. The flow channels include the flow channels respectively provided by the first, second, third, and fourth lateral channels 3033, 3034, 3035, and 3036, as well as gas distribution ports such as the third gas distribution port 3024, and riser channels such as the third riser channel 3044. A detailed view of the cross-section of one of the third lateral channels 3035 and 3035' is shown in the upper right of FIG. 30. As can be seen from the figure, in this implementation, the size (or diameter) of the third gas distribution port 3024 is reduced compared to the size (or diameter) of the third riser channel 3044. The other riser channels and gas distribution ports may be configured similarly for the other flow channels. Such an implementation can provide a higher back pressure in the third lateral channel 3035', thereby maintaining the gas flowing through it at a more uniform pressure before flowing out of the third gas distribution hole 3024 (and thus, as a result, the gas flow / distribution exiting the showerhead becomes more uniform).

[0117] Also, as is apparent in FIG. 30, the third lateral passage 3035 has a larger cross-section compared to the third lateral passage 3035'. As a result of such a configuration, similarly, a higher back pressure is brought about within the third lateral passage 3035' than within the third lateral passage 3035, thereby possibly resulting in a more evenly distributed gas flow through the showerhead. Other lateral passages may be configured similarly. Thus, in some implementations, it will be appreciated that the cross-section of the lateral passage may be reduced in size for a given flow path closer to the exit plane of the showerhead compared to other lateral passages for that flow path further away from the exit plane of the showerhead. Similarly, the gas distribution holes for a given flow path may be dimensioned to have a smaller cross-sectional area than the riser passage for that flow path. FIG. 31 represents a projection view of the flow paths shown in FIG. 30.

[0118] In some implementations, as described above, the lateral passages may be arranged in an inserted configuration when viewed along an axis perpendicular to the central axis of the stem portion. For example, each set of lateral passages (except for the topmost or bottommost such set) may be arranged between sets of lateral passages for other flow paths. In some such embodiments, the sets of lateral passages may be arranged in an axial repeating pattern such that the riser passages for each flow path have the same length.

[0119] The above discussion has focused on lateral passages and gas distribution ports configured to form a diamond lattice pattern and, in most cases, a non-orthogonal diamond lattice pattern, but it will also be understood that the concepts discussed herein may be applicable in the context of parallelogram lattice patterns, including non-square rectangular lattice patterns and non-rhombus non-orthogonal parallelogram lattice patterns. Such additional arrangements are also considered to be within the scope of the present disclosure.

[0120] As described above, the cross-sections used for the lateral passages can, in some cases (such as those shown in the above embodiments), be manufactured using additive manufacturing techniques such as selective laser melting and utilize a specific cross-sectional shape that efficiently utilizes the available volume space within the showerhead. FIG. 32 depicts four exemplary cross-sections contemplated for use in a showerhead manufactured by an additive manufacturing method. In FIG. 32, the cross-sectional shapes are shown relative to a 1×1 square frame (the dashed square), which can represent the nominal area available for accommodating the lateral passages. If it is desired to maximize the flow conductance within the lateral passages, i.e., to have a cross-section that fits within the square reference area, a lateral passage having the same cross-sectional shape as the square will, of course, provide such a maximum amount of flow conductance. However, the horizontal upper surface of such a lateral passage would not be suitable for fabrication using additive manufacturing techniques. This is because, as discussed previously, its upper surface would be subject to slumping or other defects, compromising the surface finish and structural integrity of the upper surface. Thus, while a square passage would most efficiently utilize the square cross-sectional area, a lateral passage having such a cross-sectional shape may not be suitable for use in connection with an additive manufacturing method due to the aforementioned defects.

[0121] A circular cross-section, as shown at cross-section A, provides a relatively high utilization rate of the available cross-sectional area within the sides of the square, occupying approximately 79% thereof. However, due to the curvature of the circular profile along the upper edge (as the profile approaches top dead center, the support from below becomes increasingly less), during additive manufacturing, the circular cross-section encounters problems similar to those encountered in the case of a square cross-section, although to a somewhat lesser degree.

[0122] To avoid possible structural and surface finish problems, a diamond-shaped cross-section such as cross-section B can be used. Generally speaking, overhangs with an angle of 45° or more from horizontal can generally be fabricated using additive manufacturing methods without significant structural or surface finish problems. Accordingly, a diamond-shaped cross-sectional shape surrounded within a square region (and thus with all walls at 45° to the horizontal plane) will not encounter any problems that would afflict a circular or square cross-section and will be able to be manufactured using additive manufacturing methods (the term "square" cross-section, as used herein, refers to a square cross-section with horizontal and vertical edges, while it will be understood that a "diamond" cross-section refers to a cross-section having a bottom edge with an equal but opposite angle to the horizontal and a top edge parallel to the bottom edge). However, a diamond-shaped cross-section only utilizes 50% of the available area within the square boundary.

[0123] Cross-section C, which is triangular, is even more manufacturable using additive manufacturing techniques such as selective laser melting since the two upper walls have an angle steeper than 45° to the horizontal. However, cross-section C, like cross-section B, only utilizes 50% of the available cross-sectional area.

[0124] In contrast, cross-section D, which is in the shape of a pentagon (or more precisely, an isosceles pentagon or even more precisely, a right isosceles pentagon), is close in performance to circular cross-sectional shape A (75% compared to 79%) in terms of the percentage of the square area it uses, but as long as the two upper surfaces of the pentagon are kept at an angle of 45° or more from horizontal, it will not suffer from any problems associated with additive manufacturing such as those that occur in a circular cross-section. Accordingly, when it is generally desired to maximize the cross-sectional area of a lateral passage for the purpose of increasing flow conductance, using a pentagonal cross-sectional shape (among the shapes discussed above) can generally provide the greatest performance.

[0125] FIG. 33 shows a cross-sectional shape similar to that of FIG. 32, but is related to a frame with a reduced height and has, for example, rectangular sections of size 1×0.5 units.

[0126] The circular region A in FIG. 32 is, here, the elliptical region of FIG. 33 and will suffer from further significant problems regarding structural integrity and surface finish along its uppermost portion during additive manufacturing. Similarly, the diamond cross-section B in FIG. 32 is, here, flattened and has an upper surface with an angle significantly less than 45° from horizontal and will thus be vulnerable to defects in its upper surface during the additive manufacturing process. However, the triangular cross-section C is still able to maintain an upper surface that is at 45° or more with respect to horizontal and is thus still reliably manufacturable using additive manufacturing techniques. However, the pentagonal cross-section D has, here, an upper surface that is less than 45° with respect to horizontal and thus cannot be reliably fabricated using additive manufacturing techniques. Of course, it is possible to reduce the height of the two vertical sides of the pentagonal cross-section D to increase the angle of the upper surface, for example, to at least 45° with respect to horizontal, but for the 1×0.5 rectangular section used in FIG. 33, doing so causes the two vertical sides of the pentagonal cross-section to converge to sides of length zero and thus the pentagonal cross-section changes to the triangular cross-section C. Thus, in the context of a showerhead manufactured by an additive manufacturing method (or, any other fluid transport device manufactured by an additive manufacturing method and subject to the overhang feature angle limitations described above), the lateral passage of the pentagonal cross-section provides high flow conductance (and, in some cases, maximum flow conductance) within a rectangular cross-section region while still providing a feature shape suitable for production using such additive manufacturing techniques, although in certain cases where the lateral passage cross-section is positioned within a rectangular section where the width is twice the height, the lateral passage of the triangular cross-section may have the same advantages. In the embodiments of FIGS. 2 and 17, the cross-section of the lateral passage is generally as shown in FIG. 33A with respect to the pentagon D'. As can be seen from the figure, the pentagonal cross-sections used in those exemplary implementations feature very short vertical sides and the shape is nearly triangular. The rectangular region to which the pentagonal cross-section conforms has a size of approximately 0.55:1 and thus does not match the 0.5:1 ratio of the rectangular region of FIG. 33.

[0127] In some implementations having a lateral passage with a triangular or pentagonal cross-section, it will be understood that those cross-sections may be triangular or pentagonal only nominally. For example, FIG. 34 depicts exemplary triangular cross-sections C' and C'' characterized by rounded corners (C') or somewhat curved sides (C''), and exemplary pentagonal cross-sections D' and D'' characterized by rounded corners (D') or somewhat curved sides (D''). Such shapes are still considered nominally to be triangular or pentagonal, and when referred to as being such, will be understood to generally be triangular or pentagonal. Despite the clarity presented above, if it is necessary to remove terms such as "nominally" from such phrases in the claims, it is further understood that such removal is not intended to be a waiver of the scope of the claims, and the corrected phrases should be construed to include both the recited exact shapes, as well as other shapes consistent with the guidance presented above.

[0128] In the discussion and examples provided above and in the figures, the lateral passage is shown as extending horizontally, for example, along a direction substantially perpendicular to the central axis of the stem portion, and the gas distribution ports, riser passages, and other fluid flow paths are shown as extending vertically, for example, along a direction substantially parallel to the central axis of the stem portion. As used herein, references to a passage or other structure extending along a "substantially parallel", "substantially perpendicular", "substantially horizontal", or "substantially perpendicular" direction include not only the recited specific geometric configuration, e.g., parallelism or perpendicularity, but also geometric configurations that may be within some angular range (or other range) of the specified condition, e.g., (in some cases) parallel, perpendicular, vertical, or within ±10° of perpendicular. Despite the clarity presented above, if it is necessary to remove terms such as "substantially (generally)" from such phrases in the claims, it is further understood that such removal is not intended to be a waiver of the scope of the claims, and the corrected phrases should be construed to include both the recited exact configurations, as well as other configurations consistent with the guidance presented above.

[0129] A showerhead as shown in this specification may be manufactured from any suitable material including, for example, aluminum (or an alloy thereof), nickel (or an alloy thereof), ceramic (e.g., aluminum oxide), or silicon. The structure of a version manufactured by an additive manufacturing method of such a showerhead may utilize a melted version of such a material, such as may be output by an SLM process, for example.

[0130] As described above, such a showerhead may be used within a semiconductor processing chamber, for example, as schematically shown in FIG. 36. In FIG. 36, a pedestal 3650 may be used to support a wafer 3652 within a chamber 3651. A showerhead 3601, which may be a showerhead as described herein, may be disposed above the wafer 3652, and process gas from various process gas sources may flow through the showerhead 3601 and over the entire wafer 3652 to perform a desired processing operation.

[0131] Although the examples herein each include four separate flow paths, it will be understood that other implementations having more or fewer flow paths may also be implemented in accordance with the concepts outlined herein. It will be understood that the lateral passages and diamond grid pattern arrangements discussed herein may be implemented with or without the cross-sectional shapes of the lateral passages discussed herein, and vice versa. Thus, the use of horizontal passages having the cross-sectional shapes discussed herein in connection with a showerhead may not necessarily be implemented in connection with the diamond grid pattern arrangements discussed herein. Similarly, the diamond grid pattern arrangements discussed herein may be implemented without necessarily using the cross-sectional shapes discussed herein for the lateral passages.

[0132] The showerhead shapes discussed herein are particularly suitable for production using additive manufacturing techniques, although it will be understood that they can also be manufactured using conventional machining techniques. For example, as described above, the flow channels of the showerheads discussed herein may be manufactured by milling lateral passages / channels in a diamond lattice pattern in a plurality of disk-shaped blanks. An example of such an implementation is shown in FIG. 35. FIG. 35 includes two exploded views from different directions, each showing a disk-shaped blank (in the right exploded view, the diamond lattice pattern of the channels can be seen), as well as a perspective view of the assembled showerhead, with a seam line visible between the disk-shaped blanks.

[0133] Each disk-shaped blank may include, for example, a diamond lattice pattern of channels, as well as through-holes that may be part of riser passages or gas distribution ports. Such disks may then be aligned, laminated together, brazed, diffusion bonded, or joined, adhered, fused, or welded together in another way to produce a monolithic showerhead component having fluidically separated flow channels therein.

[0134] Accordingly, while the main focus of the above discussion is on showerheads manufactured by additive manufacturing methods, it will be understood that the showerhead shapes discussed herein may also be used, with appropriate modifications, in connection with showerheads manufactured by prior art, e.g., subtractive machining techniques that are closer to the prior art. In such alternative forms, some of the features discussed above may be omitted, for example, the use of lateral passages having triangular or pentagonal cross-sections may be avoided, and the lateral passages may instead have square, rectangular, semi-circular, or other cross-sections that can be obtained using a milling cutter.

[0135] It will also be understood that the showerheads discussed herein may be fabricated using a hybrid approach. For example, the showerhead body for a chandelier type showerhead may be manufactured using additive manufacturing techniques, while the stem for the showerhead may be fabricated using conventional machining techniques and then joined, welded, brazed, or diffusion bonded to the showerhead body.

[0136] For clarity, the phrase diamond grid pattern, as used herein, refers to a pattern in which the pattern instances are repeated at locations where they align with the intersections between two sets of lines, where the lines within each set of lines are parallel to each other and the lines within one set of lines are non-parallel to the lines within the other set of lines. A square grid pattern is an example of a diamond grid pattern where the lines in one set of lines are perpendicular to the lines in the other set of lines. A non-orthogonal grid pattern is a diamond grid pattern where the lines in one set of lines are at an oblique angle to the lines in the other set of lines. Similarly, the term diamond grid may be used to refer to the arrangement of generally linear features, such as holes or passages, that extend along an axis and are arranged in the same manner as the lines in a diamond grid pattern when viewed along a direction that is generally perpendicular to their axes. It should also be understood that references to "lines" in the foregoing discussion are intended to refer to reference lines that are not necessarily visible, such as axes.

[0137] The term right isosceles pentagon means a pentagon having three interior angles each of 90° and the remaining two interior angles each of 135°. A shape referred to as being of a generally right isosceles regular pentagon shape is a shape having three interior angles each within ±10° of 90° and two interior angles each within ±10° of 135°.

[0138] References to a shape that is "triangular" or "pentagonal" (or other well-known types of shapes) are intended to include not only exactly such shapes, but also other shapes that are clearly recognizable as such, but that include minor deviations from the true geometric definition of such shapes. For example, a triangle can have rounded corners, i.e., non-sharp vertices, but can still clearly be essentially triangular. Similarly, a pentagon can have one or more curved or slightly curved sides, but can still be readily recognizable as generally pentagonal.

[0139] In the present disclosure, the term "fluidly connected" is used with respect to volumes, plenums, holes, etc. that may be connected to each other to form a fluid connection, which will also be understood to be similar to the way the term "electrically connected" is used with respect to components that are connected together to form an electrical connection. The term "fluidly sandwiched", when used, refers to the case where a component, volume, plenum, or hole is fluidly connected to at least two other components, volumes, plenums, or holes, such that fluid flowing from one of these components, volumes, plenums, or holes to another or different component, volume, plenum, or hole first flows through the "fluidly sandwiched" component before reaching the other or different component, volume, plenum, or hole. For example, if a pump is fluidly sandwiched between a storage section and an outlet, fluid flowing from the storage section to the outlet will first flow through the pump before reaching the outlet. In the context of a set of fluid features arranged in a fluidly sandwiched configuration, for example, if a set of fluid features B is fluidly sandwiched between a set of one or more fluid features A and a set of fluid features C, this will be understood to refer to a configuration where each fluid feature B is fluidly sandwiched between at least one fluid feature A and at least one fluid feature C. It is not necessary for each fluid feature B to be fluidly sandwiched between all fluid features A and all fluid features C.

[0140] For the purposes of the present disclosure, the phrase "fluidly separated" is used to indicate that for volumes, plenums, passages, holes, etc., one or more such fluid features are separated from one or more other such fluid features. For example, a first set of passages may be fluidly separated from a second set of passages, in which case the gas flowing through the first set of passages may not be able to reach the second set of passages (and vice versa). In some cases, reference may be made to two or more sets of one or more fluid features or components that are fluidly separated from each other within a particular structure, which is intended to indicate that those fluid features or components would be fluidly separated from each other if the inlet and / or outlet of that particular structure were sealed. For example, a showerhead may have two separate sets of gas flow paths that are not connected to each other within the showerhead, but both may have gas distribution ports on a common surface of the showerhead. Gas may flow out of the gas distribution ports of one set of gas flow paths and into the gas distribution ports of the other set of gas flow paths, such that they can be considered to be fluidly connected, but this requires that the fluid connection of the gas flow be "outside" of the showerhead structure. Thus, the two sets of gas flow paths are still "fluidly separated" within the showerhead.

[0141] As used herein, when the phrase "for each <item> of one or more <items>" or "each <item> of one or more <items>" is used, it should be understood to include both a group of single items and a group of multiple items. That is, the phrase "for each" is used in the sense in which it is used in a programming language to refer to each of every collection of items being referred to. For example, if the collection of items being referred to is a single item, "each" will refer only to the single item (regardless of the fact that the dictionary definition of "each" often defines this term as referring to "each one of two or more things"), and it does not mean that there must be at least two of those items. Similarly, the terms "set" or "subset" should not be regarded as necessarily encompassing a plurality of items in themselves, and it will be understood that a set or subset can include one member or a plurality of members (unless the context indicates otherwise).

[0142] In the present disclosure and the claims, when ordinal notations such as (a), (b), (c), etc. are used, it should be understood that this does not convey a particular order or sequence, except when the order or sequence is explicitly indicated. For example, if there are three steps labeled (i), (ii), and (iii), it should be understood that these steps may be performed in any order (or simultaneously, if not otherwise prohibited) unless otherwise specified. For example, if step (ii) involves handling an element constructed in step (i), step (ii) can be considered to occur at some point after step (i). Similarly, if step (i) involves handling an element constructed in step (ii), the reverse should be understood.

[0143] Terms such as "about", "approximately", "substantially", and "nominally", when used in reference to a quantity or similar quantifiable characteristic, are to be understood as including values within ±10% of the specified value or relationship (as well as the specified actual value or relationship), unless otherwise indicated.

[0144] It should be understood that all combinations of the foregoing concepts (if such concepts are not mutually inconsistent) are considered to be part of the subject matter of the invention disclosed herein. Specifically, all combinations of the claimed subject matter described at the end of this disclosure are considered to form part of the subject matter of the invention disclosed herein. It should be understood that terms explicitly used herein and that may also appear in any disclosure incorporated by reference should be given the meaning that most closely aligns with the specific concepts disclosed herein.

[0145] Although the above disclosure focuses on specific exemplary implementations, it is not limited to the embodiments discussed and can also be applied to similar variations and mechanisms, and it should be further understood that such similar variations and mechanisms are also considered to be within the scope of this disclosure. This disclosure includes the following application examples. [Application Example 1] An apparatus comprising a showerhead body, wherein the showerhead body one or more sets of first lateral passages extending along a path substantially parallel to a first plane; a set of first gas distribution ports extending along a path substantially perpendicular to the first plane, having a first end terminating within the showerhead body and a second end terminating at a first outer surface of the showerhead body; one or more first fluid inlets, and the one or more sets of first lateral passages include a first set of first lateral passages, the first set of first lateral passages is fluidically sandwiched within the showerhead body between the set of first gas distribution ports and the one or more first fluid inlets, the first set of first lateral passages includes at least one first lateral passage having a cross - section selected from the group consisting of a nominal triangular cross - section and a nominal pentagonal cross - section. [Application Example 2] The apparatus according to Application Example 1, wherein the showerhead body is manufactured by an additive manufacturing method, and as a result, has an anisotropic micro - grain structure. [Application Example 3] The apparatus according to Application Example 1, wherein there are two or more sets of first lateral passages, the two or more sets of first lateral passages further include a second set of first lateral passages, the showerhead body further includes one or more sets of first riser passages extending along a path substantially perpendicular to the first plane, each set of the first riser passages is fluidically sandwiched between two of the sets of first lateral passages, the one or more sets of first riser passages include a first set of first riser passages fluidically sandwiched between the first set and the second set of the first lateral passages. [Application Example 4] The apparatus according to Application Example 3, wherein each first riser passage in the first set of the first riser passages is an extension of a corresponding one of the first gas distribution ports. [Application Example 5] The apparatus according to Application Example 1, wherein at least one first lateral passage in the first set of the first lateral passages has a nominal triangular cross section. [Application Example 6] The apparatus according to Application Example 5, wherein the nominal triangular cross section has a first side substantially parallel to the first plane, and second and third sides, each of the second and third sides forming an angle of 45° or more with respect to the first side. [Application Example 7] The apparatus according to Application Example 1, wherein at least one first lateral passage in the first set of the first lateral passages has a nominal pentagonal cross section. [Application Example 8] The apparatus according to Application Example 7, wherein the nominal pentagonal cross section includes a first side substantially parallel to the first plane; second and third sides, each of the second and third sides being adjacent to the first side and substantially perpendicular to the first plane; and fourth and fifth sides, each of the fourth and fifth sides being adjacent to the second and third sides, respectively, and forming an angle of 45° or more with respect to the first side. [Application Example 9] The apparatus according to Application Example 1, wherein the first gas distribution ports are arranged in a non-orthogonal rhombic lattice pattern. [Application Example 10] The apparatus according to Application Example 9, wherein the non-orthogonal rhombic lattice pattern has a maximum pitch along a first axis and a minimum pitch along a second axis perpendicular to the first axis, and the maximum pitch is approximately twice the minimum pitch. [Application Example 11] The apparatus according to Application Example 1, wherein the first lateral passages in the first set of the first lateral passages are arranged in two first linear arrays, each first linear array includes a plurality of different first lateral passages in the first set of the first lateral passages, the first lateral passages in each first linear array are substantially parallel to each other, and each intersection between the first lateral passages in the first set of the first lateral passages is aligned with a corresponding one of the first gas distribution ports. [Application Example 12] The apparatus according to Application Example 1, wherein the shower head body One or more sets of second lateral passages extending along a path substantially parallel to the first plane; A set of second gas distribution ports extending along a path substantially perpendicular to the first plane and having a first end terminating within the showerhead body and a second end terminating at the first outer surface of the showerhead body; One or more second fluid inlets, and further comprising; The one or more sets of second lateral passages include a first set of second lateral passages; The first set of second lateral passages is fluidly sandwiched within the showerhead body between the set of second gas distribution ports and the one or more second fluid inlets. [Application Example 13] The apparatus according to Application Example 12, wherein the showerhead body is; One or more sets of third lateral passages extending along a path substantially parallel to the first plane; A set of third gas distribution ports extending along a path substantially perpendicular to the first plane and having a first end terminating within the showerhead body and a third end terminating at the first outer surface of the showerhead body; One or more third fluid inlets, and further comprising; The one or more sets of third lateral passages include a first set of third lateral passages; The first set of third lateral passages is fluidly sandwiched within the showerhead body between the set of third gas distribution ports and the one or more third fluid inlets. [Application Example 14] The apparatus according to Application Example 13, wherein the showerhead body is; One or more sets of fourth lateral passages extending along a path substantially parallel to the first plane; A set of fourth gas distribution ports extending along a path substantially perpendicular to the first plane and having a first end terminating within the showerhead body and a fourth end terminating at the first outer surface of the showerhead body; One or more fourth fluid inlets, and further comprising; The one or more sets of fourth lateral passages include a first set of fourth lateral passages; The first set of fourth lateral passages is fluidly sandwiched within the showerhead body between the set of fourth gas distribution ports and the one or more fourth fluid inlets. [Application Example 15] The apparatus according to Application Example 14, wherein; The first, second, third, and fourth gas distribution ports are arranged in corresponding first, second, third, and fourth non-orthogonal rhombic lattice patterns. Each of the first, second, third, and fourth non-orthogonal rhombic lattice patterns has a maximum pitch along the corresponding first axis and a minimum pitch along the second axis, The first, second, and third non-orthogonal rhombic lattice patterns are each offset from the second, third, and fourth non-orthogonal rhombic lattice patterns by a distance of one-fourth of the maximum pitch along the first axis. [Application Example 16] The apparatus according to Application Example 14, further comprising a stem portion, The stem portion extends from the side of the shower head body opposite to the first outer surface, The stem portion, one or more first fluid inlet passages fluidly connected to the one or more first fluid inlets, one or more second fluid inlet passages fluidly connected to the one or more second fluid inlets, one or more third fluid inlet passages fluidly connected to the one or more third fluid inlets, one or more fourth fluid inlet passages fluidly connected to the one or more fourth fluid inlets. [Application Example 17] The apparatus according to Application Example 16, The one or more first fluid inlet passages surround the one or more second fluid inlet passages, The one or more second fluid inlet passages surround the one or more third fluid inlet passages, The one or more third fluid inlet passages surround the one or more fourth fluid inlet passages. [Application Example 18] The apparatus according to Application Example 16, The stem portion further includes a first fluid inlet port, The one or more first fluid inlet passages include a first annular fluid inlet passage, The first annular fluid inlet passage extends along the first axis and has a substantially annular cross-section, The first annular fluid inlet passage is fluidly sandwiched between the first fluid inlet port and the one or more fluid inlets, A diverter structure is disposed within the first annular fluid inlet passage, and a first plane is in the same plane as the first axis, passes through the first fluid inlet port, and passes through the diverter. [Application Example 19] The apparatus according to Application Example 18, wherein the diverter structure has a cross-section selected from the group consisting of a tear shape and a triangular shape when viewed along an axis perpendicular to the first axis. [Application Example 20] The apparatus according to Application Example 18, wherein all surfaces of the diverter structure facing the shower head body have an angle of 45° or more from the first plane, or are angled such that the plane in contact with the surface is 45° or more.

Claims

Claim 1. An apparatus comprising: a showerhead body; wherein the showerhead body comprises: two or more sets of first lateral passages extending along a path substantially parallel to a first plane; a set of first gas distribution ports extending along a path substantially perpendicular to the first plane and having a first end terminating within the showerhead body and a second end terminating at a first outer surface of the showerhead body; one or more first fluid inlets; wherein the two or more sets of first lateral passages include a first set of first lateral passages and a second set of first lateral passages; each first lateral passage in the second set of first lateral passages is parallel to a corresponding one of the first lateral passages in the first set of first lateral passages; the first set of first lateral passages is fluidically sandwiched within the showerhead body between the set of first gas distribution ports and the one or more first fluid inlets; the showerhead body further comprises one or more sets of first riser passages extending along a path substantially perpendicular to the first plane; each set of first riser passages is fluidically sandwiched between two of the sets of first lateral passages; the one or more sets of first riser passages include a first set of first riser passages fluidically sandwiched between the first set and the second set of first lateral passages; the first set of first lateral passages includes at least one first lateral passage having a cross-section selected from the group consisting of a nominally triangular cross-section and a nominally pentagonal cross-section, the apparatus. Claim 2. The apparatus according to claim 1, wherein the showerhead body is manufactured by an additive manufacturing method and as a result has an anisotropic micro-grain structure. Claim 3. The apparatus according to claim 1, wherein each first riser passage in the first set of first riser passages is an extension of a corresponding one of the first gas distribution ports. Claim 4. The apparatus according to claim 1, wherein the at least one first lateral passage in the first set of first lateral passages has a nominally triangular cross-section. Claim 5. The apparatus according to claim 4, wherein the nominal triangular cross-section has a first side substantially parallel to the first plane, and second and third sides, each of the second and third sides forming an angle of 45° or more with respect to the first side.

6. The apparatus according to claim 1, wherein at least one first lateral passage in the first set of first lateral passages has a nominal pentagonal cross-section.

7. The apparatus according to claim 6, wherein the nominal pentagonal cross-section has a first side substantially parallel to the first plane; second and third sides, each of the second and third sides being adjacent to the first side and substantially perpendicular to the first plane; and fourth and fifth sides, the fourth and fifth sides being adjacent to the second and third sides respectively and forming an angle of 45° or more with respect to the first side.

8. The apparatus according to claim 1, wherein the first gas distribution ports are arranged in a non-orthogonal rhombic lattice pattern.

9. The apparatus according to claim 8, wherein the non-orthogonal rhombic lattice pattern has a maximum pitch along a first axis and a minimum pitch along a second axis perpendicular to the first axis, and the maximum pitch is twice the minimum pitch.

10. The apparatus according to claim 1, wherein the first lateral passages in the first set of first lateral passages are arranged in two first linear arrays, each first linear array includes a plurality of different first lateral passages in the first set of first lateral passages, the first lateral passages in each first linear array are substantially parallel to other first lateral passages in that first linear array, the first lateral passages in the two first linear arrays intersect each other, and each intersection between the first lateral passages in the first set of first lateral passages is aligned with a corresponding one of the first gas distribution ports.

11. The apparatus according to claim 1, wherein the showerhead body has one or more sets of second lateral passages extending along a path substantially parallel to the first plane, A set of second gas distribution ports that extend along a path substantially perpendicular to the first plane and have a first end that terminates within the showerhead body and a second end that terminates at the first outer surface of the showerhead body, One or more second fluid inlets, and further comprising, One or more sets of the second lateral passages include a first set of second lateral passages, The first set of the second lateral passages is fluidly sandwiched between the set of the second gas distribution ports and the one or more second fluid inlets within the showerhead body. An apparatus. **Claim 12** The apparatus according to claim 11, wherein the showerhead body, One or more sets of third lateral passages that extend along a path substantially parallel to the first plane, A set of third gas distribution ports that extend along a path substantially perpendicular to the first plane and have a first end that terminates within the showerhead body and a third end that terminates at the first outer surface of the showerhead body, One or more third fluid inlets, and further comprising, One or more sets of the third lateral passages include a first set of third lateral passages, The first set of the third lateral passages is fluidly sandwiched between the set of the third gas distribution ports and the one or more third fluid inlets within the showerhead body. An apparatus. **Claim 13** The apparatus according to claim 12, wherein the showerhead body, One or more sets of fourth lateral passages that extend along a path substantially parallel to the first plane, A set of fourth gas distribution ports that extend along a path substantially perpendicular to the first plane and have a first end that terminates within the showerhead body and a fourth end that terminates at the first outer surface of the showerhead body, One or more fourth fluid inlets, and further comprising, One or more sets of the fourth lateral passages include a first set of fourth lateral passages, The first set of the fourth lateral passages is fluidly sandwiched between the set of the fourth gas distribution ports and the one or more fourth fluid inlets within the showerhead body. An apparatus. **Claim 14** The apparatus according to claim 13, The first, second, third, and fourth gas distribution ports are arranged in corresponding first, second, third, and fourth non-orthogonal rhombic lattice patterns. Each of the first, second, third, and fourth non-orthogonal rhombic lattice patterns has a maximum pitch along a corresponding first axis and a minimum pitch along a second axis, An apparatus, wherein each of the first, second, and third non-orthogonal rhombic lattice patterns is offset from the second, third, and fourth non-orthogonal rhombic lattice patterns by a distance of one-fourth of the maximum pitch along the first axis. **Claim 15** The apparatus according to claim 13, further comprising a stem portion, wherein the stem portion extends from a side of the shower head body opposite to the first outer surface, The stem portion, comprises one or more first fluid inlet passages fluidly connected to the one or more first fluid inlets, one or more second fluid inlet passages fluidly connected to the one or more second fluid inlets, one or more third fluid inlet passages fluidly connected to the one or more third fluid inlets, and one or more fourth fluid inlet passages fluidly connected to the one or more fourth fluid inlets. **Claim 16** The apparatus according to claim 15, wherein the one or more first fluid inlet passages surround the one or more second fluid inlet passages, the one or more second fluid inlet passages surround the one or more third fluid inlet passages, and the one or more third fluid inlet passages surround the one or more fourth fluid inlet passages. **Claim 17** The apparatus according to claim 15, wherein the stem portion further includes a first fluid inlet port, the one or more first fluid inlet passages include a first annular fluid inlet passage, the first annular fluid inlet passage extends along the first axis and has a substantially annular cross-section, the first annular fluid inlet passage is fluidly sandwiched between the first fluid inlet port and the one or more first fluid inlets, and a diverter structure is disposed within the first annular fluid inlet passage, and a first plane is in the same plane as the first axis, passes through the first fluid inlet port, and passes through the diverter. **Claim 18** The apparatus according to claim 17, wherein the diverter structure has a cross-section selected from the group consisting of a teardrop shape and a triangular shape when viewed along an axis perpendicular to the first axis. **Claim 19** The apparatus according to claim 17, wherein all surfaces of the diverter structure facing the shower head body have an angle of 45° or more from the first plane, or are angled such that the plane in contact with the surface is 45° or more.

20. An apparatus, comprising a shower head body, wherein the shower head body includes one or more sets of first lateral passages extending along a path substantially parallel to a first plane, a set of first gas distribution ports extending along a path substantially perpendicular to the first plane and having a first end terminating within the shower head body and a second end terminating at a first outer surface of the shower head body, and one or more first fluid inlets. The one or more sets of first lateral passages include a first set of first lateral passages, wherein the first lateral passages in the first set of first lateral passages are arranged in two first linear arrays, each first linear array including a plurality of the first lateral passages different in the first set of first lateral passages, the first lateral passages in each first linear array being substantially parallel to other first lateral passages in that first linear array, the first lateral passages in the two first linear arrays intersecting each other, each intersection between the first lateral passages in the first set of first lateral passages being aligned with a corresponding one of the first gas distribution ports, the first set of first lateral passages being fluidly sandwiched between the set of first gas distribution ports and the one or more first fluid inlets within the shower head body, the first set of first lateral passages including at least one first lateral passage having a cross-section selected from the group consisting of a nominal triangular cross-section and a nominal pentagonal cross-section.

21. An apparatus, comprising a stem portion and a shower head body, wherein the shower head body includes one or more sets of first lateral passages extending along a path substantially parallel to a first plane, one or more sets of second lateral passages extending along a path substantially parallel to the first plane, one or more sets of third lateral passages extending along a path substantially parallel to the first plane, and one or more sets of fourth lateral passages extending along a path substantially parallel to the first plane. A first set of gas distribution ports that extend along a path substantially perpendicular to the first plane, having a first end that terminates within the shower head body and a second end that terminates at the first outer surface of the shower head body. A second set of gas distribution ports that extend along a path substantially perpendicular to the first plane, having a first end that terminates within the shower head body and a second end that terminates at the first outer surface of the shower head body. A third set of gas distribution ports that extend along a path substantially perpendicular to the first plane, having a first end that terminates within the shower head body and a third end that terminates at the first outer surface of the shower head body. A fourth set of gas distribution ports that extend along a path substantially perpendicular to the first plane, having a first end that terminates within the shower head body and a fourth end that terminates at the first outer surface of the shower head body. One or more first fluid inlets. One or more second fluid inlets. One or more third fluid inlets. One or more fourth fluid inlets. Including One or more sets of the first lateral passages include a first set of the first lateral passages. One or more sets of the second lateral passages include a first set of the second lateral passages. One or more sets of the third lateral passages include a first set of the third lateral passages. One or more sets of the fourth lateral passages include a first set of the fourth lateral passages. The first set of the first lateral passages is fluidly sandwiched within the shower head body between the set of the first gas distribution ports and the one or more first fluid inlets. The first set of the second lateral passages is fluidly sandwiched within the shower head body between the set of the second gas distribution ports and the one or more second fluid inlets. The first set of the third lateral passages is fluidly sandwiched within the shower head body between the set of the third gas distribution ports and the one or more third fluid inlets. The first set of the fourth lateral passages is fluidly sandwiched within the shower head body between the set of the fourth gas distribution ports and the one or more fourth fluid inlets. The first set of the first lateral passages includes at least one first lateral passage having a cross-section selected from the group consisting of a nominal triangular cross-section and a nominal pentagonal cross-section. The stem portion extends from the side of the shower head body opposite to the first outer surface, The stem portion is, One or more first fluid inlet passages fluidly connected to the one or more first fluid inlets; One or more second fluid inlet passages fluidly connected to the one or more second fluid inlets; One or more third fluid inlet passages fluidly connected to the one or more third fluid inlets; One or more fourth fluid inlet passages fluidly connected to the one or more fourth fluid inlets; A first fluid inlet port, and includes, The one or more first fluid inlet passages include a first annular fluid inlet passage, The first annular fluid inlet passage extends along a first axis and has a substantially annular cross-section, The first annular fluid inlet passage is fluidly sandwiched between the first fluid inlet port and the one or more first fluid inlets, A diverter structure is disposed within the first annular fluid inlet passage, and a first plane is in the same plane as the first axis, passes through the first fluid inlet port, and passes through the diverter.

22. The apparatus according to claim 21, wherein the diverter structure has a cross-section selected from the group consisting of a tear shape and a triangular shape when viewed along an axis perpendicular to the first axis.

23. The apparatus according to claim 22, wherein all surfaces of the diverter structure facing the shower head body have an angle of 45° or more from the first plane, or are angled such that a plane in contact with the surface has an angle of 45° or more.

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