shower head faceplate

Abstract

A semiconductor processing tool showerhead design suitable for multiple gas delivery and additive manufacturing fabrication is provided, characterized by an internal spiral passageway, or internal plenum, having multiple pillars distributed throughout the plenum that span between its upper and lower surfaces.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] A PCT application is filed concurrently herewith as part of this application. Each application identified in the concurrently filed PCT application to which this application claims benefit or priority is incorporated herein by reference in its entirety for all purposes. [Background technology]

[0002] Semiconductor processing tools often utilize gas distribution systems (often referred to as showerheads) to distribute one or more process gases across semiconductor wafers being processed. Such showerheads typically have multiple gas distribution holes distributed across or located on the bottom surface of the showerhead to allow process gases from one or more internal plenums of such showerheads to flow from above onto the semiconductor wafers. In some cases, the showerhead is a single, integrated structure, e.g., made from multiple pieces that are then welded together; in other cases, the showerhead may be a disassembled, multi-piece structure, e.g., composed of multiple pieces that are fastened together using screws. Summary of the Invention

[0003] In some embodiments, a device may be provided that includes a body having a first side and a second side opposite the first side. The device may also include N helical passages located within the body, each of the helical passages following a corresponding helical path, the N helical passages including at least a first helical passage located within the body, at least a portion of the first helical passage following the first helical path and having a first cross-sectional profile along at least a portion of the first helical path, and a second helical passage located within the body, at least a portion of the second helical passage following the second helical path and having a second cross-sectional profile along at least a portion of the second helical path. The device may also include a plurality of first gas distribution holes extending from the second side to the first spiral passage, a plurality of second gas distribution holes extending from the second side to the second spiral passage, one or more first inlet ports, each extending from a corresponding location exterior to the body to the first spiral passage, and one or more second inlet ports, each extending from a corresponding location exterior to the body to the second spiral passage. In such embodiments, the first gas distribution holes may be disposed along the first spiral passage and the second gas distribution holes may be disposed along the second spiral passage.

[0004] In some embodiments, the first cross-sectional profile may have a first segment proximate the first side, a second segment disposed between the second segment and the first side, and opposing first lateral segments, each spanning the first and second segments. In such embodiments, the second cross-sectional profile may have a third segment proximate the first side, a fourth segment disposed between the fourth segment and the first side, and opposing second lateral segments, each spanning the third and fourth segments. The first segments may include corresponding first curved transition regions, and the third segments may include corresponding second curved transition regions, each of which may connect to a corresponding one of the first lateral segments, and each of which may connect to a corresponding one of the second lateral segments.

[0005] In some embodiments, each of the first curved transition regions may be tangent to the connecting first lateral segment, and each of the second curved transition regions may be tangent to the connecting second lateral segment.

[0006] In some embodiments, the first curved transition regions connected to the first lateral segments may be connected to one another such that the first segments have a circular or parabolic profile.

[0007] In some embodiments, the second curved transition regions connected to the second lateral segments may be connected to one another such that the third segment has a circular or parabolic profile in cross section.

[0008] In some embodiments, first curved transition regions connected to a first lateral segment may be connected to each other such that the first segment has a circular or parabolic profile in cross section, and second curved transition regions connected to a second lateral segment may be connected to each other such that the third segment has a circular or parabolic profile in cross section.

[0009] In some embodiments, the second segments may include corresponding third curved transition regions, the fourth segments may include corresponding fourth curved transition regions, each of the third curved transition regions may connect to a corresponding one of the first lateral segments, and each of the fourth curved transition regions may connect to a corresponding one of the second lateral segments.

[0010] In some embodiments, the third curved transition region may have a smaller cross-sectional profile than the first curved transition region, and the fourth curved transition region may have a smaller cross-sectional profile than the second curved transition region.

[0011] In some embodiments, the third segment may include a first linear portion located between the third curved transition regions, the fourth segment may include a second linear portion located between the fourth curved transition regions, and the first linear portion and the second linear portion may be parallel to a first plane defined by the first side.

[0012] In some embodiments, the first gas distribution hole may connect to the first helical passage at a cross-sectional location within the first straight portion, and the second gas distribution hole may connect to the second helical passage at a cross-sectional location within the second straight portion.

[0013] In some embodiments, the helical paths followed by the N helical passages may all be coaxial with one another, may all be oriented at different angles relative to the central axis of the helical paths, and each helical path may be 360° / N out of phase with each adjacent helical path.

[0014] In some embodiments, N=2 or N=3.

[0015] In some embodiments, the apparatus may further include N helical walls, each separating one helical passage from an adjacent helical passage and following a corresponding helical path, and a plurality of zeroth gas distribution holes, each extending from a first side of the body to a second side of the body and distributed along a corresponding helical wall path for at least one of the helical walls.

[0016] In some embodiments, the zeroth gas distribution holes may be distributed along corresponding spiral wall paths of the spiral wall.

[0017] In some embodiments, the apparatus may further include a plurality of 0th gas distribution holes disposed along the 0th helical path, each of which may extend from a first side of the body to a second side of the body, and the helical paths followed by the N helical passages and including the 0th helical path may be coaxial with one another, may be oriented at different angles relative to a central axis of the helical paths, and may be 360° / (N+1) out of phase with each adjacent helical path.

[0018] In some embodiments, the first cross-sectional profile may be a different distance from the second side in a direction perpendicular to a plane defined by the second side than the second cross-sectional profile.

[0019] In some embodiments, the first helical path and the second helical path may have the same pitch and the same number of turns.

[0020] In some embodiments, the first helical path may have 5 to 15 turns.

[0021] In some embodiments, one or more first inlet ports may connect to the first spiral passage at a location or locations proximate the end of the first spiral passage that is furthest from the center of the first spiral path, and one or more second inlet ports may connect to the second spiral passage at a location or locations proximate the end of the second spiral passage that is furthest from the center of the second spiral path.

[0022] In some such embodiments, one or more first inlet ports and one or more second inlet ports may be located at a common azimuthal position relative to the first and second helical paths.

[0023] In some embodiments, the first helical path may have an outer diameter of at least 300 mm.

[0024] In some embodiments, the body and the spiral passage may be formed by additive manufacturing.

[0025] In some embodiments, the body and the spiral passage may be formed from a material that exhibits an anisotropic micrograin structure.

[0026] In some embodiments, the material may be a metal, such as Hastelloy C-22 alloy.

[0027] In some embodiments, the first and second gas distribution holes may be drilled or electric discharge machined holes.

[0028] In some embodiments, the device may further include a plurality of outlet ports, wherein each of the spiral passages may be fluidly disposed between two of the outlet ports, and at least one of the outlet ports between which each of the spiral passages may be fluidly disposed is sealed to prevent fluid flow through the spiral passage.

[0029] In some embodiments, at least one of the inlet ports may also function as one of the outlet ports.

[0030] In some embodiments, an exit port may be used to direct abrasive material into the spiral passageway.

[0031] In some embodiments, a method of manufacturing one of the above devices may be provided, the method including manufacturing a body, manufacturing the spiral passage using additive manufacturing simultaneously with manufacturing the body, and drilling first and second gas distribution holes after manufacturing the body.

[0032] In some embodiments, drilling may be performed using a mechanical drill or electrical discharge drilling.

[0033] In some embodiments, the method may further include flowing an abrasive through the spiral passage.

[0034] In some embodiments, an apparatus may be provided that includes a body having a first side and a second side opposite the first side of the body, a first interior plenum volume located within the body, the first surface being located between a first surface and a second surface, the first surface being located between the first side and the second surface, and the second surface being located between the first surface and the second side, and a plurality of pillars including first pillars distributed throughout a first region of the first interior plenum volume, wherein each first pillar in the set of first pillars may straddle the first surface and the second surface, each first pillar in the set of first pillars may include a corresponding first gas distribution hole extending between the first side and the second side, and each first pillar in the set of first pillars may have one or more outer walls, wherein the one or more outer walls of each first pillar in the set of first pillars may connect to the first surface via a corresponding first curved transition region. The apparatus may also have a plurality of second gas distribution holes distributed throughout the first region of the first interior plenum volume, each of the second gas distribution holes spanning between the second side and the second surface.

[0035] In some embodiments, the apparatus may include a second interior plenum volume located within the body, the second interior plenum volume being located between a third surface and a fourth surface, the third surface being located between the first side and the fourth surface, the fourth surface being located between the third surface and the second side, and the third surface and the fourth surface being located between the first side and the first surface. Each first pillar in the set of first pillars may be located between two corresponding second pillars of the plurality of pillars, the two corresponding second pillars for each first pillar in the set of first pillars may be the two pillars closest to that first pillar in the first internal plenum volume, each first pillar in the set of first pillars and its corresponding second pillar may be arranged along corresponding first axes parallel to the first direction, the plurality of pillars may further include a third pillar located within the second internal plenum volume, each of the third pillars may correspond in position to one of the first pillars in the set of first pillars and have a corresponding first gas distribution hole for that first pillar extending therethrough, and each corresponding second pillar for each first pillar in the set of first pillars may include a corresponding third gas distribution hole spanning between the second side and the fourth surface.

[0036] In some embodiments, each first pillar in the set of first pillars may be located between two of the second gas distribution holes that are closest to the first pillar, and each first pillar in the set of first pillars and its two closest second gas distribution holes may be aligned along a corresponding second axis that is parallel to a second direction, which may be transverse to the first direction.

[0037] In some embodiments, the center of each first pillar in the set of first pillars may be equidistantly spaced from the centers of the two closest second pillars to that first pillar and from the centers of the two closest second gas distribution holes to that first pillar.

[0038] In some embodiments, the first direction may be perpendicular to the second direction.

[0039] In some embodiments, the first pillars in the set of first pillars may be arranged in a square array.

[0040] In some embodiments, the square array may have an array axis at 45° relative to the first direction.

[0041] In some embodiments, the apparatus may further include a second interior plenum volume located within the body, the second interior plenum volume being located between the third surface and the fourth surface, the third surface being located between the first side and the fourth surface, the fourth surface being located between the third surface and the second side, and the third surface and the fourth surface being located between the first side and the first surface. The plurality of pillars may also include a second pillar located within the first internal plenum volume and a third pillar located within the second internal plenum volume, and for each first pillar in the set of first pillars, the three nearest pillars in the first internal plenum volume may each be a second pillar equidistantly spaced from the first pillar and equidistantly spaced from each other, each of the third pillars may correspond in position to one of the first pillars in the set of first pillars and have a corresponding first gas distribution hole for that first pillar extending therethrough, and each of the second pillars may include a corresponding third gas distribution hole spanning between the second side and the fourth surface.

[0042] In some embodiments, for each first pillar in the set of first pillars, the three nearest second gas distribution holes may each be equidistantly spaced from that first pillar and equidistantly spaced from each other.

[0043] In some embodiments, each second gas distribution hole in the set of second gas distribution holes may be at the center of a hexagonal pattern of three first pillars and three second pillars.

[0044] In some embodiments, the second surface may define a first reference plane, each of the pillars in the set of pillars in the first interior plenum volume may be associated with a corresponding region of relief of the first surface, a corresponding portion of the first surface may be bounded by the corresponding region of relief for each of the pillars in the set of pillars, and a first distance between the first reference plane and the corresponding portion of the first surface for each of the pillars in the set of pillars in the first interior plenum volume may increase as a function of a second distance from the central axis of that pillar.

[0045] In some embodiments, for each pillar in the set of pillars in the first interior plenum volume, the first distance of that pillar may be determined according to a scalar function having axisymmetricity about a central axis of that pillar.

[0046] In some embodiments, the cross-sectional profile of the corresponding portion of the first surface for each pillar in the set of pillars in the first interior plenum volume may be tangent to a second reference plane parallel to the first reference plane at a boundary of the corresponding relief region of that pillar, and may be tangent to a third reference plane parallel to the second reference plane at that pillar.

[0047] In some embodiments, for each pillar in the set of pillars in the first interior plenum volume, the difference between the minimum and maximum first distance within the pillar's corresponding relief region may be 20% to 30% of the maximum distance between the central axis of the pillar and the boundary of the corresponding relief region.

[0048] In some embodiments, the corresponding relief region for each pillar in the set of pillars in the first interior plenum volume may have a boundary edge that is perpendicular to and bisects a reference line extending between that pillar and an adjacent pillar in the first interior plenum volume.

[0049] In some embodiments, for each pillar in the set of pillars within the first interior plenum volume, a corresponding relief region may be bounded by a corresponding plurality of boundary reference surfaces, and for each pillar in the set of pillars within the first interior plenum volume, each reference surface in that pillar's corresponding plurality of boundary reference surfaces may be located midway between that pillar and another pillar within the first interior plenum volume and may be parallel to the first reference surface and perpendicular to a corresponding reference axis passing through the center of that pillar and the other pillar.

[0050] In some embodiments, one or more outer walls of each first pillar in the set of first pillars may connect to the second surface via a corresponding second curved transition region, and the second curved transition region may be smaller than the first curved transition region.

[0051] In some embodiments, the first curved transition region of each first pillar in the set of first pillars may merge into the first curved transition region of at least one other of the first pillars.

[0052] In some embodiments, the first surface may be offset from the second surface by a first amount in a direction perpendicular to the first surface, and the first amount may be less than or equal to 120% of the radius of the first curved transition region.

[0053] In some embodiments, the centerline of each first pillar in the set of first pillars may be within 240% of the radius of the first curved transition region of the centerline of the first pillar immediately adjacent to that first pillar.

[0054] In some embodiments, the first region may be a circular region having a diameter of at least 300 mm.

[0055] In some embodiments, the body and the first post may be formed by additive manufacturing.

[0056] In some embodiments, the body and the first pillar may be formed from a material that exhibits an anisotropic micrograin structure.

[0057] In some embodiments, the material may be a metal, such as Hastelloy C-22 alloy.

[0058] In some embodiments, the first and second gas distribution holes may be drilled or electrical discharge machined holes. [Brief explanation of the drawings]

[0059] [Figure 1] FIG. 1 shows a reproduction of grain boundaries in vertical and horizontal planes of an exemplary component made using an exemplary DMLM process.

[0060] [Figure 2] FIG. 2 is a top view of an exemplary showerhead configured to separately route two process gases using internal spiral passages.

[0061] [Figure 3] FIG. 3 is a cross-sectional view of the example showerhead of FIG. 2 taken along the indicated section line.

[0062] [Figure 4] FIG. 4 is a cross-sectional view of the example showerhead of FIG. 2 taken along the section line indicated in FIG.

[0063] [Figure 4-1] FIG. 4' is a detailed cross-sectional view of a pair of radially adjacent spiral passages of the example showerhead of FIG.

[0064] [Figure 5] FIG. 5 is a cross-sectional view of a showerhead similar to FIG. 2, but with inlet ports near the periphery of the showerhead.

[0065] [Figure 6] FIG. 6 shows the results of the analysis, which represents the relative molar concentrations of reactants flowed through a showerhead such as the showerhead of FIG.

[0066] [Figure 7] FIG. 7 shows the results of the analysis, which represents the relative molar concentrations of reactants flowed through a showerhead such as the showerhead of FIG.

[0067] [Figure 8] FIG. 8 is a cross-sectional view of a showerhead with two spiral passages having azimuthally arranged inlet ports.

[0068] [Figure 9] FIG. 9 shows the results of the analysis, which represents the relative molar concentrations of reactants flowed through a showerhead such as the showerhead of FIG.

[0069] [Figure 10] FIG. 10 is an isometric cutaway view of an exemplary showerhead having a two-tiered spiral passageway.

[0070] [Figure 11] FIG. 11 is an isometric top cross-sectional view of the showerhead of FIG.

[0071] [Figure 12] FIG. 12 is a second isometric top cross-sectional view of the showerhead of FIG.

[0072] [Figure 13] FIG. 13 shows the analytical results, which represent the relative molar concentrations of reactants flowed through a showerhead similar to that of FIG.

[0073] [Figure 14] FIG. 14 shows a top view and a cross-sectional side view of an exemplary showerhead including spiral and spoke passages.

[0074] [Figure 15] FIG. 15 is a side view and a top cross-sectional view of the exemplary showerhead of FIG.

[0075] [Figure 16]FIG. 16 is a side view and another cross-sectional top view of the exemplary showerhead of FIG.

[0076] [Figure 17] FIG. 17 shows the analytical results, which represent the relative molar concentrations of reactants flowed through a showerhead similar to that of FIG.

[0077] [Figure 18] FIG. 18 is a cross-sectional view of an exemplary showerhead similar to the exemplary showerhead of FIG. 2, but configured to separately route three process gases using internal spiral passages.

[0078] [Figure 19] FIG. 19 is a side view of another exemplary showerhead similar to FIG. 2 but capable of separately delivering three process gases, two through internal spiral passages and one through gas distribution holes extending from one side of the showerhead to the other.

[0079] [Figure 20] FIG. 20 is a top view of the exemplary showerhead of FIG.

[0080] [Figure 21] 21 is a cross-sectional view of the exemplary showerhead of FIG. 19 taken along the cross-sectional view of FIG.

[0081] [Figure 22] 22 is an isometric cross-sectional view of the exemplary showerhead of FIG. 19 taken along the cut line of FIG. 20.

[0082] [Figure 23] FIG. 23 is a top view of another exemplary showerhead configured to separately deliver three different process gases in a manner similar to the exemplary showerhead of FIG. 19 .

[0083] [Figure 24] 24 is a cross-sectional side view of the exemplary showerhead of FIG. 23 taken along the cut line of FIG. 23.

[0084] [Figure 25] 25 is a cross-sectional view of the exemplary showerhead of FIG. 23 taken along the corresponding cut line at a certain height in FIG. 24. [Figure 26] 26 is a cross-sectional view of the exemplary showerhead of FIG. 23 taken along the corresponding cut line at a certain height in FIG. 24.

[0085] [Figure 27] FIG. 27 is a bottom view of the exemplary showerhead of FIG.

[0086] [Figure 28] FIG. 28 is a top cutaway view of an exemplary showerhead featuring two nested two-tiered spiral passages.

[0087] [Figure 29] 29 is a cross-sectional view of the exemplary showerhead of FIG. 28 taken along the dashed line in FIG.

[0088] [Figure 30] FIG. 30 is a detailed view of the portion within the dashed-dotted rectangle in the cross-sectional view of the exemplary showerhead of FIG.

[0089] [Figure 31] FIG. 31 is a side view of an exemplary showerhead featuring four nested two-tiered spiral passages.

[0090] [Figure 32] 32 is a top cutaway view of the exemplary showerhead of FIG. 31 taken along the dashed line of FIG.

[0091] [Figure 33]FIG. 33 is a top cutaway cross-sectional view of another exemplary showerhead similar to the showerhead of FIG. 31 but having six nested two-tiered spiral passages.

[0092] [Figure 34] FIG. 34 is a side view of an exemplary showerhead having nested two-tiered reverse spiral passages.

[0093] [Figure 35] FIG. 35 is an isometric exploded cross-sectional view of the exemplary showerhead of FIG.

[0094] [Figure 36] FIG. 36 illustrates the intersections between nested spiral passages in a two-tiered reverse spiral passage showerhead.

[0095] [Figure 37] FIG. 37 is a side view of an exemplary showerhead featuring an interior plenum volume having multiple columns extending between its upper and lower surfaces.

[0096] [Figure 38] 38 is an isometric cross-sectional view of the example showerhead of FIG. 37 taken along the corresponding section line of FIG. [Figure 39] 39 is an isometric cross-sectional view of the example showerhead of FIG. 37 taken along the corresponding section line of FIG. 37.

[0097] [Figure 40] FIG. 40 is a partial cutaway view of a portion of the showerhead of FIG. 37, showing multiple pillars.

[0098] [Figure 41] Figure 41 is a cross-sectional side view of a representative column, highlighting its various features.

[0099] [Figure 42]FIG. 42 is a side view of another exemplary showerhead featuring an interior plenum volume having multiple columns extending between its upper and lower surfaces.

[0100] [Figure 43] 43 is an isometric cross-sectional view of the example showerhead of FIG. 42 taken along the corresponding section line of FIG. [Figure 44] 44 is an isometric cross-sectional view of the example showerhead of FIG. 42 taken along the corresponding section line of FIG.

[0101] [Figure 45] 45 is an isometric cross-sectional view of the example showerhead of FIG. 42 taken along the corresponding section line of FIG.

[0102] [Figure 46] FIG. 46 is a perspective view of a portion of an exemplary showerhead.

[0103] [Figure 47] FIG. 47 is a cutaway perspective view of the exemplary showerhead of FIG. [Figure 48] FIG. 48 is a cutaway perspective view of the exemplary showerhead of FIG. [Figure 49] FIG. 49 is a cutaway perspective view of the exemplary showerhead of FIG. [Figure 50] FIG. 50 is a cutaway perspective view of the exemplary showerhead of FIG.

[0104] [Figure 51] FIG. 51 is a plan view of an interior portion of the example showerhead of FIG.

[0105] [Figure 52] FIG. 52 is a cutaway plan view of the portion of the exemplary showerhead of FIG. [Figure 53] FIG. 53 is a cutaway plan view of the portion of the exemplary showerhead of FIG.

[0106] [Figure 54] FIG. 54 shows various cross sections of a portion of the showerhead of FIG.

[0107] [Figure 55] FIG. 55 is a plan view of the interior portion of another exemplary showerhead.

[0108] [Figure 56] FIG. 56 is a perspective view of a portion of the exemplary showerhead of FIG. [Figure 57] FIG. 57 is a perspective and cutaway view of a portion of the exemplary showerhead of FIG. [Figure 58] FIG. 58 is a perspective and cutaway view of a portion of the exemplary showerhead of FIG.

[0109] [Figure 59] FIG. 59 is a top view of an exemplary edge-fed showerhead having two internal plenums with a pillar between the upper and lower surfaces of each plenum.

[0110] [Figure 60] FIG. 60 is a side view of the exemplary showerhead of FIG.

[0111] [Figure 61] FIG. 61 is an isometric exploded cross-sectional view of the exemplary showerhead of FIG.

[0112] [Figure 62] FIG. 62 is a detailed view of the portion of the exemplary showerhead of FIG. 61 within the dashed-dotted rectangle on the left side of FIG.

[0113] [Figure 63] FIG. 63 is a detailed view of the portion of the exemplary showerhead of FIG. 61 within the dashed-dotted rectangle on the right side of FIG.

[0114] [Figure 64] FIG. 64 is an isometric exploded cross-sectional view of an exemplary showerhead similar to those shown in FIGS. 59-63 except that one of the interior plenums is center-fed and does not have a column spanning between its top and bottom surfaces.

[0115] [Figure 65] FIG. 65 shows an example of a showerhead manufactured using traditional machining techniques.

[0116] [Figure 66] Figure 66 shows a schematic of the chamber. DETAILED DESCRIPTION OF THE INVENTION

[0117] A showerhead, in the context of this disclosure, refers to a structure typically characterized by a body containing one or more passages or internal volumes therein that form one or more internal plenum volumes. The showerhead also includes a plurality of gas distribution holes, each fluidly connected to an internal plenum volume or, if multiple such internal plenum volumes are present, to one of the internal plenum volumes. The gas distribution holes are typically distributed across the lower surface of the body and are positioned to deliver supplied process gases across the upper surface of the wafer being processed (or across the lower surface of the wafer if backside deposition or etching is occurring).

[0118] In the context of this disclosure, a showerhead faceplate refers to a showerhead designed to mate with another component (e.g., a backplate) to provide an additional plenum volume for delivering gases. For example, a showerhead may have one or more internal cavities or passages therein that form one or more plenum volumes within the showerhead and use these to distribute gases to gas distribution holes within the showerhead, each of which is fluidly connected to one of the plenum volumes (or to that plenum volume, if there is only one plenum volume in the showerhead). However, in some cases, a showerhead may have additional gas distribution holes that are not fluidly connected to the plenum volume internal to the showerhead but instead penetrate completely through the showerhead. The showerhead can then be coupled with one or more other components to form another plenum volume bounded on one side by the exterior surface of the showerhead, whereby another gas is delivered to the newly created plenum volume before flowing through the gas distribution holes that penetrate completely through the showerhead. Such a showerhead may be referred to as a showerhead faceplate.

[0119] Disclosed herein are various showerhead or showerhead faceplate designs that are specifically designed to be manufacturable using additive manufacturing techniques, such as selective laser melting (SLM), which may be used to make ceramic or silicon versions of such showerheads, or direct metal laser melting (DMLM), which may be used to make metal versions of such showerheads. In particular, the showerhead designs described herein may be particularly suitable for fabrication using laser powder bed fusion (LPBF) additive manufacturing techniques, which may include manufacturing processes such as SLM, DMLM, SLS (selective laser sintering), and DMLS (direct metal laser sintering), all of which may be used to make metal-based components (and some of these, such as SLS and SLM, may be used to make ceramic-based components).

[0120] In most additive manufacturing processes, parts are produced by adding one horizontal layer at a time to the part. Such layers can be very thin, for example, 0.02 mm at a time for DMLM parts. In DMLM, for example, a platen supporting the part is gradually lowered relative to a reference surface. The platen forms the "floor" of the cavity used to contain the part being manufactured. As the platen lowers, powder material is added to the cavity and then leveled flush with the reference surface. A laser then scans across the reference surface, applying heat to the top layer of powder material in areas where structure is desired, fusing the powder granules together and any previously fused structure in underlying layers. Once a particular layer is completed, the platen is lowered slightly, a new layer of powder material is applied, and the laser fusing process may be repeated. This process is repeated until the part is completed, at which point the DMLM machine's cavity is filled with unmelted powder material with the additively manufactured components embedded within.

[0121] Such additively manufactured components typically have very fine grain microstructures compared to bulk-manufactured components (e.g., components made by casting, where molten material is typically formed into the desired component in a single operation, as opposed to a small number of particles fused together over the course of many successive operations in SLM or DMLM). That is, structures formed by the fusion of small particles of solid material through the selective application of heat provided by a laser. Such additively manufactured components also often tend to have microstructures with pronounced directionality, with grains having profiles in the XY plane being more curved and larger than their profiles in a plane parallel to the Z direction (the XY plane corresponds to the horizontal plane, and the Z direction corresponds to the vertical direction, relative to the component as positioned during the additive manufacturing process). For example, Figure 1 depicts reproductions of grain boundaries in the vertical plane (left) and horizontal plane (right) of an exemplary component made using one exemplary DMLM process. As shown, the grain size in the vertical plane exhibits a high asymmetry with respect to its size in the Z direction compared to its size in the X or Y directions. Grains tend to have lengths in the X and / or Y directions that are much larger than their thickness in the Z direction. It should be understood that this micrograin structure is sometimes referred to herein as being an anisotropic micrograin structure to distinguish it from a micrograin structure that exhibits variations in size and shape, but does not typically exhibit dimensional variations tied to a particular axis. It will be understood that at least some of the additively manufactured showerheads described herein may exhibit such an anisotropic micrograin structure.

[0122] Such additive manufacturing techniques enable showerhead geometries that are extremely difficult or impossible to achieve using conventional (subtractive) machining processes such as milling, drilling, or turning. Such showerhead geometries, for example, allow the showerhead to have a smaller internal volume (thus reducing the amount of gas required to provide the desired gas flow through the showerhead and reducing the amount of time the showerhead needs to reach steady-state flow) and, in some cases, increase the number of different fluidically isolated flow paths within the showerhead (or at least increase the density of such paths).

[0123] The showerhead and showerhead faceplate designs described herein are designed to allow for the flow or delivery of two or more different gases used during semiconductor processing operations (e.g., precursors, reactants, or inert or non-reactive purge gases, etc.) from or through a common showerhead while keeping the gas flows separate from each other within the showerhead.

[0124] The designs of such showerheads and showerhead faceplates (for ease of reference, the term “showerhead” may be used hereinafter to refer collectively to either or both showerheads and showerhead faceplates) may have characteristics that accommodate being made using additive manufacturing techniques while avoiding geometries that potentially generate particulates. For example, such showerheads may fall into two broad categories of design: showerheads with internal spiral passages and showerheads with large, open internal plenum volumes with numerous vertical columns distributed throughout. In either case, such showerheads will have generally vertical surfaces located within the showerhead that define either the sidewalls or the columns of the spiral passages. Each of these sidewalls may extend between two opposing inner surfaces of the showerhead that are generally parallel to the lower surface of the showerhead. However, to avoid particulate generation, the transitions from these sidewall surfaces to the opposing inner surfaces of the showerhead may be designed to be curved.

[0125] Avoiding sharp interior corner edges within the showerhead body reduces the chance of particles becoming trapped in such corners and later being released. (Particles flowing against a sharp corner edge may contact two surfaces simultaneously, increasing the risk of the particle becoming trapped. However, particles flowing against a curved interior edge typically only contact one surface at a time, reducing the risk of the particle becoming trapped.)

[0126] At the same time, additively manufactured parts often have a rough surface finish, and post-additive manufacturing processing may be required to reduce the surface roughness of some surfaces. This is particularly true for showerheads, where the additive manufacturing process can result in undesirably rough surface finishes in the interior volumes of the showerhead through which gases flow. For example, some granules of the material used in the additive manufacturing process may only be loosely fused in place, posing a risk of later release from anchor points due to exposure to gases flowing through those interior spaces. To reduce or eliminate this possibility, abrasives or slurries may be pumped into the interior spaces after additive manufacturing to abrade and remove such granules, or to polish or smooth the interior passages to remove them. However, if sharp interior corners exist along the paths through which such abrasives or slurries may flow, these corners may effectively act as stagnation zones, where fluid flow is much slower than elsewhere in the interior spaces of the showerhead. Therefore, the abrasives or slurries may be significantly less effective at removing particulates that may be present in those interior corners. As a result, there may be an increased likelihood that such particulates remain after the polishing process has taken place and then potentially be released or become loose during operational use of the showerhead during semiconductor processing operations (thereby contaminating the semiconductor wafer being processed).

[0127] The likelihood of such particulate contamination occurring may be significantly reduced by curving the intersections between the sidewalls and the upper and lower interior surfaces of the showerhead that they span.

[0128] Metal additive manufacturing processes, such as those that may be used to manufacture the showerhead described above, may be used to create complex shapes that are difficult or impossible to manufacture using traditional subtractive machining and / or casting processes. Additive manufacturing, in particular, may be used to create components with internal cavities or chambers that must be machined as a single piece, typically as two or more separate pieces, and then welded or glued together. However, such capabilities are limited. For example, internal cavities or passageways with downward-facing horizontal surfaces may not be suitable for manufacturing using such techniques because these downward-facing surfaces may sag during the additive manufacturing process due to a lack of support from a rigid structure. For example, the only support for such surfaces may be provided by unfused granular material directly below them, which may be compressed by heat seeping through the fused surfaces or may fuse to some degree with itself (thus increasing its density and reducing its volume).

[0129] Generally speaking, horizontal, downward-facing surfaces greater than 1 cm in width may be at risk of sagging during additive manufacturing processes. To reduce or eliminate the possibility of such horizontal surfaces sagging, some showerheads, such as those described herein, may be designed so that the radius of the curved transition between the sidewall and top inner surface of such showerheads is large enough that the curved transition for the sidewall surface and the top inner surface(s) of the showerhead can contact adjacent sidewalls. For example, the spiral passage of such showerheads may be designed with an arcuate or parabolic "roof" that smoothly transitions to the sidewall surface, but the "roof" has a substantially infinitesimally thin horizontal element. As another example, in some showerheads in which pillars are distributed throughout the showerhead's internal plenum and span between its top and bottom inner surfaces, each pillar may be spaced from its nearest neighbor by a distance equal to twice the radius of the curved transition between the pillar sidewall and the top inner surface of the showerhead, thereby forming a continuous, smooth arch between the pillar and an adjacent pillar.

[0130] At the same time, the curved transition region where the sidewall surface meets the lower inner surface of the showerhead may be much less curved than the curved transition region at the top. As a result, there is a flat or horizontal surface between each sidewall surface of the passage or between each adjacent column. Such a flat or horizontal surface may be designed to be at least several millimeters wide. Such an approach can help ensure that when gas distribution holes are drilled into the underside of the showerhead to intersect with internal passages or volumes within the showerhead body, all of such gas distribution holes are generally positioned so that each hole is the same length (because such gas distribution holes may span between the lower horizontal surface of the showerhead and the horizontal portion of the lower inner surface of the showerhead). If the curved region at the bottom were the same size as the curved region at the top, there would be only a relatively small area of ​​the lower inner surface of the showerhead where such gas distribution holes could be positioned and all of them would be the same length. Misplaced locations of the gas distribution holes in such a showerhead could result in different lengths of such holes. For example, if a gas distribution hole exits the interior region of the showerhead at a location that is within a curved region, the length of the gas distribution hole will be longer than if the gas distribution hole exits the interior region of the showerhead at a location that is within one of the horizontal flat regions of the lower interior surface of the showerhead.

[0131] 2-45 show various examples of such showerhead designs.

[0132] Figure 2 is a top view of an example showerhead 200 configured to separately route two process gases using internal spiral passages. Figure 3 is a cross-sectional view of the example showerhead 200 of Figure 2 along the indicated section line. Figure 4 is a cross-sectional view of the example showerhead 200 of Figure 2 along the indicated section line. Figure 4' is a detailed cross-sectional view of a pair of radially adjacent spiral passages of the example showerhead 200 of Figure 2.

[0133] As best seen in FIG. 4 , showerhead 200 includes a body 202 having a pair of helical passages 214a and 214b that follow helical paths 218a and 218b, respectively, which are 180° out of phase with each other relative to a central axis 220 of the helical paths 218a and 218b (which are coaxial with each other; however, in the context of this disclosure, coaxial helical paths will be understood to refer to helical paths that share a common helical path central axis). In some embodiments, each helical passage 214 may be, for example, 6 mm to 25.5 mm wide and may be separated from each other by walls 216a and 216b, for example. Helical paths 218a and 218b, in this example, are helical paths of the same pitch and number of turns (e.g., 5 to 15 turns). Such a size range can provide sufficient uniformity in gas distribution across a portion of the underside of the showerhead having a diameter of approximately 330 mm to 360 mm. Each of the spiral passages 214a and 214b has a cross-section along most or all of its length, as shown in FIG. 4', which depicts a cross-sectional detail of two adjacent portions of the spiral passages 214a and 214b. As shown in FIG. 4', the first spiral passage 214a and the second spiral passage 214b have cross-sectional profiles that include a first segment 242 and a second segment 244, respectively, that form the "ceiling" of each spiral passage 214 (assuming the showerhead 200 is oriented as shown in FIG. 4'). The cross-sectional profiles are shown for clarity with solid black lines that bound the interior of each spiral passage 214. Additional lines offset from the solid black lines and shown as dotted or dashed are intended to identify the portions of the solid black lines that correspond to those dotted or dashed lines. The cross-sectional profile of first spiral passageway 214a may further include a third segment 246 and a pair of first side segments 254 that may each span between first segment 242 and third segment 246. Similarly, the cross-sectional profile of second spiral passageway 214b may further include a fourth segment 248 and a pair of second side segments 256 that may each span between second segment 244 and fourth segment 248.

[0134] The first segment 242 may include a first curved transition region 260 where the first segment 242 connects to the first lateral segment 254. The first curved transition region may merge smoothly with the first lateral segment 254, for example, to avoid a sharp interior edge along the length of the first helical passage 214a. Similarly, the second segment may include a second curved transition region 262 where the second segment 244 connects to the second lateral segment 256.

[0135] In a similar manner, the third segment 246 may include a third curved transition region 264 where the third segment 246 connects to the first lateral segment 254. The third curved transition region 264 may merge smoothly with the first lateral segment 254, for example, to avoid a sharp interior edge along the length of the first helical passage 214a. Similarly, the fourth segment may include a fourth curved transition region 266 where the fourth segment 248 connects to the second lateral segment 256.

[0136] As alluded to above, first curved transition region 260 may be generally larger than third curved transition region 264, and second curved transition region 262 may be generally larger than fourth curved transition region 266. For example, third curved transition region 264 and fourth curved transition region 266 may be filleted or curved inner edges having a radius of 0.01 inches to 0.02 inches, and first curved transition region 260 and second curved transition region 262 may be filleted or curved inner edges having a radius equal to approximately half the width of spiral passage 214 (which may be on the order of 1 millimeter or more in width, e.g., 2 millimeters to 6 millimeters in width, in some instances). Such an arrangement allows first segment 242 and second segment 244 to be arch-shaped in some cases (either a semicircular arch as shown, or a parabolic arch). In such cases, the first segment 242 and the second segment 244 may generally be free of horizontal portions, except for a very small portion at the highest point of the first segment 242 and the second segment 244 (where the slope of the first segment 242 and the second segment 244 reverses through zero). Such a cross-sectional profile may be used to prevent problems during additive manufacturing of such a showerhead 200. For example, avoiding horizontal spans in the first segment 242 and the second segment 244 may reduce or eliminate the possibility of partial collapse of the spiral passage 214 during additive manufacturing. At the same time, eliminating sharp inner corner edges in the cross-sectional profile of the spiral passage 214 reduces the possibility of particulates becoming trapped within the showerhead 200 and later being dislodged, contaminating wafers being processed using the showerhead.

[0137] 4, spiral passages 214a and 214b follow spiral paths 218a and 218b, respectively. In some embodiments, spiral path 218 may have an outer diameter at least equal to the diameter (e.g., 300 mm) of a wafer to be processed using showerhead 200 (the outer diameter of a spiral path is understood to be the diameter of a circle centered at the spiral center point and tangent to the outermost end of the spiral path). In some embodiments, each spiral path may have an outer diameter of at least 330 mm or 350 mm. Spiral paths 218a and 218b extend from points near the center of showerhead 200 coincident with inlet ports 210a and 210b, respectively, and then spiral radially outward, terminating, for example, at outlet ports 212a and 212b, respectively. A plurality of first gas distribution holes 208a, each extending from the second side 206 of the showerhead 200 and fluidly connecting to the first spiral passage 214a, may be located along the first spiral path 218a, and a plurality of second gas distribution holes 208b, each extending from the second side 206 of the showerhead 200 and fluidly connecting to the second spiral passage 214b, may be located along the second spiral path 218b. The first inlet port 210a may, for example, fluidly connect the first spiral passage 214a to a location on the exterior surface of the showerhead 200, thereby directing one or more first gases into the first spiral passage 214a for distribution through the first gas distribution holes 208a. Similarly, the second inlet port 210b may deliver one or more second gases to the second spiral passage 214b for distribution through the second gas distribution holes 208b, for example, by fluidly connecting the second spiral passage 214b to another location on the exterior surface of the showerhead 200.

[0138] The outlet ports 212a and 212b are optional and may be used to allow abrasive slurry or other polishing fluids to be pumped / circulated through the spiral passage 214 after additive manufacturing of the showerhead 200 is complete. For example, such a polishing fluid may be pumped into the first spiral passage 214a via the first inlet port 210a, then flow through the first spiral passage 214a before exiting the first spiral passage 214a via the first outlet port 212a. Similarly, a polishing fluid may also be pumped into the second spiral passage 214b via the second inlet port 210b, then flow through the second spiral passage 214b before exiting the second spiral passage 214b via the second outlet port 212b. After such polishing is complete, the outlet ports 212a and 212b may be plugged, sealed, or finished. In some embodiments, outlet ports 212a and 212b may be plugged, sealed, or finished using removable plugs or caps, such that, for example, fluids may be introduced to or removed from spiral passages 214a and 214b via outlet ports 212a and 212b and / or inlet ports 210a and 210b. For example, cleaning slurries or fluids may be circulated through spiral passages 214a and 214b, and the flow rate of cleaning slurries or fluids may be increased by flowing them into spiral passages 214a and 214b via inlet ports 210a and 210b, respectively, and out of spiral passages 214a and 214b via outlet ports 212a and 212b, respectively (compared to the flow rate that could be achieved by flowing such slurries or fluids from spiral passages 214a and 214b through gas distribution holes 208a and 208b).

[0139] In the depicted example, the first gas distribution holes 208a are all the same size and spaced equally apart along the first spiral path 218a, and the second gas distribution holes 208b are all the same size and spaced equally apart along the second spiral path 218a. However, in other embodiments, the gas distribution holes may be configured differently, for example, to bias the gas flow from the showerhead 200 in a manner that varies as a function of radial and / or azimuthal position. For example, the spacing of the gas distribution holes along the spiral path may vary through one or more portions of the spiral path, such that the gas distribution holes 208 in the spiral passage are more closely spaced (thus increasing the gas flow velocity in such regions) or more widely spaced in different annular regions of the showerhead 200. Alternatively, or in addition, a similar effect may be achieved by varying the size of the gas distribution holes 208 in the spiral passage as a function of radial position from the center of the spiral passage, e.g., increasing the diameter of the gas distribution holes 208 to increase the amount of gas flow and decreasing the diameter of the gas distribution holes 208 to decrease the amount of gas flow.

[0140] It will also be understood that each inlet port 210, while shown as being located near the center of the showerhead 200, does not necessarily have to be so located. For example, the inlet port 210 may instead be located at the opposite end of the spiral passage 214 so as to direct gases through the spiral passage 214 inward toward the center of the showerhead 200 rather than toward the outer periphery of the showerhead 200. In some examples, the inlet port 210 may instead be located at a location other than either end of the spiral passage 214, such as at one or more locations at a point (e.g., intermediate) between the endpoints of the spiral passage 214, such that it is fluidly connected to the spiral passage 214. It will also be understood that a given spiral passage 214 may have multiple inlet ports 210, thereby allowing gases to be introduced at multiple locations along the length of the spiral passage 214.

[0141] The spiral passage is located within the body of the showerhead and is disposed between a first side of the body and a second side of the body, the second side of the body being opposite the first side of the body.

[0142] As shown, each spiral passage has a corresponding plurality of gas distribution holes extending from the first side of the body to the corresponding spiral passage, thereby fluidly connecting that spiral passage with the ambient environment below the showerhead (or above the showerhead if the showerhead is oriented to direct process gases vertically upward rather than downward, as may be the case in a backside deposition or etch chamber).

[0143] FIG. 5 shows a cross-sectional view of a showerhead 500 having a body 502 with two helical passages 514a and 514b therein, each following a helical path 518a and 518b that are 180° out of phase with each other relative to the central axis of the helical path 518a and 518b (e.g., similar to showerhead 200 of FIG. 4). The width of the helical path 518 may be, for example, 6 mm to 25.5 mm in some embodiments. The helical paths 518a and 518b, in this example, have the same pitch and number of turns (e.g., 5 to 15 turns). Such a size range can provide sufficient uniformity in gas distribution across a portion of the underside of a showerhead with a diameter of approximately 330 mm to 360 mm. The spiral passages 514 a and 514 b may be separated from one another by intervening walls 516 a and 516 b. Each spiral passage 514 a and 514 b may have a plurality of first gas distribution holes 508 a and a plurality of second gas distribution holes 508 b, respectively, distributed along its length, and such gas distribution holes 508 may be used to direct gas flow from the spiral passage downward onto a wafer positioned below the showerhead 500.

[0144] 4, however, showerhead 500 has inlet ports 510a and 510b located at the outermost ends of spiral passages 514a and 514b, respectively. Thus, gases entering showerhead 500 through inlet ports 510a and 510b spiral inward toward the center of showerhead 500 along spiral passages 514a and 514b.

[0145] Such an approach offers notable and somewhat unexpected advantages over the previously described showerhead 200, as illustrated in FIGS. 6 and 7. FIG. 6 illustrates analytical results showing the relative molar concentrations of reactants flowed through a showerhead such as showerhead 200, i.e., a showerhead having two spiral passages 214a and 214b, each with an inlet port 210a and 210b located at the innermost end of the spiral passages 214a and 214b, respectively. Thus, in FIG. 6, the showerhead has two inlet ports 210a and 210b located near the center of the showerhead, e.g., at the innermost end of the spiral passage 214 located within the showerhead. The spiral passages in FIG. 6 are not specifically called out but are faintly visible within the showerhead. Also depicted in FIG. 6 are three dotted circles, representing the outer periphery of a wafer 692, the outer periphery of a pedestal 690 on which the wafer 692 rests, and the outer periphery 688 of the showerhead, respectively. In FIG. 6, the relative molar concentrations are shown for reactants that flowed through only one of the spiral passages 214, for example spiral passage 214a.

[0146] Figure 6 uses gradient shading to indicate different relative molar concentrations of the reactants. Figures 7, 9, 13, and 17 also show analytical results for other embodiments using similar gradient shading. To facilitate easy comparison and contrast of analytical results across all three figures, the number of gradient steps and the upper and lower limits of the gradient color values ​​are the same in each of Figures 6, 7, 9, 13, and 17. For clarity, each figure uses 16 different shades of gray, and the contours (shown as black lines) between these 16 colors (or however many are actually shown in each figure) are easily visible. However, it will be appreciated that the maximum and minimum values ​​shown in each figure are not necessarily represented in the gradient bar legend / scale along the bottom of each figure (although each gray value will appear in at least one figure).

[0147] 6, there are localized non-uniform zones 694 on wafer 692 where the relative molar concentration is up to three times greater than the rest of wafer 692. These localized non-uniform zones 694 cover approximately 25% of the top surface of wafer 692.

[0148] 7 shows analytical results representing the relative molar concentrations of reactants flowed through a showerhead such as showerhead 500, i.e., a showerhead having two spiral passageways 514a and 514b with inlet ports 510a and 510b, respectively, located at the outermost ends of spiral passageways 515a and 515b. Thus, in FIG. 7, the showerhead has two inlet ports 510a and 510b located near the periphery of the showerhead, e.g., at the outermost ends of the spiral passageways located within the showerhead. The reactants whose relative molar concentrations are shown in FIG. 7 are provided, in this example, via spiral passageway 514a. 7, while the showerhead of FIG. 6 produced two localized non-uniformity zones 694 located near the center of wafer 692 and spanning approximately 25% of wafer 792, the showerhead of FIG. 7 produced non-uniformity zones 794 (a roughly circular non-uniformity zone 794 near the center of wafer 792 and a thin, C-shaped non-uniformity zone 794 along the top edge of wafer 792, relative to the orientation of the figure) that had a much smaller total area compared to the total area of ​​non-uniformity zones 694. Additionally, the difference between the relative molar concentration of non-uniformity zones 794 and the relative molar concentration of the remainder of wafer 792 is approximately 50% smaller than in the example of FIG.

[0149] However, note that the relative molar concentrations outside the boundaries of the wafer 792 now exhibit a marked asymmetry; for example, the molar concentrations on the right side of the pedestal 790 and chamber 788 (in both cases, this refers to those regions outside the outer periphery of the wafer 792) are approximately 15% higher than the left side of the pedestal 790 and chamber 788. As a result, the pedestal 790 and chamber 788 may be unevenly exposed to the reactants flowed through the showerhead. This may result in uneven etching or deposition (depending on the reactant) of the pedestal 790 and / or chamber 788 (or components associated with either). This may increase the frequency at which cleaning operations may be required to remove undesired deposits from the pedestal 790 and / or chamber 788 (which may accumulate much faster in some areas than in others, e.g., due to uneven relative molar concentrations of the reactants).

[0150] FIG. 8 shows a cross-sectional view of a showerhead 800 having a body 802 with two helical passages 814a and 814b therein, each following a helical path 818a and 818b that are 180° out of phase with each other relative to the central axis of the helical paths 818a and 818b (e.g., similar to showerhead 500 of FIG. 5). The width of the helical path 818 may be, for example, 6 mm to 25.5 mm in some embodiments. The helical paths 818a and 818b, in this example, have the same pitch but different numbers of turns, e.g., one with 5 to 15 turns and the other with half a turn more or less. This has the effect of placing inlet ports 810a and 810b at the same azimuthal position. The spiral passages 814a and 814b may be separated from one another by intervening walls 816a and 816b. Each spiral passage 814a and 814b has a plurality of first gas distribution holes 808a and a plurality of second gas distribution holes 808b, respectively, distributed along its length.

[0151] 9 shows analytical results representing the relative molar concentrations of reactants flowed through a showerhead, such as showerhead 800, i.e., a showerhead having two spiral passageways 814a arranged at the same azimuthal position, with inlet ports 810a and 810b located at the outermost ends of spiral passageways 815a and 814b, respectively. Thus, in FIG. 9, the showerhead has two inlet ports 810a and 810b located near the periphery of the showerhead, e.g., at the outermost ends of the spiral passageways within the showerhead, and at the same azimuthal position. The relative molar concentrations shown in FIG. 9 are for reactants flowed through spiral passageway 814a via inlet port 810a. As can be seen from Figure 9, while the showerhead of Figure 8 exhibited significant bilateral asymmetry in the relative molar concentrations of reactants flowing through the showerhead in the region between the outer edge of wafer 892 and chamber 888, the showerhead of Figure 9 exhibits a much greater degree of azimuthal uniformity in the region between the outer edge of wafer 992 and chamber 988. Thus, a showerhead such as that of Figure 8 may not only significantly reduce the extent and magnitude of localized non-uniformity zones that may be present on a wafer processed using such a showerhead, but may also significantly increase the azimuthal uniformity around the periphery of the wafer, e.g., between the wafer and the chamber wall. Such an embodiment may improve wafer processing uniformity across wafer 992 compared to some other embodiments, and may also result in more uniform incidental deposition or etching on surfaces of chamber 988 and / or pedestal 990.

[0152] FIG. 10 is an isometric cutaway view of an exemplary showerhead having two-tiered spiral passages. In FIG. 10, the showerhead 1000 is shown with a first inlet port 1010a visible in a first side 1004 of the showerhead 1000, and a second inlet port is located on the opposite side of the showerhead 1000 (cut away in this view). The showerhead 1000 may include a body 1002, which may include therein a first spiral passage 1014a and a second spiral passage 1014b similar to the spiral passages 214a / b of the body 202 (see FIG. 11, which shows an isometric top cross-sectional view of the showerhead 1000 at the bottom, taken along the cut line of the showerhead 1000 shown in side view at the top of FIG. 11). The first and second spiral passages 1014a and 1014b may be arranged in a similar manner, e.g., in a circular array about a common central axis, spaced apart 180° out of phase with each other about the common central axis. The first spiral passage 1014a may have first gas distribution holes 1008a distributed along its length. Each first gas distribution hole 1008a may connect the first spiral passage 1014a to the second side 1006 of the body 1002. Similarly, the second spiral passage 1014b may have second gas distribution holes 1008b distributed along its length. Each second gas distribution hole 1008b may connect the second side 1006 of the body 1002 to the second spiral passage 1014b. In this respect, the showerhead 1000 is very similar to the showerhead 200 or showerhead 500 described above.

[0153] However, body 1002 differs from bodies 202 and 502 in that it also includes an additional first spiral passage 1014a' and an additional second spiral passage 1014b' (see FIG. 12, which shows an isometric top cross-sectional view of showerhead 1000 at the bottom, along the cut line of showerhead 1000 shown in side view at the top of FIG. 12). First spiral passage 1014a' may generally follow the same spiral path as first spiral passage 1014a, but is offset toward first side 1004 of body 1002 such that first spiral passage 1014a is at a lower height within body 1002 than first spiral passage 1014a'. Thus, when viewed along a direction perpendicular to first side 1004, first spiral passage 1014a and first spiral passage 1014a' may generally overlap one another in a generally continuous manner along their lengths. Similarly, the second helical passage 1014b' may generally follow the same helical path as the second helical passage 1014b, but is similarly offset toward the first side 1004 of the body 1002 such that the second helical passage 1014b is at a lower height within the body 1002 than the second helical passage 1014b'. In FIG. 10, the first helical passage 1014a' and the second helical passage 1014b' have the same cross-sectional profile as the first helical passage 1014a and the second helical passage 1014b, respectively, as shown, although it will be understood that the first helical passage 1014a' and the second helical passage 1014b' in other embodiments may have a different cross-sectional profile than the first helical passage 1014a and the second helical passage 1014b.

[0154] The first spiral passageway 1014a and the first spiral passageway 1014a' may be fluidly connected to one another by a plurality of ascending passageways 1015 spanning between the first spiral passageway 1014a and the first spiral passageway 1014a'. Such ascending passageways 1015 may be distributed, for example, spaced apart along the length of the first spiral passageway 1014a / 1014a'. The ascending passageways 1015 may be spaced apart, for example, by a distance that is on the order of the diameter of the ascending passageway 1015, two times that diameter, or three times that diameter. The riser passage 1015 is formed with a relatively large diameter, for example, many times larger than the diameter of the gas distribution holes in the showerhead 1000, so that the flow resistance between the first spiral passage 1014a and the first spiral passage 1014a' through the riser passage 1015 is much lower than the flow resistance from the first spiral passage 1014a to the second side 1006 through the first gas distribution holes 1008a. The riser passage 1015 may, in some cases, have a diameter on the order of 75% to 100% of the width of the first spiral passage 1014a and / or the first spiral passage 1014a'.

[0155] Such an arrangement can be particularly useful in multilayer ceramic showerheads, which are described in more detail later in this disclosure. For example, some multilayer ceramic manufacturing techniques may have limitations on the height-to-width aspect ratio, which may constrain the design of the spiral passage. For example, it may be difficult to manufacture a multilayer ceramic component having a spiral passage that is more than twice as deep as the width of the spiral passage. As a result, if a given cross-sectional area is required in the spiral passage to provide a desired hierarchy of flow conductance along the spiral passage, the spiral passage will need to be a certain minimum width to provide that cross-sectional area and the desired flow conductance while still fitting within a maximum height-to-width ratio. That minimum width, in turn, limits the helical pitch the spiral passage can have, and therefore the number of helical turns of the spiral passage that can fit within the volume of the showerhead 1000, and the proximity that the spiral passages can be to each other. This in turn limits the distance that the first gas distribution holes 1008a on adjacent spiral turns can be close to each other and the density with which the first gas distribution holes 1008a can be arranged on the second side 1006 of the body 1002.

[0156] However, such spacing limitations may be overcome by using showerhead designs such as showerhead 1000. For example, first spiral passage 1014a, riser passage 1015, and first spiral passage 1014a′ may collectively function as a single, integrated plenum volume due to the relatively large size of riser passage 1015 compared to first gas distribution holes 1008a. Such an integrated plenum volume may have an overall height-to-width ratio that exceeds the maximum height-to-width ratio that typically limits the channel depth of such a laminated ceramic showerhead 1000. At the same time, the individual first spiral passages, which may be machined or formed into the layers of ceramic material used to make body 1002 to provide first spiral passage 1014a and first spiral passage 1014a′, have a height-to-width aspect ratio that is less than the maximum height-to-width ratio discussed above.

[0157] The second spiral passageway 1014b and the second spiral passageway 1014b' may be similarly connected to the corresponding ascending passageway 1015 and may be arranged in a similar manner to provide similar advantages.

[0158] It will be understood that the embodiments shown in Figures 10-12 feature a curved or arched top surface of the spiral passageway and a curved bottom edge of the spiral passageway. Such features, as described elsewhere herein, may be included to facilitate fabrication of such showerheads by additive manufacturing. In other embodiments, such spiral passageway may have a flat bottom and / or a flat top. For example, if such showerheads are fabricated by stacking multiple machined or formed ceramic layers together, the spiral passageway may be machined or otherwise formed in one or more of the layers and then capped by another of the layers when the layers are bonded together. In such embodiments, the top and / or bottom surfaces of the spiral passageway may exhibit, for example, sharp edges, e.g., 90° corners.

[0159] Gases entering the showerhead 200 through the first inlet port 1010a and the second inlet port 1010b may first flow into the first spiral passage 1014a' and the second spiral passage 1010b', respectively, then into the first spiral passage 1014a and the second spiral passage 1010b, respectively, before flowing out through the first gas distribution holes 1008a and the second gas distribution holes 1008b, respectively.

[0160] With such an approach, such showerhead 1000 can have a densely distributed gas distribution hole, thereby distributing gas more uniformly across the wafer being processed by the showerhead, while maintaining a sufficiently high flow conductance within the spiral passage to avoid undesirable pressure drops that can adversely affect the radial uniformity of gas distribution along the length of such spiral passage. While showerhead 1000 has inlet ports 1010 a and 1010 b located on opposite sides of the showerhead, it will be understood that other such embodiments may feature inlet ports 1010 a and 1010 b on the same side of showerhead 1000, similar to the configuration of showerhead 500, for example.

[0161] 13 illustrates, for example, analytical results showing the relative molar concentrations of reactants flowed through a showerhead similar to showerhead 1000, i.e., a showerhead with stacked spiral passageways that can be used to provide a composite plenum with a higher height-to-width aspect ratio than either of the spiral passageways alone, but with inlet ports arranged like showerhead 500. For example, the showerhead of this embodiment has two inlet ports 1310a and 1310b, both located near the periphery of the showerhead, e.g., at the outermost ends of the spiral passageways located within the showerhead, and both located azimuthally close to each other (e.g., at the same azimuthal position). Thus, the spiral path followed by the spiral passageway supplied with gas through inlet port 1310a may include an extra half turn compared to the spiral path followed by the spiral passageway supplied with gas through inlet port 1310b. 13, are provided in this example via spiral passages fed by inlet port 1310a. As shown, gas distribution across the area of ​​wafer 1392 is highly uniform both azimuthally and radially, e.g., relative molar concentrations vary within about 1 percent.

[0162] FIG. 14 shows a top view (top) and a cross-sectional side view (bottom) of an exemplary showerhead including spiral passages and spoke passages. The showerhead 1400 depicted in FIG. 14 provides an alternative approach to providing more uniform gas delivery in a spiral passage showerhead. Similar to the other showerheads described above, the showerhead 1400 has a body 1402 having a first side 1404 and a second side 1406. A first spiral passage 1414a and a second spiral passage 1414b are located within the body 1402, as shown in FIG. 15, which shows a side view (top) of the showerhead 1400 and a cross-sectional top view (bottom) of the showerhead 1400 taken along the cut line indicated in the side view. The first and second spiral passages 1414a and 1414b may be spaced apart in a manner similar to that of the spiral passages 214 or 514, e.g., in a circular array about a common central axis, spaced apart 180° out of phase with each other about the common central axis. The first spiral passage 1414a may have first gas distribution holes 1408a distributed along its length. Each first gas distribution hole 1408a may connect the second side 1406 of the body 1402 to the first spiral passage 1414a. Similarly, the second spiral passage 1414b may have second gas distribution holes 1408b distributed along its length. Each second gas distribution hole 1408b may connect the second side 1406 of the body 1402 to the second spiral passage 1414b. In this respect, the showerhead 1400 is very similar to the showerheads 200, 500, and 1000 described above.

[0163] The showerhead 1400 differs from those previously described showerheads in that the showerhead 1400 body 1402 includes a plurality of spoke passages (e.g., first spoke passage 1413a and second spoke passage 1413b) therein that extend outward from a central region of the body 1402, as shown in FIG. 16. FIG. 16 shows a side view (top) of the showerhead 1400 and a top cross-sectional view (bottom) of the showerhead 1400 taken along the cut line indicated in the side view. The first spoke passage 1413a and the second spoke passage 1413b may be disposed between the second side 1406 of the body 1402 and the first and second spiral passages 1414a and 1414b.

[0164] Each first spoke passageway 1413a may have a corresponding plurality of ascending passageways 1415 that fluidly connect the first spoke passageway 1413a to the first spiral passageway 1414a. More specifically, each ascending passageway 1415 may, for example, connect to the first spiral passageway 1414a at a different location along the spiral path followed by the first spiral passageway 1414a. Similarly, each second spoke passageway 1413b may have a corresponding plurality of ascending passageways 1415 that fluidly connect the second spoke passageway 1413b to the second spiral passageway 1414b. For example, each ascending passageway 1415 may connect to the second spiral passageway 1414b at a different location along the spiral path followed by the first spiral passageway 1414b. Thus, the first spoke passage 1413a may function essentially as a radial (or somewhat radial) "bridge" connecting adjacent turns of the first helical passage 1414a together, thereby providing a fluid shortcut between adjacent turns of the first helical passage 1414a. The second spoke passage 1413b may function similarly with respect to the second helical passage 1414b. It will be understood that the first and second radial spoke passages 1413a and 1413b are fluidly isolated from one another within the showerhead.

[0165] The first and second spoke passages 1413a and 1413b may be arranged in an alternating circular pattern, e.g., ABABAB..., as shown in FIG. 16, such that gas flowing through each spiral passage 1414a and 1414b provides a generally radially symmetric flow path about the circumference of the showerhead 1400.

[0166] The spoke passages for such showerheads allow such showerheads to have improved radial uniformity in gas distribution compared to showerhead designs without such spoke passages. For example, in a showerhead with spiral passages but no spoke passages, gas flowing through a spiral passage from the inlet port (where gases entered the showerhead) to the gas distribution hole furthest from the inlet port must flow along the entire length of that spiral passage before reaching the gas distribution hole at the opposite end of the spiral passage from the inlet port. However, in a showerhead with spiral passages connected by spoke passages, such as showerhead 1400, the spoke passages for a given spiral passage allow gas introduced through the inlet port for that spiral passage to reach any of the gas distribution holes for that spiral passage that are farther from the inlet port through a much shorter flow path than would be possible without the spoke passages. This results in a more even radial distribution of gas flow.

[0167] Although showerhead 1400 has inlet ports 1410a and 1410b located on opposite sides of the showerhead, it will be understood that other such embodiments may feature inlet ports 1410a and 1410b on the same side of showerhead 1400, similar to the configuration of showerhead 500, for example.

[0168] Like the embodiment shown in FIGS. 10-12 , the embodiment of FIGS. 14-16 features a curved or arched top surface of the spiral passageway and a curved bottom edge of the spiral passageway. However, the spoke passageway has a flat bottom and top surface. The inclusion of curved features in the spiral passageway, as previously described, may facilitate the production of such showerheads by additive manufacturing. In such showerheads, the spoke passageway may similarly have a curved or arched top surface and, in some cases, a curved edge bounding the bottom surface. This is not shown in FIGS. 14-16 , but will still be understood to be within the scope of the present disclosure. In other embodiments, such spiral passageway may have a flat bottom and / or a flat top, for example, similar to the depiction of the spoke passageway in FIGS. 14-16 . For example, if such showerheads are manufactured by stacking together multiple machined or formed ceramic layers, the spiral passageway may be machined or otherwise formed in one or more of the layers and then capped by another of the layers when the layers are bonded together. In such embodiments, the top and / or bottom surfaces of the spiral passage may, for example, exhibit sharp edges, such as 90° corners.

[0169] FIG. 17 illustrates analytical results showing the relative molar concentrations of reactants flowed through a showerhead similar to showerhead 1400, i.e., a showerhead having spiral passageways connected by spoke passageways, but with inlet ports, both of which are located at the outer ends of the spiral passageways and are azimuthal (e.g., at the same azimuthal) proximity to one another. Thus, the spiral path followed by the spiral passageway supplied with gas via inlet port 1710a may include an extra half-turn compared to the spiral path followed by the spiral passageway supplied with gas via inlet port 1710b. The reactants whose relative molar concentrations are shown in FIG. 17 are provided, in this example, through the spiral passageway supplied by inlet port 1710a. As shown, gas distribution across the area of ​​wafer 1792 is highly uniform, both azimuthal and radially, e.g., within about 2 percent variation in relative molar concentration.

[0170] It will be understood that showerheads such as showerheads 1000 and 1400 may be implemented with the inlet port located at the outer end of the spiral passage as shown, or with the inlet port located at the inner end of the spiral passage, for example, as in showerhead 200.

[0171] While the above examples and analysis are for showerheads with two spiral passages, it will be understood that showerheads with more than two spiral passages (e.g., three or four spiral passages) may also benefit from similar practices in such showerheads. These practices include, for example, locating the inlet ports at the outermost ends of the spiral passages, optionally locating the inlet ports at the same azimuthal position within the showerhead, using dual spiral passages, and / or using spoke passages. It will also be understood that in dual variations, there may be more than just two spiral passages stacked on top of each other, such as three, four, five, etc. spiral passages stacked on top of each other, allowing for very high height-to-width aspect ratios. All of these variations are considered within the scope of the present disclosure.

[0172] FIG. 18 is a cross-sectional view of an exemplary showerhead similar to the exemplary showerhead of FIG. 2 but configured to separately route three process gases using internal spiral passages. As shown, this configuration is similar to the exemplary showerhead of FIG. 2 but has three spiral passages 1814a / b / c instead of the two spiral passages 214 located within the body 1802 of the showerhead 1800. The three spiral passages 1814a / b / c each follow a spiral path 1818a / b / c that is 120° out of phase with one another and are separated by a spiral wall 1816. Each spiral passage 1814a / b / c has gas distribution holes 1808a / b / c distributed therealong. It will be apparent that this arrangement may also be promoted for showerheads having even more spiral passages, for example, four, five, six, or more spiral passages. In such cases, the angular offset between adjacent helical paths followed by the helical paths may be selected to be equal to 360° / N, where N is the number of helical paths.

[0173] FIG. 19 is a side view of another exemplary showerhead similar to FIG. 2 but capable of separately delivering three process gases, two through internal spiral passages and one through gas distribution holes extending from one side of the showerhead to the other. The showerhead of FIG. 19 may be considered a showerhead faceplate, for example, as previously described. FIG. 20 is a top view of the exemplary showerhead of FIG. 19. FIG. 21 is a cross-sectional view of the exemplary showerhead of FIG. 19 along the cross-sectional view of FIG. 19. FIG. 22 is an isometric cross-sectional view of the exemplary showerhead of FIG. 19 along the cut line of FIG. 20.

[0174] As can be seen in Figure 20, the showerhead 1900 of Figure 19 features a plurality of gas distribution holes 1908x visible on the top side (first side 1904) of the body 1902 of the showerhead 1900. Such a showerhead may be fitted to (or have as part of) a backplate 1901 (see Figure 19), which may cooperate with the showerhead 1900 to define a plenum volume 1903 in which the showerhead 1900 forms a floor. Thus, gas or plasma introduced into such plenum volume 1903 may exit the plenum volume 1903 by flowing through the showerhead 1900 from its first side 1904 to its second side 1906 via the gas distribution holes 1908x. Inlet ports 1910a and 1910b visible in FIG. 20 may lead to spiral passages 1914a and 1914b, respectively, located within body 1902, as shown, for example, in FIG. 21. Spiral passages 1914a and 1914b are, in this example, identical to spiral passages 214a and 214b in showerhead 200. Various features in FIGS. 19-22 that share the last two digits of their callout with similar features in showerhead 200 should be understood to be similar to the corresponding features in FIGS. 2-4′, and the preceding discussion of those similar features is equally applicable to those same features in FIGS. 19-22, unless otherwise indicated.

[0175] As previously mentioned, showerhead 1900 differs from showerhead 200 in that it includes a third set of gas distribution holes 1908x extending through the body 1902 of showerhead 1900. As can be seen in FIG. 21 , gas distribution holes 1908x are also arranged along the same spiral path as first gas distribution holes 1908a and second gas distribution holes 1908b. The spiral path along which gas distribution holes 1908x are arranged coincides with the spiral path followed by spiral wall 1916, which separates spiral passages 1914a and 1914b. In some embodiments, spiral wall 1916 may be only 0.15 mm wide. In other embodiments, the width may be on the order of 0.5 mm or greater, or 1 mm or greater. For example, if the spiral wall has gas distribution holes therethrough, the wall thickness of the spiral wall (at least in the area around the gas distribution holes, if not along the entire length of the spiral wall) may be on the order of the diameter of the gas distribution holes plus 0.3 mm, 1 mm, 2 mm, or more. Thus, gas distribution holes 1908x may be disposed between two spiral passages 1914, effectively forming third and fourth spiral patterns of gas distribution holes 1908x in addition to the first and second spiral patterns of gas distribution holes 1908a and 1908b, respectively.

[0176] Inlet ports 1910a and 1910b, visible near the center of showerhead 1900, would naturally be sealed from plenum volume 1903 so that gases introduced into plenum volume 1903 cannot mix with gases introduced into spiral passages 1914a and 1914b through inlet ports 1910a and 1910b, respectively, at least until the gases flow through their respective gas distribution holes 1908 and exit showerhead 1900.

[0177] Gas distribution holes throughout the showerhead may be positioned along corresponding spiral paths that define the paths followed by the spiral walls (or walls) that separate the spiral paths within the showerhead. Thus, each such gas distribution hole passes through a portion of the showerhead that is solid, e.g., does not overlap any of the spiral paths, when viewed along a direction perpendicular to the plane defined by the first side of the body.

[0178] Figure 23 is a top view of another exemplary showerhead configured to separately deliver three different process gases in a manner similar to that of the exemplary showerhead of Figure 19. Figure 24 is a side cross-sectional view of the exemplary showerhead of Figure 23 taken along the section line of Figure 23. Figures 25 and 26 are cross-sectional views of the exemplary showerhead of Figure 23 taken along corresponding section lines at different heights in Figure 24. Figure 27 is a bottom view of the exemplary showerhead of Figure 23.

[0179] In this example, and as can be seen in particular in FIG. 24 , the showerhead 2300 includes a body 2302 containing therein a first spiral passageway 2314 a and a second spiral passageway 1914 b that are positioned such that they are at different heights or distances from a first side 2304 or a second side 2306 of the body 1902, thereby allowing the spiral passageways 2314 to rotate at generally the same angular orientation (see FIGS. 25 and 26 , where one of the spiral passageways 2314 a is offset generally radially inward or outward from the other of the spiral passageways 2314 , e.g., the first spiral passageway 2314 a along the length of the first spiral passageway 2314 a). (e.g., a portion of the spiral passage 2314a that is radially inward from the centerline of the first spiral passage 2314a overlaps with a portion of the second spiral passage 2314b along the length of the second spiral passage 2314b that is radially outward from the centerline of the second spiral passage 2314b, and optionally, a portion of the first spiral passage 2314a along the length of the first spiral passage 2314a that is radially outward from the centerline of the first spiral passage 2314a does not overlap with a portion of the second spiral passage 2314b along the length of the second spiral passage 2314b that is radially inward from the centerline of the second spiral passage 2314b). This causes the gas distribution holes 2308a and 2308b for each of the spiral passages 2314a and 2314b to extend vertically downward (or upward if the showerhead is used for backside deposition) to span between the second side 2306 of the body 2302 and the corresponding spiral passage 2314a or 2314b, but not intersect with the other spiral passage 2314a or 2314b. There may also be a helical region where neither helical passage 2314a nor 2314b overlaps when viewed along the central axis 2320 of the helical path followed by the helical passages, and this helical region is essentially the region where helical wall 2316a (which may be located between adjacent portions of the first helical passage 2314a) and helical wall 2316b (which may be located between adjacent portions of the second helical passage 2314b) overlap when viewed along the central axis 2320 of the helical passages 2314a and 2314b.Similar to gas distribution holes 1908x, multiple gas distribution holes 2308x may be distributed along / throughout this spiral region, spanning from the first side 2304 to the second side 2306 of the body 2302. Similar to showerhead 1900, the showerhead 2300 may be connected to a backplate (not shown, but see the example of FIG. 19 for a similar arrangement) to form a plenum volume partially bounded by the first side 2304 of the showerhead 2300. Gases delivered to this plenum volume flow through gas distribution holes 2308x and exit the second side 2306 of the showerhead 2300. Similarly, other gases may be introduced into the first spiral passageway 2314a and the second spiral passageway 2314b through separate inlet ports 23.

[0180] While the showerhead 2300 depicted in this example has two internal spiral passages at two different heights, it will be understood that other variations may feature additional such spiral passages at different heights, allowing for the separate delivery of additional gases beyond the three gases capable of being delivered by the depicted showerhead. Regardless of the number of such spiral passages, such showerheads may also provide more radially compact spacing between gas distribution holes in radially adjacent spiral passages, thereby increasing the radial density of gas distribution holes and achieving correspondingly more uniform gas distribution.

[0181] Figure 28 is a top cutaway view of an example showerhead featuring two nested two-tiered spiral passages. Figure 29 is a cross-sectional view of the example showerhead of Figure 28 taken along the dashed-dotted line in Figure 28. Figure 30 is a detailed view of the portion within the dashed-dotted rectangle in the cross-sectional view of the example showerhead of Figure 28.

[0182] The embodiment of Figures 28-30 is similar to the showerhead 1000 of Figure 10 to some extent. To avoid undue repetition, elements in the embodiment of Figures 28-30 that are similar to elements shown in Figure 10 are called out by numbers having the same last two digits as those similar elements in Figure 10. Therefore, the above description of elements in the embodiment of Figure 10 will be understood to be equally applicable to similar elements in Figures 28-30 unless otherwise indicated. For the sake of brevity, the description of these elements will not be provided to duplicate previous descriptions of similar elements herein, and the previous descriptions of such elements will be understood to be applicable to those similar elements in Figures 28-30.

[0183] As shown most clearly in FIG. 30, the spiral passages 2814a, 2814a', 2814b, 2814b' may differ from those of FIG. 10 in that one or more of the spiral passages 2814a, 2814a', 2814b, 2814b' (e.g., all of the spiral passages 2814a, 2814a', 2814b, 2814b') may have a top surface 2876, a bottom surface 2878, and opposing sidewalls 2880 extending generally between the top surface 2876 and the bottom surface 2878. The showerhead 2800 may be fabricated by stacking multiple machined or formed ceramic layers together, and the spiral passages 2814a, 2814a', 2814b, 2814b' may be machined or otherwise formed in one or more of the layers and then capped by another of the layers when the layers are bonded together.

[0184] 30 , one or more of the spiral passages 2814a, 2814a′, 2814b, 2814b′ (e.g., each of the spiral passages 2814a, 2814a′, 2814b, 2814b′) may further include a plurality of upper joints 2882 configured to join an upper end of each side wall 2880 to an adjacent top surface 2876, and a plurality of lower joints 2884 configured to join a lower end of each side wall 2880 to an adjacent bottom surface 2878. Each joint 2882, 2884 may be an interior corner reinforcement element configured to distribute loads received from the top surface 2876, the bottom surface 2878, and / or the side wall 2880 across the length or surface area of ​​that reinforcement element. The force per unit length or unit surface area of ​​joints 2882, 2884 may be less than the force experienced at a sharp 90-degree inside corner edge without a reinforcing element. For example, a single inside corner formed by the intersection of the top of sidewall 2880 with top surface 2876 may act as a stress riser, resulting in a maximum stress X when a given load is transferred from top surface 2876 to sidewall 2880. If such a single inside corner is replaced with two inside corners formed by joints 2882 (or more inside corners, e.g., formed by multiple joints 2882), the load may be divided over the multiple inside corners, reducing the peak stress at each inside corner, e.g., to about X / 2 (or about X / (the number of inside corners between two adjacent faces)). Thus, each joint 2882, 2884 serves to reduce stress risers that may occur between the sidewall 2880 and the top surface 2876 and / or bottom surface 2878 (e.g., at sharp 90-degree inside corner edges). Such a shape is particularly useful in showerheads made of ceramic materials, which may be more susceptible to fracture when subjected to high stress risers.

[0185] In one embodiment, one or more of the joints (e.g., each of joints 2882, 2884) may include a single step having a raised surface 2886 (e.g., a vertical surface), a running surface 2888 (e.g., a horizontal surface), and two corners 2890, such that the corresponding joints 2882, 2884 distribute loads across the raised surface 2886, the running surface 2888, and the two corners 2890. In other embodiments, each joint 2882 may include more than one step (and thus may include multiple raised surfaces 2886 and running surfaces 2888). In still other embodiments, one or more of joints 2882, 2884 may include a concave surface (e.g., a fillet), a chamfer, a notch, or other feature having a predetermined length or surface area over which loads may be distributed (as opposed to an inside corner edge). Thus, for example, one or more inside corners 2890 of joints 2882 and / or 2884 may be curved or chamfered inside corners. In laminated ceramic embodiments, thin, e.g., 1 mm thick, sheets of ceramic material may be machined in a two-dimensional pattern and then stacked and bonded or fused to form the body. In some such cases, the standing and running surfaces may terminate in sharp corners, e.g., rather than curved or chamfered corners.

[0186] Also visible in Figure 28 are inlet ports 2810a and 2810b, as well as outlet ports 2812a and 2812b. It will be understood that inlet ports 2810a and 2810b are located at the outermost ends of spiral passages 2814a' and 2814b' and outlet ports 2812a and 2812b are located at the innermost ends of spiral passages 2814a' and 2814b', although the locations of inlet port 2810a and outlet port 2812 may be reversed in some embodiments. It will also be understood that outlet port 2812 may be omitted entirely in some embodiments, or, if present, may be capped or plugged as described above with respect to other embodiments.

[0187] 28-30, showerhead 2800 is a two-plenum showerhead capable of simultaneously delivering two different process gases to the interior of a processing chamber, with each process gas maintained fluidly isolated from the other within showerhead 2800. However, such showerheads may be modified to deliver more than two such process gases or to have multiple sets of separate spiral passageways within the showerhead, with each set of spiral passageways delivering a separate process gas.

[0188] For example, Figure 31 is a side view of an exemplary showerhead featuring four nested, two-tiered spiral passages. Figure 32 is a top cutaway view of the exemplary showerhead of Figure 31, taken along the dash-dot line in Figure 31. As shown, Figure 31 shows a showerhead 3100, which includes a body 3102 having four spiral passages 3114a', 3114b', 3114c', and 3114d' therein. The four spiral passages 3114a', 3114b', 3114c', and 3114d' are arranged in a circular array, with the spiral passages 3114 nested within one another. It will be understood that each of the four spiral passages 3114a', 3114b', 3114c', and 3114d' may have four corresponding spiral passages 3114a, 3114b, 3114c, or 3114d directly below it, with riser passages connecting the four spiral passages 3114a', 3114b', 3114c', and 3114d' to the four spiral passages 3114a, 3114b, 3114c, and 3114d, respectively, and with gas distribution holes leading from each of the four spiral passages 3114a, 3114b, 3114c, and 3114d to the underside of the showerhead 3100.

[0189] Such a showerhead 3100 may be used, for example, to distribute two different process gases, e.g., a first process gas through spiral passages 3114a and 3114c and a second process gas through spiral passages 3114b and 3114d (e.g., a separate process gas through each set of opposing spiral passages 3114). Alternatively, four separate process gases may be distributed through the four spiral passages 3114, with each separate process gas flowing through a corresponding one of the four spiral passages 3114a, 3114b, 3114c, and 3114d. In yet another alternative, three different process gases may flow through the four spiral passages, with one of the three separate process gases flowing through two of the four spiral passages. For example, a first process gas may be passed through first and third helical passages (which may be diametrically opposite one another), a second process gas may be passed through a second helical passage, and a third process gas may be passed through a fourth helical passage.

[0190] FIG. 33 is a top cutaway cross-sectional view of another exemplary showerhead similar to the showerhead of FIG. 31 but having six nested, two-tiered spiral passages. Such a showerhead may be used, for example, to deliver up to six different process gases while maintaining fluid isolation from one another within the showerhead. However, such a showerhead is more likely to be used to deliver two or three different process gases while maintaining fluid isolation from one another within the showerhead. For example, a first process gas may be flowed through spiral passages 3114a' and 3114d', a second process gas may be flowed through spiral passages 3114b' and 3114e', and a third process gas may be flowed through spiral passages 3114c' and 3114f'. In another example, a first process gas may be flowed through spiral passages 3114a', 3114c', and 3114e', and a second process gas may be flowed through spiral passages 3114b', 3114d', and 3114f'.

[0191] In the dual-level spiral passage showerhead embodiments described above, the upper and lower spiral passages in each showerhead spiral in the same direction, and each pair of upper and lower spiral passages has the same pitch, number of turns, and number of turns. Each pair of upper and lower spiral passages in such embodiments may function as a flow path for a single corresponding process gas within the showerhead. However, other dual-level spiral passage showerhead embodiments may feature spiral passages with different configurations. For example, in some embodiments, the upper spiral passages may spiral in a first direction, e.g., with a first chirality, and the lower spiral passages may spiral in a second direction, e.g., with a second chirality opposite the first chirality. In some such embodiments, the number of upper spiral passages may differ from the number of lower spiral passages.

[0192] 34 is a side view of an exemplary showerhead having nested two-tiered reverse spiral passages. The showerhead 3400 may have a body 3402 similar to showerheads previously described herein, with sections taken along the two dashed-dotted lines shown in FIG. 34 between exploded sections.

[0193] As shown, the showerhead 3400 has three upper spiral passages 3414a', 3414b', and 3414c', which are provided with respective process gases via inlet ports 3410a, 3410b, or 3410c, respectively. Outlet ports 3412a, 3412b, and 3412c are also shown, but may be blocked or plugged during process gas delivery (or may be omitted entirely, as previously described with respect to other embodiments). The upper spiral passages 3414a', 3414b', and 3414c' spiral outward in a clockwise direction in FIG. 35.

[0194] The showerhead 3400 also has a plurality of lower spiral passages 3414a / b and 3414c that spiral in a counterclockwise direction in FIG. 35. The lower spiral passages 3414a / b and 3414c have a smaller pitch and more turns than the upper spiral passages 3414a', 3414b', and 3414c'. As a result of the reversed chirality of the upper spiral passages 3414a', 3414b', and 3414c' and the lower spiral passages 3414a / b and 3414c, there are a plurality of discrete points where the centerlines of the upper spiral passages 3414a', 3414b', and 3414c' and the lower spiral passages 3414a / b and 3414c intersect with one another. By providing the ascending passages 3415a, 3415b, and 3415c in such locations, each of the upper spiral passages 3414a', 3414b', and 3414c' may be fluidly connected to one of the lower spiral passages 3414a / b and 3414c. The lower spiral passages 3414a / b may have a corresponding plurality of gas distribution holes 3408a / b distributed along their length, and the lower spiral passage 3414c may similarly have a corresponding plurality of gas distribution holes 3408c distributed along their length (e.g., in a spiral hole pattern).

[0195] In the depicted embodiment, there are only two lower spiral passages, namely, lower spiral passage 3414a / b and lower spiral passage 3414c, and there are three upper spiral passages, namely, upper spiral passage 3414a', upper spiral passage 3414b', and upper spiral passage 3414c'. In this particular showerhead design, lower spiral passage 3414a / b is provided with process gases via both upper spiral passage 3414a' and upper spiral passage 3414b' (the a / b callouts for lower spiral passage 3414a / b are to indicate that lower spiral passage 3414a / b receives process gases from both upper spiral passage 3414a' and 3414b'), and lower spiral passage 3414c is provided with process gases only via upper spiral passage 3414c'.

[0196] Such an embodiment allows two or more process gases to be premixed in one of the lower spiral passages in the showerhead 3400, e.g., lower spiral passage 3414 a / b, before being delivered into the processing chamber and flowing over the semiconductor wafer through the gas distribution holes, e.g., gas distribution holes 3408 a / b, and a third process gas may be delivered to the process chamber through the other lower spiral passage, e.g., spiral passage 3414 c, and gas distribution hole 3408 c, without being mixed in the showerhead 3400 prior to being introduced into the process chamber.

[0197] Figure 36 illustrates the intersections between nested spiral passages in a two-tiered reverse spiral passage showerhead. This illustration may more clearly convey the nature of how the upper spiral passages 3614a', 3614b', and 3614c' and the lower spiral passages 3614a and 3614b may intersect with one another, and how the ascending passages 3615a and 3615b may be positioned where the upper spiral passages 3614a' and 3614b' cross over the lower spiral passages 3614a / b, and how the upper ascending passage 3615c may be positioned where the upper spiral passage 3614c' crosses over the lower spiral passage 3614c (Figure 36 is not to scale and is schematic in nature).

[0198] It will be understood that the two-tiered, reverse direction (or reverse chirality) spiral passage showerhead described above with respect to Figures 34 and 35 can be implemented in numerous ways. For example, in some embodiments, the number of upper and lower spiral passages may be equal, while in other embodiments, such as the examples above, the number of upper and lower spiral passages may be different. For example, three, four, five, or six upper spiral passages and two or three lower spiral passages, or four upper spiral passages and three lower spiral passages. It will be understood that when the number of upper and lower spiral passages is different, at least one of the fewer spiral passages (relative to the upper and lower spiral passages) may be fluidly connected to two or more of the more numerous spiral passages (relative to the upper and lower spiral passages) via corresponding ascending passages.

[0199] All of the above embodiments focus on showerheads with internal spiral passages in which the cross-sectional profile of the "top" surface of the passages is generally parabolic or arc-shaped, avoiding flat spots that can be problematic during additive manufacturing of such showerheads. As previously mentioned, another type of showerhead suitable for manufacturing using additive manufacturing techniques is a showerhead with a body having a large internal plenum volume bounded on one side by a first surface and on another (opposite) side by a second surface. Such showerheads may also include a plurality of pillars spanning between the first and second surfaces. The pillars may have outer or sidewalls that transition to the first surface through a curved transition region. A plurality of first gas distribution holes may span between a first side of the body and a second side of the body opposite the first side. Each of the first gas distribution holes may be located within a corresponding one of the pillars. Such showerheads may generally be suitable for providing two separate process gases to a semiconductor wafer during semiconductor processing operations and may be considered to be showerheads that are also showerhead faceplates.

[0200] Figure 37 is a side view of an example showerhead featuring an interior plenum volume having multiple columns extending between its upper and lower surfaces. Figures 38 and 39 are isometric cross-sectional views of the example showerhead of Figure 37 taken along corresponding cut lines in Figure 37.

[0201] As shown, the body 3702 of the example showerhead 3700 of FIG. 37 defines an interior plenum volume 3703 that is bounded at the top by a first surface 3726 and at the bottom by a second surface 3728. A number of posts 3724 each spanning between the first surface 3726 and the second surface 3728 of the interior plenum volume 3703 are distributed relatively densely throughout the interior plenum volume 3703.

[0202] A plurality of first gas distribution holes 3708a may fluidly connect the first side 3704 of the body 3702 and the second side 3706 of the body 3702 by penetrating the body 3702, and each such first gas distribution hole 3708a may penetrate a corresponding one of the posts 3724, thereby allowing the first gas distribution hole 3708a to travel through the body 3702 without fluidly contacting the interior plenum volume 3703. A plurality of second gas distribution holes 3708b may extend from the second surface 3728 to the second side 3706, thereby fluidly connecting the interior plenum volume 3703 with the ambient environment adjacent the second side 3706.

[0203] Each post 3724 may have an exterior surface or surface 3730 that spans between the first and second surfaces of the interior plenum volume, and this exterior surface or surface may transition to the first or second surface of the interior plenum volume through a corresponding curved transition region. Like the curved transition regions of the spiral passage showerheads described above, the curvature of the curved transition region near the side of the body where the gas distribution holes that fluidly connect to the interior plenum volume are located may be less than the curvature of the curved transition region near the other side of the body.

[0204] Figure 40 is a partial cutaway view of a portion of showerhead 3700, revealing multiple posts 3724. Figure 41 is a side cross-sectional view of a representative post 3724, highlighting various features thereof.

[0205] As shown, each post 3724 extends between a first surface 3726 and a second surface 3728 that bound the interior plenum volume 3722 of the body 3702 of the showerhead 3700. Each post 3724 has one or more exterior surfaces 3730. In the depicted example, each post 3724 is axially symmetric, and thus has a single exterior surface 3730 that has a circular cross-section in a plane perpendicular to the central axis of the first gas distribution holes 3708a that extend through the post. However, in other embodiments, the posts 3724 may have an axially asymmetric exterior surface, e.g., a surface that defines a cross-sectional shape in a plane perpendicular to the central axis of the first gas distribution holes that has radial symmetry (e.g., an exterior surface that defines a regular polygon such as a triangle, square, pentagon, hexagon, heptagon, octagon, nonagon, decagon, etc., or another shape, e.g., a trapezoid).

[0206] As can be seen from the representative post 3724 in FIG. 41 , the exterior surface 3730 of the post 4124 may have a first curved transition region 3760 and a second curved transition region 3762. The second curved transition region 3762 is shown as being smaller in size compared to the first curved transition region 3760. However, in other embodiments, the second curved transition region 3762 may be larger than shown in FIG. 41 , or may even be the same size as the first curved transition region 3760. For example, even if a) the second curved transition region 3762 is the same size as the first curved transition region 3760, and b) the first curved transition regions of two or more adjacent posts 3724 merge into one another, there will be locations on the second surface 3728 between the posts 3724 that are generally triangular regions, e.g., in the case of three posts 3724, where the first curved transition region 3760 of each post 3724 is positioned to merge into the first curved transition regions 3760 of the other two posts 3724, where the second surface 3728 will still be flat. If the second gas distribution holes 3708b are positioned to lie within these regions (and the hole placement tolerances are sufficiently precise), there may be little risk of variation in the length of such second gas distribution holes 3708b, since they will be in a position to intersect with the second curved transition region 3762.

[0207] In some embodiments, the pillars 3724 may be spaced closely enough so that the first curved transition region 3760 of each pillar merges into the first curved transition region 3760 of one or more other pillars. In some cases, the pillars 3724 may be arranged in a triangular lattice pattern, e.g., each pillar 3724 (excluding the edge or central pillars 3724 of the pattern) is surrounded by six other pillars 3724 arranged in a circle surrounding that pillar 3724, with the six pillars 3724 surrounding that pillar 3724 all spaced equidistantly from that pillar 3724, and each of the six pillars 3724 surrounding that pillar 3724 being spaced equidistantly the same amount from adjacent ones of the six pillars 3724. In some embodiments, the pillars 1424 may be arranged in a square lattice pattern, subject to similar spacing constraints as described below.

[0208] In some embodiments, the first surface 3726 and the second surface 3728 may be spaced apart from one another by a first amount that is 120% or less of the radius of the first curved transition region. In some additional or alternative such embodiments, the centerline of each pillar may be within 240% (e.g., within 200%-240%) of the radius of the first curved transition region 3760 of the centerline of any pillar 3724 immediately adjacent to it. The pillars 3724 may, in some cases, be generally distributed over a circular area the diameter of a semiconductor wafer (e.g., 300 mm) or greater. In some embodiments, a flat, horizontal area may exist in the "ceiling" of the interior plenum volume between adjacent curved transition regions, but the maximum dimension may be 10 mm or less.

[0209] In the showerhead 3700, the first gas distribution holes 3708a are arranged in multiple concentric circular arrays. The second gas distribution holes 3708b are arranged in identical circular arrays (having identical circumferential spacing and identical radius) such that each second gas distribution hole 3708b is circumferentially positioned between two circumferentially adjacent first gas distribution holes 3708a, and each first gas distribution hole 3708a is circumferentially positioned between two circumferentially adjacent second gas distribution holes 3708b. However, other embodiments of similar showerheads may feature other arrangements of gas distribution holes, as shown in Figures 42-45.

[0210] Figure 42 is a side view of another exemplary showerhead featuring an interior plenum volume having multiple columns extending between its upper and lower surfaces. Figures 43 and 44 are isometric cross-sectional views of the exemplary showerhead of Figure 42 taken along corresponding cut lines in Figure 42. Figure 45 is an isometric cross-sectional view of the exemplary showerhead of Figure 42 taken along corresponding cut lines in Figure 42.

[0211] The example showerhead 4200 of FIGS. 42-45 is identical to the showerhead 3700 of FIG. 37, except that the pillars 4224 are arranged in a triangular lattice pattern, with the first curved transition region 4260 of each pillar 4224 merging into the first curved transition regions 4260 of three or more adjacent pillars 4224. Another difference is that the second gas distribution holes 4208b are generally equidistantly spaced a first distance from the central axes of three adjacent first gas distribution holes 4208a (or, for second gas distribution holes 4208b that are not adjacent to three first gas distribution holes 4208a, they are spaced the same first distance from the center or centers of the first gas distribution holes 4208a adjacent to them).

[0212] In some embodiments, additively manufactured showerheads having pillar structures therein may be configured to provide two or more different gases. For example, some showerheads having pillar structures may be configured to provide three different gases. Two different examples of such showerheads are described below, but it will be apparent that the principles underlying them can also be applied to provide showerheads that can provide more than two different gases, for example, by adding additional internal plenum volumes and pillars.

[0213] FIG. 46 is a perspective view of an excised portion of such a showerhead. FIGS. 47-50 are cutaway perspective views of the excised portion of FIG. 46. For example, FIG. 47 shows the excised portion of the showerhead with material below dash-dotted line (1) removed, and FIG. 48 shows the excised portion of the showerhead with material above dash-dotted line (1) removed. Similarly, for example, FIG. 49 shows the excised portion of the showerhead with material below dash-dotted line (2) removed, and FIG. 50 shows the excised portion of the showerhead with material above dash-dotted line (2) removed.

[0214] 46, the showerhead 4600 has a body 4602 having a first interior plenum volume 4622a and a second interior plenum volume 4622b located therein. The body 4602 has a first side 4604 and a second side 4606 opposite the first side 4604. The first interior plenum volume 4622a can be bounded at an upper portion by a first surface 4626 and at a bottom portion by a second surface 4628. Similarly, the second interior plenum volume 4622b can be bounded at an upper portion by a third surface 4632 and at a bottom portion by a fourth surface 4634.

[0215] The showerhead 4600 may have multiple pillars 4624 therein, each pillar 4624 located within one of the interior plenum volumes 4622. For example, the first interior plenum volume 4622a may have a first pillar 4624a and a second pillar 4624b therein, and the second interior plenum volume 4622b may have a third pillar 4624c therein. Each of the third pillars 4624c may generally correspond in position to one of the first pillars 4624a such that each of the first gas distribution holes 4608a that passes through one of the first pillars 4624a also passes through a corresponding one of the third pillars 4624c. Thus, the first gas distribution holes 4608a may span between the first side 4604 and the second side 4606 of the main body 4602, with each such first gas distribution hole or hole 4608a penetrating both the corresponding first column 4624a and the corresponding third column 4624c, fluidly isolating that first gas distribution hole or hole 4608a from the first internal plenum volume 4622a and the second internal plenum volume 4622b.

[0216] The showerhead 4600 may also include second gas distribution holes 4608b each spanning between the second surface 4628 and the second side 4606, and third gas distribution holes 4608c each spanning between the fourth surface 4634 and the second side 4606. Each of the third gas distribution holes 4608c may extend through a corresponding one of the second posts 4624b, which may act to fluidically isolate the corresponding third gas distribution hole or port 4608c from the first interior plenum volume 4622a.

[0217] Such an arrangement allows a first gas to flow into an exterior plenum volume (not shown, but see for example FIG. 19 ) and be distributed from the second side 4606 of the showerhead 4600 via first gas distribution holes 4608 a, a second gas flowed into the first interior plenum volume 4622 a to be distributed from the second side 4606 of the showerhead 4600 via second gas distribution holes 4608 b, and a third gas flowed into the second interior plenum volume 4622 b to be distributed from the second side 4606 of the showerhead 4600 via third gas distribution holes 4608 c. Each such gas stream may be kept fluidly isolated from other gas streams within the showerhead 4600, and may potentially mix only after such gases exit the showerhead 4600.

[0218] 47 and 49, the first surface 4626 and the third surface 4632 forming the "ceiling" of the first interior plenum volume 4622a and the second interior plenum volume 4622b may be non-planar and exhibit some subtle contours. The first pillar 4624a and the second pillar 4624b may each span between the first surface 4626 and the second surface 4628, and the third pillar 4624c may each span between the third surface 4632 and the fourth surface 4634.

[0219] 47 and 48, the third pillars 4624c (and corresponding first pillars 4624a) and third gas distribution holes 4608c may be arranged in corresponding square grid patterns, with the square grid pattern for the third gas distribution holes 4608c oriented at a 45° angle relative to the square grid pattern for the third pillars 4624c. Similarly, and as can be seen in FIG. 50, the second pillars 4624b and corresponding third gas distribution holes 4608c may also be arranged in a square grid pattern that is the same size and oriented in the same direction as the square lattice pattern for the third gas distribution holes 4608c (but laterally offset from the other square lattice patterns).

[0220] 51 is a plan view of a portion of the showerhead 4600 with the first side 4604 removed, revealing the interior of the second interior plenum volume 4622b. The third posts 4624c and the first gas distribution holes 4608a are also visible in the exposed portion of the second interior plenum volume 4622b. The second posts 4624b, the second gas distribution holes 4608b, and the third gas distribution holes 4608c are also shown, but are shown in dotted outline because they are located within the first interior plenum volume 4622a and therefore would not normally be visible from this perspective. The first posts 4624a are not visible here, but are each located directly below one of the third posts 4624c. As shown, each first pillar 4624a in the depicted portion of the showerhead 4600 is located at the center of a unit cell of a square array (the dashed square grid represents the square array), and two second pillars 4624b are disposed within that unit cell on opposite sides of the first pillar 4624a along a first axis 4636a parallel to a first direction 4638a, e.g., such that the first pillar 4624a is positioned between the two second pillars 4624b. Each unit cell of the depicted portion of the showerhead 4600 also includes two second gas distribution holes 4608a disposed on opposite sides of the first pillar 4624a of that unit cell along a second axis 4636b parallel to the second direction 4638b. The first direction 4638a and the second direction 4638b may be perpendicular to one another in some embodiments, while in other embodiments the angle between the first direction 4638a and the second direction 4638b may be an oblique angle. Generally speaking, the second direction 4638b may be transverse to the first direction 4638a (or vice versa). Furthermore, the array axes 4680a and 4680b of the square array may be at a 45° angle with respect to the first direction 4638a and / or the second direction 4638b.

[0221] 51 , in some embodiments, the second pillars 4624b in each unit cell of the square array are the two pillars 4624 that are closest to the first pillar 4624a in that unit cell in the first interior plenum volume 4622a. Similarly, the second gas distribution holes 4608b in each unit cell of the square array are, in some embodiments, the two second gas distribution holes that are closest to the first pillar 4624a in the first interior plenum volume 4622a. In some embodiments, the centers or central axes of the second pillars 4624b and second gas distribution holes 4608b in each unit cell of the square array may be equidistantly spaced from the center or central axis of the first pillar 4624a of that unit cell.

[0222] 46-50, as previously described, has a contoured first surface 4626 and a contoured third surface 4632. A portion of the third surface 4632 and first surface 4626 are shown in plan view in FIGS. 52 and 53, respectively.

[0223] The contours used on the first surface 4626 and the third surface 4632 may be optimized for ease of modeling, manufacturing, and implementation. For example, a showerhead such as the depicted showerhead 4600 may feature a large number of posts 4624 that connect to a top surface that bounds an interior plenum volume 4622 within which such posts 4624 are located. If the interface between the posts 4624 and such a top surface is curved to the extent that there is little or no portion of the top surface that is flat and horizontal, the resulting shape may be too complex to model in a conventional solid modeling program (or, even if it could be modeled, it may be so computationally intensive that interacting with the model may consume an unnecessarily long time). However, when using a voxel-based modeling program, such as the software of the same name from nTopology, Inc. ("nTopology"), the contours where each post 4624 joins with the top surface of the interior plenum volume 4622 in which it is located may be defined according to a scalar function that can be defined in a fraction of the time (and more reliably) that might be required to define a similar contour in a traditional solid modeling program. At the same time, the resulting surface contours avoid the presence of generally flat and horizontal overhanging surfaces on the component (thereby avoiding problems encountered in additive manufacturing with such shapes) and result in a generally smooth surface that is less susceptible to erosion or particulate generation during use.

[0224] For example, in nTopology, scalar field characteristics can be applied to a component model in which a particular model value is determined according to a scalar function for each point or feature in an array of points or features. While this scalar function may be applied equally to all points or features, a model value determined using the scalar function associated with a particular point or feature may be determined only within the relief region associated with that point or feature. Such a relief region may be bounded, for example, by a boundary edge or plane that is typically perpendicular to and bisects a reference line extending from the center of the point or feature to the center of the pillar adjacent to that point or feature. Generally speaking, only the potential boundary edge closest to the pillar of interest defines the boundary of the relief region. Thus, the relief region may typically take the form of a polygon with each side equidistant from the particular pillar of interest and its adjacent pillars. Each relief region typically encloses a corresponding portion of the first surface 4626 or the third surface 4632, with the enclosed portion of the surface having a profile determined by applying the scalar function to the pillars within the relief region.

[0225] In FIG. 52, a single undulating region 4678 is shown having a square shape. It can be readily seen that each side of the square undulating region 4678 is equidistantly spaced between a third column 4624c within that undulating region 4678 and the four nearest surrounding third columns 4624c. In FIG. 53, three undulating regions 4678a and 4678b are shown (there are two undulating regions 4678b that are mirror images of each other). Here, it can be seen that undulating regions 4678a and 4678b are more complex than undulating region 4678, e.g., having a non-uniform hexagonal shape. In either case, it can be seen that the boundaries between undulating region 4678 and undulating regions 4678a / b generally correspond to valleys in the undulations of third surface 4632 and first surface 4626, respectively. The boundaries of relief region 4678 and relief regions 4678a / b may typically define limits for how far from each pillar the scalar function is applied. In other words, the scalar function is used for each pillar only to determine the model values ​​for points that are within that pillar's relief region. Model values ​​for points located outside that relief region are determined by applying the scalar function to the other pillar. The boundaries of the two relief regions are typically equidistant from both pillars within those relief regions, so the model values ​​determined using the scalar function at either relief region will typically coincide at the boundary because the input (distance from the pillar central axis) is the same for both pillars at that boundary location.

[0226] In the case of a showerhead, the model value determined according to the scalar function may be a first distance between the top surface of the interior plenum volume 4622 and a reference plane (e.g., the reference plane defined by the second side 4606). A scalar function may be defined that determines the value of the first dimension as a function of distance from the central axis of any given pillar in the set of pillars. For example, the scalar function may be configured to increase the first distance as a function of increasing the second distance from the given pillar in a direction perpendicular (or horizontal) to the central axis of that pillar. For example, the scalar function may be set to vary the first distance between X and Y millimeters, with the scalar function having an X value at the center of the given pillar and a Y value at the outermost edge or point of the relief region from the center of the given pillar. In some embodiments, the scalar function may be defined to vary the first distance between X and Y such that the radial profile defined by the scalar function relative to the central axis of a given pillar is smooth (without sharp corners) and tangent to a horizontal reference axis or line both at the central axis (or at a location within the given pillar) and at a value of the second distance equal to the maximum value that the second distance can have for any of the pillars to which the scalar field is applied before exiting the undulation region of that pillar. In other words, the undulations created for any given pillar using the scalar function may curve upward as one moves away from the given pillar and downward as one approaches the outer edge of the undulation region of the given pillar. In some embodiments, the scalar function may be axially symmetric relative to the central axis of a given pillar, e.g., producing the same value for the first distance at a given value of the second distance for a given pillar, regardless of the orientation along which a defined point is located.

[0227] FIG. 54 helps to illustrate this. Shown in FIG. 54 is the arrangement of a first column 4624a and a second column 4624b, along with one of the undulating regions 4678b. The right side of FIG. 54 shows four cross-sectional profiles, each corresponding to a cross-section taken along one of the dotted lines extending from a second column 4624b located within the undulating region 4678b to one of the four solid first or second columns 4624 surrounding that second column 4624b, with a corresponding circled numerical callout adjacent to the dotted line. The solid portion of each cross-section corresponds to the portion of the cross-section that is within the undulating region 4678b, and the dotted portion of each cross-section corresponds to the portion of the cross-section that is outside the undulating region 4678b. It will be appreciated that the cross-sectional view is simplified and does not include features related to the second interior plenum volume.

[0228] Also visible in the cross-sectional view of FIG. 54 are a first distance 4684 and a second distance 4686. The first distance 4684 is measured from the second side of the showerhead to the cross-sectional profile defined by the scalar function. In each case, the first distance 4684 and the second distance 4686 are shown as two pairs of first distances 4684a and 4684b and second distances 4686a and 4686b. The first distance 4684a and the second distance 4686a define the inner edge of the cross-sectional profile, and the first distance 4684b and the second distance 4686 define the outer edge of the cross-sectional profile. As is apparent from FIG. 54, each cross-sectional profile has the same contours as the other cross-sectional profiles to the extent that they overlap.

[0229] In some embodiments, the values ​​of X and Y may be selected such that the difference between X and Y is within 20%-30% of the maximum distance between the central axis of any pillar to which the scalar function is applied and the outermost edge or point of the pillar's relief region. Surfaces defined according to such scalar functions may generally be suitable for additive manufacturing using, for example, LBPF, while avoiding sharp interior edges and minimizing or reducing the increase in volume within each interior plenum volume, thereby reducing the amount of dead space within each such plenum volume that may require venting.

[0230] It will be appreciated, of course, that slight deviations in the first distance may occur near the boundaries of the undulating region and where columns within the undulating region meet the contoured surface. For example, small fillets or curves may be applied to any discontinuities (e.g., sharp edges) to smooth the interior of the associated interior plenum volume and reduce the likelihood of particulate generation or collection within the showerhead. Thus, for example, the last 10% at either end of the undulation described by the scalar function may not necessarily adhere to the first distance determined using the scalar function.

[0231] The contouring implementations described above may be applied to any of the pillar-based showerhead designs described herein, for example, those described above as well as additional examples below with respect to Figures 55-58.

[0232] Figure 55 is similar to Figure 51 but shows a portion of an example showerhead 5500 in which the posts 5524 are arranged in a hexagonal grid pattern as opposed to a square pattern. Figures 56-58 are perspective views of a portion of the showerhead 5500, with Figures 57 and 58 being cutaway views showing the interior of each interior plenum volume.

[0233] 56 , the showerhead 5500 may include a body 5502 having a first interior plenum volume 5522a and a second interior plenum volume 5522b therein, both located between a first side 5504 and a second side 5506 of the body 5502. The first interior plenum volume 5522a may be bounded by a first surface 5526 and a second surface 5528, and the second interior plenum volume 5522b may be bounded by a third surface 5532 and a fourth surface 5534.

[0234] Like the example showerhead 4600, the showerhead 5500 may also have multiple pillars 5524 therein, each of the pillars 5524 positioned within one of the interior plenum volumes 5522. For example, the first interior plenum volume 5522a may have a first pillar 5524a and a second pillar 5524b therein, and the second interior plenum volume 5522b may have a third pillar 5524c therein. Each of the third pillars 5524c may generally correspond in position to one of the first pillars 5524a, such that a first gas distribution hole 5508a passing through one of the first pillars 5524a also passes through a corresponding one of the third pillars 5524c. Thus, the first gas distribution holes 5508a may span between the first side 5504 and the second side 5506 of the main body 5502, with each such first gas distribution hole or hole 5508a penetrating both the corresponding first pillar 5524a and the corresponding third pillar 5524c, fluidly isolating that first gas distribution hole or hole 5508a from the first internal plenum volume 5522a and the second internal plenum volume 5522b.

[0235] The showerhead 5500 may also include second gas distribution holes 5508b each spanning between the second surface 5528 and the second side 5506, and third gas distribution holes 5508c each spanning between the fourth surface 5534 and the second side 5506. Each of the third gas distribution holes 5508c may extend through a corresponding one of the second posts 5524b, which may act to fluidically isolate the corresponding third gas distribution hole or port 5508c from the first interior plenum volume 5522a.

[0236] 55-58, showerhead 5500 differs from showerhead 4600 in that first pillars 5524a and second pillars 5524b are arranged in two staggered triangular lattice patterns with opposite orientations, with three adjacent pairs of first pillars 5524a and second pillars 5524b forming a hexagonal pattern of pillars 5524 centered on a corresponding one of second gas distribution holes 5508b. Meanwhile, third pillars 5524c may form a triangular lattice pattern that is the same size, orientation, and location as the triangular lattice pattern of first pillars 5524a.

[0237] In some embodiments, the three pillars 5524 closest to each first pillar 5524a are all second pillars 5524b, which are equidistantly spaced from the central axis of that first pillar 5524a and equidistantly spaced from each other. In some cases, the three second gas distribution holes 55 closest to each first pillar 5524a may also be equidistantly spaced from the central axis of that first pillar 5524a, equidistantly spaced from each other, and equidistantly spaced from the three second pillars 5524b closest to that first pillar 5524a.

[0238] Further variations of showerheads having pillars spanning the upper and lower surfaces of one or more internal plenums are shown in Figures 59-63. Figure 59 is a top view of an exemplary showerhead having two edge-fed internal plenums, with pillars between the upper and lower surfaces of each plenum. Figure 60 is a side view of the exemplary showerhead of Figure 59. Figure 61 is an isometric exploded cross-sectional view of the exemplary showerhead of Figure 59, with the cutting plane used to define the cross section taken along the dashed-dotted line in Figure 60. Figure 62 is a detailed view of the portion of the exemplary showerhead of Figure 61 within the dashed-dotted rectangle on the left side of Figure 61. Figure 63 is a detailed view of the portion of the exemplary showerhead of Figure 61 within the dashed-dotted rectangle on the right side of Figure 61.

[0239] As can be seen in FIG. 59 , the showerhead 5900 can feature a body 5902, which can include one or more first inlet ports 5910 a (a single first inlet port 5910 a is shown in FIG. 59 ) and one or more second inlet ports 5910 b (four second inlet ports 5910 b are shown in FIG. 59 ). The showerhead 5900, in this example, is a multi-piece showerhead, having a first body 202 a and a second body 202 b assembled together, for example, using threaded fasteners, to form an assembled showerhead. Such an approach allows the showerhead to be disassembled for easier and / or more effective cleaning. Such an approach also allows the first body 202 a and the second body 202 b to be made of different materials; for example, the first body 202 a can be made of stainless steel and the second body 202 b can be made of a ceramic material such as aluminum oxide. However, it will be understood that the showerhead 5900 may also be made as a single piece component, for example, by additive manufacturing or layered construction (where multiple individual layers of material are bonded together such that the assembled showerhead cannot be non-destructively disassembled).

[0240] As can be seen in FIG. 61 , the showerhead 5900 includes a plurality of first radial spoke passages 5933a. Each first radial spoke passage 5933a may have a first end aligned with one of the first inlet ports 5910a and a second end positioned radially outward from the first end and terminating in a corresponding first arcuate plenum 5929a. The showerhead 5900 also includes a plurality of second radial spoke passages 5933b. Each second radial spoke passage 5933b may have a first end aligned with a second inlet port 5910b and a second end positioned radially outward from the first end and terminating in an ascending passage leading to a corresponding second arcuate plenum 5929b. The first radial spoke passages 5933a and second radial spoke passages 5933b may be arranged in a circumferentially alternating pattern, for example, a first / second / first / second radial passage repeat.

[0241] A first process gas introduced into the showerhead 5900 through a first inlet port 5910a flows radially outward through first radial spoke passages 5933a into a first arcuate plenum 5929a and then through the shaded zone 5929a′ into the first plenum volume 5903a. In other words, the first plenum volume 5903a may be fluidly connected to one or more first inlet ports 5910a in the body 5902 by the first radial spoke passages 5933a.

[0242] The first process gas may then flow throughout the first plenum volume 5903a before exiting the first plenum volume 5903a via a plurality of first gas distribution holes 5908a (see FIG. 62 ). The first plenum volume 5903a, in this example, includes a plurality of first columns 5924a, which are distributed throughout the first plenum volume 5903a, for example, in a plurality of concentric circular patterns, and which span or extend between upper and lower surfaces that at least partially bound the first plenum volume 5903a. Such first columns 5924a may serve to provide structural rigidity to the showerhead 5900 and may also help distribute the flow of the first process gas more evenly throughout the first plenum volume 5903a and may act to more efficiently transfer heat between the bottom of the showerhead 5900 and the top of the showerhead 5900. In some embodiments, the first pillars 5924a may be omitted, for example, if increased thermal conduction between the bottom of the showerhead 5900 and the top of the showerhead 5900 is not needed and / or if the first plenum volume 5903a of the showerhead 5900 has sufficient structural rigidity to obviate the need for the first pillars 5924a.

[0243] Similarly, a second process gas introduced into the showerhead 5900 through the second inlet port 5910b flows radially outward through the second radial spoke passages 5933b before flowing through an upflow passage into the second arcuate plenum 5929b. The second arcuate plenum 5929b may be, for example, a portion of the second plenum volume 5903b. As can be seen in FIG. 63 , the second arcuate plenum 5929b may be partially defined by a first arcuate element 5928. The first arcuate element 5928 may be, for example, an arcuate wall separating the second arcuate plenum 5929b from the remainder of the second plenum volume 5903b. In other words, the second arcuate plenum 5929b may be considered a sub-plenum of the second plenum volume 5903b. In some embodiments, the second arc-shaped plenum 5929b may be replaced with a non-arcuate plenum, for example, a rectangular or triangular plenum. The first plenum volume 5903a and the second plenum volume 5903b may both be located between a first side and a second side of the body, with the first plenum 5903a located between the second plenum 5903b and the first side and the first plenum 5903a located between the second plenum 5903b and the second side. The second plenum volume 5903b may be fluidly connected to one or more second inlet ports 5910b in the body 5902. The first and second gas distribution holes 5908a and 5908b may, for example, extend from the first and second plenum volumes 5903a and 5903b, respectively, to a second side of the body 5902, thereby allowing process gases flowed through the first and second plenum volumes 5903a and 5903b to exit the underside of the showerhead 5900.

[0244] The depicted arrangement features both the first inlet port 5910a and the second inlet port 5910b located in a common central region of the body 5902. The first arcuate plenum 5929a, as well as the first arcuate element 5928 and the second arcuate plenum 5929b, may be arranged in an arcuate array about the central axis of the showerhead 5900, e.g., around the central region, as shown.

[0245] Each first arcuate element 5928 may have a plurality of first openings 5930 extending radially inward through that first arcuate element 5928, thereby fluidly connecting the corresponding second arcuate plenum 5929b with the remainder of the second plenum volume 5903b. In this example, each first arcuate element 5928 has two openings 5930 located at opposite ends of the corresponding second arcuate plenum 5929b.

[0246] The second plenum volume 5903b in this example may also include second arcuate elements 5931 arranged in a circular array and concentrically and radially inwardly of the first arcuate elements 5928, thereby forming a radial gap between the first arcuate elements 5928 and the second arcuate elements 5931. Each second arcuate element 5931 may be separated from an adjacent second arcuate element 5931 by a second opening 5932. Thus, when a second process gas is flowed into the second plenum volume 5903b via the second arcuate plenum 5929b, the second process gas first flows into an annular sub-plenum region bounded (at least in part) between the first arcuate element 5928 and the second arcuate element 5931. The second process gas then flows through the second opening 5932 and reaches the interior region of the second plenum volume 5903b.

[0247] It can be seen that there are N first arcuate elements 5928 and second arcuate plenums 229a and 2N first apertures 5930, and 4N second arcuate elements 5931 and 4N second apertures 5932 (N is 4 in this example). It can further be seen that each second arcuate element 5931 is azimuthally aligned such that the center of that second arcuate element 5931 is azimuthally co-located with, or azimuthally centered on, one of the first apertures 5930. "Azimuthally centered" will be understood to refer to elements that are centered about a common center point being aligned such that an element that is azimuthally centered with respect to another element has its center points positioned along the same radius extending from the common center point.

[0248] It can also be seen that all of the first arcuate elements 5928 are the same size, and all of the second arcuate elements 5931 are the same size. This arrangement has the effect of providing multiple gas flow introduction points all around the periphery of the second plenum volume 5903b, all of which generally have equivalent flow resistances, because the shortest flow path (in terms of fluid path length) from any second opening 5932 to its nearest second inlet port 5910b will generally have an equivalent flow path length (and fluid resistance) as the shortest flow path from any other second opening 5932 to its nearest second inlet port 5910b. Such an arrangement has the effect of dividing the gas flow introduced into each first arcuate plenum 5929b into two generally equal-sized gas streams, and then further dividing each of the generally equal-sized gas streams into two more generally equal-sized gas streams, thereby segmenting the second process gas flow into 4N generally equal gas streams spaced equidistantly around the circumference of the second plenum volume 5903b. This may help ensure more azimuthal uniformity in the flow of the second process gas from the second plenum volume 5903b through the second gas distribution holes 5908b. As will be further understood, the flow of the second process gas may be further uniformed azimuthally by including one or more additional concentric rings to further subdivide the flow of the second process gas. For example, each arc-shaped element in such a ring of additional arc-shaped elements may be azimuthally centered in one of the openings between the arc-shaped elements in the ring of arc-shaped elements that is immediately radially outward from that ring of additional arc-shaped elements.

[0249] As shown, the second plenum volume 5903b also features a plurality of second pillars 5924b extending between the top and bottom surfaces of the second plenum volume 5903b. Each of the second pillars 5924b has one of the first gas distribution holes 5908a extending therethrough, thereby providing a flow path from the first plenum volume 5903a through the second plenum volume 5903b without mixing the first process gas in the first plenum volume 5903a with the second process gas in the second plenum volume 5903b within the showerhead 5900.

[0250] The first plenum volume 5903a may also, in some embodiments, feature an arrangement of arc-shaped elements similar to the second plenum volume 5903b, for example, to form one or more annular sub-plenum regions each having a circular array of evenly spaced openings that allow the first process gas to flow radially inward in a more evenly distributed manner.

[0251] The showerhead 5900 features dual gas plenums, each edge-fed, i.e., where process gases introduced into each gas plenum are introduced into the respective plenum volume at multiple locations around the periphery of the plenum volume. However, such showerheads may also be implemented with center-fed plenum volumes.

[0252] For example, FIG. 64 is an isometric, exploded cross-sectional view of an exemplary showerhead similar to that shown in FIGS. 59-63 , except that one of the interior plenums is center-fed and lacks a column spanning its top and bottom. As shown, the showerhead 6400 shown in FIG. 64 includes a first plenum volume 6403 a and a second plenum volume 6403 b therein. The second plenum volume 6403 b may be similar to the second plenum volume 5903 b of the exemplary showerhead 5900 described above with respect to FIGS. 59-63 . Elements in the embodiment of FIG. 64 that are similar to those in the embodiment of FIGS. 59-63 are labeled in FIG. 64 with the same last two digits. It will be understood that the descriptions of such elements presented above with respect to FIGS. 59-63 are equally applicable to the embodiment of FIG. 64 . Therefore, such elements will not be described again here unless necessary.

[0253] While the second plenum volume 6403b is generally identical to the second plenum volume 5903b, the first plenum volume 6403a of the showerhead 6400 is entirely different from the first plenum volume 5903a. For example, the first plenum volume 5903a includes a plurality of first pillars 5924a, while the first plenum volume 6403a does not have any first pillars 5924a. However, it will be understood that the first plenum volume 6403a may still include a plurality of first pillars in some embodiments, similar to the embodiments of FIGS. 59-63.

[0254] The first plenum volume 6403a may also not include or be associated with a first arcuate plenum at all. Instead, the first process gas may enter the center of the first plenum volume 6403a through one or more first inlet ports 6410a located near the center and on the top surface of the showerhead. In the depicted embodiment, there are multiple first inlet ports 6410a arranged in a circular array about the central axis of the showerhead 6400. However, other embodiments may feature only a single centrally located inlet port 6410a. In some other embodiments, there may be multiple inlet ports 6410a located closer to the edges of the first plenum volume 6403a.

[0255] A second process gas may be introduced into the second plenum volume 6403b through a second inlet port 6410b, which is shown to be located near the periphery of the showerhead 6400. However, it will be understood that the showerhead 6400 may also feature an inlet port arrangement similar to that of the showerhead 5900. For example, the top of the showerhead 6400 may have a first inlet port 6410a and a second inlet port 6410b, both located near the central axis of the showerhead 6400. In such an embodiment, the second inlet port 6410b may be joined to an uprising passageway located outside the first plenum volume 6403a and leading to the second plenum volume 6403b, for example, by a radial spoke passageway similar to the second radial spoke passageway 5933b.

[0256] As previously mentioned, the flow conductance and / or spacing of gas distribution holes along the spiral path of a showerhead having a spiral passageway may be modified to have varying spacing and / or size (e.g., diameter) to form radial zones in which gas flow may be increased or decreased relative to other radial zones. Showerheads featuring post features as described above may similarly be designed with radially varying port sizes (e.g., diameters) and / or radially and / or circumferentially varying spacing to provide increased or decreased gas flow at different radial distances from the central axis of the showerhead.

[0257] As alluded to above, the showerheads described above may be suitable for use in the context of semiconductor processing due to features they contain, such as the ability to generally uniformly distribute one or more process gases over a large area, e.g., an area similar in size to (or larger than) a semiconductor wafer. At the same time, such showerheads may include features that reduce, minimize, or eliminate horizontal surfaces that are not supported from below (e.g., in the same orientation as the showerhead is used), thereby making such components more suitable for fabrication using additive manufacturing techniques, such as selective laser melting (SLM) or direct metal laser melting (DMLM), or other LPBF techniques. Furthermore, such components may be made from metallic materials that are compatible with the process gases (or are adapted for application of appropriate coating materials) that are configured to be delivered by such components. Examples of materials include aluminum alloys coated with an aluminum oxide coating, high-nickel alloys such as Hastelloy C22 (a nickel-chromium-molybdenum superalloy having, by weight, <0.015% C, 20%-22.5% Cr, 2%-6% Fe, ≦0.5% Mn, ≦0.08% Si, 12.5%-14.5% Mo, ≦2.5% Co, ≦0.02% P, ≦0.02% S, ≦0.35% V, 2.5%-3.5% W, and the balance Ni), or other suitable materials.Other potentially suitable materials include Inconel 625 (a nickel-chromium alloy having, by weight, <0.1% C, 20%-30% Cr, ≤5% Fe, ≤0.5% Mn, ≤0.5% Si, 8%-10% Mo, ≤1% Co, ≤0.015% P, ≤0.015% S, ≤0.4% Al, ≤0.4% Ti, 3.15%-4.15% Nb(+Ta), and the remainder Ni), or Inconel 718 (nickel-chromium alloy having, by weight, <0.1% C, 20%-30% Cr, ≤5% Fe, ≤0.5% Mn, ≤0.5% Si, 8%-10% Mo, ≤1% Co, ≤0.015% P, ≤0.015% S, ≤0.4% Al, ≤0.4% Ti, 3.15%-4.15% Nb(+Ta), and the remainder Ni). Examples of suitable materials include aluminum-chromium alloys having, by weight, <0.08% C, 17%-21% Cr, 17% Fe, ≦0.35% Mn, ≦0.35% Si, 2.8%-3.3% Mo, ≦1% Co, ≦0.015% P, ≦0.015% S, 0.2%-0.8% Al, 0.65%-1.15% Ti, 4.75%-5.5% Nb(+Cb), ≦0.006% B, ≦0.3% Cu, and the balance Ni. For showerheads used as electrodes in semiconductor process tools, such materials may typically include any metallic conductive material suitable for use in additive manufacturing processes and chemically resistant or inert to process gases used in the semiconductor process chamber in which the showerhead is used.

[0258] As previously mentioned, due to additive manufacturing process-induced surface roughness that occurs on additively manufactured components, it may be necessary or desirable to perform post-additive manufacturing processing on the additively manufactured showerhead to abrade, polish, or machine such surfaces to a finer surface finish. For example, it may be desirable to flow an abrasive slurry or paste through the spiral passages (or internal plenum volume) of the showerhead to remove potential sharp discontinuities in the internal surface. Such a flow may be introduced, for example, through an inlet port in the showerhead in much the same way that process gases can be delivered to a showerhead. Separate outlet ports may be provided at opposite ends (or both ends) of the internal cavity to be polished. Once polishing is complete, the outlet ports may optionally be sealed to prevent process gases introduced into the internal cavity from escaping the internal cavity.

[0259] Surfaces of the showerhead that are externally accessible to a tool, such as the gas distribution holes and the exterior surface of the showerhead, may be subjected to machining and / or polishing operations to make such surfaces suitable for use in a semiconductor processing chamber. For example, the exterior surfaces of such showerheads may be machined using milling, turning, or other suitable processes to remove a thin layer of material to achieve a desired surface finish after additive manufacturing is complete. Such surfaces may also be lapped or polished, if desired.

[0260] The gas distribution holes may be machined, for example, partially or fully, using post-additive manufacturing operations. For example, in some embodiments, the gas distribution holes may be formed during the additive manufacturing process as full-depth or partial-depth holes with a smaller diameter than their final form and may serve as pilot holes to guide post-additive manufacturing drilling operations. In other embodiments, the additively manufactured showerhead may not have gas distribution hole features after additive manufacturing is completed. In such cases, the gas distribution holes may instead be fully machined into the showerhead using post-additive manufacturing machining operations, such as mechanical drilling or electro-discharge drilling. Such operations ensure that the gas distribution holes have a uniform (or desired) diameter or size along their central axes, thereby allowing for more predictable gas flow through the gas distribution holes than if the gas distribution holes were fully additively manufactured. The gas distribution holes may be, for example, 0.010 inches to 0.040 inches in diameter in some embodiments, but may be larger in some embodiments.

[0261] Although the embodiments described herein are designed to be suitable for fabrication using additive manufacturing techniques, they may also be fabricated using more traditional manufacturing techniques. For example, internal showerhead features may be machined into a plate, and then the surface of that plate having those features may be brazed, welded, diffusion bonded, or otherwise joined to another plate to finish off those features into the showerhead's internal features. In such embodiments, features described above to facilitate or accommodate additive manufacturing processes may be omitted. For example, a traditionally machined showerhead may include horizontal, flat surfaces that form the "ceiling" of the internal plenum volume and / or gas passages within the showerhead, which may present manufacturing challenges if included in an additively manufactured version. Similarly, the gas passages in such a showerhead may have sharp (or much smaller radius) internal corners.

[0262] FIG. 65 shows an example of a showerhead 6500 manufactured using such traditional machining techniques, e.g., subtractive manufacturing. For example, the showerhead 6500 may be made from two pieces, an upper piece 6500a and a lower piece 6500b, as shown in the top half of FIG. 65. The lower piece 6500b may have, for example, a spiral channel machined therein, while the upper piece 6500a may generally be a flat plate (potentially with raised features on one side, e.g., for an inlet port). The upper piece 6500a may then be glued, brazed, welded, or otherwise joined to the lower piece 6500b to cap the spiral channel, resulting in the internal spiral passage of the showerhead 6500, as shown in the bottom half of FIG. 65. This, of course, is just one example of how a showerhead such as that described herein may be manufactured using traditional manufacturing techniques.

[0263] It will be further understood that such a showerhead may be fabricated as a laminated ceramic structure using one or more ceramic plates machined or formed by other methods, such as pressing, to have features such as, for example, an open spiral channel (similar to the embodiment described in FIG. 65) or an open plenum with multiple pillars extending therethrough (similar to the embodiments of FIGS. 37-58). Such single or multiple ceramic plates may then be bonded to another ceramic plate and / or to each other to cap such open channel features or plenum volumes containing pillars to form a sealed passageway or sealed plenum. For example, such ceramic plates may be bonded by sintering the ceramic plates together. Such an approach may be used to provide a multi-plenum structure in which there are multiple tiers of such passageways or plenum volumes at different heights, with the plenum volumes or passageways at each height provided by a similarly machined or formed ceramic plate as the bottom piece 6500b that is then bonded to either another such bottom piece 6500b or the top piece 6500a. It will also be understood that the channel features shown in FIG. 65 as being machined or formed in the bottom piece 6500b (or the plenum / column features that may be machined or formed in such bottom pieces for showerheads such as those shown in FIGS. 37-58) may instead or additionally be machined or formed in the top piece 6500a.

[0264] It will be understood that characterizations of how the various pillars and / or gas distribution holes are arranged as described herein, such as those referring to "each pillar" or "each gas distribution hole or port," may be general characterizations and may, for example, apply only to a set of such pillars and / or gas distribution holes, e.g., pillars and / or gas distribution holes located within the interior plenum volume as opposed to near the outer periphery (e.g., at some point, any repeating pattern of pillars and / or gas distribution holes must end, at which point the characteristics of the repeating pattern that match the pattern instances within the pattern no longer match at the outer edge of the pattern).

[0265] The showerheads described herein may be used in semiconductor processing chambers to deliver various reactants to a processing space above a semiconductor wafer being processed. FIG. 66 shows a schematic of such a chamber. As can be seen in FIG. 66, a semiconductor processing tool may include a processing chamber 6688, which may enclose an interior volume 6689. The processing chamber 6688 may include a showerhead 6600, which may be, for example, any of the showerheads described herein (the example depicted is a showerhead similar to showerhead 500, although it will be understood that other showerheads disclosed herein may be used in place of this particular design). In this example, the showerhead 6600 is a flush-mounted showerhead, e.g., a showerhead that is attached to the chamber and acts as a lid, sealing a large opening, e.g., an opening sized larger than the diameter of the semiconductor wafer 6692, and serving as the "ceiling" or part of the ceiling of the processing chamber 6688. In other embodiments, the showerhead may be supported within the interior volume 6689 by a vertical column or stem that extends into the interior volume 6689 through an aperture in the ceiling of the processing chamber 6688; such a showerhead is typically referred to as a "chandelier showerhead."

[0266] The showerhead 6600 is a dual-plenum showerhead having a first spiral passageway 6614a and a second spiral passageway 6614b. One or more first process gases may be provided to the first spiral passageway 6614a via a first inlet port 6610a, which is fluidly connected to a first gas supply 6696a via a first valve 6698a. Similarly, one or more second process gases may be provided to the second spiral passageway 6614b via a second inlet port 6610b, which is fluidly connected to a second gas supply 6696b via a second valve 6698b. A controller 6699 may be provided and may be configured to communicate with and control the first valve 6698a and the second valve 6698b to selectively enable or disable gas flow to either or both of the first spiral passage 6614a and the second spiral passage 6614b. Gases flowing into the first spiral passage 6614a or the second spiral passage 6614b may exit the first spiral passage 6614a or the second spiral passage 6614b via the first gas distribution holes 6608a or the second gas distribution holes 6608b, respectively. The semiconductor wafer 6692 may be supported in the processing chamber 6688 by a pedestal 6690. The pedestal 6690 may include, for example, a wafer support surface configured to support the semiconductor wafer 6692 from below.

[0267] It will also be appreciated that the "junction" features previously described herein may be employed in any of the previously described embodiments, including those having posts or spiral passages, to reduce stress risers. Thus, for example, the posts in some embodiments may include stepped joints at the interfaces between the posts and between the top and bottom surfaces of the posts.

[0268] For purposes of this disclosure, the term "fluidically connected" is used to refer to volumes, plenums, bores, etc. that may be connected to one another, either directly or through one or more intervening components or volumes, to form a fluid connection, just as the term "electrically connected" is used to refer to components that are interconnected to form an electrical connection. The term "fluidically interposed" may be used to refer to a component, volume, plenum, or bore that is fluidly connected to at least two other components, volumes, plenums, or bores, such that fluid flowing from one of the other components, volumes, plenums, or bores to the other or one of the other components, volumes, plenums, or bores must first flow through the "fluidically interposed" component before reaching the other or one of the other components, volumes, plenums, or bores. For example, if a pump is fluidly interposed between a reservoir and an outlet, fluid flowing from the reservoir to the outlet will first flow through the pump before reaching the outlet. The term "fluidically adjacent," when used, refers to the placement of a fluid element relative to another fluid element such that no structure is fluidly disposed between the two elements that could potentially impede fluid flow between the two elements. For example, in a flow path having a first valve, a second valve, and a third valve disposed sequentially along the flow path, the first valve is fluidly adjacent to the second valve, the second valve is fluidly adjacent to both the first and third valves, and the third valve is fluidly adjacent to the second valve.

[0269] As used herein, expressions such as "for each / each <item> of one or more <items>," "for each / each <item> of one or more <items>," and the like, are intended to include both single items and multiple items; i.e., the phrase "for each / each..." is used in the sense used in programming languages ​​to refer to each item, whatever the collection of items referred to. For example, if the collection of items referred to is a single item, "each / each" refers only to that single item (even though dictionary definitions of "each / each" often define "each / each" as meaning "one and only one of two or more things") and does not imply that there must be at least two of that item. Similarly, the terms "set" or "subset," by themselves, should not be considered to necessarily encompass multiple items. It will be understood that a set or subset can include only one member or multiple members (unless the context suggests otherwise).

[0270] In this disclosure and in the claims, the use of ordinal designations, e.g., (a), (b), (c), etc., should be understood as not conveying a particular order or sequence unless such order or sequence is explicitly indicated. For example, when there are three steps labeled (i), (ii), and (iii), it should be understood that these steps may be performed in any order (including simultaneously, unless contraindicated) unless otherwise indicated. For example, if step (ii) involves handling an element created in step (i), step (ii) may be considered to occur at some point after step (i). Similarly, if step (i) involves handling an element created in step (ii), it should be understood that the reverse is true. It should also be understood that the use of the ordinal designation "first" herein, e.g., "first item," should not be construed as implying, implicitly or inherently, that a "second" instance necessarily exists, e.g., "second item." Also, although references herein may be made to a "zero" item, this should be understood as simply referring to something that comes before another ordinal designation, e.g., a "first" item (of course, as noted above, there is no particular order implied using ordinal designations unless the context dictates otherwise). It will also be understood that references to various elements herein as "first," "second," etc. may not continue into the claims. For example, elements referred to above as "first" and "second" may be referred to as "second" and "first" elements, respectively, in the claims. Such recharacterization of such ordinal designations may be used to avoid instances where a "second" element is introduced into a claim before the corresponding "first" element.

[0271] As used herein, the term "between," when used in conjunction with a range of values, is understood to include the beginning and ending values ​​of the range unless otherwise indicated. For example, a range between 1 and 5 is understood to include the numbers 2, 3, and 4 as well as the numbers 1, 2, 3, 4, and 5.

[0272] Terms such as "about," "approximately," "substantially," "nominal," and the like, when used in reference to a quantity or similar quantifiable characteristic, unless otherwise indicated, should be understood to include values ​​within ±10% of the specified value or relationship (including the actual value or relationship specified).

[0273] It should be understood that the above disclosure, while focusing on a particular exemplary embodiment or embodiments, is not limited to only the above-mentioned examples, but may also apply to similar variations and mechanisms, and such similar variations and mechanisms are also considered to be within the scope of the present disclosure. At a minimum, the present disclosure is directed to at least the following numbered embodiments:

[0274] Embodiment 1: An apparatus, the apparatus comprising: a body having a first side and a second side of the body opposite the first side; N helical passages located within the body, each following a corresponding helical path, including at least a first helical passage located within the body and a second helical passage located within the body; At least a portion of the first helical passage follows a first helical path and has a first cross-sectional profile along at least a portion of the first helical path; a helical passageway, at least a portion of the second helical passageway following a second helical path and having a second cross-sectional profile along at least a portion of the second helical path; a plurality of first gas distribution holes extending from the second side to the first spiral passage; a plurality of second gas distribution holes extending from the second side to the second helical passage; one or more first inlet ports, each extending from a corresponding location on the exterior of the body to the first helical passage; one or more second inlet ports, each extending from a corresponding location on the exterior of the body to the second helical passage; the first gas distribution holes are disposed along the first spiral path; the second gas distribution holes are disposed along the second helical path.

[0275] Embodiment 2: 2. The device of embodiment 1, comprising: the first cross-sectional profile having a first segment proximate the first side, a second segment disposed such that the first segment is between the second segment and the first side, and first side segments opposed to each other, each spanning between the first and second segments; the second cross-sectional profile has a third segment proximate the first side, a fourth segment disposed such that the third segment is between the fourth segment and the first side, and opposing second side segments, each spanning between the third and fourth segments; the first segment includes a corresponding first curved transition region; the third segment includes a corresponding second curved transition region; each of the first curved transition regions connects to a corresponding one of the first lateral segments; The apparatus wherein each of the second curved transition regions connects to a corresponding one of the second lateral segments.

[0276] Embodiment 3: 10. The device of embodiment 2, comprising: each of the first curved transition regions is tangent to the connecting first lateral segment; The device wherein each of the second curved transition regions is tangent to the connecting second lateral segment.

[0277] Embodiment 4: 10. The device of embodiment 2, comprising: The apparatus, wherein the first curved transition regions connected to the first lateral segments connect to one another such that the first segments have a circular or parabolic profile.

[0278] Embodiment 5: 10. The device of embodiment 2, comprising: The apparatus, wherein the second curved transition regions connected to the second lateral segments are connected to one another such that the third segment has a circular or parabolic profile in cross section.

[0279] Embodiment 6: 10. The device of embodiment 2, comprising: the first curved transition regions connected to the first lateral segments connect to one another such that the first segment has a circular or parabolic profile in cross section; The apparatus, wherein the second curved transition regions connected to the second lateral segments are connected to one another such that the third segment has a circular or parabolic profile in cross section.

[0280] Embodiment 7: The device according to any one of embodiments 2 to 6, the second segment includes a corresponding third curved transition region; the fourth segment includes a corresponding fourth curved transition region; each of the third curved transition regions connects to a corresponding one of the first lateral segments; Each of the fourth curved transition regions connects to a corresponding one of the second lateral segments.

[0281] Embodiment 8: 8. The device of embodiment 7, comprising: the third curved transition region has a smaller cross-sectional profile than the first curved transition region; The apparatus wherein the fourth curved transition region has a smaller cross-sectional profile than the second curved transition region.

[0282] Embodiment 9: 9. The device of embodiment 7 or embodiment 8, comprising: the third segment includes a first linear portion located between the third curved transition regions; the fourth segment includes a second linear portion located between the fourth curved transition regions; The apparatus, wherein the first linear portion and the second linear portion are parallel to a first plane defined by the first side.

[0283] Embodiment 10: 10. The device of embodiment 9, comprising: the first gas distribution hole connects to the first spiral passage at a cross-sectional position within the first linear portion; The apparatus, wherein the second gas distribution hole connects to the second helical passage at a cross-sectional location within the second linear portion.

[0284] Embodiment 11: The device according to any one of embodiments 1 to 9, The helical paths followed by the N helical passages are all coaxial with one another, all oriented at different angles relative to a central axis of the helical paths, and each of the helical paths is 360° / N out of phase with each of the adjacent helical paths.

[0285] Embodiment 12: 12. The device of embodiment 11, comprising: N=2, the device.

[0286] Embodiment 13: 12. The device of embodiment 11, comprising: N=3, the device.

[0287] Embodiment 14: 14. The device according to any one of embodiments 1 to 13, wherein the device comprises: N helical walls, each separating one helical passage from an adjacent helical passage and following a corresponding helical wall path; a plurality of zeroth gas distribution holes, each zeroth gas distribution hole extending from the first side of the body to the second side of the body; the zero gas distribution holes are distributed along a corresponding spiral wall path for at least one of the spiral walls.

[0288] Embodiment 15: 15. The device of embodiment 14, comprising: The apparatus, wherein the zero gas distribution holes are distributed along corresponding spiral wall paths of the spiral wall.

[0289] Embodiment 16: The device according to any one of embodiments 1 to 9, further comprising a plurality of zeroth gas distribution holes arranged along the zeroth spiral path; each of the zero gas distribution holes extends from the first side of the body to the second side of the body; The helical paths followed by the N helical passages, including the helical path and the 0 helical path, are coaxial with one another, oriented at different angles relative to a central axis of the helical path, and are out of phase with each other by 360° / (N+1).

[0290] Embodiment 17: 17. The device of embodiment 16, comprising: The device, wherein the first cross-sectional profile differs in distance from the second side in a direction perpendicular to a plane defined by the second side from the first cross-sectional profile.

[0291] Embodiment 18: The device according to any one of embodiments 1 to 17, The apparatus wherein the first helical path and the second helical path have the same pitch and the same number of turns.

[0292] Embodiment 19: The device according to any one of embodiments 1 to 17, The device, wherein the first spiral path has 5 to 15 turns.

[0293] Embodiment 20: 20. The device according to any one of embodiments 1 to 19, the one or more first inlet ports connect to the first helical passage at a location or locations proximate an end of the first helical passage furthest from a center of the first helical path; the one or more second inlet ports connect to the second helical passageway at a location or locations proximate an end of the second helical passageway furthest from a center of the second helical passageway.

[0294] Embodiment 21: 21. The device of embodiment 20, comprising: the one or more first inlet ports and the one or more second inlet ports are disposed at a common azimuthal position relative to the first helical path and the second helical path.

[0295] Embodiment 22: 22. The device according to any one of embodiments 1 to 21, The apparatus wherein the first helical path has an outer diameter of at least 300 mm.

[0296] Embodiment 23: 23. The device according to any one of embodiments 1 to 22, The device, wherein the body and the spiral passage are formed by additive manufacturing.

[0297] Embodiment 24: 24. The device of embodiment 23, comprising: The device, wherein the body and the spiral passage are formed from a material exhibiting an anisotropic micro-grain structure.

[0298] Embodiment 25: 25. The device of embodiment 24, comprising: The device, wherein the material is a metal.

[0299] Embodiment 26: 26. The device of embodiment 25, comprising: The apparatus wherein the metal is Hastelloy C-22 alloy.

[0300] Embodiment 27: 27. The device according to any one of embodiments 23 to 26, The apparatus, wherein the first gas distribution holes and the second gas distribution holes are drilled or electric discharge machined holes.

[0301] Embodiment 28: 28. The device according to any one of embodiments 23 to 27, further comprising a plurality of exit ports; each of the spiral passages is fluidly disposed between two of the outlet ports; The device, wherein at least one of the outlet ports fluidly interposed between each of the spiral passages is sealed to prevent fluid flow through the spiral passage.

[0302] Embodiment 29: 29. The device of embodiment 28, comprising: A device wherein at least one of said inlet ports also functions as one of said outlet ports.

[0303] Embodiment 30: 29. The device of any of embodiments 28 or 29, comprising: The apparatus wherein the outlet port is used to flow abrasive material into the spiral passage.

[0304] Embodiment 31: A method for manufacturing a device according to any one of embodiments 1 to 30, comprising the steps of: manufacturing the body; manufacturing the spiral passage using additive manufacturing simultaneously with manufacturing the body; and drilling the first gas distribution holes and the second gas distribution holes after fabricating the body.

[0305] Embodiment 32: 32. The method of embodiment 31, comprising: The method, wherein the drilling is performed using a mechanical drill or an electrical discharge drilling.

[0306] Embodiment 33: 33. The method of any one of embodiment 31 or embodiment 32, comprising: The method further comprising flowing an abrasive through the spiral passage.

[0307] Embodiment 34: An apparatus, the apparatus comprising: a body having a first side and a second side of the body opposite the first side; a first interior plenum volume located within the body, the first interior plenum volume being located between a first surface and a second surface, the first surface being between the first side and the second surface, and the second surface being between the first surface and the second side; A plurality of pillars, first pillars distributed throughout a first region of the first interior plenum volume, each first pillar in the set of first pillars spanning between the first surface and the second surface; each of the first pillars in the set of first pillars includes a corresponding first gas distribution hole extending between the first side and the second side; each of the first posts in the set of first posts has one or more outer walls; a plurality of posts, the one or more outer walls of each first post in the first set of posts connecting to the first surface via a corresponding first curved transition region; a plurality of second gas distribution holes distributed throughout the first region of the first interior plenum volume, each second gas distribution hole spanning between the second side and the second surface.

[0308] Embodiment 35: 35. The device of embodiment 34, comprising: a second internal plenum volume located within the body, the second internal plenum volume being between a third surface and a fourth surface, the third surface being between the first side and the fourth surface, the fourth surface being between the third surface and the second side, and the third surface and the fourth surface being between the first side and the first surface; each of the first pillars in the set of first pillars is positioned between two corresponding second pillars of the plurality of pillars; the two corresponding second columns for each first column in the set of first columns are the two columns closest to that first column in the first interior plenum volume; each first pillar in the set of first pillars and its corresponding second pillar are arranged along a corresponding first axis parallel to a first direction; the plurality of pillars further including a third pillar located within the second interior plenum volume; each of the third pillars corresponds in position to one of the first pillars in the set of first pillars and has a corresponding first gas distribution hole for that first pillar extending therethrough; the corresponding second pillar for each of the first pillars in the set of first pillars includes a corresponding third gas distribution hole spanning between the second side and the fourth surface.

[0309] Embodiment 36: 36. The device of embodiment 35, comprising: each of the first pillars in the set of first pillars is positioned between two of the second gas distribution holes that are closest to that first pillar; the apparatus, wherein each of the first pillars in the set of first pillars and the two second gas distribution holes nearest thereto are arranged along corresponding second axes parallel to a second direction, the second direction being transverse to the first direction.

[0310] Embodiment 37: 37. The device of embodiment 36, comprising: wherein the center of each first pillar in the set of first pillars is spaced equidistant from the centers of the two second pillars nearest to that first pillar and from the centers of the two second gas distribution holes nearest to that first pillar.

[0311] Embodiment 38: 38. The device of embodiment 36 or embodiment 37, The apparatus, wherein the first direction is perpendicular to the second direction.

[0312] Embodiment 39: 39. The device according to any one of embodiments 36 to 38, The apparatus, wherein the first pillars in the set of first pillars are arranged in a square array.

[0313] Embodiment 40: 39. The device of embodiment 39, comprising: The apparatus wherein the square array has an array axis at 45° relative to the first direction.

[0314] Embodiment 41: 35. The device of embodiment 34, comprising: a second internal plenum volume located within the body, the second internal plenum volume being between a third surface and a fourth surface, the third surface being between the first side and the fourth surface, the fourth surface being between the third surface and the second side, and the third surface and the fourth surface being between the first side and the first surface; the plurality of columns also includes a second column located within the first interior plenum volume and a third column located within the second interior plenum volume; for each first column in the set of first columns, the three columns in the first interior plenum volume nearest thereto are second columns equidistantly spaced from the first column and equidistantly spaced from each other; each of the third pillars corresponds in position to one of the first pillars in the set of first pillars and has a corresponding first gas distribution hole for that first pillar extending therethrough; Each of the second pillars includes a corresponding third gas distribution hole spanning between the second side and the fourth surface.

[0315] Embodiment 42: 42. The device of embodiment 41, comprising: for each first pillar in the set of first pillars, the three nearest second gas distribution holes are each equidistantly spaced from that first pillar and equidistantly spaced from each other.

[0316] Embodiment 43: 43. The device of any of embodiment 41 or embodiment 42, wherein the second gas distribution holes in the set of second gas distribution holes are each at the center of a hexagonal pattern of three first pillars and three second pillars.

[0317] Embodiment 44: 44. The device according to any one of embodiments 34 to 43, the second surface defines a first reference plane; each of the pillars in the set of pillars in the first interior plenum volume is associated with a corresponding relief region of the first surface; a corresponding portion of the first surface is bounded by a corresponding relief region for each of the pillars in the set of pillars; an apparatus wherein, for each of the pillars in the set of pillars within the first interior plenum volume, a first distance between the first reference plane and the corresponding portion of the first surface increases as a function of a second distance from a central axis of that pillar.

[0318] Embodiment 45: 45. The device according to any one of embodiments 34 to 44, the apparatus, wherein, for each of the pillars in the set of pillars in the first interior plenum volume, a first distance for that pillar is determined according to a scalar function having axisymmetricity about a central axis of that pillar.

[0319] Embodiment 46: 45. The device of embodiment 44, comprising: the cross-sectional profile of the corresponding portion of the first surface, for each of the pillars in the set of pillars within the first interior plenum volume, is tangent to a second reference plane parallel to the first reference plane at a boundary of the corresponding relief region of that pillar, and is tangent to a third reference plane parallel to the second reference plane at that pillar.

[0320] Embodiment 47: 45. The device of embodiment 44, comprising: the difference between the minimum and maximum first distances within the corresponding relief region for each of the pillars in the set of pillars within the first interior plenum volume is between 20% and 30% of the maximum distance between the central axis of the pillar and the boundary of the corresponding relief region.

[0321] Embodiment 48: 45. The device of embodiment 44, comprising: the corresponding relief region for each of the columns in the set of columns in the first interior plenum volume has a boundary edge that is perpendicular to and bisects a reference line extending between that column and an adjacent column in the first interior plenum volume.

[0322] Embodiment 49: 45. The device of embodiment 44, comprising: a corresponding relief region for each of the columns in the set of columns within the first interior plenum volume is bounded by a corresponding plurality of boundary datum surfaces; the apparatus wherein, for each pillar in the set of pillars within the first internal plenum volume, each of the reference surfaces in the plurality of boundary reference surfaces corresponding to that pillar is positioned midway between that pillar and another pillar within the first internal plenum volume, is parallel to the first reference surface, and is perpendicular to a corresponding reference axis passing through a center of that pillar and another pillar.

[0323] Embodiment 50: 50. The device according to any one of embodiments 34 to 49, the one or more outer walls of each first post in the first set of posts connect to the second surface via a corresponding second curved transition region; The apparatus wherein the second curved transition region is smaller than the first curved transition region.

[0324] Embodiment 51: 51. The device according to any one of embodiments 34 to 50, The apparatus, wherein the first curved transition region of each of the first pillars in the set of first pillars merges into a first curved transition region of at least one other of the first pillars.

[0325] Embodiment 52: 52. The device according to any one of embodiments 34 to 51, the first surface is offset from the second surface by a first amount in a direction perpendicular to the first surface; The apparatus, wherein the first amount is less than or equal to 120% of the radius of the first curved transition region.

[0326] Embodiment 53: 53. The device according to any one of embodiments 34 to 52, The apparatus, wherein the centerline of each first post in the set of first posts may be within 240% of the radius of the first curved transition region of the centerline of the first post immediately adjacent to that first post.

[0327] Embodiment 54: 54. The device according to any one of embodiments 1 to 53, The apparatus, wherein the first region is a circular region having a diameter of at least 300 mm.

[0328] Embodiment 55: 55. The device according to any one of embodiments 34 to 54, The device, wherein the body and the first post are formed by additive manufacturing.

[0329] Embodiment 56: 56. The device of embodiment 55, comprising: The device, wherein the body and the first post are formed from a material exhibiting an anisotropic micrograin structure.

[0330] Embodiment 57: 57. The device of embodiment 56, wherein the material is a metal.

[0331] Embodiment 58: 58. The device of embodiment 57, wherein the metal is Hastelloy C-22 alloy. Embodiment 59: The device according to any one of embodiments 55 to 58, The apparatus, wherein the first gas distribution holes and the second gas distribution holes are drilled or electric discharge machined holes.

[0332] Embodiment 60: An apparatus, the apparatus comprising: a body having a first side and a second side opposite the first side of the body, the body having a first plenum volume and a second plenum volume therein, the first plenum volume being located between the first side and the second plenum volume, and the second plenum volume being located between the second side and the first plenum volume; one or more first inlet ports fluidly connected to the first plenum volume within the body; one or more second inlet ports fluidly connected to the second plenum volume within the body; a plurality of first pillars distributed throughout the second plenum volume, each first pillar extending between an upper surface bounding the second plenum volume and a lower surface of the second plenum volume; a plurality of first gas distribution holes, each extending between the second side and the first plenum volume and penetrating one of the first pillars; a plurality of second gas distribution holes, each extending between the second side and the second plenum volume.

[0333] Embodiment 61: 61. The device of embodiment 60, comprising: further comprising a plurality of second pillars; The apparatus, wherein each of the second posts extends between an upper surface bounding the first plenum volume and a lower surface bounding the first plenum volume.

[0334] Embodiment 62: 61. The device of embodiment 60, comprising: further comprising a plurality of first arcuate elements disposed within the second plenum volume; each of the first arcuate elements being generally of the same diameter and concentric with one another and each partially defining a corresponding sub-plenum of the second plenum volume; wherein each of the sub-plenums is fluidly connected to at least one of the one or more second inlet ports in the body.

[0335] Embodiment 63: 63. The device of embodiment 62, comprising: the second plenum volume includes a plurality of first openings extending radially inward; The apparatus wherein each of the first openings is located at a different end of one of the first arcuate elements.

[0336] Embodiment 64: 63. The device of embodiment 62, comprising: The apparatus, wherein the plurality of first pillars are located within a perimeter defined by the first arcuate element.

[0337] Embodiment 65: 64. The device of embodiment 63, comprising: further comprising a plurality of second arcuate elements disposed within the second plenum volume; The apparatus wherein each of the second arcuate elements is generally of the same diameter and concentric with one another.

[0338] Embodiment 66: 66. The device of embodiment 65, comprising: the second plenum volume includes a plurality of second openings extending radially inward; The apparatus wherein each of the second openings is located at a different end of one of the second arcuate elements.

[0339] Embodiment 67: 67. The device of embodiment 66, comprising: each of the second arcuate elements is azimuthally centered with respect to one of the first apertures; each of the second openings is azimuthally centered with respect to one of the first arcuate elements.

[0340] Embodiment 68: 67. The device of embodiment 66, comprising: The apparatus wherein a radial gap exists between the first arcuate element and the second arcuate element.

[0341] Embodiment 69: 67. The device of embodiment 66, comprising: The apparatus, wherein the plurality of first pillars are located within a perimeter defined by the second arcuate element.

[0342] Embodiment 70: The device according to any one of embodiments 60 to 10, the one or more first inlet ports are located in a central region of the body and on the first side; the one or more second inlet ports are located in a central region of the body and on the first side and include a plurality of second inlet ports; a plurality of first radial spoke passages and a plurality of second radial spoke passages disposed between the first plenum volume and the first side; each of the first radial spoke passages extends from one of the one or more first inlet ports to a location proximate an outer periphery of the first plenum volume; the apparatus, wherein each of the second radial spoke passages extends from one of the one or more second inlet ports to a location proximate an outer periphery of the second plenum volume.

[0343] Embodiment 71: 71. The device of embodiment 70, comprising: The apparatus, wherein the first radial spoke passages and the second radial spoke passages are arranged in a circumferentially alternating circular pattern.

[0344] Embodiment 72: 72. The device of embodiment 71, comprising: The apparatus wherein each of the first radial spoke passages terminates intermediate a corresponding arcuate plenum leading to the first plenum volume.

[0345] Embodiment 73: 71. The device of embodiment 70, comprising: The apparatus, wherein the first plenum volume does not have a column extending therethrough.

[0346] Embodiment 74: 71. The device of embodiment 70, comprising: the first plenum volume having a plurality of second pillars distributed throughout the first plenum volume; The apparatus, wherein each of the second posts extends between an upper surface bounding the first plenum volume and a lower surface of the first plenum volume.

[0347] Embodiment 75: The device according to any one of embodiments 60 to 10, the one or more first inlet ports are located in a central region and on the first side of the body and are fluidly connected to the first plenum volume at a central region of the first plenum volume.

[0348] Embodiment 76: 76. The device of embodiment 75, comprising: further comprising a plurality of radial spoke passages interposed between the first side and the first plenum volume; each said radial spoke passage extending from one of said second inlet ports to a corresponding riser passage located outside the periphery of said first plenum volume, fluidly connecting said radial spoke passage to said second plenum volume within said body.

[0349] Embodiment 77: The device according to any one of embodiments 60 to 10, at least one of the first columns has sides that merge into upper and lower surfaces that bound the second plenum volume at corresponding junctions; each of the joints includes a standing surface and a running surface; the running surfaces of the corresponding joints face each other, and the upstanding surfaces of the corresponding joints face radially outward relative to the central axis of the side surface, and the upstanding surfaces of the joints between the top surface and the side surface form an inner corner with the top surface that bounds the second plenum volume; the upstanding surface of the junction between the lower surface and the side surface forms an interior corner with the lower surface that bounds the second plenum volume; The running surface of each of the joints forms an inside corner with the side surface.

[0350] Embodiment 78: 78. The device of embodiment 77, comprising: the standing surface and the running surface of each of the joints meet at an outside corner.

[0351] Embodiment 79: The device according to any one of embodiments 60 to 10, the body is additively manufactured; the first pillar merges into the top surface bounding the second plenum volume via a curved transition.

[0352] Embodiment 80: An apparatus, the apparatus comprising: a body having a first side and a second side of the body opposite the first side; N ingress port sets, each including one or more corresponding ingress ports; N gas distribution hole sets, each set including a plurality of corresponding gas distribution holes; N spiral passages located within the body, each of the spiral passages follows a corresponding spiral path; each of the spiral passages having a corresponding cross-sectional profile along at least a portion of the corresponding spiral path; the gas distribution holes in a corresponding one of the gas distribution hole sets extend between its helical passage and the second side of the body and are distributed along the length of the corresponding helical path of its helical passage; each of the spiral passages fluidly connects within the body to at least one inlet port in a corresponding one of the inlet port sets; the N inlet port sets include at least a first inlet port set and a second inlet port set; the N gas distribution hole sets include at least a first gas distribution hole set and a second gas distribution hole set; The N spiral paths include at least a first helical passageway, the gas distribution holes of the first gas distribution hole set extending between the first helical passageway and the second side of the body, the first helical passageway fluidly connecting to at least one inlet port in the first inlet port set within the body; a second helical passageway, the gas distribution holes of the second gas distribution hole set extending between the second helical passageway and the second side of the body, the second helical passageway fluidly connecting to at least one inlet port in the second inlet port set within the body; the gas distribution holes in the first set of gas distribution holes are arranged along the first helical path; the gas distribution holes in the second set of gas distribution holes are arranged along the second helical path.

[0353] Embodiment 81: 81. The device of embodiment 80, comprising: further comprising M upper spiral passages; each of the upper spiral passages is associated with a corresponding one of the spiral passages; there are M ascending passage sets, each of the ascending passage sets corresponding to one of the upper spiral passages and including one or more ascending passages, each of the ascending passages fluidly connecting a corresponding one of the upper spiral passages to a corresponding one of the spiral passages within the body; a device wherein at least a portion of each of the upper spiral passages is positioned within the body between the corresponding spiral passage and at least one inlet port in the inlet port set to which the corresponding spiral passage is fluidly connected within the body.

[0354] Embodiment 82: 82. The device of embodiment 81, comprising: the upper spiral passageway is disposed between the spiral passageway and the first side of the body; the spiral passageway is disposed between the upper spiral passageway and the second side of the body.

[0355] Embodiment 83: 82. The device of embodiment 81, comprising: The apparatus wherein the gas distribution holes are smaller in size than the riser passages.

[0356] Embodiment 84: 82. The device of embodiment 81, comprising: The device, wherein the helical passageway and the upper helical passageway are arranged in a circular array about a common axis and have the same chirality.

[0357] Embodiment 85: 85. The device of embodiment 84, comprising: M=N, the device.

[0358] Embodiment 86: 86. The device of embodiment 85, comprising: M=2, the device.

[0359] Embodiment 87: 86. The device of embodiment 85, comprising: M=3, the device.

[0360] Embodiment 88: 86. The device of embodiment 85, comprising: M=4, the device.

[0361] Embodiment 89: 86. The device of embodiment 85, comprising: M=6, the device.

[0362] Embodiment 90: 82. The device of embodiment 81, comprising: the helical passage and the upper helical passage are arranged in a circular array about a common axis; the helical pathway has a first chirality; the upper helical passage has a second chirality; The device, wherein the first chirality is opposite to the second chirality.

[0363] Embodiment 91 91. The device of embodiment 90, comprising: the apparatus, wherein each of the ascending passages in each of the sets of ascending passages is at a location corresponding to an intersection between a corresponding upper spiral passage and a corresponding spiral passage associated with the corresponding upper spiral passage.

[0364] Embodiment 92: 92. The device of embodiment 91, comprising: M is greater than N, an apparatus wherein at least one of the spiral passages is associated with and fluidly connected to two or more of the upper spiral passages via the ascending passages in the ascending passage set corresponding to those upper spiral passages.

[0365] Embodiment 93: 93. The device of embodiment 92, comprising: A device where N=2 and M=3.

[0366] EMBODIMENT 94: 93. The device of embodiment 92, comprising: The apparatus has N=3 and M=4.

[0367] EMBODIMENT 95 93. The device of embodiment 92, comprising: The apparatus has N=2 and M=4.

[0368] EMBODIMENT 96 The device according to any one of embodiments 80 to 16, at least one of the cross-sectional profiles defines a corresponding top surface, a corresponding bottom surface, and two corresponding sidewalls; the corresponding top surfaces join the corresponding two side walls at corresponding two junctions; the corresponding bottom surface also joins the corresponding two side walls at corresponding two junctions; each of the joints includes a standing surface and a running surface; Each of the running surfaces of the corresponding joints between the corresponding side walls and the corresponding bottom surfaces faces the corresponding top surface; each of the running surfaces of the corresponding joints between the corresponding side walls and the corresponding top surfaces faces the corresponding bottom surface; each of the upstanding surfaces of the corresponding joints faces one of the corresponding side walls; the upstanding surfaces of the corresponding joints between the corresponding side walls and the corresponding top surfaces form interior corners with the corresponding top surfaces; the upstanding surfaces of the corresponding joints between the corresponding side walls and the corresponding bottom surfaces form interior corners with the corresponding bottom surfaces; the running surface of each of the joints forms an inside corner with a corresponding one of the side walls.

[0369] EMBODIMENT 97 97. The device of embodiment 96, comprising: the standing surface and the running surface of each of the joints meet at an outside corner.

[0370] EMBODIMENT 98: 97. The device of embodiment 96, comprising: at least one of the joints includes a plurality of standing surfaces and a plurality of running surfaces; each of the upright surfaces of the joints is separated from each of the other upright surfaces of the joints by one of the running surfaces of the joints; each of the running surfaces of the joints is separated from each of the other running surfaces of the joints by one of the upstanding surfaces of the joints; The apparatus, wherein the upstanding surfaces of the joints and the running surfaces of the joints form alternating inside and outside corners.

[0371] EMBODIMENT 99: The device according to any one of embodiments 80 to 16, the body is additively manufactured; The first cross-sectional profile is: A first segment; a second segment positioned such that the first segment is between the second segment and the first side and the second segment is between the first segment and the second side; and opposing first side segments, each spanning between the first and second segments; The second cross-sectional profile is: The third segment and a fourth segment positioned such that the third segment is between the fourth segment and the first side and the fourth segment is between the third segment and the second side; and opposing second side segments, each spanning between the third and fourth segments; the first segment includes a corresponding first curved transition region; the third segment includes a corresponding second curved transition region; each of the first curved transition regions connects to a corresponding one of the first side segments; Each of the second curved transition regions connects to a corresponding one of the second lateral segments.

Claims

1. 1. An apparatus comprising: a body having a first side and a second side of the body opposite the first side; N ingress port sets, each including one or more corresponding ingress ports; N gas distribution hole sets, each set including a plurality of corresponding gas distribution holes; N spiral passages located within the body; each of the spiral passages follows a corresponding spiral path; each of the spiral passages having a corresponding cross-sectional profile along at least a portion of the corresponding spiral path; the gas distribution holes in a corresponding one of the gas distribution hole sets extend between the helical passage and the second side of the body and are distributed along the length of the corresponding helical path of the helical passage; each of the spiral passages fluidly connects within the body to at least one inlet port in a corresponding one of the inlet port sets; the N inlet port sets include at least a first inlet port set and a second inlet port set; the N gas distribution hole sets include at least a first gas distribution hole set and a second gas distribution hole set; The N spiral paths include at least a first spiral passageway, the gas distribution holes of the first set of gas distribution holes extending between the first spiral passageway and the second side of the body, the first spiral passageway fluidly connected to at least one inlet port in the first set of inlet ports within the body; a second spiral passageway, the gas distribution holes of the second set of gas distribution holes extending between the second spiral passageway and the second side of the body, the second spiral passageway fluidly connected to at least one inlet port in the second set of inlet ports within the body; the gas distribution holes in the first set of gas distribution holes are arranged along the first helical path; the gas distribution holes in the second set of gas distribution holes are arranged along the second helical path.

2. 10. The apparatus of claim 1, further comprising: M upper spiral passages; each of the upper spiral passages is associated with a corresponding one of the spiral passages; there are M ascending passage sets, each of the ascending passage sets corresponding to one of the upper spiral passages and including one or more ascending passages, each of the ascending passages fluidly connecting a corresponding one of the upper spiral passages to a corresponding one of the spiral passages within the body; At least a portion of each of the upper spiral passages is located within the body between the corresponding spiral passage and at least one inlet port in the inlet port set to which the corresponding spiral passage is fluidly connected within the body.

3. 3. The apparatus of claim 2, the upper helical passage is disposed between the helical passage and the first side of the body; the helical passageway is disposed between the upper helical passageway and the second side of the body.

4. 3. The apparatus of claim 2, The gas distribution holes are smaller in size than the riser passages.

5. 3. The apparatus of claim 2, The device, wherein the spiral passageway and the upper spiral passageway are arranged in a circular array about a common axis and have the same chirality.

6. 6. The apparatus of claim 5, A device in which M=N.

7. 7. The apparatus of claim 6, A device in which M=2.

8. 7. The apparatus of claim 6, A device in which M=3.

9. 7. The apparatus of claim 6, A device in which M=4.

10. 7. The apparatus of claim 6, A device where M=6.

11. 3. The apparatus of claim 2, the helical passage and the upper helical passage are arranged in a circular array about a common axis; the helical passage has a first chirality and the upper helical passage has a second chirality; The device, wherein the first chirality is opposite to the second chirality.

12. 12. The apparatus of claim 11, the apparatus, wherein each of the ascending passages in each of the sets of ascending passages is at a location corresponding to an intersection between a corresponding upper spiral passage and a corresponding spiral passage associated with the corresponding upper spiral passage.

13. 13. The apparatus of claim 12, M is greater than N, at least one of the spiral passages is associated with and fluidly connected to two or more of the upper spiral passages via the ascending passages in the ascending passage set corresponding to the upper spiral passages.

14. 14. The apparatus of claim 13, An apparatus in which N=2 and M=3.

15. 14. The apparatus of claim 13, An apparatus wherein N=3 and M=4 or M=6.

16. 14. The apparatus of claim 13, An apparatus wherein N=2 and M=4 or M=6.

17. 17. An apparatus according to any one of claims 1 to 16, comprising: at least one of the cross-sectional profiles defines a corresponding top surface, a corresponding bottom surface, and two corresponding sidewalls; the corresponding top surfaces meet the corresponding two side walls at corresponding two junctions; the corresponding bottom surface also joins the corresponding two side walls at two corresponding joints; each of the joints includes a standing surface and a running surface; each of the running surfaces of the corresponding joints between the corresponding side walls and the corresponding bottom surfaces faces the corresponding top surface; each of the running surfaces of the corresponding joints between the corresponding side walls and the corresponding top surfaces faces the corresponding bottom surface; each of the upstanding surfaces of the corresponding joints faces one of the corresponding side walls; the upstanding surfaces of the corresponding joints between the corresponding side walls and the corresponding top surfaces form interior corners with the corresponding top surfaces; the upstanding surfaces of the corresponding joints between the corresponding side walls and the corresponding bottom surfaces form interior corners with the corresponding bottom surfaces; The running surface of each of the joints forms an inside corner with a corresponding one of the side walls.

18. 18. The apparatus of claim 17, The standing surface and the running surface of each of the joints meet at an outside corner.

19. 18. The apparatus of embodiment 17, comprising: At least one of the joints includes a plurality of standing surfaces and a plurality of running surfaces; each of the upstanding surfaces of the joints is separated from each of the other upstanding surfaces of the joints by one of the running surfaces of the joints; each of the running surfaces of the joints is separated from each of the other running surfaces of the joints by one of the upstanding surfaces of the joints; The apparatus, wherein the upstanding surfaces of the joints and the running surfaces of the joints form alternating inside and outside corners.

20. 17. An apparatus according to any one of claims 1 to 16, comprising: the body is additively manufactured; The first cross-sectional profile is A first segment; a second segment positioned such that the first segment is between the second segment and the first side and the second segment is between the first segment and the second side; and opposing first side segments, each spanning between the first and second segments; The second cross-sectional profile is A third segment; and a fourth segment positioned such that the third segment is between the fourth segment and the first side and the fourth segment is between the third segment and the second side; and opposing second side segments, each spanning between the third and fourth segments; the first segment includes a corresponding first curved transition region; the third segment includes a corresponding second curved transition region; each of the first curved transition regions connects to a corresponding one of the first lateral segments; Each of the second curved transition regions connects to a corresponding one of the second lateral segments.

Images