Showerhead with faceplate having internal contour - Patents.com

Abstract

A showerhead for semiconductor processing equipment is disclosed that includes various features designed to reduce non-uniformity and tailor the deposited film profile.

Description

[Technical field]

[0001] Related Applications A PCT application is being filed contemporaneously herewith as a part of this application. Each application identified in that contemporaneously filed PCT application to which this application claims benefit or priority is hereby incorporated by reference in its entirety for all purposes. [Background technology]

[0002] Semiconductor processing tools often include components designed to distribute process gases relatively uniformly across a semiconductor substrate or wafer. Such components are commonly referred to in the industry as "showerheads." Showerheads typically include a faceplate that faces a semiconductor processing volume in which semiconductor substrates or wafers can be processed. The faceplate may include a number of gas distribution ports that allow gases in the plenum volume of the showerhead to flow through the faceplate and into a reaction space between the substrate and the faceplate (or between a wafer support that supports a wafer and the faceplate). Summary of the Invention

[0003] In one embodiment, a showerhead may be provided. The showerhead may include a faceplate having a front surface, a back surface, and a plurality of through holes extending through the faceplate from the front surface to the back surface, a gas inlet, and a plenum volume fluidly connected to the gas inlet in the showerhead and at least partially defined by the back surface. The back surface has an outer boundary and an inner boundary extending about a central axis of the faceplate and offset from one another a first distance along the central axis, the outer boundary being closer to the gas inlet in a direction parallel to the central axis than the inner boundary, the outer boundary being offset radially outward from the inner boundary, and including a non-planar region having a non-planar surface extending between the inner and outer boundaries.

[0004] In some embodiments, the underside may further include a circular planar region having an outer periphery perpendicular to the central axis and defined by an inner boundary of the non-planar region.

[0005] In some embodiments, the non-planar surface may be a surface of revolution defined by a linear profile rotating about a central axis, extending between an inner boundary and an outer boundary, and oriented at an oblique angle relative to the central axis.

[0006] In some embodiments, the non-planar surface may be a frusto-conical surface.

[0007] In some embodiments, the non-planar surface may be a conical surface.

[0008] In some embodiments, the non-planar surface may be a surface of revolution defined by a non-linear profile rotating about a central axis and extending between an inner boundary and an outer boundary.

[0009] In some embodiments, one or more first through holes of the plurality of through holes may extend from the non-planar region to the front surface, each of the one or more through holes having a first length, one or more second through holes of the plurality of through holes may extend from the non-planar region to the front surface and be disposed farther from the central axis in a direction parallel to the central axis than the one or more first through holes, and the one or more second through holes may each have a second length that is longer than the first length of the one or more first through holes.

[0010] In some embodiments, each through hole may form an edge on the front surface, and each edge may have a radius.

[0011] In some such embodiments, the radius of each edge and the diameter of each through hole may be substantially the same.

[0012] In some such embodiments, each through-hole may have a diameter of between about 0.01 and 0.03 inches (0.254 and 0.762 millimeters).

[0013] In some such embodiments, the radius may be formed by electropolishing.

[0014] In some such embodiments, the radius may be formed by machining and electropolishing.

[0015] In some embodiments, the through holes may be arranged in a plurality of hexagonal patterns, each hexagonal pattern having six outer holes arranged around a central hole, and the six outer holes may be equally spaced from each other and from the central hole.

[0016] In some such embodiments, the distance between the six outer holes and the central hole of each hexagonal pattern may be between about 0.1 and 0.4 inches (2.54 and 10.16 millimeters).

[0017] In some embodiments, the diameter of the outer boundary may be greater than the diameter of the semiconductor substrate.

[0018] In some such embodiments, the outer boundary may have a diameter between 7.5 inches and 13 inches (190.5 to 330.2 millimeters).

[0019] In some embodiments, the first distance may be between 0.01 inches and 0.075 inches (0.254 and 1.905 millimeters).

[0020] In some embodiments, the inner boundary may have a diameter of between about 0 inches and 8.5 inches (0 to 215.9 millimeters).

[0021] In some embodiments, the showerhead may further include a backplate having a gas inlet and a first surface, and the plenum volume may be further defined by the first surface.

[0022] In some embodiments, the showerhead may further include a baffle plate having a baffle plate outer diameter and positioned within the plenum volume.

[0023] In some such embodiments, the diameter of the baffle plate outer diameter and the inner boundary may be substantially the same.

[0024] In one embodiment, a faceplate for use in a processing chamber of a semiconductor processing apparatus may be provided. The faceplate may include a front surface and a back surface including a center point and a non-planar region, the non-planar region may extend about a central axis of the faceplate and have an outer boundary and an inner boundary offset from one another by a first distance along the central axis, the inner boundary being closer to the center point in a direction parallel to the central axis than the outer boundary, the outer boundary being offset radially outward from the inner boundary, and the non-planar surface extending between the inner and outer boundaries. The faceplate may also include a plurality of through holes extending through the faceplate from the front surface to the back surface, each through hole forming an edge on the front surface, the edge having a radius.

[0025] In some embodiments, the non-planar surface may be a surface of revolution defined by a linear profile rotating about a central axis, extending between an inner boundary and an outer boundary, and oriented at an oblique angle relative to the central axis.

[0026] In some embodiments, the non-planar region may be a frusto-conical surface, and the underside may further include a circular planar region having an outer periphery perpendicular to the central axis and defined by an inner boundary of the non-planar region.

[0027] In some embodiments, the non-planar region may be a conical surface.

[0028] In some embodiments, the non-planar surface may be a surface of revolution defined by a non-linear profile rotating about a central axis and extending between an inner boundary and an outer boundary.

[0029] In one embodiment, a method may be provided. The method may include fabricating a showerhead, the showerhead including a faceplate having a front surface, a back surface, and a plurality of through holes extending through the faceplate from the front surface to the back surface, a gas inlet, and a plenum volume fluidly connected to the gas inlet in the showerhead and at least partially defined by the back surface. The back surface may have an outer boundary and an inner boundary extending about a central axis of the faceplate and offset from one another a first distance along the central axis, the outer boundary being closer to the gas inlet in a direction parallel to the central axis than the inner boundary, the outer boundary being offset radially outward from the inner boundary, and may include a non-planar region having a non-planar surface extending between the inner and outer boundaries.

[0030] In some embodiments, the underside may further include a circular planar region having an outer periphery perpendicular to the central axis and defined by an inner boundary of the non-planar region.

[0031] In some embodiments, the non-planar surface may be a surface of revolution defined by a linear profile rotating about a central axis, extending between an inner boundary and an outer boundary, and oriented at an oblique angle relative to the central axis.

[0032] In some embodiments, the non-planar surface may be a frusto-conical surface.

[0033] In some embodiments, the non-planar surface may be a conical surface.

[0034] In some embodiments, the non-planar surface may be a surface of revolution defined by a non-linear profile rotating about a central axis and extending between an inner boundary and an outer boundary.

[0035] In some embodiments, one or more first through holes of the plurality of through holes may extend from the non-planar region to the front surface, each of the one or more through holes may have a first length, one or more second through holes of the plurality of through holes may extend from the non-planar region to the front surface and may be disposed farther from the central axis in a direction parallel to the central axis than the one or more first through holes, and the one or more second through holes may each have a second length that is longer than the first length of the one or more first through holes.

[0036] In some embodiments, each through hole may form an edge on the front surface, and each edge may have a radius.

[0037] In some such embodiments, the radius of each edge and the diameter of each through hole may be substantially the same.

[0038] In some such embodiments, each through-hole may have a diameter of between about 0.01 and 0.03 inches.

[0039] In some such embodiments, the radius may be formed by electropolishing.

[0040] In some such embodiments, the radius may be formed by machining and electropolishing.

[0041] In some embodiments, the through holes may be arranged in a plurality of hexagonal patterns, each hexagonal pattern having six outer holes arranged around a central hole, and each of the six outer holes being equally spaced from an adjacent through hole and equally spaced from the central hole.

[0042] In some such embodiments, the distance between each adjacent outer hole and the distance between each outer hole and the central hole of each hexagonal pattern is between about 0.1 and 0.4 inches.

[0043] In some embodiments, the diameter of the outer boundary may be greater than the diameter of the semiconductor substrate.

[0044] In some such embodiments, the outer boundary may have a diameter greater than 11 inches (279.1 millimeters).

[0045] In some embodiments, the first distance may be between 0.01 inches and 0.075 inches.

[0046] In some embodiments, the inner boundary may have a diameter of between about 1.25 inches and 3.5 inches (31.75 to 88.9 millimeters).

[0047] In some embodiments, the showerhead may further include a backplate having a gas inlet and a first surface, the plenum volume further defined by the first surface.

[0048] In some embodiments, the showerhead may further include a baffle plate having a baffle plate outer diameter and positioned within the plenum volume.

[0049] In some such embodiments, the baffle plate outer diameter and the diameter of the inner boundary may be substantially the same. [Brief description of the drawings]

[0050] [Figure 1A] FIG. 1A illustrates an isometric view of an exemplary showerhead according to disclosed embodiments.

[0051] [Figure 1B] FIG. 1B shows a cross-sectional off-angle view of the showerhead of FIG. 1A.

[0052] [Figure 1C] FIG. 1C is a cross-sectional side view of the showerhead of FIG. 1B.

[0053] [Figure 2A] FIG. 2A shows an off-angle view of a simplified faceplate having a non-planar backside. [Figure 2B] FIG. 2B shows an off-angle view of a simplified faceplate having a non-planar back surface.

[0054] [Figure 2C] FIG. 2C shows a cross-sectional off-angle view of the faceplate of FIG. 2A.

[0055] [Figure 2D] FIG. 2D shows a side view of a sliced ​​cross section of the faceplate of FIG. 2C.

[0056] [Diagram 3] FIG. 3 shows an exemplary frustum surface.

[0057] [Figure 4A] FIG. 4A shows a sliced ​​cross section of a faceplate having a conical non-planar region. [Figure 4B] FIG. 4B shows a sliced ​​cross section of a faceplate having a non-conical, non-planar region.

[0058] [Diagram 5] FIG. 5 shows a sliced ​​cross section of half the faceplate of FIG. 1C.

[0059] [Figure 6] FIG. 6 shows the thickness of material deposited on the five wafers in the first deposition experiment.

[0060] [Figure 7] FIG. 7 shows the thickness of material deposited on the two wafers in the second deposition experiment.

[0061] [Figure 8] FIG. 8 shows a first through-hole pattern in a faceplate.

[0062] [Figure 9A]FIG. 9A shows the measured non-uniformity of material deposited on the first wafer using a conventional showerhead in the third deposition experiment. [Figure 9B] FIG. 9B shows the measured non-uniformity of the material deposited on the second wafer in the third deposition experiment.

[0063] [Figure 10] FIG. 10 shows a close-up, partial cross-sectional view of two exemplary through-holes in a faceplate.

[0064] [Figure 11] FIG. 11 shows a schematic of a substrate processing apparatus for depositing films on semiconductor substrates using any number of processes.

[0065] [Figure 12] FIG. 12 illustrates an exemplary multi-station substrate processing apparatus. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0066] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the presented concepts. The presented concepts may be practiced without some or all of these specific details. In other instances, well-known process operations have not been described in detail in order not to unnecessarily obscure the described concepts. While some concepts will be described in connection with specific embodiments, it will be understood that there is no intent to limit these embodiments.

[0067] In this application, the terms "semiconductor wafer," "wafer," "substrate," "wafer substrate," and the like are used interchangeably. Wafers or substrates used in the semiconductor device industry typically have diameters of 200 mm, 300 mm, or 450 mm, but may be non-circular and of other dimensions. In addition to semiconductor wafers, other workpieces that may utilize the present invention include a variety of articles such as printed circuit boards, magnetic recording media, magnetic recording sensors, mirrors, optical elements, micromechanical elements, and the like.

[0068] In some of the drawings and discussions of this disclosure, certain conventions may be adopted. For example, at various points reference is made to a "volume," e.g., a "plenum volume." While these volumes may generally be illustrated in the various figures, it is understood that the figures and accompanying numerical identifiers represent approximations of such volumes, and that the actual volumes may extend, for example, to various solid surfaces that bind the volumes. Various smaller volumes, e.g., gas inlets or other apertures that lead to the boundary surfaces of the plenum volumes, may be fluidly connected to those plenum volumes.

[0069] For purposes of this disclosure, the term "fluidically connected" is used for volumes, plenums, holes, etc. that may be connected to one another to form a fluid connection, similar to why the term "electrically connected" is used for components that are connected together to form an electrical connection. When using the term "fluidically intervening," it may be used to refer to a component, volume, plenum, or hole that is fluidly connected to at least two other components, volumes, plenums, or holes, causing fluid flowing from one of those other components, volumes, plenums, or holes to the other or other of those components, volumes, plenums, or holes to first flow through the "fluidically intervening" component before reaching the other or other of those components, volumes, plenums, or holes. For example, if a pump is fluidly intervening between a reservoir and an outlet, fluid flowing from the reservoir to the outlet will first flow through the pump before reaching the outlet.

[0070] It should be understood that the use of relative terms such as "above," "on top," "below," "below" and the like refers to the spatial relationship of components relative to the orientation of those components during normal use of the showerhead or relative to the orientation of a drawing on a page. In normal use, the showerhead is generally oriented to distribute gases downward toward a substrate during substrate processing operations.

[0071] In semiconductor processing, it is desirable to reduce non-uniformity of the material deposited on the wafer, reduce particle generation, reduce the occurrence of unwanted hollow cathode discharge (HCD) during plasma generation, and adjust the profile of the deposited material. Features of the showerhead for semiconductor processing and the flow characteristics in and through the showerhead can cause some of these unwanted effects. For example, structures within the showerhead can cause localized non-uniformity and particle generation on the substrate near these structures. For example, the internal baffle plate and support structure can cause localized non-uniformity on the substrate in the area under or near the baffle plate, and the structure supporting the baffle plate can cause particle generation and contamination on the substrate. The configuration of the through holes in the showerhead can also lead to non-uniformity and HCD.

[0072] Described herein is a showerhead having various features configured to reduce non-uniformity of material deposited on a substrate, reduce particle contamination on the substrate, reduce the occurrence of unwanted hollow cathode discharge (HCD), and generate a desired film profile across the substrate. The showerhead includes a faceplate with a front surface facing the substrate, a back surface partially defining a plenum volume of the showerhead, and through holes extending between the two surfaces. The back surface of the faceplate is a non-planar surface configured to improve flow in and through the showerhead, thus reducing non-uniformity, and the geometric characteristics of the non-planar region of the back surface may affect the film profile, and changes in these geometric characteristics may result in different film profiles, such as profiles with higher or lower radius edges. The non-planar region may have various shapes, such as a frustoconical surface, a conical surface, a concave surface, and a curved surface.

[0073] The through-holes in the faceplate may also have properties and configurations that provide various advantages. In some embodiments, the diameter of the through-holes may be small enough to prevent unwanted plasma generation within each hole and create a pressure drop between the plenum volume of the showerhead and the volume outside the showerhead, which reduces non-uniformity across the substrate, local non-uniformity, and particle generation, and this pressure drop may work in conjunction with non-planar surfaces to create different film profiles. In some embodiments, the edges of each through-hole in the front surface of the faceplate may be rounded to a radius, which reduces unwanted HCD.

[0074] As described in more detail below, the ability to reduce non-uniformity and affect film profiles using faceplates having backsides with non-planar regions using some of the dimensions described below was a surprising result. In some cases, the dimension of the depth of the non-planar region will typically fall within a general tolerance range or a default tolerance range. In some embodiments, the non-planar region includes outer and inner boundaries that are offset from one another along the central axis of the faceplate by a small offset distance that is not achievable with typical manufacturing techniques, such that the offset distance may be within or close to typical acceptable limits. Similarly, the offset distance may be a very small percentage of the total thickness of the faceplate in the region that is located above the semiconductor wafer during processing, such as, for example, between about 2.5% of the nominal thickness of the faceplate. Some of the offset distances described herein are small enough that they will fall within a general tolerance range or a default tolerance range for some showerheads. That is, the presence or absence of such a profile would be considered "within tolerance" for such showerheads. Nevertheless, the small offset distances of the non-planar regions provided herein had a surprising and significant effect of reducing non-uniformity and changing film profiles.

[0075] FIG. 1A shows an isometric view of an exemplary showerhead according to disclosed embodiments, and FIG. 1B shows a cross-sectional off-angle view of the showerhead of FIG. 1A. The cross-sectional view of FIG. 1B is taken along section line AA of FIG. 1A. The exemplary showerhead in all figures herein is an exemplary schematic view intended to convey the concepts described herein, and is not intended to be an accurate representation, and is not to scale. The showerhead 100 includes a backplate 102, a faceplate 104, and a gas inlet 106. The gas inlet 106 is considered part of the showerhead 100 itself, and may be, for example, at the end of a stem of the showerhead 100.

[0076] 1B , interior features of the showerhead 100 are seen, including the baffle plate 108 (which may be omitted in some implementations), posts 110 supporting the baffle plate 108 (which may also be omitted if the baffle plate 108 is not used), a back surface 112 of the faceplate 104, and a first surface 114 of the backplate 102. The back surface 112 of the faceplate 104 and the first surface 114 of the backplate 102 together partially define a plenum volume 116 within the showerhead 100. In some embodiments, as shown in FIG. 1B , the baffle plate 108 may be located within the plenum volume 116. The backplate 102 and the faceplate 104 may be located opposite one another within the showerhead 100, such that the first surface 114 of the backplate 102 and the non-planar back surface 112 of the faceplate 104 face one another. The faceplate 104 also includes a number of through-holes 122 (some of which are identified) extending from the back surface 112 to the front surface 120 (the front surface 120 is identified but not fully visible in FIG. 1B ) that fluidly connect the plenum volume 116 with an environment outside the showerhead 100, such as where a substrate is placed during semiconductor processing operations.

[0077] The gas inlet 106 is considered part of the showerhead 100 and may also partially define the plenum volume 116, and as shown in FIG. 1B, the gas inlet 106 is a port in the backplate 102, identified by light shading. As described herein, the gas inlet 106 may be fluidly connected to other fluid conduit hardware, such as pipes, valves, and / or the stem of a chandelier style showerhead. In FIGS. 1A and 1B, the gas inlet 106 is fluidly connected to a fluid conduit 118, which may be, for example, the stem of a showerhead. In some embodiments, the baffle plate 108 may be centered below the gas inlet 106 such that the central axis of the baffle plate 108 is collinear with the central axis of the gas inlet 106.

[0078] Figure 1C is a cross-sectional side view of the showerhead of Figure 1B. In Figure 1C, some of the features identified above are seen, including the first surface 114 of the backplate 102, and the front surface 120, back surface 112, and through-holes 122 of the faceplate 104, with the plenum volume 116 also depicted in light shading. As noted above, the back surface 112 of the faceplate 104 is a non-planar surface, and Figure 1C illustrates the cross-sectional profile 112A of the back surface 112 with a thick solid line. Additional aspects of the non-planar back surface 112 are illustrated in Figures 2A-2D.

[0079] 2A and 2B show off-angle views of a simplified faceplate having a non-planar back surface, FIG. 2C shows a cross-sectional off-angle view of the faceplate of FIG. 2A, and FIG. 2D shows a sliced ​​cross-sectional side view of the faceplate of FIG. 2C. However, in these figures, the faceplate 104 of FIGS. 1A-1C is shown without the through holes and baffle plate for illustrative purposes, but it should be understood that in all embodiments, the faceplate 104 includes the through holes. In FIG. 2A, the faceplate 104 includes a central axis 124 and a non-planar back surface 112, highlighted with a lighter shade. In FIG. 2B, the non-planar back surface 112 includes a non-planar region 126 extending about the central axis 124, highlighted with a darker shade. Non-planar region 126 has an outer boundary 128 that extends about central axis 124 and forms an outermost boundary of the surface region relative to central axis 124, an inner boundary 130 that extends about central axis 124 and forms an innermost boundary of the surface region relative to central axis 124, and a non-planar surface extending between inner boundary 130 and outer boundary 128, which non-planar surface is also indicated by the shaded area identified as 126. Inner boundary 130 and outer boundary 128 in Figures 2A and 2B are shown as thick lines.

[0080] In some embodiments, as shown in Figure 2B, the non-planar back surface 112 may also include a central region 132, which may in some cases be planar. The central region 132 in Figure 2B is a planar circular surface that is perpendicular to the central axis 124 and has an outer boundary formed by an inner boundary 130 of the non-planar region 126. In some cases, the junction of these boundaries may have a radius or curve to smoothly transition between the non-planar surface of the non-planar region 126 and the planar central region 132.

[0081] The non-planar region 126 of the faceplate 104 may have various geometric shapes and configurations, such as conical, frusto-conical, or curved. The non-planar region 126 shown in FIGS. 1A-2D may be considered a frusto-conical surface. A frusto-conical surface, as the term is used herein, is a right circular or conical surface without a sharp end, and a plane perpendicular to the axis of rotation of the frusto-conical surface is truncated or cut off. The conical surfaces described herein may also be considered as right frusto-conical surfaces. FIG. 3 illustrates an exemplary frusto-conical surface. As can be seen, the frusto-conical surface S is defined by a first circumference C1 having a first radius R1 and a second circumference C2 having a second radius R2 greater than the first radius R1, the two circumferences being offset from each other by a height H along a central axis perpendicular to the plane defined by both circumferences. The length L of the frusto-conical surface extends between the first circumference C1 and the second circumference C2. The frustum surface is offset from the central axis by a first angle θ1.

[0082] The shape of non-planar region 126 is further described with reference to Figure 2C, which shows a cross-sectional off-angle view of the faceplate of Figure 2B. In Figure 2C, non-planar surface 126 extends between a first circumference, inner boundary 130, and a second circumference, outer boundary 128, having a length 134. Non-planar region 126 has a height 136 defined by the distance that outer boundary 128 and inner boundary 130 are offset from one another along central axis 124. Outer boundary 128 and inner boundary 130 may also be considered to be offset from one another by height 136 in a direction parallel to central axis 124, which height may also be referred to herein as the depth of the non-planar region.

[0083] The features of the faceplate are further illustrated in the cross-sectional side view of FIG. 2D, which shows a slice of the faceplate taken in a plane along the central axis, with cross-hatching omitted for purposes of illustration. In FIG. 2D, the side profile of the non-planar region is visible and highlighted with a bold line. The profile of the non-planar region includes a first section 138A and a second section 138B having the same length 134. The inner boundary 130 and the outer boundary 128 are also visible and are represented as points, with the first section 138A and the second section 138B each extending between the outer boundary 128 and the inner boundary 130. As discussed above and seen in FIG. 2D, the outer boundary 128 and the inner boundary 130 are offset from each other by a height 136 in a direction along or parallel to the central axis 124 when viewed perpendicular to the central axis 124. In some embodiments, the outer boundary 128 and the inner boundary 130 may also be considered to be offset from one another such that, when viewed perpendicular to the central axis 124, the inner boundary 130 is closer to the front surface 120 in a direction parallel to or along the central axis 124 than the outer boundary 128.

[0084] When viewed perpendicular or parallel to the central axis, the inner boundary 130 and the outer boundary 128 are also offset from one another. In some embodiments, such as in FIG. 2D , the inner boundary 130 is offset from the central axis 124 by a first radial distance 140 in a direction perpendicular to the central axis 124, and the outer boundary 128 is offset from the central axis 124 by a second radial distance 142 that is greater than the first radial distance 140 in a direction perpendicular to the central axis 124. 128 may be considered to be offset from inner boundary 130 a third radial distance 144 in a direction perpendicular to central axis 124. First section 138A and second section 138B may be angled away from the central axis at an oblique first angle θ1, shown in this view as an acute angle, which decreases as height 136 (first distance) increases.

[0085] In some embodiments, the non-planar region may be considered to be defined by a profile that extends between an inner boundary and an outer boundary and rotates about a central axis. In FIG. 2D , the profile of the non-planar region 126 is defined by a first section 138A (or a second section 138B), which in this embodiment is a linear profile. B ) as the linear profile. As discussed above, the linear profile is bent away from the central axis at a first angle θ1, which is oblique. The linear profile, first section 138A, rotates entirely about the central axis 124, as represented by the curved double arrow. In some embodiments, as in FIG. 2D, the linear profile is radially offset from the central axis 124 by a distance 140. The rotation of the linear profile about the central axis 124 creates a non-planar region.

[0086] In some embodiments, the non-planar region of the non-planar back surface of the faceplate may have other shapes and geometries, as illustrated in FIGS. 4A and 4B, which show various examples of sliced ​​cross sections of the faceplate. For example, the non-planar region of the non-planar back surface may have a cone shape, i.e., a cone with a point at its center, as seen in FIG. 4A. In FIG. 4A, the non-planar region includes an outer boundary 428 and an inner boundary 430, which may be a single point as shown, and the non-planar surface extends between this point 430 and the outer boundary 428. This illustrated side profile shows that a first section 438A and a second section 438B share a common inner point 430. The non-planar surface has a length 434 that extends from the inner boundary, i.e., point 430, to the outer boundary 428, and the outer boundary 428 and the inner boundary 430 are offset from each other by a height 436 in a direction along or parallel to the central axis 424. Additionally, the outer boundary is offset from the central axis 424 by a second radial distance 442 in a direction perpendicular to the central axis 424. The inner boundary 430 is located on the central axis 424 and is not offset from the central axis 424. Additionally, the first section 438A and the second section 438B (which are two sections of the same non-planar region) may be angled away from the central axis at an oblique first angle θ1, shown in this view as an acute angle. Similar to above, the conical non-planar region of FIG. 4A may be defined by a linear profile, section 438A, that rotates about the central axis 424.

[0087] In some embodiments, the non-planar region may have a shape formed by a non-linear profile rotating about the central axis. FIG. 4B shows a sliced ​​cross-section of a faceplate with a non-planar region having a non-linear cross-sectional profile. Again, the non-planar region includes an outer boundary 428 and an inner boundary 430 that are offset from one another from the central axis 424. In FIG. 4B, the non-planar surface extending between the outer boundary 428 and the inner boundary 430 has a non-linear, e.g., curved, profile. This side profile shows that the first section 438A and the second section 438B are non-linear, and in this embodiment, curved. Again, the outer boundary 428 and the inner boundary 430 are offset from one another by a height 436 along or in a direction parallel to the central axis 424. Similar to FIG. 2D, in FIG. 4B, the inner boundary 430 is offset from the central axis 424 by a first radial distance 440 in a direction perpendicular to the central axis 424, and the outer boundary 428 are offset in a direction perpendicular to the central axis 424 by a second radial distance 442 that is greater than the first radial distance 440. In some other embodiments, the inner boundary of FIG. 430 may be a single point on the central axis 424, as shown in FIG. 4A.

[0088] The curvature of the nonlinear profile may have a constant curvature, may have two or more curves, and may be defined by a variety of nonlinear equations that may change the curvature as the radial distance from the central axis 424 changes. For example, the curvature may be defined by a polynomial function, such as a quadratic, cubic, or quartic function.

[0089] In some embodiments, the non-planar regions of the non-planar surface of the faceplate may be considered to be configured such that the through-holes have different, e.g., longer, lengths as the radial distance from the central axis increases, and these varying lengths reduce non-uniformity and allow for tailoring of the film profile. FIG. 5 shows a sliced ​​cross-section of the half faceplate of FIG. 1C. In FIG. 5, the central axis 124, half of the central region 132, the second section 138B of the non-planar region, the inner boundary 130, and the outer boundary 128 can be seen. This view also includes a number of through-holes 122, a portion of which have different lengths from each other. In the central region, the through-holes 122 have equal lengths, and along the second section 138B, the length of the through-holes increases as the radial distance from the central axis 124 increases. For example, through-hole 122A is radially closer to the central axis 124 than through-hole 122B. Through hole 122A is offset from central axis 124 a first radial distance 544A and has a first length 546A, while through hole 122B is offset from central axis 124 a second radial distance 544B that is greater than first radial distance 544A and through hole 122B has a second length 546B that is greater than first length 546A. Similarly, through hole 122C has a third radial distance 544C that is greater than first radial distance 544A and second radial distance 544B, respectively, and has a first length 546A. 5 46A and has a third length 546C that is longer than the second length 546B.

[0090] As illustrated in Figure 5, the length of the through-holes extending through the non-planar region increases as the radial distance from the central axis increases due to the tapered profile of the non-planar region relative to the central axis. Similarly, the shapes of the non-planar regions illustrated in Figures 4A and 4B provide the same effect of having through-holes with variable lengths that increase as the radial distance from the central axis increases. As described herein, these variable and increasing lengths reduce non-uniformity and allow for tailoring of the membrane profile.

[0091] The non-planar back surface of the faceplate and the dimensions of the through-holes described herein provide a number of unexpected advantages, including reduced non-uniformity and adjustable film profile on the wafer. For example, in some embodiments, the depth 136 of the non-planar region 126 of the faceplate 104 may range between about 0.01 inches and 0.075 inches, including, for example, 0.01 inches (0.254 millimeters), 0.011 inches (0.2794 millimeters), 0.012 inches (0.3048 millimeters), 0.013 inches (0.3302 millimeters), 0.015 inches (0.381 millimeters), 0.017 inches (0.4318 millimeters), 0.02 inches (0.508 millimeters), 0.025 inches (0.635 millimeters), 0.035 inches (0.889 millimeters), 0.05 inches (1.27 millimeters), 0.055 inches (1.397 millimeters), 0.065 inches (1.651 millimeters), and 0.075 inches (1.905 millimeters). Varying the depth of the non-planar region changed the overall length of the through-holes, which in turn tuned the flow characteristics through the faceplate, resulting in reduced non-uniformity and tunable membrane profile.

[0092] In some embodiments, the inner diameter 130 of the non-planar region 126 may have a diameter between about 0 inches and 8.5 inches, including 2.1 (53.34), 2.3 (58.42), 3 (76.2), 4 (101.6), 5 (127), 6 (152.4), 7 (177.8), 8 (203.2), and 8.5 (215.9) inches (millimeters). In some embodiments, the inner diameter 123 may be equal or substantially equal (e.g., within about ±5%) to the outer diameter of the baffle plate, although these diameters may not be exactly the same, e.g., due to manufacturing tolerances and imperfections, and may be considered substantially the same. In some implementations, the outer diameter 128 of the non-planar region 126 may also be between 7.5 inches and 13 inches, including, for example, 7.5 (190.5), 8, 8.5, 9 (228.6), 12 (304.8), 12.3 (312.42), 12.5 (317.5), 12.75 (323.85), and 13 (330.2) inches (millimeters). In some examples, the size of the outer diameter 128 may be greater than the outer diameter of the substrate, which may be at least 300 millimeters. Thus, in some implementations, the depth of the non-planar region may be between about 0.006% and 0.052% of its outer diameter, for example, between 12 inches and 12.5 inches. To provide perspective, the interior, plenum-defining surface features of a typical showerhead are typically machined to a tolerance of about ±0.005 inches (0.127 millimeters). With such tolerances, features such as some of the non-planar regions discussed above may experience size and aspect ratio changes that may cause those features to lose their effectiveness. For example, a planar back surface may technically be within ±0.005 inches of a non-planar region having a depth of 0.010 inches (0.254 millimeters), but in this case the non-planar region would essentially disappear. Thus, due to the potentially small depth of such non-planar regions, the back surface of a faceplate having non-planar regions may be machined to conform to much tighter tolerances than are typically used for showerhead features, e.g., ±0.001 inches or ±0.0005 inches.

[0093] While having a non-planar backside of the faceplate provides numerous advantages, including reduced non-uniformity, as compared to many typical showerheads that use a planar backside, the inventors have further discovered that in some embodiments, when the internal showerhead pressure is increased to higher pressures, such as at least 5 Torr and between 5 Torr and 25 Torr, utilizing and tuning non-planar surfaces having relatively small depths, for example, below or close to typical mechanical tolerances, provides numerous advantages, including substantial tunability and reduced non-uniformity.

[0094] For example, in one experiment, five different depositions were performed under the same conditions except that the showerhead used for each deposition process had a faceplate with a different backside profile than the other faceplates. Figure 6 shows the thickness of material deposited on five wafers in the first deposition experiment. In Figure 6, the x-axis is the measurement point along the substrate, with 0 being the center of the wafer, while the y-axis is the normalized thickness of the deposited layer. In this figure, there are five data sets, and the first Set ofset is for a planar back surface, a second set is for a non-planar surface with a frustum surface having a first depth, a third set is for a non-planar surface with a frustum surface having a second depth greater than the first depth, a fourth set is for a non-planar surface with a frustum surface having a third depth greater than the second depth, and a fifth set is for a non-planar surface with a frustum surface having a fourth depth greater than the fifth depth. In this figure, the depth of the frustum surface is in the range between 0.01 inches and 0.075 inches, including, for example, 0.01 inches, 0.011 inches, 0.012 inches, 0.013 inches, 0.015 inches, 0.017 inches, 0.02 inches, 0.025 inches, 0.035 inches, 0.05 inches, 0.055 inches, 0.065 inches, and 0.075 inches, as described above. As can be seen, under these process conditions, the second data set using the first depth has less non-uniformity than the first data set with a planar backside surface. Also, the shallowest depth of the second data set, the first depth, produced the best uniformity, while the largest depth, the fourth depth, produced the least uniformity and smallest edge thickness. The second largest depth, the third depth, produced the second smallest edge thickness. The third, fourth, and fifth data sets illustrate both the sensitivity of the film profile to different contour depths and the ability to adjust and tune the film profile with different non-planar backside depths. For example, it may be desirable to adjust the film profile to produce non-planar or non-uniform regions on the substrate, such as thicker or thinner films at the radial edges compared to the center of the wafer.

[0095] The inventors have found that decreasing the diameter of the through-holes in the faceplate can create a desired internal showerhead pressure by restricting the flow to an extent that the desired internal showerhead pressure can be maintained at steady state. Changing the flow rate to obtain higher pressures can have detrimental effects on the process, such as greater flow non-uniformity. Typical through-hole diameters for showerheads can be at least 0.04 inches, or greater than 0.05 inches. It has been found that when the diameter of the through-holes is reduced below 0.04 inches, such as, for example, from about 0.02 inches to 0.015 inches, the internal showerhead pressure increases to high pressures, including at least 5 Torr and up to 25 Torr. Thus, in some embodiments, the diameter of the through-holes can range from about 0.01 inches to 0.03 inches, including, for example, about 0.01, 0.015, 0.018, 0.019, 0.02, 0.025, 0.027, and 0.03 inches.

[0096] The increased pressure caused by decreasing the diameter of the through-holes has many advantageous and unexpected results. For example, the higher internal pressure of the showerhead causes the internal volume to have a plenum effect, which increases pressure uniformity and results in increased flow sensitivity to the length of the through-holes in the faceplate caused by the non-planar areas of the faceplate. This increased sensitivity allows fine tuning of the film profile due to the non-planar back surface of the faceplate and its relatively small dimensions and adjustments thereto. Again, adjusting the length of the through-holes adjusts the pressure drop along the faceplate, allowing adjustment of the film profile.

[0097] This increased pressure also reduced the unfavorable effects caused by the baffle plate. The use of a baffle plate is advantageous for a number of reasons, including reducing the internal volume, using less process gas, and improving flow distribution throughout the showerhead. For example, referring back to FIG. 1C, a portion of the gas flow into the showerhead 100 is represented by the black arrows 121, which travel through the conduit 118, to the gas inlet 106, through the gas inlet 106 into the plenum volume 116, over the baffle plate 108, and radially outward and below the baffle plate 106. The inventors have found that baffle plates can cause localized non-uniformities associated with the outer edge of the baffle plate, which can result in unintended adverse effects, including particle generation that contaminates the wafer. For example, in a second experiment, material was deposited onto one wafer using a conventional showerhead with a faceplate having a planar backside and 0.040 diameter through-holes, and material was deposited onto a second wafer using a showerhead with a faceplate having a non-planar frusto-conical backside and 0.020 diameter through-holes.

[0098] FIG. 7 shows the thickness of material deposited on two wafers in the second deposition experiment. In FIG. 7, the x-axis is the measurement point along the substrate, with 0 being the center of the wafer, while the y-axis is the normalized thickness. As can be seen, the 0.020 diameter through-holes produced less non-uniformity across the wafer than the 0.040 inch diameter through-holes. Also, the 0.020 diameter through-holes reduced the localized non-uniformity caused by the baffle plate. In these experiments, the showerhead included a baffle plate having an outer diameter of about 100 mm located approximately -50 mm to 50 mm from the center of the wafer, and the pile of material located -50 mm to 50 mm in FIG. 7 shows the non-uniformity associated with the edge of the baffle plate. The 0.020 diameter through-holes reduced this local non-uniformity caused by the baffle plate because the reduced cross-sectional area of ​​such through-holes created a higher internal pressure within the plenum, which resulted in a more uniform pressure distribution across the back surface of the faceplate, which in turn was less affected by the baffle plate.

[0099] The inventors discovered that the posts supporting the baffle plate can cause particle generation and contamination on the wafer. As above, the 0.020 diameter through holes reduced this particle generation and contamination caused by the baffle plate posts.

[0100] In some embodiments, the through-holes of the faceplate may be arranged in a pattern that reduces non-uniformity as well. The pattern includes six peripheral holes arranged in a hexagonal pattern around a central hole, with all seven holes equally spaced from each other. The pattern may be considered a hexagonal, hexagonal close-packed, double hexagonal, or equilateral triangular pattern with a central hole. FIG. 8 illustrates a first through-hole pattern for a faceplate. In FIG. 8, six through-holes are arranged in a hexagonal shape 950 around a central through-hole 922C, with all seven through-holes equally spaced from the nearest adjacent through-hole, as shown by the distance D1 between some of these holes. For example, adjacent peripheral through-holes 922A and 922B are equally spaced from each other by a separation distance D1 and from the central through-hole 922C by a separation distance D1. In some cases, this separation distance D1 between the through holes may be between about 0.100 inches and 0.400 inches, including about 0.150, 0.162, 0.200, and 0.250 inches. The inventors have discovered that using this hexagonal pattern with a hole in the center of the faceplate (e.g., the central axis of the through hole is substantially collinear with the central axis of the faceplate) and with a central hole pattern throughout the majority of the faceplate, and in some embodiments, throughout all of the faceplate, reduces non-uniformity as compared to a conventional hexagonal pattern without a central hole.

[0101] In a third experiment, material was deposited on one wafer using a conventional showerhead with a faceplate having a planar back surface and a hexagonal pattern of through-holes with a diameter of 0.040, and material was deposited on a second wafer using a showerhead with a faceplate having a non-planar frusto-conical back surface and a central hole pattern and a hexagonal through-hole with a diameter of 0.020. FIG. 9A shows the measured non-uniformity of material deposited on a first wafer using a conventional showerhead in the third deposition experiment, and FIG. 9B shows the measured non-uniformity of material deposited on a second wafer in the third deposition experiment. In these figures, the x and y axes are the measurement positions on the substrate, and a legend of the non-uniformity shown is on the right side of each figure. In FIG. 9A, six through-holes in a hexagonal pattern are also shown, and as can be seen, there is non-uniformity in the center of the hexagonal pattern, represented by the light shading, while there is a different thickness of material around the outer surface of the pattern, represented by the dark shading. In Figure 9B, a hexagon with a central hole pattern is shown, indicating that the non-uniformity is reduced and the deposited material is more uniform with this pattern, as represented by the absence of light shading and the more consistent dark shading around and within the pattern. It will be understood that in both experiments, additional hexagonal patterns of holes were also included, but each figure shows only a single such pattern.

[0102] In some embodiments, the edges of each of the through-holes in the front surface of the faceplate may be rounded to a radius, which provides advantageous results. Each through-hole extends through the faceplate and forms an edge that intersects with the front surface of the faceplate. The edge may be referred to as a sharp edge or a rounded edge. In the case of a sharp edge, the edge refers to the area where two surfaces intersect, for example, the cylindrical through-hole surface and the front surface of the faceplate. In the case of a rounded edge, the intersecting surfaces may not actually intersect, since the rounding acts to terminate the surfaces before they contact each other. However, such rounded geometries are still referred to herein as "edges" despite the lack of actual surface intersection. As used herein, a sharp edge refers to an edge that does not have any intentional roundness or radius, and a sharp edge may be generated by two surfaces that intersect and have an interior angle of less than 180 degrees, such as 90 degrees. However, it should be understood that some rounded sharp edges may be introduced that are not intended to be there, for example, sharp edges may become rounded over time due to wear and tear from repeated handling and cleaning operations.

[0103] Using conventional machining processes, through-holes in faceplates typically have sharp or non-rounded edges, and such processes may result in burrs or other sharp, uneven points. It has been discovered by the present inventors that through-holes with sharp edges may adversely affect semiconductor processing operations. For example, hollow cathode discharge (HCD) is the ignition of plasma around and within through-holes with sharp edges or burrs, and HCD may also be caused by the confluence of plasma sheaths within through-holes whose diameters are too large. HCD creates a localized high-density plasma within and around the through-holes, which results in more localized deposition at that location on the wafer, which may lead to localized non-uniformity and wafer defects. The present inventors have discovered that this HCD effect may be reduced by rounding the edges of each through-hole with a large enough radius and / or by making the through-hole diameter small enough, below a certain amount, such as the 0.02 inches mentioned above, so that some plasma sheaths do not coalesce within the through-hole.

[0104] FIG. 10 shows a close-up, partial cross-sectional view of two exemplary through-holes in a faceplate. In FIG. 10, the left through-hole 1022A forms a sharp edge 1052 on the front surface 1020 of the faceplate, while the right through-hole 1022B forms a rounded edge 1054 with a radius R on the front surface 1020 of the faceplate. The inventors have further found that in some embodiments, making the radius equal or substantially equal (e.g., within ±10%, 25%, and 50%) to the hole diameter prevents the occurrence of HCD. For example, the inventors have further found that using a through-hole diameter of 0.02 inches and a rounded edge with a radius of 0.02 inches prevents the occurrence of HCD, while using a through-hole diameter of 0.02 inches and a rounded edge with a radius of 0.005 inches did not reduce the occurrence of HCD. In FIG. 10, the radius R of the edge 1054 of the through-hole 1022B may be considered to be substantially equal to the diameter D of the through-hole 1022B, for example, within 10%.

[0105] In some embodiments, the radii on each through-hole may be formed by electropolishing the faceplate. This electrochemical process involves immersing the metal faceplate in a solution and applying a voltage that preferentially reduces material from apexes and sharp points, thus smoothing the sharp edges of the through-holes. Such rounding, which involves rounding the periphery of a 0.02 inch through-hole to a 0.02 inch radius, is difficult to achieve by mechanical polishing, as such processes may actually produce a large number of burrs.

[0106] The showerheads described herein may be used in a variety of semiconductor processing chambers and substrate processing equipment. FIG. 11 shows a schematic diagram of a substrate processing equipment for depositing a film on a semiconductor substrate using any number of processes. The equipment 1160 of FIG. 11 has a single processing chamber 1162 with a single substrate holder 1164 (e.g., pedestal or electrostatic chuck) in an interior volume that may be maintained under vacuum by a vacuum pump 1166. Also, a gas supply system 1168 and a showerhead 1104 are fluidly coupled to the chamber for supplying (for example) film precursors, carrier and / or purge and / or process gases, secondary reactants, etc. The showerhead 1104 may be any showerhead described herein. Also shown in FIG. 11 is an apparatus for generating plasma in the processing chamber. The equipment shown generally in FIG. 11 is for performing atomic layer deposition (ALD), but may be adapted for performing other film deposition operations, such as conventional chemical vapor deposition (CVD), particularly plasma enhanced CVD (PECVD).

[0107] For simplicity, the processing equipment 1160 is shown as a stand-alone process station having a process chamber body 1162 to maintain a low pressure environment. However, it will be understood that multiple process stations may be included within a common process tool environment, such as a common reaction chamber as described herein. For example, FIG. 12 illustrates an embodiment of a multi-station processing tool, which is described in more detail below. Additionally, it will be understood that in some embodiments, one or more hardware parameters of the processing equipment 1160, including those described in more detail herein, may be programmatically adjusted by one or more system controllers.

[0108] The process station 1162 is in fluid communication with a gas supply system 1168 that supplies process gases, which may include liquids and / or gases, to the showerhead 1104. The gas supply system 1168 includes a mixing vessel 1170 for mixing and / or conditioning the process gases supplied to the showerhead 1104. One or more mixing vessel inlet valves 1172 and 1174 may control the introduction of process gases into the mixing vessel 1170.

[0109] Some reactants may be stored in liquid form prior to vaporization and after delivery to the process chamber 1162. The embodiment of FIG. 11 includes a vaporization point 1176 for vaporizing the liquid reactants delivered to the mixing vessel 1170. In some embodiments, the vaporization point 1176 may be a heated liquid injection module. In some other embodiments, the vaporization point 1176 may be a heated vaporizer. In still other embodiments, the vaporization point 1176 may be removed from the process station. In some embodiments, a liquid flow controller (LFC) upstream of the vaporization point 1176 may be provided to control the mass flow rate of liquid for vaporization and delivery to the process chamber 1162.

[0110] The showerhead 1104 distributes process gases and / or reactants (e.g., film precursors) toward a substrate 1178 at a process station, the flow of which is controlled by one or more valves (e.g., valves 1180, 1172, and 1174) upstream from the showerhead. In the embodiment shown in FIG. 11, the substrate 1178 is shown positioned below the showerhead 1104 and resting on a pedestal 1164. In some embodiments with more than one station, the gas delivery system 1168 includes valves or other flow control structures upstream from the showerhead, which allow independent control of the flow of process gases and / or reactants to each station, such that gas is flowed to one station but not to another. Additionally, the gas delivery system 1168 may be configured to independently control the process gases and / or reactants supplied to each station in a multi-station apparatus, such that the gas compositions provided to different stations are different, e.g., partial pressures of gas components may be varied between stations simultaneously.

[0111] Volume 1180 is located below the showerhead 1104. In some implementations, the pedestal 1164 may be raised or lowered to expose the substrate 1178 to volume 1180 and / or to change the volume of volume 1180. Optionally, the pedestal 1164 may be lowered and / or raised during a portion of the deposition process to adjust the process pressure, reactant concentrations, etc. within volume 1180.

[0112] In FIG. 11, the showerhead 1104 and pedestal 1164 are electrically connected to an RF power source 1182 and a matching network 1184 for powering the plasma. In some implementations, the plasma energy may be controlled (e.g., via a system controller having suitable machine-readable instructions and / or control logic) by controlling one or more of the process station pressure, gas concentration, RF power source, RF source frequency, and plasma power pulse timing. For example, the RF power source 1182 and the matching network 1184 may operate at any suitable power to form a plasma having a desired composition of radical species. Similarly, the RF power source 1182 may provide RF power of any suitable frequency and power. The apparatus 1160 may also include a DC power source 1186 configured to provide a direct current to the pedestal 1164, which may be an ESC, to generate and provide an electrostatic clamping force to the ESC 1164 and the substrate 1178. The pedestal 1164 may also have one or more temperature control elements 1188 configured to heat and / or cool the substrate 1164 .

[0113] In some implementations, the apparatus is controlled with suitable hardware and / or suitable machine-readable instructions in a system controller that may provide control instructions via a sequence of input / output control (IOC) instructions. In one example, instructions for setting plasma conditions for plasma ignition or plasma maintenance are provided in the form of a plasma activation recipe of a process recipe. In some cases, a process recipe may be sequentially arranged such that all instructions for a process are executed simultaneously with that process. In some implementations, instructions for setting one or more plasma parameters may be included in a recipe preceding a plasma process. For example, a first recipe may include instructions for setting flow rates of an inert (e.g., helium) gas and / or a reactive gas, instructions for setting a plasma generator to a power set point, and time delay instructions for the first recipe. A second, subsequent recipe may include instructions for enabling the plasma generator and time delay instructions for the second recipe. A third recipe may include instructions for disabling the plasma generator and time delay instructions for the third recipe. It will be understood that these recipes may be further subdivided and / or repeated in any suitable manner within the scope of the present disclosure.

[0114] As mentioned above, one or more process stations may be included in a multi-station substrate processing tool. FIG. 12 illustrates an exemplary multi-station substrate processing apparatus. Through the use of a multi-station processing apparatus as illustrated in FIG. 12, various efficiencies can be achieved for equipment costs, operating expenses, as well as increased throughput. For example, a single vacuum pump may be used to evacuate used process gases, etc. for all four process stations to generate a single high vacuum environment. Depending on the implementation, each process station may have its own dedicated showerhead for gas delivery, but may share the same gas delivery system. Similarly, certain elements of the plasma generation apparatus may be shared between process stations (e.g., power supplies), but depending on the implementation, certain aspects may be process station specific (e.g., when a showerhead is used to apply a plasma generating potential, etc.). Again, it will be understood that such efficiency can be achieved to a greater or lesser extent by using a greater or lesser number of process stations per process chamber, such as 2, 3, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or 16, or a greater or lesser number of process stations per reaction chamber.

[0115] The substrate processing apparatus 1260 of FIG. 12 may employ a single substrate processing chamber 1262 that includes multiple substrate processing stations, each of which may be used to perform processing operations on a substrate held on a wafer holder, e.g., a pedestal or an ESC, at that process station. In this particular embodiment, the multi-station substrate processing apparatus 1260 is shown having four process stations 1291, 1292, 1293, and 1294. Other similar multi-station processing apparatus may have more or fewer processing stations depending on the implementation and, e.g., the desired level of parallel wafer processing, size / space constraints, cost constraints, etc. Also shown in FIG. 12 is a substrate handler robot 1296 and a controller 1298.

[0116] As shown in FIG. 12, the multi-station processing tool 1260 has a substrate load port 12100 and a robot 1296 configured to move substrates from a cassette loaded via a pod 12102 through the atmospheric port 12100 into the processing chamber 1262 and to one of four stations 1291, 1292, 1293, and 1294. The tool 1260 also has a wafer handling system 1295 for transporting wafers into the processing chamber 1262. In some embodiments, the wafer handling system 1295 may transport wafers between various process stations and / or between a process station and a load lock. It should be understood that any suitable wafer handling system may be employed. Non-limiting examples include a wafer carousel (as shown in FIG. 12) and a wafer handling robot.

[0117] The processing chamber 1262 shown in FIG. 12 includes four process stations, 1291, 1292, 1293, and 1294. RF power is generated by an RF power system 1282 and distributed to each of the stations 1291, 1292, 1293, and 1294, and similarly a DC power source 1286 is distributed to each of the stations. The RF power system 1282 may include one or more RF power sources, e.g., high frequency (HFRF) and low frequency (LFRF) sources, impedance matching modules, and filters. In certain implementations, the power sources may be limited to only high frequency or low frequency sources. The distribution system of the RF power system may be symmetric about the reactor and may have a high impedance. This symmetry and impedance result in approximately equal amounts of power being provided to each station.

[0118] 12 also illustrates an embodiment of a system controller 1298 employed to control the process conditions and hardware states of the process tool 1260 and its process stations. The system controller 1298 may include one or more memory devices 12104, one or more mass memory devices 12106, and one or more processors 12108. The processor 12108 may include one or more CPUs, ASICs, general purpose and / or special purpose computers, one or more analog and / or digital input / output connections, one or more stepper motor control boards, etc.

[0119] The system controller 1298 may execute machine-readable system control instructions 12110 on the processor 12108, which in some implementations are loaded into the storage device 12104 from the mass storage device 12106. The system control instructions 12110 include instructions for controlling the timing, mixture of gas and liquid reactants, chamber and / or station pressure, chamber and / or station temperature, wafer temperature, target power levels, RF power levels, RF exposure times, DC power and duration of clamping the substrate, substrate pedestal, chuck and / or susceptor position, plasma formation at each station (which may include independent plasma formation at one or more stations, as described above), gas and liquid reactant flows (which may include independent flows at one or more stations, as described above), and other parameters of the particular processes performed by the process tool 1260. These processes may include various types of processes, including, but not limited to, processes associated with the deposition of a film on a substrate. The system control instructions 1298 may be arranged in any suitable manner.

[0120] The electronics may be referred to as a "controller," which may control various components or subparts of one or more systems. Depending on the processing requirements and / or type of system, the controller may be programmed to control any of the processes disclosed herein, and may also be programmed to control various parameters affecting semiconductor processing, such as supply of process gases, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow settings, fluid supply settings, position and motion settings, loading and unloading of wafers into and out of the tool and other transport tools and / or load locks connected or coupled to a particular system.

[0121] In broad terms, a controller may be defined as an electronic device having various integrated circuits, logic, memory, and / or software that receive instructions, issue instructions, control operations, enable cleaning operations, enable endpoint measurements, etc. Integrated circuits may include chips in the form of firmware that store program instructions, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and / or one or more microprocessors or microcontrollers that execute the program instructions (e.g., software). Program instructions may be instructions communicated to the controller in the form of various individual settings (or program files) that define operational parameters for performing a particular process on or for a semiconductor wafer or for a system. In some embodiments, the operational parameters may be part of a recipe defined by a process engineer to accomplish one or more processing steps during the manufacture of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or dies of a wafer.

[0122] In some implementations, the controller may be part of or coupled to a computer that is integral with, coupled to, or otherwise networked to the system, or a combination thereof. For example, the controller may be in the "cloud" or may be all or part of a fab host computer system, allowing remote access of wafer processing. The computer may allow remote access to the system to monitor the current progress of a fabrication operation, examine the history of past fabrication operations, examine trends or performance criteria from multiple fabrication operations, modify parameters of a current process, set processing steps following a current process, or initiate a new process. In some examples, a remote computer (e.g., a server) may provide process recipes to the system over a network, which may include a local network or the Internet. The remote computer may include a user interface that allows entry or programming of parameters and / or settings, which are then communicated from the remote computer to the system. In some examples, the controller receives instructions in the form of data, which identifies parameters for each of the processing steps performed during one or more operations. It should be understood that the parameters may be specific to the type of process being performed and the type of tool with which the controller is configured to interface or control. Thus, as discussed above, the controller may be distributed, such as by having one or more individual controllers networked together and cooperating toward a common purpose, such as the processes and controls described herein. One example of a distributed controller for such purposes would include one or more integrated circuits on the chamber that are located remotely (such as at the platform level or as part of a remote computer) and communicate with one or more integrated circuits coupled to control the process on the chamber.

[0123] Exemplary systems may include, but are not limited to, a plasma etch chamber or module, a deposition chamber or module, a spin rinse chamber or module, a metal plating chamber or module, a cleaning chamber or module, a bevel edge etch chamber or module, a physical vapor deposition (PVD) chamber or module, a chemical vapor deposition (CVD) chamber or module, an atomic layer deposition (ALD) chamber or module, an atomic layer etch (ALE) chamber or module, an ion implantation chamber or module, a tracking chamber or module, and any other semiconductor processing system that may be associated with or used in the fabrication and / or manufacturing of semiconductor wafers.

[0124] As described above, depending on the process step or steps being performed by the tool, the controller may communicate with one or more other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, nearby tools, tools located throughout the factory, a main computer, another controller, or tools used for material transport to and from tool locations and / or load ports of wafers within a semiconductor manufacturing factory.

[0125] As used herein, the term "wafer" may refer to a semiconductor wafer or substrate, or other similar types of wafers or substrates. As used herein, the term wafer station may refer to any location within a semiconductor processing tool where a wafer may be placed during any of the various wafer processing or wafer transfer operations. Wafer support is used herein to refer to any structure within a wafer station configured to receive and support a semiconductor wafer, e.g., a pedestal, electrostatic chuck, wafer support shelf, etc.

[0126] It should also be understood that any use of ordinal indicators, e.g., (a), (b), (c), ... herein is for organizational purposes only and is not intended to convey any particular order or importance to the items associated with each ordinal indicator. Nonetheless, some items associated with ordinal indicators may inherently require a particular order, e.g., "(a) obtain information about X, (b) determine Y based on information about X, (c) obtain information about Z," where in this example (a) requires the execution of (b) because (b) relies on information obtained in (a), but (c) can be executed before or after either (a) and / or (b).

[0127] Use of the term "each," as used herein, such as in the phrases "for each <item> of one or more <items>" and "of each <item>," should be understood to include both single and multiple items. That is, the phrase "for each..." is used in the sense that it is used in programming languages ​​to refer to each item of whatever the referenced collection of items is. For example, if the referenced collection of items is a single item, then "each" would only refer to that single item (despite the fact that dictionary definitions of "each" are often used to refer to "one of two or more things") and would not imply that there must be at least two of the items. Similarly, if a selected item may have one or more subitems, and a selection of one of those subitems is made, then if the selected item has only one subitem, then the selection of that one subitem will be understood to be implicit in the selection of the item itself.

[0128] Also, references to multiple controllers collectively configured to perform various functions will be understood to be intended to encompass situations where only one of the controllers is configured to perform all of the disclosed or discussed functions, as well as situations where the various controllers each perform a subportion of the discussed functions.

[0129] Various modifications to the embodiments described in this disclosure will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments without departing from the spirit or scope of the disclosure. Accordingly, it is not intended that the claims be limited to the embodiments shown herein, but are to be accorded the widest scope consistent with this disclosure, the principles and novel features disclosed herein.

[0130] Certain features described herein in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Furthermore, even if features are described above as acting in a particular combination and are initially claimed as such, one or more features from the claimed combination may in some cases be deleted from the combination, and the claimed combination may relate to a subcombination or a variation of the subcombination.

[0131] Similarly, although operations are shown in the figures in a particular order, this should not be understood as requiring such operations to be performed in the particular order shown, or in any sequential order, or as requiring all of the operations shown to achieve desired results. Additionally, the figures may generally depict one or more exemplary processes in the form of a flow diagram. However, other operations not shown may be incorporated into the exemplary processes depicted in the schematic. For example, one or more additional operations may be performed before, after, simultaneously, or between any of the depicted operations. In certain circumstances, multitasking and parallel processing may be advantageous. Additionally, the separation of various system components in the above-described embodiments should not be understood as requiring such separation in all embodiments, and it should be understood that the described program components and systems may generally be integrated together in a single software product or packaged within multiple software products. Additionally, other embodiments are within the scope of the following claims. In some cases, the operations recited in the claims may be performed in a different order and still achieve desired results.

[0132] Unless otherwise clearly required in the context of this disclosure, words using the singular or plural number generally also include the plural or singular, respectively. When the word "or" is used in reference to a list of two or more items, the word covers all interpretations of any of the items in the list, all of the items in the list, and any combination of the items in the list. The term "embodiment" refers to an embodiment of the techniques and methods described herein, as well as a physical object that embodies the structure and / or incorporates the techniques and / or methods described herein.

[0133] As used herein, the term "substantially" means within 5% of the referenced value unless otherwise specified. For example, substantially perpendicular means within ±5% of parallel. The term "substantially" may be used herein to indicate precision of measurements and relationships, but precision is not always achieved or achievable due to manufacturing imperfections and manufacturing tolerances. For example, two separate features may be intended to be manufactured to have the same size (e.g., two holes), but due to various manufacturing imperfections, the features may be close to, but not exactly, the same size.

Claims

1. A shower head, a faceplate having a front surface, a back surface, and a plurality of cylindrical through holes extending through the faceplate from the front surface to the back surface, each edge formed by an intersection of the front surface of the faceplate with each of the through holes having a radius; A gas inlet; a plenum volume fluidly connected to the gas inlet in the showerhead and at least partially defined by the backside; Equipped with The back surface is a non-planar region, extending about a central axis of the faceplate; having an outer boundary and an inner boundary offset from one another by a first distance along the central axis, the outer boundary being closer to the gas inlet in a direction parallel to the central axis than the inner boundary, the outer boundary being offset radially outward from the inner boundary, the back surface further including a circular planar region having an outer periphery perpendicular to the central axis and defined by the inner boundary of the non-planar region; having a non-planar surface extending between said inner boundary and said outer boundary; A showerhead including a non-planar area.

2. 10. The showerhead of claim 1, The non-planar surface is defined by a linear profile rotating about the central axis; extending between the inner boundary and the outer boundary; and Oriented at an oblique angle to said central axis A rotating surface is the shower head.

3. 10. The showerhead of claim 1, The showerhead, wherein the non-planar surface is a frusto-conical surface.

4. 10. The showerhead of claim 1, the non-planar surface is a surface of revolution defined by a non-linear profile rotating about the central axis and extending between the inner boundary and the outer boundary.

5. 10. The showerhead of claim 1, one or more first through holes of the plurality of through holes extend from the non-planar region to the front surface, each of the one or more through holes having a first length; one or more second through holes of the plurality of through holes extend from the non-planar region to the front surface and are disposed farther from the central axis in a direction parallel to the central axis than the one or more first through holes; and the one or more second through holes each have a second length that is longer than the first length of the one or more first through holes.

6. 10. The showerhead of claim 1, the radius of each of the edges and the diameter of each of the through-holes are substantially the same.

7. 10. The showerhead of claim 1, The showerhead, wherein each through-hole has a diameter of between 0.01 and 0.03 inches (0.254 and 0.762 millimeters).

8. 10. The showerhead of claim 1, The showerhead, wherein the radius is formed by electropolishing.

9. 10. The showerhead of claim 1, The showerhead, wherein the radius is formed by machining and electropolishing.

10. 10. The showerhead of claim 1, The through holes are arranged in a plurality of hexagonal patterns; Each hexagonal pattern has six exterior holes arranged around a central hole; and The six exterior holes are equally spaced from one another and equally spaced from the central hole.

11. 11. The showerhead of claim 10, the distance between the six outer holes and the central hole of each hexagonal pattern is between 0.1 and 0.4 inches (2.54 and 10.16 millimeters).

12. 10. The showerhead of claim 1, The showerhead, wherein the diameter of the outer boundary is greater than a diameter of a semiconductor substrate.

13. 13. The showerhead of claim 12, the outer boundary has a diameter between 7.5 inches and 13 inches (190.5 to 330.2 mm).

14. 10. The showerhead of claim 1, the first distance is between 0.01 inches and 0.075 inches (0.254 to 1.905 mm).

15. 10. The showerhead of claim 1, The showerhead, wherein the inner boundary has a diameter greater than 0 inches and between 0 inches and 8.5 inches (0 to 215.9 mm).

16. 10. The showerhead of claim 1, the showerhead further comprising a backplate having the gas inlet and a first surface, the plenum volume further defined by the first surface.

17. 10. The showerhead of claim 1, The showerhead further comprises a baffle plate having a baffle plate outer diameter and positioned within the plenum volume.

18. 20. The showerhead of claim 17, The showerhead, wherein the baffle plate outer diameter and the inner boundary diameter are substantially the same.

19. 1. A faceplate for use in a processing chamber of a semiconductor processing apparatus, comprising: The face plate includes: The front and a back surface including a non-planar region; the non-planar region extends about a central axis of the faceplate; the non-planar region has outer and inner boundaries that are offset from one another by a first distance along the central axis; the underside further includes a circular planar region having an outer periphery perpendicular to the central axis and defined by the inner boundary of the non-planar region; the inner boundary is closer to the central axis than the outer boundary in a direction parallel to the central axis, and the outer boundary is offset radially outward from the inner boundary; the non-planar region has a non-planar surface extending between the inner boundary and the outer boundary; and a plurality of cylindrical through holes extending through the faceplate from the front surface to the back surface; Equipped with each edge formed by an intersection of the front surface of the faceplate with each of the through-holes has a radius.

20. 20. The faceplate of claim 19, The non-planar surface is defined by a linear profile rotating about the central axis; extending between the inner boundary and the outer boundary; and Oriented at an oblique angle to said central axis The surface of rotation, the faceplate.

21. 20. The faceplate of claim 19, The non-planar region is a frusto-conical surface.

22. 20. The faceplate of claim 19, The non-planar surface is a surface of revolution defined by a non-linear profile rotating about the central axis and extending between the inner boundary and the outer boundary.

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