Showerhead Assembly and Components

Abstract

To provide a shower head assembly that is improved in throughput and also reduced in cost by shortening a cycle time with respect to an embodiment of a shower head assembly used for an atomic layer deposition (ALD) process.SOLUTION: A shower head plate 202 is configured to distribute steam to a reaction chamber, and comprises a first surface, a second surface on the opposite side from the first surface, and a plurality of openings 204 extending from the first surface to the second surface, and a shower head is approximately 25-35 thick between the first surface and the second surface.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 62 / 961,588, filed January 15, 2020, the entire contents of which are incorporated herein by reference in their entirety and for all purposes.

[0002] The present disclosure relates generally to a showerhead assembly for a gas-phase reactor, and more particularly to a vapor distribution system and components of the vapor distribution system for a gas-phase reactor. [Background technology]

[0003] Gas-phase reactors, such as chemical vapor deposition (CVD), plasma-enhanced chemical vapor deposition (PECVD), atomic layer deposition (ALD), and the like, can be used for a variety of applications, including depositing and etching materials on substrate surfaces. For example, gas-phase reactors can be used to deposit and / or etch layers on substrates to form semiconductor devices, flat panel display devices, photovoltaic devices, microelectromechanical systems (MEMS), and the like.

[0004] A typical gas-phase reactor system includes a reactor including a reaction chamber, one or more precursor vapor sources fluidly connected to the reaction chamber, one or more carrier and / or purge gas sources fluidly connected to the reaction chamber, a vapor distribution system for delivering gases (e.g., precursor gases and / or carrier or purge gases) to the surface of the substrate, and an exhaust source fluidly connected to the reaction chamber. The system also typically includes a susceptor for holding the substrate in place during processing. The susceptor can be configured to move up and down to receive the substrate and / or can rotate during substrate processing.

[0005] The vapor distribution system may include a showerhead assembly for distributing vapor(s) to the surface of the substrate. The showerhead assembly is typically positioned above the substrate. During substrate processing, vapor(s) flow downward from the showerhead assembly toward the substrate and then radially outward across the substrate. A typical showerhead assembly includes a showerhead having a chamber adjacent to one surface of the showerhead and multiple openings extending between the chamber and the distribution surface (substrate side) of the showerhead. The openings are generally cylindrical in shape, although other shapes are possible, and are spaced apart to leave significant horizontal portions on both the chamber side surface and the distribution surface of the showerhead. Summary of the Invention

[0006] In one aspect, a showerhead plate for distributing vapor to a reaction chamber is provided, the showerhead plate including a first surface, a second surface opposite the first surface, and a plurality of openings extending from the first surface to the second surface, wherein a thickness of the showerhead plate between the first surface and the second surface is in a range from about 27 mm to about 33 mm.

[0007] In some embodiments, the thickness of the showerhead plate between the first surface and the second surface is in the range of about 29 mm to about 31 mm. In some embodiments, the width of the showerhead plate is in the range of about 210 mm to about 260 mm. In some embodiments, the width of the showerhead plate is in the range of about 310 mm to about 360 mm. In some embodiments, the width of the showerhead plate is in the range of about 460 mm to about 500 mm. In some embodiments, the number of openings in the plurality of openings is in the range of about 1,500 to 4,500 openings. In some embodiments, the number of openings is in the range of about 1,500 to 2,500 openings.

[0008] In some embodiments, at least one opening of the plurality of openings includes: a first axial inlet section extending from the first surface along a vertical axis of the showerhead plate; a first tapered section extending from the first axial inlet section, the first tapered section including an inwardly angled sidewall angling inwardly from the first axial inlet section; a conduit section extending from the first tapered section and oriented along the vertical axis of the showerhead plate, the conduit section having a smaller major lateral dimension than the first axial inlet section; and a second tapered section extending from the conduit section to the second surface, the second tapered section including an outlet configured to deliver steam to the reaction chamber.

[0009] In another aspect, a reactor assembly is provided, the reactor assembly including: a showerhead assembly including a showerhead plenum and a showerhead plate as described above, wherein the showerhead plenum is disposed above the showerhead plate; a substrate support adapted to support a substrate; and a reaction chamber at least partially defined by the substrate support and the showerhead plate, wherein a height of the reaction chamber between a top surface of the substrate support and a bottom surface of the showerhead plate is in the range of 3 mm to 7 mm.

[0010] In some embodiments, the reactor assembly further includes a vaporizer configured to vaporize the solid source precursor.

[0011] In another aspect, a showerhead plate for distributing vapor to a reaction chamber is provided, the showerhead plate including a first surface, a second surface opposite the first surface, and a plurality of openings extending from the first surface to the second surface, the plurality of openings including: a first axial inlet section extending from the first surface along a vertical axis of the showerhead plate; a first tapered section extending from the first axial inlet section, the first tapered section including an inwardly angled sidewall angling inwardly from the first axial inlet section; a conduit section extending from the first tapered section and oriented along the vertical axis of the showerhead plate, the conduit section having a smaller major lateral dimension than the first axial inlet section; and a second tapered section extending from the conduit section to the second surface, the second tapered section including an outlet configured to deliver vapor to the reaction chamber.

[0012] In some embodiments, the thickness of the showerhead plate between the first surface and the second surface is in the range of about 27 mm to about 33 mm. In some embodiments, the thickness of the showerhead plate between the first surface and the second surface is in the range of about 29 mm to about 31 mm. In some embodiments, the conduit section has a length in the range of about 15 mm to about 20 mm. In some embodiments, the first axial inlet section has a vertical height in the range of about 3.5 mm to about 4.5 mm. In some embodiments, the first tapered section has a vertical height in the range of about 3.5 mm to about 4.5 mm. In some embodiments, the second tapered section has a vertical height in the range of about 2.5 mm to about 3.5 mm.

[0013] In some embodiments, the angle between opposing sidewalls of the first tapered section is in the range of about 60 degrees to about 90 degrees. In some embodiments, the angle between opposing sidewalls of the second tapered section is in the range of about 60 degrees to about 90 degrees.

[0014] In another aspect, a reactor assembly is provided, the reactor assembly including: a showerhead assembly including a showerhead plenum and a showerhead plate including a plurality of openings therethrough, the showerhead plenum being disposed above the showerhead plate; a substrate support adapted to support a substrate; and a reaction chamber at least partially defined by the substrate support and the showerhead plate, wherein a height of the reaction chamber between a top surface of the substrate support and a bottom surface of the showerhead plate is in the range of 3 mm to 7 mm.

[0015] In some embodiments, the reactor assembly further includes a spacer that mechanically supports the showerhead plate. In some embodiments, the reaction chamber volume is about 1280 to 1920 mm 2 In some embodiments, the reaction chamber width is in the range of about 200 mm to about 440 mm. In some embodiments, the ratio of the reaction chamber height to the reaction chamber width is in the range of about 1:80 to 1:29. In some embodiments, the spacer has a thickness in the range of about 20 mm to 30 mm. In some embodiments, the reactor assembly further includes a vaporizer configured to vaporize the solid source precursor.

[0016] In another aspect, a showerhead plate for distributing vapor to a reaction chamber is provided, the showerhead plate including a first surface, a second surface opposite the first surface, and a plurality of openings extending from the first surface to the second surface, the plurality of openings including a plurality of exterior openings having an aperture portion extending along a vertical axis of the showerhead plate and one or more interior openings angled inward toward a central region of the showerhead plate.

[0017] In some embodiments, the outer opening is disposed radially outward and at least partially surrounds the inner opening(s). In some embodiments, the inner opening(s) are angled inward at an angle in the range of 5 degrees to 55 degrees relative to a vertical axis of the showerhead plate. In some embodiments, the inner opening(s) include a first angled opening located closest to a center position of the showerhead plate. In some embodiments, the inner opening(s) further include a second angled opening located on the opposite side of the center position of the showerhead plate from the first angled opening. In some embodiments, the showerhead plate does not have an opening at a center position of the showerhead plate. In some embodiments, the plate body portion of the showerhead plate is located at a center position of the showerhead plate.

[0018] In some embodiments, at least one of the external openings includes: a first axial inlet section extending from the first surface along a vertical axis of the showerhead plate; a first tapered section extending from the first axial inlet section, the first tapered section comprising an inwardly angled sidewall angling inward from the first axial inlet section; a conduit section extending from the first tapered section and oriented along the vertical axis of the showerhead plate, the conduit section having a smaller major lateral dimension than the first axial inlet section; and a second tapered section extending from the conduit section to the second surface, the second tapered section comprising an outlet configured to deliver steam to the reaction chamber.

[0019] In another aspect, a reactor assembly is provided, the reactor assembly including: a reactor manifold having holes; a showerhead assembly comprising the showerhead plenum and showerhead plate disclosed above, wherein the holes are positioned laterally at a central location of the showerhead plate; and a substrate support adapted to support a substrate.

[0020] In some embodiments, the substrate support is adapted to support the substrate at a location where a center position of the showerhead plate is aligned with a center position of the substrate.

[0021] In another aspect, a method of constructing a reactor assembly is provided, the method including: providing a reactor assembly having a reaction chamber including a substrate support; selecting a showerhead plate having a thickness that provides a predetermined reaction chamber height, the reaction chamber being defined at least in part between a bottom surface of the showerhead plate and a top surface of the substrate support; and mounting the showerhead plate within the reaction chamber above the substrate support to provide the predetermined reaction chamber height.

[0022] In some embodiments, the method further includes removing a second showerhead plate from the reactor assembly and retrofitting the reactor assembly with the showerhead plate. In some embodiments, the showerhead plate is thicker than the second showerhead plate. In some embodiments, selecting the showerhead plate includes selecting the showerhead plate from a plurality of showerhead plates to provide a predetermined reaction chamber height.

[0023] These and other features, aspects, and advantages of the present invention will now be described with reference to drawings of several embodiments, which are intended to illustrate, but not limit, the invention. [Brief explanation of the drawings]

[0024] [Figure 1] FIG. 1 is a cross-sectional side view of semiconductor processing equipment according to various embodiments. [Figure 2] FIG. 2 is a side cross-sectional view of a portion of a showerhead assembly. [Figure 3A] FIG. 3A is a side cross-sectional view of a portion of a showerhead assembly according to various embodiments. [Figure 3B] FIG. 3B is an enlarged view of the cross section shown in FIG. 3A. [Figure 4] FIG. 4 is a cross-sectional side view of a showerhead assembly according to another embodiment. [Figure 5] Figure 5A is a bottom view of the showerhead plate of the showerhead assembly of Figure 2. Figure 5B is a bottom view of the showerhead plate of the showerhead assembly of Figures 3A and 3B. [Figure 6] 6A and 6B are cross-sectional views of the showerhead assembly during injection of vaporized reactant during injection of a first reactant vapor and after a previous purge step. [Figure 7] 7A and 7B are bottom views of a showerhead plate according to various embodiments. [Figure 8A] FIG. 8A is a cross-sectional view of a showerhead assembly having a central opening according to various embodiments. [Figure 8B] FIG. 8B is a cross-sectional view of a showerhead assembly without a central opening, according to various embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0025] The descriptions of exemplary embodiments provided below are merely exemplary and are intended for illustrative purposes only, and the following descriptions are not intended to limit the scope of the present disclosure or the claims. Moreover, the recitation of multiple embodiments having stated features is not intended to exclude other embodiments having additional features or other embodiments incorporating different combinations of the stated features.

[0026] In some semiconductor processing equipment, reactant vapor flows from a plenum of a distributor (such as a showerhead assembly), through openings in the distributor assembly (e.g., openings in the showerhead assembly), and toward a substrate (e.g., a semiconductor wafer). The time it takes to purge a semiconductor processing equipment with an inert gas may depend, at least in part, on the volume of the distributor's plenum. For example, distributors with larger plenums may require increased purge times, e.g., additional time and / or reduced vacuum pressure may be used to purge the reactant(s) from the distributor and reaction chamber surfaces. During a typical ALD process, pulses of reactant in vapor form may be pulsed sequentially into the reaction chamber with purge steps between reactant pulses to avoid direct interaction between reactants in the gas phase. For example, pulses of an inert or inert gas, or a "purge" pulse, may be provided between reactant pulses. The inert gas purges the chamber from one reactant pulse before the next reactant pulse is delivered to avoid gas-phase mixing. Increasing purge time and / or decreasing vacuum pressure can reduce throughput and increase costs during ALD processing. Therefore, it can be advantageous to reduce the size of the plenum of the distributor to reduce purge time and improve throughput.

[0027] The present disclosure generally relates to a vapor distribution system, a showerhead assembly for the vapor distribution system, a showerhead for the vapor distribution system, and a reactor system including the vapor distribution system, as well as methods of using the vapor distribution system, showerhead assembly, showerhead, and reactor system. The vapor distribution system, showerhead assembly, showerhead, and reactor system as described herein can be used to process substrates (such as semiconductor wafers) in gas-phase reactors (such as chemical vapor deposition (CVD) reactors, including plasma-enhanced CVD (PECVD) reactors, low-pressure CVD (LPCVD) reactors, atomic layer deposition (ALD) reactors, and the like). By way of example, the assemblies and components described herein can be used in showerhead-type gas-phase reactor systems, in which gases generally flow downward from the showerhead and toward the substrate.

[0028] The vapor distribution system may include (but is not limited to) the components shown in FIG. 1 . FIG. 1 illustrates a semiconductor processing apparatus 10 also shown and described in connection with FIG. 8B of U.S. Patent Publication No. 2017-0350011, which is incorporated herein by reference in its entirety for all purposes. FIG. 1 illustrates a manifold 100 that is part of the overall semiconductor processing apparatus 10. The manifold 100 may include holes 130 that inject vapor downward toward a distribution apparatus including a showerhead assembly 820. It is understood that the manifold 100 may include multiple blocks connected together, as shown, or may include one single body. The manifold 100 may be connected upstream of a reaction chamber 810. In particular, the outlets of the holes 130 may communicate with a distribution mechanism in the form of a reactant injector, specifically a showerhead assembly 820. The showerhead assembly 820 includes a showerhead plate 822 that defines a showerhead plenum 824 or chamber above the plate 822. Showerhead assembly 820 conducts vapor from manifold 100 to reaction space 826 below showerhead 820. Reaction chamber 810 includes a substrate support 828 configured to support a substrate 829 (e.g., a semiconductor wafer) in reaction space 826. The reaction chamber also includes an exhaust opening 830 connected to a vacuum source. While shown with a single-wafer, showerhead-type reaction chamber, those skilled in the art will appreciate that the manifold can also be connected to other types of reaction chambers (e.g., batch or furnace-type horizontal or cross-flow reactors, etc.) having other types of injectors.

[0029] Any suitable number or type of reactants can be supplied to the reaction chamber 810. Various embodiments disclosed herein can be configured to deposit metal oxide layer(s) on a substrate. In some embodiments, one or more of the reactant sources can contain natural, gaseous ALD reactants, such as nitrogen and oxygen precursors (e.g., H, NH, N, O, or O). Additionally or alternatively, one or more of the reactant sources can include a vaporizer for vaporizing reactants that are solid or liquid at room temperature and atmospheric pressure. The vaporizer(s) can be, for example, a liquid bubbler or a solid sublimation vessel. Examples of solid or liquid reactants that can be held and vaporized in the vaporizer include various HfO and TiN reactants. Solid or liquid reactants that can be held and vaporized can include, but are not limited to, liquid organometallic precursors (such as trimethylaluminum (TMA), TEMAHf, or TEMAZr), liquid semiconductor precursors (such as dichlorosilane (DCS), trichlorosilane (TCS), trisilane, organosilanes, or TiCl), and vaporized metal or semiconductor precursors such as powdered precursors (such as ZrCl or HfCl). Those skilled in the art will understand that embodiments can include any desired combination and arrangement of gaseous, solid, or liquid reactant sources in nature.

[0030] The semiconductor processing apparatus 10 can also include at least one controller 860, which includes a processor(s) and memory having programming for controlling the various components of the apparatus 10. While shown schematically connected to the reaction chamber 810, those skilled in the art will understand that the controller 860 communicates with the various components of the reactor (such as vapor control valves, heating systems, gate valves, robotic wafer carriers, etc.) to execute the deposition process. In operation, the controller 860 can be arranged for a substrate 829 (such as a semiconductor wafer) to be loaded onto the substrate support 828, and for the reaction chamber 810 to be closed, purged, and typically pumped down in preparation for a deposition process, particularly an atomic layer deposition (ALD) process. The controller 829 can further be configured to control the sequence of deposition. For example, the controller 829 can send control commands to the reactant valve(s) to open the reactant valve(s) and supply reactant vapor to the manifold 100. The controller 829 can also send control commands to the inert gas valve(s) to cause the inert gas valve(s) to open and supply inert purge gas to the manifold 100. The controller 829 can be configured to control other aspects of the process as well.

[0031] Manifold 100 can inject multiple reactants, such as a first reactant vapor and a second reactant vapor, simultaneously to induce mixing or sequentially to cycle between the reactants. During some processes, a purge gas can be injected into showerhead assembly 820 through holes 130 to purge the first reactant vapor to prevent it from contaminating or mixing with a subsequently injected second reactant vapor. Similarly, after deposition of the second reactant vapor and before deposition of another reactant (e.g., the first reactant vapor or a different reactant vapor), an additional purge step is performed in which an inert gas is delivered downward through inlet 120 into showerhead assembly 820 and reaction chamber 826.

[0032] Keeping purge time (e.g., the length of time it takes for the inert gas to purge the reactant(s) from the device 10) as short as possible is advantageous for increasing throughput and reducing costs. Purge time may be related to the size of the reactor chamber 826 and / or the size of the showerhead assembly 820. Reducing the size of one or both of the showerhead assembly 820 and the reaction chamber 826 can beneficially improve throughput. The showerhead assembly 820 and the reactor chamber 826 are described below in the description of Figures 2-4.

[0033] FIG. 2 illustrates a cross-sectional view of a portion of a reactor assembly 20 including a showerhead assembly 200. The showerhead assembly 200 includes a showerhead plate 202 including a plurality of cylindrical openings 204 formed therein. A top plate 212 can at least partially define a showerhead plenum 201, which can include a chamber that collects and laterally distributes gas delivered to the showerhead assembly 200 from the holes 13. The top plate 212 can include an exhaust opening 216 that can be connected to a vacuum source. The reactor assembly 20 further includes a spacer 208 and a substrate support 210 adapted to support a substrate 214 (such as a semiconductor wafer). A reaction chamber 206 can be formed by the showerhead 202, the spacer 208, and the substrate support 210. Alternatively, there can be other components surrounding the substrate 214 to define the reaction chamber 206. The thickness A of the showerhead plate can be inversely proportional to the chamber height B; the greater the showerhead thickness A, the smaller the chamber height B. In the illustrated arrangement, the number of openings 204 formed in the showerhead plate 202 is about 1000. The chamber height B of the reactor assembly 20 is about 8 mm.

[0034] FIG. 3A illustrates a cross-sectional view of a portion of a reactor chamber assembly 30 including a showerhead assembly 300 according to various embodiments. Similar to the showerhead assembly 200 of FIG. 2, the showerhead assembly 300 includes a showerhead plate 302 including a plurality of openings 304 formed therein and a top plate 312 that at least partially defines a showerhead plenum 301 to collect and distribute gases from the holes 130 into the showerhead plate 302. As shown in FIGS. 3A and 3B, the shape of the openings 304 can be significantly different from the openings 204 shown in FIG. 2. The shape of the openings is further shown and described in FIG. 3B. The reactor chamber assembly 30 further includes a substrate support 310 configured to support a substrate 314. A reaction chamber 306 can be formed by the showerhead plate 302, the spacer 308, and the substrate support 310. As shown in FIG. 3A , the spacer 308 can function to mechanically support the showerhead plate 302 and can be mechanically coupled to an edge portion of the substrate support 310. The distance from the bottom surface 303 of the showerhead plate 302 to the upper support surface 305 of the substrate support 310 can determine the chamber height B and therefore the volume of the reaction chamber 306. A flow control ring 316 and a lower chamber isolation component 318 can be included to separate the reaction chamber 306 from a lower loading chamber (not shown). The loading chamber can provide access to the substrate support 310 or susceptor. For example, the substrate support 310 can be lowered into the lower loading chamber, and a substrate, such as a wafer, can be loaded onto the substrate support 310. The substrate support 310 can be raised to expose the substrate to the reaction chamber 306. The control ring 316 and isolation component 318 can therefore function to prevent process gases from leaking into the lower loading chamber. In the illustrated embodiment, the isolation component 318 may contact the substrate support 310 .The flow control ring 316 may be supported by the spacer 308 and may be connected to or in contact with the separation component 318 .

[0035] The thickness A of the showerhead plate 302 of FIG. 3A can be made thicker compared to the showerhead plate 202 of FIG. 2 to reduce the chamber height B, and therefore the overall volume of the reaction chamber 306, compared to the showerhead plate 202 of FIG. 2. The reduced chamber size results in reduced purge time, which, as discussed above, can improve throughput and reduce costs. While there are other ways to reduce chamber size, implementing a showerhead plate 302 with increased thickness allows for increased customization of chamber size without significantly increasing the expense of building the chamber, allowing for inexpensive and rapid customization of the effective chamber dimensions by replacing the showerhead plate 302. In some embodiments, the chamber height B can be reduced from approximately 8 mm in the arrangement of FIG. 2 to a chamber height B of approximately 2 mm to 7 mm, or 2.5 mm to 7 mm, or 2.5 mm to 6.5 mm, or 3 mm to 7 mm, or 3 mm to 6.5 mm, or 3 mm to 6 mm, or 3 mm to 5 mm, or approximately 3.5 mm to 4.5 mm, for example, to a chamber height B of approximately 4 mm in some embodiments. In various embodiments, the thickness A of the showerhead plate 302 can be approximately 25 mm to approximately 35 mm, or approximately 26 mm to approximately 34 mm, or approximately 27 mm to approximately 33 mm, or approximately 29 mm to approximately 31 mm. In some embodiments, the thickness A of the showerhead plate 302 can be approximately 27 mm, or approximately 31 mm, or approximately 33 mm. The thickness A of the showerhead plate 302 can include a minimum thickness of the plate 302. For example, if the thickness of the showerhead plate 302 varies across its width, the thickness A mentioned above may include the minimum thickness of the plate 302 in the portion of the plate that includes the opening 304.

[0036] The width of the showerhead plate can depend on the size of the substrates that the reactor chamber is adapted to process. In some embodiments, the reactor chamber can be adapted to process 200 mm substrates, and in these embodiments, the width of the showerhead plate can be about 210 mm to about 260 mm, or about 210 mm to about 230 mm. In some embodiments, the reactor chamber can be adapted to process 300 mm substrates, and in these embodiments, the width of the showerhead plate can be about 310 mm to about 360 mm, or about 310 mm to about 330 mm. In some embodiments, the reactor chamber can be adapted to process 450 mm substrates, and in these embodiments, the width of the showerhead plate can be about 460 mm to about 500 mm, or about 460 mm to about 475 mm.

[0037] The embodiments disclosed herein can allow a user to customize a reaction chamber so that the reaction chamber has a desired or predetermined reaction chamber height B. In various embodiments, the showerhead plate 302 can be retrofitted into an existing reactor assembly having an existing showerhead plate. In such embodiments, the existing showerhead plate can be removed and the showerhead plate 302 can be installed. In some embodiments, a user can select from multiple showerhead plates, for example, having different thicknesses. A user can install the selected showerhead plate into an existing reactor or design a new reactor to accommodate multiple sizes of showerhead plates.

[0038] However, using a reduced chamber height B as shown in FIG. 3B may result in an increased impingement force of the incident gas flow on the substrate 314, which can create non-uniformities in deposition. To distribute and reduce the impingement force, the showerhead plate 302 of FIGS. 3A-3B can have an increased number of openings 304 compared to the showerhead plate 202 of FIG. 2. For example, the showerhead plate 202 of FIG. 2 includes 1,000 openings 204. In the illustrated embodiment of FIG. 3A, the showerhead plate 302 can include a number of openings 304 in the range of approximately 1,500 to 4,500, or in the range of 1,500 to 4,000, or in the range of 2,000 to 4,500, or in the range of 2,000 to 4,000, or in the range of 2,500 to 3,500, for example, in some embodiments, approximately 3,000 openings 304. The showerhead plate 302 can include at least 1,200, or at least 1,500, or at least 2,000 openings 304. Those skilled in the art will understand that the number of openings is merely exemplary of a showerhead assembly adapted for a particular substrate size, and that alternative substrate sizes will have increased or decreased numbers of openings 304.

[0039] FIG. 3B illustrates an enlarged cross-sectional view of a portion of the showerhead assembly 300 shown in FIG. 3A. The openings 304 are enlarged to show additional structural details. In FIG. 3B, each of the plurality of openings 304 has an inlet portion 304a. The inlet portion 304a can have a first axial section 307 at an upper portion of the showerhead plate 302 exposed to the showerhead plenum 301, as shown in FIGS. 3A-3B. As shown, the first axial section 307 can have vertically straight sidewalls extending along a vertical axis y of the showerhead plate 302. The vertical axis y can correspond to the direction of gas flow from the showerhead plenum 301, through the showerhead plate 302, and into the reaction chamber 306. The sidewalls of the first axial section 307 can be generally perpendicular to the upper surface 311 of the showerhead plate 302 exposed to the showerhead plenum 301. The first axial section 307 can beneficially function as a counterbore to aid in the manufacturing of the opening 304 in a thicker showerhead plate 302. As described below, the shape of the first axial section 307 when viewed in a top or bottom view can be polygonal (e.g., hexagonal), although other shapes (e.g., other polygonal shapes, or rounded shapes) may be suitable.

[0040] Additionally, the inlet portion 304a can have a second tapered section 309 that transitions from the first axial section 307 to an elongated conduit portion 304b that extends along the vertical axis y. The second tapered section 309 can have an angled sidewall that is angled inward from the first axial section 307 relative to the vertical axis y. For example, as shown in FIG. 3B , the major transverse dimension of the opening 304 can decrease from the first axial portion 304a to the conduit portion 304b.

[0041] Like the first axial portion 307, the conduit portion 304b can have vertically straight sidewalls extending along the vertical axis y of the showerhead plate 302. The sidewalls of the conduit portion 304b can be generally perpendicular to the top surface 311 of the showerhead plate 302. The conduit 304b leads to the outlet portion 304c, which can include a tapered section exposed to the reactor chamber 306. As shown in FIG. 3B , the sidewalls of the outlet portion 304c can be angled outward with respect to the vertical axis y such that the major lateral dimension of the opening 304 increases from the conduit portion 304b to the bottom surface 303 of the showerhead plate 302. Including a tapered section in the outlet portion 304c can reduce gas stagnation points and promote gas flow in a desired direction. For example, the tapered sections in the inlet portion 304a and the outlet portion 304c may promote gas flow in a direction substantially perpendicular to the surface of the substrate 314. The tapered sections in the inlet portion 304a and the outlet portion 304c can be continuously tapered (e.g., linearly tapered), or can be tapered with another contour (e.g., truncated pyramidal or truncated conical shape), or can include a curve (e.g., partially spherical or partially elliptical). The angle between the vertical axis y and the sidewall of the tapered section 309, 304c can be in the range of about 30 degrees to about 90 degrees, or in the range of about 60 degrees to about 90 degrees, or in the range of about 75 degrees to 90 degrees, or in the range of about 77 degrees to about 85 degrees, for example, about 82 degrees in one embodiment.

[0042] To accommodate an increased number of openings 304 in the showerhead plate 302 of FIGS. 3A-3B, the maximum lateral dimension of the openings 304 can be reduced. In various embodiments, for example, the first width w1 of the first axial section 307 of the inlet portion 304a can be in the range of about 5 mm to about 6 mm, or about 5.66 mm, in one embodiment. The second width w2 of the conduit portion 304b can be in the range of about 0.5 mm to about 1 mm, or about 0.79 mm, in one embodiment. The third width w3 of the conduit portion 304b can be in the range of about 5 mm to about 6 mm, or about 5.48 mm, in one embodiment. As discussed above, the thickness A of the showerhead plate 302 can also be increased. In various embodiments, the first length l1 of the first axial section 307 can be in the range of about 3.5 mm to about 4.5 mm, or about 4 mm, in one embodiment. The second length l2 of second tapered section 309, in one embodiment, can be in the range of about 3.5 mm to about 4.5 mm, or about 4 mm. The third length l3 of conduit portion 304b, in one embodiment, can be in the range of about 15 mm to about 20 mm, or about 17.97 mm. The fourth length l4 of outlet portion 304c, in one embodiment, can be in the range of about 2.5 mm to about 3.5 mm, or about 3 mm.

[0043] In the thick showerhead plate 302 of FIGS. 3A-3B, it can be difficult to fabricate high aspect ratio openings 304. The use of a straight first axial section 307 can beneficially function as a counterbore to improve the manufacturability of the elongated conduit portion 304b. Furthermore, in some devices, high aspect ratio openings may be undesirable; for example, reactant vapors may decompose and / or deposit on or clog the openings. The shape of the openings 304 may include axial and tapered portions that can help mitigate these problems.

[0044] FIG. 4 illustrates a cross-sectional view of a reactor chamber assembly 40 including a showerhead assembly 400. The showerhead assembly 400 includes a showerhead plate 302, which may be identical to or generally similar to the showerhead plate 302 of FIGS. 3A and 3B. The showerhead plate 302 may include a plurality of openings 304 having the shape and size described above in FIG. 3B. FIG. 4 also shows a substrate support 310 configured to support a substrate 314. However, the spacers 402 of the reactor assembly 40 of FIG. 4 differ from the spacers 308 of FIG. 3A. In FIG. 4, the spacers 402 can function to set the height between the showerhead plate 302 and the substrate support 310 by spacing the showerhead plate 302 from the substrate support 310, which changes the chamber height B. The showerhead plate 302 has a thickness A. 4, the size of the spacers 402 can be modified to position the substrate support 310 closer to the showerhead plate 302, thereby reducing the chamber height B and reducing the chamber volume. By varying the size of the spacers 308, the chamber size can be customized based on different parameters for different process recipes. For example, in the illustrated embodiment, the reactor volume can be reduced, which can beneficially increase throughput.

[0045] In some embodiments, the height of the chamber can be in the range of 2.5 mm to 15 mm, or in the range of 2.5 mm to 14 mm, or in the range of 3 mm to 13 mm, or in the range of 4 mm to 12 mm, or in the range of 5 mm to 10 mm, for example, in some embodiments, it can be about 8 mm, or in some embodiments, it can be about 6 mm. In some embodiments, the volume of the reaction chamber can be about 1280 mm. 2 ~Approx. 1920mm 2In some embodiments, the reaction chamber width can be within a range of about 200 mm to about 440 mm. The ratio of the reaction chamber height to the reaction chamber width can be within a range of about 1:80 to about 1:29. In addition, the spacer thickness can be within a range of about 20 mm to about 30 mm.

[0046] 5A and 5B respectively illustrate bottom views comparing the showerhead plate 202 of FIG. 2 with the showerhead plate 302 of FIG. 3A. As noted above in FIG. 3A, the showerhead plate 302 of FIG. 3A includes a greater number of openings 304 than the showerhead plate 202 of FIG. 2. As shown in FIGS. 5A and 5B, not only is the number of openings 304 greater in the showerhead plate 302 of FIG. 3A, but the opening density in FIG. 3A is also higher than the opening density in FIG. 2.

[0047] For example, as described above, the number of openings 304 in the showerhead plate 302 can be 1,500 or more, or 2,000 or more, such as in the range of 1,500 to 5,000, or 1,500 to 4,000, or 2,000 to 5,000, or 2,000 to 4,000, or 2,500 to 3,500, e.g., approximately 3,000 openings 304 in some embodiments. The showerhead plate 302 of FIG. 5B can therefore have an increased opening density, which reduces the spacing between openings as well as the impact force of the gas flow impinging on the substrate. The reduced spacing between openings 304 can reduce the impact force of the gas contacting the substrate. As shown in FIG. 5B, the shape of the openings 304 in a bottom view (or top view) can be polygonal, e.g., hexagonal. However, in other embodiments, the shape of the opening 304 can be different (eg, circular, oval, triangular, rectangular, square, pentagonal, heptagonal, octagonal, etc.).

[0048] FIG. 6A illustrates a cross-sectional view of a showerhead plate 402 during injection of a first reactant vapor. FIG. 6A can be utilized with any suitable process recipe, such as deposition of a metal halide material, a metal (at a lower vapor pressure) from a solid precursor, a metal chloride precursor, an oxidizer, water, a metal oxide, HfO, or the like. In the illustrated embodiment, the reactant vapor includes hafnium tetrachloride (HfCl). The embodiment of FIG. 6A can be used in a cyclic deposition process. In various embodiments, the plate 402 can be used in an ALD process. The showerhead plate 402 can include multiple openings 404, each having an inlet tapered portion 404a, an elongated conduit portion 404b, and an outlet tapered portion 404c. The openings 404 in FIG. 6A may not include an axial portion at the inlet (such as the first axial segment 307 described in connection with FIG. 3B). The first reactant vapor (e.g., HfCl) exits the outlet portion 404c of the opening 404, as illustrated by the annotated portion in FIG. 6A. However, as FIG. 6A shows, the surfaces and / or volumes between adjacent openings 404 on the showerhead plate 402 may trap inert purge gas (e.g., N) from a previous purge cycle or other vapors (e.g., HO) from other process steps. The arrows in FIG. 6A illustrate that the trapped vapor (e.g., HO) can diffuse into the first reactant (e.g., HfCl) pulsed into the reaction chamber. This diffusion can cause a non-uniform concentration of the first reactant vapor (e.g., HfCl) during the diffusion.

[0049] FIG. 6B illustrates a cross-sectional view of the showerhead 402 of FIG. 6A during a short injection of a first reactant vapor, such as HfCl, after a previous purge step. The first reactant vapor (such as HfCl) is illustrated by the annotated portion exiting the outlet portion 404c of the opening 404. An inert purge gas (e.g., N) is represented by the annotated dots and portions. As illustrated in FIG. 6A, during the injection of HfCl, the purge gas may become trapped between the injection openings 404, thereby diluting the surface concentration of the first reactant vapor (e.g., HfCl). This problem may be particularly prevalent with short injections of reactant due to the limited time the reactant has to diffuse into the area between the injection openings 404. Limiting the cycle time results in a short injection time, and gas trapped between the injection openings 404 may be problematic.

[0050] 7A and 7B illustrate schematic bottom views of showerhead plates according to various embodiments. In FIG. 7A, showerhead plate 702 includes a plurality of openings 704 formed therethrough. Showerhead plate 702 may include approximately 1000 openings 704. In contrast, FIG. 7B illustrates showerhead plate 706, which may include a greater number of openings 708 than plate 702. For example, as described above, the number of openings 708 in the showerhead plate 706 can be 1,500 or more, or 2,000 or more, such as in the range of 1,500 to 5,000, or 1,500 to 4,000, or 1,500 to 2,500, or 2,000 to 5,000, or 2,000 to 4,000, or 2,500 to 3,500, for example, approximately 3,000 openings 304 in some embodiments. The showerhead plate 706 of FIG. 7B can therefore have an increased opening density, which reduces the spacing between openings. By reducing the spacing between openings, the showerhead 706 may have a smaller amount of gas trapped between the openings 708, as described in FIGS. 6A and 6B, thereby providing more uniform injection, especially during short injection times. 7B, the shape of the opening 708 when viewed from a bottom view (or top view) can be polygonal, for example, hexagonal. However, in other embodiments, the shape of the opening 708 can be different (e.g., circular, oval, triangular, rectangular, square, pentagonal, heptagonal, octagonal, etc.).

[0051] FIG. 8A illustrates a cross-sectional view of a showerhead assembly 800. The showerhead assembly 800 includes a top plate 802, which defines a showerhead plenum 801 above a showerhead plate 804 having a plurality of openings 806. The openings 806 may be vertically straight, as shown in FIG. 2, or may have tapered sections, as shown in FIGS. 3A and 3B. Additionally, the showerhead assembly 800 may include other components shown in FIG. 2 or 3A. As shown in FIG. 1, steam enters the showerhead assembly 820 through holes 130. The holes 130 inject steam into the showerhead plenum 801 of the showerhead assembly 800, which distributes the steam over the showerhead plate 804. The steam can enter the reactor chamber through the openings 806. A high-velocity steam flow zone at the center of the showerhead 802 can result in increased deposition in the middle of the substrate 818, which can create uneven deposition in the middle of the substrate 818. For example, an opening 806a of the plurality of openings 806 that is exactly in the middle of the showerhead 804 may have the highest velocity of vapor passing therethrough, for example, because the opening 806a may be aligned with the center of the holes 130. An opening 806b of the plurality of openings 806 that is next to or otherwise near the middle opening 806a may also transmit vapor at a high velocity. Therefore, a showerhead plate 804 having vertical openings 806a, 806b in a central region of the showerhead plate 804 that is directly in the path of vapor delivered from the holes 130 may cause excessive deposition in the central region of the substrate 818.

[0052] FIG. 8B illustrates a cross-sectional view of a showerhead assembly 808 according to various embodiments. The showerhead assembly 808 includes a top plate 810, which defines a showerhead plenum 810 above a showerhead plate 812 having a plurality of openings 814. Similar to FIG. 8A, the openings 814 can be vertically straight, as shown in FIG. 2, or can have tapered sections, as shown in FIGS. 3A and 3B. Additionally, the showerhead assembly 808 can include other components shown in FIG. 2 or 3A. As shown in FIG. 1, steam enters the showerhead assembly 820 through holes 130. At the center of the showerhead 812, a high-velocity steam flow zone may impinge on a central region 816 of the showerhead plate 812. To compensate for the high-velocity flow zone, the plurality of openings 814 may not include an opening at the center of the showerhead plate 812, so that the maximum velocity component of the steam flow does not pass through the showerhead plate 812. Rather, the plate body 817 of the showerhead plate 812 can extend along a central position of the showerhead plate 812. Further, as shown in FIG. 8B , the plurality of openings 814 can include a first outer opening 814a and a second inner opening 814b disposed near the center of the showerhead plate 812 in a central region 816 of the showerhead plate 812. The first opening 814a can be disposed radially or laterally outside the second inner opening 814b and, in some embodiments, can surround the inner opening 814b. The first opening 814a can comprise a vertically straight or axial opening 814a extending along the vertical axis y of the showerhead plate 812. The first opening 814a can also include a tapered portion as shown in FIGS. 3A-3B above.

[0053] Additionally, as shown in FIG. 8B , the internal openings 814b can be angled inward to direct at least a portion of the vapor flow toward the central region of the substrate 818. Because the embodiment of FIG. 8B does not include an opening at the center of the showerhead plate 812, the central region of the substrate 818 may not be deposited with a sufficient amount of reactant. Therefore, to ensure that the central region of the substrate 818 is adequately dosed with reactant, the angled internal openings 814b can provide vapor flow to the central region of the substrate 818 at a relatively slower rate. While only the internal openings 814b adjacent to or near the central region 816 are illustrated as angled, more openings further away from the center 816 can be angled. The angle of the internal openings 814b can be in the range of 5 degrees to 55 degrees, or in the range of 5 degrees to 25 degrees, relative to the vertical axis y.

[0054] Although the foregoing has been described in detail by way of illustration and example for purposes of clarity and understanding, it will be apparent to those skilled in the art that certain changes and modifications may be practiced. Therefore, the description and examples should not be construed as limiting the scope of the invention to the specific embodiments and examples described herein, but rather encompassing all modifications and alternatives that fall within the true scope and spirit of the invention. Moreover, not all of the features, aspects, and advantages described herein above are necessarily required to practice the present invention.

Claims

1. 1. A reactor assembly comprising: Shower head plenum, a showerhead plate for distributing vapor into a reaction chamber, comprising: A first surface; a second surface opposite the first surface; and a plurality of openings extending from the first surface to the second surface; a showerhead plate, wherein a thickness of the showerhead plate between the first surface and the second surface is in a range of about 25 mm to about 35 mm; wherein the showerhead plenum is disposed above the showerhead plate; and a substrate support adapted to support a substrate; a reaction chamber at least partially defined by the substrate support and the showerhead plate, wherein a height of the reaction chamber between a top surface of the substrate support and a bottom surface of the showerhead plate is in a range of 3 mm to 7 mm; a spacer that mechanically supports the showerhead plate; Equipped with The reactor assembly, wherein the spacer can function to set a height between the showerhead plate and the substrate support by spacing the showerhead plate from the substrate support, and the spacer is configured to be replaceable with one having a different thickness and is used to change the height of the reaction chamber depending on process conditions.

2. 10. The reactor assembly of claim 1, wherein the thickness of the showerhead plate between the first surface and the second surface is in the range of about 27 mm to about 33 mm.

3. 10. The reactor assembly of claim 1, wherein the thickness of the showerhead plate between the first surface and the second surface is in the range of about 29 mm to about 31 mm.

4. 10. The reactor assembly of claim 1, wherein the showerhead plate has a width in the range of about 210 mm to about 260 mm.

5. 10. The reactor assembly of claim 1, wherein the showerhead plate has a width in the range of about 310 mm to about 360 mm.

6. 10. The reactor assembly of claim 1, wherein the showerhead plate has a width in the range of about 460 mm to about 500 mm.

7. 10. The reactor assembly of claim 1, wherein said plurality of openings comprises a number of openings in a range of about 1,500 to 4,500 openings.

8. 10. The reactor assembly of claim 1, wherein the number of openings is in the range of about 1,500 to 2,500 openings.

9. At least one of the plurality of openings is a first axial inlet section extending from the first surface along a vertical axis of the showerhead plate; a first tapered section extending from the first axial inlet section, the first tapered section including an inwardly angled sidewall angling inwardly from the first axial inlet section; a conduit section extending from the first tapered section and oriented along the vertical axis of the showerhead plate, the conduit section having a major lateral dimension smaller than the first axial inlet section; a second tapered section extending from the conduit section to the second surface, the second tapered section comprising an outlet configured to deliver the vapor to the reaction chamber.

10. The reactor assembly of claim 1 , further comprising a vaporizer configured to vaporize the solid source precursor.

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