Shower head with three plenums

Abstract

The substrate processing system includes a processing chamber, a plasma source that generates and supplies plasma to the processing chamber, and a showerhead disposed between the processing chamber and the plasma source to supply gas to the processing chamber and the plasma source and to supply plasma to the processing chamber. The showerhead includes a body, a first set of holes, and a second set of holes. The body has a first surface, a second surface, and a side surface that define first and second plenums. The first set of holes extends from the first plenum to the first surface and is in fluid communication with the processing chamber. The second set of holes extends from the second plenum to the second surface and is in fluid communication with the plasma source.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application No. 63 / 418,671, filed October 24, 2022. The entire disclosures of the above-referenced applications are incorporated herein by reference.

[0002] The present disclosure relates generally to substrate processing systems, and more particularly to a showerhead with three plenums. [Background technology]

[0003] The background description provided herein is intended to generally present the contents of the present disclosure. To the extent described in this background section, the work of the currently named inventors, as well as aspects of the description that may not be considered prior art at the time of filing, are not admitted, expressly or impliedly, as prior art to the present disclosure.

[0004] Atomic layer deposition (ALD) is a thin-film deposition technique that uses sequential gaseous chemical processes to deposit thin films on a material surface (e.g., the surface of a substrate such as a semiconductor wafer). Most ALD processes use at least two chemicals, called precursors (reactants), that react sequentially and self-limitingly with the material surface, one precursor at a time. For example, a typical ALD process involves a series of dosing and purging steps, which are repeated in sequence. By repeated exposure to distinct precursors, thin films are gradually deposited on the material surface.

[0005] Plasma-enhanced ALD (PEALD) processes use a plasma after the input step. In some substrate processing systems, the plasma can be generated in situ within the processing chamber. Alternatively, the plasma can be generated externally or remotely from the processing chamber and delivered to the processing chamber. Summary of the Invention

[0006] The substrate processing system includes a processing chamber, a plasma source that generates and supplies plasma to the processing chamber, and a showerhead disposed between the processing chamber and the plasma source to supply gas to the processing chamber and the plasma source and to supply plasma to the processing chamber. The showerhead includes a body, a first set of holes, and a second set of holes. The body has a first surface, a second surface, and a side surface that define first and second plenums. The first set of holes extends from the first plenum to the first surface and is in fluid communication with the processing chamber. The second set of holes extends from the second plenum to the second surface and is in fluid communication with the plasma source.

[0007] As an additional feature, the second plenum and second set of holes are an inverse replica of the first plenum and first set of holes.

[0008] As an additional feature, the showerhead distributes gas uniformly radially and azimuthally throughout the showerhead through the first and second sets of holes.

[0009] As an additional feature, the showerhead distributes gases radially and azimuthally uniformly across the showerhead in opposite directions through the first and second sets of holes, respectively.

[0010] As an additional feature, the showerhead delivers gases to the processing chamber and the plasma source through first and second sets of holes, respectively, so that the showerhead delivers gases radially and azimuthally uniformly throughout the showerhead through the first and second sets of holes.

[0011] In an additional feature, the showerhead is cylindrical. The first and second plenums are stacked axially, perpendicular to the diameter of the showerhead. The first and second plenums extend radially across the entire showerhead.

[0012] As an additional feature, the processing chamber further includes a pedestal and a substrate disposed on the pedestal. The showerhead is cylindrical. The first and second plenums are stacked in an axial direction perpendicular to a diameter of the showerhead. The first and second plenums extend radially across the substrate.

[0013] As an additional feature, the second plenum and the second set of holes are separate from the first plenum and the first set of holes.

[0014] In an additional feature, the showerhead is cylindrical, the first and second plenums extend radially throughout the showerhead, and the first and second sets of holes are distributed radially throughout the showerhead.

[0015] As an additional feature, the showerhead is cylindrical, with the first and second sets of holes extending in an axial direction perpendicular to the diameter of the showerhead.

[0016] As an additional feature, the first and second sets of holes have the same diameter.

[0017] As an additional feature, the showerhead further includes a third set of holes extending between the first and second surfaces, the third set of holes being separate from the first and second plenums and the first and second sets of holes.

[0018] As an additional feature, the showerhead is cylindrical. A second set of holes delivers one of the gases to the plasma source in a radially and azimuthal uniform manner across the showerhead. A third set of holes delivers one of the gases from the plasma source to the processing chamber in a radially and azimuthal uniform manner across the showerhead.

[0019] As an additional feature, the showerhead is cylindrical, and the third set of holes extends axially perpendicular to the diameter of the showerhead.

[0020] As an additional feature, the showerhead is cylindrical, and the third set of holes is radially distributed throughout the showerhead.

[0021] As an additional feature, the showerhead is cylindrical, and the first, second, and third sets of holes are radially interstitially distributed throughout the showerhead.

[0022] In an additional feature, the processing chamber further comprises a pedestal and a substrate disposed on the pedestal. The showerhead is cylindrical. The third set of holes are distributed radially across the substrate.

[0023] As an additional feature, the processing chamber further comprises a pedestal and a substrate disposed on the pedestal. The showerhead is cylindrical. The first and second plenums are stacked in an axial direction perpendicular to a diameter of the showerhead. The first and second plenums extend radially across the substrate. The third set of holes is distributed radially across the substrate.

[0024] In an additional feature, the showerhead is cylindrical. The diameter of the third set of holes is equal to or greater than the diameter of at least one of the first and second sets of holes.

[0025] In an additional feature, the showerhead is cylindrical, the first and second sets of holes have a first diameter, and the third set of holes has a second diameter that is larger than the first diameter.

[0026] As an additional feature, a third set of holes supplies radicals from the plasma to the processing chamber.

[0027] In an additional feature, the showerhead is cylindrical. The showerhead further includes a cooling channel disposed between the first and second plenums. The cooling channel and the first and second plenums extend radially throughout the showerhead and are separated from one another.

[0028] As an additional feature, the plasma source may be dome-shaped, elliptical, cylindrical, or conical.

[0029] As an additional feature, the substrate processing system further includes a gas delivery system that supplies gas to the showerhead, and a controller. The controller is configured to supply a first gas from the gas source to the first plenum during a loading step of an atomic layer deposition (ALD) process. The controller is configured to supply a second gas from the gas source to the second plenum to generate a plasma, and the third set of holes is configured to supply radicals from the plasma to the processing chamber. The controller is configured to supply a third gas from the gas source to the second plenum during a purge step of the ALD process. The third gas flows into the processing chamber uniformly in radial and azimuth directions throughout the showerhead to prevent material flow from the processing chamber to the plasma source.

[0030] In yet another feature, the showerhead includes a body, a first set of holes, and a second set of holes. The body has a first surface, a second surface, and a side surface that define first and second plenums. The first and second surfaces are opposite each other. The first set of holes extends from the first plenum to the first surface. The second set of holes extends from the second plenum to the second surface.

[0031] As an additional feature, the second plenum and second set of holes are an inverse replica of the first plenum and first set of holes.

[0032] In an additional feature, the showerhead is cylindrical. The first and second plenums are stacked axially, perpendicular to the diameter of the showerhead. The first and second plenums extend radially across the entire showerhead.

[0033] As an additional feature, the second plenum and the second set of holes are separate from the first plenum and the first set of holes.

[0034] In an additional feature, the showerhead is cylindrical, the first and second plenums extend radially throughout the showerhead, and the first and second sets of holes are distributed radially throughout the showerhead.

[0035] As an additional feature, the showerhead is cylindrical, with the first and second sets of holes extending in an axial direction perpendicular to the diameter of the showerhead.

[0036] As an additional feature, the first and second sets of holes have the same diameter.

[0037] As an additional feature, the showerhead further includes a third set of holes extending between the first and second surfaces, the third set of holes being separate from the first and second plenums and the first and second sets of holes.

[0038] As an additional feature, the showerhead is cylindrical, and the third set of holes extends axially perpendicular to the diameter of the showerhead.

[0039] As an additional feature, the showerhead is cylindrical, and the third set of holes is radially distributed throughout the showerhead.

[0040] As an additional feature, the showerhead is cylindrical, and the first, second, and third sets of holes are radially spaced apart throughout the showerhead.

[0041] As an additional feature, the showerhead is cylindrical, with the third set of holes being larger in diameter than the first and second sets of holes.

[0042] In an additional feature, the showerhead is cylindrical, the first and second sets of holes have a first diameter, and the third set of holes has a second diameter that is larger than the first diameter.

[0043] In an additional feature, the showerhead is cylindrical. The showerhead further includes a cooling channel disposed between the first and second plenums. The cooling channel and the first and second plenums extend radially throughout the showerhead and are separated from one another.

[0044] In yet another feature, the substrate processing system includes a processing chamber, a plasma source that generates and supplies plasma to the processing chamber, and a showerhead disposed between the processing chamber and the plasma source to supply gas to the processing chamber and radicals from the plasma to the processing chamber. The showerhead includes a body, a first plenum, a second plenum, and a third plenum. The body has a first surface, a second surface, and a side surface that define the first, second, and third plenums. The first surface faces the plasma source, and the second surface faces the processing chamber. The first plenum includes a first set of holes extending from the first surface to the second surface of the showerhead. The first set of holes is in fluid communication with the plasma source and the processing chamber. The second plenum includes a second set of holes extending from the second plenum to the second surface. The second set of holes is in fluid communication with the processing chamber. The third plenum is disposed between the second plenum and the second surface. The third plenum includes a third set of holes extending from the third plenum to the second surface, the third set of holes being in fluid communication with the processing chamber.

[0045] As an additional feature, the third plenum is configured to supply gas to the processing chamber during a first time period and evacuate material from the processing chamber during a second time period to prevent flow of material from the processing chamber through the first set of holes to the plasma source.

[0046] As an additional feature, the third plenum further includes a fourth set of holes extending from the third plenum to the second surface. The fourth set of holes is in fluid communication with the processing chamber. Adjacent pairs of holes in the third and fourth sets of holes are disposed on either side of the second set of holes in the second plenum. Adjacent pairs of holes in the third and fourth sets of holes are disposed between adjacent pairs of holes in the first plenum.

[0047] In an additional feature, the third plenum includes a removable plate configured to be attached to the top of the showerhead, the removable plate including the third and fourth sets of holes of the third plenum, the second surface of the showerhead, and some of the first and second sets of holes of the first and second plenums, and the top includes the second plenum and some of the remaining first and second sets of holes of the first and second plenums.

[0048] As an additional feature, the first plenum is configured to supply radicals from the plasma source to the processing chamber through the first set of holes, the second plenum is configured to supply precursors to the processing chamber, and the third plenum is configured to prevent flow of precursors from the processing chamber through the first set of holes to the plasma source by supplying a purge gas through the third set of holes during a first time period and evacuating precursors from the processing chamber through the third set of holes during a second time period.

[0049] As an additional feature, the first plenum is configured to supply radicals from the plasma source to the processing chamber through the first set of holes, the second plenum is configured to supply precursors to the processing chamber, and the third plenum is configured to prevent flow of precursors from the processing chamber through the first set of holes to the plasma source by supplying a purge gas through the third and fourth sets of holes during a first time period and evacuating precursors from the processing chamber through the third set of holes during a second time period.

[0050] As an additional feature, the first, second and third plenums are separate.

[0051] In an additional feature, the showerhead is cylindrical, the first, second, and third plenums extend radially throughout the showerhead, and the first, second, and third sets of holes are distributed radially throughout the showerhead.

[0052] In an additional feature, the showerhead is cylindrical, the first, second, and third plenums extend radially throughout the showerhead, and the first, second, third, and fourth sets of holes are distributed radially throughout the showerhead.

[0053] As an additional feature, the showerhead is cylindrical, with the first, second, and third sets of holes extending in an axial direction perpendicular to the diameter of the showerhead.

[0054] As an additional feature, the showerhead is cylindrical, with the first, second, third and fourth sets of holes extending in an axial direction perpendicular to the diameter of the showerhead.

[0055] As an additional feature, the showerhead is cylindrical, and the first, second, and third sets of holes are radially spaced apart throughout the showerhead.

[0056] As an additional feature, the showerhead is cylindrical, and the first, second, third and fourth sets of holes are radially spaced apart throughout the showerhead.

[0057] In an additional feature, the processing chamber includes a pedestal and a substrate disposed on the pedestal, the showerhead is cylindrical, and the first, second, and third sets of holes are radially distributed across the substrate.

[0058] In an additional feature, the processing chamber includes a pedestal and a substrate disposed on the pedestal, the showerhead is cylindrical, and the first, second, third, and fourth sets of holes are radially distributed across the substrate.

[0059] In an additional feature, the showerhead is cylindrical. The showerhead further includes a cooling channel disposed between the first surface of the showerhead and the second plenum. The cooling channel and the first, second, and third plenums extend radially throughout the showerhead and are separated from one another.

[0060] As an additional feature, the third set of holes has a larger diameter than the second set of holes and a smaller diameter than the first set of holes.

[0061] As an additional feature, the third and fourth sets of holes have a larger diameter than the second set of holes and a smaller diameter than the first set of holes.

[0062] In yet another feature, a showerhead for a substrate processing system includes a body, a first set of holes, a second set of holes, and a third set of holes. The body has a first surface, a second surface, and a side surface that define first, second, and third plenums. The third plenum is disposed between the second plenum and the second surface of the showerhead. The third plenum can be configured as a supply plenum and an exhaust plenum. The first set of holes in the first plenum extend from the first surface to the second surface. The second set of holes extend from the second plenum to the second surface. The third set of holes extend from the third plenum to the second surface and to the third set of holes.

[0063] As an additional feature, the third plenum is configured to supply gas to the processing chamber during a first time period and evacuate material from the processing chamber during a second time period to prevent flow of material from the processing chamber to the first set of holes.

[0064] As an additional feature, the showerhead further includes a fourth set of holes extending from the third plenum to the second surface, wherein adjacent pairs of holes in the third and fourth sets of holes are disposed on either side of the second set of holes in the second plenum, and adjacent pairs of holes in the third and fourth sets of holes are disposed between adjacent pairs of holes in the first plenum.

[0065] In an additional feature, the showerhead further includes a removable plate configured to be attached to a top of the showerhead, the removable plate including the third and fourth sets of holes in the third plenum, the second surface of the showerhead, and some of the first and second sets of holes in the first and second plenums, and the top of the showerhead including the second plenum and some of the remaining first and second sets of holes in the first and second plenums.

[0066] As an additional feature, the first plenum is configured to supply radicals from the plasma source to the processing chamber through the first set of holes, the second plenum is configured to supply precursors to the processing chamber, and the third plenum is configured to prevent flow of precursors from the processing chamber through the first set of holes to the plasma source by supplying a purge gas through the third set of holes during a first time period and evacuating precursors from the processing chamber through the third set of holes during a second time period.

[0067] As an additional feature, the first plenum is configured to supply radicals from the plasma source to the processing chamber through the first set of holes, the second plenum is configured to supply precursors to the processing chamber, and the third plenum is configured to prevent flow of precursors from the processing chamber through the first set of holes to the plasma source by supplying a purge gas through the third and fourth sets of holes during a first time period and evacuating precursors from the processing chamber through the third set of holes during a second time period.

[0068] As an additional feature, the first, second and third plenums are separate.

[0069] In an additional feature, the showerhead is cylindrical, the first, second, and third plenums extend radially throughout the showerhead, and the first, second, and third sets of holes are distributed radially throughout the showerhead.

[0070] In an additional feature, the showerhead is cylindrical, the first, second, and third plenums extend radially throughout the showerhead, and the first, second, third, and fourth sets of holes are distributed radially throughout the showerhead.

[0071] As an additional feature, the showerhead is cylindrical, with the first, second, and third sets of holes extending in an axial direction perpendicular to the diameter of the showerhead.

[0072] As an additional feature, the showerhead is cylindrical, with the first, second, third and fourth sets of holes extending in an axial direction perpendicular to the diameter of the showerhead.

[0073] As an additional feature, the showerhead is cylindrical, and the first, second, and third sets of holes are radially spaced apart throughout the showerhead.

[0074] As an additional feature, the showerhead is cylindrical, and the first, second, third and fourth sets of holes are radially spaced apart throughout the showerhead.

[0075] In an additional feature, the showerhead is cylindrical. The showerhead further includes a cooling channel disposed between the first surface of the showerhead and the second plenum. The cooling channel and the first, second, and third plenums extend radially throughout the showerhead and are separated from one another.

[0076] As an additional feature, the third set of holes has a larger diameter than the second set of holes and a smaller diameter than the first set of holes.

[0077] As an additional feature, the third and fourth sets of holes have a larger diameter than the second set of holes and a smaller diameter than the first set of holes.

[0078] In yet another feature, the substrate processing system includes a processing chamber, a plasma source that generates and supplies plasma to the processing chamber, and a showerhead disposed between the processing chamber and the plasma source that supplies gas to the processing chamber and radicals from the plasma to the processing chamber. The showerhead includes a body, a first plenum, a second plenum, and a third plenum. The body has a first surface, a second surface, and a side surface that define the first, second, and third plenums. The first surface faces the plasma source, and the second surface faces the processing chamber. The first plenum includes a first set of holes extending from the first surface to the second surface of the showerhead. The first set of holes is in fluid communication with the plasma source and the processing chamber. The second plenum includes a second set of holes extending from the second plenum to the second surface. The second set of holes is in fluid communication with the processing chamber. The third plenum is connected to the first plenum.

[0079] As an additional feature, the third plenum is configured to supply gas to the processing chamber through the first plenum to prevent flow of material from the processing chamber to the plasma source through the first set of holes.

[0080] As an additional feature, the first plenum is configured to deliver radicals from the plasma source to the processing chamber through the first set of holes, the second plenum is configured to deliver precursors to the processing chamber, and the third plenum is configured to deliver a purge gas through the first set of holes to prevent flow of precursors from the processing chamber through the first set of holes to the plasma source.

[0081] As an additional feature, the second plenum is separate from the first and third plenums.

[0082] As an additional feature, the third plenum is joined to the first plenum by a plurality of coupling members configured to couple the third plenum to the first set of holes.

[0083] As an additional feature, at the intersection of the first and third plenums, a portion of the first set of holes under the third plenum extend radially outward and upward to form a funnel-shaped structure attached to the underside of the third plenum.

[0084] As an additional feature, the coupling member includes a plurality of passages connecting the third plenum to the first set of holes, the passages controlling gas flow from the third plenum to the first set of holes.

[0085] As an additional feature, the passageway extends from a central portion of the coupling member to a periphery of the coupling member. The passageway extends between the upper and lower ends of the coupling member.

[0086] As an additional feature, the coupling member is configured to conduct heat from the second surface of the showerhead to the first surface of the showerhead.

[0087] As an additional feature, the third plenum is joined to the first plenum at a location closer to the first surface of the showerhead than to the second surface of the showerhead.

[0088] As an additional feature, the third plenum is joined to the first plenum at a location closer to the second surface of the showerhead than to the first surface of the showerhead.

[0089] As an additional feature, the showerhead is cylindrical. The showerhead further includes a cooling channel. A third plenum is disposed between the first surface of the showerhead and the cooling channel. A second plenum is disposed between the cooling channel and the second surface of the showerhead. The cooling channel and the first, second, and third plenums extend radially throughout the showerhead.

[0090] In an additional feature, the showerhead is cylindrical. The showerhead further includes a cooling channel disposed between the first surface of the showerhead and the second plenum. A third plenum is disposed between the second plenum and the second surface of the showerhead. The cooling channel and the first, second, and third plenums extend radially throughout the showerhead.

[0091] In an additional feature, the showerhead is cylindrical, the first, second, and third plenums extend radially throughout the showerhead, and the first and second sets of holes are radially distributed throughout the showerhead.

[0092] As an additional feature, the showerhead is cylindrical, with the first and second sets of holes extending in an axial direction perpendicular to the diameter of the showerhead.

[0093] As an additional feature, the showerhead is cylindrical, and the first and second sets of holes are radially spaced apart throughout the showerhead.

[0094] In an additional feature, the processing chamber includes a pedestal and a substrate disposed on the pedestal, the showerhead is cylindrical, and the first and second sets of holes are radially distributed across the substrate.

[0095] As an additional feature, the second set of holes has a smaller diameter than the first set of holes.

[0096] As an additional feature, the second plenum is separate from the first and third plenums.

[0097] Further scope of applicability of the present disclosure will become apparent from the detailed description, claims, and drawings. The detailed description and specific examples are for purposes of illustration only and are not intended to limit the scope of the present disclosure. [Brief explanation of the drawings]

[0098] The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:

[0099] [Figure 1] FIG. 1 illustrates an example of a substrate processing system that includes a dual plenum showerhead positioned between a processing chamber and a dome-shaped plasma source.

[0100] [Figure 2A] FIG. 2A illustrates a schematic representation of the backflow of gas from the processing chamber into the plasma source during a purge process performed in the substrate processing system of FIG. [Figure 2B] FIG. 2B schematically illustrates the backflow of gas from the processing chamber into the plasma source during a purge process performed in the substrate processing system of FIG. [Figure 2C] FIG. 2C schematically illustrates the backflow of gas from the processing chamber into the plasma source during a purge process performed in the substrate processing system of FIG.

[0101] [Figure 3A] FIG. 3A shows a first example of a three-plenum showerhead according to the present disclosure.

[0102] [Figure 3B] FIG. 3B shows an example of various hole patterns in the showerhead of FIG.

[0103] [Figure 4]FIG. 4 illustrates an example of a substrate processing system including the showerhead of FIG. 3 positioned between a processing chamber and a dome-shaped plasma source.

[0104] [Figure 5] FIG. 5 illustrates an example of a substrate processing system including the showerhead of FIG. 3 positioned between a processing chamber and an elliptical plasma source.

[0105] [Figure 6] FIG. 6 illustrates an example of a substrate processing system including the showerhead of FIG. 3 positioned between a processing chamber and a cylindrical plasma source.

[0106] [Figure 7A] FIG. 7A shows an example of a substrate processing method using the showerhead of FIG. 3 in the substrate processing system of FIGS.

[0107] [Figure 7B] FIG. 7B shows an example of gas flow through the showerhead during the method of FIG. 7A. [Figure 7C] FIG. 7C shows an example of gas flow through the showerhead during the method of FIG. 7A. [Figure 7D] FIG. 7D shows an example of gas flow through the showerhead during the method of FIG. 7A.

[0108] [Figure 8A] FIG. 8A shows a second example of a three-plenum showerhead according to the present disclosure.

[0109] [Figure 8B] FIG. 8B shows an example of a diverter valve used to operate the purge plenum of the showerhead shown in FIGS. 8A-12C.

[0110] [Figure 8C] FIG. 8C shows an example of a processing method on a substrate using the showerhead of FIGS. 8A, 11, and 12A to 12C in the substrate processing system of FIG.

[0111] [Figure 9A] FIG. 9A shows a third example of a three-plenum showerhead according to the present disclosure. [Figure 9B] FIG. 9B shows a third example of a three-plenum showerhead according to the present disclosure. [Figure 9C] FIG. 9C illustrates a third example of a three-plenum showerhead according to the present disclosure. [Figure 9D] FIG. 9D shows a third example of a three-plenum showerhead according to the present disclosure. [Figure 9E] FIG. 9E shows a third example of a three-plenum showerhead according to the present disclosure. [Figure 9F] FIG. 9F shows a third example of a three-plenum showerhead according to the present disclosure.

[0112] [Figure 10] FIG. 10 shows an example of a substrate processing method using the showerhead of FIGS. 9A to 9F in the substrate processing system of FIG.

[0113] [Figure 11] FIG. 11 illustrates a fourth example of a three-plenum showerhead according to the present disclosure.

[0114] [Figure 12A] FIG. 12A shows a fifth example of a three-plenum showerhead according to the present disclosure. [Figure 12B] FIG. 12B shows a fifth example of a three-plenum showerhead according to the present disclosure. [Figure 12C] FIG. 12C shows a fifth example of a three-plenum showerhead according to the present disclosure.

[0115] In the drawings, reference numbers may be reused to identify similar and / or identical elements. DETAILED DESCRIPTION OF THE INVENTION

[0116] In some substrate processing systems, a processing chamber includes a pedestal that supports the substrate, a showerhead disposed at the top of the processing chamber above the pedestal, and a plasma source disposed above the showerhead that supplies plasma to the processing chamber. The plasma source is typically a dome-shaped structure. The showerhead is disposed between the plasma source and the processing chamber. The showerhead separates the plasma source and the processing chamber. Because the plasma source is external to the processing chamber, the plasma supplied to the processing chamber by the plasma source is called remote plasma.

[0117] An atomic layer deposition (ALD) process can be performed to deposit materials on a substrate. An ALD cycle includes a dosing step and a purge step. The showerhead is typically a dual-plenum showerhead. During the dosing step, precursors are supplied through the first plenum of the showerhead. Process gases are supplied through an injector located at the top of the plasma source. A coil is disposed around the plasma source. Radio frequency (RF) power is supplied to the coil to activate the process gases and generate plasma within the plasma source. The second plenum of the showerhead includes a through-hole (called a radical hole). The second plenum is separate from (i.e., not in fluid communication with) the first plenum. The second plenum (i.e., the radical hole) filters ions in the plasma and delivers radicals from the plasma into the processing chamber. The radicals react with the precursors to deposit material on the substrate. Then, during a purge step, the plasma is extinguished and a purge gas is supplied into the plasma source through the injector and into the processing chamber through the second plenum to purge the plasma source and the processing chamber. The cycle of the injection step followed by the purge step can be repeated to deposit material on the substrate.

[0118] The uniformity of material deposition on a substrate depends on the uniform flow of gas through the plasma source and processing chamber. However, as described in detail below, the dome shape and the central injection point of the gas (hereinafter referred to as the source gas) in the plasma source result in non-uniform gas flow within the plasma source. Furthermore, due to the large size of the radical holes, the non-uniform gas flow within the plasma source continues uninterrupted into the processing chamber. Due to the non-uniform gas flow within the processing chamber, during the post-load purge process, some of the precursor is not completely evacuated from the processing chamber and is trapped near the center of the substrate. The trapped precursor migrates upstream through the large radical holes in the showerhead and back into the plasma source (a problem known as backflow).

[0119] The present disclosure solves the backflow problem by providing a third plenum within the showerhead to prevent precursors from migrating upstream from the processing chamber and back into the plasma source. As described in detail below, instead of using an injector, the third plenum is used to supply gas into the plasma source. The third plenum is identical to the first plenum, which uniformly supplies precursors into the processing chamber, except that the third plenum is inverted and includes upward-facing through-holes that open into the plasma source. The third plenum creates a uniform flow of source gas within the plasma source along a horizontal plane across the showerhead (i.e., parallel to the diameter of the showerhead). The source gas flows from the plasma source through the radical holes into the processing chamber uniformly across the diameter of the showerhead.

[0120] Because flow uniformity is achieved upstream of the showerhead in the plasma source, the source gas also flows uniformly downstream and into the processing chamber through the showerhead. The uniform gas flow in the processing chamber prevents precursors from migrating upstream through the center of the showerhead and back into the plasma source. Therefore, the uniform flow of source gas in the processing chamber prevents precursors from being confined near the center of the substrate and migrating upstream through the large radical holes in the showerhead and back into the plasma source. Instead, all precursors are pushed out of the processing chamber by the uniform flow of source gas in the processing chamber and purged (completely evacuated) into the exhaust system downstream of the processing chamber by the vacuum pump.

[0121] Specifically, because the first plenum of the showerhead uniformly delivers precursors into the processing chamber, the present disclosure provides a third plenum that is a replica of the first plenum and a mirror image (and therefore an inverted replica) of the first plenum. The third plenum has the same shape (same distribution and size of through-holes) as the first plenum. The third plenum is essentially the same as the first plenum, except that the through-holes of the first plenum open downward into the processing chamber, whereas the third plenum is rotated 180 degrees with the through-holes opening upward into the plasma source.

[0122] Instead of being supplied from an injector centrally located at the top of the plasma source, the source gas is supplied from the bottom of the plasma source through a third plenum. Thus, the third plenum delivers the source gas uniformly across the diameter of the showerhead into the plasma source, similar to how the first plenum delivers precursors uniformly across the diameter of the showerhead into the processing chamber. As a result, the source gas flows uniformly through the plasma source and then into the processing chamber through the radical holes in the showerhead.

[0123] Additionally, reducing the volume and modifying the shape of the plasma source dome can further improve the uniformity of source gas flow within the plasma source and processing chamber. For example, the dome can be reduced to an elliptical enclosure. In some applications, the dome can be replaced with a cylindrical enclosure. Reducing the dome volume can shorten the cycle time of the ALD process, thereby increasing throughput. Furthermore, reducing the dome volume can also reduce the amount of chemicals used in the ALD process. These and other features of the present disclosure are described in further detail below.

[0124] The present disclosure is organized as follows. First, to explain the problem solved by the present disclosure, an example of a processing chamber equipped with a dual plenum showerhead and a dome-shaped plasma source is illustrated and described with reference to FIG. 1 . The problem solved by the present disclosure is illustrated and described using FIGS. 2A-2C . A first example of a three-plenum showerhead according to the present disclosure is illustrated and described with reference to FIGS. 3A and 3B . An example of a substrate processing system equipped with a three-plenum showerhead is illustrated and described with reference to FIGS. 4-6 . How the three-plenum showerhead solves the backflow problem is described in detail with reference to FIG. 4 . The reduction of the plasma source volume is described with reference to FIGS. 5 and 6 . A substrate processing method using a three-plenum showerhead in the substrate processing system of FIGS. 4-6 and the corresponding gas flow through the three-plenum showerhead are illustrated and described with reference to FIGS. 7A-7D . An additional example of a three-plenum showerhead according to the present disclosure is illustrated and described with reference to FIGS. 8A-12C .

[0125] (Example of a system with a dual plenum shower head) FIG. 1 shows an example of a substrate processing system 100 including a processing chamber 102, a dual plenum showerhead 104, and a dome-shaped plasma source 106. The showerhead 104 includes a metallic material (e.g., aluminum or alloy). The plasma source 106 includes a ceramic (e.g., dielectric) material. The plasma source 106 has a circular base. The plasma source 106 extends upward from the circular base and includes a dome-shaped (e.g., parabolic or conical) cross-section toward a top central portion. The plasma source 106 includes an injector 107 located in the top central portion of the plasma source 106.

[0126] The showerhead 104 is positioned between the processing chamber 102 and the plasma source 106. The showerhead 104 is positioned at the top of the processing chamber 102 and at the bottom of the plasma source 106. The showerhead 104 separates the plasma source 106 from the processing chamber 102. The processing chamber 102 is positioned on a first side (i.e., the side facing the substrate) of the showerhead 104. The plasma source 106 is positioned on a second side of the showerhead 104, opposite the first side of the showerhead 104.

[0127] The processing chamber 102 includes a pedestal 108. A substrate 110 is placed on the pedestal 108 during processing. An actuator 112 is coupled to a stem portion of the pedestal 108. The actuator 112 can move the pedestal 108 vertically up and down relative to the showerhead 104 to adjust the gap between the substrate 110 and the showerhead 104.

[0128] The substrate processing system 100 includes a gas delivery system 120 that supplies various gases to the processing chamber 102 and the plasma source 106 during substrate processing. For example, the gas delivery system 120 includes a process gas supply 122, a purge gas supply 124, and a precursor supply 126. The process gas supply 122 can supply one or more process gases (e.g., nitrogen) depending on the process being performed on the substrate 110. The purge gas supply 124 can supply one or more process gases (e.g., one or more inert gases). In some processes, the purge gas may also include nitrogen. The precursor supply 126 can supply one or more precursors (reactants) depending on the process being performed on the substrate 110.

[0129] Additionally, although not shown, the gas delivery system 120 may also include a cleaning gas supply that can provide one or more cleaning gases for cleaning the processing chamber 102, the showerhead 104, and the plasma source 106 during preventive maintenance. Additionally, although not shown, the process gas supply 122, the purge gas supply 124, and the precursor supply 126 (and cleaning gas supply) each include valves and mass flow controllers for controlling the delivery of the respective gases.

[0130] The gas delivery system 120 further includes a plurality of valves (e.g., valves 130, 132, 134, and 136). The process gas supply 122 supplies one or more process gases to the injector 107 via valve 130. The purge gas supply 124 can supply one or more purge gases to the injector 107 via valve 132. The purge gas supply 124 can supply one or more purge gases to the showerhead 104 via valve 134. The precursor supply 126 can supply one or more precursors to the showerhead 104 via valve 136.

[0131] The showerhead 104 is a dual-plenum showerhead. The showerhead 104 is generally cylindrical in shape. The showerhead 104 includes an upper portion 103 and a lower portion 105. The upper portion 103 is cylindrical. The lower portion 105 is annular. The showerhead 104 has a unitary structure. That is, the upper portion 103 and the lower portion 105 are integral (i.e., molded as a single piece). The upper portion 103 is also referred to as the body of the showerhead 104. The body of the showerhead 104 (i.e., the upper portion 103) includes an upper surface, a lower surface, and side surfaces that define a plenum within the showerhead 104, as described in more detail below.

[0132] The plasma source 106 is attached to the upper portion 103. Specifically, a circular base of the plasma source 106 is attached to the upper portion 103. The lower portion 105 extends vertically downward from a lower peripheral region of the upper portion 103. The upper portion 103 extends radially outward from an upper region of the lower portion 105 to form a flange 101. The sidewall of the processing chamber 102 is attached to the lower end of the lower portion 105. The flange 101 extends radially outward from the sidewall of the processing chamber 102.

[0133] The outer diameter (OD) of the flange 101 is the OD of the upper portion 103. The OD of the lower portion 105 is the same as the OD of the sidewall of the processing chamber 102. The OD of the upper portion 103 is larger than the OD of the lower portion 105. The inner diameter (ID) of the lower portion 105 is larger than the OD of the pedestal 108. Therefore, the pedestal 108 can be moved vertically up and down by the actuator 112 to adjust the gap between the substrate 110 and the showerhead 104.

[0134] The showerhead 104 includes two plenums in the upper portion 103. The two plenums are defined by the top, bottom, and side surfaces of the upper portion 103. A first plenum 140 extends radially across the upper portion 103 of the showerhead 104. The first plenum 140 includes an inlet 121 located on the periphery of the upper portion 103 (e.g., on the flange 101). The first plenum 140 receives one or more precursors through the inlet 121 from a precursor supply 126 via a valve 136. The first plenum 140 includes a plurality of holes 142-1, 142-2, ..., and 142-N (collectively holes 142, where N is a positive integer). The first plenum 140 supplies one or more precursors into the processing chamber 102 through the holes 142. Accordingly, the holes 142 are also referred to as precursor holes 142. The inlet 121, the first plenum 140, and the precursor holes 142 are in fluid communication with each other.

[0135] The precursor holes 142 extend from the first plenum 140 to the underside of the upper portion 103 of the showerhead 104 (i.e., the surface facing the substrate or the surface facing the process chamber 102). For convenience, the first plenum 140 containing the precursor holes 142 will be collectively referred to as the precursor plenum 140. The precursor holes 142 are distributed radially across the upper portion 103 of the showerhead 104, from the center of the showerhead 104 to the ID of the lower portion 105 of the showerhead 104. The diameter of the first plenum 140 is larger than the diameter of the substrate 110.

[0136] The upper portion 103 of the showerhead 104 includes a second plenum including a plurality of through-holes 144-1, 144-2, ..., and 144-N (collectively referred to as through-holes 144, where N is a positive integer). The through-holes 144 extend from an upper surface of the upper portion 103 of the showerhead 104 to a lower surface of the upper portion 103. As described below, when a plasma is formed in the plasma source 106, ions from the plasma are filtered by the through-holes 144, and radicals from the plasma pass through the through-holes 144 into the processing chamber 102. Therefore, the through-holes 144 are also referred to as radical holes 144. The radical holes 144 are radially distributed across the upper portion 103 of the showerhead 104 from the center of the showerhead 104 to the ID of the lower portion 105 of the showerhead 104.

[0137] The radical holes 144 have a larger diameter than the precursor holes 142 (see FIG. 3B). In some embodiments, the diameter of the radical holes 144 may also be smaller, and therefore equal to the diameter of the precursor holes 142. The radical holes 144 are not in fluid communication with the first plenum 140 and the precursor holes 142. For convenience, the radical holes 144 are collectively referred to as the second plenum 144. The first plenum 140 and the second plenum 144 are separate from each other (i.e., not in fluid communication with each other).

[0138] A coil 114 is disposed around the plasma source 106. An RF power supply 116 supplies RF power to the coil 114. A process gas is injected into the plasma source 106 through an injector 107, and the RF power supply 116 supplies RF power to the coil 114. The RF power supplied to the coil 114 activates the process gas to generate a plasma in the plasma source 106. A second plenum 144 (i.e., radical hole 144) filters ions from the plasma and supplies radicals from the plasma into the processing chamber 102.

[0139] The showerhead 104 further includes cooling channels 146 disposed in the upper portion 103 of the showerhead 104. The cooling channels 146 are disposed above the first plenum 140 (i.e., the precursor plenum 140). The cooling channels 146 extend radially across the upper portion 103 of the showerhead 104. A fluid delivery system 150 circulates a coolant through the cooling channels 146 via an inlet and an outlet (neither shown) located on the periphery of the upper portion 103 (e.g., on the flange 101). The cooling channels 146, the first plenum 140, and the second plenum 144 are separate from one another (i.e., not in fluid communication with one another).

[0140] Although not shown, the pedestal 108 also includes cooling channels. The fluid delivery system 150 also circulates a coolant through the cooling channels in the pedestal 108 via an inlet and an outlet (neither of which are shown) provided in the pedestal 108. The pedestal 108 further includes a heater 109. The heater 109 heats the pedestal 108, thereby heating the substrate 110. The pedestal 108 includes a temperature sensor 152 that senses the temperature of the pedestal 108. The showerhead 104 also includes a temperature sensor 154 that senses the temperature of the showerhead 104. The system controller 160 controls the heater 109 and the supply of coolant from the fluid delivery system 150 to the pedestal 108 and the showerhead 104 to control the temperatures of the pedestal 108 and the showerhead 104.

[0141] The processing chamber 102 includes multiple exhaust ports (not shown) disposed around the lower periphery of the sidewall of the processing chamber 102. The exhaust ports are coupled to a foreline 162 connected to the processing chamber 102. The substrate processing system 100 further includes a vacuum pump 164 coupled to the processing chamber 102 via the foreline 162 through a valve 166. The vacuum pump 164 maintains a pressure (e.g., vacuum) within the processing chamber 102 during substrate processing. The vacuum pump 164 also evacuates gases (e.g., precursors, process gases, purge gases, etc.) and reaction by-products from the processing chamber 102 during the substrate processing process and during cleaning processes performed during preventive maintenance. A system controller 160 controls all of the above-described elements of the substrate processing system 100.

[0142] Described next is an example of an ALD cycle including a loading step and a purge step that can be performed on a substrate 110 in the substrate processing system 100. For example, in the loading step, precursors are supplied into the processing chamber 102 through the precursor plenum 142. To maintain a positive pressure in the plasma source 106, a purge gas (e.g., an inert gas) is trickled (i.e., supplied at a low flow rate) into the plasma source 106 through the injector 107.

[0143] The loading step is followed by a post-loading purge step in which the plasma source 106 and the processing chamber 102 are purged with an inert gas. In the post-loading purge step, a trickle of inert gas is maintained through the plasma source 106 and a purge gas is supplied into the processing chamber 102 through the precursor plenum 140. In some cases, the flow rate of the purge gas through the plasma source 106 may be increased beyond the trickle flow.

[0144] The post-load purge step is followed by a conversion step. In the conversion step, a process gas (e.g., nitrogen) is supplied into the plasma source 106 through the injector 107 at a flow rate greater than a trickle. (Nitrogen can also be supplied as a purge gas used in the purge step of an ALD cycle.) The RF power source 116 supplies RF power to the coil 114, which activates the process gas to form a plasma 115 in the plasma source 106. The second plenum 144 filters ions from the plasma 115 and supplies radicals from the plasma 115 into the process chamber 102. The radicals react with precursors previously deposited on the substrate 110 during the load step to deposit a desired material (e.g., silicon nitride) on the substrate 110.

[0145] The conversion step is followed by a second purge step. In the second purge step of the ALD cycle, at the end of the conversion step, the RF power supply 116 stops supplying RF power to the coil 114, thereby extinguishing the plasma 115 in the plasma source 106. The plasma source 106 and processing chamber 102 are purged as described in the post-load purge step above. These steps are cycled repeatedly until the desired thickness of material is deposited on the substrate 110. During the purge step, the vacuum pump 164 evacuates gases and reaction by-products from the processing chamber 102.

[0146] In some processes, the same or different precursors may be used in the dose steps of alternating ALD cycles, depending on the recipe used to process substrate 110. For example, a first precursor may be used during a first dose step in a first ALD cycle, and a second precursor may be used during a second dose step in a second ALD cycle that follows the first ALD cycle. These ALD cycles are repeated until a desired thickness of material is deposited on substrate 110.

[0147] (precursor reflux) 2A-2C, the backflow of precursors from the processing chamber 102 into the plasma source 106 is described in more detail below. Figures 2A-2C schematically illustrate only the processing chamber 102, showerhead 104, and plasma source 106 shown in Figure 1. Figures 2A-2C are used to explain the backflow that occurs in the substrate processing system 100 shown in Figure 1.

[0148] 2A shows the beginning of the post-load purge step. When source gas is injected into the plasma source 106 through an injector 107 located at the top center of the dome of the plasma source 106, the source gas enters the dome through a small orifice in the injector 107 and spreads across a wide area of ​​the dome. As a result, the flow of source gas tends to be more concentrated toward the periphery of the plasma source 106 than near the center of the plasma source 106, as indicated by arrows 111. Furthermore, while spreading, the source gas also tends to recirculate within the dome, thereby forming a recirculation zone within the dome. As a result, the source gas spreads unevenly throughout the dome.

[0149] Meanwhile, precursors are injected into the processing chamber 102 through the precursor plenum 140 during the loading step before the post-load purge step, and remain in the processing chamber 102 at the loading level while a flow of the source gas occurs within the dome of the plasma source 106. At this point in the post-load purge step, the flow of the source gas from the plasma source 106 into the processing chamber 102 through the second plenum 144 of the showerhead 104 is more concentrated toward the edge of the substrate 110 than toward the center of the substrate 110 (referred to as edge-concentrated flow). This non-uniform flow of the source gas into the plasma source 106 and processing chamber 102 is caused by the geometry of the plasma source 106 and the central injection point of the source gas through the injector 107, which is located at the top central portion of the dome of the plasma source 106.

[0150] 2B shows the progress of the post-load purge process. The radical holes 144 are designed with a large diameter so as not to restrict the flow of radicals from the plasma source 106 upstream of the showerhead 104 into the processing chamber 102 (so that the radicals can reach the substrate 110 reliably). Due to the large size of the radical holes 144, the flow of source gas into the processing chamber 102 downstream of the showerhead 104 through the radical holes 144 is also non-uniform, similar to the non-uniform flow of source gas in the plasma source 106 upstream of the showerhead 104. In other words, due to the dome shape, the central injection point of the source gas, and the large size of the radical holes 144, the non-uniformity of the flow of source gas in the plasma source 106 is transferred or reproduced in the processing chamber 102.

[0151] At this point in the post-load purge step, the precursor begins to be pushed out of the process chamber 102 by the source gas being purged (exhausted) by the vacuum pump 164 to an exhaust system downstream of the process chamber 102. However, due to the uneven and edge-focused flow of source gas within the process chamber 102, the exhaust of the precursor also occurs more predominantly near the edge of the substrate 110 than near the center of the substrate 110.

[0152] 2C shows further progress in the post-load purge step. The source gas now begins to distribute laterally through the showerhead 104. The concentrated flow of source gas at the edges of the process chamber 102 leaves gaps near the center of the substrate 110 and a film around the edge of the substrate 110, causing precursors to migrate up through the central portion of the showerhead 104 and back into the plasma source 106. Therefore, the uneven flow of source gas within the process chamber 102 traps some precursor near the center of the substrate 110, as shown at 113, rather than being completely evacuated from the process chamber 102. Because the large radical holes 144 do not restrict precursor flow, which would cause undesired backflow of precursor into the plasma source 106, the trapped precursor migrates upstream through the large radical holes 144 and back into the plasma source 106, as shown at 117.

[0153] (First example of a 3-plenum shower head) 3A and 3B illustrate a three-plenum showerhead 200 including a third plenum according to the present disclosure. The showerhead 200 solves the backflow problem described above as follows. Specifically, during a post-load purge process, the third plenum of the showerhead 200 provides a uniform flow of source gas (radially and azimuthally throughout the showerhead 200) both upstream of the showerhead 200 in the plasma source 106 and downstream of the showerhead 200 in the processing chamber 102. The uniform flow of source gas upstream and downstream of the showerhead 200 prevents precursors from flowing upstream of the processing chamber 102 back into the plasma source 106, thereby solving the backflow problem described above. The three-plenum showerhead 200 will now be described in detail below with reference to FIGS. 3A, 3B, and 4. Subsequently, additional exemplary substrate processing systems including the showerhead 200 will be illustrated and described with reference to FIGS. 5 and 6.

[0154] Figure 4 shows a substrate processing system 250 that includes a showerhead 200. The plasma source 106 in the substrate processing system 250 has the same dome shape as in Figure 1. Figure 5 shows a substrate processing system 270 that includes the showerhead 200. The plasma source 106 in the substrate processing system 270 has an elliptical shape. Figure 6 shows a substrate processing system 290 that includes the showerhead 200. The plasma source 106 in the substrate processing system 290 has a cylindrical shape.

[0155] In Figures 3A-6, elements of showerhead 200 that are identified with the same reference numbers as showerhead 104 shown in Figure 1 will not be described again for the sake of brevity. Additionally, in Figures 4-6, elements of substrate processing systems 250, 270, and 290 that are identified with the same reference numbers as substrate processing system 100 shown in Figure 1 will not be described again for the sake of brevity.

[0156] 3A, 3B, and 4, showerhead 200 is also generally cylindrical and, like showerhead 104, includes an upper portion 103 and a lower portion 105, and a flange 101. Showerhead 200 differs from showerhead 104 only in that showerhead 200 includes an additional third plenum 202 in addition to first plenum 140 and second plenum 144. First plenum 140 and second plenum 144 are identical to those shown and described with reference to FIG. 1 above, and thus will not be described again for the sake of brevity. The main body of showerhead 200 (i.e., upper portion 103) includes an upper surface, a lower surface, and side surfaces that define first, second, and third plenums 140, 144, and 202 within showerhead 200, as described in detail below.

[0157] The third plenum 202 is disposed in the upper portion 103 of the showerhead 200 above the first plenum 140 and above the cooling channels 146. The cooling channels 146 are disposed between the third plenum 202 and the first plenum 140. Thus, the third plenum 202 and the first plenum 140 (and the cooling channels 146 therebetween) are axially stacked relative to the substrate 110. Because the third plenum is disposed in the available space above the cooling channels 146 in the upper portion 103 of the showerhead 200, the external shapes (e.g., diameter and height) of the upper and lower portions 103 and 105 of the showerhead 200 and the flange 101 are unchanged and are identical to those of the showerhead 104.

[0158] The first plenum 140, the second plenum 144, and the third plenum 202 extend radially from the center of the showerhead 200 across the top 103 of the showerhead 200. The first plenum 140, the second plenum 144, and the third plenum 202 extend radially through the top 103 of the showerhead 200 across the substrate 100. The first plenum 140 and the third plenum 202 are defined by the top, bottom, and side surfaces of the top 103 of the showerhead 200.

[0159] The third plenum 202 is an inverted replica of the first plenum 140. Specifically, the third plenum 202 is identical to the first plenum 140 except that the third plenum 202 is an inverted version of the first plenum 140. Thus, the third plenum 202 is the same as the first plenum 140 rotated 180 degrees.

[0160] 1 , the first plenum 140 includes precursor holes 142 that open downward into the processing chamber 102 toward the substrate 110. Instead, the third plenum includes multiple holes 204-1, 204-2, ..., and 204-N (collectively holes 204, where N is a positive integer) that open upward into the plasma source 106. The holes 204 extend from the third plenum 202 to the upper surface of the top portion 103 of the showerhead 200 (i.e., the surface facing the plasma source 106). The first plenum 140 and the third plenum 202 uniformly supply gases (radially and azimuthally across the showerhead 200) into the processing chamber 102 and the plasma source 106, respectively (i.e., in opposite directions), as described in more detail below.

[0161] For convenience, the third plenum 202 and the holes 204 are collectively referred to as the third plenum 202. The holes 204 of the third plenum 202 are radially distributed across the top 103 of the showerhead 200 from the center of the showerhead 200 to the ID of the bottom 105 of the showerhead 200. Thus, the diameter of the third plenum 202 is larger than the diameter of the substrate 110.

[0162] The first plenum 140 (i.e., precursor plenum 140), the second plenum 144 (i.e., radical hole 144), and the third plenum 202 are separate from each other (i.e., not in fluid communication with each other). Furthermore, the first plenum 140, the second plenum 144, the third plenum 202, and the cooling channel 146 are separate from each other (i.e., not in fluid communication with each other).

[0163] 3B shows an example of a pattern of holes 142 in the first plenum 140, holes 204 in the third plenum 202, and radical holes 144. FIG. 3B shows only a portion of the pattern. The pattern is the same when viewing the showerhead 200 from above (i.e., downward from the third plenum 202) as when viewing the showerhead 200 from below (i.e., upward from the first plenum 140). The holes 142 in the first plenum 140, holes 204 in the third plenum 202, and radical holes 144 are vertical (i.e., parallel to an axis perpendicular to the diameter of the showerhead 200). The holes 142 in the first plenum 140, holes 204 in the third plenum 202, and radical holes 144 are parallel to each other and to an axis perpendicular to the diameter of the showerhead 200.

[0164] The holes 142 in the first plenum 140 and the holes 204 in the third plenum 202 have the same diameter. The diameters of the holes 142 in the first plenum 140 and the holes 204 in the third plenum 202 are less than (i.e., smaller than) the diameter of the radical holes 144. In some embodiments, the diameter of the radical holes 144 may also be smaller, and thus the diameters of the holes 142 in the first plenum 140 and the holes 204 in the third plenum 202 are equal to or less than the diameter of the radical holes 144. Furthermore, in some embodiments, the holes 142 in the first plenum 140 and the holes 204 in the third plenum 202 do not have the same diameter. For example, the diameter of the holes 204 in the third plenum 202 may need to be optimized to deliver a different type of gas than the precursor delivered by the holes 142 in the first plenum 140. Thus, in some embodiments, the diameter of the radical holes 144 may be equal to or greater than the diameter of the holes 142 in the first plenum 140 and / or the diameter of the holes 204 in the third plenum 202. That is, the diameter of the radical holes 144 may be equal to or greater than the diameter of at least one of the holes 142 in the first plenum 140 and the diameter of the holes 204 in the third plenum 202. The holes 142 in the first plenum 140, the holes 204 in the third plenum 202, and the radical holes 144 are spaced apart in a hexagonal pattern, such as the example shown in FIG. 3B. Additional examples of these hole patterns are described below after the description of FIGS. 5 and 6.

[0165] 4, the showerhead 200 is disposed between the processing chamber 102 and the plasma source 106. The showerhead 200 separates the plasma source 106 from the processing chamber 102. The showerhead 200 is disposed at the top of the processing chamber 102 and the bottom of the plasma source 106. Thus, the plasma source 106 is disposed above the showerhead 200, and the processing chamber 102 is disposed below the showerhead 200. The processing chamber 102 is disposed on a first side of the showerhead 200 (i.e., the side facing the substrate). The plasma source 106 is disposed on a second side of the showerhead 200, opposite the first side of the showerhead 200.

[0166] As described in detail below, the showerhead 200 provides multidirectional (e.g., at least bidirectional) gas flow. Precursors flow in a second (downward) direction from a first (lower) side of the showerhead 200 through a first plenum 140 into the processing chamber 102. Process and purge gases flow in a second (upward) direction from a second (upper) side of the showerhead 200 through a third plenum 202 into the plasma source 106. In addition, process and purge gases also flow from the plasma source 106 to the processing chamber 102 through a second plenum 144 and from the second (upper) side of the showerhead 200 to the first (lower) side of the showerhead 200. Furthermore, these gas flows are uniform (radially and azimuthally) throughout the showerhead 200 in both the first and second directions. Furthermore, these gases flow uniformly within the plasma source 106 and the processing chamber 102.

[0167] 4, gas delivery system 120 is identical to gas delivery system 120 shown in FIG. 1, except that the outputs of valves 130 and 132 are connected to a third plenum 202 instead of injector 107. Third plenum 202 eliminates injector 107, which is not used in plasma source 106 of substrate processing system 250. Third plenum 202 includes an inlet 123 located on the periphery of the top 103 of showerhead 200 (e.g., on flange 101). Third plenum 202 receives one or more process gases through inlet 123 from process gas supply 122 via valve 130. Third plenum 202 receives one or more purge gases through inlet 123 from purge gas supply 124 via valve 132. Third plenum 202 supplies one or more process gases and one or more purge gases into plasma source 106 through holes 204. The inlet 123, the third plenum 202, and the hole 204 are in fluid communication with each other.

[0168] In the substrate processing system 250, when the third plenum 202 is used, the process gas and purge gas are supplied upward into the plasma source 106 through the holes 204 in the third plenum 202, rather than being supplied downward into the plasma source 106 through the injectors 107. Furthermore, the process gas and purge gas are supplied uniformly (radially and azimuthally) across the diameter of the showerhead 200 through the holes 204 in the third plenum 202, rather than being supplied centrally into the plasma source 106 through the injectors 107.

[0169] Therefore, during the post-load purge step, the purge gas flows uniformly from the third plenum 202 into the plasma source 106 (radially and azimuthally across the showerhead 200) and then flows uniformly through the radical holes 144 (i.e., through the second plenum 144) into the processing chamber 102 (radially and azimuthally across the showerhead 200). Because the purge gas flows uniformly into the processing chamber 102, the precursors in the processing chamber 102 are uniformly pushed out and completely pumped out of the processing chamber 102 through the exhaust port of the processing chamber 102 by the vacuum pump. As a result, the uniform flow of purge gas in the processing chamber 102 prevents the precursors from being confined near the center of the substrate 110 and prevents the precursors from migrating upstream through the large radical holes 144 in the showerhead and back into the plasma source 106.

[0170] Thus, the third plenum 202 solves the precursor backflow problem even though the plasma source 106 is still dome-shaped. The uniformity of the flow of purge gas from the third plenum 202 into the plasma source 106 and into the processing chamber can be further improved by modifying the geometry of the plasma source, as described below with reference to Figures 5 and 6.

[0171] For convenience, one or more precursors may be collectively referred to as a first gas, one or more process gases may be collectively referred to as a second gas, and one or more purge gases may be collectively referred to as a third gas. Thus, the first plenum 140 (i.e., precursor plenum 140) delivers a first gas (precursor) uniformly (radially and azimuthally across the showerhead 200) into the processing chamber 102 through precursor holes 142 (also referred to as a first set of holes) during the loading step. The third plenum 202 delivers a second gas and a third gas (i.e., a process gas and a purge gas) uniformly (radially and azimuthally across the showerhead 200) into the plasma source 106 through holes 204 (also referred to as a third set of holes). The second plenum 144 uniformly supplies the second and third gases (i.e., process and purge gases) supplied by the third plenum 202 into the plasma source 106 (radially and azimuthally throughout the showerhead 200) from the plasma source 106 through the radical holes 144 (also referred to as the second set of holes) into the processing chamber 102 during the purge step. The uniform gas flow (radially and azimuthally throughout the showerhead 200) of the purge gas from the plasma source 106 through the second plenum 144 into the processing chamber 102 during the purge step completely exhausts precursors from the processing chamber 102 and prevents backflow of precursors from the processing chamber 102 into the plasma source 106.

[0172] (Another example of a system with a 3-plenum shower head) 5 and 6, as described in more detail below, the third plenum 202 can further improve flow uniformity within the processing chamber 102 and reduce the volume (i.e., amount) of chemicals used by reducing the volume of the plasma source 106. Specifically, the third plenum 202 also simplifies the geometry of the plasma source 106 as follows:

[0173] 5 illustrates a substrate processing system 270. The substrate processing system 270 is identical to the substrate processing system 250 illustrated in FIG. 4, except that the plasma source 106 in the substrate processing system 270 is elliptical instead of dome-shaped as illustrated in the substrate processing system 250 of FIG. 4. In the substrate processing system 270, the plasma source 106 includes a circular base attached to the top 103 of the showerhead 200. It extends upward from the circular base and has an elliptical cross-section toward a top central portion. The plasma source 106 includes a ceramic (e.g., dielectric) material.

[0174] Due to the elliptical shape, the volume of the plasma source 106 in the substrate processing system 270 is smaller than the volume of the dome-shaped plasma source 106 shown in the substrate processing system 250 of FIG. 4. The reduced volume of the plasma source 106 in the substrate processing system 270 further improves the flow uniformity in the processing chamber 102 compared to the flow uniformity in the processing chamber 102 in the substrate processing system 250 of FIG. 4. Furthermore, because the volume of the plasma source 106 is reduced in the substrate processing system 270, the volume (i.e., amount) of chemicals used is also further reduced compared to the volume (i.e., amount) of chemicals used in the substrate processing systems 100 and 250. Furthermore, although not shown, the plasma source 106 in the substrate processing system 270 may also be conical and may have a smaller volume than the volume of the dome-shaped plasma source 106 shown in the substrate processing system 250 of FIG. 4.

[0175] 6 shows a substrate processing system 290. The substrate processing system 290 is identical to the substrate processing system 250 shown in FIG. 4, except that the plasma source 106 in the substrate processing system 290 is cylindrical instead of dome-shaped as shown in the substrate processing system 250 of FIG. 4. In the substrate processing system 290, the plasma source 106 includes a circular base attached to the top 103 of the showerhead 200. The plasma source 106 extends vertically upward from the circular base with a cylindrical cross-section along an axis perpendicular to the substrate 110.

[0176] A dielectric window 119 is disposed on top of the plasma source 106. The dielectric window 119 has the same diameter as the plasma source 106. A coil 114 is disposed on the dielectric window 119. Due to its cylindrical shape and small height (e.g., 0.1 to 1.0 inches), the volume of the plasma source 106 in the substrate processing system 290 is smaller than the volume of the dome-shaped plasma source 106 in the substrate processing system 250. The volume of the plasma source 106 in the substrate processing system 290 is also smaller than the volume of the plasma source 106 in the substrate processing system 270, which is already smaller than the volume of the plasma source 106 in the substrate processing system 100. For example, the volume of the plasma source 106 in the substrate processing system 290 can be 0.3 to 3.0 liters, while the volume of the plasma source 106 in the substrate processing system 100 is typically 10 to 12 liters.

[0177] The reduced volume of the plasma source 106 in the substrate processing system 290 further increases the flow uniformity in the processing chamber 102 compared to the flow uniformity in the processing chamber 102 in the substrate processing systems 250 and 270. Furthermore, because the volume of the plasma source 106 is further reduced in the substrate processing system 290, the volume (i.e., amount) of chemicals used is also further reduced compared to the volume (i.e., amount) of chemicals used in the substrate processing systems 250 and 270.

[0178] Although not shown, the holes 142 in the first plenum 140, the holes 204 in the third plenum 202, and the radical holes 144 can be arranged in patterns other than the example pattern shown in Figure 3B. Additionally, in the substrate processing systems 250 and 270, the diameters of the holes 142 in the first plenum 140 and the holes 204 in the third plenum 202 can be varied to further improve the uniformity of the gas flow within the plasma source 106 and the processing chamber 102.

[0179] For example, in substrate processing systems 250 and 270, the diameters of the holes 142 in the first plenum 140 and the holes 204 in the third plenum 202 can be gradually reduced as the radial distance of the holes 142 in the first plenum 140 and the holes 204 in the third plenum 202 increases from the center of the first plenum 140 and the third plenum 202. Regardless of the change in diameter, the diameters of the holes 142 in the first plenum 140 and the holes 204 in the third plenum 202 are the same and are smaller than the diameters of the radical holes 144.

[0180] Additionally, although not shown, in some embodiments, in the substrate processing systems 250 and 270, the holes 204 in the third plenum 202 need not be vertical. Instead, the holes 204 in the third plenum 202 may be sloped. For example, the holes 204 in a region from the center of the third plenum 202 to approximately half or three-quarters of the diameter of the third plenum 202 may be sloped. For example, the holes 204 in this region may be sloped radially outward. The slope (angle) at which these holes 204 are sloped may gradually increase as the radial distance of these holes 204 increases from the center of the third plenum 202.

[0181] Additionally, although not shown, in some embodiments, in the substrate processing systems 250, 270, and 290, the holes 142 in the first plenum 140, the holes 204 in the third plenum 202, and the radical holes 144 need not be cylindrical (or circular). Instead, the holes can be any other polygonal shape (e.g., hexagonal, square, etc.). The holes in different sets can have different shapes and sizes. That is, the shapes and sizes of the holes can vary from plenum to plenum or within a single plenum. Any combination of all of the above geometric variations and patterns of the holes described above can be used.

[0182] (Substrate processing method using a 3-plenum showerhead) 7A-7C illustrate a method 300 for performing an ALD process on a substrate 110 using the showerhead 200 in the substrate processing systems 250, 270, and 290. For example, the system controller 160 of the substrate processing systems 250, 270, and 290 performs the method 300. The system controller 160 controls the valves 130, 132, 134, and 136 to flow gases through the first plenum 140 and the third plenum 202, as described below.

[0183] FIG. 7A shows a flowchart of method 300. FIGS. 7B-7D show various gas flows during the loading and purging steps described in method 300. For clarity and simplicity of illustration, showerhead 200 is identified only by reference numeral 200 in FIGS. 7B and 7C. All other reference numerals used in FIGS. 3A-6 to identify other features of showerhead 200 are omitted in FIGS. 7B and 7C but are assumed to be present. Additionally, elements shown in FIGS. 3A-6 are referenced in the following description of method 300.

[0184] 7B, in a DOSE step, precursors are supplied into the processing chamber 102 through a first plenum (e.g., precursor plenum 140) of the showerhead 200 to deposit the precursors on a substrate 110 in the processing chamber 102. In 304, a purge gas (e.g., an inert gas) is trickled into the plasma source 106 (i.e., supplied at a low flow rate referred to as a first flow rate) through a third plenum (e.g., third plenum 202) to maintain a positive pressure in the plasma source 106.

[0185] 7C, in a post-load purge (PDP) step (i.e., at the end of the load step or after the precursor supply is stopped), the plasma source 106 and the processing chamber 102 are purged with a purge gas (e.g., an inert gas). In the post-load purge step, the trickle flow of purge gas supplied in 304 is maintained through the plasma source 106, and the purge gas is supplied into the processing chamber 102 through a first plenum (e.g., precursor plenum 140). In some cases, the flow rate of the purge gas entering the plasma source 106 through a third plenum (e.g., third plenum 202) may be increased beyond the trickle flow (i.e., supplied at a second flow rate greater than the first flow rate).

[0186] At 308, as shown in FIG. 7D, a process gas (e.g., nitrogen or hydrogen) is supplied at a flow rate greater than the trickle flow (i.e., a second flow rate) into the plasma source 106 through a third plenum (e.g., third plenum 202) in a conversion (CONV) step. (Nitrogen can also be supplied as a purge gas used in the purge step of method 300.)

[0187] At 310, the RF power supply 116 supplies RF power to the coil 114, which activates the process gas and strikes the plasma 115 in the plasma source 106. At 312, the method 300 waits for a predetermined period of time. During the predetermined period, the second plenum 144 (i.e., the radical hole 144) of the showerhead 200 filters ions from the plasma 115 and delivers radicals from the plasma 115 into the processing chamber 102 through the radical hole 144. The radicals react with precursors previously deposited on the substrate 110 during the input step (at 302) to deposit a desired material (e.g., silicon nitride) on the substrate 110.

[0188] At 314, in a second post-conversion purge (PCP) step, the RF power supply 116 stops supplying RF power to the coil 114, thereby extinguishing the plasma 115 in the plasma source 106. At 316, as shown in FIG. 7B , the plasma source 106 and processing chamber 102 are purged as described in the post-load purge step above. Specifically, in the second post-conversion purge step, as in the post-load purge step, a trickle flow of purge gas is supplied through a third plenum (e.g., third plenum 202) and maintained through the plasma source 106, and purge gas is supplied into the processing chamber 102 through the first plenum (e.g., precursor plenum 140). In some cases, the flow rate of purge gas entering the plasma source 106 through the third plenum (e.g., third plenum 202) may be increased beyond the trickle flow (i.e., supplied at a second flow rate greater than the first flow rate).

[0189] In 318, the method 300 determines whether to continue (i.e., repeat) processing the substrate 110 (e.g., whether a desired thickness of material has been deposited on the substrate 110). The method 300 repeats steps 302-318 until a desired thickness of material has been deposited on the substrate 110. The method 300 ends once a desired thickness of material has been deposited on the substrate 110.

[0190] In the method 300, during the purge step, the third plenum 202 provides a uniform gas flow (radially and azimuthally across the showerhead 200) within the plasma source 106 and the processing chamber 102, which allows for complete evacuation of precursors from the processing chamber 102 and prevents backflow of precursors from the processing chamber 102 into the plasma source 106.

[0191] In some processes, the same or different precursors may be used in the dosage steps of alternating ALD cycles when repeating steps 302-318, depending on the recipe used to process substrate 110. For example, a first precursor may be used during a first dosage step in a first ALD cycle of steps 302-318, and a second precursor may be used during a second dosage step in a second ALD cycle of steps 302-318 that follows the first ALD cycle. These ALD cycles, each comprising steps 302-318, are repeated until a desired thickness of material is deposited on substrate 110.

[0192] The above description from Figure 3A onwards is provided using a deposition process as an example. The above description from Figure 3A onwards, particularly the use of the showerhead 200 to provide uniform gas flow (radially and azimuthally throughout the showerhead 200) within the plasma source 106 and the processing chamber 102 during a purge step and to prevent backflow of precursors from the processing chamber 102 into the plasma source 106, and more particularly the use of the third plenum 202, also applies when performing an etching process on a substrate 110 in the substrate processing systems 250, 270, and 290 instead of a deposition process.

[0193] Additionally, the above description equally applies to cleaning processes performed to clean the plasma source 106 and processing chamber 102, in which cleaning and purge gases and plasma are used to remove residual deposits from the plasma source 106 and processing chamber 102. These residual deposits must be completely evacuated from the plasma source 106 and processing chamber 102 to prevent contamination of the plasma source 106 and processing chamber 102. The uniform gas flow (radially and azimuthally across the showerhead 200) provided by the showerhead 200 also prevents backflow of contaminants from the processing chamber 102 into the plasma source 106 during the cleaning process.

[0194] (Example of adding a 3-plenum shower head) 8A-12C show additional examples of three-plenum showerheads. These showerheads can be used in place of the showerhead 104 in the substrate processing system 100 shown in FIG. 1. As described below, the purge plenums in these showerheads prevent backflow of precursors from the processing chamber 102 into the plasma source 106 through the radical holes 144 shown in FIG. 1. These showerheads include various arrangements of purge plenums, precursor plenums 140, radical holes (also called radical plenums or plasma plenums) 144, and cooling channels 146, which are described below with reference to FIGS. 8A-12C. Throughout the following description, reference numerals shown in FIGS. 8A-12C and previously shown with reference to FIGS. 1-7D will not be repeated for the sake of brevity.

[0195] 8A shows an example of a three-plenum showerhead 400 according to the present disclosure. The showerhead 400 includes a precursor plenum 140 and a radical plenum 144 with respective holes 142 and 144, as well as a cooling channel 146, which have already been described above with reference to FIGS. 1-7D and will not be described again for the sake of brevity. The showerhead 400 additionally includes a third plenum, referred to as a purge plenum 402. The purge plenum 402 is disposed between the precursor plenum 140 and the cooling channel 146. The radical plenum 144, precursor plenum 140, purge plenum 402, and cooling channel 146 are separate (i.e., not in fluid communication with one another).

[0196] The purge plenum 402 includes a plurality of holes 404-1, 404-2, ..., and 404-N (collectively holes 404, where N is a positive integer). The holes 404 are positioned between the radical holes 144 and the precursor holes 142. That is, each hole 404 in the purge plenum is positioned between a radical hole 144 and a precursor hole 142. Thus, the holes in the radical plenum 144, purge plenum 402, and precursor plenum 140 are arranged in the following order: 144, 404, 142. The purge plenum 402 is used both as a purge plenum for supplying purge gas into the processing chamber 102 and as an exhaust plenum for exhausting precursors from the processing chamber 102 to an exhaust system, as described in detail below with reference to FIG. 8C. The operation of the showerhead 400 and the three plenums 144, 402, 142 is described with reference to FIG. 8C.

[0197] 8B shows a valve assembly 410 used to operate the purge plenum of the showerhead shown in FIGS. 8A-12C, as described with reference to FIGS. 8C and 10. The valve assembly 410 is connected to the purge plenum of the showerhead shown in FIGS. 8A-12C. The valve assembly 410 is connected to the purge gas supply 124, the system controller 160, and the pump 164, all of which are illustrated and described above with reference to FIG. 1. The valve assembly 410 is used in combination with some of the valves of the gas delivery system 120 shown in FIG. 1. The system controller 160 controls some of the valves of the gas delivery system 120 to supply gases to the precursor plenum 140 and the injector 107, as described above with reference to FIG. 1. The system controller 160 controls the valve assembly 410, as described with reference to Figures 8C and 10, to operate the purge plenum of the showerhead shown in Figures 8A-12C to prevent backflow of precursors from the processing chamber 102 into the plasma source 106 through the radical holes 144.

[0198] The valve assembly 410 includes two valves that are mechanically and pneumatically part of the same valve assembly 410. The two valves are interlocked so that when one valve opens, the other closes, and vice versa. Thus, the two valves are fast-acting / switching valves. When one valve blocks downstream gas delivery to the processing chamber 102, the gas is not simply blocked but is diverted to the exhaust system through a secondary path, called the shunt path, thereby preventing pressure buildup. The valve assembly 410 operates the two valves in an on / off square wave fashion rather than a sine wave that passes between partial on and partial off, thereby preventing gas mixing within the processing chamber 102.

[0199] 8C shows a flowchart of a method 500 for operating the purge plenum 402 of the showerhead 400 to prevent backflow of precursors into the plasma source 106 through the radical plenum 144. The method 500 applies equally to the showerheads shown in FIGS. 11-12C. The purge plenums referenced in the description of FIG. 8C refer to the purge plenums 402, 802, and 902.

[0200] For example, Figure 8C illustrates a method 500 for performing an ALD process on a substrate 110 in a substrate processing system 100 using any of the showerheads 400, 800, and 900. For example, a system controller 160 of the substrate processing system 100 can perform the method 500 using the elements shown in Figures 1, 8A, 8B, and 11-12C. The system controller 160 controls the valves of the gas delivery system 120 shown in Figure 1 and the valve assembly 410 shown in Figure 8B to flow gases through the injector 107, the precursor plenum 140, and the purge plenums (e.g., 402, 802, or 902) of the showerheads 400, 800, and 900, as described below.

[0201] At 502, in a dose (DOSE) step, precursors are supplied into the processing chamber 102 through the showerhead precursor plenum 140 to deposit the precursors on the substrate 110 in the processing chamber 102. At 504, in a dose step, a purge gas (e.g., an inert gas) is trickled (i.e., supplied at a low flow rate) into the processing chamber 102 through the showerhead purge plenum. The purge gas flowing through the purge plenum prevents the precursors from backflowing (back-diffusing) into the plasma source 106 through the radical holes 144. Thus, most of the precursors flow to the substrate 110, and the flow of purge gas through the purge plenum guides the precursors to the substrate 110.

[0202] In 506, during a post-load purge (PDP) step (i.e., at the end of the load step or after the precursor supply is stopped), a purge gas is supplied into the processing chamber 102 through the precursor plenum 140 to purge the precursor from the processing chamber 102. In addition, during the post-load purge step, a trickle flow of purge gas is not supplied through the purge plenum. Instead, the purge plenum is used as an exhaust plenum by controlling the valve assembly 410 in a shunt mode to facilitate removal of any residual precursor that may remain in the processing chamber 102 from the processing chamber 102 to the exhaust system through the purge plenum. By not supplying purge gas through the purge plenum, the purge plenum provides a low-pressure path for the residual precursor, which flows out through the purge plenum instead of flowing into the plasma source 106 through the radical holes 144. The residual precursor is purged to the exhaust system through the purge plenum. Therefore, the purge plenum prevents the residual precursor from flowing back into the plasma source 106 through the radical holes 144.

[0203] At 508, a conversion (CONV) step provides a process gas (e.g., nitrogen or hydrogen) into the plasma source 106 above the showerhead through an injector 107. Nitrogen can also be provided as a purge gas used in a purge step of the method 500. At 510, an RF power source 116 provides RF power to the coil 114, thereby activating the process gas to strike a plasma 115 in the plasma source 106.

[0204] At 512, the method 500 waits a predetermined period of time during which the showerhead radical plenum 144 (i.e., radical holes 144) filters ions from the plasma 115 and delivers radicals from the plasma 115 into the processing chamber 102 through the radical holes 144. The radicals react with precursors previously deposited on the substrate 110 during the input step (at 302) to deposit a desired material (e.g., silicon nitride) on the substrate 110.

[0205] At 514, the conversion step also trickles a purge gas through the purge plenum into the processing chamber 102. The trickle of purge gas supplied through the purge plenum creates a curtain of purge gas around the radical holes 144 to prevent the radicals from mixing with any residual precursor remaining in the processing chamber 102, prevent the residual precursor from depositing in the radical holes 144, and prevent the residual precursor from flowing back into the plasma source 106 through the radical holes 144.

[0206] At 516, after a predetermined period of time, the RF power supply 116 stops supplying RF power to the coil 114, thereby extinguishing the plasma 115 in the plasma source 106. At 518, in a post-conversion purge (PCP) step, the plasma source 106 and the processing chamber 102 are purged by supplying a purge gas into the plasma source 106 through the injector 107 and into the processing chamber 102 through the precursor plenum 140. As described above in the post-load purge step, using the purge plenum as an exhaust plenum provides an additional boost to purging the processing chamber 102. Near the end of the post-conversion purge (PCP) step, the method 500 again begins supplying a trickle of purge gas through the purge plenum to prepare for the next load step.

[0207] In 520, the method 500 determines whether to continue (i.e., repeat) processing the substrate 110 (e.g., whether a desired thickness of material has been deposited on the substrate 110). The method 500 repeats steps 502-518 until a desired thickness of material has been deposited on the substrate 110. The method 500 ends once a desired thickness of material has been deposited on the substrate 110.

[0208] In some processes, when steps 502-518 are repeated, the same or different precursors may be used in the dose steps of alternating ALD cycles, depending on the recipe used to process substrate 110. For example, a first precursor may be used during a first dose step in a first ALD cycle of steps 502-518, and a second precursor may be used during a second dose step in a second ALD cycle of steps 502-518 that follows the first ALD cycle. These ALD cycles, each comprising steps 502-518, are repeated until a desired thickness of material is deposited on substrate 110.

[0209] 9A shows an example of a three-plenum showerhead 600 according to the present disclosure. The showerhead 600 includes a precursor plenum 140 and a radical plenum 144 with respective holes 142 and 144, as well as a cooling channel 146, which have already been described above with reference to FIGS. 1-7D. The showerhead 600 additionally includes a third plenum, referred to as a purge plenum 602. The purge plenum 602 is positioned above the cooling channel 146, which is positioned above the precursor plenum 140.

[0210] The purge plenum 602 is joined (i.e., fluidically coupled) with the radical plenum 144. The purge plenum 602 intersects with the radical holes 144. The radical holes 144 are not cylindrical throughout their height (length). Instead, at each intersection of the purge plenum 602 and the radical holes 144, a portion of the radical holes 144 and the purge plenum 602 is shaped to fluidly couple the purge plenum 602 and the radical holes 144 to one another. Generally, at the intersections, the upper and lower portions of the purge plenum 602 extend downward and radially inward to fluidly connect to the radical holes 144. Specifically, at each intersection, a portion of the radical holes 144 flares upward and radially outward to form a funnel-shaped structure 610. The upper circumference of each of the funnel-shaped structures 610 is attached to a hole in the bottom of the purge plenum 602. The holes at the bottom of the purge plenum 602 surround the radical holes 144. Additionally, at the intersection, the upper portion of the purge plenum 602, which surrounds the radical holes 144 and is above the funnel-shaped structure 610, slopes downward and radially inward and is fluidly connected to the radical holes 144. Thus, when purge gas is supplied to the purge plenum 602, the purge gas flows downstream through the radical holes 144 into the processing chamber 102, as described in more detail below with reference to FIG. 10 . The holes in the radical plenum 144 and the precursor plenum 140 are arranged in alternating order 144, 142.

[0211] FIG. 9B shows an example of a three-plenum showerhead 650 according to the present disclosure. The showerhead 650 includes a precursor plenum 140 and a radical plenum 144 with respective holes 142 and 144, as well as a cooling channel 146, as already described above with reference to FIGS. 1-7D. The showerhead 650 additionally includes a third plenum, referred to as a purge plenum 652. The showerhead 650 differs from the showerhead 600 shown in FIG. 9A in that the purge plenum 652 is positioned below the precursor plenum 140, which is positioned below the cooling channel 146. Similar to the showerhead 600, the purge plenum 650 is joined (i.e., fluidically coupled) to the radical plenum 144. The purge plenum 652 intersects with the radical holes 144. The radical holes 144 are not cylindrical throughout their entire height (length). Instead, at each intersection of the purge plenum 652 and the radical holes 144, a portion of the radical holes 144 and the purge plenum 652 is shaped to fluidly couple the purge plenum 652 and the radical holes 144 to one another, as described with reference to FIG. 9A . The showerhead 650 differs from the showerhead 600 in that, in the showerhead 650, the funnel-shaped structure 610 is formed near the bottom of the radical holes 144 instead of near the top of the radical holes 144. The purge plenum 652 of the showerhead 650 operates similarly to the purge plenum 602 of the showerhead 600, as described below with reference to FIG. 10 . The holes in the radical plenum 144 and the precursor plenum 140 are arranged in alternating order 144, 142.

[0212] 9C-9F illustrate further differences between the showerhead 650 and the showerhead 600. FIG. 9C shows an enlarged view of the funnel-shaped structure 610 of the showerhead 650. The showerhead 650 conducts heat radiated from the pedestal 108 (see FIG. 1), which is located adjacent to the bottom of the showerhead 650 during the ALD process. The purge plenum 650 is located below the precursor plenum 140, which is located below the cooling channels 146. Therefore, the cooling channels 146 are relatively far from the bottom of the showerhead 650. Furthermore, because the funnel-shaped structure 610 is formed near the bottom of the radical holes 144 in the showerhead 650, a thermal break (thermal discontinuity) 620 exists in a portion of the purge plenum 652 at the intersection between the purge plenum 652 and the radical holes 144. Thus, heat absorbed by the bottom of the showerhead 650 must travel the distance between the purge plenum 652 and the cooling channels 146 , impeded by the heat break 620 .

[0213] Furthermore, in the showerhead 650, a funnel-shaped structure 610 is formed near the lower end of the radical holes 144, so that when purge gas is supplied to the purge plenum 652, the purge gas flows unrestrictedly into the downstream processing chamber 102 through the radical holes 144. To promote heat transfer through the purge plenum 652 and restrict the downstream flow of purge gas through the radical holes 144, a cylindrical coupling member 630 shown in FIGS. 9D-9F is interposed at the intersection between the purge plenum 652 and the radical holes 144.

[0214] 9D shows the coupling member 630 in dashed lines. FIG. 9E shows a perspective view of the coupling member 630, which includes a gas passage 632 for purge gas to flow from the purge plenum 652 to the radical holes 144. FIG. 9F shows a perspective view of the gas passage 632 and the radical holes 144. As shown in FIG. 9D and as can be seen in FIG. 9E, at the intersection between the purge plenum 652 and the radical holes 144, the coupling member 630 eliminates the thermal break (thermal discontinuity) 620 in a portion of the purge plenum 652. Thus, the coupling member 630 provides a path for heat to flow from the bottom of the showerhead 650 to the cooling channels 146.

[0215] Additionally, as shown in FIG. 9E and seen in FIG. 9F , a gas passage 632 extends between the upper and lower ends of the connecting member 630. The gas passage 632 slopes from the upper end to the lower end of the connecting member 630. The gas passage 632 curves clockwise (or counterclockwise) between the upper and lower ends of the connecting member 630. The gas passage 632 provides a restricted flow path for purge gas to flow from the purge plenum 650 into the radical hole 144. The gas passage 632 creates a vortex flow of the purge gas into the radical hole 144. The vortex flow of the purge gas through the radical hole 144 functions like an injection gas, driving a top-to-bottom flow through the radical hole 144. The vortex flow controls the direction of the gas flow through the radical hole 144 so that the purge gas flow only promotes a downward flow within the radical hole 144, thereby preventing backflow of precursors into the plasma chamber 106 through the radical hole 144. Although three channels 632 are shown, any number of channels can be used. Additionally, the channels 632 can be shaped and arranged differently than shown.

[0216] 10 shows a flowchart of a method 700 for operating the purge plenums 602 and 652 of the showerheads 600 and 650 to prevent backflow of precursors into the plasma source 106 through the radical plenum 144. The method 700 similarly applies to the showerheads 600 and 650 shown in FIGS. 9A and 9B. The purge plenums referenced in the description of FIG. 10 refer to the purge plenums 602 and 652 of the showerheads 600 and 650 shown in FIGS. 9A and 9B.

[0217] 10 illustrates a method 700 for performing an ALD process on a substrate 110 in a substrate processing system 100 using either of the showerheads 600 and 650. For example, the system controller 160 of the substrate processing system 100 can perform the method 700 using the elements shown in FIGS. 1, 8B, and 9A-9F. The system controller 160 controls the valves of the gas delivery system 120 shown in FIG. 1 and the valve assembly 410 shown in FIG. 8B to flow gases through the injector 107, the precursor plenum 140, and the purge plenum (e.g., 602 or 652) of the showerheads 600 and 652, as described below.

[0218] At 702, in a dosing (DOSE) step, precursors are supplied into the processing chamber 102 through the showerhead precursor plenum 140 to deposit the precursors on the substrate 110 in the processing chamber 102. At 704, in a dosing step, a purge gas (e.g., an inert gas) is supplied at a first pressure P1 through the purge plenum into the showerhead radical plenum 144 and into the processing chamber 102. The purge gas flowing through the purge plenum prevents the precursors from backflowing (back-diffusing) through the radical holes 144 into the plasma source 106. Thus, most of the precursors flow to the substrate 110, and the flow of purge gas through the purge plenum directs the precursors to the substrate 110.

[0219] In 706, during the post-injection purge (PDP) process (i.e., at the end of the injection process or after stopping the supply of the precursor), a purge gas is supplied into the processing chamber 102 through the precursor plenum 140 to purge the precursor from the processing chamber 102. Additionally, during the post-injection purge process, while purging the processing chamber 102, the purge gas is supplied into the radical plenum 144 through the purge plenum at a second pressure P2 < P1 to facilitate removing any residual precursor that may remain in the processing chamber 102 from the processing chamber 102 to the exhaust system. The residual precursor is purged from the processing chamber 102 to the exhaust system. Thus, by flowing the purge gas into the radical plenum 144 during the PDP process, the purge plenum prevents the residual precursor from flowing back into the plasma source 106 through the radical holes 144.

[0220] In 708, in the conversion (CONV) process, a process gas (e.g., nitrogen or hydrogen) is supplied through the injector 107 into the plasma source 106 above the showerhead. Nitrogen can also be supplied as the purge gas used in the purge process of method 500. In 710, the RF power supply 116 supplies RF power to the coil 114, thereby activating the process gas to irradiate the plasma 115 in the plasma source 106.

[0221] In 712, method 500 waits for a predetermined period. During the predetermined period, the radical plenum 144 of the showerhead (i.e., the radical holes 144) filters ions from the plasma 115 and supplies radicals from the plasma 115 into the processing chamber 102 through the radical holes 144. The radicals react with the precursor previously deposited on the substrate 110 during the injection process (at 302) to deposit a desired material (e.g., silicon nitride) on the substrate 110.

[0222] In 714, in the conversion step, purge gas is also supplied into the radical plenum 144 through the purge plenum at a third pressure P3 < P2 and supplied into the processing chamber 102. The purge gas supplied into the radical plenum 144 through the purge plenum prevents mixing with any residual precursors in which radicals remain in the processing chamber 102, prevents the residual precursors from depositing at the radical holes 144, and prevents the residual precursors from flowing back into the plasma source 106 through the radical holes 144.

[0223] In 716, after a predetermined period, the RF power supply 116 stops supplying RF power to the coil 114, thereby extinguishing the plasma 115 in the plasma source 106. In 718, in the post-conversion purge (PCP) step, the plasma source 106 and the processing chamber 102 are purged by supplying purge gas into the plasma source 106 through the injector 107 and by supplying purge gas into the processing chamber 102 through the precursor plenum 140. Further facilitation for purging the processing chamber 102 is provided by supplying purge gas into the radical plenum 144 through the purge plenum at a first pressure P1. At the end of the post-conversion purge (PCP) step, the method 700 is ready for the next input step.

[0224] In 720, the method 700 determines whether to continue (i.e., repeat) the processing of the substrate 110 (e.g., whether a material of a desired thickness is being deposited on the substrate 110). The method 700 repeats steps 702 to 718 until a material of a desired thickness is deposited on the substrate 110. The method 700 ends when a material of a desired thickness is deposited on the substrate 110.

[0225] In some processes, when steps 702-718 are repeated, the same or different precursors may be used in the dosage steps of alternating ALD cycles, depending on the recipe used to process substrate 110. For example, a first precursor may be used during a first dosage step in a first ALD cycle of steps 702-718, and a second precursor may be used during a second dosage step in a second ALD cycle of steps 702-718 that follows the first ALD cycle. These ALD cycles, each comprising steps 702-718, are repeated until a desired thickness of material is deposited on substrate 110.

[0226] FIG. 11 shows an example of a three-plenum showerhead 800 according to the present disclosure. The showerhead 800 includes a precursor plenum 140 and a radical plenum 144 with respective holes 142 and 144, and a cooling channel 146, which have already been described above with reference to FIGS. 1-7D . The showerhead 800 additionally includes a third plenum, referred to as a purge plenum 802. The showerhead 800 differs from the showerhead 400 shown in FIG. 8A in that the precursor plenum 140 is positioned below the cooling channel 146 and the purge plenum 802 is positioned below the precursor plenum 140. In addition, the purge plenum 802 includes two sets of holes: 406-1 and 408-1, 406-2 and 408-2, ..., and 406-N and 408-N (collectively holes 406, 408). The holes 406, 408 are positioned between the radical holes 144, and each precursor hole 142 is positioned between the holes 406, 408. Thus, the holes in the radical plenum 144, purge plenum 802, and precursor plenum 140 are arranged in the following order: 144, 406, 142, 408. The purge gas plenum 802 provides a curtain of purge gas around the radical holes 144 to prevent precursors from depositing in the radical holes 144 and to prevent precursors from backflowing through the radical holes 144 into the plasma source, as described in detail with reference to FIG. 8C . The purge plenum 802 of the showerhead 800 operates similarly to the purge plenum 402 of the showerhead 400, as described above with reference to FIG. 8C .

[0227] 12A-12C show a three-plenum showerhead 900 according to the present disclosure. The showerhead 900 includes a precursor plenum 140 and a radical plenum 144 with respective holes 142 and 144, as well as a cooling channel 146, which have already been described above with reference to FIGS. 1-7D. The showerhead 900 additionally includes a third plenum, referred to as a purge plenum 902. The showerhead 900 is similar to the showerhead 800 shown in FIG. 11, except that the purge plenum 902 of the showerhead 900 is disposed within a detachable (removable and reattachable) plate 950, as shown in FIGS. 12B and 12C. The purge plenum 902 of the showerhead 900 is similar to the purge plenum 802 of the showerhead 800 in that the purge plenum 902 also includes holes 406, 408 arranged in the same order 144, 406, 142, 408.

[0228] Specifically, the showerhead 900 includes a top portion 940 and a plate 950 that forms a portion of the purge plenum 902. The top portion 940 includes the cooling channels 146, the precursor plenum 140, a portion of the precursor holes 142, a portion of the radical plenum (radical holes) 144, and a first portion of the purge plenum 902. The first portion of the purge plenum 902 in the top portion 940 does not include the holes 406, 408 of the purge plenum 902. The plate 950 includes a portion of the precursor holes 142, a portion of the radical plenum (radical holes) 144, and a portion of the purge plenum 902 with the holes 406, 408. When the plate 950 is attached to the top portion 940 of the showerhead 900, the following occurs: A portion of the precursor holes 142 and a portion of the radical plenum (radical holes) 144 in the plate 950 mate with respective portions of the precursor holes 142 and respective portions of the radical plenum (radical holes) 144 in the top portion 940. A portion of the purge plenum 902 with holes 406, 408 in the plate 950 mates with a portion of the purge plenum 902 in the top portion 940. Thus, the holes in the radical plenum 144, purge plenum 902, and precursor plenum 140 are arranged in the following order: 144, 406, 142, 408.

[0229] 8A and subsequent descriptions are provided using a deposition process as an example. The above description from FIG. 8A and subsequent descriptions, particularly the use of showerheads 400, 600, 650, 800, and 900 to prevent backflow of precursors from the processing chamber 102 into the plasma source 106, and more particularly the use of purge plenums 402, 602, 652, and 902, equally apply when performing an etching process on a substrate 110 in the substrate processing system 100 instead of a deposition process.

[0230] Additionally, the above description equally applies to cleaning processes performed to clean the plasma source 106 and processing chamber 102, in which cleaning and purge gases and plasma are used to remove residual deposits from the plasma source 106 and processing chamber 102. These residual deposits must be thoroughly evacuated from the plasma source 106 and processing chamber 102 to prevent contamination of the plasma source 106 and processing chamber 102. The use of showerheads 400, 600, 650, 800, and 900, and more specifically, the use of the purge plenums 402, 602, 652, and 902 described above, can also prevent backflow of contaminants from the processing chamber 102 into the plasma source 106 during the cleaning process.

[0231] In showerheads 400, 600, 650, 800, and 900, the diameter of the hole in the third plenum (i.e., the purge plenum) is larger than the diameter of the precursor hole 142 and smaller than the diameter of the radical hole 144. In these showerheads, the purge gas supplied through the purge plenum improves separation between the precursor and plasma gas (radicals) to prevent the precursor from back-diffusing through the radical hole 144 into the plasma source 106. In these showerheads, the flow of purge gas through the purge plenum, as described above, increases the pressure gradient from the substrate 110 to the bottom of the showerhead and the plasma / radical hole 144. The pressure gradient makes it increasingly difficult for the precursor to flow toward the bottom of the showerhead and the plasma / radical hole 144. The purge gas flowing through the purge plenum prevents the precursor from back-flowing (back-diffusing) through the radical hole 144 into the plasma source 106. Thus, most of the precursors flow to the substrate 110 and the flow of purge gas through the purge plenum directs the precursors to the substrate 110 .

[0232] The foregoing description is merely exemplary in nature and is not intended to limit the disclosure, its application, or its uses. The broad teachings of the disclosure can be embodied in a variety of forms. Accordingly, while the disclosure includes specific embodiments, the true scope of the disclosure should not be so limited, as other variations will become apparent upon review of the drawings, this specification, and the following claims.

[0233] It should be understood that one or more steps of the method may be performed in a different order (or simultaneously) without altering the principles of the present disclosure. Furthermore, although each of the embodiments is described above as having certain features, any one or more of those features described with respect to any embodiment of the present disclosure can be implemented with and / or combined with any feature of any other embodiment, even if that combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and substituting one or more embodiments for one another remains within the scope of the present disclosure.

[0234] Spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.) are described using various terms, including "connected," "engaged," "coupled," "adjacent," "next to," "on top of," "above," "below," and "disposed." When a relationship between first and second elements is described in the above disclosure, unless expressly described as "direct," the relationship may be a direct relationship where no other intervening elements exist between the first and second elements, or an indirect relationship where one or more intervening elements exist (both spatially and functionally) between the first and second elements. As used herein, the phrase "at least one of A, B, and C" should be interpreted to mean a non-exclusive logical "or" (A or B or C), and not to mean "at least one of A, at least one of B, and at least one of C."

[0235] In some embodiments, the controller is part of a system that may be part of the above examples. Such a system may include semiconductor processing equipment, including one or more processing tools, one or more chambers, one or more processing platforms, and / or specific processing components (such as a wafer pedestal, gas flow system, etc.). These systems may be integrated with electronics for controlling their operation before, during, and after processing of semiconductor wafers or substrates. This electronics may be referred to as a "controller" and may control various components or subportions of one or more systems.

[0236] The controller may be programmed to control any of the processes disclosed herein depending on the processing requirements and / or type of system, including process gas delivery, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid delivery settings, position and operation settings, wafer loading and unloading into the tool, and wafer loading and unloading into other transfer tools and / or load locks connected or interfaced with the particular system.

[0237] Broadly, a controller may be defined as an electronic device having various integrated circuits, logic, memory, and / or software that receives instructions, issues instructions, controls operations, enables cleaning operations, enables 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 program instructions (e.g., software).

[0238] Program instructions may be instructions communicated to the controller in the form of various personalizations (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 fabrication of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or dies of a wafer.

[0239] In some embodiments, the controller may be part of a computer integrated with, coupled to, or otherwise networked to the system, or may be coupled to such a computer, 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, thereby enabling remote access to wafer processing. The computer may enable remote access to the system to monitor the current progress of a fabrication operation, analyze the history of past fabrication operations, analyze trends or performance metrics from multiple fabrication operations, and modify parameters of a current process, set up processing steps following the current process, or initiate a new process.

[0240] In some examples, a remote computer (e.g., a server) can provide the process recipe 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 for 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 that specify parameters for each of the processing steps performed during one or more operations. It should be understood that the parameters can be specific to the type of process being performed and the type of tool the controller is configured to interface with or control.

[0241] Thus, as noted above, the controller may be distributed, such as by including one or more individual controllers networked together and working toward a common purpose, such as the processes and controls described herein. An example of a distributed controller for such purposes would include one or more integrated circuits on the chamber that are in communication with one or more integrated circuits located remotely (e.g., at the platform level or as part of a remote computer) and that are coupled to control the process on the chamber.

[0242] Without limitation, example systems may include 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 track chamber or module, and any other semiconductor processing system related to or that may be used in the fabrication and / or manufacturing of semiconductor wafers.

[0243] As noted above, depending on the process step or steps being performed by the tool, the controller may communicate with one or more of 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 in material transport to and from tool locations and / or load ports within the semiconductor fabrication factory to transport containers of wafers.

Claims

1. 1. A substrate processing system, comprising: a processing chamber; a plasma source for generating and delivering plasma to the processing chamber; a showerhead disposed between the processing chamber and the plasma source to supply gas to the processing chamber and the plasma source and to supply the plasma to the processing chamber; The shower head is a body having a first surface, a second surface, and a side surface that define first and second plenums; a first set of holes extending from the first plenum to the first surface and in fluid communication with the processing chamber; a second set of holes extending from the second plenum to the second surface and in fluid communication with the plasma source; A substrate processing system comprising:

2. 10. The substrate processing system of claim 1, The substrate processing system, wherein the second plenum and the second set of holes are an inverse replica of the first plenum and the first set of holes.

3. 10. The substrate processing system of claim 1, The showerhead distributes the gases radially and azimuthally uniformly across the showerhead through the first and second sets of holes.

4. 10. The substrate processing system of claim 1, The showerhead supplies the gases in opposite directions, radially and azimuthally uniformly across the showerhead, through the first and second sets of holes.

5. 10. The substrate processing system of claim 1, the showerhead delivers the gases to the processing chamber and the plasma source through the first and second sets of holes, respectively; The showerhead distributes the gases radially and azimuthally uniformly across the showerhead through the first and second sets of holes.

6. 10. The substrate processing system of claim 1, the showerhead is cylindrical; the first and second plenums are stacked in an axial direction perpendicular to a diameter of the showerhead; The first and second plenums extend radially across the showerhead.

7. 10. The substrate processing system of claim 1, the processing chamber further comprising a pedestal and a substrate disposed on the pedestal; the showerhead is cylindrical; the first and second plenums are stacked in an axial direction perpendicular to a diameter of the showerhead; The first and second plenums extend radially across the substrate.

8. 10. The substrate processing system of claim 1, The substrate processing system, wherein the second plenum and the second set of holes are separate from the first plenum and the first set of holes.

9. 10. The substrate processing system of claim 1, the showerhead is cylindrical; the first and second plenums extend radially across the showerhead; The first and second sets of holes are radially distributed across the showerhead.

10. 10. The substrate processing system of claim 1, the showerhead is cylindrical; The first and second sets of holes extend in an axial direction perpendicular to a diameter of the showerhead.

11. 10. The substrate processing system of claim 1, The first and second sets of holes have the same diameter.

12. 10. The substrate processing system of claim 1, the showerhead further includes a third set of holes extending between the first and second surfaces; The substrate processing system, wherein the third set of holes is separate from the first and second plenums and the first and second sets of holes.

13. 13. The substrate processing system of claim 12, the showerhead is cylindrical; the second set of holes supplies one of the gases to the plasma source radially and azimuthally uniformly across the showerhead; The third set of holes delivers the one of the gases from the plasma source to the processing chamber radially and azimuthally uniformly across the showerhead.

14. 13. The substrate processing system of claim 12, the showerhead is cylindrical; The third set of holes extends in an axial direction perpendicular to a diameter of the showerhead.

15. 13. The substrate processing system of claim 12, the showerhead is cylindrical; The third set of holes is radially distributed across the showerhead.

16. 13. The substrate processing system of claim 12, the showerhead is cylindrical; The first, second and third sets of holes are radially spaced apart throughout the showerhead.

17. 13. The substrate processing system of claim 12, the processing chamber further comprising a pedestal and a substrate disposed on the pedestal; the showerhead is cylindrical; The third set of holes is radially distributed across the substrate.

18. 13. The substrate processing system of claim 12, the processing chamber further comprising a pedestal and a substrate disposed on the pedestal; the showerhead is cylindrical; the first and second plenums are stacked in an axial direction perpendicular to a diameter of the showerhead; the first and second plenums extend radially across the substrate; The third set of holes is radially distributed across the substrate.

19. 13. The substrate processing system of claim 12, the showerhead is cylindrical; A substrate processing system wherein the diameter of the third set of holes is equal to or greater than the diameter of at least one of the first and second sets of holes.

20. 13. The substrate processing system of claim 12, the showerhead is cylindrical; The first and second sets of holes have a first diameter, and the third set of holes has a second diameter that is larger than the first diameter.

21. 13. The substrate processing system of claim 12, The third set of holes supplies radicals from the plasma to the processing chamber.

22. 10. The substrate processing system of claim 1, the showerhead is cylindrical; the showerhead further includes a cooling channel disposed between the first and second plenums; The cooling channel and the first and second plenums extend radially across the showerhead and are separated from one another.

23. 10. The substrate processing system of claim 1, The substrate processing system, wherein the plasma source is dome-shaped, elliptical-shaped, cylindrical-shaped, or conical-shaped.

24. 10. The substrate processing system of claim 1, a gas delivery system that supplies the gas to the showerhead; a controller; The controller supplying a first gas from the gas source to the first plenum during an input step of an atomic layer deposition (ALD) process; supplying a second gas from the gas source to the second plenum to generate the plasma, and the third set of holes supplying radicals from the plasma to the processing chamber; supplying a third gas from the gas mixture to the second plenum during a purge step of the ALD process; It is configured as follows: the third gas flows into the processing chamber through the third set of holes uniformly radially and azimuthally across the showerhead to prevent material flow from the processing chamber to the plasma source. Substrate processing system.

25. 1. A showerhead for a substrate processing system, comprising: a body having a first surface, a second surface, and a side defining first and second plenums, the first and second surfaces being opposite one another; a first set of holes extending from the first plenum to the first surface; a second set of holes extending from the second plenum to the second surface; and Including the shower head.

26. 26. The showerhead of claim 25, the second plenum and the second set of holes are inverse replicas of the first plenum and the first set of holes.

27. 26. The showerhead of claim 25, the showerhead is cylindrical; the first and second plenums are stacked in an axial direction perpendicular to a diameter of the showerhead; The first and second plenums extend radially across the showerhead.

28. 26. The showerhead of claim 25, the second plenum and the second set of holes are separate from the first plenum and the first set of holes.

29. 26. The showerhead of claim 25, the showerhead is cylindrical; the first and second plenums extend radially across the showerhead; The first and second sets of holes are radially distributed throughout the showerhead.

30. 26. The showerhead of claim 25, the showerhead is cylindrical; The showerhead, wherein the first and second sets of holes extend in an axial direction perpendicular to a diameter of the showerhead.

31. 26. The showerhead of claim 25, The first and second sets of holes have the same diameter.

32. 26. The showerhead of claim 25, further comprising a third set of holes extending between the first and second surfaces; the third set of holes is separate from the first and second plenums and the first and second sets of holes.

33. 33. The showerhead of claim 32, the showerhead is cylindrical; The showerhead, wherein the third set of holes extends in an axial direction perpendicular to a diameter of the showerhead.

34. 33. The showerhead of claim 32, the showerhead is cylindrical; The third set of holes is radially distributed throughout the showerhead.

35. 33. The showerhead of claim 32, the showerhead is cylindrical; the first, second, and third sets of holes are radially spaced apart throughout the showerhead.

36. 33. The showerhead of claim 32, the showerhead is cylindrical; The showerhead, wherein the third set of holes has a larger diameter than the first and second sets of holes.

37. 33. The showerhead of claim 32, the showerhead is cylindrical; the first and second sets of holes have a first diameter, and the third set of holes has a second diameter that is larger than the first diameter.

38. 26. The showerhead of claim 25, the showerhead is cylindrical; the showerhead further includes a cooling channel disposed between the first and second plenums; The cooling channels and the first and second plenums extend radially throughout the showerhead and are separated from one another.

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