Multi-zone gas distribution system and method

Abstract

To provide a substrate processing system that includes a gas distribution assembly for generating a uniform plasma during a semiconductor processing operation or for processing the interior of a semiconductor processing chamber, and a substrate processing method.SOLUTION: In a substrate processing system, a substrate processing chamber 1001 includes a zonal distribution manifold 1010 having first and second manifold channels 1015 and 1016. First gas flows through the first manifold channel and second gas flows through the second manifold channel. The substrate processing chamber also includes a zonal distribution plate 1029 that is attached to the zonal distribution manifold, has two separate flow channels therein and prevents any mixing between the first gas and the second gas, and the zonal distribution plate includes an inner zone channel 1018 that receives the first gas from an inner zone expansion region 1017 and an outer zone channel 1019 that receives the second gas from the second manifold channel.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 15 / 847,411, filed December 19, 2017, which is incorporated by reference herein in its entirety for all purposes.

[0002]

[0002] The present technology relates to components and apparatus for semiconductor manufacturing. More particularly, the present technology relates to gas distribution assemblies and methods of operation. [Background technology]

[0003]

[0003] Integrated circuits are made possible by processes that form layers of materials in complex patterns on substrate surfaces. Creating patterned materials on substrates requires controlled methods for forming and removing material. The uniformity of the plasma used to excite reactants can have a direct impact on the final product. Variations in plasma uniformity in remote plasmas can result in regions of higher etching or deposition rates near the edge of the substrate than in the center, and vice versa. Etch uniformity has been controlled by adjusting the spacing between the substrate surface and the showerhead, but this also changes the rate of etching. Depending on the degree of variation along the surface of the substrate, inconsistencies created by the etching process can result in device failure.

[0004]

[0004] Furthermore, plasma uniformity has been found to be particularly unstable in the presence of fluorine and other electronegative species. Negatively charged species are less likely to release electrons, making a symmetric plasma more difficult to maintain. A symmetric plasma around the surface of the substrate can result in a more uniform etching process.

[0005]

[0005] Therefore, there is a need for improved systems and methods that can be used to manufacture high quality devices and structures. These and other needs are addressed by the present technology. Summary of the Invention

[0006] The present technology includes an improved gas distribution design for generating a uniform plasma during semiconductor processing operations or for processing the interior of a semiconductor processing chamber. While conventional gas distribution assemblies may receive specific reactants or reactant ratios that are then distributed into the plasma region, the presently described technology allows for improved control of reactant input distribution. The technology allows for separate flows of reactants to different regions of the plasma, which can offset any observed irregularities in process uniformity. A first precursor may be distributed to the center of the plasma above the center of the substrate / pedestal, while a second precursor may be distributed to the outer portion of the plasma above the outer portion of the substrate / pedestal. By doing so, improved operation may be achieved because a substrate placed on the pedestal may experience a more uniform etching or deposition profile across its surface.

[0007] In one embodiment, a zone distribution manifold has two separate channels for precursors that are supplied to two separate regions of a zone distribution plate. The zone distribution plate may supply a first gas to an inner portion of a zone blocker plate and a second gas to an outer portion of the zone blocker plate. The inner portion may have an inner showerhead centrally located within the zone blocker plate. The inner showerhead may be circular. The outer portion may have an outer showerhead centered on the zone blocker plate and may have an annular shape around the inner showerhead. When all elements are assembled and attached to each other, the first gas and the second gas remain separated until they pass through the zone blocker plate.

[0008] Advantages of the devices described herein include the ability to tailor gas distribution to the center of the plasma compared to gas distributed to the outer portions of a localized or remote plasma. Substrate processing plasmas are very thin, yet still need to provide a uniform net effect across the substrate surface or around the interior of a substrate processing system for cleaning procedures. Etching and cleaning often rely on highly negatively charged reactants, such as fluorine-containing precursors. Fluorine's high electronegativity exacerbates plasma uniformity issues. Because fluorine ions are very difficult to generate, there are insufficient electrons available to sustain the plasma throughout the thin, wide plasma region. This means that some regions may sustain an electron breakdown cascade that impairs plasma health in other portions of the plasma region. The hardware described herein can provide the benefit of more uniform plasmas and / or more uniform processes (e.g., removal rates) across the plasma region (across the dimension perpendicular to the thin dimension). In some cases, the hardware described herein can even be used to avoid distorted plasma that would otherwise collapse to one side of the plasma region. Thus, the hardware and methods described herein can be used to generate concentric plasmas that benefit plasma control efforts and also make the process more uniform.

[0009] Disclosed embodiments include a substrate processing system. The substrate processing system includes a zone distribution manifold having a first manifold channel and a second manifold channel. The substrate processing system further includes a zone distribution plate attached to the zone distribution manifold. The zone distribution plate has an inner zone channel configured to receive a first gas from the first manifold channel and an outer zone channel configured to receive a second gas from the second manifold channel. The substrate processing system further includes a zone blocker plate attached to the zone distribution plate. The zone blocker plate has an upper inner recess configured to receive the first gas from the inner zone channel and an upper outer recess configured to receive the second gas from the outer zone channel. The zone blocker plate further includes a lower inner recess fluidly coupled to the upper inner recess through an inner showerhead portion and a lower outer recess fluidly coupled to the upper outer recess through an outer showerhead portion. The substrate processing system further includes a faceplate attached to the zone blocker plate having through-holes configured to pass the first gas and the second gas into the plasma region.

[0010] The outer zone channel may include a groove formed in an upper portion of the zone distribution plate. The zone distribution plate may include a plurality of bottom holes evenly spaced around a circumference centered on the zone blocker plate. The groove may be configured to receive the second gas from the second manifold channel at a starting point. A path length from the starting point to each of the plurality of bottom holes along the groove may be the same for each of the plurality of bottom holes. The plurality of bottom holes may include at least eight bottom holes. The zone distribution manifold, the zone distribution plate, and the zone blocker plate may be configured to prevent the first gas and the second gas from mixing until they enter the plasma region. The substrate processing system may further include a showerhead parallel to the face plate. The plasma region may be disposed between the face plate and the showerhead. The plasma region may border each of the face plate and the showerhead. The substrate processing system may further include a substrate processing region adjacent to the showerhead on an opposite side of the showerhead from the plasma region. The plasma region may be a localized plasma region configured to accommodate a substrate for processing. The zone distribution plate and the zone blocker plate may have a disk shape and may be coaxial. The first manifold channel may include a narrow channel portion and a wide channel portion disposed closer to the zone distribution plate. The narrow channel portion has a first diameter and the wide channel portion has a second diameter, the second diameter being larger than the first diameter. The first manifold channel may be configured to allow the first gas to expand and mix before entering the upper inner recess.

[0011]

[0011] Disclosed embodiments include a processing method. The method includes applying RF power between an anode and a cathode. The anode and cathode are planar and parallel, and a plasma region is disposed between the anode and the cathode. The anode and the cathode are adjacent to or border the plasma region, respectively. The method includes generating a hydrogen-containing plasma by flowing a hydrogen-containing precursor into the center of the plasma region. The method includes generating a hydrogen-fluorine-containing plasma by further flowing a fluorine-containing precursor into the plasma region. The hydrogen-containing precursor and the fluorine-containing precursor first encounter and mix within the plasma region. The method includes generating a fluorine-containing plasma by stopping the flow of the hydrogen-containing precursor into the plasma region.

[0012] The processing method may process a substrate or an interior surface of a substrate processing chamber. The anode may be a faceplate or a showerhead, and the cathode may be a showerhead or a faceplate. The substrate processing region may be located on the opposite side of the showerhead from the plasma region. In another embodiment, the anode may be a showerhead or a substrate pedestal, and the cathode may be a substrate pedestal or a showerhead. The substrate processing region may be located between the anode and the cathode. The substrate processing region may be adjacent to or border both the anode and the cathode. The anode, cathode, and plasma region may be circular. The hydrogen-containing precursor may include one of hydrogen (H2) and ammonia (NH3). The fluorine-containing precursor may include nitrogen trifluoride (NF3).

[0013] Disclosed embodiments include a semiconductor processing system. The semiconductor processing system includes a zone distribution manifold having a first manifold channel and a second manifold channel. The semiconductor processing system includes a zone distribution plate attached to the zone distribution manifold. The zone distribution plate has an inner zone channel configured to receive a first gas from the first manifold channel and an outer zone channel configured to receive a second gas from the second manifold channel. The semiconductor processing system includes a zone blocker plate attached to the zone distribution plate. The zone blocker plate has a central through-hole configured to receive the first gas from the inner zone channel and an upper outer recess configured to receive the second gas from the outer zone channel. The zone blocker plate further includes a lower outer recess fluidly coupled to the upper outer recess through an outer showerhead portion. The semiconductor processing system further includes a face plate attached to the zone blocker plate. The face plate has through-holes configured to pass the second gas into the plasma region. The zone blocker plate has a central faceplate hole configured to receive the first gas from the central through-hole and pass the first gas into the plasma region.

[0014] The zone distribution manifold, the zone distribution plate, and the zone blocker plate may be configured to prevent the first gas and the second gas from mixing until they enter the plasma region. The semiconductor processing system may further include a showerhead parallel to the faceplate. The plasma region may be disposed between the faceplate and the showerhead. The plasma region may be adjacent to each of the faceplate and the showerhead. The semiconductor processing system may further include a substrate processing region adjacent to the showerhead on an opposite side of the showerhead from the plasma region. The plasma region may be a localized plasma region configured to accommodate a substrate for processing. The zone distribution plate may include a plurality of bottom holes evenly spaced around a circumference centered on the center of the zone blocker plate. The zone distribution plate and the zone blocker plate may be circular or coaxial.

[0015] Disclosed embodiments include a plasma processing method. The method includes generating a hydrogen- and fluorine-containing plasma by applying RF power between an anode and a cathode. A plasma region containing a hydrogen-containing precursor and a fluorine-containing precursor, respectively, is disposed between the anode and the cathode. The anode and the cathode are planar and parallel to each other. The method further includes generating the fluorine-containing plasma by removing the hydrogen-containing precursor from the plasma region.

[0016] The anode may be a faceplate or a showerhead, and the cathode may be the other element (showerhead or faceplate). The substrate processing region may be located on the opposite side of the showerhead from the plasma region. In another embodiment, the anode may be a showerhead or a substrate pedestal, and the cathode may be a substrate pedestal or a showerhead (the remaining element of the two). The substrate processing region may be located between the anode and the cathode. The substrate processing region may be adjacent to both the anode and the cathode. The anode, cathode, and plasma region may be circular. The hydrogen-containing precursor may include at least one of hydrogen (H2) and ammonia (NH3). The fluorine-containing precursor may include nitrogen trifluoride (NF3).

[0017]

[0016] A further understanding of the nature and advantages of the disclosed technology may be realized by reference to the remaining portions of the specification and the drawings. [Brief explanation of the drawings]

[0018] [Figure 1]

[0017] A top view of an exemplary processing system according to the present technology is shown. [Figure 2A]

[0018] A schematic cross-sectional view of an exemplary processing chamber is shown, in accordance with an embodiment of the present technique. [Figure 2B]

[0019] 1 shows a detailed view of an exemplary showerhead in accordance with an embodiment of the present technique. [Figure 3]

[0020] FIG. 1 illustrates a bottom view of an exemplary showerhead, in accordance with embodiments of the present technique. [Figure 4]

[0021] 1 shows a schematic partial cross-sectional view of an exemplary substrate processing system, in accordance with an embodiment of the present technique; [Figure 5A]

[0022] 1 shows a schematic partial cross-sectional view of an exemplary blocker plate, in accordance with an embodiment of the present technique; [Figure 5B]

[0023] FIG. 1 illustrates a top view of an exemplary zone blocker plate, in accordance with an embodiment of the present technique; [Figure 5C]

[0024] FIG. 10 illustrates a bottom view of an exemplary zone blocker plate, in accordance with an embodiment of the present technique. [Figure 6A]

[0025] 1 illustrates a top view of an exemplary zone distribution plate, in accordance with an embodiment of the present technique. [Figure 6B]

[0026] FIG. 10 illustrates a bottom view of an exemplary zone distribution plate, in accordance with an embodiment of the present technique. [Figure 7]

[0027] 1 shows a schematic partial cross-sectional view of a zonal distribution manifold in accordance with an embodiment of the present technology; [Figure 8A]

[0028] 1 shows a schematic partial cross-sectional view of an exemplary substrate processing system, in accordance with an embodiment of the present technique; [Figure 8B]

[0029] 1 shows a schematic partial cross-sectional view of an exemplary substrate processing system, in accordance with an embodiment of the present technique; [Figure 9A]

[0030] 1 shows a schematic partial cross-sectional view of an exemplary substrate processing system, in accordance with an embodiment of the present technique; [Figure 9B]

[0031] 1 shows a schematic partial cross-sectional view of an exemplary substrate processing system, in accordance with an embodiment of the present technique; [Figure 9C]

[0032] 1 shows a schematic partial cross-sectional view of an exemplary substrate processing system, in accordance with an embodiment of the present technique; [Figure 9D]

[0033] 1 shows a schematic partial cross-sectional view of an exemplary substrate processing system, in accordance with an embodiment of the present technique; [Figure 9E]

[0034] 1 shows a schematic partial cross-sectional view of an exemplary substrate processing system, in accordance with an embodiment of the present technique; [Figure 10]

[0035] 1 illustrates a method for generating a plasma, in accordance with an embodiment of the present technique. [Figure 11]

[0036] 1 illustrates a method for generating a plasma, in accordance with an embodiment of the present technique. [Figure 12]

[0037] 10 shows plots of exemplary plasma parameters during a process in accordance with an embodiment of the present technique. DETAILED DESCRIPTION OF THE INVENTION

[0019]

[0038] Some drawings are included as schematic diagrams. It should be understood that the drawings are for illustrative purposes and should not be considered to scale unless expressly stated to be to scale. Furthermore, as schematic diagrams, the drawings are provided to aid in understanding and may not include all aspects or information compared to realistic depictions and may include exaggerated material for illustrative purposes.

[0020]

[0039] In the accompanying drawings, similar components and / or features may have the same reference numerals. Furthermore, various components of the same type may be distinguished according to the reference numeral, with a letter distinguishing between the similar components. When only a first reference numeral is used in this specification, the description is applicable to any of the similar components having the same first reference numeral, regardless of the letter.

[0021]

[0040] The present technology includes an improved gas distribution design for generating a uniform plasma during semiconductor processing operations or for processing the interior of a semiconductor processing chamber. While conventional gas distribution assemblies may receive specific reactants or reactant ratios that are then distributed into the plasma region, the presently described technology allows for improved control of reactant input distribution. The technology allows for separate flows of reactants to different regions of the plasma, which can offset any observed irregularities in process uniformity. A first precursor may be distributed to the center of the plasma above the center of the substrate / pedestal, while a second precursor may be distributed to the outer portion of the plasma above the outer portion of the substrate / pedestal. By doing so, improved operation may be achieved because a substrate placed on the pedestal may experience a more uniform etching or deposition profile across its entire surface. These and other advantages will be described in detail below.

[0022]

[0041] Advantages of the devices described herein include the ability to tailor the concentration of gas near the center of a localized or remote plasma compared to gas away from the center or near the edge. Substrate processing plasmas are particularly difficult to maintain when they are very thin and the overwhelming majority of gases flowing through the plasma contain highly negatively charged atoms, such as fluorine. Argon is often added to aid in the initial plasma formation, but due to space constraints, the thin plasma region may still not support a healthy, stable, concentric plasma. Because argon is heavy, sputtering can unnecessarily damage or reduce the lifespan of internal components of the substrate processing chamber. Helium is used to enhance plasma uniformity, but it does not improve the initial strikeability and subsequent stability of the plasma. Positively charged fluorine ions are very difficult to generate, and therefore the electron concentration remains low even in the plasma. This means that the thin plasma region may support an electron breakdown cascade that impairs plasma health in other parts of the plasma region. The hardware described herein can provide the benefit of making the plasma more uniform and / or the benefit of making the process (e.g., removal rate) more uniform across the plasma region (across the dimension perpendicular to the thin dimension). In some cases, the hardware described herein (in conjunction with the processes described herein) can even be used to avoid the off-center "collapsed" plasma observed with fluorine plasma. Thus, the hardware and methods described herein can be used to generate concentric plasmas that benefit plasma control efforts and make the process more uniform.

[0023]

[0042] While the remainder of the disclosure will routinely identify specific etching processes utilizing the disclosed technology, it will be readily understood that the systems and methods are equally applicable to deposition and cleaning processes that may occur in the described chambers. Thus, the technology should not be considered limited to use with etching processes alone. This disclosure will describe one possible system and chamber that may be used with the present technology to perform a particular removal operation, before describing additional modifications and adjustments to this system according to embodiments of the present technology.

[0024]

[0043] 1 illustrates a top view of one embodiment of a processing system 100 for deposition, etch, bake, and cure chambers, according to an embodiment. In the figure, a pair of FOUPs (Front Opening Up Platforms) 102 provide substrates of various sizes, which are placed in a low-pressure holding area 106 before being received by a robotic arm 104 and placed into one of the substrate processing chambers 108a-f, positioned within tandem sections 109a-c. A second robotic arm 110 can be used to transport substrate wafers from the holding area 106 to the substrate processing chambers 108a-f and back from the substrate processing chambers 108a-f to the holding area 106. Each substrate processing chamber 108a-f can be equipped to perform numerous substrate processing operations, including cyclical layer deposition (CLD), atomic layer deposition (ALD), chemical vapor deposition (CVD), physical vapor deposition (PVD), etching, pre-cleaning, degassing, orientation, and other substrate processing, as well as the dry etch processes described herein.

[0025]

[0044] The substrate processing chambers 108a-f may include one or more system components for depositing, annealing, curing, and / or etching a dielectric film on a substrate wafer. In one configuration, two pairs of processing chambers (e.g., 108c-d and 108e-f) may be used to deposit a dielectric material on a substrate, and a third pair of processing chambers (e.g., 108a-b) may be used to etch the deposited dielectric. In another configuration, all three pairs of chambers (e.g., 108a-f) may be configured to etch a dielectric film on a substrate. Any one or more of the described processes may be performed in a separate chamber(s) from the fabrication system shown in various embodiments. It should be understood that additional configurations of deposition chambers, etch chambers, anneal chambers, and curing chambers for dielectric films are contemplated in system 100.

[0026]

[0045] 2A shows a cross-sectional view of an exemplary processing chamber system 201 having partitioned plasma generation regions within the processing chamber. During etching of a film (e.g., titanium nitride, tantalum nitride, tungsten, silicon, polysilicon, silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbide, etc.), processing gases can flow through a gas inlet assembly 205 into a first plasma region 215. A remote plasma system (RPS) 202 can optionally be included in the system and can process the first gas. The first gas then travels through the gas inlet assembly 205. The inlet assembly 205 can include two or more different gas supply channels, and a second channel (not shown), if included, can bypass the RPS 202.

[0027]

[0046] A cooling plate 203, a faceplate 217, an ion suppressor 223, a showerhead 225, and a substrate support 265 with a substrate 255 disposed thereon are shown, each of which may be included according to an embodiment. The pedestal 265 may have heat exchange channels through which a heat exchange fluid flows to control the temperature of the substrate. The heat exchange channels may be operated to heat and / or cool the substrate or wafer during processing operations. The wafer support platter of the pedestal 265 may comprise aluminum, ceramic, or a combination thereof, and may be resistively heated to achieve relatively high temperatures (e.g., from about 100 degrees Celsius or less to about 1100 degrees Celsius or more) using built-in resistive heating elements.

[0028]

[0047] The face plate 217 may be pyramidal, conical, or another similar structure that is narrow at the top and widens toward the bottom. Additionally, the face plate 217 may be flat as shown and may include multiple through channels used to distribute process gases. Depending on the use of the RPS 202, plasma-generating gases and / or plasma-excited species may pass through multiple holes in the face plate 217 shown in FIG. 2B and be more uniformly distributed into the first plasma region 215.

[0029]

[0048] An exemplary configuration may include gas inlet assembly 205 opening to a gas feed region 258 separated from first plasma region 215 by faceplate 217, allowing gases / species to flow into first plasma region 215 through holes in faceplate 217. Structural and operational features may be selected to prevent bulk backflow of plasma from first plasma region 215 into feed region 258, gas inlet assembly 205, and fluid delivery system 210. Faceplate 217 (or the conductive top of the chamber) and showerhead 225 are shown with an insulating ring 220 positioned between their features, allowing an AC potential to be applied to faceplate 217 relative to showerhead 225 and / or ion suppressor 223. Insulating ring 220 may be positioned between faceplate 217 and showerhead 225 and / or ion suppressor 223, allowing for the generation of a capacitively coupled plasma (CCP) in the first plasma region. Additionally, baffles (not shown) may be positioned within the first plasma region 215 or otherwise coupled to the gas inlet assembly 205 to affect the flow of fluid into the region through the gas inlet assembly 205.

[0030]

[0049] The ion suppressor 223 may include a plate or other shape defining a plurality of apertures across its structure. These apertures are configured to suppress the migration of ionic-charged species out of the first plasma region 215 while allowing uncharged neutral or radical species to pass through the ion suppressor 223 and into the activated gas supply region between the suppressor and the showerhead. In embodiments, the ion suppressor 223 may comprise a perforated plate having various aperture configurations. These uncharged species may include highly reactive species that are carried with a less reactive carrier gas through the apertures. As discussed above, the migration of ionic species through the apertures can be reduced, and in some cases, completely suppressed. Controlling the amount of ionic species that pass through the ion suppressor 223 advantageously provides improved control over the gas mixture that is brought into contact with the underlying wafer substrate, thereby providing improved control over the deposition and / or etching characteristics of the gas mixture. For example, adjustments in the ion concentration of the gas mixture can affect its etch selectivity (e.g., SiN). x :SiO x Etching ratio, Si:SiO x The deposition ratios, etc., can be significantly altered. In alternative embodiments where deposition is performed, the balance between conformal and flowable style deposition for dielectric materials can also be shifted.

[0031]

[0050] The plurality of apertures in the ion suppressor 223 may be configured to control the passage of activated gas (i.e., ionic species, radical species, and / or neutral species) through the ion suppressor 223. For example, the aspect ratio of the apertures (i.e., diameter to length of the aperture) and / or the geometry of the apertures may be controlled to reduce the flow rate of ionic charged species in the activated gas passing through the ion suppressor 223. The apertures in the ion suppressor 223 may include a tapered portion facing the plasma excitation region 215 and a cylindrical portion facing the showerhead 225. The cylindrical portion may be shaped and dimensioned to control the flow rate of ionic species passing to the showerhead 225. As an additional means for controlling the flow rate of ionic species through the ion suppressor 223, an adjustable electrical bias may be applied to the ion suppressor 223.

[0032]

[0051] The ion suppressor 223 can function to reduce or eliminate the amount of ionic charged species that travel from the plasma generation region to the substrate. Uncharged neutral and radical species can still pass through openings in the ion suppressor to react with the substrate. Note that in embodiments, complete removal of ionic charged species in the reaction region surrounding the substrate may not be performed. In certain cases, ionic species are intended to reach the substrate to perform etching and / or deposition processes. In these cases, the ion suppressor can help control the concentration of ionic species in the reaction region to an extent that aids in processing.

[0033]

[0052] The showerhead 225, in combination with the ion suppressor 223, allows the plasma present in the first plasma region 215 to avoid directly exciting gases in the substrate processing region 233, while still allowing excited species to migrate from the chamber plasma region 215 into the substrate processing region 233. In this manner, the chamber can be configured to prevent the plasma from contacting the substrate 255 being etched. This advantageously protects various intricate structures and films patterned on the substrate, which could be damaged, misaligned, or otherwise distorted if directly contacted by the generated plasma.

[0034]

[0053] In some embodiments, an ion suppressor (which may be a showerhead) can be used to provide radical and / or neutral species for the gas phase etch. The ion suppressor may also be referred to as an ion suppression element. In embodiments, for example, the ion suppressor is used to filter the etch plasma effluent on its path from the remote plasma region to the substrate processing region. The ion suppressor can be used to provide a reactive gas having a higher concentration of radicals than ions. The plasma effluent passes through the ion suppressor positioned between the remote plasma region and the substrate processing region. The ion suppressor functions to significantly reduce or substantially eliminate ion species traveling from the plasma generation region to the substrate. The ion suppressor described herein is just one way to achieve a low electron temperature in the substrate processing region during the gas phase etch processes described herein.

[0035]

[0054] In some embodiments, an electron beam passes through the substrate processing region in a plane parallel to the substrate to reduce the electron temperature of the plasma effluents. When the electron beam is applied in this manner, a simpler showerhead may be used. In some embodiments, the electron beam may pass as a layered sheet disposed above the substrate. In some embodiments, the electron beam provides a source of negative charge neutralization, providing a more active means for reducing the flux of positively charged ions toward the substrate, improving etch selectivity. Various parameters governing the flow of plasma effluents and the operation of the electron beam can be adjusted to reduce the electron temperature measured in the substrate processing region.

[0036]

[0055] During plasma excitation in a remote plasma, electron temperature may be measured within the substrate processing region using a Langmuir probe. The electron temperature may be less than 0.5 eV, less than 0.45 eV, less than 0.4 eV, or less than 0.35 eV. This extremely low value of electron temperature is possible due to the presence of the electron beam, showerhead, and / or ion suppressor. Uncharged neutral and radical species may pass through openings in the electron beam and / or ion suppressor and react at the substrate. Such processes using radical and other neutral species can reduce plasma damage compared to conventional plasma etching processes, including sputtering and bombardment. Embodiments of the present invention are also advantageous over conventional wet etching processes, where the surface tension of the liquid can cause bending and peeling of small features.

[0037]

[0056] The substrate processing region may be described herein as "plasma-free" during the etching processes described herein. "Plasma-free" does not necessarily mean that the region is plasma-free. Ionized species and free electrons generated within the plasma region may travel through holes (apertures) in the showerhead at very low densities. The boundary of the plasma within the chamber plasma region may penetrate to some extent into the substrate processing region through the apertures in the showerhead. Furthermore, a low-intensity plasma may be generated within the substrate processing region without eliminating the desirable characteristics of the etching processes described herein. Any cause for the plasma to have a much lower ion density than the chamber plasma region during generation of energized plasma effluents does not depart from the scope of "plasma-free" as used herein.

[0038]

[0057] The processing system may further include a power supply 240 electrically connected to the processing chamber. The power supply 240 supplies power to the faceplate 217, the ion suppressor 223, the showerhead 225, and / or the pedestal 265 to generate a plasma in the first plasma region 215 or processing region 233. The power supply may be configured to supply an adjustable amount of power to the chamber depending on the process being performed. Such a configuration may allow an adjustable plasma to be used in the process being performed. Unlike remote plasma units, which often provide an on or off function, an adjustable plasma may be configured to supply a specific amount of power to the plasma region 215. This may allow for the development of specific plasma characteristics, which may dissociate precursors in a specific manner to enhance the etch profile produced by those precursors.

[0039]

[0058] The plasma can be ignited either in the chamber plasma region 215 above the showerhead 225 or in the substrate processing region 233 below the showerhead 225. In embodiments, the plasma generated in the substrate processing region 233 can be a DC-biased plasma generated using a pedestal acting as an electrode. For example, a plasma can exist in the chamber plasma region 215 to generate radical precursors from the inflow of a fluorine-containing precursor or other precursor. An AC voltage, typically in the radio frequency (RF) range, can be applied between a conductive top portion of the processing chamber, such as the faceplate 217, and the showerhead 225 and / or ion suppressor 223 to ignite a plasma in the chamber plasma region 215 during deposition. The RF power source can generate a high RF frequency of 13.56 MHz, and can also generate other frequencies alone or in combination with the 13.56 MHz frequency.

[0040]

[0059] FIG. 2B shows a detailed view 253 of features that affect the distribution of process gas through the face plate 217. As shown in FIGS. 2A and 2B, the face plate 217, cooling plate 203, and gas inlet assembly 205 intersect to define a gas delivery region 258 into which process gas may be delivered from the gas inlets 205. Gas may permeate the gas delivery region 258 and flow through apertures 259 in the face plate 217 to the first plasma region 215. The apertures 259 may be configured to direct flow in a substantially unidirectional manner, allowing process gas to flow into the processing region 233 but partially or completely preventing backflow into the gas delivery region 258 after traversing the face plate 217.

[0041]

[0060] Gas distribution assemblies such as showerhead 225 used in processing chamber section 201 may be referred to as dual channel showerheads (DCSHs) and are described in more detail in the embodiment depicted in Figure 3. Dual channel showerheads can provide etching processes that allow separation of etchants outside of the processing region 233, resulting in limited interaction with chamber components and each other before being delivered into the processing region.

[0042]

[0061] The showerhead 225 may include an upper plate 214 and a lower plate 216. The plates may be coupled to one another to define a volume 218 between the plates. The coupled plates may provide a first fluid channel 219 through the upper and lower plates and a second fluid channel 221 through the lower plate 216. The formed channels may be configured to provide fluid access from the volume 218 through the lower plate 216 only via the second fluid channel 221, and the first fluid channel 219 may be fluidically isolated from the volume 218 between the plates and the second fluid channel 221. The volume 218 may be fluidically accessible through a side of the gas distribution assembly 225.

[0043]

[0062] 3 is a bottom view of a showerhead 325 for use with a processing chamber, according to an embodiment. The showerhead 325 may correspond to the showerhead 225 shown in FIG. 2A. The through-holes 365, which represent a view of the first fluid channel 219, may have multiple shapes and configurations to control and influence the flow of precursors through the showerhead 225. The small holes 375, which represent a view of the second fluid channel 221, are substantially evenly distributed on the surface of the showerhead, even among the through-holes 365. Compared to other configurations, these small holes 375 may help provide more uniform mixing of precursors as they exit the showerhead.

[0044]

[0063] 4 shows a schematic partial cross-sectional view of an exemplary substrate processing system in accordance with embodiments of the present technique. The substrate processing chamber 1001 includes a zonal distribution manifold 1010 having a first manifold channel 1015 and a second manifold channel 1016. A first gas may flow through the first manifold channel 1015, and a second gas may flow through the second manifold channel 1016. In various embodiments, the first manifold channel 1015 and the second manifold channel 1016 are separated to prevent the first gas and the second gas from mixing together within the zonal distribution manifold 1010. The first gas may expand from the more restrictive first manifold channel 1015 into the less restrictive inner zonal expansion region 1017.

[0045]

[0064] The substrate processing chamber 1001 may further include a zone distribution plate 1029, which may be attached to the zone distribution manifold 1010. The zone distribution plate 1029 also has two separate flow channels to prevent any mixing between the first gas and the second gas within the zone distribution plate 1029. The zone distribution plate 1029 has an inner zone channel 1018 configured to receive the first gas from the inner zone expansion region 1017. The zone distribution plate 1029 further includes an outer zone channel 1019 configured to receive the second gas from the second manifold channel 1016. When the zone distribution plate 1029 and the zone distribution manifold are attached to each other during assembly (as shown), a seal (e.g., an O-ring) may be included to maintain separation between the first gas and the second gas.

[0046]

[0065] According to an embodiment, the substrate processing chamber 1001 may further include a zone blocker plate 1033, which may be attached to the zone distribution plate 1029. The zone blocker plate 1033 has an upper inner recess 1035 configured to receive a first gas from the inner zone channel 1018 and an upper outer recess 1034 configured to receive a second gas from the outer zone channel 1019. The zone blocker plate 1033 further includes a lower inner recess 1037 fluidly coupled to the upper inner recess 1035 through the inner showerhead portion 1032. The zone blocker plate 1033 may further include a lower outer recess 1036 fluidly coupled to the upper outer recess 1034 through the outer showerhead portion 1031. The substrate processing chamber 1001 may further include a face plate 1039 attached to the zone blocker plate 1033, the face plate 1039 having through holes configured to pass the first gas and the second gas into the plasma region. The upper inner recess 1035 is laterally sealed from the upper outer recess 1034 by a separation wall 1051-1 that seals against the zone distribution plate 1029 (e.g., using an O-ring). The lower inner recess 1037 is laterally sealed from the lower outer recess 1036 by a separation wall 1051-2 that seals against the face plate 1039 (e.g., using an O-ring). In this manner, the first gas and the second gas do not encounter each other until they enter the plasma region 1041. According to an embodiment, the zone distribution manifold 1010, the zone distribution plate 1029, and the zone blocker plate 1033 may be configured to prevent the first gas and the second gas from mixing until they enter the plasma region 1041.

[0047]

[0066] Plasma power is applied between the faceplate 1039 and the showerhead 1049 by an RF plasma power source 1043. Plasma is generated in the plasma region 1041 from a mixture of a first gas and a second gas. The technical aspects of the hardware just described allow for adjustment of the ratio of the first gas to the second gas across the lateral dimension of the plasma region 1041. An electrically insulating insert 1042 may be disposed between the faceplate 1039 and the showerhead 1049 to allow application of RF power from the RF plasma power source 1043 to the faceplate 1039 relative to the showerhead 1049. Below the showerhead 1049 and within the substrate processing region, a wall 1071 may be disposed around a substrate 1055 supported by a substrate support pedestal 1065.

[0048]

[0067] The showerhead 1049 may be held at ground while the faceplate 1039 is at RF voltage. In another configuration, the faceplate 1039 may be grounded while the showerhead 1049 is held at RF voltage to generate a plasma using RF power. Generally speaking, the anode is held at ground while the cathode is at RF voltage. In several embodiments, the anode is the faceplate 1039 (or showerhead 1049) and the cathode is the showerhead 1049 (or faceplate 1039), respectively. The substrate processing region may be located on the opposite side of the showerhead 1049 from the plasma region or may be adjacent to the showerhead 1049. The configuration just described is a remote plasma because the plasma is not inside the substrate processing region.

[0049]

[0068] According to embodiments, the methods and hardware described herein may also be used to improve the uniformity of the local plasma and / or the local plasma process. RF plasma power may be applied from the RF plasma power supply 1043 to the faceplate 1039 relative to the substrate support pedestal 1065, or to the substrate support pedestal 1065 relative to the faceplate. In some embodiments, when generating a local plasma, the showerhead 1049 is not present. In the local plasma configuration, the anode is the faceplate 1039 (or substrate support pedestal 1065), and the cathode is the substrate support pedestal 1065 (or faceplate 1039), respectively. A substrate processing region is disposed between the anode and the cathode and abuts both the anode and the cathode.

[0050]

[0069] According to an embodiment, the zone distribution plate and the zone blocker plate may be circular or may have a disk shape. In an embodiment, the zone distribution plate and the zone blocker plate may be coaxial.

[0051]

[0070] FIG. 5A shows a schematic partial cross-sectional view of an exemplary zone blocker plate in accordance with an embodiment of the present technology. FIG. 5B shows a top view of an exemplary zone blocker plate in accordance with an embodiment of the present technology. FIG. 5C shows a bottom view of an exemplary zone blocker plate in accordance with an embodiment of the present technology. The zone blocker plate 1133 is depicted prior to attachment to a zone distribution plate or faceplate. The zone blocker plate 1133 has an upper outer recess 1134 and an upper inner recess 1135 separated by a separation wall 1151-1. The zone blocker plate 1133 further has a lower outer recess 1136 and a lower inner recess 1137 separated by a separation wall 1151-2. An outer showerhead 1160 is disposed between the upper outer recess 1134 and the lower outer recess 1136 and configured to transfer a second gas through the outer through-holes 1140. The inner showerhead 1161 is disposed between the upper inner recess 1135 and the lower inner recess 1137 and is configured to transfer a first gas through the inner through-holes 1141 .

[0052]

[0071] According to an embodiment, the inner showerhead 1161 may be circular and may be centered on the center of the zone blocker plate 1133. In an embodiment, the outer showerhead 1160 may be annular as shown and may be centered on the center of the inner showerhead 1161 and / or the zone blocker plate 1133. According to an embodiment, the ratio of the area of ​​the outer showerhead 1160 to the area of ​​the inner showerhead 1161 may be selected to benefit plasma or process uniformity, and the size and density of the through-holes may be constant across both the outer showerhead and the inner showerhead. In an embodiment, the density of the through-holes may differ from each other for the outer showerhead and the inner showerhead. According to an embodiment, the size of the through-holes in the inner showerhead may differ from the through-holes in the outer showerhead.

[0053]

[0072] In embodiments, a first gas may be flowed through the inner showerhead, and a second gas may be flowed through the outer showerhead. The inner showerhead may be between 25% and 75%, between 30% and 70%, between 35% and 65%, or between 40% and 60% of the area of ​​the outer showerhead. The density of the through-holes may be the same for the inner showerhead and the outer showerhead. According to embodiments, the size of the through-holes in the inner showerhead may also be the same as the size of the through-holes in the outer showerhead. The areas of the separation wall and outer flange are not included in the area calculation. In embodiments, an upper O-ring 1150-1 may optionally be used to improve sealing between the upper outer recess 1134 and the upper inner recess 1135. Similarly, in embodiments, a bottom O-ring 1150-2 may optionally be used to improve sealing between the lower outer recess 1136 and the lower inner recess 1137 during assembly. The sizes of the inner and outer showerheads may be selected to facilitate the use of standard O-ring sizes. The outer diameter of the outer showerhead may be approximately 12 inches or greater for processing 12-inch circular substrates or wafers. According to embodiments, the inner showerhead may have a diameter between 4 inches and 10 inches, between 5 inches and 9 inches, or between 6 inches and 8 inches. In embodiments, the outer showerhead may have an inner diameter greater than 4 inches, greater than 5 inches, greater than 6 inches, or greater than 7 inches. According to embodiments, the outer showerhead may have an outer diameter less than 14 inches or less than 13 inches. The total flow rate of the first gas may be approximately equal to the flow rate of the second gas for an outer showerhead area close to that of the inner showerhead (for the same through-hole density and geometry). Starting from such a design can simplify optimization of the flow rate ratio of the first gas to the second gas for some processes. Other types of processes will be introduced in the following description of this specification.

[0054]

[0073] According to embodiments, the inner showerhead may have through-holes with diameters between 0.1 mm and 3 mm, between 0.3 mm and 2 mm, or between 0.5 mm and 1.5 mm. The diameters given herein describe the narrowest diameters when the diameter varies along the through-hole. According to embodiments, the outer showerhead may have through-holes with diameters between 0.1 mm and 3 mm, between 0.3 mm and 2 mm, or between 0.5 mm and 1.5 mm. In embodiments, the inner showerhead may have between 30 and 2,000 through-holes, between 50 and 1,000 through-holes, or between 100 and 500 through-holes. According to embodiments, the outer showerhead may have between 30 and 2,000 through-holes, between 50 and 1,000 through-holes, or between 100 and 500 through-holes. A range of through-hole densities in either the inner showerhead or the outer showerhead can be calculated using the range of total through-hole counts in conjunction with the range of corresponding showerhead dimensions. In embodiments, the inner showerhead can have an open area between 0.1% and 50%, between 0.2% and 30%, between 0.5% and 15%, or between 1% and 10% of its total area. According to embodiments, the outer showerhead can have an open area between 0.1% and 50%, between 0.2% and 30%, between 0.5% and 15%, or between 1% and 10% of its total area.

[0055]

[0074] It has been found that some processes benefit from a relatively small inner showerhead surrounded by a relatively thick annular outer showerhead. Exemplary processes will be presented herein. A first gas (central gas) can help generate a stable plasma whose main component is the second gas. In embodiments, the first gas can be flowed through the inner showerhead, and the second gas can be flowed through the outer showerhead. The inner showerhead can be less than 25%, 20%, 15%, 10%, 5%, or 4% of the area of ​​the outer showerhead. According to embodiments, the diameter of the inner showerhead can be less than 10%, 9%, 8%, 7%, 6%, or 5% of the diameter of the outer showerhead. According to embodiments, the first gas can simply flow through a single through-hole in the center of the zone blocker plate. The dimensions of the through-hole in the outer showerhead can be as described above. In embodiments, the inner showerhead, if present, can possess through-holes having the dimensions described above. Alternatively, the central single through-hole may have a diameter between 0.1 mm and 3 mm, between 0.3 mm and 2 mm, between 0.5 mm and 1.5 mm, or less than 3 mm, according to an embodiment. In an embodiment, the central single through-hole may be aligned directly above a central hole in a face plate disposed below the zone blocker plate.

[0056]

[0075] According to embodiments, the thickness of the outer upper recess may be between 1 mm and 5 mm or between 2 mm and 4 mm. The thickness of the outer upper recess may be approximately the same as the thickness of the inner upper recess. In embodiments, the inner upper recess may have a thickness between 1 mm and 5 mm or between 2 mm and 4 mm. According to embodiments, the thickness of the outer lower recess may be between 1 mm and 5 mm or between 2 mm and 4 mm. The thickness of the outer lower recess may be approximately the same as the thickness of the inner lower recess. In embodiments, the inner lower recess may have a thickness between 1 mm and 5 mm or between 2 mm and 4 mm. According to embodiments, the thickness of the outer showerhead may be between 1 mm and 5 mm or between 2 mm and 4 mm. The thickness of the outer showerhead may be approximately the same as the thickness of the inner showerhead. In embodiments, the inner showerhead may have a thickness between 1 mm and 5 mm or between 2 mm and 4 mm.

[0057]

[0076] FIG. 6A shows a top view of an exemplary zone distribution plate in accordance with an embodiment of the present technology. FIG. 6B shows a bottom view of an exemplary zone distribution plate in accordance with an embodiment of the present technology. The zone distribution plate 1233 has a central through-hole 1241 configured to pass a first gas into the upper inner recess of the zone blocker plate. The zone distribution plate 1233 has an upper groove 1261 formed in its upper surface configured to form a channel for passing a second gas into the upper outer recess of the zone blocker plate. When assembled, the bottom surface of a zone distribution manifold coupled to the upper groove 1261 may be pressed against the top edge of the zone distribution plate 1233 to form a second gas channel. When assembled, the upper groove 1261 is configured to direct the second gas from an initiation point to a plurality of bottom holes 1255. The plurality of bottom holes 1255 open through the bottom of the zone distribution plate 1233 into the upper outer recess of the zone blocker plate. The upper groove 1261 may be configured to receive the second gas from the second manifold channel at a starting point (determined by the termination of the second manifold channel of the zonal distribution manifold). According to an embodiment, the path length from the starting point to each of the plurality of bottom holes along the groove may be the same for each of the plurality of bottom holes. According to an embodiment, the plurality of bottom holes may include at least two bottom holes, at least four bottom holes, at least six bottom holes, at least eight bottom holes, or at least ten bottom holes. The plurality of bottom holes may include an even number of bottom holes. The plurality of bottom holes may be arranged circumferentially about the center of the zonal distribution plate 1233. In an embodiment, the plurality of bottom holes may be evenly spaced (equally spaced) along the circumference.

[0058]

[0077] According to embodiments, the central through-hole may have a diameter between 0.1 mm and 30 mm, between 0.5 mm and 20 mm, or between 1 mm and 5 mm. In embodiments, each of the multiple bottom holes may have the same dimension, and its diameter may be between 0.1 mm and 10 mm, between 0.3 mm and 5 mm, or less than 3 mm. According to embodiments, the upper groove 1261 may have a width between 1 mm and 10 mm, between 2 mm and 8 mm, or between 3 mm and 7 mm. While various architectures for the upper groove 1261 can achieve the same path length goal, one option is depicted in FIG. 6A . The upper groove 1261 may begin at a starting point 1260 at a first radius from the central through-hole 1241. The upper groove 1261 may have a circumferential portion at a first radius before a radial portion extending outward from the central through-hole 1241 to a second radius. The upper groove 1261 may have a 180-degree circumferential portion that divides the radial portion into two at a second radius. The two radial portions extend outward from the ends of the 180-degree circumferential portion to a third radius. Each of the two radial portions of the upper groove 1261 may branch into two 90-degree circumferential portions. Each end of the two 90-degree circumferential portions is connected to four additional radial portions that begin at the third radius and extend outward to a fourth radius. Finally, four 45-degree circumferential portions branch off from the four additional radial portions at the fourth radius. Each of the four 45-degree circumferential portions may terminate in one of the eight bottom holes of the zone distribution plate 1233. Each of the listed circumferential portions may be circumferential with respect to the center of the zone distribution plate 1233. According to an embodiment, the fourth radius can be larger than the third radius, which can be larger than the second radius, which can be larger than the first radius. The listed architecture represents one way of distributing a first gas to the upper inner recess and a second gas to the upper outer recess. An O-ring 1251 can be included on the bottom of the zone distribution plate 1233 to seal the upper inner recess from the upper outer recess of the zone blocker plate.

[0059]

[0078] FIG. 7 shows a schematic partial cross-sectional view of a zone distribution manifold 1311 according to an embodiment of the present technology. The zone distribution manifold has a first manifold channel 1321 and a second manifold channel 1331. The first manifold channel 1321 is fluidly coupled to an expansion region 1322 to improve internal mixing of the first gas before it enters the upper inner recess through the central through-hole of the zone distribution plate. An inner zone channel O-ring 1341 may be included to further separate the first gas from prematurely mixing with the second gas. The second manifold channel 1331 is fluidly coupled to allow the second gas to pass through the upper groove of the zone distribution plate and then through a plurality of bottom holes into the upper outer recess of the zone blocker plate. In an embodiment, an outer zone channel O-ring 1342 may be included to maintain separation between the first gas and the second gas. According to an embodiment, the first manifold channel may have a circular cross-section and a diameter greater than 2 mm, greater than 5 mm, or greater than 10 mm. In embodiments, the second manifold channel may have a circular cross-section and a diameter greater than 2 mm, greater than 5 mm, or greater than 10 mm. According to embodiments, the expansion region may have a circular cross-section and a diameter greater than 5 mm, greater than 10 mm, or greater than 15 mm.

[0060]

[0079] 8A and 8B show schematic partial cross-sectional views of an exemplary substrate processing system in accordance with embodiments of the present technique. The illustrated hardware is described to illustrate process challenges that can be overcome by aspects of the techniques presented herein. A fluorine-containing plasma is generated within the substrate processing system and exhibits instabilities addressed by the methods and systems described herein. The substrate processing chamber 1401 includes a zone distribution manifold 1410 having a first manifold channel 1415 and a second manifold channel 1416. A hydrogen-containing precursor sometimes flows through the first manifold channel 1415, and a fluorine-containing precursor sometimes flows through the second manifold channel 1416. The hydrogen-containing precursor expands from the first manifold channel 1415 into an expansion region 1417. The substrate processing chamber 1401 further includes a zone distribution plate 1429 attached to the zone distribution manifold 1410. The hydrogen-containing precursor flows from the expansion region 1417 into an inner zone channel 1418. The fluorine-containing precursor flows from the second manifold channel 1416 into the outer zone channel 1419. The two channels are separated and no mixing occurs in the depicted hardware until the hydrogen-containing precursor and the fluorine-containing precursor exit the zone distribution plate 1429.

[0061]

[0080] According to an embodiment, the substrate processing chamber 1401 further includes a zone blocker plate 1433 attached to the zone distribution plate 1429. The zone blocker plate 1433 has an upper recess 1435 configured to receive a hydrogen-containing precursor from the inner zone channels 1418. In contrast to the hardware of FIG. 4, the upper recess 1435 is also configured to receive a fluorine-containing precursor from the outer zone channels 1419. In this case, the two precursors can mix because there is no separating wall. The zone blocker plate 1433 includes a lower inner recess 1437 fluidly coupled to the upper recess 1435 through an inner showerhead portion. The zone blocker plate 1433 further includes a lower outer recess 1436 fluidly coupled to the upper recess 1435 through an outer showerhead portion. The substrate processing chamber 1401 further includes a face plate 1439 attached to the zone blocker plate 1433 having through-holes configured to pass hydrogen-containing precursors and / or fluorine-containing precursors into the plasma region to generate plasma 1441-1. Plasma power is applied between the face plate 1439 and the showerhead 1449 by an RF plasma power source 1443. An electrically insulating insert 1442 may be disposed between the face plate 1439 and the showerhead 1449 to enable application of RF power from the RF plasma power source 1443 to the face plate 1439 relative to the showerhead 1449. Below the showerhead 1449 and within the substrate processing region, a wall 1471 may be disposed around a substrate 1455 supported by a substrate support pedestal 1465.

[0062]

[0081] Plasma 1441-1 is initially generated within the plasma region from a fluorine-containing precursor without a hydrogen-containing precursor. The fluorine plasma 1441-1 may initiate centrally within the plasma region, but instabilities have been observed. The instabilities can cause the initial fluorine plasma 1441-1 to collapse into an off-center fluorine plasma 1441-2. The off-center fluorine plasma 1441-2 may reside at the edge of the plasma region and occupy less than half or even a quarter of the circular plasma region. Off-center plasmas can result in unacceptable process variability. Cleaning plasmas and substrate processing plasmas are particularly difficult to maintain when they are very thin and the overwhelming majority of gases flowing through the plasma contain highly negatively charged atoms, such as fluorine. Because positively charged fluorine ions are very difficult to generate, the electron concentration remains low even within the plasma. These characteristics can result in the observed off-center plasma.

[0063]

[0082] Two techniques are presented herein, which may be used separately or in combination to provide a solution to plasma instability. The hardware described herein (along with the process described herein) can even be used to avoid the off-center "collapsed" plasma observed with fluorine plasma. Thus, the hardware and methods described herein can be used to generate a centered, concentric plasma, which benefits plasma control efforts and makes the process more uniform.

[0064]

[0083] 9A-9E show schematic partial cross-sectional views of an exemplary substrate processing system in accordance with an embodiment of the present technique. The illustrated hardware partially ameliorate the plasma instability shown in FIG. 8B. The substrate processing chamber 1501-1 includes a zone distribution manifold 1510 having a first manifold channel 1515 and a second manifold channel 1516. A hydrogen-containing precursor flows through the first manifold channel 1515, and a fluorine-containing precursor flows through the second manifold channel 1516. The hydrogen-containing precursor expands from the first manifold channel 1515 into an expansion region 1517. The substrate processing chamber 1501-1 further includes a zone distribution plate 1529 attached to the zone distribution manifold 1510. From the expansion region 1517, the hydrogen-containing precursor flows into an inner zone channel 1518. From the second manifold channel 1516, the fluorine-containing precursor flows into an outer zone channel 1519. The two channels are separated, and no mixing occurs in the depicted hardware until the hydrogen-containing precursor and the fluorine-containing precursor enter the downstream plasma region. As shown, in embodiments, the outer zone channels 1519 may comprise grooves formed in the top of the zone distribution plate 1529, or may comprise channels formed on the inside of the zone distribution plate 1529.

[0065]

[0084] According to an embodiment, the substrate processing chamber 1501-1 further includes a zone blocker plate 1533-1 attached to the zone distribution plate 1529. The zone blocker plate 1533-1 has an upper inner recess 1535 configured to receive the hydrogen-containing precursor from the inner zone channels 1518. The zone blocker plate 1533-1 has an upper outer recess 1534 configured to receive the fluorine-containing precursor from the outer zone channels 1519. The separation wall prevents the hydrogen-containing precursor from mixing with the fluorine-containing precursor. The zone blocker plate 1533-1 includes a lower inner recess 1537 fluidly coupled to the upper inner recess 1535 through an inner showerhead portion. The zone blocker plate 1533-1 further includes a lower outer recess 1536 fluidly coupled to the upper outer recess 1534 through an outer showerhead portion. The substrate processing chamber 1501-1 further includes a faceplate 1539 attached to the zone blocker plate 1533-1 having through-holes configured to pass hydrogen-containing precursors and / or fluorine-containing precursors into the plasma region to generate plasma 1541-1. Plasma power is applied between the faceplate 1539 and a showerhead 1549 by an RF plasma power source 1543. An electrically insulating insert 1542 may be disposed between the faceplate 1539 and the showerhead 1549 to enable application of RF power from the RF plasma power source 1543 to the faceplate 1539 relative to the showerhead 1549.

[0066]

[0085] According to an embodiment, plasma 1541-1 may initially be generated in the plasma region from a hydrogen-containing precursor without a fluorine-containing precursor. Once the hydrogen plasma is initiated, a fluorine-containing precursor is then flowed into the plasma region. The hydrogen in the plasma is more likely to lose electrons, helping to initiate a healthy plasma 1541-2 of the fluorine-containing precursor. Once a healthy plasma 1541-2 is initiated, the hydrogen-containing precursor flow into the plasma region may be shut off or stopped. The fluorine plasma generated in this manner was observed to be more intense and desirably located in the center of the plasma region. The stability of fluorine plasma 1541-2 was further tested by initiating another flow of fluorine-containing precursor in the center of fluorine plasma 1541-2 (e.g., using the first manifold channel 1515 instead of the second manifold channel 1516). The fluorine plasma 1541-2 migrates to the side, generating a distorted plasma 1541-3. However, according to an embodiment, when the fluorine-containing precursor is shut off or turned off, the fluorine plasma 1541-4 returns to the center (and also possesses high intensity).

[0067]

[0086] Hydrogen atoms within the plasma more readily or freely donate electrons to the plasma, which initiate more widespread ionization of fluorine atoms within the plasma. Introducing hydrogen atoms can be beneficially influenced by flowing a hydrogen-containing precursor (e.g., using the first manifold channel) into the center of the plasma region. The introduction of a "fresh" fluorine-containing precursor (which is difficult to ionize) tends to extinguish the plasma because the hydrogen source is not present at this stage. In response, the plasma is pushed to the side, but significant initial ionization persists despite the absence of hydrogen and the presence of the new fluorine-containing precursor flow. The introduction of the additional fluorine-containing precursor flow was introduced to establish the stability and integrity of the fluorine plasma, rather than to suggest a desired process flow.

[0068]

[0087] Further embodiments can be used to generate stable fluorine plasma 1541-2 and possibly other processes. In embodiments, zone blocker plate 1533-2 may have a central through-hole formed in inner channel insert 1540. The central through-hole may be configured to receive a first gas (e.g., a hydrogen-containing precursor) from inner zone channel 1518. Zone blocker plate 1533-2 may include an upper outer recess 1534 configured to receive a second gas (e.g., a fluorine-containing precursor) from outer zone channel 1519. Zone blocker plate 1533-2 may further include a lower outer recess 1536 fluidly coupled to upper outer recess 1534 through an outer showerhead portion. Zone blocker plate 1533-2 may further include a face plate 1539 attached to zone blocker plate 1533-2 having a through-hole configured to pass the second gas into the plasma region. The zone blocker plate 1533-2 may have a central faceplate hole configured to receive a first gas from a central through-hole in the inner channel insert 1540 and pass the first gas into the plasma region to generate the plasma 1541-1. The substrate processing chamber 1501-2 can be used to generate a stable fluorine plasma 1541-2 by performing a hydrogen-containing precursor sequence (described above). In this case, the hydrogen-containing precursor would flow (through the central through-hole) through the inner channel insert 1540.

[0069]

[0088] 10 and 11 illustrate a method for generating a plasma according to an embodiment of the present technique. FIG. 12 illustrates a plot of exemplary plasma parameters during a process according to an embodiment of the present technique. A method 1601 for generating a plasma includes flowing a hydrogen-containing precursor into a plasma region in operation 1605. In operation 1610, RF plasma power is applied to the plasma region to generate a plasma from the hydrogen-containing precursor. According to an embodiment, no fluorine is present in the plasma region. In an embodiment, the concentration of fluorine may be less than the concentration of hydrogen (measured in atomic concentration), or less than 50%, less than 20%, less than 10%, or less than 5% of the concentration of hydrogen. According to an embodiment, the hydrogen-containing precursor may be flowed into the plasma region before initiating RF power, or RF power may be applied first before flowing the hydrogen-containing precursor into the plasma region. In FIG. 12, plot 1801 illustrates RF power 1810 applied before flowing the hydrogen-containing precursor 1820.

[0070]

[0089] In operation 1615, the method 1601 further includes flowing a fluorine-containing precursor into the plasma region. The flow of the fluorine-containing precursor is represented as 1830 in plot 1801 shown in FIG. 12 . Then, applied RF power excites the mixture of hydrogen-containing and fluorine-containing precursors in operation 1619 to generate a stronger plasma in the plasma region. The flow of the hydrogen-containing precursor into the plasma region may be stopped in operation 1620. In operation 1625, continuing to apply RF power results in a fluorine plasma. In embodiments, while hydrogen is no longer present, the fluorine plasma may be permanently altered and more stable against various destabilizing forces that may inevitably occur in a manufacturing environment. In operation 1630, the RF plasma power is turned off and the flow of the fluorine-containing precursor is stopped.

[0071]

[0090] 11 , in operation 1705, an RF plasma is generated in the plasma region from a mixture of a hydrogen-containing precursor and a fluorine-containing precursor. In operation 1710, the hydrogen-containing precursor is removed from the plasma region. Then, in operation 1720, an RF plasma is generated in the plasma region from only the fluorine-containing precursor. In operation 1730, the RF plasma power is turned off and the flow of the fluorine-containing precursor is stopped. According to an embodiment, the RF plasma power may be turned off before or after the flow of the fluorine-containing precursor is stopped.

[0072]

[0091] In embodiments, the hydrogen-containing precursor may be flowed into the plasma region for between 1 and 30 seconds, between 2 and 20 seconds, or between 3 and 15 seconds.

[0073]

[0092] In all embodiments described herein, the flow rate of a first gas (e.g., hydrogen) may be controlled by a first mass flow controller (MFC), and the flow rate of a second gas (e.g., fluorine) may be controlled by a second mass flow controller. The first and second mass flow controllers may be positioned outside the substrate processing chamber and upstream from the zone distribution manifold. According to embodiments, the flow rate of an exemplary hydrogen-containing precursor may be between 1 sccm and 200 sccm, between 5 sccm and 100 sccm, or between 10 sccm and 50 sccm. According to embodiments, the flow rate of an exemplary fluorine-containing precursor may be between 20 sccm and 5,000 sccm, between 50 sccm and 2,000 sccm, or between 100 sccm and 1,000 sccm. Hydrogen-containing precursors can generate strong and stable fluorine plasmas at significantly lower flow rates than fluorine-containing precursors. A flow of helium was included as a carrier gas in each precursor flow. Although helium normally stabilizes plasmas, flowing helium into the plasma region was not sufficient to avoid collapsing the fluorine plasma described herein. The inclusion of a hydrogen-containing precursor in the early plasma stage prevented the plasma from collapsing.

[0074]

[0093] The pressure within the plasma region affects the likelihood of collapse of the fluorine plasma. At lower pressures, the fluorine plasma may remain homogeneous without the initial presence of a hydrogen-containing precursor. Increasing the pressure within the fluorine plasma increases the likelihood of collapse of the fluorine plasma, which may be related to the high electronegativity of fluorine atoms and a reduced mean free path. According to embodiments, the pressure within the plasma region may be greater than 2 Torr, greater than 3 Torr, greater than 4 Torr, greater than 5 Torr, greater than 6 Torr, or greater than 7 Torr.

[0075]

[0094] The plasma power applied to the plasma region also affects the likelihood of fluorine plasma collapse. Increased plasma power can also result in a higher likelihood of fluorine plasma collapse. Rapid hydrogen exposure as described herein resulted in stable plasma at high plasma power. In embodiments, the RF plasma power may be greater than 200 watts, greater than 300 watts, greater than 400 watts, greater than 500 watts, or greater than 750 watts.

[0076]

[0095] According to an embodiment, the first gas may be a hydrogen-containing precursor, and the second gas may be a fluorine-containing precursor. Alternatively, the first gas may be a mixture of hydrogen and fluorine at a first atomic concentration ratio, and the second gas may have a second atomic concentration ratio. The second atomic concentration ratio may be different from the first atomic concentration ratio. In an embodiment, such a configuration generally allows fine tuning of the process uniformity, where both the first gas and the second gas may be present throughout the substrate processing period. The hydrogen-containing precursor may be one of hydrogen (H2) and ammonia (NH3), and the fluorine-containing precursor may be nitrogen trifluoride (NF3).

[0077]

[0096] In the foregoing description, for purposes of explanation, numerous details have been presented in order to facilitate an understanding of various embodiments of the present technology. However, it will be apparent to one skilled in the art that particular embodiments may be practiced without some of these details, or with additional details.

[0078]

[0097] Although several embodiments have been disclosed, those skilled in the art will recognize that various modifications, alternative constructions, and equivalents may be used without departing from the spirit of the embodiments. Additionally, some well-known processes and elements have not been described to avoid unnecessarily obscuring the technology. Therefore, the above description should not be construed as limiting the scope of the technology.

[0079]

[0098] Where a range of values ​​is provided, it is to be understood that, unless the context clearly indicates otherwise, each intervening value between the upper and lower limits of that range is specifically disclosed, to the smallest unit of the lower limit. Any subranges between any stated or unstated intervening value in a stated range, and any other stated or intervening value in that stated range, are also included. The upper and lower limits of these smaller ranges may be individually included or excluded from the range, and each range in which either, neither, or both limits are included in the subranges is also encompassed within the scope, subject to any explicitly excluded limits in the stated range. When a stated range includes one or both limits, ranges excluding either or both of those included limits are also included.

[0080]

[0099] As used in this specification and claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, a reference to "a material" includes a plurality of such materials, a reference to "the precursor" includes a reference to one or more precursors and equivalents thereof known to those skilled in the art, and so forth.

[0081]

[0100] Furthermore, the terms "comprise(s)", "comprising", "contain(s)", "containing", "include(s)", and "including", when used in this specification and claims, are intended to specify the presence of stated features, integers, components, or steps, but do not exclude the presence or addition of one or more other features, integers, components, steps, operations, or groups.

Claims

1. applying RF power between an anode and a cathode, the anode and the cathode being planar and parallel, a plasma region being disposed between the anode and the cathode, and the anode and the cathode being each adjacent to the plasma region; generating a hydrogen-containing plasma by flowing a hydrogen-containing precursor into a center of the plasma region; generating a hydrogen-fluorine-containing plasma by further flowing a fluorine-containing precursor into the plasma region; and 10. A method of processing comprising: generating a fluorine-containing plasma by stopping the flow of the hydrogen-containing precursor into the plasma region.

2. The method of claim 1 , wherein the method treats a substrate or an interior surface of a substrate processing chamber.

3. 2. The processing method of claim 1, wherein the anode is one of a face plate or a shower head, the cathode is the other of the shower head or the face plate, and a substrate processing region is disposed on an opposite side of the shower head from the plasma region.

4. the anode is one of the showerhead or the substrate pedestal, and the cathode is the other of the substrate pedestal or the showerhead; 10. The method of claim 1, wherein a substrate processing region is disposed between and borders both the anode and the cathode.

5. The method of claim 1 , wherein the anode, the cathode, and the plasma region are circular.

6. The hydrogen-containing precursor is hydrogen (H 2 ) and ammonia (NH 3 ), and the fluorine-containing precursor is nitrogen trifluoride (NF 3 2. The method of claim 1 , wherein

7. The method of claim 1 , wherein the hydrogen-containing precursor and the fluorine-containing precursor mix within the plasma region.

8. 10. The method of claim 1, wherein no fluorine is present in the plasma region when the hydrogen-containing plasma is generated.

9. 10. The processing method of claim 1, further comprising turning off the RF power and stopping the flow of the fluorine-containing precursor after the fluorine-containing plasma is generated.

10. 10. The processing method of claim 9, wherein the RF power is turned off before the flow of the fluorine-containing precursor is stopped.

11. 10. The processing method of claim 9, wherein the RF power is turned off after the flow of the fluorine-containing precursor is stopped.

12. 10. The processing method of claim 1, wherein the hydrogen-containing precursor is flowed through a first manifold channel of a zonal distribution manifold and the fluorine-containing precursor is flowed through a second manifold channel of the zonal distribution manifold.

13. the hydrogen-containing precursor flows into an inner zone channel of the zonal distribution manifold; the fluorine-containing precursor flows from the second manifold channel to an outer zone channel of the zonal distribution manifold; The method of claim 12 , wherein the inner zone channel and the outer zone channel are separated from each other.

14. 14. The processing method of claim 13, wherein the hydrogen-containing precursor expands from the first manifold channel into an expansion region of the zonal distribution manifold and flows into the inner zonal channels of the zonal distribution manifold.

15. the hydrogen-containing precursor flows from the inner zone channel into an upper inner recess of a zone blocker plate; 14. The process of claim 13, wherein the fluorine-containing precursor flows from the outer zone channel into an upper outer recess of the zone blocker plate.

16. 16. The processing method of claim 15, wherein the hydrogen-containing precursor and the fluorine-containing precursor are delivered from the zone blocker plate to the plasma region through a plurality of apertures formed in a face plate.

17. 10. The method of claim 1, wherein the hydrogen-containing precursor is flowed into the plasma region for 1 to 30 seconds.

18. The method of claim 1 , wherein the pressure in the plasma region is greater than 2 Torr.

19. 10. The method of claim 1, wherein the RF power is greater than 200 watts.

20. 10. The process of claim 1, wherein the flow rate of the hydrogen-containing precursor is between 1 sccm and 200 sccm and the flow rate of the fluorine-containing precursor is between 20 sccm and 5000 sccm.

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