Showerhead optimization to reduce showerhead impedance in semiconductor manufacturing apparatus

Abstract

Apparatus and methods are provided herein. In certain embodiments, a reactance control apparatus for a showerhead in a processing chamber includes a bottom edge disposed to contact at least a portion of a top surface of the showerhead. The reactance control device may include a body surface having an inner connection edge and an outer periphery connected to the bottom edge via a sidewall, the inner connection edge having a smaller diameter than the outer periphery of the body surface, where the inner connection edge defines a bore configured to receive a portion of a shaft of the showerhead, and where the bore is configured to receive a portion of the shaft of the showerhead. And the inner connecting edge is further configured to engage with a mounting device disposed near the shaft portion of the showerhead in order to secure the reactance control device to the showerhead.

Description

[0001] Incorporation by Reference The PCT Application Table, which is part of this application, is concurrently filed with the specification. Each of the applications listed in the concurrently filed PCT Application Table from which this application claims benefit or priority is incorporated by reference herein in its entirety and for all purposes. BACKGROUND

[0002] Plasma-based operations, such as plasma-enhanced chemical vapor deposition (PECVD), atomic layer deposition (ALD), atomic layer etching (ALE), and the like, are typically performed in a plasma reactor that includes two electrodes for sustaining a plasma in a region located between the electrodes. When an RF signal is provided to an energized electrode of the two electrodes, a plasma can be ignited and / or sustained.

[0003] The background description provided herein is for the purpose of generally presenting the context of the disclosure. The work of the presently named inventors, to the extent the work is described in this background section as well as in this description and the accompanying drawings, neither is, nor is submitted to be, prior art against the present disclosure. SUMMARY

[0004] Systems, apparatuses, and methods for adjusting a station impedance during plasma operations are disclosed herein.

[0005] In certain implementations, a reactance control device for a showerhead in a processing chamber includes a bottom edge configured to contact at least a portion of a top surface of a showerhead. The reactance control device can include a body surface having an inner connecting edge and an outer periphery connected to the bottom edge via a sidewall, the inner connecting edge having a diameter that is less than the outer periphery of the body surface, wherein the inner connecting edge defines a through-hole configured to accommodate a portion of a shaft of the showerhead, and the inner connecting edge is further configured to engage with a mounting device disposed proximate to the shaft portion of the showerhead so as to secure the reactance control device to the showerhead.

[0006] In certain examples, the body surface is configured to fill at least a portion of a station of the processing chamber between the top surface of the showerhead and a top wall of the station, the body surface including a conductive material and configured to maintain electromagnetic coupling when the showerhead is powered by an RF source. In certain examples, the sidewall defines a height of the reactance control device, and the height of the reactance control device is less than a distance between the top surface of the showerhead and the top wall of the station.

[0007] In certain examples, the reactance control device includes one or more subcomponents, and each of the one or more subcomponents defines a portion of the inner connecting edge.

[0008] In certain examples, a top portion of the body surface is flat.

[0009] In certain examples, a top portion of the body surface is at least partially sloped.

[0010] In certain examples, the body surface forms a convex shape, and wherein an inner area formed by the convex shape is not filled.

[0011] In certain examples, the conductive material includes aluminum.

[0012] In certain examples, a perimeter of the bottom edge is in a range of about 30 inches to 50 inches.

[0013] In certain examples, when the reactance control device experiences thermal expansion, a range of about 40% to 60% of the bottom edge is configured to remain in contact with the at least a portion of the top surface of the showerhead.

[0014] In certain examples, the mounting device is a collar configured to secure the reactance control device. In certain examples, the collar is made of a material including Inconel.

[0015] In certain examples, the reactance control device is configured to reduce an inductance associated with the showerhead by at least about one half relative to an inductance associated with the showerhead when not in contact with the reactance control device.

[0016] In certain examples, the reactance control device is configured to reduce an inductance associated with the showerhead to less than about 30 nH.

[0017] According to certain embodiments, a showerhead apparatus is provided, including: a showerhead; and a reactance control device connected to a portion of a shaft of the showerhead. The reactance control device can include: a bottom edge configured to contact at least a portion of a top surface of the showerhead; and a body surface having an inner connecting edge and an outer perimeter connected to the bottom edge via a sidewall, the inner connecting edge having a diameter that is less than the outer perimeter of the body surface, wherein the inner connecting edge defines a through-hole configured to accommodate a portion of a shaft of the showerhead, and the inner connecting edge is further configured to engage with a mounting device disposed proximate to the shaft portion of the showerhead so as to secure the reactance control device to the showerhead.

[0018] In certain examples, the reactive control device is secured to the showerhead.

[0019] In certain examples, a top portion of the body surface is flat.

[0020] In certain examples, a top portion of the body surface is at least partially sloped.

[0021] In certain examples, the body surface forms a convex shape, and wherein an inner area formed by the convex shape is not filled.

[0022] In certain examples, the conductive material comprises aluminum.

[0023] In certain examples, the reactive control device is configured to reduce an inductance associated with the showerhead by at least about one half relative to an inductance associated with the showerhead when not in contact with the reactive control device.

[0024] In certain examples, the showerhead reactive control device is configured to reduce an inductance associated with the showerhead to less than about 30 nH.

[0025] In certain examples, the showerhead is configured in a station of a multi-station chamber, the multi-station chamber comprising at least two or more stations.

[0026] According to certain embodiments, a method of installing a reactive control device to a showerhead in a processing chamber is provided. The method can involve aligning the reactive control device with a mounting device disposed proximate a shaft portion of the showerhead, wherein the reactive control device comprises a bottom edge configured to contact at least a portion of a top surface of the showerhead, and a body surface having an inner connecting edge and an outer periphery, the outer periphery connected to the bottom edge, the inner connecting edge having a diameter less than the outer periphery of the body surface, wherein the inner connecting edge defines a through-hole configured to engage the mounting device disposed proximate the shaft portion of the showerhead. The method can involve securing the reactive control device to the showerhead via the mounting device, wherein at least a portion of the bottom edge contacts at least a portion of the top surface of the showerhead when secured.

[0027] In certain examples, the method further involves installing the showerhead on a processing station.

[0028] In certain examples, the reactive control device comprises two or more components, each of the two or more components defining a portion of the inner connecting edge, and wherein securing the reactive control device to the showerhead comprises connecting the two or more components of the reactive control device to the mounting device.

[0029] According to certain embodiments, a showerhead is disclosed herein. The showerhead can include a bottom portion including one or more ports disposed to dispense a process gas. The showerhead can include a shaft disposed to secure the showerhead to a top wall of a processing station. The showerhead can include a top portion including a conductive material, wherein the top portion encloses at least a bottom portion of the shaft such that the top portion is disposed to fill at least a portion of a gap between a top plate of the showerhead and the top wall of the processing station. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is a schematic diagram of an exemplary apparatus according to certain embodiments.

[0031] Figure 2 is a schematic diagram according to certain embodiments depicting components of an apparatus configured for plasma operation as equivalent circuit elements.

[0032] FIGS. 3A, 3B, and 3C illustrate exemplary configurations of a showerhead reactance control apparatus according to certain embodiments.

[0033] FIGS. 4A and 4B illustrate exemplary shapes of a showerhead reactance control apparatus according to certain embodiments.

[0034] FIGS. 5A and 5B depict a relationship between a reactance control apparatus size and a showerhead impedance according to certain embodiments.

[0035] Figure 6 is a flowchart of an exemplary process to vary a showerhead impedance or inductance via a showerhead reactance control apparatus according to certain embodiments.

[0036] According to certain embodiments, Figure 7 is a flowchart of an exemplary process to install a showerhead reactance control apparatus. DETAILED DESCRIPTION

[0037] Plasma-based operations, such as plasma-enhanced chemical vapor deposition (PECVD), atomic layer deposition (ALD), atomic layer etching (ALE), and the like, are typically performed in a plasma reactor that includes two electrodes for sustaining a plasma in a region between the two electrodes. The plasma can be ignited and / or sustained when an RF signal is provided to an energized electrode of the two electrodes. The unenergized electrode of the two electrodes is fixed to a wall of the plasma reactor, which can be effectively DC grounded at relatively low RF frequencies. However, at higher RF frequencies, the unenergized electrode can develop a voltage with respect to the wall of the plasma reactor. The voltage can have detrimental effects on the plasma within the reactor, such as causing parasitic plasma in regions of the reactor outside of the region between the two electrodes. The detrimental effects on the plasma can result in unpredictable and / or adverse conditions for semiconductor manufacturing operations, such as non-uniformity of deposited layers, non-uniformity of etched layers, and the like.

[0038] The reactance control device disclosed herein can be configured to attach to or otherwise contact the showerhead of the station, such as when the showerhead of the station is the unenergized electrode. The reactance control device can be made of a conductive material that conducts the RF signal. The reactance control device can reduce the gap between the top portion of the showerhead and the top wall of the station and / or the top plate of the showerhead, thereby reducing the inductance of the showerhead and, thus, the reactance and impedance associated with the showerhead. In other words, the reactance control device can effectively fill a portion of the region between the top portion of the showerhead and the top wall of the station or the top plate of the showerhead with an RF conductive material. By reducing the inductance, reactance, or impedance of the showerhead, parasitic plasma can be reduced.

[0039] The reactance control device can have a shape with an inner diameter for receiving the stem portion of the showerhead. The reactance control device can have a bottom edge configured to contact at least a portion of the top surface of the showerhead. The reactance control device can have a body surface configured to fill at least a portion of the station between the top surface of the showerhead and the top wall of the station or the top plate of the showerhead. The reactance control device can be made of a conductive material (such as aluminum or an aluminum alloy) that resists various chemical reactions that can occur in the station. The reactance control device can be clamped or bolted to a portion of the showerhead, such as by a collar. In certain embodiments, the reactance control device can be secured to a portion of the showerhead via a friction-based securing device, such as an RF gasket. In certain embodiments, the reactance control device can have an inverted bowl shape such that the interior portion of the reactance control device is empty. In certain embodiments, the body surface and / or the top surface of the reactance control device can be a metal mesh rather than primarily formed of a metal sheet. The reactance control device can be a monolithic component or can be composed of two or more pieces.

[0040] The reactance control device can include a bottom edge configured to contact at least a portion of a top surface of the showerhead. The reactance control device can include a body surface having an inner connecting edge and an outer periphery connected to the bottom edge via a sidewall. The inner connecting edge can have a diameter that is less than the outer periphery of the body surface. The inner connecting edge can define a through hole that can be used to accommodate a portion of a shaft of the showerhead. The reactance control device can be secured to at least a portion of the shaft of the showerhead via a mounting device. In certain embodiments, the inner connecting edge of the reactance control device can be configured to engage with the mounting device. In certain embodiments, the mounting device can be disposed proximate to the shaft portion of the showerhead. For example, the mounting device can include a collar that is fastened around the shaft portion of the showerhead. In certain embodiments, the mounting device can be bolted to the shaft portion of the showerhead. In certain embodiments, the mounting device can be a feature on the showerhead shaft or can be a separate component.

[0041] It is noted that in certain embodiments, the showerhead can be manufactured to have a shape that corresponds to the showerhead and reactance control device as one integral component, rather than having a reactance control device secured to the showerhead. In other words, it is understood that a modified showerhead shape is contemplated in which at least a portion of the top plate of the showerhead extends upward to fill the gap leading to the top portion of the station.

[0042] Figure 1 A manufacturing tool is shown represented as a substrate processing apparatus 100. The apparatus 100 can be used to utilize any number of processes to deposit films on or over a semiconductor substrate. For example, the apparatus 100 can be particularly useful for performing PECVD, ALD, or ALE.

[0043] Figure 1 The processing apparatus 100 of FIG. 1 can utilize a single processing station 102 of a processing chamber having a single substrate holder 108 (e.g., a susceptor) in an internal volume that can be held under vacuum by a vacuum pump 118. A showerhead 106 and a gas delivery system 101 (which is fluidly coupled to the processing chamber) can allow for the transport of, for example, film precursors, as well as carrier and / or purge and / or process gases, secondary reactants, and the like. It is understood that, Figure 1 The single station depicted in FIG. 1 is merely an example, and in certain embodiments, the reactance control device disclosed herein can be used in a single station, or in each station of a multi-station module.

[0044] In Figure 1 In FIG. 1, the gas delivery system 101 includes a mixing vessel 104 for mixing and / or conditioning process gases for delivery to the showerhead 106. One or more mixing vessel inlet valves 120 can control the introduction of process gases to the mixing vessel 104. Specific reactants can be stored in liquid form prior to vaporization and subsequent delivery to the processing station 102 of the processing chamber. Figure 1The implementation includes a vaporization point 103 for vaporizing liquid reactants to be supplied to mixing vessel 104. In some implementations, vaporization point 103 may include a heated liquid injection module. In some other implementations, vaporization point 103 may include a heated vaporizer. In still other implementations, vaporization point 103 may be removed from the processing station. In some implementations, a liquid flow controller upstream of vaporization point 103 may provide control over the mass flow rate of the liquid used for vaporization and delivery to processing station 102.

[0045] Nozzle 106 is operable to distribute process gas and / or reactants (e.g., membrane precursors) toward substrate 112 at the processing station, the flow rate of which is controlled by one or more valves (e.g., valves 120, 120A, 105) upstream of the nozzle. Figure 1 In the illustrated embodiment, substrate 112 is depicted as located below nozzle 106 and shown as resting on base 108. Nozzle 106 may include any suitable shape and may include any suitable number and arrangement of ports to distribute process gas to substrate 112. In some embodiments involving two or more stations, gas delivery system 101 includes valves or other flow control structures upstream of the nozzles that can independently control the flow of process gas and / or reactants to each station, such that gas flow is allowed to one station while simultaneously preventing gas flow to a second station. Furthermore, gas delivery system 101 may be configured to independently control the process gas and / or reactants delivered to each station in a multi-station apparatus, such that the gas composition supplied to different stations is different; for example, the partial pressure of the gas components may vary between multiple stations at the same time.

[0046] exist Figure 1In some implementations, plasma volume 107 is depicted as located below nozzle 106. In some implementations, base 108 may be raised or lowered to expose substrate 112 to plasma volume 107 and / or to change the size of plasma volume 107. The gap between base 108 and nozzle 106 is sometimes referred to as a “gap.” Optionally, base 108 may be lowered and / or raised during portions of the deposition process to adjust the processing pressure, reactant concentration, etc., within plasma volume 107. Nozzle 106 and base 108 are depicted as electrically coupled to RF signal generator 114 and matching network 116 to couple power to the plasma generator. Thus, nozzle 106 can be used as an electrode for coupling radio frequency power to the processing station 102. RF signal generator 114 and matching network 116 can operate at any suitable RF power level and can be operated to form a plasma with a desired composition of radical matter, ions, and electrons. Additionally, the RF signal generator 114 can provide RF power with more than one frequency component, such as a low-frequency component (e.g., less than about 2 MHz) and a high-frequency component (e.g., greater than about 2 MHz). In some implementations, plasma ignition and maintenance conditions are controlled using appropriate hardware and / or appropriate machine-readable instructions in a system controller, which can provide control commands via a sequence of input / output control instructions.

[0047] As described above Figure 1 The processing station may include a nozzle and a base, each of which can be considered an electrode. As described above, an RF signal can be applied to one of these electrodes, such as the base. In such an example, the nozzle can be considered an unenergized electrode. The unenergized nozzle can still function as an inductor in the processing station, where its inductance is generally referred to herein as... L shd When not powered on, the nozzle inductance is typically in the range of 10nH–50nH. It is well known that inductive reactance (usually expressed as...) X L Z is a subcomponent of impedance, which is usually represented by Z. For simplicity, the relationship can be described as Z = R + jX, where Z is impedance, R represents resistance, j is the imaginary part, and X is reactance. When the circuit is connected in series with an inductor, X can be equal to X... L = 2πƒL = ωL, where ƒ is the frequency measured in Hertz (Hz) and L is the inductance measured in Henry (H). Therefore, in a processing station, the inductance of the nozzle (energized or de-energized) is increased. L shd This can increase the reactance (X) and impedance (Z) of the nozzle. When the RF signal is on and the resistance is not significant (R=0), the impedance associated with the nozzle (which is usually referred to here as...) Z shd) can be L shd The decision was made so that Z shd = jcoL shd Note that because the inductance of the nozzle does not affect the resistance R, the impedance Z associated with the nozzle for a given RF frequency can be determined solely based on the inductance of the nozzle. L shd Related inductors and reactances X L The effect of printhead inductance on printhead-related impedance is negligible at relatively low RF frequencies. Therefore, the voltage across the printhead is negligible. In other words, at relatively low RF frequencies, the printhead can be effectively DC grounded, thus having the same potential as the chamber. However, at higher RF frequencies (e.g., above 20MHz, above 30MHz, above 40MHz, etc.), the printhead-related impedance can increase, resulting in a voltage across the printhead relative to the chamber (which is typically referred to here as the voltage across the chamber). V shd The corresponding addition is as follows. It should be understood that when an RF signal is applied to the nozzle, the base can be considered as an unenergized electrode. Similar to the description above regarding the voltage generated across the nozzle at higher RF frequencies when the nozzle is an unenergized electrode, a voltage can be generated across the base when the base is an unenergized electrode.

[0048] When the processing station 102 is activated, the base, the nozzle, and the plasma generated between the base and the nozzle can be represented as an equivalent circuit of resistors, inductors, and / or capacitors. In particular, the equivalent circuit can be a series RLC circuit. When the base is an energized electrode, the RLC circuit may include an inductor representing the base hardware that allows the RF signal generator to be electrically coupled to the base, a series capacitor and resistor representing the plasma maintained between the base and the nozzle, and an inductor representing the nozzle. As discussed above, the voltage across the nozzle ( V shd The voltage at the top of the base (often referred to here as V) is affected by the characteristics of the RF signal applied to the base. ped The characteristics of RF signals also affect the top portion of the base, which corresponds to the surface of the substrate on which the processed material is placed. Furthermore, because the circuit elements are coupled in series, the voltage (V) across the nozzle... Shd It will also affect the voltage (V) at the top of the base. pedThis can have an impact. Therefore, undesirable voltage across the nozzle (e.g., due to the nozzle's inductance) can cause undesirable voltage variations on the substrate surface, which can consequently lead to undesirable changes in the plasma state within the processing station. It should be understood that, as used herein, undesirable voltage can be a voltage across a component (e.g., the nozzle and / or substrate) exceeding a voltage threshold. In some cases, the voltage threshold can be approximately 0V. For example, such undesirable voltages across various components in the station can cause parasitic plasma. As more specific examples, such parasitic plasma can include plasma between the nozzle and the wall, plasma beneath a portion of the substrate, etc. Furthermore, such undesirable voltage variations can have undesirable manufacturing effects on wafers being processed within the reactor, such as uneven deposition, uneven etching, etc. It should be understood that in embodiments where the energized electrode is the nozzle and the unenergized electrode is the substrate, an RF signal generator can be electrically coupled to an inductor representing the nozzle.

[0049] Figure 2 A schematic diagram according to some embodiments is shown, illustrating components of a reactor depicted as equivalent circuit elements, the reactor utilizing a base as an energized electrode. As shown, the RF generator 202 is represented by a current source 204. (As described above...) Figure 1 The RF signal generator 202 can be configured to provide RF signals at one or more frequencies, including low frequencies (e.g., about 2 MHz) and / or high frequencies (e.g., above 2 MHz). The RF signal generator 202 is electrically coupled to a base 206. The base's stem is supported by an inductor 208 (referred to as...). L ped As indicated by ). Figure 2 As shown, the voltage at the top portion of the base 206 is generally referred to here as... V ped Plasma 210, when present, is maintained between base 206 and nozzle 216. Plasma 210 can be maintained by a capacitor 212 connected in series (generally referred to herein as C). 等离子体 ) and resistor 214 (usually referred to here as R) 等离子体 ) indicates. Generally speaking, R 等离子体 Represents plasma layer resistance, and C 等离子体 This refers to the plasma sheath capacitance. The nozzle 216, when fixed to the reactor wall (as in a conventional mechanism), is controlled by an inductor 220 (referred to herein as...). L Shd This indicates that it is sequentially coupled to the ground (i.e., the station wall). This configuration is sometimes referred to as a "grounding sprinkler configuration." Figure 2 As shown, the voltage across the nozzle. V ShdThis is equivalent to the voltage at the node of the ungrounded inductor 220.

[0050] In some embodiments, a reactor control device may be installed at the station in the processing chamber to effectively reduce the reactance associated with the nozzle (and thus reduce impedance). In particular, the reactor control device may be configured to be attached as part of the nozzle and occupy the area or space between the top portion of the nozzle and the top wall of the station or the top plate of the nozzle. The reactor control device may be made of a conductive material to allow RF signals to travel on its surface. The reactor control device may be compliant with various chemical reactions occurring in the station. In some embodiments, the reactor control device may be made of aluminum or an aluminum alloy.

[0051] In some embodiments, the reactor control device may have an inner diameter corresponding to a portion of the reactor control device used to receive the nozzle. The reactor control device may also have an outer diameter, wherein the diameter of the bottom edge of the reactor control device is the same as the outer diameter. The bottom edge may be positioned on at least a portion of the top portion of the nozzle. In some embodiments, the reactor control device may be secured to a portion of the nozzle by bolts and / or clamps. For example, the reactor control device may be fastened to the nozzle rod via a collar. The bolts and / or clamps used to attach the reactor control device to the nozzle may be made of a material with relatively high tensile strength. For example, the bolts and / or clamps may be made substantially of stainless steel, Inconel, etc.

[0052] In some embodiments, the bottom edge of the reactor control device may be configured to contact the top portion of the nozzle. Note that during the execution of various processing operations, the station may rise to relatively high temperatures, such as above 400 degrees Celsius, above 500 degrees Celsius, above 600 degrees Celsius, etc. During processing, portions of the reactor control device and / or nozzle may experience thermal expansion due to the increased temperature. For example, during thermal expansion, the top portion of the nozzle may become convex or bend in one direction, causing the top portion of the nozzle to detach from the bottom edge of the reactor control device. In some embodiments, the reactor control device may be secured to a portion of the nozzle by bolts and / or clamps to maintain at least a portion of the bottom edge of the reactor control device in contact with the top portion of the nozzle when the reactor control device and / or nozzle undergo thermal expansion. For example, in some embodiments, approximately 40% to 60% of the bottom edge of the reactor control device may remain in contact with the top portion of the nozzle when the reactor control device and / or nozzle undergoes thermal expansion. As another example, in some embodiments, approximately 45% to 55% of the bottom edge of the reactor control device remains in contact with the top portion of the nozzle when the reactor control device and / or nozzle undergo thermal expansion. In some embodiments, the portion of the bottom edge not in contact with any part of the nozzle may be less than approximately 10 inches of the perimeter of the bottom edge. In some embodiments, the portion of the bottom edge not in contact with any part of the nozzle may be less than approximately 6 inches of the perimeter of the bottom edge.

[0053] Note that in some implementations, the nominal inductance associated with the nozzle may be about 40 nH. Attaching a reactance control device to the nozzle may reduce the inductance to less than about 30 nH, less than about 20 nH, less than about 15 nH, or less than about 10 nH. This reduction in the nozzle-associated inductance may reduce the nozzle-associated reactance (and thus the impedance), which in turn reduces the voltage across the nozzle (when it is grounded). This may reduce parasitic plasma, such as plasma in an undesirable region of the station located outside the area between the bottom portion of the nozzle and the wafer being processed.

[0054] Figures 3A and 3B illustrate an exemplary configuration of a reactor control device within a station in a processing chamber. Note that Figures 3A and 3B show cross-sectional side views of the station and the reactor control device. Referring to Figure 3A, station 302 includes a nozzle 304. The nozzle 304 has a stem 308. A reactor control device 306 is configured such that its bottom edge 312 contacts the top surface of the nozzle 304. As shown, the reactor control device 306 includes an inner diameter through which the stem 308 is positioned. The reactor control device 306 includes an outer diameter 314. Note that the bottom edge 312 of the reactor control device 306 may have a generally circular shape with a diameter corresponding to the outer diameter 314. In the example shown in Figure 3A, the reactor control device 306 has a height such that there is a 0.5-inch gap between the top surface of the reactor control device 306 and the top plate of the nozzle. The reactor control device 306 also includes an inner connecting edge 311. As shown in Figure 3A, at least a portion of the nozzle shaft can be positioned within the inner connecting edge 311.

[0055] Referring to Figure 3B, the reactor control device 356 has the same inner and outer diameters as the reactor control device 306 of Figure 3A. However, the height of the reactor control device 356 differs from that of the reactor control device 306 of Figure 3A. In particular, the height of the reactor control device 356 is less than that of the reactor control device 306, so that the gap between the top surface of the reactor control device 356 and the top plate of the nozzle is 1 inch (e.g., twice the size of the gap between the top portion of the reactor control device 306 and the top plate of the nozzle). Note that, as described below in conjunction with Figure 5A, impedance is proportional to the gap, such that a smaller gap (e.g., the gap of the reactor control device shown in Figure 3A) is associated with a relatively low inductance of the nozzle, and therefore a relatively low impedance, relative to a larger gap between the top surface of the reactor control device and the top wall of the station or the top plate of the nozzle. It should be understood that inductance is generally expressed as magnetic flux divided by current. When current flows through a looped conductor, the magnetic flux can be reduced by decreasing the cross-sectional area of ​​the loop. Similarly, with a conductor, the cross-sectional area of ​​the loop can be reduced by effectively straightening the conductor. As described above, reducing the magnetic flux reduces the inductance. A similar effect can be achieved by reducing the gap between the nozzle top plate and the station wall (i.e., the cross-sectional area of ​​the horizontal space between the nozzle and the top plate) via a reactance control device.

[0056] Note that while Figures 3A and 3B show a reactor control device with sidewalls that are substantially at a 90-degree angle to the top wall, this is only an example. In some embodiments, the sidewalls of the reactor control device may be at an angle greater than 90 degrees (e.g., 100 degrees, 120 degrees, 130 degrees, etc.) or less than 90 degrees (e.g., 85 degrees, 80 degrees, 60 degrees, etc.).

[0057] Figure 3CA cross-sectional side view of an exemplary reactor control device 360 ​​is shown according to certain embodiments. As shown, the reactor control device 360 ​​includes a top surface 362. Although the top surface 362 is... Figure 3C The example shown is substantially flat, but in some examples, the top surface 362 may be skewed, tilted, curved, etc. Furthermore, while the top surface 362 is depicted as having a uniform thickness, in some examples, the top surface 362 may have a different thickness, for example, with an increase or decrease in thickness at the edges of the top surface 362 relative to its central portion. The reactance control device 360 ​​also includes a sidewall 364, which is the radially outward-facing surface of the reactance control device 360. Note that while the sidewall 364 is depicted as being approximately perpendicular to the top surface 362, in some examples, the sidewall 364 may be non-right-angled with the top surface 362, for example, at 60 degrees, 70 degrees, 80 degrees, 100 degrees, 110 degrees, 120 degrees, etc. Although the sidewall 364 is depicted as having a uniform thickness, in some instances, the thickness may vary across the sidewall 364. For example, the portion of the sidewall 364 closer to the top surface of the nozzle may have increased or decreased thickness compared to other portions of the sidewall 364.

[0058] The reactor control device 360 ​​is attached to the nozzle stem 366 via attachment point 370. In some examples, the reactor control device 360 ​​may have holes in its top surface 362, through which mounting devices (e.g., bolts and / or collars) can be used to secure the reactor control device 360 ​​to the nozzle stem 366. When the reactor control device 360 ​​is secured to the nozzle stem 366, its bottom edge is positioned to rest on the top surface 368 of the nozzle. Note that even when the reactor control device 360 ​​and the nozzle undergo thermal expansion, a portion of the bottom edge remains in contact with the top surface 368 of the nozzle.

[0059] Note that although the top surface 360 ​​and sidewall 364 of the reactance control device 360 ​​are shown as solid, in some embodiments, portions of the top surface 360 ​​and / or sidewall 364 may be replaced by conductive metal rods, metal grids, and / or conductive metal mesh. Furthermore, in some embodiments, different materials may be used for the top surface 362 and sidewall 364.

[0060] The reactor control device described above, in conjunction with Figures 3A, 3B, and 3C, has a relatively flat top surface and is symmetrical with respect to the axis defined by the nozzle stem. However, in some embodiments, the reactor control device may have a sloping top surface. Furthermore, or alternatively, in some embodiments, the reactor control device may be asymmetrical with respect to the axis defined by the nozzle stem. Figure 4A depicts an exemplary reactor control device 404 with a sloping top surface. Note that while the sloping top surface of the reactor control device 404 is curved, in some embodiments, the top surface may have a sloping, non-curved shape (e.g., as shown in Figure 5B). Figure 4B depicts an exemplary reactor control device 454 with an asymmetrical shape relative to the axis defined by the nozzle stem. As shown, the first half 456 of the reactor control device 454 has a substantially flat top surface, while the second half 458 has a sloping top surface.

[0061] As described above, the inductance associated with the nozzle, and therefore the reactance and / or impedance associated with the nozzle, can be proportional to the gap between the top surface of the nozzle and the top wall and / or the top plate of the station. Reducing the gap between the top surface of the nozzle and the top wall and / or the top plate by filling at least a portion of the gap with a reactance control device can reduce the gap, thereby reducing the inductance, reactance, and / or impedance associated with the nozzle. The inductance, reactance, and / or impedance associated with the nozzle can also be proportional to the logarithm of the ratio of the inner diameter of the reactance control device to the outer diameter of the reactance control device. For example, the impedance can be expressed as: In the equations given above, “OD” represents the outer diameter of the reactor control device (e.g., the outer diameter of the circle formed by the bottom edge of the reactor control device), and “ID” represents the inner diameter of the reactor control device used to house the nozzle. As shown in the equations above, the impedance associated with the nozzle (and relatedly, the reactance and / or inductance associated with the nozzle) can be changed by altering the shape, size, or dimensions of the reactor control device. For example, the nozzle impedance can be reduced by decreasing the gap between the top surface of the reactor control device and the top wall of the station or the top plate of the nozzle (e.g., by using a reactor control device with a higher height). As another example, the nozzle impedance can be reduced by decreasing the ratio of the outer diameter to the inner diameter of the reactor control device.

[0062] Figure 5A is a diagram illustrating various parameters of the reactor control device, which can be adjusted to change the impedance associated with the nozzle. For example, Figure 5A shows the gap between the top portion of the nozzle 304 and the top wall 502 of the station. Figure 5A also shows that the inner diameter of the reactor control device is defined and / or limited by the diameter associated with the nozzle's stem. For example, in some embodiments, because the inner diameter of the reactor control device is used to accommodate the nozzle's stem, the inner diameter of the reactor control device is not smaller than the diameter associated with the nozzle's stem. As another example, because the bottom edge of the reactor control device is configured to contact the top portion of the nozzle, the outer diameter of the reactor control device (e.g., the bottom edge of the reactor control device) is limited by the diameter associated with the nozzle.

[0063] Figure 5B illustrates exemplary reactor control devices with different shapes and sizes. For example, reactor control device 552 has a certain height and shape such that the gap between the top surfaces of reactor control device 552 is significantly larger than that between the other half of reactor control device 552. In other words, reactor control device 552 is asymmetrical with respect to the axis defined by the rod portion in terms of the gap between the top surface of the reactor control device and the top wall of the station. Furthermore, note that for a portion of reactor control device 552, the top surface of reactor control device 552 is substantially flat, while for the remaining portion of reactor control device 552, the top surface of reactor control device 552 is inclined. The left side wall of reactor control device 552, which connects the top surface of reactor control device 552 to the bottom edge of reactor control device 552, is approximately right-angled.

[0064] The reactor control device 554 depicted in Figure 5B is also asymmetrical with respect to the axis defined by the nozzle rod. The top surface of the reactor control device 554 is inclined, and due to the asymmetry of the reactor control device 554, there is a larger gap on one side of the reactor control device 554 compared to the other side. The sidewalls used to connect the top surface of the reactor control device 554 to the bottom edge of the reactor control device 554 are substantially right-angled.

[0065] The reactor control device 556 depicted in Figure 5C is also asymmetrical with respect to the axis defined by the nozzle rod. The top surface of the reactor control device 556 is inclined, and due to the asymmetry of the reactor control device 556, there is a larger gap on one side of the reactor control device 556 compared to the other side. The sidewall used to connect the top surface of the reactor control device 556 to the bottom edge of the reactor control device 556 is obtuse.

[0066] In some embodiments, the reactor control device can be removably attached to the nozzle, allowing it to be exchanged or replaced. For example, to adjust the inductance, reactance, and / or impedance associated with the nozzle to, for instance, conform to specific process parameters, a second reactor control device can replace the first. As a more specific example, the replaced reactor control device may have a size and / or shape for changing the inductance, reactance, and / or impedance of the nozzle to approximate target values, which may depend on the process being performed within the station. Furthermore, it should be noted that in some embodiments, the asymmetry of the reactor control device, or other physical characteristics of the reactor control device, can be used to compensate for asymmetries across stations in a multi-station room. For example, each station may utilize reactor control devices of different shapes, selected for the characteristics of the nozzles in that station, and allowing the inductance, reactance, and / or impedance of the nozzles in that station to compensate for asymmetries caused by other stations in the multi-station room.

[0067] Figure 6 This is a flowchart of an exemplary process 600 in which a second reactor control device replaces a first reactor control device according to certain embodiments. Process 600 may be performed in response to design selections for reactor control devices to be utilized in a given station for a given process.

[0068] Process 600 may begin at 602, providing a first reactance control device associated with the nozzle of the station. The first reactance control device may have first physical characteristics, such as the asymmetry of the reactance control device relative to the axis defined by the rod of the nozzle, and the height related to the gap between the top surface of the reactance control device and the top wall of the station or the top plate of the nozzle, the shape of the top surface (e.g., whether the top surface is flat, whether it is inclined in a curved manner, whether it is inclined in a non-curved manner, etc.), etc.

[0069] In 604, a second reactor control device can replace the first reactor control device. The second reactor control device, relative to the first, creates a different gap between the top portion of the second reactor control device and the top wall of the station chamber, and / or creates a different size or shape. Replacing the first reactor control device with the second reactor control device allows the inductance associated with the nozzle to be changed to approximate the changed nozzle inductance. Note that in some embodiments, the second reactor control device can be confirmed or selected based on the following decisions: at least by adjusting the inductance associated with the nozzle to approximate the changed nozzle inductance, thereby adjusting the processing performed in the station. Note that because of the relationship between inductance, reactance, and impedance, adjusting the nozzle inductance also adjusts the reactance and impedance associated with the nozzle. The changed nozzle inductance can be determined based on experimental data representing the amount or location of parasitic plasma within the station, and / or any other suitable experimental data. For example, the changed nozzle inductance can be lower or higher than the current inductance associated with the nozzle. Note that in some implementations, process 600 can be cyclical, allowing the second reactor control device to be replaced by a third reactor control device, and so on. This allows for iterative convergence of the reactor control devices to optimize the nozzle inductance for the processing performed at the station.

[0070] Figure 7 This is a flowchart of an exemplary process 700 for installing a reactor control device according to certain embodiments. Process 700 can be performed by an installer of the reactor control device, who, for example, installs the reactor control device in a given station. The installation procedure may include fastening or otherwise securing the reactor control device to a portion of the nozzle's shaft, ensuring that at least a portion of the bottom edge of the reactor control device contacts the top surface of the nozzle, etc. Note that the reactor control device may be mounted (e.g., secured) to the nozzle of the station before being installed in the tool.

[0071] Process 700 may begin at 702, aligning the reactor control device with a mounting device disposed near the shaft portion of the nozzle. As described above, the reactor control device may include a bottom edge configured to contact at least a portion of the top surface of the nozzle. The reactor control device may include a body surface having an inner connecting edge and an outer periphery connected to the bottom edge via sidewalls. The diameter of the inner connecting edge may be smaller than the outer periphery of the body surface. The inner connecting edge may define a through-hole for receiving a portion of the nozzle shaft. Therefore, the step of aligning the reactor control device may include aligning the through-hole with the shaft of the nozzle.

[0072] In step 704, process 700 allows the reactor control device to be secured to the nozzle via an installation device. After securing the reactor control device, at least a portion of the bottom edge periphery of the reactor control device (e.g., at least about 40% to 60%, at least about 45% to 55%, at least about 50%, etc.) can be positioned to contact the top surface of the nozzle. As described above, the installation device may include a collar, one or more bolts, etc.

[0073] Note that process 700 can be repeated for multiple stations (e.g., multiple stations in a multi-station module or processing room).

[0074] in conclusion In this description, numerous specific details are presented to provide a thorough understanding of the implementation scheme. The disclosed implementation scheme can be implemented without some or all of these specific details. In other instances, well-known processing operations are not described in detail to avoid unnecessary confusion regarding the disclosed implementation scheme. Although the disclosed implementation scheme is described together with these specific implementation schemes, it should be understood that the specific implementation schemes are not intended to limit the disclosed implementation scheme.

[0075] Unless otherwise stated, the methods, operations and apparatus features disclosed herein include techniques and apparatus commonly used in metrology, semiconductor device manufacturing technology, software design and programming, and statistics, which are within the scope of the art.

[0076] Unless otherwise defined herein, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Various scientific dictionaries containing the terms included herein are well known to and can be used by one of ordinary skill in the art to which this invention pertains. While any methods and materials similar or equivalent to those described herein may be used to practice or test the embodiments disclosed herein, certain methods and materials are still described.

[0077] A numerical range includes the number that defines the range. The purpose is that each maximum numerical limit given throughout this specification includes each lower numerical limit as if such lower numerical limits were explicitly stated herein. Each minimum numerical limit given throughout this specification will include each larger numerical limit as if such larger numerical limits were explicitly stated herein. Each numerical range given throughout this specification will include each narrower numerical range falling within such a wider numerical range as if such narrower numerical ranges were explicitly stated herein.

[0078] The headings provided herein are not intended to limit the content of this disclosure.

[0079] As used herein, the singular terms “a,” “one,” and “the” include the plural forms, unless the context otherwise requires. The term “or,” as used herein, means non-exclusive, unless otherwise stated.

[0080] Various computing elements, including processors, memory, instructions, routines, models, or other components, can be described or declared as being "configured" to perform one or more tasks. In this context, the phrase "configured" refers to a structure containing components (such as stored instructions, circuits, etc.) that performs one or more tasks during operation. Therefore, even when a particular component is not currently operational (e.g., not in an on state), it can be said that a unit / circuit / component is configured to perform a task.

[0081] Components used with the term "configured as" may refer to hardware—for example, circuitry, or memory storing executable program instructions for operation. Furthermore, "configured as" may refer to a general-purpose structure (such as a general-purpose circuit) manipulated by software and / or firmware (such as an FPGA or a general-purpose processor executing software) to operate in a manner capable of performing the tasks (multiple tasks). Additionally, "configured as" may refer to one or more memories or memory elements storing computer-executable instructions for performing the tasks (multiple tasks). Such memory elements may comprise on-chip memory for a computer chip having processing logic. In some contexts, "configured as" may also include adapting manufacturing processes (such as semiconductor manufacturing facilities) to manufacturing equipment (such as integrated circuits) adapted to implement or perform one or more tasks.

Claims

1. A reactance control apparatus for a showerhead in a processing chamber, the reactance control apparatus comprising: a bottom edge configured to contact at least a portion of a top surface of a showerhead; a body surface having an inner connecting edge and an outer periphery, the outer periphery connected to the bottom edge via a sidewall, the inner connecting edge having a diameter that is less than the outer periphery of the body surface, wherein the inner connecting edge defines a through-hole configured to accommodate a portion of a shaft of the showerhead, and the inner connecting edge is further configured to engage with a mounting apparatus disposed proximate the shaft portion of the showerhead so as to secure the reactance control apparatus to the showerhead.

2. The reactance control apparatus of claim 1, wherein the body surface is configured to fill at least a portion of a station between the top surface of the showerhead and a top wall of the station of the processing chamber, the body surface comprising a conductive material and configured to maintain electromagnetic coupling when the showerhead is powered by an RF source.

3. The reactance control apparatus of claim 2, wherein the sidewall defines a height of the reactance control apparatus, and the height of the reactance control apparatus is less than a distance between the top surface of the showerhead and the top wall of the station.

4. The reactance control apparatus of claim 1, comprising one or more sub-components, and each of the one or more sub-components defines a portion of the inner connecting edge.

5. The reactance control apparatus of claim 1, wherein a top portion of the body surface is flat.

6. The reactance control apparatus of claim 1, wherein a top portion of the body surface is at least partially sloped.

7. The reactance control apparatus of claim 1, wherein the body surface forms a convex shape, and wherein an inner area formed by the convex shape is not filled.

8. The reactance control apparatus of claim 1, wherein the conductive material comprises aluminum.

9. The reactance control apparatus of any of claims 1-8, wherein a periphery of the bottom edge is in a range of about 30 inches to 50 inches.

10. The reactance control apparatus of any of claims 1-8, wherein about 40% to 60% of the bottom edge is configured to remain in contact with the at least a portion of the top surface of the showerhead when the reactance control apparatus undergoes thermal expansion.

11. The reactance control apparatus of any of claims 1-8, wherein the mounting apparatus is a collar configured to secure the reactance control apparatus.

12. The reactance control apparatus of claim 11, wherein the collar is made of a material comprising Inconel.

13. The reactance control apparatus of any of claims 1-8, wherein the reactance control apparatus is configured to reduce an inductance associated with the showerhead by at least about one half relative to an inductance associated with the showerhead when not in contact with the reactance control apparatus.

14. The reactance control device of any of claims 1-8, wherein the reactance control device is configured to reduce an inductance associated with the showerhead to less than about 30 nH.

15. A showerhead apparatus comprising: a showerhead; and a reactance control device coupled to a portion of a shaft of the showerhead, the reactance control device comprising: a bottom edge configured to contact at least a portion of a top surface of the showerhead; and a body surface having an inner connecting edge and an outer periphery, the outer periphery coupled to the bottom edge via a sidewall, the inner connecting edge having a diameter that is less than the outer periphery of the body surface, wherein the inner connecting edge defines a through-hole configured to receive a portion of a shaft of the showerhead, and the inner connecting edge is further configured to engage with a mounting device disposed proximate to the shaft portion of the showerhead to secure the reactance control device to the showerhead.

16. The showerhead apparatus of claim 15, wherein the showerhead reactance control device is fastened to the showerhead.

17. The showerhead apparatus of claim 15, wherein a top portion of the body surface is flat.

18. The showerhead apparatus of claim 15, wherein a top portion of the body surface is at least partially sloped.

19. The showerhead apparatus of claim 15, wherein the body surface forms a convex shape, and wherein an inner region defined by the convex shape is not filled.

20. The showerhead apparatus of claim 15, wherein the conductive material comprises aluminum.

21. The showerhead apparatus of any of claims 15-20, wherein the showerhead reactance control device is configured to reduce an inductance associated with the showerhead by at least about one half relative to an inductance associated with the showerhead when not in contact with the reactance control device.

22. The showerhead apparatus of any of claims 15-20, wherein the showerhead reactance control device is configured to reduce an inductance associated with the showerhead to less than about 30 nH.

23. The showerhead apparatus of any of claims 15-20, wherein the showerhead is configured in a station of a multi-station chamber, the multi-station chamber comprising at least two or more stations.

24. A method of mounting a reactance control device to a showerhead in a processing chamber, the method comprising: aligning the reactance control device with a mounting device disposed proximate to a shaft portion of the showerhead, wherein the reactance control device comprises: a bottom edge configured to contact at least a portion of a top surface of the showerhead; and a body surface having an inner connecting edge and an outer periphery, the outer periphery coupled to the bottom edge, the inner connecting edge having a diameter that is less than the outer periphery of the body surface, wherein the inner connecting edge defines a through-hole configured to engage with the mounting device disposed proximate to the shaft portion of the showerhead, and securing the reactance control device to the showerhead via the mounting device, wherein at least a portion of the bottom edge contacts at least a portion of the top surface of the showerhead when secured.

25. The method of claim 24, further comprising mounting the showerhead to the processing station.

26. The method of claim 24, wherein the reactance control device comprises two or more components each defining a portion of the inner connecting edge, and wherein securing the reactance control device to the showerhead comprises connecting the two or more components of the reactance control device to the mounting device.

27. A showerhead, comprising: a bottom portion comprising one or more ports disposed to dispense a process gas; a shaft disposed to secure the showerhead to a top wall of a processing station; and a top portion comprising a conductive material, wherein the top portion encloses at least a bottom portion of the shaft such that the top portion is disposed to fill at least a portion of a gap between a top plate of the showerhead and the top wall of the processing station.

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