Plasma chamber with multiphase rotating crossflow including uniformity adjustment

Abstract

The plasma processing chamber includes one or more sidewalls, with a support surface within the sidewalls holding the workpiece. An array of individual gas injectors are distributed around the periphery of the sidewalls. Pump ports are located along the sidewalls to evacuate gas from the chamber. The uniformity of the etch rate of the material on the workpiece is controlled by using the array gas injectors to inject one or more gas flows across the workpiece, injecting a first gas flow from a first set of adjacent individual gas injectors to etch the material on the workpiece, and simultaneously injecting a second gas flow from the remaining gas injectors. The second gas flow either dilutes the first gas to reduce areas on the workpiece that have a faster etch rate, or acts as an additional etchant to increase the etch rate in areas of the workpiece that have a faster etch rate.

Description

Technical Field

[0001] Cross - reference to Related Applications This application claims the benefit of U.S. Provisional Patent Application No. 63 / 236,166, filed Aug. 23, 2021, and claims the priority of U.S. Patent Application No. 17 / 831,781, filed Jun. 3, 2022, the entire contents of which are incorporated herein by reference.

[0002] Embodiments of the present disclosure relate to the field of semiconductor processing, and more particularly to plasma chambers including rotational cross - flow and uniformity adjustment.

Background Art

[0003] During plasma etching, deposition, or other processing operations, a workpiece such as a semiconductor wafer is inserted into a sealed plasma reactor chamber, gas is injected into the chamber over the wafer, and then pumped out of the chamber. Plasma chambers often include either (1) a parallel - plate capacitively - coupled plasma (CCP) source (one electrode having the workpiece on the surface facing the plasma and the other electrode having an array of gas - inlet holes (showerhead) on the surface facing the plasma), or (2) an inductively - coupled plasma (ICP) or microwave source (a high - frequency (RF) window generally opposite the workpiece and facing the workpiece, and gas - inlet holes within or near the window).

[0004] In the above-described axisymmetric gas flow approach, differences occur in the treatment from the center to the edge of the workpiece due to pressure and concentration gradients. Further, due to the proximity to high-density plasma and breakdown by high electric fields, extraneous plasma is formed at the gas inlet holes, and the non-uniformity may change over time. More specifically, the gas inlet holes are typically formed in a plate of a material such as silicon or silicon carbide. When high-energy ions collide with the edges of the holes, the holes can deform or facet over time. The deformed holes then generate a high-intensity plasma that destroys the plate, requiring the replacement of the showerhead after a certain period of time (e.g., 600 hours). Depending on the application, about $15 of the cost of a semiconductor wafer may be allocated solely to the cost of the showerhead. SUMMARY OF THE INVENTION

[0005] Embodiments disclosed herein include a plasma processing chamber that includes one or more sidewalls. A support surface within the one or more sidewalls holds a workpiece. An array of individual gas injectors is dispersed around the outer periphery of the one or more sidewalls. One or more pump ports for exhausting gas from the plasma processing chamber are located along the one or more sidewalls. A controller is configured to control the plasma processing chamber during an etching application. The uniformity of the etching rate of the material on the workpiece is adjusted or controlled by: i) using the array of individual gas injectors to inject one or more gas flows in a direction generally parallel to and across the surface of the workpiece; ii) injecting a first gas flow from a first set of adjacent ones of the individual gas injectors to etch the material on the workpiece; and iii) simultaneously injecting a second gas flow from at least the remaining set of the individual gas injectors. According to an embodiment, the second gas flow is used to: i) dilute the first gas to reduce an area on the workpiece having a faster etching rate; or ii) act as an additional etchant to increase the etching rate within an area of the workpiece having a faster etching rate.

[0006] The embodiments disclosed herein further include a plasma processing chamber including one or more sidewalls. A support surface within the one or more sidewalls holds a workpiece. An array of individual gas injectors is dispersed around the outer periphery of the one or more sidewalls. One or more pump ports for exhausting gas from the plasma processing chamber are located along the one or more sidewalls. A controller is configured to control the plasma processing chamber during an etching application. The uniformity of the etching rate of the material on the workpiece is adjusted or controlled by: i) using the array of individual gas injectors to inject a gas flow in a direction generally parallel to and across the surface of the workpiece, and ii) varying the gas flow injection angle across the workpiece by selecting between a wide set of adjacent ones of the individual gas injectors and a narrow set of adjacent ones of the individual gas injectors before or during the gas flow injection, wherein selecting the narrow set of adjacent ones of the individual gas injectors reduces the gas flow injection angle and performs the varying of the gas flow injection angle.

[0007] The embodiments disclosed herein include a method of controlling the uniformity of the etching rate of a material on a workpiece within a plasma processing chamber. The method includes injecting a first gas flow from a first set of adjacent ones of the individual gas injectors in a direction generally parallel to and across the surface of the workpiece to etch the material on the workpiece. The method includes simultaneously injecting a second gas flow from at least a portion of the remaining set of the individual gas injectors in a direction generally parallel to and across the surface of the workpiece, wherein the second gas flow is used to: i) dilute the first gas to reduce an area on the workpiece having a faster etching rate, or ii) act as an additional etchant to increase the etching rate within an area of the workpiece having a faster etching rate.

Brief Description of the Drawings

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[0009] The disclosed embodiments relate to a plasma chamber having a rotational modulation crossflow and uniformity adjustment. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the present disclosure. It will be apparent to those skilled in the art that the embodiments of the present disclosure can be practiced without these specific details. In other instances, well-known aspects such as integrated circuit manufacturing are not described in detail so as not to unnecessarily obscure the embodiments of the present disclosure. Furthermore, it should be understood that the various embodiments shown in the figures are illustrative representations and are not necessarily drawn to scale.

[0010] Conventional plasma chambers (i.e., CCP or ICP) typically inject gas symmetrically along a line onto a workpiece from a gas inlet hole that is normally positioned symmetrically above or around the periphery of the workpiece. As described above, an axisymmetric gas flow causes pressure and concentration gradients, and there is a possibility that the gas hole inlet is damaged, resulting in non-uniformity on the workpiece. That is, wear occurs at the gas holes in the plasma region with high density and high |E|, so the shape dimensions of the holes change, and as the plasma penetrates, the holes may change the local plasma characteristics near the holes. Furthermore, as a result of the change in shape dimensions, the local gas flow rate and velocity may change. Therefore, it is necessary to replace the shower head relatively frequently, increasing the cost of the workpiece.

[0011] Accordingly, the embodiments disclosed herein are directed to plasma chambers (e.g., CCP or ICP) having a multiphase rotating modulated gas crossflow for etching, deposition, or other material processing. The plasma processing chamber includes two or more gas injectors and two or more pump ports along the sidewalls. In a first phase, a gas stream is made generally parallel to and in one direction across the surface of a workpiece or device by one of the gas injectors, and the gas is then pumped out via a pump port. In a second phase, another gas injector is used to rotate the gas stream, making the gas stream generally parallel to and in another direction across the surface of the workpiece, where the gas is then pumped out via another pump port. In another embodiment, a gas inlet valve connected to the gas injector and / or a throttle valve connected to the pump port may be used to modulate the rotating gas stream.

[0012] A plasma processing chamber with a rotating modulated gas crossflow eliminates the need for a showerhead (and gas inlet holes) in the high density |E| plasma region. Thus, the cause of plasma non-uniformity is precluded. By the disclosed embodiments, plasma formation in the gas holes due to proximity to a high density plasma or breakdown by a high electric field is prevented, and non-uniformity and plasma characteristics from changing over time are prevented. By the disclosed embodiments, high center-to-edge pressure and concentration gradients that cause differences in processing from the center to the edge are avoided. To minimize plasma non-uniformity, the pressure distribution can be adjusted across the plasma space. Further, the disclosed embodiments eliminate a stagnant region (i.e., the center of the workpiece) with a low gas flow rate to remove uniform reactants and by-products.

[0013] Figures 1A - 1C are diagrams showing embodiments of a plasma processing chamber of a plasma reactor having a multiphase rotating crossflow operation. Figure 1A is a diagram showing a top view of a plasma processing chamber having a multiphase rotating crossflow operation according to one embodiment. Figures 1B and 1C show cross-sectional views of the plasma processing chamber in different embodiments.

[0014] Referring to both FIGS. 1A and 1B, the plasma processing chamber 100A includes one or more chamber sidewalls 112 having a support surface 114 therein for holding a workpiece 116 (e.g., a semiconductor wafer) for processing. The plasma processing chamber 100 can be used to perform various processes on the workpiece 116, such as etching, deposition, surface treatment, material modification, etc., by distributing gas within the chamber. For example, the plasma processing chamber 100A can include, but is not limited to, a plasma etching chamber, a plasma enhanced chemical vapor deposition chamber, a physical vapor deposition chamber, an ion implantation chamber, an atomic layer deposition (ALD) chamber, an atomic layer etching (ALE) chamber, or other suitable vacuum processing chambers for manufacturing various devices.

[0015] In one illustrated embodiment, one or more sidewalls 112 surround a processing region 110 where the workpiece 116 (e.g., a wafer or substrate) is processed. In the illustrated example, the plasma processing chamber 100A is shown in an axisymmetric shape (e.g., cylindrical) that provides a single cylindrical sidewall 112. However, in other embodiments, the plasma processing chamber 100A may have any other shape, such as an elliptical shape, in which case there would still be a single sidewall 112, or it may have a shape such as a square or rectangle, in which case the plasma processing chamber 100A would have four sidewalls.

[0016] According to the disclosed embodiments, the plasma processing chamber 100 includes at least two gas injectors 118A and 118B (collectively referred to as gas injector 118) and at least two pump ports 120A and 120B (collectively referred to as pump port 120) located generally along one or more sidewalls 112. In one embodiment, the gas injector is formed within an opening that penetrates the liner of the sidewall 112. The plasma processing chamber 100A can be configured to use the gas injector 118 and the pump port 120 to rotate the gas flow 124 laterally across the workpiece 116 to provide a multiphase rotational cross-flow operation. In one embodiment, the multiphase rotational cross-flow operation includes at least a two-phase cycle, and may include a three-phase cycle, a four-phase cycle, etc. At this time, each phase gas is injected from one side of the plasma processing chamber 100A and pumped out generally from the opposite side. As used herein, the term "located generally along the sidewall(s)" is intended to explain that either the gas injector 118 and / or the pump port 120 may be located on the sidewall, in horizontal contact or adjacent to the sidewall, or located in the outer peripheral region of the chamber lid or the outer peripheral region of the chamber bottom.

[0017] The lateral rotation of the gas flow across the workpiece 116 improves the control of the gas velocity and pressure gradient, resulting in good process uniformity across the wafer and from wafer to wafer.

[0018] Referring to FIG. 1B, the plasma processing chamber 100A further includes a chamber lid 104 that covers the sidewall 112. The support pedestal 108 may include a support surface 114 on which the workpiece 116 is placed. In an embodiment, the support pedestal 108 and the support surface 114 are fixed and non-rotatable, and the workpiece 116 attached thereto does not rotate during processing. In an embodiment, the workpiece 116 is electrostatically attached to the support surface 114. In another embodiment, the support surface 114 is axially movable for plasma gap adjustment or wafer transfer. The processing region 110 within the plasma processing chamber 100A is defined by the area between the chamber lid 104, the support pedestal 108 (and the support surface 114), and the sidewall 112. There is a chamber floor 106 under the sidewall 112, and the chamber floor 106 is under the processing region 110. The support pedestal 108 is under the chamber lid 104 and above the chamber floor 106, and is surrounded by the sidewall 112. In an embodiment, the chamber lid 104 and the support surface 114 may be separated by a distance of about 25 mm to 200 mm. In an embodiment, the plasma processing chamber 100A is a parallel plate capacitively coupled plasma (CCP) process chamber with an upper electrode 105 above the workpiece 116. The bottom electrode is included at a position 113 within the support pedestal 108 under the support surface 114. In one embodiment, the upper electrode 105 is connected to an RF source having a frequency in the range of 40 - 200 MHz, including power in the range of 200 - 10,000 watts. In one embodiment, the lower electrode is connected to ground. Plasma is generated above the wafer and between the two electrodes. In one embodiment, the workpiece 116 is electrostatically clamped to the support surface 114 by one or more clamp electrodes within or under the support surface 114. In an embodiment, the workpiece 116 is connected to a bias electrode (e.g., at a low RF frequency in the range of 0.1 - 20 MHz) for additional plasma control during processing. The generated plasma can be pulsed during processing by pulsing the power to the first electrode 105.

[0019] In an embodiment, the workpiece 116 can include any substrate commonly used in a semiconductor manufacturing environment. For example, the workpiece can include a semiconductor wafer. In an embodiment, the semiconductor material can include, but is not limited to, silicon or a III-V semiconductor material. The semiconductor wafer can be, in some embodiments, a semiconductor-on-insulator (SOI) substrate. Typically, semiconductor wafers have standard dimensions (e.g., 200 mm, 300 mm, 450 mm, etc.). However, it should be understood that the workpiece 116 can have any dimensions. Embodiments can also include workpieces that include non-semiconductor materials such as glass or ceramic materials. In an embodiment, the workpiece 116 can include a circuit or other structure manufactured using semiconductor processing equipment. In yet another embodiment, the workpiece 116 can include a reticle or other lithography mask object.

[0020] Figures 1A and 1B illustrate an example of a two-phase cycle rotary crossflow operation. In a first phase, the gas injector 118A injects a first gas flow 124A in a first direction generally parallel to and across the surface of the workpiece 116, and has a pump port 120A on the opposite side along one or more sidewalls 112 generally opposite the gas injector 118A to pump out the gas flow 124A. In a second phase, the gas injector 118B injects a second gas flow 124B in a second direction generally parallel to and across the surface of the workpiece 116, and has a pump port 120B on the opposite side along one or more sidewalls 112 generally opposite the gas injector 118B to pump out the gas flow 124B. In an embodiment, the direction of the second gas flow 124B is different from the direction of the first gas flow 124A. In one embodiment, generally parallel means within about 0° to 15°, and generally opposite means within about 0° to 30°.

[0021] Thus, while the pump port 120A on the side opposite the gas injector 118A forms one gas injector - pump port pair, the pump port 120B on the side opposite the gas injector 118B forms a second gas injector - pump port pair. In one embodiment, each of the gas injectors 118A and 118B may include an array of individual gas injectors, as shown in FIG. 1A. In an alternative embodiment, each of the gas injectors 118A and 118B includes only a single vent gas injector. In some embodiments, gas injector 118A includes an array of individual gas injectors and gas injector 118B is a single vent gas injector, or vice versa.

[0022] As shown in FIG. 1A, along a horizontal plane generally parallel to the orientation of the workpiece 116, each gas injector - pump port pair (i.e., the pump port on the side opposite the gas injector) is symmetrically positioned along the sidewall 112 of the plasma processing chamber 100A. Any number of gas injectors 118 and pump ports 120 may be provided. Generally, one gas injector - pump port pair is offset from the position of an adjacent injector - pump port pair by an angle equal to 360 degrees divided by the number of injector - pump port pairs, so that the gas distribution can be ensured to be equal. For example, if there are two injector - pump port pairs, the injector - pump port pairs are offset from each other by 180° (360° / 2). If there are three injector - pump port pairs, the injector - pump port pairs are offset by 120° (FIGS. 2A and 2B). In some embodiments, as shown, the span of the gas injector is smaller than the span of the corresponding pump port. In other embodiments, the span of the gas injector is the same as the span of the corresponding pump port. In other embodiments, the span of the gas injector is larger than the span of the corresponding pump port. The gas can be injected from gas injector openings of various shape dimensions such as holes, slots, etc., and different gas injectors can have the same or different shape dimensions and sizes.

[0023] In some embodiments, the number of gas injectors 118 and pump ports 120 are equal, while in other embodiments, the number of gas injectors 118 and pump ports 120 may be different. In some embodiments, a single pump port is associated with a corresponding gas injector as depicted. In other embodiments, an array of pump ports is associated with corresponding gas injectors.

[0024] As shown in FIG. 1B, the gas injector 118 is positioned within an opening of the sidewall 112 within the processing region 110. For example, the opening may be disposed within a liner of the sidewall 112. In an embodiment, the opening of the sidewall 112 is in a vertical position between the chamber lid 104 and the substrate support pedestal 108. In the illustrated embodiment, the opening of the sidewall 112 is adjacent to the bottom of the chamber lid 104.

[0025] Along a vertical plane generally parallel to the orientation of the support pedestal 108, the position of the pump port 120 may be vertically offset from the position of the gas injector 118 by a distance approximately equal to the distance between the bottom of the chamber lid 104 and the top of the support pedestal 108 in one embodiment. In this embodiment, the pump port 120 may be located within a cavity between the sidewall 112 and the support pedestal 108 and above the chamber floor 106. In another embodiment, the pump port 120 may be located within an additional opening of the sidewall 112 anywhere between the chamber lid 104 and the chamber floor 106. In another embodiment, gas may be injected from the outer peripheral region of the chamber lid and / or pumped in from the outer peripheral region of the chamber bottom and flow over the workpiece processing region still substantially parallel to the workpiece.

[0026] As described above, the plasma processing chamber 100A of the disclosed embodiment generally injects gas in parallel and across the workpiece 116. This is in contrast to typical axially symmetric top-down gas flow injection from a "showerhead" electrode in a CCP source reactor, and also in contrast to radially outward / downward gas injection from a nozzle array near the central axis in an ICP or microwave source reactor. Additionally, in the embodiment, instead of a pump port or pumping plenum that is axially symmetrically located on the outer periphery of the workpiece, the gas is preferentially pumped out from the side of the workpiece generally opposite to the injection side.

[0027] In an embodiment, the gas flow 124 of each cross-flow phase can be switched on / off to control the rotation of the gas flow. In another embodiment, instead of switching the gas flow 124 on / off, a modulation function may be applied to the flow rate of the gas flow 124 from the gas injector 118 and / or the exit conductance (or pressure) generated by the pump port 120, approximating an open / closed state or ramping between states using a modulating function such as a sine wave. As shown in FIG. 1B, the flow rate of one or both of the first and second gas flows 124A and 124B can be modulated using one or more gas inlet valves 122A and 122B (e.g., piezoelectric valves) connected to the gas injectors 118A and 118B, respectively. In an embodiment, the gas inlet valves 122A and 122B are connected to one or more gas sources 126 such that a single type of gas, or a mixture of different types of gas, can be injected into the processing region 110 during each rotational phase. In one embodiment, a constant total gas flow is applied by the gas injector 118, and the gas flow can be smoothly and sequentially injected across different sides of the workpiece 116 in a complete cycle, and this can be repeated as needed.

[0028] In addition, in some embodiments, one or more of the pump ports 120 may be modulated. For example, the conductance (pressure) of the pump ports may be modulated using the individual pressure control valves 127A and 127B on the pump ports 120A and 120B. It is also shown that the pump ports 120A and 120B are connected to one or more pumps 132 for discharging gas. In the illustrated example, the pressure control valve 127A of the pump port 120A is in the closed position, while the pressure control valve 127B is shown in the open position for discharging the first gas stream 124A. The pressure control valves 127A and 127B can be operated smoothly between two states of conductance or pressure and then circulated in the same order as the gas injectors 118A and 118B. In one embodiment, the pressure control valves 127A and 127B include throttle valves.

[0029] The plasma chamber 100A can inject various types of process gases. Exemplary process gases can include the following: i) a dielectric etching gas containing one or more of C4F8, C4F6, C3F6, CH2F2, C3H2F4; ii) a deposition gas containing one or more of CH4, C2H2; iii) an additional gas for co-flow for either etching or deposition containing one or more of Ar, N2, O2, He, Kr, Xe, COS; iv) a semiconductor material etching and deposition gas containing one or more of SiCl4, SiCH2Cl2; v) a hydride-based deposition gas containing one or more of BH3, AlH3, GaH3, NH3; vi) an oxide material etching and deposition gas containing one or more of SiCl4, SiCH2Cl2, O2; and vii) an annealing gas containing one or more of NH3, N2, Ar.

[0030] In some embodiments, the plasma processing chamber 100A may further include sensors 131 and a system for highly sensitive and real-time monitoring of monitor process chamber conditions including gas flow, velocity, pressure, temperature, etc. Certain embodiments may include capacitive wall sensors, on-chip or off-chip thermal sensors, pressure sensors, and / or integrated sensors (capacitive sensors and thermal sensors) on a ceramic substrate, or a substrate such as a glass substrate, a silicon substrate, or a flexible substrate. In some embodiments, the sensors are distributed throughout the chamber to monitor chamber conditions at various locations and correlate them to overall process performance such as etch rate, etch non-uniformity, particle generation, process drift, pressure uniformity, etc. In one embodiment, a plurality or an array of pressure sensors may be distributed throughout the chamber to provide data regarding the gas flow (e.g., rotational speed, uniformity, velocity) during processing.

[0031] FIG. 1B further shows that the plasma processing chamber 100A may be connected to a controller 140, and this controller may be connected to a user interface 142. In some embodiments, the controller may be connected to the gas inlet valve 122, the pressure control valve 127, the gas source 126, the pump 132, and the sensors 131 to control the operation of the plasma processing chamber 100A. A user may set the process parameters and monitoring operations of the plasma processing chamber 100A from the user interface 142 through the controller 140.

[0032] The multi-phase architecture of the plasma processing chamber allows for many different configuration options. For example, FIG. 1C shows a cross-sectional view of a plasma processing chamber 100B in an embodiment that includes a top-down gas flow in addition to one or more pairs of gas injectors 118 and pump ports 120 that provide a side-to-side gas flow. In this embodiment, the chamber lid 104 can be configured with a showerhead plate 128 (the controller and UI of FIG. 1B are not shown for simplicity). The showerhead plate 128 can have a central manifold 129 and one or more outer manifolds 130 for distributing gas into the processing region 110 along with the gas distributed by the gas injectors 118A and 118B. Using the showerhead plate 128, additional gas can be introduced into the chamber with a vertical velocity component. However, the injection of gas from one side by the gas injector 118A and the pumping out to the other side of the workpiece 116 by the pump port 120B generally results in a horizontal component of the gas velocity across most of the workpiece 116. Similarly, the pump port 120 can be on the sidewall 112, or on the top or bottom surface of the chamber, but is generally on the opposite side of the injection side. Thus, while there can be a velocity component of the exhaust gas in the vertical direction, the gas velocity is generally horizontal and parallel to the workpiece 116 in the region above the workpiece 116.

[0033] Figures 2A-2C are diagrams showing a plasma processing chamber of a plasma reactor having a three-phase rotating cross-flow operation according to one embodiment. FIG. 2A is a schematic diagram of a perspective translucent view of a three-phase rotating cross-flow plasma processing chamber. FIG. 2B is a schematic diagram of a top view of a three-phase rotating cross-flow plasma processing chamber according to another embodiment.

[0034] Referring to FIG. 2A, a plasma processing chamber 200A having a three-phase rotating cross-flow operation is similar to the embodiment shown with respect to FIGS. 1A - 1C in that the chamber 200 includes sidewalls 212 that surround the workpiece 216. However, in addition to the two gas injectors 218A and 218B and the pump ports 220A and 220B on two opposite sides, the plasma processing chamber 200 further includes gas injectors 218C located generally on the opposite side of the sidewall 212 and opposite pump ports 220C for pumping out the gas flow. The pump port 220A opposite the gas injector 218A forms one gas injector - pump port pair. The pump port 220B opposite the gas injector 218B forms a second gas injector - pump port pair. And the pump port 220C opposite the gas injector 218C forms a third gas injector - pump port pair. (The gas injectors 218A - 218C are collectively referred to as the gas injector 218, and the pump ports 220A - 220C are collectively referred to as the pump ports 220).

[0035] In this embodiment, each of the gas injectors 218 is configured as a single vent within the sidewall 212 as shown. In one embodiment, as shown, the gas injectors 218 are arranged symmetrically with respect to the central axis of the plasma processing chamber 200, and the pump ports 220 are arranged symmetrically with respect to the central axis of the plasma processing chamber 200. In a three-phase rotating cross-flow embodiment including three injector - pump port pairs, the injector - pump port pairs are offset from each other by 120° (360° / 3). More specifically, the gas injectors 218 are located approximately 120° from each other, and the pump ports 220 are located 120° from each other. The pump ports 220 are laterally arranged between the spaced - apart gas injectors 218 and are vertically offset from the gas injectors 218.

[0036] FIG. 2B shows a top view of a plasma processing chamber 200B including an array of individual gas injectors, referred to as gas injector array 218D. Here, the individual gas injectors are dispersed around the outer periphery of sidewall 212. Also shown are three gas inlet valves 122A - 122C and three pressure control valves 127A - 127C, one for each pump port (see FIG. 1B). A set of smaller individual gas injectors (such as four injectors as shown) within gas injector array 218 can be modulated by a single one of gas inlet valves 122A - 122C to form gas flows in various directions across workpiece 216. The gas flow is then delivered by one of the pump ports controlled by the corresponding valves of pressure control valves 127A - 127C, generally opposite the regulating gas inlet valves 122A - 122C. In this case, in the embodiment, the span of the gas injectors is larger than the span of the corresponding pump ports, resulting in a somewhat converging flow (e.g., flow 299) into the relatively narrow pump ports.

[0037] FIG. 2C shows in more detail a timing diagram for a three - phase rotating cross - flow operation performed by plasma processing apparatus chamber 200B. The timing diagram assumes the presence of three gas inlet valves 122 (GV1, GV2, GV3) and three pressure control valves 127 (PV1, PV2, PV3). The X - axis represents time, and the Y - axis represents i) the percentage of open gas valves in the bottom row, the percentage of closed pump ports in the middle row, and the chamber pressure measured by a Baratron (manometer) in the top row.

[0038] The controller can be connected to the plasma processing chamber 200 and configured to control gas inlet valves 122A - 122C and pressure control valves 127A - 127C. The controller starts the first phase by fully opening GV1 to 100% and partially opening GV2 and GV3, for example, at about 2 - 5%. In the first phase, PV1 is opened while PV2 and PV3 are closed, and the chamber pressure is between 1 mT and 500 mT.

[0039] GV1 begins to close near the transition between the first and second phases, rotates the direction of the gas flow by opening GV2 fully to 100%, and starts the second phase. GV1 and GV3 are partially open at about 2 - 5%. During the second phase, the controller opens PV2 and keeps PV1 and PV3 closed. The chamber pressure can be maintained between 1 mT and 500 mT in some embodiments and between 10 mT and 200 mT in other embodiments.

[0040] Near the transition between the second and third phases, GV2 is ramped down and the direction of the gas flow is rotated by opening GV3 to 100%, starting the third phase. GV1 and GV2 are partially open at about 2 - 5%. During the third phase, the controller opens PV3 and keeps PV1 and PV2 closed. Thus, the three - phase cycle is completed and can be repeated as needed. As shown, a relatively constant chamber pressure is maintained in the three gas - flow phases. In one embodiment, by sequentially opening and closing GV1, GV2, and GV3, a rotational gas flow that can mimic the rotation of the wafer is effectively created. In one embodiment, a single full rotation of the gas flow is performed at a speed in the range of approximately 100 milliseconds to 10 seconds.

[0041] Various changes can occur between the phase and the cycle of the gas flow. That is, each parameter that controls the operation of the plasma processing chamber can change over the phase and the cycle. For example, the time to complete a full cycle may be the same or different over various cycles. The time to complete a certain phase may be the same or different within one cycle, and may be the same or different over various cycles. The rotational direction of the gas flow (e.g., clockwise, counterclockwise) may be the same or different within the phase of the cycle, may be discontinuous, and may be the same or different over the cycle. The speed of the gas flow may be the same or different within the phase of the cycle, and may be the same or different over the cycle. The opening rate (%) of the gas valve and the time the gas valve is open may be the same or different within the phase of the cycle, or may be the same or different over the entire cycle. The opening rate (%) of the pressure control valve and the time the pressure control valve is open may be the same or different within the phase of the cycle, or may be the same or different over the entire cycle. For example, in an embodiment, the rotation is performed at a certain speed for the first part of the process and then decelerated to a second speed for the second part of the process. In an embodiment, the rotation is performed at a certain speed for the first part of the process and then accelerated to a second speed for the second part of the process. In an embodiment, the rotation is fast in the first part of a single rotation cycle and slow in the second part of the rotation. In an embodiment, the rotation is slow in the first part of a single rotation cycle and accelerated in the second part of the rotation. By changing the rotation speed within a single cycle or between cycles, the non-uniformity of the process can be compensated. In other embodiments, the direction is changed between clockwise and counterclockwise within a cycle, between cycles, or between a set of cycles. Similarly, in an embodiment, the gas flow rate between a first phase, a second phase, and a third phase can be changed within a cycle, between cycles, or between a set of cycles.

[0042] Figure 2D shows a perspective view of the upper part of the chamber lid 104, with a gas supply system shown above it. In one embodiment, the gas supply system 225 includes an array of gas inlet valves 122, each of which is located above the outer periphery of the chamber lid 104 and is symmetrically arranged. In the illustrated embodiment, the gas supply system 225 includes six gas inlet valves 122, but the specific number can vary, for example, two or more. The upper side of each gas inlet valve 122 can be connected to a gas line assembly 250 arranged in a spoke and hub formation. Here, the hub is connected to the gas source 126 shown in FIGS. 1B and 1C. The bottom side of the gas inlet valve 122 can be connected to respective sets of the recirculating gas lines 252. Each set of the recirculating gas lines 252 can be connected to one or more gas injectors 118. In the particular illustrated embodiment, there are six sets of recirculating gas lines 252 each having four inlets connected to each gas injector 118, for a total of 24 inlets.

[0043] In an embodiment, the gas inlet valve 122 can include an analog variable conductance high-speed gas valve that allows for high-speed response without excessive pressure spikes that could lead to gas ignition or arc discharge or make it difficult to follow RF matching control. Specific examples of gas inlet valves include commercially available Swagelok eDE valves and Fujikin Piezo valves. The opening and closing time of the Swagelok eDE valve can be 15 - 20 milliseconds. Also, it has good air / vacuum sealing and a lifespan of 40 million cycles. The Fujikin Piezo valve has a proportional flow, an opening and closing time of 10 milliseconds, and can have a lifespan far exceeding 40 million cycles depending on usage. Both can supply a gas flow of up to 2.5 slm at an upstream pressure of 400 T.

[0044] Figure 2E shows a perspective cross-sectional view of the plasma chamber. This figure shows the connection between the recursive gas line 252 and the gas injector 118. Also, in one embodiment, the side wall 112 includes an outer side wall 112A and an inner side wall 112B (or liner), the gas injector is formed in the space between the outer side wall 112A and the inner side wall 112B, and it is shown that gas is injected from the recursive gas line 252 through the opening of the inner side wall 112B.

[0045] Figures 2F - 2H are perspective and cross-sectional views of the vacuum chamber in which the pump port 120 is formed. In the embodiment, the vacuum chamber 275 is under a dynamic vacuum controlled by a pump 132 (Figs. 1B and 1C). In one embodiment, the vacuum pressure can be in the range of 1 mT to 500 mT. In one embodiment, the chamber floor 106 includes an upper chamber floor 106A and a lower chamber floor 106B. The pump port 120 is formed in a cavity within the vacuum chamber 275 between the upper chamber floor 106A and the lower chamber floor 106B. The pump ports 120 are also symmetrically arranged about the support pedestal 108.

[0046] The actuator 277 is connected to a pressure control valve 127 to control each pump port 120. Figure 2H shows that the pump port 120 is opened and closed by one of the actuators 277 that raises and lowers the corresponding pressure control valve 229 within the cavity of each pump port 120. While Figure 2F shows that in one embodiment, the pressure control valve 229 can include a single integral body for sealing the associated port, Figure 2G shows that in another embodiment, the pressure control valve 229 can be divided into one or more adjacent sections (in this case two) each controlled by the corresponding actuator 277. In the embodiment, referring to Figure 2H, the left pressure control valve 127 is downward (open) and the right pressure control valve 127 is upward (closed). Figures 2F and 2G show that all the pressure control valves are in the closed position.

[0047] Figures 2I through 2K are diagrams showing perspective semi-transparent views of an exemplary inductively coupled plasma (ICP) chamber having a three-phase rotating crossflow according to one embodiment. As shown in FIG. 2I, the ICP plasma chamber 280 includes an electrode 282 in the form of a planar multi-spiral coil adjacent to a chamber lid (not shown). The electrode 282 includes an RF-driven post 286 and may include three ground terminals 284 along the maximum radius. FIG. 2J shows a gas injector 288 symmetrically disposed around the outer periphery of the chamber lid. In one embodiment, the gas injector 288 may include an inlet with a width of 60° having a space with a width of 60° therebetween. FIG. 2K shows a pump port 290 symmetrically disposed around the outer periphery of the bottom of the chamber, with each pump port located on the 180° opposite side of one of the gas injectors 288.

[0048] Figures 3A through 3F are diagrams showing top views of a plasma processing chamber having a four-phase rotating crossflow operation according to one embodiment. FIG. 3A shows a plasma processing chamber 300 that may have a square shape with four sidewalls 312. Each of the four sidewalls 312 includes one of four gas injector arrays 318A through 318D and one of four pump ports 320A through 320D on the opposite side.

[0049] FIG. 3B is a diagram for explaining the four-phase rotating crossflow operation. In the four-phase cycle, gas is injected from each of the four sidewalls 312 and pumped out from the opposite side. The conductance of each of the pump ports 320A through 320D can be modulated with a high-speed individual throttle valve. The first phase shows the first gas flow from left to right. Phase 2 shows a clockwise rotation to the second gas flow from top to bottom. Phase 3 shows a clockwise rotation to the third gas flow from right to left. And phase 4 shows a clockwise rotation to the fourth gas flow from bottom to top. In one embodiment, each phase may last from about 0.5 seconds to 2 seconds depending on the application.

[0050] Figures 3C and 3D are diagrams showing a four-phase rotational cross-flow operation with intentionally non-uniform central and edge gas injection by counter-side side-port pumping, according to a further aspect of the disclosed embodiments. In this embodiment, each individual gas injector in each of the gas injector arrays 318A-318D can be switched on / off or can have a modulated flow rate controlled by the gas inlet valve 122. Figure 3C shows an example of four phases of gas flow from the center to the edge. Here, in each phase, the gas flow injected from the central gas injector of each individual gas injector in the gas injector arrays 318A-318D has a greater flow rate relative to the edge gas injectors of the gas injector arrays 318A-318D. Figure 3D shows an example of four phases of gas flow from the edge to the center. The gas flow injected from the edge gas injectors of each individual gas injector in each of the gas injector arrays 318A-318D has a greater flow rate relative to the central gas injectors in the gas injector arrays 318A-318D. Such non-uniform central and edge gas injection of the disclosed embodiments is intentionally varied and can be controlled over time to control the uniformity of the workpiece process. In one embodiment, one or more relative central flows and edge flows of the gas injectors are changed within a cycle, between cycles, or between sets of cycles.

[0051] Figure 3E is a diagram showing one phase of a multi-phase (e.g., four-phase) rotational cross-flow operation, where at least a portion of the gas flow is diverted to the side of the workpiece rather than 100% cross-flow across the workpiece. In this extreme case, the opposite pump ports are closed while the side pump ports are open, minimizing gas flow and velocity across the center of the workpiece. This process can be used to control uniformity. In an embodiment, such a diverted gas flow as shown in Figure 3E is used for the entire process, or only a portion of the cycle, or one set or a smaller set of cycles in the process scheme. In an embodiment, the diverted gas flow is rotated around the chamber for one cycle or multiple cycles.

[0052] Figure 3F is a diagram of one phase of the multiphase cycle, and the gas flow is directed across the workpiece using pump points of a smaller width. As in Figure 3C, the gas flow from the central gas injector of each individual gas injector in the gas injector array has a greater flow rate relative to the gas injectors at the edge of the gas injector array, the opposite pump port is open, while the other ports are closed. In a further embodiment, due to the pump ports being narrower compared to the above embodiment, the gas flow will cover the central region of the workpiece. In this embodiment, for a typical 300 mm wafer chamber, the smaller pump ports can have a dimension of an arc length in the radial direction of the center line with a width of 3.5 inches × (1 / plurality) × 14 inches in length. On the other hand, the larger single pump port can have a dimension of an arc length in the radial direction of the center line with a width of 3.5 inches × 14 inches in length. Generally, the pump ports should have dimensions or sizes suitable for the flow conductance of the process application, while having an opening with a port width narrow enough to promote a uniform "cross-flow" on the wafer from the gas inlet side of the chamber to the pump port side.

[0053] Multiphase Rotating Cross-Flow for Etching Rate Uniformity Adjustment Using rotational modulation cross-flow can enable control of process uniformity from the outer peripheral boundary of the chamber. With this adjustment ability, without introducing discontinuities in the shape dimensions (i.e., gas injection holes), gas injection and / or pumping at the outer peripheral boundary and outside the high-density plasma region are used as control inputs to minimize drift due to etching, wear, or coating, or changes over time of the surface facing the exposed plasma, i.e., the electrode / showerhead with gas holes or gas nozzles, while enabling the formation of a uniform plasma.

[0054] The adjustment of the etching rate uniformity of the disclosed embodiments includes two aspects. As shown in FIG. 3G, the first aspect of adjusting the etching rate uniformity includes changing the gas flow injection angle across the workpiece.

[0055] The second aspect of adjusting the etching rate uniformity can be used alone or in combination with the first aspect and includes simultaneously injecting across the workpiece a process mixed gas and an independent gas injection (IGI) mixture, where the IGI mixture is used as a gas curtain that increases or decreases the area of the workpiece having a faster etching rate, as shown in FIGS. 3H-3K.

[0056] Referring to FIG. 3G, a four-phase rotating crossflow according to the first aspect of adjusting the etching rate uniformity by changing the gas flow injection angle across the workpiece is shown. In this example, the sidewalls are cylindrical and, except that the pump ports are not shown for clarity, the plasma processing chamber includes one or more gas injector arrays 318 that include individual gas injectors distributed around the outer perimeter of the sidewalls surrounding the workpiece 316, similar to the embodiment shown in FIG. 3A. In the example shown, three gas injector arrays 318 are shown. In phase 1, the gas flow 324 is injected from above toward the workpiece 316, as indicated by one set of arrows, and pumped out from the opposite side, as indicated by another set of arrows directed away from the workpiece 316.

[0057] In this embodiment, each individual gas injector in the gas injector array 318 can be switched on / off or has a modulated flow rate controlled by the gas inlet valve 122 (FIG. 2B), and changes the gas flow injection angle across the workpiece 316. The controller 140 (FIG. 1B) can be configured to change the gas flow injection angle phase by phase by changing the number of adjacent individual gas injectors used to inject the gas flow 324. Before, during, or after the gas flow injection, the controller 140 can select between a wide set of adjacent individual gas injectors or a narrow set of adjacent individual gas injectors. Selecting a wide set of adjacent individual gas injectors (i.e., a set with a large number of injectors) increases the injection angle of the gas flow. Selecting a narrow set of adjacent individual gas injectors (i.e., a set with a small number of injectors) decreases the gas flow injection angle. Further, the set of adjacent gas injectors can include individual gas injectors from a single gas injector array 318 or individual gas injectors from adjacent gas injector arrays 318, as shown.

[0058] In the example of FIG. 3G, the injection angle of the gas flow 316 decreases from one phase to the next. The gas flow injection angle in the first phase is relatively wide, for example, about 116°. The gas flow injection angle in the second phase decreases to about 79°. The gas flow injection angle in the third phase decreases to about 42°. And the injection angle of the gas flow in the fourth phase decreases to a relatively narrow injection angle of 6°.

[0059] By increasing or decreasing the injection angle of the gas flow from one phase to the next, phases with different flow rates can be provided, and the uniformity of the etching rate on the workpiece changes. Such non-uniform gas flow injection angles in the disclosed embodiments can be intentionally varied and controlled over time to control the uniformity of the workpiece process. As an example, by reducing the gas flow injection angle, the uniformity of the etching rate can be enhanced. In one embodiment, one or more gas flow injection angles of the gas injector can be changed during one phase or cycle, between phases or cycles, or between a set of cycles.

[0060] Referring to FIGS. 3H-3K, a diagram is shown depicting one phase of a multiphase cycle in which both a process mixed gas and an independent gas injection (IGI) mixture are injected, in accordance with a second aspect of etching rate uniformity adjustment. Similar to the embodiment shown in FIG. 3G, the plasma processing chamber includes one or more gas injector arrays 318 that include individual gas injectors distributed around the outer periphery of the sidewall surrounding the workpiece 316. A controller 140 (shown in FIG. 1B) can be configured to control the plasma processing chamber during etching application. Here, the etching rate uniformity and critical dimension uniformity (CDU) of the material on the workpiece 316 are adjusted or controlled by using the gas injector array 318 to inject one or more gas flows in a direction generally parallel to the surface of the workpiece 316 and across the surface of the workpiece 316.

[0061] Each crossflow phase can inject a gas flow that includes a process mixed gas 324A or 324B, such as an etchant gas, and an IGI mixture 326A or 326B. According to the disclosed embodiments, the IGI mixture 326A is used as a gas curtain that acts as a dilution booster for the process mixed gas 324A, and the IGI mixture 326B is used as a gas curtain that acts as an etchant concentration ratio booster for the process mixed gas 324B.

[0062] Figures 3H and 3I show the use of the IGI mixture 326A as a gas curtain acting as a dilution booster for the process mixed gas 324 to reduce the area on the workpiece 316 having the fastest etching rate. Figure 3H shows that during operation, a first gas stream containing the process mixed gas 324A is injected across the workpiece 316 from a subset of the individual gas injectors and pumped out from the opposite side. At the same time, a second gas stream containing the IGI mixture 326A is injected across the workpiece 316 from at least a portion of the remaining individual gas injectors. In one example, the first gas stream or the process mixed gas 324A may include a baseline gas, and the second gas stream or the IGI mixture 326A may include a krypton (Kr) gas curtain. All or just some of the individual gas injectors not used to inject the process mixed gas 324A may be used to inject the IGI mixture 326A. Also, in an alternative embodiment, the process mixed gas and the IGI mixture may be injected at overlapping times rather than simultaneously.

[0063] Figure 3I shows that when the process mixed gas 324A includes an etchant gas, the etching rate of the workpiece 316 is different because the process mixed gas 324A concentrates only on a portion of the workpiece 316. The fastest etching rate occurs in the area 328A along the edge of the workpiece 316 adjacent to the gas flow source, while the lowest etching rate occurs in the area 330A along the remaining edge area of the workpiece 316 covered by the IGI mixture 326A. Since the IGI mixture 326B dilutes the process mixed gas 324A, the diluted etchant reduces the area 328A of the workpiece having the fastest etching rate. Thus, the radial uniformity of the workpiece 316 becomes an edge slope profile. By injecting the IGI mixture 326B and changing the number of gas injectors used to increase or decrease the dilution effect of the IGI mixture 326B, the area 328A of the faster etching rate can be further decreased or increased, respectively.

[0064] Figure 3J shows the use of the IGI mixture 326B as a gas curtain that acts as an etchant concentration booster for the process mixture gas 324B to increase the area of the workpiece having the fastest etching rate. During operation, a first gas stream containing the process mixture gas 324B is injected across the workpiece 316 from a subset of the individual gas injectors and pumped out from the opposite side. At the same time, a second gas stream containing the IGI mixture 326B is injected across the workpiece 316 from the remaining ones of the individual gas injectors. All or only some of the remaining individual gas injectors can be used to inject the IGI mixture 326B. As an example, while the first gas stream or the process mixture gas 324B can include a baseline gas, the second gas stream or the IGI mixture gas 326B can include a C3F6 / O2 gas curtain.

[0065] Figure 3K shows that the fastest etching rate 328B occurs in the area 328B along the edge of the workpiece 316 adjacent to the gas flow source, while the lowest etching rate occurs in the area 330B along the remaining edge of the workpiece 316 covered by the IGI mixture 326B. Since the IGI mixture 326B concentrates the process mixture gas 324B, additional etchant increases the area 328B of the workpiece 316 having the fastest etching rate. Thus, the radial uniformity becomes a high-speed profile at the edge.

[0066] Figures 3H - 3K show that the etchant concentration can be increased or decreased to increase or decrease the area of the fastest etching rate, respectively, by changing the gas flow injection angle of the first gas stream or the process mixture gases 324A or 324B and / or the gas flow injection angle of the second gas stream or the IGI mixture gases 330A and 330B (e.g., by changing the number of gas injectors used). Figures 3H - 3K show that the process mixture gas and the IGI mixture are injected during a single phase without rotation.

[0067] FIG. 3L is a diagram showing the results of multiple gas flow phases or rotations to achieve radial etching rate uniformity on the workpiece. By repeating the simultaneous injection of the process mixed gas and the IGI mixture during multiple gas flow phases or rotations (e.g., three 120° rotations), the difference between the faster etching rate and the slower etching rate can, as shown, achieve radial etching rate uniformity on the workpiece.

[0068] In an embodiment, the process mixed gases 324A and 324B may include an etchant gas or a deposition gas. Examples of etchant gases may include C X F Y (such as C3F6, C4F6, C4F8, C5F8, etc.), C X H Y F Z (such as CHF3, CH2F2, C3H2F4, etc.), fluorine-rich gases (such as NF3, SF6, etc.), C X H Y (such as CH4, C2H2, etc.).

[0069] The process mixed gases 324A and 324B or the IGI mixtures 326A and 326B may include a diluent, an inert gas, or a cleaning gas. Examples of diluent gases may include He, Ne, Ar, Kr, Rn, N, and Xe. Examples of cleaning gases may include O X , N2, SF x , NF xIt may include the like. As is well known in the technical field of plasma etching, generally, the higher the carbon-to-fluorine ratio and the hydrogen-to-fluorine ratio, the higher the surface deposition probability, and the lower the ratio, the higher the surface etching probability tends to be. That is, a gas (such as CH3F) with a high carbon-to-fluorine ratio (e.g., 1 / 1) or a high hydrogen / fluorine ratio (e.g., 3 / 1) generally acts as a more deposition gas, while a gas (such as CHF3) with a low carbon-to-fluorine ratio (e.g., 1 / 3) or a low hydrogen / fluorine ratio (e.g., 1 / 3) acts as a more etching gas. The dielectric etching / deposition gas can act as an etchant gas or a deposition (polymerization) gas depending on the plasma (the other gases present and their concentrations, the electron density and electron energy distribution in the bulk plasma, the ion energy distribution at the surface) and the surface conditions (temperature and material composition).

[0070] The advantages of these aspects of the disclosed embodiments include the following. (1) The cross-flow gas flow has a horizontal flow velocity that is at least twice as fast along the edge of the workpiece and up to five times faster at the center than when using a showerhead. (2) The cross-flow design can maintain a Peclet number greater than 1 at any location on the workpiece at all times. That is, advective transport can minimize the re-dissociation under the plasma. (3) In the cross-flow operation, the overall density of the fluorocarbon and etching by-products is more uniform, so the uniformity of the plasma (sheath) is improved.

[0071] Figures 4A to 4C are diagrams showing top views of the rotating gas flow in a three-phase rotating cross-flow plotted against time every 60°. The arrows are vectors indicating the magnitude of the velocity, and the contour lines represent the pressure gradient. Snapshots of the gas flow at 0°, 60°, 120°, 180°, 240°, and 300° are shown. The graph in Figure 4C shows that the pressures of the gas injector and the pump port are relatively constant over time and across three phases. The exemplary processes shown in Figures 4A to 4C can be used individually or, more likely, in combination over repeated cycles to maximize the uniformity of the process.

[0072] Reactive Ion Etching As an exemplary application, the plasma processing chamber can be used to perform precise reactive ion etching during semiconductor manufacturing.

[0073] FIG. 5 shows a cross-sectional view of a portion of a wafer including a stacked memory device processed by a plasma processing chamber having a rotating gas crossflow according to one embodiment. In one embodiment, an intermediate structure of a stacked memory device during manufacturing is shown. In one embodiment, the intermediate structure 400 comprises a 3D-NAND structure and includes a substrate 402, an alternating layer stack 404 on the substrate 402, an interlayer dielectric (ILD) layer 406 on the alternating layer stack 404, and a mask layer 408 on the ILD layer 406. The alternating layer stack 404 can include alternately arranged insulator layers 404A and 404B (e.g., silicon nitride, silicon oxide, etc.). Examples of the ILD layer 406 can include spin-on glass, SOC, amorphous carbon (a-C), amorphous silicon (a-Si), metal hard mask (W, WBC, etc.), and SiON.

[0074] The mask layer 408 can have a pattern that defines the pattern of the integrated circuit and guides the deposition or removal of material from the wafer in subsequent patterning steps. In this example, reactive ion etching is performed by a plasma processing chamber to remove material between some of the openings in the mask layer 408 to form an opening 410 that reaches the substrate 402 through the ILD layer 406 and the alternating layer stack 404. Here, the intersection of the opening 410 and the metal layer 404A can ultimately form a memory cell. The gas flow injected by the plasma processing chamber (described above) can be customized to control both the uniformity of the etching depth and the uniformity of the aspect ratio (depth to width) of the opening 410. In one embodiment, one or more of the openings 410 can be etched to have a first aspect ratio through the ILD layer 406 and a second aspect ratio through the alternating layer stack 404. In an embodiment, one or more of the openings 410 can have a varying aspect ratio, referred to as bowing, through the alternating layer stack 404, as shown. In one embodiment, the opening 410 can be etched to have a high aspect ratio greater than 8-1, 9-1, or 10-1. In embodiments, one or more of the openings 410 can also have a varying etching depth.

[0075] In embodiments, 3D-NAND ion etching applications can include the pillar etching, slit etching, peri contact etch, staircase contact etch, cell contact-1 etch, and cell contact-1 etch described above. In embodiments, the aspect ratio, etching depth, and bowing characteristics can be parameters monitored by a machine learning model, as described below.

[0076] Use of a Machine Learning (ML) Model to Control a Plasma Processing Chamber Having a Multiphase Rotating Crossflow To configure the plasma processing chamber described above to achieve a desired result on a workpiece (e.g., a wafer), a process recipe is required that involves a complex combination of many different individually controllable process parameters (i.e., knobs). Examples include gas flow mixtures, gas pressure (in millitorr), gas flow lamp open time (in milliseconds), gas flow time (in milliseconds), gas flow lamp close time (in milliseconds), etc.

[0077] To develop a high-volume manufacturing (HVM) process recipe, the process engineer relies on their experience and expertise to identify a baseline recipe that can provide a rough approximation of the desired result on the wafer. Next, a design of experiments (DoE) that depends on the processing of one set of wafers (or coupons) is generated around the baseline recipe to identify how the knobs interact. To further refine the baseline recipe, the results of the DoE can be interpreted by the process engineer. Additionally, additional DoEs may be performed to converge on the desired result on the wafer. Such an iterative process requires time and resources.

[0078] Furthermore, once the final processing recipe is developed, chamber drift can occur during repeated processing of different wafers, which may cause the results on the wafers to change. Chamber drift can be the result of erosion of worn parts of the chamber, degradation of components (sensors, lamps, etc.), deposition of by-product films on the surface, etc. Therefore, even after a large-scale recipe development process, further adjustments are required.

[0079] As a result, recipe development and chamber baselining require time and resources. In particular, the process space available to adjust and optimize a given process is very large, and it is virtually impossible to empirically explore the entire process space within any reasonable time frame. Additionally, due to the interaction between processing parameters and the effects they have on the performance of the process, it is extremely difficult to predict the combined effects of simultaneous changes in multiple processing parameters by manually scanning one processing parameter at a time.

[0080] A second aspect of the disclosed embodiments includes a semiconductor manufacturing tool that utilizes one or more machine learning (ML) models to control a plasma processing chamber having a multiphase rotating crossflow. The ML model can be used for developing a process recipe and / or processing a device or workpiece. The ML model can couple the input processing parameters to the output of the device.

[0081] In an embodiment, the method of controlling the process includes querying the ML model to control the timing of the rotation of the gas flow. In an embodiment, the method for developing a semiconductor manufacturing process recipe includes selecting one or more device results and querying the ML model to obtain a recommendation of a process recipe suitable for obtaining the device results when processed by a plasma processing chamber having a multiphase rotating crossflow. This can be referred to as feed-forward process tuning. In an embodiment, the method can further include performing a design of experiments (DoE) on a set of wafers to verify the process recipe recommended by the ML model. The measurements of the DoE can be obtained for feedback process tuning and can be used to change the process recipe for future wafers.

[0082] Further, the ML model can be updated when the performance on the tool becomes available during wafer processing in the chamber, and then the process recommendations can be updated or the recipe can be actively changed. This can be referred to as "on the fly" or real-time process tuning.

[0083] Recipe changes can include modifications to the recipe within a step, such as increasing the rotation frequency of the gas flow when etching the upper part of the wafer and decreasing the rotation frequency when reaching the lower part, or vice versa. Another example is that an updated machine learning model modifies input parameters within a single rotation range, such as slightly varying the etching depth at the beginning and end of the gas flow rotation when processing the stacked memory device of FIG. 5. The updated ML model enables accurate tracking of chamber drift and allows for modification of the process recipe without using a large-scale DoE of physical wafers or relying solely on the experience and knowledge of process engineers.

[0084] Accordingly, the embodiments disclosed herein utilize the use of an ML model to query the entire process space without the need to process physical wafers in a large-scale design of experiments (DoE). Accordingly, the time and resources spent on recipe development can be significantly reduced.

[0085] The ML model can be a model of the process space generated from a combination of a statistical model and a physical model. As used herein, "process space" may refer to a multi-dimensional process space that maps process parameters to one or more device results on a wafer. Process parameters, sometimes called knobs, are variables that can be controlled to control the process. For example, the knob or process parameter can be temperature, RF source power, bias power, gas pressure (mTorr), gas flow ramp open time (msec), gas flow time (msec), gas flow ramp close time (msec), gas flow fraction at various gas injectors, gas composition at various injectors, gas flow rate towards various injectors, gas flow rotation frequency, gas flow composition frequency, gas flow velocity / speed (pressure gradient), gas flow direction, gas rotation phase, electron / plasma density, plasma density gradient, electron temperature, ion current density, plasma potential, sheath electric field, potential, sheath electric field tilt angle, sheath electric field z-component, mass fraction, flux, any combination of ion current density to the workpiece, but is not limited thereto.

[0086] The results of the device may refer to measurable characteristics of features on the processed wafer. For example, the results of a selected device may include any combination of feature profile, layer thickness, thickness uniformity, layer material composition, composition uniformity, porosity, film stress, process uniformity across a chamber in the facility (e.g., chamber alignment), uniformity between wafers, uniformity between different wafer lots, etc. During an etching process, the results of a selected device may further include any combination of etching rate, etch or uniformity center-to-edge, azimuthal uniformity of etching rate, uniformity of etching features (generally described by top-to-bottom critical dimension (CD)), tilt, bow, and mask remainder. That is, the results of the device are not limited to the results on a single wafer. Each point in the process space can be a set of process parameter values and a display of one or more results of the device generated by the set of process parameters.

[0087] In embodiments, the statistical model of the ML model can be constructed using a DoE of actual wafers to populate a portion of the process space. Next, an algorithm can be used to extrapolate the remaining portion of the process space. Physical models are based on real-world physical and chemical interactions occurring within the processing chamber. To generate a physical model, simulations of physical and chemical interactions within the processing chamber over a range of various process parameters can be used. In embodiments, the physical model is integrated with the statistical model to provide the ML model. For example, the physical model can be used to fill in any gaps in the statistical model and / or to verify the extrapolated data points.

[0088] Next, referring to FIG. 6, a block diagram of a processing tool 600 that utilizes an ML model according to an embodiment is shown. The processing tool 600 includes tool hardware 640 corresponding to the plasma processing chamber described above, a machine learning model server 620, a front-end server 660, and a control server 650.

[0089] In an embodiment, the ML model server 620 may include a statistical model 625 and a physical model 627. The statistical model 625 and the physical model 627 may be communicatively connected to a database 630 for storing input data (e.g., sensor data, model data, metrology data, etc.) used to construct and / or update the statistical model 625 and the physical model 627.

[0090] In an embodiment, the statistical model 625 is generated from a physical DoE and may provide an extended process space model using interpolation. The physical wafers being processed may be used to map process parameters to specific device results. The physical DoE may also be used to identify interactions between different process parameters. After data (such as metrology data, sensor data, process parameter data, etc.) for the physical wafers is provided, interpolation is used to fill in the gaps in the process space. In an embodiment, data such as metrology data may be obtained using an external tool communicatively connected to the ML model server 620 by a data link (e.g., a wired or wireless data link). The algorithms may include, but are not limited to, neural networks, deep learning, or other known techniques used for regression analysis (e.g., linear, partial least squares, Gaussian, polynomial, convolutional neural networks for regression, regression trees, etc.).

[0091] In an embodiment, the statistical model 625 can be provided as a module that is sold or licensed for use in combination with a processing tool. That is, the physical DoE for the statistical model 625 can be performed by the manufacturer of the processing tool. In other embodiments, the statistical model 625 can be generated by performing a physical DoE on-site. In yet another embodiment, a general statistical model 625 can be provided by the tool manufacturer, and a subsequent physical DoE can be performed on-site to provide calibration of the statistical model 625 to more faithfully model a particular processing tool under investigation.

[0092] In an embodiment, the physical model 627 can be generated using real-world physics and chemistry relationships. For example, physical and chemical equations regarding various interactions within the processing chamber can be used to construct the physical model. The physical model 627 can also utilize chamber shape dimensions or other chamber configurations to enhance the accuracy of the physical model 627. The physical model 627 can be the result of a simulation of physical and chemical interactions within the processing tool across multiple different processing parameters. The physical model 627 can be a module that is sold or licensed for use in combination with a processing tool.

[0093] In an embodiment, the physical model 627 and the statistical model 625 can be mutually referable (as indicated by the arrows). The mutual reference of the two models 627 and 625 allows for the verification of each model and the filling of any gaps in the individual models. In an embodiment, the physical model 627 and the statistical model 625 can be combined to provide a more robust ML model.

[0094] As shown, the ML model server 620 can be integrated with the processing tool 600. For example, the ML model server 620 can be communicatively connected to the front-end server 660 via a network connection, as indicated by the arrow. However, in other embodiments, the ML model server 620 can be external to the processing tool 600. For example, the ML model server 620 can be communicatively connected to the processing tool 600 through an external network or the like.

[0095] In an embodiment, the front - end server 660 may include a user interface 665 for the ML model server 620. The user interface 665 provides an interface for a process engineer to utilize ML modeling, which is intended to perform various operations such as recipe development or chamber - based lining. In one embodiment, the user interface 665 may correspond to the user interface 142 of FIG. 1B.

[0096] The control server 650 may include a smart monitoring and control block 655. The smart monitoring and control block 655 may include modules for providing diagnosis and other monitoring of the processing tool 600. The modules may include, but are not limited to, health checks, sensor drift, defect recovery, leak detection, etc. The smart monitoring and control block 655 may receive as input data from various sensors implemented in the tool hardware 640. The sensors may include standard sensors 647 that are commonly present in the semiconductor manufacturing tool 600 to enable the operation of the tool 600. The sensors may also include modeling sensors 645 added within the tool 600. The modeling sensors 645 provide additional information necessary for building highly detailed ML models. For example, the modeling sensors may include virtual sensors and / or eyewitness sensors. Virtual sensors may perform interpolation and / or extrapolation to utilize data obtained from two or more physical sensors and provide additional sensor data that cannot be obtained by physical sensors alone. In a particular example, a virtual sensor may utilize an upstream pressure sensor and a downstream pressure sensor to calculate the flow rate through a part of the processing tool such as a gas cartridge. Generally, the modeling sensors may include, but are not limited to, any type of sensors such as pressure sensors, temperature sensors, gas concentration sensors, etc. In an embodiment, the smart monitoring and control block 655 may provide data used by the ML model server 620. In other embodiments, the output data from various modeling sensors 645 may be provided directly to the ML model server 620. In one embodiment, the control server 650 may correspond to the controller 140 of FIG. 1B.

[0097] Next, referring to FIG. 7A, a flowchart showing a process for generating an ML model according to an embodiment is shown. In the embodiment, the input from the modeling DoE 715 is input to the statistical model engine 724. The modeling DoE 715 may include the processing of a number of physical wafers. DoE 715 may include various data sources supplied to the statistical model engine 724. For example, measurement data 716 obtained during or after wafer processing may be provided to the statistical model engine 724. Further, sensor data 217 from sensors within the processing tool may be provided to the statistical model engine 724. Process parameters 718 (i.e., the values of various process parameters during wafer processing) may also be provided to the statistical model engine 724.

[0098] In the embodiment, the statistical model engine 724 may be implemented as hardware and / or software suitable for analyzing various data sources and outputting a statistical model 725. The statistical model engine 724 may utilize machine learning based on a neural network, or any other known technique used in regression analysis (e.g., linear, partial least squares, Gaussian, polynomial, convolutional neural network for regression, regression trace, etc.) to interpolate a larger process space than that available from physical DoE data alone.

[0099] In the embodiment, a physical model engine 726 is used to generate a physical model 727. In the embodiment, the physical model engine 726 may be implemented as hardware and / or software. The physical model engine 726 takes as input the chamber configuration and real-world physical and chemical equations. The physical model engine 726 may perform simulations of physical and chemical interactions within the processing tool across a plurality of different process parameters to construct the physical model 727. Thus, changes to the process parameters that modify the physical and / or chemical reactions within the processing tool may be mapped to the expected device results.

[0100] In an embodiment, the statistical model 725 and the physical model 727 are used as inputs for generating the ML model 728. For example, the statistical model 725 and the physical model 727 can be inputs to the ML model engine 729. The ML model engine 729 processes the physical model 727 and the statistical model 725 and outputs the ML model 728. In some embodiments, the physical model 727 can be used to derive some physical measurements that cannot be measured. The output of the physical model 727 can be considered as an additional input to the statistical model. In such a situation, the ML model engine 729 adds the information from the physical model 727 to the statistical model 725 to provide the ML model 728. Thus, the ML model 728 allows the two models 725 and 727 to be used for verifying individual points in the process space and provides a more complete process space that can be individually adjusted to a given processing tool. However, in some embodiments, the physical model 727 and the statistical model 725 can be standalone models depending on the output. That is, in some embodiments, the statistical model 725 and the physical model 727 may not be merged into the ML model.

[0101] In an embodiment, the ML model can also be regarded as another instance of the statistical model 725. For example, in FIG. 7B, the physical model 727 output by the physical model engine 726 can be used as an input to the statistical model engine 724. Thus, the statistical model engine 724 has additional inputs for generating the statistical model 725 that includes information from the physical model 727. In particular, the statistical model engine 724 may already contain data from the physical model 727, and it may not be necessary to use the ML model engine to generate the ML model in all embodiments.

[0102] Next, referring to FIG. 8, a flowchart showing a process 870 for developing a process recipe using an ML model according to an embodiment is shown. The target process recipe is a process recipe having a set of process parameters that result in desired device results on a wafer. In an embodiment, process 870 may begin with step 871 that includes determining the desired device results. In an embodiment, the device results may be in wafer device dimensions, material compositions, etc. For example, the device results may include the thickness of the layers of the stacked memory device shown in FIG. 5, the thickness uniformity across the wafer, the material composition of the layers, or the material composition uniformity.

[0103] In an embodiment, process 870 may continue with step 872 that includes querying the ML model to select a set of process parameters. In an embodiment, the ML model may be a model of the process space generated from a combination of a statistical model and a physical model. The statistical model may be generated using the actual wafer DoE as described above. The physical model may be based on real-world physics and chemistry equations. For example, the physical model may be generated from simulations of physical and chemical interactions within a processing tool across a plurality of different process parameters. In an embodiment, the ML model may cover the entire process space available to the processing tool.

[0104] The ML model enables identification of a stable process recipe without relying solely on the experience and knowledge of the process engineer. Instead, a baseline recipe expected to result in device results that closely match the target device results can be selected from the process space of the ML model.

[0105] In an embodiment, process 870 may continue to step 873, which includes performing a small DoE to verify the model recommendation. Since the accuracy of the ML model is high, only a small DoE (e.g., wafers of 20 or less) may be needed to verify the model's recommendation. In an embodiment, the DoE may be designed by a process engineer. In another embodiment, the DoE may be designed using the ML model.

[0106] In an embodiment, process 870 may continue in step 874, which includes measuring the DoE wafer results with one or more metrology tools. The metrology data can be used to verify that the results of the target devices were achieved on the wafer.

[0107] In an embodiment, process 870 may continue in step 875, which includes determining whether the desired device results have been achieved. If the desired device results are obtained, the process proceeds to step 876 and the process is complete. If the desired results are not obtained, the process may repeat step 872 or provide feedback to step 872. In an embodiment, data from the small DoE may be fed back to the ML model to update the ML model. For example, if the process repeatedly returns to step 872, the next DoE executed in step 873 may be designed based on knowledge of where the ML model is lacking (e.g., for a particular process or plasma chamber) based on additional knowledge learned from the DoE executed in the previous cycle. The updated ML model may then be queried to provide a second baseline recipe. In this way, even if the first iteration is unsuccessful, the process can still quickly converge to an appropriate recipe without requiring a large-scale DoE and wasting resources.

[0108] Next, referring to FIG. 9, a flowchart showing a process 980 for baselining a processing tool according to an embodiment is shown. In an embodiment, the baseline process may be useful for considering chamber drift during wafer processing within the processing tool. In an embodiment, the baseline process may be performed at any desired frequency. For example, process 980 may be performed for each lot, for each planned maintenance (PM) event, or when the device results of the processed wafers are outside a specified range.

[0109] In an embodiment, process 980 may begin with step 981 that includes performing a limited DoE of wafers using external measurements to baseline chamber performance. In an embodiment, the limited DoE may include 20 or fewer wafers. The limited DoE may utilize a process recipe recorded as a baseline. The external measurements may include any measurements suitable for determining the device results of the processed wafers. For example, in the case of an oxidation process, ellipsometry may be used to investigate the film thickness and thickness uniformity across the wafer.

[0110] In an embodiment, process 980 may continue with step 982 that includes adding the device results and other measurement data to an ML model. The additional data added to the ML model may be referred to as a calibration data set. The calibration data set is used to update the ML model so that the ML model more accurately reflects the current conditions of the processing tool. For example, process 580 may include step 583 that includes adjusting the model predictions to account for specific chamber conditions. That is, the process space of the ML model is updated to more closely align with the conditions of the processing tool under investigation.

[0111] In an embodiment, the ML model can be a model of a process space generated from a combination of a statistical model and a physical model. The statistical model can be generated using the DoE of an actual wafer as described above. The physical model may be based on real-world physics and chemical equations. For example, the physical model can be generated from a simulation of physical and chemical interactions within a processing tool, such as a plasma processing chamber having a rotational crossflow across a plurality of different process parameters. In an embodiment, the ML model can cover the entire process space available to the processing tool.

[0112] In an embodiment, process 980 can continue in step 984, which includes predicting process parameters optimized to achieve the desired wafer results for the wafers being processed in the chamber. The optimized process parameters can be selected after the ML model is updated to include a calibration data set. Thus, the new process recipe provides wafer parameters that result in wafer results more precisely aligned with the target values, despite changes in the chamber conditions. In this way, chamber drift can be monitored and accounted for to maintain a tight process window and improve uniformity, repeatability, and yield. Further, since the process recipe can be accurately adjusted considering chamber drift, unplanned downtime of the tool is reduced. Additionally, if PM occurs, process 980 can be implemented to reduce the recovery time and increase the utilization of the tool.

[0113] In an embodiment, the ML model can further be used to provide continuous (or nearly continuous) modification of the process recipe considering chamber drift. For example, wafer and process data obtained during the processing of device wafers can be acquired and used to update the ML model. That is, a dedicated DoE may not be required to provide a calibration data set. Wafer data from device wafers can be acquired for all wafers or for a subset of the wafers being processed.

[0114] Such embodiments may include providing an ML model for a processing tool. The ML model may include a statistical model and a physical model similar to the ML models described above. In an embodiment, the process may begin with a recipe being executed within the processing tool to process a first wafer. After processing the first wafer, wafer data from the first wafer and process data from the processing tool regarding the execution of the recipe may be obtained. In an embodiment, the wafer data may include, but is not limited to, measurement data such as thickness, thickness uniformity, and profile. In an embodiment, the process data may include data obtained from sensors within the processing tool and / or tool configuration information. In an embodiment, the wafer data and the process data are provided to the ML model to generate an updated ML model. In an embodiment, the updated ML model is used to generate a modified recipe that takes into account chamber drift within the processing tool. The embodiment may then include executing the modified recipe within the processing tool to process a second wafer. Although processing a single first wafer has been described above, it should be understood that multiple first wafers may be processed before the updated ML model is generated. In such embodiments, multiple sets of wafer data and process data may be used to generate the updated ML model.

[0115] FIG. 10 shows a diagrammatic representation of a machine in an exemplary form of a computer system 1000 within which a set of instructions for causing a machine to execute any one or more of the methods described herein can be executed. In alternative embodiments, the machine can be coupled (e.g., network-connected) to other machines in a local area network (LAN), intranet, extranet, or the Internet. The machine can operate in the role of a server or a client machine in a client-server network environment, or as a peer machine in a peer-to-peer (or distributed) network environment. The machine can be a personal computer (PC), tablet PC, set-top box (STB), web appliance, server, network router, switch or bridge, or any machine capable of executing a set (sequential or otherwise) of instructions that specify actions to be taken by that machine. Further, although only a single machine is illustrated, the term “machine” shall also be construed to include any collection of machines (such as computers, etc.) that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methods described herein.

[0116] The exemplary computer system 1000 includes a processor 1002, main memory 1004 (e.g., dynamic random access memory (DRAM) such as read only memory (ROM), flash memory, synchronous DRAM (SDRAM), or Rambus DRAM (RDRAM)), static memory 1006 (e.g., flash memory, static random access memory (SRAM), MRAM, etc.), and secondary storage device 1018 (such as a data storage device), which communicate with each other via bus 1030.

[0117] Processor 1002 represents one or more general-purpose processing devices such as a microprocessor or a central processing unit. More specifically, processor 1002 can be a complex instruction set computing (CISC) microprocessor, a reduced instruction set computing (RISC) microprocessor, a very long instruction word (VLIW) microprocessor, a processor implementing other instruction sets, or a processor implementing a combination of instruction sets. Processor 1002 can also be one or more special-purpose processing devices such as an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a digital signal processor (DSP), a network processor, etc. Processor 1002 is configured to execute processing logic 1026 for performing the processes described in this specification.

[0118] Computer system 1000 may further include a network interface device 1008. Computer system 1000 may also include a video display unit 1010 (such as a liquid crystal display (LCD), a light emitting diode display (LED), or a cathode ray tube (CRT)), an alphanumeric input device 1012 (such as a keyboard), a cursor control device 1014 (such as a mouse), and a signal generation device 1016 (such as a speaker).

[0119] Secondary memory 1018 may include a machine-accessible storage medium (or more specifically, a computer-readable storage medium) 1032 in which one or more instruction sets (such as software 1022) that embody any one or more of the methods or functions described in this specification are stored. Software 1022 may reside completely or at least partially in main memory 1004 and / or processor 1002 while it is being executed by computer system 1000, and main memory 1004 and processor 1002 also constitute machine-readable storage media. Software 1022 can also be transmitted and received over network 1020 via network interface device 1008.

[0120] In an illustrative embodiment, machine-accessible storage medium 1032 is shown as a single medium, but the term "machine-readable storage medium" should be interpreted to include a single medium or multiple media (e.g., a centralized database or a distributed database, as well as / or associated caches and servers) that store one or more instruction sets. The term "machine-readable storage medium" should also be interpreted to include any medium that is capable of storing or encoding a set of instructions executable by a machine and that causes the machine to perform any one or more of the methods of the present disclosure. Thus, the term "machine-readable storage medium" should be interpreted to include, but not be limited to, solid-state memory, optical media, and magnetic media.

[0121] According to an embodiment of the present disclosure, a machine-accessible storage medium stores instructions that cause a data processing system to perform a method of processing a wafer using insights from an ML model and / or a method of updating or constructing an ML model.

[0122] Embodiments of a plasma chamber having a rotating modulation crossflow are disclosed.

[0123] Embodiment 1. The plasma processing chamber includes one or more sidewalls. The support surface within the one or more sidewalls holds the workpiece. An array of individual gas injectors is dispersed around the outer periphery of the one or more sidewalls. One or more pump ports for discharging gas from the plasma processing chamber are located along the one or more sidewalls. The controller is configured to control the plasma processing chamber during the application of etching. The uniformity of the etching rate of the material on the workpiece is adjusted or controlled by: i) using the array of individual gas injectors to inject one or more gas flows in a direction generally parallel to and across the surface of the workpiece; ii) injecting a first gas flow from a first set of adjacent ones of the individual gas injectors to etch the material on the workpiece; and iii) simultaneously injecting a second gas flow from at least the remaining set of the individual gas injectors. According to the embodiment, the second gas flow is used: i) to dilute the first gas and reduce the area on the workpiece having a faster etching rate, or ii) to act as an additional etchant to increase the etching rate within the area of the workpiece having a faster etching rate.

[0124] Embodiment 2. The plasma processing chamber according to Embodiment 1, wherein the first gas flow includes a process gas mixture containing an etchant gas and the second gas flow includes an independent gas injection (IGI) mixture.

[0125] Embodiment 3. The plasma processing chamber according to Embodiment 2, wherein the controller is further configured to vary the gas flow injection angle of the process gas mixture or the gas flow injection angle of the IGI mixture to increase or decrease the concentration of the etchant gas, respectively.

[0126] Embodiment 4. The plasma processing chamber according to Embodiment 2, wherein the process gas mixture and the IGI mixture are injected during one phase without gas flow rotation.

[0127] Embodiment 5: The plasma processing chamber according to Embodiment 2, wherein the process mixed gas and the IGI mixture are injected between multiple phases with rotation of the gas flow to achieve uniformity of the radial etching rate on the workpiece.

[0128] Embodiment 6: The plasma processing chamber according to Embodiment 2, wherein the process mixed gas contains one of C X F Y 、C X H Y F Z 、and C X H Y 。

[0129] Embodiment 7: The plasma processing chamber according to Embodiment 2, wherein the IGI mixture contains a dilution gas including He, Ne, Ar, Kr, Rn, N, or Xe.

[0130] Embodiment 8: The plasma processing chamber according to Embodiment 2, wherein the IGI mixture contains a cleaning gas including O X 、N2、SF x 、or NF x 。

[0131] Embodiment 9: The plasma processing chamber according to Embodiment 1, wherein the array of individual gas injectors is located within one or more openings in one or more sidewalls.

[0132] Embodiment 10: The plasma processing chamber according to Embodiment 1, wherein the position of one or more pump ports is vertically offset from the position of the array of individual gas injectors. Embodiment 11: The plasma processing chamber according to Embodiment 1, wherein the first gas flow and the second gas flow are switched on / off to control the rotation of the gas flow.

[0133] Embodiment 12: The plasma processing chamber according to Embodiment 2, further including a modulation function applied to at least one of the flow rates of the first gas flow and the second gas flow, or applied to the outlet conductance generated by at least one of the first pump port and the second pump port.

[0134] Embodiment 13: The plasma processing chamber includes one or more sidewalls. The support surface within the one or more sidewalls holds the workpiece. An array of individual gas injectors is distributed around the outer periphery of the one or more sidewalls. One or more pump ports for discharging gas from the plasma processing chamber are located along the one or more sidewalls. The controller is configured to control the plasma processing chamber during an etching application. The uniformity of the etching rate of the material on the workpiece is adjusted or controlled by: i) using the array of individual gas injectors to inject a gas flow in a direction generally parallel to the surface of the workpiece and across the surface of the workpiece, and ii) varying the gas flow injection angle across the workpiece by selecting between a wide set of adjacent ones of the individual gas injectors and a narrow set of adjacent ones of the individual gas injectors before or during the gas flow injection, wherein selecting the narrow set of adjacent ones of the individual gas injectors reduces the gas flow injection angle.

[0135] Embodiment 14: The plasma processing chamber according to Embodiment 13, wherein the array of individual gas injectors includes a plurality of gas injector arrays each having a number of individual gas injectors, and the selected set of adjacent gas injectors includes individual gas injectors from a particular one of the gas injector arrays.

[0136] Embodiment 15: The plasma processing chamber according to Embodiment 13, wherein the array of individual gas injectors includes a plurality of gas injector arrays each having a number of individual gas injectors, and the selected set of adjacent gas injectors includes individual gas injectors from adjacent ones of the gas injector arrays.

[0137] Embodiment 16 The gas flow includes a first gas flow, and the controller is further configured to simultaneously inject a second gas flow from at least a portion of the remaining set of individual gas injectors, i) to dilute the first gas flow to reduce an area on the workpiece having a faster etching rate, or ii) to act as an additional etchant to increase the etching rate within an area of the workpiece having a faster etching rate, the plasma processing chamber according to Embodiment 13, wherein the second gas flow is used.

[0138] Embodiment 17 Reducing the gas flow injection angle increases the uniformity of the etching rate, the plasma processing chamber according to Embodiment 13.

[0139] Embodiment 18 The array of individual gas injectors is located within one or more openings in one or more sidewalls, the plasma processing chamber according to Embodiment 13.

[0140] Embodiment 19 The position of one or more pump ports is vertically offset from the position of the array of individual gas injectors, the plasma processing chamber according to Embodiment 13.

[0141] Embodiment 20 The first gas flow and the second gas flow are switched on / off to control the rotation of the gas flow, the plasma processing chamber according to Embodiment 13.

[0142] Embodiment 21 Further includes a modulation function applied to at least one of the flow rates of the first gas flow and the second gas flow, or applied to the outlet conductance generated by at least one of the first pump port and the second pump port, the plasma processing chamber according to Embodiment 13.

[0143] Embodiment 21 The embodiments disclosed herein include a method of controlling the uniformity of the etching rate of a material on a workpiece within a plasma processing chamber. The method includes injecting a first gas flow from a first set of adjacent ones of the individual gas injectors in a direction generally parallel to the surface of the workpiece and across the surface of the workpiece to etch the material on the workpiece. The method includes simultaneously injecting a second gas flow from at least a portion of the remaining sets of the individual gas injectors in a direction generally parallel to the surface of the workpiece and across the surface of the workpiece, wherein the second gas flow is used to: i) dilute the first gas to reduce an area on the workpiece having a faster etching rate, or ii) act as an additional etchant to increase the etching rate within an area of the workpiece having a faster etching rate.

[0144] Embodiment 23 The method according to embodiment 21, further comprising querying a machine learning (ML) model to control the timing of the first gas flow and the second gas flow.

[0145] Embodiment 24 The embodiments disclosed herein include a method of performing a rotating gas crossflow within a plasma processing chamber and a non-transitory computer-readable medium storing software instructions. When executed by a processor, these software instructions cause the processor to: i) use an array of individual gas injectors to inject one or more gas flows in a direction generally parallel to and across the surface of the workpiece; ii) inject a first gas flow from a first set of adjacent ones of the individual gas injectors to etch material on the workpiece; and iii) simultaneously inject a second gas flow from at least the remaining set of the individual gas injectors, thereby causing the processor to rotate the gas crossflow within the plasma processing chamber. According to an embodiment, the second gas flow is used to: i) dilute the first gas to reduce an area on the workpiece having a faster etching rate, or ii) act as an additional etchant to increase the etching rate within an area of the workpiece having a faster etching rate.

[0146] Embodiment 25 The embodiments disclosed herein include a method of performing a rotating gas crossflow within a plasma processing chamber and a non-transitory computer-readable medium storing software instructions. When executed by a processor, these software instructions cause the processor to: i) use an array of individual gas injectors to inject a gas flow in a direction generally parallel to and across the surface of the workpiece; and ii) vary the gas flow injection angle across the workpiece by selecting between a broad set of adjacent ones of the individual gas injectors and a narrow set of adjacent ones of the individual gas injectors before or during the gas flow injection, thereby causing the processor to rotate the gas crossflow within the plasma processing chamber. At this time, selecting the narrow set of adjacent ones of the individual gas injectors reduces the gas flow injection angle.

Claims

1. A plasma processing chamber, comprising: one or more sidewalls; a support within the one or more sidewalls for holding a workpiece; an array of individual gas injectors dispersed around the outer periphery of the one or more sidewalls; one or more pump ports along the one or more sidewalls for discharging gas from the plasma processing chamber; a controller configured to control the plasma processing chamber during etching application, wherein the uniformity of the etching rate of the material on the workpiece is using the array of individual gas injectors to inject one or more gas flows in a direction generally parallel to the surface of the workpiece and across the surface of the workpiece; injecting a first gas flow from a first set of adjacent ones of the individual gas injectors to etch the material on the workpiece; simultaneously injecting a second gas flow from at least a portion of the remaining set of the individual gas injectors, wherein the second gas flow is used to: i) dilute the first gas to reduce an area on the workpiece having a faster etching rate, or ii) act as an additional etchant to increase the etching rate within the area on the workpiece having the faster etching rate; a controller adjusted or controlled thereby; A plasma processing chamber comprising the same.

2. The plasma processing chamber according to claim 1, wherein the first gas flow comprises a process gas mixture containing an etchant gas, and the second gas flow comprises an independent gas injection (IGI) mixture.

3. The plasma processing chamber according to claim 2, wherein the controller is further configured to vary a gas flow injection angle of the process gas mixture or a gas flow injection angle of the IGI mixture to increase or decrease the concentration of the etchant gas, respectively.

4. The plasma processing chamber according to claim 2, wherein the process gas mixture and the IGI mixture are injected in one phase without gas flow rotation.

5. The plasma processing chamber according to claim 2, wherein the process mixed gas and the IGI mixture are injected between multiple phases with rotation of the gas flow to achieve uniformity in the radial etching rate on the workpiece.

6. The process mixed gas contains C Ｘ F Ｙ C Ｘ H Ｙ F Ｚ and C Ｘ H Ｙ The plasma processing chamber according to claim 2, including one of them.

7. The plasma processing chamber according to claim 2, wherein the IGI mixture includes a dilution gas containing He, Ne, Ar, Kr, Rn, N, or Xe.

8. The IG mixture is O Ｘ , N ２ , SF ｘ , or NF ｘ The plasma processing chamber according to claim 2, comprising a cleaning gas containing

9. The plasma processing chamber according to claim 1, wherein the array of individual gas injectors is located within one or more openings in the one or more sidewalls.

10. The plasma processing chamber according to claim 1, wherein the position of the one or more pump ports is vertically offset from the position of the array of individual gas injectors.

11. The plasma processing chamber according to claim 1, wherein the first gas flow and the second gas flow are switched on / off to control the rotation of the gas flow.

12. The plasma processing chamber according to claim 1, further including a modulation function applied to at least one of the flow rates of the first gas flow and the second gas flow, or applied to the outlet conductance generated by at least one of the first pump port and the second pump port.

13. A plasma processing chamber, one or more sidewalls, a support within the one or more sidewalls for holding a workpiece, an array of individual gas injectors dispersed around the outer periphery of the one or more sidewalls, one or more pump ports along the one or more sidewalls for discharging gas from the plasma processing chamber, a controller configured to control the plasma processing chamber during etching application, wherein the uniformity of the etching rate of the material on the workpiece is using the array of individual gas injectors to inject a gas flow in a direction generally parallel to the surface of the workpiece and across the surface of the workpiece. By selecting between a wide set of the adjacent ones of the individual gas injectors and a narrow set of the adjacent ones of the individual gas injectors before or during the gas flow injection, changing the gas flow injection angle across the workpiece, wherein selecting the narrow set of the adjacent ones of the individual gas injectors decreases the gas flow injection angle, changing the gas flow injection angle A controller that is adjusted or controlled by performing A plasma processing chamber comprising

14. The plasma processing chamber according to claim 13, wherein the array of the individual gas injectors includes a plurality of gas injector arrays each having a number of the individual gas injectors, and the selected set of adjacent gas injectors includes the individual gas injectors from a particular one of the gas injector arrays.

15. The plasma processing chamber according to claim 13, wherein the array of the individual gas injectors includes a plurality of gas injector arrays each having a number of the individual gas injectors, and the selected set of adjacent gas injectors includes the individual gas injectors from the adjacent ones of the gas injector arrays.

16. The gas flow includes a first gas flow, and the controller is further configured to simultaneously inject a second gas flow from at least a part of the remaining set of the individual gas injectors, wherein the second gas flow is used for i) diluting the first gas flow to reduce an area on the workpiece having a faster etching rate, or ii) acting as an additional etchant to increase the etching rate within the area on the workpiece having the faster etching rate. The plasma processing chamber according to claim 13.

17. The plasma processing chamber according to claim 13, wherein decreasing the gas flow injection angle increases the uniformity of the etching rate.

18. The plasma processing chamber according to claim 13, wherein the array of the individual gas injectors is located within one or more openings in one or more sidewalls.

19. The plasma processing chamber according to claim 13, wherein the position of the one or more pump ports is vertically offset from the position of the array of the individual gas injectors.

20. The plasma processing chamber according to claim 16, wherein the first gas flow and the second gas flow are switched on / off to control the rotation of the gas flow.

21. The plasma processing chamber according to claim 16, further comprising a modulation function applied to at least one of the flow rates of the first gas flow and the second gas flow, or applied to the outlet conductance generated by at least one of the first pump port and the second pump port.

22. A method for controlling the uniformity of the etching rate of a material on a workpiece in a plasma processing chamber, comprising: Injecting a first gas flow from a first set of adjacent ones of the individual gas injectors in a direction generally parallel to and across the surface of the workpiece to etch the material on the workpiece; Simultaneously injecting a second gas flow from at least a portion of the remaining sets of the individual gas injectors in a direction generally parallel to and across the surface of the workpiece, wherein the second gas flow is used to: i) dilute the first gas to reduce an area on the workpiece having a faster etching rate, or ii) act as an additional etchant to increase the etching rate within the area on the workpiece having the faster etching rate. A method comprising the above.

23. The method according to claim 22, further comprising querying a machine learning (ML) model to control the injection of the first gas flow and the second gas flow.

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