Control of nonuniformity in plasma discharges using magnetic fields.

Abstract

A method, system, apparatus, and computer program for controlling the uniformity of a plasma discharge using a magnetic field are presented. The substrate processing apparatus includes a vacuum chamber including a processing zone for processing a substrate. The apparatus further includes a magnetic field sensor for detecting a first signal representing an axial magnetic field associated with the vacuum chamber and a second signal representing a radial magnetic field. The apparatus includes at least two magnetic field sensors for generating an auxiliary axial magnetic field and an auxiliary radial magnetic field through the processing zone of the vacuum chamber. The apparatus includes a magnetic field controller coupled to the magnetic field sensors and the at least two magnetic field sources. The magnetic field controller adjusts at least one characteristic of either or both of the auxiliary axial magnetic field and the auxiliary radial magnetic field based on the first signal and the second signal.

Description

[Technical Field]

[0001] [Priority claim] This application claims the benefit of priority to U.S. Patent Application No. 63 / 080,513, filed September 18, 2020, which is incorporated herein by reference in its entirety.

[0002] The subject matter disclosed herein generally relates to methods, systems, and machine-readable storage media for controlling etch rate and plasma uniformity using magnetic fields in plasma-based substrate manufacturing, such as capacitively coupled plasma (CCP) or inductively coupled plasma (ICP) substrate manufacturing. [Background technology]

[0003] Semiconductor substrate processing systems are used to process semiconductor substrates by techniques including etching, physical vapor deposition (PVD), chemical vapor deposition (CVD), plasma-enhanced chemical vapor deposition (PECVD), atomic layer deposition (ALD), plasma-enhanced atomic layer deposition (PEALD), pulsed deposition layer (PDL), plasma-enhanced pulsed deposition layer (PEPDL), and resist removal. One type of semiconductor substrate processing apparatus is a plasma processing apparatus that uses a CCP, which includes a vacuum chamber including an upper electrode and a lower electrode, where radio frequency (RF) power is applied between the electrodes to excite a process gas into a plasma for processing semiconductor substrates in the reaction chamber. Another type of semiconductor substrate processing apparatus is an ICP plasma processing apparatus.

[0004] In semiconductor substrate processing systems, such as CCP- or ICP-based vacuum chambers for manufacturing substrates, etch uniformity and ion tilt at the substrate center are affected by plasma density uniformity and have been shown to be sensitive to weak magnetic fields. For example, plasma density uniformity in CCP- and ICP-based vacuum chambers can be affected by magnetic fields associated with magnetized chamber components (which may have a magnetic field strength of 5-10 Gauss) and other external magnetic fields, including the Earth's magnetic field (which may have a magnetic field strength of 0.25-0.65 Gauss) or other ambient magnetic fields (which may have a magnetic field strength of 0.4-0.5 Gauss).

[0005] Currently, adjusting plasma uniformity is difficult, especially at the center and across the substrate surface. Varying the dimensions of the ground electrode within the chamber, the flow of gases and chemicals, or the frequency content of the delivered radio frequency (RF) are the primary factors used to control plasma uniformity. However, the magnetization of processing chamber components and their exposure to external magnetic fields affect plasma density uniformity, which varies significantly between chambers within a manufacturing site and between chambers in different manufacturing sites. To date, improvements in hardware design and the utilization of process controls have addressed the industry's need for stringent plasma uniformity requirements. Nevertheless, increasingly demanding uniformity specifications necessitate additional techniques to achieve highly uniform density across the substrate surface. The present disclosure seeks to address, among other things, the shortcomings associated with conventional techniques for plasma density uniformity.

[0006] The Background Art set forth herein is intended to generally present the content of the present disclosure. Please note that the information set forth in this section is presented to provide those skilled in the art with the content of the subject matter disclosed below and should not be considered admitted prior art. Specifically, the inventions of the presently named inventors are not admitted expressly or impliedly as prior art to the present disclosure to the extent that they are described in this Background Art section and in a descriptive manner that does not constitute prior art at the time of filing. Summary of the Invention

[0007] Methods, systems, and computer programs for controlling etch rate and plasma uniformity using magnetic fields in substrate manufacturing are described. One general aspect includes a substrate processing apparatus. The apparatus includes a vacuum chamber with a processing zone for processing a substrate using plasma. The apparatus further includes a magnetic field sensor configured to detect a first signal representing an axial magnetic field and a second signal representing a radial magnetic field associated with the vacuum chamber. The radial magnetic field is a magnetic field parallel to the substrate and perpendicular to the axial magnetic field. The apparatus further includes at least two magnetic field sources configured to generate an axial auxiliary magnetic field and a radial auxiliary magnetic field through the processing zone of the vacuum chamber. The apparatus further includes a magnetic field controller coupled to the magnetic field sensor and the at least two magnetic field sources. The magnetic field controller is configured to adjust at least one characteristic of either or both of the axial auxiliary magnetic field and the radial auxiliary magnetic field based on the first signal and the second signal.

[0008] One general aspect includes a method for processing a substrate using a vacuum chamber. The method includes detecting a first signal representing an axial magnetic field within a processing zone of the vacuum chamber, the processing zone being for processing the substrate using plasma. The method further includes detecting a second signal representing a radial magnetic field within the processing zone. The radial magnetic field is a magnetic field parallel to the substrate and perpendicular to the axial magnetic field. The magnitude of the first signal representing the axial magnetic field and the magnitude of the second signal representing the radial magnetic field are determined at multiple locations within the processing zone. The method further includes generating, using at least two magnetic field sources, an auxiliary axial magnetic field and an auxiliary radial magnetic field through the processing zone of the vacuum chamber based on the determined magnitudes of the first and second signals.

[0009] One general aspect includes a non-transitory machine-readable storage medium comprising instructions that, when executed by the machine, cause the machine to perform an operation including detecting a first signal representative of an axial magnetic field within a processing zone of a vacuum chamber for processing a substrate using a plasma. A second signal representative of a radial magnetic field within the processing zone is detected. The radial magnetic field is a magnetic field parallel to the substrate and perpendicular to the axial magnetic field. The magnitude of the first signal representative of the axial magnetic field and the magnitude of the second signal representative of the radial magnetic field are determined at multiple locations within the processing zone. A supplemental axial magnetic field and a supplemental radial magnetic field through the processing zone of the vacuum chamber are generated using at least two magnetic field sources based on the determined magnitudes of the first and second signals. [Brief explanation of the drawings]

[0010] The various accompanying drawings depict only exemplary embodiments of the present disclosure and are not to be considered as limiting its scope.

[0011] [Figure 1] 1 is a diagram of a vacuum chamber, such as an etch chamber, for manufacturing substrates using CCP, according to some example embodiments.

[0012] [Figure 2] 1 is a diagram of a vacuum chamber surrounded by a magnetic shield structure and the application of axial and radial magnetic fields to improve control of etch rate and plasma uniformity, according to some exemplary embodiments.

[0013] [Figure 3A] FIG. 1 illustrates a perspective view of a vacuum chamber with supplemental axial and radial magnetic fields in a processing zone including a CCP, according to some example embodiments.

[0014] [Figure 3B] 3B is a top view of the vacuum chamber of FIG. 3A, in accordance with some exemplary embodiments.

[0015] [Figure 3C] 3B is a side view of the vacuum chamber of FIG. 3A, in accordance with some exemplary embodiments.

[0016] [Figure 4] 4A and 4B illustrate the effect of an axial magnetic field on plasma uniformity in a vacuum chamber, according to some example embodiments. [Figure 5] 4A and 4B illustrate the effect of an axial magnetic field on plasma uniformity in a vacuum chamber, according to some example embodiments.

[0017] [Figure 6] 4A and 4B illustrate the effect of a radial magnetic field on plasma uniformity in a vacuum chamber, according to some example embodiments.

[0018] [Figure 7] 4A and 4B illustrate the combined effect of axial and radial magnetic fields on plasma uniformity in a vacuum chamber, according to some example embodiments. [Figure 8] 4A and 4B illustrate the combined effect of axial and radial magnetic fields on plasma uniformity in a vacuum chamber, according to some example embodiments. [Figure 9] 4A and 4B illustrate the combined effect of axial and radial magnetic fields on plasma uniformity in a vacuum chamber, according to some example embodiments.

[0019] [Figure 10A] FIG. 1 is a perspective view of a vacuum chamber with a single coil used as a magnetic field source for axial and radial auxiliary magnetic fields, according to some exemplary embodiments.

[0020] [Figure 10B] FIG. 10B is a side view of the vacuum chamber of FIG. 10A showing mounting options for the magnetic field source, according to some exemplary embodiments.

[0021] [Figure 11A]A vacuum chamber with a single coil used as a magnetic field source for axial and radial auxiliary magnetic fields, according to some exemplary embodiments.

[0022] [Figure 11B] 11B is a graph illustrating the magnitude of the axial and radial auxiliary magnetic field in the vacuum chamber of FIG. 11A, as well as the ratio of the axial to radial magnitude, according to some exemplary embodiments.

[0023] [Figure 12A] A vacuum chamber with two coils used as a combined magnetic field source for axial and radial auxiliary magnetic fields, according to some exemplary embodiments.

[0024] [Figure 12B] Graph showing the magnitude of the axial and radial auxiliary magnetic fields resulting from the two coils in FIG. 12A when the number of turns in one coil and the current therethrough are fixed, according to some exemplary embodiments.

[0025] [Figure 12C] Graph showing the magnitude of the axial and radial auxiliary magnetic fields resulting from the two coils in FIG. 12A when the current through both coils is fixed but the number of turns in one coil is varied, according to some exemplary embodiments.

[0026] [Figure 13A] A vacuum chamber with four coils used as a combined magnetic field source for axial and radial auxiliary magnetic fields, according to some exemplary embodiments.

[0027] [Figure 13B] 13B is a graph showing the ratio of axial to radial magnitudes as well as the magnitudes of the axial and radial auxiliary magnetic fields resulting from the four coils in FIG. 13A, according to some embodiments.

[0028] [Figure 14]A vacuum chamber equipped with different types of magnetic sensors and magnetic field controllers to configure one or more auxiliary magnetic fields to improve plasma uniformity, according to some exemplary embodiments.

[0029] [Figure 15] 1 is a flowchart of a method for processing a substrate using a vacuum chamber, according to some example embodiments.

[0030] [Figure 16] FIG. 1 is a block diagram illustrating an example of a machine upon which one or more exemplary method embodiments may be implemented or upon which one or more exemplary embodiments may be controlled. DETAILED DESCRIPTION OF THE INVENTION

[0031] Exemplary methods, systems, and computer programs are directed to controlling etch rate and plasma uniformity using magnetic fields in a substrate manufacturing apparatus. The examples are merely representative of possible variations. Unless otherwise specified, components and functions are optional and may be combined or sub-divided, and operations may be reordered, combined, or sub-divided. In the following description, for purposes of explanation, several specific details are set forth to provide a thorough understanding of exemplary embodiments. However, it will be apparent to those skilled in the art that the present subject matter may be practiced without these specific details.

[0032] Substrate uniformity across the substrate surface is difficult to control because it depends on the etch process conditions. As conditions change, uniformity can change. Static solutions for controlling plasma uniformity (such as adjusting the dimensions of the ground electrode) may not be effective over a wide range of process conditions. Solutions involving process parameters may have undesirable side effects when modified to address uniformity.

[0033] The techniques described herein use axial and radial magnetic fields to control plasma uniformity within a vacuum chamber. As used herein, the term "axial magnetic field" refers to a magnetic field perpendicular to the surface of a substrate within a vacuum chamber. As used herein, the term "radial magnetic field" refers to a magnetic field parallel to the surface of a substrate within a vacuum chamber. The disclosed techniques are based on the versatility and effectiveness of a combination of radial and axial magnetic fields. More specifically, the radial magnetic field increases plasma density across the substrate, while the axial magnetic field suppresses plasma density at the substrate center, resulting in a high edge profile (e.g., when the substrate radius r is greater than 80 mm). In this regard, a combination of both radial and axial magnetic fields may be used to control plasma density across the entire surface of a substrate within a vacuum chamber of a substrate processing apparatus (e.g., a CCP-based or ICP-based substrate processing apparatus).

[0034] In some embodiments, the disclosed techniques may be used to detect existing radial and axial magnetic fields, and auxiliary axial and radial magnetic fields may be generated such that the resulting radial and axial magnetic fields in the chamber reach a desired threshold. Specifically, one or more magnetic field sensors may be used to detect the residual magnetic field (ΔB) in the processing zone of the vacuum chamber based on the existing radial and axial magnetic fields. For example, the magnetic sensors may detect the magnitude of the axial magnetic field (Bz) and the magnitude of the radial magnetic field (Br) that form the residual magnetic field detected in the vacuum chamber. The auxiliary axial and radial magnetic fields may be generated using at least two magnetic field sources such that the magnitudes of the resulting axial and radial magnetic fields reach a threshold, or the ratio of the magnitudes is adjusted to reach a desired threshold. Various techniques and options for configuring the radial and axial magnetic fields to improve plasma uniformity across the substrate surface are illustrated in connection with FIGS. 2-16.

[0035] 1 shows a vacuum chamber 100 (e.g., an etch chamber) for fabricating substrates using CCP, according to one embodiment. Exciting an electric field between two electrodes is one way to obtain a radio frequency (RF) gas discharge within the vacuum chamber. The discharge obtained when an oscillating voltage is applied between the electrodes is called a CCP discharge.

[0036] The plasma 102 may be generated using a stable source gas to yield a wide variety of chemically reactive byproducts produced by dissociation of various molecules caused by electron-neutral collisions. The chemical aspects of etching involve the reaction of neutral gas molecules and their dissociated byproducts with molecules on the surface being etched, and the generation of volatile molecules, which can be pumped away. When the plasma is generated, positive ions are accelerated from the plasma across a space-charge sheath that separates the plasma from the chamber walls and strike the substrate surface with sufficient energy to remove material from the surface. This is known as ion bombardment or ion sputtering. However, some industrial plasmas do not produce ions with enough energy to efficiently etch a surface by physical means alone.

[0037] A controller 116 manages the operation of the vacuum chamber 100 by controlling different elements within the chamber, such as an RF generator 118, a gas source 122, and a gas pump 120. In one embodiment, fluorocarbon gases such as CF4 and C4F8 are used in the dielectric etch process due to their anisotropic and selective etching capabilities, although the principles described herein can be applied to other plasma-generating gases. Fluorocarbon gases are readily dissociated into chemically reactive byproducts, including smaller molecular and atomic radicals. These chemically reactive byproducts etch away the dielectric material.

[0038] Vacuum chamber 100 depicts a processing chamber comprising an upper electrode 104 and a lower electrode 108. The upper electrode 104 may be grounded or coupled to an RF generator (not shown), and the lower electrode 108 is coupled to RF generator 118 via a matching network 114. RF generator 118 provides RF power at one or more (e.g., two or three) different RF frequencies. At least one of the three RF frequencies can be turned on or off depending on the desired configuration of vacuum chamber 100 for a particular operation. In the embodiment shown in FIG. 1 , RF generator 118 is configured to provide frequencies of, for example, 2 MHz, 27 MHz, and 60 MHz, although other frequencies are possible.

[0039] The vacuum chamber 100 includes a gas showerhead on the upper electrode 104 for introducing process gases provided by a gas source 122 into the vacuum chamber 100, and a perforated confinement ring 112 that allows gases to be evacuated from the vacuum chamber 100 by a gas pump 120. In some exemplary embodiments, the gas pump 120 is a turbomolecular pump, although other types of gas pumps may be used.

[0040] When substrate 106 is present in vacuum chamber 100, silicon focus ring 110 is positioned adjacent to substrate 106 to provide a uniform RF field at the bottom of plasma 102 for uniform etching of the surface of substrate 106. The embodiment of FIG. 1 shows a triode reactor configuration in which upper electrode 104 is surrounded by a symmetric RF ground electrode 124. Insulator 126 is a dielectric that insulates ground electrode 124 from upper electrode 104. Other embodiments of vacuum chamber 100, including ICP-based embodiments, are possible without changing the scope of the disclosed embodiments.

[0041] Substrate 106 can include, for example, a wafer (e.g., a wafer having a diameter of 100 mm, 150 mm, 200 mm, 300 mm, 450 mm, or more) and includes, for example, an elemental semiconductor material (e.g., silicon (Si) or germanium (Ge)) or a compound semiconductor material (e.g., silicon germanium (SiGe) or gallium arsenide (GaAs)). Additionally, other substrates include dielectric materials such as quartz or sapphire, on which semiconductor materials can be coated.

[0042] Each frequency generated by the RF generator 118 may be selected for a specific purpose in the substrate fabrication process. The example of FIG. 1 uses RF power provided at 2 MHz, 27 MHz, and 60 MHz, with the 2 MHz RF power providing ion energy control and the 27 MHz and 60 MHz power providing control of plasma density and chemical dissociation patterns. This configuration, in which each RF power can be turned on or off, enables certain processes that use ultra-low ion energy on the substrate or wafer, and certain processes (e.g., soft etching of low-k materials) where ion energy must be low (e.g., less than 700 or 200 eV).

[0043] In another embodiment, 60 MHz RF power is used on the top electrode 104 to obtain ultra-low energy and very high density. This configuration allows for chamber cleaning with high-density plasma while minimizing sputtering on the electrostatic chuck (ESC) surface when the substrate 106 is not in the vacuum chamber 100. The ESC surface is exposed when the substrate 106 is not present, and any ion energy on the surface should be avoided. Therefore, the bottom 2 MHz and 27 MHz power supplies can be turned off during cleaning.

[0044] In some embodiments, the vacuum chamber 100 is exposed to an external magnetic field, such as the Earth's magnetic field or other ambient magnetic fields (e.g., magnetic fields from magnetized components of the vacuum chamber, such as a hoist, as shown in FIG. 2). The resulting residual magnetic field within the vacuum chamber 100 is undesirable because it can adversely affect the etch rate and plasma uniformity, particularly around the central region 132 of the substrate 106 within the processing zone 134. In an exemplary embodiment, an axial magnetic field 130A of magnitude Bz and a radio magnetic field 130B of magnitude Br may be introduced within the processing zone 134 such that the ratio of magnitude Bz / Br reaches a desired threshold to facilitate plasma uniformity across the surface of the substrate 106 within the processing zone 134. Various techniques for generating axial and radial magnetic fields, or adjusting plasma uniformity across the substrate surface, are described in connection with FIGS. 2-16.

[0045] 2 illustrates a vacuum chamber surrounded by a magnetic shield structure and the application of axial and radial magnetic fields to improve control of etch rate and plasma uniformity, according to some example embodiments. Referring to FIG. 2, a vacuum chamber, such as the vacuum chamber 100 of FIG. 1, may be surrounded by a magnetic shield structure 200 to reduce the effects of external magnetic fields.

[0046] In an exemplary embodiment, magnetic shield structure 200 may comprise upper shield portion 210 and lower shield portion 218, and each shield portion may include multiple shield sub-portions as shown in FIG. 2. For example, upper shield portion 210 may include shield sub-portions 212, 214, 216, and 217. Lower shield portion 218 may include shield sub-portions 220, 222, and 224. In some aspects, magnetic shield structure 200 may include one or more openings 228 to accommodate various equipment used in the vacuum chamber (e.g., openings to accommodate RF components and communication links, ventilators, gas supplies, heaters, high-voltage clamps, substrate feeding mechanisms, etc.).

[0047] In an exemplary embodiment, magnetic shield structure 200 may be made from a high magnetic permeability material having a thickness of at least 40 mils. In an exemplary embodiment, various shielding sub-portions of magnetic shield structure 200 may be bolted (or securely attached by other means) to various surfaces of the vacuum chamber.

[0048] In an exemplary embodiment, the shield sub-portion 224 may be formed as a tunnel surrounding a vacuum chamber opening 226 used for loading and unloading substrates from the processing zone using the CCP.

[0049] Due to imperfections in the magnetic shield structure 200 (e.g., one or more openings 228 for accommodating vacuum chamber equipment), a residual magnetic field 202 can exist below the magnetic shield structure 200 and inside the vacuum chamber 100 as a result of external magnetic fields, including magnetic fields from magnetization chamber components (e.g., magnetization hoist 230). In an exemplary embodiment, one or more auxiliary magnetic fields, such as an axial auxiliary magnetic field 204 (magnitude Bz) and a radial auxiliary magnetic field 206 (magnitude Br), may be generated within the vacuum chamber 100 (e.g., using the techniques disclosed in connection with FIGS. 12A and 13A ) to counteract the effects of the residual magnetic field 208 (e.g., to achieve resulting radial and axial magnetic fields with a specific ratio of magnitudes) and adjust plasma uniformity across the substrate surface.

[0050] 3A shows a perspective view 300 of a vacuum chamber 302 with supplemental axial and radial magnetic fields in a processing zone containing a CCP, according to some illustrative embodiments. Referring to FIG. 3A, the vacuum chamber 302 can be exposed to external magnetic fields, such as a first external magnetic field 306 and a second external magnetic field 308, that collectively form a residual magnetic field 309 in the processing zone 304 (e.g., the CCP-filled volume in the vacuum chamber 302). The residual magnetic field 309 can be formed by an axial magnetic field 316 (magnitude Bz) and a radial magnetic field 318 (magnitude Br).

[0051] In an exemplary embodiment, the effect of the residual magnetic field 309 on plasma uniformity across the substrate surface in the processing zone 304 can be mitigated by introducing auxiliary magnetic fields, including an axial auxiliary magnetic field 320 and a radial auxiliary magnetic field 322, having corresponding magnitudes Bz and Br. The magnetic fields generated within the processing zone 304 (e.g., including the residual magnetic field 309 and the auxiliary magnetic fields, including the axial auxiliary magnetic field 320 and the radial auxiliary magnetic field 322) can be configured to provide greater plasma uniformity across the substrate surface within the processing zone 304. Specifically, multiple magnetic field sources (e.g., as described in connection with FIGS. 12A and 13A) can be used to generate the auxiliary magnetic fields to achieve a desired ratio of the magnitudes of the axial auxiliary magnetic field 320 and the radial auxiliary magnetic field 322. FIGS. 4-9 illustrate that a combination of both radial and axial magnetic fields can control plasma density across the surface of a substrate in the processing zone. In this regard, multiple magnetic field sources can be used to generate axial and radial magnetic fields such that the ratio of magnitudes (e.g., Bz / Br) is adjusted to achieve the desired plasma uniformity across the substrate surface.

[0052] Figure 3B shows a top view of the vacuum chamber 302 of Figure 3A according to some illustrative embodiments. Figure 3C shows a side view of the vacuum chamber 302 of Figure 3A according to some illustrative embodiments. Referring to Figure 3C, the vacuum chamber 302 can include a top plate 312 and various equipment 314 (e.g., RF components and communication links, gas supplies, heaters, high-voltage clamps, substrate feeding mechanisms, etc.) used in connection with substrate processing within the processing zone 304. The top plate 312 can include thermocouples and auxiliary components for operating gas flow, power for temperature control, mechanical components associated with gas vacuum functions, etc.

[0053] In an exemplary embodiment, the top plate 312 or fixture 314 may be used to mount at least one magnetic field source capable of generating one or more auxiliary magnetic fields (e.g., an axial auxiliary magnetic field and a radial auxiliary magnetic field) to counteract residual magnetic fields within the vacuum chamber 302 and achieve a desired ratio of magnitudes Bz / Br for plasma uniformity across the substrate surface.

[0054] 4 and 5 illustrate the effect of an axial magnetic field on plasma uniformity in a vacuum chamber, according to some exemplary embodiments. Referring to FIGS. 4 and 5, graphs 400, 402, 404, 406, 408, 410, and 500 are shown of the effect of an axial magnetic field when 300 W of 60 MHz RF power is supplied to the lower electrode of the vacuum chamber (e.g., the lower electrode 108 of the vacuum chamber 100). Graph 400 illustrates the plasma distribution when no magnetic field is applied to the vacuum chamber 100 (e.g., the magnetic field has a magnitude of 0 Gauss (0 G)). Graphs 402-410 and 500 illustrate the plasma uniformity when axial magnetic fields of magnitudes of 0.25 G (graph 402), 0.5 G (graph 404), 1 G (graph 406), 2 G (graph 408), 3 G (graph 410), and 10 G (graph 500) are applied to the vacuum chamber 100, respectively. As can be seen from Figures 4 and 5, the plasma distribution in the vacuum chamber changes as the magnitude of the applied axial magnetic field increases.

[0055] Graph 504 in Figure 5 shows the mid-gap plasma density across the centerline 502 of the vacuum chamber 100 when an axial magnetic field of magnitudes 0 G, 0.25 G, 0.5 G, 1 G, 2 G, 3 G, and 10 G is applied. As can be seen from graph 504 (as with graphs 400-410 and 500), the plasma distribution changes from high (0 G) near the substrate center to a more uniform distribution across the substrate (e.g., 0.25 G) and then high (e.g., 1 G to 10 G) near the substrate edge. Applying an axial magnetic field increases the electron loss rate to the top and bottom electrodes while decreasing the radial electron mobility. Due to the presence of a high electric field near the substrate edge (fringing effect), electrons are confined to that region, causing a peak in plasma density near that location. In this regard, applying an axial magnetic field suppresses density near the substrate center (e.g., chamber centerline 502) while increasing density near the substrate edge (e.g., due to limited electron diffusion to adjacent radii due to reduced electron mobility).

[0056] FIG. 6 illustrates the effect of a radial magnetic field on plasma uniformity within a vacuum chamber, according to some exemplary embodiments. Referring to FIG. 6 , graphs 600, 602, and 604 of the radial magnetic field effect are shown when 300 W of 60 MHz RF power is supplied to the lower electrode of the vacuum chamber (e.g., the lower electrode 108 of the vacuum chamber 100). Graph 600 illustrates the plasma distribution when no magnetic field is applied to the vacuum chamber 100 (e.g., the magnetic field has a magnitude of 0 Gauss (0 G)). Graphs 602 and 604 illustrate the plasma uniformity when radial magnetic fields of magnitudes of 0.25 G (graph 602) and 0.5 G (graph 604) are applied within the vacuum chamber 100. Graph 606 in FIG. 6 illustrates the mid-gap plasma density across the centerline of the vacuum chamber 100 when radial magnetic fields of magnitudes of 0 G, 0.25 G, and 0.5 G are applied. As can be seen from graph 604, the radial magnetic field slightly increases the plasma density at a magnitude of 0.5 G. In this regard, applying a radial magnetic field parallel to the substrate surface can reduce electron losses to the top and bottom electrodes. The reduced loss rate results in an increase in bulk plasma density. As a result, adjusting the strength of the radial magnetic field can be used to adjust the plasma density within a desired range of values.

[0057] 7, 8, and 9 illustrate the combined effect of axial and radial magnetic fields on plasma uniformity in a vacuum chamber, according to some example embodiments.

[0058] Referring to FIG. 7, graphs 700, 702, 704, and 706 are shown of the combined magnetic field effect (e.g., a combination of both axial and radial magnetic fields) when 300 W of 60 MHz RF power is supplied to the lower electrode of a vacuum chamber (e.g., the lower electrode 108 of the vacuum chamber 100). Graph 700 shows the plasma distribution when no magnetic field is applied to the vacuum chamber 100 (e.g., a magnetic field with a magnitude of 0 Gauss (0 G)). Graph 702 shows the plasma uniformity when a radial magnetic field with a magnitude of 0.25 G is applied (G is the Gaussian measure for the radial magnetic field). Graph 704 shows the plasma uniformity when an axial magnetic field with a magnitude of 0.25 G is applied (G is the Gaussian measure for the axial magnetic field). Graph 706 shows the plasma uniformity when a radial magnetic field with a magnitude of 0.25 G and an axial magnetic field with a magnitude of 0.25 G are applied in the vacuum chamber. Graph 708 shows the mid-gap plasma density across the centerline of the vacuum chamber 100 when a magnetic field of magnitude 0 G, 0.25 Gr, 0.25 Gz, and 0.25 Gz is applied.

[0059] Referring to FIG. 8 , graphs 800, 802, 804, and 806 are shown of the combined magnetic field effect (e.g., a combination of both axial and radial magnetic fields) when 300 W of 60 MHz RF power is supplied to the lower electrode of a vacuum chamber (e.g., the lower electrode 108 of the vacuum chamber 100). Graph 800 shows the plasma distribution when no magnetic field is applied to the vacuum chamber 100 (e.g., a magnetic field with a magnitude of 0 Gauss (0 G)). Graph 802 shows the plasma uniformity when a radial magnetic field with a magnitude of 0.5 G is applied. Graph 804 shows the plasma uniformity when an axial magnetic field with a magnitude of 0.5 G is applied. Graph 806 shows the plasma uniformity when a radial magnetic field with a magnitude of 0.5 G and an axial magnetic field with a magnitude of 0.5 G are applied in the vacuum chamber. Graph 808 shows the mid-gap plasma density across the centerline of the vacuum chamber 100 when a magnetic field of magnitude 0 G, 0.5 Gr, 0.5 Gz, and 0.5 Gr of 0.5 Gz is applied.

[0060] 9, graphs 900, 902, 904, and 906 are shown of the combined magnetic field effect (e.g., a combination of both axial and radial magnetic fields) when 300 W of 60 MHz RF power is supplied to the lower electrode of a vacuum chamber (e.g., the lower electrode 108 of the vacuum chamber 100). Graph 900 shows the plasma distribution when no magnetic field is applied to the vacuum chamber 100 (e.g., a magnetic field of 0 Gauss (0 G)). Graph 902 shows the plasma uniformity when a radial magnetic field of 0.5 Gr magnitude and an axial magnetic field of 0.25 Gz magnitude are applied. Graph 904 shows the plasma uniformity when a radial magnetic field of 0.25 Gr magnitude and an axial magnetic field of 0.5 Gz magnitude are applied. Graph 906 shows the plasma uniformity when a radial magnetic field of 0.5 Gr magnitude and an axial magnetic field of 0.5 Gz magnitude are applied in the vacuum chamber. Graph 908 shows the mid-gap plasma density across the centerline of the vacuum chamber 100 when magnetic fields of magnitude 0 G, 0.5 Gr of 0.25 Gz, 0.25 Gr of 0.5 Gz, and 0.5 Gr of 0.5 Gz are applied.

[0061] Based on the graphical data of FIGS. 4-9, applying both radial and axial magnetic fields can balance the above-described trends associated with the individual application of the axial or radial magnetic fields, providing a tuning knob for increasing plasma density variation near the substrate center or substrate edge. In this regard, by adjusting the ratio Bz / Br of the magnitudes of the axial and radial magnetic fields, plasma uniformity may be adjusted across the substrate surface within the vacuum chamber. In exemplary embodiments, controlling the ratio Bz / Br may be achieved by individually controlling the currents (or other characteristics) of multiple magnetic field sources, as described in connection with FIGS. 12A-13B. In some embodiments, when a pre-existing magnetic field (e.g., a residual magnetic field) is already present within the vacuum chamber, the magnitudes of the axial and radial magnetic fields relative to the residual magnetic field may be determined, and the auxiliary axial and auxiliary radial magnetic fields may be generated to achieve a resultant (e.g., combined) magnetic field having radial and axial components (e.g., magnitudes Bz and Br) of desired magnitudes.

[0062] 10A shows a perspective view of a vacuum chamber 1002 with a single coil used as a magnetic field source for axial and radial magnetic fields, according to some illustrative embodiments. Referring to FIG. 10A, the vacuum chamber 1002 can be exposed to a residual magnetic field 1003 measured at a location 1008 within a processing zone of the vacuum chamber. In some embodiments, a magnetic field source 1004 (e.g., a single coil) can be configured to generate an auxiliary magnetic field 1006 within the vacuum chamber 1002. The auxiliary magnetic field 1006 has a magnitude Bz. shaft It may include a directional magnetic field 1010 and a radial magnetic field 1012 of magnitude Br. One or more characteristics of the auxiliary magnetic field (e.g., the current, number of turns of the coil 1004, etc.) may be configured to adjust the uniformity of the plasma distribution within the vacuum chamber.

[0063] In an exemplary embodiment, the residual magnetic field 1003 may be detected and measured by a magnetic field sensor located at or near location 1008. An exemplary magnetic field sensor that can be used to detect the residual magnetic field is shown in connection with FIG. 14 . Additionally, a magnetic field controller (e.g., as shown in FIG. 14 ) may be used to adjust one or more characteristics of the auxiliary magnetic field 1006. For example, the magnetic field controller may adjust the current (e.g., direct current (DC)) in the coil 1004, thereby varying the magnitude of the auxiliary magnetic field 1006 (and the corresponding magnitudes Bz and Br). In some embodiments, the current may be adjusted so that the magnitude of the auxiliary magnetic field 1006 combined with the magnitude of the residual magnetic field 1003 results in a desired magnitude Bz or Br, thereby achieving a uniform plasma distribution within the vacuum chamber. In other embodiments, the magnetic field controller may adjust different characteristics (e.g., number of turns, distance to the centerline of the chamber, etc.) to achieve a desired overall Bz and / or Br within the chamber.

[0064] 10B is a side view of the vacuum chamber 1002 of FIG. 10A showing mounting options for the magnetic field source 1004, according to some exemplary embodiments. Referring to FIG. 10B, in an exemplary embodiment, the magnetic field source 1004 (e.g., a coil) may be mounted inside the vacuum chamber 1002, proximate to the processing zone 1014. In an exemplary embodiment, the coil 1004 may be mounted on a pedestal 1018 that is fixed to a top plate 1016 of the vacuum chamber 1002. In an exemplary embodiment, the coil 1004 may be attached to an inner surface of the vacuum chamber 1002 (e.g., the top surface as shown in FIG. 10B) via a connection 1020.

[0065] In an exemplary embodiment, the vacuum chamber 1002 may be enclosed within a magnetic shield structure, such as magnetic shield structure 200, and the coil 1004 may be fixed within the magnetic shield structure but outside the vacuum chamber 1002 (e.g., on the inner surface of the magnetic shield structure). In an exemplary embodiment, the coil 1004 may be located outside the magnetic shield structure and the vacuum chamber 1002. In an exemplary embodiment, multiple coils may be used as magnetic field sources to generate axial and radial auxiliary magnetic fields (e.g., as shown in FIGS. 12A and 13A), and each coil may be located separately (e.g., inside or outside the vacuum chamber).

[0066] 11A shows a diagram 1100A of a vacuum chamber 1102 with a single coil 1108 used as a magnetic field source for axial and radial auxiliary magnetic fields, according to some example embodiments. Referring to FIG. 11A, the single coil 1108 is used as a source of an axial auxiliary magnetic field 1110 of magnitude Bz and a radial auxiliary magnetic field 1112 of magnitude Br.

[0067] FIG. 11B is a graph 1100B illustrating the magnitude of the axial and radial auxiliary magnetic field and the ratio of the axial and radial magnitudes in the vacuum chamber of FIG. 11A, according to some embodiments.

[0068] During substrate processing of a substrate 1106 mounted on a pedestal 1104, a single coil 1108 is operated to generate an axial auxiliary magnetic field 1110 and a radial auxiliary magnetic field 1112. The magnitude of the axial auxiliary magnetic field 1110 is higher at position A (near the single coil 1108) than at position S (near the midpoint of the substrate 1106). As shown in graph 1100B, Bz varies from about 3 G near the substrate center to about 2.1 G near the substrate edge (for a 300 mm diameter substrate). The magnitude Br of the radial auxiliary magnetic field 1112 varies from about 0.1 G near the substrate center to about 1.5 G near the substrate edge. The ratio of Bz / Br near the substrate edge is about 1.5.

[0069] In an exemplary embodiment, the position of the single coil 1108 (e.g., inside or outside the vacuum chamber 1102), the distance H of the single coil to the top surface of the vacuum chamber (or the distance of the single coil to the substrate 1106), the current through the single coil 1108, or other characteristics of the single coil may be changed (e.g., during vacuum chamber setup or dynamically during processing) to achieve different amplitudes of the Bz / Br ratio to adjust the plasma uniformity across the substrate surface. However, while changes in the characteristics of the single coil 1108 result in proportional changes in Bz and Br, the ratio Bz / Br remains unchanged.

[0070] In an exemplary embodiment, to achieve tunability of the ratio Bz / Br and more optimal plasma uniformity across the substrate surface within the vacuum chamber, multiple magnetic field sources (e.g., at least two magnetic field sources) may be used to generate axial and radial magnetic fields within the vacuum chamber, where the processing characteristics of the magnetic field sources may be individually adjusted (e.g., at a set time or dynamically during substrate processing). Example embodiments using multiple magnetic field sources are described in connection with Figures 12A-13B.

[0071] 12A shows a diagram 1200A of a vacuum chamber 1202 with two coils (e.g., coils 1204 and 1206) used as a combined magnetic field source for axial and radial auxiliary magnetic fields, according to some exemplary embodiments. Referring to FIG. 12A, coils 1204 and 1206 are used as a combined source of an axial auxiliary magnetic field 1214 of magnitude Bz and a radial auxiliary magnetic field 1212 of magnitude Br.

[0072] 12A, substrate 1210 is placed on pedestal 1208 within vacuum chamber 1202. Coil 1204 is placed a distance H1 from the top surface of vacuum chamber 1202, and coil 1206 is placed a distance H2 from the bottom surface of vacuum chamber 1202. Although coils 1204 and 1206 are both illustrated as being outside vacuum chamber 1202, the disclosure is not limited in this respect, and either coils 1204 and 1206 may be located inside or outside vacuum chamber 1202.

[0073] During substrate processing of a substrate 1210 placed on a pedestal 1208, coils 1204 and 1206 are activated to generate an axial auxiliary magnetic field 1214 and a radial auxiliary magnetic field 1212. Figure 12B is a graph 1200B illustrating the magnitude of the axial and radial auxiliary magnetic fields (1214 and 1212) resulting from the two coils 1204 and 1206 of Figure 12A when the number of turns in one coil and the current therethrough are fixed, according to some example embodiments. Specifically, graph 1200B shows the magnitudes Bz and Br when coil 1206 is fixed at 40 turns and a current of 10 A, and the current through coil 1204 is varied from 1 A to 5 A.

[0074] 12C is a graph 1200C illustrating the magnitude of the axial and radial auxiliary magnetic fields (1214 and 1212) resulting from the two coils 1204 and 1206 in FIG. 12A when the current through both coils is fixed but the number of turns in one coil is varied, according to some exemplary embodiments. Specifically, graph 1200C shows the magnitudes Bz and Br when coil 1204 is fixed at 40 turns and a current of 5 A, while coil 1206 has a current of 10 A and varies between 40 and 80 turns.

[0075] 12B and 12C, when coil 1206 is fixed at 10 A and 40 turns, Bz is approximately equal to Br at a coil 1204 current of 5 A. Furthermore, when the number of turns in coil 1206 is increased to 80 (or when the lower coil 1206 current is increased to 20 A), the magnitude of Br may be further reduced.

[0076] In an exemplary embodiment, the positions of coils 1206 and 1204 (e.g., inside or outside vacuum chamber 1202), the distances H1 and H2 to the corresponding top and bottom surfaces of the vacuum chamber (or the respective distances of coils 1204 and 1206 to substrate 1210), the current through each of coils 1204 and 1206 (or any other process characteristic of the coils) may be varied individually for each coil (e.g., by magnetic field controller 1418 during vacuum chamber setup or dynamically during processing) to achieve different Bz / Br ratios to optimally adjust plasma uniformity across the substrate surface.

[0077] 13A shows a diagram 1300A of a vacuum chamber 1310 with four coils (e.g., coils 1302, 1304, 1306, and 1308) used as a combined magnetic field source of axial and radial auxiliary magnetic fields, according to some exemplary embodiments. Referring to FIG. 13A, coils 1302-1308 are used as a combined source of an axial auxiliary magnetic field 1318 of magnitude Bz and a radial auxiliary magnetic field 1316 of magnitude Br.

[0078] 13A, substrate 1314 is mounted on pedestal 1312 within vacuum chamber 1310. Coils 1308, 1306, 1304, and 1302 are mounted at corresponding distances H1, H2, H3, and H4 from the top surface of vacuum chamber 1310. Although coils 1302-1308 are illustrated as being outside vacuum chamber 1310, the disclosure is not limited in this respect, and any of coils 1302-1308 may be positioned inside or outside vacuum chamber 1310 (while remaining parallel to each other and to substrate 1314).

[0079] In an exemplary embodiment, as shown in Figure 13A, the coils 1302-1308 have different diameters. However, the disclosure is not limited in this respect, and two or more of the coils 1302-1308 may have the same diameter. Furthermore, while Figure 13A only shows coils 1302-1308 for generating axial and radial auxiliary magnetic fields, the disclosure is not limited in this respect, and more coils may similarly be used and arranged in different configurations on multiple sides of the vacuum chamber 1310.

[0080] During substrate processing of a substrate 1314 mounted on a pedestal 1312, coils 1302-1308 are activated to generate an axial auxiliary magnetic field 1318 and a radial auxiliary magnetic field 1316. Figure 13B is a graph 1300B illustrating the ratio of the axial to radial magnitudes (Bz / Br) as well as the magnitudes of the axial and radial auxiliary magnetic fields resulting from 5 A of current in the four coils of Figure 13A, according to some embodiments. As can be seen from Figure 13B, Bz varies from approximately 4.2 G near the substrate center to approximately 3.2 G near the substrate edge, while Br varies from approximately 0.4 G near the substrate center to approximately 2.4 G near the substrate edge.

[0081] In an exemplary embodiment, the position of the coils 1302-1308 (e.g., inside or outside the vacuum chamber 1310), the distances H1-H4 to the top surface of the vacuum chamber (or the respective distances of the coils 1302-1308 to the substrate 1314), the current through each of the coils 1302-1308 (or any other process characteristic of the coils) may be varied individually for each coil (e.g., by the magnetic field controller 1418 during vacuum chamber setup or dynamically during processing) to achieve different Bz / Br ratios to optimally adjust the plasma uniformity across the substrate surface.

[0082] 14 illustrates a vacuum chamber 1402 equipped with different types of magnetic sensors and magnetic field control devices to configure one or more auxiliary magnetic fields to improve plasma uniformity, according to some example embodiments. Referring to FIG. 14, the vacuum chamber 1402 includes a magnetic field of magnitude Bz. shaft A residual magnetic field 1403 may be produced within the vacuum chamber upon exposure to an external magnetic field consisting of a directional magnetic field 1404 and a radial magnetic field 1406 of magnitude Br.

[0083] In an exemplary embodiment, the vacuum chamber 1402 includes a magnetic field controller 1418, which may be the same as the controller 116 of FIG. 1 . The magnetic field controller 1418 includes appropriate circuitry, logic, interfaces, and / or code configured to receive magnetic field sensor data and adjust one or more characteristics of the auxiliary magnetic field generated by at least one magnetic field source. In an exemplary embodiment, a smart wafer 1412 may be loaded into a processing zone of the vacuum chamber 1402 through an opening 1410. The smart wafer 1412 may include multiple sensors 1414 (e.g., magnetic field sensors) configured to detect and measure residual magnetic fields (e.g., residual magnetic field 1403) after the smart wafer 1412 is placed in the processing zone within the vacuum chamber 1402. In an exemplary embodiment, the magnetic field controller 1418 may use one or more stand-alone sensors 1416 (e.g., magnetic field sensors) to detect and measure residual magnetic fields (e.g., residual magnetic field 1403) and magnetic fields in specific directions (e.g., measuring axial and radial magnetic fields).

[0084] In an exemplary embodiment, the magnetic field controller 1418 may use sensors 1414 and / or 1416 to detect the magnitude and direction of the residual magnetic field 1403. The magnetic field controller 1403 may adjust at least one characteristic of one or more auxiliary magnetic fields, including either or both of the axial auxiliary magnetic field 1408 (magnitude Bzs) and / or the radial auxiliary magnetic field 1409 (magnitude Brs), to achieve a combined magnetic field having a particular Bz / Br ratio. For example, the magnetic field controller 1418 may adjust the current through at least one magnetic field source that generates the auxiliary magnetic field (e.g., adjust the current individually for multiple magnetic field sources, such as the magnetic field sources shown in FIGS. 12A and 13A). Additionally, the magnetic field controller 1418 may activate or deactivate one or more of a plurality of available magnetic field sources (such as multiple coils configured as shown in Figures 12A and 13A, or another configuration) to achieve a desired radial magnetic field magnitude Bz in the vacuum chamber 1402, a desired axial magnetic field magnitude Br in the vacuum chamber 1402, or a desired ratio of magnitudes Bz / Br.

[0085] In an exemplary embodiment, the vacuum chamber 1402 may further include a plasma density sensor (not shown in FIG. 14) coupled to the magnetic field controller 1418. In some aspects, the plasma density sensor may also be coupled to one or both of the one or more magnetic field sensors 1414 and / or 1416 and may be configured to measure the density of the plasma within the vacuum chamber.

[0086] In an exemplary embodiment, sensors 1414 and / or 1416 may be used for initial magnetic field measurements so that magnetic field controller 1418 makes adjustments that result in the generation of an auxiliary magnetic field having a desired magnitude and direction, thereby achieving an overall (resulting) magnetic field having the desired Bz, Br, or Bz / Br.

[0087] In some embodiments, periodic measurements and adjustments may be performed using sensors 1414 and / or 1416. In an exemplary embodiment, a standalone sensor 1416 may be used for automatic (dynamic) measurements and adjustments in the characteristics of the auxiliary magnetic field. In an exemplary embodiment, one magnetic field sensor (or a set of magnetic field sensors) may be used per magnetic field source, such that different sensors may be associated with different magnetic field sources. In an exemplary embodiment, magnetic field controller 1418 may wirelessly communicate with sensors 1414 and 1416 to receive sensor data.

[0088] In an exemplary embodiment, either of sensors 1414 and / or 1416 may include an optical or thermal sensor configured to measure plasma density. In this case, magnetic field controller 1418 is also configured to generate an axial auxiliary magnetic field 1408 (magnitude Bzs) and a radial auxiliary magnetic field 1409 (magnitude Brs) to achieve a combined magnetic field having a magnitude of a particular Bz / Br ratio based on the plasma density measured by sensors 1414 and / or 1416.

[0089] FIG. 15 is a flowchart of a method 1500 for processing a substrate using a vacuum chamber, according to some illustrative embodiments. The method 1500 includes operations 1502, 1504, 1506, and 1508, which may be performed by a magnetic field controller, such as the magnetic field controller 1418 of FIG. 14 or the processor 1602 of FIG. 16. Referring to FIG. 15, in operation 1502, a first signal representative of an axial magnetic field is detected within a processing zone of a vacuum chamber. The processing zone is for processing a substrate using a plasma. For example, either sensor 1414 or 1416 detects the first signal representative of the axial magnetic field 1404 within the processing zone of the vacuum chamber 1402. In operation 1504, a second signal representative of a radial magnetic field within the processing zone is detected. The radial magnetic field is a magnetic field that is parallel to the substrate and perpendicular to the axial magnetic field. For example, a magnetic sensor may further detect the second signal representative of the radial magnetic field 1406. In operation 1506, a magnitude of a first signal representing the axial magnetic field and a magnitude of a second signal representing the radial magnetic field are determined at a plurality of locations within the processing zone. For example, a magnitude Bz of the first signal representing the axial magnetic field 1404 and a magnitude Br of the second signal representing the radial magnetic field 1406 are determined (e.g., by the magnetic field controller 1418). In operation 1508, an auxiliary axial magnetic field and an auxiliary radial magnetic field are generated through the processing zone of the vacuum chamber using at least two magnetic field sources based on the determined magnitudes of the first and second signals. For example, the auxiliary axial magnetic field 1408 and the auxiliary radial magnetic field 1409 are generated using at least two magnetic field sources (e.g., the magnetic field sources shown in connection with FIGS. 12A and 13A) based on the determined magnitudes Bz and Br. For example, the axial and radial auxiliary magnetic fields can be generated such that the resulting axial and radial auxiliary magnetic fields (e.g., magnetic fields based on a combination of existing / residual magnetic fields 1404 and 1406 and auxiliary magnetic fields 1409 and 1408) are generated by at least two magnetic field sources that are individually configured with their currents, coil sizes (e.g., number of turns), or other characteristics, resulting in axial and radial auxiliary magnetic fields with a desired magnitude ratio.

[0090] FIG. 16 is a block diagram illustrating an example of a machine 1600 upon which one or more exemplary process embodiments described herein may be implemented or controlled. In another embodiment, the machine 1600 may operate as a stand-alone device or may be connected (e.g., networked) to other machines. In a networked arrangement, the machine 1600 may operate as a server machine, a client machine, or both in a server-client network environment. In one example, the machine 1600 may function as a peer machine in a peer-to-peer (P2P) (or other distributed) network environment. Furthermore, while only one machine 1600 is illustrated, the term “machine” should also be interpreted to include a group of machines that individually or cooperatively execute a set (or sets) of instructions to perform any one or more of the methods described herein, such as via cloud computing, software as a service (SaaS), or other computer cluster configurations.

[0091] The examples described herein may include or operate by logic, several components, or mechanisms. Circuitry is a collection of circuits implemented in a tangible entity that includes hardware (e.g., simple circuits, gates, logic). The circuitry elements soften over time, altering the underlying hardware. Circuitry includes elements that, when in operation, can perform specific operations, either alone or in combination. In one example, the circuitry hardware may be invariably designed to perform specific operations (e.g., hardwired operations). In one example, the circuitry hardware may include variably connected physical components (e.g., execution units, transistors, simple circuits) that include computer-readable media that are physically altered (e.g., magnetically, electrically, by movable arrangements of invariant particles) to encode instructions for specific operations. When connecting the physical components, the underlying electrical properties of the hardware components are altered (e.g., from insulator to conductor, or vice versa). The instructions enable the embedded hardware (e.g., execution unit or loading mechanism) to create the circuitry elements within the hardware through variable connections to perform some of the specific operations during operation. Thus, the computer-readable medium is communicatively coupled to other components of the circuitry when the device is operating. In some aspects, any of the physical components may be used in more than one member of more than one circuitry. For example, during operation, an execution unit may be used in a first circuit of a first circuitry at one time and reused at a different time by a second circuit of the first circuitry or by a third circuit of the second circuitry.

[0092] The machine (e.g., a computer system) 1600 includes a hardware processor 1602 (e.g., a central processing unit (CPU), a hardware processor core, or any combination thereof), a graphics processing unit (GPU) 1603, a main memory 1604, and a static memory 1606, some or all of which may communicate with each other via an interlink (e.g., a bus) 1608. The machine 1600 may further include a display device 1610, an alphanumeric input device 1612 (e.g., a keyboard), and a user interface (UI) navigation device 1614 (e.g., a mouse). In one example, the display device 1610, the alphanumeric input device 1612, and the UI navigation device 1614 may be touchscreen displays. The machine 1600 may further include a mass storage device (e.g., a drive unit) 1616, a signal generator 1618 (e.g., a speaker), a network interface device 1620, and one or more sensors 1621 (such as a Global Positioning System (GPS) sensor, a compass, an accelerometer, or another sensor). The machine 1600 may include an output control device 1628, such as a serial connection (e.g., Universal Serial Bus (USB)), a parallel connection, or other wired or wireless (e.g., infrared (IR), near field communication (NFC)) connection, to communicate with or control one or more peripheral devices (e.g., a printer, a card reader).

[0093] In an exemplary embodiment, the hardware processor 1602 may perform at least the functions of the magnetic field controller 1418 described above in connection with FIGS.

[0094] Mass storage device 1616 may include machine-readable medium 1622 on which is stored one or more sets of data structures or instructions 1624 (e.g., software) embodied in or utilized by any one or more of the techniques or functions described herein. Instructions 1624 may also reside, completely or at least partially, within main memory 1604, static memory 1606, hardware processor 1602, or GPU 1603 during their execution by machine 1600. In one example, one or any combination of hardware processor 1602, GPU 1603, main memory 1604, static memory 1606, and mass storage device 1616 may constitute machine-readable media.

[0095] Although the machine-readable medium 1622 is illustrated as a single medium, the term “machine-readable medium” may include a single medium or multiple media (e.g., a centralized or distributed database, and / or associated caches and servers) configured to store one or more instructions 1624.

[0096] The term “machine-readable medium” refers to any medium capable of storing, encoding, or carrying instructions 1624 for execution by machine 1600, and may include any medium capable of causing machine 1600 to perform any one or more of the techniques of this disclosure or storing, encoding, or carrying data structures used by or related to such instructions 1624. Non-limiting examples of machine-readable media may include solid-state memory, and optical and magnetic media. In one example, a mass machine-readable medium comprises a machine-readable medium 1622 with a plurality of particles having an unchanging (e.g., stationary) mass. Thus, a mass machine-readable medium is not a transitory, propagating signal. Specific examples of mass machine-readable media may include non-volatile memory such as semiconductor memory devices (e.g., electrically programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM)) and flash memory devices, magnetic disks such as internal hard disks and removable disks, magneto-optical disks, and CD-ROM and DVD-ROM disks.

[0097] The instructions 1624 may also be transmitted or received over a communications network 1626 using a transmission medium via the network interface device 1620 .

[0098] Implementations of the above-described techniques may be realized in any number of specifications, configurations, or exemplary arrangements of hardware and software. It should be understood that functional units or functions described herein may be referred to or categorized as components or modules to more specifically emphasize their implementation independence. Such components may be embodied in any number of software or hardware forms. For example, a component or module may be implemented as a hardware circuit made of custom very large scale integrated (VLSI) circuits or gate arrays, off-the-shelf semiconductors (such as logic chips, transistors, or other discrete components). A component or module may also be implemented in programmable hardware devices, such as field programmable gate arrays, programmable array logic, or programmable logic devices. A component or module may also be implemented in software for execution by various types of processors. An identified component or module of executable code may include one or more physical or logical blocks of computer instructions, which may be organized as, for example, an object, a procedure, or a function. Nevertheless, an executable file for an identified component or module need not be physically located together but may include heterogeneous instructions stored in different locations that, when logically combined together, comprise the component or module and realize the specific purpose of the component or module.

[0099] Indeed, a component or module of executable code may be a single instruction or many instructions, and may be distributed across several different code segments, different programs, and several memory devices or processing systems. In particular, some aspects of the described processes (such as code rewriting and code analysis) may be performed on a processing system (e.g., a computer in a data center) different from the processing system on which the code is deployed (e.g., a computer embedded in a sensor or robot). Similarly, operational data is identified and depicted herein within components or modules and may be embodied in any suitable form and organized within any suitable type of data structure. Operational data may be collected as a single data set or distributed in different locations, including different storage devices, and may exist, at least in part, simply as electronic signals on a system or network. Components or modules, including agents operable to perform desired functions, may be passive or active.

[0100] Other notes and examples

[0101] Example 1 is a substrate processing apparatus comprising: a vacuum chamber including a processing zone for processing a substrate using plasma; a magnetic field sensor configured to detect a first signal representative of an axial magnetic field and a second signal representative of a radial magnetic field associated with the vacuum chamber, the radial magnetic field being parallel to the substrate and perpendicular to the axial magnetic field; at least two magnetic field sources configured to generate an auxiliary axial magnetic field and an auxiliary radial magnetic field through the processing zone of the vacuum chamber; and a magnetic field controller coupled to the magnetic field sensor and the at least two magnetic field sources, the magnetic field controller configured to adjust at least one characteristic of either or both of the auxiliary axial magnetic field and the auxiliary radial magnetic field based on the first signal and the second signal.

[0102] In Example 2, the subject matter of Example 1 includes the magnetic field sensor being a wafer sensor located within the processing zone of a vacuum chamber.

[0103] In Example 3, the subject matter of Example 2 includes the wafer sensor comprising an array of magnetic field sensors configured to measure one or more parameters of the axial magnetic field and the radial magnetic field at a plurality of locations within the processing zone, and the magnetic field controller adjusting at least one characteristic of the axial and radial supplemental magnetic fields based on the measured one or more parameters.

[0104] In Example 4, the subject matter of Examples 1-3 includes the magnetic field sensor configured to measure a magnitude of a first signal representative of an axial magnetic field and a magnitude of a second signal representative of a radial magnetic field.

[0105] In Example 5, the subject matter of Example 4 includes wherein the at least one characteristic includes one or both of a magnitude and a direction of an axial auxiliary magnetic field and a radial auxiliary magnetic field.

[0106] In Example 6, the subject matter of Example 5 includes the at least two magnetic field sources comprising a first magnetic field source and a second magnetic field source parallel to one another, and the magnetic field control device configured to adjust one or both of a current through the first magnetic field source and a current through the second magnetic field source to adjust one or both of a magnitude and a direction of the axial auxiliary magnetic field and the radial auxiliary magnetic field.

[0107] In Example 7, the subject matter of Example 6 includes, wherein the magnetic field controller is configured to adjust the current through the first magnetic field source independently from the current through the second magnetic field source.

[0108] In Example 8, the subject matter of Examples 6-7 includes, wherein the magnetic field control device is configured to adjust the current through the first magnetic field source and the current through the second magnetic field source until a ratio between a magnitude of the first signal representative of the axial magnetic field and a magnitude of the second signal representative of the radial magnetic field reaches a ratio threshold.

[0109] In Example 9, the subject matter of Examples 6-8 includes, wherein the magnetic field control device is configured to adjust the current through the first magnetic field source and the current through the second magnetic field source until a magnitude of the first signal representative of the axial magnetic field reaches a first threshold and a magnitude of the second signal representative of the radial magnetic field reaches a second threshold.

[0110] In Example 10, the subject matter of Examples 1-9 includes wherein the at least one characteristic of either or both of the axial auxiliary magnetic field and the radial auxiliary magnetic field includes one or more of: a number of turns in each of the at least two magnetic field sources; a distance from a first magnetic field source of the at least two magnetic field sources to the substrate; a distance from a second magnetic field source of the at least two magnetic field sources to the substrate; and a distance between the at least two magnetic field sources.

[0111] In Example 11, the subject matter of Examples 1-10 includes wherein the at least two magnetic field sources include a plurality of coils, each coil including a plurality of windings.

[0112] In Example 12, the subject matter of Example 11 includes the plurality of coils being mounted outside the vacuum chamber.

[0113] In Example 13, the subject matter of Examples 11-12 includes at least one of the plurality of coils being mounted inside the vacuum chamber.

[0114] In Example 14, the subject matter of Examples 11-13 includes the plurality of coils comprising at least four coils parallel to each other and to the substrate, and the magnetic field controller configured to independently adjust the current through each of the at least four coils based on the magnitude of one or both of the axial auxiliary magnetic field and the radial auxiliary magnetic field measured by the magnetic field sensor.

[0115] In Example 15, the subject matter of Examples 1-14 includes the substrate processing apparatus further comprising a plasma density sensor coupled to the magnetic field controller and configured to measure a density of plasma in the vacuum chamber, the magnetic field controller configured to independently adjust a current through each of the at least two magnetic field sources based on the measured density of the plasma.

[0116] Example 16 is a method for processing a substrate using a vacuum chamber, the method including: detecting a first signal representing an axial magnetic field in a processing zone of the vacuum chamber for processing the substrate using a plasma; detecting a second signal representing a radial magnetic field in the processing zone, the radial magnetic field being parallel to the substrate and perpendicular to the axial magnetic field; determining a magnitude of the first signal representing the axial magnetic field and a magnitude of the second signal representing the radial magnetic field at a plurality of positions in the processing zone; and generating an auxiliary axial magnetic field and an auxiliary radial magnetic field through the processing zone of the vacuum chamber using at least two magnetic field sources based on the determined magnitudes of the first and second signals.

[0117] In Example 17, the subject matter of Example 16 includes adjusting a current through at least one of the at least two magnetic field sources to adjust one or both of the magnitude and direction of the axial supplemental magnetic field and the radial supplemental magnetic field.

[0118] In Example 18, the subject matter of Example 17 includes independently adjusting current through at least one of the at least two magnetic field sources until a ratio between a magnitude of a first signal representative of an axial magnetic field and a magnitude of a second signal representative of a radial magnetic field reaches a ratio threshold.

[0119] In Example 19, the subject matter of Examples 17-18 includes independently adjusting current through at least one of the at least two magnetic field sources until a magnitude of a first signal representative of an axial magnetic field reaches a first threshold and a magnitude of a second signal representative of a radial magnetic field reaches a second threshold.

[0120] Example 20 is a non-transitory machine-readable storage medium containing instructions that, when executed by a machine, cause the machine to perform operations including detecting a first signal representative of an axial magnetic field within a processing zone of a vacuum chamber for processing a substrate using a plasma and detecting a second signal representative of a radial magnetic field within the processing zone, where the radial magnetic field is parallel to the substrate and orthogonal to the axial magnetic field; determining a magnitude of the first signal representative of the axial magnetic field and a magnitude of the second signal representative of the radial magnetic field at a plurality of locations within the processing zone; and generating, using at least two magnetic field sources, a supplemental axial magnetic field and a supplemental radial magnetic field through the processing zone of the vacuum chamber based on the determined magnitudes of the first and second signals.

[0121] In Example 21, the subject matter of Example 20 further includes adjusting either or both of the current through the first magnetic field source and the current through the second magnetic field source to adjust either or both of the magnitude and direction of the axial supplemental magnetic field and the radial supplemental magnetic field.

[0122] In Example 22, the subject matter of Example 21 further includes independently adjusting currents through the at least two magnetic field sources until a ratio between a magnitude of the first signal representative of the axial magnetic field and a magnitude of the second signal representative of the radial magnetic field reaches a ratio threshold.

[0123] In Example 23, the subject matter of Examples 21-22 further includes independently adjusting current through the at least two magnetic field sources until a magnitude of the first signal representative of the axial magnetic field reaches a first threshold and a magnitude of the second signal representative of the radial magnetic field reaches a second threshold.

[0124] Example 24 is at least one machine-readable medium comprising instructions that, when executed by processing circuitry, cause the processing circuitry to perform operations to implement any of Examples 1-23.

[0125] Example 25 is an apparatus equipped with means for carrying out any one of Examples 1 to 23.

[0126] Example 26 is a system for carrying out any one of Examples 1 to 23.

[0127] Example 27 is a method for carrying out any of Examples 1-23.

[0128] Throughout this specification, multiple examples may include components, operations, or structures that are described as a single example. Although individual operations of one or more methods are illustrated and described as separate operations, one or more of the individual operations may be performed simultaneously, and the operations need not be performed in the order shown. Structures and functions are presented such that separate components (e.g., configurations) may be implemented as composite structures or components. Similarly, structures and functions presented as a single component may be implemented as separate components. These and other variations, modifications, additions, and improvements fall within the scope of the subject matter of this specification.

[0129] The embodiments described herein are described in sufficient detail to enable those skilled in the art to practice the teachings of the disclosure. Other embodiments may be utilized and derived therefrom, such that structural and logical substitutions and changes may be made without departing from the scope of the disclosure. Accordingly, the detailed description is not to be construed in a limiting sense, and the scope of various embodiments is defined only by the appended claims, along with the full scope of equivalents to which such claims are entitled.

[0130] The claims need not recite all features disclosed herein, as embodiments may feature a subset of the features. Moreover, embodiments may include fewer features than are disclosed in a particular example. Thus, the following claims are incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment.

[0131] The term "or" as used herein may be interpreted in either an inclusive or exclusive sense. Also, multiple examples may be provided for a resource, operation, or structure described herein as an example. Moreover, boundaries between various resources, operations, modules, engines, and data stores are somewhat arbitrary, and particular operations are described in terms of specific illustrative configurations. Other allocations of functionality are contemplated and may be included within the scope of various embodiments of the present disclosure. In general, structures and functionality presented as separate resources in an illustrative configuration may be implemented as a composite structure or resource. Similarly, structures and functionality presented as a single resource may be implemented as a separate resource. These and other variations, modifications, additions, and improvements fall within the scope of embodiments of the present disclosure, as expressed in the appended claims. Accordingly, the specification and drawings are to be regarded as illustrative and not restrictive. The present disclosure may be realized in the following forms. [Form 1] A substrate processing apparatus, a vacuum chamber including a processing zone for processing a substrate using plasma; a magnetic field sensor configured to detect a first signal representative of an axial magnetic field associated with the vacuum chamber and a second signal representative of a radial magnetic field, the radial magnetic field being parallel to the substrate and orthogonal to the axial magnetic field; at least two magnetic field sources configured to generate an auxiliary axial magnetic field and an auxiliary radial magnetic field through the processing zone of the vacuum chamber; a magnetic field controller coupled to the magnetic field sensor and the at least two magnetic field sources, the magnetic field controller configured to adjust at least one characteristic of either or both of the axial auxiliary magnetic field and the radial auxiliary magnetic field based on the first signal and the second signal; A substrate processing apparatus comprising: [Form 2] 10. The device according to claim 1, The apparatus, wherein the magnetic field sensor is a wafer sensor located within the processing zone of the vacuum chamber. [Form 3] The device according to aspect 2, the wafer sensor comprises an array of magnetic field sensors configured to measure one or more parameters of the axial magnetic field and the radial magnetic field at a plurality of locations within the processing zone; The magnetic field control device adjusts the at least one characteristic of the axial auxiliary magnetic field and the radial auxiliary magnetic field based on the measured one or more parameters. [Form 4] 10. The device according to claim 1, The apparatus, wherein the magnetic field sensor is configured to measure a magnitude of the first signal representative of the axial magnetic field and a magnitude of the second signal representative of the radial magnetic field. [Form 5] The device according to claim 4, The apparatus, wherein the at least one characteristic includes one or both of a magnitude and a direction of the axial auxiliary magnetic field and the radial auxiliary magnetic field. [Form 6] The device according to claim 5, the at least two magnetic field sources include a first magnetic field source and a second magnetic field source parallel to each other; The magnetic field control device is configured to adjust one or both of a current through the first magnetic field source and a current through the second magnetic field source to adjust the magnitude and the direction or both of the axial auxiliary magnetic field and the radial auxiliary magnetic field. [Form 7] The device according to claim 6, The magnetic field control device is configured to adjust the current through the first magnetic field source independently of the current through the second magnetic field source. [Form 8] The device according to claim 6, The magnetic field control device is configured to adjust the current through the first magnetic field source and the current through the second magnetic field source until a ratio between the magnitude of the first signal representing the axial magnetic field and the magnitude of the second signal representing the radial magnetic field reaches a ratio threshold. [Form 9] The device according to claim 6, The magnetic field control device is configured to adjust the current through the first magnetic field source and the current through the second magnetic field source until the magnitude of the first signal representing the axial magnetic field reaches a first threshold and the magnitude of the second signal representing the radial magnetic field reaches a second threshold. [Form 10] 10. The device according to claim 1, The at least one characteristic of either or both of the axial auxiliary magnetic field and the radial auxiliary magnetic field is the number of turns in each of the at least two magnetic field sources; a distance from a first of the at least two magnetic field sources to the substrate; a distance from a second one of the at least two magnetic field sources to the substrate; and the distance between the at least two magnetic field sources 10. An apparatus comprising: [Form 11] 10. The device according to claim 1, The apparatus, wherein the at least two magnetic field sources include a plurality of coils, each coil including a plurality of windings. [Form 12] 12. The apparatus of claim 11, The apparatus, wherein the plurality of coils are mounted outside the vacuum chamber. [Form 13] 12. The apparatus of claim 11, At least one of the plurality of coils is mounted inside the vacuum chamber. [Form 14] 12. The apparatus of claim 11, the plurality of coils comprises at least four coils parallel to each other and to the substrate; The magnetic field control device is configured to independently adjust the current through each of the at least four coils based on the magnitude of one or both of the axial auxiliary magnetic field and the radial auxiliary magnetic field measured by the magnetic field sensor. [Form 15] 10. The device according to claim 1, the substrate processing apparatus further comprising a plasma density sensor coupled to the magnetic field control device and configured to measure a density of the plasma in the vacuum chamber; The magnetic field controller is configured to independently adjust a current through each of the at least two magnetic field sources based on the measured density of the plasma. [Form 16] 1. A method for processing a substrate using a vacuum chamber, comprising: detecting a first signal representative of an axial magnetic field within a processing zone of the vacuum chamber for processing a substrate with a plasma; detecting a second signal representative of a radial magnetic field within the processing zone, the radial magnetic field being parallel to the substrate and orthogonal to the axial magnetic field; determining a magnitude of the first signal representative of the axial magnetic field and a magnitude of the second signal representative of the radial magnetic field at a plurality of locations within the processing zone; generating, using at least two magnetic field sources, an auxiliary axial magnetic field and an auxiliary radial magnetic field through the processing zone of the vacuum chamber based on the determined magnitudes of the first signal and the second signal; A method comprising: [Form 17] 17. The method of claim 16, further comprising: adjusting a current through at least one of at least two magnetic field sources to adjust one or both of the magnitude and direction of the axial supplemental magnetic field and the radial supplemental magnetic field. [Form 18] 18. The method of claim 17, further comprising: independently adjusting the current through the at least one of the at least two magnetic field sources until a ratio of the magnitude of the first signal representing the axial magnetic field to the magnitude of the second signal representing the radial magnetic field reaches a ratio threshold. [Form 19] 18. The method of claim 17, further comprising: independently adjusting the current through the at least one of the at least two magnetic field sources until the magnitude of the first signal representative of the axial magnetic field reaches a first threshold and the magnitude of the second signal representative of the radial magnetic field reaches a second threshold. [Form 20] A machine-readable storage medium containing instructions, The instructions, when executed by a machine, detecting a first signal representative of an axial magnetic field within a processing zone of a vacuum chamber for processing a substrate with a plasma; detecting a second signal representative of a radial magnetic field in the processing zone, the radial magnetic field being parallel to the substrate and orthogonal to the axial magnetic field; determining a magnitude of the first signal representative of the axial magnetic field and a magnitude of the second signal representative of the radial magnetic field at a plurality of locations within the processing zone; generating, using at least two magnetic field sources, an auxiliary axial magnetic field and an auxiliary radial magnetic field through the processing zone of the vacuum chamber based on the determined magnitudes of the first signal and the second signal; A machine-readable storage medium that causes the machine to execute the [Form 21] 21. The machine-readable storage medium of claim 20, the operations further including adjusting one or both of a current through a first magnetic field source of the at least two magnetic field sources and a current through a second magnetic field source of the at least two magnetic field sources to adjust one or both of a magnitude and a direction of the axial supplemental magnetic field and the radial supplemental magnetic field. [Form 22] 22. The machine-readable storage medium according to claim 21, the operations further include independently adjusting the currents through the at least two magnetic field sources until a ratio between the magnitude of the first signal representing the axial magnetic field and the magnitude of the second signal representing the radial magnetic field reaches a ratio threshold. [Form 23] 22. The machine-readable storage medium according to claim 21, the operations further include independently adjusting the currents through the at least two magnetic field sources until the magnitude of the first signal representing the axial magnetic field reaches a first threshold and the magnitude of the second signal representing the radial magnetic field reaches a second threshold.

Claims

1. A substrate processing apparatus, a vacuum chamber including a processing zone for processing a substrate using plasma; a magnetic field sensor configured to detect a first signal representative of an axial magnetic field associated with the vacuum chamber and a second signal representative of a radial magnetic field, the radial magnetic field being parallel to the substrate and orthogonal to the axial magnetic field; at least two magnetic field sources configured to generate an auxiliary axial magnetic field and an auxiliary radial magnetic field through the processing zone of the vacuum chamber; a magnetic field controller coupled to the magnetic field sensor and the at least two magnetic field sources, the magnetic field controller configured to adjust at least one characteristic of either or both of the axial auxiliary magnetic field and the radial auxiliary magnetic field based on the first signal and the second signal; Equipped with The apparatus, wherein the magnetic field sensor is a wafer sensor located within the processing zone of the vacuum chamber.

2. 10. The apparatus of claim 1, the wafer sensor comprises an array of magnetic field sensors configured to measure one or more parameters of the axial magnetic field and the radial magnetic field at a plurality of locations within the processing zone; The magnetic field control device adjusts the at least one characteristic of the axial auxiliary magnetic field and the radial auxiliary magnetic field based on the measured one or more parameters.

3. A substrate processing apparatus, a vacuum chamber including a processing zone for processing a substrate using plasma; a magnetic field sensor configured to detect a first signal representative of an axial magnetic field associated with the vacuum chamber and a second signal representative of a radial magnetic field, the radial magnetic field being parallel to the substrate and orthogonal to the axial magnetic field; at least two magnetic field sources configured to generate an auxiliary axial magnetic field and an auxiliary radial magnetic field through the processing zone of the vacuum chamber; a magnetic field controller coupled to the magnetic field sensor and the at least two magnetic field sources, the magnetic field controller configured to adjust at least one characteristic of either or both of the axial auxiliary magnetic field and the radial auxiliary magnetic field based on the first signal and the second signal; Equipped with the magnetic field sensor is configured to measure a magnitude of the first signal representative of the axial magnetic field and a magnitude of the second signal representative of the radial magnetic field; the at least one characteristic includes one or both of a magnitude and a direction of the axial auxiliary magnetic field and the radial auxiliary magnetic field; the at least two magnetic field sources include a first magnetic field source and a second magnetic field source parallel to each other; the magnetic field control device is configured to adjust one or both of a current through the first magnetic field source and a current through the second magnetic field source to adjust the magnitude and / or the direction of the axial auxiliary magnetic field and the radial auxiliary magnetic field; The magnetic field control device is configured to adjust the current through the first magnetic field source and the current through the second magnetic field source until a ratio between the magnitude of the first signal representing the axial magnetic field and the magnitude of the second signal representing the radial magnetic field reaches a ratio threshold.

4. 4. The apparatus of claim 3, The apparatus, wherein the magnetic field control device is configured to adjust the current through the first magnetic field source independently of the current through the second magnetic field source.

5. 4. The apparatus of claim 3, The magnetic field control device is configured to adjust the current through the first magnetic field source and the current through the second magnetic field source until the magnitude of the first signal representing the axial magnetic field reaches a first threshold and the magnitude of the second signal representing the radial magnetic field reaches a second threshold.

6. A substrate processing apparatus, a vacuum chamber including a processing zone for processing a substrate using plasma; a magnetic field sensor configured to detect a first signal representative of an axial magnetic field associated with the vacuum chamber and a second signal representative of a radial magnetic field, the radial magnetic field being parallel to the substrate and orthogonal to the axial magnetic field; at least two magnetic field sources configured to generate an auxiliary axial magnetic field and an auxiliary radial magnetic field through the processing zone of the vacuum chamber; a magnetic field controller coupled to the magnetic field sensor and the at least two magnetic field sources, the magnetic field controller configured to adjust at least one characteristic of either or both of the axial auxiliary magnetic field and the radial auxiliary magnetic field based on the first signal and the second signal; Equipped with The at least one characteristic of either or both of the axial auxiliary magnetic field and the radial auxiliary magnetic field is the number of turns in each of the at least two magnetic field sources; a distance from a first of the at least two magnetic field sources to the substrate; a distance from a second one of the at least two magnetic field sources to the substrate; and the distance between the at least two magnetic field sources 10. An apparatus comprising:

7. A substrate processing apparatus, a vacuum chamber including a processing zone for processing a substrate using plasma; a magnetic field sensor configured to detect a first signal representative of an axial magnetic field associated with the vacuum chamber and a second signal representative of a radial magnetic field, the radial magnetic field being parallel to the substrate and orthogonal to the axial magnetic field; at least two magnetic field sources configured to generate an auxiliary axial magnetic field and an auxiliary radial magnetic field through the processing zone of the vacuum chamber; a magnetic field controller coupled to the magnetic field sensor and the at least two magnetic field sources, the magnetic field controller configured to adjust at least one characteristic of either or both of the axial auxiliary magnetic field and the radial auxiliary magnetic field based on the first signal and the second signal; Equipped with the at least two magnetic field sources include a plurality of coils, each coil including a plurality of windings; The apparatus, wherein the plurality of coils are mounted outside the vacuum chamber.

8. 8. The apparatus of claim 7, At least one of the plurality of coils is mounted inside the vacuum chamber.

9. 8. The apparatus of claim 7, the plurality of coils comprises at least four coils parallel to each other and to the substrate; the magnetic field control device is configured to independently adjust the current through each of the at least four coils based on a magnitude of one or both of the axial auxiliary magnetic field and the radial auxiliary magnetic field measured by the magnetic field sensor.

10. A substrate processing apparatus, comprising: a vacuum chamber including a processing zone for processing a substrate using plasma; a magnetic field sensor configured to detect a first signal representative of an axial magnetic field associated with the vacuum chamber and a second signal representative of a radial magnetic field, the radial magnetic field being parallel to the substrate and orthogonal to the axial magnetic field; at least two magnetic field sources configured to generate an auxiliary axial magnetic field and an auxiliary radial magnetic field through the processing zone of the vacuum chamber; a magnetic field controller coupled to the magnetic field sensor and the at least two magnetic field sources, the magnetic field controller configured to adjust at least one characteristic of either or both of the axial auxiliary magnetic field and the radial auxiliary magnetic field based on the first signal and the second signal; Equipped with the substrate processing apparatus further comprising a plasma density sensor coupled to the magnetic field control device and configured to measure a density of the plasma in the vacuum chamber; The apparatus, wherein the magnetic field controller is configured to independently adjust a current through each of the at least two magnetic field sources based on the measured density of the plasma.

11. 1. A method for processing a substrate using a vacuum chamber, comprising: detecting a first signal representative of an axial magnetic field within a processing zone of the vacuum chamber for processing a substrate with a plasma; detecting a second signal representative of a radial magnetic field within the processing zone, the radial magnetic field being parallel to the substrate and orthogonal to the axial magnetic field; determining a magnitude of the first signal representative of the axial magnetic field and a magnitude of the second signal representative of the radial magnetic field at a plurality of locations within the processing zone; generating, using at least two magnetic field sources, an auxiliary axial magnetic field and an auxiliary radial magnetic field through the processing zone of the vacuum chamber based on the determined magnitudes of the first signal and the second signal; and adjusting a current through at least one of the at least two magnetic field sources to adjust the magnitude and / or direction of the axial auxiliary magnetic field and the radial auxiliary magnetic field; independently adjusting the current through the at least one of the at least two magnetic field sources until a ratio of the magnitude of the first signal representing the axial magnetic field to the magnitude of the second signal representing the radial magnetic field reaches a ratio threshold.

12. 12. The method of claim 11 further comprising: independently adjusting the current through the at least one of the at least two magnetic field sources until the magnitude of the first signal representative of the axial magnetic field reaches a first threshold and the magnitude of the second signal representative of the radial magnetic field reaches a second threshold.

13. A machine-readable storage medium containing instructions, The instructions, when executed by a machine, detecting a first signal representative of an axial magnetic field within a processing zone of a vacuum chamber for processing a substrate with a plasma; detecting a second signal representative of a radial magnetic field in the processing zone, the radial magnetic field being parallel to the substrate and orthogonal to the axial magnetic field; determining a magnitude of the first signal representative of the axial magnetic field and a magnitude of the second signal representative of the radial magnetic field at a plurality of locations within the processing zone; generating, using at least two magnetic field sources, an auxiliary axial magnetic field and an auxiliary radial magnetic field through the processing zone of the vacuum chamber based on the determined magnitudes of the first signal and the second signal; A machine-readable storage medium that causes the machine to execute the

14. 14. The machine-readable storage medium of claim 13, the operations further include adjusting one or both of a current through a first magnetic field source of the at least two magnetic field sources and a current through a second magnetic field source of the at least two magnetic field sources to adjust one or both of a magnitude and a direction of the axial supplemental magnetic field and the radial supplemental magnetic field.

15. 15. The machine-readable storage medium of claim 14, the operations further include independently adjusting the currents through the at least two magnetic field sources until a ratio between the magnitude of the first signal representing the axial magnetic field and the magnitude of the second signal representing the radial magnetic field reaches a ratio threshold.

16. 15. The machine-readable storage medium of claim 14, the operations further include independently adjusting the currents through the at least two magnetic field sources until the magnitude of the first signal representing the axial magnetic field reaches a first threshold and the magnitude of the second signal representing the radial magnetic field reaches a second threshold.

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