High power low frequency coil

Abstract

A coil having a coil body and a plurality of concentric cross-section windings of conductors arranged around the coil body, the conductors having a spacing between adjacent turns of approximately 0.25 to 1.0 times the radius of the conductors. Also, a coil for a plasma processing apparatus having a coil body and a plurality of concentric cylindrical cross-section windings of conductors arranged around the coil body, the conductors having a spacing between adjacent turns of approximately 0.25 to 1.0 times the radius of the conductors, and having a diameter-to-length ratio between approximately 2:1 and approximately 3:1.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Patent Application No. 62 / 893,066, filed on August 28, 2019, and U.S. Non-Provisional Patent Application No. 17 / 006,693, filed on August 28, 2020, the contents of which are incorporated herein by reference. Background Art

[0003] Radio frequency (RF) plasma enhanced processes are widely used in semiconductor manufacturing to etch different types of films, deposit thin films at low to moderate process temperatures, and perform surface treatment and cleaning. These processes are characterized by the use of plasma, a partially ionized gas, which is used to generate neutral species and ions from precursors within a reaction chamber, provide energy for ion bombardment, and / or perform other actions. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] When with Figure 1 The present disclosure can be best understood from the following detailed description when read together. It should be emphasized that, in accordance with standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of various features can be arbitrarily increased or decreased for the sake of clarity of discussion.

[0005] Figure 1 is a schematic diagram of an RF plasma processing system according to an embodiment of the present disclosure.

[0006] Figure 2 is a side view of a coil according to an embodiment of the present disclosure.

[0007] Figure 3 According to the embodiment of the present disclosure Figure 2 A side elevation view of the coil.

[0008] Figure 4 According to the embodiment of the present disclosure Figure 2 End view of the coil.

[0009] Figure 5 According to the embodiment of the present disclosure Figure 2 A side perspective view of a coil.

[0010] Figure 6 According to the embodiment of the present disclosure Figure 2 Side view of the coil.

[0011] Figure 7 is a side view of a coil in a coil block according to an embodiment of the present disclosure.

[0012] Figure 8 is a coil block according to an embodiment of the present disclosure Figure 7Schematic diagram of the coil in perspective.

[0013] Fig. 9 is a schematic cross-sectional view of a coil according to an embodiment of the present disclosure.

[0014] Fig.10 is a schematic diagram of a three-wire inductor according to an embodiment of the present disclosure.

[0015] Fig.11 is a flow chart of a method for forming a coil for a plasma processing device according to an embodiment of the present disclosure DETAILED DESCRIPTION

[0016] The following illustrative examples of the claimed subject matter will now be disclosed. For the sake of clarity, not all features of an actual implementation are described in this specification. It will be appreciated that in the development of any such actual implementation, many implementation-specific decisions may be made to achieve the developer's particular goals, such as compliance with system-related and business-related constraints, which will vary from implementation to implementation. Furthermore, it will be appreciated that such development work, even if complex and time consuming, will be a routine task for a person of ordinary skill in the art having the benefit of this disclosure.

[0017] In addition, as used herein, the article "a" is intended to have its ordinary meaning in the patent field, i.e., "one or more". In this article, the term "about" when applied to a value generally means within the tolerance range of the equipment used to produce the value, or in some examples, means plus or minus 10%, or plus or minus 5%, or plus or minus 1%, unless otherwise expressly specified. In addition, as used herein, the term "substantially" means most, or almost all, or all, or an amount with a range of, for example, about 51% to about 100%. In addition, the examples herein are intended to be used only for illustration and are presented for the purpose of discussion rather than in a limiting manner.

[0018] Typical cylindrical single layer coils may have many problems and limitations in use. For example, typical cylindrical single layer coils may have a reduced Q factor when the length is greater than the diameter. In addition, such coils experience poor cooling when wound on a dielectric cylinder due to trapped air adjacent to the cylindrical coil form. The coil may also have a relatively long magnetic field return path, which may result in a high coupling coefficient with the aluminum shielding enclosure wall, thereby generating eddy current losses that result in a lower Q value. Typical coils may also have a lower inductance per unit length of wire, which may result in a lower Q value. Such coils may also have manufacturing tolerances that are more difficult to predict.

[0019] Embodiments of the present disclosure can reduce the loss of voltage and current at high power, which leads to better Q value due to better storage and dissipation energy ratio. Embodiments of the present disclosure can also advantageously maximize the inductance of the wire used per unit length, thereby producing better Q value. Such embodiments can also reduce the distributed voltage across the winding, thereby reducing the voltage stress potential internally. Embodiments can further reduce the magnetic field coupled to the aluminum shielding shell by optimizing the magnetic field return path, thereby reducing the eddy current loss of the coupling to the shield. Embodiments can also increase the airflow around the inductor wire to improve cooling. Other advantages can include providing a mechanical body with predictable wire dimension spacing in the X, Y and Z directions, resulting in a tighter manufacturing tolerance range. Not all embodiments will exhibit all of these features, and to the extent that they exhibit more than one feature, they may not exhibit them to the same extent.

[0020] Embodiments of the present disclosure may provide relatively high power low frequency coils, such as, for example, coils having a frequency of about 400k. In other embodiments, the coils disclosed herein may have frequencies below 400k and / or above 400k, depending on the application. In addition, the disclosed geometry compresses the magnetic field to reduce coupling interactions with the shielding wall surrounding the coil. In addition, the registered starting point of each winding from the same side reduces the voltage stress between layers, thereby allowing higher voltage operation compared to coils with multiple layers of continuous filaments that traverse from one side to the other. The geometric positioning of the equally spaced wires may also result in tight tolerance repeatability approaching + / -1%.

[0021] Steering Figure 1 , shows a side schematic diagram of an RF plasma processing system 100 according to an embodiment of the present disclosure. The RF plasma processing system 100 includes a first RF generator 105 and a second RF generator 110, a first impedance matching network 115, a second impedance matching network 120, a sheath 125, a plasma driving (powering) device such as a showerhead 130 or an equivalent driven element such as an electrode, and a pedestal 135. As used herein, a plasma power device may refer to any device that introduces power to generate a plasma and may include, for example, a showerhead 130 and / or other types of electrodes, as well as antennas, etc.

[0022] The RF plasma processing system 100 may include one or more first RF generators 105 and second RF generators 110 that deliver power to a reaction chamber 140 through one or more impedance matching networks 115, 120. RF power flows from the first RF generator 105 through the impedance matching network 115 to the showerhead 130 into the plasma in the reaction chamber 140, to an electrode (not shown) other than the showerhead 130, or to an inductive antenna (not shown) that electromagnetically provides power to the plasma, and then the power flows from the plasma to ground and / or to the pedestal 135 and / or to the second impedance matching network 120. In general, the first impedance matching network 115 compensates for changes in load impedance within the reaction chamber 140, so that by adjusting reactive components (not separately shown) within the first impedance matching network 115, such as variable capacitors, the combined impedance of the showerhead 130 and the first impedance matching network 115 is equal to the output of the first RF generator 105, such as 50 ohms.

[0023] The impedance matching networks 115, 120 are designed to adjust their internal reactive elements so that the load impedance matches the source impedance. Embodiments of the present disclosure may be used for impedance matching networks 115, 120, filters (not shown), resonators (not shown), and the like.

[0024] Steering Figure 2 , a side view of a coil according to an embodiment of the present disclosure is shown. In this embodiment, the coil 200 includes a coil body 205, which is shown as having six coil body extensions 210. Although six coil body extensions 210 are shown, in other embodiments, the coil body 205 can be three, four, five, seven or more coil body extensions 210. The coil body extensions 210 can protrude radially outward from the coil body center 215. The coil body center 215 can be used to attach the coil 200 to a block (not shown), which will be described below.

[0025] exist Figure 3 and Figure 5 One or more spacers 220 / 222 best shown in the figure can be arranged on the radially outward edge of one or more coil body extensions 210. In this embodiment, two spacers 220 / 222 are illustrated, wherein one inward spacer 220 is arranged radially inwardly, and a second outward spacer 222 is arranged radially outwardly. The spacers 220 / 222 can be formed of the same material as the coil body 205, or can be formed of other materials in other embodiments.

[0026] The wire 225 can be concentrically wrapped around the coil body 205 and the coil body extension 210, starting from the center, i.e., at the radially outward edge of the coil body 205. The inward spacer 220 can then be disposed on top of the coil body 205, and the wire 225 can be wrapped through the inward spacer 220. The outward spacer 222 can then be disposed on top of the inward spacer 200, and the wire 225 can be wrapped through the outward spacer 222.

[0027] In other embodiments, more than one wire 225 may be used. For example, a first wire may be wound around the coil body 205. A second wire may be wound around the inward spacer 220 and a third wire may be wound around the outward spacer 222. The three wires may then be connected using one or more electrical connectors, such as an electrical bus.

[0028] In operation, coil 200 comprises cylindrical winding, and this cylindrical winding comprises multilayer, comprises three-layer winding in this embodiment.Winding begins at the innermost diameter, and winding continues around seven turns, and this will be described in more detail below.At the innermost diameter end, wire 225 returns to the starting position by the center of coil body 205, then covers the first winding to start the second winding at the place where the first winding begins.The second winding continues to its end, and it comprises eight turns in this embodiment.The second winding returns by the center of coil body 205 once it arrives at the end.Wire 225 can continue the 3rd winding then, and it comprises nine turns in this embodiment.At the end of the 3rd winding, wire can leave coil 200, to be electrically connected to other parts by the electrical connector of for example wiring lug (not shown) or other types.

[0029] By providing three continuous windings, the number of layers used is reduced. Thus, by using three windings, the voltage stress can be divided by three. If each winding includes turns of the same length, the wire 225 will eventually have the same amount of voltage at its two ends. In addition, such a geometric structure compresses the magnetic field so as to reduce coupling interactions with a shield wall (not shown) surrounding the coil 200 in operation.

[0030] Aspects of the coil 200 may also include starting each winding from the same side of the coil 200, coil body 205, and coil body extension 210. By starting from the same side of the coil 200, voltage stress can be reduced layer by layer, thereby allowing higher voltage operation compared to a continuous filament sequential winding coil in which multiple layers are traversed from one side to the other. In addition, the geometric positioning of the wires provides equal spacing, which results in close tolerance repeatability within about 1%. Specific design aspects of the coil 200 as a multi-strand coil will be discussed in detail below.

[0031] Steering Figure 3, a side view of a coil 200 according to an embodiment of the present disclosure is shown. As discussed above, the coil 200 includes a coil body 205, which is shown as having six coil body extensions 210. As shown, the coil body extensions 210 protrude radially outward from the coil body center 215. One or more spacers 220 / 222 can be arranged on the radially outward edges of the one or more coil body extensions 210. In this embodiment, two spacers 220 / 222 are illustrated, wherein one of the inward spacers 220 is arranged radially inwardly, and a second outward spacer 222 is arranged radially outwardly.

[0032] The wire 225 can be concentrically wrapped around the coil body 205 and the coil body extension 210, starting at the center, i.e., at the radially outward edge of the coil body 205. The inward spacer 220 can then be placed on top of the coil body 205, and the wire 225 can be wrapped through the inward spacer 220. The outward spacer 222 can then be placed on top of the inward spacer 200, and the wire 225 can be wrapped through the outward spacer 222.

[0033] Both ends of the wire 225 may include electrical connectors 230, such as terminal lugs. In some embodiments, the electrical connector 230 may include other types of connectors, such as, for example, male and female connectors, threaded connectors, bolt connectors, and / or any other type of electrical connector 230 used or applicable in the art. In some embodiments, the electrical connector 230 may be insulated or partially insulated, depending on operational requirements.

[0034] Steering Figure 4 , an end view of a coil 200 according to an embodiment of the present disclosure is shown. As discussed above, the coil 200 includes a coil body 205, which is shown as having six coil body extensions 210. As shown, the coil body extensions 210 protrude radially outward from the coil body center 215. One or more spacers 220 / 222 can be arranged on the radially outward edges of the one or more coil body extensions 210. In this embodiment, two spacers 220 / 222 are illustrated, wherein one of the inward spacers 220 is arranged radially inwardly, and a second outward spacer 222 is arranged radially outwardly.

[0035] The wire 225 can be concentrically wrapped around the coil body 205 and the coil body extension 210, starting at the center, i.e., at the radially outward edge of the coil body 205. The inward spacer 220 can then be placed on top of the coil body 205, and the wire 225 can be wrapped through the inward spacer 220. The outward spacer 222 can then be placed on top of the inward spacer 200, and the wire 225 can be wrapped through the outward spacer 222.

[0036] like Figure 4 As shown in , the third winding, i.e., the outermost radial winding, includes nine windings. As discussed above, the middle or second winding includes eight windings, and the innermost radial winding includes seven windings. Thus, a triangular winding body is produced, which can provide one or more of the advantages discussed above. The triangular winding body will be described and discussed in more detail below.

[0037] Go to Figure 5 , shows a side perspective view of a coil 200 according to an embodiment of the present disclosure. Figure 5 In the embodiment of the present invention, for the clarity of the geometric structure of other parts such as coil body 205 and spacer 220 / 222, some parts of wire 225 have been removed.As discussed above, coil 200 comprises coil body 205, and it is shown as having six coil body extensions 210.As shown in the figure, coil body extension 210 is radially outwardly outstanding from coil body center 215.One or more spacers 220 / 222 can be arranged on the radially outward edge of one or more coil body extensions 210.In this embodiment, two spacers 220 / 222 are illustrated, wherein one of them inward spacer 220 is arranged radially inwardly, and second outward spacer 222 is arranged radially outwardly.

[0038] The wire 225 can be concentrically wrapped around the coil body 205 and the coil body extension 210, starting at the center, i.e., at the radially outward edge of the coil body 205. The inward spacer 220 can then be placed on top of the coil body 205, and the wire 225 can be wrapped through the inward spacer 220. The outward spacer 222 can then be placed on top of the inward spacer 200, and the wire 225 can be wrapped through the outward spacer 222.

[0039] Go to Figure 6 , a side view of a coil 200 according to an embodiment of the present disclosure is shown. As discussed above, the coil 200 includes a coil body 205, which is shown as having six coil body extensions 210. As shown, the coil body extensions 210 protrude radially outward from the coil body center 215. One or more spacers 220 / 222 can be arranged on the radially outward edges of the one or more coil body extensions 210. In this embodiment, two spacers 220 / 222 are illustrated, wherein one of the inward spacers 220 is arranged radially inwardly, and a second outward spacer 222 is arranged radially outwardly.

[0040] The wire 225 can be concentrically wrapped around the coil body 205 and the coil body extension 210, starting at the center, i.e., at the radially outward edge of the coil body 205. The inward spacer 220 can then be placed on top of the coil body 205, and the wire 225 can be wrapped through the inward spacer 220. The outward spacer 222 can then be placed on top of the inward spacer 200, and the wire 225 can be wrapped through the outward spacer 222.

[0041] As about Figure 5 As discussed, the outermost winding 235 is returned to the center of the winding 240 before leaving the coil 200 to connect to another device. Similarly, the middle winding 245 is also returned to the center of the winding 240 before being wound into the third winding 240. The innermost winding 250 is also returned to the center of the winding 240 before being wound into the middle winding 245.

[0042] Go to Figure 7 , a side view of a coil in a coil block according to an embodiment of the present disclosure is shown. In this embodiment, the coil 200 includes a coil body 205, which is shown as having six coil body extensions 210. As shown, the coil body extensions 210 protrude radially outward from the coil center of the coil body. One or more spacers 220 / 222 can be arranged on the radially outward edges of the one or more coil body extensions 210. In this embodiment, two spacers 220 / 222 are illustrated, wherein one inward spacer 220 is arranged radially inwardly, and a second outward spacer 222 is arranged radially outwardly.

[0043] In this illustration, the coil 200 is shown disposed within a coil block 255. The coil 200 may be connected to the coil block 255 by various types of mechanical attachments 260, such as, for example, bolts. The coil block 255 may be formed from a variety of materials, including those materials that form the coil 200. The coil block 255 may be used to hold the coil 200 in place during operation and may be connected to a housing (not shown) or other components using one or more attachment points 265. The coil block 255 and the wire 225 windings may be connected to the coil block 255. Figure 8 Explain in more detail.

[0044] Steering Figure 8, shows one side of a schematic cross-sectional view of a coil according to an embodiment of the present disclosure. As discussed above, coil 200 includes a coil body 205, which is shown as having six coil body extensions 210. As shown, the coil body extensions 210 protrude radially outward from the coil body center 215. One or more spacers 220 / 222 can be arranged on the radially outward edges of one or more coil body extensions 210. In this embodiment, two spacers 220 / 222 are illustrated, wherein one inward spacer 220 is arranged radially inwardly, and a second outward spacer 222 is arranged radially outwardly.

[0045] The wire 225 can be concentrically wrapped around the coil body 205 and the coil body extension 210, starting at the center, i.e., at the radially outward edge of the coil body 205. The inward spacer 220 can then be disposed on top of the coil body 205, and the wire 225 can be wrapped through the inward spacer 220. The outward spacer 222 can then be disposed on top of the inward spacer 200, and the wire 225 can be wrapped through the outward spacer 222. The wire 225 can pass through the corresponding groove sets 223 formed in the coil body 205, the inward spacer 220, and the outward spacer 222.

[0046] The coil 200 is also shown as having two electrical connectors 230 / 232. The first electrical connector 230 starts from the innermost first winding, and the second electrical connector ends at the outermost third winding. As shown, the two electrical connectors 230 / 232 are shown as terminals, but other electrical connectors, such as those described above, may also be used.

[0047] In this illustration, the coil 200 is shown disposed within a coil block 255. The coil 200 may be connected to the coil block 255 by various types of mechanical attachments 260, such as, for example, bolts. The coil block 255 may be formed from a variety of materials, including those materials that form the coil 200. The coil block 255 may be used to hold the coil 200 in place during operation, and may be connected to a housing (not shown) or other components using one or more attachment points 265.

[0048] Steering Fig. 9, a schematic cross-sectional view of a coil 200 according to an embodiment of the present disclosure is shown. In this embodiment, the coil 200 is shown as having three windings of a conductor 225. The innermost first winding 250, the middle second winding 245 and the outermost third winding 235. Each winding wound relative to each adjacent conductor is spaced apart at a fixed distance in the axial and radial directions so that the cross section of the complete concentric layers of the winding forming a unilateral triangle is the setting of all conductor centers. The unilateral triangle geometry is shown at reference numeral 270. The progression of the number of winding turns of one turn per layer can thus optimize the field return path. The number of winding turns of one turn per layer is shown at reference numeral 275.

[0049] Thus, embodiments of the present disclosure may provide multiple concentric cylindrical or polygonal cross-section wire windings such that the spacing between any adjacent turns is equal and is on the order of 0.25 to 1 radius of the wire used. Such embodiments may include concentric cylindrical wires connected such that the starting point of a first winding continues to the final turn and then returns axially to the same starting end of the first winding to begin a new, larger diameter cylindrical winding layer concentric with the first winding, thereby surrounding the first winding. The starting point of a second winding continues to the final turn and then returns axially to the same starting end as the first winding and the second winding to begin a new cylindrical winding concentric with the second winding and the first winding.

[0050] The concentric coils can thus have co-registered start and end points for each winding. The total cross-section of the winding includes a diameter 280 and a length that together form a ratio of diameter to length 285, i.e., an average diameter, between 2:1 and 3:1, and in some embodiments between 2.4:1 and 2.5:1, and in still other embodiments about 2.46:1.

[0051] The wire turns can be parallel and perpendicular to the coil axis up to 5 / 6 turns and step from one guide slot to the next up to 1 / 6 turn. Thus, this mechanical technique can simplify the construction of the coil during manufacturing. Thus, adding one turn per layer can provide the advantage of improved magnetic field coupling and can maintain wire separation as the wires rise radially from a lower layer to the next layer.

[0052] Steering Fig.10, a schematic diagram of a three-wire inductor according to an embodiment of the present disclosure is shown. As shown, the first electrical connector 230, which is a first terminal block in this embodiment, is connected to a power source (not shown). The wire 225 is then wound into three concentric windings. The first winding 250 includes seven turns and forms the innermost portion of the coil. The second winding 245 includes eight turns and forms the middle portion of the coil. The third winding 235 includes nine turns and forms the outermost portion of the coil. The wire 225 then leaves the coil and is cut off at the second end connector 232.

[0053] Steering Fig.11 , a flow chart of a method for forming a coil for a plasma processing device according to an embodiment of the present disclosure is shown. The method includes feeding a wire (block 300) through a coil body center portion of the coil body. The coil body center portion may include one or more holes that allow the wire to pass through the coil body.

[0054] The method may also include winding (block 305) a wire around the coil body to form a first winding. The wire may initially pass through a hole in the coil body and then around a radially outward portion of the coil body. Depending on operational requirements, the wire may pass through a groove preformed in the coil body or may be pressed against the coil body.

[0055] The method may also include returning (block 310) the wire to a central portion of the coil body center of the coil body. The wire may thus be returned to the central portion at a position on the same side as the start of the first winding. The final position of the first winding, while on the same side of the coil body, may be longitudinally located at a different position relative to the hole through which the wire was initially passed.

[0056] The method may also include winding (block 315) a wire around the coil body to form a second winding, which is radially farther from the center of the coil body center than the first winding. Thus, the second winding is outside the first winding. The second winding may start by passing through a second hole, which is located on the same side of the coil body as the first hole, but may be located at a different longitudinal position.

[0057] The method may also include returning (block 320) the wire to a center portion of the coil body center of the coil body. The wire may thus be returned to the center portion at a position on the same side as the position where the first winding begins and ends. The final position of the second winding, while on the same side of the coil body, may be longitudinally located at a different position relative to the hole through which the wire initially passed to begin the second winding.

[0058] The method can also include winding (block 325) wire around the coil body to form a 3rd winding, which is farther radially than the second winding from the center of the coil body. Thereby the wire can be returned to the center at a position on the same side as the position where the first winding and the second winding begin and end. The final position of the 3rd winding, although on the same side of the coil body, can be longitudinally located at different positions relative to the wire initially passing through the hole that starts the first winding and / or the second winding.

[0059] In some embodiments, a first winding is disposed on at least a portion of the coil body, a second winding is disposed on at least a portion of a first spacer, the first spacer being disposed on a radially distal portion of the coil body, and a third winding is disposed on at least a portion of a second spacer, the second spacer being disposed on the first spacer. The first spacer may be added to the coil after the first winding occurs. The second spacer may be added to the coil after the second winding occurs. Because the spacers are added sequentially, the coil may be assembled more easily because the radially outermost edge of the coil may be accessible during any given winding.

[0060] In certain embodiments, the first winding may include seven turns, the second winding may include eight turns, and the third winding may include nine turns. In other embodiments, the number of turns of any given winding may vary based on the quantity of coil body extensions and the desired result of a particular operation. For example, in certain embodiments, the coil may include three progressive windings of four, five and six windings. Those of ordinary skill in the art will recognize that the number of turns that changes for easy winding may vary based on the desired result.

[0061] In certain embodiments, the advantages of the present disclosure may provide reduced voltage and current losses at high power. The reduced voltage and current losses at high power may thereby result in an increase in quality factor compared to a typical cylindrical single layer coil.

[0062] In certain embodiments, advantages of the present disclosure may provide an increased quality factor due to the ratio of stored to dissipated energy.

[0063] In certain embodiments, advantages of the present disclosure may provide optimized / maximized inductance per unit length of wire used.

[0064] In certain embodiments, advantages of the present disclosure may provide a reduced distributed voltage across a winding, thereby reducing internal voltage stress potential.

[0065] In certain embodiments, advantages of the present disclosure may reduce magnetic field coupling to an aluminum shield housing by optimizing the magnetic field return path, thereby reducing eddy current losses coupled to the shield.

[0066] In certain embodiments, an advantage of the present disclosure may be to provide increased airflow around the inductor wires for improved cooling.

[0067] In certain embodiments, advantages of the present disclosure may provide a mechanical body that provides predictable wire dimension spacing along the X-axis, Y-axis, and Z-axis, resulting in a tighter manufacturing tolerance range.

[0068] For the purpose of explanation, the foregoing description uses specific nomenclature to provide a thorough understanding of the present disclosure. However, it will be apparent to those skilled in the art that specific details are not required to practice the systems and methods described herein. The foregoing descriptions of specific examples are presented for the purpose of illustration and description. They are not intended to be exhaustive or to limit the present disclosure to the precise form described. Obviously, in view of the above teachings, many modifications and variations are possible. The examples are shown and described in order to best explain the principles of the present disclosure and practical applications, so that other technical personnel in the art can best utilize the present disclosure and various examples with various modifications suitable for the intended specific purpose. The scope of the present disclosure is intended to be defined by the claims and their equivalents below.

Claims

1. A coil for a plasma processing device, the coil comprising: Coil body; as well as a plurality of concentric cross-sectional windings of a conductor disposed about the coil body, the spacing between adjacent turns of the conductor being 0.25 to 1.0 times the radius of the conductor; The plurality of concentric cross-sectional windings of wire have a diameter to length ratio of between 2:1 and 3:

1.

2. The coil according to claim 1, wherein The plurality of concentric cross-sectional windings of wire are at least one of cylindrical and polygonal.

3. The coil according to claim 1, wherein The plurality of concentric cross-sectional windings of wire are connected such that the start of a first winding continues to a terminal turn and returns axially to the start end of the first winding to begin a second winding that is larger than the first winding.

4. The coil according to claim 3, wherein: The second winding substantially surrounds the first winding.

5. The coil according to claim 1, wherein The start of the second winding continues to the terminal turn and returns axially to the start ends of the first and second windings to begin the third winding.

6. The coil according to claim 1, wherein The plurality of concentric cross-sectional windings of wire have co-registered start and end points for each winding.

7. The coil according to claim 1, wherein Each of the plurality of concentric cross-sectional windings of wire are axially and radially spaced apart by a fixed distance.

8. The coil according to claim 7, wherein The plurality of concentric cross-sectional windings of the wire form a single-sided triangle in the arrangement of all conductor centers.

9. The coil according to claim 1, wherein The plurality of concentric cross-sectional windings of the conductor comprise a progression of winding turns of 1 turn per layer.

10. The coil according to claim 1, wherein The coil is disposed in at least one of an impedance matching network, a filter, and a resonator.

11. A plasma processing device, comprising: Coil body; as well as A plurality of concentric cylindrical section windings of a wire disposed about a coil body having a spacing between adjacent turns of the wire of 0.25 to 1.0 times the radius of the wire and having a diameter to length ratio of between 2:1 and 3:

1.

12. A method of forming a coil for a plasma processing apparatus, the method comprising: feeding the wire through a center portion of the coil body of the coil body; Winding a conductive wire around a coil body to form a first winding; Return the wire to the center portion of the coil body at the center of the coil body; winding a wire around the coil body to form a second winding, the second winding being radially farther from a center portion of the center of the coil body than the first winding; Return the wire to the center portion of the coil body at the center of the coil body; as well as winding a wire around the coil body to form a third winding, the third winding being radially farther from a center portion of the center of the coil body than the second winding; Therein, the plurality of concentric cross-sectional windings of wire have a diameter to length ratio between 2:1 and 3:

1.

13. The method of claim 12, wherein: The first winding is disposed on at least a portion of the coil body, the second winding is disposed on at least a portion of a first spacer disposed on a radially distal portion of the coil body, and the third winding is disposed on at least a portion of a second spacer disposed on the first spacer.

14. The method of claim 12, wherein: The first winding, the second winding, and the third winding return to a center portion of the center of the coil body on the same side of the coil.

15. The method of claim 12, wherein: The first winding includes 7 turns, the second winding includes 8 turns, and the third winding includes 9 turns.

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