Coil and plasma generating device

Abstract

The invention relates to the technical field of plasma processing, and discloses a coil and a plasma generating device. The coil comprises a first coil part and a second coil part, the first coil part and the second coil part are spiral coils which are connected in parallel and wound in the same direction, and the two ends of the first coil part and the two ends of the second coil part serve as power feed-in ends or grounding ends respectively. And the directions of currents flowing through the first coil part and the second coil part are the same. The device is suitable for ICP discharge of a large-size cavity and provides uniform Plasma distribution.

Description

Technical Field

[0001] The present application relates to the field of plasma processing technology, and in particular to a coil and a plasma generating device. Background Art

[0002] At present, the inductively coupled plasma source (ICP) generates plasma by exciting gas with a high-frequency electromagnetic field generated by a high-frequency current passing through a coil. It can work at a relatively low chamber pressure and has the characteristics of high plasma density and little damage to the workpiece. Therefore, ICP is widely used in fields such as plasma etching, ultra-large-scale integrated circuit manufacturing, and thin film deposition. The performance of the coils used in ICP and the effect of plasma are closely related to the structure of the coils and the distribution of the magnetic field. For example, in a plasma accelerator, the magnetic field generated by the coils can be used to confine and accelerate plasma. In order to meet the market demand for batch processing of plasma processes in large-size cavities, the large-size cavity must not only meet the required plasma concentration, but also consider the impact of plasma uniformity on the process.

[0003] In the process of implementing the embodiments of the present disclosure, it is found that there are at least the following problems in the related art:

[0004] Coils in related technologies are usually used in small-sized planar discharge cavities. However, due to the restrictions on the size and shape of the coils in small-sized planar discharge cavities, the plasma and electron temperature / density cannot be evenly distributed in large-sized cavities, and ultimately cannot meet the requirements for plasma concentration and uniformity in large-sized cavities. Therefore, it has become a technical problem to be solved to specifically design and improve coils for ICP discharge in large-sized cavities.

[0005] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present application, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0006] In order to provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. The summary is not an extensive review, nor is it intended to identify key / critical components or delineate the scope of protection of these embodiments, but rather serves as a prelude to the detailed description that follows.

[0007] The embodiments of the present disclosure provide a coil and a plasma generating device to adapt to ICP discharge in a large-sized cavity and provide uniform plasma distribution.

[0008] In some embodiments, the coil includes a first coil portion and a second coil portion, wherein the first coil portion and the second coil portion are spiral coils connected in parallel and wound in the same direction, wherein the two ends of the first coil portion and the two ends of the second coil portion serve as power feed ends or ground ends respectively, and the current flowing through the first coil portion and the second coil portion has the same direction.

[0009] Optionally, a common coil segment is provided between the first coil portion and the second coil portion, and the first coil portion and the second coil portion are wound together in a clockwise or counterclockwise spiral around a midpoint of the common coil segment.

[0010] Optionally, the first coil portion includes a first end portion located outside the first coil portion and a third end portion located inside the first coil portion, and the second coil portion includes a second end portion located outside the second coil portion and a fourth end portion located inside the second coil portion;

[0011] The first end and the second end are respectively used as one of the power supply feeding end and the grounding end, and the third end and the fourth end are used as the other corresponding end of the power supply feeding end and the grounding end.

[0012] Optionally, current flows into the first coil portion and the second coil portion through the power feed end, and current directions flowing through two adjacent coil segments of the first coil portion and the second coil portion are the same, and current directions flowing through the common coil segment are opposite.

[0013] Optionally, a turn distance between the common coil segment and the first coil portion and between two adjacent coil segments in the second coil portion is 50 mm to 200 mm.

[0014] Optionally, the first coil portion is nested in the second coil portion and is coplanar, and the first coil portion and the second coil portion are wound together in a clockwise or counterclockwise spiral with the inner side of the first coil portion as the center.

[0015] Optionally, the first coil portion is a spiral coil wound with multiple turns, and the first coil portion is respectively provided with a first end and a third end at both ends, and the first end and the third end are respectively used as a power feed end or a grounding end; the second coil portion is a spiral coil wound with a single turn, and the second coil portion is respectively provided with a second end and a fourth end at both ends, and the second end and the fourth end are respectively used as a power feed end or a grounding end, and the current flowing through the first coil portion and the second coil portion has the same direction.

[0016] Optionally, the current flows into the first coil part and the second coil part respectively through the two power feed ends, and then flows out from the two grounding ends through the coil segment of the first coil part and the coil segment of the second coil part, and the current flowing through the two adjacent coil segments of the first coil part and the second coil part has the same direction.

[0017] Optionally, a turn distance between two adjacent coil segments in the first coil part is 50 mm to 200 mm; and / or a turn distance between two adjacent coil segments in the first coil part and the second coil part is 20 mm to 80 mm.

[0018] In some embodiments, the plasma generating device comprises a coil as described in the present application.

[0019] The coil and plasma generating device provided in the embodiments of the present disclosure can achieve the following technical effects:

[0020] The present application is directed to large-sized cavity discharge, by setting a first coil portion and a second coil portion, the first coil portion and the second coil portion are spiral coils connected in parallel and wound in the same direction, and the current flowing through the first coil portion and the second coil portion has the same direction. In this way, compared with the situation where the current has different directions, the discharge area is increased and the resistance of the coil is reduced. And while enhancing the overall strength of the electromagnetic field, the electromagnetic field strength at the center and the center edge of the coil is weakened, and a large area of ​​uniform electromagnetic field is achieved to achieve the purpose of optimizing the magnetic field distribution, improve the coil quality and improve the plasma source power coupling performance. At the same time, the discharge is carried out in the form of a combination of the first coil portion and the second coil portion in parallel, which increases the Plasma electron heating area. In this way, the coil structure of the present application can generate a relatively uniform electromagnetic field, thereby achieving uniform distribution of Plasma and uniform distribution of electron temperature / density in a large-sized chamber, and meeting the requirements for Plasma concentration and uniformity in a large-sized cavity.

[0021] The above general description and the following description are exemplary and explanatory only and are not intended to limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] One or more embodiments are exemplarily described by corresponding drawings, which do not limit the embodiments. Elements with the same reference numerals in the drawings are shown as similar elements, and the drawings do not constitute a scale limitation, and wherein:

[0023] Figure 1 is a schematic diagram of a coil structure provided by an embodiment of the present disclosure;

[0024] Figure 2 is another schematic diagram of a coil structure provided by an embodiment of the present disclosure;

[0025] Figure 3 is a schematic diagram of magnetic field distribution generated by a coil provided in an embodiment of the present disclosure;

[0026] Figure 4 is a schematic diagram of electron temperature distribution generated by a coil provided in an embodiment of the present disclosure;

[0027] Figure 5 is a schematic diagram of electron density distribution generated by a coil provided in an embodiment of the present disclosure;

[0028] Figure 6 is a schematic diagram of an electron density distribution curve generated by a coil provided in an embodiment of the present disclosure;

[0029] Figure 7 is a schematic diagram of a coil structure provided by an embodiment of the present disclosure;

[0030] Figure 8 is another schematic diagram of a coil structure provided by an embodiment of the present disclosure;

[0031] Fig. 9 is a schematic diagram of magnetic field distribution generated by another coil provided in an embodiment of the present disclosure;

[0032] Fig.10 is a schematic diagram of electron temperature distribution generated by another coil provided in an embodiment of the present disclosure;

[0033] Fig.11 is a schematic diagram of electron density distribution generated by another coil provided in an embodiment of the present disclosure;

[0034] Fig.12 It is a schematic diagram of an electron density distribution curve generated by another coil provided in an embodiment of the present disclosure.

[0035] Reference numerals:

[0036] 100 - first coil portion; 200 - second coil portion; 300 - common coil segment; 400 - power supply feed-in terminal; 500 - ground terminal. DETAILED DESCRIPTION

[0037] In order to be able to understand the features and technical contents of the embodiments of the present disclosure in more detail, the implementation of the embodiments of the present disclosure is described in detail below in conjunction with the accompanying drawings. The attached drawings are for reference only and are not used to limit the embodiments of the present disclosure. In the following technical description, for the convenience of explanation, a full understanding of the disclosed embodiments is provided through multiple details. However, one or more embodiments can still be implemented without these details. In other cases, to simplify the drawings, well-known structures and devices can be simplified for display.

[0038] The terms "first", "second", etc. in the specification and claims of the embodiments of the present disclosure and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged where appropriate, so as to describe the embodiments of the embodiments of the present disclosure described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0039] In the embodiments of the present disclosure, the terms "upper", "lower", "inside", "middle", "outside", "front", "back" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. These terms are mainly intended to better describe the embodiments of the present disclosure and their embodiments, and are not intended to limit the indicated devices, elements or components to have a specific direction, or to be constructed and operated in a specific direction. Moreover, in addition to being used to indicate directions or positional relationships, some of the above terms may also be used to indicate other meanings. For example, the term "upper" may also be used to indicate a certain dependency or connection relationship in certain circumstances. For those of ordinary skill in the art, the specific meanings of these terms in the embodiments of the present disclosure can be understood according to specific circumstances.

[0040] In addition, the terms "disposed", "connected", and "fixed" should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present disclosure can be understood according to specific circumstances.

[0041] Unless otherwise stated, the term "plurality" means two or more.

[0042] In the embodiment of the present disclosure, the character " / " indicates that the preceding and following objects are in an "or" relationship. For example, A / B indicates: A or B.

[0043] The term "and / or" is a description of the association relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or, A and B.

[0044] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present disclosure may be combined with each other.

[0045] In related technologies, the coil requires a large area of ​​uniform discharge, which usually requires increasing the size of the coil, which will cause the impedance of the coil to change. The increase in the length of the coil will increase the real resistance R, thereby enhancing the capacitive discharge of the coil, reducing the coupling efficiency of the coil, and also having a significant impact on the uniformity of the plasma. At the same time, the change in the inductance value of the coil will also have an important impact on the power coupling efficiency. The definition of power coupling efficiency is as follows:

[0046]

[0047] Among them, P abs is the plasma absorbed power, P coil is the coil heat loss power, R c is the coil resistance, R p and L p are the plasma resistance and inductance, L m is the mutual inductance between the coil and the plasma. The power coupling efficiency is related to both the coil and plasma parameters, but when the plasma discharge is stable and has fixed plasma parameters, the power coupling efficiency depends on k 2 Q / ω, k is the coupling coefficient, ω is the angular frequency. For a certain RF frequency, the higher the quality factor Q of the coil, the better the power coupling performance of the ion source.

[0048] Based on the above-mentioned technical requirements related to coil design, this application optimizes the design of coil turn pitch, coil structure and arrangement, realizes and optimizes the magnetic field distribution through a large-area uniform electromagnetic field, and improves the coupling performance of the ion source power source.

[0049] In this regard, an embodiment of the present disclosure provides a coil, including a first coil portion and a second coil portion, wherein the first coil portion and the second coil portion are spiral coils connected in parallel and wound in the same direction, wherein two ends of the first coil portion and two ends of the second coil portion serve as power feed ends or ground ends, respectively, and the directions of currents flowing through the first coil portion and the second coil portion are the same.

[0050] The coil provided by the embodiment of the present disclosure is adopted, and the first coil part and the second coil part are arranged, and the first coil part and the second coil part are spiral coils connected in parallel and wound in the same direction, and the current flowing through the first coil part and the second coil part has the same direction. In this way, compared with the situation where the current has different directions, the discharge area is increased and the resistance of the coil is reduced. And while enhancing the overall strength of the electromagnetic field, the electromagnetic field strength at the center and the center edge of the coil is weakened, and a large area of ​​uniform electromagnetic field is achieved to achieve the purpose of optimizing the magnetic field distribution, improve the coil quality and improve the plasma source power coupling performance. At the same time, the discharge is carried out in the form of a combination of the first coil part and the second coil part in parallel, which increases the Plasma electron heating area. In this way, the coil structure of the present application can generate a relatively uniform electromagnetic field, thereby achieving uniform distribution of Plasma and uniform distribution of electron temperature / density in a large-sized chamber, and meeting the requirements for Plasma concentration and uniformity in a large-sized cavity.

[0051] In one embodiment of the present application, a common coil segment is provided between the first coil portion and the second coil portion of the present application, and the first coil portion and the second coil portion are wound together in a clockwise or counterclockwise spiral with the midpoint of the common coil segment as the center. Specifically, the first coil portion and the second coil portion are arranged in pairs, and the number thereof can be 2n (i.e., an even number), wherein n is a positive integer greater than or equal to 1. The 2n (or even number) first coil portions and the second coil portions are centrally symmetrical with the midpoint of the common coil segment as the center. At the same time, the first coil portion includes a first end portion located outside the first coil portion and a third end portion located inside the first coil portion, and the second coil portion includes a second end portion located outside the second coil portion and a fourth end portion located inside the second coil portion. Wherein, the first end portion and the second end portion are respectively used as one end of the power supply feed end or the grounding end, and the third end portion and the fourth end portion are used as the corresponding other end of the power supply feed end or the grounding end.

[0052] And, the turn distance between the first coil portion and the second coil portion is greater than the turn distance between the coil segments inside the first coil portion and the second coil portion. At the same time, the direction of the current flowing through the common coil segment is partially opposite. Here, "partially opposite" means that the current direction in the common coil segment can include two current directions, for example, left direction along the horizontal direction or right direction along the horizontal direction, so that a current direction is partially opposite to the current direction in the branch coil.

[0053] In a practical application of this application, combined with Figure 1 and Figure 2As shown, the coil in this embodiment includes a first coil portion 100 in a right-angle spiral winding in a plane and a second coil portion 200 in a right-angle spiral winding in a plane, and the first coil portion 100 and the second coil portion 200 are centrally symmetrically arranged with the midpoint of the common coil segment 300 as the center. At the same time, the first coil portion 100 and the second coil portion 200 are wound in a clockwise or counterclockwise spiral. Among them, the clockwise spiral winding refers to the winding direction when the coil is formed, and the counterclockwise spiral winding refers to the winding direction when the coil is formed, and does not involve the current direction. Furthermore, jointly spirally wound in a clockwise or counterclockwise direction means that, when the first coil portion 100 and the second coil portion 200 are centrally symmetrically arranged with the midpoint of the common coil segment 300 as the center, if the first coil portion 100 is wound clockwise with the midpoint of the common coil segment 300 as the starting point, the second coil portion 200 is also wound clockwise with the midpoint of the common coil segment 300 as the starting point; if the first coil portion 100 is wound counterclockwise, the second coil portion 200 is also wound counterclockwise.

[0054] At the same time, in the above practical application, the number of turns of the first coil part 100 is multiple, and the specific number of turns can be set according to the size of the plasma discharge area, such as two to four turns (preferably two turns), which includes a first end located outside the first coil part and a third end located inside the first coil part. The number of turns of the second coil part 200 is multiple, and the specific number of turns can be set according to the size of the plasma discharge area, such as two to four turns (preferably two turns), which includes a second end located outside the second coil part and a fourth end located inside the second coil part. In one embodiment, the first end and the second end are respectively connected in series with the two ends of the common coil segment to serve as the power supply feed end 400, and the third end and the fourth end are respectively used as ground ends 500. Thus, as indicated by the directional arrows in the figure, the current flows into the common coil segment 300 through the power supply feeding terminal 400, and flows into the first coil portion 100 and the second coil portion 200 respectively through the first end portion and the second end portion in opposite directions in the common coil segment, and then flows out from the two grounding terminals 500 in the first coil portion 100 and the second coil portion 200 in the same direction, and the current flowing through the two adjacent coil segments of the first coil portion 100 and the second coil portion 200 has the same direction.

[0055] In addition, combined Figure 1 and Figure 2As shown, in the above practical application, on the basis of maintaining the single coil parallel connection, the power supply feed end 400 of the RF power supply is arranged in the middle of the common coil segment. At this time, the current direction of the common coil segment is opposite to the current direction of the first coil part and the second coil part in a partial area, and the turn distance between the common coil segment and the two adjacent coil segments in the first coil part and the second coil part is 50mm to 200mm (preferably 75mm, 85mm, 95mm, 105mm or 115mm), thereby weakening the magnetic field at the center and the center edge of the coil and improving the uniformity of Plasma.

[0056] And, combined with Figure 1 and Figure 2 As shown, the resistance of the coil in the above practical application is 0.316Ω and the inductance is 4.2674×10 -7 H, the coil quality factor Q is about 116.

[0057] Figures 3 to 5 The electromagnetic field distribution and electron temperature distribution of the coil at a distance of 10 mm from the coil ceramic plate and the plasma density distribution at 140 mm (where the carrier is located) in the above practical application are shown. Figure 6 The figure shows the electron density distribution of the coil in the plane center axial direction at 140 mm from the ceramic plate in actual application. It can be seen that the electron density distribution generated by the coil in this embodiment has a relatively obvious smooth line segment, which can prove that it has good uniformity. The uniformity α of Plasma is calculated by the following formula:

[0058]

[0059] Among them, n ave is the average electron density, n max is the maximum value, n min is the minimum value. Figure 6 It can be calculated from the given data that the uniformity α of the Plasma obtained by the coil excitation in this embodiment is about 30.3%, which is about 2.5 times higher than the uniformity of the Plasma of the coil in the related art, and has a significant improvement effect.

[0060] In another embodiment of the present application, the first coil portion of the present application is nested in the second coil portion and coplanar, and the first coil portion and the second coil portion are wound together in a clockwise or counterclockwise spiral with the inner side of the first coil portion as the center. The number of turns of the first coil portion and the second coil portion can be selected as one or more turns as needed.

[0061] Specifically, in one case, the coil in this embodiment is fed into the same power supply at two points, and the overall structure is still connected in parallel. The first coil portion is a spiral coil wound in multiple turns, and the two ends of the first coil portion are respectively provided with a first end and a third end, and the first end and the third end are respectively used as a power supply feeding end or a grounding end. The second coil portion is a spiral coil wound in a single turn, and the two ends of the second coil portion are respectively provided with a second end and a fourth end, and the second end and the fourth end are respectively used as a power supply feeding end or a grounding end, and the current direction flowing through the first coil portion and the second coil portion is the same. That is, the current flows into the first coil portion and the second coil portion respectively through the two power supply feeding ends, and then flows out from the two grounding ends in the same direction in the first coil portion and the second coil portion, and the current direction flowing through the two adjacent coil segments of the first coil portion and the second coil portion is the same.

[0062] In another case, the coil in this embodiment is fed into the same power supply at two points, and the overall structure is still connected in parallel. The first coil portion is a spiral coil wound with multiple turns, and the two ends of the first coil portion are respectively provided with a first end and a third end, and the first end and the third end are respectively used as a power supply feeding end or a grounding end. The second coil portion is also a spiral coil wound with multiple turns, and the two ends of the second coil portion are respectively provided with a second end and a fourth end, and the second end and the fourth end are respectively used as a power supply feeding end or a grounding end, and the direction of the current flowing through the first coil portion and the second coil portion is the same. That is, the current flows into the first coil portion and the second coil portion respectively through the two power supply feeding ends, and then flows out from the two grounding ends in the same direction in the first coil portion and the second coil portion, and the direction of the current flowing through the two adjacent coil segments of the first coil portion and the second coil portion is the same.

[0063] At the same time, the first coil portion 100 and the second coil portion 200 are simultaneously wound in a clockwise and counterclockwise spiral. Among them, clockwise spiral winding refers to the winding direction when the coil is formed, and counterclockwise spiral winding refers to the winding direction when the coil is formed, and does not involve the current direction. Further, simultaneously winding in a clockwise and counterclockwise spiral means that if the first coil portion 100 is wound clockwise with one of its ends as the starting point, the second coil portion 200 is also wound clockwise with one of its ends as the starting point; if the first coil portion 100 is wound counterclockwise with one of its ends as the starting point, the second coil portion 200 is also wound counterclockwise with one of its ends as the starting point.

[0064] In another practical application of the present application, Figure 7 and Figure 8As shown, the first coil part 100 of the present application is a spiral coil wound with multiple turns, the number of turns is one to four turns (preferably one or two turns), the second coil part 200 is a spiral coil wound with a single turn, the first end is used as a power supply feed-in end 400 and the third end is used as a grounding end 500, the first end is arranged at one end of the first coil part 100 close to the second coil part 200, and the third end is arranged at one end of the first coil part 100 away from the second coil part 200. The second end is used as the power supply feed-in end 400 and the fourth end is used as the grounding end 500, and the second end and the fourth end are arranged adjacent to each other at a vertex of the second coil part. At the same time, as shown by the direction arrows in the figure, the current flows into the first coil part 100 and the second coil part 200 respectively through the two power supply feed-in ends 400, and then flows out from the two grounding ends 500 through the coil segments of the first coil part 100 and the coil segments of the second coil part 200, and the current flowing through the adjacent two coil segments of the first coil part 100 and the second coil part 200 has the same direction.

[0065] Meanwhile, in the above practical application, the turn distance between two adjacent coil segments of the first coil part 100 and the second coil part 200 is 20 mm to 80 mm (preferably 50 mm), the turn distance between two adjacent coil segments in the first coil part 100 is 50 mm to 200 mm (preferably 90 mm or 100 mm), and the length and width of the second coil part 200 are 630 mm and 280 mm. In addition, the resistance of the coil in this embodiment is 0.0965 Ω, and the inductance is 5×10 -7 H, the quality factor Q is about 441.

[0066] Figures 9 to 12 The corresponding magnetic field distribution, electron temperature and electron density distribution of the coil in the above practical application are shown. Fig.12 The electron density distribution of the coil in the plane center axial direction at 140 mm from the ceramic plate in actual application is shown. It can be seen that the electron density distribution of the coil of the present application is large and has a wide range, and it can be calculated by the aforementioned formula in the specification that the uniformity α of the Plasma obtained by the coil excitation in this embodiment is about 22.3%, which is about 1.8 times higher than the uniformity of the Plasma of the coil in the related art. In this way, the discharge area and Plasma uniformity can be increased while reducing the resistance of the coil and improving the quality factor Q.

[0067] In addition, the embodiment of the present disclosure provides a plasma generating device, including a large-sized cavity, and a heating plate for placing wafers is arranged inside the large-sized cavity. The coil as described in the present application is arranged above the large-sized cavity. The external RF power supply is connected to the coil through the connected matcher to supply power to the coil. After the coil is energized, an electromagnetic field can be generated in the large-sized cavity. The electromagnetic field generated by the wire can ionize the process gas (for example, nitrogen) in the large-sized cavity into plasma, and the excess gas can be pumped out of the large-sized cavity by a vacuum pump. It can be understood that the plasma generating device can adopt left and right air intake, can also adopt all-around air intake, can also adopt up and down air intake as needed, or other air intake methods, such as air intake from the center above the cavity.

[0068] The above description and the accompanying drawings sufficiently illustrate the embodiments of the present disclosure to enable those skilled in the art to practice them. Other embodiments may include structural and other changes. The embodiments represent only possible variations. Unless explicitly required, individual components and functions are optional, and the order of operations may vary. Portions and features of some embodiments may be included in or replace portions and features of other embodiments. The embodiments of the present disclosure are not limited to the structures described above and shown in the accompanying drawings, and various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A coil, characterized in that: It includes a first coil portion and a second coil portion, wherein the first coil portion and the second coil portion are spiral coils connected in parallel and wound in the same direction, wherein two ends of the first coil portion and two ends of the second coil portion serve as power supply feed ends or ground ends respectively, and the currents flowing through the first coil portion and the second coil portion have the same direction.

2. The coil according to claim 1, characterized in that A common coil segment is provided between the first coil portion and the second coil portion, and the first coil portion and the second coil portion are wound together in a clockwise or counterclockwise spiral around a midpoint of the common coil segment.

3. The coil according to claim 2, characterized in that The first coil portion includes a first end portion located outside the first coil portion and a third end portion located inside the first coil portion, and the second coil portion includes a second end portion located outside the second coil portion and a fourth end portion located inside the second coil portion; The first end and the second end are respectively used as one of the power supply feeding end and the grounding end, and the third end and the fourth end are used as the other corresponding end of the power supply feeding end and the grounding end.

4. The coil according to claim 3, characterized in that Current flows into the first coil part and the second coil part through the power supply feeding end, and the current flowing through the two adjacent coil segments of the first coil part and the second coil part has the same direction, and the current flowing through the common coil segment has the opposite direction.

5. The coil according to claim 2, characterized in that A turn distance between the common coil segment and two adjacent coil segments in the first coil portion or the second coil portion is 50 mm to 200 mm.

6. The coil according to claim 1, characterized in that The first coil portion is nested in the second coil portion and is coplanar, and the first coil portion and the second coil portion are wound together in a clockwise or counterclockwise spiral with the inner side of the first coil portion as the center.

7. The coil according to claim 6, characterized in that The first coil portion is a spiral coil wound with multiple turns, and a first end and a third end are respectively provided at two ends of the first coil portion, and the first end and the third end are respectively used as a power supply input end or a grounding end; the second coil portion is a spiral coil wound with a single turn, and a second end and a fourth end are respectively provided at two ends of the second coil portion, and the second end and the fourth end are respectively used as a power supply input end or a grounding end, and the current flowing through the first coil portion and the second coil portion has the same direction.

8. The coil according to claim 7, characterized in that The current flows into the first coil part and the second coil part respectively through the two power supply feeding ends, and then flows out from the two grounding ends through the coil segment of the first coil part and the coil segment of the second coil part, and the current flowing through the two adjacent coil segments of the first coil part and the second coil part has the same direction.

9. The coil according to claim 6, characterized in that The turn distance between two adjacent coil segments in the first coil part is 50 mm to 200 mm; and / or the turn distance between two adjacent coil segments in the first coil part and the second coil part is 20 mm to 80 mm.

10. A plasma generating device, characterized in that: Comprising the coil according to any one of claims 1 to 9.

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