KR101123787B1 - Plasma accelerator including decoupling device - Google Patents

Abstract

A plasma accelerator comprising a decoupling device is disclosed. Plasma accelerator according to the present invention, the top is blocked, the bottom is open, the chamber portion is surrounded by the outer wall, the top coil portion, which is located on the upper surface of the chamber portion wound in a predetermined direction to increase the radius from the central axis of the chamber, the chamber And a first coil surrounding the outer wall of the chamber, a second coil surrounding the outer wall of the chamber, and spaced apart from the first coil by a predetermined distance, and a decoupling unit to attenuate mutual inductance between the first coil and the second coil. As a result, mutual inductance induced in the driving circuit of the plasma accelerator can be compensated.

Plasma Accelerator, Electromagnetic Accelerator, Decoupler, Mutual Inductance

Description

Plasma accelerator including decoupling device {Plasma accelerator including decoupling device}

1 is a cross-sectional view showing a conventional annular plasma accelerator,

2 is a block diagram of a decoupling apparatus according to an embodiment of the present invention;

3 is a perspective cross-sectional view of the plasma accelerator according to an embodiment of the present invention;

4A and 4B are diagrams illustrating specific values of the first inductor 351 and the second inductor 352 of FIG. 3;

FIG. 5 is a graph illustrating a relationship between the distance between the first inductor 351 and the second inductor 352 of FIG. 3 and the mutual inductance M ₁₂ ;

6 is a perspective cross-sectional view of an annular plasma accelerator according to another embodiment of the present invention, and

7 is a cross-sectional view of an annular plasma accelerator according to another embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

310: chamber portion 320: top coil portion

330: first coil 340: second coil

350: decoupling unit 351: first inductor

352: second inductor

The present invention relates to a decoupling apparatus and a plasma accelerator including the same, and more particularly, to a decoupling apparatus capable of compensating mutual inductance by connecting a decoupler to a driving circuit of the plasma accelerator and a plasma accelerator including the same.

The plasma accelerator is an apparatus for accelerating the flow of plasma generated or existing in a certain space by using electrical energy and magnetic energy, and is also called an electro-magnatic accelerator (EMA).

Plasma accelerators have been developed as rocket engines for long-distance travel, and have been used for etching wafers in semiconductor manufacturing processes.

1 is a cross-sectional view showing a conventional annular plasma accelerator.

As shown in FIG. 1, the conventional plasma accelerator has an inner coil 1, 2, 3, an outer coil 4, 5, 6, and a discharge coil 7 having an inner cylinder 11 and an outer cylinder. The channel 10 formed by 12 is wound up. The upper channel 13 is blocked by the inner cylinder 11 and the outer cylinder 12 is connected.

The inner coils 1, 2, 3 and the outer coils 4, 5, 6 are coaxially arranged side by side, and each consists of three coils, each of which winds up a channel 10. The inner coils 1, 2, 3 are numbered from the bottom of the channel 10 to the first coil 1, the second coil 2, and the third coil 3, respectively.

The outer coils 4, 5 and 6 are numbered from the bottom of the channel 10 to the fourth coil 4, the fifth coil 5 and the sixth coil 6, respectively. The discharge coil 7 is located in the upper part of the channel 13 and is numbered with the seventh coil 7.

Each coil 1, 2, 3, 4, 3, 5, 6, 7 is supplied with current by 7 independent RF generators. A current is applied to each of the coils 1, 2, 3, 4, 3, 5, 6, and 7 to induce a magnetic field in the channel 10 of the plasma accelerator.

The magnetic field generated in the channel 10 by each coil 1, 2, 3, 4, 3, 5, 6, 7 induces secondary currents according to the Maxwell induction equation, which is secondary The current converts the gas inside the accelerator into a plasma state.

In order to accelerate the plasma, a conventional plasma accelerator applies a predetermined current having a predetermined phase to each of the coils 1, 2, 3, 4, 3, 5, 6, and 7 as shown in Table 1 below.

Number of coils Current (A) Phase 7 60 0 6 45 0 3 50 0 5 15 45 2 20 45 4 0 90 One 5 90

The application of current according to Table 1 creates a magnetic field inside the plasma accelerator and accelerates the plasma to the bottom of the channel 10.

The mutual inductance generated between each coil (1, 2, 3, 4, 3, 5, 6, 7) by applying the current according to Table 1 7) causes a negligible current. The current induced by mutual inductance due to a matching box circuit may exceed the initial current of the seventh coil 7. Moreover, the phase difference of the current flowing through each coil 1, 2, 3, 4, 3, 5, 6, 7 cannot be adjusted appropriately. The reason is that the total current flowing in each of the coils 1, 2, 3, 4, 3, 5, 6, 7 is summed with induced currents having different phases.

Table 2 is a matrix of self inductance and mutual inductance of each coil in the plasma accelerator of FIG. Since each inductance value is symmetric about the diagonal axis, the relative inductance value on the diagonal axis is omitted. The unit of inductance value is μH.

One 2 3 4 5 6 7 One 0.26 0.094 0.044 0.078 0.070 0.053 0.12 2 0.26 0.089 0.070 0.078 0.069 0.19 3 0.26 0.053 0.069 0.084 0.31 4 0.59 0.27 0.16 0.25 5 0.59 0.26 0.36 6 0.59 0.54 7 2.59

All seven coils (1, 2, 3, 4, 3, 5, 6, 7) receive current independently from the seven separate RF generators.

For example, the current flowing through the first coil is I ₁ , the current flowing through the second coil is I ₂ , the self inductance of the first coil is L ₁ , the self inductance of the second coil is L ₂ , and the mutual inductance is M ₂ . _{Suppose 12} , the magnetic field energy (W) stored in the coil is represented by the following equation (1).

Current I ₁ , current I ₂ 0 and 1 respectively, and in each case the magnetic field energy is calculated and L ₁ , L ₂ , M ₁₂ Can be obtained. Therefore, each element of the matrix of Table 2 can be obtained.

As Table 2 shows, the mutual inductance M ₆₇ of the sixth coil 6 and the seventh coil 7 is 0.54 μH, and the self inductance L ₆ of the sixth coil ₆ is 0.59 μH. The value of mutual inductance (M ₆₇ ) 0.54 μH and the value of self inductance (L ₆ ) 0.59 μH are very close. This causes a strong coupling between the sixth coil 6 and the seventh coil 7.

As described above, mutual inductance has a problem of preventing stably applying the magnitude and phase of current to the coil of the plasma accelerator. Therefore, if the magnitude and phase of the current is unstable, there is a problem that the plasma accelerator cannot operate stably.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a decoupling apparatus capable of compensating mutual inductance by connecting a decoupler to a driving circuit of a plasma accelerator, and a plasma accelerator including the same.

Plasma accelerator according to an embodiment of the present invention for achieving the above object, the upper portion is blocked, the lower portion is open, the chamber side is surrounded by the outer wall, the chamber is located on the upper surface of the chamber portion from the central axis of the chamber portion A top coil part wound in a predetermined direction to increase a radius, a first coil surrounding an outer wall of the chamber part, a second coil surrounding an outer wall of the chamber part and spaced apart from the first coil by a predetermined distance, and the first coil and the second coil It includes a decoupling portion for reducing the mutual inductance between the coils.

The decoupling unit is connected between the first coil and the ground and is wound between a first inductor in a predetermined direction, and is connected between the second coil and the ground and is wound in a direction opposite to the first inductor. And a second inductor coupled with the first inductor.

Plasma accelerator according to another embodiment of the present invention, the upper chamber is clogged, the lower portion is open, the outer chamber is surrounded by the first outer wall, the upper chamber is located in the interior of the outer chamber, the upper surface is located on the same plane as the upper surface of the outer chamber An inner chamber having an open surface and a lower closed surface located on the same plane as the lower surface of the outer chamber, the inner side of which is surrounded by a second outer wall and is separated from the outer chamber by the second outer wall, the upper side of the outer chamber A top coil part disposed on a surface and wound in a predetermined direction to increase a radius from a central axis of the outer chamber, a first coil part including a plurality of coils surrounding an outer surface of the first outer wall, and an inner side of the second outer wall A second coil part comprising a plurality of coils surrounding a side, and mutual inductance between the coils forming the first coil part and the second coil part; It includes a decoupling portion for attenuating mutual inductance between the coils forming the coil portion.

The decoupling unit may include: a first decoupling unit connected to each of the coils forming the first coil unit, the first decoupling unit including a plurality of inductors formed in a form wound in opposite directions with other inductors connected to adjacent coils, and coupled to each other; A second decoupling unit is connected to each of the coils forming the second coil unit and includes a plurality of inductors coupled to other inductors connected to adjacent coils in mutually opposite directions.

According to another embodiment of the present invention, a plasma accelerator may further include a third decoupling unit for reducing mutual inductance between the first coil unit and the top coil unit, and attenuating mutual inductance between the second coil unit and the top coil unit. It further includes a fourth decoupling portion.

Hereinafter, with reference to the accompanying drawings will be described in more detail the present invention.

2 is a block diagram of a decoupling apparatus according to an embodiment of the present invention.

As shown in FIG. 2, the decoupling apparatus includes a first RF generator 210, a first matching box 220, a second RF generator 230, and a second matching box 240. ), The coil unit 250 and the decoupling unit 260. The coil unit 250 includes a first coil A and a second coil B. The decoupling unit 260 includes a first decoupler coil 1 and a second decoupler coil 2.

The first RF generator 210 applies a current to the first coil A through the first matching box 220. Meanwhile, the second RF generator 230 applies a current to the second coil B through the second matching box 240.

The first matching box 220 prevents the current output from the first RF generator 210 from being reflected and inputted back to the first RF generator 210. The second matching box 240 also functions in the same way.

The coil unit 250 is formed by coupling the first coil A and the second coil B to each other. The current I ₁ applied to the first coil A induces electromotive force E ₁ to the second coil B by mutual inductance M _AB according to Equation 2 below.

The electromotive force E ₁ changes the current of the second coil B and changes the phase shift of the voltage V ₂ .

The decoupling portion 260 consists of two coupled coils 1 and 2, each coil 1 and 2 being wound in opposite directions.

The current I ₁ applied to the first decoupler coil 1 induces an electromotive force E ₂ to the second decoupler coil 2 by mutual inductance M ₁₂ according to Equation 3 below.

The voltage V ₂ applied to the second coil B and the second decoupler coil ₂ is expressed by Equation 4 below.

If M _AB and M ₁₂ are the same, the voltage V ₂ applied to the second coil B and the second decoupler coil ₂ is expressed by Equation 5 below.

Therefore, the current I ₂ and the phase flowing in the second coil B become independent of the current I ₁ flowing in the first coil A, and the values thereof can be stably maintained.

3 is a perspective cross-sectional view of the plasma accelerator according to an embodiment of the present invention.

As shown in FIG. 3, the plasma accelerator includes a chamber unit 310, a top coil unit 320, a first coil 330, a second coil 340, and a decoupling unit 350. The decoupling unit 350 includes a first inductor 351 and a second inductor 352.

The chamber portion 310 is clogged at the top and opened at the bottom, and has a side surface surrounded by an outer wall. The top coil part 320 is positioned on the upper surface of the chamber part 310 and wound in a predetermined direction so that the radius increases from the central axis of the chamber part 310.

The first coil 330 surrounds the outer wall of the chamber 310, and the second coil 340 is spaced apart from the first coil 330 by a predetermined distance to surround the outer wall of the chamber 310.

The decoupling unit 350 has a structure including a first inductor 351 and a second inductor 352 to attenuate mutual inductance induced between the first coil 330 and the second coil 340.

The first inductor 351 is connected between the first coil 330 and the ground and is a coil wound in a predetermined direction. The second inductor 352 is connected between the second coil 340 and the ground, and is coupled to the first inductor 351 in a form wound in a direction opposite to the first inductor 351.

The mutual inductance induced between the first inductor 351 and the second inductor 352 has a sign opposite to the mutual inductance induced between the first coil 330 and the second coil 340, thereby attenuating the overall mutual inductance. Let's do it.

4A and 4B are diagrams illustrating specific values of the first inductor 351 and the second inductor 352 of FIG. 3.

As shown in FIGS. 4A and 4B, the distance between the first inductor 351 and the second inductor 352 is about 2 mm, and the distance between the first inductor 351 and the second inductor 352 is about 70 mm on average. Each radius is 46 mm and the coil uses an 8 × 8 mm square coil. Arrows indicate that the first inductor 351 and the second inductor 352 are wound in opposite directions.

FIG. 5 is a graph illustrating a relationship between the distance between the first inductor 351 and the second inductor 352 of FIG. 3 and the mutual inductance M ₁₂ .

As shown in FIG. 5, when the distance between the first inductor 351 and the second inductor 352 is changed from 0 to 140 mm, the mutual inductance M ₁₂ may be measured to be inversely proportional to each other.

By changing the distance near the average distance of 70 mm between the first inductor 351 and the second inductor 352, the mutual inductance can be compensated in the range of 0.01-0.22 μH. .

6 is a perspective cross-sectional view of an annular plasma accelerator according to another embodiment of the present invention.

As shown in FIG. 6, the plasma accelerator has an outer chamber 610, an inner chamber 620, a top coil part 630, a first coil part 640, a second coil part 650, and a decoupling part. 660. The decoupling unit 660 may include a first decoupling unit 661, a second decoupling unit 662, a third decoupling unit 663, and a fourth decoupling unit 664.

The outer chamber 610 has a shape where the upper part is blocked, the lower part is opened, and the side surface is surrounded by the first outer wall 611. The inner chamber 620 is located inside the outer chamber 610, the upper part is open and the lower part is closed. The upper open surface is located on the same plane as the upper surface of the outer chamber 610, and the lower closed surface is located on the same plane as the lower surface of the outer chamber 610. The side surface of the inner chamber 620 is surrounded by the second outer wall 621 and is separated from the outer chamber 610 by the second outer wall 621.

The top coil part 630 is positioned on the upper surface of the outer chamber 610, and is wound in a predetermined direction so that the radius increases from the central axis of the outer chamber 610.

The first coil part 640 is composed of a plurality of coils surrounding the outer surface of the first outer wall 611, and the second coil part 650 is a plurality of coils surrounding the inner surface of the second outer wall 621. Is made of.

The decoupling unit 660 attenuates the mutual inductance between the coils of the first coil unit 640 and the mutual inductance between the coils of the second coil unit 650.

The decoupling portion 660 includes a first decoupling portion 661 and a second decoupling portion 662. The first decoupling unit 661 is connected to each of the coils constituting the first coil unit 640 and includes a plurality of inductors which are manufactured in a form wound in opposite directions with other inductors connected to adjacent coils and coupled to each other. .

The second decoupling unit 662 is connected to each of the coils constituting the second coil unit 650, and includes a plurality of inductors coupled to each other in an opposite direction to other inductors connected to adjacent coils.

The decoupling unit 660 may further include a third decoupling unit 663 and a fourth decoupling unit 664. The third decoupling part 663 attenuates mutual inductance between the first coil part 640 and the top coil part 630, and the fourth decoupling part 664 is the second coil part 650 and the top coil part ( 630 attenuates mutual inductance.

7 is a cross-sectional view of an annular plasma accelerator according to another embodiment of the present invention.

As shown in FIG. 7, the plasma accelerator is an annular plasma accelerator including a chamber portion 710 including an inner cylinder 711, an outer cylinder 712, and a connecting portion 713.

The chamber portion 710 is blocked at the top and opened at the bottom thereof, and the side surface is formed outside the inner cylinder 711 and the inside of the outer cylinder 712.

The first coil parts 721, 722, 723, and 724 are formed of a plurality of coils surrounding the inner outer wall of the inner cylinder 711.

The second coil parts 725, 726, 727, and 728 are formed of a plurality of coils surrounding the outer outer wall of the outer cylinder 712.

The third coil part 713 is positioned on the upper part 713 of the chamber part and is wound in a predetermined direction so that the radius increases about the central axis of the inner cylinder 711.

The first coil 721, the second coil 722, the third coil 723, and the fourth coil 724 surround the inner cylinder 711 from the bottom to the top of the accelerator in order. The fifth coil 725, the sixth coil 726, the seventh coil 727, and the eighth coil 728 surround the outer cylinder 712 from the bottom to the top of the accelerator in order. The ninth coil 729 is positioned above the connector 713.

Each coil 721, 722, 723, 724, 725, 726, 727, 728, 729 is energized by nine independent RF generators. The current applied to each coil 721-729 is applied with a phase difference, and the applied current generates a magnetic field inside the accelerator, and accelerates the plasma by the movement of the generated magnetic pressure.

The first coil 721 is wound in the opposite direction with the adjacent second coil 722 before being grounded to form a decoupler d12, thereby compensating mutual inductance M ₁₂ . Before the ground, the second coil 722 forms decouplers d12 and d23 with the adjacent first coil 721 and the third coil 723 to compensate for mutual inductances M ₁₂ and M ₂₃ . The third coil 723 forms decouplers d23 and d34 with adjacent second coils 722 and fourth coils 724, respectively, to compensate for mutual inductances M ₂₃ and M ₃₄ before being grounded.

In the same way, the fourth coil 724 forms the decoupler d49, the fifth coil 725 forms the decoupler d56, and the sixth coil 726 respectively decouples d56 and d67. The seventh coil 727 forms decouplers d67 and d78, respectively, the eighth coil 728 forms decouplers d78 and d89, and the ninth coil 729 is formed respectively. Decouplers d49 and d89 are formed.

Each decoupler d12, d23, d34, d49, d56, d67, d78, d89 winds two coils in opposite directions to compensate for mutual inductance induced in each series-connected coil 721-729. . In addition, mutual inductance is compensated for by adjusting the distance between two coils forming the decoupler.

Therefore, the magnitude and phase of the current can be stably applied to the coil of the plasma accelerator. Meanwhile, the wafer for fabricating the semiconductor chip may be etched using the accelerator according to the embodiment of the present invention.

As described above, according to the present invention, mutual inductance can be compensated by connecting a decoupler to the driving circuit of the plasma accelerator.

The magnitude and phase of the current can be stably applied to the coil of the plasma accelerator. Therefore, the magnitude and phase of the current is stable, so that the plasma accelerator can operate stably.

In addition, although the preferred embodiment of the present invention has been shown and described above, the present invention is not limited to the above-described specific embodiment, the technical field to which the invention belongs without departing from the spirit of the invention claimed in the claims. Anyone of ordinary skill in the art as well as various modifications can be made, of course, such modifications will not be understood individually from the technical spirit or prospects of the present invention.

Claims (5)

A chamber portion of which an upper portion is blocked and an lower portion is opened, and a side surface is surrounded by an outer wall; A top coil part positioned on an upper surface of the chamber part and wound in a predetermined direction to increase a radius from a central axis of the chamber part; A first coil surrounding an outer wall of the chamber part; A second coil surrounding an outer wall of the chamber and spaced apart from the first coil by a predetermined distance; And, And a decoupling unit to attenuate mutual inductance between the first coil and the second coil. The method of claim 1, The decoupling unit, A first inductor connected between the first coil and the ground and wound in a predetermined direction; And, And a second inductor coupled between the second coil and the ground and coupled to the first inductor in a form wound in a direction opposite to the first inductor. An outer chamber of which an upper part is blocked, an lower part is opened, and a side surface is surrounded by a first outer wall; It is located inside the outer chamber, has an upper open surface located on the same plane as the upper surface of the outer chamber and a lower closing surface located on the same plane as the lower surface of the outer chamber, the side surface is surrounded by a second outer wall An inner chamber separated from the outer chamber by a second outer wall; A top coil part positioned on an upper surface of the outer chamber and wound in a predetermined direction to increase a radius from a central axis of the outer chamber; A first coil part including a plurality of coils surrounding an outer surface of the first outer wall; A second coil part including a plurality of coils surrounding an inner side surface of the second outer wall; And, And a decoupling unit for attenuating mutual inductance between coils forming the first coil unit and mutual inductance between coils forming the second coil unit. The method of claim 3, The decoupling unit, A first decoupling unit including a plurality of first inductors connected to respective coils forming the first coil unit; And And a second decoupling unit including a plurality of second inductors connected to each coil constituting the second coil unit. The first inductors adjacent to each other among the plurality of first inductors may be manufactured in a form wound in opposite directions and coupled to each other. Among the plurality of second inductors, second inductors adjacent to each other are manufactured in a form wound in opposite directions and coupled to each other. 5. The method of claim 4, A third decoupling unit to attenuate mutual inductance between the first coil unit and the top coil unit; And, And a fourth decoupling unit to attenuate mutual inductance between the second coil unit and the top coil unit.

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