KR20050005818A - Plasma source having low ion flux and high impedance, -and Plasma chamber using the same - Google Patents

Abstract

PURPOSE: A plasma source having low ion flux and high impedance, and a plasma chamber using the same are provided to increase effective length of unit coils and reduce plasma density and ion flux in an edge of a wafer by using wave-shapes unit coils. CONSTITUTION: A coil bushing(410) is used for receiving electric power. Unit coils(421,422,423) of m number are branched from the coil bushing. Each of the unit coils has a wave-shaped curve. The unit coils are formed around the coil bushing. The unit coils are arranged spirally along a circumference of the coil bushing.

Description

Plasma source having low ion flux and high impedance, and plasma chamber employing the same

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to semiconductor manufacturing equipment, and more particularly, to a plasma source having a low ion flux and a high impedance and a plasma chamber employing the same.

The manufacturing technology of Ultra-Large Scale Integrate (ULSI) circuit elements has evolved remarkably over the past two decades. This was possible because of the semiconductor manufacturing facilities that could support the process technologies that required extreme technology. Plasma chambers, one of these semiconductor fabrication facilities, are being used in a wide variety of applications, in addition to the etching processes that were commonly used.

The plasma chamber is a semiconductor manufacturing facility for forming a plasma therein and performing processes such as etching and deposition using the plasma. The plasma chamber may include an electron cyclotron resonance (ECR) plasma source, a helicon-wave excited plasma (HWEP) source, and a capacitively coupled plasma (CCP) depending on the plasma generation source. Sources, and inductively coupled plasma (ICP) sources. Among them, the ICP source supplies RF (Radio Frequency) power to the induction coil to generate a magnetic field, and traps electrons in the center of the chamber by the electric field induced by the generated magnetic field to generate a high density plasma even at a low pressure. Such ICP sources are widely used because of their advantages in terms of structural simplicity and relatively easy to obtain large-area plasma compared to ECR plasma sources or HWEP sources.

1 and 2 are diagrams illustrating a coil shape constituting a conventional plasma source. Specifically, FIG. 1 illustrates a case in which a single coil having less than one turn is used, and FIG. This is the case when a single coil is used more than once. 3 is a graph showing the CD change rate in the plasma chamber using the plasma source of FIGS.

First, as shown in FIG. 1, when using a single coil 110 having less than one turn, the strength (H), the total coil length (L), and the impedance (Z) of the magnetic field around the coil 110 are respectively. It can be expressed as Equation 1 below.

, ,

In Equation 1, I is the amount of current flowing through the coil 110, R is the radius from the center of the coil, ω represents the resonant frequency.

Next, as shown in FIG. 2, when using a single coil 210 having one or more turns, the strength (H), the total coil length (L), and the impedance (Z) of the magnetic field around the coil 210 are Each may be represented by Equation 2 below.

, ,

In Equation 2, I is the amount of current flowing through the coil 210, R 'is the effective radius from the center of the coil, n is the number of turns, and ω represents the resonant frequency.

However, the change rate of CD (Critical Dimension) in the plasma chamber employing such a plasma source (hereinafter, ΔCD; ΔCD is defined as the difference between the expected CD before the process is performed and the result CD after the process). As shown in FIG. 3, the deviation between the wafer center portion and the wafer edge portion is large. That is, while ΔCD is maintained at a constant value at the center of the wafer, ΔCD drops sharply at the edge within a certain distance d from the outermost portion of the wafer. This phenomenon is more serious in the semiconductor etching process using the plasma chamber as the size of the semiconductor wafer is increased. For example, in the case of a 200 mm semiconductor wafer, ΔCD is rapidly reduced at an edge portion within a distance of approximately 10 nm from the outermost angle of the wafer, and in the case of a 300 mm semiconductor wafer, within a distance of approximately 30 nm from the outermost angle of the wafer At the edge part, ΔCD is drastically reduced. The reason for this phenomenon is due to the difference in diffusion rate at which the byproducts generated by the chemical reaction are removed during the etching at the center of the wafer and the edge of the wafer. In other words, the diffusion rate of by-products is relatively slow in the center portion of the wafer, while the diffusion rate of by-products is relatively fast in the wafer edge portion. Therefore, in order to eliminate such a problem, it is necessary to lower the etching rate at the wafer edge.

It is an object of the present invention to provide a plasma source having a low ion flux and a high impedance in order to reduce the plasma density at the wafer edge.

Another object of the present invention is to provide a plasma chamber employing the plasma source.

1 is a view showing an example of a coil shape constituting a conventional plasma source.

2 is a view showing another example of the shape of the coil constituting the conventional plasma source.

3 is a graph showing the CD change rate (ΔCD) in the plasma chamber employing the plasma source of FIGS. 1 and 2.

4 is a plan view showing a plasma source according to an embodiment of the present invention.

5 is a plan view showing a plasma source according to another embodiment of the present invention.

6 illustrates a plasma source according to another embodiment of the present invention.

7 is a graph showing the CD change rate (ΔCD) in the plasma chamber employing a plasma source according to the present invention.

8 is a cross-sectional view showing a plasma chamber according to an embodiment of the present invention.

9 is a cross-sectional view showing a plasma chamber according to another embodiment of the present invention.

10 is a cross-sectional view showing a plasma chamber according to another embodiment of the present invention.

In order to achieve the above technical problem, a plasma source according to an embodiment of the present invention, in the plasma source for receiving a power from a power source to form a plasma in a predetermined reaction space, the coil for receiving the power bushing; And m unit coils, each of which is an integer of 2 or more, which is branched from the coil bushing and is arranged to surround the coil bushing while having a wave-shaped bend.

The unit coils may be arranged in a spiral form along a circumference of the coil bushing.

In order to achieve the above technical problem, a plasma source according to another embodiment of the present invention, in the plasma source for receiving a power from a power source to form a plasma in a predetermined reaction space, the coil for receiving the power A first plasma source region comprising m first unit coils of at least two integers branched from a bushing and arranged in a spiral form around the coil bushing; And m second unit coils of at least two integers extending from the first unit coils of the first plasma source region and having a wave-like curvature and arranged around the first plasma source region. And a plasma source region.

In order to achieve the above technical problem, a plasma source according to another embodiment of the present invention, in the plasma source for receiving a power from a power source to form a plasma in a predetermined reaction space, the first surface of the lower and A bushing column having an upper second surface and erected in a vertical direction; And surrounding the circumference of the coil bushing while branching from the bushing pillar on the same horizontal surface as the second surface of the bushing pillar and having a wave-shaped curvature. At least two unit coils extending on the same horizontal surface as the first surface while maintaining.

In an exemplary embodiment, the insulator pillar may be further disposed between the first surface and the second surface to be surrounded by the unit coil while surrounding the bushing pillar.

It is preferable that the unit coils have n revolutions, which is an integer of 2 or more, which is a positive real number on the same horizontal surface as the second surface.

In order to achieve the above technical problem, a plasma chamber according to an embodiment of the present invention, the chamber having a side wall and an upper dome, the chamber defining a reaction space in which the plasma is formed by the outer wall and the dome structure; A support for mounting a semiconductor wafer disposed below the chamber to be processed; A plasma source consisting of a coil bushing and m unit coils of at least two integers branched from the coil bushing and having a wave-like curvature and arranged to surround the coil bushing; And an induction power supply for supplying power to the unit coils through the coil bushing.

In order to achieve the above technical problem, a plasma chamber according to another embodiment of the present invention, the chamber having a side wall and the upper dome, the chamber defining a reaction space in which the plasma is formed by the outer wall and the dome structure; A support for mounting a semiconductor wafer disposed below the chamber to be processed; A first plasma source region comprising m first unit coils of at least two integers branched from a coil bushing and arranged in a spiral form around the coil bushing, and first unit coils of the first plasma source region A plasma source region extending from the second plasma source region including m second unit coils having at least two integers and arranged to surround the circumference of the first plasma source region; And an induction power supply for supplying power to the unit coils through the coil bushing.

In order to achieve the above technical problem, a plasma chamber according to another embodiment of the present invention, the chamber having a side wall and an upper dome, the chamber defining a reaction space in which the plasma is formed by the outer wall and the dome structure; A support for mounting a semiconductor wafer disposed below the chamber to be processed; A bushing column erected in a vertical direction with a lower first surface and an upper second surface, and branched from the bushing column on the same horizontal surface as the second surface of the bushing column to have a wave-shaped bend of the coil bushing; A plasma source disposed to surround the circumference, the plasma source including at least two unit coils extending on the same horizontal surface as the first surface while maintaining the constant radius in a vertical direction at a position reaching a constant radius; And an induction power source connected to the bushing pillar to supply power to the unit coils.

In an exemplary embodiment, the insulator pillar may be further disposed between the first surface and the second surface to be surrounded by the unit coil while surrounding the bushing pillar.

It is preferable that the unit coils have n revolutions, which is an integer of 2 or more, which is a positive real number on the same horizontal surface as the second surface.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, embodiments of the present invention may be modified in many different forms, and the scope of the present invention should not be construed as being limited by the embodiments described below.

4 is a plan view showing a plasma source according to an embodiment of the present invention.

Referring to FIG. 4, the plasma source includes a bushing 410 and a plurality of unit coils 421, 422, and 423. Bushing 410 is made of a conductive material, such as copper (copper) material. Although not shown in the drawing, the bushing 410 is connected to and supplied with an RF power source. In addition, although the bushing 410 is illustrated in a circular shape in the drawing, the present invention is not limited thereto, but the shape of the bushing 410 is not limited thereto. Of course, it may be natural to have a polygonal shape including an octagonal donut shape or triangular shape.

The first, second and third unit coils 421, 422, and 423 are branched from the bushing 410 and are disposed in a spiral shape surrounding the bushing 410. In the present embodiment, three unit coils are shown as an example, but it is obvious that the present invention is not limited thereto. I.e. unit coils, when m is an integer, m It may be m in the range of two. Each unit coil may also have n revolutions, where n represents a positive real value. Since the first, second and third unit coils 421, 422, and 423 are branched from the bushing 410, the power supplied to the bushing 410 is controlled by the first, second and third unit coils 421, 422, 423).

The first, second, and third unit coils 421, 422, and 423 are not shaped to rotate around the bushing 410 while maintaining a constant distance from the center of the bushing 410, but have a wave-shaped bend. 410 has a shape that rotates around. Thus, depending on the location, it may be relatively far from the center of the bushing 410 or relatively close. However, the spacing between the first, second and third unit coils 421, 422, and 423 is preferably kept constant. The total coil length L, the intensity H of the magnetic field, and the impedance Z of the first, second and third unit coils 421, 422, and 423 are respectively represented by Equations 3 to 5 below. Can be represented as:

,

In Equations 3 to 5, I is an amount of current flowing through the coils 421, 422, and 423, R _e is an effective radius from the center of the coil, n is the number of turns, and ω is a resonance frequency. Indicates.

First, as can be seen from Equation 3, the total coil length (L) is proportional to the effective radius (R _e ) of the coil. As in the present invention, when having a structure that is bent in a wave shape surrounding the bushing 410, it has a total coil length (L) that is relatively longer than the conventional coil structure of Figs. In this way, when the total coil length L becomes larger, the effective radius R _e of the coil also becomes larger when the rotation speed n is constant. However, this effective radius R _e is inversely proportional to the strength H of the magnetic field, as shown in Equation 4 above. In addition, the effective radius R _e is proportional to the impedance Z as shown in the above expression (5). That is, as the effective radius R _e increases, the intensity H of the magnetic field decreases, while the impedance Z increases.

It is well known that the intensity H of the magnetic field is proportional to the plasma density or ion flux in the plasma chamber, while the impedance Z is inversely proportional to the plasma density or ion flux. Here, the ion flux may mean an ion flux inside the coil, or may mean an ion flux inside the plasma chamber. However, in both cases there is no benefit of distinction because they have a proportional relationship. As the ion flux is lowered due to the decrease of the magnetic field strength H and the increase of the impedance Z, the plasma density at the wafer edge is also lowered. As the plasma density decreases, the etching rate also decreases. As a result, even though the diffusion rate by which chemical by-products are removed during the etching process is high, the etching rate is also slowed down, thereby reducing the ΔCD.

5 is a plan view showing a plasma source according to another embodiment of the present invention.

Referring to FIG. 5, the plasma source includes a first plasma source portion A in the center and a second plasma source portion B in the edge. The first plasma source portion A includes a centrally located bushing 510 and first unit coils 521a, 522a and 523a branched from the bushing 510 and running around the bushing 510. The second plasma source unit B may extend from the first unit coils 521a, 522a, and 523a to extend along the circumference of the first plasma source unit A. 523b).

More specifically, the bushing 510 disposed in the center of the first plasma source region A may be made of a conductive material, for example, copper, and similarly, first unit coils 521a made of a conductive material, for example, copper. , 522a, 523a are branched from the central bushing 510. Although three unit coils 521a, 522a, and 523a are shown in the figures, this is merely exemplary and it is obvious that more than m unit coils may be used, which is at least two positive integers. The branched first unit coils 521a, 522a, and 523a are arranged in a spiral form around the bushing 510. At this time, the first unit coils 521a, 522a, and 523a wind the bushing pillar 510 while having n revolutions, which is a positive real number.

The second unit coils 521b, 522b, and 523b disposed in the second plasma source region B are branched from the first unit coils 521a, 522a, and 523a. That is, the second unit coil 421b is branched from the first unit coil 521a, the second unit coil 422b is branched from the first unit coil 522a, and the second unit coil 423b is the first It is branched from the unit coil 523a. The second unit coils 521b, 522b, and 523b have a wave-shaped curvature and have a shape that rotates around the first plasma source region A. FIG. Therefore, the position may be relatively far from or relatively close to the first plasma source region A depending on the position. However, the spacing between the second unit coils 521b, 522b, and 523b is preferably kept constant.

Also in the case of the plasma source according to the present embodiment, the second unit coils 521b, 522b, and 523b in the second plasma source region B are bent in a wave shape to surround the first plasma source region A. Since it has a structure, it has a total coil length L which is relatively long compared with the conventional coil structure of FIG. 1 and FIG. In this way, when the total coil length L becomes larger, the effective radius R _e of the coil also becomes larger when the rotation speed n is constant. As the effective radius R _e increases, the intensity H of the magnetic field decreases, while the impedance Z increases. As a result, as the ion flux is lowered due to the decrease in the intensity H of the magnetic field and the increase in the impedance Z, the plasma density at the wafer edge is also lowered. As described with reference to FIG. 4, as the plasma density decreases, the etching rate is also lowered. Accordingly, even though the diffusion rate by which the by-products of the chemical reaction are removed during the etching process is high, the etching rate is also slowed, so that the ΔCD is reduced.

6 illustrates a plasma source according to another embodiment of the present invention.

Referring to FIG. 6, the plasma source according to the present embodiment includes an insulating pillar 600 having a bottom A ′ surface and a top B ′ surface. The insulating pillar 600 is a cylinder, and a conductive bushing pillar 410 penetrating the insulating pillar 600 in the vertical direction is disposed therein. Although the insulating pillar 600 and the bushing pillar 410 are both shown in a circular columnar shape on the drawing, it is not necessarily limited thereto. In some cases, the insulating pillar 600 and the bushing pillar 410 may be formed in various pillar shapes such as a square pillar or a polygonal pillar. In addition, the insulating pillar 600 may be an empty space. The A ″ surface under the bushing pillar 410 is disposed on the same horizontal plane as the A ′ surface of the insulating pillar 600, and the B ″ surface above the bushing pillar 410 is also the same as the B ′ surface of the insulating pillar 600. Disposed on a horizontal plane.

A plurality of unit coils, for example, first, second and third unit coils 421, 422, 423, are branched from the circumference of the B ″ surface of the bushing pillar 410 to the B ′ surface of the insulating pillar 600. The arrangement shape and structure of the first, second and third unit coils 421, 422 and 423 are the same as the plasma source shown in Fig. 4. That is, the first, second and third unit coils ( 421, 422, and 423 all have a wave-like bend and have a shape that rotates around the bushing pillar 410. Thus, depending on the position, the 421, 422, and 423 may be relatively far from or relatively close to the center of the bushing pillar 410. Although only three unit coils are shown in the figures, this is merely illustrative, and it is obvious that a larger number of unit coils may be used, such as at least two positive integers of at least two. Surrounding first, second and When the three unit coils 421, 422, and 423 reach the predetermined points a, b, and c located at the edges of the insulating pillar 600 spaced apart from the bushing pillar 410 by a predetermined distance r in the radial direction. It is no longer on the surface of B ', for example, in the case of the first unit coil 421, the first of the edge of the insulating pillar 600 spaced apart by a predetermined distance r in the radial direction from the bushing pillar 410. After reaching point (a), it no longer proceeds in the horizontal direction but proceeds downward while winding the side surface of the insulating pillar 600 toward the lower surface A 'in the vertical direction. In the case of the third unit coil 423, the second point b and the third point c of the edge of the insulating pillar 600 spaced apart from the bushing pillar 410 by a predetermined distance r in the radial direction. After each approach to), it will no longer proceed in the horizontal direction, but in the vertical direction It proceeds downward while winding the side of the insulating pillar 600 toward the A 'side of the.

In the case of the plasma source according to the present embodiment, the first, second and third unit coils 421, 422, and 423 on the upper surface are curved in a wave shape and have a structure surrounding the bushing pillar 410. Further, since it has a three-dimensional structure that is also arranged in the vertical direction, it has a total coil length L that is relatively longer than the conventional coil structure of FIGS. 1 and 2. If the total coil length L is larger in this manner, the effective radius R _e of the coil is also larger when the rotation speed n is constant, and the strength H of the magnetic field is smaller as the effective radius R _e is larger. On the other hand, the impedance Z becomes large. As a result, as the ion flux is lowered due to the decrease in the intensity H of the magnetic field and the increase in the impedance Z, the plasma density at the wafer edge is also lowered. As described with reference to FIG. 4, as the plasma density decreases, the etching rate is also lowered. Accordingly, even though the diffusion rate by which the by-products of the chemical reaction are removed during the etching process is high, the etching rate is also slowed, thereby reducing the ΔCD.

7 is a graph showing ΔCD in the plasma chamber employing the plasma source according to the present invention.

As shown in FIG. 7, it can be seen that when using the plasma source according to the present invention, ΔCD at the wafer edge shows a small value. The ΔCD value is shown as negative at the wafer edge when indicated by reference numeral 701, and the curve indicated by the reference mark 702 as the ΔCD value as positive value at the wafer edge. In any case, however, the ΔCD value is small compared to the conventional plasma sources of FIGS. 1 and 2.

8 is a cross-sectional view showing a plasma chamber according to an embodiment of the present invention.

Referring to FIG. 8, in the plasma chamber 810 according to the present exemplary embodiment, an inner space 804 of a predetermined size is defined by the chamber outer wall 802 and the dome 812. Although the chamber interior space 804 is shown open outwardly on the drawing, this is for simplicity of the drawing and is actually closed to maintain the vacuum state. In the inner space 804, a wafer support 806 is disposed in the lower space for supporting the semiconductor wafer 808 having certain patterns to be processed. An RF power source 816 is connected to the wafer support 806.

A plasma source is disposed on the outer surface of the dome 812, which is the same as the plasma source described with reference to FIG. 4. That is, the plasma source includes a bushing 410 and a plurality of unit coils 421, 422, and 423. The RF power source 814 is connected to the bushing 410 to receive power. In the drawing, the bushing 410 is illustrated in a circular shape, but is not limited thereto, and a circular shape, a circular donut shape, a square shape, a square donut shape, a hexagonal shape, a hexagonal donut shape, an octagonal shape, Naturally, it may have a polygonal shape including an octagonal donut shape or a triangular shape. The first, second and third unit coils 421, 422, and 423 all have a wave-shaped bend and have a shape that rotates around the bushing 410. Thus, depending on the location, it may be relatively far from the center of the bushing 410 or relatively close.

In the plasma chamber 810 having such a structure, the first, second and third unit coils 421, 422, and 423 supplied with the RF power by the RF power source 814 generate an electric field. This electric field passes through the dome 812 and is induced into the chamber interior space 804. The induced electric field in the chamber internal space 804 generates a discharge in the gas in the chamber internal space 804 to plasma the gas, and reacts the chemical reaction between the neutral radical particles generated therein and the charged ions. By causing the surface of the semiconductor wafer 808 to be processed.

In the plasma chamber 810, since the first, second and third unit coils 421, 422, and 423 constituting the plasma source are bent in a wave shape, they have a structure surrounding the bushing 410. It has a longer overall coil length L than when employing a conventional plasma source. As described above, as the overall coil length L becomes larger, the ion flux is lowered due to a decrease in the intensity H of the magnetic field and an increase in the impedance Z, and consequently, the plasma density at the wafer edge is also lowered. . As the plasma density at the wafer edge is lowered, the etching speed at the wafer edge is also lowered. Therefore, the ΔCD is reduced because the etching speed is also slowed at the wafer edge even if the diffusion rate by which the chemical reaction by-products are removed during the etching process is high.

9 is a cross-sectional view showing a plasma chamber according to another embodiment of the present invention.

Referring to FIG. 9, the basic structure of the plasma chamber 820 according to the present embodiment is similar to the basic structure of the plasma chamber 810 of FIG. 8. Only the plasma source for generating the plasma in the plasma chamber 820 is different. Operations and effects of the plasma chamber according to the present embodiment are the same as those described with reference to FIG. 8, and thus description thereof will be omitted.

The plasma source employed in the plasma chamber 820 according to the present embodiment is the same as the plasma source described with reference to FIG. 5. In other words, the plasma source includes a central first plasma source portion A and an edge second plasma source portion B. FIG. The first plasma source portion A includes a centrally located bushing 510 and first unit coils 521a, 522a and 523a branched from the bushing 510 and running around the bushing 510. The second plasma source unit B may extend from the first unit coils 521a, 522a, and 523a to extend along the circumference of the first plasma source unit A. 523b).

More specifically, the bushing 510 disposed in the center of the first plasma source region A may be made of a conductive material, for example, copper, and similarly, first unit coils 521a made of a conductive material, for example, copper. , 522a, 523a are branched from the central bushing 510. Although three unit coils 521a, 522a, and 523a are shown in the figures, this is merely exemplary and it is obvious that more than m unit coils may be used, which is at least two positive integers. The branched first unit coils 521a, 522a, and 523a are arranged in a spiral form around the bushing 510. At this time, the first unit coils 521a, 522a, and 523a wind the bushing pillar 510 while having n revolutions, which is a positive real number.

The second unit coils 521b, 522b, and 523b disposed in the second plasma source region B are branched from the first unit coils 521a, 522a, and 523a. That is, the second unit coil 421b is branched from the first unit coil 521a, the second unit coil 422b is branched from the first unit coil 522a, and the second unit coil 423b is the first It is branched from the unit coil 523a. The second unit coils 521b, 522b, and 523b have a wave-shaped curvature and have a shape that rotates around the first plasma source region A. FIG. Therefore, the position may be relatively far from or relatively close to the first plasma source region A depending on the position.

10 is a cross-sectional view showing a plasma chamber according to another embodiment of the present invention.

Referring to FIG. 10, the basic structure of the plasma chamber 830 according to the present embodiment is similar to the basic structure of the plasma chamber 810 of FIG. 8. Only the plasma source for generating the plasma in the plasma chamber 830 is different. Operations and effects of the plasma chamber according to the present embodiment are the same as those described with reference to FIG. 8, and thus description thereof will be omitted.

The plasma source employed in the plasma chamber 830 according to the present embodiment is the same as the plasma source described with reference to FIG. 6. That is, the plasma source includes an insulating pillar 600 having a lower A 'surface and an upper B' surface. The insulating pillar 600 is a cylinder, and a conductive bushing pillar 410 penetrating the insulating pillar 600 in the vertical direction is disposed therein. Although the insulating pillar 600 and the bushing pillar 410 are both shown in a circular columnar shape on the drawing, it is not necessarily limited thereto. In some cases, the insulating pillar 600 and the bushing pillar 410 may be formed in various pillar shapes such as a square pillar or a polygonal pillar. In addition, the insulating pillar 600 may be an empty space. The A ″ surface under the bushing pillar 410 is disposed on the same horizontal plane as the A ′ surface of the insulating pillar 600, and the B ″ surface above the bushing pillar 410 is also the same as the B ′ surface of the insulating pillar 600. Disposed on a horizontal plane.

A plurality of unit coils, for example, first, second and third unit coils 421, 422, 423, are branched from the circumference of the B ″ surface of the bushing pillar 410 to the B ′ surface of the insulating pillar 600. The arrangement shape and structure of the first, second and third unit coils 421, 422 and 423 are the same as the plasma source shown in Fig. 4. That is, the first, second and third unit coils ( 421, 422, and 423 all have a wave-shaped bend and have a shape that rotates around the bushing pillar 410. Thus, depending on the position, the 421, 422, and 423 may be relatively far from or relatively close to the center of the bushing pillar 410. Although only three unit coils are shown in the figures, this is merely illustrative, and it is obvious that a larger number of unit coils may be used, such as at least two positive integers of at least two. Surrounding first, second and When the three unit coils 421, 422, and 423 reach the predetermined points a, b, and c located at the edges of the insulating pillar 600 spaced apart from the bushing pillar 410 by a predetermined distance r in the radial direction. It is no longer on the surface of B ', for example, in the case of the first unit coil 421, the first of the edge of the insulating pillar 600 spaced apart by a predetermined distance r in the radial direction from the bushing pillar 410. After reaching point (a), it no longer proceeds in the horizontal direction but proceeds downward while winding the side surface of the insulating pillar 600 toward the lower surface A 'in the vertical direction. In the case of the third unit coil 423, the second point b and the third point c of the edge of the insulating pillar 600 spaced apart from the bushing pillar 410 by a predetermined distance r in the radial direction. ), After each approach, do not proceed in the horizontal direction anymore. Towards the surface of A 'flew closed side of the insulating pillar 600 goes down.

As described above, according to the plasma source and the plasma chamber employing the plasma source according to the present invention, the effective length of the unit coil is increased by making the unit coils constituting the plasma source have a wave-shaped bend. By reducing the plasma density or ion flux at the wafer edge, it provides the effect that the rate of diffusion of by-products generated by chemical reactions during the etching process can be reduced at a relatively slow rate at the edge of the wafer, thereby reducing the magnitude of the CD change rate. .

Although the present invention has been described in detail with reference to preferred embodiments, the present invention is not limited to the above embodiments, and various modifications may be made by those skilled in the art within the technical spirit of the present invention. Do.

Claims (11)

In the plasma source for receiving the power from the power source to form a plasma in a predetermined reaction space, A coil bushing for receiving the power; And And m unit coils, each of which is two or more integers arranged to enclose a circumference of the coil bushing while branching from the coil bushing and having a wave-shaped bend. The method of claim 1, The unit coils are arranged in a spiral form along the circumference of the coil bushing. In the plasma source for receiving the power from the power source to form a plasma in a predetermined reaction space, A first plasma source region branching from the coil bushing for receiving power and including m first unit coils of at least two integers arranged in a spiral form around the coil bushing; And A second plasma including m second unit coils of at least two integers extending from the first unit coils of the first plasma source region and having a wave-like curvature and arranged around the first plasma source region; And a source region. In the plasma source for receiving the power from the power source to form a plasma in a predetermined reaction space, A bushing column erected in a vertical direction with a lower first surface and an upper second surface; And It is arranged to surround a circumference of the coil bushing while branching from the bushing pillar on the same horizontal surface as the second surface of the bushing pillar and having a wave-shaped bend, and maintaining the constant radius in the vertical direction at a position reaching a certain radius. And at least two or more unit coils extending on the same horizontal surface as the first surface. The method of claim 4, wherein And an insulator column arranged to be surrounded by the unit coil while surrounding the bushing column between the first surface and the second surface. The method of claim 5, Wherein said unit coils have n revolutions, n being integers greater than or equal to 2, which is a positive real number on the same horizontal surface as said second surface. A chamber having a side wall and an upper dome, the chamber defining a reaction space in which plasma is formed by the outer wall and the dome structure; A support for mounting a semiconductor wafer disposed below the chamber to be processed; A plasma source consisting of a coil bushing and m unit coils of at least two integers branched from the coil bushing and having a wave-like curvature and arranged to surround the coil bushing; And And an induction power supply for supplying power to the unit coils through the coil bushing. A chamber having a side wall and an upper dome, the chamber defining a reaction space in which plasma is formed by the outer wall and the dome structure; A support for mounting a semiconductor wafer disposed below the chamber to be processed; A first plasma source region comprising m first unit coils of at least two integers branched from a coil bushing and arranged in a spiral form around the coil bushing, and first unit coils of the first plasma source region A plasma source region extending from the second plasma source region including m second unit coils having at least two integers and arranged to surround the circumference of the first plasma source region; And And an induction power supply for supplying power to the unit coils through the coil bushing. A chamber having a side wall and an upper dome, the chamber defining a reaction space in which plasma is formed by the outer wall and the dome structure; A support for mounting a semiconductor wafer disposed below the chamber to be processed; A bushing column erected in a vertical direction with a lower first surface and an upper second surface, and branched from the bushing column on the same horizontal surface as the second surface of the bushing column to have a wave-shaped bend of the coil bushing; A plasma source disposed to surround the circumference, the plasma source including at least two unit coils extending on the same horizontal surface as the first surface while maintaining the constant radius in a vertical direction at a position reaching a constant radius; And And an induction power source connected to the bushing pillar to supply power to the unit coils. The method of claim 9, And an insulator column arranged to be surrounded by the unit coil while surrounding the bushing column between the first surface and the second surface. The method of claim 10, Wherein said unit coils have n revolutions, n being integers of two or more, on the same horizontal surface as said second surface, having n revolutions.