KR100882449B1 - Treating device of inductively coupled plasma and its antenna - Google Patents

Abstract

The present invention relates to an inductively coupled plasma processing apparatus, and more particularly, to an antenna of an inductively coupled plasma processing apparatus.

The present invention provides an inductively coupled plasma processing apparatus, wherein an antenna is divided into at least two parts, and a connection part of each part is formed of a linear wire and a wire enclosing the linear wire, and a wire enclosing the linear wire and the linear wire. Provides an inductively coupled plasma processing apparatus, which is electrically shorted with each other.

Therefore, according to the present invention, the current induced by the antenna of the inductively coupled plasma processing apparatus is formed so as not to break, thereby implementing rotational symmetry of the induction electric field, and power is supplied to the antenna in parallel to improve the matching stability of the impedance. A plurality of antennas are provided and the height of the antenna can be adjusted to increase the plasma uniformity in the radial direction.

ICP, Y-shaped connection

Description

Inductively coupled plasma processing apparatus and its antenna TECHNICAL FIELD

1 is a view schematically showing a structure of a conventional antenna for inductively coupled plasma generation,

FIG. 2 is a diagram illustrating rotational symmetry and uniformity of plasma generated by the antenna for generating an inductively coupled plasma shown in FIG. 1;

3 is a view showing an antenna portion of an embodiment of an inductively coupled plasma processing apparatus according to the present invention,

4 is a view showing an antenna of another embodiment of an inductively coupled plasma processing apparatus according to the present invention;

5 is a view showing an antenna of another embodiment of an inductively coupled plasma processing apparatus according to the present invention;

6 is a view showing an antenna of another embodiment of an inductively coupled plasma processing apparatus according to the present invention.

<Explanation of symbols for the main parts of the drawings>

100a and 100b: first antenna unit 110a and 110b: second antenna unit

120a, 120b: third antenna portion 120a ': first end

120a ": 2nd end 224, 227: fixing part

The present invention relates to an inductively coupled plasma processing apparatus, and more particularly, to an antenna of an inductively coupled plasma processing apparatus.

When a solid substance is heated, the state changes in the order of liquid and gas. When energy is further applied by heating or discharging in the gas state, the gas dissociates into smaller particles, such as atoms, ions, and electrons, and these particles are mixed, which is called a plasma state. There are many types of plasma, but the phenomena seen in everyday life include fluorescent lights, lightning, polar aurora and the inside of the sun. Industrially used plasmas are divided into low temperature plasmas and thermal plasmas. Cold plasmas are widely used in semiconductor manufacturing processes, and thermal plasmas are applied to cutting and thermal spraying.

Currently, the most commonly used plasma generation method in the semiconductor manufacturing process and display field is RF, which is divided into inductively coupled plasma (ICP) and capacitively coupled plasma (CCP). Inductively coupled plasma has a structurally coiled antenna, and when RF power is applied thereto, a current flows in the antenna, and this current forms an induced magnetic field around the antenna. At this time, positive and negative charges are alternately charged on the surface of the antenna at an RF frequency, which causes a secondary induced current to flow around the antenna. In general, the inductively coupled plasma uses an argon gas (argon gas: liquid argon or compressed argon gas with a purity of 99.99% or more) as the plasma gas to the induction coil in the frequency (13.56 MHz) region generated from the crystal oscillation high frequency generator. Is generated.

However, the above-described conventional inductively coupled plasma has the following problems.

The conventional antenna for inductively coupled plasma generation has various shapes and characteristics, but the symmetry of the rotation direction is not good. That is, as shown in Figure 1, by generating a magnetic field by flowing a radio frequency (RF) current to the antenna for inductively coupled plasma generation, the induction electric field is generated by this time-varying magnetic field. The electrons are accelerated by the above-described induction electric field to generate and maintain plasma. However, as shown in FIG. 1, since the antenna cannot be completely circular, there is a portion where the current is cut off. That is, since the antenna is not connected at the portion where the positive electrode of the power supply is connected to the negative electrode, a portion where the current is cut off is naturally formed.

Since the antenna is not completely circular, the induced current is broken, there are the following problems. As shown in Figure 2, the broken portion of the antenna affects the rotational symmetry and uniformity of the inductively coupled plasma. In other words, the magnetic field is weak in the a portion, so the oscillation is weak. Therefore, it is difficult to generate a uniform plasma in a rotational direction and a radial direction in a large area of 300 mm or more.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to form a connection portion of the antenna without breaking, to realize rotational symmetry of the induced magnetic field and the electric field.

Another object of the present invention is to supply power to the antenna in parallel, thereby reducing the impedance of the antenna to increase the stability of the matching of the impedance.

Still another object of the present invention is to increase the uniformity in the radial direction of the inductively coupled plasma by arranging a plurality of antennas and adjusting the heights of the antennas.

In order to achieve the above object, the present invention is an inductively coupled plasma processing apparatus, the antenna is divided into at least two parts, the connection portion of each of the portion is wrapped around the linear lead and the linear lead and the lead is not shorted with the linear lead It provides an inductively coupled plasma processing apparatus comprising a.

Here, the linear wire and the conductive wire surrounding the linear wire are separated from each other by 5 mm or more and are not shorted to each other.

The end of the conductive line surrounding the linear conductive line may have a shape of <, or c or c.

In addition, the antenna may be provided in the shape of a circle, a square, or a triangle.

In addition, the above-described inductively coupled plasma processing apparatus includes a reaction chamber for generating an inductively coupled plasma; And a stage provided below the reaction chamber to perform a plasma processing process.

In addition, the above-described inductively coupled plasma processing apparatus includes two or more antennas, and each of the antennas may have concentricity.

Here, each of the antennas, the heights are different from each other, may be dome (dome) shape as a whole, each may be fixed at the same position with respect to the concentric.

The antenna may include at least two power input units. The power input unit may be connected to the first end of the connection unit and may be fixed to the antenna through the power input unit.

In addition, the power input unit may supply power to the antenna in parallel.

Also, the antenna can be grounded at the second end of the connection.

In addition, the connection portion of each antenna may be formed spaced apart from each other at the same angle with respect to the concentric.

According to another embodiment of the present invention, the first to Mth antenna parts are included (wherein M is an integer of 1), and each of the antenna parts includes the first to Nth parts, where N An integer of ≥ 2), and the connection portion of each of the portions provides a linear conductor and a conductor surrounding the linear conductor.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention that can specifically realize the above object will be described.

The same components as the prior art are given the same names and the same reference numerals for convenience of description, and detailed description thereof will be omitted.

3 is a view showing an antenna portion of an embodiment of an inductively coupled plasma processing apparatus according to the present invention. Referring to Figure 3 describes the antenna portion of an embodiment of the inductively coupled plasma processing apparatus according to the present invention.

In this embodiment, the antenna is divided into at least two parts, and the connection portion of each part is characterized by consisting of a linear conductor and a conductor surrounding the linear conductor. Here, the connection portion does not mean that the two parts are short-circuited, that is, they are physically bonded, but they are spaced apart from each other, but the current flows without breaking. In addition, the portion enclosing the linear conductor may be the structure shown in 120 "of FIG. 3, but it is sufficient to enclose the linear structure by <-, c-, or V-shape, etc. provided that the linear conductor and the enclosing conductor of the connection part Specifically, three antennas of concentric circles are shown in FIG. 3, which is represented and described as a first antenna part, a second antenna part, and a third antenna part in order from the inside.

Here, the first, second, and third antenna units are divided into two parts. That is, the first antenna portion is composed of the first portion 100a and the second portion 100b, the second antenna portion is divided into the first portion 110a and the second portion 110b, and the third antenna portion is the first portion. It is divided into part 120a and second part 120b. The distance from the common center to the first antenna portion may be equal to the distance between the first antenna portion and the second antenna portion and the distance between the second antenna portion and the third antenna portion.

In the antenna unit, the two parts are connected to each other in a <, or c, or ⊂ type. (However, in the drawings, <type is shown as an embodiment.) Here, the first part and the second part The silver shall be wrapped around the other but not shorted. As an example, if more than 5 mm (millimeters) apart will not short. And, either side of the above-mentioned connection portion should be <type or c type or ⊂ type. For convenience of description, the portions of the first and second portions of the third antenna portion having the <-, c-, or V-shaped ends are called second ends, and the remaining ends are called first ends. In the first portion and the second portion of the third antenna portion, one end 120a 'has a straight shape, and the other end 120a "has a <, or c-, or V-shape.

3, the first end 120a 'and the second end 120a "of the first and second portions of the third antenna unit are spaced apart from each other. Here, the first end 120a' is provided with a power supply. The power supply is made by connecting a power input unit to the first end 120a 'In this embodiment, since one antenna unit is divided into two parts, two power input units are connected to each antenna unit. In addition, two power input units connected to one antenna unit may be connected in parallel.

In the present invention, one or more antenna units are sufficient, and in the case of two or more antenna units, the positional relationship of each connection unit will be described below.

In FIG. 3, two connecting parts are formed in the first antenna part, two connecting parts in the second antenna part, and two connecting parts in the third antenna part. Therefore, six connection parts are formed as a whole. Each connection portion may be formed at different angles, but may be formed to be spaced apart from each other at the same angle with respect to a common center as shown in FIG. In FIG. 3, the six connection parts are spaced apart from each other by an angle of 60 degrees. Even if the current is not broken at the connection, there is a possibility of weak flow. Therefore, if the connection portion is separated at the same angle as described above, the portion where the current flows weakly is not biased, and thus the uniformity of the electric field can be improved.

In FIG. 4, two antenna units are provided in a rectangular shape with respect to one center. Here, the two antenna parts are divided into two parts, respectively, and their connection part is made of a <type or a c type or a ⊂ type. (However, in the drawing, the j-shape is shown as an embodiment.) The connecting portion provided in the internal antenna portion and the connecting portion provided in the external antenna portion are spaced apart from each other by the same angle. In FIG. 5, three antenna units are provided in a triangular shape with respect to one center. Here, the three antenna parts are each divided into two parts, their connection parts are made of <-or c- or ⊂-type, and the points at which each connection part is spaced by the same angle are the same as the above-described embodiment.

In the above-described embodiments, each antenna unit is composed of two parts, but may be three or more. The first end of the portion of the antenna is not only connected to the power input, but also a portion of the antenna is fixed at this point. In addition, each antenna portion may be formed at the same height, but may be formed by changing the height. If the two or more antenna units vary in height from each other, and the internal antenna unit is formed higher, the antennas generally form a dome. In addition, the above-described antenna units are not fixed and may be adjusted in height. Thus, depending on the plasma treatment process to be used, the shape of the antenna can be changed into a dome shape or another shape.

6 is a view showing an antenna of another embodiment of an inductively coupled plasma processing apparatus according to the present invention. In FIG. 6, the antenna consists of three antenna parts having concentric circles, and each antenna part consists of four parts. Thus, each antenna portion comprises four connections. The shape of the connecting portion is the same as the above-described embodiment. As shown in the drawing, the first end 220a 'and the second end 220b' form a <-, c-, or w-shaped connection. In addition, a fixing portion 224 is provided at the first end 220a '. Each fixing part 224 is connected to one fixing part 227 to fix the antenna.

Inductively coupled plasma processing apparatus according to the present invention comprises a reaction chamber and a stage and the antenna described above. Here, the reaction chamber is a region for processing the inductively coupled plasma, and the above-described antenna is provided therein. In addition, the stage is provided under the reaction chamber to perform a process such as plasma etching and deposition, specifically, performed on a substrate provided in the stage. Here, the antenna is made of a common material such as stainless steel and aluminum.

In the above-described inductively coupled plasma processing apparatus, electrons generated at the time of discharge are accelerated by a magnetic field generated when a high frequency current flows through the induction coil, and at this time, they are ionized by colliding with argon gas around and new electrons and argon ions. Create The electrons generated by the above-mentioned process again ionize argon gas to propagate electrons, thereby maintaining a plasma state with a very high electron density. In the structure of the above-described inductively coupled plasma, a low-temperature, low-electron density region is formed at the center thereof to form a donut.

In addition, since the connection portion of the antenna is not broken, the rotational symmetry of the induction electric field can be realized, and power is supplied in parallel to the antenna to reduce the impedance of the antenna, thereby improving the stability of matching of the impedance. Since a plurality of antennas are provided and the height of the antenna can be adjusted, the uniformity in the radial direction is improved.

The antenna provided in the above-described inductively coupled plasma processing apparatus is capable of efficiently radiating radio waves in a space to achieve the purpose of communication in a conventional antenna, that is, wireless communication, as well as generation of inductively coupled plasma (ICP), or May be used to efficiently induce electromotive force.

Here, the antenna is composed of M antenna units. In detail, the antenna includes first to Mth antenna parts, and each antenna part includes first to Nth parts. Here, M is an integer of 1 or more, and N is an integer of 2 or more. In addition, the connection part of the first to Nth parts described above includes a linear conductive line and a conductive line surrounding the linear conductive line. In addition, each antenna unit is supplied with power in parallel, concentric with each other, and provided in a circular or rectangular shape. Then, power may be supplied through the first end of the first to Nth parts and grounded through the second end.

The present invention is not limited to the above-described embodiments, and such modifications are included in the scope of the present invention even if modifications are possible by those skilled in the art to which the present invention pertains.

Referring to the effects of the antenna and the inductively coupled plasma processing apparatus according to the present invention described above are as follows.

First, one side of the antenna is connected to the other side of the inductively coupled plasma processing apparatus, and the power input is connected to each other, so that the current flows without disconnection without being physically connected, thereby causing rotational symmetry of the induction electric field. Can be implemented.

Second, since power is supplied in parallel to the antenna of the inductively coupled plasma processing apparatus, the impedance of the antenna is reduced, thereby improving the stability of matching of the impedance.

Third, since a plurality of antennas are provided in the inductively coupled plasma processing apparatus and the height of the antennas can be adjusted, the uniformity in the radial direction of the generated inductively coupled plasma can be increased.

Claims (18)

A reaction chamber for generating an inductively coupled plasma, a stage provided below the reaction chamber to perform a plasma treatment process, gas supply means for supplying gas to the chamber, an electrode provided on the stage, and the An inductively coupled plasma processing apparatus comprising a power supply means for generating a potential difference between a stage and an electrode, The antenna consists of at least two parts separated from each other, Adjacent portions of the separated portions, the inductively coupled plasma processing apparatus comprising a linear lead that is a part of the first part, and a portion of the second part that surrounds the linear lead and the linear lead and the unshorted lead . The method of claim 1, Inductively coupled plasma processing apparatus, characterized in that the linear wire and the conductive wire surrounding the linear lead is spaced at least 5 millimeters apart from each other. The method of claim 1, Inductively coupled plasma processing apparatus, characterized in that the end of the conductive wire surrounding the linear conductive wire is a <-or c-shaped or ⊂-shaped. The method of claim 1, wherein the antenna, Inductively coupled plasma processing apparatus, characterized in that provided in the shape of a circle or square or triangle. delete The method of claim 1, And at least two antennas, each antenna having concentricity. The method of claim 6, wherein each of the antennas, Inductively coupled plasma processing apparatus, characterized in that the height is different from each other, and dome (dome) as a whole. The method of claim 6, And each antenna is fixed at equal intervals with respect to the concentric. The method of claim 1, wherein the antenna, Inductively coupled plasma processing apparatus comprising at least two power input. The method of claim 9, The power input unit is connected to the first end of the adjacent portion, the inductively coupled plasma processing apparatus, characterized in that the antenna is fixed through the power input unit. The method of claim 9, wherein the power input unit, Inductively coupled plasma processing apparatus, characterized in that for supplying power in parallel to the antenna. The method of claim 1, And the antenna is grounded at the second end of the adjacent portion. The method of claim 6, Adjacent portions of the respective antennas, the inductively coupled plasma processing apparatus, characterized in that formed spaced apart from each other at the same angle with respect to the concentric. Including first to Mth antenna parts separated from each other (wherein an integer of M≥1), Wherein each antenna portion comprises first to Nth portions separated from each other (wherein an integer of N ≧ 2), Inductively coupled plasma processing apparatus, wherein the adjacent portions of the separated portions include a linear lead that is a part of the first part, and a lead that is part of the second part and surrounds the linear lead and is not shorted with the linear lead. Antenna. The method of claim 14, The antenna for the inductively coupled plasma processing apparatus, characterized in that each of the antenna unit is supplied with power in parallel. The method of claim 14, Each antenna unit is concentric with each other, the antenna for inductively coupled plasma processing apparatus, characterized in that provided in the shape of a circle, triangle or square. The method of claim 14, And an electric power is supplied in parallel through the first end of the N-th portion. The method of claim 14, And the antenna is grounded through the second end of the N-th portion.

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