KR100785401B1 - Inductively coupled plasma treatment apparatus - Google Patents

Abstract

The present invention relates to an inductively coupled plasma processing apparatus, comprising: a coil wound around a reaction chamber, the coil comprising: a first coil in which current flows in a clockwise direction and a second in which current flows in a counterclockwise direction; The coils are connected to each other via a power supply and a ground to induce a bidirectional magnetic field. According to the present invention, a bi-directional magnetic field is induced due to the two-turn coil structure capable of applying a high frequency such that the directions of the electric fields are opposite to each other. This improves the plasma uniformity as compared with the plasma generated by the unidirectional magnetic field.

Semiconductor, Plasma Treatment, Inductively Coupled Plasma

Description

Inductively Coupled Plasma Treatment Unit {INDUCTIVELY COUPLED PLASMA TREATMENT APPARATUS}

1 is a perspective view showing an inductively coupled plasma processing apparatus according to an embodiment of the present invention.

Figure 2 is a perspective view showing a coil structure in the inductively coupled plasma processing apparatus according to an embodiment of the present invention.

<Description of Symbols for Major Parts of Drawings>

100; Inductively Coupled Plasma Treatment Equipment

110; Reaction chamber

120; Two-turn coil

122; Upper coil

124; Bottom coil

130; Power supply

140; Ground

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

The plasma processing apparatus is a processing apparatus useful for manufacturing a semiconductor device using a plasma. The plasma processing apparatus may be roughly classified into a capacitively coupled plasma (CCP) processing apparatus and an inductively coupled plasma (ICP) processing apparatus based on the plasma generation method. An inductively coupled plasma processing apparatus is a device that generates a plasma by installing a spiral coil (or antenna) in a reaction chamber and then applying high frequency induction power to induce a magnetic field in the reaction chamber. Such inductively coupled plasma processing apparatuses are widely used because of their relatively simple structure and relatively easy to obtain large-area plasma.

However, the inductively coupled plasma processing apparatus has a problem in that non-uniform plasma is distributed due to a unidirectional magnetic field. It is considered that the coil structure is unidirectionally wound in the reaction chamber so that power is applied through one high frequency input line and the induced current generated is grounded through one high frequency output line.

Accordingly, the present invention has been made to solve the above-mentioned problems in the prior art, an object of the present invention is to provide an inductively coupled plasma processing apparatus that can obtain a uniform plasma distribution by improving the coil structure.

Inductively coupled plasma processing apparatus according to the present invention for achieving the above object is characterized in that the coil structure is improved to a dual structure to form a bidirectional magnetic field.

In the inductively coupled plasma processing apparatus according to an embodiment of the present invention capable of implementing the above characteristics, in the inductively coupled plasma processing apparatus in which a coil is wound around a reaction chamber, the coil is inversely opposite to the first coil in which current flows in a clockwise direction. A second coil in which a current flows in a clockwise direction is connected to each other through a power supply and a ground to induce a bidirectional magnetic field.

In the present embodiment, the front end of the first coil is connected to the rear end of the second coil and the power supply unit, the rear end of the first coil through the front end of the second coil and the grounding unit. Are connected to each other.

In the present embodiment, the power supply unit simultaneously applies the plasma source power to the front end of the first coil and the rear end of the second coil.

Inductively coupled plasma processing apparatus according to a modified embodiment of the present invention that can implement the above characteristics, the reaction chamber, the upper coil winding the upper portion of the reaction chamber and the lower coil winding the lower portion of the reaction chamber And one end of the upper coil connected to the other end of the lower coil and the other end of the upper coil to induce magnetic fields in opposite directions connected to one end of the upper coil; And a power supply unit for simultaneously applying a high frequency plasma source power to the other end of the lower coil, and a ground unit for grounding the other end of the upper coil and one end of the lower coil.

In this modified embodiment, the circular current direction flowing in the upper coil and the circular current direction flowing in the lower coil are opposite to each other.

In this variant embodiment, each of the upper and lower coils is of an annular shape having the same diameter or of an annular shape having a different diameter.

According to the present invention, a bi-directional magnetic field is induced due to the two-turn coil structure capable of applying a high frequency such that the directions of the electric fields are opposite to each other. This improves the plasma uniformity as compared with the plasma generated by the unidirectional magnetic field. In addition, the coil length can be greatly reduced, thereby reducing the inductance value, thereby increasing power efficiency, thereby increasing the density of the plasma.

Hereinafter, an inductively coupled plasma processing apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

Advantages over the present invention and prior art will become apparent through the description and claims with reference to the accompanying drawings. In particular, the present invention is well pointed out and claimed in the claims. However, the present invention may be best understood by reference to the following detailed description in conjunction with the accompanying drawings. Like reference numerals in the drawings denote like elements throughout the various drawings.

(Example)

1 is a perspective view showing an inductively coupled plasma processing apparatus according to an embodiment of the present invention.

Referring to FIG. 1, the inductively coupled plasma processing apparatus 100 of the present embodiment provides a place where an inductively coupled plasma (ICP) is generated, and provides a reaction chamber 110 in which a predetermined plasma treatment such as plasma etching is performed. Have The reaction chamber 110 may be cylindrical. Although not shown in detail in the drawing, the reaction chamber 110 has a supply and discharge portion of a reaction gas required for plasma processing, and is generally required for plasma processing such as a stage on which a plasma processing object such as a semiconductor wafer is mounted. Members are provided.

At the outer side of the reaction chamber 110 is wound an annular coil 110 through which a circular current inducing a magnetic field flows. The coil 120 is a two-turen wound structure. That is, the two-turn coil 120 is composed of an annular upper coil 122 winding the upper side of the reaction chamber 110 and an annular lower coil 124 winding the lower side. The upper coil 122 and the lower coil 124 may have annular shapes having the same diameter or may have annular shapes having different diameters. A portion of the coil 120 is disposed with a power supply 130 for applying plasma source power having a high frequency of, for example, 2 MHz to 100 MHz, and is connected to the ground portion 140 at another portion.

2 is a perspective view illustrating a coil structure of an inductively coupled plasma processing apparatus according to an embodiment of the present invention.

2, in the two-turn coil 120, the upper coil 122 is integrally formed with the lower coil 124. It is assumed that the upper coil 122 is divided into the first half 122a and the second half 122b, and similarly, the lower coil 124 is divided into the first half 124a and the second half 124b. The second half 122b of the upper coil 122 is connected to the first half 124a of the lower coil 124 via the ground 140, and the second half 124b of the lower coil 124 connects the power supply 130. It is connected to the first half (122a) of the upper coil 122 by a medium, to form a two-turn coil 120 as a whole. In one example, the coil 120 is comprised of approximately 3/8 inch copper tubes, and the spacing d between the upper coil 122 and the lower coil 124 is approximately 50 mm.

The power supply unit 130 simultaneously applies the high frequency plasma source power to the first half 122a of the upper coil 122 and the second half 124b of the lower coil 124. When a high frequency plasma source power is applied, current flows from the first half 122a of the upper coil 122 toward the second half 122b, and simultaneously from the second half 124b of the lower coil 124 toward the first half 124a. That is, a clockwise circular current (solid arrow) flows through the upper coil 122, and a counterclockwise circular current (dashed arrow) flows through the lower coil 124. Therefore, an upward magnetic field is induced in the upper coil 122, and a downward magnetic field is induced in the lower coil 124, thereby forming a bidirectional magnetic field. The formation of a bidirectional magnetic field increases the probability of collision between electrons and other particles that make a spiral motion in the magnetic field. The higher the collision probability, the higher the plasma density, and the higher the plasma uniformity.

In addition, to improve plasma uniformity, a plurality of high frequency plasma source powers are not required as in the related art, and the length of the coil 120 does not need to be increased. Therefore, since the plasma processing apparatus 100 of the present embodiment does not need to increase the length of the coil 120 in order to improve the plasma uniformity, the inductance value due to the decrease in the length of the coil 120 is reduced and compared with the prior art. Power efficiency is increased.

The foregoing detailed description illustrates the present invention. In addition, the foregoing description merely shows and describes preferred embodiments of the present invention, and the present invention can be used in various other combinations, modifications, and environments. And, it is possible to change or modify within the scope of the concept of the invention disclosed in this specification, the scope equivalent to the written description, and / or the skill or knowledge in the art. The above-described embodiments are for explaining the best state in carrying out the present invention, the use of other inventions such as the present invention in other state known in the art, and the specific fields of application and uses of the present invention. Various changes are also possible. Accordingly, the detailed description of the invention is not intended to limit the invention to the disclosed embodiments. Also, the appended claims should be construed to include other embodiments.

As described above, according to the present invention, the bi-directional magnetic field is induced due to the two-turn coil structure capable of applying high frequency so that the directions of the electric fields are opposite to each other. This improves the plasma uniformity as compared with the plasma generated by the unidirectional magnetic field. In addition, the coil length can be greatly reduced, thereby reducing the inductance value, thereby increasing the power efficiency, thereby increasing the density of the plasma. As a result, it is possible to generate a high-density uniform plasma, thereby increasing the plasma treatment effect. In addition, these two-turn coils have excellent process reproducibility because of their relatively simple structure.

Claims (6)

In an inductively coupled plasma processing apparatus in which a coil is wound around a reaction chamber, The coil is an inductively coupled plasma processing apparatus, characterized in that the first coil in which the current flows in a clockwise direction and the second coil in which the current flows in a counterclockwise direction are connected to each other through a power supply and a ground portion to induce a bidirectional magnetic field. . The method of claim 1, A front end of the first coil is connected to the rear end of the second coil and the power supply unit, and the rear end of the first coil is connected to each other via the front end of the second coil and the ground. Inductively Coupled Plasma Treatment Apparatus. The method of claim 2, And the power supply unit simultaneously applies plasma source power to the front end of the first coil and the rear end of the second coil. A reaction chamber in which plasma processing is performed; And an upper coil wound around the upper portion of the reaction chamber and a lower coil wound around the lower portion of the reaction chamber, wherein the circular current direction flowing in the upper coil and the circular current direction flowing in the lower coil are opposite to each other. A two-turn coil inducing magnetic fields in the direction; A power supply unit simultaneously applying high frequency plasma source power to one end of the upper coil and the other end of the lower coil; And A grounding part for grounding the other end of the upper coil and one end of the lower coil; Inductively coupled plasma processing apparatus comprising a. The method of claim 4, wherein One end of the upper coil and the other end of the lower coil is connected to each other via the power supply unit, the other end of the upper coil and one end of the lower coil are connected to each other via the grounding unit inductively coupled plasma treatment Device. The method of claim 4, wherein Each of the upper and lower coils has an annular shape having the same diameter or an annular shape having a different diameter.

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