KR20170112512A - Plasma generator with improved ion decomposition rate - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a plasma generator having an improved ion decomposition rate. A plasma generator with improved ion degradation rate of the present invention includes a plasma source for providing ionization energy for forming a plasma, And ion accelerating means comprising at least one permanent magnet or induction magnet for providing energy to form a second ion acceleration direction in a direction different from the first ion acceleration direction formed by said ionization energy, . According to the plasma generator in which the ion decomposition rate of the present invention is improved, it is possible to increase the residence time in the plasma channel by changing the motion locus of the reactive gas ions, thereby improving the gas decomposition rate. It is possible to maximize the plasma discharge efficiency in comparison with the same power supply. In addition, it is possible to prevent recombination of decomposed ions after the plasma is discharged, so that the plasma state can be maintained and supplied continuously.

Description

PLASMA GENERATOR WITH IMPROVED ION DECOMPOSITION RATE [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a plasma generator having an improved ion degradation rate, and more particularly, to a plasma generator having an improved ion degradation rate for improving decomposition efficiency of a reactive gas.

Plasma discharges are used in gas excitation to generate active gases including ions, free radicals, atoms, and molecules. Active gases are widely used in various fields and are typically used in a variety of semiconductor manufacturing processes such as etching, deposition, cleaning, and ashing.

In recent years, wafers and LCD glass substrates for manufacturing semiconductor devices have become larger. Thus, there is a demand for a plasma source that has a high controllability against plasma ion energy, has a large area processing capability, and is easy to expand. The use of remote plasma in a semiconductor manufacturing process using plasma is known to be very useful. For example, in cleaning process chambers or in ashing processes for photoresist strips. However, as the substrate to be processed becomes larger, the volume of the process chamber is also increased, and a plasma source capable of sufficiently supplying high-density active gas remotely is required.

A remote plasma generator generates a plasma outside the process chamber to remotely supply the process gas to the process chamber. The types of remote plasma generators vary according to the structure of the plasma source. For example, inductively coupled plasma sources, capacitively coupled plasma sources, and microwave plasma sources have been used in remote plasma generators. In the case of an inductively coupled plasma source, the method employing a transformer is called a transformer coupled plasma. A remote plasma generator using a transformer coupled plasma source has a structure in which a magnetic core having a primary winding coil is mounted on the plasma chamber body of the toroidal structure.

In the plasma generator, the process gas supplied to the inside is discharged by the plasma source, and the discharged plasma ions are discharged to the outside of the plasma generator. The reaction gas supplied to the plasma generator is instantaneously supplied at a very high speed, so that all of the reaction gas is discharged and complete decomposition is not achieved. Therefore, the decomposition rate with respect to the reaction gas is lowered and the treatment efficiency is lowered.

Also, after igniting the plasma, it is necessary to maintain the plasma continuously and discharge the decomposed plasma ions. At this time, the decomposed ions may be recombined again before being discharged, so it is necessary to make efforts to continuously maintain the plasma discharge state. In addition, a separate ignition electrode must be provided for ignition for plasma discharge in the plasma generator. A separate ignition electrode must be provided to increase the manufacturing cost of manufacturing the plasma generator.

It is an object of the present invention to provide an improved plasma generator capable of improving the decomposition rate of the reaction gas by increasing the residence time of the reaction gas by changing the ion trajectory of the reaction gas inside the plasma generator.

According to an aspect of the present invention, there is provided a plasma generator having an improved ion decomposition rate. A plasma generator with improved ion degradation rate of the present invention includes a plasma source for providing ionization energy for forming a plasma, And ion accelerating means comprising at least one permanent magnet or induction magnet for providing energy to form a second ion acceleration direction in a direction different from the first ion acceleration direction formed by said ionization energy, .

In one embodiment, the plasma source comprises a toroidal plasma chamber in which an annular plasma is formed; A power transformer having a primary winding coupled to the ferrite core and one or more ferrite cores mounted such that a portion of the plasma chamber passes therethrough; And a power source for supplying power to the primary winding.

In one embodiment, the induction magnet includes a magnetic core having a magnetic flux entrance so that a magnetic field can be formed in the plasma; And an induction coil wound around the magnetic core.

According to the plasma generator in which the ion decomposition rate of the present invention is improved, it is possible to increase the residence time in the plasma channel by changing the motion locus of the reactive gas ions, thereby improving the gas decomposition rate. It is possible to maximize the plasma discharge efficiency in comparison with the same power supply. In addition, it is possible to prevent recombination of decomposed ions after the plasma is discharged, so that the plasma state can be maintained and supplied continuously.

1 is a view showing a concept of a plasma generator according to the present invention.
2 is a conceptual diagram showing a state in which a plasma generator according to a preferred embodiment of the present invention is installed in a process chamber.
3 is a view showing a first embodiment of the plasma generator equipped with the permanent magnet of the present invention.
4 and 5 are views showing various arrangement structures of the permanent magnets.
6 is a view showing a second embodiment of the plasma generator equipped with the permanent magnet of the present invention.
7 and 8 are views showing an embodiment of the plasma generator equipped with the induction magnet of the present invention.
9 is a view showing an ion motion locus at a portion where the induction magnet is mounted in the plasma generator.
10 is a view showing a state in which the power coil is wound on the induction magnet of the present invention.

For a better understanding of the present invention, a preferred embodiment of the present invention will be described with reference to the accompanying drawings. The embodiments of the present invention may be modified into various forms, and the scope of the present invention should not be construed as being limited to the embodiments described in detail below. The present embodiments are provided to enable those skilled in the art to more fully understand the present invention. Therefore, the shapes and the like of the elements in the drawings can be exaggeratedly expressed to emphasize a clearer description. It should be noted that the same components are denoted by the same reference numerals in the drawings. Detailed descriptions of well-known functions and constructions which may be unnecessarily obscured by the gist of the present invention are omitted.

1 is a view showing a concept of a plasma generator according to the present invention.

Referring to FIG. 1, a plasma generator according to the present invention includes a plasma source that provides ionization energy for generating a plasma 118. The first ion acceleration direction 142 is determined by the ionization energy provided from the plasma source. At this time, the ion acceleration means according to the present invention forms a second ion acceleration direction 144 in a direction different from the first ion acceleration direction 142 in the plasma 118. Therefore, the motion trajectory of the ions is changed by the first and second ion acceleration directions 142 and 144, and the rotational acceleration 146 is generated by a very complicated path. The rotation acceleration 146 increases the residence time of the ions in the plasma 118 and increases the ion decomposition rate.

2 is a conceptual diagram showing a state in which a plasma generator according to a preferred embodiment of the present invention is installed in a process chamber.

Referring to FIG. 2, a plasma generator 200 according to the present invention includes a plasma source for providing ionization energy and ion acceleration means. The active gas accelerated by the ion accelerating means in the plasma generator 200 is supplied to the process chamber 195 connected through the adapter 190. The process chamber 195 is provided with a susceptor 196 on which the substrate 197 is placed and an exhaust pump 198 is connected to the exhaust port formed in the process chamber 195.

FIG. 3 is a view showing a first embodiment of the plasma generator equipped with the permanent magnet of the present invention, and FIGS. 4 and 5 are views showing various arrangement structures of the permanent magnets.

Referring to FIG. 3, a plasma generator 200 according to the present invention includes a plasma source for providing ionization energy and ion acceleration means. The active gas accelerated by the ion accelerating means in the plasma generator 200 is supplied to the process chamber 50 connected through the adapter. The process chamber 50 is provided with a susceptor 196 on which the substrate 197 is placed.

The plasma source provides ionization energy into the plasma chamber 210 such that a plasma 118 is generated within the plasma chamber 210. The plasma source is formed of any one of a capacitive coupled plasma, an inductively coupled plasma, and a transfer coupled plasma. The plasma source includes a plasma chamber 210, a power transformer 220, and an ignition electrode unit 280. The plasma chamber 210 includes a toroidal chamber body 212 in which an annular plasma 118 is formed. The chamber body 212 is formed separately from at least two. An ignition electrode unit 280 for initial ionization may be provided on the chamber body 212 to ignite the plasma. A gas inlet 214 for supplying gas into the plasma chamber 210 is provided at the upper center of the plasma chamber 210 and a gas outlet 216 for discharging the active gas generated in the plasma chamber 210 is provided at the lower portion. . The material of the plasma chamber 210 is formed of a conductor such as aluminum or formed of quartz. Although not shown in the drawing, a cooling channel may be provided in the plasma chamber 210.

The ignition electrode portion 280 is formed of a conductor and includes an ignition electrode 282 for igniting the plasma 118 into the plasma chamber 210, an insulating plate 284 for protecting the ignition electrode 282 from the plasma 118, And at least one O-ring 286. The insulating plate 284 prevents the ignition electrode 282 from being exposed to the plasma 118 generated within the plasma chamber 210 and may be formed of an insulating material (e.g., sapphire). An inert gas, such as argon, injected into the plasma chamber 210 reduces the voltage needed to ignite the plasma. By applying a high voltage to the ignition electrode 282, free charges are generated into the plasma chamber 110 to provide an initial ionization event.

The power transformer 220 includes a ferrite core 222 and a primary winding 224. One or more ferrite cores 222 are mounted for passage through a portion of the plasma chamber 210 and a primary winding 224 is coupled to the ferrite core 222 and connected to a power source 202. The plasma 118 generated in the plasma chamber 210 forms the secondary side of the power transformer 220.

The ion acceleration means provides energy into the chamber body 112 to accelerate the ions in the plasma chamber 210. The ionization energy provided from the plasma source forms an annular first ion acceleration direction 142 in the chamber body 210. At this time, the second ion acceleration direction 144 is formed by the energy provided from the ion acceleration means. At this time, the first ion acceleration direction 142 and the second ion acceleration direction 144 are formed in directions different from each other. In other words, the second ion acceleration direction 144 is formed to have a predetermined angle (?> 0 과) with the first ion acceleration direction 142. In the present invention, since the first ion acceleration direction 142 and the second ion acceleration direction 144 are perpendicular to each other, the ions are rotated and the ion acceleration path becomes very complicated.

As the ion rotating means, a plurality of permanent magnets 230 may be used. The permanent magnet 230 is installed around the chamber body 212 of the plasma generator 290a or inserted into the chamber body 212. A magnetic field (a second ion acceleration direction) is formed in the chamber body 212 by providing the permanent magnets 230 having different polarities to be opposed to each other with respect to the plasma formed in the chamber body 212. The plurality of permanent magnets 230 are installed in a region of the chamber body 212 where the transformer 220 including the ferrite core 222 and the primary winding 224 is installed. The gas supplied to the interior of the chamber body 212 through the gas inlet 214 has a high rate of decomposition in the region of the chamber body 212 where the ferrite core 222 is installed. The reaction gas injected into the plasma chamber 210 is accelerated and moved by the first ion acceleration direction 142. At this time, the original motion locus is changed by the second ion acceleration direction 144, and the rotation acceleration 146 is performed while rotating. Therefore, the retention time of the rotated ions in the chamber body 212 is increased and the collision between the ions is easily generated by the rotation, so that the gas decomposition efficiency is increased and the plasma density is increased. Also, by providing a plurality of permanent magnets 230 in the region where the ferrite core 222 is installed, the acceleration path of the gas ions by the permanent magnets is complicated, and the decomposition rate is improved. The decomposed gas is discharged through the gas outlet 216.

A plurality of permanent magnets 230 may be installed around the insulation region of the chamber body 212. A magnetic field is formed in the insulating region by the plurality of permanent magnets 230, thereby rotating the gas ions passing through the insulating region to accelerate the ion acceleration path. Therefore, the residence time of the ions is increased, and it is possible to prevent the decomposed ions from being discharged in a state where they are recombined or not decomposed.

The chamber body 212 is preferably made of a material capable of inducing a magnetic field formed by the permanent magnet 230 into the chamber body 212. Here, the entire chamber body 212 may be made of a material capable of inducing a magnetic field inside thereof, or may be made of a material capable of inducing a magnetic field only in a region where the permanent magnet 230 is installed.

Referring to FIG. 4A, the plurality of permanent magnets 230 are installed such that the first and second permanent magnet modules 230a and 230b are opposed to each other. Here, the first and second permanent magnet modules 230a and 230b may be arranged in parallel so that the plurality of permanent magnets 230 face each other with different polarities. The first and second permanent magnet modules 230a and 230b are installed in the chamber body 212 so as to face each other with a different polarity to form a magnetic field.

Referring to FIG. 4 (b), the plurality of permanent magnets 230 are installed such that the first and second permanent magnet modules 230c and 230d face each other. Here, the first and second permanent magnet modules 230c and 230d may be arranged in parallel so that the plurality of permanent magnets 230 face the same polarity. The first and second permanent magnet modules 230a and 230b are installed in the chamber body 212 so as to face each other with a different polarity to form a magnetic field.

Referring to FIG. 5, a plurality of permanent magnets 230 may be installed in the chamber bodies 212a and 212b having various shapes such as a rectangular shape or a circular shape in cross section of the internal discharge space. The plurality of permanent magnets 230 may be inserted into the chamber bodies 212a and 212b or may be coupled to the chamber bodies 212a and 212b by a clamping member (not shown).

6 is a view showing a second embodiment of the plasma generator equipped with the permanent magnet of the present invention.

Referring to FIG. 6, the plasma generator 200a may be provided with a plurality of permanent magnets 230 as upper and lower portions of the chamber body 212 as ion rotating means. The chamber body 212 has a gas injection port 214 through which gas is injected and a gas discharge port 216 through which the decomposed gas is discharged. The plurality of permanent magnets 230 are installed so that the polarities of the permanent magnets 230 are opposite to each other with respect to the plasma 118 formed in the chamber body 212. Therefore, the gas injected into the gas injection port 214 is trapped in the chamber body 212 by the permanent magnet 230, so that the ion residence time is further increased, thereby increasing the ion decomposition rate. Also, the gas that has been moved to be discharged to the gas discharge port 216 is trapped in the chamber body 212 by the permanent magnet 230, so that the ion retention time is further increased, thereby increasing the ion decomposition rate.

The plurality of permanent magnets 230 may be installed only on one of the upper and lower portions of the chamber body 212. Further, it may be installed in a region where the ferrite core 222 is installed. As shown in FIG. 6 (b), a plurality of permanent magnets 230 may be disposed around the inner space of the chamber body 212.

FIGS. 7 and 8 are views showing an embodiment of a plasma generator equipped with an induction magnet according to the present invention, and FIG. 9 is a view showing an ion motion locus at a portion where the induction magnet is mounted in the plasma generator.

Referring to FIGS. 7 to 9, the plasma generator 300 is an ion acceleration means, and one or more induction magnet portions 350 are installed in the chamber body 312. The induction magnet section 350 includes a magnetic core 352 formed with a magnetic flux entrance and an induction coil 354 wound around the magnetic core 352. The induction coil 354 is connected to the induction magnet power supply source 351 and is supplied with driving power. Here, the induction coil 354 may be connected to a power source 302 connected to the primary winding 224 to receive power. The magnetic core 352 is mounted on the outside of the chamber body 312 such that the magnetic flux entrance 352 faces the inside of the chamber body 312. When the induction coil 354 is driven by the power supplied from the induction magnet power supply source 351, a magnetic field 358 formed between the magnetic flux entrance of the magnetic core 352 and the transformer 320 An electric field induced into the chamber body 312 is mixed. In other words, the electric field induced by the transformer into the chamber body 312 has a first ion acceleration direction, and the magnetic field 358 has another ion acceleration direction. Therefore, the gas ion path is complicated, the ion retention time is increased, and the ion decomposition rate is improved. The electric field induced by the magnetic core 352 has a second ion acceleration direction 358. [ Also, since the first ion acceleration direction is different from the second ion acceleration direction, the acceleration path of the ions is complicated, and the residence time of the ions is increased to improve the ion decomposition rate.

The induction magnet part 350 may be installed on the upper part of the chamber body 312. In particular, the induction magnet unit 350 may be installed at a portion where the chamber body 312 is formed in an annular shape. The gas injected into the gas injection port is distributed to both sides of the upper part of the chamber body 312 and linearly descends in the middle part where the ferrite core 322 is installed. ), The retention time of the ions is increased.

10 is a view showing a state in which the power coil is wound on the induction magnet of the present invention.

Referring to FIG. 10, the induction magnet unit 350 may be connected to the power coils 354a and 354b wound on the ferrite core 322. Power coils 354a and 354b wound on the ferrite core 322 are wound around the magnetic core 352 of the induction magnet unit 350 so that power supplied from the power source 302 to the primary winding 324 is supplied to the power coil 354a and 354b so that a magnetic field is formed at the magnetic flux entrance of the magnetic core 352. [ Here, the magnetic core 352 may be connected to one power coil or two power coils 354a and 354b.

The embodiments of the plasma generator with improved ion degradation rate of the present invention described above are merely exemplary and those skilled in the art will appreciate that various modifications and equivalent embodiments can be made without departing from the scope of the present invention. You will know the point.

Accordingly, it is to be understood that the present invention is not limited to the above-described embodiments. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims. It is also to be understood that the invention includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.

210: plasma chamber 212, 312: chamber body
214, 314: gas inlet 216, 316: gas outlet
118: plasma 142: first ion acceleration direction
144: second ion acceleration direction 146: rotation acceleration
195: process chamber 196: susceptor
197: substrate to be processed 198: exhaust pump
200, 200a, 300, 300: plasma generator
202, 302: main power source 220, 320: power transformer
222, 322: ferrite core 224, 324: primary winding
212a, 212b: second chamber body 230: permanent magnet
230a, 230b: first and second permanent magnet modules 280: ignition electrode part
282: ignition electrode 284: insulating plate
286: O-ring 350: Induction magnet section
351: Induction magnet power source 352: Magnetic core
354: induction coil 354a: first power coil
354b: second power coil 356: magnetic field

Claims (3)

A remote plasma generator for providing plasma ions to a process chamber,
A plasma source for providing ionization energy to form a plasma; And
And ion accelerating means comprising one or more permanent magnets or induction magnets that provide energy to form a second ion acceleration direction in a direction different from the first ion acceleration direction formed by the ionization energy to change the motion trajectory of the ions Wherein the plasma generator is a plasma generator. The method according to claim 1,
The plasma source
A toroidal plasma chamber in which an annular plasma is formed;
A power transformer having a primary winding coupled to the ferrite core and one or more ferrite cores mounted such that a portion of the plasma chamber passes therethrough;
And a power source for supplying power to the primary winding. The method according to claim 1,
The induction magnet
A magnetic core having a magnetic flux entrance port for forming a magnetic field in the plasma; And
And an induction coil wound around the magnetic core, wherein the induction coil is wound on the magnetic core.

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