KR100972371B1 - Compound plasma source and method for dissociating gases using the same - Google Patents

Abstract

The composite plasma source is posted here. The composite plasma source includes a transformer for generating inductively coupled plasma and first and second capacitively coupled electrodes for generating capacitively coupled plasma. The transformer has a magnetic core, part of which is located inside the plasma discharge chamber, and a primary winding wound thereon and connected to the first power supply. The first capacitive coupling electrode is composed of a body forming a plasma discharge chamber. The magnetic core located in the plasma discharge chamber is protected by the core protection tube. The core capacitive tube is provided with a second capacitive coupling electrode. The second capacitively coupled electrode is connected to a second power source. In the complex plasma source, when power supply is started from the first and second power sources, an annular first electric field and a radial second electric field are formed in the plasma discharge chamber so that the inductively coupled plasma and the capacitively coupled plasma are formed inside the plasma discharge chamber. Occurs in combination.

Inductive coupling, capacitive coupling, plasma, gas separation

Description

COMPONENT PLASMA SOURCE AND METHOD FOR DISSOCIATING GASES USING THE SAME}

In order to more fully understand the drawings used in the detailed description of the invention, a brief description of each drawing is provided.

1 is a cross-sectional view of a composite plasma source in accordance with a preferred embodiment of the present invention.

2 is a cross-sectional view taken along the line A-A of FIG.

3 to 6 are views showing various modifications of the power supply structure of the complex plasma source.

7 and 8 are cross-sectional views illustrating examples of configuring a gas inlet and a gas outlet in a plasma discharge chamber.

9 is a diagram showing an example of applying the complex plasma source of the present invention to a remote plasma processing system.

10 is a view showing an example of applying the complex plasma source of the present invention to a process chamber for substrate processing. And

11 is an exemplary diagram for describing an expandable structure of a complex plasma source.

* Description of the symbols for the main parts of the drawings *

10: complex plasma source 20: body, first capacitively coupled electrode

21: plasma discharge chamber 22, 41: insulation region

22: opening 30: transformer

31: magnetic core 32: primary winding

33: core protection tube 34: magnetic flux

35: first electric field 40: second capacitive coupling electrode

42: second electric field 50: first power supply source

51: second power source 52: common power source

53: power distribution unit 60: gas inlet

61 gas exhaust port 70 process chamber

71: substrate support 72: substrate to be processed

73: bias power 55, 75: switch

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma source for generating an active gas by plasma discharge, and more particularly, to a complex plasma source employing a combination of a capacitively coupled plasma and an inductively coupled plasma generating structure.

Plasma discharges are used for gas excitation to generate active gases containing ions, free radicals, atoms, and molecules. The active gas is widely used in various fields and is typically used in various semiconductor manufacturing processes such as etching, deposition, and cleaning.

There are a number of plasma sources for generating plasma, such as capacitively coupled plasma using radio frequency and inductively coupled plasma.

As is already known, capacitively coupled plasma sources have the advantage of high process capacity compared to other plasma sources due to their high capacity for precise capacitive coupling and ion regulation. On the other hand, since the energy of the radio frequency power supply is almost exclusively connected to the plasma through capacitive coupling, the plasma ion density can only be increased or decreased by increasing or decreasing the capacitively coupled radio frequency power supply. However, increasing the power source increases the ion bombardment energy, and as a result, there is a limit to preventing damage caused by the ion bombardment.

On the other hand, the inductively coupled plasma source can easily increase the ion density with the increase of the radio frequency power source, the ion bombardment is relatively low, it is known to be very suitable for obtaining a high density plasma. However, induction coils have little or no control over plasma ion energy, so a separate device must be added to control the ion energy. For example, a bias technique of applying an independent radio frequency to a substrate support provided in the process chamber is an example. However, the radio frequency power applied to the bias applied to the substrate support has an important problem of low process productivity due to low controllability of plasma ion energy.

On the other hand, wafers and LCD glass substrates for the manufacture of semiconductor devices are becoming larger in size. Therefore, there is a demand for a plasma source having a high controllability with respect to plasma ion energy and having a large-area processing capacity.

Accordingly, the present invention has been made to solve the above-mentioned problems, and its object is to adopt both the advantages of the inductively coupled plasma and the capacitively coupled plasma, so that the controllability to plasma ion energy is high and the scalability with large-area processing capacity is easy. A composite plasma source and a gas separation method for generating an active gas using the same are provided.

One aspect of the present invention for achieving the above technical problem relates to a complex plasma source. The composite plasma source of the present invention comprises: a body forming a plasma discharge chamber and comprising a conductive metal; A transformer having a magnetic core and a primary winding coupled to the plasma discharge chamber; A core protection tube surrounding a portion of the magnetic core positioned inside the plasma discharge chamber and including a dielectric material; And a capacitive coupling electrode installed in the core protection tube, wherein the capacitively coupled plasma by the body and the capacitively coupled electrode and the inductively coupled plasma by the transformer are generated in the plasma discharge chamber.

In one embodiment, the body includes an insulating region for forming electrical discontinuity for reducing the eddy current.

In one embodiment, the capacitively coupled electrode includes an insulating region for forming electrical discontinuity to reduce the eddy current.

In one embodiment, a first power supply for supplying power for generation of inductively coupled plasma to the primary winding of the transformer; And a second power supply source supplying power for generation of a capacitively coupled plasma to the capacitively coupled electrode.

In one embodiment, it includes a first impedance matcher connected to the output end of the first power supply and a second impedance matcher connected to the output end of the second power supply.

In one embodiment, a common power supply for supplying power for the generation of the capacitively coupled plasma and the inductively coupled plasma, the power output from the common power supply is the primary of the capacitively coupled electrode and the transformer And a power distribution unit for separate supply to the windings.

In one embodiment, it comprises a common power supply for supplying power for the generation of the capacitively coupled plasma and the inductively coupled plasma, wherein the capacitively coupled electrode and the primary winding of the transformer are connected in series to a common power supply do.

In one embodiment, an impedance matcher is coupled to the output of the common power supply.

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In one embodiment, it comprises a cooling water supply channel installed inside or inside the core protection tube.

In one embodiment, it comprises a cooling water supply channel configured through the central portion of the magnetic core.

The apparatus may further include a process chamber including a gas inlet for injecting gas into the plasma discharge chamber and a gas exhaust port for outputting a plasma, and containing a plasma output through the gas exhaust port and having a substrate support therein. do.

In one embodiment, the substrate support is connected to a bias power source.

In one embodiment, the substrate support includes a substrate support positioned in the plasma discharge chamber on which the substrate to be processed is placed, the substrate support being connected to a bias power source.

In one embodiment, the first switch for switching the capacitive coupling electrode between the second power supply and ground; And a second switch for switching the substrate support between a bias power source and a ground, wherein the first and second switches interlock with each other.

Another aspect of the present invention relates to a gas separation method using a complex plasma source. A gas separation method using a complex plasma source of the present invention includes the steps of: forming a plasma discharge chamber into which gas is to be injected, and providing a body including a conductive metal; Providing a transformer having a primary core and a magnetic core coupled to the plasma discharge chamber; Providing a core protection tube surrounding a portion of the magnetic core located inside the plasma discharge chamber and comprising a dielectric material; Providing a capacitive coupling electrode installed inside the core protection tube; And generating a capacitively coupled plasma by driving the capacitively coupled electrode and an inductively coupled plasma by driving the transformer in the interior of the plasma discharge chamber.

In one embodiment, the drive of the capacitively coupled electrode is driven first prior to driving the transformer to provide an initial ionization step.

In one embodiment, the gas is selected from the group comprising an inert gas, a reactive gas, and a mixed gas of inert gas and reactive gas.

DETAILED DESCRIPTION In order to fully understand the present invention, the operational advantages of the present invention, and the objects achieved by the embodiments of the present invention, reference should be made to the accompanying drawings which illustrate preferred embodiments of the present invention and the contents described in the accompanying drawings. In understanding the drawings, it should be noted that like parts are intended to be represented by the same reference numerals as much as possible. And detailed description of known functions and configurations that are determined to unnecessarily obscure the subject matter of the present invention is omitted.

(Example 1)

Hereinafter, with reference to the accompanying drawings illustrating a preferred embodiment of the present invention, an atmospheric pressure plasma generator and an atmospheric pressure plasma processing system having the same will be described in detail.

1 is a cross-sectional view of a composite plasma source according to a preferred embodiment of the present invention and FIG. 2 is a cross-sectional view taken along line A-A of FIG. The complex plasma source 10 according to the preferred embodiment of the present invention produces an active gas by decomposing the gas by inductively coupled plasma and capacitively coupled plasma.

The composite plasma source 10 has a transformer 30 having a magnetic core 31 and a primary winding 32 for inductively coupled plasma generation. The magnetic core 31 is a ring-shaped ferrite core in which the primary winding 32 is wound to constitute a transformer 30.

The magnetic core 31 is made of ferrite material but may be made of other alternative materials such as iron and air. In particular, the magnetic core 31 is coupled to the body 20 such that a portion of the magnetic core 31 is positioned inside the body 20 forming the plasma discharge chamber 21. A portion of the magnetic core 31 located inside the plasma discharge chamber 21 is protected by the core protection tube 33. The core protection tube 33 is composed of quartz, ceramic and dielectric material in one embodiment. The core protection tube 33 is connected at both ends to openings 22 formed at opposite side walls of the body 20. At this time, the openings 22 of both sidewalls to which the core protection tube 33 and the body 20 are connected are sealed by an appropriate sealing member although not specifically shown in the drawings.

Body 20 is made of a metallic material such as aluminum, stainless steel, copper. Or coated metal, for example anodized aluminum or nickel plated aluminum. Or refractory metal. Alternatively, it is also possible to reconstruct the body 20 with an insulating material such as quartz, ceramic, or other materials suitable for the intended plasma process to be performed. The body 20 may be manufactured in a hollow cylindrical shape as a whole. However, it can be easily understood that the deformation can be made into a rectangular box structure or other various forms.

Primary winding 32 is electrically connected to first power source 50. The first power supply 50 is an AC power supply for supplying RF power. Although not shown in the figure, an impedance matcher for impedance matching may be provided at an output terminal of the first power supply 50. However, one of ordinary skill in the art will appreciate that the RF power source can be configured using a controllable output voltage without a separate impedance matcher.

The complex plasma source 10 includes a first capacitive coupling electrode and a second capacitive coupling electrode 40 for generating capacitively coupled plasma. Here, the first capacitive coupling electrode is composed of a body 20 including a conductive metal. In this embodiment, the body 20 soon functions as the first capacitive coupling electrode. However, those skilled in the art can understand that the first capacitive coupling electrode can be configured around the body 20 using a separate conductive metal, and that a specific portion of the body 20 where the conductive metal is installed must form a dielectric window. There will be.

The second capacitive coupling electrode 40 is configured inside the core protection tube 33. In one embodiment, it has a cylindrical structure that entirely encloses a portion of the magnetic core 31 inserted into the core protection tube 33. The second capacitive coupling electrode 40 may be made of the same material as the material of the body 20 functioning as the first capacitive coupling electrode.

The second capacitive coupling electrode 40 is electrically connected to the second power source 51, and the body 20 serving as the first capacitive coupling electrode is grounded. The body 20 serving as the first capacitive coupling electrode functions as a cathode and the second capacitive coupling electrode 40 functions as an anode. However, their functions can be replaced as needed.

The second power supply 51 is an AC power supply for supplying RF power. Although not shown in the drawing, an impedance matcher for impedance matching may be provided at an output terminal of the second power supply 50. However, one of ordinary skill in the art will appreciate that the RF power source can be configured using a controllable output voltage without a separate impedance matcher.

The body 20 and the second capacitive coupling electrode 40 each functioning as the first capacitive coupling electrode each have an insulating region 22 to form an electrical discontinuity to minimize the eddy current caused by the inductively coupled plasma. 41).

When the composite plasma source 10 having the above-described configuration starts to supply power from the first and second power sources 50 and 51, respectively, the annular first electric field (as indicated by dotted lines in Figs. 35 and a radial second electric field 42 are formed in the plasma discharge chamber 21. Thus, the inductively coupled plasma and the capacitively coupled plasma are combined in the plasma discharge chamber 21.

The first electric field 35 is induced by the transformer 30, and the second electric field 42 is generated by the body 20 and the second capacitive coupling electrode 40 functioning as the first capacitive coupling electrode. That is, the first is annularly guided to surround the core protection tube 33 located inside the plasma discharge chamber 21 by the magnetic field 34 focused along the magnetic core 31 by the primary winding 32. Electric field 35 is generated. This forms an inductively coupled plasma that illuminates the secondary circuit of transformer 30.

Such capacitively coupled plasmas and inductively coupled plasmas are generated in combination with each other. In particular, the first electric field 35 and the second electric field 42 are formed to cross each other perpendicularly, thereby accelerating the spiral motion of the gas ion particles in the plasma discharge chamber 21, thereby having a very high gas decomposition capability. Therefore, the plasma ion density can be controlled very easily according to the power control of the first and second power sources 50 and 51. That is, high plasma ion density can be obtained without excessive increase in ion energy. In addition, since the first electric field 35 is substantially parallel to the body 20 and the core protection tube 33, it is caused by gas ion particles that are complexly accelerated by the first and second electric fields 35 and 42. Damage to the inner wall of the plasma discharge chamber 21 due to the ion bombardment is minimized so that harmful particles are extremely minimized.

The gas injected into the plasma discharge chamber 21 may be selected from a group including an inert gas, a reactive gas, or a mixed gas of an inert gas and a reactive gas. The body 20 and the second capacitive coupling electrode 40 functioning as the first capacitive coupling electrode may be driven first prior to driving the transformer 30 to provide an initial ionization step.

3 to 6 are views showing various modifications of the power supply structure of the complex plasma source. The complex plasma source 10 as described above may be modified by a power supply scheme having various structures as described below.

Referring to FIG. 3, as a variation, the composite plasma source 10 includes one common power source for the body 20 and the second capacitive coupling electrode 40 that function as the transformer 30 and the first capacitive coupling electrode. 52 can be used to supply power. To this end, the power distribution unit 53 may be configured at the output terminal of the common power supply 52. The power distribution unit 53 may configure a power distribution circuit using a transformer or a parallel capacitor. In addition, the power distribution unit 53 may be configured using various electronic circuits, and in the case of variably configuring the capacity of a transformer or a parallel capacitor, power may be properly adjusted.

Referring to FIG. 4, as another variation, the composite plasma source 10 may include a body 20 and a second capacitive coupling electrode 40 serving as a transformer 30 and a first capacitive coupling electrode as one common power supply. It can be configured by connecting to 52 in series. In this case, as shown in FIG. 5, the second capacitive coupling electrode 40 may be configured to be connected to ground. The common power supply 52 is an AC power supply for supplying RF power.

Referring to FIG. 6, as another variation, the complex plasma source 10 may manufacture the second capacitively coupled electrode 40 in the form of a single winding coil so as to serve as a function of the electrode and the coil.

As such, when the common power source 52 is used, the number of the RF power sources can be reduced, thereby making it possible to construct a complex plasma source more cheaply and simply. Although not shown in the figure, an impedance matcher for impedance matching may be provided at an output terminal of the second power supply 50. However, one of ordinary skill in the art will appreciate that the RF power source can be configured using a controllable output voltage without a separate impedance matcher.

Although not specifically illustrated in the drawing, the complex plasma source 10 includes a cooling water supply channel for supplying cooling water at a very suitable position. For example, the cooling water supply channel may be configured inside the core protection tube 33. Alternatively, the cooling water supply channel may be configured through the center of the magnetic core 31. Alternatively, the cooling water supply channel may be configured in the body 20.

7 and 8 are cross-sectional views illustrating examples of configuring a gas inlet and a gas outlet in the plasma discharge chamber. As shown in FIG. 7 and FIG. 8, the complex plasma source 10 includes a gas inlet 60 and a gas outlet 61 for supplying and exhausting gas into the plasma inversion chamber 21. Is configured on location.

9 is a diagram showing an example of applying the complex plasma source of the present invention to a remote plasma processing system. Referring to FIG. 9, the complex plasma source 10 may be mounted in the plasma process chamber 70 to configure a remote plasma system for remotely supplying plasma.

The process chamber 70 is connected to the complex plasma source 10, receives a plasma discharged through the gas exhaust port 61 of the complex plasma source 10, and supports a substrate 72 to support the substrate 72 therein. 71). The substrate support 71 may include a bias electrode (not shown) connected to the bias power source 73 to accelerate gas ion particles to the substrate. In addition, a heater for heating the substrate may be provided.

10 is a view showing an example of applying the complex plasma source of the present invention to a process chamber for substrate processing. Referring to FIG. 10, the complex plasma source 10a may be fabricated such that the body 20 functions as a process chamber. A substrate support 71 for supporting the substrate 72 is provided inside the plasma discharge chamber 21. The substrate support 71 may include a bias electrode (not shown) connected to the bias power source 73 to accelerate gas ion particles to the substrate. In addition, a heater for heating the substrate may be provided.

In particular, in this configuration, the second capacitive coupling electrode 40 may be configured to be connected to the first switch 55 that is switched between the second power source 51 and the ground. In addition, the substrate support 71 may be configured to be connected to the second switch 75 that is switched between the bias power source 73 and the ground. The first and second switches 55 and 75 are interlocked opposite to each other. In addition, the first and second switches 55 and 75 may be configured as a three-pole switch including a floating potential.

9 and 10, the process chamber 70 or the body 20 may be an etching chamber for performing a plasma etching process. Or a deposition chamber for performing a plasma deposition process. Or an ashing chamber for stripping the photoresist. In addition, the composite plasma source 10 may be usefully used for processing various materials such as solid surfaces, powders, and gases. It can also be used as an ion beam source for ion implantation or ion milling. In one embodiment, suitable ion accelerators are configured around the gas exhaust port 61 for use as an ion beam source.

11 is an exemplary diagram for describing an expandable structure of a complex plasma source. As illustrated in FIG. 11, in the complex plasma source 10b, the magnetic core 31 may be installed such that portions positioned in the plasma discharge chamber 21 are arranged in parallel. At this time, two core protection tubes 33 and two second capacitive coupling electrodes 40 are also installed in the plasma discharge chamber 21. Such a structure can be repeated to expand the complex plasma source 10b. In addition, the length of the magnetic core 31 can be extended to broaden the plasma generating area as a whole. This expansion is well suited for the composite plasma source of the present invention to generate large area plasma, and is characterized by high density of large area plasma and easy control of plasma ion energy.

As described above, the present invention has been described with reference to the embodiments shown in the drawings, but this is merely exemplary, and those skilled in the art to which the present invention pertains have various modifications and equivalent embodiments. You can see that it is possible. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

According to the complex plasma source of the present invention and the gas separation method using the same as described above, by adopting the advantages of both inductively coupled plasma and capacitively coupled plasma, it has high controllability to plasma ion energy and has a large area processing capability. This easy composite plasma source and a gas separation method for generating an active gas using the same can be provided.

Claims (23)

A body including a conductive metal and forming a plasma discharge chamber; A transformer having a magnetic core and a primary winding coupled to the plasma discharge chamber; A core protection tube surrounding a portion of the magnetic core positioned inside the plasma discharge chamber and made of a dielectric material; And Including a capacitive coupling electrode installed inside the core protection tube, And a capacitively coupled plasma by the body, the capacitively coupled electrode, and an inductively coupled plasma by the transformer are generated in the plasma discharge chamber. The method of claim 1, Wherein the body comprises an insulating region for forming electrical discontinuity for reducing the eddy current. The method according to claim 1 or 2, And the capacitively coupled electrode comprises an insulating region for forming electrical discontinuity for reducing the eddy current. The method of claim 1, A first power supply for supplying power for generation of inductively coupled plasma to the primary winding of the transformer; And And a second power source for supplying power for generation of a capacitively coupled plasma to the capacitively coupled electrode. The method of claim 4, wherein And a second impedance matcher connected to the output terminal of the first power supply and a second impedance matcher connected to the output terminal of the second power supply. The method of claim 1, A common power supply for supplying power for generation of the capacitively coupled plasma and generation of the inductively coupled plasma; And a power distribution unit for separately supplying power output from the common power supply source to the capacitive coupling electrode and the primary winding of the transformer. The method of claim 1, A common power supply for supplying power for generation of the capacitively coupled plasma and generation of the inductively coupled plasma; The capacitive coupling electrode and the primary winding of the transformer are connected in series to a common power source. The method according to any one of claims 6 to 7, And an impedance matcher coupled to the output of the common power supply. delete The method of claim 1, And a cooling water supply channel installed inside or inside the body of the core protection tube. The method of claim 1, And a coolant supply channel configured through a central portion of the magnetic core. The method of claim 1, A gas inlet for injecting gas into the plasma discharge chamber and a gas exhaust port for outputting plasma; And a process chamber receiving the plasma output through the gas exhaust port and having a substrate support therein. The method of claim 12, And the substrate support is connected to a bias power source. The method of claim 1, And a substrate support positioned in the plasma discharge chamber on which the substrate to be processed is placed, the substrate support being connected to a bias power source. The method of claim 4, wherein A first switch for switching the capacitively coupled electrode between the second power supply and ground; And a second switch for switching a substrate support provided in the plasma discharge chamber between a bias power source and a ground, wherein the first and second switches interlock with each other in opposite directions. Forming a plasma discharge chamber into which gas is to be injected, and providing a body comprising a conductive metal; Providing a transformer having a primary core and a magnetic core coupled to the plasma discharge chamber; Providing a core protection tube surrounding a portion of the magnetic core positioned inside the plasma discharge chamber and formed of a dielectric material; Providing a capacitive coupling electrode installed inside the core protection tube; And And generating a capacitively coupled plasma by driving the capacitively coupled electrode and an inductively coupled plasma by driving the transformer in the interior of the plasma discharge chamber. The method of claim 16, The drive of the capacitively coupled electrode is driven prior to the drive of the transformer to provide an initial ionization step. The method of claim 16, Wherein said gas is selected from the group comprising an inert gas, a reactive gas, and a mixed gas of an inert gas and a reactive gas. A body that forms a plasma discharge chamber and includes a conductive metal and is grounded; A transformer having a magnetic core and a primary winding coupled to the plasma discharge chamber; And A core protection tube surrounding a portion of the magnetic core positioned inside the plasma discharge chamber and formed of a dielectric material; The primary winding is installed inside the core protection tube And a capacitively coupled plasma generated by the capacitive coupling of the body and the primary winding and the inductively coupled plasma generated by the transformer are generated in the plasma discharge chamber by the driving of the transformer. The method of claim 19, Wherein said primary winding is comprised of a single winding coil. The method of claim 19, And a cooling water supply channel installed inside or inside the body of the core protection tube. The method of claim 19, A gas inlet for injecting gas into the plasma discharge chamber and a gas exhaust port for outputting plasma; And a process chamber receiving the plasma output through the gas exhaust port and having a substrate support therein. The method of claim 22, And the substrate support is connected to a bias power source.

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