KR101028215B1 - Plasma generation apparatus - Google Patents

Abstract

PURPOSE: A plasma generating device is provided to supply columnar direction of inducing magnetic field by using a ferrite core of a rod-like in round the barrel-type reactor. CONSTITUTION: A plurality of magnetic cores(132) is arranged to an axial direction of a vacuum container according to an external side surface of a vacuum container(152). A plurality of coils(122) protects each magnetic cores. The power supplies current to the coils. The inducing magnetic field by coils forms the plasma inside the vacuum container. The magnetic core includes upper magnetic cores which is arrange in surrounding of the vacuum container and lower magnetic cores which is arranged in the magnetic cores.

Description

Plasma Generator {PLASMA GENERATION APPARATUS}

The present invention relates to a plasma generating device, and more particularly to a plasma generating device using a magnetic core and a dielectric tube.

Conventional inductively coupled plasma (ICP) sources are equipped with RF antenna coils on the outer side of the cylindrical plasma reactor. A Faraday Shield is used between the RF antenna coil and the plasma reactor to suppress the voltage of the RF antenna coil from being applied into the reactor. Using a Faraday shield can reduce the voltage applied to the antenna coil inside the reactor, but plasma ignition is very difficult.

The ICP source has a very low density of time-varying magnetic fields derived from RF antenna coils, resulting in low magnetic field penetration efficiency into the plasma reactor. Therefore, the plasma generation efficiency of the induction field is not high.

In order to improve this, development of an ICP source using a ferrite core is actively progressing. However, the plasma current of the ICP source using the ferrite core corresponds to the secondary side by the transformer model. Therefore, the plasma current must make a closed loop so that the ICP source using the ferrite core is efficient. Using a ferrite core, a time-varying magnetic field can be trapped inside the ferrite core. Therefore, more efficient plasma generation is possible, and high efficiency plasma generation is possible even at low power.

In order to achieve a closed loop of such plasma currents, the plasma reactor structure is mostly a toroidal or complex structure that can form a closed loop. Therefore, there is a great difficulty in maintaining the source, and a great difficulty in production.

A donut type ferrite core surrounds the donut type plasma reactor. The coil wraps around the donut ferrite core. If the plasma reactor is not a closed loop structure, plasma generation is difficult. That is, power delivered from the power source is not delivered into the plasma but is consumed in the ferrite core or the primary RF antenna coil. Therefore, deterioration of peripheral structures such as ferrite cores occurs.

One technical problem to be solved of the present invention is to provide a plasma generating apparatus of high efficiency.

A plasma generating apparatus according to an embodiment of the present invention is a cylindrical vacuum vessel, a plurality of magnetic cores disposed in the axial direction of the vacuum vessel along the outer side of the vacuum vessel, a plurality of coils surrounding each of the magnetic cores And a power supply for supplying current to the coils. An induced electric field by the coils forms a plasma inside the vacuum vessel.

A substrate processing apparatus according to an embodiment of the present invention includes a process vessel for processing a substrate, a gas distribution unit for distributing gas to the process container, a remote plasma apparatus for supplying active species to the gas distribution unit, and the remote plasma apparatus And a spacer connecting the process vessel. The remote plasma apparatus includes a pipe-shaped vacuum vessel, a plurality of magnetic cores disposed in the axial direction of the vacuum vessel at regular intervals along the outer side of the vacuum vessel, a plurality of coils surrounding each of the magnetic cores, And a power supply for supplying current to the coils. An induced electric field by the coils forms a plasma inside the vacuum vessel.

Conventional ICP sources are difficult to focus on time-varying magnetic fields. On the other hand, the plasma generating apparatus according to an embodiment of the present invention can increase the time-varying magnetic field using a magnetic core. Thus, high efficiency plasma can be generated.

On the other hand, the plasma generating apparatus using a conventional ferrite core has a disadvantage that it has a donut-type reactor structure.

Plasma generator according to an embodiment of the present invention provides a direction of the induction electric field (plasma current) in the circumferential direction in the form of a cylindrical reactor. A rod-shaped ferrite core is used around the cylindrical reactor. The direction of the induction field is maintained in the circumferential direction inside the reactor. The plasma may form a closed loop. The cylindrical reactor structure is advantageous for the construction of maintenance and repair reactors.

1A and 1B are diagrams illustrating a plasma generating apparatus according to an embodiment of the present invention.
2 is a view for explaining a plasma generating apparatus according to another embodiment of the present invention.
3 is a view for explaining a plasma generating apparatus according to another embodiment of the present invention.
4 is a view for explaining a plasma generating apparatus according to another embodiment of the present invention.
5 is a diagram illustrating a substrate processing apparatus according to an embodiment of the present invention.

A high efficiency plasma generating apparatus according to an embodiment of the present invention includes a ferrite core, a cylindrical vacuum vessel, and a coil. Ferrite cores are rod-shaped or rod-shaped. The cylindrical vacuum vessel is ceramic or quartz and insulator. The ferrite core is disposed horizontally to the longitudinal direction of the vacuum vessel around the cylindrical vacuum vessel. A coil surrounds the ferrite core. The time-varying magnetic field induced by the coil corresponding to the primary coil of the transformer is focused on the ferrite core. Time-varying magnetic fields induce an induction field. The induction field induces a current in the plasma corresponding to the secondary coil of the transformer in the circumferential direction inside the cylindrical vacuum vessel. Accordingly, the plasma current corresponding to the secondary side in the transformer model forms a closed loop. High efficiency plasma is generated in a cylindrical vacuum vessel. Therefore, the structure of the vacuum container can be configured very simply.

In addition, the reactor structure in the form of a donut occupies excessive reactor area. The plasma generating apparatus according to the present invention can reduce the area. In addition, the plasma loss due to recombination in the wall can be reduced, so that high efficiency plasma can be generated. In addition, the plasma generating apparatus of the present invention has a structure that is very advantageous for maintenance and repair. The plasma generating apparatus of the present invention can reduce manufacturing cost and maintenance cost. Plasma generator according to an embodiment of the present invention is a vacuum container of the insulator Can be used to minimize the corrosion rate.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosure may be made thorough and complete, and to fully convey the spirit of the invention to those skilled in the art. In the drawings, the components have been exaggerated for clarity. Portions denoted by like reference numerals denote like elements throughout the specification.

1A and 1B are diagrams illustrating a plasma generating apparatus according to an embodiment of the present invention.

1A and 1B, the plasma generating apparatus includes a cylindrical vacuum vessel 152 and a plurality of magnetic cores disposed in an axial direction of the vacuum vessel 152 along an outer side surface of the vacuum vessel 152. 132, a plurality of coils 122 surrounding each of the magnetic cores 132, and a power supply 112 for supplying current to the coils 122. The induction electric field by the coils 122 forms a plasma inside the vacuum vessel 122.

The vacuum container 152 may be cylindrical. The vacuum container 152 may have a straight portion. The vacuum container 152 may be deformed into a rectangular cylinder shape or bell-jar type. The vacuum container 152 may be a dielectric. The vacuum container 152 may be made of quartz, alumina, or ceramic.

The vacuum container 152 may include a lid 154. The lid 154 may be formed of metal. The gas line 153 may be disposed on the central portion of the lid 154. Gas may be supplied through the gas line 153. The gas may include a carrier gas such as argon, helium, nitrogen, and a process gas. The process gas may be a fluorine containing gas such as NF 3 or a chlorine containing gas such as BCl 3. The process gas may be variously modified according to the process proceeding in the process vessel.

The magnetic cores 132 may be a ferrite material. The magnetic cores 132 may have a rod shape or a rod shape. The cross section of the magnetic core 132 is not limited to a quadrangle and may be variously modified into a circle, an ellipse, a polygon, or the like. The magnetic cores 132 may be disposed at regular intervals outside the vacuum container 152 in the direction of the central axis of the vacuum container 152. Four or more magnetic cores 132 may be preferable.

The coil 122 may surround the magnetic core 132. The number of turns of the coil 122 may be one turn or more. The winding directions of the coils 122 may be all the same. The magnetic field B generated by the alternating current or the RF current flowing through the coil 122 may be focused on the magnetic core 132. The length of the magnetic core 132 may be longer than the length of the vacuum vessel 152. In this case, the magnetic field by the magnetic core may pass through the interior of the vacuum container 152 less.

When the magnetic field B changes in time, an induction electric field E1 may be generated in a circumferential direction (azimuth direction) surrounding the magnetic core 132 inside and outside the magnetic core 132. Accordingly, the induction electric field generated inside the magnetic core 132 may heat the magnetic core 132 by an eddy current. In addition, the change of the magnetic field over time may cause hysteresis loss to heat the magnetic core 132. An induction electric field E1 generated outside the magnetic core 132 may generate a plasma inside the vacuum container 152. When the magnetic cores 132 are densely arranged around the vacuum vessel 152, the induction field may form an induction field in an azimuth direction with respect to the central axis of the vacuum vessel 152. Accordingly, the induction electric field may induce an efficient discharge by forming a secondary shaft coil of the transformer. The plasma 10 may decompose or excite the gas to form active species.

The cooling unit 133 may be a means for cooling the magnetic core 132. The cooling unit 133 may include at least one of a heat pipe using a capillary phenomenon, a cooling plate through which a refrigerant flows, and a metal strip. The cooling unit 133 may be in surface contact with the magnetic core 132.

The coil 122 may wind the magnetic core 132. The coil 122 may be in the form of a wire or a strip. The coils 122 may be silver plated with copper or copper. The auxiliary coil 123 may connect the adjacent coils 122 to each other. The coils 122 may be wound in the same direction. The direction of the magnetic field formed by the coils 122 may be the same direction. Accordingly, an induction field induced by the coils 122 may interfere constructively. The auxiliary coil 123 may have a circular coil shape or a helical shape surrounding the vacuum container 152. Accordingly, the induction electric field E2 formed by the auxiliary coil 123 may have an azimuth component in the vacuum container 152. The electric field E1 formed by the coils 122 and the induction electric field E2 formed by the auxiliary coil 123 may induce a plasma current of an azimuth component. The coils 122 may be connected in series with each other. The voltage applied to the auxiliary coil 123 may induce a plasma initial discharge.

According to a modified embodiment of the present invention, the auxiliary coil 123 surrounds the vacuum container and may be directly connected to the power source.

The power supply 112 may output a sinusoidal wave of 10 KHz to 20 Mhz. The frequency of the power source 112 may depend on the characteristics of the magnetic core 132. When the magnetic core 132 is a ferrite core, the frequency of the power supply 112 may be 100 Khz to 1Mhz. More preferably, the frequency of the power supply 112 may be around 400Khz.

The impedance matching circuit 114 may be a means for maximally transferring power of the power source 112 to the load. If the frequency of the power supply 112 is increased, the impedance matching circuit 114 may be necessary.

The connection part 148 may be disposed at the other end of the vacuum container 152 to connect the vacuum container 152 and the process container 142 with each other. For example, when the diameter of the vacuum vessel 152 and the diameter of the process vessel 142 are different, the connection portion 148 may be tapered.

The process container 142 may perform an ashing process, an etching process, a surface treatment process, a deposition process, and the like. The process container 142 may perform a semiconductor process or an LCD process. The process vessel 142 may include separate gas lines and exhaust lines.

The gas distributor 143 may be a means for distributing active species generated in the vacuum vessel 152 to the process vessel 142. The gas distribution part 143 may be a baffle including a plurality of holes. The structure of the gas distributor 143 may be variously modified. In addition, a separate RF power or DC power may be applied to the gas distribution unit 143. The gas distribution part 143 may be disposed in an area where the process container 142 and the connection part 148 contact each other. Accordingly, the active species generated in the vacuum vessel 152 may be uniformly distributed to the process vessel 142.

According to a modified embodiment of the present invention, the plasma generated in the vacuum vessel 152 may directly reach the process vessel 142 without the gas distributor 143.

The substrate holder 146 may be a means for supporting the substrate 144. The substrate 144 may be a semiconductor substrate, a plastic substrate, a glass substrate, or the like. A semiconductor device, an LCD device, a solar cell, and the like may be generated on the substrate 144. The substrate holder 146 may include energy application means. The energy applying means may be RF power.

The plasma generating apparatus according to an embodiment of the present invention includes a magnetic core having a rod or rod shape on the outside of the cylindrical vacuum container. RF current or alternating current flows through the coil around the magnetic core. The winding direction of the coil remains the same. Accordingly, the direction of the time-varying magnetic field induced in the magnetic core is kept the same. In this case, the winding method of the coil wound around the magnetic core may be modified in various ways depending on the situation and purpose.

Coils wound around the magnetic core may be connected in series or in parallel. In this case, the number of turns of the coil, the winding direction and the series parallel connection are related to the impedance matching circuit.

The number and spacing of the magnetic cores may be configured to satisfy optimal conditions for the plasma initial discharge. In addition, the magnetic core is preferably the initial plasma discharge to the voltage applied to the auxiliary coil across the ferrite rod and the bar while maintaining the ferrite rod shape.

2 is a view for explaining a plasma generating apparatus according to another embodiment of the present invention. Descriptions overlapping with those described in FIG. 1 will be omitted.

1A and 2, the power distributor 115 may be disposed between the impedance matching circuit 114 and the coils 122. The coils 122 may be connected in parallel to each other. The power distribution unit 115 may provide a connection relationship between the coils. The auxiliary coil 123 is disposed to surround the vacuum container 152 and may be connected to the power source 112.

According to a modified embodiment of the present invention, some of the coils 122 may be connected in series, or some of the coils 122 may be connected in parallel. In addition, some of the coils 122 may be connected to a separate power source.

3 is a view for explaining a plasma generating apparatus according to another embodiment of the present invention. Descriptions overlapping with those described in FIG. 1 will be omitted.

Referring to FIG. 3, the magnetic cores 132a and 132b include an upper magnetic core 132a and a lower magnetic core 132b. In addition, the coils 122a and 122b include an upper coil 122a surrounding the upper magnetic core 132a and a lower coil 122b surrounding the lower magnetic core 132b.

The upper magnetic core 132a is disposed at equal intervals around the vacuum container 152. In addition, the lower magnetic core 132b is spaced apart from the upper magnetic core 132a and is disposed at equal intervals around the vacuum container 152. The number of the upper magnetic cores 132a and the number of the lower magnetic cores 132b may be the same. In addition, the upper magnetic core 132a and the lower magnetic core 132b may be aligned with each other.

The direction of the magnetic field formed by the upper coils 122a may be the same. In addition, the direction of the magnetic field formed by the lower coils 122b may be the same. On the other hand, the phase of the magnetic fields formed on the upper coils 122a may have a 180 degree difference from the phases of the magnetic fields formed on the lower coils 122b. Accordingly, an induction electric field may not be generated in an inner region of the vacuum container 152 between the upper coils 122a and the lower coils 122b. In this case, the gas line 153 may be disposed on the side of the vacuum container 152 adjacent to the region where the induction electric field does not occur.

The magnetic cores 132a and 132b may be divided into two or more stages. In this case, in order to improve the uniformity of the plasma density inside the cylindrical vacuum vessel, the segmented magnetic cores may be alternately disposed.

In addition, a winding direction of a coil connected to the magnetic cores 132a and 132b may be reversed in a forward direction as needed, and electrical connections of the coils 122a and 122b may be serial and / or parallel connections. .

Since the direction of the magnetic field applied to the magnetic cores 132a and 132b is determined according to the winding direction of the coil connected to the magnetic cores 132a and 132b, an optimal plasma may be generated through an appropriate combination.

4 is a view for explaining a plasma generating apparatus according to another embodiment of the present invention. Descriptions overlapping with those described in FIG. 1 will be omitted.

Referring to FIG. 4, the coil 122 is disposed to surround the magnetic core 132. The coil 122 is connected to a neighboring coil. The auxiliary coil 123 may connect neighboring coils. The auxiliary coil 123 may have a helical shape and may be disposed to surround the vacuum container.

5 is a diagram illustrating a substrate processing apparatus according to an embodiment of the present invention. Descriptions overlapping with those described in FIG. 1 will be omitted.

Referring to FIG. 5, a substrate processing apparatus supplies active species to a process vessel 142 for processing a substrate, a gas distributor 143 for distributing gas to the process vessel 142, and the gas distributor 143. A remote plasma apparatus 100, and a spacer 162 connecting the remote plasma apparatus 100 and the process vessel 142.

The process container 142 may perform an etching process, a deposition process, or the like. The gas distribution unit 143 may be disposed at an upper end of the process vessel 142 to provide the active species of the remote plasma apparatus 100 to the substrate 144 or the process vessel 142.

The remote plasma apparatus 100 includes a pipe-shaped vacuum container 152 and a plurality of magnetic cores 132 disposed in the axial direction of the vacuum container 152 at regular intervals along the outer side surface of the vacuum container 152. ), A plurality of coils 122 surrounding each of the magnetic cores 132, and a power supply 112 for supplying current to the coils 122. The induction electric field by the coils 122 forms a plasma inside the vacuum vessel 152. The lid 154 may be disposed at one end of the vacuum container 154. The lower port 155 may be disposed at the other end of the vacuum container 152. The lower port 155 may be a means for exhausting gas, plasma, and active species in the vacuum container 152.

The lower port 152 may be connected to the process container 142 through the spacer 162. The spacer 162 may have a cylindrical shape having a constant diameter.

 The connection part 148 may connect the spacer 162 and the process container 142. The connection part 148 may have a tapered cylindrical shape.

While the invention has been shown and described with respect to certain preferred embodiments thereof, the invention is not limited to these embodiments, and has been claimed by those of ordinary skill in the art to which the invention pertains. It includes all the various forms of embodiments that can be implemented without departing from the spirit.

152: vacuum container
132: magnetic cores
122: coils
112: power
114: impedance matching circuit
162: spacer
148: connection
154: lid

Claims (18)

A cylindrical vacuum vessel formed of a dielectric;
A plurality of rod-shaped magnetic cores disposed in an axial direction of the vacuum vessel along an outer side surface of the vacuum vessel;
A plurality of coils surrounding each of the magnetic cores; And
A power supply for supplying current to the coils,
And the induced electric field by the coils forms a plasma inside the vacuum chamber. Cylindrical vacuum vessel;
A plurality of magnetic cores disposed in the axial direction of the vacuum vessel along the outer side of the vacuum vessel;
A plurality of coils surrounding each of the magnetic cores; And
A power supply for supplying current to the coils,
An induction electric field by the coils forms a plasma inside the vacuum vessel,
The magnetic core is:
Upper magnetic cores disposed around the vacuum vessel; And
Lower magnetic cores spaced apart from the upper magnetic cores,
The plurality of coils surrounding the magnetic cores are:
A plurality of upper coils surrounding portions of the upper magnetic cores; And
And a plurality of lower coils surrounding a portion of the lower magnetic cores. The method according to claim 1 or 2,
Further comprising an auxiliary coil connecting the adjacent coils to each other,
The auxiliary coil surrounds the vacuum vessel, is in close contact with the vacuum vessel to induce an initial discharge of the plasma, plasma generating apparatus, characterized in that to form an induction electric field of the azimuth component inside the vacuum vessel. The method according to claim 1 or 2,
All or some of the coils are connected in series or in parallel with each other. The method according to claim 1 or 2,
The direction of the magnetic field induced in the magnetic cores by the coils are in the same direction as each other. The method according to claim 1,
The magnetic core is:
Upper magnetic cores disposed around the vacuum vessel; And
Lower magnetic cores spaced apart from the upper magnetic cores,
The plurality of coils surrounding the magnetic cores are:
A plurality of upper coils surrounding portions of the upper magnetic cores; And
And a plurality of lower coils surrounding a portion of the lower magnetic cores. The method of claim 6,
And the direction of the magnetic fields of the upper magnetic cores and the direction of the magnetic fields of the lower magnetic cores are opposite to each other. The method according to claim 1 or 2,
And the coils are connected to each other to enclose the vacuum vessel in a helical form. The method according to claim 1 or 2,
Further comprising a cooling unit disposed in contact with the magnetic core,
And the cooling unit cools heat generated from the magnetic core. 10. The method of claim 9,
And the cooling unit includes at least one of a heat pipe, a cooling plate through which a refrigerant flows, and a metal strip. The method according to claim 1 or 2,
A lid disposed at one end of the vacuum container;
A connection part disposed at the other end of the vacuum container;
A process container including a substrate holder and connected to the connection portion and performing a process; And
Further comprising at least one of a gas distribution portion disposed between the process vessel and the connection portion or above the process vessel,
And providing the active species generated in the vacuum vessel to the process air. The method according to claim 1 or 2,
And an impedance matching circuit disposed between the power supply and the coils to transfer the power of the power supply to the coils. The method according to claim 1 or 2,
The frequency of the power source is a plasma generator, characterized in that 100 Khz to 1 Mhz. The method according to claim 1 or 2,
Wherein said magnetic cores are rod-shaped ferrite cores. The method according to claim 1 or 2,
And at least four magnetic cores and arranged at uniform intervals. The method according to claim 1 or 2,
And at least one winding number of the coils, and a winding direction of the coils is the same. Pipe-shaped vacuum vessels;
A plurality of magnetic cores disposed axially of the vacuum vessel at regular intervals along the outer side of the vacuum vessel;
A lid disposed at one end of the vacuum vessel and including a gas line to which gas is supplied;
A plurality of coils surrounding each of the magnetic cores; And
A power supply for supplying current to the coils,
An induction electric field by the coils forms a plasma inside the vacuum vessel,
The magnetic core is:
Upper magnetic cores disposed around the vacuum vessel; And
Lower magnetic cores spaced apart from the upper magnetic cores,
The plurality of coils surrounding the magnetic cores are:
A plurality of upper coils surrounding portions of the upper magnetic cores; And
And a plurality of lower coils surrounding a portion of the lower magnetic cores. A process vessel for processing the substrate;
A gas distribution unit distributing gas to the process vessel;
A remote plasma apparatus for supplying active species to the gas distribution unit; And
A spacer connecting the remote plasma apparatus and the process vessel;
The remote plasma device is:
Pipe-shaped vacuum vessels;
A plurality of magnetic cores disposed axially of the vacuum vessel at regular intervals along the outer side of the vacuum vessel;
A plurality of coils surrounding each of the magnetic cores; And
A power supply for supplying current to the coils,
An induction electric field by the coils forms a plasma inside the vacuum vessel,
The magnetic core is:
Upper magnetic cores disposed around the vacuum vessel; And
Lower magnetic cores spaced apart from the upper magnetic cores,
The plurality of coils surrounding the magnetic cores are:
A plurality of upper coils surrounding portions of the upper magnetic cores; And
And a plurality of lower coils surrounding a portion of the lower magnetic cores.

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