JP2010118324A - Plasma antenna, and plasma processing device including the same - Google Patents

Abstract

A plasma antenna and a plasma processing apparatus using the same are provided.
A plasma antenna according to an embodiment of the present invention is a plasma antenna of a plasma generator, wherein the plasma antenna is supplied with power from a power supply unit and is branched toward an outer periphery of a dielectric at a branching unit. The branched antennas are collected in the center and grounded at the grounding portion.
[Selection] Figure 2

Description

  The present invention relates to a plasma antenna and a plasma processing apparatus including the same, and more particularly to a shape of a plasma antenna in a plasma processing apparatus that performs process processing using plasma on a large area substrate. is there.

  Plasma processing apparatuses are widely used in manufacturing processes of semiconductor substrates and liquid crystal displays. The plasma processing apparatus activates the reaction gas and transforms it into a plasma state, whereby the cations or radicals (Radical) of the reaction gas in the plasma state process a predetermined region of the semiconductor substrate.

  Plasma processing apparatuses include a plasma enhanced chemical vapor deposition (PECVD) apparatus for thin film deposition, an etching apparatus for etching and patterning a deposited thin film, a sputter, and an ashing apparatus.

  As a plasma source of such a plasma generator, a capacitively coupled plasma source (CCP: Capacitive Coupled Plasma), an inductively coupled plasma source (ICP: Inducted Coupled Plasma), an ECR (Electron Cyclotron Resonance) plasma source using microwaves, There are SWP (Surface Wave Plasma) plasma sources and the like.

  In the CCP type, RF power is applied to parallel plate electrodes facing each other to generate a plasma using an RF electromagnetic field formed perpendicularly between the electrodes, and in the ICP type, induction is performed by an antenna to which high frequency power is applied. The reactive gas is transformed into a plasma state using an induction electromagnetic field.

  The ICP type plasma generator has a structure in which a dielectric made of an insulating material is formed on an upper part of a process chamber and a plasma antenna is formed on the upper part of the dielectric. Recently, as the size of liquid crystal display substrates has increased, the size of plasma processing apparatuses has increased, and the size of dielectrics has increased accordingly.

  When the dielectric is increased in size, the thickness of the dielectric must be increased to have sufficient strength to withstand the pressure difference between the upper and lower portions of the dielectric and its own weight. However, when the dielectric becomes thicker, the distance between the plasma antenna and the plasma region becomes longer, which causes a problem that the energy efficiency is lowered and the density of the generated plasma is lowered.

  Accordingly, since the dielectric is divided and supported by the grid-shaped frame 20 as shown in FIG. 1, the size of each dielectric 30 can be reduced, and the thickness of the dielectric 30 can also be reduced. However, in order for the cross-shaped frame 20 to stably support the dielectric 30, the width of the frame 20 has to be increased. Therefore, the effective area of the dielectric 30 is narrowed by the frame 20, and the plasma generation efficiency is reduced.

  In particular, the efficiency of the plasma generated at the central portion where the outer periphery including the four corner portions of the dielectric 30 and the cross-shaped frame 20 are located is reduced.

Various types of plasma antennas have been studied to solve the problem that the plasma efficiency at the point is lowered, but the shape is complicated, it is difficult to mass-produce, and the plasma efficiency at the point is greatly improved. I couldn't.
Korea registration number 0775592

  The present invention has been devised in order to improve the above-described problems, and an object of the present invention is to provide a plasma antenna capable of generating plasma uniformly even on a large area substrate. There is to do.

  It is another object of the present invention to provide a plasma processing apparatus capable of processing a substrate by generating plasma uniformly even on a large area substrate.

  The objects of the present invention are not limited to the objects mentioned above, and other objects not mentioned will be clearly understood by those skilled in the art from the following description.

  In order to achieve the above object, a plasma antenna according to an embodiment of the present invention is a plasma antenna of a plasma generator, wherein the plasma antenna is supplied with power from a power supply unit and is directed to the outer periphery of the dielectric at a branching unit. The branched antennas are collected in the center and grounded at the grounding portion.

  In order to achieve the above object, a plasma antenna according to an embodiment of the present invention is a plasma antenna of a plasma generator, wherein the plasma antenna is supplied with power from a power supply unit and is placed on the outer periphery of a dielectric at a first branching unit. The first and second antennas, which are branched toward the center, are gathered in the center and grounded at a grounding portion, and are formed in the first antenna in the same shape as the first antenna. The first antenna and the second antenna are connected in parallel.

  To achieve the above object, a plasma processing apparatus according to an embodiment of the present invention is formed in the middle of a process chamber so as to be divided into a process chamber, an upper antenna chamber of the process chamber, and a lower substrate processing chamber. The plasma antenna includes a dielectric, a gas supply unit that supplies gas to the substrate processing chamber, and a plasma antenna formed in the antenna chamber. The plasma antenna receives power from the power supply unit and receives power from the first branch unit. A first antenna that is branched toward the outer periphery of the dielectric, the branched antennas are collected in the center and grounded at a grounding portion, and the first antenna has the same shape as the first antenna. The first antenna and the second antenna are connected in parallel.

  According to the plasma antenna of the present invention and the plasma processing apparatus including the same as described above, the plasma is generated nonuniformly at the outer periphery and the center including the corner portion of the substrate, and the processing efficiency of the plasma at the point is lowered. There is an advantage that the point can be solved.

  Further, there is an advantage that a variable capacitor is formed between the first plasma antenna and the second plasma antenna connected in parallel and the variable capacitor is adjusted to generate various plasma environments.

  Specific details of the embodiments are included in the detailed description and figures.

  Advantages, features, and methods of achieving the same of the present invention will be apparent with reference to the embodiments described below in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, and can be embodied in various forms different from each other. This embodiment is provided merely for the purpose of completely informing the person skilled in the art to which the present invention pertains the scope of the invention so that the disclosure of the present invention is complete. The invention is defined only by the claims. Throughout the specification, the same reference numerals denote the same components.

  Hereinafter, the present invention will be described with reference to the drawings for explaining a plasma antenna and a plasma processing apparatus including the same according to an embodiment of the present invention.

  FIG. 2 is a perspective view illustrating a plasma antenna according to an embodiment of the present invention, and FIG. 3 is a cross-sectional view illustrating a plasma processing apparatus according to an embodiment of the present invention.

  First, the plasma processing apparatus 100 according to an embodiment of the present invention will be described, and the shapes of the plasma antennas 150a and 150b formed in the plasma processing apparatus 100 will be described.

  The plasma processing apparatus 100 according to an embodiment of the present invention may include a process chamber 110, a dielectric 120, a gas supply unit 130, and plasma antennas 150a and 150b.

  The process chamber 110 is made of a conductive material, for example, aluminum or an aluminum alloy whose inner wall surface is subjected to bipolar oxidation treatment, and is assembled so as to be decomposed to provide a space for performing the plasma process treatment.

  A pipe 111 for supplying a reaction gas from the gas supply unit 130 into the process chamber 110 may be formed on one side of the process chamber 110.

  The process chamber 110 is grounded by a ground line 112.

  Further, a vacuum pump (not shown) is connected to a lower part or a side surface of the process chamber 110 so that the inside of the process chamber 110 is in a vacuum state, and after the processing process, the gas remaining in the process chamber 110 is discharged to the outside. An exhaust port 113 for discharging may be formed.

  The dielectric 120 is formed in the middle of the process chamber 110 and is divided into an antenna chamber 114 above the process chamber 110 and a substrate processing chamber 115 in which a plasma process process is performed below. In the drawing, the process chamber 110 is divided into two parts, that is, an upper process chamber 110b and a lower process chamber 110a by a dielectric 120. However, the process chamber 110 is integrally formed and a dielectric is formed inside the process chamber 110. The body 110 may be divided into an antenna chamber 114 and a substrate processing chamber 115. When the process chamber 110 is divided into the upper process chamber 110b and the lower process chamber 110a by the dielectric 120 as shown in the drawing, the divided portion is sealed to provide an inside / outside of the process chamber 110 and the antenna chamber 114. The space between the substrate processing chamber 115 can be sealed.

  Since the size of the dielectric 120 must be increased in order to process the large area substrate (S), each dielectric 120 is supported by being divided into four by a grid-shaped frame as shown in FIG. Can be formed.

  The dielectric 120 may be made of an insulating material such as ceramic or quartz so that an induction electromagnetic field generated from the upper plasma antennas 150a and 150b is transmitted into the substrate processing chamber 115 of the process chamber. The dielectric 120 made of an insulating material reduces the capacitive coupling between the plasma antennas 150a and 150b and the plasma and supports the energy generated from the plasma antennas 150a and 150b to be transferred to the plasma by inductive coupling.

  A time-varying electromagnetic field is generated in the vertical downward direction by the plasma antennas 150a and 150b at the upper portion, and a horizontal electromagnetic field is induced in the process chamber 110 by the time-varying electromagnetic field, and is accelerated by the induced electromagnetic field. When the electrons collide with the neutral gas, ions and radicals (Radical) are generated. At this time, the process is performed on the substrate (S) fixed inside the process chamber 110 by the generated ions and radicals.

  The gas supply unit 130 supplies a reaction gas to the inside of the process chamber 110, more specifically, to the substrate processing chamber 115. The gas supply unit 130 supplies a reaction gas into the process chamber 110 through a pipe 111 penetrating the process chamber 110.

  A substrate support 140 for fixing the substrate (S) may be formed under the process chamber 110. The substrate support 140 may be made of a conductive material, for example, aluminum whose surface is bipolar oxidized. The substrate support 140 may be driven up and down by a driving device (not shown). The substrate support table 140 can be connected to the matching unit 142 and the high-frequency power supply 144. By applying high-frequency power for biasing during the plasma process processing through the high-frequency power supply, ions in the plasma generated inside the process chamber 110 are transferred to the substrate ( Adjust the incident energy toward S).

  The plasma antennas 150a and 150b are located in the antenna chamber 114 separated by the dielectric 120. Hereinafter, the plasma antennas 150a and 150b according to an embodiment of the present invention will be described with reference to FIG.

  The plasma antennas 150 a and 150 b are formed in the antenna chamber 114 divided by the dielectric 120, and are supplied with high-frequency RF power from the power supply unit 180 through the feeder line 181. At this time, the power supply unit 180 may be formed on the ceiling wall of the antenna chamber 114 to supply power to the plasma antennas 150a and 150b. The frequency of the power supply unit 180 is determined to match the purpose of the process in which the plasma processing apparatus 100 is used, and thus can be changed by a person having ordinary knowledge in the art. A matcher 182 that is a matching unit may be formed between the plasma antennas 150a and 150b and the power supply unit 180, and this matches the impedance so that energy is transmitted to the plasma antennas 150a and 150b to the maximum. To play a role.

  As shown in FIG. 2, the overall shape of the plasma antennas 150 a and 150 b according to an embodiment of the present invention is supplied with power from the power supply unit 180, and the outer periphery of the dielectric 120 is formed by the branch unit 151. The antennas branched off are gathered in the lower center and connected to the grounding part 159 in the center. More specifically, a corner of each dielectric (a corner farthest from the center) with respect to each dielectric 120 that is supplied with power from the upper center of the dielectric 120 and is divided into four by the frame 170 at the branch 151. Branch to 152). The branched antenna is connected to the center grounding part 159 again, but is further divided into two branches 153a and 153b at each corner 152, and the two branched antennas 153a and 153b are shown. In this manner, a square is formed on the top of the dielectric 120 and is connected to the center grounding portion 159 again. As shown in the figure, the shapes of the antennas divided into four can be all symmetrically the same.

  At this time, as shown in FIG. 2, the plasma antennas 150a and 150b are preferably composed of a first antenna 150a and a second antenna 150b formed inside the first antenna 150a.

  As described above, the first antenna 150a is supplied with the high frequency power from the power supply unit 180 and is branched toward the corners 152 of the dielectric 120 by the first branching unit 151, and the branched antenna is centered again. The shape is collected and grounded to the grounding portion 159.

  Further, the second antenna 150b has the same shape as that of the first antenna 150a, but the size of the second antenna 150b can be reduced by a certain ratio and can be formed inside the first antenna 150a. At this time, the first branch point 151 of the first antenna 150a and the second branch point 155 of the second antenna are electrically connected through a feeder line 156 as shown in the figure. Accordingly, the first antenna 150a and the second antenna 150b are connected in parallel.

  A variable capacitor (C) 157 may be formed between the first branch point 151 and the second branch point 155. Therefore, by adjusting the variable capacitor 157, a phase difference can be given to the first antenna 150a and the second antenna 150b, and the amount of current flowing through each of the antennas 150a and 150b can be controlled. Accordingly, the plasma environment can be changed in various ways according to the user's application by adjusting the variable capacitor 157.

  Looking at the path through which the current flows, a high-frequency current flows from the power supply unit 180 and reaches the first branching unit 151 through the matcher 182. The current that has reached the first branching portion 151 flows to each antenna of the first antenna 150a branched into four by the first branching portion 151. At this time, current flows from the first branch 151 to the second branch 155 through the feeder 156 that electrically connects the first branch 151 of the first antenna 150a and the second branch 155 of the second antenna 150b. . At this time, by adjusting the variable capacitor 157 formed on the feeder line 156, the amount of current flowing through the first antenna 150a and the amount of current flowing through the second antenna 150b can be adjusted. Current flows into the four corners of the dielectric 120 through the antennas branched into four at the first branch 151, and the antennas 153a and 153b are further branched into two at the four corners. A current flows through the grounded portion 159 through the antennas 153a and 153b. A current flows through the antenna branched into four in the same manner as the first antenna 150a in the second branching portion 155 of the second antenna 150b, and the current flows again to the center grounding portion 159.

  In the above-described embodiment, the first antenna 150a and the second antenna 150b are described. However, the plasma antenna 150a can be variously formed in a shape in which another third antenna is formed inside the second antenna 150b. The shape of 150b can be expanded and changed.

  As described above, the plasma antennas 150a and 150b according to the embodiment of the present invention can concentrate current on the outer periphery and the central portion including the corners of the dielectric 120 as shown in the figure. It is possible to solve the problem that the efficiency of the plasma falls at the corner and the center.

  Those having ordinary knowledge in the technical field to which the present invention pertains can understand that the present invention can be implemented in other specific forms without departing from the technical idea and essential features thereof. . Therefore, it should be understood that the above embodiment is illustrative in all aspects and not limiting. The scope of the present invention is defined by the following claims rather than the above detailed description, and all modifications or variations derived from the meaning, scope, and equivalent concepts of the claims are within the scope of the present invention. Should be construed as included in

It is a figure which shows the dielectric material divided | segmented by the flame | frame. It is a perspective view which shows the plasma antenna by one Embodiment of this invention. It is sectional drawing which shows the plasma processing apparatus by one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 110 Process chamber 120 Dielectric 130 Gas supply part 140 Substrate support stand 150 Plasma antenna 180 Power supply part

Claims (12)

In the plasma antenna of the plasma generator,
The plasma antenna is supplied with power from a power supply unit, and is branched toward the outer periphery of the dielectric at the branching unit. The branched antennas are collected at the center and grounded at the grounding unit. Plasma antenna.   The plasma antenna according to claim 1, wherein the plasma antenna has a symmetrical shape branched toward four corners of the dielectric.   3. The plasma antenna according to claim 2, wherein the plasma antenna has a shape in which the plasma antenna is further branched at four corners of the dielectric and collected in the center and grounded at the grounding portion. In the plasma antenna of the plasma generator,
The plasma antenna is
A first antenna having a shape in which power is supplied from a power supply unit and is branched toward the outer periphery of the dielectric at the first branching unit, and the branched antennas are collected in the center and grounded at the grounding unit. And a second antenna formed in the same shape as the first antenna and formed inside the first antenna,
A plasma antenna in which the first antenna and the second antenna are connected in parallel.   The plasma antenna according to claim 4, wherein the first antenna has a shape branched toward four corners of the dielectric.   6. The plasma antenna according to claim 5, wherein the plasma antenna has a shape in which the plasma antenna is further branched from four corner points of the dielectric and collected in the center and grounded at the grounding portion.   The first branch part and the second branch part branched by the second antenna are electrically connected, and the first antenna and the second antenna are connected in parallel, but the first branch part and the second antenna are connected in parallel. The plasma antenna according to claim 5, wherein a variable capacitor is formed between the two branch portions. A process chamber;
A dielectric formed in the middle of the process chamber so as to be divided into an upper antenna chamber and a lower substrate processing chamber of the process chamber;
A gas supply unit for supplying a gas to the substrate processing chamber;
Including a plasma antenna formed in the antenna chamber;
The plasma antenna is
A first antenna having a shape that is supplied with power from a power supply unit and is branched toward the outer periphery of the dielectric at the first branching unit, and the branched antennas are collected in the center and grounded at the grounding unit; And a second antenna formed in the same shape as the first antenna and formed inside the first antenna,
The plasma processing apparatus, wherein the first antenna and the second antenna are connected in parallel.   The plasma processing apparatus according to claim 8, wherein the first antenna has a shape branched toward four corners of the dielectric.   10. The plasma processing apparatus according to claim 9, wherein the plasma antenna has a shape in which the plasma antenna is further branched from four corner points of the dielectric and collected in the center and grounded by the grounding portion.   The second branching part branched by the first branching part and the second antenna is electrically connected, and the first antenna and the second antenna are connected in parallel. The plasma processing apparatus according to claim 8, wherein a variable capacitor is formed between the second branch portion.   The plasma antenna according to claim 8, wherein the dielectric is divided into four parts and supported by a cross-shaped cross-shaped frame.

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