KR100734954B1 - A printed circuit board type antenna for inductively coupled plasma generating device - Google Patents

Abstract

An antenna for an inductively coupled type plasma generation device having a PCB(Printed Circuit Board) is provided to simplify manufacture of the antenna having a complicated shape for improving the uniformity of a plasma by patterning an antenna circuit on a substrate. An antenna for an inductively coupled type plasma generation device includes a PCB(10), and a connection unit(30). Antenna patterns are etched and formed on the PCB(10). The connection unit(30) has a core unit(32), and a supporting unit(34). The core unit(32) supports to stack the PCB(10) in parallel, and has a metallic material on a center thereof to electrically connect the antenna patterns formed on the PCB(10). The connection unit(30) has a supporting unit which is formed as an insulator on an outer side of the core unit(32). The antenna patterns are formed on both upper/lower planes of the PCB(10). The PCB(10) has a hollow shape or donut shape of a rectangular shape by removing the other area except an antenna pattern forming area.

Description

A printed circuit board type antenna for inductively coupled plasma generating device

1 is an exploded perspective view showing an antenna structure according to an embodiment of the present invention;

FIG. 2 is a combined perspective view showing the antenna structure shown in FIG. 1 and shows a completed form of the antenna in a solid line.

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

4 is a cross-sectional view taken along the line B-B of FIG.

5 is an exploded perspective view showing an antenna structure according to another embodiment of the present invention;

Figure 6 shows the shape of the antenna in the combined perspective view of Figure 5 in a solid line,

7 is a cross-sectional view showing an antenna structure according to another embodiment of the present invention;

8 is a cross-sectional view showing an antenna structure according to another embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

10: upper substrate 12, 14, 16, 18: antenna pattern

12a, 12b: connection part 14a, 14b: connection part

16a16b: connection part 18a18b: connection part

20: lower substrate 22, 24: antenna pattern

22a, 22b: connection part 24a, 24b: connection part

30: connector 32: core portion

34: support part C: oxidation resistant coating film

100: upper substrate 110-180: antenna pattern

200: lower substrate 210-240: antenna pattern

300: connector

The present invention relates to an antenna structure for an inductively coupled plasma generator, and in detail, a high-performance antenna can be manufactured at a low cost by forming a complex antenna on a substrate such as bakelite, glass epoxy, Teflon, ceramic, or the like. I would have to.

BACKGROUND ART Plasma is widely used in not only deposition and etching of thin films, but also ion implantation into a substrate, polymer or surface modification, etc. in device manufacturing processes such as semiconductor wafers and various electric, electronic and optical devices. Increasingly, applications in the fabrication of microelectronic devices such as etching and lamination are increasing, and such plasma sources include ECR plasma, inductively coupled plasma (ICP), and capacitively coupled plasma (TCP). The sources can generate a high density plasma at low pressure for the ultrafast processing required for the manufacture of large scale integrated circuits having a diameter of 200 mm and super-scale integrated circuits having a diameter of about 300 mm.

When the present invention is limited to the inductively coupled plasma source, the uniformity of the plasma in the chamber is primarily due to the spatial uniformity of an energy source applied externally, for example, an electric field or a magnetic field, to generate the plasma. It is determined that, if the spatial distribution of the externally supplied energy source to generate the plasma is uniform, the generated plasma also has a spatially uniform characteristic. However, most of the plasma processing apparatuses do not have a uniform spatial distribution of external energy sources, so that the shape of the RF coil (antenna) may be complicated to change the shape of the RF coil (antenna) or permanent magnet or Since the electromagnets and the like must be properly disposed, there is a problem that the plasma processing apparatus becomes complicated and the price increases.

In view of the above, the present applicant has a structure of using a plasma source antenna as a parallel antenna and having a structure in which each antenna is crossed up and down or in and out so that the impedance is lowered by parallel coupling so that the voltage is even at low voltage. It is possible to distribute, thereby suppressing the generation of dust particles affecting the yield by applying a high voltage, and symmetrically distributes the plasma density distribution with respect to the direction of rotation within the chamber in which the wafer is processed without the need for difficult voltage regulation. It can generate | occur | produce so that the wafer of large diameter can be processed.

On the other hand, the existing antenna, which is manufactured in the form of a metal tube including the plasma antenna of Patent No. 488363, basically uses a bending process, and thus has a disadvantage in that the manufacturing tolerance is large and accordingly the electrical characteristic tolerance of the antenna is increased.

In addition, in order to prevent the tube from being damaged in the bending process of the metal tube, there is a minimum radius of curvature in forming the antenna. As a result, there is a limit in manufacturing an antenna having a complicated shape, that is, excellent plasma uniformity.

In addition, when the antenna is manufactured by performing the bending process and the welding process together, the metal tube may exceed the limit due to the minimum curvature radius, but the welding process also has problems such as thermal deformation and thermal expansion compared to the bending process. There was a big problem in the dimensions and shape errors of the antenna after fabrication.

In addition, the antenna manufactured in the form of a metal tube is easy to bend or twisted when subjected to an external force during the assembly and mounting process has the disadvantage that the electrical characteristics of the antenna, or the plasma generation distribution does not come out as intended.

The present invention has been made to solve the above-mentioned conventional problems, an object of the present invention is to produce an antenna of an inductively coupled plasma generator having a complicated form as it improves the uniformity of the plasma at a simple and low cost It is to provide a antenna of a new structure that can be.

In order to achieve the above object, the present invention provides an antenna for an inductively coupled plasma generator, comprising: a plurality of substrates on which an antenna pattern is etched; It provides an antenna for an inductively coupled plasma generator comprising a; connector to support the substrate to be stacked in parallel up and down and to electrically connect the antenna patterns formed on the upper and lower substrates to complete the antenna.

In the present invention, the substrate may be an antenna pattern formed on one side or both sides of the substrate, the remaining portion except for the region where the antenna pattern is formed is preferably made of a circular or rectangular donut shape of the inside empty.

In another embodiment of the present invention, the substrate may further include a Faraday shield for attenuating the strength of the electric field, and an impedance adjusting means such as a coil or a capacitor for adjusting inductance when a parallel antenna pattern is formed. This can be implemented.

In addition, an oxidation-resistant coating film may be formed on the surface of the substrate on which the antenna of the present invention is formed, and at the outermost and innermost sides of the substrate, a powered end terminal to which a powered end for applying RF power and a ground end for grounding are connected; The ground end terminal connection can be formed in a pattern over the entire area.

Preferably, a cooling means such as a cooling fan or a cooling air spray nozzle for air cooling the heat generated from the antenna may be further provided on the outside of the substrate.

Specifically, in the present invention, the antenna pattern is a loop pattern formed concentrically from the center of the substrate, a spiral pattern, a spiral pattern or crosses up and down and in and out, or each antenna pattern is branched into two or more branch lines. Or, in the case of the rectangular antenna, the corner portion may be made of a common conductor without being branched, and may be simply designed and manufactured in any of various and complicated forms for improving the uniformity of the plasma density.

Hereinafter, with reference to the accompanying drawings, preferred embodiments that do not limit the present invention will be described in detail.

1 is an exploded perspective view showing an antenna structure according to an embodiment of the present invention, Figure 2 is a combined perspective view showing the antenna structure shown in Figure 1 showing the complete form of the antenna in solid lines, Figure 3 and 4 is a cross-sectional view taken along a line A-A and line B-B of FIG. 2, respectively.

As shown in FIG. 1 to FIG. 4, the antenna of the present embodiment has a very simple and basic shape. The antenna substrates 12, 14, 16, 18, 22, and 24 are formed by etching the upper and lower substrates 10. 20); The upper and lower substrates 10 and 20 are supported to be stacked in parallel to each other, and the antenna patterns 12, 14, 16, 18, 22, and 24 formed on the upper and lower substrates 10 and 20 are mutually supported. It comprises a; connector 30 to electrically connect to complete the antenna.

In the present exemplary embodiment, the antenna patterns 12, 14, 16, 18, 22, and 24 formed on the upper and lower substrates 10 and 20 may have two loop antennas a1, as shown in FIG. 2. a2), which is electrically connected in parallel, and the powered end P and the ground end G of each of the loop antennas a1 and a2 are disposed symmetrically with respect to the center of the antenna.

In addition, in this embodiment, the powered end P and ground end G of each of the antennas a1 and a2 are located on the upper substrate 10 located at a position far from the chamber not shown, and each of the antennas a1 and a2. The antenna patterns 22 and 24 corresponding to the middle portion of the are positioned on the lower substrate 20 close to the chamber.

In addition, the antenna patterns 12, 14, 16, 18 of the upper substrate 10 and the antenna patterns 22, 24 of the lower substrate 20 forming the antennas a1 and a2 are connected to each other by the connector 30. The positions are shifted up and down while being connected, and the antenna patterns formed on the upper and lower substrates 10 and 20 are located within the same radius with respect to the center of the antenna, but are not twisted with each other so as to be connected to both ends 12a and 12b and 14a and 14b. (16a16b) (18a18b) (22a, 22b) (24a, 24b) is patterned in the state bent inwardly and inwardly.

Holes are drilled in the connecting portions 12a, 12b, 14a, 14b, 16a16b, 18a18b, 22a, 22b, 24a, and 24b so that the connector 30 can be electrically connected. There is no coating film is formed so that the soldering or other electrical connection can be made completely in the connector 30 is inserted.

On the other hand, the connector 30 is made of a core portion 32 made of a metal material in the center, and the middle portion except for the upper and lower ends of the core portion is made of an insulator such as a synthetic resin or made of the same metal material as the core portion. It consists of a support 34 to serve as a gap maintaining or support so as to keep the gap between the upper and lower substrates 10 and 20 in parallel.

In addition, in the present embodiment, the upper and lower substrates 10 and 20 are formed in a donut shape with the inner part of the inner part being removed except for the antenna pattern formed in a loop shape around the substrate. Cooling efficiency is improved when air cooling by mounting a cooling means such as an electrically operated fan or cooling air spray nozzle to the air, and when the resistance value of the antenna pattern to be formed of metal changes with temperature, If there are no holes in the substrates, the air may stagnate and the resistance of the antenna pattern may change gradually over time. Since the resistance change of these antennas eventually results in a change in plasma characteristics, air is stagnated by drilling holes in the substrate. This is because it is advantageous to be able to be circulated without.

On the surfaces of the substrates 10 and 20, it is desirable to form an oxidation-resistant coating film for preventing the antenna patterns from oxidizing in contact with the atmosphere and protecting these patterns from harmful environments.

In the present invention, when the antenna pattern is formed on one surface of the substrate and stacked in a multi-layer, there is no fear of generating an arc since the pattern surfaces of the upper and lower substrates do not face each other, and have stability compared to an antenna using a conventional metal tube. do.

The substrate that can be used in the present invention is a material such as a conventional bakelite, glass epoxy, Teflon, ceramic, etc. as long as it meets the durability or other conditions required by the plasma generating apparatus may not be the above-mentioned materials.

5 is an exploded perspective view showing the antenna structure according to another embodiment of the present invention, Figure 6 is a combined perspective view of Figure 5 shows the complete form of the antenna in a solid line.

5 and 6 are more complicated than the antennas shown in Figs. 1 to 4, but the number of antennas coupled in parallel has increased from 2 to 4, and only the difference between these antennas in a circular to semicircular shape is shown. Only the power end P and the ground end G of each antenna are positioned on the upper substrate 100, and antenna patterns 210, 220, 230, and 240 corresponding to the middle portion of each antenna are positioned on the lower substrate 200. .

5 and 6, four antennas are arranged in concentric circles from the center of the substrate, and these antennas are twisted up and down, that is, antenna patterns 110 to 180 formed on the upper substrate 100. And the antenna patterns 210 to 240 formed on the lower substrate 200 are rotated by forming a shape in which a half portion is positioned at the top and the other half is positioned at the lower portion by the connector 300 and crosses up and down concentrically with other antennas. Uniformity of the plasma density with respect to the direction has a relatively better performance than the antenna of the embodiment shown in FIGS.

7 is a cross-sectional view illustrating an antenna structure according to another embodiment of the present invention, in which antenna patterns 12 and 12 'are formed on upper and lower layers of the substrate 10.

FIG. 8 is a cross-sectional view illustrating an antenna structure according to still another embodiment of the present invention, and includes a plurality of substrates having antenna patterns 12, 12 ', 22, 22', and 22 "formed on top, top, and bottom surfaces thereof. 10, 10 ', 20, 20') is a cross-sectional view showing a state in which a plurality of layers are closely stacked.

In the drawing, reference numeral C denotes an oxidation resistant coating film formed on upper and lower surfaces of the substrates 10 and 20 'exposed to the outside.

As shown in the embodiments of FIG. 7 and FIG. 8, there are advantages and disadvantages of using a multilayer substrate and using a single layer substrate as in the embodiment of FIGS. 1 to 6. In this case, since the antenna pattern (conductor) is separated by the substrate, it has arc resistance which is difficult to generate an arc, but has a disadvantage of large loss power because of a large resistance.In the case of using a multi-layer substrate, the antenna patterns face each other. Although disadvantageous, the area through which current can flow increases the power loss in the antenna.

Meanwhile, in the present invention, different patterns may be formed on upper and lower surfaces of a single substrate, and different antenna patterns may be formed on and below one substrate, and the patterns may be connected to connectors. Of course, the completed antenna can also be achieved.

1 to 8 described above, only the antenna pattern of a very simple form for explaining the concept of the present invention, but the present invention is not limited to this, all types of antenna pattern of the metal tube developed so far Of course, even very complex antenna patterns that could not be fabricated from metal tubes can be easily manufactured. Examples of such antenna patterns include the above mentioned loop, spiral and single or double or triple helical. Etc., when a plurality of antenna patterns are formed in parallel, an impedance adjusting means for adjusting the impedance between the antenna patterns may be mounted on the substrate itself, and the donut type upper and lower substrates as shown in FIG. An inner antenna pattern 110 electrically coupled in parallel with the antenna patterns 110 to 180 formed on the inner side (100,200). '~ 140') may be formed together, or another substrate having an inner antenna pattern may be further installed.

On the other hand, when forming the antenna pattern on the substrate in the antenna of the present invention, the appropriate thickness of the antenna pattern is a lot of RF current flows within the thickness called the skin depth (skin depth), so the thickness of the antenna pattern is formed above this surface thickness shall.

For reference, the surface thickness in the antenna pattern is defined as follows.

As described above, according to the present invention, the antenna circuit is patterned on a substrate to easily fabricate a complex structure and to place it in space in an antenna of a conventional metal tube bending method. In order to improve the uniformity of the plasma, an antenna having a complicated shape can be manufactured very simply and inexpensively, thereby providing a plasma antenna having excellent performance.

Claims (13)

Antenna for inductively coupled plasma generator, A substrate on which an antenna pattern is etched; A connector having a core part made of a metal material in the center and a support part formed of an insulator outside the core part to support the substrate to be stacked up and down in parallel and to electrically connect the antenna patterns formed on the substrate to complete the antenna. Antenna for inductively coupled plasma generator comprising a PCB (PCB), characterized in that comprises a. The method according to claim 1, The substrate is an antenna for an inductively coupled plasma generator comprising a PCB (PCB), characterized in that the antenna pattern is formed on both sides. The method according to claim 1 or 2, The substrate is an antenna for an inductively coupled plasma generator consisting of a PCB (PCB), characterized in that the remaining portion is removed except for the region in which the antenna pattern is formed, and has a hollow or round donut shape. The method according to claim 1, Faraday shield is formed on the substrate further comprises an antenna for an inductively coupled plasma generator comprising a PCB (PCB). The method according to any one of claims 1, 2, and 4, An antenna for an inductively coupled plasma generator comprising a PCB, characterized in that an impedance adjusting means is mounted on the substrate. The method according to any one of claims 1, 2, and 4, An antenna for an inductively coupled plasma generator comprising a PCB (PCB), wherein an oxidation-resistant coating film is formed on a surface of the substrate on which the antenna pattern is formed. The method according to claim 1, The substrate is an antenna for an inductively coupled plasma generator comprising a PCB (PCB), characterized in that selected from bakelite, glass epoxy, Teflon, ceramic substrate. The method according to claim 1, An antenna for an inductively coupled plasma generator (PCB) comprising a cooling means including a cooling fan or a cooling air spray nozzle for air-cooling heat generated from the antenna outside the substrate. . The method according to claim 1 or 2, The antenna pattern is an antenna for an inductively coupled plasma generator comprising a PCB (PCB), characterized in that the loop-shaped pattern is formed concentrically from the center of the substrate. The method according to claim 1 or 2, The antenna pattern is an antenna for an inductively coupled plasma generator comprising a PCB, characterized in that a spiral pattern. The method according to claim 1 or 2, The antenna pattern is an antenna for an inductively coupled plasma generator consisting of a PCB (PCB), characterized in that the spiral (helical) pattern. The method according to claim 3, An antenna for an inductively coupled plasma generator (PCB) consisting of a PCB (PCB) is further provided on an inner side of the donut-type substrate, the substrate having an antenna electrically coupled in parallel with an antenna formed on an outer substrate. The method according to claim 3, An antenna for an inductively coupled plasma generator (PCB) consisting of a PCB, wherein an inner antenna pattern electrically connected in parallel with an antenna pattern formed on an outer side of the donut-type substrate is formed together.

Images