KR20080069755A - Inductively coupled plasma reactor capable - Google Patents

Abstract

An inductively coupled plasma reactor is provided to generate high density plasma uniformly by supplying gas uniformly and increasing magnetic flux transfer efficiency. An inductively coupled plasma reactor comprises a vacuum chamber(10), a dielectric window(34), a wireless frequency antenna(30), a flat panel electrode, a plurality of gas supply holes(36), and a gas supply part(25). The vacuum chamber has a substrate support device(16). The dielectric window is installed on the vacuum chamber. The gas supply holes are formed in the dielectric window. The gas supply part supplies process gas into the vacuum chamber through the gas supply holes. A magnetic core cover(32) is installed toward the dielectric window. First and second power supply sources(50,52) supply first and second powers to the wireless frequency antenna and to the flat panel electrode.

Description

Inductively Coupled Plasma Reactor {INDUCTIVELY COUPLED PLASMA REACTOR CAPABLE}

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 schematic perspective view of an inductively coupled plasma reactor of the present invention.

2 is an exploded perspective view of the main configuration of the inductively coupled plasma reactor of FIG.

3 is a cross-sectional view of the inductively coupled plasma reactor of FIG. 1.

4 to 8 illustrate various modifications of the plate electrode structure.

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

10: vacuum chamber 11: chamber body

14: gas outlet 16: substrate support

20: gas supply unit 21: gas supply cover

22: gas inlet 23: bottom plate

24: gas distribution plate 25: gas introduction pipe

30: radio frequency antenna 32: magnetic core cover

34: dielectric window 36: gas supply hole

40, 40a, 40b, 40c, 40d: flat electrode 50: first power source

51: impedance matcher 52: second power source

53: impedance matcher 54: third power source

55: fourth power source 56: impedance matcher

57: power split supply

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inductively coupled plasma reactor using radio frequency. Specifically, the present invention relates to an induction that can generate a high density plasma having a higher uniformity and a more uniform control of plasma ion energy. A coupled plasma reactor.

Plasma is a highly ionized gas containing the same number of positive ions and electrons. Plasma discharges are used for gas excitation to generate active gases containing ions, free radicals, atoms, molecules. The active gas is widely used in various fields and is typically used in a variety of semiconductor manufacturing processes such as etching, deposition, cleaning, ashing, and the like.

There are a number of plasma sources for generating plasma, and the representative examples are capacitive coupled plasma and inductive coupled plasma using radio frequency.

The capacitively coupled plasma source has the advantage of high process productivity compared to other plasma sources due to its high capacity for precise capacitive coupling control and ion control. 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. However, increasing radio frequency power increases ion bombardment energy. As a result, in order to prevent damage caused by ion bombardment, there is a limit of radio frequency power supplied.

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 suitable for obtaining a high density plasma. Therefore, inductively coupled plasma sources are commonly used to obtain high density plasma. Inductively coupled plasma sources are typically developed using a radio frequency antenna (RF antenna) and a transformer (also called transformer coupled plasma). The development of technology to improve the characteristics of plasma, and to increase the reproducibility and control ability by adding an electromagnet or a permanent magnet or adding a capacitive coupling electrode.

Radio frequency antennas are generally used as spiral type antennas or cylinder type antennas. The radio frequency antenna is disposed outside the plasma reactor and transmits induced electromotive force into the plasma reactor through a dielectric window such as quartz. Inductively coupled plasma using a radio frequency antenna can easily obtain a high density plasma, but the plasma uniformity is affected by the structural characteristics of the antenna. Therefore, efforts have been made to improve the structure of the radio frequency antenna to obtain a uniform high density plasma.

However, in order to obtain a large plasma, it is limited to widen the structure of the antenna or increase the power supplied to the antenna. For example, it is known that a non-uniform plasma is generated in the radiographic state by a standing wave effect. In addition, when high power is applied to the antenna, the capacitive coupling of the radio frequency antenna increases, so that the dielectric window must be thickened, thereby increasing the distance between the radio frequency antenna and the plasma, thereby lowering power transmission efficiency. Losing problems occur.

In the recent semiconductor manufacturing industry, plasma processing technology has been further improved due to various factors such as ultra-miniaturization of semiconductor devices, the enlargement of silicon wafer substrates for manufacturing semiconductor circuits, the enlargement of glass substrates for manufacturing liquid crystal displays, and the emergence of new target materials. This is required. In particular, there is a need for improved plasma sources and plasma processing techniques that have good processing capabilities for large area workpieces.

Accordingly, the present invention has been made to solve the above-mentioned problems, and its object is to improve the flux transfer efficiency of the antenna and to control plasma ion energy, thereby inducing coupled plasma reaction which can generate a more uniform high-density plasma. To provide a flag.

One aspect of the present invention for achieving the above technical problem relates to an inductively coupled plasma reactor. An inductively coupled plasma reactor of the present invention comprises: a vacuum chamber having a substrate support on which a substrate to be processed is placed; A dielectric window installed above the vacuum chamber; A radio frequency antenna mounted on top of the dielectric window; A plate electrode disposed between the radio frequency antenna and the dielectric window; A plurality of gas supply holes formed through the dielectric window in other portions except for the region where the radio frequency antenna is disposed; And a gas supply unit supplying a process gas into the vacuum chamber through the plurality of gas supply holes.

In one embodiment, the magnetic flux entrance includes a magnetic core cover installed toward the dielectric window to be covered along the radio frequency antenna.

In one embodiment, a first power supply for supplying a first power source to a radio frequency antenna; And a second power supply source for supplying a second power source to the plate electrode.

In one embodiment, the gas supply unit has a gas separation supply structure for separately supplying different process gases.

In one embodiment, the plate electrode has an opening between the radio frequency antenna and the dielectric window, and the opening includes at least one structure selected from a comb tooth structure, a concentric structure, a spiral structure, a network structure, and a radial structure.

In one embodiment, the substrate support is biased with bias power supplied from one or more bias power sources.

In one embodiment, the substrate support has a zero potential without supply of bias power.

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. The embodiments of the present invention may be modified in various forms, and the scope of the present invention should not be construed as being limited by the embodiments described below. This embodiment is provided to more completely explain the present invention to those skilled in the art. Accordingly, the shape of the elements in the drawings and the like are exaggerated to emphasize a clearer description. 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)

Hereinafter, with reference to the accompanying drawings illustrating a preferred embodiment of the present invention, the inductively coupled plasma reactor having a uniform plasma processing performance of the present invention will be described in detail.

1 is a schematic perspective view of an inductively coupled plasma reactor of the present invention, and FIG. 2 is an exploded perspective view of a main configuration of the inductively coupled plasma reactor of FIG. 1. 3 is a cross-sectional view of the inductively coupled plasma reactor of FIG. 1.

1 to 3, the inductively coupled plasma reactor of the present invention includes a vacuum chamber 10 composed of a chamber body 11 and a dielectric window 34 forming a ceiling of the chamber body 11. The substrate support 16 on which the substrate to be processed W is placed is provided in the vacuum chamber 100. The lower end of the chamber body 11 is provided with a gas outlet 14 for gas exhaust. The gas outlet 14 is connected to a vacuum pump (not shown). The substrate W to be processed is, for example, a silicon wafer substrate for producing a semiconductor device or a glass substrate for producing a liquid crystal display or a plasma display.

The chamber body 11 is made of a metallic material such as aluminum, stainless steel or copper. Or coated metal, for example anodized aluminum or nickel plated aluminum. Or refractory metal. Alternatively, it is also possible to rewrite the chamber body 11 entirely with an electrically insulating material such as quartz, ceramic, or other materials suitable for carrying out the intended plasma process. Dielectric window 34 is comprised of an insulating material, such as, for example, quartz or ceramic.

The radio frequency antenna 30 is installed above the dielectric window 34. The radio frequency antenna 30 has a flat spiral structure in the region of the dielectric window 34. One end of the radio frequency antenna 30 is connected to the first power supply 50 supplying the radio frequency of the first frequency through the impedance matcher 51 and the other end is connected to ground. The first power source 50 may be configured using a radio frequency power source capable of controlling the output power without a separate impedance matcher.

A plate electrode 40 is provided between the radio frequency antenna 30 and the dielectric window 34. The plate electrode 40 and the radio frequency antenna 30 are electrically insulated. The plate electrode 230 is connected to a second power supply 52 which supplies a radio frequency of a second frequency through the impedance matcher 53. The flat electrode 40 can increase the control ability of the plasma ion energy generated inside the vacuum chamber 10 and can generate a more uniform plasma. As a result, a more uniform plasma treatment can be performed on the substrate, thereby forming a high quality thin film on the substrate W. FIG.

The plate electrode 40 basically has an area opened between the radio frequency antenna 30 and the dielectric window 34. The open area may be formed in various structures such as a comb tooth structure, a concentric circle structure, a spiral structure, a mesh structure, and a radial structure, as shown in FIGS. 2 and 4 to 8.

The plate electrode 40 may be modified so as to receive a radio frequency from the second power source 52 but receive power separately from a power supply 54 or 55 that supplies bias power to the substrate support 16. In this case, the number of power supply sources can be reduced, thereby reducing the installation cost.

The radio frequency antenna 30 is covered by a magnetic core cover 32. The magnetic core cover 32 is installed so that the vertical cross-sectional structure has a horseshoe shape and is covered along the radio frequency antenna 30 so that the magnetic flux entrance 35 faces the dielectric window 34. Therefore, the magnetic field generated by the radio frequency antenna 30 is focused by the magnetic core cover 32 and generated inside the upper portion of the vacuum chamber 10. The electric field induced by this magnetic field is generated essentially parallel to the dielectric window 34.

Magnetic core cover 32 is made of ferrite material, but may be made of other alternative materials. Magnetic core cover 34 may be configured by assembling a plurality of horseshoe-shaped ferrite core pieces. Alternatively, an integrated ferrite core may be used. In the case of using a plurality of pieces, each piece can be connected by inserting a nonmagnetic material layer such as an insulating material on the assembly surface. Although the cooling water supply channel is not illustrated in detail, for example, the cooling water supply channel may be provided between the radio frequency antenna 30 and the magnetic core cover 32.

The gas supply unit 20 is configured above the vacuum chamber 10. The dielectric window 34 is formed with a plurality of gas supply holes 36 formed through other portions except the region where the radio frequency antenna 30 is disposed. A plurality of gas supply holes 36 are formed along the spiral radio frequency antenna 30. The gas supply unit 20 includes a gas supply cover 21 covering the radio frequency antenna 30 as a whole, a gas inlet 22 connected to a gas supply source (not shown), and a gas supply connected to a plurality of gas supply holes 36. It consists of one or more gas distribution diaphragms 24 for evenly distributing gas between the tube 25, the gas inlet 22 and the gas introduction tube 25. The gas introduction pipe 25 is connected to the lower plate 23 of the gas supply unit 20.

The gas supply unit 12 injects process gas into the vacuum chamber 10 along the helical radio frequency antenna 30. Therefore, the process gas may be uniformly supplied into the vacuum chamber 10 through the upper portion of the dielectric window 34 in a portion other than the region where the radio frequency antenna 30 is installed, thereby increasing the uniformity of the plasma treatment.

The gas supply unit 20 may be modified in a dual gas supply structure. Through these two gas supply paths, two different process gases may be separately supplied. By uniformly supplying different process gases, the uniformity of the plasma treatment may be increased.

Referring to FIG. 3, the substrate support 16 is electrically connected and biased through an impedance matcher 56 to third and fourth power supplies 54, 55 that supply second and third radio frequencies. The third and third power sources 54 and 55 supply different radio frequencies to the substrate support 16. The dual power supply structure of the substrate support 16 facilitates plasma generation inside the vacuum chamber 10 and further improves plasma ion energy control on the surface of the substrate W to further improve process productivity. Can be. The third and fourth power sources 54 and 55 may be configured using a radio frequency power source capable of controlling the output voltage without a separate impedance matcher. The substrate support 16 has a dual bias structure, but may have a single bias structure by one power supply. Alternatively, the substrate support 16 may be configured to have zero potential without supply of bias power.

Embodiments of the inductively coupled plasma reactor having a uniform plasma processing performance of the present invention described above are merely exemplary, and those skilled in the art to which the present invention pertains can make various modifications and equivalents therefrom. It will be appreciated that examples are possible. Therefore, it is to be understood that the present invention is not limited to the specific forms mentioned in the above description. Therefore, the true technical protection scope of the present invention should be defined by the technical spirit of the appended claims, and the present invention is intended to cover all modifications, equivalents, and substitutes within the spirit and scope of the present invention as defined by the appended claims. It should be understood to include.

According to the inductively coupled plasma reactor having a uniform plasma treatment performance of the present invention as described above, high density plasma can be generated uniformly by uniform gas supply by the gas supply unit and improvement of magnetic flux transfer efficiency by the magnetic core cover. have. In addition, the plate electrode can control the plasma ion energy and generate a more uniform high-density plasma.

Claims (7)

A vacuum chamber having a substrate support on which a substrate to be processed is placed; A dielectric window installed above the vacuum chamber; A radio frequency antenna mounted on top of the dielectric window; A plate electrode disposed between the radio frequency antenna and the dielectric window; A plurality of gas supply holes formed through the dielectric window in other portions except for the region where the radio frequency antenna is disposed; And Inductively coupled plasma reactor comprising a gas supply for supplying a process gas into the interior of the vacuum chamber through a plurality of gas supply holes. 2. The inductively coupled plasma reactor of claim 1, comprising a magnetic core cover having a magnetic flux entrance facing the dielectric window to cover along the radio frequency antenna. 2. The apparatus of claim 1, further comprising: a first power source for supplying first power to the radio frequency antenna; And And a second power supply for supplying a second power source to the plate electrode. The inductively coupled plasma reactor of claim 1, wherein the gas supply unit has a gas separation supply structure for separating and supplying different process gases. The flat panel electrode of claim 1, wherein the plate electrode has an area opened between the radio frequency antenna and the dielectric window, And wherein the opened region comprises at least one structure selected from comb teeth, concentric circles, spirals, meshes, and radials. 6. The inductively coupled plasma reactor of Claims 1 to 5, wherein the substrate support is biased by receiving bias power from one or more bias power sources. 6. The inductively coupled plasma reactor of claim 1, wherein the substrate support has a zero potential without supply of bias power. 7.

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