KR20080067042A - Inductively coupled plasma reactor with core cover - Google Patents

Abstract

An inductively coupled plasma reactor with a core cover is provided to generate a large area high density plasma that is more uniform and has a high control capability relative to plasma ion energy by improving the magnetic flux transmitting efficiency of an antenna. An inductively coupled plasma reactor with a core cover comprises: a substrate treating chamber(100) in which a substrate holder(110) is installed; at least one plasma discharge chamber(200) installed above the substrate treating chamber; a wireless frequency antenna(310) installed on an outer portion of the at least one plasma discharge chamber; a core cover(300) which is installed along the wireless frequency antenna, and of which a magnetic flux doorway faces the plasma discharge chamber; and a power supply source(320) for supplying a power for plasma discharge to the wireless frequency antenna, wherein a magnetic flux induced by the wireless frequency antenna is collected and provided into the plasma discharge chamber by the core cover to induce plasma discharge within the plasma discharge chamber. Further, the core cover contains a non-magnetic spacer, and the wireless frequency antenna is a single wireless frequency antenna operated by single wireless frequency.

Description

INDUCTIVELY COUPLED PLASMA REACTOR WITH CORE COVER}

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 perspective view of a plasma reactor according to a preferred embodiment of the present invention.

2 is a cross-sectional view of the plasma reactor of FIG.

3 is a perspective view of a plasma reactor having two plasma discharge chambers.

4 is a cross-sectional view of the plasma reactor of FIG. 3.

5 is a perspective view of a plasma reactor having three plasma discharge chambers.

6 and 7 are diagrams for explaining modifications of the plasma reactor having a dual frequency supply structure.

8 and 9 are perspective views illustrating examples in which the structures of the plasma discharge chamber and the substrate processing chamber are modified in the shape of a square column.

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

100: substrate processing chamber 101: gas outlet

110: substrate support 120, 122: bias power

112: substrate to be processed 124: impedance matcher

200: plasma discharge chamber 201: gas inlet

300: core cover 310: induction antenna

320: power source 322: impedance matcher

330: baffle punk

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inductively coupled plasma reactor using radio frequency. Specifically, the core cover and one or more radio frequency antennas are used to control plasma ion energy with higher uniformity. An inductively coupled plasma reactor capable of generating a large area of high density plasma.

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.

Capacitively coupled plasma sources have the advantage of high process productivity compared to other plasma sources due to their high capacity for precise capacitive coupling 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 obtain a high density plasma relatively easily, 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, an object of the present invention is to solve the above-described problems, and an object thereof is to provide a core cover capable of generating high density plasma having a high uniformity and a more uniform control of plasma ion energy by improving the flux transfer efficiency of the antenna. An inductively coupled plasma reactor is provided.

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 substrate processing chamber provided with a substrate support; At least one plasma discharge chamber disposed above the substrate processing chamber; A radio frequency antenna installed outside the at least one plasma discharge chamber; A core cover installed along the radio frequency antenna and installed so that the magnetic flux entrance and exit may face the plasma discharge chamber; And a power supply source for supplying power for plasma discharge to the radio frequency antenna, wherein the magnetic flux induced by the radio frequency antenna is focused by the core cover and provided to the inside of the plasma discharge chamber to discharge the plasma into the plasma discharge chamber. This is induced.

In one embodiment, the core cover comprises a nonmagnetic spacer.

In one embodiment, the radio frequency antenna consists of a single radio frequency antenna driven by a single radio frequency.

In one embodiment, the radio frequency antenna comprises two or more radio frequency antennas driven by different frequencies; The power supply includes two or more power supplies that supply different frequencies.

In one embodiment, the outer side of the plasma discharge chamber is configured to include a cooling channel for preventing overheating of the plasma discharge chamber and the radio frequency antenna and the core cover.

In one embodiment, the substrate support is biased by a single bias power source.

In one embodiment, the substrate support is multi-biased by two or more bias power sources.

In one embodiment, a baffle plate is provided above the substrate processing chamber.

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 core cover of the present invention will be described in detail.

1 is a perspective view of a plasma reactor according to a preferred embodiment of the present invention, Figure 2 is a cross-sectional view of the plasma reactor of FIG.

1 and 2, the inductively coupled plasma reactor according to the present invention includes a substrate processing chamber 100 and a plasma discharge chamber 200 installed above the substrate processing chamber 100. In the substrate processing chamber 100, a substrate support 112 on which the substrate to be processed 112 is placed is installed. The substrate 112 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 substrate processing chamber 100 is made of metal materials such as aluminum, stainless steel, and copper. Or coated metal, for example anodized aluminum or nickel plated aluminum. Or refractory metal. Or other materials suitable for carrying out the intended plasma process.

The opening is connected to the front chamber 200. The plasma discharge chamber 200 is provided with a spiral wound around the radio frequency antenna 310 which is warmed by the core cover 300 to the outer side wall. Sidewalls of the plasma discharge chamber 200 where the radio frequency antenna 310 is installed are configured using a dielectric material. The substrate processing chamber 100 and the plasma discharge chamber 200 have a cylindrical shape as a whole. The plasma reaction chamber 200 has a smaller diameter than the substrate processing chamber 100.

A gas inlet 201 is provided at the ceiling of the plasma discharge chamber 200, and a gas outlet 101 is provided at the lower end of the substrate processing chamber 100. The gas inlet 201 is connected to a gas supply source (not shown) for supplying a process gas, and the gas outlet 101 is connected to a vacuum pump (not shown). The process gas flowing through the gas inlet 201 is activated by the plasma discharge in the plasma reaction chamber 200 and flows into the substrate processing chamber 100. After reaction with the unreacted gas, by-product gases are exhausted to the outside through the gas outlet 101.

The radio frequency antenna 310 is electrically connected through a impedance matcher 322 to a power supply 320 that supplies radio frequencies. The power supply source 320 generates a radio frequency and supplies it to the radio frequency antenna 200. When a current is driven in the radio frequency antenna 200, induced electromotive force is transferred into the plasma discharge chamber 200 to generate a plasma discharge in the plasma discharge chamber 200.

The core cover 300 is installed along the radio frequency antenna 310 with the magnetic flux entrance and exit facing the interior of the plasma discharge chamber 200. Therefore, the magnetic flux generated by the radio frequency antenna 310 is strongly concentrated by the core cover 300 and is transferred into the plasma discharge chamber 200. Since the radio frequency antenna 310 is covered by the core cover 300, it is possible to prevent loss of magnetic flux as much as possible.

The core cover 300 is made of ferrite material but may be made of other alternative materials. The core cover 300 may be configured by assembling pieces of horseshoe-shaped ferrite cores. In the case of using a plurality of pieces, each piece can be connected by inserting a nonmagnetic spacer such as an insulating material on the assembly surface. Alternatively, an integrated ferrite core may be used. A Faraday shield may be selectively configured between the radio frequency antenna 310 and the sidewall of the plasma discharge chamber 200. The baffle plate 330 may be selectively installed on the substrate processing chamber 100.

Although not shown in the drawing, a cooling channel for preventing overheating of the plasma discharge chamber 200, the radio frequency antenna 310, and the core cover 300 is configured by the outside of the plasma discharge chamber 200. The cooling channel may be installed along the radio frequency antenna 310 inside the core cover 300.

The substrate support 110 is connected to two bias power sources 120 and 122 through an impedance matcher 124. The two bias power sources 120 generate different frequencies to supply the substrate supports. The dual bias structure of the substrate support 110 may further improve plasma ion energy control ability on the surface of the substrate 112 to further improve plasma processing efficiency of the substrate 112. The substrate support 110 may have a structure that is single biased by a single bias power source in addition to the dual bias structure. Alternatively, the present invention may have a structure that is multi-biased by a bias power source having two or more different frequencies.

3 is a perspective view of a plasma reactor having two plasma discharge chambers, and FIG. 4 is a cross-sectional view of the plasma reactor of FIG. 3. And FIG. 5 is a perspective view of a plasma reactor having three plasma discharge chambers.

3 and 4, the plasma reactor of the present invention may be modified to have a structure in which two plasma discharge chambers 200-1 and 200-2 are formed on one substrate processing chamber 100. . In this modification, repeated descriptions of the same configurations as the above-described examples will be omitted.

The two plasma discharge chambers 200-1 and 200-2 are provided with radio frequency antennas 310-1 and 310-2 and core covers 300-1 and 300-2, respectively. The two radio frequency antennas 310-1 and 310-2 may be connected in parallel or in series to the power supply 320 through an impedance matcher 322. When connected in parallel, it is desirable to configure an appropriate power split circuit. Alternatively, the two radio frequency antennas 310-1 and 310-2 may be configured to separately supply power from independent power sources.

The plasma reactor of the present invention may include one or two plasma discharge chambers 200 (200-1, 200-2) on the substrate processing chamber 100. Alternatively, as shown in FIG. 5, three plasma discharge chambers 200-1, 200-2, and 200-3 may be provided. Even with three plasma discharge chambers 200-1, 200-2, and 200-3, each discharge chamber has a radio frequency antenna (not shown) and a core cover 300-1, 300-2, 300. -3) is installed.

As described above, the plasma reactor of the present invention may include an appropriate number of plasma discharge chambers on the substrate processing chamber 100 in order to generate the required plasma according to the size of the substrate to be processed. At this time, the radio frequency antenna provided in each plasma discharge chamber may be connected in series or in parallel to one power supply. Alternatively, independent power supply may be achieved by separate power sources.

6 and 7 are diagrams for explaining modifications of the plasma reactor having a dual frequency supply structure.

The plasma reactor shown in FIG. 6 has the same configuration as the plasma reactor of FIG. 1 described above. However, two radio frequency antennas 310a and 310b are spirally wound in parallel to the plasma discharge chamber 200. The two radio frequency antennas 310a and 310b are connected to two power sources 320a and 320b supplying different frequencies through impedance matchers 322a and 322b, respectively. Two radio frequency antennas 310a and 310b driven by different frequencies may generate more uniform high density plasma.

The plasma reactor shown in FIG. 7 has the same configuration as the plasma reactor of FIG. 3 described above. However, two radio frequency antennas 310a-1 and 310b-1 and 310a-2 and 310b-2 are respectively wound in parallel in two plasma discharge chambers 200-1 and 200-2. Each of the two radio frequency antennas 310a-1 and 310b-1 and 310a-2 and 310b-2 is an impedance matcher 322a and 322b respectively to two power sources 320a and 320b which supply different frequencies. Through).

8 and 9 are perspective views illustrating examples in which the structures of the plasma discharge chamber and the substrate processing chamber are modified in the shape of a square column.

8 and 9, in the plasma reactor of the present invention, the shape of the substrate processing chamber 100 and the one or more plasma discharge chambers 200 (200-1 and 200-2) may have a square pillar shape. As described above, the substrate processing chamber 100 and the one or more plasma discharge chambers 200 (200-1, 200-2) may be variously modified, such as a cylindrical shape or a square column shape, depending on the shape and size of the substrate to be processed. Do.

Embodiments of the inductively coupled plasma reactor having a core cover of the present invention described above are merely exemplary, and those skilled in the art to which the present invention pertains have various modifications and equivalent embodiments. You can see that it is possible. Therefore, 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 core cover of the present invention as described above, in a plasma reactor having at least one plasma discharge chamber above the substrate processing chamber, a core is formed in a radio frequency antenna spirally wound outside the plasma discharge chamber. It is possible to increase the plasma generation efficiency by preventing the loss of magnetic flux by providing a cover, and by constructing two or more radio frequency antennas driven by different frequencies in parallel to generate a high density and uniform plasma, It is possible to increase the plasma treatment efficiency for the process, thereby improving the process production capacity.

Claims (8)

A substrate processing chamber provided with a substrate support; At least one plasma discharge chamber disposed above the substrate processing chamber; A radio frequency antenna installed outside the at least one plasma discharge chamber; A core cover installed along the radio frequency antenna and installed so that the magnetic flux entrance and exit may face the plasma discharge chamber; And Includes a power source for supplying power for plasma discharge to the radio frequency antenna, The magnetic flux induced by the radio frequency antenna is focused by the core cover and provided into the plasma discharge chamber to induce plasma discharge into the plasma discharge chamber. The inductively coupled plasma reactor of claim 1, wherein the core cover comprises a nonmagnetic spacer. 2. The inductively coupled plasma reactor of claim 1, wherein the radio frequency antenna is comprised of a single radio frequency antenna driven by a single radio frequency. 2. The antenna of claim 1, wherein the radio frequency antenna comprises at least two radio frequency antennas driven by different frequencies; An inductively coupled plasma reactor, characterized in that the power source comprises two or more power sources for supplying different frequencies. The inductively coupled plasma reactor of claim 1, comprising a cooling channel configured to be outside of the plasma discharge chamber to prevent overheating of the plasma discharge chamber, the radio frequency antenna, and the core cover. An inductively coupled plasma reactor as claimed in claim 1, wherein the substrate support is biased by a single bias power source. 5. The inductively coupled plasma reactor according to any one of claims 1, 3 and 4, wherein the substrate support is multi-biased by two or more bias power sources. 2. The inductively coupled plasma reactor as recited in claim 1, comprising a baffle plate mounted over the substrate processing chamber.

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