KR100777841B1 - Inductive coupled plasma reactor with improved vertical etching efficiency - Google Patents

Abstract

An inductive coupled plasma reactor with improved vertical etching performance is provided to form vertical electric field in an inside of a chamber by using a vertical antennal coil and a magnetic core. A vacuum chamber(10) has a sidewall(14) including a dielectric material. An antenna coil(20) is installed vertically along the outside of the sidewall of the vacuum chamber in order to generate electric field which is induced vertically in the inside of the vacuum chamber. A magnetic core(22) is installed at the outside of the sidewall of the vacuum chamber in order to cover the antenna coil. The magnetic core is used for condensing inductive magnetic field generated by the antennal coil, and applying the inductive magnetic field to the inside of the vacuum chamber. An upper electrode(13) is positioned at a ceiling of the vacuum chamber. A lower electrode(16) is positioned at a lower part of the vacuum chamber facing the upper electrode.

Description

INDUCTIVE COUPLED PLASMA REACTOR WITH IMPROVED VERTICAL ETCHING EFFICIENCY}

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 diagram of an inductively coupled plasma reactor according to a preferred embodiment of the present invention.

FIG. 2 is a horizontal sectional view of the plasma reactor of FIG. 1.

3 is a vertical sectional view of the plasma reactor of FIG. 1.

4 to 6 are diagrams showing a winding structure of an antenna coil.

7 and 8 illustrate modifications of the divided power supply structure.

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

10: vacuum chamber 12: gas inlet

13: upper electrode 14: side wall

16: substrate support 18: gas distribution plate

20: antenna coil 22: magnetic core

The present invention relates to an inductively coupled plasma reactor, and specifically, an antenna coil wound vertically along the outside of a sidewall of a vacuum chamber and a magnetic core covering the antenna coil to focus the induced magnetic field more strongly to improve energy transfer efficiency. An inductively coupled plasma reactor with vertical etching performance.

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 due to ion bombardment, radio frequency power is limited.

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).

As the radio frequency antenna, a spiral type antenna or a cylinder type antenna is generally used. 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, until now, a plasma reactor using a spiral type antenna or a cylinder type antenna has a difficulty in increasing vertical etching performance on a substrate to be processed because the induced electric field is basically horizontal to the substrate. In addition, it is also limited to widen the structure of the antenna or increase the power supplied to the antenna to obtain a large plasma.

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 a plasma source and plasma processing technology which has excellent processing ability for a large area of the workpiece and is excellent in vertical etching ability for the substrate to be processed.

Accordingly, an object of the present invention is to provide an inductively coupled plasma reactor capable of uniform plasma processing on a large-area target substrate while having an improved vertical etching performance.

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 sidewalls comprising a dielectric material; An antenna coil installed vertically along the outside of the sidewall of the vacuum chamber to generate an electric field induced vertically inside the vacuum chamber; And a magnetic core installed outside the sidewall of the vacuum chamber to cover the antenna coil to focus the induced magnetic field generated by the antenna coil to be incident into the vacuum chamber.

In one embodiment, the upper electrode comprising a ceiling of the vacuum chamber and the lower electrode is disposed opposite the upper electrode and the lower electrode on which the substrate to be processed is placed.

In one embodiment, a gas inlet configured on a vacuum chamber ceiling; And at least one gas distribution plate installed across the top of the vacuum chamber to evenly distribute the process gas input through the gas inlet to be sprayed onto the substrate to be processed.

In one embodiment, a first power supply for supplying a first power source to the upper electrode; A second power supply for supplying a second power source to the antenna coil; One or more bias power supplies for supplying bias power to the bottom electrode.

In one embodiment, a first power supply for supplying a first power source to the upper electrode and the antenna coil; A power split supply configured to separately supply the first power provided from the first power supply to the upper electrode and the antenna coil; One or more bias power supplies for supplying bias power to the bottom electrode.

In one embodiment, a first power supply for supplying a first power source to the upper electrode; A second power supply for supplying a second power source to the antenna coil and the lower electrode; A power split supply configured to separately supply the second power provided from the second power source to the antenna coil and the lower electrode; And a bias power supply for supplying bias power to the bottom electrode.

In one embodiment, the antenna coil is wound zigzag vertically along the outside of the sidewall of the vacuum chamber but at least once.

In one embodiment, a cooling water supply channel is installed along the antenna coil.

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 of the present invention will be described in detail.

1 is a diagram illustrating an inductively coupled plasma reactor according to a preferred embodiment of the present invention, and FIG. 2 is a horizontal cross-sectional view of the plasma reactor of FIG. 1. 3 is a vertical cross-sectional view of the plasma reactor of FIG.

Referring to FIG. 1, an inductively coupled plasma reactor according to a preferred embodiment of the present invention includes an antenna coil 20 and an antenna installed vertically along the outside of the sidewall 14 of the vacuum chamber 10 and the vacuum chamber 10. It is configured to include a magnetic core 22 installed to the outside of the side wall 14 of the vacuum chamber 10 to cover the coil 20.

The side wall 14 of the vacuum chamber 10 includes a dielectric material. For example, the side wall 14 of the vacuum chamber 10 may be entirely composed of a dielectric tube. Although not shown in the drawings, a protective film such as a Faraday shield may be installed to prevent the inner wall of the vacuum chamber from being damaged by the electrostatic coupling generated by the antenna coil 20. Although not shown in detail in the drawing, the antenna coil 20 is configured according to the cooling water supply channel. The cooling water supply channel may have a tube shape to surround the antenna coil 20 and may be installed along the antenna coil 20.

The magnetic core 22 is installed outside the side wall 14 of the vacuum chamber 10 to cover the antenna coil 20 to focus the induced magnetic field 26 generated by the antenna coil to be incident into the vacuum chamber. do. As shown in FIGS. 2 and 3, the electric field 24 induced by the antenna coil 20 is formed perpendicular to the interior of the vacuum chamber 10. As a result, the vertical etching performance of the substrate W to be placed on the substrate support 16 provided on the inner lower side of the vacuum chamber 10 is improved.

Referring to FIG. 3, the upper electrode 13 formed of the ceiling of the vacuum chamber 10 and the substrate support 16 provided to face the upper electrode 13 constitute the lower electrode 16. A gas inlet 12 is formed at the center of the ceiling of the vacuum chamber 10, and a gas outlet 15 is formed at the bottom of the vacuum chamber 10. One or more gas distribution plates 18 are installed across the upper portion of the vacuum chamber 10 so that the process gas input through the gas inlet 12 is evenly distributed and sprayed onto the processing target substrate W.

The first electrode of the first frequency is supplied to the upper electrode 13 from the first power source 30. The first power source may be supplied through the impedance matcher 31 for impedance matching. The antenna coil 20 is supplied with a second power source of a second frequency from the second power source 32. The second power source may be supplied through the impedance matcher 33 for impedance matching. Here, the first frequency and the second frequency may be different frequencies or may use the same frequency. The lower electrode 16 is supplied with bias power from one or more bias power sources 34 and 35. A bias power source can be supplied through the impedance matcher 36 for impedance matching. When bias power is supplied from two bias power sources 34 and 35, each bias power source has a different frequency.

A uniform plasma is generated inside the vacuum chamber 10 by the vertical electric field generated by the upper electrode 13 and the lower electrode 16, thereby enabling uniform plasma treatment on a large-area target substrate. Do. In addition, a vertical electric field 24 is formed inside the vacuum chamber 10 by the antenna coil 20 and the magnetic core 22 installed vertically along the outer side of the side wall 14 of the vacuum chamber 10. Improved vertical etching performance with respect to the substrate W can be obtained.

4 to 6 are diagrams showing a winding structure of an antenna coil.

Referring to FIG. 4, the antenna coil 20 is basically wound once vertically in a zigzag form on the outside of the side wall 14 of the vacuum chamber 10 as a whole. However, as shown in FIG. 5, it may be wound back and forth or may be wound back and forth several times as shown in FIG. 6. The number of turns of the antenna coil 20 may be appropriately selected in consideration of the size and process characteristics of the vacuum chamber.

7 and 8 illustrate modifications of the divided power supply structure.

Referring to FIG. 7, the upper electrode 13 and the antenna coil 20 may be commonly supplied with the first power from the first power supply 30. To this end, the power split supply unit 37 is provided. The power split supply unit 37 separately supplies the first power provided from the first power source 30 to the upper electrode 13 and the antenna coil 20. The power split supply 37 may be configured by various circuit configurations. For example, the transformer may be configured such that the primary side is connected to the first power source 30 and the antenna coil 20, and the secondary side is connected to the upper electrode 13 to ground. Alternatively, a voltage division capacitor can be used. The bias power supply structure of the lower electrode 16 can be configured in the same manner as shown in FIG.

Referring to FIG. 8, the antenna coil 20 and the lower electrode 16 may be commonly supplied with the first power by the second power supply 32. To this end, as illustrated in FIG. 7, the power split supplier 37 separately supplies the second power provided from the second power supply 32 to the antenna coil 20 and the lower electrode 16.

As such, when the power is supplied by power division, the number of power supply sources can be reduced, thereby reducing the overall equipment configuration cost.

Embodiments of the inductively coupled plasma reactor of the present invention described above are merely illustrative, and those skilled in the art to which the present invention pertains may various modifications and equivalent other embodiments. You will know. 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 of the present invention as described above, evenly generated plasma is generated by the vertical electric field generated by the upper electrode and the lower electrode, which enables uniform plasma treatment on a large-area target substrate. In addition, an electric field perpendicular to the inside of the vacuum chamber is formed by the antenna coil and the magnetic core installed vertically along the outside of the sidewall of the vacuum chamber, thereby obtaining an improved vertical etching performance of the substrate.

Claims (8)

A vacuum chamber having sidewalls comprising a dielectric material; An antenna coil installed vertically along the outside of the sidewall of the vacuum chamber to generate an electric field induced vertically inside the vacuum chamber; And An inductively coupled plasma reactor including a magnetic core installed outside the sidewall of the vacuum chamber to cover the antenna coil and focusing the induced magnetic field generated by the antenna coil to be incident into the vacuum chamber. The inductively coupled plasma reactor of claim 1, further comprising an upper electrode configured as a ceiling of the vacuum chamber and a lower electrode disposed below the vacuum chamber opposite to the upper electrode and on which the substrate to be processed is placed. The gas inlet of claim 1, further comprising: a gas inlet configured on the vacuum chamber ceiling; And An inductively coupled plasma reactor comprising one or more gas distribution plates installed across the top of the vacuum chamber to evenly distribute the process gas input through the gas inlet to be sprayed onto the substrate to be processed. 3. The power supply of claim 2, further comprising: a first power source for supplying a first power source to the upper electrode; A second power supply for supplying a second power source to the antenna coil; An inductively coupled plasma reactor comprising one or more bias power sources for supplying bias power to the bottom electrode. 3. The apparatus of claim 2, further comprising: a first power supply source for supplying a first power source to the upper electrode and the antenna coil; A power split supply configured to separately supply the first power provided from the first power supply to the upper electrode and the antenna coil; An inductively coupled plasma reactor comprising one or more bias power sources for supplying bias power to the bottom electrode. 3. The power supply of claim 2, further comprising: a first power source for supplying a first power source to the upper electrode; A second power supply for supplying a second power source to the antenna coil and the lower electrode; A power split supply configured to separately supply the second power provided from the second power source to the antenna coil and the lower electrode; An inductively coupled plasma reactor comprising a bias power source for supplying bias power to the bottom electrode. The inductively coupled plasma reactor of claim 1, wherein the antenna coil is wound zigzag vertically along the outside of the sidewall of the vacuum chamber and at least once. The inductively coupled plasma reactor of claim 1, further comprising a cooling water supply channel installed along the antenna coil.

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