JP2001052895A - Plasma generating device and plasma processing device equipped therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasma generating device and a plasma processing device capable of generating plasma capable of enhancing the in-plane uniformity of the processing of a processed object. SOLUTION: An antenna 3 made up of a plurality of antenna pieces 3a concentrically disposed in one plane and different in diameter from each other, a high-frequency power supply 1 for antenna for supplying high-frequency power to the antenna 3, and a vacuum container 7 for introducing thereinto a process gas G to be turned into plasma by using the antenna 3 are provided. Electric currents opposite directed to each other flow through antenna pieces 3a radially neighboring each other of the antenna 3. An annular and magnetically neutral region is formed within the vacuum container 7 by an induction field caused by the antenna 3. The plasma generated within the vacuum container 7 is diffused toward the magnetically neutral region, thus forming the plasma into an annular shape within the vacuum container 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma generating apparatus and a plasma processing apparatus provided with the apparatus, and more particularly to performing fine processing, thin film formation, surface treatment, and the like on an object to be processed such as a semiconductor substrate or a disk substrate. And a plasma processing apparatus having the same.

[0002]

2. Description of the Related Art Conventionally, in a semiconductor manufacturing process, a disk manufacturing process, or the like, processes such as microfabrication of a substrate surface and formation of a thin film are performed using plasma generated by a plasma generator. In particular, in a semiconductor manufacturing process, a processing technique for a substrate surface using plasma is indispensable in order to achieve high integration of a semiconductor.

As described above, in a semiconductor manufacturing process, a disk manufacturing process, and the like, a plasma generator and a plasma processing apparatus including the plasma generator are widely used.

[0004]

However, in the conventional plasma generator and plasma processing apparatus, it has been difficult to generate plasma that can uniformly process the entire workpiece. In other words, the plasma generated by the conventional plasma generator has a higher density at the central portion than at the peripheral portion. The processing speed (for example, the etching speed or the film forming speed) of the part becomes higher than that of the peripheral part, and as a result, the in-plane uniformity of the processing deteriorates.

Therefore, in the case of a disk-shaped workpiece such as a semiconductor wafer, if a disk-shaped or annular plasma can be generated directly above the workpiece, the in-plane uniformity of the processing can be improved. it can.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a plasma generator capable of generating plasma capable of improving the in-plane uniformity of processing of an object to be processed and a plasma processing apparatus provided with the plasma generator.

[0007]

In order to solve the above-mentioned problems, a plasma generating apparatus according to the present invention comprises an antenna comprising a plurality of antenna pieces having different diameters arranged concentrically in the same plane; A high-frequency power supply for an antenna that supplies high-frequency power to the antenna, and a vacuum container into which a process gas that is turned into plasma using the antenna is introduced. The antenna pieces adjacent to each other in the radial direction of the antenna are connected to each other. Currents in different directions are caused to flow, and an annular magnetic neutral region is formed inside the vacuum vessel by the electromagnetic field induced by the antenna, and the plasma formed inside the vacuum vessel moves toward the magnetic neutral region. Diffusion, whereby an annular plasma is generated inside the vacuum vessel.

Preferably, the plurality of antenna pieces are electrically connected in series.

Each of the antenna pieces is formed by an annular member having one discontinuous portion, and at least one of both ends of the annular member in the discontinuous portion is formed in a radial direction of the antenna. In the above, it is preferable that the adjacent antenna pieces are connected to each other, whereby the plurality of antenna pieces are electrically connected in series.

Also, at least one of the plurality of antenna pieces is displaced from the same plane along the center axis direction of the antenna with respect to the other antenna pieces, thereby generating a plasma. Can also be controlled.

Further, the antenna further includes a Faraday shield extending along the direction in which the antenna piece extends, and an antenna impedance matching device for matching the impedance of the high-frequency power supply for the antenna, the antenna, and the impedance of the Faraday shield. Is preferred.

Further, it is preferable that the wavelength of the power supplied from the high frequency power supply for the antenna is at least １ ／ of the total length of the antenna.

It is preferable that the frequency of the power supplied from the high frequency power supply for an antenna is in the range of 1 kHz to 100 MHz.

In order to solve the above-mentioned problems, a plasma processing apparatus according to the present invention includes any one of the above-described plasma generators, and an object to be processed using the plasma is provided inside the vacuum vessel. Is provided with a processing table for mounting the.

Further, the processing table further includes an electrode high-frequency power supply for supplying high-frequency power to the electrode, and an electrode impedance matching device for matching the impedance of the electrode and the electrode high-frequency power supply. Preferably, it is provided.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a plasma generating apparatus according to an embodiment of the present invention and a plasma processing apparatus provided with the apparatus will be described with reference to the drawings.

FIG. 1 is a longitudinal sectional view of the plasma processing apparatus according to the present embodiment, and FIG. 2 is a view of the plasma processing apparatus shown in FIG. 1 as viewed from above.

As shown in FIGS. 1 and 2, the plasma generator includes an antenna 3 composed of a plurality of coil-shaped antenna pieces 3a having different diameters and arranged concentrically in the same plane. As shown in FIG. 2, each antenna piece 3a is formed by each annular member having one discontinuous portion 3b, and at least one of both ends of the annular member in the discontinuous portion 3b is The antenna pieces 3a adjacent to each other in the radial direction are connected by a communication antenna piece 3c, whereby the plurality of antenna pieces 3a are electrically connected in series.

The Faraday shields 4 extend concentrically along the extending direction of the antenna piece 3a, and each Faraday shield 4 is grounded. Although the Faraday shield 4 is effective in controlling the induced electromagnetic field pattern formed by each antenna piece 3a, the Faraday shield 4 is not essential in the present invention and can be omitted. .

The plasma generator according to the present embodiment includes an antenna high-frequency power supply 1 for supplying high-frequency power to the antenna 3. The antenna high-frequency power supply 1 is connected to one end of the antenna 3. The antenna 3
Is grounded at the other end. Further, an antenna impedance matching unit 2 for matching the impedances of the antenna high-frequency power supply 1, the antenna 3, and the Faraday shield 4 is provided between the antenna high-frequency power supply 1 and the antenna 3.

The plasma processing apparatus according to the present embodiment includes a vacuum vessel 7 into which a process gas G to which high-frequency power radiated from the antenna 3 is applied is introduced. It is sealed by an insulating plate 8. The antenna 3 and the Faraday shield 4 described above are arranged on the insulating plate 8.

Further, a gas inlet 5 for introducing the process gas G is formed on a side surface of the vacuum container 7, and a gas outlet 6 is formed on a bottom surface of the vacuum container 7.

Inside the vacuum vessel 7, there is provided a processing table 10 on which a disk-shaped object 9 to be processed using plasma is placed. The processing table 10 forms a lower electrode, and the lower electrode is connected to an electrode high-frequency power supply 11 for supplying high-frequency power. Between the processing table (lower electrode) 10 and the electrode high-frequency power supply 11, a processing table (lower electrode) 10 and an electrode high-frequency power supply 11 are provided.
Is provided with an electrode impedance matching device 12 for matching the impedance of the electrodes.

In the plasma generating apparatus according to the present embodiment, currents in different directions flow through the antenna pieces 3a adjacent to each other in the radial direction of the antenna 3. Specifically, when the current direction of the innermost antenna piece 3a is, for example, counterclockwise in FIG. 2, the current direction of the outer antenna piece 3a is clockwise, and the outer side is counterclockwise, and the outermost antenna piece 3a is counterclockwise. It is structured to be grounded at the end of the antenna piece 3a.

In the present embodiment, the antenna piece 3a of the antenna 3 has a total of three turns, but the number of turns is not limited to this, and the antenna piece 3a is a two-turn antenna piece in which currents flow in opposite directions. 3 or four or more turns.

In order to reduce the loss of energy supplied from the high frequency power supply for antenna 1 to the antenna 3,
It is preferable that the wavelength of the electric power supplied by the antenna high-frequency power supply 1 is at least １ ／ of the entire length of the antenna 3.

In order to stably obtain a desired plasma, the frequency of the electric power supplied by the high frequency power supply for antenna 1 is preferably in the range of 1 kHz to 100 MHz.

Next, the operation of the plasma generating apparatus according to the present embodiment and the plasma processing apparatus provided with the apparatus will be described.

The high-frequency power from the high-frequency power supply 1 for the antenna is supplied to the antenna 3 after being matched by the impedance matching device 2 for the antenna, and a high-frequency current flows through the antenna 3. Is formed.

As described above, currents in directions different from each other are caused to flow through the antenna pieces 3a adjacent to each other in the radial direction of the antenna 3 so that each antenna piece 3a
Vessel 7 by the induction electromagnetic field pattern formed by
An annular magnetic neutral region is formed inside the. For this reason,
The plasma generated inside the vacuum container 7 diffuses toward the annular magnetic neutral region, and as a result, an annular plasma is generated inside the vacuum container 7.

Here, the number of turns of the antenna pieces 3a, the interval between the antenna pieces 3a, the presence or absence of the Faraday shield 4 between the antenna pieces 3a, the width of the Faraday shield 4, the height of the Faraday shield 4, and the like are appropriately selected. By doing
By controlling the pattern of the induction electromagnetic field, a desired ring-shaped magnetic neutral region can be generated, and a desired ring-shaped plasma can be generated directly above the workpiece 9.

By applying high frequency power from the electrode high frequency power supply 11 to the processing table (lower electrode) 10,
The ions in the plasma can be attracted to the object 9 to promote physical sputtering.

As described above, according to the present embodiment, by generating a ring-shaped magnetic neutral region inside the vacuum vessel 7, a ring-shaped plasma is generated directly above the object 9 to be processed. Therefore, the in-plane uniformity of the processing of the workpiece 9 can be improved.

Further, as a modification of the present embodiment, at least one of the plurality of antenna pieces 3a is connected to the center axis O of the antenna 3 with respect to the other antenna pieces 3a (see FIG. 2).
), Thereby controlling the characteristics (position, shape, density, etc.) of the generated plasma.

[0035]

As described above, according to the present invention, by generating a ring-shaped magnetic neutral region inside a vacuum vessel, it is possible to generate a ring-shaped plasma directly above a workpiece. Therefore, the in-plane uniformity of the processing of the processing object can be improved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a plasma processing apparatus according to an embodiment of the present invention.

FIG. 2 is a view of the plasma processing apparatus shown in FIG. 1 as viewed from above.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 High frequency power supply for antennas 2 Impedance matching device for antennas 3 Antenna 3a Antenna piece 3b Discontinuous part 3c Communication antenna piece 4 Faraday shield 5 Gas inlet 6 Gas exhaust port 7 Vacuum container 8 Insulating plate 9 Workpiece 10 Electrode) 11 High frequency power supply for electrode 12 Impedance matching device for electrode G Process gas O Central axis of antenna

Claims (9)

[Claims] 1. An antenna comprising a plurality of antenna pieces having different diameters concentrically arranged in the same plane, a high-frequency power supply for an antenna for supplying high-frequency power to the antenna, and a plasma generated by using the antenna. A vacuum vessel into which a process gas is introduced. Currents in directions different from each other flow through the antenna pieces adjacent to each other in the radial direction of the antenna, and the inside of the vacuum vessel is induced by an electromagnetic field induced by the antenna. An annular magnetic neutral region is formed, and the plasma formed inside the vacuum container diffuses toward the magnetic neutral region, whereby an annular plasma is generated inside the vacuum container. A plasma generator characterized by the above-mentioned. 2. The plasma generator according to claim 1, wherein said plurality of antenna pieces are electrically connected in series. 3. Each of the antenna pieces is formed by an annular member having one discontinuous portion, and at least one of both end portions of the annular member in the discontinuous portion is formed in a radial direction of the antenna. 3. The plasma generating apparatus according to claim 2, wherein the plurality of antenna pieces are electrically connected in series by connecting the adjacent antenna pieces. 4. A plasma generated by displacing at least one of the plurality of antenna pieces with respect to the other antenna pieces from the same plane along a center axis direction of the antenna. The plasma generator according to any one of claims 1 to 3, wherein the characteristic is controlled. 5. A Faraday shield extending along an extending direction of the antenna piece, a high-frequency power supply for the antenna,
5. The antenna according to claim 1, further comprising an antenna impedance matching unit that matches impedance of the Faraday shield and the antenna.
The plasma generator according to any one of the above. 6. The antenna according to claim 1, wherein the wavelength of the power supplied from the antenna high-frequency power source is at least １ ／ of the total length of the antenna. 3. The plasma generator according to claim 1. 7. The plasma generator according to claim 1, wherein the frequency of the power supplied by the high frequency power supply for the antenna is in a range of 1 kHz to 100 MHz. 8. A plasma generator according to claim 1, wherein an object to be processed using said plasma is placed inside said vacuum vessel. Plasma processing apparatus provided with a processing table for processing. 9. The processing table further includes an electrode high-frequency power supply for supplying high-frequency power to the electrode, and an electrode impedance matching device for matching the impedance of the electrode and the electrode high-frequency power supply. The plasma processing apparatus according to claim 8, further comprising: