KR100793569B1 - Magnetron sputtering apparatus - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetron sputtering apparatus, comprising: a support located inside a chamber, a support on which a substrate is mounted, a target facing the substrate, a target made of a deposition material, plasma generating means for forming a plasma between the target and the substrate, and alternating the target A magnetic field generating means for forming a magnetic field, a power supply unit for supplying an alternating current to the magnetic field generating means, and a frequency converter for varying the magnitude and frequency of the alternating current. By controlling the magnitude and frequency of the alternating current to form a time-varying magnetic field of a specific frequency throughout the target, the density of plasma ions is increased, the sputtering efficiency is increased, and the deposition rate is improved. The entire surface of the target is consumed uniformly by the distribution.

Magnetron Sputtering, Electromagnets, AC Power, Frequency Converters, Targets

Description

Magnetron sputtering apparatus

1 is a configuration diagram for explaining a conventional magnetron sputtering device.

2 is a conceptual diagram for explaining a process in which deposition is performed in a conventional magnetron sputtering apparatus.

3 is a cross-sectional view of a heterogeneously consumed target.

4 is a block diagram for explaining a magnetron sputtering apparatus according to the present invention.

5A and 5B are plan views illustrating an embodiment of the magnetic field generating means shown in FIG.

6 is a graph showing the density change of plasma ions with a frequency change.

7 is a graph illustrating changes in etching ratio and etching uniformity due to an alternating magnetic field;

<Explanation of symbols for the main parts of the drawings>

10, 110: gas inlet 11, 111: chamber

12, 112: support 13, 113: target

14: permanent magnet 20, 120: substrate

130: power supply 140: frequency converter

150: magnetic field generating means 151: core

152: coil

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetron sputtering apparatus, and more particularly, to a magnetron sputtering apparatus having a high sputtering efficiency and capable of uniform consumption of the entire surface of a target.

In general, metal wires or electrodes are formed by a sputtering method in a process of manufacturing a semiconductor device or a light emitting device. The sputtering method forms a plasma under a target made of a deposition material and bombards the plasma ions with the target so that atoms of the target surface are separated by the energy to deposit a thin film. At this time, since the deposition rate of the thin film is proportional to the density of the plasma, a magnetic field is formed to increase the plasma density. This method is called a magnetron sputtering method.

FIG. 1 is a schematic configuration diagram of a conventional magnetron sputtering apparatus, in which a support 12 for supporting a substrate 20 is installed in a chamber 11 in which a gas injection hole 10 is formed, and is deposited on the support 12. A target 13 made of a material is installed, and a permanent magnet 14 for forming a magnetic field below the target 13 is installed above the target 13.

The substrate 20 is transferred into the chamber 11 and placed on the support 12, and then a predetermined voltage is applied between the target 13 and the substrate 20 and the chamber 11 is provided through the gas inlet 10. Supply process gas to the interior. Typically, when a negative voltage is applied to the target 13, electrons generated by the discharge collide with gas molecules to generate plasma below the target 13. That is, the process gas is ionized and excited in the plasma state by colliding with the gas molecules in the course of the electron movement.

As shown in FIG. 2, the generated plasma ions are subjected to a helical motion based on the direction of the magnetic field 30 formed in the direction perpendicular to the electric field under the target 13 by the permanent magnet 14. Since the time remaining near the target 13 becomes longer, the collision with gas molecules becomes frequent and the plasma density increases. Therefore, high-density plasma ions collide with the surface of the target 13, and the atoms of the surface of the target 13 are separated by the collision energy, and a thin film is deposited on the substrate 20.

In the conventional magnetron sputtering device configured as described above, magnetic force lines are distributed according to the shape and position of the permanent magnet 14, and the shape and the position of the permanent magnet 14 are fixed, so that the trace of the magnetic force line is constant and the density is high. Since only sputtering is continuously performed, the target 13 is not uniformly consumed as shown in part A of FIG. 3, and the thickness of the deposited thin film is also nonuniform. This problem is more severe in processes using large area substrates. In addition, since the magnetic force of the permanent magnet 14 decreases with time, the magnitude of the magnetic field is reduced and the deposition rate is reduced.

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetron sputtering device in which a target is uniformly consumed by an alternating magnetic field.

Another object of the present invention is to provide a magnetron sputtering device capable of maximizing sputtering efficiency by adjusting the magnitude and frequency of alternating current.

Magnetron sputtering apparatus according to an aspect of the present invention for achieving the above object is a chamber, a support located in the chamber and the substrate is mounted, a target positioned opposite to the substrate and made of a deposition material, the target and the substrate Plasma generating means for forming a plasma therebetween, magnetic field generating means for forming an alternating magnetic field in said target, a power supply for supplying alternating current to said magnetic field generating means, and a frequency converter for varying the magnitude and frequency of said alternating current; do.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are provided to those skilled in the art to fully understand the present invention, and may be modified in various forms, and the scope of the present invention is limited to the embodiments described below. no.

4 is a schematic diagram of a magnetron sputtering apparatus according to a preferred embodiment of the present invention.

A support 112 for supporting the substrate 120 is installed in the chamber 111 in which the gas injection hole 110 is formed, and a target 113 made of a deposition material such as a metal or an insulator is installed on the support 112. The upper portion of the target 113 is provided with a magnetic field generating means 150 for forming an alternating magnetic field on one surface of the target 113. The target 113 and the substrate 120 are supplied with direct current or alternating current power from a power supply unit (not shown) for plasma generation, and the magnetic field generating unit 150 is supplied with an alternating current from the power supply unit 130. 140 may adjust the magnitude and frequency of the alternating current.

The magnetic field generating means 150 includes a coil or a core configured to allow an alternating magnetic field to be uniformly distributed throughout the target 113 by an alternating current, and an electromagnet composed of a coil. As an example, as shown in FIG. 5A, the coil 152 is wound around the core 151 having a plate or cylindrical shape having a size greater than or equal to the target 113 so as to overlap the target 113. The coil 152 flows an alternating current supplied from the power supply unit 130. Alternatively, as shown in FIG. 5B, a plurality of coils 152 are wound around the core 151 at predetermined intervals, and each coil 152 is provided with an alternating current supplied from each power supply unit 130. Flows.

Next, a process of depositing a metal in the magnetron sputtering apparatus of the present invention configured as described above will be described.

First, a target 113 made of a metal or an insulating material such as aluminum (Al) is prepared. The substrate 120 is transferred into the chamber 111 and positioned on the support 112, and then a predetermined voltage is applied between the target 113 and the substrate 120 and the chamber 111 is provided through the gas injection hole 110. ) Supplies process gas such as argon (Ar) or oxygen (O). When a negative voltage is applied to the target 113, electrons generated by the discharge collide with gas molecules to form a plasma under the target 113. That is, the process gas is ionized and excited in the plasma state by colliding with the gas molecules in the course of the electron movement.

The plasma ions generated as described above undergo a spiral motion around the direction of the magnetic field formed in the direction perpendicular to the electric field under the target 113. As a result, the time remaining near the target 113 becomes longer due to the spiral motion. As a result, collisions with gas molecules are frequently increased, thereby further increasing plasma density. Therefore, high-density plasma ions collide with the surface of the target 113, and many atoms of the surface of the target 113 are separated by the collision energy to deposit a thin film on the substrate 120.

When the thin film is deposited on the substrate 120 through the above process, an alternating magnetic field, that is, a time-varying magnetic field of a specific frequency, is formed by the magnetic field generating means 150 around the target 113. In addition, since the direction of the magnetic field changes at regular intervals, the rotation and movement of electrons are further accelerated according to the change of the magnetic field, thereby increasing the density of plasma ions. In addition, since the alternating magnetic field is formed to surround the entire target 113, the entire surface of the target 113 is uniformly consumed by the high density plasma ions.

For example, the alternating current supplied from the power supply unit 130 by the frequency converter 140 may be adjusted in a range of about 1 to 10A, and the frequency may be adjusted in a range of about 20 to 200 Hz. As described above, the density of plasma ions may be maximized at a frequency of about 80 Hz in an oxygen (O) gas atmosphere, and the density of plasma ions may be maximized at a frequency of about 40 Hz in an argon (Ar) gas atmosphere. Therefore, depending on the type of target and the process gas, while maximizing the density of plasma ions within the frequency range of 40 to 170Hz, the entire surface of the target 113 can be uniformly consumed by the high density plasma ions.

The control of the magnitude and frequency of the alternating current by the frequency converter 140 includes a technique that improves the etching rate by increasing the density of plasma ions using an alternating magnetic field in an inductively coupled plasma (ICP) etching apparatus. It can be easily adjusted to maximize the sputtering efficiency (O. Beom-hoan et al., "The magnetization frequency dependence of enhanced inductively coupled plasma", Surface and Coating Technology 146-47 (2001) 528-531 , Beom-hoam O et al., "Improvement of ICP plasma with periodic control of axial magnetic field", Surface and Coating Technology 120-131 (1999) 752-756).

Referring to FIG. 7, in the case of increasing the density of plasma ions using an alternating magnetic field in an inductively coupled plasma (ICP) etching apparatus, an etch rate is compared with a case in which DC power (0 Hz) is applied or a magnetic field is not formed. And it can be seen that the etching uniformity (uniformity) can be greatly improved. Therefore, even in the case of sputter deposition for etching the target to be deposited, the deposition rate of the thin film can be improved by the high etching ratio and the etching uniformity, and the consumption of the target can be made uniform.

As described above, the preferred embodiment of the present invention has been disclosed through the detailed description and the drawings. The terms are used only for the purpose of describing the present invention and are not used to limit the scope of the present invention as defined in the meaning or claims. Therefore, those skilled in the art will understand that various modifications and equivalent other embodiments are possible from this. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

As described above, the present invention adjusts the magnitude and frequency of the alternating current to form a time-varying magnetic field of a specific frequency throughout the target to increase the density of plasma ions, thereby increasing the sputtering efficiency, thereby improving the deposition rate, and increasing the uniformity of the magnetic field. Since the entire surface of the target is uniformly consumed by the distribution, the manufacturing cost can be reduced.

Claims (9)

chamber; A support positioned in the chamber and on which a substrate is mounted; A target positioned opposite the substrate and made of a deposition material; Plasma generating means for forming a plasma between the target and the substrate; And a magnetic field generating means, comprising a core positioned to overlap the target and a coil wound around the core, wherein an alternating magnetic field is formed in the target by an alternating current supplied to the coil. The magnetron sputtering apparatus of claim 1, wherein the plasma generating unit comprises a power supply unit for applying a negative voltage to the target. delete delete delete The magnetron sputtering apparatus of claim 1, wherein the coil is formed of a plurality of coils wound at regular intervals. The magnetron sputtering apparatus according to claim 1, further comprising a power supply unit supplying the alternating current to the coil of the magnetic field generating means. 8. The magnetron sputtering apparatus of claim 7, further comprising a frequency converter for varying the magnitude and frequency of the alternating current. 9. The magnetron sputtering apparatus according to claim 8, wherein the alternating current is adjusted in the range of 1 to 10 A, and the frequency is varied in the range of 20 to 200 Hz.

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