KR20010098215A - Counter Target Sputtering Device - Google Patents

Abstract

The present invention relates to a thin film deposition apparatus using an opposing target sputtering method, wherein the crystallinity is reduced even under a gas pressure of 0.1 to several tens of mTorr while minimizing damage to the film due to substrate collision of particles having high energy generated during thin film deposition. It is an apparatus which can produce this favorable film | membrane at high speed. The present invention also relates to a counter target sputtering (FTS) device capable of depositing a thin film of a magnetic target at a low substrate temperature.

Description

Opposing Targeted Sputtering Device {.}

1) In the opposite target sputtering apparatus, as shown in FIG. 1, two targets are disposed to face each other. In addition, as shown in FIG. 2, the permanent magnet is disposed on the back of the target so that the magnetic field is distributed perpendicularly to the target surface. A negative potential is applied to both targets, and a ground potential is applied to the potential of the chamber and the substrate. Therefore, while inducing rotational movement of γ-electrons, one target becomes a reflective electrode of γ-electrons emitted from the opposite target, and γ-electrons reciprocate between two targets. Since the γ-electrons between the targets reciprocate and rotate, the ionization rate of the atmospheric gas is higher than that of other sputtering apparatuses, so that high density plasma can be formed and stable discharge even at low gas pressure (0.1 mTorr).

2) The magnetic field generated by the permanent magnets mounted on the back of the two targets is applied in a direction perpendicular to the target surface and not parallel. In other words, if the magnetic field applied from one target is the N pole, the magnetic field generated from the other target is the S pole, so that the target is a high-speed sputter of all materials without being magnetic or non-magnetic.

4) The two targets shown in FIG. 1 can be moved up and down to adjust the strength of the magnetic field between the targets. In addition, the substrate holder supporting the substrate can also be moved back and forth between the two target centers, thereby changing the position of the substrate.

5) Since the arrangement of the substrate is in a state spaced apart from the plasma (plasma-free), it is possible to suppress the substrate collision of the particles with high energy generated during sputtering as much as possible. Thus, not only γ-electrons but also substrate collisions of particles with high energy due to negative ions are completely eliminated. For this reason, not only the problem of damage to the substrate and the deviation of the composition is overcome, but also a film having extremely good crystallinity can be produced.

In the opposite target sputtering apparatus, a high density plasma can be generated even at a low discharge gas pressure of 0.1 mTorr which is 1 mTorr or less, and a film deposition rate of several thousand kW can be easily achieved for 1 minute. In addition, it has a strong adhesion between the substrate and the thin film, and has a high deposition rate, so it is suitable for mass production of thin films. Accordingly, an object of the present application is to explain that it is possible to deposit a thin film at a higher speed, a lower temperature, and a lower pressure than a conventional device in manufacturing a thin film using a sputtering device. In the future, we intend to promote the sputtering technology.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to deposition of a thin film using a sputtering method, and more particularly, to a counter-target sputtering apparatus having a structure in which two targets face each other and a substrate is spaced apart from a plasma.

The conventional magnetron sputtering method has a position of a substrate and an arrangement of permanent magnets on the back of the target as shown in FIG. When the target and the substrate face each other and a high voltage is applied to the target and the substrate, a discharge phenomenon occurs and sputtered particles emitted from the target are deposited on the substrate. At this time, the collision of the substrate with high energy particles (neutron, cation, electron, etc.) can be suppressed to some extent by the permanent magnet on the back of the target, but the particles emitted from the target corresponding to the center of the magnet, that is, the pole part, cannot be suppressed. do. Therefore, the substrate surface corresponding to this portion has a locally high temperature, making it difficult to obtain a good film. In addition, as shown in FIG. 5, when the target is a magnetic material, the generation of a magnetic field due to a permanent magnet is suppressed (the magnetic target forms a magnetic path, which makes it difficult to form a magnetic field outside of the target). Therefore, a problem arises in that high-density plasma and high-speed deposition cannot be performed.

With the advancement of the thin film manufacturing technology by the sputtering method, the sputtering method has been used in a wide range of fields including the semiconductor industry. However, many problems remain to be solved, such as the realization of high-speed and low-temperature sputtering of ferromagnetic materials and the removal of substrate shocks by negative ions emitted from the target.

An object of the present invention is to solve such a problem, it is possible to suppress the damage of the thin film deposited on the substrate because the position of the substrate does not face the target, high vacuum state (0.1mTorr) for the production of high purity thin film ) Is a development of sputtering device that can produce thin film by maximizing ionization rate by reciprocating rotational movement of γ-electron and maintaining stable discharge.

1 is a schematic diagram of an opposing target sputtering apparatus;

Figure 2 is a target layout of the opposed target sputtering device

3 is a magnetic field distribution diagram of a magnetron sputtering device

4 is a magnetic field distribution diagram of a counter target sputtering apparatus;

5 is a magnetic field distribution in the case of a ferromagnetic target

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 1 and FIG. 2, the two targets are in positions facing each other. Atmospheric gas Ar (or O ₂ ) is injected into the chamber, and when a direct current (-) potential is applied to both targets, a local discharge is formed between the target and the shield ring. As such, when an initial local discharge occurs after the voltage is applied, ionization of the gas injected into the chamber is promoted between the targets, thereby generating a plasma in the form of a discharge between the two targets. Such plasma is composed of γ-electrons, anions, cations and the like.

At this time, γ-electron plays a major role in ionizing the injection gas. In the opposite target sputtering apparatus, since γ-electrons reciprocally rotate between targets, even when oxygen gas having a lower ionization rate than Ar gas is used as the injection gas, it has a higher deposition rate than the conventional sputtering apparatus.

Therefore, even in the case of depositing a thin film using oxygen gas, that is, reactive sputtering, a high deposition rate can be regarded as a suitable method for implementing counter production.

In the case of the conventional sputtering method in which the substrate faces the target, the negative ions collide with the thin film deposited on the substrate to cause fatal damage. Thus, the negative ions are shown in FIG. As shown, permanent magnets were placed on the back of the target to suppress substrate collision between γ-electrons and anions. In addition, γ-electrons are constrained by the leakage magnetic field formed on the target surface to increase the ionization rate of the atmospheric gas in the vicinity of the target, thereby forming a high density plasma. However, as shown in FIG. 3, the γ-electrons in the pole center of the permanent magnet are not trapped by the leakage magnetic field formed on the target surface but collide with the substrate with a high energy corresponding to the voltage applied to the target. There is no change in damage.

Therefore, in order to solve such a problem, a high density plasma is formed and a thin film is manufactured while the position of the substrate does not face the target. As shown in FIG. 4, damage to the film may be reduced by maximally suppressing substrate collision of particles having high energy generated during thin film deposition by not facing the target of the substrate.

5 illustrates a case of using a magnetic target. In the case of the conventional magnetron sputtering device, a leakage magnetic field outside the target is not formed, and thus the discharge itself is difficult. However, in the case of the opposing target sputtering apparatus, even when using a magnetic target, as shown in FIG. 5, a high-density plasma can be formed to realize a high deposition rate.

As described above, the opposite target type sputtering apparatus has a high deposition rate because of the damage of the thin film deposited due to the substrate collision of the particles with high energy, which is a problem in the conventional sputtering method, and the difficulty of thin film deposition using the magnetic target. It is expected to make a significant contribution to the field of industry, academia and research that uses thin film deposition using sputtering.

Claims (3)

Place two targets facing each other Permanent magnet on the back of each target (Target 1 is N pole target 2 is S pole) Placement of the substrate spaced from the center between two targets