JPS6376867A - Reactive sputtering device - Google Patents

Abstract

PURPOSE:To activate a reactive gas and to execute sputtering with high reactivity by introducing the reactive gas through an electron cyclotron resonance ionization device into a vacuum vessel at the time of sputtering. CONSTITUTION:The electron cyclotron resonance ionization device (ECR ionization device) 2 is mounted to the center of a substrate 3 of a sputtering device or the position of targets 1. While the targets 1 in the vacuum vessel A are sputtered, reactive ions are supplied from the ECR ionization device 2 to form the reaction product on the substrate 3 or in the vessel A. Said product is deposited on the substrate 3. The threshold of the intensity at which microwave and electron cyclotron frequencies coincide is generated at the center of the ionization part 2 by an electromagnet 4 at this time. The reactive gas is satisfactorily activated by charging of the relatively low-power microwaves by the above-mentioned mechanism.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a reactive sputtering apparatus. Specifically, the present invention relates to a sputtering apparatus in which a reactive gas such as nitrogen gas or oxygen gas is introduced into a vacuum chamber of the sputtering apparatus, and sputtering is performed while causing a desired reaction.

[Conventional technology]

Reactive sputtering, reactive ion blating, and the like are conventionally known methods for producing thin films of tinides, oxides, and the like.

In reactive sputtering, tinides and oxides are usually produced by mixing a gas to be reacted, such as N2.02, into an inert gas for sputtering, or by using these gases as a discharge gas.

[Problem that the invention seeks to solve]

The problem with the above-mentioned method of reactive sputtering is that due to insufficient activation of N2 and O2 during sputtering, nitrogen and oxygen are not sufficiently introduced into the film, resulting in the formation of advanced oxides and nitrides. There was a problem with not being able to get things.

For example, when trying to form a film of Nb-N, which is attracting attention as a superconducting material, the bonding ratio of Nb and N is /:
The current situation is that the critical temperature is lower than the theoretical value.

Another adverse effect of the reactive gas being difficult to activate is the 02 (0) emitted from the vacuum chamber and substrate during sputtering.
Since the amount of the gas is not sufficient for activation compared to N20, OH, and OH, these gases may be mixed into the film in addition to N-bonds and O-bonds.

Another problem is that if the reaction gas is not activated sufficiently, the deposition rate must be slowed down in order to obtain a nitride film or oxide film close to stoichiometry.

Therefore, a method has been proposed in which, for example, in addition to the sputtering discharge, a microwave discharge is added to thereby activate the reactive gas to solve these problems.

However, it cannot be said that even microwave discharge is sufficient to activate the gas, and a large amount of microwaves must be applied to achieve sufficient activation.

Therefore, in order to solve the above-mentioned difficulties, the present inventor discovered that it is possible to efficiently produce a high-quality thin film by combining an electron cyclotron resonance (FC!R) ionization device with a sputtering device. , arrived at the present invention.

That is, the gist of the present invention is that, in a reactive sputtering apparatus that performs sputtering by introducing a reactive gas into a vacuum chamber, the reactive gas is introduced into the vacuum chamber through an electron cyclotron resonance ionization device installed in the vacuum chamber. A reactive sputtering apparatus is characterized in that it has a structure in which:

[Means for solving problems]

The present invention will be explained in detail below.

FIG. 2 shows a case where an EOR ionization device is incorporated into a sputtering device.

That is, an ECR ionization device is installed at the center of the substrate of a normal sputtering device (Figure 2) or at the target position (Figure 2).

The target sputtering method is normal RF sputtering,
DC sputtering and magnetron sputtering are used. First, to perform reactive sputtering, sputter the target (1) in the vacuum chamber (A) while using the ECR ionization device (2).
) supplies reactive ions (Nζ, N+, etc.). In this way, reactants are formed on the substrate (3) or in the vacuum chamber (A) and deposited on the substrate.

In the figure, (4) is an evening magnet for generating a critical force at the center of the ionization section (2) with a strength that matches the microwave and electron sarcroton frequencies, (5) is a reactant gas inlet, and (6) is a microwave waveguide.

In the case of the apparatus shown in figure 2, it is not necessarily necessary to rotate the substrate, but in the case of figure 2, it is necessary to rotate the substrate at an appropriate speed.

As the ECR ionization device, an ionization device of a CVD device or an eleching device equipped with a commercially available EOR ionization device can be used.

When ECR is used to activate a gas, electrons placed in a magnetic field have an angular velocity mc! m: mass of electron, C: speed of light) and magnetic force,
[(7) Rotate instead of t. When the cyclotron motion of the electrons matches this frequency, the electrons are efficiently accelerated and obtain a kinetic energy component in the direction perpendicular to the magnetic field. This magnetic field also suppresses the diffusion of electrons across the magnetic field. For example, when there are few electron/ion collisions or electron/neutron collisions (low pressure), the typical diffusion length is 2πυ/K, where the velocity of the electron in the direction across the magnetic field is τ. Therefore, in KCR, electrons with high density and heated with high humidity can be obtained.

Since it is easy to obtain activated electrons in this way, a gas with a high activation probability of collision between electrons and neutral atoms and ionization of neutral atoms can be obtained.

According to this apparatus, it is possible to suitably perform surface treatment (surface titration, etc.) on the produced thin film, for example, to form a protective film. That is, after forming the thin film, in the case shown in the figure, the ionization device is placed directly above the ECR ionization device, and then ECR ions are supplied.

In this device, a preferred embodiment can be provided by further making the device in-line.

This in-line device is a sputtering device in which a large number of sputtering chambers are connected in a vacuum state, and each sputtering chamber can perform film formation or surface treatment of different materials.

For example, it is suitable for (1) forming a dielectric layer on a substrate and further providing a citrus recording layer, (11) providing protection of titanium, etc. + tK on a magnetic recording layer, and further providing a dielectric layer. It is.

〔Effect of the invention〕

The apparatus according to the present invention provides a highly reactive sputtering method and has the following features.

By using an EOR ionization device as an activation source for a reactive gas that reacts with the deposition gas or sputtered atoms in the vacuum chamber or on the substrate, relatively low power (≦/KW) can be achieved.
The reaction gas can be sufficiently activated by applying microwaves.

Moreover, this discharge can be stably caused.

[Brief explanation of the drawing]

7(a), (b) and FIGS. 7(a) and 7(b) schematically show the main parts of the vacuum evaporation apparatus according to the present invention. /: Target, , 2: ECR ionization unit 3: Substrate, A: Vacuum chamber (sputtering device) Applicant: Mitsubishi Chemical Industries, Ltd. Agent Patent attorney Hase - (7 others)

Claims (1)

[Claims] (1) In a reactive sputtering device that performs sputtering by introducing a reactive gas into a vacuum chamber, the reactive gas is introduced into the vacuum chamber through an electron cyclotron resonance ionization device installed in the vacuum chamber. A reactive sputtering device featuring: