JPS61272373A - Sputtering device - Google Patents

Abstract

PURPOSE:To reduce the effect of a magnetron magnetic filed on a substrate and to obtain a magnetic substance film having excellent uniaxial anisotropy by providing a thin grooved part on the surface of a target. CONSTITUTION:A magnetron magnetic filed is generated by a magnet 8 on the front surface of a target 7 to obtain locally high-density plasma and the particles sputtered by the plasma are deposited on a substrate 14 to form a thin film. At this time, a thin grooved part 17 is provided on the inside of the magnet 8 of the target 7. Consequently, the part is saturated with magnetic flux, a part of a clockwise magnetic line of force 16 is leaked into the space, a counterclockwise magnetic line of force 16' is pushed to the left in the figure and the effect of the magnetron magnetic field on the substrate 14 is reduced as shown by the chain line. By this constitution, a magnetic field having excellent parallelism can be impressed on the substrate 14 and a magnetic substance film having excellent uniaxial anisotropy can be obtained.

Description

[Detailed description of the invention] [Field of application of the invention] The present invention relates to a sputtering apparatus.

[Background of the Invention] Sputtering is known as one of the methods for thinning various materials. In particular, Brehner-type magnetroton sputtering equipment, which uses a permanent magnet or electromagnet behind the target to generate a plasma confinement magnetic field, is well known, with the aim of increasing the speed of film production or improving the quality of the produced film by increasing the vacuum. For example, JP-A-58-199861), on the other hand, for the purpose of imparting uniaxial anisotropy to the produced film when sputtering a magnetic material.

A method of applying a magnetic field to a film-forming substrate is also disclosed in Japanese Patent Application Laid-Open No. 58-2547.
It is known as 5th grade. However, according to these methods.

A radial magnetic field is applied, and permanent magnets are placed parallel to both ends of the substrate, which makes it impossible to obtain isotropic uniaxial anisotropy.

Alternatively, this problem can be avoided by using a magnetic field generating means such as a large-diameter magnetic field generating coil or an electromagnet, but the following new problem arises. That is, the magnetron magnetic field generated in front of the target is generally on the order of several hundred Gauss, whereas the magnetic field applied to the substrate is on the order of several tens of Gauss. Therefore, the influence of the target magnetic field on the substrate-side magnetic field is large, and the parallelism of the applied magnetic field is disturbed. Although it is possible to reduce the influence of the target magnetic field by increasing the strength of the substrate-side magnetic field, this would conversely disturb the target magnetic field strength, causing a bias in the plasma density distribution.

[Purpose of the invention]

An object of the present invention is to provide a structure in a magnetron type sputtering apparatus that can apply a highly parallel magnetic field onto a substrate with less influence of the magnetron magnetic field.

(Summary of the Invention) In order to achieve the above object, the present invention reduces the thickness of the inner part of the target than the second lotion part to suppress the influence of the magnetron magnetic field on the substrate side.

[Embodiments of the invention]

An embodiment of the present invention will be explained below. In the cross-sectional view of FIG. 1, a target section 2 and a substrate section 3 are arranged within a vacuum vessel 1. The inside of the vacuum container 1 is exhausted from an exhaust port 5 by an exhaust device (not shown).

After evacuating to an ultra-high vacuum of usually around 10'' Torr,
A desired gas, such as Ar gas, is supplied through the air supply port 4 through a gas supply system (not shown) while controlling the flow rate to maintain a constant atmospheric gas pressure inside the vacuum vessel 1. Target 7 kept insulated from 1
, a permanent magnet 8, an iron core 9 that provides a return path for the magnetic flux emitted from the permanent magnet 8, a container 10 that houses them, and a vacuum container 1.
It consists of an earth shield 11 having the same potential as .

The substrate section 3 includes a substrate holder 13 held insulated from the vacuum device 1 by a fiber, a substrate 14, and a magnet 15 that applies a parallel magnetic field to the substrate 14. Electrically, vacuum capacity I
II is normally set at ground potential, and a negative potential power source is connected to the target to supply power capable of maintaining glow discharge. High frequency power sources are also often used depending on the purpose. Although the substrate portion 3 is at ground potential here, it may be connected to a negative potential of several tens of volts or a high frequency voltage for purposes such as bias sputtering.

As a result, glow discharge occurs between the target section 2 and the substrate section 3, and plasma is generated. At this time, a remagnetron magnetic field is generated in front of the target by the permanent magnet 8, and high-density plasma is generated locally. Electromagnets are often used instead of permanent magnets, and the sputtered particles adhere to the substrate 14 to form a thin film.

Here, when forming a magnetic thin film having -axis anisotropy,
In order to make the magnetic anisotropy uniform, it is necessary to arrange the magnets 15 in advance and apply a uniform magnetic field parallel to the substrate surface. At this time, as mentioned earlier, the key point in the design is to eliminate the influence of the plasma confinement magnetic field generated in front of the target 7. This is the second ri! This effect will be explained by comparing the magnetic field mapping results of the prior art shown in I and the example according to the present invention shown in FIG.

Generally, the target shape is often used as a symmetrical shape such as a circle or a rectangle. In this case, only half of the target shape is shown in the figure because the mapping result is also the target.

Although the case of an axially symmetrical circular target is shown here, the results here have a qualitatively similar tendency for targets such as rectangles. In FIG. 3, the key point of the present invention is that a thin wall portion 17 is provided in a portion of the target 7 corresponding to the inside of the magnet 8', so that the magnetic flux is saturated in this portion so that the clockwise magnetic lines of force partially leak into the space. This is what I did.

As a result.

The counterclockwise magnetic field lines 16' are pushed to the left, as can be seen from the comparison with FIG.
The effect on the parts is small. Cutting shape in the center 17
As shown in Figure 4, the effect is the same even if it is installed on the vacuum side.
This is more suitable when used by pasting it on a backing plate.

As shown in FIG. 5, the same effect can be obtained by machining the groove shape 17, which is convenient when machining a fixing screw in the center part. ' and two surrounding lotion parts 7'. As a result, only the peripheral erosion part 71 that is subject to severe wear can be replaced, which increases the economic efficiency of maintenance with respect to the wear and tear of the target 7.

〔Effect of the invention〕

As described above, according to the present invention, since the influence of the magnetron magnetic field on the substrate can be reduced, it is possible to apply a magnetic field with good parallelism to the substrate, and - to obtain a magnetic film with good axial anisotropy. There is an effect that can be done.

Brief Description of the Drawings FIG. 1 is a sectional view of an embodiment of the sputtering apparatus of the present invention, and FIG.
The figure is a cross-sectional view of the main part showing the magnetic field distribution of the configuration according to the conventional technology, FIG. 3 is a cross-sectional view of the main part showing the magnetic field component of the structure of FIG.
FIG. 4, FIG. 5, and FIG. 6 are sectional views of the target portion inside the vacuum chamber of other embodiments of the sputtering apparatus of the present invention.

1... Container, 7... Target, 14... Substrate.

Claims (1)

[Claims] 1. At least a container kept airtight, a target made of a pair of film forming materials held in the container, and a substrate on which a film is to be formed, the target having means for generating magnetic flux on its front surface. 1. A sputtering apparatus comprising means capable of applying a magnetic field substantially parallel to the substrate surface, wherein a groove-shaped thin section is provided on the target surface inside the magnetic flux generating means.