JP2000273628A - Sputtering method and apparatus - Google Patents

Abstract

(57) [Problem] To provide a sputtering method and an apparatus for obtaining a required film thickness distribution and film thickness uniformity when forming a substrate. SOLUTION: An electromagnet 5 arranged on the back surface of a target 3
Height of the center yoke 7 (position with respect to the target 3)
Is made variable using the driving device 13. With this configuration, the height of the central yoke 7 of the electromagnet 5 is adjusted so that the target 3
By controlling the distribution of lines of magnetic force formed on the surface of the substrate, the film thickness distribution can be controlled, the required film thickness distribution and film thickness uniformity can be obtained, and the substrate 4 having the required film thickness distribution can be obtained. be able to.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a sputtering method, and more particularly to a method for controlling a film thickness distribution during film formation.

[0002]

2. Description of the Related Art A magnetron sputtering technique is widely used as a technique for forming a thin film on a substrate. The magnetron sputtering technology repels sputtered particles from the target by colliding ions in the plasma generated near the target with the target,
The particles are attached to a substrate to form a thin film. The magnetron sputtering technique is capable of generating high-density plasma and performing high-speed film formation, and is therefore the mainstream of the current thin film forming method.

An outline of a conventional sputtering apparatus will be described with reference to FIG. In FIG. 4, reference numeral 1 denotes a vacuum vessel (vacuum processing chamber) having an exhaust unit connected to a vacuum pump. In the vacuum vessel 1, a target 3 as a film forming material and a substrate 4 as a film forming material face each other. It is arranged. A sputtering gas (for example,
(Argon gas) is introduced, and a DC or high-frequency voltage is applied to the cathode electrode 2 disposed on the back surface of the target 3 to generate plasma between the substrate 4 and the cathode unit 2 (target 3). . The argon ions in the plasma are accelerated by the electric field and collide with the target 3, and the target material jumps into the vacuum in an atomic state,
These atoms adhere to the substrate 4 to form a thin film.

[0004] An electromagnet 5 is disposed on the inner and outer sides of the target 3 and includes a center yoke (magnetic pole) 7 and an outer yoke (magnetic pole) 8 having different polarities, and a coil for passing a DC current. Is provided. This electromagnet 5
Electrons jumped out of the target 3 and accelerated by the magnetic field 6 and electrons existing in the plasma are confined near the surface of the target 3 and move according to the lines of magnetic force to generate high-density plasma, thereby increasing the film forming speed. I have.

[0005] The shape of the magnetic field 6 by the electromagnet 5 conventionally used for film formation is controlled by the shape of the magnet.

[0006]

However, when film formation is continued using one target 3, the shape of the target 3 changes due to sputtering, and the target shape changes from the initial use of the target to the life of the target. Accordingly, the film thickness distribution of the substrate 4 to be formed changes. As a result, there was a problem that the uniformity of the film thickness, which was good at the initial stage of using the target, changes with the lapse of time due to the use of the target.

An object of the present invention is to obtain a required film thickness distribution and film thickness uniformity when forming a substrate in such a sputtering method and its apparatus.

[0008]

According to the sputtering method of the present invention, a film-forming material and a film-forming material are arranged in a sputtering gas so as to face each other, and a plasma is formed between the film-forming material and the film-forming material. And forming a magnetic field on the surface of the film-forming material to form a thin film of the film-forming material on the surface of the film-forming material, wherein the shape of the magnetic field formed on the surface of the film-forming material Is adjusted with time, thereby controlling the film thickness distribution at the time of film formation.

According to the present invention, a material for forming a film (substrate)
When forming a film, a sputtering method for obtaining a required film thickness distribution and film thickness uniformity can be obtained.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the first aspect of the present invention, a film-forming material and a film-forming material are arranged in a sputtering gas so as to face each other, and a space between the film-forming material and the film-forming material is provided. To generate plasma, and further form a magnetic field on the surface of the film-forming material,
A sputtering method for forming a thin film made of a film-forming material on a surface of a film-forming material, wherein the shape of a magnetic field formed on the surface of the film-forming material is adjusted with time to form a film thickness distribution during film formation. When forming a film-forming material (substrate), a required film thickness distribution and film thickness uniformity can be obtained, and a substrate having a required film thickness distribution can be obtained. It has the effect of being able to.

According to a second aspect of the present invention, in the first aspect of the invention, the shape of the magnetic field is adjusted by adjusting the line of magnetic force to be higher or lower than the surface of the film-forming material. The required film thickness distribution and film thickness uniformity can be obtained by controlling the magnetic field line distribution by making the magnetic field lines higher or lower than the surface of the film forming material. Having.

[0012] According to a third aspect of the present invention, in the vacuum vessel,
The film-forming material and the film-forming material are arranged to face each other, a sputtering gas is introduced into the vacuum vessel, and a voltage is applied to the electrode arranged on the back of the film-forming material. A central yoke and a peripheral yoke with different polarities arranged on the outside,
And a sputtering device for forming a magnetic field on the surface of the film-forming material by an electromagnet constituted by a coil for flowing a direct current, comprising a mechanism for adjusting a position of a center yoke of the electromagnet with respect to the film-forming material. By adjusting the position of the center yoke of the electromagnet with respect to the film-forming material to adjust the shape of the line of magnetic force to control the distribution of the lines of magnetic force, by controlling the distribution of the lines of magnetic force,
This has the effect that the required film thickness distribution and film thickness uniformity can be obtained.

Hereinafter, a sputtering method and an apparatus according to an embodiment of the present invention will be described with reference to the drawings. The same components as those of the conventional example shown in FIG. 4 are denoted by the same reference numerals, and description thereof is omitted. FIG. 1 is a vertical sectional front view showing a schematic configuration of a sputtering apparatus for realizing a sputtering method according to an embodiment of the present invention.

The sputtering apparatus of the present invention is newly
There is provided a yoke height adjustment mechanism that can freely adjust the height of the electromagnet center yoke (the position with respect to the film forming material) on the back surface of the target using a driving device installed in the atmosphere. That is, the electromagnet 5 on the back of the target 3 is placed in the atmosphere, the central yoke 7 is fixed to the tip of the ball screw 11,
The end of the ball screw 11 is fixed to the timing pulley 12, and the timing pulley 12 is connected to the driving device 13 and the belt 14.
Connected. Reference numeral 15 denotes a ball bush configured to circulate the balls of the ball screw 11. The center yoke 7 is sealed between the atmosphere and the vacuum by an oil seal 16 or the like.

In this yoke height adjusting mechanism, the height can be adjusted by driving the driving device 13 in the atmosphere to move the center yoke 7 back and forth. FIG.
7 shows the shape of the magnetic field 6 when the center yoke 7 is moved back and forth. As shown in the figure, when the center yoke 7 is advanced (increased), the magnetic lines of force (magnetic lines from the inner periphery) generated from the center yoke 7 become higher than the target 3,
When the central yoke 7 is retracted (lowered), the lines of magnetic force generated from the central yoke 7 decrease.

The yoke height adjustment mechanism adjusts the height by moving the center yoke 7 back and forth, so that the magnetic force lines generated from the center yoke 7 (magnetic lines from the inner periphery) are applied to the target 3.
By making the height higher or lower, the shape of the magnetic field of the electromagnet 5 formed on the surface of the target 3 can be adjusted, and a required magnetic field line distribution can be obtained. FIG.
The tendency of the radial thickness distribution according to the height t of the central yoke 7 is shown in FIG.

As the inner peripheral portion of the line of magnetic force increases, the thickness of the inner peripheral portion of the film forming substrate 4 tends to increase. In accordance with these trends, the yoke height adjusting mechanism adjusts the height of the yoke 7 at the center of the electromagnet to cope with the temporal change in the film thickness distribution with the temporal change in the film thickness. The substrate 4 formed by controlling the magnetic field line distribution can obtain the required film thickness distribution and film thickness uniformity.

In the above embodiment, the center yoke 7 is configured to be movable back and forth.
Can also be changed back and forth. With this configuration, the distribution of the lines of magnetic force can be changed in more detail.

[0019]

As described above, according to the present invention, by adjusting the shape of the magnetic field formed on the surface of the film forming material,
The film thickness distribution can be controlled, the required film thickness distribution and the required film thickness uniformity can be obtained, and an advantageous effect that a film-forming material having the required film thickness distribution can be obtained can be obtained.

[Brief description of the drawings]

FIG. 1 is a vertical sectional front view showing a schematic configuration of a sputtering apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a film thickness distribution control method / magnetic field shape control method using the sputtering apparatus.

FIG. 3 is a diagram showing a change in radial thickness distribution with respect to a center yoke height in a sputtering apparatus.

FIG. 4 is a vertical sectional front view showing a schematic configuration of a conventional sputtering apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vacuum container 2 Cathode electrode 3 Target 4 Substrate 5 Electromagnet 6 Magnetic field 7 Central yoke 8 Outer peripheral yoke 11 Ball screw 12 Timing pulley 13 Drive device 14 Belt 15 Ball bush 16 Oil seal

Continuing from the front page (72) Inventor Isamu Aokura 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. 4K029 CA05 DC41 EA01

Claims (3)

[Claims] 1. A film-forming material and a film-forming material are arranged in a sputtering gas so as to face each other, a plasma is generated between the film-forming material and the film-forming material, and a magnetic field is applied to the surface of the film-forming material. And forming a thin film of the film-forming material on the surface of the film-forming material, wherein the shape of the magnetic field formed on the surface of the film-forming material is adjusted with time, and A sputtering method characterized by controlling the film thickness distribution in the above. 2. The sputtering method according to claim 1, wherein the shape of the magnetic field is adjusted by adjusting the lines of magnetic force to be higher or lower than the surface of the film-forming material. 3. A film-forming material and a film-forming material are arranged opposite to each other in a vacuum vessel, and a sputtering gas is introduced into the vacuum vessel.
A voltage is applied to the electrode arranged on the back surface of the film forming material,
A sputtering apparatus for forming a magnetic field on the surface of a film-forming material by an electromagnet including a center yoke and an outer peripheral yoke having different polarities disposed inside and outside a back surface of the film-forming material, and a coil for passing a direct current. And a mechanism for adjusting a position of a center yoke of the electromagnet with respect to the film forming material.