JPS62142764A - Method for regulating film thickness during magnetron sputtering - Google Patents

Abstract

PURPOSE:To facilitate film thickness regulating operation by changing the intensity and distribution of a magnetic field formed in a space near a target set in a vacuum vessel with a magnet placed at the outside of the vessel so as to regulate the thickness of a thin film formed on a substrate. CONSTITUTION:A magnet 17 is placed at the outside of a vacuum vessel 2 and a magnetic field is formed in a space near a target 12 set in the vessel 2. The intensity and distribution of the magnetic field are changed by changing the distance between the magnet 17 and the target 12 and the position of the magnet 17. Thus, the thickness distribution of a thin film formed on a substrate 13 is regulated.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application This invention relates to a film thickness adjustment method for uniformly adjusting the film thickness distribution of a thin film formed on a substrate in magnetron sputtering.

(b) Conventional technology Magnetron sputtering is a method in which a magnetic field is formed in the space near a target such as aluminum placed in a vacuum container, and a plasma of argon gas or the like sealed in the vacuum container is confined within the magnetic field. Positive ions of the inert gas from the plasma collide with the target surface, causing atoms on the target surface to fly out, and depositing these atoms on a substrate provided in the vacuum container to face the target. This process forms a thin film.

Conventionally, as a method of forming a magnetic field in the space near the target, a permanent magnet or electromagnet is attached and fixed to the back of the target if the target also serves as a cathode, or to the back of the cathode if the target is attached to the surface of the cathode. Was.

(C) Problems to be Solved by the Invention In the conventional magnetron sputtering described above, when the thickness distribution of the thin film formed on the substrate is not uniform due to differences in target materials, etc., the distance between the target and the substrate is We made adjustments to obtain a uniform film thickness distribution, but
Since the target and substrate are located in a vacuum container,
The Lfi had the disadvantage that the adjustment process was difficult and time-consuming.

The present invention was made in view of the above-mentioned disadvantages, and an object of the present invention is to provide a film thickness adjustment method in magtron sputtering, which allows easy adjustment of the film thickness distribution of a thin film formed on a substrate.

(d) Means for Solving the Problems As a means for solving the above-mentioned disadvantages, the film F (adjustment method) in magnetron sputtering of the present invention is to form a magnetic field in the space from the target layer 1 placed in a vacuum container to the nearby space. A magnet is provided outside the vacuum vessel, and the distance between the magnet and the target and the attitude of the magnet with respect to the target are changed to change the strength and distribution of the magnetic field generated in the space near the target.

(e) Effect The film thickness adjustment method in magnetron sputtering of the present invention is based on the density distribution of plasma such as argon gas confined in this magnetic field by changing the intensity and distribution of the magnetic field formed in the space near the target. By changing the plasma, positive ions such as argon gas collide with the target surface to control the number of target atoms without flying out, and adjust the thickness distribution of the η11 film formed on the substrate to be uniform. It is something to do. At this time, the magnet is in the vacuum field 2)
:Since it is provided outside, the operation for adjusting the film thickness can be done easily.

(f) Embodiment An embodiment of this invention is shown in FIGS. 1, 2, and 3 (al.
, FIG. 3 fbl and FIG. 3 fc), the following explanation will be given.

FIG. 1 is a longitudinal sectional view of a planar magnetron sputtering apparatus 1 to which the film thickness adjustment method of the present invention is applied. 2 is a vacuum container constructed by placing a Pelger 3 on a flat base 4. A pipe 5 connected to a vacuum pump (not shown) is inserted from below into the base 4, and the vacuum container 2
The air inside is evacuated and a high vacuum is maintained. Also, base 4
An opening 6 is provided for medium heat.

The opening 6 is closed from below by the upper surface of the cathode 9 via an insulator 7a made of fluororesin or the like. The cathode 9 has its lower surface attached to the lower surface of the base 4 with bolts 7c, 7.
It is supported by L-shaped insulators 7b, 7b made of fluororesin or the like and fixed at c. This cathode 0 is connected to the other pole of a DC or high frequency voltage source (1), one pole of which is grounded.

A recess 10 is provided on the upper surface of the cathode 9, and a backing plate 1 is provided to seal the four parts IO.
covered by 1. Cooling water W is circulated in the four parts 1O by a circulation means (not shown). Said Huff-1
A target 12 made of an aluminum plate or the like is fixed on the ring brake 1-11. Further, a shield 8 is provided along the upper edge of the opening 6 to shield the upper surface of the cup F9 and the periphery of the backing plate If.

On both sides of the target 124, a substrate 13 on which a thin film is to be formed is supported by support means (not shown) so as to face the surface of the target 12, and a ground or bias voltage is applied by appropriate means. .

From both sides of the bottom of the cathode 9 are L-shaped stays 14.
．． 14 are installed vertically. Stay 14. Horizontal part 1 of the lower end of 14
Push screws 16.16 are screwed into 4a and 14a, respectively. A magnet 17 for forming a magnetic field in the space near the 1i force target 12 is mounted on the upper end of the push screw 16, 16.

As shown in FIG. 2, the magnet 17 includes a magnet piece 19a made of a rod-shaped permanent magnet at the center of a flat magnet support plate 18.
is attached so that one pole is on the top surface, and on the other hand, a magnet piece 1 made of a frame-shaped permanent magnet is attached to the periphery of the lower surface of the magnet support plate 18.
9b is attached so that the pole opposite to the pole of the upper surface of the magnet piece 19a is the upper surface.

On the lower surface of the magnet support plate 18, the tips of the fixed poles 1-15, . Female screw holes 18a for screwing into each...
, 18a are provided at the four corners.

Next, an example of the use of this planar magneto apparatus will be described below.

First, move the Pelger 3 upward, turn off the vacuum container 2, set the target 12 on the banking plate 11, and place the substrate 13 with the side on which you want to form a thin film facing down.
is supported by support means (not shown).

Next, the Pel jar 3 is moved down to seal the vacuum container 2,
The air inside the vacuum container 2 is exhausted from the vibrator 5 to create a high vacuum state. Then, argon gas or the like is injected by an injection means (not shown) (the pressure of the argon gas or the like in the vacuum container 2 after injection is lO-' to lO-'torr (appropriate)).

Continuing the explanation below using argon as an example, the substrate 13
A direct current or high frequency voltage (for example, 5kv) is applied between the voltage source
(hereinafter referred to as e-) and electrons (hereinafter referred to as e-).

Parts of A, e, and e- are captured by the magnetic field formed by the magnet 17 in the space near the targera 1-12, and move in a cycloid.

At this time, Ar' and e- collide with unionized argon molecules, and as a result, Ar' and e- are multiplied, and a high-density plasma is generated in the space near the target 12. When Ar' collides with the surface of the target 12, surface atoms (for example, aluminum atoms) of the target 12 fly upward, are captured and deposited on the lower surface of the substrate 13, and a W film is formed.

The film thickness adjustment operation for making the film thickness distribution of the thin film formed between the substrates I33 constant is first performed by tightening the fixing screws 15, . . .
..., loosen 15, rotate set screws 16 and 16,
Adjust the height and the inclination around the X axis in Figure 2. Next, when tightening the fixing screws 15, . . . , 15, adjust the amount of screwing in, set the inclination of the magnet 17 around the Y axis, and fix it.

When the magnet 17 is brought close to the target 12, the target 1
As a result, the magnetic field formed in the 2-neighborhood space becomes stronger and the density of the generated plasma becomes higher. As a result, the film thickness distribution of the thin film formed on the lower surface of the substrate 13 along the center line y-y of the lower surface of the substrate 13 is as shown in FIG. (As shown in al, the maximum film thickness value is taken at the position corresponding to the gap G between the poles on the upper surfaces of the magnet pieces 19a and 19b.

On the other hand, when the magnet 17 is moved away from the target 12, the magnetic field formed in the space near the target 12 becomes weaker, and the density of the generated plasma decreases. As shown in FIG. 3(b), the film thickness distribution along y-y is represented by a curve that takes a maximum at the center.

Therefore, the magnet 17 is placed at an appropriate distance from the target 12.
By locating this, it becomes possible to make the film thickness distribution of the thin film formed on the lower surface of the substrate 13 uniform. In addition, if the film j7 is biased to one side only due to the difference in the material and shape of the target 12 [see Fig. 3 (see C1]), the magnet 17 is tilted to correspond to the part where the film thickness is large on the lower surface of the substrate 13. By increasing the distance between the target section 1-12 and the magnet 17, the film thickness distribution can be adjusted to be uniform.

Note that the planar magnetron sputtering device 1 in the above embodiment is the most basic device for manufacturing a single item, but
In order to enable continuous processing of large quantities of substrates, we have developed automated equipment that is equipped with a loading means for loading unprocessed substrates into a vacuum container and a loading means for transporting substrates on which thin films have been formed out of the vacuum chamber. The method for adjusting the membrane 17 of the present invention can also be applied.

Furthermore, in the above embodiment, an example in which the present invention is applied to a planar magnetron sputtering apparatus is shown.
The present invention is also applicable to other types of magnetron sputtering devices such as -Gun sputtering devices.

(G) Effects of the Invention The method of adjusting the film thickness 311 in magnetron sputtering of the present invention includes providing a magnet outside the vacuum container that forms a magnetic field in a space near a target placed in a vacuum container, and forming a gap between the magnet and the target. distance and 11; change the attitude of the magnet i with respect to the target, change the intensity and distribution of the magnetic field generated in the space near the target, and place the substrate at a position facing the target in the vacuum container; Since it adjusts the thickness distribution of the thin 11A film formed on the substrate, there is no need to adjust the distance 1ijt between the substrate and the target inside the vacuum chamber, and the distance between the W film on the substrate from outside the vacuum chamber can be adjusted. Adjustment of film thickness distribution Since 1 mulberry cultivation is possible, 11 glJ
This has the advantage that adjustment operations are easy.

In addition, even if the thin 119 distribution on the substrate is biased to one side, the attitude of the magnet with respect to the target can be changed (
It also has the advantage that the film thickness distribution can be easily adjusted to be uniform by moving the magnet relative to the target.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a planar magnet 1-ron sputtering device used in an embodiment of the present invention, FIG. 2 is a partially enlarged perspective view showing the magnet of the same device and its mounting state, and FIG.
FIG. 3(a), FIG. 3(tb), and FIG. 3(C) are diagrams for explaining the film thickness distribution of a thin film formed on a substrate by the same apparatus. 2; Vacuum container, 12: Target, I3: Substrate,
17: Magnet. Patent applicant ROHM Co., Ltd. agent
Patent Attorney Shigeru Nakamura Figure 1 Figure 2 Figure 3 ((7) Figure 3 (b) Figure 3 (C)

Claims (1)

[Claims] (1) A magnet that forms a magnetic field in a space near a target placed in a vacuum container is provided outside the vacuum container, and the distance between the magnet and the target and the attitude of the magnet with respect to the target are changed, and the distance between the magnet and the target is changed. A film thickness adjustment method in magnetron sputtering, which adjusts the film thickness distribution of a thin film formed on a substrate placed in a position facing the target in the vacuum container by changing the strength and distribution of a magnetic field generated in space.