JPH0372072A - Earth shielding structure of sputtering device - Google Patents

Abstract

PURPOSE:To provide the above earth sealing structure which prevents the collision of diagonal incident ions and uniformizes target erosion by forming a shielding body to a cylindrical body having a deep depth and constituting the shielding body so as to overhang highly from a target surface. CONSTITUTION:The target 1 is disposed to face the substrate apart a prescribed distance therefrom and, for example, the long cylindrical shielding body 10 is so provided as to dispose the target 1 at the deep end of the cylinder. The cylindrical front end 10a of the shielding body 10 overhangs long from the target surface 1a and the better effect is obtd. if the height (d)(cm) thereof is set at d>=10<-2>/P of the pressure P (Torr) at the time of film production. Since the shielding body is made to overhang highly from the target surface according to the above-mentioned earth shielding structure, the above mentioned effect is exhibited and the improvement in a sputtering rate and target utilizing efficiency is attained. In addition, a uniform film thickness is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a sputtering apparatus, and particularly to the structure of an earth shield placed around a target in a cathode section.

(Prior art) For example, in the sputtering method used to produce alloy films and magnetic films on substrates, an earth shield is installed around the target in order to stabilize the discharge from the target, which is the film raw material. The sides of the shield are surrounded by the shield. FIG. 3 is a schematic diagram of a conventional conventional sputtering apparatus. ``iii. A target l, which is a film material, and a substrate 2 on which a film is to be formed are placed in a container 3 so as to face each other, and connected to the power supply circuit 4 so that the target 1 is used as a cathode and the substrate 2 is used as an anode. A shield body 5 is installed around the target 1 and a shank 6 is provided between the target 1 and the substrate 2.The container 3 has an inlet 7 and a svanta gas inlet 8 for creating a negative pressure inside the container.
This is provided. Argon gas is generally used as the spanner gas.

9 is a substrate holder. Due to the negative voltage of target 1,
Argon ions of the introduced argon gas are attracted to the target surface 1a, and the collision causes the target material to fly out from the target 1 and adhere to the substrate surface 2a.

In such sputtering equipment, the conventional earth shield structure has a target ladle l-
1 and the end surface 5a of the shield body 5.
Is it approximately the same height as the target surface La?
Alternatively, as shown in FIG. 4(b), target 1 part 1b
The shield body 5 had a shallow concave shape extending slightly around the target surface 1a, and the height h of the shield body 5 was not much different from the surface height of the target 1.

(Problems to be Solved by the Invention) As mentioned above, in the conventional earth shield structure, the height of the target surface and the tip of the shield body are approximately the same, or are only raised to the extent that the periphery of the target surface is slightly hidden. Therefore, collisions of obliquely incident ions cannot be prevented, and erosion of the target surface cannot be made uniform during film fabrication. As shown in Figure 5, the area around the target surface 1a is locally sputtered as shown by symbol A, and it must be replaced with a new target immediately.Furthermore, the film thickness on the substrate 2 tends to be uneven, so the film thickness rate is also used. There was a problem that it changed over time. 4th
In the case of Fig. 4), the target 1 is slightly hidden by the shield body 5, so although the local erosion is somewhat alleviated compared to Fig. 4(a), the same phenomenon still occurs.

(Means for Solving Problem 41) Therefore, the present invention has a shield body having a deep cylindrical shape and protruding high from the target surface to prevent obliquely incident ions from colliding with the target. - Uniform erosion.

This is an attempt to improve target utilization efficiency.

That is, the earth shield structure of the sputtering apparatus according to the present invention is characterized in that the shield body surrounding the outer part of the target is formed into a deep cylindrical shape, and the distance from the target surface to the cylindrical tip of the shield body is increased. That is.

According to one form of the present invention, the cylindrical inner surface of the shield body is formed in a tapered shape so that the cylindrical tip opening of the shield body becomes narrow.

(Example) Next, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic side sectional view of an earth shield structure according to a first embodiment of the present invention. As explained in FIG. 3, the target layer 1-1 faces the substrate 2 (FIG. 3) on which the metal film is to be applied, separated by a predetermined distance, and the shield body 10 is provided around it. In this embodiment, the shield body 10 has a long cylindrical shape, and a targera 1 is disposed at the rear end of the cylinder. The cylinder tip 10a of the shield body 10 protrudes from the target surface 1a, and its height d (CI
) is d≧1 for the pressure P (Torr) during membrane preparation.
It is effective to set it to 0-''/P.

FIG. 2 is a side sectional view of an earth shield structure showing a second embodiment of the present invention. Shield body 11 of this embodiment
It has a long cylindrical shape as a whole, and the target blade 1 is installed on its real end (base end side), which is the same as the example in Figure 1, but the inner peripheral surface of the cylinder Ilb is tube tip @ L
It is tapered so that the diameter gradually becomes smaller toward the opening of La.

The taper angle θ depends on the pressure during film formation, but is approximately 0° to 30'
range is appropriate.

To explain the film production operation using the sputtering apparatus of the present invention, first, the inside of the container containing the target and substrate is evacuated to about 10-' Torr, and then argon gas is introduced to bring the temperature to 10-2 to 10-' Torr. First, a voltage is applied to the target layer 1 surrounded by the cylindrical shield body 10 or the tapered shield body 11. In the container, argon is converted to Ar・+e−, and argon ion Ar”
is attracted to the target 1 and collides with it, and the target material (particles) is ejected from the target surface 1a by the impact and impinges on and adheres to the substrate 2 on the anode side (see FIG. 3).

In the present invention, since the target is deeply covered with the cylindrical shield body 10, it is possible to prevent etching of the target by obliquely incident ions, thereby making the erosion on the target surface uniform, as shown in FIG. As such, almost the entire surface except the outer peripheral portion 1b is subject to erosion equally. In the embodiment shown in FIG. 2, since the inner surface of the shield body 11 is tapered, the target 7) 1 is covered more deeply within the tapered portion of the shield body 11, compared to the case of FIG. Although the sputtering rate is slightly lower, more uniform erosion can be obtained.

(Effects of the Invention) As explained above, according to the present invention, since the shield body is formed into a cylindrical shape so as to protrude high from the surface of the target, the entire target is deeply covered by the shield body, and the oblique This has the effect of preventing incident ions, making the erosion of the target surface uniform, improving the sputtering rate, improving the target utilization efficiency, and obtaining a uniform film thickness.

[Brief explanation of drawings]

FIG. 1 is a side sectional view of the earth shield structure according to the first embodiment of the present invention, FIG. 2 is a side sectional view of the second embodiment of the present invention, and FIG. 3 is a schematic diagram of a general sputtering apparatus. , FIG. 4(a), Φ) are side sectional views showing various examples of earth shield structures in conventional sputtering equipment, FIG. 5 is a sectional view showing conventional target erosion states, and FIG. FIG. 3 is a cross-sectional view showing a target erosion state. 1...Target, 1a...Target surface, tb
...Target side part, 2...Substrate, 5.10.11
...Shield body, 10a, lla...Tip of cylinder, llb...Inner peripheral surface.

Claims (2)

[Claims] (1). An earth shield structure for a sputtering device, characterized in that a shield body surrounding the outer part of a target is formed into a deep cylindrical shape, and the distance from the sputtering surface of the target to the cylindrical tip of the shield body is long. (2). 2. The earth shield structure for a sputtering apparatus according to claim 1, wherein the cylindrical inner surface of the shield body is formed into a tapered shape so that the cylindrical tip opening of the shield body becomes narrow.