JPH0978234A - Sputtering device and its method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the characteristics of the films formed by sputtering and the uniformity of the characteristics and to simultaneously improve productivity. SOLUTION: Pallets 1, 2 having the prescribed curvature for holding substrates 3 to be formed with the desired films are constituted by curving these pallets. The substrates are so held that the segments connecting a sputtering target 4 and the central points of the substrates 3 is kept within 70 to 90 deg. with the substrate surface. The films are formed by revolving and rotating or rotating and revolving, etc., the pallets 1, 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film forming technique, and more particularly to a sputtering apparatus for forming a magnetic thin film or a ferroelectric film and a forming method thereof.

[0002]

2. Description of the Related Art A sputtering method is relatively simpler than a CVD method or a vacuum evaporation method, and a large amount of film can be formed.
Further, it is a low temperature process as compared with the CVD method, and its composition can be easily controlled when forming a compound or the like as compared with the vapor deposition method, and it has excellent homogeneity such as film thickness distribution and step coverage characteristics. Therefore, it is widely used industrially.

This sputtering method is a method in which sputtered particles are blown from a target and applied to an opposing substrate to form a thin film of a desired substance on the substrate. The substrate is mounted on a predetermined pallet, and the pallet is revolved. It is advantageous to form the film while allowing it to have higher uniformity and productivity than the stationary film formation. However, in the auto-revolution film forming method used in the conventional sputtering apparatus, a flat plate is used as the pallet for mounting the substrate, and the flat plate pallet is rotated and revolved to form a film.

By the way, recently, in the field of magnetic heads, a laminate head has been attracting attention in place of a metal-in-gap (MIG) head, and Fe-Zr-N, Fe-Ta-N and the like used for these have been noticed. A high-quality and inexpensive manufacturing technique for magnetic thin films is desired. These Fe
A thin film such as -Zr-N has been formed by a sputtering method at a laboratory level or in a small-scale production scale.

[0005]

However, the fact that there was no problem in the conventional small-volume production has become clear in the mass production stage. That is, according to the conventional sputtering method using a flat-plate pallet, the larger the pallet for depositing a large amount of thin film at a time, the larger the number of substrates that can be mounted at one time, but the incident angle of sputtered particles. Becomes shallow. If the incident angle becomes shallow, the Fe-
The disadvantages such as anisotropy in a thin film such as Zr-N or a partial decrease in density and deterioration of soft magnetic properties are caused by these F
It has become clear at the stage of mass production of films such as e-Zr-N. On the other hand, if the pallet is made small in order not to make the incident angle shallow, the number of substrates to be mounted becomes small, the productivity is lowered, and there is a problem that it is not suitable for mass production. Further, the present inventors have also investigated the problem that the substrates mounted at different distances from the center of revolution or rotation have different incident angles and cause variations in physical properties such as magnetic permeability μ ^−. Has become clearer.

As a concrete example, Fe-Z for magnetic heads
When a soft magnetic film such as r-N or Fe-Ta-N is formed, a portion with a small incident angle becomes a component whose coercive force is not small. The sputtering means causes the coercive force of the entire film not to become small. For example, after heat treatment of a sample A having a Fe-Zr-N film formed thereon and a sample B having a substrate made to face each other at an incident angle of 90 degrees by a conventional sputtering apparatus having a flat substrate mounting pallet, When the magnetic permeability μ ⁻ is compared, the sample A is 1500 in all directions, and the sample B is 2000 and 500.
It has been clarified by the experiments of the present inventor that variations in the characteristics that the directions of (1) appear. Further, the coercive force in this case was 40 [Oe] in Sample A, and it became clear that there was no soft magnetism. On the other hand, there is a method of providing a shielding plate so that a portion having a small incident angle is not formed, but this is not preferable because it impairs productivity. It is said that the incident angle is limited by vapor deposition.
Sputtering has a larger energy of particles adhering to the substrate and better adhesion than vapor deposition, while in the vapor deposition method, Fe,
Since the vapor pressures of Zr and N are also different, it may be difficult to control their composition. Due to the difference in the physical structure such as the crystal structure and magnetic permeability, the film formation by sputtering cannot be supplemented by vapor deposition. In particular, sputtering film formation is indispensable for forming a soft magnetic film.

In order to solve the above problems, the present invention provides
By improving the geometrical arrangement of the pallet that orbits the substrate in the sputtering apparatus or revolving the substrate and keeping the angle of incidence of sputtered particles on the substrate deep, Fe-Zr-
By improving the uniformity of characteristics such as the film thickness, magnetic permeability, and dielectric constant of magnetic thin films such as N, Fe-Ta-N and ferroelectric films, and by forming films on a large number of substrates at once. , Aim to improve productivity.

[0008]

To achieve the above object, the first feature of the present invention is to provide a curved rotating pallet as shown in FIGS. More specifically, the angle formed by the line segment connecting the arbitrary point on the substrate 3 for forming a desired film and the arbitrary point on the sputter emission surface of the sputtering targets 4, 41, 42 and the substrate surface is , 70
A rotating pallet 1, 11, 12, having a radius of curvature that allows the substrate 3 to be mounted within 90 °
2, 21-27. Preferably, as shown in FIG. 1, the rotating pallet is a rotating pallet 2 and a revolution pallet 1 having substantially the same radius of curvature, and the rotating pallet 2 is attached to the revolution pallet 1. However, as shown in FIG. 2, only the revolution pallet can be used as shown in FIG.
Alternatively, a sputtering apparatus having only a rotating pallet as shown in FIG.

With this structure, the sputtered particles are always incident on the surface of the substrate at a deep incident angle in the range of 70 to 90 °, and adhere to and deposit on the surface of the substrate. The film formation rate and the physical properties of the film for each substrate placed at different positions on the pallet become constant and uniform, and the film formation rate within and between the substrates becomes uniform, and the magnetic permeability, etc. Also improves the film quality. Therefore, it is possible to form a thin film having high uniformity and improved characteristics on a large number of substrates by one-time sputtering, and Fe-Zr-N,
Mass production of magnetic thin films such as Fe-Ta-N, which has been difficult to mass-produce in the past, becomes possible.

The second feature of the present invention is to use a curved rotating pallet as shown in FIGS. 1 to 4 so that the sputtered particles emitted from the sputtering targets 4, 41 and 42 are always directed to the surface of the substrate 3. This is a film forming method by sputtering in which the incident particles are arranged so as to be incident at an angle of 70 to 90 ° and the sputtered particles are attached to the surface of the substrate 3 while rotating the substrate 3 around a predetermined rotation axis. That is, a second feature of the present invention is a sputtering method for mass production, in which sputtered particles are always incident on the surface of a large number of substrates at a vertical angle of about 70 ° to approximately 70 °. Is what you are doing. More specifically, as shown in FIG. 2, the line segment connecting the center points of the sputter emission surfaces of the sputtering targets 41 and 42 and the center point of the substrate 3 for depositing sputtered particles is the surface of the substrate 3. This is a method in which the radius of curvature of the revolution pallet 5 on which the substrate 3 is mounted is set so as to be within 70 to 90 ° and sputtering is performed while revolving the revolution pallets 11 and 12 to form a desired thin film on the substrate 3. It is characterized by

Further, another feature of the sputtering method of the present invention is that, as shown in FIG. 1, a line connecting the center point of the sputter emission surface of the sputtering target 4 and the center point of the substrate 3 for depositing sputtered particles. The radius of curvature and the arrangement of the rotating pallet 2 on which the substrate 3 is mounted are set so that the distance is within 70 to 90 ° with respect to the surface of the substrate 3, and the rotating pallet has the same radius of curvature as that of this rotating pallet. That is, the desired thin film is formed on the substrate 3 while being attached to the revolutionary pallet 1 and revolving the substrate 3 on its own axis.

With this structure, the sputtered particles are always incident on the substrate surface at a deep incident angle in the range of 70 to 90 °, and are deposited and deposited on the substrate surface. The film forming rate and the physical characteristics of the film for each substrate placed inside and on different positions of the pallet become constant, and the film forming rate within the substrate and between the substrates becomes uniform. Further, physical properties such as magnetic permeability are also improved. Therefore, it is possible to form a thin film having high uniformity and improved characteristics on a large number of substrates by one-time sputtering, which enables mass production.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an arrangement of pallets and targets in a chamber of a sputtering apparatus according to the first embodiment of the present invention. Figure 1 shows Fe-Z
The structure in the case of forming an r-N film is shown as follows: Fe-Zr-N
A substrate 3 on which a film is to be formed is attached to a rotating pallet 2 having a radius of 100 mm, and the rotating pallet 2 is attached to each of the revolution pallets 1. The revolution pallet 1 and the rotation pallet 2 are curved with the same radius of curvature.
The orbital pallet 1 is sized so that the curved surface of the orbital pallet 1 is cut at a central angle of 120 degrees, and the orbital pallet 1 has a predetermined circumference. Further, eight rotation pallets 2 are attached at substantially equal intervals. The Fe-Zr target 4 was opposed to the revolution pallet 1 and the rotation pallet 2 as shown in FIG. With the configuration of the apparatus shown in FIG. 1, the incident angle of sputtered particles from the Fe—Zr target 4 to the substrate 3 is always 9
0 degree is kept. 1 x 1 vacuum chamber containing these
A vacuum of 0 ^-5 Pa is drawn, Ar + N ₂ gas is introduced so that the partial pressure of nitrogen is 20% and the total gas pressure is 0.7 Pa.
The Fe-Zr target 4 was sputtered at 500 W. After pre-sputtering for 10 minutes, substrate revolution speed 30
~ 80 rpm, rotation speed 100-150 rpm, Fe-
Distance between Zr target 4 and substrate T / S = 100 mm, sputter rate 0.1 μm / min, 2 μm
Fe-Zr-N film was formed on a substrate of non-magnetic oxide or the like with a thickness of. After further heat treating this film in vacuum at 570 ° C.,
The magnetic properties were evaluated. Membrane permeability measured at 8-shaped coil mu ^- is isotropic at approximately 4000 to all the in-plane direction, the saturation magnetostriction constant was measured by optical lever method 2 × 10 ^-7 about, B-H The coercive force measured by a loop tracer was a soft magnetism of about 0.

On the other hand, as described in the prior art, the Fe-Zr- film formed under the same conditions as the first embodiment of the present invention by the conventional sputtering apparatus in which the substrate mounting pallet is a flat surface. Fe film made of N film (Sample A) and the substrate stationary facing each other at an incident angle of 90 degrees
Characteristics after heat treatment -N film (Sample B), the magnetic permeability mu ^- is,
Sample A has a small value of 1500 in all directions, and sample B has 2000 directions and 500 directions. Sputtering according to the first embodiment of the present invention has much better uniformity of characteristics. I understand. Further, according to the conventional sputtering apparatus, the coercive force was 40 [Oe], which was not soft magnetic in Sample A. However, according to the first embodiment of the present invention, the coercive force is surely made soft magnetic. It can be an extremely small value that can be regarded.

FIG. 2 is a diagram for explaining the second embodiment of the present invention. In FIG. 2, the revolution pallets 11 and 12
Has a diameter of 150 mm and has a donut-like continuous shape that becomes a part of a spherical surface having a radius of 90 mm. The Fe-Ta target 4 has a revolution mechanism.
It is possible to freely move between the position A facing 1 and the position B facing the SiO ₂ target 42. The revolution pallet at the position A is called the revolution pallet 12, and the Fe-Ta target 41 is arranged at the center position of the spherical surface including the revolution pallet 12. Also, position B
The orbital pallet in the above condition is referred to as the orbital pallet 11, and the SiO ₂ targets 42 are placed at the center positions of the spherical surfaces including the orbital pallet 11. In FIG. 2, the substrate 3 is directly attached to the revolution pallets 11 and 12. The vacuum chamber containing these is evacuated to a pressure of 1 × 10 ⁻⁵ Pa, Ar gas is introduced so as to have a pressure of 0.7 Pa, and SiO ₂ is first deposited at a position B. Revolution pallet 11
Revolves at an orbital speed of 30 to 80 rpm, the sputter rate is 0.005 μm / min, and DC2 is 0.02 at 800 W.
A μm film was formed. Next, with the vacuum chamber as it is, the revolution pallet 11 is moved to the position A to form the revolution pallet 12, and the Ar + N ₂ gas has a nitrogen partial pressure of 25% and a total pressure of 0.6 Pa.
Then, the Fe-Ta target 41 was subjected to nitrogen reaction sputtering, and the Fe-Ta-N film was formed on the SiO ₂ film while revolving at a revolution speed of 30 to 80 rpm. The sputtering conditions are RF 500 W and a sputtering rate of 0.2 μm / min. The film was formed to a film thickness of 2.2 μm. After the film formation, the gas flow was stopped, the vacuum chamber was evacuated to a pressure of 5 × 10 ⁻⁴ Pa, the revolution pallet 12 was moved to the position B again, and the revolution pallet 11 was obtained. Then, Ar was introduced so as to have a pressure of 0.7 Pa, and Fe-Ta was introduced.
SiO ₂ was formed on the −N film. The revolution pallet 11 is revolved at a revolution speed of 30 to 80 rpm and the sputter rate is 0.005 μm / min and DC2 is 0.02 μ at 800 W.
m was formed into a film. In this way, the Fe-Ta film formed according to the second embodiment of the present invention and having both ends sandwiched by SiO ₂ films is formed.
As for the -N film, after the heat treatment in vacuum at 570 ° C., its characteristics were measured, and as a result, similarly to the first embodiment of the present invention, it was magnetically isotropic and the saturation magnetostriction constant was about 2 × 10 ⁻⁷ . The soft magnetic film has a magnetic force of about 0.

In FIG. 2, the case where the substrate 3 is directly attached to the revolution pallet has been described.
Needless to say, it may be revolved around as in the above embodiment. FIG. 3 shows a modification of the second embodiment of the present invention, which is a rotation pallet 21 attached to the revolution pallet 11 (12).
The substrate was attached to (22), the SiO ₂ film was formed while revolving at position B, and the Fe− film was revolving at position A while revolving.
A Ta-N film can be formed. With the configuration shown in FIG. 3, a soft magnetic film that is more homogeneous and has a large magnetic permeability μ ⁻ can be obtained.

The gist of the present invention is that the line segment connecting the center point of the sputter emission surface of the sputter target and the center line of the substrate is
Keep the temperature within 70-90 ° C with the surface of the substrate,
The film is formed while rotating the substrate around a predetermined rotation axis to improve the physical properties and homogenize the material formed by sputtering. Therefore, any method other than the revolution and the self-revolution as shown in FIGS. 1 to 3 may be used as long as it satisfies the above purpose. FIG. 4 shows a sputtering chamber 101 in which a rotating pallet 23, 24, 25, 26, 2 having a predetermined curvature in a direction in which all surfaces are 90 ° with respect to the direction of sputtered particles.
7 is the case where it is attached. The sputtering chamber is connected via a vacuum exhaust port 104 to a predetermined vacuum exhaust pump such as a turbo molecular pump or a mechanical booster pump. A valve 103 and an inlet 1 are provided above the sputtering chamber 101.
02 is attached, and Ar + N ₂ gas can be introduced through them. Using the sputtering apparatus shown in FIG. 4, while rotating the substrate 3 on the rotating pallet, the Fe-Zr target 4 was sputtered on the surface of the substrate 3 to form the Fe-Zr-N film. The results were as follows. . That is, after sputtering, vacuum heat treatment was performed at 570 ° C., and the magnetic permeability μ ⁻ measured thereafter was uniform, and all the values were as large as 4000. In addition, the coercive force was about 0, which was a sufficient characteristic as a soft magnetic film.

In the first and second embodiments of the present invention, the film formation of the magnetic film has been described. However, the present invention is not only applied to the film formation of the magnetic film, but also other than the magnetic film can be formed by sputtering. It is possible to improve the characteristics of the formed thin film. For example, in forming a ferroelectric film of PZT or other perovskite composition, it was difficult in the past to achieve both productivity and isotropic polarization characteristics. However, using the method of the present invention makes it easy to obtain polarization characteristics easily. An isotropic dielectric film can be obtained. For ITO film, by using this method,
It is possible to obtain a film in which the resistivity is isotropic in both the direction parallel to the film surface and the direction perpendicular to the film surface.

[0019]

According to the present invention as described above, Fe-Zr-N and Fe-T films formed by sputtering.
Capable of depositing a large amount of substrates at one time while maintaining the film characteristics and film uniformity of magnetic thin films such as aN, PZT, and other thin films such as ferroelectric films of perovskite composition. Therefore, productivity can be improved. The productivity can be easily achieved at least four times as high as the conventional one.

Particularly according to the present invention, good quality Fe-Zr-
A large number of N, Fe-Ta-N and other films can be simultaneously formed on a large number of substrates at the same time, and a large number of laminating heads (magnetic heads) using these films can be inexpensively supplied. Becomes

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a sputtering apparatus when there is one target according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a sputtering apparatus when there are two targets according to a second embodiment of the present invention.

FIG. 3 is a diagram showing a configuration of a sputtering apparatus according to a modified example of the second embodiment of the present invention.

FIG. 4 is a diagram showing a configuration of a sputtering apparatus according to a third embodiment of the present invention.

[Explanation of symbols]

1,11,12 Revolution pallet 2,21,22,23,24,25,26 Rotation pallet 3 Substrate 4 Fe-Zr target 41 Fe-Ta target 42 SiO ₂ target

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location H01L 41/22 H01L 41/22 Z

Claims (5)

[Claims] 1. An angle between a line segment connecting an arbitrary point on a substrate for forming a desired film and an arbitrary point on a sputter emission surface of a sputtering target and the surface of the substrate is 70 to 90.
A sputtering apparatus equipped with a rotating pallet having a radius of curvature that allows a substrate to be mounted within an angle of °. 2. The rotating pallet is a rotating pallet and an orbiting pallet having substantially the same radius of curvature,
The sputtering apparatus according to claim 1, wherein the rotation pallet is attached to the revolution pallet. 3. A sputtering method for simultaneously forming a film on a plurality of substrates, wherein sputtered particles emitted from a sputtering target have an angle of 70 to 90 ° with respect to any surface of the plurality of substrates. The sputtering method is characterized in that the substrate is arranged so as to be always incident on the substrate, and the sputtered particles are attached to the surface of the substrate while rotating the substrate around a predetermined rotation axis. 4. A line segment connecting a center point of a sputter emission surface of a sputtering target and a center point of a substrate for depositing sputtered particles is within 70 to 90 ° with respect to the surface of the substrate. The substrate is mounted on a pallet curved with a radius of curvature of, and the sputtering target is sputtered while rotating the pallet around a predetermined rotation axis to form a desired thin film on the substrate. And a sputtering method. 5. A line segment connecting a center point of a sputter emission surface of a sputtering target and a center point of a substrate for depositing sputtered particles is within 70 to 90 ° with respect to the surface of the substrate. The substrate is mounted on a rotating pallet curved with a radius of curvature of, the rotating pallet is mounted on a revolution pallet having the same radius of curvature as the predetermined radius of curvature, and the desired rotation pallet and revolution pallet are rotated respectively. A sputtering method, wherein a thin film is formed on the substrate.