JPH0774440B2 - Ion beam spreader device - Google Patents

Description

The present invention relates to an ion beam sputtering apparatus improved so that an alloy film having a desired composition ratio can be formed on the surface of a substrate.

[Conventional technology]

FIG. 3 and FIG. 4 are schematic side views showing an example of a conventional ion beam sputtering apparatus, respectively. A composite target 5 held by a target holder 8 is housed in a vacuum container 1 that is evacuated to a predetermined vacuum through an exhaust port 2 by a vacuum exhaust device (not shown), and an ion source is directed toward the composite target 5. From 3, the ion beam 4 made of an inert gas ion such as argon is irradiated. Further, the vacuum container 1 is provided with the substrate 9 held by the substrate holder 10 so as to face the composite target 5, and the composite target 5 is provided by the ion beam 4.
The particles sputtered from adhere to the surface of the substrate 9,
As a result, an alloy film is formed on the surface of the substrate 9.

The apparatus shown in FIG. 3 is an example in which the ion source 3 and the substrate 9 are arranged horizontally and the composite target 5 is inclined, and the apparatus shown in FIG. 4 shows the composite target 5 horizontally and the ion source 3, In this example, the substrate 9 is arranged so as to be inclined.

As the composite target 5, for example, as shown in FIG. 5, a plurality of metal pieces 7 are placed on a metal plate 6, or as shown in FIG. There is a structure in which the hole 6a is opened and the metal piece 7 is put in the hole 6a. These composite targets 5 are
It can be used with either the device as shown or the device as shown in FIG.

The composition ratio of the alloy film formed on the surface of the substrate 9 is
It depends on the surface area ratio between the metal plate 6 and the metal piece 7 in the composite target 5 (more strictly, the surface area ratio on the side irradiated with the ion beam 4).

[Problems to be solved by the invention]

However, in such an ion beam sputtering device,
Since the above-mentioned composite target 5 is used, the sputtering rate of each target portion (that is, the portion of the metal plate 6 and the metal piece 7) is different, and since the sputtering is performed by the single ion source 3, the composite target is formed during the sputtering. There is an inconvenience that the composition ratio of each target portion of the target 5, that is, the surface area ratio to be sputtered changes, and the composition ratio of the alloy film formed on the substrate 9 is not desired.

Further, if the composite target 5 as shown in FIG. 5 is used, it must be arranged horizontally, and the degree of freedom in designing the entire device of this type is reduced, and the composite target 5 as shown in FIG. 6 is used. In addition to the fact that the holes 6a must be formed in the metal plate 6, they are easily oxidized by the processing (for example, cutting) at that time. Especially when the metal piece 7 is made of a rare earth metal, a large amount of oxide is oxidized. It becomes easy to include. However, in the case of forming an amorphous perpendicular magnetization film, for example, predetermined characteristics may not be obtained unless the amount of the above oxides is reduced as much as possible.

Therefore, it is a main object of the present invention to provide an ion beam sputtering apparatus capable of forming an alloy film having a desired composition ratio on the surface of a substrate without using the complex target having many problems as described above.

[Means for solving problems]

The ion beam sputtering apparatus of the present invention is a vacuum container that is evacuated to a vacuum, and a polygonal columnar target holder that is housed in the vacuum container, and has a plurality of target fixing regions that are divided in the axial direction. And a target holder that can fix targets on multiple side surfaces in each target fixing area, and that rotates this target holder from outside the vacuum container in stages by 360 degrees divided by the number of side surfaces of the holder. A rotating mechanism and a plurality of targets that are respectively fixed to each side surface of the target holder and are simultaneously irradiated with an ion beam, and side surfaces at specific positions in each target fixing area of the target holder. The target is fixed to the An ion source having the same number as the constant region, and a substrate holder that is provided in the vacuum container and holds the substrate so that particles sputtered from a plurality of targets irradiated with the ion beam enter the substrate. And a substrate holder rotating mechanism for rotating the substrate holder from outside the vacuum container.

[Action]

Ion beams are respectively irradiated from different ion sources to different types of targets on the target holder, and the particles sputtered thereby adhere to the surface of the rotating substrate to form a predetermined film, for example, an alloy film.

〔Example〕

FIG. 1 is a side view showing an ion beam sputtering apparatus according to an embodiment of the present invention, and FIG. 2 is a plan view thereof.

In this embodiment, a target holder 24 having a polygonal column shape, more specifically a square column shape, is provided in a vacuum container 20 that is evacuated to a predetermined vacuum degree through a vacuum exhaust port 22 by a vacuum exhaust device (not shown). Has been. The target holder 24 is divided from the outside of the vacuum container in the direction of arrow A, for example, by 360 degrees by the number of side surfaces of the target holder 24 by a target holder rotating mechanism 28 attached to the outside of the vacuum container 20 via a shaft 26. Step by step (every 90 degrees in this example)
Is rotated. Therefore, it is preferable that the rotation mechanism 28 is provided with a latch mechanism that can reliably position the target holder 24 at each predetermined angle (in this example, every 90 degrees).

The target holder 24 includes a plurality of target fixing areas 25a and 25b, which are divided into a plurality of axially divided target holders in this example.
have. Then, for example, plate-shaped targets 61a to 64a and 61b to 64b are fixed to the four side surfaces 51a to 54a and 51b to 54b of the target fixing areas 25a and 25b of the target holder 24, respectively. Each target 61a
Each of ~ 64a and 61b to 64b may be a single metal or an alloy. As the fixing means, various kinds of fixing means, such as screwing or adhesion, can be adopted.

The targets 61a to 64a (or 61b to 64b) in the same target fixing region 25a (or 25b) may be the same or different from each other, but the ion sources 34a and 34b to be described later.
From which the ion beams 36a and 36b are simultaneously irradiated are attached so as to be different from each other.

In the vacuum container 20, the same number of dedicated ion sources 34a and 34b are attached to the target fixing regions 25a and 25b. Each ion source 34a, 34b is a target holder
The ion beams 36a and 36b are directed toward the target fixed on the side surface (in this example, one side surface facing obliquely downward as shown in FIG. 1) at a specific position in each of the target fixing areas 25a and 25b of 24. Each can be irradiated at the same time. Each of the ion beams 36a and 36b is made of an inert gas ion such as argon. In this example, the two ion sources 34a and 34b are arranged so that their axes do not face each other, as is apparent from FIG. 2, to avoid mutual interference. In the state of the illustrated example, the ion beam 36a is directed to the target 64a,
The ion beam 36b is applied to each target 61b (which is located on the back side of the target 61a in FIG. 1).

Further, in the vacuum container 20 and below the target holder 24, particles 46a and 46b sputtered from two targets irradiated with the ion beams 36a and 36b, respectively, are provided on the substrate 38.
A substrate holder 40 that holds the substrate 38 so as to be incident on is provided. The substrate holder 40 includes a substrate holder rotating mechanism 44 attached to the outside of the vacuum container 20 via a shaft 42.
By means of a predetermined direction during sputtering, for example arrow B
It is rotated continuously in the direction.

Explaining an example of the operation of the above device, the target holder
With the 24 fixed in the position shown, for example, the substrate holder 40
While rotating the ion beam 36a from the ion source 34a
Are simultaneously irradiated to the target 64a and the ion beam 36b from the ion source 34b to the target 61b. As a result, the targets 64a and 61b are sputtered, respectively, and particles 46a and 46b are respectively ejected therefrom, and these particles are incident on the surface of the rotating substrate 38 and adhered thereto, whereby a predetermined film is formed on the substrate 38 with a desired composition ratio. Formed on the surface of 38. In this case, since the substrate 38 is rotated as described above, excellent in-plane uniformity of film quality formed on the surface can be obtained. Further, the composition ratio of the formed film can be easily adjusted by changing the beam current of the ion beams 36a and 36b or the sputtered surface area of the targets 61a to 64a and 61b to 64b.

If the targets 64a and 61b are sputtered and consumed,
If the target holder 24 is rotated by one step by the target holder rotating mechanism 28, that is, in this example, by rotating 90 degrees to the right, for example, then the targets 61a and 62b can be sputtered, respectively. Can be used.

According to this ion beam sputtering apparatus, the targets 61a to 64a and 61a to 64b fixed to the respective target fixing regions 25a and 25b of the target holder 24 have the corresponding ion source 34
Since they are sputtered by the ion beams 36a and 36b from a and 34b respectively, even if the sputter rates of the targets are different from each other, the surface area ratio does not change during sputtering as in the conventional target. Therefore, the composition ratio of the alloy film formed on the surface of the substrate 38 is desired.

Further, since each of the targets 61a to 64a and 61b to 64b need only have a simple shape, its manufacture is easy and the cost is low. Further, in the conventional case, like the target 5, a large number of metal pieces 7 are processed or holes are formed.
Since it is unnecessary to process many 6a, it is possible to obtain the targets 61a to 64a and 61b to 64b having a small amount of oxidized surface area and a small amount of impurities. As a result, a high-purity alloy film can be formed.

Moreover, by rotating the target holder 24 stepwise from the outside of the vacuum container, new targets can be used one after another, resulting in a longer target replacement cycle, reducing the time loss associated with target replacement, and improving efficiency. Membrane treatment can be performed.

Further, since the target is fixed to the side surface of the target holder 24, the direction of the target in the state of being irradiated with the ion beam can be set to any of horizontal, vertical and oblique, and accordingly the substrate Also, the degree of freedom in arranging the ion source is increased.

The target holder 24 is not necessarily limited to the quadrangular prism as described above, but may be a triangular prism, a pentagonal prism, a hexagonal prism, or the like depending on the usage conditions.

Further, the target fixing area of the target holder 24 may be set to three or more and the same number of ion sources may be arranged, and even in this case, a multi-element alloy film of ternary or more can be formed. If this is used together with the use of an alloy target as the target, it is possible to form a multi-element alloy film.

〔The invention's effect〕

As described above, according to the present invention, a high quality alloy film having a desired composition ratio can be formed on the surface of a substrate without using a composite target.

In addition, since the new target can be used sequentially by rotating the target stepwise from outside the vacuum container, the target replacement cycle becomes longer, and the time loss associated with target replacement is reduced and film formation is efficient. Processing can be performed.

Further, since the target is fixed to the side surface of the target holder, the direction of the target in the state of being irradiated with the ion beam can be set to any of horizontal, vertical, and diagonal directions, and the substrate and The degree of freedom in arranging the ion source is also increased.

[Brief description of drawings]

FIG. 1 is a side view showing an ion beam sputtering apparatus according to an embodiment of the present invention, and FIG. 2 is a plan view thereof. FIG. 3 and FIG. 4 are schematic side views showing an example of a conventional ion beam sputtering apparatus, respectively. FIG. 5 (A) is a plan view showing an example of the composite target, and FIG. 5 (B) is a sectional view taken along the line VI-VI. FIG. 6 (A) is a plan view showing another example of the composite target,
FIG. 6 (B) is a sectional view taken along the line VII-VII. 20 ... Vacuum container, 24 ... Target holder, 25a, 25b ...
… Target fixing area, 51a-54a, 51b-54b …… Side, 2
8 …… Target holder rotation mechanism, 61a to 64a, 61b to 64b…
… Target, 34a, 34b …… Ion source, 36a, 36b …… Ion beam, 38 …… Substrate, 40 …… Substrate holder, 44 …… Substrate holder rotation mechanism.

Claims (1)

[Claims] 1. A vacuum container evacuated to a vacuum, and a polygonal columnar target holder housed in the vacuum container, each target holder having a plurality of target fixing regions divided in the axial direction thereof. A target can be fixed to each of a plurality of side surfaces in the fixing area, and a target holder rotation mechanism that rotates the target holder from outside the vacuum container in stages by 360 degrees divided by the number of side surfaces of the holder. A plurality of targets that are fixed to each side surface of the target holder and are simultaneously irradiated with an ion beam are different from each other, and are fixed to a side surface at a specific position in each target fixing area of the target holder. The target target area and the same number of ion sources, A substrate holder that is provided in the vacuum container and holds the substrate so that particles sputtered from a plurality of targets irradiated with the ion beam are incident on the substrate, and the substrate holder is provided from outside the vacuum container. An ion beam sputtering apparatus, comprising: a substrate holder rotating mechanism that rotates.