JP2003138373A - Sputtering apparatus and sputtering method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sputtering apparatus and a sputtering method in which a film of a multi-layer structure with films of different material alternately laminated on each other is deposited on a work to be film-deposited with a uniform film thickness distribution. SOLUTION: A work holding means 5 which holds a work 6 to be film- deposited and is rotated, and a plurality of target holding means 2 and 3 to hold a plurality of targets A and B are disposed in a film deposition chamber 1a facing each other, a rotary shutter 7 to separate a space between the work holding means 5 and the target holding means 2 and 3 is provided, through holes 8 are partially formed in the rotary shutter 7, and the targets A and B are intermittently communicated with the work 6 through the through holes 8 as the rotary shutter 7 is rotated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sputtering apparatus and a sputtering method for simultaneously sputtering a plurality of targets of different materials to form a mixed film of two or more kinds of materials on a film-forming target, and more particularly to a sputtering method. Is
The present invention relates to a sputtering apparatus and a sputtering method suitable for forming a recording layer of a magneto-optical disk.

[0002]

2. Description of the Related Art The recording layer of a rewritable magneto-optical disk is generally composed of a mixed film of 3 to 4 elements. As one of the film forming methods, there is a method of simultaneously sputtering a plurality of targets containing an element forming the recording layer. FIG. 10 shows a schematic diagram of an apparatus for performing the sputtering.

In the film forming chamber 1a in the vacuum chamber 1, there are a substrate holder 5 and a plurality of (two in this example) target holders 2.
3 are arranged so as to face each other. The substrate holder 5 has a rotary shaft 5a extending in the vertical direction, and is rotatably arranged around the rotary shaft 5a in a horizontal plane.

When a gas for plasma generation is introduced into the film forming chamber 1a and power is applied to the target holders 2 and 3 (the substrate holder 5 is grounded), plasma is generated in the film forming chamber 1a and the target is generated. The two targets A and B respectively held by the holders 2 and 3 are simultaneously sputtered. By this sputtering, each particle (atom or molecule) a, which jumps out from each target A, B,
b is deposited on the substrate 6 held by the substrate holder 5, and a mixed film of the material of the target A and the material of the target B is formed on the substrate 6. At this time, the substrate holder 5 is rotated around the rotation axis 5a and the substrate 6 is rotated in a horizontal plane in order to obtain a uniform film thickness distribution in the plane of the substrate 6.

As a structure of the recording layer (magnetic layer) of the magneto-optical disk, an alloy film in which a rare earth metal and a transition metal are irregularly mixed is generally used. However, in recent years, a multi-layer structure has been adopted in which rare earth metal-based layers and transition metal-based layers are alternately and repeatedly stacked. It is known that the recording layer having such a structure enhances the coercive force and is excellent in the magneto-optical effect and the perpendicular magnetic characteristics.

In the apparatus shown in FIG. 10, the sputtered particles a and b are mixed irregularly and adhered to the substrate 6, so that a multi-layer structure cannot be realized. Therefore, as shown in FIG. 11, there is a method of realizing a multi-layer structure with a device provided with a shield plate 13. The shielding plate 13 is disposed so as to extend vertically between the targets A and B so that the particles a protruding from the target A and the particles b protruding from the target B reach the substrate 6 without being mixed with each other. ing. The same components as those of the apparatus shown in FIG. 10 are designated by the same reference numerals and have the same operation.

[0007]

However, when a film having a multi-layer structure is formed in a device provided with such a shielding plate 13, there is a large variation in the film thickness within the plane of the substrate 6 and a uniform film thickness. There is a problem that the film thickness distribution cannot be obtained.

The present invention has been made in view of the above problems, and a sputtering device and a sputtering apparatus for forming a film having a multi-layer structure in which films of different materials are alternately laminated on a film-forming object with a uniform film thickness distribution. The challenge is to provide a method.

[0009]

In a sputtering apparatus of the present invention, a film forming body holding means for holding and rotating a film forming body and a plurality of target holding means for holding a plurality of targets respectively, The rotary shutters are arranged so as to face each other in the film formation chamber, and a rotary shutter is provided between the target object holding means and the target holding means, and a through hole is partially formed in the rotary shutter to rotate the rotary shutter. As the shutter rotates,
Each target is intermittently communicated with the film formation target through the through hole.

The sputtering method of the present invention is a sputtering method in which a plurality of targets made of different materials are simultaneously sputtered so that films made of different materials are alternately laminated on a film-forming target. And a plurality of targets, the rotary shutter having a through hole partially formed therein is rotated to intermittently communicate the target with the film formation target through the through hole.

That is, when a plurality of targets are simultaneously sputtered while rotating the rotary shutter having the through holes, only when the through holes pass over each target,
The particles that have jumped out from each target can reach and adhere to the film formation target. Accordingly, films of different materials can be alternately stacked on the film formation target. Further, the film thickness can be made uniform in the plane.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a schematic view of a sputtering apparatus 10 according to this embodiment. A substrate holder 5 and a plurality of (two in the present embodiment) target holders 2 and 3 are arranged to face each other in a film forming chamber 1 a in the vacuum chamber 1.
The substrate holder 5 has a rotating shaft 5a extending in the vertical direction,
It is arranged rotatably in a horizontal plane around the rotary shaft 5a. The substrate holder 5 and the target holders 2 and 3 are
Respectively, the means for holding a film forming object in the claims,
Corresponds to the target holding means.

A disk-shaped rotary shutter 7 is horizontally arranged between the substrate holder 5 (substrate 6) and the target holders 2 and 3 (targets A and B). The planar size of the rotary shutter 7 is a size that covers all the targets A and B. A rotary shaft 7a extending in the vertical direction is attached to the rotary shutter 7, and the rotary shaft 7a is connected to a motor (not shown). Therefore, the rotary shutter 7 is rotatable in the horizontal plane around the rotary shaft 7a.

FIG. 2 shows a plan view of the rotary shutter 7. In the rotary shutter 7, for example, one circular through hole 8 is formed. The diameter of the through hole 8 is the same as or slightly larger than the diameters of the targets A and B (the targets A and B have the same diameter). The through-hole 8 moves in a circular path along with the rotation of the rotary shutter 7, and the targets A and B are arranged below the moving path. Further, when the through hole 8 is located right above each target A, B, the center of the through hole 8 and the center of each target A, B are made to coincide with each other.

Next, the film forming action will be described.

The inside of the film forming chamber 1a is evacuated, and at the same time, Ar gas is introduced into the film forming chamber 1a through the gas introducing pipe 9 as a gas for plasma generation.
Is applied (the substrate holder 5 is grounded). As a result, plasma is generated in the film forming chamber 1a, and the two targets A held in the target holders 2 and 3,
B is sputtered at the same time.

At this time, the rotary shutter 7 is rotating in the horizontal plane around the rotary shaft 7a, and only when the through hole 8 passes over each of the targets A and B, the substrate 6 which is the film-forming target.
The particles a jumping out of the target A or the particles b jumping out of the target B are attached. When one particle a or b is flying to the substrate 6 through the through hole 8, the other particle b or a is transferred to the substrate 6 by the rotary shutter 7.
Is prevented from coming to Japan. Therefore, the film made of the material of the target A and the film made of the material of the target B are alternately laminated on the substrate 6. At this time, in order to make the film thickness distribution in the plane of the substrate 6 uniform, the substrate holder 5 is mounted on the rotating shaft 5a.
The substrate 6 is rotated in the horizontal plane.

(Example) Diameter 1 as a substrate (body to be film-formed)
A 20 mm circular glass substrate 6 was attached to the substrate holder 5, and the substrate holder 5 (glass substrate 6) was rotated at 60 rpm. The distance between the targets A and B and the glass substrate 6 was 120 mm. The atmosphere in the film forming chamber 1a is first evacuated to 3 × 10 ⁻⁵ Pa or less, then 25 sccm of Ar gas is introduced from the gas introducing pipe 9, and the pressure in the film forming chamber 1a is set to 0.5 Pa. And

A specific configuration of the rotary shutter 7 will be described with reference to FIG. The shape is a disk shape, and the material is a material (for example, Ti) that is difficult to deform even at high temperature.
The dimensions are 360 mm in diameter and 1.5 mm in thickness. Then, one through hole 8 having a diameter of 130 mm is formed.
The center of the through hole 8 is located 85 mm radially outward from the center of the rotary shutter 7.

Rotating the rotary shutter 7 at 15 rpm, 250 W for a Tb target A having a diameter of 100 mm and 900 W for a FeCo alloy target B having a diameter of 100 mm.
Power is applied to form a TbFeCo film on the glass substrate 6 with a thickness of 200 nm.
A film was formed. Furthermore, the rotation speed of the rotary shutter 7 is set to 1.5r.
The same film formation was performed when pm was set to 150 rpm. Further, as a comparative example, the rotary shutter 7 was removed, and the atoms of the targets A and B were randomly mixed.
The TbFeCo film was also formed under the same conditions.

FIG. 6 shows the relationship between the power applied to the Tb target A and the deposition rate of the Tb film on the glass substrate 6. As can be seen from this result, the power applied to the target and the film formation rate are in a proportional relationship.

FIG. 7 shows the relationship between the rotation speed of the rotary shutter 7 and the film thickness of the Tb film formed on the glass substrate 6 per one rotation of the rotary shutter 7. The case where the power applied to the Tb target A is 250 W and the case where it is 1000 W is shown. The rotation speed of the rotary shutter 7,
The film thickness formed per rotation of the rotary shutter 7 is in inverse proportion to the film thickness. Further, Table 1 shows the results when the applied power to the Tb target A in FIG. That is, the rotation speed of the rotary shutter 7 is 1.5r.
At pm, a 4 nm Tb film is formed, at 15 rpm, a 0.4 nm Tb film is formed, and at 150 rpm, 0.
A 04 nm Tb film is formed.

[0024]

[Table 1]

As can be seen from these results, by controlling the electric power applied to each of the targets A and B and the rotation speed of the rotary shutter 7, the Tb film and the FeCo film are alternately laminated with a desired film thickness. I can go.

FIG. 8 shows the relationship between the film thickness formed per one rotation of the rotary shutter 7 (that is, the film thickness of one layer in the multilayer structure) and the magnetic characteristics. Comparing the coercive force Hc at the same saturation magnetization Ms, when the film thickness per rotation is 0.4 nm, the value is three times or more as high as when it is 0.04 nm and 4 nm, which is the most excellent magnetic property. You can see that Further, in comparison with a film formed by removing the rotary shutter 7 and in which each atom is randomly mixed (saturation magnetization Ms of this film is shown by □, coercive force Hc is shown by ○), one rotation The coercive force Hc is 1.5 times higher when the film thickness per hit is 0.4 nm, and it can be seen that a film having excellent magnetic properties can be formed as compared with the conventional sputtering without using the rotary shutter 7. . By controlling the rotation speed of the rotary shutter 7 and the electric power applied to each of the targets A and B, the film thickness per rotation (that is, the film thickness of one layer in the multi-layer structure) can be reduced to 0.
It can be controlled to 4 nm. The reason why excellent magnetic properties are obtained when the film thickness formed per revolution is 0.4 nm is considered to be due to the fact that the diameter of one atom is approximately 0.4 nm. .

FIG. 9 shows a comparison result of film thickness distributions formed by the conventional apparatus using the shield plate 13 shown in FIG. 11 and the apparatus of the present embodiment using the rotary shutter 7. The various film forming conditions are the same. That is, the only difference is whether the shield plate 13 is provided or the rotary shutter 7 is provided. As can be seen from this result, the film thickness formed by the apparatus using the rotary shutter 7 can be made substantially uniform in the plane of the substrate 6, and the superiority to the conventional apparatus can be confirmed.

Although the embodiment of the present invention has been described above, the present invention is not limited to this, and various modifications can be made based on the technical idea of the present invention.

The number of targets is not limited to two. For example, as shown in FIG. 3, when three targets are used, the three targets A, B, and C are arranged along the circular movement path of the through hole 8. That is, the through hole 8 repeatedly moves in accordance with the rotation of the rotary shutter 7 about o as a rotation center, namely, a position indicated by a solid line → a position indicated by a one-dot chain line → a position indicated by a two-dot chain line → a position indicated by a solid line. To go. As a result, the targets A, B, and C are intermittently communicated with the film formation target. The same applies to the case of four or more.

Furthermore, the number of through holes 8 is not limited to one. For example, as shown in FIG. 4, when two through holes 8 are formed, a mixed film of the targets A and C is formed on the target object in the illustrated state, and the rotary shutter 7 is in the illustrated state. In the state of being rotated counterclockwise by 120 ° from the above, a mixed film of the targets A and B is formed on the target object, and the rotary shutter 7
However, when it is further rotated counterclockwise by 120 °, a mixed film of targets B and C is formed on the film-forming target. Further, the through hole 8 is not limited to a circular shape, but may be a quadrangular shape, for example.

For example, as an example of the material of each target used for forming the recording layer of the magneto-optical disk, Tb,
Dy, Gd, Fe, Co, Cr, Ge, Sb, Te, S
Elementary elements of n, Ag, and In, alloys obtained by arbitrarily combining these elements, and at least one of these elements
Examples include alloys containing three or more elements as main components.

Further, the present invention can be applied to optical disks as well as magneto-optical disks. Furthermore, the technique is effective not only for these disc-shaped recording media, but also for all those that form a multi-layered film with a uniform film thickness distribution.

[0033]

According to the present invention, since the rotary shutter in which the through holes are partially formed is provided between the plurality of targets and the film-forming target facing them, the film-forming speed of each target is increased. By arbitrarily adjusting the rotation speed of the rotary shutter based on the above, it becomes possible to alternately form films of the material of each target on the film formation target with a desired thickness. Further, it is possible to form a film having a uniform thickness while suppressing variations in the film thickness distribution in the surface direction.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a sputtering apparatus according to an embodiment of the present invention.

FIG. 2 is a plan view showing a positional relationship between a through hole formed in the rotary shutter and each target in the same embodiment.

FIG. 3 is a plan view showing a positional relationship between a through hole formed in a rotary shutter and each target when there are three targets.

FIG. 4 is a plan view showing a positional relationship between each through hole and each target when there are three targets and two through holes.

FIG. 5 is a plan view showing specific dimensions of a rotary shutter.

FIG. 6 is a graph showing the relationship between applied power and film formation rate for a Tb target.

FIG. 7 is a graph showing the relationship between the rotation speed of the rotary shutter and the film thickness of a Tb film formed per rotation.

FIG. 8 is a graph showing the relationship between the film thickness of the Tb film formed per rotation of the rotary shutter and the magnetic characteristics.

FIG. 9 is a graph showing a film thickness distribution comparison between a case where a conventional shield plate is used and a case where the rotary shutter of the present embodiment is used.

FIG. 10 is a schematic view of a conventional sputtering apparatus.

FIG. 11 is a schematic view of another conventional sputtering apparatus using a shield plate.

[Explanation of symbols]

1 ... Vacuum tank, 1a ... Deposition chamber, 2, 3 ... Target holding means (target holder), 5 ... Deposition object holding means (substrate holder), 6 ... Deposition object (substrate) , 7 ... Rotary shutter, 8 ... Through hole, 9 ... Gas inlet tube, 10 ...
… Sputtering equipment, AC… Target.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Noriaki Tani             523 Yokota, Sanmu-cho, Sanmu-gun, Chiba Prefecture             Lubac Chiba Institute for Materials Research (72) Inventor Haruki Ken Iwai             2500 Hagien, Chigasaki-shi, Kanagawa Al             In the back (72) Inventor Shoji Nagasawa             2500 Hagien, Chigasaki-shi, Kanagawa Al             In the back (72) Inventor Tetsuya Shimada             2500 Hagien, Chigasaki-shi, Kanagawa Al             In the back F-term (reference) 4K029 BA21 BA24 BA26 BB02 BD12                       CA05 DA12 DC15 EA01                 5D075 EE03 FF01 FF04 GG11 GG16

Claims (5)

[Claims] 1. A film forming body holding unit that holds a film forming body and is rotated, and a plurality of target holding units that respectively hold a plurality of targets are arranged to face each other in a film forming chamber. In the sputtering device, a rotary shutter that separates the film-forming body holding means and the target holding means is provided, and a through hole is partially formed in the rotary shutter, and each of the above-mentioned rotary shutters is rotated. The sputtering apparatus is characterized in that the target is intermittently communicated with the film formation target through the through hole. 2. The film-forming target is a magneto-optical disk, and the targets are Tb, Dy, Gd, Fe, Co,
Cr, Ge, Sb, Te, Sn, Ag, In single elements,
Alternatively, the sputtering apparatus according to claim 1, wherein the sputtering apparatus is made of an alloy containing at least one of these elements. 3. A sputtering method in which a plurality of targets made of different materials are simultaneously sputtered, and films made of the different materials are alternately laminated on a film-forming target, wherein the film-forming target and the film-forming target are formed during the sputtering. By rotating a rotary shutter that is provided with a plurality of targets separated from each other and partially formed with through holes, the targets and the film formation target are intermittently communicated through the through holes. A sputtering method comprising: 4. The film formation target is a magneto-optical disk, and each of the targets is Tb, Dy, Gd, Fe, Co,
Cr, Ge, Sb, Te, Sn, Ag, In single elements,
Alternatively, the sputtering method according to claim 3, comprising an alloy containing at least one of these elements. 5. The film thickness formed per one rotation of the rotary shutter is controlled by controlling the rotation speed of the rotary shutter and the electric power applied to each of the targets. The sputtering method according to claim 4.