JPH10102248A - Sputtering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form coating having a uniform coating thickness in a short time. SOLUTION: In a chamber introduced with an inert gas, a fixed target 23, an object to be worked supported so as to opposite to the target 23 and a magnet field generating means 24 generating concentric leakage magnetic field regions at least composed of duplication or above on the space between the target 23 and the object 29 to be worked. Then, as for the magnetic field generating means 24, in the primary leakage magnetic field region to be generated on the side of the inner circumference on the target, the erosion rate, the sputtering rate or the total of sputtering atoms sprung out from the target per unit time is reduced, and in the secondary leakage magnetic field region to be generated on the side of the outer circumference on the target, the erosion rate, the sputtering rate or the total of sputtering atoms spung out from the target per unit time is made higher than that in the primary leakage magnetic field region to be generated on the side of the inner circumference.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[Table of Contents] The present invention will be described in the following order. Technical field to which the invention pertains Prior art (FIG. 6) Problems to be solved by the invention (FIG. 7) Means for solving the problems Embodiments of the invention (1) First Example (FIGS. 1 to 4) 2) Second embodiment (FIG. 5) (3) Other embodiments Advantages of the invention

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spatter device, and is suitably applied to, for example, a spatter device used in a process of forming a reflection film of an optical disc.

[0003]

2. Description of the Related Art Conventionally, in optical disks, in addition to a read-only type such as a compact disk (CD) and a laser disk (LD), a recordable type magneto-optical disk (M
O) is common today. This recordable type magneto-optical disc has a magnetic film (hereinafter referred to as a signal recording surface) for recording signals on one surface of a disk-shaped substrate made of a transparent synthetic resin material such as polycarbonate. An MO film is formed, a reflective film is formed on the surface of the magnetic film, and then a protective film is laminated on the reflective film.

In the manufacturing process of manufacturing such a magneto-optical disk, a reflective film is usually formed by depositing a highly reflective material (usually aluminum) on the signal recording surface of the substrate using a special spatter device. It is performed by spattering and depositing. For example, as shown in FIG. 6, in a magnetron-type spatter device 1, a backing plate 3 disposed at a predetermined position in a chamber 2 is provided.
A disk-shaped target 4 is adhered and fixed thereon, and a column-shaped magnet 6 is fixed at a central portion on a magnet plate 5 disposed below the target 4, and a plurality of magnets 7 are further provided at a peripheral end portion. They are arranged and fixed in a circular shape in a state of being in close contact with each other.

Here, the magnetic poles of the magnet 6 and the magnet 7 are arranged such that N poles and S poles are alternated. A substrate holder 8 is provided at a position facing the target 4, and a substrate 9 to be processed is held on the surface of the substrate holder 8.

Further, while the target 4 is connected to a cathode power supply (not shown), the housing portion 2A of the chamber 2 holding the substrate holder 8 is grounded, and the target 4 serves as a cathode during operation. The target 4 is operated by operating the substrate holder 8 as an anode.
A plasma is generated in a space between the substrate and the substrate 9 (hereinafter, this is referred to as a sputtering region). At this time, a ring-shaped magnetic field (indicated by a dashed line) generated by the magnets 6 and 7 disposed below the target 4 leaks from the surface of the target 4 to generate a leakage magnetic field in the sputtering area.

Therefore, in the sputter device 1, Ar atoms supplied as Ar gas into the sputter ring region are ionized, and the ionized Ar atoms are turned into an erosion ring (erosion region) 10 on the surface of the target 4 by a leakage magnetic field. The aluminum atoms are ejected from the surface of the erosion ring 10 of the target 4 by attracting and colliding, and the aluminum atoms are
Has been deposited on the surface. At this time, the spatter device 1 rotates the substrate holder 8 at a position where the axis center of the substrate holder 8 and the axis center of the target 4 are slightly shifted, that is, in an eccentric state, so that the surface of the substrate 9 has a desired thickness. It is designed to form a film.

[0008]

By the way, in the spatter device 1 having such a structure, the aluminum atoms which have protruded from the surface of the erosion ring 10 are short in the distance to the substrate 9, that is, the inner peripheral portion of the erosion ring 10. Is easily deposited on the surface of the substrate 9 corresponding to the surface of the substrate 9, and hardly deposited on the portion of the substrate 9 corresponding to the long distance to the substrate 9, that is, the outer peripheral portion of the erosion ring 10.

In practice, the thickness of the reflective film formed on the surface of the substrate 9 tends to be thicker at the portion corresponding to the inner peripheral side of the erosion ring 10 and to be smaller at the portion corresponding to the outer peripheral side. Accordingly, the film thickness of the reflective film formed on the surface of the substrate 9 is not uniform as a whole, and the optical characteristics such as the refractive index and the reflectance of the reflective film and the magneto-optical characteristics such as the Kerr rotation angle are different on the substrate. Variations in the distribution, such as differences between the inner peripheral portion and the outer peripheral portion, have become extremely large.

Therefore, as shown in FIG.
Then, the distribution correction mask 11 is used, and the substrate holder 8 is used.
Is rotated in the direction of the arrow to obtain the distribution correction mask 1.
The aluminum atoms passing through the opening 1 are sputtered evenly on the surface of the rotating substrate 9 to form a film having a uniform thickness.

However, in this case, since the sputtering atoms (aluminum atoms) flying to the substrate 9 are only the amount that has passed through the opening of the distribution correction mask 11, the film forming speed is very slow and the film forming process is difficult. There was a problem that it took a lot of time.

The present invention has been made in view of the above points, and it is an object of the present invention to propose a spatter apparatus capable of forming a film having a uniform thickness in a short time.

[0013]

In order to solve the above-mentioned problems, the present invention comprises a target fixed in a chamber into which an inert gas is introduced, a workpiece supported to face the target, Magnetic field generating means for generating at least a double or more concentric leakage magnetic field region in the space between the target and the workpiece, wherein the magnetic field generating means generates the first leakage generated on the inner peripheral side on the target. The erosion rate or spatter rate in the magnetic field region, or the sum of sputtering atoms jumping out of the target per unit time is reduced, and the erosion rate or sputter rate in the second leakage magnetic field region generated on the outer peripheral side of the target is reduced. Alternatively, add the sum of the sputtering atoms jumping out of the target per unit time to the inner circumference. So as to increase in comparison with the first leakage magnetic field region for antibody. Thus, the entire surface of the object can be sputtered at one time, and sputtering atoms can be uniformly deposited on the surface of the object.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

(1) First Embodiment FIG. 1 shows a magnetron type spatter device 20 according to the embodiment as a whole. A disc-shaped sputter device 20 is provided on a backing plate 22 disposed at a predetermined position in a chamber 21. The target 23 is adhered and fixed, a columnar magnet 25 is fixed at a central portion on a magnet plate 24 disposed below the target 23, and a plurality of magnets 26 are adhered to the peripheral end surface portion in a circular manner. The magnet 26
A plurality of magnets 27 are arranged and fixed so as to form a double concentric circle with a plurality of magnets in close contact with each other at a substantially intermediate position between the magnet 27 and the magnet 25.

Here, the magnetic poles of the magnets 25, 26, and 27 are arranged so that N poles and S poles are alternated. A substrate holder 28 is provided at a position facing the target 23. The central axis of the substrate holder 28 and the central axis of the target 23 are aligned with each other, and the surface of the substrate holder 28 is an object to be processed. A substrate 29 is attached.

Further, while the target 23 is connected to a cathode power supply (not shown), the housing portion 21A of the chamber 21 holding the substrate holder 28 is grounded, and the target 23 serves as a cathode during operation. Works,
By operating the substrate holder 28 as an anode,
A plasma is generated in a sputtering region between the target 23 and the substrate 29. At this time, the magnet 2 disposed below the target 23
The magnetic field generated by 5, 26 and 27 is the target 2
Leakage from the surface of No. 3 generates a leakage magnetic field in the sputter region.

Accordingly, in the spatter device 20, Ar atoms supplied as Ar gas into the sputter ring region are ionized, and the ionized Ar atoms are attracted to the surface of the target 23 by the leakage magnetic field and collide. As a result, in the spatter device 20, the erosion ring 30 is formed at the position of the radius r1, and the erosion ring 31 is formed at the position of the radius r2. Aluminum atoms jump out of the surfaces of the erosion rings 30, 31. The aluminum atoms are deposited on the surface of the substrate 29 to form a reflective film having a desired thickness.

In this case, the spatter device 20 adjusts the strength of the leakage magnetic field from the surface of the target 23 by the magnetic force of the magnet 25, the magnets 26 and 27, and thereby the erosion ring on the innermost peripheral side (radius r1). In the 30 regions, the peak of the erosion rate or the sputter rate, or the sum of the spattering atoms jumping out of the target 23 per unit time (hereinafter collectively referred to as the sputtering rate) is minimized, and the outermost side ( The spattering rate is maximized in the area of the erosion ring 31 having a radius of r2).

In the above arrangement, when the electric field from the cathode power supply is applied perpendicularly to the target 23 as shown in FIG. 2, the magnetic field lines 32 of the leakage magnetic field coming out of the surface of the target 23 are generated in the target device 23. Ar atoms are attracted to and collided with a position parallel to
Sputtering atoms (aluminum atoms) are repelled, and thus erosion rings 30 and 31 are formed concentrically on the target 23. As described above, in the sputter device 20, the distribution of the sputter rate increases with the position (the erosion region) on the target 23 where many Ar atoms are attracted and collided as a peak.

In the spatter device 20, the strength of the leakage magnetic field from the surface of the target 23 is reduced by the magnetic force of the magnet 25 arranged at the center and the magnets 26 and 27 arranged concentrically around the magnet 25. By adjusting, the spattering rate can be minimized in the area of the erosion ring 30 and the spattering rate can be maximized in the area of the erosion ring 31. As a result, the spatter device 20 changes the peak value of the spattering rate to the target 23 as shown in FIG.
(E (r1) <E (r2) <E (r) in the radial direction (r1 <r2 <r3) from the center of
3)). For example, an erosion ring
In the case of triple or quadruple formation in the radial direction from the center of the ring, the peak value of the spattering rate increases as the erosion ring on the outer peripheral side increases.

That is, the erosion ring 31 on the outer circumference side has a larger total sum S (r) of the sputtering atoms protruding from the target 23 than the erosion ring 30 on the inner circumference side of the target 23. As a result, the sputter device 20 can sputter the entire surface of the substrate 29 at once without using the mask 11 as in the related art, thereby forming a film having a uniform thickness. Further, since the sputter device 20 does not need to use the mask 11, a uniform film can be formed on the surface of the substrate 29 without deteriorating the film forming speed, and thus the optical characteristics such as the refractive index and the reflectivity of the reflective film and the Kerr rotation Variations in magneto-optical characteristics such as angles can be reduced.

In practice, the sputter device 20 sets the peak position of the spattering rate at r1 = 29 [mm] and r2 = 74.
[mm], the peak value ratio of the spattering rate is 0.55 (r
1) The magnets 25 to 27 are arranged so as to be 1 (r2), and the Ar gas pressure is set to 5 × as a sputtering condition.
10 ^-3 [Torr], applied power DC 7.5 [kW], film formation time 1
2 [seconds], the distance between the target 23 and the substrate 29 is 45 [m
m], and sputtering was performed on the target 23 using an aluminum disk. As a result, FIG.
As shown in the figure, the film thickness within a radius of 65 [mm] was 199 ± 4 [nm], and a favorable film thickness distribution could be obtained. That is, the sputter device 20 can form a substantially uniform film on the surface of the substrate 29 in a short time under the above-described set conditions.

Also, under the same magnet arrangement conditions as above, the Ar gas pressure is set to 5 × 10
^-3 [Torr], applied power is DC 2 [kW], and deposition time is 45
[Sec], the distance between the target 23 and the substrate 29 is 45 [mm]
And sputtering was performed using an Si target in which boron was added to the target 23. Also in this case, the same good film thickness distribution as in FIG. 4 could be obtained.

According to the above configuration, the spatter device 20 minimizes the spatter ring rate in the area of the erosion ring 30 on the inner peripheral side, and reduces the spatter ring 3 on the outer peripheral side.
By maximizing the spattering rate in one region, it is possible to perform sputtering on the substrate 29 at once without using the mask 11, and thus to uniformly coat the surface of the substrate 29 in a short time without impairing the film forming speed. A film having an appropriate thickness can be formed.

(2) Second Embodiment In FIG. 5, in which parts corresponding to those in FIG. 1 are assigned the same reference numerals, reference numeral 40 designates the configuration of the magnetron type spatter device according to the embodiment as a whole, and Divide into two parts in a circle for each area where the ring is formed,
The power applied to the divided targets 41A and 41B can be adjusted respectively. In practice, the sputter device 40 is provided with a target 41A including an area on which an inner erosion ring 42 is formed and a target 41B including an area on which an outer erosion ring 43 is formed. Cathode power supply 44, 4
5 so that the intensity of the electric field can be adjusted by the control unit 46. Here, the backing plates 41C and 41D fixed to the target 41A and the target 41B are also united and divided.

In this case, the spatter device 40 fixes the magnets 47 to 49 having the same magnetic force in the same arrangement as in the first embodiment, and the control unit 46 controls the targets 41A and 41B.
The intensity of the voltage is adjusted by controlling the value of the voltage applied to the.

Thus, the spatter device 40 is controlled by the control unit 4
6, the electric field applied to the target 41A is weakened,
By adjusting the electric field applied to the target 41B to be strong, the sputtering rate is minimized in the area of the erosion ring 42, and the erosion ring 4
The spattering rate is maximized in three regions.

In the above configuration, the spatter device 40 adjusts the intensity of the electric field by the control unit 46 to minimize the spatter ring rate in the area of the erosion ring 42 on the inner peripheral side, and to reduce the spatter rate on the outer peripheral side. Erosion ring 4
The spattering rate was set to be the highest in three regions.

As a result, the sputter device 40 increases the peak value of the sputter ring rate from the center of the target 41 in the radial direction (r1 <r2) (E (r
1) <E (r2)). In other words, the total sum S (r) of the spattering atoms jumping out of the target 41 is greater in the erosion ring 43 on the outer periphery than in the erosion ring 42 on the inner periphery of the target 41.

Thus, the sputter device 40 can sputter the entire surface of the substrate 29 at once without using the mask 11 as in the prior art, thereby forming a uniform film. Further, since the sputter device 40 does not need to use the mask 11, a uniform film can be formed on the surface of the substrate 29 without deteriorating the film forming speed. Variations in magneto-optical characteristics such as angles can be reduced.

The sputter device 40 includes a target 41
Is divided for each region where the erosion rings 42 and 43 are formed, and an applied voltage corresponding to each of the divided targets 41A and 41B is applied.
Since only the target 41A or 41B which has been quickly eroded and lost by the spattering need only be replaced, the target 41 can be used effectively.

In practice, the sputter device 40
Aluminum targets divided according to the Jillon area
The peak position of the erosion rate is determined by r
1 = 31 [mm] and r2 = 74 [mm]
And the Ar gas pressure is 5 × 10 ^-3[Torr], applied voltage at inner circumference
1.6 kW DC to the target 41A on the outer side,
DC 5.9 [kW], film formation time 12 [seconds]
The distance between the target 41 and the substrate 29 is 45 [mm].
Set to sputter. Again, in this case
As in the case of the first embodiment of FIG.
A film thickness distribution was obtained.

According to the above configuration, the spatter device 40 adjusts the applied voltage by the control unit 46 so as to minimize the spatter ring rate in the area of the erosion ring 42 on the inner circumference side, and adjust the erosion rate on the outer circumference side. Since the spattering rate is maximized in the region of the ring 43, the mask 1
Sputtering can be performed at once on the substrate 29 without using the substrate 1, and a film having a uniform thickness can be formed on the surface of the substrate 29 in a short time without impairing the film forming speed.

(3) Other Embodiments In the above-described first and second embodiments, the case where the erosion ring is formed in double on the targets 23 and 41 and the sputtering is performed on the substrate 29 has been described. However, the present invention is not limited to this, and the erosion ring may be formed in triple or quadruple. Also in this case, if the peak value of the spattering rate is increased radially from the center in the radial direction, the same effect as in the first and second embodiments can be obtained.

In the first and second embodiments, the peak value of the sputtering rate increases from the inner circumference to the outer circumference of each target (E (r1) <E).
(R2)) The case where the leakage magnetic field is adjusted so as to satisfy (r2)) has been described. However, the present invention is not limited to this, and the total sum S (r) of the sputtering atoms increases radially from the center of the target (S If (r1) <S (r2)), the peak value of the sputtering rate becomes E (r
1)> E (r2) or E (r1) = E (r2) may be satisfied.

In the first and second embodiments, the magnets 25 to 27 and 47 are used as the magnetic field generating means.
Although the description has been given of the case where .about.49 are used, the present invention is not limited to this, and other various magnetic field generating means such as an electromagnet may be used.

Further, in the first and second embodiments described above, the north poles of the magnets 25 and 47 located at the center are arranged toward the targets 23 and 41, and the south poles and the north poles are arranged in that order in the radial direction. Although the case where it is arranged to be a pole has been described, the present invention is not limited to this,
The south poles of the magnets 25 and 47 located at the center may be arranged toward the targets 23 and 41, and may be arranged so that the north pole and the south pole are sequentially directed toward the outer peripheral side from there. In short, it is only necessary that the magnets are arranged so as to generate a magnetic field between adjacent magnets.

Further, in the above-described first embodiment, the case in which the integrated target 23 is used has been described. However, the present invention is not limited to this, and the target 23 is used for each erosion region as in the target 41 of the second embodiment. May be divided. As a result, only the target that has been eroded earlier can be replaced, and the target can be used effectively.

Further, in the above-described first embodiment, the strength of the leakage magnetic field from the surface of the
Although the description has been given of the case where the adjustment is made by the magnetic force of the magnets 25 to 27, the present invention is not limited to this.
The strength of the stray magnetic field may be adjusted by other methods such as the arrangement of the magnets 7 or the difference in the surface area of the magnets 25 to 27 with respect to the target 23.

[0041]

As described above, according to the present invention, a target fixed in a chamber into which an inert gas is introduced,
A workpiece supported to face the target,
Magnetic field generating means for generating at least a double or more concentric leakage magnetic field region in the space between the target and the workpiece, wherein the magnetic field generating means generates the first leakage generated on the inner peripheral side on the target. The erosion rate or spatter rate in the magnetic field region, or the sum of sputtering atoms jumping out of the target per unit time is reduced, and the erosion rate or sputter rate in the second leakage magnetic field region generated on the outer peripheral side of the target is reduced. Alternatively, the total sum of the sputtering atoms jumping out of the target per unit time is set to be larger than the first leakage magnetic field region generated on the inner peripheral side. As a result, the entire surface of the workpiece can be sputtered at once, and the sputtering atoms can be uniformly deposited on the surface of the workpiece, thus forming a film having a uniform thickness in a short time. A spatter device that can be used.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a configuration of a spatter device according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram illustrating a relationship between a magnetic field and an electric field.

FIG. 3 is a schematic diagram illustrating a relationship between a sputtering rate and a radial position on a target.

FIG. 4 is a graph showing a state of a film thickness at each position on a substrate.

FIG. 5 is a schematic diagram illustrating a configuration of a spatter device according to a second embodiment of the present invention.

FIG. 6 is a schematic diagram illustrating a configuration of a conventional spatter device.

FIG. 7 is a schematic diagram for explaining a problem that occurs when a mask is used in a conventional spatter device.

[Explanation of symbols]

1, 20, 40 ... spatter device, 2, 21 ... chamber, 3, 22 ... backing plate, 4, 23, 41
…… Target, 5, 24 …… Magnet plate,
6, 7, 25-27, 47-49 ... magnet, 8,
28: substrate holder, 9, 29: substrate, 10, 30,
31, 42, 43 ... Erosion ring, 11 ... Mask, 44, 45 ... Cathode power supply, 46 ... Control unit.

Claims (3)

[Claims] 1. A target fixed in a chamber into which an inert gas is introduced, a processing object supported to face the target, and at least a space between the target and the processing object. Magnetic field generating means for generating a concentric leakage magnetic field area having two or more layers, wherein the magnetic field generating means includes an erosion rate or a sputter in a first leak magnetic field area generated on an inner peripheral side of the target. Rate or the total amount of spattering atoms jumping out of the target per unit time is reduced, and the erosion rate or sputter rate in the second leaked magnetic field region generated on the outer peripheral side on the target or the target per unit time is reduced. Leakage magnetic field that generates the sum of sputtering atoms jumping out from the inner circumference side Sputter apparatus characterized by larger than the region. 2. The device according to claim 1, wherein the target is divided into a first leakage magnetic field region generated on the inner peripheral side and a second leakage magnetic field region generated on the outer peripheral side. Spatter equipment. 3. The magnetic field generating means according to claim 1, wherein each of said first and second leakage magnetic field regions generated on said inner peripheral side and said second leakage magnetic field region generated on said outer peripheral side has a voltage value to be applied to a target divided. 3. The sputter according to claim 2, wherein the sputter rate is adjusted in the first and second stray magnetic field regions by changing the sputter rate or the total sum of sputtering atoms ejected from the target per unit time. apparatus.