JP2003193228A - Sputtering apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To deposit a uniform flexible magnetic film on a substrate and an etched groove. <P>SOLUTION: A sputtering apparatus in which a raw material sputter- evaporated from a target is deposited on the substrate on a revolving substrate holder has a tool 1103 which is installed between the target and the substrate, has an aperture of the same shape as that of an erosion area 1102 of the target 1101, and unifies the raw material reaching the substrate from the target on the substrate. <P>COPYRIGHT: (C)2003,JPO

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 more particularly to a sputtering apparatus applied to manufacture a master disk or the like for writing information by magnetic transfer.

[0002]

2. Description of the Related Art Recording / reproduction in a hard disk drive is performed by a rotating disk-shaped magnetic recording medium (hereinafter
A magnetic head provided in a flying mechanism called a slider flies over the surface of a medium) while keeping a distance of several tens nm. The bit information is recorded on data tracks arranged concentrically on the surface of the medium. The magnetic head moves at a high speed to a target data track on the medium, performs positioning, and records / reproduces data.

A positioning signal (hereinafter referred to as a servo signal) for detecting the relative position between the magnetic head and the data track is written concentrically on the surface of the medium. The magnetic head that records / reproduces data reads the servo signal and detects its position at regular time intervals. The servo signal is written on the medium by a dedicated device called a servo writer after the medium is incorporated into the hard disk device. At this time, writing is performed so that the center of the servo signal and the center of the medium or the center of the head trajectory are not decentered.

In recent years, the recording density at the development level of hard disk devices has reached ²⁰ Gbits / in ² , with an annual rate of 50%.
It is increasing at the above rate. Along with this, the recording density of the servo signal is also increased, and the writing time to the medium is increased, so that the productivity of the hard disk device is decreased and the manufacturing cost is increased. Therefore, unlike the writing method by the servo writer, a method of collectively writing the servo signals on the medium by magnetic transfer is performed.

FIG. 1 is a diagram for explaining a servo signal writing method by magnetic transfer. FIG. 2 is a diagram for explaining the principle of magnetic transfer. FIG. 1A shows the medium in the initial degaussing process, and FIG. 2A shows the degaussing method. In the initial degaussing step, the magnetic layer 201 formed on the surface of the medium 101 is magnetized in a fixed direction. Magnetic layer 201 after film formation
Is not magnetized in a fixed direction. Therefore, the permanent magnet 211 is moved while keeping a constant distance from the surface of the medium, and due to the leakage magnetic flux from the gap 212 of the permanent magnet,
The magnetic layer 201 is magnetized in a fixed direction. The arrow a indicates the moving direction of the permanent magnet 211, and the arrow c indicates the direction of the magnetic field due to the leakage magnetic flux.

FIG. 1B shows the alignment with the master disk 102. The medium 101 is placed on the surface having the magnetic layer 201, and the alignment is performed. FIG. 1C shows the medium in the writing process. Master disk 102 and medium 10
1 and the magnetic pattern recorded on the master disk 102 by the permanent magnet for magnetic transfer.
To the magnetic layer 201.

FIG. 2B shows a writing method. The master disk 102 has a structure in which the pattern of the soft magnetic layer 202 is embedded in a silicon substrate. Permanent magnet 21
1 is moved in the direction of arrow b, the magnetic field direction is reversed, and the pattern of the soft magnetic layer 202 is transferred to the magnetic layer 201. The direction of the magnetic field due to the leakage flux is the reverse arrow d in the degaussing process. The leakage magnetic flux from the permanent magnet 211 is generated by the soft magnetic layer 20.
In the place where 2 exists, it passes through the soft magnetic layer 202 which is a magnetic path having a small magnetic resistance. Therefore, the magnetic layer 201
The magnetic field reaching the magnetic field 201 becomes small, and the magnetic layer 201 is not magnetized. On the other hand, in the place where the soft magnetic layer 202 is not present, the leakage magnetic flux from the permanent magnet 211 reaches the magnetic layer 201 and magnetizes in the direction opposite to the demagnetization step. In this way, servo signals are collectively written on the medium by magnetic transfer.

FIG. 3 is a diagram for explaining a conventional master disk manufacturing process. On the surface of the silicon substrate 301 having a plate thickness of about 500 μm, a thickness of 1
A μm resist 302 is applied. The resist 302 is patterned by using the photolithography method. The result of patterning is shown in FIG. The silicon substrate 301 is dry-etched to a depth of 500 nm by a reactive plasma etching method using methane trichloride as a reaction gas. Etching groove 30 formed by etching
3 is shown in FIG.

As shown in FIG. 3C, the sputtering method is used.
The results of forming the Co-based soft magnetic film 304 to a thickness of 500 nm are shown. Next, the silicon substrate 301 is dipped in a solvent that dissolves the resist 302, and unnecessary resist 302 and the soft magnetic film 304 are removed to complete a master disk. Figure 3
The completed master disk is shown in (d).

FIG. 4A shows the pattern of the soft magnetic film on the entire master disk. FIG. 4B is a partially enlarged view. The width of the pattern is 0.52-0.65 μm at the inner circumference,
It is 0.98 to 1.49 μm on the outer periphery.

[0011]

FIG. 5 is a diagram showing the waveform of the servo signal read from the transferred medium. FIG. 5A shows a waveform when there is no thickness distribution of the soft magnetic film of the master disk. From the medium, the main pulses 501a and 501b can be read at the changing points in the direction of the magnetic field according to the pattern of the soft magnetic film. When forming the soft magnetic film, it is desirable that the film thickness distribution in the etching groove of the master disk be uniform.

FIG. 5B shows a waveform when there is a film thickness distribution. It can be seen that sub-pulses 512a and 512b are generated in addition to the main pulses 511a and 511b.
If there is a film thickness distribution, when an external magnetic field is applied by a permanent magnet, magnetic flux lines concentrate in the thin film portion, and the magnetic field strength locally increases. Further, when the saturation magnetic flux density of the soft magnetic material is exceeded, a magnetic field leaks from the soft magnetic layer to the medium, which causes a subpulse. The generation of the sub-pulse causes an error in reading the servo signal, which causes a problem of deteriorating the positioning accuracy of the magnetic head.

FIG. 6 is a block diagram showing a conventional sputtering apparatus. In the sputtering apparatus, a target holder 601 which also serves as a cathode and a substrate holder 60 which also serves as an anode
A high frequency electric field is applied between the two and argon (Ar) gas is introduced. Ar ions generated by the glow discharge bombard the target 603 and evaporate by sputtering. The source material by sputter evaporation reaches the substrate 604 and a film is formed. Substrate 604 fixed to substrate holder 602
Is rotated by the revolution device 606 to form a uniform film.

FIG. 7 is a diagram showing the structures of a target and a substrate in a conventional sputtering apparatus. In this sputtering apparatus, three types of targets 603a to 603c can be mounted on a target holder 601, and a jig 605 having an aperture that determines an equivalent diameter of the target is provided. The substrate holder 602 has four substrates 6
When 04a to 604d are mounted and rotated by the revolution device 606, each of the substrates 604a to 604d crosses the three types of targets 603a to 603c.

FIG. 8 is a diagram showing the relationship among the target, the aperture and the substrate. Normally, it is necessary to separate the target 603 and the substrate 604 by 100 mm or more so that the resist applied to the silicon substrate is not burned by the heat of sputtering, and in this apparatus, the distance is 135 mm. The diameters of the targets 603a to 603c of this device are 8 inches.
Since the substrates 604a to 604d have a diameter of 4 inches, the targets 603a to 603c to 11
A jig 60 having an aperture of 100 mm in 5 mm
5a and 605b are provided.

FIG. 9 is a cross-sectional view of a master disk formed by a conventional sputtering apparatus. The results of forming an etching groove having a width of 2 μm with the above-described sputtering apparatus are shown. The soft magnetic film formed in the etching groove has a film thickness distribution,
The sub-pulse shown in FIG. 5B may occur. The film thickness distribution becomes thinner toward both ends of the etching groove. The reason is that the raw material substance sputter-evaporated from the target is blocked by the resist 302. From this, it is found that the directivity of particles sputter-evaporated is broad.

FIG. 10 is a diagram showing the measurement results of the film thickness of the master disk formed by the conventional sputtering apparatus. FIG. 10A shows the measurement points on the master disk.
The measurement result is shown in 0 (b). 22% variation in film thickness
Has also reached. The cause is that, in the arrangement of the target, the jig, and the substrate shown in FIG. 7, the amount of the raw material substance that reaches the substrate is different depending on the portion of the substrate because the time taken for sputtered particles to pass through the aperture of the jig is different. This is because.

The present invention has been made in view of the above problems, and an object thereof is to provide a sputtering apparatus capable of forming a uniform soft magnetic film on a substrate and an etching groove. It is in.

[0019]

In order to achieve such an object, the present invention according to claim 1 forms a source material sputter-evaporated from a target on a substrate on a revolving substrate holder. In a sputtering apparatus for film formation, a raw material that is installed between the target and the substrate and has an opening having the same shape as the shape of the erosion region of the target and that reaches the substrate from the target It is characterized in that it is equipped with a jig for making uniform.

The invention according to claim 2 is characterized in that the opening according to claim 1 has a width proportional to the distance from the center of revolution of the substrate holder.

According to a third aspect of the present invention, the jig according to the first or second aspect includes a first plate having the opening, and a structure in which cylindrical or hollow polygonal columns are bundled, The structure is characterized in that the structure is connected to the first plate so as to cover the opening by a cross section of one end of the structure.

The invention according to claim 4 is characterized in that the structure in which the hollow polygonal columns according to claim 3 are bundled has a honeycomb structure.

According to a fifth aspect of the present invention, a structure in which the hollow polygonal columns are bundled according to the third aspect is a structure in which flat plates having cut grooves are combined in a grid pattern to bundle prisms. It is characterized by doing.

According to a sixth aspect of the present invention, in the jig according to the third, fourth or fifth aspect, the jig has a second plate having the opening connected to the other end of the structure, and the first plate. A plate is fixed to the second plate, and a casing covering a side surface of the structure is included.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. By making the width of the aperture of the jig proportional to the distance from the center of revolution of the substrate holder, the particles sputter-evaporated are uniformly irradiated regardless of the site of the substrate.

FIG. 11 is a perspective view showing a target used in the sputtering apparatus according to the embodiment of the present invention. The target 1101 has a region where a source material is easily vaporized by sputtering. This region is called an erosion region 1102, and is a concentric region corresponding to 75 to 85% of the outer diameter of the target. The diameter of the target 1101 is 5 inches, and the erosion area is 4 inches.
It corresponds to the substrate of h.

FIG. 12 is a diagram showing the relationship between the target and the jig of the sputtering apparatus according to the embodiment of the present invention. FIG. 13 shows an enlarged view of the jig. The aperture of the jig 1103 is the erosion area 1 of the target 1101.
By adjusting to the shape of 102, sputter-evaporated particles passing through the aperture uniformly reach each part of the substrate.

As shown in FIG. 7, the substrate is fixed to the substrate holder and revolves. Distance Rm from the center of revolution
When the revolution speed is Y rpm, the time T across the aperture width dmm at a position m away is T = 60d / 2πRY. The time T is represented by the reciprocal of the distance R. Therefore,
The irradiation time of sputter-evaporated particles passing through the aperture differs depending on the sputter position, so if the width d is increased in proportion to the distance R, the time T becomes constant.

FIG. 14 is a diagram showing the relationship between the distance from the center of revolution, the width of the aperture, and the time T. 14
FIG. 14A shows the relationship between the distance from the center of revolution and the width of the aperture, and FIG. 14B shows the relationship between the distance from the center of revolution and time T. Strictly speaking, since the emission density is also distributed in the erosion region, the width of the aperture needs to be considered in this distribution as well, but it may be considered to be uniform in practical use.

FIG. 15 is a configuration diagram showing a jig of a sputtering apparatus according to one embodiment of the present invention. Since particles sputter-evaporated have a wide directivity, this is a jig for taking out only a highly straight component. The jig includes a first plate 1501 having an aperture, a cylindrical assembly 1503, and a second plate 1502 having an aperture.
And are sequentially connected, and are fixed by a casing 1504.
By installing such a jig between the target and the substrate, only particles with high straightness pass through the jig, and other particles cannot collide with, adhere to the side wall of the cylinder and pass through. .

For example, if the inner diameter of the cylinder is 7 mm and the length of the cylinder is 80 mm, only particles within an incident angle of 5 degrees will pass. By connecting the apertures of the first plate 1501 and the second plate 1502 with this cylindrical assembly 1503, at any position of the aperture,
Only particles with high straightness can be passed. The casing 1504 prevents sputter-evaporated particles from irradiating a peripheral substrate other than the substrate on which a film is formed. As the cylindrical aggregate 1503, a structure in which hollow polygonal columns are bundled or a honeycomb structure may be used.

FIG. 16 is a constitutional view showing a jig structure of a sputtering apparatus according to an embodiment of the present invention. The flat plates are combined to form a structure in which prisms are bundled so as to form a structure in which hollow polygonal columns are bundled. As shown in FIG. 16 (a), a plurality of flat plates are used, each of which has cut grooves reaching half the length of the flat plate in the vertical direction and provided at equal intervals in the horizontal direction. Figure 1
As shown in 6 (b), the cut grooves of the flat plate are opposed to each other,
The flat plates are combined in a grid pattern so that they are combined to form a structure in which prisms are bundled. With such a structure, FIG.
The first plate 1501 and the second plate 150 shown in FIG.
By connecting the two apertures, a jig for the sputtering apparatus is constructed.

[0033]

As described above, according to the present invention,
The sputtering device is installed between the target and the substrate,
With the opening having the same shape as the shape of the erosion region of the target, the raw material that reaches the substrate from the target,
Since the jig for uniformizing on the substrate is provided, it becomes possible to form a uniform soft magnetic film on the substrate and on the etching groove.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a servo signal writing method by magnetic transfer.

FIG. 2 is a diagram for explaining the principle of magnetic transfer.

FIG. 3 is a diagram for explaining a conventional master disk manufacturing process.

FIG. 4 is a diagram showing a pattern of a soft magnetic film of a conventional master disk.

FIG. 5 is a diagram showing a waveform of a servo signal read from a transferred medium.

FIG. 6 is a configuration diagram showing a conventional sputtering apparatus.

FIG. 7 is a diagram showing a configuration of a target and a substrate in a conventional sputtering apparatus.

FIG. 8 is a diagram showing a relationship among a target, a jig, and a substrate.

FIG. 9 is a cross-sectional view of a master disk formed by a conventional sputtering apparatus.

FIG. 10 is a diagram showing a measurement result of a film thickness of a master disk formed by a conventional sputtering apparatus.

FIG. 11 is a perspective view showing a target used in the sputtering apparatus according to the embodiment of the present invention.

FIG. 12 is a diagram showing a relationship between a target and a jig of the sputtering apparatus according to the embodiment of the present invention.

FIG. 13 is an enlarged view showing a jig of the sputtering apparatus according to the embodiment of the present invention.

FIG. 14 is a diagram showing the relationship between the distance from the center of revolution, the width of the aperture, and the time T.

FIG. 15 is a configuration diagram showing a jig of a sputtering apparatus according to an embodiment of the present invention.

FIG. 16 is a configuration diagram showing a jig structure of a sputtering apparatus according to an embodiment of the present invention.

[Explanation of symbols]

101 medium 102 master disk 201 magnetic layer 202 soft magnetic layer 211 permanent magnet 212 gap 301 silicon substrate 302 resist 303 etching groove 304 soft magnetic film 601 target holder 602 substrate holder 603, 603a to 603c, 1101, 1101a to
1101c Targets 604, 604a to 604d Substrates 605, 605a, 605b, 1103 Jig 606 Revolution device 1102, 1102a to 1102c Erosion region 1501 First plate 1502 Second plate 1503 Cylindrical assembly 1504 Casing

Claims (6)

[Claims] 1. A sputtering apparatus for depositing a raw material sputter-evaporated from a target on a substrate on a revolving substrate holder, the sputtering device being installed between the target and the substrate, and having the same shape as an erosion region of the target. A sputtering apparatus comprising a jig having a shaped opening and making a source material reaching the substrate from the target uniform on the substrate. 2. The sputtering apparatus according to claim 1, wherein the opening has a width proportional to a distance from a center of revolution of the substrate holder. 3. The jig includes a first plate having the opening and a structure in which cylindrical or hollow polygonal columns are bundled, and the opening is covered by a cross section of one end of the structure. The sputtering apparatus according to claim 1 or 2, wherein the sputtering apparatus is connected to the first plate as described above. 4. The sputtering apparatus according to claim 3, wherein the structure in which the hollow polygonal columns are bundled has a honeycomb structure. 5. The sputter according to claim 3, wherein the structure in which the hollow polygonal columns are bundled is a structure in which flat plates having slits are combined in a grid pattern to bundle prisms. apparatus. 6. The jig fixes a second plate having the opening connected to the other end of the structure, the first plate and the second plate, and covers a side surface of the structure. The sputtering apparatus according to claim 3, 4 or 5, comprising a casing.