JPH10163058A - Device for manufacturing magnetic thin film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for manufacturing a magnetic thin film in which nonuniformity in a plasma density in the neighborhood of the surface of a substrate is eliminated, and nonuniformity in etching distribution, etc., is eliminated, and improve yield. SOLUTION: In this manufacturing device, a film forming mechanism which forms a magnetic thin film on a substrate 13 held by a substrate holder 12, and a magnetic anisotropy control mechanism which imparts anisotropy to the magnetic thin film are provided, and magnets 14 and 15 generating parallel magnetic field, etc., are used for the magnetic anisotropy control mechanism. The magnetic anisotropy control mechanism is so constituted that an apply range such as a parallel magnetic field 17, etc., contains part ranges parallel to the surface of the substrate and is generated by continuously joining these part ranges. Thereby the applying range of the magnetic field is made into annular shape, and a moving route of an electron drift in plasma generated around the surface of the substrate is closed by the apply range.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a magnetic thin film manufacturing apparatus, and more particularly to a magnetic thin film manufacturing apparatus for manufacturing a magnetic thin film used for a magnetic head or the like.

[0002]

2. Description of the Related Art For example, in the formation of a magnetic thin film used for a magnetic head, in addition to a normal film forming mechanism, the surface of the substrate on which the magnetic thin film is formed is provided to impart magnetic anisotropy to the magnetic thin film. A magnetic anisotropy control mechanism using a permanent magnet or an electromagnet coil (hereinafter, referred to as “magnet”) near the (film formation surface) is used. The magnetic field generated by the magnetic anisotropy control mechanism is a magnetic field having a uniform strength and a parallel direction in a film forming surface of the substrate.

In the formation of the above magnetic thin film, the surface of the substrate on which the film is to be formed is etched by a sputtering method before the film is formed, or the thickness of the thin film formed on the substrate is controlled. After the film formation, the thin film is etched by a sputtering method. In some cases, a film is formed by a bias sputtering method in order to improve the quality of the magnetic thin film. In performing such a sputtering method,
The plasma generated on the substrate surface is affected by the parallel magnetic field by the above-described magnetic anisotropy control mechanism.

Conventionally, the range of application of a parallel magnetic field generated by the magnetic anisotropy control mechanism is only within a limited range near the surface of the substrate or in the vicinity of the formed thin film, and in other ranges. No parallel magnetic field was applied.

[0005] An example of the above-described conventional magnetic thin film manufacturing apparatus will be specifically described with reference to FIGS. 7 and 8. In this magnetic thin film manufacturing apparatus, a sputtering mechanism provided with a permanent magnet constituting the above-described magnetic anisotropy control mechanism is schematically shown.
Permanent magnets 74 and 75 and a yoke member 76 have a uniform magnetic field strength with respect to a substrate 73 placed horizontally and horizontally on a substrate holder 72 installed in a vacuum vessel 71. A magnetic field 77 in which the direction of the magnetic field (magnetic flux lines) is parallel is applied. The substrate 73 and the substrate holder 72 are connected to a high frequency power supply 79 having a frequency of 13.56 MHz via a matching box 78 for matching impedance. The high-frequency power supply 79 and the matching box 78 supply high-frequency power required for discharging.

The vacuum vessel 71 is provided with a vacuum pump 80 for evacuating the inside thereof to a high vacuum state and a gas introducing mechanism 81 for introducing a necessary discharge gas. The discharge gas is
An inert gas having a high sputtering rate, for example, an Ar gas is used. Adjustment of the pressure of the discharge gas is performed by the valve 82.
The gas pressure in the vacuum vessel 71 is indicated by a pressure gauge 83.

[0007] Using the sputtering mechanism having the above structure,
A method for etching the surface of the substrate 73 will be described. The substrate 73 is placed on the substrate holder 72, and the vacuum container 71 is evacuated to a high vacuum by the vacuum pump 80.
At 1, the gas introduction mechanism 81 operates to introduce a discharge gas at a desired flow rate, and the gas pressure in the vacuum vessel 71 is maintained at a desired pressure using the valve 82. The high frequency power supply 79 and the matching box 78 operate, and the substrate 73 and the substrate holder 72 are operated.
Is supplied to the substrate 73 and a permanent magnet 74, 75 generates an electric field orthogonal to the magnetic field 77 on the substrate 73 and the substrate holder 72.

[0008] The electrons in the plasma generated by the supply of the high-frequency power act in a direction perpendicular to the magnetic and electric fields by Lorentz force. The electrons are trapped on the surface of the substrate by the magnetic field 77, perform cyclotron motion, collide with the discharge gas molecules, and promote ionization. The ionized discharge gas sputters the surface of the substrate 73.

FIG. 9 schematically shows cyclotron motion of electrons. Electrons 84 in the plasma drift in the direction 85 shown in FIG. As shown in FIG. 8, when the magnetic field 77 is working, the electrons drift from A to B, so that the electrons concentrate on B. As a result, FIG.
Therefore, the plasma density in the region indicated by reference numeral B becomes higher than the plasma density in the region indicated by reference numeral A, and the etching distribution of the substrate 73 is biased. FIG. 10 shows that the substrate 73
₂ shows the results of etching distribution when etching was performed using an Si substrate having a diameter of 100 mm deposited at a thickness of 1 μm and maintaining an Ar gas at 1 mTorr. As is apparent from FIG. 10, the etching distribution in the surface of the substrate was biased.

[0010]

As described above, when the application range of the parallel magnetic field by the magnetic anisotropy control mechanism is limited only to the inside of the substrate surface, the etching distribution is biased, and the portion that is not etched on the substrate surface is reduced. As a result, there is a portion that is not cleaned on the substrate surface. In the film formation by the bias sputtering method, a portion where a bias effect cannot be obtained is formed, and a film having a different film quality is formed in the substrate surface, which causes a reduction in yield.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and to provide a magnetic thin film manufacturing apparatus in which the unevenness of the plasma density near the substrate surface and the unevenness of the etching distribution and the like are eliminated to improve the yield. It is in.

[0012]

In order to achieve the above object, a magnetic thin film manufacturing apparatus according to a first aspect of the present invention (corresponding to claim 1) has a magnetic thin film on a substrate held by a substrate holder. A magnetic thin film manufacturing apparatus that includes a film forming mechanism for forming a film and a magnetic anisotropy control mechanism that imparts magnetic anisotropy to the magnetic thin film. The anisotropy control mechanism is generated by including a partial range in which the application range of the parallel magnetic field or the like by the magnet is substantially parallel to the substrate surface (or the substrate disposition surface) and continuously connecting the plurality of partial ranges. In such a configuration, the application range of the magnetic field is generated so as to be annular, and the moving path of the electron drift in the plasma generated near the surface of the substrate is closed by the annular application range. The route It is characterized in.

The cause of the uneven plasma density is that the electron drift path is not closed. Therefore, if the drift path is closed, the bias of the plasma density due to the drift is eliminated. To close the drift path,
The application range of the magnetic field created by the magnet of the magnetic anisotropy control mechanism is not limited to the area near the substrate deposition surface, but a magnetic field is also created outside the substrate deposition surface, and the magnetic field application range is continuously annular. It should be done. In the configuration of the first aspect, the magnets (permanent magnets or electromagnet coils) used in the magnetic anisotropy control mechanism are formed so as to generate an application range consisting of an annularly continuous magnetic field passing over the substrate surface. doing. As a result, the plasma is not biased on the substrate deposition surface, and a film of uniform film quality can be obtained in the substrate surface in favorable etching distribution and bias sputtering.

According to a second aspect of the present invention (corresponding to claim 2), in the magnetic thin film producing apparatus according to the first aspect, the substrate holder preferably has a polygonal column shape and is arranged in an upright state. And using at least one of the plurality of sidewall outer surfaces of the substrate holder as a substrate placement surface, disposing magnets at each of both ends of the substrate holder to generate the application range around the sidewall outer surface of the substrate holder. It is characterized by the following.

According to a third aspect of the present invention (corresponding to claim 3), in the magnetic thin film manufacturing apparatus according to the first aspect of the present invention, the substrate holder preferably has a polygonal column shape and is laid horizontally. And using at least one of the plurality of side wall outer surfaces of the substrate holder as a substrate placement surface and arranging magnets at each of both ends of the substrate holder to generate the application range around the side wall outer surface of the substrate holder. It is characterized by having done.

According to a fourth aspect of the present invention (corresponding to claim 4), in the magnetic thin film manufacturing apparatus according to the first aspect, the substrate holder preferably has a plate-like form having a relatively large area surface. Having a magnet at each of the center and the periphery of the surface of the substrate holder,
An application range is generated on a surface of the substrate holder, and at least one substrate is disposed on a surface between the magnet disposed at the center and the magnet disposed at the periphery.

According to a fifth aspect of the present invention (corresponding to claim 5), in the magnetic thin film manufacturing apparatus according to the above-mentioned respective aspects, the magnetic anisotropy control mechanism for generating the magnetic field application range is used. The etching is performed by a sputtering method before or after forming a substrate.

According to a sixth aspect of the present invention (corresponding to claim 6), the magnetic thin film manufacturing apparatus according to the above-described aspects of the invention uses the magnetic anisotropy control mechanism for generating the application range of the magnetic field. The substrate is formed by a bias sputtering method.

[0019]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a first embodiment of a magnetic thin film manufacturing apparatus according to the present invention. The magnetic thin film manufacturing apparatus according to this embodiment has a configuration having a permanent magnet as a magnetic anisotropy control mechanism, and has a mechanism for etching a substrate by a sputtering method. 2 (a), (b),
(C) schematically shows a configuration of a permanent magnet for forming a magnetic field application range in a ring shape and a portion of a substrate holder.

As shown in FIG. 1, a substrate holder 12 is provided upright in a vacuum vessel 11.
As shown in FIG. 2, the substrate holder 12 has, for example, a quadrangular prism shape, and at least one of the four outer wall surfaces is used as a substrate placement surface. In the illustrated example, the substrate 13 is arranged on the outer surface of one side wall of the substrate holder 12. The substrate 13 is also held upright. The substrate holder 12 is made of non-magnetic aluminum (Al). At the upper and lower ends of both ends of the substrate holder 12, permanent magnets 14, 15 formed in a square shape and a yoke member 16 are provided. A magnetic field (parallel magnetic field) 17 having a uniform magnetic field strength and a parallel direction of the magnetic field (magnetic flux lines) is applied to the substrate 13 placed on the substrate holder 12 by the permanent magnets 14 and 15 and the yoke material 16. Has been applied. The area of the magnetic field 17 created by the permanent magnets 14, 15 and the yoke 16 is formed around the side wall of the substrate holder 12. The portions of the permanent magnets 14 and 15 involved in creating the magnetic field 17 form a rectangular ring. The permanent magnets 14, 15 are made of a noble earth magnetic metal. The yoke member 16 is made of a stainless steel material (SUS430), which is a magnetic material, in a square plate shape.

In the above description, the permanent magnets 14 and 15 and the yoke 16 constitute a magnetic anisotropy control mechanism for giving magnetic anisotropy to the magnetic thin film formed on the substrate 13. In the present embodiment, the magnetic anisotropy control mechanism is also a means for etching the surface of the substrate 13 by a sputtering method, and is used as a means for eliminating plasma bias. The application range of the parallel magnetic field generated by the permanent magnets 14 and 15 includes a region parallel to the surface (film formation surface) of the substrate 13 as a part. Also, as noted above, and as clearly shown in FIG. 2, the permanent magnets 14 and 15 are arranged to create a magnetic field 17 around the four sidewall outer surfaces of the substrate holder 12. Accordingly, each of the application ranges of the magnetic field generated corresponding to one outer wall surface is continuously connected to form an annular shape around the outer wall surface of the substrate holder 12. Therefore, the movement path of the electron drift in the plasma generated near the surface of the substrate 13 is formed to be a closed path.

In FIG. 1, the illustration of a film forming mechanism for forming a magnetic thin film on the substrate 13 holding the substrate holder 12 is omitted.

The substrate 13 and the substrate holder 12 are connected to a high frequency power supply 19 having a frequency of 13.56 MHz via a matching box 18 for matching impedance. High frequency power required for generating plasma discharge is supplied by the high frequency power supply 19 and the matching box 18.

The vacuum vessel 11 has a vacuum pump 20 for evacuating the inside and a gas introducing mechanism 21 for introducing a necessary discharge gas. As a discharge gas, an inert gas (Ar gas or the like) having a high sputtering rate is used. Adjustment of the pressure of the discharge gas is performed by the valve 22. Vacuum container 11
The gas pressure inside is measured by the pressure gauge 23 and displayed.

Next, a method for etching the surface of the substrate 13 by a sputtering method based on the above mechanism will be described.
After the substrate 13 is placed on the substrate holder 12 as described above and the vacuum vessel 11 is evacuated to a high vacuum by the vacuum pump 20, the gas introduction mechanism 21 operates to introduce the discharge gas into the vacuum vessel 11 at a desired flow rate. Then, the gas pressure in the vacuum vessel 11 is maintained at a desired pressure by using the valve 22. When the high-frequency power supply 19 and the matching box 18 operate and high-frequency power is applied to the substrate 13 and the substrate holder 12, the magnetic field 1 generated by the permanent magnets 14 and 15 on the substrate 13
An electric field orthogonal to 7 is created.

The electrons in the plasma generated by the supply of the high-frequency electric power act in a direction perpendicular to the magnetic field and the electric field by Lorentz force. The electrons are trapped on the surface of the substrate by the magnetic field 17 and perform cyclotron motion to collide with the discharge gas molecules to promote ionization. The ionized discharge gas sputters the substrate 13.

In the sputtering of this embodiment, as described above, the application range of the magnetic field 17 is formed in an annular shape around the outer surface of the side wall of the substrate holder 12. The electron drift travel path is closed. Therefore, it is possible to eliminate the bias of the plasma density.

FIG. 3 shows that the substrate 13 is made of SiO ₂ of 1 μm.
This graph shows the etching distribution on the substrate surface when the above-mentioned etching was performed using an Si substrate having a thickness of 100 m and a diameter of 100 mm and maintaining the Ar gas pressure at 1 mTorr. As is clear from this figure, it is clear that the etching distribution has no bias as compared with the conventional etching distribution shown in FIG.

FIG. 4 shows another example of use in the first embodiment. In the embodiment shown in FIGS. 1 and 2, an example in which one substrate 13 is etched using one side wall outer surface of the square pillar substrate holder 12 has been described.
In the embodiment, the four substrates 13 are etched at a time by using all the four outer surfaces of the side walls of the substrate holder 12. All the substrates 13 arranged on each of the outer surfaces of the side walls of the substrate holder 12 were able to obtain the same results as those shown in FIG.

FIG. 5 shows a second embodiment of the present invention. In this embodiment, a plan view of a substrate holder, an arrangement state of a plurality of substrates on a substrate arrangement surface of the substrate holder, and an arrangement state of two magnets are shown. In this embodiment, the substrate holder 31
The substrate placement surface is preferably circular in shape, and the substrate holder 31 is placed in the vacuum vessel so that the substrate placement surface is substantially horizontal. On the substrate placement surface of the substrate holder 31, a permanent magnet 32 is disposed at the center thereof,
An annular permanent magnet 33 is arranged on the periphery. The permanent magnets 32, 33 create a magnetic field 34, which is directed in the radial direction indicated by the arrow and toward the center. On the board placement side,
A plurality of substrates 13 are arranged in a space between the permanent magnets 32 and 33 in an annular manner.

Also in the second embodiment, the movement path of the electron drift in the plasma generated near each surface of the plurality of substrates 13 is closed in the annular region around the permanent magnet 32 at the center. Made to be a path. Therefore, it is possible to prevent the density of plasma generated in the vicinity of each of the plurality of substrates 13 from being biased on the substrate surface, and to prevent the etching on the surface of each substrate from being biased. 1 μm of SiO _{2 on the} substrate 13
Using a substrate with a thickness of 100 mm and a film thickness of
As a result of etching while maintaining the r gas pressure at 1 mTorr, the same effect as in the first embodiment could be obtained.

In the second embodiment, by forming the substrate placement surface of the substrate holder 31 and the permanent magnets 32 and 34 in a rectangular shape, the arrangement region of the plurality of substrates 13 can be formed in a rectangular shape.

FIG. 6 shows a third embodiment of the present invention.
In this embodiment, an example in which a film is formed by a bias sputtering method will be described. FIG. 6 further includes a magnetron cathode 41, a target 42, and a DC power supply 43 in addition to the configuration of the magnetic thin film manufacturing apparatus described in the first embodiment so that a film can be formed on a substrate by a bias sputtering method. In FIG. 6, elements substantially the same as the elements described in FIGS. 1 and 4 are denoted by the same reference numerals.

The structures of the substrate holder 12, the permanent magnets 14, 15 and the yoke member 16 according to the present embodiment are the same as those of the first embodiment, but in the case of the present embodiment, they are arranged horizontally. . Other configurations related to the magnetic thin film production equipment
This is the same as that described in the first embodiment.

Magnetron cathode 41 and target 4
2 is provided at a position above the substrate holder 12 in the vacuum vessel 11. Magnetron cathode 41 is disposed at a position facing the substrate 13, N _i F _e of the target 42 of a magnetic material is mounted in front of the magnetron cathode 41. The magnetron cathode 41 includes a magnet assembly 45 that generates a leakage magnetic field 44 through the target 42, and a cooling mechanism 46 for cooling the target 42. A DC power supply 4 is connected to the magnetron cathode 41.
3 is connected and the desired power is applied. The distance between the magnetron cathode 41 and the substrate 13 is adjusted so that the leakage magnetic field 44 on the target 42 due to the magnetron cathode 41 and the magnetic field 17 generated by the permanent magnets 14 and 15 do not interact with each other.

Next, the film formation by the bias sputtering method will be described. The vacuum vessel 11 is evacuated to a high vacuum using a vacuum exhaust pump 20, and then Ar gas is introduced into the vacuum vessel 11 by a gas introduction mechanism 21, and the Ar gas pressure in the vacuum vessel is adjusted to a desired pressure using a valve 22. Keep at pressure. Thereafter, the DC power supply 43 is operated to sputter the target 42 to form a film on the substrate 13, and at the same time, bias power is applied to the substrate 13 by the high frequency power supply 19 and the matching box 18.

When a glass substrate was used as the substrate 13, an Ar gas pressure was maintained at 1 mTorr, a DC power of 3 kW was applied to the target 42, and a high-frequency power of 400 W was applied to the substrate 13. Regarding the distribution, a result similar to the result of FIG. 3 was obtained for the distribution state.

In each of the above embodiments, a permanent magnet is used as the magnetic anisotropy control mechanism. However, when an electromagnet coil is used for the magnetic anisotropy control mechanism, the application range of the parallel magnetic field or the like generated by the electromagnet coil is as described above. In the same manner as the magnetic fields 17 and 34 described above, if they are formed annularly and continuously, the same effects as those of the above-described embodiment using a permanent magnet can be obtained.

[0040]

As is apparent from the above description, according to the present invention, a magnetic thin film manufacturing apparatus provided with a magnetic anisotropy control mechanism comprising a magnet utilizes a magnetic field generated by the magnetic anisotropy control mechanism. When the surface of the substrate is etched by sputtering, the magnetic anisotropy control mechanism that makes the application range of the magnetic field annular so as to close the drift movement path of the electrons generated by the plasma is used. The bias can be eliminated and the etching distribution can be improved.

In the case of bias sputtering film formation using plasma on the substrate surface, a magnetic anisotropy control mechanism for generating an annular magnetic field application range is used in the same manner as described above. The film thickness distribution of the formed thin film can be improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a part of a sputtering mechanism of a magnetic thin film manufacturing apparatus according to a first embodiment of the present invention.

FIGS. 2A and 2B are views showing a configuration near a substrate holder and a permanent magnet in the first embodiment, wherein FIG. 2A is a front view and FIG.
FIG. 2 is a side view, and FIG. 2C is an arrow view taken along line A1-A1 in FIG.

FIG. 3 is a diagram showing an etching distribution on a substrate surface when performing etching according to the first embodiment.

FIGS. 4A and 4B are diagrams showing a configuration in the vicinity of a substrate holder and a permanent magnet in a modification of the first embodiment, wherein FIG. 4A is a front view, FIG. 4B is a side view, and FIG. B1-B
It is the arrow view cut by 1 line.

FIG. 5 is a plan view of a part of a substrate holder of a magnetic thin film manufacturing apparatus according to a second embodiment of the present invention.

FIG. 6 is a view showing a configuration relating to bias sputtering of a magnetic thin film manufacturing apparatus according to a third embodiment of the present invention.

FIG. 7 is a configuration diagram showing a sputtering mechanism of a conventional magnetic thin film manufacturing apparatus.

FIG. 8 is a plan view of a substrate holder part of a conventional magnetic thin film manufacturing apparatus.

FIG. 9 is a diagram illustrating a drift direction of electrons due to a magnetic field and an electric field.

FIG. 10 is a diagram showing an etching distribution obtained by etching using a conventional apparatus.

DESCRIPTION OF SYMBOLS 11 Vacuum container 12, 31 Substrate holder 13 Substrate 14, 15 Permanent magnet 16 Yoke material 17 Magnetic field 20 Vacuum exhaust pump 21 Gas introduction mechanism 22 Valve 23 Pressure gauge 32, 33 Permanent magnet 34 Magnetic field 41 Magnetron cathode 42 Target 45 Magnet assembly 46 Cooling mechanism

Claims (6)

[Claims] A film forming mechanism for forming a magnetic thin film on a substrate held by a substrate holder; and a magnetic anisotropy control mechanism for imparting magnetic anisotropy to the magnetic thin film. In a magnetic thin film manufacturing apparatus using a magnet that creates a magnetic field in the mechanism, the magnetic anisotropy control mechanism includes a partial range in which the application range of the magnetic field by the magnet is parallel to the surface of the substrate, and a plurality of the partial areas. The application range of the magnetic field is generated so as to be annular, and the electron drift in the plasma generated near the surface of the substrate due to the annular application range. A magnetic thin film manufacturing apparatus, wherein a moving path of the magnetic thin film is a closed path. 2. The substrate holder according to claim 1, wherein said substrate holder has a shape of a polygonal prism and is arranged in an upright state, and at least one of a plurality of side wall outer surfaces of said substrate holder is used as a substrate arrangement surface. The magnetic thin film manufacturing apparatus according to claim 1, wherein the magnet is arranged in each of the first and second regions to generate the application range around the outer surface of the side wall of the substrate holder. 3. The substrate holder has a shape of a polygonal prism and is arranged in a state of being laid horizontally, and at least one of a plurality of side wall outer surfaces of the substrate holder is used as a substrate arrangement surface. 2. The magnetic thin film manufacturing apparatus according to claim 1, wherein the magnet is arranged at each of both ends, and the applied range is generated around the outer surface of the side wall of the substrate holder. 4. The substrate holder has a plate-like form having a relatively large surface area and is disposed substantially horizontally, and the substrate holder has a central portion and a peripheral portion on each of the surface and the peripheral portion. A magnet is disposed to generate the application range on the surface of the substrate holder, and at least one substrate is provided on the surface between the magnet disposed at the center and the magnet disposed at the peripheral portion. The magnetic thin film manufacturing apparatus according to claim 1, wherein is disposed. 5. The method according to claim 1, wherein the etching is performed by a sputtering method before or after the substrate is formed by using the magnetic anisotropy control mechanism for generating the application range of the magnetic field. Item 5. The magnetic thin film production apparatus according to any one of Items 1 to 4. 6. The substrate according to claim 1, wherein the substrate is formed by a bias sputtering method by using the magnetic anisotropy control mechanism for generating the application range of the magnetic field. Item 6. The magnetic thin film production apparatus according to item 1.