JP2007270189A - Film-forming apparatus and method for manufacturing magnetic disk - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a batch-feeding type film-forming apparatus for forming a film on a plurality of non-electroconductive substrates with a bias sputtering technique, which can adequately apply a DC-bias while keeping the productivity. <P>SOLUTION: This film-forming apparatus comprises: a base 6 for holding the non-electroconductive substrates 1; and a bias application means for applying a biased voltage to an electroconductive film by making a terminal 13 for applying the bias contact with the electroconductive film formed on the substrates 1. The terminal 13 for applying the bias is made of a member which changes its shape according to temperature, such as a shape memory alloy, and contacts with or separates from the substrate 1 held on the base 6 by changing the shape according to the change of the temperature. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a magnetic disk mounted on a hard disk device or the like, and also relates to a film forming apparatus that can be used for manufacturing such a magnetic disk.

  Conventionally, a magnetic disk mounted on a hard disk drive is manufactured by forming a laminated film on a disk substrate with a vacuum apparatus (a sputtering apparatus or the like). This laminated film is formed, for example, by placing a disk substrate held on a base in a process chamber (film formation chamber) in which a plurality of targets are installed, evacuating, sputtering, CVD, or the like. Be filmed.

  The laminated film formed on the disk substrate is formed by sequentially forming films such as a base layer and a recording layer. It is known that the temperature of the disk substrate at the time of forming each of these layers greatly affects the surface state and film characteristics of the film, and the disk substrate is heated in a vacuum. Has been.

  Incidentally, in recent years, such a magnetic disk has been required to improve the recording density. In order to improve the recording density of the magnetic disk, it is necessary to maintain and improve the signal quality and to improve the resistance to the self-demagnetization effect as the pit size is reduced. In order to maintain and improve signal quality, an intermediate nonmagnetic layer is provided between the underlayer and the magnetic film in order to reduce noise. In order to improve the resistance to the self-demagnetization effect, in order to reduce the thickness of the magnetic film and increase the coercive force, the exchange coupling magnetic film is introduced, Pt is introduced into the magnetic film, and the disk is formed at the time of film formation. A bias potential is applied to the substrate.

  That is, as described in Patent Document 1 to Patent Document 3, by performing bias sputtering in which a negative DC bias voltage (substrate bias) is applied to the disk substrate during the formation of the magnetic film, the magnetic disk has a high height. It is known that recording density can be increased. This can be achieved by increasing the adhesion of the magnetic film by applying a substrate bias, reducing the surface roughness, increasing the hardness by increasing the density of the magnetic film, as well as the orientation of the microcrystalline film and the length of the crystal axis. This is because it becomes possible to change the length.

  When a non-conductive glass substrate or the like is used as the disk substrate, as described in Patent Document 4, a base layer made of a metal film is formed as the first layer, and a substrate bias is applied to the base layer. A method is known in which a magnetic layer or the like is formed on the underlayer by application. In such a case, as described in Patent Document 5 and Patent Document 6, various methods have been proposed as a method for bringing the bias application terminal into contact with the underlying layer on the disk substrate.

  In recent years, magnetic disks include not only 2.5-inch type mounted on so-called notebook computers and 3.5-inch type mounted on so-called desktop computers, but also mobile phones, digital cameras, Small-diameter magnetic disks, such as 1.0-inch type and 0.85-inch type, which are mounted on storage devices of small devices such as carnavigation and portable music players are manufactured. Productivity cannot be improved unless film formation on such a small-diameter disk substrate is performed by holding a plurality of disk substrates on one base.

  Therefore, in the manufacture of these small-diameter magnetic disks, in order to improve productivity, for example, as described in Patent Document 7, a plurality of small-diameter disk substrates are held on one base having a large diameter. A method of forming a film on a plurality of disk substrates at a time using a single-wafer type film forming apparatus has been proposed.

IEEE-E Transactions on Magnetics. 26, 1282, 1990. JP-A-7-225935 Japanese Patent Laid-Open No. 5-205240 JP-A-4-79025 Japanese Patent No. 3002632 JP-A-7-243037 JP 2001-011625 A

  By the way, in bias sputtering for applying a DC bias to a disk substrate, a claw-shaped member made of a conductive material (for example, metal) is provided on the base, and each disk substrate is held by the claw-shaped member. This claw-like member is also used as a bias application terminal.

  When bias sputtering is performed using a non-conductive disk substrate, it is necessary to apply a DC bias to the underlying layer formed on the non-conductive disk substrate. The underlayer is formed in a state where the disk substrate is held by a claw-like member used also as a bias application terminal. In this case, the base layer is not formed on the portion of the disk substrate covered with the claw-like member. For this reason, the contact between the nail-like member and the base layer becomes insufficient, and there is a possibility that the substrate bias cannot be applied appropriately.

  Therefore, after the base layer is formed, the position of the disk substrate is changed and reattached to the nail member so that the nail member and the base layer are in sufficient contact. In this way, the electric conduction necessary for applying the substrate bias is ensured, so that the substrate bias can be appropriately applied in the subsequent film forming process.

  However, in order to reattach the disk substrate, the disk substrate is once taken out of the film forming apparatus and is put into the film forming apparatus again, so that the productivity is remarkably deteriorated. In particular, when film formation is performed simultaneously on a plurality of disk substrates, it is difficult to improve productivity because it is necessary to apply a DC bias to each disk substrate. Further, once the disk base is taken out into the atmosphere, there is a possibility that particles may adhere to the disk substrate, which may lead to deterioration of quality.

  Therefore, the present invention has been proposed in view of the above circumstances, and in a single wafer type film forming apparatus that performs film formation by bias sputtering on a plurality of non-conductive substrates, productivity is improved. It is an object of the present invention to provide a method for manufacturing a magnetic disk that is capable of satisfactorily applying a DC bias while maintaining a high density and that is compatible with high-density recording.

  In order to solve the above-described problems and achieve the above object, a film forming apparatus according to the present invention has any one of the following configurations.

[Configuration 1]
A single-wafer type film forming apparatus for forming a film by bias sputtering on a non-conductive substrate, comprising a base for holding at least one non-conductive substrate and a bias application terminal. Bias application means for applying a bias voltage to the conductive film by bringing the terminal into contact with a conductive film formed on a non-conductive substrate, and the bias application terminal has a shape corresponding to the temperature. Is formed by a member that changes, and is brought into contact with and separated from a non-conductive substrate held on a base by deformation due to temperature change.

[Configuration 2]
In the film forming apparatus having the configuration 1, the member whose shape changes in accordance with the temperature forming the bias application terminal is a shape memory alloy.

[Configuration 3]
In the film forming apparatus having the structure 1, the member whose shape changes according to the temperature forming the bias application terminal is a bimetal.

[Configuration 4]
In the film forming apparatus having any one of the structures 1 to 3, the bias application terminal is deformed by a temperature rise accompanying the film formation and contacts the non-conductive substrate held on the base, It is characterized by being deformed by a temperature drop accompanying the completion of film formation and being separated from a non-conductive substrate held on a base.

[Configuration 5]
The film forming apparatus having any one of Configurations 1 to 3 includes temperature control means for controlling the temperature of the bias application terminal, and the temperature of the bias application terminal is raised by the temperature control means during film formation. And deformed by contacting the non-conductive substrate held on the base and being lowered by the temperature control means after completion of the film formation and held on the base. It is characterized by being separated from the non-conductive substrate.

[Configuration 6]
The film forming apparatus having any one of Configurations 1 to 3 includes current supply means for supplying current to the bias application terminal, and the bias application terminal is supplied with current by the current supply means during film formation. When the temperature rises, it deforms and contacts the non-conductive substrate held on the base, and after the film formation is finished, the current supply by the current supply means is cut off and the temperature is lowered to deform. Thus, the substrate is separated from the non-conductive substrate held on the base.

[Configuration 7]
In the film forming apparatus having any one of Structures 1 to 6, a disk substrate is used as a substrate, and an underlayer, a magnetic layer, and a protective layer are sequentially formed on the disk substrate.

  A magnetic disk manufacturing method according to the present invention has any one of the following configurations.

[Configuration 8]
A method of manufacturing a magnetic disk in which a base layer, a magnetic layer, and a protective layer are sequentially formed on a non-magnetic and non-conductive disk substrate, the step of holding the disk substrate on a base, and a base in a vacuum chamber. A step of forming a conductive film on the disk substrate held on the table, and the bias application terminal of the bias application means are deformed in the vacuum chamber to form the bias application terminal on the disk substrate. A magnetic layer and a protective layer are sequentially formed on the conductive film while applying a bias voltage to the conductive film via a bias application terminal by a bias applying means in a vacuum chamber. A bias applying member formed by a member whose shape changes according to temperature and held on the base by deformation due to temperature change. And it is characterized in the use of those contact and separation to sexual substrate.

[Configuration 9]
In the method of manufacturing a magnetic disk having the configuration 8, a shape memory alloy is used as a member whose shape changes according to the temperature forming the bias application terminal.

[Configuration 10]
In the method of manufacturing a magnetic disk having the configuration 8, a bimetal is used as a member whose shape changes depending on the temperature forming the bias application terminal.

[Configuration 11]
In the method of manufacturing a magnetic disk having any one of Configurations 8 to 10, the bias application terminal is deformed by a temperature rise accompanying film formation and is brought into contact with a nonconductive substrate held on a base. At the same time, it is deformed by a temperature drop accompanying the completion of film formation, and is separated from the non-conductive substrate held on the base.

[Configuration 12]
In the method of manufacturing a magnetic disk having any one of Configurations 8 to 10, the bias application terminal is deformed by increasing the temperature during film formation using temperature control means for controlling the temperature of the bias application terminal. And contact with the non-conductive substrate held on the base, and by deforming the film by lowering the temperature after completion of the film formation, separating from the non-conductive substrate held on the base. It is characterized by.

[Configuration 13]
In the method of manufacturing a magnetic disk having any one of Configurations 8 to 10, the current is supplied to the bias application terminal during film formation by using current supply means for supplying current to the bias application terminal. It is deformed by being raised and brought into contact with a non-conductive substrate held on the base, and after the film formation is completed, the current supply is cut off and the temperature is lowered to be deformed and held on the base. It is characterized by being separated from the non-conductive substrate formed.

  In the film forming apparatus according to the present invention having the configuration 1, the bias application terminal is formed of a member whose shape changes according to temperature, and is non-conductive held on the base by deformation due to temperature change. Therefore, the bias application terminal and the substrate can be brought into contact with or separated from each other with the base installed in the vacuum chamber or the like.

  That is, in this film forming apparatus, the conductive film can be formed in a state where the bias application terminal and the substrate are not in contact with each other, and the conductive film can be satisfactorily conductive even at the position where the bias application terminal should be in contact with the substrate. A functional film can be formed. Therefore, the conductive film and the bias application terminal can be appropriately electrically connected.

  Further, in this film forming apparatus, the bias application terminal and the substrate are brought into contact with each other by deformation of the bias application terminal, so that the base is not taken out into the atmosphere, and is almost the same as the case where the conductive substrate is used. A substrate bias can be applied by this process. Therefore, even when a non-conductive substrate is used, high mass productivity can be realized.

  In the film forming apparatus according to the present invention having the configuration 2, since the bias application terminal is made of a shape memory alloy, it can be deformed into a desired shape at a predetermined temperature.

  In the film forming apparatus according to the present invention having the configuration 3, since the bias applying terminal is made of bimetal, a desired deformation amount can be obtained by a predetermined temperature change.

  In the film forming apparatus according to the present invention having the configuration 4, the bias application terminal is deformed by the temperature change accompanying the film formation and the film formation, and is in contact with the nonconductive substrate held on the base. Therefore, the application of the bias to the substrate is started and ended without performing any special operation.

  In the film forming apparatus according to the present invention having the configuration 5, since the temperature of the bias application terminal is controlled by the temperature control means, the deformation state of the bias application terminal can be controlled.

  In the film forming apparatus according to the present invention having the configuration 6, since the temperature of the bias application terminal is controlled by the current supply means, the deformation state of the bias application terminal can be controlled.

  In the film forming apparatus according to the present invention having the configuration 7, a disk substrate is used as a substrate, and an underlayer, a magnetic layer, and a protective layer are sequentially formed on the disk substrate, so that it can be used for manufacturing a magnetic disk. it can.

  In the method of manufacturing a magnetic disk according to the present invention having the structure 8, the non-conductive member formed on the base by the deformation due to the temperature change formed by a member whose shape changes according to the temperature as the bias application terminal. Since a substrate that contacts and separates from the substrate is used, each bias application terminal and each disk substrate can be brought into contact with and separated from each other while the base is still installed in the vacuum chamber.

  That is, in this magnetic disk manufacturing method, the conductive film can be formed in a state where the bias application terminal and the disk substrate are not in contact with each other, and the bias application terminal can be contacted with the disk substrate. A conductive film can be formed satisfactorily. Therefore, the conductive film and the bias application terminal can be appropriately electrically connected.

  In this method of manufacturing a magnetic disk, a conductive disk substrate can be used without bringing the disk base into the atmosphere by bringing the bias application terminal into contact with the disk substrate by deformation of the bias application terminal. Substrate bias can be applied by substantially the same process as in the case of the above. Therefore, even when a non-conductive disk substrate is used, high mass productivity can be realized.

  In the method of manufacturing a magnetic disk according to the present invention having the configuration 9, since the bias application terminal made of a shape memory alloy is used, the bias application terminal can be deformed into a desired shape at a predetermined temperature.

  In the method of manufacturing a magnetic disk according to the present invention having the configuration 10, since the bias application terminal made of bimetal is used, the bias application terminal can be set to a desired deformation amount by a predetermined temperature change.

  In the method of manufacturing a magnetic disk according to the present invention having the structure 11, the bias application terminal is deformed by the temperature change accompanying the film formation and the film formation, and the non-conductive substrate held on the base is formed. Since the contact and separation are performed, it is possible to start and end the application of the bias to the substrate without performing any special operation.

  In the method of manufacturing a magnetic disk according to the present invention having the configuration 12, the temperature control means controls the temperature of the bias application terminal, so that the deformation state of the bias application terminal can be controlled.

  In the method of manufacturing a magnetic disk according to the present invention having the structure 13, the temperature of the bias application terminal is controlled by the current supply means, so that the deformation state of the bias application terminal can be controlled.

  That is, the present invention is to apply a DC bias satisfactorily while maintaining productivity in a single wafer type film forming apparatus that performs film formation by bias sputtering on a plurality of non-conductive substrates. Further, by using this film forming apparatus, it is possible to provide a manufacturing method with high productivity of a magnetic disk compatible with high-density recording.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

[Outline of magnetic disk and its manufacturing method]
FIG. 1 is a plan view (a) and a cross-sectional view (b) showing the configuration of a magnetic disk manufactured by the method of manufacturing a magnetic disk according to the present invention.

  A magnetic disk manufactured by the method of manufacturing a magnetic disk according to the present invention is a magnetic disk mounted on a hard disk drive, and is made of a nonmagnetic and nonconductive material as shown in FIG. Using a circular disk substrate 1 having a central hole 1a, an underlayer 2, a magnetic layer 3, and a protective layer 4 are formed on the surface 1b of the disk substrate 1, as shown in FIG. The layers are sequentially stacked to form a film.

  The disk substrate 1 is made of, for example, chemically strengthened glass such as aluminosilicate glass, aluminoborosilicate glass, or soda lime glass. In the case of a 1.0 inch type, the outer diameter is 27 mm and the inner diameter (the diameter of the center hole 1a). Is 7 mm and the thickness is 0.381 mm. The surface 1b of the disk substrate 1 is mirror-polished so that the surface roughness is 0.4 nm or less in Ra and 5 nm or less in Rmax.

  In order to manufacture the magnetic disk 1, first, the first underlayer 2a is formed on the surface 1b of the disk substrate 1 by physical vapor deposition such as DC magnetron sputtering. The first underlayer 2a is an AlRu alloy thin film having a thickness of 5 nm. Next, the second underlayer 2b is formed on the first underlayer 2a by a DC magnetron sputtering method or the like. The second underlayer 2b is, for example, a CrMoTi alloy thin film having a thickness of 50 nm. The underlayer 2 composed of the first underlayer 2a and the second underlayer 2b is formed in order to improve the crystal structure of the magnetic layer 3.

  Next, the magnetic layer 3 is formed on the underlayer 2 (second underlayer 2b) by physical vapor deposition such as DC magnetron sputtering. The magnetic layer 3 is, for example, a CoCrB alloy thin film having a thickness of 15 nm.

  Next, the protective layer 4 is formed on the magnetic layer 3 by plasma CVD. The protective layer 4 is made of, for example, amorphous diamond-like carbon having a thickness of 3 nm, and has a function of improving the wear resistance and protecting the magnetic layer 3.

  Next, the lubricating layer 5 is formed on the surface of the protective layer 4 by a dipping method. The lubricating layer 5 is made of, for example, a perfluoropolyether layer having a thickness of 1.2 nm, and has a function of mitigating impact when contacting the magnetic head.

[Configuration of deposition system]
FIG. 2 is a plan view (a) showing the configuration of a rotary transfer type single wafer reaction chamber and a plan view (b) showing the configuration of a straight transfer type single wafer reaction chamber in the film forming apparatus according to the present invention. is there.

  In the magnetic disk manufacturing apparatus according to the present invention, the film forming apparatus according to the present invention is used to form the underlayer 2, the magnetic layer 3, and the protective layer 4 on the surface 1b of the disk substrate 1. In this film forming apparatus, as shown in FIG. 2A, a plurality of disc substrates 1 (four in this embodiment) are held by a base (substrate holder) 6. Thus, the film is conveyed in the reaction chamber of the film forming apparatus.

  Each disk substrate 1 is supported on its outer peripheral end on the inner peripheral side of the through hole formed in the base 6, and is held with one surface facing upward and the other surface facing downward. ing.

  In the reactive chamber of this film forming apparatus, first to third targets 7, 8, 9 for forming the underlayer 2 and the magnetic layer 3 are arranged along the rotational conveyance direction of the base 6. Has been. The first target 7 is an AlRu target for forming the first underlayer 2a, the second target 8 is a CoCrTi target for forming the second underlayer 2b, and the third target Reference numeral 9 denotes a CoCrB target for forming the magnetic layer 3. Each target 7, 8, 9 is disposed on the upper surface side and the lower surface side so as to sandwich the disk substrate 1 held on the transported base 6 from both surfaces in the reaction chamber.

  The space in which the targets 7, 8, 9 are arranged is partitioned while allowing the movement of the base 6 as necessary.

  In this film forming apparatus, the disk substrate 1 held by the base 6 is first opposed to the first target 7 and the first underlayer 2a is formed by a vapor phase growth method such as a DC magnetron sputtering method. A film is formed. Next, the disk substrate 1 held by the base 6 is heated to a predetermined temperature in the heating chamber 10. Then, the disk substrate 1 is transported through the reactive chamber while being held on the base 6, and is sequentially opposed to the second and third targets 8 and 9, and a vapor phase growth method such as a DC magnetron sputtering method. Thus, the second underlayer 2b and the magnetic layer 3 are formed. The disc substrate 1 that has been successfully deposited is discharged from the reactive chamber.

  In addition, this film-forming apparatus is good also as what has a linear conveyance type single wafer reaction chamber, as shown in FIG.2 (b). In this film forming apparatus, the base 6 holding the disk substrate 1 is conveyed linearly in the reactive chamber.

  In this film forming apparatus, the disk substrate 1 held by the base 6 is first opposed to the first target 7 and the first underlayer 2a is formed by a vapor phase growth method such as a DC magnetron sputtering method. A film is formed. Next, the disk substrate 1 held by the base 6 is heated to a predetermined temperature in the heating chamber 10. Then, the disk substrate 1 is transported through the reactive chamber while being held on the base 6, and is sequentially opposed to the second and third targets 8 and 9, and a vapor phase growth method such as a DC magnetron sputtering method. Thus, the second underlayer 2b and the magnetic layer 3 are formed. The disc substrate 1 that has been successfully deposited is discharged from the reactive chamber.

  The disk substrate 1 having been formed up to the magnetic layer 3 in this way is sent to a plasma CVD chamber (not shown), and the protective layer 4 is formed by plasma CVD.

[Configuration of base]
FIG. 3 is a plan view showing the configuration of the base in the film forming apparatus according to the present invention.

  As shown in FIG. 3, the base 6 in the film forming apparatus according to the present invention has a disk-like base main body (base) 6a, and the base main body 6a allows a plurality of pieces (in the present embodiment, The four (4) disk substrates 1 for 1.0-inch magnetic disks are configured to be on the same plane and can be held at equal angular intervals in the circumferential direction.

  The base body 6a is made of, for example, titanium and has an outer shape of, for example, 95 mm. Each of the targets 7, 8, and 9 in the reaction chamber has a disk shape having an outer diameter larger than that of the base body 6a, for example, an outer diameter of 120 mm. Therefore, the disk substrate 1 is arranged on the periphery of the position facing the center of each target 7, 8, 9 with respect to each target 7, 8, 9 by being held on the base 6.

  In the base body 6a, four through holes 11 larger than the disk substrate 1 are formed at equal intervals in the circumferential direction. A plurality of external chucking 12 that sandwich and hold the outer peripheral end of the disk substrate 1 is provided in the inner peripheral portion of these through holes 11.

  As shown in FIG. 3A, the base body 6a has bias applying means having a number of bias applying terminals 13 corresponding to the number of disk substrates 1 held on the base body 6a. Is provided. This bias applying means applies a bias voltage to the conductive film by bringing each bias applying terminal 13 into contact with the conductive film formed on the non-conductive disk substrate 1.

Each bias application terminal 13 is formed of a member whose shape changes according to the temperature, and contacts and separates from the non-conductive disk substrate 1 held on the base body 6a by deformation due to temperature change. Examples of the member whose shape changes according to the temperature forming the bias application terminal 13 include a material having a large thermal expansion coefficient. In addition, examples of members whose shape changes according to temperature include so-called shape memory alloys and bimetals. Shape memory alloys generally memorize the shape at this time by applying a high heat treatment as a desired shape. Even if it is deformed at room temperature, it has the property of returning to its original desired shape when heated to a so-called transformation temperature (Af). As such a shape memory alloy, for example, a NiTiCu wire or the like can be used. Bimetal is a laminate of two metal alloys having different thermal expansion coefficients, and is deformed (warped) due to a stress caused by a difference in thermal expansion of each metal alloy due to a temperature change.

  Each bias application terminal 13 has its distal end facing each disk substrate 1 and its proximal end attached to a bias application member 14. The bias applying member 14 is made of a conductive material such as metal and is formed in an annular shape so as to surround the base body 6a. Each bias application terminal 13 is deformed by a temperature change in a state where the base end side is supported by the bias application member 14, so that the front end side is a nonconductive disk substrate held on the base body 6 a. Close to 1

  Each bias application terminal 13 is supported by a bias application member 14 via an elastic flange 15, and when it comes into contact with each disk substrate 1, each bias application terminal 13 is caused by the elastic force of the flange 15. The front end side is pressed against the disk substrate 1.

  A DC bias voltage is applied to the bias applying member 14 via a DC voltage supply terminal 16 installed outside the base 6.

  In the base 6, when the second underlayer 2 b and the magnetic layer 3 are formed, each bias application terminal 13 is brought into contact with a plurality of disk substrates 1 held by the base body 6 a, thereby A DC bias is simultaneously applied to the disk substrate 1.

  Note that the DC bias voltage may be applied from the bias applying member 14 to the conductive film formed on the disk substrate 1 via each bias applying terminal 13 (b) in FIG. As shown in FIG. 3, the external DC voltage supply terminal 16 may be applied to the conductive film formed on the disk substrate 1 through the conductive wire 17 and the bias application terminals 13.

  FIG. 4 is a graph showing the relationship between the film forming process and the bias application terminal deformation in the film forming apparatus according to the present invention.

  In this film forming apparatus, each bias applying terminal 13 is heated by a temperature control means (not shown) when forming the second underlayer 2b and the magnetic layer 3 as shown in FIG. The tip side is brought into contact with the non-conductive disk substrate 1 held on the base body 6a. At this time, a bias voltage is applied to the conductive film formed on the non-conductive disk substrate 1 via the DC voltage supply terminal 16 and the bias applying member 14.

  Each bias application terminal 13 is deformed by the temperature being lowered by the temperature control means after the film formation is completed, and is separated from the non-conductive disk substrate 1 held on the base body 6a. As described above, when each bias application terminal 13 is separated from the disk substrate 1 after the film formation is completed, the disk substrate 1 can be easily detached from the base 6.

  FIG. 5 is a plan view showing another example of the configuration of the bias application terminal in the film forming apparatus according to the present invention.

  In order to make it easier to remove each disk substrate 1 from the base 6, it is preferable that each bias application terminal 13 be separated from each disk substrate 1 after application of the DC bias. That is, each bias application terminal 13 is brought into contact with the disk substrate 1 as shown by an arrow a in the figure when heated to the transformation temperature or higher as shown in FIG. A first leaf spring 13a made of a shape memory alloy set in advance and a second leaf spring 13a that holds the first leaf spring 13a at a position separated from the disk substrate 1 at a temperature lower than the transformation temperature (for example, room temperature). The leaf spring 13b can be combined. The bias applying terminal 13 has the base end sides of the first and second leaf springs 13a and 13b fixed to the base body 6a, and the front end faces the disk substrate 1 held by the base body 6a. ing.

  As shown in FIG. 5B, the bias applying terminal 13 configured as described above is separated from the disk substrate 1 by the force of the second leaf spring 13b as shown by an arrow b in the drawing, as shown in FIG. When the temperature is kept at a separated position and becomes equal to or higher than the transformation temperature, the disk substrate 1 is brought into contact with the first plate spring 13a as shown in FIG. Therefore, the bias applying terminal 13 does not get in the way when the disk substrates 1 are removed from the base 6, and the disk substrate 1 can be easily removed.

  Further, when each bias application terminal 13 is formed of a shape memory alloy, the transformation temperature (Af) is set by appropriately adjusting the alloy component, for example, the Ni content or changing the temperature at which the high heat treatment is performed. Can be changed. Thereby, each bias application terminal 13 is deformed by the temperature rise in the reactive chamber accompanying the film formation without being controlled by the temperature control means, and is non-conductive held on the base body 6a. Is brought into contact with the disk substrate 1 and is taken out of the vacuum sputtering apparatus upon completion of the film formation, so that the temperature is lowered to the room temperature by being lowered to the room temperature, and is deformed and held on the base body 6a. Further, it can be separated from the non-conductive disk substrate 1.

  Further, each bias application terminal 13 is deformed by being supplied with a current by a current supply means (not shown) during the film formation and the temperature thereof is increased, so that the non-conductive terminal 13 held on the base body 6a. The front end side may be brought into contact with the disk substrate 1. In this case, each bias application terminal 13 is deformed when the current supply by the current supply means is interrupted and the temperature is lowered after the film formation is completed, so that the non-conductive held on the base body 6a. The disk substrate 1 is separated.

  FIG. 6 is a plan view showing another example of the configuration of the base in the film forming apparatus according to the present invention.

  Further, as shown in FIG. 6A, the bias application terminal 13 may be processed into a coil spring shape in order to increase the displacement amount (operation amount). The coil spring-like bias application terminal 13 is sufficiently long to contact the disk substrate 1. The bias application terminal 13 expands and contracts as shown by an arrow c in the figure due to a temperature change, and comes in contact with and separates from the disk substrate 1 held on the base body 6a.

  Also in this case, the DC bias voltage may be applied to the conductive film formed on the disk substrate 1 from the bias applying member 14 via each bias applying terminal 13. As shown in (b), the voltage may be applied from the external DC voltage supply terminal 16 to the conductive film formed on the disk substrate 1 through the bias application terminal 13 via the lead wire 17. .

[Effects of the present embodiment]
In this embodiment, when the magnetic layer 3 is formed, a DC bias can be simultaneously applied to a plurality of disk substrates 1 held by the base 6, which corresponds to a high recording density. Magnetic disks can be manufactured with good productivity.

  That is, after forming a conductive film on the disk substrate 1, it is not necessary to remove it from the chamber of the vacuum sputtering apparatus in order to apply a DC bias, the manufacturing process is simplified and the productivity is improved. Since four films can be formed at a time, productivity can be improved by a factor of four or more compared to the conventional manufacturing method in which one film is formed at a time, taken out into the atmosphere once, and a bias is applied. it can.

  The DC bias may be applied not only when the magnetic layer 3 is formed but also when the second underlayer 2b is formed. In both the formation of the second underlayer 2b and the magnetic layer 3, the DC bias may be applied. You may go.

  The DC bias may be applied at the time of forming the soft magnetic film on the perpendicular magnetic recording disk. In this case, since the soft magnetic layer requires a film thickness of about 50 nm, the soft magnetic layer is first formed without applying a DC bias, and the thickness of the soft magnetic layer is such that a DC bias can be applied. Then, the application of the DC bias may be started.

[Example of magnetic disk manufacturing method]
Using the base 6 configured as described above, the base layer 2 (the first base layer (GIF layer) 2a and the second base layer (UL) are formed on the surface of the non-conductive disk substrate (glass substrate) 1. Layer) 2b) and magnetic layer 3 (a plurality of magnetic layers divided by spacers in the case of a so-called AFC structure) are first formed into a 1.0-inch type subjected to precision polishing and chemical strengthening treatment. A disk substrate 1 for a magnetic disk is held by a base 6. The magnetic disk has the same configuration on both sides of the disk substrate, but only one side will be described here.

  And as shown in FIG. 2, this base 6 is mounted | worn with an automatic conveyance apparatus, and the base 6 is introduce | transduced in a reactive chamber. The base 6 is transported at a predetermined transport speed, and film formation is performed in a state where the base 6 is installed facing each target 7, 8, 9 in a substantially concentric state. After the first underlayer (GIF layer) 2 a is formed, it is introduced into the heating chamber 10. In the heating chamber 10, the disk substrate 1 is heated by a heater, for example, at 300 ° C. for 1 minute. By this heating, each bias application terminal 13 returns to a predetermined original shape, and comes into contact with the outer peripheral edge portion where the first underlayer 2a of the plurality of disk substrates 1 held by the base body 6a is formed. .

  Next, the second underlayer 2b and the magnetic layer 3 are formed. At this time, each bias applying terminal 13 is in contact with the outer peripheral edge portion where the first underlayer 2a of the plurality of disk substrates 1 held by the base body 6a is formed. A DC bias is applied. At least the magnetic layer 3 is formed in this manner with a DC bias applied to each disk substrate 1.

  In this way, the base layer 2 composed of the AlRu layer (first base layer 2a) having a thickness of 5 nm and the CrMoTi (second base layer 2b) having a thickness of 50 nm and the thickness of 15 nm are formed on both surfaces of the disk substrate 1. The CoCrB magnetic layer 3 is formed. Here, the sputtering conditions in the reactive chamber are, for example, a sputtering pressure of 5 mtorr and a sputtering atmosphere of an inert gas of argon.

  When film formation is completed in this way, the base 6 holding each disk substrate 1 is discharged from the reactive chamber. For the disk substrate 1 discharged from the reactive chamber, a protective layer 4 is formed on the magnetic layer 3 by plasma CVD or the like. Further, a lubricating layer 5 is formed on the protective layer 4 by applying a perfluoroether-based lubricant by a dipping method. The lubricant layer 5 is obtained by applying a perfluoroether lubricant to the outermost layer of the disk substrate 1 by heating the disk substrate 1 at 100 ° C. for about 1 hour after applying the perfluoroether lubricant. It is formed by fixing. As the perfluoropolyether lubricant, for example, “Fomblin-Z-Tetraol” (trade name) manufactured by “Solvay Solexis” can be used.

  Here, when the film thickness of the lubricating layer 5 was measured with a Fourier transform infrared spectrophotometer (FTIR), it was 1.2 nm.

[Comparative example]
As a comparative example (1), the second underlayer 2b and the magnetic layer 3 were formed without applying a DC bias, and a magnetic disk was prepared in the same manner as in the previous embodiment.

  Further, as a comparative example (2), after the first base layer (GIF layer) 2a is formed, each disk substrate 1 is taken out into the atmosphere, and each bias applying terminal 13 is brought into contact with these disk substrates 1. Returning to the reactive chamber, the second underlayer 2b and the magnetic layer 3 were formed by applying a DC bias, and a magnetic disk was prepared in the same manner as in the previous embodiment.

[Effect of DC bias]
FIG. 7 is a graph showing the relationship (a) with the holding force and the relationship (b) with the S / N ratio as the effect of the DC bias in the magnetic disk manufacturing method according to the present invention.

  With respect to the magnetic disk manufactured as described above, as shown in FIG. 7A, when the DC bias dependency of the holding force Hc was confirmed, the holding force Hc was reduced by setting the DC bias to about 400V. It was confirmed to be the best. Further, as shown in FIG. 7B, when the dependency of the SN ratio on the DC bias was confirmed, it was confirmed that the higher the DC bias, the better the SN ratio.

  The DC bias takes a negative value (minus), but in FIG. 6, it is shown as a positive value instead of a minus value. For example, 400V means a DC bias of -400V.

  Further, as shown in [Table 1] below, the magnetic disk of the example of the present invention has an SNR (signal noise) indicating electromagnetic conversion characteristics as compared with the magnetic disk (without DC bias) of the comparative example (1). Ratio) was improved.

  As shown in [Table 1], the magnetic disk of Comparative Example (2) has the same SNR as that of the magnetic disk of the Example, but as described above, the first underlayer 2a was formed. Since the particles are once taken out into the atmosphere later, particle contamination is recognized, and it takes time to take out the bias application terminals 13 and contact each disk substrate 1 after forming the first underlayer 2a. Therefore, it was confirmed that the mass productivity is remarkably lowered.

1A and 1B are a plan view and a cross-sectional view showing a configuration of a magnetic disk manufactured by a magnetic disk manufacturing method according to the present invention. FIG. 2 is a plan view (a) showing a configuration of a rotary transfer type single wafer reaction chamber in a film forming apparatus according to the present invention and a plan view (b) showing a configuration of a straight transfer type single wafer reaction chamber. It is a top view which shows the structure of the base in the film-forming apparatus which concerns on this invention. It is a graph which shows the relationship between the film-forming process in the film-forming apparatus which concerns on this invention, and the deformation | transformation of the terminal for bias application. It is a top view which shows the other example of a structure of the terminal for bias application in the film-forming apparatus which concerns on this invention. It is a top view which shows the other example of a structure of the base in the film-forming apparatus which concerns on this invention. It is a graph which shows the relationship (a) with coercive force, and the relationship (b) with SN ratio as an effect of DC bias in the manufacturing method of the magnetic disc concerning this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Disc substrate 2 Underlayer 2a 1st underlayer 2b 2nd underlayer 3 Magnetic layer 4 Protective layer 5 Lubricating layer 6 Base 6a Base main body 7 1st target 8 2nd target 9 3rd target 13 Bias application terminal 14 Bias application member 15 collar 16 DC voltage supply terminal 17 Conductor

Claims (13)

A single-wafer type film forming apparatus that performs film formation by bias sputtering on a non-conductive substrate,
A base for holding at least one non-conductive substrate;
Bias applying means for applying a bias voltage to the conductive film by bringing the bias applying terminal into contact with a conductive film formed on the non-conductive substrate. Prepared,
The bias application terminal is formed of a member whose shape changes according to temperature, and contacts and separates from a non-conductive substrate held on the base by deformation due to temperature change. Deposition device. The film forming apparatus according to claim 1, wherein the member whose shape changes according to the temperature forming the bias application terminal is a shape memory alloy. The film forming apparatus according to claim 1, wherein the member whose shape changes according to the temperature forming the bias application terminal is a bimetal. The bias application terminal is deformed by a temperature rise accompanying the film formation, contacts the non-conductive substrate held on the base, and is deformed by a temperature drop accompanying the end of the film formation, The film forming apparatus according to claim 1, wherein the film forming apparatus is separated from a non-conductive substrate held on a base. Temperature control means for controlling the temperature of the bias application terminal;
The bias application terminal is deformed when the temperature is raised by the temperature control means during film formation, contacts the non-conductive substrate held on the base, and after the film formation is completed. 4. The device according to claim 1, wherein the temperature control unit is deformed when the temperature is lowered and is separated from a non-conductive substrate held on the base. 5. Film forming equipment. Current supply means for supplying current to the bias application terminal;
The bias application terminal is deformed by increasing the temperature by being supplied with current by the current supply means during film formation, and comes into contact with a non-conductive substrate held on the base, and the film is formed. The current supply by the current supply means is interrupted after the end of the process and the temperature is lowered to cause deformation, thereby separating from the nonconductive substrate held on the base. The film forming apparatus according to claim 3. The film forming apparatus according to claim 1, wherein a disk substrate is used as the substrate, and an underlayer, a magnetic layer, and a protective layer are sequentially formed on the disk substrate. A method of manufacturing a magnetic disk in which an underlayer, a magnetic layer, and a protective layer are sequentially formed on a nonmagnetic and nonconductive disk substrate,
Holding the disk substrate on a base;
Forming a conductive film on a disk substrate held on the base in a vacuum chamber;
In the vacuum chamber, by deforming the bias application terminal of the bias application means, the bias application terminal is brought into contact with the conductive film formed on the disk substrate; and
In the vacuum chamber, a step of sequentially forming a magnetic layer and a protective layer on the conductive film while applying a bias voltage to the conductive film through the bias application terminal by the bias applying means; Have
A magnetic disk, wherein the bias applying member is formed of a member whose shape changes according to temperature, and contacts and separates from a non-conductive substrate held on the base by deformation due to temperature change. Manufacturing method. The method of manufacturing a magnetic disk according to claim 8, wherein a shape memory alloy is used as a member whose shape changes according to a temperature forming the bias application terminal. The method of manufacturing a magnetic disk according to claim 8, wherein a bimetal is used as a member whose shape changes according to a temperature forming the bias application terminal. The bias application terminal is deformed by a temperature rise accompanying the film formation and brought into contact with a non-conductive substrate held on the base, and is deformed by a temperature drop accompanying the end of the film formation, The method of manufacturing a magnetic disk according to any one of claims 8 to 10, wherein the magnetic disk is separated from a non-conductive substrate held on a base. Using a temperature control means for controlling the temperature of the bias application terminal, the bias application terminal is deformed by raising the temperature during film formation, and is a non-conductive substrate held on the base. 11. The method according to claim 8, wherein the substrate is deformed by lowering the temperature after completion of film formation and separated from a non-conductive substrate held on the base. A method for producing a magnetic disk as described in 1. Using a current supply means for supplying current to the bias application terminal, the bias application terminal was deformed by supplying a current during film formation to increase the temperature and held on the base. It is brought into contact with a non-conductive substrate, and is deformed by cutting off the current supply and lowering the temperature after the film formation is completed, and is separated from the non-conductive substrate held on the base. The method for manufacturing a magnetic disk according to claim 8.

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