WO2012073384A1

WO2012073384A1 - Plasma cvd device, magnetic recording medium and method for manufacturing same

Info

Publication number: WO2012073384A1
Application number: PCT/JP2010/071772
Authority: WO
Inventors: 本多　祐二; 荒木　智幸; 晶久老川; 田中　正史
Original assignee: 株式会社ユーテック
Priority date: 2010-11-29
Filing date: 2010-11-29
Publication date: 2012-06-07
Also published as: JP5764789B2; SG190912A1; JPWO2012073384A1

Abstract

Provided is a plasma CVD device in which discharge at the rear face of an anode can be suppressed. The plasma CVD device of the present invention is characterized by comprising: a chamber; a plasma wall (8) which is arranged within the chamber and has openings at both ends; a holding part which holds a substrate (1) on which a film is to be deposited, the substrate (1) being arranged in the vicinity of an opening at one end of the plasma wall; an anode which is arranged so as to cover the opening at the other end of the plasma wall; a filament-shaped cathode which is arranged inside of the anode and in the vicinity of the opening at the other end of the plasma wall; an AC power source which is electrically connected to one end of the cathode by way of a first wire, and is electrically connected to the other end of the cathode by way of a second wire; and holes which are provided in the anode and have the first and second wires passing therethrough.

Description

Plasma CVD apparatus, magnetic recording medium, and manufacturing method thereof

The present invention relates to a plasma CVD apparatus, a magnetic recording medium, and a manufacturing method thereof.

4A is a cross-sectional view schematically showing a conventional plasma CVD apparatus, and FIG. 4B is a diagram showing a cathode and an AC power source as viewed from the direction of the arrow shown in FIG. 4A. is there.
This plasma CVD apparatus has a symmetrical structure with respect to the deposition target substrate (for example, a disk substrate) 101, and is an apparatus capable of forming films on both sides of the deposition target substrate 101 simultaneously. ) Shows the left side with respect to the deposition target substrate 101, and the right side is omitted.
The plasma CVD apparatus has a chamber 102, and a gas introduction flange 115 is attached to the chamber 102. A film forming chamber is formed by the gas introduction flange 115 and the chamber 102. A hot cathode (cathode electrode) 103 is formed in the gas introduction flange 115. Both ends of the hot cathode 103 are electrically connected to an AC power source 105 located outside the gas introduction flange 115. One end of the AC power source 105 is electrically connected to the ground 106.
A disc-shaped cathode back plate 111 is formed in the gas introduction flange 115, and the cathode back plate 111 is located between the hot cathode 103 and the AC power source 105 and has a float potential. An anode 104 including an anode cone 104a and an anode base 104b is disposed in the gas introduction flange 115, and a gap 113 is provided between the anode cone 104a and the cathode back plate 111.
The anode base 104b is electrically connected to the DC power source 107. The positive potential side of the DC power source 107 is electrically connected to the anode base 104 b, and the negative potential side of the DC power source 107 is electrically connected to the ground 106.
A deposition target substrate 101 is disposed in the chamber 102. The deposition target substrate 101 is electrically connected to a DC power source (DC power source) 112 as a power source for ion acceleration. The negative potential side of the DC power source 112 is electrically connected to the deposition target substrate 101, and the positive potential side of the DC power source 112 is electrically connected to the ground 106.
A plasma wall 108 is disposed in the gas introduction flange 115 and the chamber 102 connected to the ground so as to cover the space between the hot cathode 103 and the anode 104 and the deposition target substrate 101. The plasma wall 108 is electrically connected to a float potential (not shown). The plasma wall 108 has a cylindrical shape. A ring-shaped space 114 is provided between the plasma wall 108 and the anode cone 104a, and the width of the space 114 is about 15 mm. A magnet 109 is disposed outside the chamber 102.
Next, a method for forming a DLC (Diamond Like Carbon) film on the deposition target substrate 101 using the plasma CVD apparatus illustrated in FIG. 4 will be described.
First, the inside of the chamber 102 is set to a predetermined vacuum state, and for example, toluene (C ₇ H ₈ ) gas is introduced into the chamber 102 as a film forming source gas from the gas introduction portion 115 a of the gas introduction flange 115. After the chamber 102 reaches a predetermined pressure, the hot cathode 103 is heated by supplying an AC current to the hot cathode 103 from the AC power source 105. Further, a direct current is supplied to the anode 104 by a DC power source 107, and a direct current is supplied to the deposition target substrate 101 by a DC power source 112.
By heating the hot cathode 103, a large amount of electrons are emitted from the hot cathode 103 toward the anode cone 104a, and glow discharge is started between the hot cathode 103 and the anode cone 104a. Toluene gas as a film forming raw material gas inside the chamber 102 is ionized by a large amount of electrons to be in a plasma state. At this time, since a magnetic field is generated in the region where the toluene gas located in the vicinity of the hot cathode 103 is converted into plasma by the magnet 109, the plasma can be densified by this magnetic field. Then, the film-forming raw material molecules in the plasma state are directly accelerated by the negative potential of the film formation substrate 101, fly toward the film formation substrate 101, and adhere to the surface of the film formation substrate 101. Is done. Accordingly, a thin DLC film is formed on the deposition target substrate 101 (see, for example, Patent Document 1).
In the conventional plasma CVD apparatus, since there is a gap 113 between the cathode back plate 111 and the anode cone 104a, when a DLC film is formed on the deposition target substrate 101, discharge occurs on the back surface of the anode cone 104a. The carbon film 110a may adhere. In addition, a discharge may occur in the space 114 between the plasma wall 108 and the anode cone 104a, and a carbon film may adhere to the wall surface of the space 114. The adhered carbon film 110a is peeled off and deposited between the anode base 104b and the gas introduction flange 115, and as a result, the insulation between the anode 104 and the gas introduction flange 115 is caused by the deposited carbon film particles 110b. Deteriorates and it becomes difficult to discharge stably. Further, when the carbon film 110a is peeled off, the carbon film 110a may adhere to the deposition target substrate 101 and cause a defect.
In addition, since the electric power consumed by the discharge generated in the back surface or the space 114 of the anode cone 104a is a loss that does not contribute to the film formation on the deposition target substrate 101, the power loss is used for the decomposition of the source gas. As the energy decreases, the film quality of the film formed on the deposition target substrate 101 may decrease.

JP 2010-7126 A

An object of one embodiment of the present invention is to provide a plasma CVD apparatus capable of suppressing the occurrence of discharge on the back surface of an anode, a magnetic recording medium using the plasma CVD apparatus, or a manufacturing method thereof.

One embodiment of the present invention includes a chamber;
A plasma wall disposed in the chamber and having a cylindrical shape with open ends or a polygonal cross section; and
A holding unit that is disposed in the chamber and holds a deposition target substrate disposed in the vicinity of an opening at one end of the plasma wall;
An anode disposed in the chamber and disposed to cover an opening at the other end of the plasma wall;
A filament-shaped cathode disposed in the chamber, disposed inside the anode and in the vicinity of the opening of the other end of the plasma wall, and opposed to the substrate to be processed held in the holding unit;
An AC power source or a DC power source disposed outside the chamber, electrically connected to one end of the cathode via a first wiring, and electrically connected to the other end of the cathode via a second wiring; ,
A hole provided in the anode, through which each of the first wiring and the second wiring;
A first DC power source disposed outside the chamber and electrically connected to the anode;
A second DC power source disposed outside the chamber and electrically connected to the deposition target substrate held by the holding unit;
A gas supply mechanism for supplying a source gas into the chamber;
An exhaust mechanism for exhausting the chamber;
A plasma CVD apparatus characterized by comprising:
According to one embodiment of the present invention, it is possible to provide a plasma CVD apparatus that can suppress the occurrence of discharge on the back surface of the anode by disposing the anode so as to cover the opening at the other end of the plasma wall.
In one embodiment of the present invention, the maximum gap between the other end of the plasma wall and the anode is 5 mm or less, and the maximum gap between the hole and each of the first wiring and the second wiring is It is preferable that it is 5 mm or less. Thereby, the plasma CVD apparatus which can suppress that discharge arises in the back surface of an anode can be provided.
In one embodiment of the present invention, the gap between the chamber and the anode is connected to the gap between the other end of the plasma wall and the anode, and the maximum portion of the gap is 5 mm or less. preferable. Thereby, it can suppress more effectively that discharge arises in the back surface of an anode.
In one embodiment of the present invention, there is a gap between the chamber and the plasma wall connected to a gap between the other end of the plasma wall and the anode, and the maximum portion of the gap is 5 mm or less. Is preferred. Thereby, it can suppress more effectively that discharge arises in the back surface of an anode.
One aspect of the present invention is a method of manufacturing a magnetic recording medium using the plasma CVD apparatus described above.
Holding the film formation substrate on which at least the magnetic layer is formed on the nonmagnetic substrate in the holding unit,
The source gas is turned into a plasma state by discharge between the filament-shaped cathode and the anode heated under vacuum in the chamber, and the plasma is applied to the surface of the deposition target substrate held in the holding portion. A method of manufacturing a magnetic recording medium, comprising forming a protective layer mainly composed of carbon by accelerated collision.
Further, in the method for manufacturing a magnetic recording medium according to the present invention, the source gas is a source gas for forming a DLC layer as the protective layer on the deposition target substrate, and a gas containing carbon and hydrogen It is preferable to contain.
One aspect of the present invention is a magnetic recording medium manufactured using the above-described method for manufacturing a magnetic recording medium,
The deposition substrate;
The DLC layer formed on the deposition target substrate;
A magnetic recording medium comprising:

By applying one embodiment of the present invention, it is possible to provide a plasma CVD apparatus capable of suppressing the occurrence of discharge on the back surface of the anode, a magnetic recording medium using the plasma CVD apparatus, or a method for manufacturing the same.

FIG. 1A is a cross-sectional view schematically showing a plasma CVD apparatus according to an embodiment, and FIG. 1B is a view showing a cathode and an AC power source viewed from the direction of an arrow 16 shown in FIG. It is.
FIG. 2A is a photograph showing that no carbon film adheres to the gap between the anode 4 and the gas introduction flange 15 after the 8-hour continuous discharge test was performed on the plasma CVD apparatus shown in FIG. 2 (B) is a photograph showing that no carbon film adheres to the gap between the anode cone 4a and the first and second wirings 17a and 17b, and FIG. 2 (C) is shown in FIG. FIG. 2D is a photograph showing that a carbon film is adhered to the gap between the anode 104 and the gas introduction flange 115 after the 8-hour continuous discharge test in the plasma CVD apparatus. FIG. It is a photograph which shows that there exists adhesion of a carbon film in the clearance gap with the backplate 111. FIG.
FIG. 3 is a diagram showing a relationship curve between the contact angle of water and Knoop hardness.
4A is a cross-sectional view schematically showing a conventional plasma CVD apparatus, and FIG. 4B is a view showing a cathode and an AC power source viewed from the direction of an arrow 116 shown in FIG. 4A. .

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it will be easily understood by those skilled in the art that modes and details can be variously changed without departing from the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited to the description of the embodiments below.
FIG. 1A is a cross-sectional view schematically showing a plasma CVD apparatus according to an embodiment of the present invention. FIG. 1B shows a cathode viewed from the direction of arrow 16 shown in FIG. It is a figure which shows an alternating current power supply.
This plasma CVD apparatus has a symmetrical structure with respect to a film formation substrate (for example, a disk substrate) 1, and is an apparatus that can form films on both surfaces of the film formation substrate 1 simultaneously. ) Shows the left side with respect to the deposition target substrate 1, and the right side is omitted.
The plasma CVD apparatus has a chamber 2, and a gas introduction flange 15 is attached to the chamber 2. The gas introduction flange 15 is connected to the ground. Since the film forming chamber is formed by the gas introduction flange 15 and the chamber 2, the gas introduction flange 15 and the chamber 2 may be referred to as a chamber.
A plasma wall 8 is disposed in the chamber. The plasma wall 8 is attached to a gas introduction flange 15, and the plasma wall 8 is electrically connected to a float potential (not shown). The plasma wall 8 is disposed in a state of being insulated from the chamber 2 and is also insulated from the gas introduction flange 15. The plasma wall 8 has a cylindrical shape with both ends opened or a polygonal cross section.
A film thickness correction plate 8a is provided at one end of the plasma wall 8, and the film thickness correction plate 8a is electrically connected to the float potential. The thickness of the film formed on the outer peripheral portion of the deposition target substrate 1 can be controlled by the film thickness correction plate 8a.
A film formation substrate 1 is disposed in the vicinity of the opening at one end of the plasma wall 8, and the film formation substrate 1 is provided by a holder (holding unit) not shown and a transfer device (handling robot or rotary index table) not shown. Are sequentially supplied to the illustrated positions.
The deposition target substrate 1 is electrically connected to a DC power source (direct current power source) 12 as an ion accelerating power source, and the DC power source 12 is disposed in an insulated state with respect to the chamber 2. The negative potential side of the DC power source 12 is electrically connected to the deposition target substrate 1, and the positive potential side of the DC power source 12 is electrically connected to the ground 6. As the DC power source 12, for example, a power source of 0 to 1500 V, 0 to 100 mA (milliampere) can be used.
An anode 4 composed of an anode cone 4a and an anode base 4b is disposed in the gas introduction flange 15. The cathode back plate 111 as shown in FIG. 4 is not provided, and the anode cone 4a shown in FIG. 1 is shaped so that the anode cone 104a and the cathode back plate 111 shown in FIG. The gap between the anode cone 104a and the cathode back plate 111 shown in FIG. 4 is filled. Thereby, it can suppress that discharge arises in the back surface of the anode cone 4a, and a CVD film adheres.
In other words, the anode cone 4 a is disposed so as to cover the opening at the other end of the plasma wall 8. Further, the anode cone 4 a is shaped like a speaker, and the anode cone 4 a is disposed with the maximum inner diameter side facing the film formation substrate 1.
A gap 18a is provided between the anode cone 4a and the other end of the plasma wall 8, and the maximum portion of the gap 18a is preferably 5 mm or less, more preferably 3 mm or less. In the present embodiment, the interval of the maximum portion of the gap 18a is 3 mm. Thus, the maximum gap between the anode cone 4a and the other end of the plasma wall 8 is set to 5 mm or less so as not to prevent the plasma from being confined in the space surrounded by the anode cone 4a and the plasma wall 8. Can do. That is, if the maximum gap is larger than 5 mm, the plasma may be dispersed from the gap larger than 5 mm to the back surface or outside of the anode cone 4a (that is, outside the space surrounded by the anode cone 4a and the plasma wall 8). Otherwise, abnormal discharge may occur on the back or outside. In other words, by setting the maximum gap to 5 mm or less, it is possible to suppress the formation of a CVD film on the back surface or outside of the anode cone 4a.
Further, gaps 18b and 18c between the gas introduction flange 15 and the anode 4 and the plasma wall 8 are connected to the gap 18a, and the maximum portions of the gaps 18b and 18c are preferably 5 mm or less.
The entire gap 18b between the gas introduction flange 15 and the anode 4 may be up to 5 mm or less, but a part of the gap 18b between the gas introduction flange 15 and the anode 4 is up to 5 mm and a part thereof. The gap 18b may be connected to the gap 18a. Further, the entire gap 18c between the gas introduction flange 15 and the plasma wall 8 may be up to 5 mm or less, but a part of the gap 18c between the gas introduction flange 15 and the plasma wall 8 is up to 5 mm or less. A state where a part of the gap 18c is connected to the gap 18a may be used. In this way, by setting at least a part of each of the gaps 18b and 18c connected to the gap 18a to 5 mm or less, it is possible to more effectively suppress abnormal discharge on the back surface of the anode 4, and It can suppress more effectively that a CVD film will be formed.
An anode base 4b is provided outside the anode cone 4a (the side opposite to the inside of the plasma wall 8), and the anode base 4b is connected to the anode cone 4a. The anode base 4 b is electrically connected to a DC power source (DC power source) 7, and the DC power source 7, the anode base 4 b and the anode cone 4 a are disposed in a state of being insulated from the gas introduction flange 15. The positive potential side of the DC power source 7 is electrically connected to the anode base 4 b and the anode cone 4 a, and the negative potential side of the DC power source 7 is electrically connected to the ground 6. As the DC power source 7, for example, a power source of 0 to 500V, 0 to 7.5A (ampere) can be used.
A filament-like cathode (hot cathode) 3 made of, for example, tantalum is formed in the gas introduction flange 15, and the hot cathode 3 is disposed so as to face the deposition target substrate 1. The hot cathode 3 is disposed inside the anode cone 4a and in the vicinity of the opening at the other end of the plasma wall 8, and is disposed so as to be surrounded by the anode cone 4a.
Both ends of the hot cathode 3 are electrically connected to an AC power source 5 located outside the gas introduction flange 15. That is, one end of the hot cathode 3 is electrically connected to the AC power source 5 via the first wiring 17a, and the other end of the hot cathode 3 is electrically connected to the AC power source 5 via the second wiring 17b. It is connected. The AC power supply 5 is disposed in an insulated state with respect to the gas introduction flange 15. As the AC power source 5, for example, a power source of 0 to 50V, 10 to 50A (ampere) can be used. One end of the AC power supply 5 is electrically connected to the ground 6. In the present embodiment, the AC power supply 5 is used, but a DC power supply may be used instead of the AC power supply 5.
Each of the first wiring 17a and the second wiring 17b extends from the inside to the outside of the anode cone 4a through a hole 4c provided in the anode cone 4a. The hole 4c may be one hole or two holes. That is, both the first wiring 17a and the second wiring 17b may pass through one hole, the first wiring 17a passes through one hole, and the second wiring 17b passes through the other hole. You may make it pass through a hole.
The maximum gap between the hole 4c and each of the first wiring 17a and the second wiring 17b is preferably 5 mm or less, more preferably 3 mm or less. Thus, by setting the maximum gap to 5 mm or less, it is possible to prevent the plasma from being confined in the space surrounded by the anode cone 4 a and the plasma wall 8. That is, if the maximum gap is larger than 5 mm, the plasma is dispersed from the gap larger than 5 mm to the back and outside of the anode cone 4a, and abnormal discharge may occur on the back and outside. In other words, by setting the maximum gap to 5 mm or less, it is possible to suppress the formation of a CVD film on the back surface or outside of the anode cone 4a.
Further, the gap between the hole 4c and each of the first wiring 17a and the second wiring 17b is connected to the gap between the gas introduction flange 15 and the anode 4, and the maximum portion of the gap is 5 mm or less. May be. However, it is not essential that the maximum portion of the gap is 5 mm or less.
The gap between the gas introduction flange 15 and the anode 4 may be 5 mm or less at the maximum, but a part of the gap between the gas introduction flange 15 and the anode 4 is 5 mm or less and this part. This gap may be connected to the gap between the hole 4c and each of the first wiring 17a and the second wiring 17b. By doing in this way, it can suppress more effectively that abnormal discharge arises in the back surface of the anode 4, and it can suppress more effectively that a CVD film is formed in the back surface of the anode 4. FIG.
A neodymium magnet 9 is disposed outside the gas introduction flange 15. The neodymium magnet 9 has, for example, a cylindrical shape or a polygonal cross section, and the distance between the inner diameter of the cylindrical side surface or the polygonal side surface passing through the center of the cylindrical direction and the hot cathode 3 is within 50 mm (more preferably within 35 mm). It is preferable that The center of the inner diameter is the center of the magnet, and the center of the magnet is positioned so as to face the approximate center of the hot cathode 3 and the approximate center of the film formation substrate 1. The neodymium magnet 9 preferably has a magnetic force at the center of the magnet of 50G to 200G (Gauss), more preferably 50G to 150G. The reason why the magnetic force at the magnet center is set to 200 G or less is that in the case of a neodymium magnet, it is a manufacturing limit to increase the magnetic force at the magnet center to 200 G. The reason why the magnetic force at the center of the magnet is preferably 150 G or less is that if the magnetic force at the center of the magnet exceeds 150 G, the cost of making the magnet increases.
Further, the plasma CVD apparatus has an evacuation mechanism (not shown) for evacuating the chamber. Further, the plasma CVD apparatus has a gas supply mechanism (not shown) for supplying a film forming raw material gas into the chamber, and a gas introduction portion 15 a of the gas supply mechanism is provided in the gas introduction flange 15.
Next, a method for forming a DLC film on the deposition target substrate 1 using the plasma CVD apparatus shown in FIG. 1 will be described.
First, the vacuum evacuation mechanism is activated, the inside of the chamber is brought into a predetermined vacuum state, and, for example, toluene (C ₇ H ₈ ) gas is introduced into the chamber as a film forming source gas by the gas introduction mechanism. After the inside of the chamber reaches a predetermined pressure, the hot cathode 3 is heated by supplying an AC current to the hot cathode 3 from the AC power supply 5. Further, a direct current is supplied to the anode 4 by a DC power source 7, and a direct current is supplied to the deposition target substrate 1 by a DC power source 12.
By heating the hot cathode 3, a large amount of electrons are emitted from the hot cathode 3 toward the anode cone 4a, and glow discharge is started between the hot cathode 3 and the anode cone 4a. Toluene gas as a film forming raw material gas inside the chamber is ionized by a large amount of electrons to be in a plasma state. At this time, since a magnetic field is generated in the region where the toluene gas located in the vicinity of the hot cathode 3 is converted into plasma by the neodymium magnet 9, the plasma can be densified by this magnetic field, and ionization efficiency is improved. Can do. The deposition raw material molecules in the plasma state are directly accelerated by the negative potential of the deposition target substrate 1, fly toward the deposition target substrate 1, and adhere to the surface of the deposition target substrate 1. Is done. Thereby, a thin DLC film is formed on the deposition target substrate 1. At this time, the reaction of the following formula (1) occurs on the surface of the film formation substrate 1.
C ₇ H ₈ + e ⁻ → C _a H _b + xH ₂ ↑ (1)
Next, a method for manufacturing a magnetic recording medium using the plasma CVD apparatus shown in FIG. 1 will be described.
First, a film formation substrate having at least a magnetic layer formed on a nonmagnetic substrate is prepared, and this film formation substrate is held by a holding unit. Next, the raw material gas is changed to a plasma state by discharge between the hot cathode 3 and the anode cone 4a heated in a predetermined vacuum condition in the chamber, and the surface of the deposition target substrate held in the holding unit. Accelerate collision. As a result, a protective layer mainly composed of carbon is formed on the surface of the film formation substrate. Note that in the case of forming a DLC layer as a protective layer, a gas containing carbon and hydrogen can be used as a source gas.
Next, effects obtained by the present embodiment will be described.
In the conventional plasma CVD apparatus shown in FIG. 4, since there is a gap 113 between the cathode back plate 111 and the anode cone 104a, discharge may occur on the back surface of the anode cone 104a, and the carbon film 110a may adhere.
On the other hand, in the plasma CVD apparatus of the present embodiment shown in FIG. 1, the anode cone 4a shown in FIG. 1 is shaped so that the anode cone 104a and the cathode back plate 111 shown in FIG. The maximum gap between the hole 4c of 4a and each of the first wiring 17a and the second wiring 17b is 5 mm or less, and the maximum gap between the anode cone 4a and the other end of the plasma wall 8 is 5 mm or less. Thus, it is possible to suppress the occurrence of discharge on the back surface of the anode cone 4a and the deposition of the CVD film. Further, when the attached CVD film is peeled off as in the prior art, it is possible to prevent the peeled CVD film from adhering to the deposition target substrate and causing a defect in the magnetic recording medium.
By suppressing the occurrence of discharge on the back surface of the anode cone 4a, there is no loss of power consumption as in the prior art, so that the energy used for decomposition of the raw material gas is not reduced by this power loss. There is no possibility that the film quality of the film formed on the film formation substrate 1 will deteriorate.

[Example 1]
The plasma CVD apparatus shown in FIG. 1 was subjected to a continuous discharge test for 8 hours.
(Common test conditions)
Deposition substrate: Si wafer Material gas: C ₇ H ₈
Gas flow rate: 3.25sccm
Pressure: 0.3 Pa
Anode voltage Vp (voltage of DC power supply 7): 75V
Plasma current Ip (current of DC power supply 7): 1650 mA
Substrate bias (voltage of DC power supply 12): −250V
Hot cathode 3: Tantalum filament Output of AC power supply 5: 200W
External magnetic field: 50 gauss (Result)
No carbon film adhered to the gaps between the anode cone 4a and the first and second wirings 17a and 17b (see FIG. 2B).
No carbon film adhered to the gap between the anode 4 and the gas introduction flange 15 and there was no trace of abnormal discharge (see FIG. 2A).
[Comparative Example 1]
The plasma CVD apparatus shown in FIG. 4 was subjected to a continuous discharge test for 8 hours.
(Common test conditions)
Deposition substrate: Si wafer Material gas: C ₇ H ₈
Gas flow rate: 3.25sccm
Pressure: 0.3 Pa
Anode voltage Vp (voltage of DC power supply 7): 75V
Plasma current Ip (current of DC power supply 7): 1650 mA
Substrate bias (voltage of DC power supply 12): −250V
Hot cathode 3: Tantalum filament Output of AC power supply 5: 200W
External magnetic field: 50 gauss (Result)
A carbon film adhered to the gap between the anode 104 and the cathode back plate 111 (FIGS. 2C and 2D).
A carbon film adhered to the gap between the anode 104 and the gas introduction flange 115, and there were traces of abnormal discharge in some places (FIG. 2C).
[Example 2]
A DLC film with a thickness of 40 nm is formed on a 3.5-inch medium using the plasma CVD apparatus shown in FIG. 1 under the following common test conditions, and the contact angle of the formed DLC film with water is measured. Then, the hardness of the DLC film was evaluated. The relationship between the contact angle and the hardness is as shown in FIG.
(Common test conditions)
Film formation substrate: 3.5-inch media Material gas: C ₇ H ₈
Gas flow rate: 3.25sccm
Pressure: 0.3 Pa
Anode voltage Vp (voltage of DC power supply 7): 75V
Plasma current Ip (current of DC power supply 7): 1650 mA
Substrate bias (voltage of DC power supply 12): -250V, -300V, -350V
Hot cathode 3: Tantalum filament Output of AC power supply 5: 200W
External magnetic field: 50 gauss (Result)
Substrate bias −250V: Knoop hardness 2930HK (contact angle 57 °)
Substrate bias −300V: Knoop hardness 2970HK (contact angle 56 °)
Substrate bias −350V: Knoop hardness 3000 HK (contact angle 55 °)
[Comparative Example 2]
A DLC film having a thickness of 40 nm is formed on a 3.5-inch medium using the plasma CVD apparatus shown in FIG. 4 under the following common test conditions, and the contact angle of the formed DLC film with water is measured. Then, the hardness of the DLC film was evaluated. The relationship between the contact angle and the hardness is as shown in FIG.
(Common test conditions)
Film formation substrate: 3.5-inch media Material gas: C ₇ H ₈
Gas flow rate: 3.25sccm
Pressure: 0.3 Pa
Anode voltage Vp (voltage of DC power supply 7): 75V
Plasma current Ip (current of DC power supply 7): 1650 mA
Substrate bias (voltage of DC power supply 12): -250V, -300V, -350V
Hot cathode 3: Tantalum filament Output of AC power supply 5: 200W
External magnetic field: 50 gauss (Result)
Substrate bias −250V: Knoop hardness 2650HK (contact angle 65 °)
Substrate bias −300V: Knoop hardness 2770HK (contact angle 62 °)
Substrate bias −350V: Knoop hardness 2830HK (contact angle 60 °)
According to the results of Example 2 and Comparative Example 2, since the contact angle of Example 2 is smaller than that of Comparative Example 2, the DLC film having a higher hardness than that of Comparative Example 2 is obtained in Example 2. It was confirmed that the film was formed.

DESCRIPTION OF SYMBOLS 1,101 ... Film-forming substrate 2,102 ... Chamber 3,103 ... Cathode (hot cathode)
4, 104 ... anode 4a, 104a ... anode cone 4b, 104b ... anode base 4c ...

hole

5, 105 ...

AC power source

6, 106 ... ground 7, 107 ... DC power source 8, 108 ... plasma wall 8a ... film thickness correction plate 9 ... Neodymium magnet 12,112 ... DC power supply 15,115 ...

Gas introduction flange

15a, 115a ... Gas introduction part 17a ... First wiring 17b ... Second wiring 109 ... Magnet 110a ... Carbon film 110b ... Carbon film particle 111 ... Cathode back plate 113 ... gap 114 ... ring-shaped space 116 ... arrow

Claims

A chamber;
A plasma wall disposed in the chamber and having a cylindrical shape with open ends or a polygonal cross section; and
A holding unit that is disposed in the chamber and holds a deposition target substrate disposed in the vicinity of an opening at one end of the plasma wall;
An anode disposed in the chamber and disposed to cover an opening at the other end of the plasma wall;
A filament-shaped cathode disposed in the chamber, disposed inside the anode and in the vicinity of the opening of the other end of the plasma wall, and opposed to the substrate to be processed held in the holding unit;
An AC power source or a DC power source disposed outside the chamber, electrically connected to one end of the cathode via a first wiring, and electrically connected to the other end of the cathode via a second wiring; ,
A hole provided in the anode, through which each of the first wiring and the second wiring;
A first DC power source disposed outside the chamber and electrically connected to the anode;
A second DC power source disposed outside the chamber and electrically connected to the deposition target substrate held by the holding unit;
A gas supply mechanism for supplying a source gas into the chamber;
An exhaust mechanism for exhausting the chamber;
A plasma CVD apparatus comprising:
In claim 1,
The maximum gap between the other end of the plasma wall and the anode is 5 mm or less,
A plasma CVD apparatus, wherein a maximum gap between the hole and each of the first wiring and the second wiring is 5 mm or less.
In claim 2,
A plasma CVD apparatus having a gap between the chamber and the anode connected to a gap between the other end of the plasma wall and the anode, wherein a maximum portion of the gap is 5 mm or less.
In claim 2 or 3,
A plasma CVD apparatus having a gap between the chamber and the plasma wall connected to a gap between the other end of the plasma wall and the anode, wherein a maximum portion of the gap is 5 mm or less.
In the manufacturing method of the magnetic-recording medium using the plasma CVD apparatus as described in any one of Claims 1 thru | or 4,
Holding the film formation substrate on which at least the magnetic layer is formed on the nonmagnetic substrate in the holding unit,
The source gas is turned into a plasma state by discharge between the filament-shaped cathode and the anode heated under vacuum in the chamber, and the plasma is applied to the surface of the deposition target substrate held in the holding portion. A method of manufacturing a magnetic recording medium, comprising forming a protective layer containing carbon as a main component by accelerated collision.
6. The magnetic recording according to claim 5, wherein the source gas is a source gas for forming a DLC layer as the protective layer on the deposition target substrate and includes a gas containing carbon and hydrogen. A method for producing a medium.
A magnetic recording medium manufactured using the method for manufacturing a magnetic recording medium according to claim 6,
The deposition substrate;
The DLC layer formed on the deposition target substrate;
A magnetic recording medium comprising: