JP2002105624A - Film forming apparatus for cubic boron nitride thin film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film forming apparatus capable of simultaneously forming uniform and stable boron nitride films on substrates of cemented carbide and high speed steel or on surfaces of many tool members consisting thereof and having a special shape on their top end parts. SOLUTION: The apparatus has an evaporation source 2 provided with a crucible 2b filled with an evaporation material 2a and an electron gun 2c at the center part of a vacuum vessel 1, many substrate holders 3 for supporting the substrates T are fitted at equal intervals to an outer peripheral section of a disk shape plate 35 rotating/revolving around the evaporation source 2 in a vertical direction, yokes 10a, 10b are symmetrically arranged at a prescribed interval above the evaporation source 2 and between the evaporation source 2 and many substrate holders 3 fitted to the disk shape plate 35, a prescribed interval on a rear face, a pair of magnetic poles 9a, 9b integrated with permanent magnets 9 are arranged to be inclined, and a cathode 6 for discharging a thermal electron and an anode 5 facing thereto in the same plane as the magnetic poles are arranged between a pair of the magnetic poles 9a, 9b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for forming a cubic boron nitride film, and more particularly, to a high hardness, low friction coefficient,
A cubic boron nitride film having better heat resistance and other properties than other materials is applied to the surface of a substrate, a cutting tool, a tool such as a wear-resistant tool (hereinafter referred to as a substrate), and the length of the substrate is reduced. The present invention relates to a film forming apparatus capable of achieving a long service life, expanding a film forming range when applying the cubic boron nitride film, and mass-producing with high stability.

[0002]

2. Description of the Related Art Cubic boron nitride (hereinafter referred to as cBN)
Has a hardness of 4000 to 6000 Hv, which is equivalent to 8000 to 10000 Hv of diamond, and has excellent thermal and chemical stability even at 1000 ° C. or higher, and has a lower reactivity with iron-based materials than diamond. CBN sintered body obtained by sintering under ultra-high pressure and high temperature is cut into appropriate size by wire electric discharge machine etc. It is used as a tool for cutting or as a material for wear-resistant articles.

However, as described above, the production of a cBN sintered body requires an ultra-high pressure and a high temperature, so that it is difficult to obtain a complicated shape, low mass productivity, and high production cost. For this reason, the range of use is significantly limited.

[0004]

In order to take advantage of the above-mentioned properties of cBN, it has been proposed to form a coating layer made of cBN on a substrate surface by a CVD method or a PVD method.
Although it has become possible to form a coating by vapor phase synthesis of cBN, it is necessary to improve the adhesion of the cBN film to the substrate and the weather resistance of the film, or to put a large amount of substrates into practical use by gas phase synthesis (mass production). There is a demand for the development of an apparatus capable of simultaneously forming a film and having an expanded film forming range.

In view of the above, the present invention provides an apparatus for forming a cBN film on a substrate, which enables uniform film formation even on a substrate having a special shape and expands the range of film formation. It is an object to provide a membrane device. Also, by rotating a number of substrate holders supporting the substrate around the evaporation source, the film can be simultaneously formed on a plurality of substrates, and high uniformity of film quality can be obtained between the substrates. By providing a film forming apparatus suitable for mass production, and by rotating the substrate itself, even a three-dimensional object having a complicated shape, such as a mold or a drill, can be substantially entirely formed. It is an object of the present invention to provide a film forming apparatus capable of uniformly forming a film.

[0006]

According to the first aspect of the present invention, there is provided a vacuum chamber whose inside is evacuated by exhaust means,
An evaporation source provided with a crucible and an electron gun arranged in the center of the vacuum chamber and filled with the evaporation material, and revolves around the evaporation source so as to rotate vertically around the evaporation source. A plurality of substrate holders mounted at equal intervals on an outer peripheral portion of a disk-shaped plate provided with means for supporting a substrate, and a plurality of substrate holders mounted above the evaporation source and mounted on the evaporation source and the disk-shaped plate A pair of magnetic poles having built-in permanent magnets disposed at a required interval and inclined at left and right contrast positions, and a rectangular parallelepiped yoke attached to the back of each of the pair of magnetic poles, A thermionic emission cathode and an anode opposed thereto disposed between the pair of magnetic poles having the required interval and in the same plane as the magnetic poles, and a heater for heating the substrate provided below the evaporation source. Ingredient A film forming apparatus cubic boron nitride thin film are.

According to the first aspect of the present invention, this film forming apparatus is configured such that an outer peripheral portion of a disk-shaped plate provided with a self-revolving means around an evaporation source disposed at a central portion in a vacuum chamber. Substrates supported by substrate holders attached at equal intervals rotate up and down around the evaporation source, and there is a required space between the evaporation source and the substrate above it. A pair of magnetic poles containing a permanent magnet are arranged at an inclined position at right and left positions, a rectangular parallelepiped yoke is attached to the back of the magnetic poles, and a pair of magnetic poles having the required interval are provided. A cathode for thermionic emission and an anode facing the same are provided in the same plane as the magnetic pole, and the degree of inclination to the outside of the pair of magnetic poles is measured from the top of the magnetic pole of the rectangular parallelepiped yoke attached to the back of the magnetic pole. Degree of height The film formation range in three directions, that is, a direction just above the evaporation source (a direction of the height of the magnetic poles), a direction parallel to the magnetic poles between the magnetic poles, and a longitudinal direction of the magnetic poles with respect to the substrate rotating vertically above the evaporation source. While expanding
As a result, uniform and stable film formation can be simultaneously performed on a large number of substrates rotating in the vertical direction above the evaporation source.

Further, in the first aspect, the length of the rectangular parallelepiped yoke attached to the back of each of the pair of magnetic poles is equal to or longer than the length of the magnetic poles (Claim 2). And the inclination of the rectangular parallelepiped yoke on the back side is 5 to 45 ± 3 ° from the upright state to the outside.
(Claim 3), the distance between the magnetic poles of the pair of magnetic poles is 100 to 800 mm (claim 4), and the magnetic poles are arranged in the same plane between the pair of magnetic poles having a required interval. A plurality of thermionic emission cathodes are used in accordance with the increasing distance of the magnetic poles in the longitudinal direction (Claim 5), and an anode arranged in the same plane as the magnetic poles between a pair of magnetic poles having a required interval Increasing the length of the magnetic pole in accordance with the increasing distance in the longitudinal direction of the magnetic pole (claim 6);
Alternatively, in the rotation of the disk-shaped plate on which the substrate holder supporting the substrate is attached by the self-revolution means,
High-frequency power to the substrate is introduced from a plurality of equally-distributed introduction paths to a ring-shaped fixed gear having rotation gears at both ends connected to the disc-shaped plate by a shaft via a rotation shaft support mechanism. By adding the above (claim 7) and the like, it is possible to more reliably perform the expansion of the film formation range, the simultaneous achievement of uniform and stable film formation on a large number of substrates (mass production), and the like.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of a c-BN thin film forming apparatus according to the present invention will be described below with reference to the drawings. FIG. 1 is a schematic front view of a film forming apparatus, FIG. 2 is a cross-sectional view of the rear side of the apparatus viewed from line AA ′ in FIG. 1, and FIG.
It is the front side sectional view of the apparatus seen from the line. In the figure,
1 is a vacuum chamber. Although not shown, the vacuum chamber 1 is provided with an exhaust port at a lower portion and is connected to a vacuum pump, and the vacuum pump 1 is evacuated by the vacuum pump.

An evaporation source 2 is located near the center of the vacuum chamber 1.
Is provided. The evaporation source 2 includes a crucible 2b containing an evaporation material 2a such as boron and titanium, and an evaporation material 2a.
It comprises an electron gun 2c for heating and evaporating a. Although only one evaporation source 2 is shown in the figure, it can be used as a multi-point hearth or a multi-source evaporation mechanism.

The center of the rotary shaft 8a of the substrate rotating motor 8 outside the vacuum chamber 1 is fixed to the vertical edge of the evaporation source 2 provided near the center of the vacuum chamber 1 described above. ,
A disk-shaped plate 35 that rotates in the vertical direction of the evaporation source 2 by a self-revolution means (described later) 30 is arranged. A plurality of substrate holders 3 supporting a substrate or a work (for example, a tool, hereinafter referred to as a substrate) T are provided at equal intervals on the outer peripheral portion of the disk-shaped plate 35.
It is arranged so that it may face. The distance between a large number of substrate holders 3 supporting the substrate T attached to the outer peripheral portion of the disk-shaped plate 35 and the evaporation source 2 provided at the center in the vacuum chamber 1 is set such that boron is stably reduced to 0. .2
In order to evaporate at a film formation rate of up to 6.0 nm / sec, 250 to 700 mm is generally required.

The substrate T supported by the large number of substrate holders 3 is provided with a bias power supply 12 provided outside the vacuum chamber 1.
Are connected via a matching box 11 to which a high-frequency voltage is applied. The other end of the bias power supply 12 is grounded. 4 is a gas nozzle for introducing Ar, the N _2, H ₂ etc. of gas or a mixture of two or more gas thereof into the vacuum chamber 1, the flow rate control valve provided in the inlet pipe which extends outside the vacuum chamber 1 13 The flow rate is adjusted by means of. Above the evaporation source 2, between the evaporation source 2 and a number of substrate holders 3 supporting the substrate T attached to the disk-shaped plate 35, a cathode 6 for emitting thermoelectrons and facing the cathode. As described above, the anode 5 is provided. A pair of magnetic poles including a permanent magnet 9 is formed so that a parallel magnetic field is formed at the same horizontal plane as the cathode 6 and the anode 5 and in the same direction as the direction of the electric field formed by the cathode 6 and the anode 5. 9a and 9b are arranged at the required left and right contrast positions in such a manner as to be inclined outward by the same angle.

On the back side of the inclined magnetic poles 9a and 9b, in order to obtain a necessary magnetic flux density near the substrate,
The yokes 10a and 10b are attached. further,
The anode 5 is arranged at the same angle as the magnetic pole 9a. The whole part related to the above-mentioned plasma generation mechanism is provided in the vacuum chamber 1 at an intermediate position between the evaporation source 2 and the substrate holder 3 supporting the substrate T, for example, at a position at least 150 mm away from the evaporation source 2. Is preferred.
The distance between the cathode 6 and the anode 5 is preferably 120 to 1000 mm in order to widen the plasma space.

The cathode 6 is made of a filament made of a hot cathode material such as W or W / Th.
And emits thermoelectrons by being electrically heated. The anode 5 has a positive DC voltage with respect to the ground potential, for example, 30 V.
A DC voltage of ~ 70 V is applied by the power supply 16. 14 is a filament bias power supply, 17 is a vacuum chamber 1
It is a heater that heats the inside. The pair of magnetic poles 9 described above
a and 9b face each other, and the intensity of the magnetic flux density is 6 at an intermediate point between the two magnetic poles in order to form a high-density plasma.
It is preferably set to 10 to 10 mT.

Next, the self-revolution means 30 in the apparatus of the present invention will be described with reference to a partially enlarged view of FIG. The rotation means 30 includes a fixed gear 34 having rotation gears 32 at both ends, a disk-shaped plate 35, and a substrate rotation introduction plate 36. The fixed gear 34 is fixed to one side wall 1a of the vacuum chamber 1 by a fixed insulator 34a. At both ends of the fixed gear 34, a disc-shaped plate 35 is provided.
A rotation gear 32 for rotating each of a large number (for example, 72) of substrate holders 3 attached via a shaft 38 to an outer peripheral portion of the substrate holder 3 is attached. The rotation gear 32 is connected to the other end of the shaft 38 supported by a rotation shaft support mechanism 37 such as a bearing having a mechanism capable of introducing rotation to the disk-shaped plate 35. The disk-shaped plate 35 is fixed to both ends of a substrate rotation introducing plate 36 whose center is connected to the shaft end of the rotation shaft 8a of the substrate rotation motor 8 outside the vacuum chamber 1 by a rotation mechanism fixing insulator 36a. Have been. Therefore, the disk-shaped plate 35 rotates in conjunction with the rotation of the substrate rotation introducing plate 36 caused by the rotation of the motor rotation shaft 8a by the start of the motor 8, and the outer peripheral portion of the disk-shaped plate 35 is rotated via the shaft 38. A large number (for example, 72) of the attached substrate holders 3 rotate (revolve) at equal intervals around the evaporation source 2 installed at the center position in the vacuum chamber 1. At this time, as described above, the rotation gears 32 provided at both ends of the fixed gear 34 are attached to the disc-shaped plate 3.
5 is connected to the shaft 38 supported by a rotation shaft support mechanism 37 having a mechanism capable of introducing rotation to the substrate 5, so that the rotation of the substrate rotation introduction plate 36 by the start of the motor 8 described above, The disk-shaped plate 35 is rotated by using the force of the disk-shaped plate 35 revolving.
Are rotated around the shaft shaft 38.

When the substrate supported by the substrate holder passes through the film formation region immediately above the evaporation source and immediately above the magnetic poles by such a self-revolving means, each substrate rotates 4 to 60 times per revolution cycle. By performing the rotation of the rotation,
This enables intermittent film formation to uniformly irradiate each substrate from various angles. In this intermittent film formation, the total amount of ions applied to a unit area per pass time of the substrate is 0.15 to 1.5 A / cm ² .

To explain an example of film formation by such a film forming apparatus, first, some substrates T are set on the substrate holder 3 and the vacuum chamber 1 is evacuated. After that, Ar gas or the like is introduced from the gas nozzle 4 into the vacuum chamber 1 and cleaning of the substrate T by ion bombardment is performed for a predetermined time, and then film formation is performed. In this film forming process, Ar gas and N ₂ gas of predetermined components are introduced into the vacuum chamber 1 by the gas nozzle 4, and the cathode 6 is energized and a positive voltage is applied to the anode 5. Thereby, plasma is formed in combination with the parallel magnetic field of the magnetic poles 9a and 9b. In this state, the electron gun 2c of the evaporation source 2 is operated to evaporate boron (B) as an evaporation material. As a result, the evaporated particles of boron (B) rise and pass through the plasma and adhere to the substrate T set on the substrate holder 3, while being generated in the plasma by a self-bias voltage generated by the high-frequency power applied to the substrate T. The Ar and N ₂ gases are attracted and collide with the substrate T. As a result, a cBN film is deposited on the surface of the substrate T as a reaction product film.

Next, features of the film forming apparatus will be described. The film forming apparatus of the present invention enables a uniform and stable film formation even when the number of substrates to be formed is increased by expanding a film formation range when a cBN thin film is formed on a substrate. The biggest purpose is to make it possible.

The above-described expansion of the range in which the film can be formed is achieved by the outer peripheral portion of the disk-shaped plate 35 rotatably arranged by the self-revolution means 30 on the periphery of the evaporation source 2 arranged near the center in the vacuum layer 1. As shown in the schematic diagram of the cBN film formation region in FIG. 5, the X direction (the direction parallel to the gap between the magnetic poles) and the Y direction ( In the three directions of the magnetic pole longitudinal direction) and the Z direction (height direction, that is, the direction immediately above the evaporation source), by introducing the structures of the items described below, the X direction is 100 to 80.
0 mm, Y-direction 100-800 mm, Z-direction 30-20
0 mm, maximum 800 (X) × 800 (Y) × 170
A film formation range of (Z) mm can be realized.

(1) Z direction (height direction, ie, just above the evaporation source): As shown in the enlarged view of the vicinity of the substrate in FIG.
a, 9b from the upright state to the outside by the required angle (β
°) while tilting, the pair of magnetic poles 9a, 9b
The iron yokes 10a and 10b are respectively installed on the back side of the. This yoke is used to use the magnetic flux generated on the non-opposing magnetic pole surface side of the magnet 9 in the magnetic poles 9a and 9b on the opposing surface side, and as shown in FIG. Ys (0-130 ± 20m) from J (55mm)
m) By using a high rectangular parallelepiped shape, the magnetic flux from the magnetic pole facing surface can be strongly attracted to the yoke, and the direction in which the magnetic flux is emitted can be changed. That is, the magnetic poles 9a, 9b
By providing the iron yokes 10a and 10b on the back side, a strong equal magnetic flux density is generated in the Z direction near the magnetic pole, and the actual magnetic flux can be changed in the direction of the substrate by this magnetic field. As a result, the magnetic flux density is set to a maximum of 1.7 on the revolving surface of the substrate immediately above the center of the magnetic pole, compared with the case where there is no yoke.
The magnetic flux density can be increased to about four times by inclining the yoke and the magnetic pole.

The height Yh of the rectangular parallelepiped yokes 10a and 10b is represented by the magnetic pole height J + Ys. When the magnetic pole height J is 55 mm, Ys is 0 to 130 ± 20 m.
m is appropriate. In FIG. 6, the thickness Y of the yoke is shown.
It is appropriate that w is 5 to 20 mm and depth Yd is 100 to 860 mm.

In order to realize a magnetic flux density of 1 mT or more on the substrate, the magnetic poles are inclined. This inclination angle is changed by the distance L between the magnetic poles 9a and 9b. As shown in FIG. 7, the distance between the magnetic poles 9a and 9b is L, and a vertical line extending from the center of each of the magnetic pole faces of the opposing magnetic poles 9a and 9b is defined by the center Q between the magnetic poles and the plane of intersection R of the substrate. Is the point at which the line intersects the line connecting R, R is the substrate orbital plane, and R is the top line between the magnetic poles
Assuming that an intersection with the -Q line is S, a point P at which the perpendiculars formed from the centers of the respective magnetic pole surfaces intersect is a point P from the intersection of the substrate revolution surface R and the RQ line of the top line between the magnetic poles from the substrate. Is appropriate.

In FIG. 7, 1/1/3 of the distance L between the magnetic poles is used.
Ms = tanα = PS / (L / 2) where Ms is the ratio of 2 to the distance between the PSs on the RQ line, and is represented by Ms = tanα = PS / (L / 2). From the magnetic flux density decay curve, considering that a decrease in magnetic flux density is recognized when the magnetic pole inclination angle exceeds 45 °, the magnetic pole inclination angle is suitably 5 to 45 ° ± 3 °. The inclination of the magnetic pole is determined from an angle when the magnetic pole is tilted outward from an upright state around a yoke provided on the back surface of the magnetic pole and compared with a vertical state.
Table 1 shows the magnetic pole inclination angle calculated from the magnetic pole distance L and the PS distance. In order to satisfy the condition of 5-45 ° ± 3 °, the magnetic pole distance L must be 200 mm or more. I understand. Table 2 shows the magnetic pole inclination angles in Table 1 as の of the distance L between the magnetic poles in the above equation and PS on the RQ line.
Is calculated as tan α, the ratio to the distance between
It can be seen that tan α <1.0 to satisfy the condition of 45 ° ± 3 °.

Table 3 shows the distance between magnetic poles L = 260 m.
The relationship between the magnetic pole inclination angle, the yoke height Yh, the yoke height Ys from the top surface of the magnetic pole, and the like and the magnetic flux density when m and PS = 120 mm are shown. It is recognized that there is an effect of increasing the magnetic flux density in a range of up to 130 ± 20 mm.

With the above structure and the above structure,
The substrate incident current density can be set to 30 to 50 mA / cm ^2, and the filament bias can be controlled to be in a range of 0 to -40 V, an anode voltage of 30 to 80 V, and an anode current of 20 to 150 A.

[0026]

[Table 1]

[0027]

[Table 2]

[0028]

[Table 3]

(2) Y direction (longitudinal direction of the magnetic pole): In order to generate a uniform discharge in the Y direction (longitudinal direction of the magnetic pole) between the magnetic poles, a diagram corresponding to an increase in the substrate area due to an increase in the size of the substrate. 5, the length of the magnetic poles 9a, 9b is increased, and the yokes 10a, 10b
In addition, the length of the anode electrode 5 is also increased in the longitudinal direction by the same amount as the magnetic pole length, and the thermoelectron emission cathode 6 is structured such that it increases by one for every 100 mm increase in the length of the magnetic pole. When the number is Fn, the current value flowing to the anode is 20+ (Fn-1) × 25 ± 10 A
And an abnormal discharge prevention measure, it is possible to make a stable discharge in the longitudinal direction. With such a structure, it is possible to select a film formation range of cBN in the longitudinal direction within a range of about 100 to 800 mm by increasing the uniform anode current of 50 to 150 A in the longitudinal direction. It becomes.

In FIG. 5, a hot filament having a wire diameter of 1 to 2 mmφ made of a hot cathode material such as W or Th / W is used as the thermionic emission cathode 6, and 6a, 6b,
6c shows a case where three of them are used. In this case, the thermofilaments 6a, 6b, 6c each having an inverted U-shape are arranged at a distance parallel to the magnetic pole 9b in a discharge space formed by the yoke 10b and the magnetic pole 9b as shown in FIGS. In addition, the structure is such that the side of the filament in the height direction is kept at the horizontal level with the anode, and each bent end is pressed from above and below outside the discharge space with the filament presses 6f and 6g and fixed with the bolt 6e. . As described above, by preventing the filament holding portion from being present in the discharge space, it is possible to prevent a temperature rise and abnormal discharge due to ion irradiation incident on the filament holding portion, and to prevent filament breakage and electrode damage. dfh is the length of the filament, which is larger than the distance Mh to the midpoint in the height direction of the magnetic pole 9b, and is up to 100 mm. The filament width dfw is 40 to 100 m.
m, and the position is desirably the same as the distance Mh to the midpoint in the height direction of the magnetic pole 9b.

(3) X direction: stabilization of discharge by filament bias, increase of anode current of 50 to 150 A, and application of substrate magnetic field by yoke and magnetic pole inclination, thereby making the range of cBN film formation in the X direction possible. 100-800mm
To the extent possible.

That is, in FIG. 5, at the distance L (100 to 800 mm) in the X direction between the magnetic poles 9a and 9b, the magnetic flux density is 6-1 at the position of L / 2, that is, at the center between the magnetic poles 9a and 9b.
Both magnetic poles are arranged so as to be 0 mT. Further, as shown in FIG. 5, the position of the thermionic emission cathode 6 is determined by an electrostatic field EA (discharge of the electrostatic field before discharge) generated by a voltage difference between the anode 5 and the filament bias voltage applied to the thermionic emission cathode 6. The range is 2.0 to 4.0 V / cm) and the electrostatic field EF between the filament bias voltage applied to the thermionic emission cathode 6 and the magnetic pole 9b at the ground potential (the range of the electrostatic field is 2.0).と す る 3.0 V / cm), or a position where EA> EF. By setting the thermionic emission cathode 6 at such a position, a discharge of 50 A or more can be stably performed between the magnetic poles. Even if the deposition distance in the X direction is changed, the discharge does not change and a stable deposition can be performed. And the deposition distance range is 100 to 80
It can be enlarged to about 0 mm.

In the film forming apparatus of the present invention, the supply of RF power from the high frequency (RF) power supply 12 to the substrate T via the matching box 11 is performed by a self-revolution means shown in FIG.
As shown in the figure, a position where the ring-shaped fixed gear 34 is equally divided from the vicinity of the center point of the ring-shaped fixed gear 34 at an equal angle, for example, an equidistant Y _{1 in} which the angle is shifted by 90 ° with respect to 360 °. by introducing the position of the four positions of ~ Y _4, it is possible to enable application of RF power. This is done by connecting the power line to one point of the ring-shaped fixed gear and
If an attempt is made to introduce RF power by the conventional method of introducing C power, the RF power introduction path has an infinite distance in the ring-shaped fixed gear, and no voltage is generated. As a result, the maximum value of the Vpp value, which is the absolute value of the voltage value oscillating in the high frequency (RF) ±, is as low as −50 V or less. This is to prevent such a state. This is due to the case where the RF power of the present invention is introduced into the substrate T and the case of the conventional RF power introduction method (the RF introduction point in FIG. 13).
From FIG. 14 showing the relationship with the voltage in the case where only one point is used among Y ₁ to Y ₄ ), it is recognized that no voltage is generated on the substrate unless RF is applied.

As described above, the yokes 10a and 10b provided on the back surface of the magnetic poles 9a and 9b have an effect of increasing the magnetic flux density by the height Ys of the upper surface from the height J of the magnetic pole among the heights Yh. As shown in the magnetic flux density curve immediately above the center between the magnetic poles in FIG. 10, a change in the magnetic field applied to the substrate is observed depending on the value of the height of Ys. This shows a large difference in the magnetic flux density depending on the height and the inclination angle of the magnetic pole. It is shown. The effect of the yoke appears in the rise of the substrate self-bias as shown in FIG. 11 showing the relationship between the height of the yoke and the substrate self-bias. Just changing it will change the generated voltage. Since the self-bias is the amount of electrons gathering near the substrate, the presence of the yoke increases the efficiency of electron irradiation on the substrate.

[0035]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS With the film forming apparatus of the present invention described above, a high-speed steel straight drill having a length of 100 mm and a diameter of 6.0 mm was used as a substrate T, and cB was applied to the surface of the drill.
An embodiment in which an N thin film is applied will be described. The materials used for the film formation are boron (B) having a purity of 99.9%, titanium (Ti) having a purity of 99%, N ₂ and A having a purity of 99.99%.
r.

In the above apparatus, the distance L between the magnetic poles 9a and 9b: 260 mm, the magnetic poles 9a and 9b and the yoke 10
a, 10b: 25 ° each, height J of magnetic poles 9a, 9b: 55 mm, height Yh of yokes 10a, 10b: 1
00 mm (height Ys from the upper surface of the magnetic poles 9a and 9b: 45)
mm), and hot filament 6: width dfw 60 mm, height dfh 60 mm, and three ends 6a, 6b and 6c were used as shown in FIG.

The above drill is used as a processing substrate T in the vacuum chamber 1
Are attached to 72 substrate holders 3, 3,... Attached to a shaft 38 at an outer peripheral portion of a disc-shaped plate
(R-1 to R-12 in FIG. 1). Thereafter, the inside of the vacuum chamber 1 was evacuated to 1 × 10 ⁻⁴ Pa, and the inside of the chamber was heated to 250 to 500 ° C. while revolving the substrate T on its own axis. Thereafter, while maintaining the same temperature, (A) substrate cleaning (substrate bombardment) was first performed, and then (B) film formation was performed.

(A) Substrate Cleaning As the substrate cleaning, the following two types of bombarding were successively performed. (1) High vacuum bombard: Ar gas was introduced into the tank at a pressure of 6.7 × 10 ⁻² Pa, anode current was 4.2 kW, filament bias was 1 kW, cathode current was 1200 W,
The substrate surface was cleaned for 60 minutes under the condition of applying a high frequency power of 1800 W to the substrate. (2) Ti bombard: Ti is heated and evaporated with a 3.5 kW electron gun, Ar gas of 1 to 4 × 10 ⁻² Pa is introduced, anode current is 4.2 kW, filament bias is 1
kW, cathode current 1200 W, high frequency power 30
Substrate cleaning was performed for 10 minutes under the condition of applying 0 W.

(B) Film Formation (1) Film Formation of TiN Film A Ti thin film / TiN thin film / Ti thin film was formed on the substrate T whose surface was cleaned as described above. That is, the evaporation material Ti is heated and evaporated by an electron gun having a power of 6.0 kW, and Ar gas of 1 to 4 × 10 ⁻² Pa is supplied to the gas nozzle 4.
Introduced from the anode current 4.2 kW, the filament bias 1 kW, while made to perform discharge under the conditions of the cathode current 1200W ionize the Ti, the high-frequency power 200~40W applied to the substrate T, the N ₂ gas (a) For two minutes
0 mL, (b) 5 minutes, 120 mL / min, (c) 4
Min, 40 mL / min, (d) 4 min, 120 mL / min
min, (e) 2 minutes, 0 mL, etc., the introduction amount was changed in 5 steps and the introduction was carried out for 17 minutes, and the intermediate layer was made of TiN.
A TiN thin film having a thickness of 0.2 to 0.4 μm and having a three-layer structure of a Ti thin film / TiN thin film / Ti thin film, which is rich in Ti, was formed.

(2) Formation of cBN Film Next, a cBN thin film was formed on the substrate T on which a three-layered TiN thin film in which the intermediate layer obtained above was rich in TiN was formed. Since the TiN thin film on the substrate T has a Ti thin film formed on the outermost surface, in forming the cBN film in this step, the B thin film is formed in a stepwise manner in order to achieve adhesion with the cBN film. A BN thin film having a different ratio was formed under the following conditions, and then a cBN thin film was formed. (A) B film deposition conditions: Electron gun output of evaporation material B 2.7 kW Anode current 4.2 kW Filament bias 1.0 kW Cathode current 1200 W Introduced Ar gas pressure 6.7 × 10 ^-2 Pa Introduced Ar gas amount 60 mL / Min RF output 600 W Film formation time 2 minutes (b) Film formation conditions of the BN film and cBN film in which the composition ratio is changed stepwise: After forming the B film as described above, the N ₂ gas is replaced with the above Ar gas was introduced simultaneously at the same pressure as the pressure, N ₂ gas and Ar gas both flow ratio, RF power, the film formation time _{N 2: Ar = 0.5: 1} RF = 1100W, 4 min N _2: Ar = 0. 6: 1 RF = 1300 W, 4 minutes N ₂ : Ar = 0.6: 1 RF = 1400 W, 4 minutes N ₂ : Ar = 0.7: 1 RF = 1600 W, 10 minutes N ₂ : Ar = 0.8: 1 RF = 1600 W, 20 minutes Thereby, as the BN layer is formed from the lower layer to the upper layer on the B film layer, the amount of N _{2 is} increased and the boron-excess amorphous BN is formed. Finally, a B film is coated on the cBN film under the B film formation conditions of (a) above to form a 0.4 to 0.3 mm B film.
An 8 μm thick cBN thin film was formed. In the above description, a high-speed steel straight drill was used as a substrate for forming a cBN film. However, depending on the type of the substrate, the operations of (1) forming a TiN film and (2) forming a cBN film described above. Is preferably repeated a plurality of times.

(3) Formation of TiN Film A TiN film was formed as a final protective film on the c-BN film having the outermost surface coated with the B film. That is, the electron gun output of the evaporation material Ti is 6.0 kW, the anode current is 4.2 kW, the filament bias is 1 kW, the cathode current is 1200 W, the introduced Ar gas pressure is 2 × 10 ⁻² Pa, and the high frequency power is 200 to 4
0 W was applied and N ₂ gas was (a) 2 minutes, 0 mL,
(B) 5 minutes, 120 mL / min, (c) 4 minutes, 4
The introduction amount was changed in four steps such as 0 mL / min, (d) for 4 minutes, and 120 mL / min, and the introduction was carried out for 15 minutes, and a TiN thin film of 0.2 to 0.4 μm was formed. This TiN film improves the weather resistance by preventing the cBN film from being directly exposed to the atmosphere by covering the cBN film because the cBN film is weak in the weather resistance and may be gradually peeled off due to the deterioration of the weather resistance. Things.

Thus, in order to identify whether or not the coating obtained in the above embodiment has a cubic boron nitride phase, the vicinity of the cutting edge of the drill obtained by polishing only the TiN film finally formed above was used. By Fourier transform infrared absorption spectroscopy (FT-
IR), the cBN as shown in FIG.
A film was included, and it was confirmed that cBN phase film formation was possible in the entire apparatus by intermittent film formation.

[0043]

As described above, in the film forming apparatus of the present invention, the evaporation source having the crucible filled with the evaporation material and the electron gun is arranged near the center of the vacuum chamber. In addition to supporting the processing substrate on a number of substrate holders attached to a disk-shaped plate that rotates in the vertical direction around the periphery thereof, above the evaporation source, the substrate is mounted on the evaporation source and a number of substrate holders attached to the disk-shaped plate. A yoke is attached to the back surface at a position opposite to the right and left with a required interval between the substrate and the supported substrate, and a pair of magnetic poles incorporating a permanent magnet are arranged in an inclined state, and between the pair of magnetic poles In the same plane as the magnetic pole, the cathode for thermionic emission and the anode opposed thereto are arranged, the interval between the pair of magnetic poles, the height of the yoke provided on the back of the magnetic pole from the top of the magnetic pole,
By adjusting the inclination angles of the magnetic poles and yokes, the introduction of high-frequency power to the substrates supported by a large number of substrate holders, etc., it is possible to expand the film formation range on the substrates and achieve simultaneous film formation on many substrates. It is.

[Brief description of the drawings]

FIG. 1 is a schematic front view of a film forming apparatus of the present invention.

FIG. 2 is a rear cross-sectional view of the device as viewed from the line AA 'in FIG.

FIG. 3 is a front sectional view of the apparatus taken along line AA ′ in FIG. 1;

FIG. 4 is an enlarged view near a substrate in the film forming apparatus of the present invention.

FIG. 5 is a schematic view showing a cBN film forming region by the film forming apparatus of the present invention.

FIG. 6 is an explanatory view showing the shape of a yoke.

FIG. 7 is an explanatory diagram of a magnetic pole tilt state.

FIG. 8 is a diagram showing attenuation of a magnetic flux density at a center portion between magnetic poles due to magnetic pole inclination.

FIG. 9 is an explanatory view of the arrangement when a plurality of filaments are used.

FIG. 10 is a diagram showing a relationship between a magnetic pole inclination angle, a yoke height and a magnetic flux density.

FIG. 11 is a diagram showing the relationship between yoke height and substrate self-bias.

FIG. 12 shows IR of a cBN film obtained in an example of the present invention.
It is a spectrum diagram.

FIG. 13 is an explanatory diagram of a self-revolution mechanism.

FIG. 14 is an explanatory diagram showing the effect of introducing RF power to a substrate.

[Explanation of symbols]

 T substrate 1 vacuum chamber 2 evaporation source 3 substrate holder 4 gas nozzle 5 anode 6 thermoelectron emission cathode 8 substrate rotation motor 9 permanent magnet 9a, 9b magnetic pole 10a, 10b yoke 12 bias power supply 14 filament bias power supply 32 rotation gear 34 fixed gear 35 Disc-shaped plate 36 Substrate rotation introduction plate 38 Shaft

Claims (7)

[Claims] 1. An evaporation source comprising: a vacuum chamber whose inside is evacuated by an exhaust means; a crucible which is arranged in the center of the vacuum chamber and is filled with an evaporation material; and an electron gun. A large number of substrate holders mounted at equal intervals on the outer peripheral portion of a disk-shaped plate provided with revolving means so as to rotate around the evaporation source in the vertical direction around the evaporation source and supporting the substrate; A pair of magnetic poles containing permanent magnets arranged at an upper position and inclined at right and left symmetrical positions with a required interval between the evaporation source and a number of substrate holders attached to the disk-shaped plate. A rectangular-parallelepiped-shaped yoke attached to the back surface of each of the pair of magnetic poles, a thermionic emission cathode disposed between the pair of magnetic poles having the required interval and in the same plane as the magnetic poles, and an anode opposed thereto. A heater for heating a substrate provided below the evaporation source. 2. The cubic boron nitride thin film according to claim 1, wherein the length of the rectangular parallelepiped yoke attached to the back surface of each of the pair of magnetic poles is equal to or longer than the length of the magnetic poles. Film forming equipment. 3. The cubic boron nitride according to claim 1, wherein the inclination of the pair of magnetic poles and the rectangular parallelepiped yoke on the back surface thereof is an inclination angle of 5 to 45 ± 3 ° from the upright state to the outside. Thin film deposition equipment. 4. A distance between magnetic poles of said pair of magnetic poles is 100 to 100.
4. The apparatus for forming a cubic boron nitride thin film according to claim 1, wherein the thickness is 800 mm. 5. A method according to claim 1, wherein a plurality of thermionic emission cathodes are arranged on the same plane as the magnetic poles between a pair of magnetic poles having a required interval in accordance with an increasing distance in a longitudinal direction of the magnetic poles. An apparatus for forming a cubic boron nitride thin film according to claim 1. 6. An anode disposed in the same plane as a magnetic pole between a pair of magnetic poles having a required interval, the length of the anode being increased in accordance with an increasing distance in a longitudinal direction of the magnetic pole. Item 6. An apparatus for forming a cubic boron nitride thin film according to any one of Items 1 to 5. 7. A high-frequency power to a substrate is connected to the disk-shaped plate by a shaft via a rotation shaft support mechanism when the disk-shaped plate on which a substrate holder supporting the substrate is mounted is rotated by the rotation means. 2. The cubic boron nitride thin film forming apparatus according to claim 1, wherein said rotating gear is introduced into a ring-shaped fixed gear having both ends thereof from a plurality of introduction paths distributed at equal intervals.