JPH02111874A - Sputtering method - Google Patents

Abstract

PURPOSE:To widen the control range of sputtering by forming a cathode with a first section and a plurally divided second section surrounding annularly the first section, and applying a controlled AC current to the electromagnet coils of both sections. CONSTITUTION:The cathode 100 is formed with the annular second section 100b consisting of plural subsections 130 and the first section 100a on the inside of the second section. Discrete magnetic field generating means are provided on the rear of the target 7 of the first section 100a and on the rear of the targets corresponding to the subsections 130 of the second section 100b. AC currents with the phase difference theta of the waveform shifted by 0<theta<2pi from each other are applied to the electromagnet coils 84 and 94 of the sections 100a and 100b. The currents applied to the coils 84 and 94 are maintained so that the plasma on the surfaces of the targets 1-7 is not extinguished, and both sections 100a and 100b are alternately sputtered to form a thin film.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for continuously forming a thin film having a single-layer structure on a substrate as a film-forming target, and particularly to a method for manufacturing a magneto-optical recording medium (wood). This invention relates to an effective sputtering method.

[Conventional technology]

Sputtering technology is a technology in which a glow discharge of Ar, etc., is generated in a low-pressure atmosphere, and ions in the plasma collide with a cathode target to knock out atoms from the target material and deposit them on a substrate, and it is widely used industrially. has been done. In particular, the magnetron sputtering method, which is characterized by forming a magnetic field component parallel to the target plane on the target and generating a magnetic field component approximately orthogonal to the electric field, is a useful method with a high film formation rate and is widely used industrially. It's being used.

In recent years, magneto-optical recording media have been widely used for large-capacity data files as magneto-optical disks that can be written and read using laser light.

This magneto-optical recording medium has a multilayer structure in which a conductive layer, a recording layer, a protective layer, an adhesive layer, etc. are laminated with a thickness of several 10A to several 100A each on a transparent substrate such as glass or plastic using a sputtering method. has.

In the magneto-optical recording medium, the recording layer exhibiting the magneto-optical effect is a single layer of a mixed alloy of a rare earth metal (hereinafter referred to as RE gold metal) and a transition metal (hereinafter referred to as 7M metal), or the above-mentioned RE gold metal. A layer made of the 7M metal (hereinafter referred to as the TM layer) and a layer made of the 7M metal (hereinafter referred to as the TM layer) are alternately formed by at least 2 to 10 layers each.
A stack of more than one layer is used. In particular, the RE layer and T
A recording layer in which M layers are alternately laminated has the advantage that it has excellent magnetization, coercive force, and magneto-optical effect (Kerr effect), and its characteristics are easy to control.

As a method for forming the above laminated thin film, magnetron-type co-sputtering (Co-sputtering) has been used for a long time.
There is a sputtering method using a sputtering apparatus for forming a laminated film equipped with a plurality of cathodes, which is called 3-put ter ing. This sputtering method is disclosed in JP-A-59-21247 and JP-A-62-26.
No. 659, Japanese Patent Application Laid-open No. Sho f1i1-108112,
JP-A-62-71041, JP-A-62-1280
It is disclosed in Japanese Patent Application No. 41, etc., and its basic configuration is schematically shown in FIG.

In the sputtering apparatus equipped with a plurality of cathodes shown in FIG. 10, each cathode 100 has a circular tarp 101a, 101b which is a film forming material, and a permanent magnet 102 to enable magnetron discharge.
It is equipped with The shield part 103 and a chamber (not shown) are at ground potential, and the tarp 7) 101a
, 101b is a sputtering power source 104a outside the chamber.
, 104b. The substrates 105 are each fixed to a rotating substrate holder 106b. For example, the cathode 100 is composed of two circular sputter electrodes, each consisting of a substance a (material a) and a substance 5 (b (
Targera) 101a made of different materials of material b),
101b, which are arranged at predetermined intervals.

Then, the plurality of substrates 105 are placed in the rotating substrate holder 106.
A laminated thin film of substances a and b is formed on the substrate 105 while fixing it on the substrate 105 and rotating it. The composition of the thin film can be changed by controlling the ratio of sputtering power input from the sputtering power source 104a1104b. In order to make the composition distribution uniform over the entire surface of the substrate 105, a film thickness distribution correction plate 107a is provided.
, 107b are arranged. As can be seen from the above,
In the conventional apparatus, in order to make the film thickness distribution uniform, the substrate is simply rotated, and the film thickness distribution correction plate 107a,
107b, or a method of forming a film using a complicated rotational film forming method involving large rotations is common.

However, according to conventional methods, relying heavily on mechanical operating structures to achieve film thickness uniformity is undesirable from the viewpoint of cleanliness within the vacuum chamber, and there are also problems from the viewpoint of maintainability. . Further, the adjustment of the film thickness distribution correction plate used in the apparatus shown in FIG. 10 is complicated, and there is a drawback that sputtering efficiency is greatly reduced due to blocking of sputtered particles.

Further, the rotation speed of the rotating substrate holder 106b used in the apparatus shown in FIG. 10 is usually 10 to 50 rpm.
m range is used, and this rotational speed has a limit on the lamination period of material a and material nb due to mechanical constraints, making it difficult to form a laminated thin film with an extremely short period, and the film formation control range is narrow. It is difficult to obtain a thin film with an arbitrary lamination period.

In addition, as mentioned above, a method for forming a high-quality mixed thin film without relying heavily on mechanical operation was published in Japanese Patent Laid-Open No. 5
It is disclosed in JP 8-199860 and the like. This method controls the excitation current of an electromagnetic coil installed on the back side of a target in which different types of materials are arranged in a ring shape, and the position of the ring-shaped plasma on the target surface (20-john region) is controlled.
This method attempts to form a mixed thin film with a predetermined composition ratio of materials on a substrate by magnetically moving the materials. However, in the conventional apparatus as typified by JP-A-58-199860, in order to form the evaporation region 120 (erosion region) of the tarp 101c shown in FIG. as shown in Figure 11)
A device is used that incorporates a permanent magnet, an electromagnet, or a magnetic field generating means that is a combination of these in order to generate a leakage magnetic field 110 that is substantially parallel to the surface of the magnetic field. Here, since the magnetic field strength of the leakage magnetic field 110 on the surface of the target 101C can be adjusted appropriately according to the material and thickness of the target material, as shown in FIG. 11, a solenoid coil is wound concentrically around the center of the target. The use of magnetic fields has been considered.

In this case, the electromagnet power source is, for example, a power source 114 for the center solenoid coil 111 and a power source 114 for the outer solenoid coil 112.
The magnetic field strength was adjusted to -1 over the entire target surface by the two power supplies, or when the strength was changed, it was changed to -1 over the entire target surface. The disadvantage of this method is that the target 101
As the radius of C increases, the radius of the solenoid coils 111 and 112 increases accordingly. At this time, if the amperage of the solenoid coils 111 and 112 is the same as when the diameter is small, the magnetic flux density will decrease, and the magnetic field strength will therefore become weaker. On the other hand, if you want to obtain the same magnetic field strength even when the diameter of the target 101C becomes larger, the solenoid coils 111 and 112
It is necessary to increase the number of turns or increase the coil current. However, when the target diameter is large and the space in which the coil can be wound is relatively narrow, or when a ferromagnetic material is used as the target material, the ferromagnetic material affects the magnetic flux, resulting in a strong magnetic field strength. When necessary, that is, when using a magnetic target, ferromagnetic materials have high magnetic permeability, so most of the magnetic field lines coming out of the magnetic poles pass through the inside of the target. There will be a shortage of leakage magnetic flux. Therefore, when using a ferromagnetic target, it is necessary to apply a magnetic field strong enough to exceed the saturation magnetic flux of the target itself and cause further leakage magnetic flux to appear on the target surface. In such cases, sufficient magnetic field strength cannot be obtained using conventional methods.

In addition, even if a large magnetic field strength is obtained, the cost of equipment and running costs will increase, and JP-A-58-19986
There was also a problem in the controllability of the mixed thin film in the formation of the mixed thin film as shown in Publication No. 0, and it was almost impossible to form a laminated thin film.

In addition, as another method, JP-A No. 62-137753 discloses that the RE gold metal 7M metal alloy target and the substrate are faced to each other, and a film is formed by temporally changing the bias power applied therebetween. A method of bonding layers having different composition ratios of gold metal 7M metal is disclosed. The method of changing the bias power over time as in JP-A No. 62-137753 can increase the film formation speed, but
The RE layer and the TM layer cannot be clearly distinguished and laminated, and the formation of alternately laminated thin films of the RE layer and TM layer is difficult and insufficient from the viewpoint of improving the characteristics of the recording layer. Ta. Furthermore, there is a problem in that a complicated control mechanism is required to change the bias power in a short period.

In addition, in sputtering, especially when controlling the composition of the formed thin film using electrodes, plasma ignition,
Due to arc extinguishing, the plasma impedance changes greatly, and as in the past, the transient current every time the power supply is switched places a large burden on the sputtering power supply side, and the sputtering cycle due to switching is reduced due to the damage to the electric circuit. There was a problem in that it was not possible to shorten the length below a certain level.

Furthermore, there was a problem with the excitation power source for the electromagnetic coil (hereinafter sometimes referred to as "solenoid coil"). This problem is because the electromagnetic coil is an inductive load, so if the current change rate is large as in the case of a rectangular waveform as shown in Figure 13, a large back electromotive force will be generated and damage the electric circuit of the excitation power supply. There was a problem with it. In particular, when the electromagnetic coil is large and the amount of current supplied is large, the above problem is extremely serious.

[Purpose of the invention]

The present invention has been made in order to solve the various problems mentioned above, and it is possible to improve the adhesion efficiency of sputtered particles (film formation efficiency) in the film formation process of magneto-optical recording media by sputtering, and to form the RE layer and the TM layer. It is an object of the present invention to provide a sputtering method that allows recording layers of at least two alternating layers with a definite arbitrary lamination period to be formed continuously at high speed with a uniform film thickness distribution, and that also reduces the load on a power supply device. It is something to do.

[Means to solve the problem]

The above object of the present invention is to provide a magnetic field generating means on the back side of a target disposed to face a substrate on which a thin film is formed, and a cathode that generates a magnetic field substantially orthogonal to an electric field on the surface of the target is connected to the substrate. The first one facing from the front.
and a second section that surrounds the first section in an annular shape and faces the substrate with an inclination toward the center of the substrate, and the second section is composed of a plurality of divided parts, and The generating means has a plurality of individual configurations corresponding to the divided portions of the target, and each has an electromagnet whose magnetic force can be independently controlled, and current is applied to the electromagnetic coils of the first section and the second section. An alternating current with a waveform difference θ shifted in the range of 0<θ<2π is applied to the first section and the electromagnetic coil is kept energized so that the plasma on the surface of each target is not extinguished. This is achieved by a sputtering method characterized in that a thin film is formed by alternately sputtering the second sections.

Hereinafter, the present invention will be explained in detail based on a sputtering apparatus to which the method of the present invention is applied.

(Embodiment) FIG. 1 is a schematic view of the main parts of a sputtering apparatus according to this embodiment, and shows a cathode portion as a sectional view.

The sputtering apparatus shown in FIG. 1 is constructed entirely within a vacuum chamber 91, which can be evacuated to a desired pressure through an exhaust port 93 using a vacuum pump (not shown), and into which appropriate gas can be introduced through a gas inlet 92. A cathode 10 consisting of a second section 100b formed of a plurality of divided parts 130 (see FIG. 3) so as to have an annular shape, and a circular first section 100a inside the second section 100b.
0 and an anode side having a rotatable holder 19 that removably holds a substrate 9, which is a member to be sputtered, so as to face the cathode 100.

The first section 100a has a magnetic field formed by an assembly of two permanent magnets 86 and 87 as main magnets and an electromagnet as an auxiliary magnet consisting of a soft magnetic yoke portion 85 and a solenoid coil 84 on the back side of the circular target 7. Generating means is provided. The target 7 is a target power source 70
The solenoid coil 84 is connected to the electromagnetic power source 17.

Each target (1, . . .
...6) each has the shape of a part of an annular ring as shown in FIG. ) has an appropriate inclination angle (α).

Each target (1, . . . 6) has six separate target power supplies (10, 20, 6 in the figure) corresponding to each of the targets (1, . . . 6).
0 only), and on the back side of each target (on the anti-anode side) there is a combination of two permanent magnets 96 and 97, which are main magnets, and an electromagnet, which is an auxiliary magnet, consisting of a soft magnetic yoke part 95 and a solenoid coil 94. Body-based magnetic field generation means are provided. As shown in FIG. 3, in this magnetic field generating means, the permanent magnets 96 corresponding to the inner edges of the Kugets (1, . . . 6) and the permanent magnets 97 corresponding to the outer edges are attached to the yoke portion 95. The solenoid coil 94 is wound around the yoke portion 95 as a core. Each of the targets (1
, ... 6), a magnetic field (Xa) is generated that is approximately orthogonal to the electric field generated between the anode side and the cathode side, and the strength of this magnetic field is controlled by controlling the excitation current of the solenoid coil 94. It has a structure that can be changed. In this way, the magnetic field generating means is activated by the target (1, .
...6) The N pole placed over almost the entire area of the outer edge 97b and the S pole placed on the inner edge 96a form a nearly continuous closed magnetic field (Xa) in an annular shape along the target shape. Plasma can be trapped within a nearly corresponding tunnel-like magnetic field.

It is preferable that the permanent magnets 86, 87, 96, 97 are rare earth cobalt magnets (Sm, Co).

These permanent magnets have a higher coercive force and a higher maximum magnetic energy than conventional ferrite-based and alnico-based magnets, so the volume of the magnet can be small enough to obtain the necessary magnetic field. As a result, the capacity of the solenoid coils 84, 94 can be reduced, and even when a ferromagnetic material is used as a target, a sufficient magnetic field strength can be obtained.

The solenoid coils 84, 94 are controlled by connecting the solenoid coils 84 to the electromagnet power source 17, as shown in FIGS. (12...1
6) respectively. Then, all the electromagnet power supplies (12...16, 17) are generated by an arbitrary waveform generator 98 to generate a sine waveform (
A signal is given that has a rectangular waveform (a waveform without sudden current changes). The arbitrary waveform generator 98 is appropriately controlled by a control means 99 such as a microcombination unit. As is clear from FIG. 8, this control is performed when the phase θ of the waveform of the exciting current of the solenoid coil 84 and the solenoid coil 94 is in the range of 0 < θ minus 2π, that is, in an arbitrary range, for example, 174 cycles (1/2π )
It seems to shift. It is desirable to shift the phase of the excitation current so that the peaks of both plasma discharges are most distant in time, but this does not mean reversing the waveforms of the phases. That is, the peak of plasma discharge is influenced by various conditions such as target material, vacuum degree, magnetic field strength, and excitation current magnitude. By controlling the phase θ, the strength of the magnetic field can be manipulated, and the plasma density can be alternately switched between dark and dark. Furthermore, the plasma density can also be changed over time by changing the strength of the current flowing through the solenoid coils 84, 94.

Further, the offset value CIA'' of the excitation current is set to an appropriate value, that is, the minimum value of the solenoid coil current value is the coil current to obtain the magnetic field strength necessary to maintain the plasma on the target surface. By setting the value to the lowest value within the range, no transient current flows during plasma switching, avoiding problems with plasma impedance.
can be greatly increased or decreased.

Also, the frequency of the excitation current may be set to 0.058Z to 20H2, for example.
For example, when the first
When the spectrum corresponding to the sputtering of the material (for example, terbium) on the side of section 100a is observed with a photomultiplier, as shown in FIG. 9, the movement of the waveform has a timing that roughly corresponds to the waveform in FIG. 8. If ON/OFF is defined as a threshold value when the light intensity ratio is 20% or less of the peak, changes in the light intensity ratio with respect to the excitation current waveform will be observed up to about 12Hz, and above that, it will always change. Since the result is the same as that of a continuous sputtering discharge, it has been found that the discharge can be controlled by changing the excitation current at, for example, 12 Hz or less, although it varies somewhat depending on other sputtering conditions. Therefore, the first section 1
If the second section 100a and the second section 100b are made of targets made of different materials, it is possible to form laminated thin films of different types with clearly different compositions in an extremely short period.

The electromagnet power supplies (12...16) on the second section 100b side are controlled simultaneously, but six independent electromagnets are provided corresponding to each solenoid coil 94 and each divided section 130. Each magnetic field (Xa
) It is also extremely easy to freely control the strength of each part. It is also possible to change the target material for each divided portion 130, and the control range of the film formation composition becomes extremely wide.

The substrate 9 is located on the target central axis, and each of the targets (1, . . . 6) is tilted depending on the distance from the substrate 9 and the amount of sputtered particles with respect to the first section 100a. Since the angle (α) is appropriately adjusted, uneven incidence of particles scattered from each of the targets (1, . . . 6) on the substrate 9 is prevented, and it is possible to avoid relying heavily on the mechanical movement structure as in the past. Therefore, it is possible to prevent unevenness in film thickness.

The configuration for setting the inclination angle (α) of each target (1, . . . 6) includes a configuration in which the height (h) of the permanent magnets 96 and 97 is changed, or a configuration in which the inclination angle (α) is fixed. However, as shown in FIG. 1, the heights (h) of the permanent magnets 96 and 97 are the same, and the magnetic field generating means is attached to the bottom of the vacuum chamber 91 in an inclined manner, for example, by tightening with bolts. It is preferable that the inclination angle (α) be adjustable for each of the divided portions 130 using a well-known structure such as . Since the continuity of (Xa) will deteriorate, it is desirable to configure the solenoid coil 94 so that it does not protrude from the yoke portion 95. Although this gap varies somewhat depending on the magnetic field strength etc., it is preferable that it is about 3 mm or less. preferable.

Each target (1,...6) is sputter discharge,
This causes a rise in temperature and a decrease in sputtering efficiency.

For this purpose, although not shown, a well-known structure is provided in which cooling water flows under the target.

In order to cool or heat the substrate 9 depending on the characteristics of the deposited film, the substrate 9 is provided with a well-known structure or heater (not shown) through which cooling water flows on the back surface.

The target 7 provided in the first section 100a
The targets (1...6) provided in the second section 100b contain rare earth metals (RE) and transition gold X (
TM), it is possible to form a laminated thin film of both metals. RE for the RE git
Gold metals include, for example, cd, rb, 1)ySNd, and Sm.
, or an elemental metal of HO or an alloy thereof such as Gd
50, Tb50 is used.

On the other hand, as the TM metal for the TM jitat, Fe
, Co, or N1, or alloys thereof such as Fe55CO+s are used. In order to improve the corrosion resistance of the TM layer, Pt, Ti, Or
Alternatively, Cu may be added in an amount of 5% or less.

The purity of these target metals is 99% or more, preferably 99.9% or more.

The composition ratio and film thickness distribution in the total film area of the substrate 9 sensitively reflect the characteristics such as C/N, sensitivity, envelope, etc. of the magneto-optical recording medium, so the deviation in the composition ratio is ±5. If the total film thickness distribution is not within ±5.0%, a practical problem will occur. However, according to the method of the present invention, the annular or polygonal target (1 Since the surface of 6) faces the substrate at an angle (α), all of these conditions can be satisfied.

However, in a mixed thin film of material a and material A, the composition ratio of material a is expressed as the atomic % of material a relative to the total number of atoms in the mixed thin film, and the deviation in the composition ratio is defined as the composition ratio atomic %.
It represents the difference in the ratio between up and down.

The composition ratio and film thickness distribution in the total film area of the substrate 9 will be explained in more detail.

As shown in FIG. 4, a disc-shaped first target (7a) is a material (a), for example, an RE gold metal annular target (9).
b is not installed obliquely on the substrate 105, the amount of particles sputtered from each target is expressed as
5 as a reference plane, the sputtering distribution line is expressed as 3
3.35.

As can be seen from the sputtering distribution line 33, the film thickness distribution on the substrate made of RE gold metal of the target 7a has a concave shape in which the peripheral portion of the substrate 105 is thick and the center portion is slightly concave. Show the distribution. Further, the distribution of the sputtered particles of the TM gold metal of the annular target layer 9b is such that, as is clear from the sputtering distribution line 35, the center of the substrate is largely convex and thick, and the peripheral portions of the substrate are thin. Therefore, when the sputtered particles are sputtered simultaneously or alternately from each target and the sputtered particles are totaled, the total film thickness distribution on the substrate is as follows.
．． 35, which usually causes an error of ±8°0% or more. Moreover, the radius from the center of the substrate 1 is several tens of meters.
m measurement point) X2 and the center measurement point of the substrate 1)
When comparing XI, a difference of about 20% in the composition ratio occurs between the composition ratio of the specific atom at measurement point X1 and the composition ratio of the specific atom at measurement point X2.

According to the sputtering method according to the present invention as shown in FIG. 6, the targets (1...
6) surrounds the first section 100a in an annular shape and is inclined (α) with respect to the substrate 9 so as to face toward the center of the substrate.
Therefore, the sputtering distribution line 45 of sputtering particles sputtered from the targets (1...6) is represented by a flat line similar to the sputtering distribution line 43 due to the target 7. be able to. Therefore, the incident state of sputtered particles on the substrate 9 is greatly improved compared to the method shown in FIG. 4, and the film thickness distribution on the substrate 9 can be made less than ±5.0%.

Furthermore, when comparing the composition ratio (atomic %) of a specific atom at the measurement point X2 and the measurement point X1 in the same way as above, the difference in composition ratio between measurement point) XI and measurement point) X2 is ±5.0. % or less, and the composition ratio can be made extremely uniform over the entire area of the substrate 9.

From the above, by alternately performing sputtering using the first section 100a and the second section 100b, it is possible to improve not only the uniformity of the overall film thickness and composition ratio, but also the film thickness distribution and composition ratio of each layer. Also, it is possible to form a recording layer of extremely high quality.

Furthermore, as described above, it is possible to form laminated thin films with extremely short cycles at high speed without imposing a large load on the power supply device.

Further, in the present invention, the shape of the divided portion 130 is not particularly limited and can be changed as appropriate. For example, when the trapezoidal dividing part 130 shown in FIG. 5 divides the target of the annular second section 100b shown in FIG. ...8b) la, 2a, 3a
, 4a materials in group A, 5'l, 6b, 7b
, 3b are configured as group B, the current value of each of the solenoid coils 94 is set to the same condition for each group of materials, and the holder has its center axis aligned with the target center axis above the target. 190
Film formation is performed while rotating around the rotating shaft 19a. As a result, a laminated thin film of a mixed film (composite film) of materials A and B and a single composition film formed by the target 7 can be successfully created with a desired composition. The composition ratio of the mixed film can be easily controlled by changing the number of combinations of the materials ASB or by changing the strength of the magnetic field (Xa), and the conventional film thickness distribution shown in Fig. 10 etc. Since a correction plate is not used, there is no waste of sputtered particles, and thin films of arbitrary compositions can be formed at high speed.

Furthermore, since each of the divided portions 130 is small, it is easy to obtain the number of amperes required to strengthen the magnetic field (Xa), and it is possible to increase the magnetic field strength compared to the conventional one. It is also extremely effective that it can be achieved at low cost.

In the apparatus to which the method of the present invention is applied, the combination of electromagnets and permanent magnets is not limited to the permanent magnet as the main magnetic field generating means and the electromagnet as the adjusting magnetic field generating means as in the above embodiment, but the electromagnet as the main magnetic field generating means. , a permanent magnet may be used as the adjustment magnetic field generating means, or a structure including only electromagnets is also possible.

〔Effect of the invention〕

As described above, the present invention has a first section in which the cathode faces the substrate from the front, and a second section that surrounds the first section in an annular shape and faces the substrate at an angle facing toward the center of the substrate. said second section.
The section is made up of a plurality of divided parts, and the magnetic field generating means has a plurality of individual configurations corresponding to the divided parts of the target, each having an electromagnet whose magnetic force can be independently controlled, and the first section The phase difference θ of the current waveforms between the electromagnetic coils of the second section is set to 0<
Sputtering the first section and the section alternately while flowing alternating currents shifted in the range of θ<2π and maintaining energization of the electromagnetic coil so that the plasma on the surface of each target is not extinguished. Even if the overall size of the cathode is large, it is easy to obtain amperage, a large magnetic field strength can be obtained, and the film formation rate can be increased. By appropriately setting an offset value for the excitation current of the electromagnetic coil, the load on the power supply device during ignition and extinguishment of plasma discharge can be reduced, and since the magnetic field strength of the divided section can be independently controlled, sputtering can be controlled. The range can be wider than before, the controllability during film formation is improved, and high-quality films can be obtained. Especially when forming laminated thin films of different materials, it is extremely easy to control the composition ratio. The reproducibility of the film composition can be improved.

By using a sinusoidal waveform for the excitation current of the electromagnetic coil, generation of a back electromotive force by the electromagnetic coil can be avoided, and sputtering can be suitably performed for a long time without any load such as heat generation on the power supply circuit.

Further, by appropriately tilting the surface of the tarp 7) toward the substrate with the target of the second section positioned on the target center axis line, it is possible to create a conventional complex rotating structure and film thickness distribution correction plate. The film thickness distribution can be made more uniform than before without depending on the operation. Furthermore, the inclination allows the sputtered particles to be distributed to the substrate at a high density, and by providing directionality so that the sputtered particles are evenly scattered, it is possible to increase the film forming rate.

Hereinafter, the effects of the present invention can be further clarified through Examples.

〔Example〕

The present invention will be further explained using examples.

○ Example-1 A sputtering device that is almost the same as the device shown in FIGS. 1 and 2 is used, and the specifications are as follows: Target of the first section: material Tb.

φ5. 1/4' thickness ■ Second section target (1...5)...
Material FeaoCO2o + Inscribed circle diameter 140 mm.

Slope width 50 meters.

Inclination angle 45° ■First section electromagnet...200T x 128 (rated) ■Number of divisions in second section...5 blocks ■Second section electromagnet...140T x 2OA
(Rating) ■ Board... 130o opening φ, PCC resin lid Distance between target board... 110 City stationary facing ■ Target power supply for 1st section... DC600
W■■Second section target power supply...DCl, 6
9+■Lamination period...8 people (2H2) In addition to the above conditions, the target Tb of the first section
The excitation current of the electromagnet built into the back surface was applied as shown in Fig. 8(a) (in this case, the offset current IA giving the magnetic field strength at the limit of plasma arc extinction was 2.5 amperes). The excitation currents of the Fe5oCb magnets of the two-section targets (1...5) are compared with the excitation currents for the first target 3, and a delay of π/2 is given, as shown in FIG.
b) (The offset current IA giving the magnetic field strength at the plasma arc extinction limit in this case was 4.5 amperes).

I tried to detect the resulting film formation status.

As a method for detecting Tb film formation (lamination), light emission within the chamber was picked up using an optical fiber.

The wavelength of this light was set using a monochromator to a peak with less noise of Tb, and then the intensity of the light was measured using a photomultiplier. As shown in FIG. 9, it was possible to change the amount of sputtering on the target by reliably following the change in magnetic field strength, although slightly later than the Tb excitation current (FIG. 8a).

As a result, the film thickness distribution ±
4.7% and a film formation rate of 820 persons/min, which were extremely excellent results.

○ Example-2 Similar to Example-1, a sputtering apparatus as shown in FIGS. 1 and 4 was used, and the specifications were as follows.

■Target of the 1st section... Nd3゜Dy
7°.

φ5Z5n+m thickness ■Second section target...Fes. CO31
1Tl□.

Inscribed circle diameter 140 proofφ Slope width 50mm.

Inclination angle 60゜■First section electromagnet 6...200T X8A■
Number of second section divisions...8 blocks ■Each electromagnet in the second section 7...100T x 16A ■Substrate...130 city φ, PC resin ■Distance between target of first section and substrate・・・
・120 parts Stationary facing ■Target electrode 10 of the 1st section...RF60
01 (■Target power supply of the second section 11...D
C16KW■ Excitation current waveform...sine wave (0,6 flz
) ■ Lamination period...28 people, Nd0) 1 In addition to the above conditions, the phase difference of the excitation current between the first section and the second section is set to π/4, and an Sln wave is applied to form a laminated thin film on the substrate. The results are shown in Table 1.

Table 1. However, A: Distance from the center of the substrate 1li1t [IlmB: Film thickness distribution (target center is taken as 100°) C: Composition ratio of Fe atoms (atomic %) - Composition ratio detection method is based on Auger electron spectroscopy.

・Measurement of film thickness distribution is done using a stylus type film thickness meter.

As shown in Table 1, the distance from the center of the board is 5Q m+
++ Even at the periphery of the distant substrate, the difference in film thickness distribution is within 5% compared to the center, and the deviation in composition ratio is also 5%.
We were able to obtain a very uniform film thickness and film composition distribution.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a sputtering apparatus that is an embodiment of the present invention, FIG. 2 is a plan view of the target of the cathode shown in FIG. 1, and FIG. 3 is a main part of the divided portion of the cathode shown in FIG. FIG. 4 is a plan view showing the shape of another target according to the present invention, FIG. 5 is a perspective view of a main part of a divided part corresponding to the shape of the target shown in FIG. 4, and FIG. Figure 7 is a schematic side view showing the concept of sputtering distribution lines in the magnetron sputtering apparatus used in the method for forming laminated thin films; ) and (b) are waveform diagrams showing the excitation currents of the solenoid coils of the first section and the second section of the cathode, a schematic diagram of a conventional sputtering device,
The figure is FIG. 8 (a) related to the method of forming a laminated thin film of the present invention.
) is a graph showing the light intensity of a specific atom by a photomultiplier that roughly corresponds to the waveform of the solenoid coil excitation current, and Fig. 10 is a schematic diagram of a conventional sputtering device.
Fig. 11 is a schematic cross-sectional view of the cathode portion in a conventional sputtering device, Fig. 12 is a plan view of the target shown in Fig. 11, Fig. 13 is a waveform diagram showing the conventional exciting current waveform, and Fig. 14 is a diagram of the cathode. FIG. 2 is a schematic side view showing the concept of a sputtering distribution line in a magnetron sputtering apparatus in which a part is not inclined. 1.2.3.4.5.6.7・・Target, 9・・
Substrate, 1O120,60,70・Target power supply, 12.16.17・・Electromagnet power supply, 19・・Substrate holder, 19a・・Rotation shaft, 84.94・・Solenoid coil, 85.95・・・Yoke part, 86 .87.96.97...Permanent magnet 96a...Inner edge, 91...Vacuum chamber 92...Gas inlet, 93...Exhaust port, 97b...Outer edge, 98...Arbitrary waveform generator, 99... - Control means, 100... Cathode, 100a...
First section, 100b...Second section, 130...Divided part. 5th Funeral Figure 'J4 (11, 12, ·----, +6) Figure 5 Funeral Figure 14

Claims (1)

[Claims] A magnetic field generating means is provided on the back side of a target arranged to face a substrate on which a thin film is formed, and a cathode that generates a magnetic field substantially perpendicular to an electric field on the surface of the target faces the substrate from the front. and a second section that surrounds the first section in an annular shape and faces the substrate with an inclination toward the center of the substrate, and the second section is composed of a plurality of divided parts, and The generating means has a plurality of individual configurations corresponding to the divided portions of the target, and each has an electromagnet whose magnetic force can be independently controlled, and current is applied to the electromagnetic coils of the first section and the second section. An alternating current with a waveform phase difference θ shifted in the range of 0 < θ < 2π is applied to the first section and the first section while energizing the electromagnetic coil is maintained so that the plasma on the surface of each target is not extinguished. A sputtering method characterized by forming a thin film by performing sputtering in two sections alternately.