JP4933744B2 - Multi-pole magnetron sputtering deposition system - Google Patents

Description

  The present invention relates to a multi-pole magnetron sputtering film forming apparatus and a film forming method for forming a thin film on a substrate to be processed.

  The sputtering film forming method is a method for discharging film material particles from a target by colliding ionized ions with a target including a film material and depositing the film material particles on a substrate to be processed. A magnetron sputtering film forming method in which a magnetic field is formed in the vicinity of a target surface is widely used as a method capable of simultaneously realizing an improvement in film forming speed and an improvement in in-plane uniformity of film thickness.

  FIG. 11 is a schematic view showing a conventional typical flat-plate magnetron sputtering film forming apparatus. Magnetic field generating means 101 and 102 are arranged on the back surface (non-sputtering surface) 107b of the flat target 107. A yoke 111 is installed on the back side of the magnetic field generating means 101 and 102 to form a magnetic closed circuit. A target substrate 108 is disposed so as to face the target 107. In this magnetron sputtering apparatus, a magnetic field is formed by the magnets 101 and 102 provided on the back surface 107b side of the target 107 so as to draw a loop in which the lines of magnetic force Q exit from the back surface b of the target 107 to the front surface 107a side and return to the target 107 side again. Is done. The magnetic field P is formed in the vicinity of the surface (sputter surface) 107a by the magnetic lines of force Q, and an ionization state is formed such that the plasma density increases corresponding to a ring-shaped, ie, donut-shaped region surrounding the center of the target 107. . By this magnetic field P, the collision frequency of the rare gas 122 such as argon gas introduced into the vacuum chamber 121 and the electrons is increased, ionization of the atmospheric gas is promoted, and plasma is formed on the target surface 107a. The film material particles in the target 107 are released by sputtering. The film material particles are deposited on the surface 108a of the substrate 108 to be processed.

  However, in the conventional magnetron sputtering film forming apparatus, the magnetic field P is formed so as to draw a loop in which the magnetic field lines Q are drawn from the back surface 107b of the target 107 to the front surface 107a side and return to the target 107 side again. It cannot be said that the magnetic field is weak and the plasma density is high enough.

  In addition, the donut-shaped high plasma density region formed by the loop-shaped magnetic field lines Q is effective for improving the in-plane uniformity of the film thickness, but the target 107 is preferentially consumed. The part to be sputtered locally occurs. In other words, the in-plane distribution of the sputtering rate of the target 107 is determined by the state of the magnetic field on the target surface 107a. Therefore, there is a problem in that the use area of the target 107 is small and the target 107 cannot be effectively consumed.

  Further, when a magnetic material is used as the target 107, since the magnetic force is absorbed by the target 107, there is a problem that the magnetic field generated on the target surface 107a is weak. In the case of the magnetic target 107, The target has to be thinned and has the disadvantage of frequent replacement.

  As described above, ordinary magnetron sputtering film forming apparatuses have many problems to be solved. As an example of the solution, a multi-pole magnetron sputtering film forming apparatus has been developed by the inventors of the present invention. This multi-pole magnetron sputtering film forming apparatus will be described with reference to FIG. The same components as those in FIG.

  External magnets 103 are arranged radially corresponding to the outer peripheral magnets 102 at outer positions on the outer periphery on the front side of the target 107. The magnetic field lines T coming out of this are attracted to the south pole of the central magnet 101 on the target back surface 107b and enter. At this time, since the external magnet 103 and the outer peripheral magnet 102 have the same polarity, they repel each other, and the magnetic force line T acts to press the magnetic force line R from the outer peripheral magnet 102 toward the central magnet 101 toward the vicinity of the target surface 107a. Due to these interactions, the line of magnetic force in the vicinity of the target surface 107a can be increased compared to that of a normal magnetron sputtering film forming apparatus (FIG. 11) without the external magnet 103, and plasma effective for sputtering. The area of density expands.

  However, some of the magnetic field lines T generated from the external magnet 103 are attracted and incident on the south pole of the central magnet 101 on the back surface of the target. . Therefore, the plasma density of the target surface 107a is still insufficient.

  For this purpose, as shown in FIGS. 13 and 14, a structure in which a second external magnet 104 is provided so as to overlap the first external magnet 103 (two-tiered) is known. That is, the center magnet 101 has an S pole on the target back surface 107b side, the four outer peripheral magnets 102a to 102d have an N pole on the target back surface 107b side, and the four first external magnets 103a to 103d and the second external magnet The magnets 104a to 104d are installed with N poles facing toward the central magnet 101.

In this structure, since the second external magnets 104a to 104d have the same polarity as the first external magnets 103a to 103d, they can repel each other and suppress the magnetic lines of force that escape from the first external magnets 103a to 103d to the substrate 108 side. The magnetic field of the target surface 107a can be dramatically increased. That is, since the magnetic lines of force from the first external magnets 103a to 103d are efficiently directed toward the center electrode 101, the magnetic field on the target surface 107a can be increased, and at the same time, the magnetic lines of force R from the outer peripheral electrode 102 toward the central electrode 101 Since it is possible to suppress the separation from the surface 107a, it is effective to concentrate the magnetic field lines on the target surface 107a. By these interactions, the magnetic density on the target surface 107a is increased, and plasma having a high ion density can be obtained over a wide surface range of the target surface 107a (Patent Document 1).
JP 2003-183828 A

  As shown in Patent Document 1, a so-called two-stage multi-pole magnetron sputtering film forming apparatus in which a first external magnet and a second external magnet are arranged to overlap each other increases the magnetic field lines on the target surface. The plasma density is greatly increased. As a result, the thickness distribution of the thin film to be formed can be kept constant, that is, the in-plane uniformity can be made relatively high as compared with the prior art.

  However, in order to obtain good device characteristics and a stable process, it is important to ensure high in-plane uniformity, increase the deposition rate, and form a uniform and dense thin film. I was not satisfied.

  The inventors have further studied the multi-pole magnetron sputtering apparatus with two layers of external magnets, and as a result, despite the generation of high-density plasma in the vicinity of the target surface 107a, the formation of a thin film on the substrate is not necessarily performed. I doubted that it was not a high performance one. Until now, research has been focused on increasing the magnetic field on the target surface, releasing membrane materials from a wide range of the target surface, and obtaining high energy, but this time the focus has changed. Then, sincerity research was repeated to move the high ion density plasma formed on the target surface to the substrate effectively without waste.

  As a result, the present inventor has provided the first external magnet and the second external magnet outside the target, so that the second external magnet suppresses the diffusion of the magnetic force lines of the first external magnet and increases the magnetic force lines toward the central magnet. However, the magnetic field lines of the second external magnet are repelled from the first external magnet, so that one part faces the central magnet, but pays attention to the fact that many parts are distributed in other directions. It is intended to make effective use of the magnetic field lines of the second external magnet that is not present, and aims to consolidate these magnetic field lines as magnetic field lines toward the substrate and to activate the magnetic field lines to increase the plasma density It is.

The invention of claim 1 is a multi-pole magnetron sputtering film forming apparatus for forming a film on a substrate,
An airtight processing chamber,
A first holding member disposed in the processing chamber and having a holding surface for supporting the substrate;
A second holding member disposed in the processing chamber so as to face the first holding member;
A target held by the second holding member so as to have a surface facing the substrate supported on the first holding member;
A central magnet disposed at the center of the back side of the target and having one magnetic pole directed to the back side of the target;
A plurality of outer peripheral magnets disposed on the outer peripheral edge of the back side of the target and having the other magnetic pole directed to the back surface of the target;
A plurality of first external magnets arranged at positions outside the outer peripheral edge of the target on the surface side of the target and having the same or different magnetic pole as the other magnetic pole of the outer peripheral magnet directed inward;
A plurality of second external magnets arranged at a position closer to the substrate than the first external magnet and having magnetic poles oriented in the same manner as the first external magnet so as to overlap the first external magnet;
It is wound around the direction connecting the target and the substrate, and the center thereof is disposed in the space between the target and the substrate, and is further disposed between the position of the second external magnet 4 and the substrate . Coils,
High-frequency power applying means for applying high-frequency power to the coil;
And a power applying unit that applies power between the target and the substrate.

  According to a second aspect of the present invention, in the multi-pole magnetron sputtering film forming apparatus according to the first aspect, all of the first external magnets are arranged with the same magnetic pole as the other magnetic pole of the outer peripheral magnet facing inward. It is the composition which is.

  According to a third aspect of the present invention, there is provided the multi-pole magnetron sputtering film forming apparatus according to the first aspect, wherein the first external magnet has the same magnetic pole as the other magnetic pole of the outer peripheral magnet facing inward, and the other of the outer peripheral magnets. The first external magnets with the magnetic poles different from the magnetic poles facing inward are alternately arranged.

The invention of claim 4 is the multi-pole magnetron sputtering film forming apparatus according to any one of claims 1 to 3,
The first external magnet and the second external magnet are arranged in proximity to or in contact with the outer wall at a position outside the outer wall of the processing chamber.

The invention of claim 5 is the multi-pole magnetron sputtering film-forming apparatus according to any one of claims 1 to 4,
The power application means includes target power application means for applying power to the target, and substrate power application means for applying power to the substrate, and the target power application means and the substrate power application means supply power to be applied. This is a configuration that can be varied.

Invention of Claim 6 is the film-forming method using the multiple magnetic pole magnetron sputtering film-forming apparatus as described in any one of Claim 1 thru | or 5, Comprising:
Placing (mounting) the substrate on the holding surface of the first holding member, and then supplying a processing gas into the processing chamber while evacuating the processing chamber; Next, the electric field is formed between the target and the substrate by the power application means, high frequency power is applied to the coil, and the film material particles are released from the target. And a treatment step of forming a thin film on the substrate surface by depositing the film material particles on the substrate surface,
A magnetic field having a magnetic field line extending from the first external magnet toward the central magnet along the target surface is formed. From the second external magnet, a magnetic field line flowing through the coil toward the substrate and a magnetic field line toward the central magnet. It is the structure which forms the magnetic field which has.

  A seventh aspect of the present invention is the multi-pole magnetron sputtering film forming method according to the sixth aspect, wherein the power value of the target power applying means and the substrate power applying means is adjusted to adjust the film forming state of the film. It is a configuration.

  According to the first aspect of the present invention, since a high magnetic field can be formed over a wide range of the target surface, the plasma density on the target surface can be maintained at a high level, and the high plasma density state can be expanded to the substrate. As a result, the film material particles (ions) released from the target surface can be incident on the substrate at high speed and in a dense state, and high in-plane uniformity can be ensured, and the substrate can be formed at a high film formation rate. A uniform and dense film is formed.

  According to the second aspect of the present invention, plasma having a high ion density can be generated on the target surface, and a magnetic field can be secured on the target surface even when the target is thickened.

  According to the invention of claim 3, since plasma with high ion density can be generated in a wider range of the target, the life of the target can be longer, higher in-plane uniformity can be ensured, and the target surface can be used without waste. it can.

  According to the invention of claim 4, it is easy to change the positions and sizes of the first external magnet and the second external magnet, and the number can be easily increased or decreased. Also, the already installed magnetron sputtering apparatus can be easily changed to a multi-pole magnetron sputtering apparatus.

  According to the invention of claim 5, the optimum target power and substrate power can be set according to the target and the substrate, and a necessary thin film can be obtained. It can be used for various targets and substrates, and the range of use of this apparatus can be expanded.

  According to the invention of claim 6, since a high magnetic field can be formed over a wide range of the target surface, the plasma density on the target surface can be maintained at a high level, and the high plasma density state can be expanded to the substrate. As a result, film material particles (ions) emitted from the target surface can be incident on the substrate 8 at high speed and in a dense state, and a uniform and dense film is formed on the substrate. In particular, since the sputtering pressure may be low, a denser film can be formed. The sputtering pressure varies depending on the thin film to be obtained, but is preferably lower than 1.33 × 10 −1 Pa, more preferably lower than 1 × 10 −2 Pa.

  According to the invention of claim 7, the optimum target power and substrate power for obtaining a necessary thin film can be easily adjusted and set according to the target and the substrate.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
The multi-pole magnetron sputtering film-forming apparatus of Embodiment 1 is demonstrated based on FIG.1 and FIG.2. A target base (holding member) 11 with a built-in magnet is disposed below a substantially cylindrical vacuum chamber (processing chamber) 21. A disk-shaped target 7 made of a magnetic material is installed on the upper surface of the target base 11, and the substrate 8 to be processed is attached to the surface 10 a of the holding member 10 disposed above the container 21. The center magnet 1 is disposed in the target table 11 at a position corresponding to the center of the target 7, and four outer peripheral magnets 2 (2 a to 2 d) are approximately 90 ° at positions corresponding to the periphery of the target 7. They are arranged at intervals. The central magnet 1 is arranged with the south pole facing the target back surface 7b, and the outer peripheral magnet 2 is arranged with the north pole facing the target back surface 7b.

  Four first external magnets 3 (3a to 3d) and four second external magnets 4 (4a) corresponding to the peripheral magnets 2a to 2d are positioned above the target 7 and outside the outer wall of the container 21. ˜4d) are arranged so as to overlap. The first external magnet 3 and the second external magnet 4 are arranged such that the N pole faces inward.

  Inside the container 21, a coil 5 wound around a line connecting the center of the target 7 and the center of the substrate 8 extends from a position close to the second external magnet 4 toward the substrate. It is installed. The coil 5 is made of a SUS304 pipe and is wound three times in a spiral shape, and one end thereof is connected to the high-frequency power source 13 via the matching circuit 12.

  In the present embodiment, the other end of the coil is free and not connected anywhere, but may be connected to ground or a high-frequency power source. A variable DC power supply 15 is connected to the target 7 via a low-pass filter 14. The substrate 8 is connected to a variable DC power source 18 through a low pass filter 16. Between the low-pass filter 16 and the variable DC power source 18, current measuring means 17 for measuring current is provided.

  Next, the operating state of the multi-pole magnetron sputtering film forming apparatus of Embodiment 1 will be described. The high frequency power supply 13 is set to 13.56 Mz. The variable DC power supplies 15 and 18 are set to a predetermined voltage value. Although not shown in the figure, a sputtering gas such as argon is introduced into the container 21 from a side wall or the like at a predetermined pressure and exhausted. As a result, as shown in FIG. 2, the magnetic field lines R directed from the outer peripheral magnet 2 to the target back surface 7 b are partially absorbed into the target 7 made of a magnetic material, but a part of the magnetic force R passes through the target 7 and passes through the target 7. The light enters the south pole of the center magnet 1 through the surface 7a.

  The magnetic force lines T1 generated from the first external magnet 3 repel each other because the first external magnet 3 and the outer peripheral magnet 2 have the same polarity, and are attracted and incident on the south pole of the central magnet 1 on the target back surface 7b. It acts to press in the vicinity of the target surface 7a. A part of the magnetic force line T1 turns in the direction opposite to the direction of the target surface 7a and tries to form a self-circuit. However, the magnetic force line T2 of the second external magnet 4 is drawn in the S-pole direction of the central magnet 1. Since the magnetic force line T1 is pressed in the direction of the target surface 7, the magnetic force line that rotates in the direction opposite to the target surface 7 direction is canceled as much as possible. As a result, the magnetic lines of force R are concentrated near the target surface 7 due to the magnetic lines of force T1, and the magnetic lines of force T1 and T2 are also directed to the target surface 7, so that a strong magnetic field is generated on the target surface 7 and plasma with a high ion density is obtained. It is done. At the same time, high plasma is obtained over a wide range of the target surface 7a.

  A part of the magnetic field lines T2 of the second external magnet 4 usually has a tendency to be dispersed not in the direction of the central magnet 1 but also in other directions. In the present invention, the magnetic field lines tending to be dispersed are applied to the coil 5. The magnetic field lines T3 are aggregated and provided as magnetic lines of force T3 toward the substrate 8. By the flow of the magnetic force lines T3, the film material particles emitted from the target 7 are directed toward the substrate 8 as much as possible, and at the same time, the speed of the film material particles in that direction is increased. In addition, since a high-frequency voltage is applied to the coil 5, the generation of plasma is promoted near the coil 5 and the plasma density is increased.

  As a result, by installing the second external magnet 4 and further by providing the coil 5, film material particles are actively released from the target surface 7a having a high plasma density in a wide range, and at the same time, the film material particles are in an active state. Can pass through a high plasma density region in the vicinity of the coil 5 at high speed, so that a uniform and dense film 8 a is formed on the substrate 8. In particular, the magnetic field lines T3 of the second external magnet 4 and the generation of plasma in the coil 5 can form a strong magnetic field directed toward the substrate 8, the electrons spirally move in the direction of the substrate, and the plasma reaches the vicinity of the substrate. Since it can spread, ions can be efficiently incident on the substrate, and a dense and uniform film can be formed.

(Embodiment 2)
A second embodiment of the present invention will be described with reference to FIGS. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  In the configuration different from the first embodiment, in the second embodiment, six outer peripheral magnets 22 are arranged around the target 7 at an interval of about 60 °, with the N pole facing the target back surface 7b, and the six first outer magnets 23, 23 'and six second external magnets 24, 24' are arranged to overlap each other, and the first external magnets 23, 23 'and the second external magnets 24, 24' have N poles and S poles alternately inside. It is arrange | positioned so that it may face.

  The operating state of the multi-pole magnetron sputtering film forming apparatus of Embodiment 2 will be described. A part of the magnetic force line R from the outer peripheral magnet 22 toward the target back surface 7b is absorbed inside the target 7 made of a magnetic material, but a part of the magnetic force R passes through the target 7 and passes through the target surface 7a. Incident to the pole. The magnetic force lines T1 generated from the first external magnet 23 repel each other because the first external magnet 23 and the outer peripheral magnet 22 have the same polarity, and are attracted and incident on the S pole of the central magnet 1 on the target back surface 7b. It acts to press in the vicinity of the target surface 7a. Similarly, the magnetic force lines T2 emitted from the second external magnet 24 act to press the magnetic force lines T1 and R toward the target surface 7a.

  On the other hand, the first external magnet 23 ′ is an S pole, which is a magnetic pole different from the outer peripheral magnet 22 and the adjacent first external magnet 23, and the magnetic force line T 4 generated from the outer peripheral magnet 22 or the first external magnet 23 is the first external magnet. 23 '. Similarly, the magnetic field lines T4 generated from the outer peripheral magnet 22 and the second external magnet 24 are also attracted to the second external magnet 24 'by the first external magnet 24'.

  As a result, a strong magnetic field is formed in a wide range in the vicinity of the target surface 7a by the magnetic field lines of T1, T2, T4, and R, so that a high magnetic field is formed on the target surface 7a.

  Similarly to the first embodiment, the flow of the magnetic force lines T3 directed toward the substrate causes the film material particles separated from the target 7 to be directed toward the substrate 8 as much as possible, and at the same time, increases the velocity of the film material particles in that direction. . In addition, since a high frequency voltage is applied to the coil 5, the generation of plasma is promoted near the coil 5 and the plasma density is increased.

  As a result, also in the second embodiment, plasma can spread to the vicinity of the substrate, ions can be efficiently incident on the substrate, and a uniform and dense film 8a can be formed on the substrate 8.

  Next, based on FIGS. 5 to 8, results of experiments on the multi-pole magnetron sputtering film forming apparatus shown in the first and second embodiments will be described.

  Ni (diameter 200 mm, thickness 5 mm) was used as the target, and Ar (purity 99.9999%) was used as the sputtering gas. After evacuating the pressure to 4.0 × 10 −5 Pa, gas was introduced, and the discharge pressure and gas flow rate were kept constant at 1.33 × 10 −1 Pa and 1 sccm, respectively. A substrate folder of 146φ was used, and the distance between the target and the substrate was 150 mm. The change in current flowing into the substrate was measured. FIG. 5 shows the result of measuring the magnetic flux density in the direction perpendicular to the target using a teslameter at a position 60 mm from the surface of the target 7 at the center of the installed coil 5. In the first and second embodiments, the voltage of the high-frequency power supply 13 is 30 W. Conventional Example 1 is a so-called typical flat-plate magnetron sputtering film forming apparatus (FIG. 11) in which the first external magnet, the second external magnet, and the coil are not provided.

  In the first and second embodiments, a high magnetic flux density can be obtained over a wide range of the target surface 7a as compared with a normal flat magnetron sputtering film forming apparatus (FIG. 11). This is because, in the first and second embodiments, by providing the first external magnet, the second external magnet, and the coil, the magnetic field on the target surface is increased and the magnetic lines of force toward the substrate are formed strongly. Conceivable.

  FIG. 6 shows the relationship between the substrate current (A) and the substrate DC bias voltage (Vs) when the target DC bias voltage (Vt) is kept constant at −400V.

  Conventional Example 1 is a flat-plate magnetron sputtering film forming apparatus shown in FIG. 11, Conventional Example 2 is a multi-pole magnetron sputtering film forming apparatus (only the first external magnet) shown in FIG. 12, and Conventional Example 3 is shown in FIG. And a multiple magnetron sputtering film forming apparatus (first external magnet and second external magnet) shown in FIG.

  As shown in FIG. 6, the current A due to ions in the region where the negative DC bias voltage is applied is greatly increased in the first and second embodiments. When the substrate DC bias voltage (Vs) = − 100 V and the high-frequency power = 30 W, the first and second embodiments increase about three times as compared with the conventional example 1. This is because the first external magnet, the second external magnet, and the coil draw plasma in the direction of the substrate due to the magnetic lines of force in the direction of the substrate, and the ionization is promoted by the effect of inductively coupled plasma by the coil, increasing the ionic current. It is because that also contributes.

  FIG. 7 shows the relationship between the substrate current (A) and the target DC bias voltage (Vt) when the substrate DC bias voltage (Vs) is kept constant at −80V.

  When Vt = −500 V and high-frequency power = 30 W, the ion current A is increased about five times in the first and second embodiments compared to the first conventional example. From this result, it can be seen that in the present invention, ionization is efficiently performed as the target DC bias voltage (Vt) increases.

  FIG. 8 shows an X-ray diffraction pattern of the Ni thin film produced by each sputtering method with the target DC bias voltage (Vt) set to a constant value of −450 V and the substrate DC bias voltage (Vs) set to −80 V. The crystal structure was evaluated by X-ray diffraction (XRD, CuKα) using a Corning 1737 glass substrate (trade name) as the substrate. In FIG. 8, Conventional Example 1 is indicated by A, Conventional Example 2 is indicated by B, Conventional Example 3 is indicated by C, and Embodiment 1 is indicated by D.

  From these results, Ni (111) and Ni (200) peaks are observed in Conventional Examples 1 to 3. On the other hand, in Embodiment 1, the peak of Ni (200) is hardly observed, and it can be seen that the relative intensity of Ni (111) is increased. That is, in the present invention, a Ni film having a good crystal orientation was obtained. This is considered to be due to the effect of generating high plasma on the target surface, strengthening the magnetic lines of force toward the substrate, and further promoting the generation of plasma in the coil region.

  The second embodiment is also omitted because the same result as that of the first embodiment is predicted.

(Embodiment 3)
Embodiment 3 will be described. The third embodiment is the same as the second embodiment except that Fe is used as a target, which is different from the second embodiment.

  Fe (200 mm diameter, 5 mm thickness, purity 99.99%) was used as the target. The high frequency (13.56 MHz) power was 30 W. The gas flow rate was fixed at 10 sccm. The distance between the target and the substrate was 150 mm. After exhausting the pressure to 4.0 × 10 −5 Pa, gas was introduced to change the sputtering pressure from 8.0 × 10 −2 Pa to 1.1 Pa.

  In the third embodiment, similarly to the second embodiment, since the first external magnet, the second external magnet, and the high frequency coil are provided, a strong magnetic field on the target surface can be secured, and further, a high ion density toward the substrate. Therefore, it was possible to maintain a high-density plasma up to the vicinity of the substrate and to form a uniform and dense film on the surface of the substrate.

  In particular, in Embodiment 3, the relationship between the electrical characteristics of the deposited film on the substrate and the sputtering pressure was experimentally observed. The electrical characteristics were the resistivity calculated from the film thickness and the sheet resistance. As shown in FIG. 9, the experimental results show that the resistivity decreased as the sputtering pressure decreased and approached the bulk value (10.1 μΩ · cm). In particular, the resistivity of the film when deposited at a sputtering pressure of 8.0 × 10 −2 Pa was about 16 μΩ · cm.

  FIG. 10 shows X-ray diffraction patterns of Fe thin films prepared at each sputtering pressure. When the sputtering pressure is 1.1 Pa, peaks of Fe (110), Fe (200), and Fe (211) are observed, indicating that these crystal structures are included. In addition, when the sputtering pressure is 6.7 × 10 −1 Pa or 1.3 × 10 −1 Pa, the peak of Fe (110) becomes strong and the peaks of Fe (200) and Fe (211) become weak. However, a new Fe (220) peak is seen, indicating that these crystal structures are included. On the other hand, when the sputtering pressure is 8.0 × 10 −2 Pa, the peak of Fe (110) becomes strong, and the peaks of Fe (200), Fe (211), and Fe (220) are almost seen. Absent.

  From these experimental results, in the present invention, plasma discharge can be maintained even when the sputtering pressure is low, and a dense Fe film having good crystal orientation with respect to the substrate can be obtained.

  In the present invention, the first external magnet, the second external magnet, and the high-frequency coil are configured to generate a plasma having a high ion density on a target surface in a wide range and maintain a high plasma state to form a thin film on the substrate surface. Since such a configuration is adopted, the above state can be ensured even when the sputtering pressure is low. In particular, since the sputtering pressure may be low, the amount of non-ionized gas such as Ar can be reduced, and the film material particles released from the target surface can be guided to the substrate at high speed and efficiently. Moreover, since precipitation of impurities such as oxygen components from the inner wall of the vacuum vessel can be suppressed, the atmospheric gas can be maintained in a high performance state, and a high purity Fe film can be obtained. Since the Fe film deposited on the substrate contains extremely little oxygen, a smooth, smooth and dense film can be formed, and an Fe film that is not easily rusted can be obtained.

  In the first embodiment, four outer magnets, first outer magnets, and second outer magnets are used. In the second embodiment, six outer magnets, first outer magnets, and second outer magnets are used. The number of magnets is not limited to this number, and any number can be provided as long as the number of the magnets is the same. In addition, although the number of central magnets has been described as one, the number is not limited to this, and a structure in which a large number of magnets are arranged on a donut may be used.

  In the above embodiment, the coil is arranged extending from the position close to the second external magnet 4 toward the substrate, but may be arranged in the space between the target and the substrate, for example, You may arrange | position in the position close | similar to a board | substrate. If placed close to the substrate, ionization near the substrate surface can be promoted, and if placed in the position as in the embodiment, the plasma density in the space can be improved, so the target / substrate, required thin film characteristics, etc. Depending on the situation, it may be arranged at an appropriate position. The coil material is stainless steel, but is not limited to this, and other materials may be used. The number of turns of the coil is not limited to three and may be set arbitrarily. The high frequency power applied to the coil is not limited to 13.56 MHz, and may be other frequencies. The coil may be set appropriately according to the target material, the substrate, the characteristics of the obtained thin film, and the like.

  The target is not limited to a magnetic material such as iron, nickel, and cobalt, but may be a non-magnetic material, not limited to a metal, and may be ceramic.

  The potential applied to the target may be direct current or alternating current. It is preferable that the potential applied to the target and the substrate can be selected freely according to the target material, the substrate material, and the like.

  In the above embodiment, the external magnet is disposed outside the vacuum vessel, but may be disposed within the vacuum vessel.

  Although the structure is such that the target is disposed at the bottom and the substrate is disposed at the top, it may be reversed.

  The present invention can also be applied to those in which reactive magnetron sputtering is performed in a mixed gas of Ar gas and N2, or Ar gas and O2, such as a Fe-N thin film and a Fe-O2 thin film.

  As described above, the invention related to the present invention is a multiple magnetic pole for forming a thin film such as a conductive film, a semiconductor film, an insulating film, a thin film of a magnetic head of a magnetic recording device, a wear resistant film, a corrosion resistant film, etc. It can be applied to a magnetron sputtering film forming apparatus.

  For example, it can be applied to semiconductor films on semiconductor wafers, decorative thin films on magnesium alloys used in personal computers and mobile phones, and electromagnetic shielding thin films on various plastic parts used in electronic parts.

1 shows an outline of a multi-pole magnetron sputtering film forming apparatus according to Embodiment 1 of the present invention. It is a figure which shows the magnetic force line of the magnetic field formed in the apparatus of FIG. It is a figure which shows the magnetic force line of the magnetic field formed in the multiple magnetic pole magnetron sputtering film-forming apparatus in connection with Embodiment 2 of this invention. It is a schematic plan view which shows the magnetic force line in FIG. It is a figure which shows the relationship between a target surface and magnetic flux density. It is a figure which shows the relationship between a board | substrate current and a board | substrate voltage. It is a figure which shows the relationship between a substrate current and a target voltage. It is a figure which shows an X-ray diffraction pattern. It is a figure which shows the relationship between the gas pressure and resistance value in Embodiment 3. It is a figure which shows the X-ray-diffraction pattern with respect to each gas pressure. It is a figure which shows the conventional magnetron sputtering film-forming apparatus. It is a figure which shows the other conventional magnetron sputtering film-forming apparatus. It is a figure which shows the other conventional magnetron sputtering film-forming apparatus. It is a schematic plan view which shows the magnetic force line in FIG.

DESCRIPTION OF SYMBOLS 1 Center magnet 2 Perimeter magnet 3 1st external magnet 4 2nd external magnet 5 Coil 7 Target 8 Board | substrate

Claims (7)

A multi-pole magnetron sputtering film forming apparatus for forming a film on a substrate,
An airtight processing chamber,
A first holding member disposed in the processing chamber and having a holding surface for supporting the substrate;
A second holding member disposed in the processing chamber so as to face the first holding member;
A target held by the second holding member so as to have a surface facing the substrate supported on the first holding member;
A central magnet disposed at the center of the back side of the target and having one magnetic pole directed to the back side of the target;
A plurality of outer peripheral magnets disposed on the outer peripheral edge of the back side of the target and having the other magnetic pole directed to the back surface of the target;
A plurality of first external magnets arranged at positions outside the outer peripheral edge of the target on the surface side of the target and having the same or different magnetic pole as the other magnetic pole of the outer peripheral magnet directed inward;
A plurality of second external magnets arranged at a position closer to the substrate than the first external magnet and having magnetic poles oriented in the same manner as the first external magnet so as to overlap the first external magnet;
It is wound around the direction connecting the target and the substrate, and the center thereof is disposed in the space between the target and the substrate, and is further disposed between the position of the second external magnet 4 and the substrate . Coils,
High-frequency power applying means for applying high-frequency power to the coil;
A multi-pole magnetron sputtering film-forming apparatus, comprising: a power applying unit that applies power between the target and the substrate. The multi-pole magnetron sputtering film forming apparatus according to claim 1,
All of the first external magnets are arranged with the same magnetic pole as the other magnetic pole of the outer peripheral magnet facing inward. The multi-pole magnetron sputtering film forming apparatus according to claim 1,
The first external magnet with the same magnetic pole as the other magnetic pole of the outer peripheral magnet facing inward and the first external magnet with the magnetic pole different from the other magnetic pole of the outer peripheral magnet facing inward are alternately arranged. It is provided. In the multi-pole magnetron sputtering film forming apparatus according to any one of claims 1 to 3,
The first external magnet and the second external magnet are arranged at positions outside the outer wall of the processing chamber in proximity to or in contact with the outer wall. In the multiple magnetic pole magnetron sputtering film-forming apparatus as described in any one of Claims 1 thru | or 4,
The power application means includes target power application means for applying power to the target, and substrate power application means for applying power to the substrate, and the target power application means and the substrate power application means supply power to be applied. It is characterized by being variable. A film forming method using the multi-pole magnetron sputtering film forming apparatus according to any one of claims 1 to 5,
Placing (mounting) the substrate on the holding surface of the first holding member, and then supplying a processing gas into the processing chamber while evacuating the processing chamber; Next, the electric field is formed between the target and the substrate by the power application means, high frequency power is applied to the coil, and the film material particles are released from the target. And a treatment step of forming a thin film on the substrate surface by depositing the film material particles on the substrate surface,
A magnetic field having a magnetic field line extending from the first external magnet toward the central magnet along the target surface is formed. A method of forming a multi-pole magnetron sputtering film, comprising: forming a magnetic field having:   7. The multi-pole magnetron sputtering film forming method according to claim 6, wherein a power value of the target power applying unit and the substrate power applying unit is adjusted to adjust a film forming state of the film.

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