JP2020152968A - Sputtering device - Google Patents

Abstract

To maintain a film deposition rate, while lowering a voltage to be applied to a target; to suppress temperature rise of a substrate following film deposition; and to improve utilization efficiency of the target.SOLUTION: A vacuum vessel (2) of a sputtering device (1) includes a target holder (32), first magnetic substance (52a)-second magnetic substance (52b), and an antenna (20). The first magnetic substance-second magnetic substance form a parallel magnetic field less than the strength at which magnetron discharge occurs, on a position facing to the whole surface of a target (30).SELECTED DRAWING: Figure 1

Description

The present invention relates to a sputtering apparatus.

Conventionally, various sputtering devices have been proposed. Examples of the sputtering apparatus include Patent Documents 1 and 2. Patent Document 1 discloses a sputtering apparatus including at least two magnets arranged at the lower part of the target and at least two magnets arranged at the upper side of the target. Further, Patent Document 2 discloses a sputtering apparatus including a discharge electrode having a magnetic material and a target upper magnet. The magnetic material is provided along both side edges on the surface side of the target and faces each other across the target, and the magnet on the top of the target is provided in combination with the magnetic material on the opposite side of the target across the magnetic material. It is a relationship of different polarities across the target.

Japanese Unexamined Patent Publication No. 61-124567 (published on June 12, 1986) Japanese Patent No. 5853487 (issued on February 9, 2016)

However, in the techniques of Patent Documents 1 and 2, it is not assumed that the voltage applied to the target is lowered.

One aspect of the present invention is to maintain the film formation rate while reducing the voltage applied to the target, suppress the temperature rise of the substrate due to the film formation, and improve the utilization efficiency of the target. The purpose is to realize a possible sputtering apparatus.

In order to solve the above problems, the sputtering apparatus according to one aspect of the present invention is a sputtering apparatus that sputters a target in a vacuum vessel into which a gas for sputtering is introduced to form a film on a substrate. The vacuum vessel is provided with a holding portion for holding the target, magnetic materials having different polarities, and an antenna that generates plasma by supplying power independently of the power supply to the target. The magnetic material forms a parallel magnetic field having a strength lower than the strength at which magnetron discharge occurs at a position facing the entire surface of the target held by the holding portion.

According to one aspect of the present invention, the voltage applied to the target is reduced, the film formation rate is maintained, the temperature rise of the substrate due to the film formation is suppressed, and the utilization efficiency of the target is improved. be able to.

It is the schematic which shows the structural example near the upper surface part of the vacuum vessel in the sputtering apparatus which concerns on Embodiment 1, (a) is the sectional view near the upper surface part, and (b) is seen from the lower side around the upper surface part. It is a plan view of time. It is a figure which shows the overall configuration example of the said sputtering apparatus. It is a figure for demonstrating the sputtering apparatus which concerns on a comparative example, (a) is a schematic diagram which shows the structural example near the upper surface part of a vacuum vessel, (b) is sputtered by the sputtering apparatus of a comparative example. It is a figure which shows an example of a target. It is a figure for demonstrating the sputtering apparatus which concerns on another comparative example, and is the schematic diagram which shows the structural example inside the vacuum container. It is a graph which shows the temperature change with time of the substrate in the sputtering apparatus of this Example, and the sputtering apparatus which concerns on another comparative example. It is the schematic which shows the structural example of the sputtering apparatus which concerns on the modification. It is the schematic which shows the structural example of the sputtering apparatus which concerns on Embodiment 2.

[Embodiment 1]
Hereinafter, one embodiment of the present invention will be described in detail with reference to FIGS. 1 to 6.

<Overall configuration of sputtering equipment>
First, the overall configuration of the sputtering apparatus 1 according to the present embodiment will be described with reference to FIG. FIG. 2 is a diagram showing an overall configuration example of the sputtering apparatus 1.

As shown in FIG. 2, the sputtering apparatus 1 is an apparatus in which the target 30 is sputtered in the vacuum vessel 2 into which the gas 10 for sputtering is introduced to form a film on the substrate 12.

Specifically, the sputtering device 1 includes a vacuum container 2 that is evacuated by the vacuum exhaust device 4. The vacuum vessel 2 is electrically grounded, and a gas 10 for sputtering is introduced into the vacuum vessel 2. The gas 10 is introduced from the gas source 6 into the vacuum vessel 2 while the flow rate is adjusted by the flow rate controller 8. The gas 10 is, for example, argon gas. When performing reactive sputtering, the gas 10 may be a mixed gas of an argon gas and an active gas (for example, oxygen gas, nitrogen gas, etc.).

A substrate holder 14 for holding the substrate 12 is provided in the vacuum container 2. In the present embodiment includes a substrate bias power supply 16, and applying a substrate bias voltage V _S to the substrate holder 14. Substrate bias voltage V _S is to may be a negative DC voltage, a negative pulse voltage, may also be a AC voltage or the like. Further, the substrate holder 14 may be electrically grounded. Reference numeral 40 denotes an insulating portion having a vacuum sealing function. Further, the substrate 12 is an object to be processed in which a thin film is formed by the sputtered particles emitted from the target 30. As the substrate 12, a glass substrate, a semiconductor substrate, or the like is used, but the substrate 12 is not limited thereto.

Further, the upper surface portion 3 of the vacuum vessel 2 is provided with a target holder (backing plate) 32 (holding portion) for holding the target 30 at a position facing the substrate holder 14. As a result, the target 30 is held inside the vacuum vessel 2 at a position facing the substrate 12. The planar shape of the target 30 is, for example, a rectangular shape (see (b) of FIG. 1), but is not limited to this, and may be a circular shape or the like. The target holder 32 is provided with a water passage 36 through which cooling water flows to cool the target 30 with water. An insulating portion 42 having a vacuum sealing function is provided between the target holder 32 and the vacuum container 2 (specifically, the upper surface portion 3).

The material of the target 30 may be one suitable for the film formed on the substrate 12. For example, when forming an oxide semiconductor thin film on the substrate 12, the target 30 is, for example, In-Ga-Zn-O (indium-gallium-zinc-oxygen) or In-Sn-Zn-. Although it is an oxide semiconductor composed of O (indium-tin-zinc-oxygen) and the like, the material of the target 30 is not limited to this.

A target bias power supply 34 is connected to the target 30 via a target holder 32. Target bias power source 34 is for supplying a target bias voltage V _T to the target 30 (applied). The target bias voltage V _T, the ions in the plasma 22 (in the present application means a positive ion) is a voltage for sputtering by drawing the target 30, for example, (a) a negative DC voltage, (b) positive and negative alternating Pulse voltage (or negative DC pulse voltage), (c) AC voltage. The AC voltage may be a high frequency voltage on the order of MHz such as 13.56 MHz, or a low frequency voltage having a frequency lower than the output of the high frequency power supply 24 (for example, 13.56 MHz) (for example, about 10 kHz to 100 kHz). It doesn't matter. When the low frequency voltage is set, it becomes easy to avoid interference with the plasma generation operation using the high frequency power supply 24.

Target bias voltage V _T output from the target bias power source 34 is determined, for example, according to the material of the target 30 or the like. Target bias voltage V _T, for example, if the target 30 is electrically conductive, may be any voltage shown in the above (a) ~ (c). On the other hand, when the target 30 is an insulator, by setting the voltage shown in (b) or (c) above, the surface of the insulator is covered with the positive charge of the inflowing ions, so that the sputtering is stopped. Can be prevented.

Target bias power source 34, as a target bias voltage V _T, to may be output one type of voltage among the voltage of the (a) ~ (c), may be outputted by switching a plurality of types of voltages Absent.

Further, an antenna 20 is arranged inside the vacuum container 2. In the present embodiment, the two antennas 20 are arranged so as to face each other so as to sandwich the target 30 held by the target holder 32 from both sides. Insulating portions 41 having a vacuum sealing function are provided in the penetrating portions through which the two antennas 20 penetrate the upper surface portion 3.

A high frequency power supply 24 is connected to each antenna 20 via a matching circuit 26. Specifically, a matching circuit 26 is connected to one end of each antenna 20, and the other end of each antenna 20 is electrically grounded. One end of the high frequency power supply 24 is also electrically grounded. A high frequency power supply 24 and a matching circuit 26 may be provided for each antenna 20.

High-frequency power source 24 is for supplying a high frequency power P _R to each antenna 20. Specifically, by the high frequency power P _R is supplied in parallel to each antenna 20, in the vicinity of the surface of the target 30 to generate an inductively coupled plasma 22. Frequency of the high frequency power _{P R} outputted from the high frequency power source 24 is, for example, is a common 13.56 MHz, the invention is not limited thereto.

Further, the sputtering device 1 includes a control device 46. The control device 46 controls each part of the sputtering device 1 in an integrated manner, and particularly controls the power supply from the high frequency power supply 24 and the target bias power supply 34.

Further, the vacuum vessel 2 is provided with a first magnetic body 52a (magnetic material) and a second magnetic body 52b (magnetic material) having different polarities.

<Structure near the upper surface of the vacuum vessel>
Next, with reference to FIG. 1, a specific configuration in the vicinity of the upper surface portion 3 of the vacuum container 2 will be described in detail. 1A and 1B are schematic views showing a configuration example near the upper surface portion 3 of the vacuum vessel 2, FIG. 1A is a cross-sectional view of the vicinity of the upper surface portion 3, and FIG. 1B is a view of the vicinity of the upper surface portion 3 from below. It is a plan view of time.

In the vicinity of the upper surface portion 3, mainly
-Target holder 32 for holding the target 30,
Insulating portion 42 that insulates the target holder 32 and the vacuum vessel 2.
The first magnetic body 52a and the second magnetic body 52b that form a parallel magnetic field at positions facing the entire surface of the target 30 held by the target holder 32, and
Antenna 20 that generates plasma 22 near the surface of the target 30
Is provided.

(antenna)
As shown in FIG. 1A, the antenna 20 is arranged inside the vacuum vessel 2 in the vicinity of the target holder 32 (specifically, in the vicinity of the surface of the target 30 held by the target holder 32). There is. In the present embodiment, as shown in FIG. 1B, the two antennas 20 sandwich the target 30 held by the target holder 32 from both sides and are located on the sides of the substantially rectangular target 30. It is arranged along the line.

By arranging the two antennas 20 in this way, it is possible to generate the plasma 22 so as to face the entire surface of the target 30. As a result, the entire surface of the target 30 can be sputtered, and the utilization efficiency of the target 30 can be improved. However, if this point is not taken into consideration, for example, one antenna 20 may be arranged along one side of the target 30.

Further, each antenna 20 is a rod-shaped conductor (antenna conductor) except for both end portions, and is bent toward the upper surface portion 3 side at both end portions. Both ends of each antenna 20 penetrate the upper surface portion 3 and project upward from the upper surface portion 3 and are connected to the matching circuit 26.

Each antenna 20 may have a solid structure in which the inside is clogged, or may have a hollow structure (eg, tubular or tubular). In the case of a hollow structure, a water cooling structure may be provided in which a cooling water channel is provided and cooling water is allowed to flow to cool each antenna 20. Further, each antenna 20 may have a structure in which a capacitor is inserted in the middle of the antenna conductor.

The shape of the antenna 20 is not limited to the shape described above, and the entire antenna 20 may be rod-shaped, U-shaped, C-shaped, coil-shaped, or the like. Further, the shape of the antenna 20 may be a shape corresponding to the planar shape of the target 30. For example, when the planar shape of the target 30 is circular, the planar shape of the antenna 20 may be circular.

Further, the antenna 20 has a structure in which the antenna conductor is housed inside the insulating member regardless of its structure or shape.

The structure or shape of the antenna 20 described above is merely an example, and the antenna 20 may have a structure or shape capable of generating plasma 22.

Further, the antenna 20, the RF power P _R is supplied independently of the supply of the target bias voltage V _T of the target 30. Specifically, the control device 46 (see FIG. 2), and control target bias power source 34 for supplying a target bias voltage V _T to the target 30, independently and high-frequency power source 24 supplies high frequency power P _R to the antenna 20 To do.

Generally, in order to improve the film formation rate, it is necessary to increase the number of ions (the number of argon ions in this embodiment) or increase the energy of the ions incident on the target 30. When the target bias voltage _VT is lowered, the energy of the ions incident on the target 30 can be reduced, so that the energy of the sputtered particles ejected from the target 30 can be suppressed. Therefore, the energy generated when the sputtered particles collide with the substrate 12 can be suppressed, so that the temperature rise of the substrate 12 can be suppressed. However, on the other hand, since the energy of the ions becomes low, the film forming speed decreases.

In the sputtering apparatus 1, since it is possible to independently control the target bias power source 34 and the high frequency power source 24, when lower target bias voltage V _T, it is possible to enhance the high frequency power P _R is supplied to the antenna 20. In this case, the number of ions in the plasma 22 can be increased. Therefore, it is possible to compensate by a decrease in sputtering rate due to the decrease of the energy of the ions due to decrease of the target bias voltage V _T, to increase the number of ions in the plasma 22.

Thus, an antenna 20, the control unit 46 by independently controlling the supply of the target bias voltage V _T and the high-frequency power P _R, the sputtering apparatus 1, while achieving lower voltage of the target bias voltage V _T , The film formation rate (high-speed film formation) can be maintained. Moreover, the low voltage of the target bias voltage V _T, so the energy that occurs when the sputtered particles to the substrate 12 collide can be suppressed, it is possible to improve the quality of the film formed on the substrate 12.

(1st magnetic material, 2nd magnetic material)
As shown in FIG. 1A, the first magnetic body 52a and the second magnetic body 52b are located in the vicinity of the target holder 32 inside the vacuum vessel 2 (specifically, the target held by the target holder 32). (Near the surface of 30). In the present embodiment, as shown in FIG. 1B, the first magnetic body 52a and the second magnetic body 52b have a substantially rectangular shape so as to sandwich the target 30 held by the target holder 32 from both sides. It is arranged along the side of the target 30 of.

In other words, the first magnetic body 52a and the second magnetic body 52b are on the surface side (sputtered side) of the target 30, and when the target holder 32 is viewed in a plan view, the positions facing each other with the target 30 in between. Is located in. That is, in the present embodiment, the first magnetic pole MPa (magnetic pole) and the second magnetic pole MPb (magnetic pole) having different polarities are formed at the positions. Further, the first magnetic body 52a and the second magnetic body 52b (that is, the first magnetic pole MPa and the second magnetic pole MPb) are arranged so as to extend along the above-mentioned sides.

With such an arrangement, a magnetic field distribution (parallel magnetic field) having a component of magnetic field lines ML substantially parallel to the surface can be formed at least at a position facing the entire surface of the target 30. Therefore, electrons (secondary electrons) generated by the collision of ions at the target 30 can be efficiently captured. As a result, the movement of electrons toward the substrate 12 can be suppressed, so that the energy generated by the collision of the electrons with the substrate 12 can be suppressed from flowing into the substrate 12. Therefore, the temperature rise of the substrate 12 due to the energy can be suppressed.

Further, by setting a low target bias voltage V _T, although it is possible to lower the energy when colliding electrons to the substrate 12, it can not significantly alter the number of electrons impinging on the substrate 12. By forming the parallel magnetic field as described above, the number of electrons colliding with the substrate 12 can be reduced, so that the temperature rise of the substrate 12 can be further suppressed.

Further, by forming a parallel magnetic field at a position facing the entire surface of the target 30, it is possible to uniformly capture electrons over the entire surface of the target 30. By arranging the two antennas 20 as described above, it is possible to generate the plasma 22 so as to face the entire surface of the target 30. However, even in this case, the density of the plasma 22 may be localized on the surface of the target 30. By capturing electrons by forming the parallel magnetic field, localization of the density of the plasma 22 can be suppressed. Therefore, the entire surface of the target 30 can be uniformly sputtered, and the utilization efficiency of the target 30 can be further improved.

Further, when a magnet is provided on the back side of the target 30 to form a magnetic field on the surface of the target 30 (see FIG. 3), when the target 30 is made of a ferromagnetic material, the surface of the target 30 is predetermined. It can be difficult to form a strong magnetic field. This is because the magnetic force generated by the magnet is likely to be drawn toward the target 30 side.

On the other hand, by arranging the first magnetic body 52a and the second magnetic body 52b on the surface side of the target 30, it is possible to make it difficult for the generated magnetic force to be drawn into the target 30 side. Therefore, even when the target 30 of the ferromagnetic material is held, a magnetic field having a predetermined strength is likely to be formed on the surface of the target 30. Therefore, even if the target 30 is made of a ferromagnetic material, it is possible to perform sputtering in the same manner as the target 30 made of other materials. In this embodiment, the first magnetic body 52a and the second magnetic body 52b are provided in the vicinity of the side surface of the target 30.

Further, in the present embodiment, the first magnetic body 52a functions as an N pole and the second magnetic body 52b functions as an S pole. Therefore, as shown in FIG. 1 (b), the first magnetic body 52a (first magnetic pole MPa) is parallel to the second magnetic body 52b (second magnetic pole MPb) at least on the surface of the target 30. The magnetic field lines ML are formed. Further, as shown in FIG. 1A, a magnetic field line ML is formed near the surface of the target 30. Even when the first magnetic body 52a functions as the S pole and the second magnetic body 52b functions as the N pole, a magnetic field having the same distribution is formed only by reversing the directions of the magnetic field lines ML.

Further, as shown in FIG. 1A, the first magnetic body 52a and the second magnetic body 52b are provided at positions closer to the surface of the target 30 than the antenna 20 in the height direction. That is, the first magnetic body 52a and the second magnetic body 52b are provided so as to form a parallel magnetic field near the surface of the target 30 (specifically, directly above the surface of the target 30). In the present embodiment, as described above, the first magnetic body 52a and the second magnetic body 52b are provided in the vicinity of the side surface (upper side surface) of the target 30.

Since the electrons are ejected from the target 30 over a wide range, the probability (capture rate, yield) of capturing the electrons decreases as the first magnetic body 52a and the second magnetic body 52b move away from the surface of the target 30. The configuration of the sputtering apparatus 1 becomes large. By providing the first magnetic body 52a and the second magnetic body 52b at the above positions, the yield of electrons is improved, and the sputtering apparatus 1 is downsized when the first magnetic body 52a and the second magnetic body 52b are provided. Can be planned.

Further, the magnetic flux strength (magnetic flux density) formed by the first magnetic body 52a and the second magnetic body 52b is less than the strength at which magnetron discharge occurs. In the sputtering apparatus 1, since the plasma 22 is generated by the antenna 20 as described above, it is not necessary to generate a high-intensity magnetic field that causes magnetron discharge.

Further, when the gas molecules are converted into plasma by generating magnetron discharge (moving electrons by entwining them with a magnetic field for a long distance) separately from the generation of plasma 22 by the antenna 20, the plasma is biased. By setting the magnetic field strength to less than the strength at which magnetron discharge occurs, it is possible to prevent the occurrence of such a biased plasma.

Specifically, the strength of the parallel magnetic field formed by the first magnetic body 52a and the second magnetic body 52b is less than 100 gauss at any of the positions. Generally, when the strength of the magnetic field is 100 gauss or more, magnetron discharge occurs. Therefore, if the strength of the parallel magnetic field formed facing the surface of the target 30 is less than 100 gauss, it is possible to prevent the magnetron discharge from occurring.

Further, the first magnetic body 52a and the second magnetic body 52b are magnetic fields having a strength such that the rammer radius _{RL of the} electrons emitted from the target 30 becomes smaller than the distance between the target 30 and the substrate 12 as parallel magnetic fields. To form. As a result, the collision of electrons with the substrate 12 can be prevented, so that the temperature rise of the substrate 12 due to electrons can be reliably prevented.

The rammer radius _RL is defined by _RL = mv / | q | B (m: electron mass, v: electron velocity, q: electron charge, B: magnetic field strength). That is, the smaller the magnetic field strength, the larger the Ramer radius _RL . Further, if the magnetic field strength becomes too small, the electrons emitted from the target 30 cannot be captured. Therefore, the first magnetic body 52a and the second magnetic body 52b have an intensity such that the rammer radius _RL is smaller than the distance between the target 30 and the substrate 12, and the electrons emitted from the target 30 are emitted. A parallel magnetic field with a captureable strength may be formed.

Incidentally, Larmor radius R _L is adjusted by the magnetic field strength and the target bias voltage V _T.

The strength of the parallel magnetic field is adjusted by the magnetic strength of the first magnetic body 52a and the second magnetic body 52b and the distance between the first magnetic body 52a and the second magnetic body 52b. As the distance between the first magnetic body 52a and the second magnetic body 52b increases, the strength of the parallel magnetic field decreases and the distribution thereof deteriorates. If the distribution is poor, a parallel magnetic field cannot be formed on the entire surface of the target 30, and there is a possibility that the capture of electrons will be uneven. Therefore, the distance between the first magnetic body 52a and the second magnetic body 52b is set to such a distance that a parallel magnetic field can be formed at a position facing the entire surface of the target 30 in consideration of the above magnetic strength. To. In the present embodiment, the first magnetic body 52a and the second magnetic body 52b are provided at positions outside the target 30 and close to the target 30 when the target holder 32 is viewed in a plan view.

Further, in the present embodiment, the first magnetic body 52a and the second magnetic body 52b are provided near the inner end portion of the upper surface portion 3 that supports the target holder 32 via the insulating portion 42.

The upper surface portion 3 is electrically grounded and supports the target holder 32 via the insulating portion 42. Therefore, it is possible to prevent the ions in the plasma 22 from being drawn into the upper surface portion 3, so that the temperature of the upper surface portion 3 rises due to the sputtering of the upper surface portion 3 or the collision of the ions with the upper surface portion 3. Can be prevented.

Therefore, when the first magnetic body 52a and the second magnetic body 52b are provided on the upper surface portion 3 and are electrically grounded, the ions are attracted to the first magnetic body 52a and the second magnetic body 52b as described above. Can be prevented. Therefore, it is possible to prevent the first magnetic body 52a and the second magnetic body 52b from spattering or the temperature rise of the first magnetic body 52a and the second magnetic body 52b. Even if the first magnetic body 52a and the second magnetic body 52b are not provided on the upper surface portion 3, the effect can be exhibited as long as they are electrically grounded.

Even if the upper surface portion 3, the first magnetic body 52a and the second magnetic body 52b are electrically grounded, there is a possibility that ions will be drawn in due to the potential of the plasma 22 and the grounding and potential difference. Therefore, in order to prevent the temperature from rising due to the attraction of ions, a cooling water channel may be provided inside the upper surface portion 3. When the first magnetic body 52a and the second magnetic body 52b are provided on the upper surface portion 3, the first magnetic body 52a and the second magnetic body 52b are provided in the vicinity of the first magnetic body 52a and the second magnetic body 52b. Can be cooled efficiently.

In the present embodiment, for example, a permanent magnet is used as the first magnetic body 52a and the second magnetic body 52b. Thereby, the parallel magnetic field described above can be formed inexpensively and easily.

Further, the shapes of the first magnetic body 52a and the second magnetic body 52b are not limited to the above-mentioned shapes, and may be shapes according to the planar shape of the target 30. For example, when the planar shape of the target 30 is circular, the planar shapes of the first magnetic body 52a and the second magnetic body 52b may be arcuate.

(Arrangement relationship between the antenna and the first and second magnetic materials)
As shown in FIGS. 1A and 1B, the antenna 20 is arranged outside the first magnetic body 52a and the second magnetic body 52b when the target holder 32 is viewed in a plan view.

When the antenna 20 is provided inside the first magnetic body 52a and the second magnetic body 52b, the generation region of the plasma 22 in the vacuum vessel 2 becomes local. Therefore, the collision region of ions at the target 30 may also be local. In addition, the sputtered particles emitted from the target 30 collide with the antenna 20. Therefore, the utilization efficiency of the target 30 is lowered. In addition, the antenna 20 becomes dirty due to the adhesion of sputtered particles. In consideration of these points, when the target holder 32 is viewed in a plan view, the antenna 20 is arranged outside the first magnetic body 52a and the second magnetic body 52b, so that the utilization efficiency of the target 30 is lowered. , It is possible to prevent the antenna 20 from becoming dirty.

The antenna 20 may be at the same position as the first magnetic body 52a and the second magnetic body 52b when the target holder 32 is viewed in a plan view, but in this case, the antenna 20 may be at the same position as when it is arranged outside. There is a high possibility that sputtered particles will collide or adhere to the antenna 20. From this point of view, the antenna 20 should be arranged outside the first magnetic body 52a and the second magnetic body 52b.

Further, the distance from the target 30 in the height direction may be adjusted so that the sputter particles do not collide with or adhere to the antenna 20.

<Comparison with comparative example>
Next, a comparative example of the sputtering apparatus 1 of the present embodiment will be described with reference to FIGS. 3 to 5.

(Comparison with Comparative Example 1)
First, the sputtering apparatus 101 according to Comparative Example 1 will be described with reference to FIG. 3A and 3B are views for explaining the sputtering apparatus 101, FIG. 3A is a schematic view showing a configuration example in the vicinity of the upper surface portion 3, and FIG. 3B is a schematic view showing a configuration example of the vicinity of the upper surface portion 3; FIG. It is a figure which shows an example.

As shown in FIG. 3A, in the sputtering apparatus 101, the upper surface portion 3 supports the target holder 132 via the insulating portion 42. The target holder 132 includes a water passage 36 and a magnetic circuit 150 formed by including a first magnet 151, a second magnet 152, and a third magnet 153. The magnetic circuit 150 causes a magnetron discharge.

Specifically, the magnetic pole MP102 is formed by providing the second magnet 152 near the center of the target holder 132. Further, the magnetic poles MP101 and MP103 are formed by providing the first magnet 151 and the third magnet 153 near both ends of the target holder 132, respectively. The first magnet 151 and the second magnet 152 have different polarities from each other, and the second magnet 152 and the third magnet 153 have different polarities from each other. Therefore, in the magnetic circuit 150, the magnetic field line ML is formed between the first magnet 151 and the second magnet 152, and the magnetic field line ML is formed between the second magnet 152 and the third magnet 153.

As shown in FIG. 3A, high-density plasma generated by the magnetic field lines ML formed between the magnetic poles MP101 and the magnetic poles MP102 is generated in one region on the surface of the target 30. Further, in the other region, high-density plasma is generated by the magnetic field lines ML formed between the magnetic poles MP102 and the magnetic poles MP103.

Therefore, the surface of the target 30 is sputtered by the plasma generated at the two locations on the surface of the target 30. As a result, as shown in FIG. 3B, sputtered regions (consumable portions) P1 and P2 in which the target 30 is locally sputtered are generated.

As described above, in the sputtering apparatus 101, the utilization efficiency of the target 30 is lowered due to the formation of a local sputtering region by localizing the high-density plasma on a part of the surface of the target 30. As a result, the material cost (cost for the target 30) increases. Further, the ejection angle of the sputtered particles from the target 30 varies greatly depending on the material of the target 30 and the ejection position. Therefore, due to the formation of the local sputtering region, the film quality of the film formed on the substrate 12 may become non-uniform depending on the material of the target 30.

In the sputtering apparatus 1 of the present embodiment, a parallel magnetic field is formed at a position facing the entire surface of the target 30. Therefore, local sputtering regions such as the sputtering regions P1 and P2 are not formed, and the ions in the plasma 22 can be uniformly collided with the entire surface of the target 30. Therefore, the utilization efficiency of the target 30 can be improved.

Further, the sputtering apparatus 101 is not provided with an antenna 20 (controller does not perform the supply control of the high frequency power _{P R} of the antenna 20), the first magnet 151, a plasma by the second magnet 152 and the third magnet 153 It is occurring. On the other hand, in the sputtering apparatus 1, to generate plasma 22 by supplying high-frequency power P _R to the antenna 20, it is not necessary to produce a magnetron discharge as the sputtering apparatus 101. Therefore, it is possible to prevent the generation of plasma bias that may occur due to magnetron discharge. Further, since the target bias voltage V _T can supply the high frequency power P _R to the antenna 20 independently while achieving lower voltage of the target bias voltage V _T, can maintain the deposition rate.

Further, in the sputtering apparatus 101, a first magnet 151, a second magnet 152, and a third magnet 153 are provided on the back surface of the target 30. Therefore, in the case of the target 30 made of a ferromagnetic material, the magnetic force generated by these magnets is likely to be drawn toward the target 30 side. On the other hand, in the sputtering apparatus 1, since the first magnetic material 52a and the second magnetic material 52b are provided on the surface side of the target 30, even if the target 30 is made of a ferromagnetic material, it is sputtered in the same manner as the other targets 30. Can be done.

(Comparison with Comparative Example 2)
Next, the sputtering apparatus 102 according to Comparative Example 2 will be described with reference to FIG. FIG. 4 is a diagram for explaining the sputtering apparatus 102, and is a schematic view showing a configuration example inside the vacuum vessel 2.

As shown in FIG. 4, the sputtering device 102 includes an antenna 20 like the sputtering device 1. Therefore, while achieving lower voltage of the target bias voltage V _T, it can maintain the deposition rate.

However, as shown in FIG. 4, in the sputtering apparatus 102, since the upper surface portion 3 does not include the first magnetic body 52a and the second magnetic body 52b, the electrons emitted when the ions are drawn into the target 30. Cannot be captured by the magnetic field. Therefore, when the electrons collide with the substrate 12, unnecessary energy due to the electrons flows into the substrate 12, so that the temperature of the substrate 12 rises. On the other hand, in the sputtering apparatus 1, the first magnetic body 52a and the second magnetic body 52b are provided on the upper surface portion 3, and a parallel magnetic field is formed at a position facing the entire surface of the target 30, so that electrons can be generated on the entire surface of the target 30. Can be captured. Therefore, it is possible to suppress a temperature rise due to collision of electrons with the substrate 12.

(Comparison result between Example and Comparative Example 2)
Next, the temperature change of the substrate 12 between the sputtering apparatus 1 of this embodiment and the sputtering apparatus 102 of Comparative Example 2 will be described with reference to FIG. FIG. 5 is a graph showing the temperature change of the substrate 12 with time in the sputtering apparatus 1 of this embodiment and the sputtering apparatus 102 of Comparative Example 2.

In this experiment, a 6-inch diameter circular Al—Si alloy (including 1 wt% Si) was used as the target 30. As the substrate 12 (evaluation substrate), a silicon wafer having a thickness of 0.5 mm was used. As the gas 10, argon (Ar) gas was used. The antenna 20 supplies a high-frequency power _P R (RF power) of 2.0 kW, the target 30 was supplied with a target bias voltage _{V T} of -400 V.

Also, when assuming target bias voltage V _T corresponding energy as the energy of the electrons, near the center of a line connecting the first pole MPa and the second magnetic pole MPb the first magnetic body 52a and the second magnetic member 52b is formed When the magnetic field strength is 100 gauss, the Ramer radius _RL can be calculated as 10 mm. Further, when the magnetic field strength near the center is 10 gauss, the rammer radius _RL can be calculated as 100 mm.

In the sputtering apparatus 1, the intensity of the parallel magnetic field on the surface of the target 30 is set so that the rammer radius _RL is smaller than the distance between the target 30 and the substrate 12. In consideration of this point, the distance between the substrate 12 and the target 30 is set to 125 mm, and the characteristics (magnetic) of the first magnetic body 52a and the second magnetic body 52b are set so that the rammer radius _RL is less than 125 mm. The strength) and the positions of the first magnetic body 52a and the second magnetic body 52b were set.

Specifically, in order to form a parallel magnetic field at a position facing the entire surface of the target 30, as shown in FIG. 1, a rod-shaped rod is formed near the side surface of the target 30 on the surface side and along the side of the target 30. The first magnetic body 52a and the second magnetic body 52b were arranged. As the first magnetic body 52a and the second magnetic body 52b, permanent magnets having a magnetic field strength near the surface thereof of about 1000 gauss were used. The distance between the first magnetic body 52a and the second magnetic body 52b was set to about 200 mm. At this time, a magnetic field strength of 7 gauss was obtained near the center, 4 gauss at a position 30 mm from the center to the target 30 and 4 gauss at a position 30 mm from the center to the substrate 12.

Under this condition, a thermolabel (registered trademark) was attached to the substrate 12 and the temperature of the substrate 12 was measured. The temperature of the substrate 12 (the temperature inside the vacuum vessel 2) before the start of film formation was about 25 ° C.

As a result, as shown in FIG. 5, it was confirmed that the temperature rise rate of the substrate 12 was about 2.8 ° C./sec in the sputtering apparatus 102 (graph of “no magnetic field” in FIG. 5) in which no magnetic field was formed. Was done. On the other hand, in the sputtering apparatus 1 in which the parallel magnetic field was formed (graph of “with magnetic field” in FIG. 5), it was confirmed that the temperature was about 0.52 ° C./sec.

As described above, according to the sputtering apparatus 1, it can be seen that the temperature rise of the substrate 12 can be suppressed by forming a parallel magnetic field at a position facing the entire surface of the target 30.

For example, as a substrate for a flexible display, a substrate having high heat resistance is generally used, but the higher the heat resistance, the higher the price of the substrate. That is, when a relatively cheap substrate is used in order to make the flexible display inexpensive, the heat resistance of the substrate is lowered. Therefore, it can be said that it is useful to suppress the temperature rise of the substrate by using the sputtering apparatus 1, especially when the film is formed on the substrate having low heat resistance.

<Modification example>
FIG. 6 is a schematic view showing a configuration example of the sputtering device 1A according to a modified example of the sputtering device 1. As shown in FIG. 6, in the sputtering device 1A, the arrangement positions of the first magnetic body 52a and the second magnetic body 52b are different from those in the sputtering device 1.

The sputtering apparatus 1A has a configuration in which a magnetic circuit 54 including a first magnetic body 52a and a second magnetic body 52b is provided as a magnetic body forming a parallel magnetic field. When the target holder 32 is viewed in a plan view, the magnetic circuit 54 forms a first magnetic pole MPa and a second magnetic pole MPb having different polarities at positions facing each other across the target 30. That is, if the first magnetic pole MPa and the second magnetic pole MPb are formed at the above positions, the arrangement positions of the first magnetic body 52a and the second magnetic body 52b are not limited to the above positions.

Specifically, as shown in FIG. 6, the magnetic circuit 54 is formed of a first magnetic body 52a, a first transmission member 53a, a second magnetic body 52b, and a second transmission member 53b. The first magnetic body 52a and the second magnetic body 52b are, for example, permanent magnets. The first transmission member 53a transmits the magnetic force from the first magnetic body 52a to the first magnetic pole MPa, and the second transmission member 53b transmits the magnetic force from the first magnetic pole MPa from the second magnetic pole MPb to the second magnetic pole MPb. It is transmitted to the body 52b.

Also with this configuration, a parallel magnetic field can be formed between the first magnetic pole MPa and the second magnetic pole MPb at a position facing the entire surface of the target 30.

[Embodiment 2]
Other embodiments of the present invention will be described below. For convenience of explanation, the same reference numerals will be added to the members having the same functions as the members described in the above embodiment, and the description will not be repeated.

FIG. 7 is a schematic view showing a configuration example of the sputtering apparatus 1B according to the present embodiment. As shown in FIG. 7, the sputtering apparatus 1B includes target holders 32a and 32b for one substrate holder 14. The target holders 32a and 32b have the same configuration and function as the target holder 32.

Two antennas 20 are arranged to face each of the target holders 32a and 32b. Specifically, the antenna 20 existing between the target holders 32a and 32b is shared with respect to the target holders 32a and 32b. Similarly, the upper surface portion 3 existing between the target holders 32a and 32b is also common to the target holders 32a and 32b. That is, the upper surface portion 3 supports both the target holders 32a and 32b. Further, the upper surface portion 3 is provided with a second magnetic body 52b for the target holder 32a and a first magnetic body 52a for the target holder 32b.

Further, in the sputtering apparatus 1B, the substrate holder 14 moves in a substantially horizontal direction (arrangement direction of the targets 30) with respect to the target holders 32a and 32b. This movement is executed by the control device 46 (see FIG. 2) controlling the drive mechanism (not shown) connected to the substrate holder 14. The control device 46 moves the substrate holder 14 in, for example, the direction in which the target holders 32a and 32b are lined up (in the direction of the arrow shown in FIG. 7).

In FIG. 7, the configuration in which the target holders 32a and 32b are arranged side by side has been described, but the present invention is not limited to this. Three or more target holders 32 may be arranged side by side so as to extend in one direction. Further, the plurality of target holders 32 may be arranged side by side so as to extend in two directions (that is, in a matrix). In this case, the drive mechanism is provided so that the substrate holder 14 can be moved in each of the two directions (that is, also in the depth direction of the paper surface).

As described above, the sputtering apparatus 1B has a configuration in which a plurality of combinations of the target holder 32 (that is, the target 30), the first magnetic body 52a and the second magnetic body 52b, and the antenna 20 are arranged. Therefore, the sputtering apparatus 1B can form a film on a relatively wide substrate 12.

Further, in the sputtering apparatus 1B, the substrate holder 14 is moved (swinged) in a substantially horizontal direction with respect to the target holder 32. Therefore, a more uniform and homogeneous film can be formed on the substrate 12.

[Additional notes]
The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Is also included in the technical scope of the present invention.

1, 1A, 1B Sputtering device 2 Vacuum container 10 Gas 12 Board 20 Antenna 22 Plasma 30 Target 32, 32a, 32b Target holder (holding part)
52a First magnetic material (magnetic material)
52b Second magnetic material (magnetic material)
54 Magnetic circuit (magnetic material)
MPa 1st magnetic pole (magnetic pole)
MPb second magnetic pole (magnetic pole)
_RL Ramer radius

Claims (8)

A sputtering device that sputters a target in a vacuum vessel into which a gas for sputtering is introduced to form a film on a substrate.
In the vacuum container
The holding part where the target is held and
Magnetic materials with different polarities and
An antenna that generates plasma by supplying electric power independently of the electric power supply to the target is provided.
A sputtering device in which the magnetic material forms a parallel magnetic field having a strength lower than the strength at which magnetron discharge occurs at a position facing the entire surface of the target held by the holding portion. The sputtering according to claim 1, wherein the magnetic material forms a magnetic field having a strength such that the rammer radius of electrons emitted from the target becomes smaller than the distance between the target and the substrate as the parallel magnetic field. apparatus. The sputtering apparatus according to claim 1 or 2, wherein the magnetic material forms the parallel magnetic field in the vicinity of the surface of the target. Any of claims 1 to 3, wherein the magnetic material forms magnetic poles having different polarities from each other at positions facing each other across the target when the holding portion is viewed in a plan view on the surface side of the target. The sputtering apparatus according to item 1. The sputtering apparatus according to claim 4, wherein the magnetic material is a permanent magnet arranged at the position. The sputtering apparatus according to claim 4, wherein the magnetic material is a magnetic circuit that forms the magnetic pole at the position. The sputtering apparatus according to any one of claims 1 to 6, wherein the magnetic material is grounded. The sputtering apparatus according to any one of claims 1 to 7, wherein the antenna is arranged outside the magnetic material when the holding portion is viewed in a plan view.

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