JP6644617B2 - Magnetron sputter deposition system - Google Patents

Description

  The present invention relates to a magnetron sputtering film forming apparatus capable of forming a smooth thin film.

  Examples of a film forming method by sputtering include a bipolar sputtering method and a magnetron sputtering method. For example, in a bipolar sputtering method using a high frequency (RF), there are problems that a film formation rate is low and a temperature of a base material is easily increased by irradiation of secondary electrons that jump out of a target. Due to the low deposition rate, the RF bipolar sputtering method is not suitable for mass production. On the other hand, according to the magnetron sputtering method, secondary electrons jumping out of the target are captured by the magnetic field generated on the target surface. Therefore, the temperature of the base material does not easily rise. Further, ionization of gas is promoted by the captured secondary electrons, so that the film formation speed can be increased.

JP 2013-108115 A JP-A-10-265952

  Among the magnetron sputtering methods, a magnetron sputtering method using a DC (direct current) power supply (including a pulse DC power supply) is frequently used because the film formation speed is high. However, in the case of DC magnetron sputtering, unless a certain high voltage is applied to the magnetron cathode, problems occur in plasma generation and stable discharge. For this reason, a high voltage of several hundred volts is normally applied to the magnetron cathode. When the applied voltage is high, ions generated by the magnetron discharge are further accelerated and collide with the target. As a result, particles having a large particle diameter such as cluster particles may fly out of the target. When particles having a large particle diameter adhere to the substrate, irregularities are generated on the surface of the formed film. When the unevenness of the surface of the film is large, oxygen and the like are easily adsorbed to the concave portion, and the film itself and a partner material in contact with the film may be deteriorated. Moreover, there is a possibility that the mating material is deteriorated by the convex portions.

  In this regard, Patent Document 1 describes a magnetron sputtering film forming apparatus including an ECR plasma generation apparatus that generates plasma by electron cyclotron resonance (ECR) using microwaves. According to the film forming apparatus, a film is formed by sputtering a target with magnetron plasma while generating ECR plasma between a substrate and a target. By generating ECR plasma, the voltage applied to the cathode can be reduced. This suppresses projection of particles having a large particle diameter from the target and reduces irregularities on the surface of the thin film to be formed. However, even with the use of the film forming apparatus, the effect of reducing the unevenness on the surface of the thin film is not sufficient. Patent Document 2 discloses a method of performing sputtering by applying a voltage obtained by superimposing a VHF high-frequency voltage of 80 to 120 MHz on a DC voltage to a target. In the method described in Patent Document 2, the VHF high-frequency voltage is continuously superimposed on the DC voltage at a constant voltage. Also in this method, the effect of reducing the unevenness on the surface of the thin film is not sufficient, and further smoothing of the thin film is required.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a magnetron sputtering film forming apparatus capable of forming a thin film having small surface irregularities.

  In order to solve the above problems, the magnetron sputtering film forming apparatus of the present invention includes a base material, a target disposed to face the base material, and a magnetic field forming means for forming a magnetic field on the surface of the target, , A pulse DC power supply, a VHF power supply, and a control device for controlling a VHF voltage supplied by the VHF power supply, wherein the VHF voltage is cycled to a pulse DC voltage supplied from the pulse DC power supply. And a VHF superposition mechanism that superimposes the voltage to apply a voltage to the magnetron cathode, and sputters the target with plasma generated by magnetron discharge, and sputters out the sputtered particles on the surface of the base material. The thin film is formed by attaching the thin film.

  When only the pulse DC power supply is used, an overshoot voltage fluctuation occurs in which the voltage protrudes and increases at the beginning of discharge. This overshoot voltage contributes to the generation of particles having a large particle diameter from the target. In this regard, in the magnetron sputtering film forming apparatus of the present invention, a voltage is applied to the magnetron cathode by the VHF superposition mechanism. The VHF superimposing mechanism superimposes the VHF voltage on the pulse DC voltage by periodically changing the voltage. For example, when the VHF voltage is superimposed at the start of the supply of the pulse DC voltage (between the start of the supply and about 10 μs), the fluctuation of the overshoot voltage can be reduced. Thereby, the acceleration of the ions generated by the magnetron discharge is suppressed, and the particles with a large particle diameter can be suppressed from jumping out of the target. As described above, according to the magnetron sputtering film forming apparatus of the present invention, the VHF voltage is periodically changed and superimposed on the pulse DC voltage, and by controlling the voltage applied to the magnetron cathode, the surface unevenness is reduced. A smooth thin film can be formed.

  “To superimpose the VHF voltage by periodically changing the voltage” means to superimpose the VHF voltage by periodically repeating the raising and lowering of the VHF voltage. Specifically, a mode in which the voltage is raised from 0 to a predetermined value and then returned to 0, that is, a mode in which supply and stop of the voltage are repeated, or a cycle in which the voltage is raised from the base voltage to a higher voltage and then returned to the base voltage is repeated , And the like. The former is a mode in which the VHF voltage is intermittently supplied, and the latter is a mode in which the constantly supplied VHF voltage is intermittently increased.

FIG. 2 is a left-right cross-sectional view of the magnetron sputtering film forming apparatus of the first embodiment. It is front-back direction sectional drawing of the same magnetron sputter film-forming apparatus. It is a schematic diagram of the voltage waveform supplied to the magnetron cathode. It is a horizontal direction sectional view of a magnetron sputter film-forming device of a second embodiment. It is sectional drawing which looked at the magnetron sputter film-forming apparatus from the upper part. It is a front view of the microwave plasma generation apparatus in the same magnetron sputter film-forming apparatus. FIG. 7 is a sectional view taken along line VII-VII of FIG. 6. FIG. 3 is a schematic diagram of a voltage waveform supplied to a magnetron cathode in manufacturing a sputtered film of Example 1. FIG. 9 is a schematic diagram of a voltage waveform supplied to a magnetron cathode in manufacturing a sputtered film of Example 2. FIG. 9 is a schematic diagram of a voltage waveform supplied to a magnetron cathode in manufacturing a sputtered film of Example 3. FIG. 9 is a schematic diagram of a voltage waveform supplied to a magnetron cathode in manufacturing a sputtered film of Comparative Example 2. 14 is an SPM photograph of the surface of the ITO film of Example 4. 14 is an SPM photograph of the surface of the ITO film of Example 5. 4 is an SPM photograph of the surface of an ITO film of Comparative Example 1. 9 is an SPM photograph of the surface of an ITO film of Comparative Example 2.

  Hereinafter, embodiments of the magnetron sputtering film forming apparatus of the present invention will be described.

<First embodiment>
[Magnetron sputter deposition system]
First, the configuration of the magnetron sputtering film forming apparatus of the present embodiment will be described. FIG. 1 is a cross-sectional view in the left-right direction of the magnetron sputtering film forming apparatus of the present embodiment. FIG. 2 shows a sectional view in the front-rear direction of the magnetron sputtering film forming apparatus.

  As shown in FIGS. 1 and 2, the magnetron sputtering film forming apparatus 1 includes a vacuum vessel 8, a substrate 10, a substrate support member 11, a magnetron cathode 12, and a VHF superimposing mechanism 2. .

  The vacuum container 8 is made of aluminum steel and has a rectangular parallelepiped box shape. A gas supply hole 80 is formed in the left wall of the vacuum vessel 8. The gas supply hole 80 is connected to a downstream end of a gas supply pipe (not shown) for supplying a gas such as argon (Ar) into the vacuum vessel 8. An exhaust hole 81 is formed in the lower wall of the vacuum container 8. A vacuum exhaust device (not shown) for exhausting gas inside the vacuum vessel 8 is connected to the exhaust hole 81.

  The base member 11 has a table 110 and a pair of legs 111. The table 110 is made of stainless steel and has a hollow rectangular plate shape. The inside of the table 110 is filled with a cooling liquid. The table 110 is cooled by the circulation of the cooling liquid. The pair of legs 111 are arranged on the upper surface of the table 110 so as to be separated in the left-right direction. Each of the pair of legs 111 is made of stainless steel and has a columnar shape. The outer peripheral surfaces of the pair of legs 111 are covered with an insulating layer. The table 110 is attached to the upper wall of the vacuum vessel 8 via a pair of legs 111.

  The base material 10 is a polyethylene terephthalate (PET) film, and has a rectangular shape. The base material 10 is attached to the lower surface of the table 110.

  The magnetron cathode 12 has a target 13, a backing plate 14, permanent magnets 15a to 15c, and a cathode body 16. The cathode main body 16 is made of stainless steel, and has a rectangular parallelepiped box shape that opens upward. An earth shield 17 is arranged around the cathode body 16, the target 13, and the backing plate 14. The cathode main body 16 is arranged on the lower surface of the vacuum vessel 8 via an earth shield 17. The cathode main body 16 is connected to the VHF superposition mechanism 2.

  The permanent magnets 15a to 15c are arranged inside the cathode main body 16. Each of the permanent magnets 15a to 15c has an elongated rectangular parallelepiped shape. The permanent magnets 15a to 15c are spaced apart in the front-rear direction and arranged to be parallel to each other. As for the permanent magnets 15a and 15c, the upper side is the N pole and the lower side is the S pole. As for the permanent magnet 15b, the upper side is the south pole and the lower side is the north pole. A magnetic field is formed on the surface of the target 13 by the permanent magnets 15a to 15c. The permanent magnets 15a to 15c are included in the magnetic field forming means in the present invention.

  The backing plate 14 is made of copper and has a rectangular plate shape. The backing plate 14 is arranged so as to cover the upper opening of the cathode body 16.

  The target 13 is a composite oxide of indium oxide-tin oxide (ITO) and has a rectangular thin plate shape. The target 13 is arranged on an upper surface of the backing plate 14. The target 13 is arranged to face the substrate 10.

  The VHF superposition mechanism 2 includes a pulse DC power supply 20, a VHF power supply 21, a delay pulse generator 22, an arbitrary waveform generator 23, a VHF cut filter 24, and a matching unit 25. The delay pulse generator 22 is connected to the pulse DC power supply 20 and determines when to supply the VHF voltage based on the output signal of the pulse DC power supply 20. The arbitrary waveform generator 23 is connected between the delay pulse generator 22 and the VHF power supply 21 and determines the waveform of the VHF voltage to be supplied (shape, frequency, width, etc. of the VHF wave). The VHF power supply 21 is connected to the matching unit 25. The pulse DC power supply 20 is connected to a matching unit 25 via a VHF cut filter 24. Matching device 25 is connected to cathode body 16. The delay pulse generator 22 and the arbitrary waveform generator 23 are included in the control device according to the present invention.

[Method of manufacturing sputtered film]
Next, a method for manufacturing a sputtered film using the magnetron sputtering film forming apparatus 1 will be described. In the method for manufacturing a sputtered film according to the present embodiment, first, the vacuum exhaust device (not shown) is operated to exhaust the gas inside the vacuum container 8 from the exhaust hole 81, and the inside of the vacuum container 8 is evacuated. I do. Next, argon gas and a trace amount of oxygen gas are supplied into the vacuum vessel 8 from the gas supply pipe, and the pressure in the vacuum vessel 8 is set to 0.4 Pa. Next, the VHF superimposing mechanism 2 is operated to superimpose the VHF voltage on the pulse DC voltage and apply the voltage to the cathode main body 16. Then, a magnetron discharge occurs on the upper surface of the target 13. Thereby, the argon gas is ionized, and the magnetron plasma P1 is generated above the target 13. The target 13 is sputtered by the magnetron plasma P1 (argon ions), and sputter particles are beaten from the target 13. The sputtered particles jumping out of the target 13 scatter toward the substrate 10 and adhere to the lower surface of the substrate 10. Thus, the ITO film is formed on the lower surface of the base material 10.

  The superimposition of the VHF voltage on the pulse DC voltage was performed in an on / off pattern in which supply and stop of the VHF voltage were periodically repeated. FIG. 3 shows a schematic diagram of a voltage waveform supplied to the magnetron cathode. As shown in FIG. 3, the pulse DC voltage and the VHF voltage are both supplied as rectangular waves that are repeated every predetermined time. The period of the VHF wave is different from the period of the pulse DC wave. First, when the VHF voltage is supplied at the start of the supply of the pulse DC voltage, the operation is immediately stopped once. Thereafter, a cycle of supplying the VHF voltage for a predetermined time and stopping the operation is repeated. The timing for supplying the VHF voltage includes both when the pulse DC voltage is not supplied and when the supply of the next pulse DC voltage is started. In other words, the stop time of the VHF voltage is provided in the middle of the time during which the pulse DC voltage is supplied. When the pulse DC voltage is being supplied, both the supply and the stop of the VHF voltage are performed.

[Effects]
Next, the operation and effect of the magnetron sputtering film forming apparatus of the present embodiment will be described. In the magnetron sputtering film forming apparatus 1 of the present embodiment, a voltage is applied to the magnetron cathode 12 by the VHF superposition mechanism 2. The VHF superposition mechanism 2 includes a delay pulse generator 22 that determines a timing for supplying the VHF voltage, and an arbitrary waveform generator 23 that determines a waveform of the VHF voltage. Accordingly, the VHF superimposing mechanism 2 periodically repeats the supply and stop of the VHF voltage, and superimposes the VHF voltage at least at the start of the supply of the pulse DC voltage and at the time when the pulse DC voltage is not supplied. That is, in the method for manufacturing a sputtered film of the present embodiment, a voltage obtained by intermittently superimposing the VHF voltage on the pulse DC voltage is applied to the magnetron cathode 12. When the VHF voltage is superimposed at the start of the supply of the pulse DC voltage, the fluctuation of the overshoot voltage is reduced. Thereby, the acceleration of the ions generated by the magnetron discharge is suppressed, and the particles with a large particle diameter can be suppressed from jumping out of the target. Therefore, according to the magnetron sputtering film forming apparatus 1 of the present embodiment, it is possible to form a smooth ITO film having few surface irregularities.

<Second embodiment>
[Magnetron sputter deposition system]
The difference between the magnetron sputter film forming apparatus of the present embodiment and the magnetron sputter film forming apparatus of the first embodiment is that a microwave plasma generating apparatus for generating microwave plasma between a substrate and a target is used. It is a point to prepare. Therefore, the following description focuses on the differences.

  First, the configuration of the microwave plasma generation device in the magnetron sputtering film forming apparatus of the present embodiment will be described. FIG. 4 is a cross-sectional view in the left-right direction of the magnetron sputtering film forming apparatus of the present embodiment. FIG. 5 shows a sectional view of the magnetron sputtering film forming apparatus as viewed from above. FIG. 6 shows a front view of a microwave plasma generator in the magnetron sputtering film forming apparatus. FIG. 7 is a sectional view taken along line VII-VII of FIG. 4, members corresponding to those in FIG. 1 are denoted by the same reference numerals.

  As shown in FIG. 4, the magnetron sputtering film forming apparatus 1 includes a vacuum vessel 8, a substrate 10, a substrate supporting member 11, a magnetron cathode 12, a VHF superposition mechanism 2, a microwave plasma generation device 3, , Is provided.

  As shown in FIGS. 5 to 7, the microwave plasma generation device 3 includes an upstream first waveguide 30U, a downstream first waveguide 30D, a plasma generation unit 31, and an upstream third waveguide. It has a tube 32U and a downstream third waveguide 32D.

  The upstream first waveguide 30U is made of aluminum and has a tubular shape with a rectangular cross section. The upstream first waveguide 30U has an L-shape when viewed from above. The upstream end of the upstream first waveguide 30U is connected to a microwave transmission unit (not shown). The microwave transmission unit includes a microwave power supply, a microwave oscillator, an isolator, a power monitor, and an EH matching device. The downstream end of the upstream first waveguide 30U is connected to the upstream third waveguide 32U.

  The downstream first waveguide 30D is made of aluminum and has a tubular shape with a rectangular cross section. When viewed from above, the downstream first waveguide 30D has an L-shape (inverted L-shape) symmetric with the upstream first waveguide 30U with the plasma generation unit 31 interposed therebetween. The upstream end of the downstream first waveguide 30D is connected to the downstream third waveguide 32D. A plunger 33 is arranged downstream of the downstream first waveguide 30D. The plunger 33 is movable in the front-rear direction, and the front surface of the plunger 33 forms the end of the downstream first waveguide 30D.

  Two waveguide insertion holes 83U and 83D are formed in the partition wall 82 on the rear side of the vacuum container 8. The upstream first waveguide 30U is inserted into the waveguide insertion hole 83U. The downstream first waveguide 30D is inserted into the waveguide insertion hole 83D.

  The plasma generator 31 has a main body 34 and a pair of magnets 35a and 35b. The main body 34 has a housing 40, a second waveguide 41, and three cooling plates 42. The housing 40 is made of Ni-plated iron and has a rectangular parallelepiped shape. The housing 40 has a concave portion 400. The concave portion 400 has a C-shaped cross section and extends in the left-right direction. Each of the three cooling plates 42 is made of stainless steel, and extends in the left-right direction. The three cooling plates 42 are arranged one at a time on the upper, lower, and rear sides of the recess 400.

  The second waveguide 41 is arranged in the concave portion 400 and extends linearly in the left-right direction. The second waveguide 41 has a tube wall 43, a slot antenna 44, and a second dielectric 45. The tube wall 43 is made of Ni-plated iron. The slot antenna 44 is made of iron and has a rectangular plate shape. The slot antenna 44 is disposed on the H plane of the second waveguide 41. The slot antenna 44 forms the front wall of the second waveguide 41. The slot antenna 44 has a plurality of slots 440 penetrating in the front-rear direction. Each of the plurality of slots 440 has a long hole shape extending in the left-right direction, and is arranged in upper and lower two rows. The slot 440 is arranged corresponding to the position of the antinode of the standing wave of the microwave. The tube wall 43 and the slot antenna 44 form a space having a rectangular cross section. The second dielectric 45 is filled in the space. The second dielectric 45 is made of alumina and has a rectangular parallelepiped shape. The second dielectric 45 covers the slot 440 from behind.

  The pair of magnet portions 35 a and 35 b are arranged one above the other on the front surface of the main body 34 so as to sandwich the slot antenna 44. The upper magnet portion 35a extends linearly in the left-right direction. The magnet section 35a has a permanent magnet 50a and two cooling pipes 51a and 52a. The permanent magnet 50a is composed of ten permanent magnets connected linearly in the left-right direction. Each of the ten permanent magnets is a samarium-cobalt magnet, and has a rectangular parallelepiped shape. The lower side of the ten permanent magnets is the north pole, and the upper side is the south pole. The NS direction of the permanent magnet 50a is parallel to the front surface of the slot antenna 44. The lower surface of the permanent magnet 50a is covered with a cover member 53a made of aluminum. The cooling pipes 51a and 52a are arranged so as to sandwich the permanent magnet 50a in the front-rear direction. A cooling liquid flows in the cooling pipes 51a and 52a. The configuration of the lower magnet portion 35b is the same as the configuration of the magnet portion 35a. That is, the magnet portion 35b extends linearly in the left-right direction, and has the permanent magnet 50b and the two cooling pipes 51b and 52b. The permanent magnet 50b is composed of ten permanent magnets connected linearly. The upper side of the ten permanent magnets is the north pole, and the lower side is the south pole. The NS direction of the permanent magnet 50b is parallel to the front surface of the slot antenna 44. The upper surface of the permanent magnet 50b is covered with a cover member 53b made of aluminum. The cooling pipes 51b and 52b are arranged so as to sandwich the permanent magnet 50b in the front-rear direction. A cooling liquid flows in the cooling pipes 51a and 52b.

  A magnetic field is formed by the permanent magnets 50a and 50b on the front surface (the surface on the plasma generation side) of the slot antenna 44. At the position of the slot 440, the magnetic flux density at a point 10 mm forward from the front surface of the slot antenna 44 is 87.5 mT.

  The upstream third waveguide 32U is made of aluminum and has a short tubular shape with a rectangular cross section. The upstream third waveguide 32U is disposed between the upstream first waveguide 30U and the plasma generation unit 31. The upstream end of the upstream third waveguide 32U is connected to the downstream end of the upstream first waveguide 30U. The downstream end of the upstream third waveguide 32U is connected to the upstream end of the second waveguide 41. The inside of the upstream third waveguide 32U is filled with a third dielectric 36. The third dielectric 36 is made of quartz and has a rectangular parallelepiped shape. The right end of the third dielectric 36 is in contact with the second dielectric 45. The refractive index of the third dielectric 36 (quartz) is an intermediate value between the refractive index of the inside (air) of the upstream first waveguide 30U and the refractive index of the second dielectric 45 (alumina).

  The downstream third waveguide 32D is made of aluminum, and has a short tubular shape with a rectangular cross section. The downstream third waveguide 32D is disposed between the downstream first waveguide 30D and the plasma generation unit 31. The upstream end of the downstream third waveguide 32D is connected to the downstream end of the second waveguide 41. The downstream end of the downstream third waveguide 32D is connected to the upstream end of the downstream first waveguide 30D. The configuration of the downstream third waveguide 32D is the same as the configuration of the upstream third waveguide 32U. That is, the inside of the downstream third waveguide 32D is filled with the third dielectric 36. The left end of the third dielectric 36 is in contact with the second dielectric 45. As shown in FIGS. 5 and 6, the inside of the tube in the section V from the upstream third waveguide 32U to the downstream third waveguide 32D is evacuated. Seal members (not shown) are arranged at the upstream end of the upstream third waveguide 32U and the downstream end of the downstream third waveguide 32D.

[Method of manufacturing sputtered film]
Next, a method for manufacturing a sputtered film using the magnetron sputtering film forming apparatus 1 will be described. In the method for manufacturing a sputtered film according to the present embodiment, first, the vacuum exhaust device (not shown) is operated to exhaust the gas inside the vacuum container 8 from the exhaust hole 81, and the inside of the vacuum container 8 is evacuated. I do. Next, argon gas and a trace amount of oxygen gas are supplied into the vacuum vessel 8 from the gas supply pipe, and the pressure in the vacuum vessel 8 is set to 0.4 Pa.

  Subsequently, the microwave power supply of the microwave transmission unit is turned on, and a microwave having a frequency of 2.45 GHz is oscillated from the microwave oscillator. The oscillated microwave propagates in the upstream third waveguide 32U through the upstream first waveguide 30U as shown by a white arrow in FIG. The inside of the upstream third waveguide 32U is filled with a third dielectric 36 made of quartz. Therefore, the wavelength of the microwave is converted and shortened in the upstream third waveguide 32U. Subsequently, the microwave propagates in the second waveguide 41 of the plasma generation unit 31. The second waveguide 41 is filled with a second dielectric 45 made of alumina. For this reason, the wavelength of the microwave is further shortened in the second waveguide 41. The microwave passing through the second waveguide 41 propagates through the downstream third waveguide 32D to the downstream first waveguide 30D.

  In the second waveguide 41, the microwave passes through the slot 440 of the slot antenna 44 and propagates on the front surface of the slot antenna 44. Due to the strong electric field of the microwave, the gas in the vacuum vessel 8 is ionized, and microwave plasma is generated in front of the slot antenna 44. The electrons in the generated microwave plasma make a clockwise rotation with respect to the direction of the line of magnetic force according to the cyclotron angular frequency. On the other hand, the microwave propagating in the microwave plasma excites the electron cyclotron wave. The angular frequency of the electron cyclotron wave matches the cyclotron angular frequency with a magnetic flux density of 87.5 mT. This results in ECR. Electrons whose energy has been increased by the ECR collide with surrounding neutral particles while being constrained by the lines of magnetic force. Thereby, neutral particles are ionized one after another. Electrons generated by ionization are also accelerated by ECR, and further ionize neutral particles. Thus, the ECR plasma P2 is generated in front of the slot antenna 44.

  Next, the VHF superimposing mechanism 2 is operated to superimpose the VHF voltage on the pulse DC voltage and apply the voltage to the cathode main body 16. Then, a magnetron discharge occurs on the upper surface of the target 13. Thereby, the argon gas is ionized, and the magnetron plasma P1 is generated above the target 13. The target 13 is sputtered by the magnetron plasma P1 (argon ions), and sputter particles are beaten from the target 13. The sputtered particles jumping out of the target 13 scatter toward the substrate 10 and adhere to the lower surface of the substrate 10. Here, the ECR plasma P2 is generated between the base material 10 and the target 13 (including the magnetron plasma P1 generation region). Accordingly, the sputtered particles are irradiated with the ECR plasma P2. Thus, the ITO film is formed on the lower surface of the base material 10. The VHF voltage was superimposed on the pulse DC voltage in the same on / off pattern as in the first embodiment (see FIG. 3 described above).

[Effects]
Next, the operation and effect of the magnetron sputtering film forming apparatus of the present embodiment will be described. The magnetron sputter film forming apparatus of the present embodiment and the magnetron sputter film forming apparatus of the first embodiment have the same function and effect with respect to portions having a common configuration. Further, according to the magnetron sputtering film forming apparatus 1 of the present embodiment, by generating the ECR plasma P2 between the base material 10 and the target 13, even if the voltage applied to the magnetron cathode 12 is reduced, the magnetron plasma P1 is generated. Can be maintained stably. This makes it possible to further prevent particles having a large particle diameter, such as cluster particles, from jumping out of the target 13. As a result, the variation in the particle diameter of the sputtered particles is suppressed, and the unevenness on the surface of the formed thin film can be further reduced. Further, when the ECR plasma P2 is irradiated, sputter particles are miniaturized. For this reason, a finer thin film can be formed.

  In the microwave plasma generation device 3, a second dielectric 45 is disposed inside the second waveguide 41. Thereby, the wavelength of the microwave propagating in the second waveguide 41 becomes shorter than the wavelength when propagating in the upstream first waveguide 30U. Thereby, since a large number of slots 440 can be formed in the slot antenna 44, the electric field intensity on the entire front surface of the slot antenna 44 increases. An upstream third waveguide 32U is interposed between the upstream first waveguide 30U and the second waveguide 41. The refractive index of the third dielectric 36 in the upstream third waveguide 32U is smaller than the refractive index of the second dielectric 45. Therefore, the microwave transmitted from the upstream first waveguide 30U is transmitted to the second waveguide 41 after the wavelength is once converted in the upstream third waveguide 32U. By performing the wavelength conversion in two stages, compared with the case where microwaves are directly transmitted from the upstream first waveguide 30U to the second waveguide 41, the wavelength at the time of incidence on the second waveguide 41 is reduced. Microwave reflection can be suppressed. Thereby, it is possible to suppress a decrease in microwave energy.

  As described above, in the microwave plasma generating apparatus 3, since the electric field intensity on the front surface of the slot antenna 44 is large, it is possible to radiate a substantially uniform microwave in the longitudinal direction by the elongated second waveguide 41. it can. Further, the cross-sectional area of the second waveguide 41 in the lateral direction can be reduced, so that the second waveguide 41 can be downsized. That is, the size of the plasma generation unit 31 can be reduced. Thereby, interference with the base material 10 and the magnetron cathode 12 is suppressed.

  The plasma generation unit 31 has a pair of permanent magnets 50a and 50b arranged with the slot antenna 44 interposed therebetween. Thereby, a magnetic field is formed on the front surface of the slot antenna 44, and the ECR plasma P2 can be generated. For this reason, according to the microwave plasma generation device 3, stable ECR plasma P2 can be generated even under a low pressure of 1 Pa or less, and even under an extremely low pressure of 0.5 Pa or less. In addition, it is not necessary to generate the plasma at about several tens to 100 Pa in advance, and the ECR plasma P2 can be generated in a state where the pressure in the vacuum vessel 8 is set to the sputtering. Therefore, according to the microwave plasma generating apparatus 3, high-purity processing can be performed by lowering the pressure in the vacuum vessel 8.

  The tube wall 43 of the second waveguide 41 is made of Ni-plated iron, and the slot antenna 44 is made of iron. That is, the tube wall 43 and the slot antenna 44 are both formed of a magnetic material. Therefore, as shown by a dotted arrow in FIG. 7, a magnetic circuit is formed by the permanent magnet 50a-slot antenna 44-tube wall 43, and permanent magnet 50b-slot antenna 44-tube wall 43. Accordingly, it is possible to suppress the magnetic field lines from entering the inside of the second waveguide 41 and to increase the magnetic field on the front surface of the slot antenna 44. Further, the pair of permanent magnets 50a and 50b are arranged so that the N poles face each other, and the NS direction is arranged in the vertical direction, in other words, in parallel with the plane direction of the slot antenna 44. Thereby, the magnetic field on the front surface of the slot antenna 44 can be increased while reducing the influence of the magnetic field on the inside of the second waveguide 41. In addition, the tube wall 43 has a high surface conductivity and a magnetic circuit is easily formed, and is excellent in anticorrosion.

  Cooling pipes 51a and 52a are arranged on both sides in the thickness direction of the permanent magnet 50a. Cooling pipes 51b and 52b are arranged on both sides in the thickness direction of the permanent magnet 50b. Thereby, the temperature rise of the permanent magnets 50a and 50b is suppressed, and the decrease in magnetism can be suppressed. A cooling plate 42 is also arranged around the second waveguide 41. Thereby, the temperature rise inside the second waveguide 41 is suppressed.

  In the permanent magnet 50a, the rear surface near the slot antenna 44 is in contact with the cooling pipe 51a, and the lower surface is covered with a cover member 53a. In the permanent magnet 50b, the rear surface near the slot antenna 44 is in contact with the cooling pipe 51b, and the upper surface is covered with a cover member 53b. Thus, the permanent magnets 50a and 50b are protected against the generated ECR plasma P2.

  In the microwave plasma generation device 3, waveguides (downstream third waveguide 32D and downstream first waveguide 30D) are also connected to the downstream side of the second waveguide 41. The first downstream waveguide 30D has a plunger 33 for adjusting the end position. The electric field intensity at the position of the slot 440 can be adjusted by moving the plunger 33 in the front-rear direction and adjusting the length of the downstream first waveguide 30D. This makes it easier for the microwave to propagate from the slot 440, and can generate stable plasma. The inside of the tube in the section V from the upstream third waveguide 32U to the downstream third waveguide 32D is vacuum. Thereby, between the members constituting the second waveguide 41 (eg, between the slot antenna 44 and the second dielectric 45, between the slot antenna 44 and the tube wall 43), and between the second waveguide 41 and the second waveguide 41. It is not necessary to perform a vacuum seal between the upstream third waveguide 32U and the downstream third waveguide 32D, and it is not necessary to take measures against heat of the vacuum seal.

  The upstream first waveguide 30U and the downstream first waveguide 30D are arranged in a symmetrical L-shape with the second waveguide 41 therebetween when viewed from above. Therefore, the microwave first plasma generation device 3 can be attached to the vacuum vessel 8 by passing the upstream first waveguide 30U and the downstream first waveguide 30D through the partition wall 82 of the vacuum vessel 8. Thereby, as compared with a configuration in which the upstream first waveguide 30U, the plasma generation unit 31, and the downstream first waveguide 30D are linearly arranged, mounting becomes easier and space can be saved. it can. Also, the upstream first waveguide 30U, the upstream third waveguide 32U, the plasma generation unit 31, the downstream third waveguide 32D, the downstream first waveguide 30D, and the partition 82 are unitized. By doing so, it is easy to incorporate the device into the magnetron sputtering film forming apparatus 1.

<Other forms>
The embodiment of the magnetron sputtering film forming apparatus of the present invention has been described above. However, embodiments are not limited to the above embodiments. Various modifications and improvements that can be performed by those skilled in the art are also possible.

  In the above embodiment, the VHF voltage is superimposed on the pulse DC voltage in an on / off pattern in which supply and stop of the VHF voltage are periodically repeated. However, the manner of superimposing the VHF voltage is not particularly limited as long as the VHF voltage changes periodically.

  As the on / off pattern, there is a mode in which at least one of the supply and the stop of the VHF voltage is performed when the pulse DC voltage is supplied. For example, in addition to a mode in which the VHF voltage is stopped during the time when the pulse DC voltage is supplied as in the above embodiment, a mode in which the VHF voltage is supplied only at the start of the pulse DC voltage supply, and a mode in which the pulse DC voltage is supplied In which the VHF voltage is supplied only when the pulse DC voltage is not supplied (when the pulse DC voltage is stopped), in which the VHF voltage is supplied only when both the supply of the pulse DC voltage is started and when the pulse DC voltage is not supplied, and in which the pulse DC voltage is supplied In which the VHF voltage is supplied only immediately before the stop. Here, the start of the supply of the pulse DC voltage means a period of about 10 μs from the start of the supply. When the pulse DC voltage is stopped by turning off the pulse DC power supply, a slight time lag occurs until the pulse DC voltage actually becomes 0V. The time immediately before the stop of the pulse DC voltage means a time corresponding to the time lag. Specifically, the time immediately before the stop of the pulse DC voltage is about 1 μs before the pulse DC voltage completely becomes 0V.

  Further, an offset pattern in which the voltage is intermittently increased while the VHF voltage is constantly supplied may be used. In the case of an offset pattern, it is desirable to increase the voltage when no pulse DC voltage is supplied. Some of the superimposed patterns of the VHF voltages will be described in later examples. Further, the waveform of the VHF voltage is not particularly limited, such as a sine wave and a rectangular wave. The VHF frequency band to be used is not particularly limited. For example, a frequency band of 30 MHz to 50 MHz may be used.

  The configuration of the VHF superposition mechanism is not limited to the above embodiment. As a control device for controlling the VHF voltage supplied from the VHF power supply, other devices may be used instead of or in addition to the delay pulse generator and the arbitrary waveform generator.

  The material and shape of the magnetron cathode backing plate and cathode body are not particularly limited. For example, a nonmagnetic conductive material may be used for the backing plate. Above all, a metal material such as copper having high conductivity and high heat conductivity is desirable. For the cathode body, a metal such as aluminum can be used in addition to stainless steel. Further, the configuration of the magnetic field forming means for forming a magnetic field on the surface of the target is not limited to the above embodiment. When a permanent magnet is used as the magnetic field forming means, the type and arrangement of the permanent magnet may be determined as appropriate. For example, the N pole and the S pole of each permanent magnet may be reversed from the above embodiment. The material and shape of the vacuum vessel are not particularly limited. For example, the vacuum container may be formed of a metal material. From the viewpoints of workability such as welding and cutting, corrosion resistance, and economic efficiency, the aluminum steel, stainless steel, aluminum, and the like in the above embodiment are desirable.

  In the above embodiment, ITO was used as the target. However, the material of the target is not particularly limited, and may be appropriately determined according to the type of the thin film to be formed. Similarly, the substrate on which the thin film is formed may be appropriately selected depending on the application.

In the above embodiment, the film was formed under a pressure of 0.4 Pa. However, the pressure for the film formation process is not limited to the pressure. The film formation process may be performed under an optimal pressure as appropriate. A suitable pressure is 0.1 Pa or more and 4 Pa or less. By setting a high vacuum state of 4 Pa or less, contamination of impurities can be suppressed, and the purity of treatment can be increased. Further, the microwave plasma generator of the second embodiment can generate ECR plasma under a low pressure of 0.05 Pa or more and 20 Pa or less. The gas to be supplied into the vacuum container may be appropriately determined according to the processing. For example, rare gases such as argon (Ar), helium (He), neon (Ne), krypton (Kr), and xenon (Xe), nitrogen (N ₂ ), oxygen (O ₂ ), hydrogen (H ₂ ), and the like can be used. No. The gas to be supplied may be one kind or two or more kinds.

  As in the first embodiment, the magnetron sputtering film forming apparatus does not need to include the microwave plasma generation apparatus for generating microwave plasma between the base material and the target. When the microwave plasma generation device is provided, its configuration is not particularly limited. In addition to the microwave plasma generation device used in the second embodiment, a rectangular waveguide for transmitting microwaves, a slot antenna having a slot disposed on one surface of the rectangular waveguide and through which microwaves pass, (For example, see Japanese Patent Application Laid-Open No. 2012-234643), further comprising a permanent magnet for forming a magnetic field on the surface of the dielectric portion. For example, an arranged device (for example, see Japanese Patent Application Laid-Open No. 2013-108115) can be used.

  In the microwave plasma generation device used in the second embodiment, the sizes of the first waveguide, the plasma generation unit, and the third waveguide are not particularly limited. In the second embodiment, the downstream third waveguide and the downstream first waveguide are also arranged on the downstream side of the second waveguide. However, a waveguide downstream of the second waveguide is not necessary. For example, the microwave plasma generation device may be configured by an upstream first waveguide, an upstream third waveguide, and a plasma generation unit. In this case, the end of the second waveguide may be a metal wall. In the second embodiment, the upstream first waveguide and the downstream first waveguide are arranged in an L shape when viewed from above. However, the arrangement of the upstream first waveguide and the downstream first waveguide is not particularly limited. For example, at least one of the upstream first waveguide and the downstream first waveguide and the plasma generation unit may be linearly arranged. Further, at least one of the upstream first waveguide and the downstream first waveguide may be arranged to be inclined. In this case, the inclination angle is not particularly limited. When the downstream first waveguide is arranged, the downstream first waveguide may not have a termination adjusting member such as a plunger. That is, the end of the downstream first waveguide may be a fixed end.

  In the second embodiment, as the material of the second waveguide (tube wall), Ni-plated iron is used. However, the material of the second waveguide may be a magnetic material, and the type thereof is not particularly limited. As the magnetic material, for example, iron, nickel, stainless steel, and alloys using these are suitable. In the second embodiment, an iron slot antenna is employed. However, the material of the slot antenna may be a metal, and may be aluminum, stainless steel, brass, or the like in addition to iron.

  The shape, type, number, arrangement, and the like of the magnet that forms a magnetic field on the plasma generation side surface of the slot antenna are not particularly limited as long as they can generate ECR. For example, an electromagnet may be used instead of a permanent magnet. The magnet has a magnetic flux density B [mT] at a position vertically spaced 10 mm from the surface of the slot antenna at a position where the slot is formed, where B ≧ f / 28 (f is a microwave frequency [MHz]). Is desirably arranged. In the second embodiment, magnets are arranged on both sides of the slot antenna along the longitudinal direction of the slot antenna. However, a magnet may be arranged only on one side of the slot antenna. When arranging magnets on both sides of the slot antenna, the magnets may be arranged so that the same magnetic poles face each other. By doing so, it is possible to increase the magnetic field on the surface of the slot antenna while reducing the influence of the magnetic field on the inside of the second waveguide. In the second embodiment, the pair of permanent magnets is arranged such that the N poles face each other, but may be arranged such that the S poles face each other.

  In the second embodiment, a cooling pipe is arranged near the permanent magnet in order to suppress a rise in the temperature of the permanent magnet. However, the configuration, number, arrangement, and the like of the cooling means of the permanent magnet are not particularly limited. For example, a cooling plate or the like may be arranged instead of or in combination with the cooling pipe. Further, in the second embodiment, a cooling plate is arranged around the second waveguide in order to suppress a rise in temperature inside the second waveguide. However, cooling means for the second waveguide is not always necessary. When arranging the cooling means for the second waveguide, its configuration, number, arrangement form and the like are not particularly limited.

  The number, shape, arrangement, and the like of the slots formed in the slot antenna are not particularly limited. The arrangement of the slots may be one row or two or more rows. The number of slots may be odd or even. Further, the slots may be arranged in a zigzag shape by changing the arrangement angle of the slots.

  The materials of the second dielectric and the third dielectric are not particularly limited. In any case, a material having a low dielectric constant and hardly absorbing microwaves is desirable. For example, quartz, alumina, zirconia, aluminum nitride, magnesium oxide, and the like are preferable. Here, as the third dielectric, one having a refractive index smaller than that of the second dielectric is selected. It is desirable that the refractive index of the third dielectric be a value between the refractive index inside the first waveguide and the refractive index of the second dielectric. In the second embodiment, the second dielectric is arranged over the entire space in the second waveguide. However, the second dielectric may be disposed so as to cover at least the slot, and does not necessarily need to be disposed over the entire internal space.

  In the second embodiment, a microwave having a frequency of 2.45 GHz was used to generate ECR plasma. However, the frequency of the microwave is not limited to the 2.45 GHz band, and any frequency band may be used as long as the frequency band is 300 MHz to 100 GHz. Examples of the frequency band in this range include 8.35 GHz, 1.98 GHz, and 915 MHz.

  The present invention can be considered as a method for manufacturing a sputtered film. That is, the present invention provides a magnetron sputtering method comprising: a magnetron cathode having a base material, a target disposed to face the base material, and a magnetic field forming means for forming a magnetic field on the surface of the target. A method of manufacturing a sputtered film, wherein the target is sputtered by plasma generated by magnetron discharge using a film apparatus, and sputtered particles sputtered out are attached to the surface of the base material to form a thin film. The method can be considered as a method for manufacturing a sputtered film, which comprises applying a voltage obtained by superimposing a VHF voltage by periodically changing the voltage to the magnetron cathode. According to the method for manufacturing a sputtered film, particles with a large particle diameter are prevented from jumping out of the target, so that a smooth thin film having few surface irregularities can be formed. Also, in the method for manufacturing a sputtered film, it is preferable to adopt the above-described preferred embodiment, such as performing sputtering while generating microwave plasma between a substrate and a target.

  Next, the present invention will be described more specifically with reference to examples.

<Production of sputtered film>
Using the magnetron sputtering film forming apparatus of the first embodiment or the second embodiment, the ITO film was formed by changing the superposition pattern of the VHF voltage. The reference numerals of the members in the film forming process described below correspond to FIG. 1 or FIG. 4 described above.

[Example 1]
In the magnetron sputtering film forming apparatus 1 (FIG. 1) of the first embodiment, first, the gas inside the vacuum vessel 8 was exhausted from the exhaust hole 81, and the internal pressure of the vacuum vessel 8 was set to 8 × 10 ⁻³ Pa. Subsequently, argon gas and a trace amount of oxygen gas were supplied into the vacuum vessel 8, and the internal pressure of the vacuum vessel 8 was set to 0.4 Pa. Next, the VHF superposition mechanism 2 was operated, and the VHF voltage was superimposed on the pulse DC voltage to apply a voltage to the cathode main body 16. The target 13 was sputtered by the generated magnetron plasma P1 to form an ITO film on the surface of the substrate 10 (PET film).

  The setting conditions of the pulse DC power supply 20 (“Pinnacle (registered trademark) Plus +” manufactured by Advanced Energy) in the VHF superposition mechanism 2 were set to output: 1500 W, frequency: 100 kHz, and pulse width: 6.5 μs. The VHF frequency used was 40 MHz, and the setting conditions of the VHF power supply 21 ("HFS-040-050-GENEATOR" manufactured by Japan High Frequency Co., Ltd.) were as follows: input power: 1000 W, rectangular wave mode. The delay time of the delay pulse generator 22 (“DIGITAL DELAY GENEATOR DG645” manufactured by STANDFORD RESEARCH SYSTEMS) was 4 μs. The setting conditions of the arbitrary waveform generator 23 (“MULTIFUNCTION GENEATOR WF1973” manufactured by NF Corporation) are burst mode, output waveform: rectangular wave, frequency: 300 kHz, offset: 0 V, phase: −1 degree, pulse width. : 50%.

  The superposition of the VHF voltage on the pulse DC voltage was performed in an on / off pattern for supplying the VHF voltage only at the start of the supply of the pulse DC voltage. FIG. 8 shows a schematic diagram of a voltage waveform supplied to the magnetron cathode. As shown in FIG. 8, the VHF voltage was supplied only when the supply of the pulse DC voltage was started, and the VHF voltage was stopped otherwise. That is, while the pulse DC voltage was being supplied, both the supply and the stop of the VHF voltage were performed.

[Example 2]
An ITO film was formed on the surface of the base material 10 in the same manner as in Example 1 except that the superimposed pattern of the VHF voltage was changed. The superposition of the VHF voltage on the pulse DC voltage was performed in an on / off pattern for supplying the VHF voltage only when the pulse DC voltage was not supplied. FIG. 9 shows a schematic diagram of a voltage waveform supplied to the magnetron cathode. As shown in FIG. 9, the VHF voltage was supplied only when no pulse DC voltage was supplied, and was stopped otherwise. That is, the VHF voltage was stopped while the pulse DC voltage was being supplied.

[Example 3]
An ITO film was formed on the surface of the base material 10 in the same manner as in Example 1 except that the superimposed pattern of the VHF voltage was changed. The superposition of the VHF voltage on the pulse DC voltage was performed in an offset pattern in which the voltage was intermittently increased while the VHF voltage was constantly supplied. In this case, among the setting conditions of the arbitrary waveform generator 23, the offset was set to 4V. FIG. 10 shows a schematic diagram of a voltage waveform supplied to the magnetron cathode. As shown in FIG. 10, while constantly supplying a constant VHF voltage (4 V), the voltage was increased only when no pulse DC voltage was supplied.

[Example 4]
An ITO film was formed on the surface of the base material 10 in the same manner as in Example 1 except that the superimposed pattern of the VHF voltage was changed. The VHF voltage was superimposed on the pulse DC voltage in the same on / off pattern as in the first embodiment (see FIG. 3 described above). That is, a cycle was repeated in which the VHF voltage was first supplied at the start of the supply of the pulse DC voltage, then temporarily stopped, and then supplied for a predetermined time and then stopped. The timing of supplying the VHF voltage includes both when the pulse DC voltage is not supplied and when the supply of the next pulse DC voltage is started. In other words, the VHF voltage was supplied except for a part of the time during which the pulse DC voltage was supplied.

[Example 5]
In the magnetron sputtering film forming apparatus 1 (FIG. 4) of the second embodiment, first, the gas inside the vacuum vessel 8 was exhausted from the exhaust holes 81, and the internal pressure of the vacuum vessel 8 was set to 8 × 10 ⁻³ Pa. Subsequently, an argon gas was supplied into the vacuum vessel 8, and the internal pressure of the vacuum vessel 8 was set to 25 Pa. Next, the microwave power supply was turned on, and the ECR plasma P2 was generated by the oscillated microwave having an output of 1000 W. Thereafter, the flow rate of the argon gas was immediately reduced, and the internal pressure of the vacuum vessel 8 was set to 0.4 Pa. Then, a small amount of oxygen gas was supplied into the vacuum vessel 8 (the internal pressure of the vacuum vessel 8 was 0.4 Pa). Next, the VHF superposition mechanism 2 was operated, and the VHF voltage was superimposed on the pulse DC voltage to apply a voltage to the cathode main body 16. The target 13 was sputtered by the generated magnetron plasma P1, and an ITO film was formed on the surface of the substrate 10 (PET film) while irradiating the sputtered particles with the ECR plasma P2.

  The setting conditions of the pulse DC power supply 20 and the like in the VHF superposition mechanism 2 are all the same as those in the first embodiment. The superimposition pattern of the VHF voltage is the same as in the first embodiment (= second embodiment, Example 4) (see FIG. 3 described above).

[Comparative Example 1]
In the magnetron sputtering film forming apparatus 1 (FIG. 1) of the first embodiment, the magnetron plasma P1 is generated without applying the VHF voltage to the pulse DC voltage, that is, by applying a voltage to the cathode body 16 only by the pulse DC power supply 20. Generated. An ITO film was formed on the surface of the substrate 10 in the same manner as in Example 1 except that the VHF voltage was not superimposed.

[Comparative Example 2]
An ITO film was formed on the surface of the base material 10 in the same manner as in Example 1 except that the superimposed pattern of the VHF voltage was changed. The VHF voltage was superimposed on the pulse DC voltage by a method in which the VHF power supply 21 was set to the continuous mode and a constant VHF voltage was continuously supplied. FIG. 11 shows a schematic diagram of a voltage waveform supplied to the magnetron cathode. As shown in FIG. 11, a constant VHF voltage was continuously supplied regardless of the waveform of the pulse DC voltage.

[Reference example]
In the magnetron sputtering film forming apparatus 1 (FIG. 4) of the second embodiment, the magnetron plasma P1 is generated by applying a voltage to the cathode main body 16 only by the pulse DC power supply 20 without superimposing the VHF voltage on the pulse DC voltage. Generated. An ITO film was formed on the surface of the base material 10 in the same manner as in Example 5, except that the VHF voltage was not superimposed.

<Evaluation of sputtered film>
The surface roughness of the manufactured ITO film and the particle size of the ITO were measured. Regarding the surface roughness, the arithmetic average roughness (Ra) and the maximum height (Rz) were measured using a scanning probe microscope “SPM-9700” manufactured by Shimadzu Corporation. As the particle diameter, an average value of the maximum length of ITO particles in an SPM photograph taken by a scanning probe microscope (SPM) was employed. Table 1 shows Ra, Rz, and particle diameter of the manufactured ITO film. As an example of the ITO film of the example, FIG. 12 shows an SPM photograph of the surface of the ITO film of Example 4, and FIG. 13 shows an SPM photograph of the surface of the ITO film of Example 5. FIG. 14 shows an SPM photograph of the surface of the ITO film of Comparative Example 1. FIG. 15 shows an SPM photograph of the surface of the ITO film of Comparative Example 2.

  As shown in Table 1, the ITO films of Examples 1 to 5 sputtered with the VHF voltage superimposed on the pulse DC voltage had a higher surface roughness than the ITO film of Comparative Example 1 without the superimposed VHF voltage. (Ra, Rz) and the particle size of ITO also became smaller. Above all, in the ITO film of Example 5 manufactured by irradiating ECR plasma, both the surface roughness and the particle diameter were the smallest. Also, as compared with the ITO film of Comparative Example 2 which was continuously superimposed without changing the voltage of the VHF voltage, Rz was smaller in the ITO film of Example 1, and Rz and the particle diameter were smaller in the ITO film of Example 2. Was smaller, and in the ITO films of Examples 3 to 5, Ra, Rz, and the particle diameter were all smaller. Comparing Example 5 produced by irradiating ECR plasma with Reference Example, the ITO film of Example 5 in which the VHF voltage is superimposed has a smaller surface roughness (Ra, Rz) and a smaller particle diameter of ITO. Has also become smaller.

  As shown in FIGS. 14 and 15, large particles can be seen on the surface of the ITO films of Comparative Examples 1 and 2, whereas as shown in FIGS. No large particles were observed on the surface of the ITO film, indicating that the surfaces of the ITO films of Examples 4 and 5 were smooth.

  As described above, according to the magnetron sputtering film forming apparatus and the method for manufacturing a sputtered film of the present invention, it was confirmed that a uniform thin film with little surface irregularities and fine and uniform film quality could be manufactured.

  The magnetron sputtering film forming apparatus of the present invention is useful for forming, for example, a transparent conductive film used for a touch panel, a display, an LED (light emitting diode) illumination, a solar cell, an electronic paper, and the like.

1: magnetron sputtering film forming apparatus, 10: base material, 11: base material support member, 12: magnetron cathode, 13: target, 14: backing plate, 15a to 15c: permanent magnet (magnetic field forming means), 16: cathode body , 17: earth shield, 110: table part, 111: leg part.
2: VHF superposition mechanism, 20: pulse DC power supply, 21: VHF power supply, 22: delay pulse generator (control device), 23: arbitrary waveform generator (control device), 24: VHF cut filter, 25: matching device.
3: microwave plasma generator, 30U: upstream first waveguide, 30D: downstream first waveguide, 31: plasma generation unit, 32U: upstream third waveguide, 32D: downstream third Waveguide, 33: plunger, 34: body, 35a, 35b: magnet, 36: third dielectric, 40: housing, 41: second waveguide, 42: cooling plate, 43: tube wall , 44: slot antenna, 45: second dielectric, 50a, 50b: permanent magnet, 51a, 52a, 51b, 52b: cooling pipe, 53a, 53b: cover member, 400: recess, 440: slot.
8: vacuum container, 80: gas supply hole, 81: exhaust hole, 82: partition wall, 83U, 83D: waveguide insertion hole, P1: magnetron plasma, P2: ECR plasma, V: section.

Claims (5)

A substrate,
A target disposed opposite to the base material, and a magnetron cathode having a magnetic field forming means for forming a magnetic field on the surface of the target,
A pulse DC power supply, a VHF power supply, and a control device for controlling a VHF voltage supplied by the VHF power supply, wherein the VHF voltage is periodically changed to the pulse DC voltage supplied from the pulse DC power supply. A VHF superimposing mechanism for superimposing and applying a voltage to the magnetron cathode;
With
The VHF superimposing mechanism superimposes the VHF voltage so that the VHF voltage is increased only when the pulse DC voltage is not supplied while continuously supplying the VHF voltage;
A magnetron sputter film forming apparatus, wherein the target is sputtered by plasma generated by magnetron discharge, and sputtered particles are attached to the surface of the substrate to form a thin film. A delay pulse generator that determines when to supply the VHF voltage based on an output signal of the pulse DC power supply;
An arbitrary waveform generator for determining a waveform of the VHF voltage to be supplied;
The magnetron sputtering film forming apparatus according to claim 1, further comprising:   The magnetron sputtering film forming apparatus according to claim 1, wherein the waveform of the VHF voltage is a rectangular wave. The magnetron sputtering film forming apparatus according to any one of claims 1 to 3 , further comprising a microwave plasma generating device for generating microwave plasma between the substrate and the target. The microwave plasma generator,
A first waveguide for transmitting microwaves,
A tube wall portion made of a magnetic material, a slot antenna formed with a plurality of slots through which the microwave propagating inside the tube passes, and a second dielectric disposed inside the tube so as to cover at least the slots, A second waveguide extending in one direction and having a magnetic field in which electron cyclotron resonance (ECR) is generated outside the second waveguide at a position of the slot on a plasma generation side surface of the slot antenna. A plasma generating unit having:
A third waveguide that is interposed between the first waveguide and the second waveguide and has a third dielectric material having a smaller refractive index than the second dielectric material inside the tube,
5. The magnetron sputtering film forming apparatus according to claim 4 , further comprising: generating an ECR plasma by the microwave propagating from the slot into the magnetic field.