Sputtering device and sputtering method

Abstract

Provided are a sputtering device and a sputtering method capable of stably forming a high-quality film. The sputtering device includes a vacuum chamber in which a target material and a substrate can be arranged opposite to each other, a DC power supply that can be electrically connected to the target material, and a pulsing unit that pulses the current flowing from the DC power supply to the target material, generates plasma in the vacuum chamber to form a thin film on the substrate, and further includes: an ammeter that measures the current flowing from the DC power supply to the pulsing unit; a power supply controller that performs feedback control on the DC power supply so that the current value measured by the ammeter becomes a given value; and a pulse controller that instructs the pulsing unit to have a pulse period that is offset from the control period of the DC power supply by the power supply controller.

Description

Technical Field

[0001] The present invention relates to a sputtering device and a sputtering method for forming a film on a substrate such as a semiconductor wafer. Background Art

[0002] In the manufacture of semiconductor devices, a thin film of metal, oxide, etc. is formed on a substrate to form a desired pattern, and in addition to forming electrodes and wiring, resistors, capacitors, etc. are also formed. In recent years, for example, the use environment of the device has become higher in temperature, and the passivation film that protects the device is required to be more dense, and the necessity for forming a high-density or high-crystalline thin film has increased.

[0003] In the thin film formation of the device, in general, from the viewpoint of production speed and production stability, direct current sputtering, high frequency sputtering, etc. are used for manufacturing in most cases. Among them, in the case of forming a thin film of a compound, reactive sputtering is used to react and deposit a target material that becomes a raw material with a reaction gas. However, depending on the combination of the target material and the reaction gas, sometimes a sufficient reaction speed cannot be obtained, and in particular, in the case of forming a nitride film using nitrogen, it is difficult to obtain a high-density or high-crystalline thin film in general sputtering.

[0004] Conventionally, as one of the film forming methods for forming such a high-density, highly-oriented thin film, there is pulse sputtering (for example, refer to Patent Document 1).

[0005] Therefore, the main reference Figure 6 The conventional pulse sputtering method is described below. Figure 6 This is a schematic cross-sectional view of a conventional pulse sputtering device. The vacuum chamber 1 is evacuated by a vacuum pump 2 connected via a valve 3, so that it can be decompressed and set to a vacuum state. The gas supply source 4 can supply the gas required for sputtering to the vacuum chamber 1 at a constant speed. The valve 3 can control the vacuum degree in the vacuum chamber 1 to a desired gas pressure by changing its opening and closing rate. A target material 7 is arranged in the vacuum chamber 1. The support plate 8 supports the target material 7. The power controller 40 is connected to the DC power supply 30 and can control the opening and closing of the power output to a constant timing. The output of the DC power supply 30 is electrically connected to the support plate 8, and by applying a voltage to the target material 7 via the support plate 8, a part of the gas in the vacuum chamber 1 can be dissociated to generate plasma. In the vacuum chamber 1, a substrate 6 is arranged opposite to the target material 7. The substrate holder 5 is arranged at the lower part of the substrate 6 and supports the substrate 6.

[0006] During the time when the voltage application is turned on, the target material 7 is sputtered and flies out due to the pulsed plasma generated in the vacuum chamber 1, reaches the substrate 6, and deposits a thin film of the target material 7. At the same time, the gas and plasma in the vacuum chamber 1 react with the target material 7 deposited on the substrate 6. In addition, during the time when the voltage application is turned off, the gas and plasma in the vacuum chamber 1 also react with the target material 7 deposited on the substrate 6, thereby forming a dense compound in which the target material 7 reacts with the gas. By repeating this series of pulse film formation a given number of times, a high-density compound film is obtained.

[0007] In addition, generally speaking, the magnet 11 and the yoke 12 are arranged on the back side of the target material 7, and the plasma is concentrated at a position where the parallel magnetic field relative to the plane of the target material 7 is the maximum on the surface of the target material 7, thereby improving the film forming speed. In addition, the position where the plasma is concentrated is called an erosion portion. In addition, if the erosion portion is concentrated at a specific position, only a part of the target material 7 is consumed, and the material cannot be effectively used. Therefore, although not shown in the figure, sometimes the erosion portion position is moved by moving the magnet 11 and the yoke 12 parallel to the target material 7 through a driving device.

[0008] Prior Art Literature

[0009] Patent Literature

[0010] Patent Document 1: Japanese Patent No. 5490368 Summary of the invention

[0011] However, regarding the above-mentioned conventional sputtering device (refer to Figure 6 ), when the cycle of the constant voltage control inside the DC power supply 30 is synchronized with the cycle of the timing of the pulse on and off, the pulsation of the voltage increases, the discharge current fluctuates, and the film cannot be formed stably. In addition, when the magnet 11 is rotated to move the erosion part, the discharge becomes unstable or the distribution of the film quality such as the density and refractive index of the formed thin film in the surface of the substrate 6 deteriorates according to the rotation cycle of the magnet 11, accompanied by the uneven reaction of the material and gas on the surface of the target material 7. Furthermore, during long-term film formation, the positional relationship between the target material 7 and the substrate 6 changes with the consumption of the target material 7, so there is a problem that the film quality distribution in the surface of the substrate 6 deteriorates, and the target material 7 needs to be replaced before it is used up.

[0012] In view of the above-mentioned conventional problems, an object of the present invention is to provide a sputtering device and a sputtering method capable of stably forming a high-quality film.

[0013] The sputtering device according to the present invention comprises:

[0014] A vacuum chamber in which a target and a substrate can be arranged opposite to each other;

[0015] a direct current power source capable of being electrically connected to the target; and

[0016] The pulsing unit pulses the current flowing from the DC power supply to the target.

[0017] generating plasma in the vacuum chamber to form a thin film on the substrate,

[0018] The sputtering device further comprises:

[0019] an ammeter for measuring a current flowing from the DC power source to the pulsing unit;

[0020] a power supply controller that performs feedback control on the DC power supply so that the current value measured by the ammeter becomes a given value; and

[0021] The pulse controller instructs the pulsing unit to provide a pulse cycle that is shifted from a cycle of feedback control of the DC power supply by the power supply controller.

[0022] The sputtering method of the present invention is a sputtering method for generating plasma in a vacuum chamber to form a thin film on a substrate, comprising:

[0023] The step of arranging the target and the substrate opposite to each other in the vacuum chamber;

[0024] The step of electrically connecting the target material to a DC power supply;

[0025] a step of pulsing the current flowing from the DC power source to the target material by a pulsing unit;

[0026] a step of measuring a current flowing from the DC power source to the pulsing unit;

[0027] A step of performing feedback control on the DC power supply so that the measured current value becomes a given value; and

[0028] A step of instructing the pulsing unit to provide a pulse cycle that is shifted from a cycle of feedback control of the DC power supply.

[0029] Effects of the Invention

[0030] According to the sputtering device and the sputtering method of the present invention, feedback control is performed so that the current value measured by the ammeter becomes a given value, thereby stabilizing the discharge. Even if the target material is consumed during long-term film formation, the change in the positional relationship between the eroded portion and the substrate is suppressed to a minimum, so that high-quality and uniform film quality can be maintained, and a high-quality film can be stably formed. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1This is a schematic cross-sectional view showing the structure of the sputtering device according to the first embodiment.

[0032] Figure 2 This is a timing chart showing the relationship between the voltage and current values ​​of a DC power supply and the pulse voltage and current in the sputtering device according to the first embodiment.

[0033] Figure 3A This is a diagram showing changes in plasma emission intensity and changes in current value when the pulse cycle is synchronized with the control cycle of the DC power supply in the sputtering device.

[0034] Figure 3B This is a diagram showing the change in plasma emission intensity and the change in current value when the pulse cycle and the feedback control cycle of the DC power supply are shifted.

[0035] Figure 4 This is a schematic cross-sectional view showing the structure of the sputtering device according to the second embodiment.

[0036] Figure 5 It is a timing chart showing the relationship among the cumulative number of pulses, the magnet rotation angle, the substrate position, and the number of pulses in the sputtering device according to the second embodiment.

[0037] Figure 6 This is a schematic cross-sectional view of a conventional pulse sputtering device.

[0038] Description of reference numerals:

[0039] 1 vacuum chamber; 2 pump; 3 gate valve; 4 gas supply source; 5 substrate holder; 6 substrate; 7 target; 8 support plate; 10, 10a sputtering device; 11 magnet; 12 yoke; 13 magnetic field (magnetic lines of force); 14 sputtered particles; 20 rotation mechanism; 21 lifting mechanism; 30 DC power supply; 31 ammeter; 32 pulse unit; 40 power controller; 41 pulse controller; 42 rotation controller; 43 lifting controller; PP pulse period. DETAILED DESCRIPTION

[0040] A sputtering device according to a first aspect includes:

[0041] A vacuum chamber in which a target and a substrate can be arranged opposite to each other;

[0042] a direct current power source capable of being electrically connected to the target; and

[0043] The pulsing unit pulses the current flowing from the DC power supply to the target.

[0044] Plasma is generated in the vacuum chamber to form a thin film on the substrate, and the sputtering device further comprises:

[0045] an ammeter for measuring a current flowing from the DC power source to the pulsing unit;

[0046] a power supply controller that performs feedback control on the DC power supply so that the current value measured by the ammeter becomes a given value; and

[0047] The pulse controller instructs the pulsing unit to provide a pulse cycle that is shifted from a cycle of feedback control of the DC power supply by the power supply controller.

[0048] A sputtering device according to a second aspect may be, in the above-mentioned first aspect, further comprising:

[0049] a magnet disposed on a back surface of the target material opposite to a surface thereof facing the substrate;

[0050] a rotating mechanism that rotates the magnet relative to a rotation axis that intersects the back surface of the target;

[0051] A rotation controller, controlling the rotation mechanism;

[0052] A lifting mechanism is used to lift and lower the substrate relative to the target material so that the interval between the substrate and the target material changes; and

[0053] A lifting controller controls the lifting mechanism.

[0054] A sputtering device according to a third aspect may be, in the first or second aspect,

[0055] The pulse controller calculates the turn-on time and the turn-off time and instructs the pulse unit so that when the period of the feedback control of the power controller is set to F1, the pulse period is set to F2, and the least common multiple of F1 and F2 is set to F3, the integer N obtained by F3÷F1=N becomes greater than 10.

[0056] A sputtering device according to a fourth aspect may be, in the first or second aspect,

[0057] The pulse controller calculates the on time and the off time and indicates them to the pulsing unit, so that the pulse period is shifted by more than 1% relative to the integer multiple period of the feedback control of the power controller.

[0058] A sputtering device according to a fifth aspect may be, in the above-mentioned second aspect,

[0059] The pulse controller calculates the rotation speed based on the set pulse on time and off time and instructs the rotation controller so that one cycle of the rotation of the magnet becomes more than 1000 pulses.

[0060] The pulse controller calculates a movement amount for bringing the position of the substrate closer to the target based on information on the consumption amount of the target relative to the number of pulses obtained in advance, and instructs the calculation to the lifting and lowering controller.

[0061] A sputtering method according to a sixth aspect is a sputtering method for forming a thin film on a substrate by generating plasma in a vacuum chamber, comprising:

[0062] The step of arranging the target and the substrate opposite to each other in the vacuum chamber;

[0063] The step of electrically connecting the target material to a DC power supply;

[0064] a step of pulsing the current flowing from the DC power source to the target material by a pulsing unit;

[0065] a step of measuring a current flowing from the DC power source to the pulsing unit;

[0066] A step of performing feedback control on the DC power supply so that the measured current value becomes a given value; and

[0067] A step of instructing the pulsing unit to provide a pulse cycle that is shifted from a cycle of feedback control of the DC power supply.

[0068] Hereinafter, the sputtering device and the sputtering method according to the embodiment will be described in detail with reference to the accompanying drawings. In addition, in the drawings, the same reference numerals are attached to substantially the same components.

[0069] (Implementation Method 1)

[0070] First, the main reference Figure 1 The structure of the sputtering device 10 according to the first embodiment will be described. Figure 1 It is a schematic cross-sectional view of the sputtering device 10 according to the first embodiment.

[0071] The sputtering device 10 includes a vacuum chamber 1, a DC power supply 30, a pulse unit 32, an ammeter 31, a power supply controller 40, and a pulse controller 41. In the vacuum chamber 1, a target 7 and a substrate 6 can be arranged to face each other inside. The DC power supply 30 can be electrically connected to the target 7. The current flowing from the DC power supply 30 to the target 7 is pulsed by the pulse unit 32. The current flowing from the DC power supply 30 to the pulse unit 32 is measured by the ammeter 31. The DC power supply 30 is feedback-controlled by the power supply controller 40 so that the current value measured by the ammeter 31 becomes a given value. The pulse controller 41 instructs the pulse unit 32 to have a pulse period that is offset from the control period of the DC power supply 30 by the power supply controller 40.

[0072] According to the sputtering device 10, a pulsed current flows to the target material 7 with a pulse period that is staggered from the period of feedback control of the DC power supply 30. Therefore, in the feedback control, the period of current detection is inconsistent with the period of the pulse, so a specific position of the fluctuation of the DC current value of the DC power supply is not detected. Thus, by taking the average value of the detected current value, the correct time-averaged current value can be calculated. Therefore, by feedback controlling the DC power supply based on the calculated current value, the fluctuation of the plasma intensity can be suppressed.

[0073] Hereinafter, each component constituting the sputtering device 10 will be described.

[0074] <Vacuum Chamber>

[0075] The vacuum chamber 1 can be decompressed to a vacuum state by being evacuated by a vacuum pump 2 connected via a valve 3 .

[0076] <Gas Supply Source>

[0077] The gas supply source 4 can supply the gas required for sputtering at a constant rate to the vacuum chamber 1. The gas supplied by the gas supply source 4 can be selected from gases reactive with the target material such as nitrogen and oxygen, or mixed gases of reactive gases and rare gases such as argon.

[0078] <Valve>

[0079] The valve 3 can control the vacuum degree in the vacuum chamber 1 to a desired gas pressure by changing the opening and closing rate thereof.

[0080] <Target Material>

[0081] exist Figure 1 In the embodiment, a target material 7 is arranged at the upper part of the vacuum chamber 1. The target material 7 is any sputtering material, for example, an inorganic material such as a metal material or a semiconductor material.

[0082] <Support Plate>

[0083] The support plate 8 supports the target material 7 .

[0084] <DC Power Supply>

[0085] The DC power supply 30 is electrically connected to the target 7 via the ammeter 31 , the pulsation unit 32 , and the support plate 8 , and can apply a voltage to the target 7 .

[0086] <Pulse Unit>

[0087] The pulsating unit 32 can store the DC current generated by the DC power supply 30 in a built-in capacitor or the like, and turn it on and off by a built-in semiconductor switching element or the like, thereby pulsating it.

[0088] <Galvanometer>

[0089] The ammeter 31 can detect the current flowing from the DC power supply 30 to the pulsating unit 32 .

[0090] <Power Controller>

[0091] The power supply controller 40 is connected to the ammeter 31 and the DC power supply 30 and can perform feedback control on the voltage setting value of the DC power supply so that the current value detected by the ammeter 31 is stabilized at a given value.

[0092] <Pulse Controller>

[0093] The pulse controller 41 is connected to the power supply controller 40 and the pulsing unit 32 , and controls the on-time and off-time of the pulse instructed to the pulsing unit 32 based on the state of the DC power supply 30 obtained from the power supply controller 40 .

[0094] <Magnet and Yoke>

[0095] The magnet 11 and the yoke 12 are arranged on the back side of the support plate 8, and can generate a magnetic field 13 on the surface of the target material 7. It is sufficient to have more than one magnet 11. In addition, the magnet 11 can be any one of a permanent magnet and an electromagnet. The yoke 12 is connected to one end of the magnet 11 to form a magnetic circuit, which can suppress the leakage of useless magnetic field to the opposite side of the target material 7.

[0096] <Substrate and Substrate Holder>

[0097] exist Figure 1 In the embodiment, a substrate 6 is disposed at a lower portion of the vacuum chamber 1 so as to face a target 7. A substrate holder 5 is disposed at a lower portion of the substrate 6 to support the substrate 6.

[0098] (Operation of the sputtering device)

[0099] Next, the operation of the sputtering device 10 according to the first embodiment will be described, and the sputtering method according to the first embodiment will also be described (the same also applies to the second embodiment).

[0100] (1) First, the target 7 is placed in the vacuum chamber 1 , and the substrate 6 is placed substantially horizontally below the target 7 .

[0101] (2) Next, the vacuum pump 2 is operated to reduce the pressure so that the vacuum chamber 1 becomes a vacuum state. After reaching a predetermined vacuum degree, gas is introduced from the gas supply source 4 and the opening of the gate valve 3 is adjusted so that a predetermined gas pressure is achieved.

[0102] (3) Next, a voltage is generated by the DC power supply 30 and switched at a predetermined on time and off time by the pulsing unit 32 to be pulsed and applied to the target 7 , thereby generating plasma in the vacuum chamber 1 .

[0103] <Pulse generation status>

[0104] use Figure 2 The timing diagram of FIG. 1 illustrates the pulse generation state. Figure 2 (a) to Figure 2 (d) is a diagram showing the voltage of the DC power supply of the sputtering device of Embodiment 1 ( Figure 2 (a)) and current value ( Figure 2 (b)) and pulse voltage ( Figure 2 (c)) and current ( Figure 2 (d)) is a timing diagram of the relationship between the DC power supply 30 and the pulse unit 32. The DC power supply 30 supplies a negative DC voltage and a DC current ( Figure 2 (c) Figure 2 (d)). The pulse voltage generated by the pulsing unit has a nearly rectangular pulse shape with a given on time and off time ( Figure 2 (a)). By applying the pulse voltage, plasma is generated during the pulse-on time, and the pulse current gradually increases. During the pulse-off time, the pulse current gradually decreases and becomes zero in the process of plasma disappearance ( Figure 2 (b)). At this time, in the DC power supply 30, because the current consumed by the pulse unit 32 is supplied, the voltage value of the DC power supply 30 drops in the positive direction and moves ( Figure 2 (c)). On the other hand, the current value of the DC power supply 30 moves in the negative direction toward the increasing direction ( Figure 2 (d)), that is, a fluctuation consistent with the pulse period is generated in the DC voltage and DC current of the DC power supply 30. The ammeter 31 detects the current value of the fluctuation at a constant period, and the power supply controller 40 averages the detected current value a given number of times and performs feedback control on the DC power supply 30 so that the average current value becomes a given value.

[0105] In the sputtering device, during the feedback control of the DC power supply 30, the period of the pulse is set to a value that is offset relative to the period of the feedback control, so that the period of the feedback control of the DC power supply 30 is not synchronized with the period of the pulse. In order to stagger the period of the pulse, for example, it is only necessary to slightly lengthen the time when the pulse is turned on or the time when the pulse is turned off. In addition, if the on time is changed, the rising edge of the pulse current changes, so it is preferred to change the time when the pulse is turned off. When the period of the feedback control is set to F1, the pulse period is set to F2, and the least common multiple of F1 and F2 is set to F3, the integer N obtained by N=F3÷F1 represents that the feedback control is consistent with the pulse period at a ratio of once in N times. N is preferably greater than 10, that is, the ratio of the period being consistent is preferably less than once in 10 times. In the case where the pulse becomes a large current and the current fluctuation is large, such as in the case of different sputtering materials and high-speed film formation, it is preferred to set N to more than 20 in order to further suppress the fluctuation. As for the time of the shift, specifically, it is preferred to shift the pulse period by 1% or more so as to satisfy the above-mentioned period N. As a further effect of suppressing the variation, it is preferably 5% or more. In addition, if the pulse period is shifted by 100% or 200% in a well-divided manner, the pulse period becomes an integer multiple, and thus the ratio of the period consistency becomes the same as before the shift, so it is best to avoid this situation.

[0106] <Feedback Control>

[0107] use Figure 3A as well as Figure 3B Feedback control of the DC power supply 30 for shifting the frequency of pulses will be described.

[0108] Figure 3A 1 is a graph showing the variation of plasma emission intensity when it is assumed that the pulse cycle of 10 kHz is synchronized with the cycle of 10 kHz of the feedback control of the DC power supply. Figure 3A In the example, the observation interval of the plasma luminescence intensity is more than 100 times longer than the pulse period, and the average intensity variation of more than 100 pulses is observed. Figure 2(d) is a diagram of the change in the DC current value. Frames A, B, and C have the same detection period, but the detection timing is staggered. Therefore, even if the current waveform is the same, the current value detected in each of frames A, B, and C is different. In this case, the detection period in the ammeter 31 is different from the period of the pulse, but is roughly synchronized, so as shown in the diagrams of frames A, B, and C, the fluctuations of the current value are detected at specific positions that are different. If the current value is feedback controlled based on this, an offset will occur between the average value of the detected current value and the average value of the actual current value. In addition, the offset is the differential period of the pulse period and the period of feedback control, and gradually changes with time as shown in other frame diagrams. Therefore, the fluctuation increases in feedback control and the plasma cannot be stabilized. As shown in the figure, the plasma luminescence intensity will vary greatly.

[0109] Figure 3B 1 is a graph showing the change in plasma luminous intensity when the pulse period and the feedback control period of the DC power supply are shifted by 5%. In this case, in the feedback control, the current detection period and the pulse period are consistent only once in two times, so the proportion of specific positions where the fluctuation of the DC current value of the DC power supply is detected is reduced, and by taking the average value of the detected current value, a more accurate time-averaged current value can be calculated. As described above, the pulse period is shifted by more than 1% relative to the feedback control period, and the DC power supply is feedback-controlled based on the calculated current value, thereby Figure 3B In this way, fluctuations in plasma intensity can be suppressed.

[0110] As described above, due to the pulsed plasma generated in the vacuum chamber 1, the target material 7 is sputtered and flies out, reaches the substrate 6, and deposits a thin film of the target material 7, and at the same time, the gas and plasma in the vacuum chamber 1 react with the target material 7 deposited on the substrate 6. In addition, during the time when the voltage application is turned off, the gas and plasma in the vacuum chamber 1 react with the target material 7 deposited on the substrate 6, thereby forming a dense compound of the target material 7 and the gas reaction. By repeating this series of pulse film formation a given number of times, a high-density compound thin film is obtained.

[0111] According to the above, in the pulse sputtering device 10, the feedback control of the current value measured by the ammeter is stabilized, so that the voltage and current fluctuations of the plasma discharge can be suppressed. As a result, the sputtering speed of the plasma on the target material 7 can be made constant, that is, the deposition speed of the target material 7 on the substrate 6 can be made constant without fluctuation. Therefore, the reaction of the gas and plasma with the target material 7 deposited on the substrate 6 can also be made constant without fluctuation, so that a high-quality film can be stably formed.

[0112] (Implementation Method 2)

[0113] Next, the main reference Figure 4 The structure of the sputtering device 10a according to the second embodiment will be described.

[0114] Here, Figure 4 2 is a schematic cross-sectional view showing the structure of a sputtering device 10a according to Embodiment 2. Figure 4 , for Figure 1 The same or corresponding parts are denoted by the same reference numerals, and a part of the description is omitted.

[0115] exist Figure 4 In the embodiment, a magnet 11 and a yoke 12 are arranged on the back side of the support plate 8. In the sputtering device 10a, compared with the sputtering device involved in the first embodiment, the difference is that in the yoke 12, a rotating mechanism 20 is connected at an eccentric position, and the magnet 11 and the yoke 12 can be eccentrically rotated. In addition, a rotation controller 42 is connected to the rotating mechanism 20, and the rotation of the rotating mechanism 20 can be controlled based on the setting. In addition, a pulse controller 41 is connected to the rotation controller 42, and it can receive the indicated value of the rotation and set it to a given rotation speed.

[0116] Furthermore, in the sputtering device 10a, compared with the sputtering device involved in the first embodiment, the difference is that the lifting mechanism 21 is connected to the substrate holder 5, and the opposing distance between the target material 7 and the substrate 6 can be changed. The lifting mechanism 21 is connected to the lifting controller 43, and the lifting position of the lifting mechanism 21 can be controlled based on the set value. In addition, the pulse controller 41 is connected to the lifting controller 43, and it can receive the instruction value of lifting and lowering and set it to a given lifting speed.

[0117] By rotating the magnet 11 eccentrically, the erosion portion also moves on the target surface, so the consumption of the target material 7 is not concentrated on a part of the surface of the target material 7. When the accumulated number of pulses increases, such as when film formation is continuously performed on the substrate 6 for a long time or when film formation is repeatedly performed on the substrate 6, the consumption of the surface of the target material 7 increases. For example, with respect to the thickness of the target material 7 of 5 mm, the consumption sometimes reaches 4 mm. In this case, the distance from the erosion portion position on the surface of the target material 7 to the opposing substrate 6 will be away from the distance corresponding to the consumption compared to before the target material 7 is consumed, and the energy of the sputtered particles 14 flying from the surface of the target material 7 when reaching the substrate is reduced, and sometimes a high-quality film cannot be obtained.

[0118] use Figure 5 The control procedure of the pulse, the magnet rotation, and the raising and lowering of the substrate 6 in the second embodiment will be described. Figure 5 It is a timing chart showing the relationship among the pulse, the rotation of the magnet 11 , and the raising and lowering of the substrate 6 in the sputtering device 10 a according to the second embodiment. Figure 5(a) is a timing chart showing the relationship between the cumulative pulse number and the pulse number. Figure 5 (b) is a timing chart showing the relationship between the rotation angle of the magnet and the number of pulses. Figure 5 (c) is a timing chart showing the relationship between the substrate position and the number of pulses due to the lifting of the substrate.

[0119] The pulse controller 41 sets the pulse on time and off time in the pulse unit 32, and accumulates the number of pulses executed ( Figure 5 (a)). The pulse controller 41 calculates the rotation speed based on the set values ​​of the pulse on time and off time and indicates the calculated rotation speed to the rotation controller 42, so that one cycle of the rotation of the magnet 11 becomes a time of more than 1000 pulses ( Figure 5 (b)). Thus, when the target 7 is sputtered by the pulsed plasma, the surface of the target 7 can be uniformly sputtered. Therefore, even during long-term film formation, the surface of the target 7 is not unevenly consumed by the pulses, and the sputtering film formation can be stably performed.

[0120] Furthermore, when film formation is continued for a long time, the pulse controller 41 calculates the movement amount for bringing the position of the substrate 6 closer to the target 7 based on information on the consumption amount of the target 7 relative to the number of pulses obtained in advance through experiments, and instructs the calculated value to the lifting controller 43 ( Figure 5 (c)). Thus, the surface of the target 7 can be uniformly sputtered by the rotation of the magnet 11, and further, even during long-term film formation, the positional relationship of the substrate 6 facing the eroded portion of the surface of the target 7 can be maintained, and a uniform thin film can be stably formed.

[0121] Accordingly, in the pulse sputtering device 10a, feedback control is performed so that the time average value of the current value measured by the ammeter becomes a given value, thereby stabilizing the discharge. In addition, even if the target material 7 is consumed due to long-term film formation, the change in the positional relationship between the eroded portion and the substrate 6 is suppressed to a minimum, so that high-quality and uniform film quality can be maintained, and high-quality films can be stably formed for a long period of time.

[0122] In addition, the present disclosure also includes appropriate combinations of any of the various embodiments and / or examples described above, which can achieve the effects of each embodiment and / or example.

[0123] Industrial Applicability

[0124] The sputtering apparatus and sputtering method according to the present invention can stably form a high-density silicon nitride thin film, for example, and are useful for forming a high-quality passivation thin film in the manufacture of thin-film devices.

Claims

1. A sputtering device, comprising: A vacuum chamber in which a target and a substrate can be arranged opposite to each other; A DC power supply, which can be electrically connected to the target; as well as a pulsing unit for pulsing the current flowing from the DC power supply to the target, generating plasma in the vacuum chamber to form a thin film on the substrate, The sputtering device further comprises: an ammeter connected between the DC power supply and the pulsation unit to measure the current flowing from the DC power supply to the pulsation unit; a power supply controller that performs feedback control on a voltage setting value of the DC power supply so that the current value measured by the ammeter becomes a given value; a pulse controller for indicating to the pulsing unit a pulse period that is staggered from a control period of the DC power supply by the power supply controller; a magnet disposed on a back surface of the target material opposite to a surface thereof facing the substrate; a rotating mechanism that rotates the magnet about a rotation axis that intersects the back surface of the target; and a rotation controller, which controls the rotation mechanism, The rotation controller is connected to the pulse controller, and can receive a rotation instruction value and set it to a given rotation speed.

2. The sputtering device according to claim 1, further comprising: a lifting mechanism for lifting and lowering the substrate relative to the target so that the interval between the substrate and the target changes; and A lifting controller controls the lifting mechanism.

3. According to the sputtering device according to claim 1, the pulse controller calculates the turn-on time and the turn-off time and instructs the pulse unit so that when the period of the feedback control of the power controller is set to F1, the pulse period is set to F2, and the least common multiple of F1 and F2 is set to F3, the integer N obtained by F3÷F1=N becomes greater than 10.

4. The sputtering device according to claim 1, wherein the pulse controller calculates the on time and the off time and instructs the pulse unit so that the pulse period is shifted by more than 1% relative to the integer multiple period of the feedback control of the power controller.

5. The sputtering device according to claim 2, wherein the pulse controller calculates the rotation speed based on the set on time and off time of the pulse and instructs the rotation controller so that one cycle of the rotation of the magnet becomes more than 1000 pulses. The pulse controller calculates a movement amount for bringing the position of the substrate closer to the target based on information on the consumption amount of the target relative to the number of pulses obtained in advance, and instructs the calculation to the lifting and lowering controller.

6. A sputtering method for generating plasma in a vacuum chamber to form a thin film on a substrate, comprising: The step of arranging the target material and the substrate opposite to each other in the vacuum chamber; The step of electrically connecting the target material to a DC power supply; a step of pulsing the current flowing from the DC power source to the target material by a pulsing unit; A step of measuring a current flowing from the DC power source to the pulsing unit by connecting an ammeter between the DC power source and the pulsing unit; A step of performing feedback control on the voltage setting value of the DC power supply so that the measured current value becomes a given value; The step of instructing the pulsing unit, through a pulse controller, to have a pulse cycle that is offset from a control cycle of the DC power supply; A step of rotating a magnet disposed on the back side of the target opposite to the surface facing the substrate with respect to a rotation axis intersecting the back side of the target by a rotating mechanism; as well as A step of connecting a rotation controller for controlling the rotation mechanism to the pulse controller and receiving a rotation instruction value to set the rotation speed to a given value.

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