Vacuum processing method and vacuum processing apparatus

Abstract

To obtain stable film deposition performance.SOLUTION: A vacuum processing method comprises: outputting a first high-frequency power from a first RF power supply to form discharge plasma between first and second electrodes; outputting a second high-frequency power from a second RF power supply and operating a phase regulator to set a retardation θ between phases of the first and second high-frequency powers; acquiring data obtained by detecting a voltage value Vpp of the second high-frequency power and a capacity value C1 of a first variable capacity according to the retardation θ in the state of matching output impedance of the second RF power supply and load side impedance connected to the second RF power supply; and forming the discharge plasma between the first and second electrodes while shielding a substrate to a sputtering target by a shutter before depositing a sputtering film on the substrate and supplying the second high-frequency power to the second electrode from the second RF power supply by combining and selecting the voltage value Vpp and the capacity value C1 in a predetermined range of the retardation θ.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a vacuum treatment method and a vacuum treatment apparatus.

Background Art

[0002] In electronic devices typified by 3D-NAND type flash memories, multi-layerization is progressing and the number of layers is increasingly increasing. Therefore, a film forming method for a film (for example, an insulating layer) included in the multi-layer structure becomes particularly important.

[0003] As a method for forming a film, there is a sputtering method that has a relatively high film forming speed and exhibits a good film thickness distribution. Among these, there is a sputtering method in which high-frequency power is supplied to both the sputtering target side and the substrate side, and the phase control of each high-frequency power supply is performed to improve the film forming speed and the film thickness distribution (see, for example, Patent Document 1).

[0004] In addition, in the sputtering method, pre-discharge such as pre-sputtering may be performed before film formation on the substrate (see, for example, Patent Document 2). By this pre-discharge, conditioning of a power supply that supplies power to the sputtering target and a matching circuit (hereinafter, the power supply, etc.) connected to the power supply is performed.

[0005] As the significance of performing such pre-discharge, when electronic components and wiring (hereinafter, electronic components, etc.) that constitute the power supply, etc. are energized, Joule heat is generated in the electronic components, etc., and the impedance of the power supply, etc. may change before and after energization due to the expansion, contraction, or temperature change of the electronic components, etc. Alternatively, one of the reasons is that surface cleaning of the sputtering target is performed before film formation by performing pre-discharge.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

[0007] During the pre-discharge phase, it is preferable not to supply power to the substrate. This is because supplying power to the substrate during the pre-discharge phase can cause reverse sputtering on the substrate due to the bias potential applied to it, resulting in particles flying from the substrate into the vacuum chamber or adhering to and detaching from the inner walls, fixtures, etc., of the vacuum chamber. Alternatively, depending on the degree of the bias potential, abnormal discharge may occur on the substrate during the pre-discharge phase.

[0008] However, not conditioning the substrate during the pre-discharge means that the power supply to the substrate is not energized before sputtering, and is only energized after sputtering has started. Consequently, after sputtering has started, impedance changes may occur in the electronic components that make up the power supply that supplies power to the substrate. As a result, even after sputtering has started, unstable deposition performance may occur.

[0009] In view of the above circumstances, the object of the present invention is to provide a vacuum treatment method that can obtain stable film deposition performance even when substrate conditioning is performed before sputtering film deposition, and a vacuum treatment apparatus for carrying out the vacuum treatment method. [Means for solving the problem]

[0010] To achieve the above objective, in a vacuum processing method according to one embodiment of the present invention, A first electrode including a sputtering target, A second electrode, facing the first electrode and capable of supporting the substrate, A shutter electrically connected to the second electrode and capable of exposing or shielding the substrate from the sputtering target, A first power supply source including a first high-frequency power supply that outputs first high-frequency power, and a first matching circuit connected between the first high-frequency power supply and the first electrode, A second power supply comprising: a second high-frequency power supply that outputs a second high-frequency power having the same period as the first high-frequency power and lower than the first high-frequency power; and a second matching circuit connected between the second high-frequency power supply and the second electrode, including an input terminal connected to the second high-frequency power supply, an output terminal connected to the second electrode, a first variable capacitance connected between the input terminal and ground potential, and a second variable capacitance connected in series between the input terminal and the output terminal; A phase adjuster that adjusts the phases of the first high-frequency power output from the first high-frequency power supply and input to the first matching circuit, and the second high-frequency power output from the second high-frequency power supply and input to the second matching circuit. A film deposition apparatus equipped with the following features is used. The first high-frequency power is output from the first high-frequency power supply, and a discharge plasma is formed between the first electrode and the second electrode. The second high-frequency power is output from the second high-frequency power supply, and the phase adjuster is operated to create a phase difference θ between the phase of the first high-frequency power and the phase of the second high-frequency power. When the output impedance of the second high-frequency power supply and the load impedance connected to the second high-frequency power supply are matched, data is obtained that detects the voltage value Vpp of the second high-frequency power supply and the capacitance value C1 of the first variable capacitor, corresponding to the phase difference θ. Before forming a sputtering film on the substrate, the discharge plasma is formed between the first electrode and the second electrode while shielding the substrate or the second electrode from the sputtering target with the shutter, and the second high-frequency power is supplied to the second electrode from the second high-frequency power supply by selecting a combination of the voltage value Vpp and the capacitance value C1 within a predetermined range of the phase difference θ.

[0011] With this type of vacuum processing method, stable film deposition performance can be obtained even if the substrate conditioning is performed before sputtering film deposition.

[0012] In the vacuum processing method described above, As for the above data, The phase difference θ is formed by delaying the phase of the second high-frequency power relative to the phase of the first high-frequency power. By changing the above phase difference θ, a profile curve of the voltage value Vpp and a profile curve of the capacitance value C1 corresponding to the above phase difference θ are obtained. While shielding the substrate or the second electrode from the sputtering target with the shutter, the phase difference θ may be set to a fourth range outside the third range, which is outside the first range of +30 to +50 degrees from the phase difference θ1 where the voltage value Vpp in the profile curve of the voltage value Vpp is at its lowest, outside the second range of +10 to -10 degrees from the phase difference θ2 where the voltage value Vpp in the profile curve of the voltage value Vpp is at its maximum, and outside the third range of -50 to -30 degrees from the phase difference θ2, and the second high-frequency power may be supplied from the second high-frequency power supply to the second electrode while the output impedance and the load-side impedance are matched.

[0013] With this type of vacuum processing method, stable film deposition performance can be obtained even if the substrate conditioning is performed before sputtering film deposition.

[0014] In the vacuum processing method described above, The fourth range described above may be a range from minus 10 degrees to plus 10 degrees from the phase difference θ1.

[0015] With this type of vacuum processing method, stable film deposition performance can be obtained even if the substrate conditioning is performed before sputtering film deposition.

[0016] To achieve the above objective, a vacuum processing apparatus according to one embodiment of the present invention is A first electrode including a sputtering target, A second electrode facing the first electrode and capable of supporting a substrate, A shutter electrically connected to the second electrode and capable of exposing or shielding the substrate with respect to the sputtering target, A first power supply source including a first high-frequency power supply that outputs a first high-frequency power and a first matching circuit device connected between the first high-frequency power supply and the first electrode, A second high-frequency power supply that outputs a second high-frequency power having the same period as the first high-frequency power and lower than the first high-frequency power, and a second matching circuit device connected between the second high-frequency power supply and the second electrode, the second matching circuit device including an input terminal connected to the second high-frequency power supply, an output terminal connected to the second electrode, a first variable capacitor connected between the input terminal and the ground potential, and a second variable capacitor connected in series between the input terminal and the output terminal, A phase adjuster that adjusts the phases of the first high-frequency power output from the first high-frequency power supply and input to the first matching circuit device and the second high-frequency power output from the second high-frequency power supply and input to the second matching circuit device, A control device that controls the first power supply source, the second power supply source, the shutter, and the phase adjuster. The control device includes: Causing the first high-frequency power supply to output the first high-frequency power to form a discharge plasma between the first electrode and the second electrode, Causing the second high-frequency power supply to output the second high-frequency power and operating the phase adjuster to provide a phase difference θ between the phase of the first high-frequency power and the phase of the second high-frequency power, Data detecting the voltage value Vpp of the second high-frequency power and the capacitance value C1 of the first variable capacitor according to the phase difference θ in a state where the output impedance of the second high-frequency power supply and the load-side impedance connected to the second high-frequency power supply are matched is stored, Before forming the sputtering film on the substrate, the control device forms the discharge plasma between the first electrode and the second electrode while shielding the substrate or the second electrode from the sputtering target by the shutter, and supplies the second high-frequency power from the second high-frequency power source to the second electrode by selecting a combination of the voltage value Vpp and the capacitance value C1 in a predetermined region of the phase difference θ.

[0017] With such a vacuum processing apparatus, stable film-forming performance can be obtained even if conditioning on the substrate side is performed before sputtering film formation.

[0018] In the above-described vacuum processing apparatus, In the control device, as the data, the phase difference θ is formed by delaying the phase of the second high-frequency power with respect to the phase of the first high-frequency power, a profile curve of the voltage value Vpp and a profile curve of the capacitance value C1 corresponding to the phase difference θ may be stored by changing the phase difference θ, The control device while shielding the substrate or the second electrode from the sputtering target by the shutter, sets the phase difference θ outside a first range from plus 30 degrees to plus 50 degrees from a phase difference θ1 at which the voltage value Vpp of the profile curve of the voltage value Vpp is minimum, outside a second range from plus 10 degrees to minus 10 degrees from a phase difference θ2 at which the voltage value Vpp of the profile curve of the voltage value Vpp is maximum, and outside a third range which is a range from minus 50 degrees to minus 30 degrees from the phase difference θ2, and supplies the second high-frequency power from the second high-frequency power source to the second electrode in a state where the output impedance and the load-side impedance are matched.

[0019] With such a vacuum processing apparatus, stable film-forming performance can be obtained even if conditioning on the substrate side is performed before sputtering film formation.

[0020] In the above vacuum processing apparatus, The fourth range described above may be a range from minus 10 degrees to plus 10 degrees from the phase difference θ1.

[0021] With this type of vacuum processing apparatus, stable film deposition performance can be obtained even if the substrate is conditioned before sputtering. [Effects of the Invention]

[0022] As described above, the present invention provides a vacuum treatment method that can obtain stable film deposition performance even when substrate conditioning is performed before sputtering film deposition, and a vacuum treatment apparatus for carrying out the vacuum treatment method. [Brief explanation of the drawing]

[0023] [Figure 1] This is a schematic block diagram showing an example of a film deposition apparatus according to this embodiment. [Figure 2] Figure (a) is a graph illustrating an example of a profile curve for a voltage value Vpp. Figure (b) is a graph illustrating an example of a profile curve for a capacitance value C1. [Figure 3] Figure (a) is a cross-sectional SEM image of the concave pattern before the sputtering film is formed. Figures (b) to (e) are cross-sectional SEM images of the sputtering film after it has been formed on the concave pattern. [Figure 4] This is the profile curve for the voltage value Vpp and capacitance value C1 in Test A. [Figure 5] This is a cross-sectional SEM image of a sputtered film after it has been formed in a concave pattern. [Figure 6] This is an example of a profile curve for voltage value Vpp and capacitance value C1 according to this embodiment. [Figure 7] Figures (a) and (b) are schematic cross-sections showing an example of the film deposition method according to this embodiment. Figure (c) is a cross-sectional SEM image of the sputtering film after the sputtering film has been formed in a concave pattern. [Figure 8]This is an example of a profile curve for voltage value Vpp and capacitance value C1 according to this embodiment. [Figure 9] This is an example of a profile curve for the capacity value C2 according to this embodiment. [Figure 10] This graph shows the film formation performance of the comparative example and this embodiment. [Figure 11] This graph shows the film formation performance of the comparative example and this embodiment. [Modes for carrying out the invention]

[0024] Embodiments of the present invention will be described below with reference to the drawings. Furthermore, identical components or components having the same function may be denoted by the same reference numeral, and after describing such components, their descriptions may be omitted as appropriate. Also, the numerical values ​​shown below are illustrative and not limiting to this example.

[0025] (Film forming equipment)

[0026] Figure 1 is a schematic block diagram showing an example of a film deposition apparatus according to this embodiment.

[0027] One example of a vacuum processing apparatus, the film deposition apparatus 1, comprises an electrode 11 (first electrode), an electrode 12 (second electrode), a shutter 13, a power supply source 21 (first power supply source), a power supply source 22 (second power supply source), a phase adjuster 50, and a control device 60. Electrodes 11, 12, and 13 are installed in a vacuum chamber (not shown). The potential of the vacuum chamber is set to ground potential. The film deposition apparatus 1 is a three-electrode type film deposition apparatus equipped with electrodes 11, 12, and a vacuum chamber at ground potential. The film deposition apparatus 1 is a single-wafer type film deposition apparatus capable of sputtering film deposition on each substrate individually.

[0028] The electrode 11 includes a sputtering target 111 and a back plate (support plate) 112. The sputtering target 111 contains a coating material to be sputtered onto the substrate 121. Examples of coating materials include insulators such as alumina and silicon oxide, and metals such as aluminum. The back plate 112 is made of, for example, a conductive metal.

[0029] Electrode 12 faces electrode 11. Electrode 12 also functions as a support base capable of supporting substrate 121. An electrostatic chuck may be provided on the support surface where electrode 12 supports substrate 121. Substrate 121 includes a semiconductor wafer, a silicon oxide layer, etc. Patterns such as line-and-space and through-holes are formed on the film-deposited surface of substrate 121 facing electrode 11.

[0030] The shutter 13 is installed on the electrode 12. The shutter 13 may be made of an insulator such as alumina, quartz, or glass, or it may be made of a conductor such as SUS or aluminum. If the shutter is an insulator, its potential is the floating potential. If the shutter 13 is made of a conductor, the shutter 13 is electrically connected to the electrode 12, and its potential is the same as the potential of the electrode 12. By opening and closing the shutter 13, the substrate 121 is exposed to the sputtering target 111 (open state), or the substrate 121 is shielded from the sputtering target 111 by the shutter 13 (closed state).

[0031] The power supply 21 includes a high-frequency power supply 31 (first high-frequency power supply) and a matching circuit 41 (first matching circuit). The high-frequency power supply 31 outputs first high-frequency power. The first high-frequency power is typically 13.56 MHz RF power and can output, for example, 100W to 5000W.

[0032] The matching circuit 41 is connected between the high-frequency power supply 31 and the electrode 11. The matching circuit 41 includes an input terminal 415, an output terminal 416, a variable capacitor 411, a variable capacitor 412, and an inductance 413. The input terminal 415 is connected to the high-frequency power supply 31. The output terminal 416 is connected to the electrode 11. The variable capacitor 411 is connected between the input terminal 415 and the ground potential. The variable capacitor 412 is connected in series between the input terminal 415 and the output terminal 416. The inductance 413 is connected in series with the variable capacitor 412 between the input terminal 415 and the output terminal 416. The matching circuit 41 is controlled by a control device 60, which drives the variable capacitors 411 and 412 respectively to perform automatic matching, matching the output impedance of the high-frequency power supply 31 with the load-side impedance (electrode 11 side impedance) connected to the high-frequency power supply 31.

[0033] The load-side impedance connected to the high-frequency power supply 31 includes the electrodes 11, the cable between the electrodes 11 and the matching circuit 41, the discharge plasma, and the vacuum chamber (not shown) housing the electrodes 11 and 12.

[0034] The power supply 22 includes a high-frequency power supply 32 (second high-frequency power supply) and a matching circuit 42 (second matching circuit). The high-frequency power supply 32 outputs a second high-frequency power which has the same period as the first high-frequency power but is lower than the first high-frequency power. The second high-frequency power is typically 13.56 MHz RF power and can output 50W to 500W. Note that the high-frequency power is not limited to this example as long as it is in the same frequency band.

[0035] The matching circuit 42 is connected between the high-frequency power supply 32 and the electrode 12. The matching circuit 42 includes an input terminal 425, an output terminal 426, a variable capacitor 421 (first variable capacitor), a variable capacitor 422 (second variable capacitor), and an inductance 423. The input terminal 425 is connected to the high-frequency power supply 32. The output terminal 426 is connected to the electrode 12. The variable capacitor 421 is connected between the input terminal 425 and the ground potential. The variable capacitor 422 is connected in series between the input terminal 425 and the output terminal 426. The inductance 423 is connected in series with the variable capacitor 422 between the input terminal 425 and the output terminal 426. The matching circuit 42 is controlled by the control device 60, which drives the variable capacitors 421 and 422 respectively to perform automatic matching, matching the output impedance of the high-frequency power supply 32 with the load-side impedance (electrode 12 side impedance) connected to the high-frequency power supply 32.

[0036] The load-side impedance connected to the high-frequency power supply 32 includes the electrode 12, the cable between the electrode 12 and the matching circuit 42, the discharge plasma, and the vacuum chamber (not shown) housing the electrodes 11 and 12.

[0037] Here, the capacitance of variable capacitor 421 is represented by capacitance value C1 (maximum 1000pF), and the capacitance of variable capacitor 422 (maximum 500pF) is represented by capacitance value C2. The matching circuit 42 is also equipped with a sensor 424 that detects the voltage value Vpp (Voltage peak to peak) and voltage value Vdc (Voltage direct current) of the high-frequency power within the matching circuit 42 at the output terminal 426. Voltage value Vpp means the difference between the maximum and minimum voltages of the AC voltage. Voltage value Vdc means the voltage that is midway between the maximum and minimum values ​​of Vpp when the voltage value Vpp applied to the electrode 12 is floating at a constant voltage overall. Voltage value Vdc is also called the offset voltage or bias voltage. In the case of RF discharge, voltage value Vdc is generally at a lower potential than the plasma potential (Vp). For example, if the plasma potential is positive, then voltage value Vdc is at a lower potential than this positive potential or at a negative potential.

[0038] In the matching circuit 42, the variable capacitor 421 is mainly used to match the output impedance of the high-frequency power supply 32 with the load impedance connected to the high-frequency power supply 32, and the variable capacitor 422 is mainly used to match the phase of the voltage wave with the phase of the current wave. Therefore, even when the output impedance of the high-frequency power supply 32 and the load impedance connected to the high-frequency power supply 32 are matched, depending on the capacitance value C1 of the variable capacitor 421, the second high-frequency power may be preferentially supplied from the input terminal 425 to the output terminal 426, a portion of the second high-frequency power may be discharged to ground potential, or it may not reach the output terminal 426 and be discharged to ground potential. For example, the larger the capacitance value C1 of the variable capacitor 421 is relatively, the more preferentially the second high-frequency power will be supplied from the input terminal 425 to the output terminal 426.

[0039] In the power supply source 22, the high-frequency power supply 32 has a display unit, and the voltage value Vpp, voltage value Vdc, capacitance value C1, and capacitance value C2 are displayed on this unit. These values ​​are also sent to the control device 60 and stored in a memory unit (not shown) within the control device 60. Such a sensor 424 may also be mounted in the matching circuit 41.

[0040] The phase adjuster 50 can adjust the phase of the first high-frequency power output from the high-frequency power supply 31 and input to the matching circuit 41. The phase adjuster 50 can adjust the phase of the second high-frequency power output from the high-frequency power supply 32 and input to the matching circuit 42. The phase adjuster 50 can provide a phase difference θ between the phase of the first high-frequency power and the phase of the second high-frequency power.

[0041] The control device 60 controls the power supply 21, power supply 22, phase adjuster 50, and shutter 13 (shutter opening and closing). The control device 60 may be provided independently of the power supply 21, power supply 22, and phase adjuster 50, or a part of it may be incorporated into any of the power supply 21, power supply 22, and phase adjuster 50. The control device 60 has a storage unit for storing data, a calculation unit for processing the data, etc.

[0042] (Film forming method)

[0043] In this embodiment, profile curves for the voltage value Vpp and capacitance value C1 are obtained in advance by changing the phase difference θ, corresponding to the phase difference θ. A dummy substrate may be used as the substrate 121 during the stage of obtaining these profile curves.

[0044] First, a first high-frequency power is output from the high-frequency power supply 31 to form a discharge plasma between the electrode 11 and the electrode 12. For example, argon is used as the discharge gas. The output impedance of the high-frequency power supply 31 and the load-side impedance (electrode 11-side impedance) connected to the high-frequency power supply 31 are matched by the matching circuit 41.

[0045] Next, the second high-frequency power is output from the high-frequency power supply 32, and a phase difference θ is created between the phase of the first high-frequency power and the phase of the second high-frequency power by operating the phase adjuster 50. Here, the first high-frequency power and the second high-frequency power are not changed, and their respective power values ​​are fixed. Furthermore, the second high-frequency power is set lower than the first high-frequency power, for example, to 1 / 10 to 1 / 2 of the first high-frequency power.

[0046] Next, with the discharge plasma still formed between electrode 11 and electrode 12, the matching circuit 42 detects the voltage value Vpp of the second high-frequency power and the capacitance value C1 of the variable capacitor 421, corresponding to the phase difference θ, when the output impedance of the high-frequency power supply 32 is matched with the load-side impedance (electrode 12 side impedance) connected to the high-frequency power supply 32. Then, by changing the phase difference θ, a profile curve of the voltage value Vpp corresponding to the phase difference θ when the output impedance of the high-frequency power supply 32 is matched with the load-side impedance connected to the high-frequency power supply 32 (Figure 2(a)) and a profile curve of the capacitance value C1 corresponding to the phase difference θ (Figure 2(b)) are obtained.

[0047] Here, the phase difference θ is formed by delaying the phase of the second high-frequency power relative to the phase of the first high-frequency power using the phase adjuster 50, and is appropriately changed within the range of 0 to 360 degrees. For example, when changing the phase difference θ from 0 degrees, it is changed at predetermined intervals from 0 degrees, for example, every 10 degrees: 10 degrees, 20 degrees, ..., 360 degrees. Then, a sputtering film is formed on the substrate 121 by selecting a combination of voltage value Vpp and capacitance value C1 within the predetermined range of the changed phase difference θ. Here, forming a sputtering film on the substrate 121 means embedding the sputtering film in the recessed patterns (line and space, through holes, etc.) formed on the substrate 121, and forming a sputtering film on the surface of the substrate 121 outside the recessed patterns. The sputtering film formed on the surface of the substrate 121 outside the recessed patterns may be removed as excess by methods such as chemical mechanical polishing (CMP) as needed after the sputtering film has been formed.

[0048] As described above, Figure 2(a) is a graph illustrating an example of a profile curve for the voltage value Vpp. Figure 2(b) is a graph illustrating an example of a profile curve for the capacitance value C1. In Figure 2(a), the horizontal axis is the phase difference θ and the vertical axis is the voltage value Vpp. In Figure 2(b), the horizontal axis is the phase difference θ and the vertical axis is the capacitance value C1. The first high-frequency power output from the high-frequency power supply 31 is 4000W, and the second high-frequency power output from the high-frequency power supply 32 is 400W. The reduced pressure atmosphere is 0.1 to 4.0 Pa using argon gas. The distance between the sputtering target and the substrate is 50 to 90 mm. Note that as Vdc shown in the graph increases, the bias potential applied to the electrode 12 becomes stronger on the negative bias side.

[0049] For example, Figure 2(a) shows the profile curves of the voltage value Vpp in two tests, Test A and Test B. Test A is the profile curve when a high-frequency power supply 32 is used, which outputs a second high-frequency power whose phase is synchronized with the first high-frequency power output from high-frequency power supply 31.

[0050] On the other hand, Test B is a profile curve when a high-frequency power supply 32 is used, which outputs a second high-frequency power whose phase is 50 degrees ahead of the phase of the first high-frequency power output from high-frequency power supply 31. This is equivalent to the cable length between the high-frequency power supply 32 and the matching circuit 42 being increased by 50 degrees as a phase difference due to maintenance of the film deposition apparatus 1, etc. Note that in Test B, profile curves for voltage value Vpp and capacitance value C1 were obtained in a different film deposition chamber than in Test A.

[0051] In Test A, the voltage value Vpp is high when the phase difference θ is around 0 degrees, and tends to gradually decrease as the phase difference θ increases. The voltage value Vpp is at its lowest point at a phase difference θ of 60 degrees, and thereafter tends to gradually increase as the phase difference θ increases. On the other hand, in Test B, the voltage value Vpp is also high when the phase difference θ is around 60 degrees, and tends to gradually decrease as the phase difference θ increases. The voltage value Vpp is at its lowest point at a phase difference θ of 110 degrees, and thereafter tends to gradually increase as the phase difference θ increases.

[0052] Thus, the profile curves for the voltage values ​​Vpp in both Test A and Test B both exhibit a downward-convex curve.

[0053] Furthermore, Figure 2(b) shows the p-profile curves of the volume value C1 for Test A and Test B. In Test A, the volume value C1 is low when the phase difference θ is around 0 degrees, and thereafter, the volume value C1 tends to gradually increase as the phase difference θ increases. On the other hand, in Test B, the volume value C1 is also low when the phase difference θ is around 60 degrees, and thereafter, the volume value C1 tends to gradually increase as the phase difference θ increases.

[0054] In this embodiment, these profile curves are used to set the phase difference θ to a first range from +30 degrees to +50 degrees, where the voltage value Vpp of the profile curve for the voltage value Vpp is at its lowest, and a sputtering film is formed on the substrate 121.

[0055] For example, in Test A, the phase difference θ1 at which the voltage value Vpp is lowest is 50 degrees, and the first range is 80 degrees to 100 degrees. In Test B, the phase difference θ1 at which the voltage value Vpp is lowest is 100 degrees, and the first range is 130 degrees to 150 degrees. In this embodiment, a voltage value Vpp and a capacitance value C1 belonging to this first range are applied to form a sputtering film on the substrate 121.

[0056] This section explains the difference between a sputtered film when a voltage value Vpp and capacitance value C1 belonging to the first range are applied, and a sputtered film when a voltage value Vpp and capacitance value C1 not belonging to the first range are applied.

[0057] Figures 3(a) to 3(e) are cross-sectional SEM images. Figure 3(a) is a cross-sectional SEM image of the concave pattern before the sputtering film is formed. Figure 3(a) shows a concave pattern made of silicon oxide, with a depth of 240 nm and an aspect ratio of 1.0. The part indicated by arrow A is the end where the bottom of the concave pattern and the side wall intersect at approximately 90 degrees, and the part indicated by arrow B is the uppermost end of the side wall. Figures 3(b) to 3(e) are cross-sectional SEM images of the sputtering film after it has been formed in the concave pattern. Figures 3(b) to 3(e) show the state after the alumina film, as the sputtering film, has been embedded in this concave pattern.

[0058] For example, as sputtered films when a phase difference θ not belonging to the first range is applied, Figure 3(b) shows an SEM image of Test B with a phase difference of 60 degrees (a phase difference θ to the left of the lowest value when the lowest value of the voltage value Vpp profile curve is used as the reference), and Figure 3(c) shows an SEM image of Test B with a phase difference of 100 degrees (the lowest value of the voltage value Vpp profile curve). In these alumina films, the wrapping around to the edges indicated by arrow A was poor, and a phenomenon occurred where the alumina film was sharply concave at the edges. This tendency was also observed in Test A. Furthermore, it was confirmed that the opening indicated by arrow C narrowed, and if film deposition was continued, the film closed at the top, forming a void.

[0059] On the other hand, Figure 3(d) shows an SEM image of a sputtered film with a phase difference θ belonging to the first range, with a phase difference of 100 degrees in Test A, and Figure 3(e) shows an SEM image of a sputtered film with a phase difference of 140 degrees in Test B. In these alumina films, it was found that the alumina film did not have sharp indentations at the edges, and that an alumina film with excellent step coverage was formed at the edges. Furthermore, even when the aspect ratio of the concave pattern was 0.2 to 1.0, when a phase difference θ not belonging to the first range was applied, the wrap-around to the edges indicated by arrow A was not good, while when a phase difference θ belonging to the first range was applied, an alumina film with excellent step coverage was formed.

[0060] In other words, since the profile curve of the voltage value Vpp is convex downwards, the same voltage value Vpp that belongs to the first range also exists outside the first range. However, instead of selecting this voltage value Vpp outside the first range, even if the voltage value Vpp is the same, by selecting a combination of the voltage value Vpp that belongs to the first range and a capacitance value C1 that is relatively high, an alumina film with excellent step coverage is formed. Here, in the first range, the capacitance value C1 is set to be larger than the capacitance value C2.

[0061] Next, we will explain the results when the phase difference θ is further increased from 100 degrees using Test A.

[0062] Figure 4 shows the profile curves for voltage Vpp and capacitance C1 in Test A. In Figure 4, the horizontal axis represents the phase difference θ, and the left vertical axis shows the voltage Vpp and the voltage Vdc in addition to Vpp. The right vertical axis shows the capacitance C1. Figure 4 also shows the profile curves for the case where the phase difference θ is between 0 and 110 degrees.

[0063] When the phase difference θ exceeded 100 degrees and reached 110 to 240 degrees, the capacitance value C1 exceeded its maximum capacitance value of 1000pF, resulting in a mismatch between the output impedance of the high-frequency power supply 32 and the impedance of the load connected to the high-frequency power supply 32. In this mismatch region (110 to 240 degrees), both the voltage value Vpp and the voltage value Vdc became unstable.

[0064] On the other hand, when the phase difference θ exceeded 240 degrees and reached 250 degrees, the output impedance of the high-frequency power supply 32 and the load impedance connected to the high-frequency power supply 32 matched again. Subsequently, as the phase difference θ increased, the voltage value Vpp gradually increased, reaching its maximum value at a phase difference θ of 300 degrees, and then gradually decreasing as the phase difference θ increased. It was also found that the capacitance value C1 was high around a phase difference θ of 250 degrees, and then gradually decreased as the phase difference θ increased. Furthermore, it was found that the voltage value Vdc gradually decreased in the range of 240 to 290 degrees where the voltage value Vpp increased.

[0065] Thus, it was found that when the phase difference θ is between 250 and 360 degrees, the profile curve of the voltage value Vpp is convex upwards.

[0066] Thus, it was confirmed that in the region where the phase of the waveform of the high-frequency voltage supplied to electrode 11 coincides with the waveform of the high-frequency voltage supplied to electrode 12 (referred to as the in-phase region), the voltage value Vpp is convex downwards and the capacitance value C1 is upwards to the right, whereas in the region where the phase difference θ differs from that of the waveform of the high-frequency voltage supplied to electrode 12 (referred to as the anti-phase region), the voltage value Vpp is convex upwards and the capacitance value C1 is downwards to the right.

[0067] In this embodiment, in the region where the phase difference θ is between 250 and 360 degrees, the phase difference θ is set to a second range of +10 degrees to -10 degrees from the phase difference θ2 at which the voltage value Vpp in the profile curve of the voltage value Vpp is maximum, and a sputtering film is formed on the substrate 121. For example, the phase difference θ2 at which the voltage value Vpp is maximum is 300 degrees, and the second range is between 290 and 310 degrees. Here, in the second range, the capacitance value C1 is set to be greater than the capacitance value C2.

[0068] This section explains the difference between a sputtered film when a voltage value Vpp and capacitance value C1 belonging to the second range are applied, and a sputtered film when a voltage value Vpp and capacitance value C1 belonging to a range that does not belong to the second range are applied.

[0069] Figures 5(a) and 5(b) are cross-sectional SEM images of the sputtering film after it has been formed in the concave pattern shown in Figure 3(a).

[0070] For example, as an example of a sputtering film that does not belong to the first and second ranges, we show an example where film deposition is started on an empty concave pattern under the condition of a phase difference of 260 degrees. Figure 5(a) shows an SEM image with a phase difference of 260 degrees. In this case, the voltage value Vdc becomes greater than 50 (V), and it was confirmed that the uppermost edge of the concave pattern indicated by arrow B is etched, and the alumina film becomes faceted at this uppermost edge.

[0071] On the other hand, as an example of a sputtered film belonging to the second range, Figure 5(b) shows an SEM image with a phase difference of 300 degrees. In this alumina film, it was found that wrapping around to the edges was good, and the alumina film was formed without sharp indentations at the edges, resulting in an alumina film with excellent step coverage at the edges. It was also confirmed that when the phase difference θ exceeded 310 degrees, the alumina film was sharply indented at the edges.

[0072] Thus, it was found that even if both the first high-frequency power output from the high-frequency power supply 31 and the second high-frequency power output from the high-frequency power supply 32 are fixed power, the embedding characteristics of the sputtering film for concave patterns can be changed by manipulating the phase difference θ. In particular, it was found that by setting the phase difference θ to a first range of +30 degrees to +50 degrees, starting from phase difference θ1 where the profile curve of the voltage value Vpp is at its minimum value, a sputtering film exhibiting excellent step coverage can be formed. Alternatively, it was found that by setting the phase difference θ to a second range of +10 degrees to -10 degrees, starting from phase difference θ2 where the profile curve of the voltage value Vpp is at its maximum value, a sputtering film exhibiting excellent step coverage can be formed.

[0073] Furthermore, oscilloscope observations of the high-frequency power waveforms at position 418 (Figure 1), which is between electrode 11 and matching circuit 41 and directly above electrode 11, and at position 428, which is between electrode 12 and matching circuit 42 and directly below electrode 12, revealed that from 0 to 110 degrees, the phase of the high-frequency voltage waveform supplied to electrode 11 coincided with the phase of the high-frequency voltage waveform supplied to electrode 12, while from 250 to 360 degrees, the phase of the high-frequency voltage waveform supplied to electrode 11 and the phase of the high-frequency voltage waveform supplied to electrode 12 were out of sync.

[0074] The control device 60 stores previously acquired profile curve data of voltage value Vpp and capacitance value C1. The control device 60 forms a sputtering film on the substrate 121 by selecting a combination of voltage value Vpp and capacitance value C1 within a predetermined region of phase difference θ.

[0075] For example, the control device 60 controls the phase adjuster 50 to set the phase difference θ to a first range from +30 to +50 degrees from the phase difference θ1 where the voltage value Vpp in the profile curve of the voltage value Vpp is at its lowest (voltage value Vpp: 80~130(V)), capacitance value C1: 600pF or more, or to a second range from +10 to -10 degrees from the phase difference θ2 where the voltage value Vpp in the profile curve of the voltage value Vpp is at its maximum (voltage value Vpp: 260~280(V)), capacitance value C1: 600~900(pF), Vdc: 50(V) or less), thereby forming a sputtering film on the substrate 121 with the output impedance of the high-frequency power supply 32 and the load side impedance matched.

[0076] This results in the formation of a sputtering film that exhibits excellent step-level coverage for concave patterns.

[0077] In the first or second range, the phase difference θ may be changed in steps to form a sputtering film on the substrate 121. When the phase difference θ is changed in steps, the first high-frequency power output from the high-frequency power supply 31 is kept at the same power. For example, the voltage value Vdc tends to increase as the capacitance value C1 increases. And as the voltage value Vdc increases, the concave pattern that is the base of the sputtering film becomes more susceptible to damage from the sputtering particles.

[0078] Therefore, immediately after starting sputtering deposition, the phase difference θ is set to a low voltage value Vdc to form a sputtered film in the concave pattern. Once a sputtered film of a predetermined thickness is embedded in the concave pattern, the phase difference θ may be changed to, for example, a phase difference θ that increases the deposition rate, and sputtering deposition may be performed.

[0079] Figure 6 shows an example of a profile curve for voltage value Vpp and capacitance value C1 according to this embodiment. In this example, in addition to the first and second ranges, a third range is added to the phase difference θ range.

[0080] As shown in the example in Figure 5(b), when film deposition is started on an empty concave pattern under the condition of a phase difference of 260 degrees, the uppermost edge of the concave pattern is etched. However, when employing a process that gradually changes the phase difference θ, excellent step coverage can be obtained by employing film deposition in the third range, which includes a phase difference of 260 degrees, in the later steps of the stepwise process.

[0081] For example, after forming a sputtering film on the substrate 121 in the first or second range, a sputtering film is formed on the substrate 121 in the third range. Here, the third range is the range where the phase difference θ is smaller than that of the second range and larger than that of the first range. For example, the third range is the range from minus 50 degrees to minus 30 degrees from the phase difference θ2. The capacitance value C1 in the third range is 875pF to 1000pF. When switching from film deposition in the first or second range to film deposition in the third range, the first high-frequency power output from the high-frequency power supply 31 is maintained at the same power.

[0082] Figures 7(a) and 7(b) are schematic cross-sections showing an example of the film deposition method according to this embodiment. Figure 7(c) is a cross-sectional SEM image of the sputtering film after it has been formed on the concave pattern. The aspect ratio of the concave pattern 122 shown in Figure 7(c) is the same as the aspect ratio of the concave pattern shown in Figure 3(a).

[0083] For example, as shown in Figure 7(a), in the first step, a sputtering film 125, such as an alumina film, is formed in a recessed pattern 122 made of silicon oxide under the condition that the phase difference θ is within the first or second range. As a result, the sputtering film 125 is formed within the recessed pattern 122. In the first step, the sputtering film 125 does not fill the entire interior of the recessed pattern 122, but rather fills the recessed pattern 122 while leaving unfilled portions. For example, the target film thickness in the first step is set so that the film thickness of the sputtering film 125 deposited in the parts where the recessed pattern 122 is not formed (field portions) is 40% to 60% of the opening width of the recessed pattern 122. Here, the opening width is the opening width at the uppermost end of the recessed pattern 122 when the recessed pattern 122 is cut in the direction in which the lines and spaces are arranged, if the recessed pattern 122 is line and space, and the maximum diameter at the uppermost end of the through hole if it is a through hole. In the first step, the uppermost edge 122c of the concave pattern 122 is covered (protected) by the sputtering film 125.

[0084] In the recessed pattern 122, the sputtering film 125 is deposited from the bottom of the recessed pattern 122, and also from the side walls of the recessed pattern 122. Therefore, in the sputtering film 125 formed within the recessed pattern 122, a recess 125b is formed near the center of the sputtering film 125 where the sputtering film 125 is recessed.

[0085] If a process is adopted that does not gradually change the phase difference θ, in other words, if film deposition continues while the phase difference θ remains within the first or second range, then in order to fill the recessed pattern 122 with the sputtering film 125 until the recesses 125b disappear, it is necessary to deposit a sputtering film 125 on the substrate 121 that is thicker than or equal to the depth of the recessed pattern 122. However, the thicker the sputtering film 125 deposited on the substrate 121, the greater the burden on the subsequent CMP process. Furthermore, recesses 125b are more likely to form as the aspect ratio of the recessed pattern increases, and if film deposition continues while remaining within the first or second range, the phenomenon of recesses 125b remaining as voids in the sputtering film 125 may occur.

[0086] Therefore, in this embodiment, the deposition of the film in the first or second range is stopped in the state shown in Figure 7(a), and as the next step, sputtering deposition is performed with a phase difference θ in the third range. For example, after forming the sputtered film 125, a sputtered film 126 is formed on the sputtered film 125 under the condition that the phase difference θ is in the third range. This state is shown in Figure 7(b).

[0087] In the third range, as the capacitance value C1 increases, the second high-frequency power is supplied more preferentially to the electrode 12 via the output terminal 426, and the voltage value Vdc tends to increase compared to the first and second ranges. Therefore, simultaneously with the deposition of sputtering particles on the substrate 121, ion particles (e.g., positive ions) are attracted to the substrate 121 by the bias potential applied to the substrate 121, and physical etching of the sputtering film by the ion particles also occurs. Here, when the deposition of sputtering particles on the substrate 121 is dominant over the physical etching of the sputtering film by the ion particles, the sputtering film is formed on the substrate 121 while the sputtering film is physically etched.

[0088] As a result, in sputtering deposition in the third range, the width of the recess 125b widens due to the etching effect. Also, in the sputtering film 125 covering the uppermost edge 122c of the recessed pattern 122, so-called film thinning (a phenomenon in which the film thickness becomes thinner) occurs due to the etching effect. Since the width of the recess 125b widens, it becomes easier to fill the recess 125b with the sputtering film. Furthermore, since the uppermost edge 122c of the recessed pattern 122 is protected by the sputtering film 125, the uppermost edge 122c maintains its original shape without being etched.

[0089] Therefore, even if the concave pattern 122 has a high aspect ratio, after the sputtering film 126 is formed, a sputtering film 127 without internal voids is formed within the concave pattern 122 by the sputtering film 125 and the sputtering film 126 covering the sputtering film 125. The fact that the concave pattern 122 is well filled by the sputtering film 127 without internal voids is also confirmed by the cross-sectional SEM image shown in Figure 7(c).

[0090] In this embodiment, film deposition may be performed in a first phase difference θ range followed by film deposition in a third phase difference θ range, or film deposition may be performed in a second phase difference θ range followed by film deposition in a third phase difference θ range.

[0091] To switch from the phase difference θ in the first range to the phase difference θ in the third range, the phase difference θ should be increased from the first range to the third range. However, when transitioning the phase difference θ from the first range to the third range, the phase difference θ must pass through a mismatched region before reaching the third range. Therefore, this method requires a deposition process that involves temporarily stopping the plasma discharge after deposition in the first range, and then switching from the phase difference θ in the first range to the phase difference θ in the third range.

[0092] On the other hand, to switch from the phase difference θ in the second range to the phase difference θ in the third range, it is sufficient to reduce the phase difference θ from the second range to the third range. In this case, even when the phase difference θ is shifted from the second range to the third range, there is no mismatched region between the second and third ranges, so it is not necessary to pass through a mismatched region. Therefore, after film deposition in the second range, it becomes possible to switch to the third range by continuously changing the phase difference θ without stopping the plasma discharge.

[0093] Furthermore, in this embodiment, before forming a sputtering film on the substrate 121, a second high-frequency power may be supplied to the electrode 12 while performing a preliminary discharge. For example, before forming the sputtering film, the substrate 121 or electrode 12 may be shielded from the sputtering target 111 by the shutter 13, and a discharge plasma may be formed between the electrode 11 and electrode 12 by a first high-frequency power as a preliminary discharge, while a second high-frequency power may be supplied to the electrode 12 from the high-frequency power supply 32. In this case, the phase difference θ is selected by combining a voltage value Vpp and a capacitance value C1 within a predetermined range.

[0094] Here, during the pre-discharge, one approach is to randomly supply a second high-frequency power to the electrode 12 without considering the phase difference θ. However, with this approach, if a dummy substrate is used as the substrate 121 during the pre-discharge, reverse sputtering of the dummy substrate or shutter 13 may occur depending on the degree of the bias potential applied to the electrode 12. When such reverse sputtering occurs, foreign matter such as particles and flakes are emitted from the dummy substrate or shutter 13, and this foreign matter may fly around inside the vacuum chamber or adhere to the inner wall of the vacuum chamber, jigs inside the vacuum chamber, etc. As a result, problems such as foreign matter contamination of the sputtered film after the start of sputtering deposition may occur. Alternatively, depending on the degree of the bias potential, abnormal discharge may occur on the electrode 12 side during the pre-discharge, potentially damaging not only the dummy substrate but also the electrode 12 or shutter 13.

[0095] However, if the second high-frequency power is not supplied to the electrode 12 in parallel with the pre-discharge, sputtering deposition will begin without energizing the power supply source 22 (high-frequency power supply 32, matching circuit 42). Consequently, when sputtering deposition begins, the impedance of the power supply source 22 may change due to thermal expansion and contraction of the electronic components constituting the power supply source 22. As a result, even after sputtering deposition begins, the deposition performance, such as deposition rate, deposition distribution, and film quality, may not be stable.

[0096] One possible method to suppress reverse sputtering of the shutter 13 is to set the shutter 13 to ground potential. In this case, since no bias potential is applied to the shutter 13, reverse sputtering of the shutter 13 is suppressed. Also, the electrode 12 is shielded by the shutter 13. However, with this method, a predetermined voltage is applied between the shutter 13 and the electrode 12, which may cause a discharge between the shutter 13 and the electrode 12. In this case, foreign matter will ultimately be generated from either the shutter 13 or the electrode 12.

[0097] In this embodiment, the substrate 121 or electrode 12 is shielded from the sputtering target 111 by a shutter 13 with a floating potential or the same potential as the electrode 12, while the phase difference θ is set to a fourth range which is outside the first range, outside the second range, and outside the third range, and the second high-frequency power is supplied from the high-frequency power supply 32 to the electrode 12 while the output impedance of the high-frequency power supply 32 and the load side impedance are matched. Here, "shielding the substrate 121 or electrode 12 from the sputtering target 111 by the shutter 13" includes the shutter 13 shielding the substrate 121 when a wafer substrate or dummy substrate is placed on the electrode 12, as well as the shutter 13 shielding the electrode 12 when no substrate is placed on the electrode 12.

[0098] Figure 8 shows an example of a profile curve for voltage value Vpp and capacitance value C1 according to this embodiment. Figure 9 shows an example of a profile curve for capacitance value C2 according to this embodiment. In these examples, a fourth range is added to the range of phase difference θ in Test A, in addition to the first to third ranges.

[0099] The fourth range is defined as the range of phase difference θ that is outside the first range, outside the second range, and outside the third range. For example, the fourth range is the range from minus 10 degrees to plus 10 degrees from the phase difference θ1. In the fourth range, the capacitance value C1 is 500 pF or less, and the bias potential (Vdc) is approximately 0 (V). Also, as shown in Figure 9, the capacitance value C2 in the fourth range is 300 pF or more.

[0100] In this embodiment, the phase difference θ is set to a fourth range, and while shielding the substrate 121 or electrode 12 with the shutter 13, second high-frequency power is supplied from the high-frequency power supply 32 to the electrode 12 while the output impedance of the high-frequency power supply 32 and the load side impedance are matched. Here, when the electrode 12 is shielded with the shutter 13, the substrate 121 does not need to be placed on the electrode 12. Furthermore, first high-frequency power is supplied from the high-frequency power supply 31 to the electrode 11 while the output impedance of the high-frequency power supply 31 and the load side impedance are matched, and a discharge plasma is formed between the electrode 11 and the electrode 12. As a result, both power supply sources 21 and 22 are conditioned by a preliminary discharge before sputtering film deposition.

[0101] During the conditioning of power sources 21 and 22, the shutter 13 may be opened to perform temporary sputtering deposition on multiple dummy substrates. Furthermore, if the sputtering target material and the material of the shutter 13 are the same (for example, alumina), even if sputtering particles from the sputtering target 111 are deposited on the shutter 13, the film deposited from the shutter 13 will not become airborne particles or flakes because the materials of the sputtering target material and the shutter 13 are the same.

[0102] During the conditioning of power sources 21 and 22, by setting the phase difference θ to the fourth range, a first high-frequency power is supplied to electrode 11, and a discharge plasma is formed between electrode 11 and electrode 12. At this time, the second high-frequency power output from the high-frequency power supply 32 is blocked by the variable capacitor 422 of the matching circuit 42, and flows more easily to ground via the variable capacitor 421. As a result, the high-frequency power supply 32 and the matching circuit 42 operate from a pre-discharge. In other words, both power sources 21 and 22 are conditioned by the pre-discharge.

[0103] In particular, if sputtering deposition is started without conditioning the power supply source 22, the phase difference θ set to the target value from the start of sputtering deposition may actually be shifted from the target value when sputtering deposition begins. As a result, even after sputtering deposition is started, the deposition performance, such as deposition rate, deposition distribution, and film quality, may not be stable.

[0104] In contrast, in this embodiment, since both power supply sources 21 and 22 are conditioned before sputtering film deposition begins, excellent film deposition performance can be obtained from the sputtering film deposition on the first substrate 121.

[0105] After conditioning the power supply sources 21 and 22, sputtering deposition may be started by setting the phase difference θ to a first range, or by setting the phase difference θ to a second range, or by setting the phase difference θ to the first or second range and then to a third range.

[0106] In sputtering film deposition, the bias potential applied to the electrode 12, substrate 121, or shutter 13 is suppressed by the pre-discharge, making it difficult for bias potential to be applied to the electrode 12, substrate 121, or shutter 13. As a result, foreign matter is less likely to be generated from the electrode 12, substrate 121, or shutter 13. This suppresses the inclusion of foreign matter in the sputtered film.

[0107] Figures 10(a) to 11(b) are graphs showing the film deposition performance of the comparative example and the film deposition performance of this embodiment. The same film deposition apparatus 1 is used in both the comparative example and this embodiment. In the comparative example, only the power supply source 21 is conditioned during the pre-discharge phase, and the power supply source 22 is not conditioned. In contrast, in this embodiment, both power supply sources 21 and 22 are conditioned during the pre-discharge phase.

[0108] The horizontal axis of Figure 10(a) represents the number of sputtering deposition cycles, indicated by the substrate number. That is, sputtering deposition is performed on each substrate (the same applies hereafter). The vertical axis of Figure 10(a) represents the in-plane average thickness (nm) of the sputtered film after sputtering deposition. The sputtering time is the same for all cycles. A silicon wafer is used as the substrate 121.

[0109] In the comparative example, although the film thickness stabilized after the fourth application, it decreased rapidly from the first to the third application. In contrast, in this embodiment, the film thickness was stable from the first application. The value obtained by subtracting the minimum film thickness from the maximum film thickness was Δ3.05 nm in the comparative example, while it was Δ1.31 nm in this embodiment.

[0110] The horizontal axis of Figure 10(b) represents the number of sputtering deposition cycles, indicated by the substrate number. The vertical axis of Figure 10(b) represents the in-plane thickness distribution (1σ (standard deviation)%) within the substrate.

[0111] In the comparative example, the in-plane distribution increases rapidly from the first to the third measurement, and then the film thickness stabilizes thereafter. In contrast, in this embodiment, the in-plane distribution is stable from the first measurement.

[0112] The horizontal axis in Figure 11(a) represents the number of sputtering deposition cycles, indicated by the substrate number. The vertical axis in Figure 11(b) represents the in-plane average value (n) of the refractive index of the sputtered film.

[0113] In the comparative example, the refractive index decreases rapidly from the first to the third measurement, and then stabilizes thereafter. In contrast, in this embodiment, the refractive index is stable from the first measurement.

[0114] The horizontal axis of Figure 11(b) represents the number of sputtering deposition cycles, indicated by the substrate number. The vertical axis of Figure 11(b) represents the number of particles within the substrate. Particles with a particle size of 0.034 μm or larger are counted.

[0115] As shown in Figure 11(b), the number of particles is about the same in the comparative example where the power supply source 22 is not conditioned during pre-discharge and in this embodiment where the power supply source 22 is conditioned during pre-discharge. For example, the average number of particles was 24 pcs in the comparative example and 15 pcs in this embodiment, both of which were 25 pcs or less. In other words, in this embodiment, even though the power supply source 22 is conditioned, the bias potential of the electrode 12 is about the same as in the comparative example where no bias potential is applied to the electrode 12, and it was found that particle emission from the shutter 13, substrate 12, or dummy substrate is suppressed.

[0116] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above and can be modified in various ways. For example, the conditioning described above can be applied not only to the film deposition apparatus 1 but also to a three-pole dry etching apparatus. Each embodiment is not necessarily an independent form and can be combined as much as technically possible. [Explanation of symbols]

[0117] 1...Film deposition equipment 11...Electrode 111... Sputtering target 112... Back plate 12...Electrode 121... Circuit board 122c…Top end 122... Concave pattern 125, 126, 127... Sputtering film 125b…recess 13...Shutter 21, 22...Power supply source 31, 32...High frequency power supply 41, 42...matching circuit 411, 412, 421, 422… Variable capacity 413, 423... Inductance 415, 425… Input terminals 416, 426… Output terminals 424...Sensor 50… Phase adjuster 60...Control device

Claims

1. A first electrode including a sputtering target, A second electrode facing the first electrode and capable of supporting the substrate, A shutter electrically connected to the second electrode, capable of exposing or shielding the substrate from the sputtering target, A first power supply source including a first high-frequency power supply that outputs a first high-frequency power, and a first matching circuit connected between the first high-frequency power supply and the first electrode, A second power supply comprising: a second high-frequency power supply that outputs a second high-frequency power having the same period as the first high-frequency power and lower than the first high-frequency power; and a second matching circuit connected between the second high-frequency power supply and the second electrode, including an input terminal connected to the second high-frequency power supply, an output terminal connected to the second electrode, a first variable capacitor connected between the input terminal and ground potential, and a second variable capacitor connected in series between the input terminal and the output terminal; A phase adjuster that adjusts the phases of the first high-frequency power output from the first high-frequency power supply and input to the first matching circuit, and the second high-frequency power output from the second high-frequency power supply and input to the second matching circuit. Using a film deposition apparatus equipped with, The first high-frequency power supply outputs the first high-frequency power to form a discharge plasma between the first electrode and the second electrode. The second high-frequency power is output from the second high-frequency power supply, and the phase adjuster is operated to create a phase difference θ between the phase of the first high-frequency power and the phase of the second high-frequency power. When the output impedance of the second high-frequency power supply and the load impedance connected to the second high-frequency power supply are matched, data is obtained that detects the voltage value Vpp of the second high-frequency power supply and the capacitance value C1 of the first variable capacitor, corresponding to the phase difference θ. Before forming a sputtering film on the substrate, the discharge plasma is formed between the first electrode and the second electrode while shielding the substrate or the second electrode from the sputtering target with the shutter, and the second high-frequency power is supplied to the second electrode from the second high-frequency power supply by selecting a combination of the voltage value Vpp and the capacitance value C1 within a predetermined range of the phase difference θ. As the aforementioned data, The phase difference θ is formed by delaying the phase of the second high-frequency power relative to the phase of the first high-frequency power. By changing the phase difference θ, a profile curve of the voltage value Vpp and a profile curve of the capacitance value C1 corresponding to the phase difference θ are obtained. While shielding the substrate or the second electrode from the sputtering target with the shutter, the phase difference θ is set to a fourth range outside the third range, which is outside the first range of +30 degrees to +50 degrees from the phase difference θ1 where the voltage value Vpp in the profile curve of the voltage value Vpp is at its lowest, outside the second range of +10 degrees to -10 degrees from the phase difference θ2 where the voltage value Vpp in the profile curve of the voltage value Vpp is at its maximum, and outside the third range of -50 degrees to -30 degrees from the phase difference θ2, and the second high-frequency power is supplied from the second high-frequency power supply to the second electrode while the output impedance and the load-side impedance are matched. The fourth range is the range from minus 10 degrees to plus 10 degrees from the phase difference θ1. Vacuum processing method.

2. A first electrode including a sputtering target, A second electrode facing the first electrode and capable of supporting the substrate, A shutter electrically connected to the second electrode, capable of exposing or shielding the substrate from the sputtering target, A first power supply source including a first high-frequency power supply that outputs a first high-frequency power, and a first matching circuit connected between the first high-frequency power supply and the first electrode, A second power supply comprising: a second high-frequency power supply that outputs a second high-frequency power having the same period as the first high-frequency power and lower than the first high-frequency power; and a second matching circuit connected between the second high-frequency power supply and the second electrode, including an input terminal connected to the second high-frequency power supply, an output terminal connected to the second electrode, a first variable capacitor connected between the input terminal and ground potential, and a second variable capacitor connected in series between the input terminal and the output terminal; A phase adjuster that adjusts the phases of the first high-frequency power output from the first high-frequency power supply and input to the first matching circuit, and the second high-frequency power output from the second high-frequency power supply and input to the second matching circuit. Using a film deposition apparatus equipped with, The first high-frequency power supply outputs the first high-frequency power to form a discharge plasma between the first electrode and the second electrode. The second high-frequency power is output from the second high-frequency power supply, and the phase adjuster is operated to create a phase difference θ between the phase of the first high-frequency power and the phase of the second high-frequency power. When the output impedance of the second high-frequency power supply and the load impedance connected to the second high-frequency power supply are matched, data is obtained that detects the voltage value Vpp of the second high-frequency power supply and the capacitance value C1 of the first variable capacitor, corresponding to the phase difference θ. Before forming a sputtering film on the substrate, the discharge plasma is formed between the first electrode and the second electrode while shielding the substrate or the second electrode from the sputtering target with the shutter, and the second high-frequency power is supplied to the second electrode from the second high-frequency power supply by selecting a combination of the voltage value Vpp and the capacitance value C1 within a predetermined range of the phase difference θ. As the aforementioned data, The phase difference θ is formed by delaying the phase of the second high-frequency power relative to the phase of the first high-frequency power. By changing the phase difference θ, a profile curve of the voltage value Vpp and a profile curve of the capacitance value C1 corresponding to the phase difference θ are obtained. While shielding the substrate or the second electrode from the sputtering target with the shutter, the phase difference θ is set to a fourth range outside the third range, which is outside the first range of +30 degrees to +50 degrees from the phase difference θ1 where the voltage value Vpp in the profile curve of the voltage value Vpp is at its lowest, outside the second range of +10 degrees to -10 degrees from the phase difference θ2 where the voltage value Vpp in the profile curve of the voltage value Vpp is at its maximum, and outside the third range of -50 degrees to -30 degrees from the phase difference θ2, and the second high-frequency power is supplied from the second high-frequency power supply to the second electrode while the output impedance and the load-side impedance are matched. The third range is set within the region between the first and second ranges, where the phase difference θ is greater than that of the first range and smaller than that of the second range. The fourth range is set to a region where the phase difference θ is smaller than that of the first range, and the bias voltage Vdc of the second high-frequency power is approximately zero. Vacuum processing method.

3. A first electrode including a sputtering target, A second electrode facing the first electrode and capable of supporting the substrate, A shutter electrically connected to the second electrode, capable of exposing or shielding the substrate from the sputtering target, A first power supply source including a first high-frequency power supply that outputs a first high-frequency power, and a first matching circuit connected between the first high-frequency power supply and the first electrode, A second power supply comprising: a second high-frequency power supply that outputs a second high-frequency power having the same period as the first high-frequency power and lower than the first high-frequency power; and a second matching circuit connected between the second high-frequency power supply and the second electrode, including an input terminal connected to the second high-frequency power supply, an output terminal connected to the second electrode, a first variable capacitor connected between the input terminal and ground potential, and a second variable capacitor connected in series between the input terminal and the output terminal; A phase adjuster that adjusts the phases of the first high-frequency power output from the first high-frequency power supply and input to the first matching circuit, and the second high-frequency power output from the second high-frequency power supply and input to the second matching circuit, A control device that controls the first power supply, the second power supply, the shutter, and the phase adjuster. It is equipped with, The control device is The first high-frequency power supply outputs the first high-frequency power to form a discharge plasma between the first electrode and the second electrode. The second high-frequency power is output from the second high-frequency power supply, and the phase adjuster is operated to create a phase difference θ between the phase of the first high-frequency power and the phase of the second high-frequency power. When the output impedance of the second high-frequency power supply and the load impedance connected to the second high-frequency power supply are matched, data is obtained that detects the voltage value Vpp of the second high-frequency power supply and the capacitance value C1 of the first variable capacitor, corresponding to the phase difference θ. Before forming a sputtering film on the substrate, the discharge plasma is formed between the first electrode and the second electrode while shielding the substrate or the second electrode from the sputtering target with the shutter, and the second high-frequency power is supplied to the second electrode from the second high-frequency power supply by selecting a combination of the voltage value Vpp and the capacitance value C1 within a predetermined range of the phase difference θ. As the aforementioned data, The phase difference θ is formed by delaying the phase of the second high-frequency power relative to the phase of the first high-frequency power. By changing the phase difference θ, a profile curve of the voltage value Vpp and a profile curve of the capacitance value C1 corresponding to the phase difference θ are obtained. While shielding the substrate or the second electrode from the sputtering target with the shutter, the phase difference θ is set to a fourth range outside the third range, which is outside the first range of +30 degrees to +50 degrees from the phase difference θ1 where the voltage value Vpp in the profile curve of the voltage value Vpp is at its lowest, outside the second range of +10 degrees to -10 degrees from the phase difference θ2 where the voltage value Vpp in the profile curve of the voltage value Vpp is at its maximum, and outside the third range of -50 degrees to -30 degrees from the phase difference θ2, and the second high-frequency power is supplied from the second high-frequency power supply to the second electrode while the output impedance and the load-side impedance are matched. The fourth range is the range from minus 10 degrees to plus 10 degrees from the phase difference θ1. Vacuum processing equipment.

4. A first electrode including a sputtering target, A second electrode facing the first electrode and capable of supporting the substrate, A shutter electrically connected to the second electrode, capable of exposing or shielding the substrate from the sputtering target, A first power supply source including a first high-frequency power supply that outputs a first high-frequency power, and a first matching circuit connected between the first high-frequency power supply and the first electrode, A second power supply comprising: a second high-frequency power supply that outputs a second high-frequency power having the same period as the first high-frequency power and lower than the first high-frequency power; and a second matching circuit connected between the second high-frequency power supply and the second electrode, including an input terminal connected to the second high-frequency power supply, an output terminal connected to the second electrode, a first variable capacitor connected between the input terminal and ground potential, and a second variable capacitor connected in series between the input terminal and the output terminal; A phase adjuster that adjusts the phases of the first high-frequency power output from the first high-frequency power supply and input to the first matching circuit, and the second high-frequency power output from the second high-frequency power supply and input to the second matching circuit, A control device that controls the first power supply, the second power supply, the shutter, and the phase adjuster. It is equipped with, The control device is The first high-frequency power supply outputs the first high-frequency power to form a discharge plasma between the first electrode and the second electrode. The second high-frequency power is output from the second high-frequency power supply, and the phase adjuster is operated to create a phase difference θ between the phase of the first high-frequency power and the phase of the second high-frequency power. When the output impedance of the second high-frequency power supply and the load impedance connected to the second high-frequency power supply are matched, data is obtained that detects the voltage value Vpp of the second high-frequency power supply and the capacitance value C1 of the first variable capacitor, corresponding to the phase difference θ. Before forming a sputtering film on the substrate, the discharge plasma is formed between the first electrode and the second electrode while shielding the substrate or the second electrode from the sputtering target with the shutter, and the second high-frequency power is supplied to the second electrode from the second high-frequency power supply by selecting a combination of the voltage value Vpp and the capacitance value C1 within a predetermined range of the phase difference θ. As the aforementioned data, The phase difference θ is formed by delaying the phase of the second high-frequency power relative to the phase of the first high-frequency power. By changing the phase difference θ, a profile curve of the voltage value Vpp and a profile curve of the capacitance value C1 corresponding to the phase difference θ are obtained. While shielding the substrate or the second electrode from the sputtering target with the shutter, the phase difference θ is set to a fourth range outside the third range, which is outside the first range of +30 degrees to +50 degrees from the phase difference θ1 where the voltage value Vpp in the profile curve of the voltage value Vpp is at its lowest, outside the second range of +10 degrees to -10 degrees from the phase difference θ2 where the voltage value Vpp in the profile curve of the voltage value Vpp is at its maximum, and outside the third range of -50 degrees to -30 degrees from the phase difference θ2, and the second high-frequency power is supplied from the second high-frequency power supply to the second electrode while the output impedance and the load-side impedance are matched. The third range is set within the region between the first and second ranges, where the phase difference θ is greater than that of the first range and smaller than that of the second range. The fourth range is set to a region where the phase difference θ is smaller than that of the first range, and the bias voltage Vdc of the second high-frequency power is approximately zero. Vacuum processing equipment.

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