JP2023083647A - Vacuum processing method and vacuum processing apparatus - Google Patents

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

The present invention relates to a vacuum processing method and a vacuum processing apparatus.

Electronic devices typified by 3D-NAND flash memories are becoming more multi-layered, and the number of layers tends to increase more and more. Therefore, the method of forming a film (for example, an insulating layer) included in the multilayer structure is particularly important.

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

Further, in the sputtering method, preliminary discharge such as pre-sputtering may be performed before film formation on the substrate (see, for example, Patent Document 2). This preliminary discharge conditions a power supply that supplies power to the sputtering target and a matching circuit (hereinafter referred to as a power supply, etc.) connected to the power supply.

As a significance of performing such a preliminary discharge, when the electronic parts and wiring (hereinafter referred to as electronic parts etc.) that constitute the power supply etc. are energized, Joule heat is generated in the electronic parts etc. The impedance of the power supply and the like changes before and after energization due to the current. Alternatively, one of the reasons is that the surface of the sputtering target is cleaned before film formation by performing preliminary discharge.

JP-A-08-302467 JP 2021-046577 A

In preliminary discharge, it is preferable not to supply power to the substrate side. This is because when electric power is supplied to the substrate during the preliminary discharge, reverse sputtering occurs on the substrate due to the bias potential applied to the substrate, causing particles to fly into the vacuum chamber from the substrate. This is because the particles adhere to and peel off from the inner wall of the vacuum chamber, jigs, and the like. Alternatively, depending on the degree of bias potential, abnormal discharge may occur on the substrate side during preliminary discharge.

However, the fact that the substrate side is not conditioned during the preliminary discharge means that the power source or the like for supplying power to the substrate side is not energized before the sputtering film formation, and the power is supplied to the substrate side after the sputtering film formation is started. A power source or the like is energized. Therefore, after the sputtering film formation is started, the impedance of the electronic components and the like that constitute the power source and the like may change in the power source and the like that supply power to the substrate side. As a result, even if sputtering film formation is started, a phenomenon may occur in which the film formation performance is not stable.

In view of the circumstances as described above, an object of the present invention is to provide a vacuum processing method capable of obtaining stable film formation performance even if the substrate is conditioned before sputtering film formation, and a vacuum processing apparatus for carrying out the vacuum processing method. is to provide

In order to achieve the above object, in a vacuum processing method according to one aspect of the present invention,
a first electrode comprising 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 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 high-frequency power supply that outputs a second high-frequency power that has the same period as the first high-frequency power and is lower than the first high-frequency power; and is connected between the second high-frequency power supply and the second electrode, an input terminal connected to a second high-frequency power supply, an output terminal connected to the second electrode, a first variable capacitor connected between the input terminal and a ground potential, and a connection between the input terminal and the output terminal a second power supply including a second matching circuit including a second variable capacitance connected in series therebetween;
Each 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 forming apparatus including a phase adjuster for adjusting the phase is used.
outputting the first high-frequency power from the first high-frequency power supply 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 provide a phase difference θ between the phase of the first high-frequency power and the phase of the second high-frequency power,
The voltage value Vpp of the second high-frequency power and the first voltage value Vpp according to the phase difference θ in a state where the output impedance of the second high-frequency power supply and the impedance of the load connected to the second high-frequency power supply are matched. Data is obtained by detecting the capacitance value C1 of the variable capacitor,
Before forming a sputtering film on the substrate, the discharge plasma is formed between the first electrode and the second electrode while the shutter shields the substrate or the second electrode from the sputtering target. At the same time, the second high-frequency power is supplied 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 within a predetermined range of the phase difference θ.

With such a vacuum processing method, stable film formation performance can be obtained even if the substrate side is conditioned before sputtering film formation.

In the above vacuum processing method,
As the above data
forming the phase difference θ by delaying the phase of the second high-frequency power with respect to the phase of the first high-frequency power;
obtaining a profile curve of the voltage value Vpp and a profile curve of the capacitance value C1 according to the phase difference θ by changing the phase difference θ;
While shielding the substrate or the second electrode from the sputtering target by the shutter, the phase difference θ is increased by 30 degrees from the phase difference θ1 at which the voltage value Vpp of the profile curve of the voltage value Vpp is the lowest. Outside the first range up to 50 degrees, the phase difference θ2 at which the voltage value Vpp of the profile curve of the voltage value Vpp is maximum is plus 10 degrees, and outside the second range up to minus 10 degrees, the phase difference θ2 A fourth range outside the third range, which is a range of minus 50 degrees to minus 30 degrees, is set, and in a state in which the output impedance and the load side impedance are matched, the second electrode is connected from the second high-frequency power supply to the second electrode. 2 RF power may be supplied.

With such a vacuum processing method, stable film formation performance can be obtained even if the substrate side is conditioned before sputtering film formation.

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

With such a vacuum processing method, stable film formation performance can be obtained even if the substrate side is conditioned before sputtering film formation.

In order to achieve the above object, a vacuum processing apparatus according to one aspect of the present invention includes:
a first electrode comprising 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 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 high-frequency power supply that outputs a second high-frequency power that has the same period as the first high-frequency power and is lower than the first high-frequency power; and is connected between the second high-frequency power supply and the second electrode, an input terminal connected to a second high-frequency power supply, an output terminal connected to the second electrode, a first variable capacitor connected between the input terminal and a ground potential, and a connection between the input terminal and the output terminal a second power supply including a second matching circuit including a second variable capacitance connected in series therebetween;
Each 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 phase adjuster for adjusting the phase;
a control device for controlling the first power supply, the second power supply, the shutter, and the phase adjuster;
The above controller includes:
outputting the first high-frequency power from the first high-frequency power supply to form discharge plasma between the first electrode and the second electrode;
outputting the second high-frequency power from the second high-frequency power supply 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;
The voltage value Vpp of the second high-frequency power and the first voltage value Vpp according to the phase difference θ in a state where the output impedance of the second high-frequency power supply and the impedance of the load connected to the second high-frequency power supply are matched. Data obtained by detecting the capacitance value C1 of the variable capacitor is stored,
Before the sputtering film is formed on the substrate, the control device shields the substrate or the second electrode from the sputtering target by the shutter, and controls the shutter between the first electrode and the second electrode. The second high-frequency power is supplied from the second high-frequency power source to the second electrode by forming discharge plasma and selecting a combination of the voltage value Vpp and the capacitance value C1 in the predetermined region of the phase difference θ. do.

With such a vacuum processing apparatus, stable film formation performance can be obtained even if the substrate side is conditioned before sputtering film formation.

In the above vacuum processing apparatus,
In the control device, as the data,
forming the phase difference θ 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 may be stored according to the phase difference θ by changing the phase difference θ,
The control device is
While shielding the substrate or the second electrode from the sputtering target by the shutter, the phase difference θ is increased by 30 degrees from the phase difference θ1 at which the voltage value Vpp of the profile curve of the voltage value Vpp is the lowest. Outside the first range up to 50 degrees, the phase difference θ2 at which the voltage value Vpp of the profile curve of the voltage value Vpp is maximum is plus 10 degrees, and outside the second range up to minus 10 degrees, the phase difference θ2 A fourth range outside the third range, which is a range of minus 50 degrees to minus 30 degrees, is set, and in a state in which the output impedance and the load side impedance are matched, the second electrode is connected from the second high-frequency power supply to the second electrode. 2 RF power may be supplied.

With such a vacuum processing apparatus, stable film formation performance can be obtained even if the substrate side is conditioned before sputtering film formation.

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

With such a vacuum processing apparatus, stable film formation performance can be obtained even if the substrate side is conditioned before sputtering film formation.

INDUSTRIAL APPLICABILITY As described above, according to the present invention, there is provided a vacuum processing method capable of obtaining stable film formation performance even if the substrate is conditioned before sputtering film formation, and a vacuum processing apparatus for carrying out the vacuum processing method. be done.

1 is a schematic block configuration diagram showing an example of a film forming apparatus according to this embodiment; FIG. FIG. (a) is a graph for explaining an example of the profile curve of the voltage value Vpp. FIG. (b) is a graph illustrating an example of the profile curve of the capacitance value C1. FIG. (a) is a cross-sectional SEM image of the concave pattern before the sputtering film is formed. FIGS. (b) to (e) are cross-sectional SEM images of the sputtering film after the sputtering film is formed in the recessed pattern. It is a profile curve of the voltage value Vpp and the capacitance value C1 in test A. It is a cross-sectional SEM image of the sputtering film after the sputtering film is formed in the concave pattern. It is an example of profile curves of a voltage value Vpp and a capacitance value C1 according to the present embodiment. FIGS. (a) and (b) are schematic cross sections showing an example of the film forming method according to the present embodiment. FIG. (c) is a cross-sectional SEM image of the sputtered film after the sputtered film is formed in the concave pattern. It is an example of profile curves of a voltage value Vpp and a capacitance value C1 according to the present embodiment. It is an example of a profile curve of the capacitance value C2 according to the present embodiment. 7 is a graph showing film formation performances of a comparative example and the present embodiment; 7 is a graph showing film formation performances of a comparative example and the present embodiment;

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Also, the same members or members having the same function may be denoted by the same reference numerals, and the description may be omitted as appropriate after describing the members. Also, the numerical values shown below are examples, and the present invention is not limited to these examples.

(Deposition device)

FIG. 1 is a schematic block configuration diagram showing an example of a film forming apparatus according to this embodiment.

A film forming apparatus 1, which is an example of a vacuum processing apparatus, includes an electrode 11 (first electrode), an electrode 12 (second electrode), a shutter 13, a power supply source 21 (first power supply source), and a power supply source 21 (first power supply source). It comprises a source 22 (second power supply), a phase adjuster 50 and a controller 60 . Electrode 11, electrode 12, and shutter 13 are provided in a vacuum chamber (not shown). The potential of the vacuum chamber is the ground potential. The film forming apparatus 1 is a three-electrode film forming apparatus including an electrode 11, an electrode 12, and a vacuum chamber at ground potential. The film forming apparatus 1 is a single substrate type film forming apparatus capable of sputtering film formation for each substrate.

The electrode 11 includes a sputtering target 111 and a back plate (support plate) 112 . Sputtering target 111 includes a coating material that is sputter deposited onto substrate 121 . Examples of coating materials include insulators such as alumina and silicon oxide, and metals such as aluminum. Back plate 112 is made of, for example, a conductive metal.

Electrode 12 faces electrode 11 . The electrode 12 also functions as a support base capable of supporting the substrate 121 . An electrostatic chuck may be provided on the support surface on which the electrode 12 supports the substrate 121 . Substrate 121 includes a semiconductor wafer, a silicon oxide layer, or the like. Patterns such as lines and spaces and through holes are formed on the film formation surface of the substrate 121 facing the electrode 11 .

A shutter 13 is installed on the electrode 12 . The shutter 13 may be composed of an insulator such as alumina, quartz, or glass, or may be composed of a conductor such as SUS or aluminum. If the shutter is an insulator, its potential is a floating potential. When 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 that 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).

The power supply source 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 100 W to 5000 W, for example.

A matching circuit 41 is connected between the high frequency power supply 31 and the electrode 11 . The matching circuit 41 includes an input end 415 , an output end 416 , a variable capacitance 411 , a variable capacitance 412 and an inductance 413 . The input end 415 is connected to the high frequency power supply 31 . The output end 416 is connected to the electrode 11 . A variable capacitor 411 is connected between the input terminal 415 and the ground potential. A variable capacitor 412 is connected in series between an input terminal 415 and an output terminal 416 . An inductance 413 is connected in series with the variable capacitance 412 between the input terminal 415 and the output terminal 416 . In the matching circuit 41, the variable capacitor 411 and the variable capacitor 412 are respectively driven by the control device 60, and the output impedance of the high frequency power source 31 and the load side impedance (electrode 11 side impedance) connected to the high frequency power source 31 are matched. perform automatic matching.

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

The power supply source 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 second high-frequency power having the same cycle as that of the first high-frequency power and 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.

A 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 end 425 is connected to the high frequency power supply 32 . Output 426 is connected to electrode 12 . A variable capacitor 421 is connected between the input terminal 425 and the ground potential. A variable capacitor 422 is connected in series between an input terminal 425 and an output terminal 426 . An inductance 423 is connected in series with the variable capacitance 422 between the input terminal 425 and the output terminal 426 . In the matching circuit 42, the variable capacitors 421 and 422 are respectively driven by the control device 60, and the output impedance of the high frequency power source 32 and the load side impedance (electrode 12 side impedance) connected to the high frequency power source 32 are matched. perform automatic matching.

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, the vacuum chamber (not shown) accommodating the electrodes 11 and 12, and the like.

Here, the capacitance of the variable capacitor 421 is represented by a capacitance value C1 (maximum 1000 pF), and the capacitance of the variable capacitor 422 (maximum 500 pF) is represented by a capacitance value C2. Further, the matching circuit 42 is equipped with a sensor 424 that detects the voltage value Vpp (Voltage peak to peak) and the voltage value Vdc (Voltage direct current) of the high-frequency power in the matching circuit 42 at the output terminal 426. . The voltage value Vpp means the difference between the maximum voltage and the minimum voltage of the AC voltage. The voltage value Vdc means the voltage at the midpoint between the maximum value and the minimum value of Vpp when the voltage of the voltage value Vpp applied to the electrode 12 floats at a constant voltage. The voltage value Vdc is also called an offset voltage or a bias voltage. For RF discharge, the voltage value Vdc is generally a low potential with respect to the plasma potential (Vp). For example, if the plasma potential is a positive potential, the voltage value Vdc is a potential lower than this positive potential or a negative potential.

In the matching circuit 42, the variable capacitor 421 is mainly used for matching the output impedance of the high frequency power source 32 and the impedance of the load connected to the high frequency power source 32, and the variable capacitor 422 is mainly used for matching the phase of the voltage wave. and the phase matching of the current wave. Therefore, even when the output impedance of the high-frequency power supply 32 and the impedance of the load connected to the high-frequency power supply 32 match, the second high-frequency power is preferentially supplied from the input terminal 425 depending on the capacitance value C1 of the variable capacitor 421. part of the second high-frequency power is discharged to the ground potential, or it does not reach the output end 426 and is discharged to the ground potential. For example, the second high-frequency power is more preferentially supplied from the input end 425 to the output end 426 as the capacitance value C1 of the variable capacitor 421 becomes relatively larger.

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

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.

The control device 60 controls the power supply source 21, the power supply source 22, the phase adjuster 50, and the shutter 13 (shutter opening/closing). Controller 60 may be provided independently of power supply 21 , power supply 22 , and phase adjuster 50 , some of which may be part of power supply 21 , power supply 22 , and phase adjuster 50 . It may be incorporated in either. The control device 60 has a storage unit that stores data, a calculation unit that performs arithmetic processing on data, and the like.

(Film formation method)

In the present embodiment, profile curves of the voltage value Vpp and the capacitance value C1 corresponding to the phase difference θ are obtained as data by changing the phase difference θ in advance. A dummy substrate may be used as the substrate 121 at the stage of acquiring this profile curve.

First, a first high frequency power is output from the high frequency power supply 31 to form discharge plasma between the electrodes 11 and 12 . Argon, for example, is applied as the discharge gas. A matching circuit 41 matches 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 .

Next, the second high frequency power is output from the high frequency power supply 32 and the phase adjuster 50 is operated to provide a phase difference θ between the phase of the first high frequency power and the phase of the second high frequency power. Here, each of the first high-frequency power and the second high-frequency power is set to a fixed value without being changed. Also, the second high-frequency power is lower than the first high-frequency power, and is set to, for example, 1/10 to 1/2 of the first high-frequency power.

Next, while the discharge plasma is formed between the electrodes 11 and 12, the output impedance of the high-frequency power source 32 and the load-side impedance (electrode 12-side impedance) connected to the high-frequency power source 32 are matched by the matching circuit 42. are matched, 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 are detected. Then, by changing the phase difference θ, the profile curve of the voltage value Vpp (Fig. 2(a)) and a profile curve (FIG. 2(b)) of the capacitance value C1 corresponding to the phase difference θ are obtained.

Here, 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 by the phase adjuster 50, and is appropriately changed within the range of 0 degrees to 360 degrees. For example, when changing the phase difference θ from 0 degrees, it is changed from 0 degrees to predetermined intervals, for example, 10 degrees, 20 degrees, . Then, a sputtering film is formed on the substrate 121 by selecting a combination of the voltage value Vpp and the capacitance value C1 in the changed predetermined range of the phase difference θ. Here, forming a sputtering film on the substrate 121 means embedding a sputtering film in a recessed pattern (line and space, through hole, etc.) formed on the substrate 121, and forming a sputtering film on the surface of the substrate 121 outside the recessed pattern. means to form. The sputtered film formed on the surface of the substrate 121 outside the concave pattern may be removed as an excess portion by a method such as chemical mechanical polishing (CMP) as necessary after forming the sputtered film.

As described above, FIG. 2(a) is a graph illustrating an example of the profile curve of the voltage value Vpp. FIG. 2(b) is a graph illustrating an example of a profile curve of the capacitance value C1. In FIG. 2A, the horizontal axis is the phase difference θ, and the vertical axis is the voltage value Vpp. In FIG. 2B, 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/substrate is 50-90 mm. It should be noted that the higher the Vdc shown in the graph, the stronger the bias potential applied to the electrode 12 toward the negative bias side.

For example, FIG. 2A shows profile curves of voltage values Vpp in two tests, test A and test B. FIG. Test A is a profile curve when a high-frequency power source that outputs second high-frequency power whose phase is synchronized with the phase of the first high-frequency power output from the high-frequency power source 31 is used as the high-frequency power source 32 .

On the other hand, test B is a profile curve when using a high-frequency power source that outputs a second high-frequency power whose phase is 50 degrees ahead of the phase of the first high-frequency power output from the high-frequency power source 31 as the high-frequency power source 32. is. This means that the length of the cable between the high-frequency power supply 32 and the matching circuit 42 has increased by 50 degrees as a phase difference due to maintenance of the film forming apparatus 1 or the like. Note that in test B, the profile curves of the voltage value Vpp and the capacitance value C1 were obtained in a film forming chamber different from that in test A. FIG.

In test A, the voltage value Vpp is high when the phase difference θ is around 0 degrees, and the voltage value Vpp tends to gradually decrease as the phase difference θ increases. The voltage value Vpp reaches its lowest value when the phase difference θ is 60 degrees, and thereafter, the voltage value Vpp tends to gradually increase as the phase difference θ increases. On the other hand, in test B, the voltage value Vpp is high when the phase difference θ is around 60 degrees, and the voltage value Vpp tends to gradually decrease as the phase difference θ increases. The voltage value Vpp reaches its lowest value when the phase difference θ is 110 degrees, and thereafter, the voltage value Vpp tends to gradually increase as the phase difference θ increases.

In this way, the profile curves of the voltage values Vpp of the test A and the test B both draw downwardly convex curves.

In addition, FIG. 2B shows profile curves of p of the capacitance value C1 in test A and test B. FIG. In test A, when the phase difference θ is around 0 degrees, the capacitance value C1 is low, and thereafter, the capacitance value C1 tends to gradually increase as the phase difference θ increases. On the other hand, in test B as well, when the phase difference θ is around 60 degrees, the capacitance value C1 is low, and thereafter, the capacitance value C1 tends to gradually increase as the phase difference θ increases.

In this embodiment, these profile curves are used, and the phase difference θ is set to a first range from +30 degrees to +50 degrees from the phase difference θ1 where the voltage value Vpp of the profile curve of the voltage value Vpp is the lowest. As a result, a sputtering film is formed on the substrate 121 .

For example, in test A, the phase difference θ1 at which the voltage value Vpp is the lowest is 50 degrees, and the first range is from 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 the present embodiment, the sputtering film is formed on the substrate 121 by applying the voltage value Vpp and the capacitance value C1 belonging to the first range.

Difference between a sputtering film belonging to the first range when the voltage value Vpp and the capacitance value C1 are applied and a sputtering film not belonging to the first range and when the voltage value Vpp and the capacitance value C1 are applied will be explained.

3(a) to 3(e) are cross-sectional SEM images, and FIG. 3(a) is a cross-sectional SEM image of the concave pattern before the sputtering film is formed. FIG. 3(a) shows a recessed pattern made of silicon oxide and having a depth of 240 nm and an aspect ratio of 1.0. The portion indicated by arrow A is the end portion where the bottom of the concave pattern and the side wall intersect at approximately 90 degrees, and the portion indicated by arrow B is the top end of the side wall. 3(b) to 3(e) are cross-sectional SEM images of the sputtering film after the sputtering film is formed in the concave pattern. FIGS. 3(b) to 3(e) show the state after the concave pattern is filled with an alumina film as a sputtering film.

For example, as a sputtering film when a phase difference θ that does not belong to the first range is applied, FIG. , phase difference θ on the left side of the lowest value), and FIG. In these alumina films, the wraparound to the end portion indicated by the arrow A was not excellent, and a phenomenon appeared in which the alumina film was dented at an acute angle at the end portion. Such a tendency was also observed in Test A. In addition, it was confirmed that the opening indicated by the arrow C became narrower, and if the film formation was continued, the film would close at the top, forming holes.

On the other hand, as the sputtering film when the phase difference θ belonging to the first range is applied, FIG. A SEM image with a phase difference of 140 degrees is shown. In these alumina films, it was found that an alumina film excellent in step coverage was formed at the end portion without the alumina film being recessed at an acute angle at the end portion. Further, even when the aspect ratio of the recessed pattern is 0.2 to 1.0, when the phase difference θ that does not belong to the first range is applied, the wraparound to the end indicated by the arrow A is not excellent, while the first range was found to form an alumina film with excellent step coverage.

In other words, since the profile curve of the voltage value Vpp is convex downward, the same voltage value as the voltage value Vpp belonging to the first range also exists outside the first range. Instead of selecting a voltage value Vpp outside the range, even if the voltage value Vpp is the same value, a combination of the voltage value Vpp belonging to the first range and the capacitance value C1, which is a relatively high capacitance value, is selected. An alumina film having excellent step coverage is formed. Here, in the first range, the capacitance value C1 is set larger than the capacitance value C2.

Next, the results when the phase difference θ is further increased from 100 degrees using test A will be described.

FIG. 4 shows profile curves of the voltage value Vpp and the capacitance value C1 in test A. As shown in FIG. In FIG. 4, the horizontal axis indicates the phase difference θ, and the left vertical axis indicates the voltage value Vpp, the voltage value Vpp, and the voltage value Vdc. Also, the right vertical axis indicates the capacitance value C1. FIG. 4 also shows profile curves when the phase difference θ is 0 degrees to 110 degrees.

When the phase difference θ exceeds 100 degrees and reaches 110 degrees to 240 degrees, the capacitance value C1 shakes off the maximum capacitance value of 1000 pF, and the output impedance of the high frequency power source 32 and the impedance of the load connected to the high frequency power source 32 are not matched. An irreversible phenomenon occurred. In this non-matching region (110 to 240 degrees), both the voltage value Vpp and the voltage value Vdc became unstable.

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 impedance of the load connected to the high-frequency power supply 32 matched again. After that, the voltage value Vpp gradually increased as the phase difference θ increased, reached its maximum value when the phase difference θ was 300 degrees, and then gradually decreased as the phase difference θ increased. Further, it was found that the capacitance value C1 is high when the phase difference θ is around 250 degrees, and then the capacitance value C1 gradually decreases as the phase difference θ increases. It has been found that the voltage value Vdc gradually decreases in the range of 240° to 290° where the voltage value Vpp increases.

Thus, it was found that the profile curve of the voltage value Vpp draws an upward convex curve when the phase difference θ is 250 degrees to 360 degrees.

In this way, a region with a phase difference θ where the phase of the high-frequency voltage waveform supplied to the electrode 11 and the waveform of the high-frequency voltage supplied to the electrode 12 match (referred to as an in-phase region) , the voltage value Vpp is convex downward, and the capacitance value C1 is upward-sloping. region), it was confirmed that the voltage value Vpp is upwardly convex and the capacitance value C1 is downwardly downward.

In the present embodiment, in the region where the phase difference θ is 250 degrees to 360 degrees, the phase difference θ is set from the phase difference θ2 where the voltage value Vpp of the profile curve of the voltage value Vpp is the maximum to plus 10 degrees and minus 10 degrees. A second range is set to form a sputtering film on the substrate 121 . For example, the phase difference θ2 that maximizes the voltage value Vpp is 300 degrees, and the second range is from 290 degrees to 310 degrees. Here, in the second range, the capacitance value C1 is set larger than the capacitance value C2.

A sputtering film when the voltage value Vpp and the capacitance value C1 belonging to the second range are applied, and a sputtering film when the voltage value Vpp and the capacitance value C1 not belonging to the second range are applied. Explain the difference between

5(a) and 5(b) are cross-sectional SEM images of the sputtering film after the sputtering film is formed in the concave pattern shown in FIG. 3(a).

For example, as an example of a sputtering film that does not belong to the first range and the second range, an example in which film formation is started on an empty concave pattern under the condition of a phase difference of 260 degrees will be shown. FIG. 5A shows an SEM image with a phase difference of 260 degrees. In this case, it was confirmed that the voltage value Vdc became greater than 50 (V) and the uppermost edge of the recessed pattern indicated by the arrow B was etched, and the alumina film became facet-shaped at this uppermost edge. .

On the other hand, as an example of a sputtered film belonging to the second range, FIG. 5B shows an SEM image with a phase difference of 300 degrees. In this alumina film, it was found that the wraparound to the end portion was good, and the alumina film was not dented sharply at the end portion, and an alumina film having excellent step coverage was formed at the end portion. It was confirmed that when the phase difference θ exceeded 310 degrees, the alumina film was recessed at an acute angle at the edge.

Thus, even if 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 both fixed powers, by manipulating the phase difference .theta. It has been found that the embedding properties of the membrane are altered. In particular, by setting the phase difference θ1 to the minimum value of the profile curve of the voltage value Vpp to the first range of +30 degrees to +50 degrees, a sputtering film exhibiting excellent step coverage is formed. It turns out that it will be. Alternatively, by setting the phase difference θ in the second range of plus 10 degrees and minus 10 degrees from the phase difference θ2 at which the profile curve of the voltage value Vpp reaches the maximum value, a sputtered film exhibiting excellent step coverage is formed. I found out.

In addition, at a position 418 ( FIG. 1 ) directly above the electrode 11 between the electrode 11 and the matching circuit 41 and at a position 428 directly below the electrode 12 between the electrode 12 and the matching circuit 42 Observation of the waveform of the high-frequency power with an oscilloscope revealed that the phase of the high-frequency voltage waveform supplied to the electrode 11 and the waveform of the high-frequency voltage supplied to the electrode 12 were in agreement between 0 degrees and 110 degrees, and 250 degrees. It was confirmed that the phase of the high-frequency voltage waveform supplied to the electrode 11 and the waveform of the high-frequency voltage supplied to the electrode 12 were out of phase at ~360 degrees.

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

For example, by controlling the phase adjuster 50, the control device 60 adjusts the phase difference θ to the first phase difference θ1 from +30 degrees to +50 degrees where the voltage value Vpp of the profile curve of the voltage value Vpp is the lowest. Set the range (voltage value Vpp: 80 to 130 (V), capacitance value C1: 600 pF or more), or set the phase difference θ from the phase difference θ2 where the voltage value Vpp of the profile curve of the voltage value Vpp is the maximum Set to the second range (voltage value Vpp: 260 to 280 (V)), capacitance value C1: 600 to 900 (pF), Vdc: 50 (V) or less) to plus 10 degrees and minus 10 degrees, high frequency power supply 32 A sputtering film is formed on the substrate 121 in a state where the output impedance and the load side impedance are matched.

As a result, a sputtered film that exhibits excellent step coverage with respect to concave patterns is formed.

In the first range or the second range, a sputtering film may be formed on the substrate 121 by changing the phase difference θ stepwise. When changing the phase difference θ stepwise, the first high-frequency power output from the high-frequency power supply 31 is maintained at the same level. For example, the voltage value Vdc tends to increase as the capacitance value C1 increases. As the voltage value Vdc increases, the concave pattern underlying the sputtering film is more likely to be damaged by the sputtering particles.

Therefore, immediately after the start of the sputtering film formation, the phase difference θ is set so that the voltage value Vdc is low, and the sputtering film is formed in the recessed pattern. can be changed to, for example, a phase difference θ that makes the film formation rate faster.

FIG. 6 is an example of profile curves of the voltage value Vpp and the capacitance value C1 according to this embodiment. In this example, in addition to the first and second ranges, a third range is added as the range of the phase difference θ.

As in the example of FIG. 5B, when film formation 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 adopting a process in which the phase difference θ is changed in stages, film formation in the third range including the phase difference θ of 260 degrees as the phase difference θ is adopted in the second half step of the stepwise steps, whereby excellent Step coverage can be obtained.

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

FIGS. 7A and 7B are schematic cross sections showing an example of the film forming method according to this embodiment. FIG. 7C is a cross-sectional SEM image of the sputtering film after the sputtering film is formed in the recessed pattern. The aspect ratio of the concave pattern 122 shown in FIG. 7(c) is the same as the aspect ratio of the concave pattern shown in FIG. 3(a).

For example, as shown in FIG. 7A, as a first step, a sputtering film 125 such as an alumina film is applied to a recessed pattern 122 made of silicon oxide under the condition that the phase difference θ is in the first range or the second range. formed by Thereby, a sputtering film 125 is formed in the recessed pattern 122 . In the first step, the sputtered film 125 is filled while leaving unfilled portions in the recessed pattern 122 instead of filling the entire interior of the recessed pattern 122 with the sputtered film 125 . For example, the target film thickness in the first step is set such that the film thickness of the sputtering film 125 deposited on the portion (field portion) where the recessed pattern 122 is not formed is 40% to 60% of the opening width of the recessed pattern 122. be done. Here, when the recessed pattern 122 is a line and space, the opening width is the opening 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 side by side. In the case of a through hole, it means the maximum diameter at the top end of the through hole. Also, in the first step, the uppermost edge 122c of the recessed pattern 122 is covered (protected) by the sputtering film 125. Then, as shown in FIG.

Here, in the concave pattern 122 , the sputtering film 125 is deposited from the bottom of the concave pattern 122 and the sputtering film 125 is also deposited from the side walls of the concave pattern 122 . Therefore, in the sputtering film 125 formed in the recessed pattern 122, a recess 125b is formed in which the sputtering film 125 is recessed near the center of the sputtering film 125. As shown in FIG.

In the case of adopting a process in which the phase difference θ is not changed stepwise, in other words, in the case of continuing the film formation with the phase difference θ remaining in the first range or the second range, the recessed pattern 122 is sputtered until the recessed portion 125b disappears. In order to fill with the film 125 , it is necessary to form the sputtering film 125 with a thickness equal to or greater than the depth of the recessed pattern 122 on the substrate 121 . However, as the thickness of the sputtered film 125 formed on the substrate 121 increases, the burden on the CMP process in the post-process increases. In addition, the recesses 125b are more likely to be formed as the aspect ratio of the recessed pattern increases, and if film formation is continued in the first range or the second range, a phenomenon occurs in which the recesses 125b remain as voids in the sputtering film 125. obtain.

Therefore, in this embodiment, the film formation in the first range or the second range is stopped in the state of FIG. 7A, and as the next step, sputtering film formation is performed in the third range of the phase difference θ. For example, after the sputtering film 125 is formed, the sputtering film 126 is formed on the sputtering film 125 under the condition that the phase difference θ is in the third range. This state is shown in FIG. 7(b).

In the third range, the second high-frequency power is more preferentially supplied to the electrode 12 via the output terminal 426 as the capacitance value C1 increases, and the voltage value Vdc increases more than in the first range and the second range. There is a tendency. Therefore, simultaneously with the deposition of the sputtered particles on the substrate 121, the bias potential applied to the substrate 121 attracts ions (eg, positive ions) particles to the substrate 121, and physical etching of the sputtered film by the ionic particles also occurs. Here, when the deposition of the sputtered particles on the substrate 121 works better than the physical etching of the sputtered film by the ion particles, the sputtered film is formed on the substrate 121 while being physically etched.

As a result, the width of the concave portion 125b is further widened by the etching effect in the sputtering film formation in the third range. Also, in the sputtered film 125 covering the uppermost end 122c of the concave pattern 122, so-called film thinning (a phenomenon in which the film is thinned) occurs due to the etching effect. Since the width of the recess 125b is wider, 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 is not etched and maintains its original shape.

Therefore, even if the concave pattern 122 has a high aspect ratio, after the sputtering film 126 is formed, the sputtering film 127 having no voids inside is concave due to the sputtering film 125 and the sputtering film 126 covering the sputtering film 125 . Formed in pattern 122 . It is also confirmed by the cross-sectional SEM image shown in FIG.

In the present embodiment, after film formation is performed in the first range of the phase difference θ, film formation may be performed in the third range of the phase difference θ. , film formation may be performed with the phase difference θ in the third range.

Here, in order 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 shifting the phase difference θ from the first range to the third range, the phase difference θ must pass through the non-matching region before the third range. Therefore, in this method, after film formation is performed in the first range, it is necessary to adopt a film formation process in which the plasma discharge is temporarily stopped and the phase difference θ is switched from the phase difference θ in the first range to the phase difference θ in the third range. There is

On the other hand, in order to switch from the phase difference θ in the second range to the phase difference θ in the third range, the phase difference θ should be decreased from the second range to the third range. In this case, even if the phase difference θ is shifted from the second range to the third range, it is not necessary to pass through the non-matching area because there is no non-matching area between the second range and the third range. Therefore, after film formation in the second range, it is possible to switch to the third range by continuously changing the phase difference θ without stopping the plasma discharge.

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

Here, there is also a method of randomly supplying the second high-frequency power to the electrode 12 without considering the phase difference θ during the preliminary discharge. However, in such a measure, if a dummy substrate is used as the substrate 121 during preliminary discharge, depending on the degree of bias potential applied to the electrode 12, reverse sputtering of the dummy substrate or the shutter 13 may occur. When such reverse sputtering occurs, foreign substances such as particles and flakes are emitted from the dummy substrate or the shutter 13, and these foreign substances fly around in the vacuum chamber, or cause damage to the inner wall of the vacuum chamber and the jigs in the vacuum chamber. etc. As a result, problems such as contamination of foreign matter into the sputtered film after the start of sputtering film formation occur. Alternatively, depending on the degree of the bias potential, abnormal discharge may occur on the electrode 12 side during the preliminary discharge, and not only the dummy substrate but also the electrode 12 or the shutter 13 may be damaged.

However, by not supplying the second high-frequency power to the electrode 12 in parallel with the preliminary discharge, the sputtering film formation is started while the power supply source 22 (the high-frequency power supply 32 and the matching circuit 42) is not energized. It will be. Therefore, in the power supply source 22, when sputtering film formation is started, a phenomenon may occur in which the impedance of the power supply source 22 changes due to thermal expansion and contraction of the electronic components constituting the power supply source 22 and the like. As a result, even if sputtering film formation is started, a phenomenon occurs in which film formation performance such as film formation speed, film formation distribution, and film quality is not stable.

As a method of suppressing the reverse sputtering of the shutter 13, a method of setting the shutter 13 to the ground potential is conceivable. 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, in this method, a predetermined voltage is applied between the shutter 13 and the electrode 12, and discharge may occur between the shutter 13 and the electrode 12. In this case, the foreign matter is generated from the shutter 13 or the electrode 12 after all.

In the present embodiment, the substrate 121 or the electrode 12 is shielded from the sputtering target 111 by the shutter 13 having a floating potential or the same potential as the electrode 12, while the phase difference θ is outside the first range and outside the second range. The second high-frequency power is supplied from the high-frequency power source 32 to the electrode 12 in a state in which the output impedance of the high-frequency power source 32 matches the load impedance. Here, "the shutter 13 shields the substrate 121 or the electrode 12 from the sputtering target 111" means that the shutter 13 shields the substrate 121 with a wafer substrate or a dummy substrate placed on the electrode 12, It includes shielding the electrode 12 by the shutter 13 when no substrate is placed on the electrode 12 .

FIG. 8 is an example of profile curves of the voltage value Vpp and the capacitance value C1 according to this embodiment. FIG. 9 is an example of a profile curve of the capacitance value C2 according to this embodiment. In these examples, as the range of the phase difference θ in test A, in addition to the first to third ranges, a fourth range is added.

The fourth range is defined as a range of the phase difference θ that is outside the first range, outside the second range, and outside the third range. For example, the fourth range is a range from -10 degrees to +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) in the fourth range. Also, as shown in FIG. 9, the capacitance value C2 in the fourth range is 300 pF or more.

In the present embodiment, the phase difference θ is set to the fourth range, and while the substrate 121 or the electrode 12 is shielded by the shutter 13, the output impedance of the high frequency power source 32 and the load impedance match each other. 12 is supplied with a second high frequency power. Here, when the electrode 12 is shielded by the shutter 13 , the substrate 121 may not be placed on the electrode 12 . Further, the first high frequency power is supplied from the high frequency power supply 31 to the electrode 11 in a state where the output impedance of the high frequency power supply 31 matches the load impedance, and discharge plasma is formed between the electrodes 11 and 12 . As a result, both the power supply sources 21 and 22 are conditioned by preliminary discharge before sputtering film formation.

During the conditioning of the power supply sources 21 and 22, the shutter 13 may be opened to temporarily perform sputtering deposition on a plurality of dummy substrates. If the sputtering target material and the shutter 13 are made of the same material (for example, alumina), even if the sputtering particles from the sputtering target 111 are deposited on the shutter 13, the sputtering target material and the shutter 13 are made of the same material. Therefore, the film deposited from the shutter 13 does not fly as particles or flakes.

By setting the phase difference θ to the fourth range during the conditioning of the power supply sources 21 and 22, the electrode 11 is supplied with the first high-frequency power to form a discharge plasma between the electrodes 11 and 12. be. 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 easily flows to the ground via the variable capacitor 421 . Thereby, the high frequency power supply 32 and the matching circuit 42 are activated from the preliminary discharge. That is, the preliminary discharge conditions both power supplies 21 and 22 .

In particular, if the sputtering film formation is started without conditioning the power supply source 22, the sputtering film formation is started in a state where the phase difference θ set to the target value from the sputtering film formation is actually deviated from the target value. may be As a result, even if sputtering film formation is started, a phenomenon occurs in which film formation performance such as film formation speed, film formation distribution, and film quality is unstable.

On the other hand, in the present embodiment, both the power supply sources 21 and 22 are conditioned before starting sputtering film formation. Excellent deposition performance is obtained from sputtering deposition.

After conditioning the power supply sources 21 and 22, the phase difference θ may be set in the first range to start sputtering film formation, or the phase difference θ may be set in the second range to start sputtering film formation. Alternatively, the phase difference θ may be set in the first range or the second range, and further set in the third range to start sputtering film formation.

In the sputtering deposition, the bias potential applied to the electrode 12, the substrate 121, or the shutter 13 is suppressed by preliminary discharge, and the bias potential is less likely to be applied to the electrode 12, the substrate 121, or the shutter 13. , the substrate 121, or the shutter 13 are less likely to generate foreign matter. As a result, contamination of the sputtered film with foreign matter can be suppressed.

10(a) to 11(b) are graphs showing the film forming performance of the comparative example and the film forming performance of the present embodiment. The same film forming apparatus 1 is used in the comparative example and the present embodiment. In the comparative example, only the power supply source 21 is conditioned during preliminary discharge, and the power supply source 22 is not conditioned. In contrast, in this embodiment, both the power supply sources 21 and 22 are conditioned during preliminary discharge.

The horizontal axis of FIG. 10(a) represents the number of times of sputtering deposition, which is indicated by the number of the substrate. That is, sputtering film formation is performed for each substrate (the same shall apply hereinafter). The vertical axis of FIG. 10A is the in-plane average value (nm) of the thickness of the sputtered film formed by sputtering. Sputtering time is the same for each run. A silicon wafer is used as the substrate 121 .

In the comparative example, although the film thickness stabilizes after the fourth time, the film thickness decreases sharply from the first time to the third time. In contrast, in this embodiment, the film thickness is stable from the first time. The value obtained by subtracting the minimum film thickness from the maximum film thickness was Δ3.05 nm in the comparative example, whereas it was Δ1.31 nm in this embodiment.

The horizontal axis of FIG. 10(b) is the number of sputtering depositions, which is indicated by the number of the substrate. The vertical axis of FIG. 10(b) is the in-plane distribution (1σ (standard deviation) %) of the thickness in the substrate.

In the comparative example, it can be seen that the in-plane distribution increases sharply from the first time to the third time, and the film thickness stabilizes thereafter. In contrast, in this embodiment, the in-plane distribution is stable from the first time.

The horizontal axis of FIG. 11(a) is the number of times of sputtering deposition, which is indicated by the number of the substrate. The vertical axis of FIG. 11(b) is the in-plane average value (n) of the refractive index of the sputtered film.

In the comparative example, the refractive index abruptly decreases from the first time to the third time, and after that, the refractive index stabilizes. In contrast, in this embodiment, the refractive index is stable from the first time.

The horizontal axis of FIG. 11(b) is the number of sputtering depositions, which is indicated by the number of the substrate. The vertical axis of FIG. 11(b) is the number of particles in the substrate. Particles having a particle size of 0.034 μm or more are counted.

As shown in FIG. 11B, the number of particles in the comparative example in which the power supply source 22 is not conditioned during preliminary discharge and the present embodiment in which the power supply source 22 is conditioned during preliminary discharge are the same. degree. For example, the average number of particles was 24 pcs (pieces) in the comparative example and 15 pcs (pieces) in the present embodiment, both of which were 25 pcs (pieces) or less. That is, in this embodiment, although the power supply source 22 is conditioned, the bias potential of the electrode 12 is approximately the same as in the comparative example in which no bias potential is applied to the electrode 12. 12, or the emission of particles from the dummy substrate was suppressed.

Although the embodiments of the present invention have been described above, it is needless to say that the present invention is not limited to the above-described embodiments and can be modified in various ways. For example, the conditioning described above can be applied not only to the film forming apparatus 1 but also to a triode dry etching apparatus. Each embodiment is not limited to an independent form, and can be combined as much as technically possible.

DESCRIPTION OF SYMBOLS 1... Film-forming apparatus 11... Electrode 111... Sputtering target 112... Back plate 12... Electrode 121... Substrate 122c... Uppermost edge 122... Concave pattern 125, 126, 127... Sputtering film 125b... Concave part 13... Shutter 21, 22... Power supply Source 31, 32 High-frequency power supply 41, 42 Matching circuit 411, 412, 421, 422 Variable capacitance 413, 423 Inductance 415, 425 Input terminal 416, 426 Output terminal 424 Sensor 50 Phase adjuster 60 …Control device

Claims (6)

a first electrode comprising 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 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 high-frequency power source that outputs a second high-frequency power that has the same period as the first high-frequency power and is lower than the first high-frequency power; connected between the second high-frequency power source and the second electrode; an input terminal connected to a second high-frequency power supply, an output terminal connected to the second electrode, a first variable capacitor connected between the input terminal and a ground potential, and a connection between the input terminal and the output terminal a second power supply including a second matching circuit including a second variable capacitance connected in series therebetween;
Each 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 comprising a phase adjuster for adjusting the phase,
outputting the first high-frequency power from the first high-frequency power supply to form discharge plasma between the first electrode and the second electrode;
outputting the second high-frequency power from the second high-frequency power supply 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;
The voltage value Vpp of the second high-frequency power and the first voltage value Vpp according to the phase difference θ in a state where the output impedance of the second high-frequency power supply and the impedance of the load connected to the second high-frequency power supply are matched. Acquiring data from which the capacitance value C1 of the variable capacitor is detected,
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 by the shutter. and supplying 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 within a predetermined range of the phase difference θ. A vacuum processing method according to claim 1,
As said data,
forming the phase difference θ by delaying the phase of the second high frequency power with respect to the phase of the first high frequency power;
obtaining a profile curve of the voltage value Vpp and a profile curve of the capacitance value C1 according to the phase difference θ by changing the phase difference θ;
While shielding the substrate or the second electrode from the sputtering target by the shutter, the phase difference θ is increased by 30 degrees from the phase difference θ1 at which the voltage value Vpp of the profile curve of the voltage value Vpp is the lowest. Outside the first range up to 50 degrees, the phase difference θ2 at which the voltage value Vpp of the profile curve of the voltage value Vpp is maximum is plus 10 degrees, outside the second range up to minus 10 degrees, the phase difference θ2 set to a fourth range outside the third range, which is a range of minus 50 degrees to minus 30 degrees; 2. Vacuum processing method for supplying high frequency power. A vacuum processing method according to claim 2,
The vacuum processing method, wherein the fourth range is from -10 degrees to +10 degrees from the phase difference θ1. a first electrode comprising 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 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 high-frequency power source that outputs a second high-frequency power that has the same period as the first high-frequency power and is lower than the first high-frequency power; connected between the second high-frequency power source and the second electrode; an input terminal connected to a second high-frequency power supply, an output terminal connected to the second electrode, a first variable capacitor connected between the input terminal and a ground potential, and a connection between the input terminal and the output terminal a second power supply including a second matching circuit including a second variable capacitance connected in series therebetween;
Each 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 phase adjuster for adjusting the phase;
a control device that controls the first power supply, the second power supply, the shutter, and the phase adjuster;
The control device includes:
outputting the first high-frequency power from the first high-frequency power supply to form discharge plasma between the first electrode and the second electrode;
outputting the second high-frequency power from the second high-frequency power supply 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;
The voltage value Vpp of the second high-frequency power and the first voltage value Vpp according to the phase difference θ in a state where the output impedance of the second high-frequency power supply and the impedance of the load connected to the second high-frequency power supply are matched. Data obtained by detecting the capacitance value C1 of the variable capacitor is stored,
Before forming a sputtering film on the substrate, the control device shields the substrate or the second electrode from the sputtering target by the shutter, and controls the shutter between the first electrode and the second electrode. The second high-frequency power is supplied from the second high-frequency power supply to the second electrode by forming a discharge plasma and selecting a combination of the voltage value Vpp and the capacitance value C1 in the predetermined region of the phase difference θ. Vacuum processing equipment. A vacuum processing apparatus according to claim 4,
As the data in the control device,
forming the phase difference θ 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 are stored according to the phase difference θ by changing the phase difference θ,
The control device is
While shielding the substrate from the sputtering target by the shutter or the second electrode, the phase difference θ is increased by 30 degrees from the phase difference θ1 at which the voltage value Vpp of the profile curve of the voltage value Vpp is the lowest. Outside the first range up to 50 degrees, the phase difference θ2 at which the voltage value Vpp of the profile curve of the voltage value Vpp is maximum is plus 10 degrees, outside the second range up to minus 10 degrees, the phase difference θ2 set to a fourth range outside the third range, which is a range of minus 50 degrees to minus 30 degrees; 2 Vacuum processing equipment that supplies high-frequency power. A vacuum processing apparatus according to claim 5,
The fourth range is a range from minus 10 degrees to plus 10 degrees from the phase difference θ1. Vacuum processing apparatus.

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