TW202012699A - Film forming device and film forming method - Google Patents

Abstract

This film forming device includes an evacuable process vessel, a lower electrode, an upper electrode, a gas supply unit, and a voltage applying unit. A substrate to be processed is set on the lower electrode. The upper electrode is disposed opposite the lower electrode in the process vessel. The gas supply unit supplies a process space between the upper electrode and the lower electrode with a film forming raw material gas that changes to plasma in the process space. The voltage applying unit applies, to the upper electrode, AC voltage for which the reference potential changes up and down alternatively over time.

Description

Film forming device and film forming method

The present disclosure relates to a film forming apparatus and a film forming method.

In the manufacture of a semiconductor integrated circuit, a film is formed on a substrate such as a semiconductor wafer by a film forming device. In the film forming apparatus, the substrate is arranged in a chamber (processing container) set to a predetermined vacuum degree, and a film-forming raw material gas is supplied into the chamber to generate a plasma, thereby forming a film on the substrate. As a film forming technique, for example, plasma CVD (Chemical Vapor Deposition), plasma ALD (Atomic Layer Deposition), etc. are known. [Prior Technical Literature] [Patent Literature]

[Patent Literature 1] JP 2009-239012

[Problems to be solved by the invention]

Under high-pressure conditions of hundreds of mTorr to several Torr, such as plasma CVD or plasma ALD, it is necessary to generate a plasma capable of obtaining a high electron density. On the other hand, in the oxide film forming process, a low frequency of several MHz or less is required to increase the electron density, and a high frequency of several tens of MHz or more is required to reduce the ion energy. However, in the process of forming a nitride film, a high frequency of several hundred MHz or more is required for increasing electron density, while a low frequency of several tens of MHz or less is required for high uniformity.

Therefore, in the conventional film-forming apparatus, it is difficult to achieve high electron density, low ion energy, and high uniformity at the same time. Therefore, no matter what kind of film forming process, it is expected that a film forming apparatus that can achieve high electron density, low ion energy, and high uniformity can be achieved at the same time.

The present disclosure provides techniques that can simultaneously achieve high electron density, low ion energy, and high uniformity. [Means to solve the problem]

A film forming apparatus according to one aspect of the present disclosure includes: a processing container that can be vacuum-evacuated; a lower electrode; an upper electrode; a gas supply unit; and a voltage application unit. The substrate to be processed is placed on the lower electrode. The upper electrode is arranged to face the lower electrode in the processing container. The gas supply unit supplies the film-forming raw material gas plasmatized in the processing space between the upper electrode and the lower electrode to the processing space. The voltage applying unit applies an alternating voltage whose reference potential alternates up and down with the passage of time to the upper electrode. [Effect of the invention]

According to the disclosed technology, high electron density, low ion energy, and high uniformity can be achieved at the same time.

The embodiments of the disclosed technology will be described below with reference to the drawings.

<Structure of film forming device> FIG. 1 is a diagram showing a configuration example of a film forming apparatus of an embodiment.

In FIG. 1, the film forming apparatus 1 has a chamber 10 that is a metal processing container made of aluminum, stainless steel, or the like. The chamber 10 is safely grounded.

In the chamber 10, a disk-shaped susceptor 12 is arranged horizontally, and the susceptor 12 is provided as a semiconductor wafer W on which a substrate to be processed is placed. The receiver 12 also functions as a lower electrode. On the side wall of the chamber 10, a gate valve 28 for opening and closing the carrying-in/out port of the semiconductor wafer W is installed. The susceptor 12 is made of AlN ceramic, for example, and is supported by an insulating cylindrical support portion 14 extending vertically upward from the bottom of the chamber 10.

An annular exhaust path is formed along the outer circumference of the cylindrical support portion 14 between the conductive cylindrical support portion (inner wall portion) 16 extending vertically upward from the bottom of the chamber 10 and the side wall of the chamber 10 18. An exhaust port 22 is provided at the bottom of the exhaust path 18.

The exhaust port 22 is connected to the exhaust device 26 through the exhaust pipe 24. The exhaust device 26 includes, for example, a vacuum pump such as a turbo molecular pump, and decompresses the processing space in the chamber 10 to a desired vacuum degree. It is preferable to maintain a certain pressure within the range of 200 mTorr to 1700 mTorr in the chamber 10, for example.

Between the susceptor 12 used as the lower electrode and the ground, an impedance adjustment circuit 100 having a coil 101 and a variable capacitor 102 is electrically connected via a connecting rod 36.

The semiconductor wafer W to be processed is placed on the susceptor 12, and a ring portion 38 is provided so as to surround the semiconductor wafer W. The ring portion 38 is formed of a conductive material (for example, Ni, Al, etc.), and is detachably attached to the upper surface of the receiver 12.

An electrostatic chuck 40 for wafer suction is provided on the upper surface of the susceptor 12. The electrostatic chuck 40 is formed by sandwiching a sheet-shaped or mesh-shaped conductor between film-shaped or plate-shaped dielectrics. The electric conductor in the electrostatic chuck 40 is electrically connected to the DC power source 42 arranged outside the chamber 10 via the on/off switch 44 and the power supply line 46. The semiconductor wafer W is attracted and held on the electrostatic chuck 40 by the DC voltage applied by the DC power source 42 and the Coulomb force generated by the electrostatic chuck 40.

An annular refrigerant chamber 48 extending in the circumferential direction is provided inside the receiver 12. In the refrigerant chamber 48, a refrigerant (for example, cooling water) of a predetermined temperature is circulated and supplied from a cooler unit (not shown) via pipes 50 and 52. The temperature of the semiconductor wafer W on the electrostatic chuck 40 is controlled by the temperature of the refrigerant. In addition, in order to further improve the accuracy of the wafer temperature, the heat conduction gas (for example, He gas) from the heat conduction gas supply part (not shown) is supplied to the electrostatic chuck through the gas supply pipe 51 and the gas passage 56 in the susceptor 12 Between 40 and the semiconductor wafer W.

The patio of the chamber 10 is parallel to the receiver 12 (that is, opposite), and is provided with a disc-shaped inner upper electrode 60 and a ring-shaped outer upper electrode 62 in a concentric shape. As a preferable dimension in the radial direction, the inner upper electrode 60 has the same diameter (diameter) as the semiconductor wafer W, and the outer upper electrode 62 has the same diameter (inner diameter/outer diameter) as the ring portion 38. However, the inner upper electrode 60 and the outer upper electrode 62 are electrically insulated (more precisely DC (direct current)) from each other. A ring-shaped insulator 63 made of ceramic is interposed between the two electrodes 60 and 62, for example.

The inner upper electrode 60 has: an electrode plate 64 that truly faces the susceptor 12; and an electrode support 66 that detachably supports the electrode plate 64 from behind (upper). The material of the electrode plate 64 is preferably a conductive material such as Ni or Al. The electrode support 66 is made of, for example, anodized aluminum. The outer upper electrode 62 also has an electrode plate 68 facing the receiver 12 and an electrode support 70 that detachably supports the electrode plate 68 from the back (upper side). The electrode plate 68 and the electrode support 70 are preferably made of the same material as the electrode plate 64 and the electrode support 66, respectively. Hereinafter, the inner upper electrode 60 and the outer upper electrode 62 may be collectively referred to as "upper electrodes 60, 62". In this way, in the film forming apparatus 1, the disk-shaped receiver 12 (that is, the lower electrode) and the disk-shaped upper electrodes 60 and 62 are opposed to each other in parallel.

In this embodiment, an example is given in which the upper electrodes 60 and 62 are composed of two members of the inner upper electrode 60 and the outer upper electrode 62. However, the upper electrode may be composed of one member.

In order to supply the film forming raw material gas to the processing space PS set between the upper electrodes 60 and 62 and the susceptor 12, the inner upper electrode 60 is also used as a shower head. More specifically, a gas diffusion chamber 72 is provided inside the electrode support 66, and a plurality of gas discharge holes 74 penetrating from the gas diffusion chamber 72 to the receiver 12 side are formed in the electrode support 66 and the electrode plate 64. The gas inlet 72 a provided above the gas diffusion chamber 72 is connected to a gas supply pipe 78 extending from the raw gas supply portion 76. In addition, not only the inner upper electrode 60 but also the outer upper electrode 62 may be provided with a shower head.

A voltage applying part 5 that outputs an applied voltage is arranged outside the chamber 10. The voltage application unit 5 is connected to the upper electrodes 60 and 62 via a power supply line 88. The voltage applying section 5 includes: a high-frequency power supply 30; a matching unit 34; a variable DC power supply 80; a pulse generator 84; a filter 86; an overlay 91; and an on/off switch 92.

The high-frequency power supply 30 generates a high-frequency AC voltage (hereinafter sometimes referred to as "high-frequency voltage") that contributes to the generation of plasma, and switches the generated high-frequency voltage through the matching unit 34 and on/off The switch 92 is supplied to the overlapper 91. When the on/off switching switch 92 is turned on, the high-frequency voltage is supplied to the superimposed device 91. On the other hand, when the on/off switching switch 92 is turned off, the high-frequency voltage is not supplied to the superimposing device 91. The frequency of the high-frequency voltage generated by the high-frequency power source 30 is preferably 13 MHz or more.

Fig. 2 is a diagram showing an example of a high-frequency voltage according to an embodiment. As shown in FIG. 2, the high-frequency power supply 30 generates, for example, a high-frequency voltage V1 of -250V to 250V with a reference potential RP of 0V. The matching unit 34 obtains a match between the impedance of the high-frequency power supply 30 side and the impedance of the load (mainly electrodes, plasma, chamber) side.

The output terminal of the variable DC power supply 80 is connected to the pulse generator 84, and the variable DC power supply 80 outputs a negative DC voltage (ie, a negative DC voltage) to the pulse generator 84. The pulse generator 84 uses the negative DC voltage input from the variable DC power supply 80 to generate a square-wave DC pulse voltage (that is, DC pulse voltage), and supplies the generated DC pulse voltage to the superimulator 91 through the filter 86. The frequency of the DC pulse voltage generated by the pulse generator 84 is preferably 10 kHz to 1 MHz, for example. In addition, the duty ratio of the DC pulse voltage generated by the pulse generator 84 is preferably 10% to 90%.

Fig. 3 is a diagram showing an example of a DC pulse voltage according to the embodiment. As shown in FIG. 3, the pulse generator 84 generates a square-wave DC pulse voltage V2 of, for example, -500V to 0V. The filter 86 is configured to pass the DC pulse voltage output from the pulse generator 84 and output it to the overlapper 91. On the other hand, the high-frequency voltage output from the high-frequency power supply 30 flows into the ground line without flowing into the pulse generator 84 side.

The overlapping device 91 generates a voltage that overlaps the high-frequency voltage and the DC pulse voltage by overlapping the high-frequency voltage output by the high-frequency power supply 30 and the DC pulse voltage output by the pulse generator 84 (hereinafter sometimes referred to as " Overlap voltage"). The generated overlapping voltage is applied to the upper electrodes 60 and 62 via the power supply line 88. The overlapping device 91 is an example of a voltage overlapping portion.

4 is a diagram showing an example of the superimposed voltage in the embodiment. When the high-frequency voltage V1 shown in FIG. 2 and the DC pulse voltage V2 shown in FIG. 3 are superimposed, the superimposed voltage V3 shown in FIG. 4 is generated. By superimposing the DC pulse voltage on the high-frequency voltage, as shown in FIG. 4, the superimposed voltage V3 is matched with the waveform of the square-wave DC pulse voltage V2 (see FIG. 3) to make the high-frequency voltage V1 (see FIG. 2) The reference potential RP alternates up and down with the passage of time. That is, when the on/off switch 92 is turned on, the voltage applying unit 5 outputs a high-frequency voltage that changes in a pulse shape (that is, a rectangular wave shape).

In addition, when the on/off switch 92 is turned on, the high-frequency voltage output from the matching unit 34 is supplied to the overlapper 91, so the overlapped voltage is output from the overlapper 91. On the other hand, when the on/off changeover switch 92 is turned off, the high-frequency voltage output from the matching unit 34 is not supplied to the overlayer 91, and therefore the DC pulse voltage output from the filter 86 is directly output from the overlayer 91.

In addition, a ring-shaped ground member 96 formed of a conductive member such as Ni or Al is attached to an appropriate portion in the chamber 10 facing the processing space PS (for example, the outer side of the outer upper electrode 62 in the radial direction). The ground member 96 is attached to, for example, a ring-shaped insulator 98 formed of ceramic, and is connected to the patio wall of the chamber 10 and is grounded through the chamber 10. When a superimposed voltage is applied to the upper electrodes 60 and 62 from the voltage application unit 5 in the plasma process, electron current flows between the upper electrodes 60 and 62 and the ground member 96 through the plasma.

The components in the film forming apparatus 1 (for example, the exhaust device 26, the high-frequency power supply 30, the on/off switching switches 44, 92, the raw gas supply unit 76, the cooler unit (not shown), and the heat conduction gas supply unit ( (Not shown) etc.) The operations of each and the entire operation (sequence) of the film forming apparatus 1 are controlled by a control unit (not shown) formed by a microcomputer, for example.

<Film Forming Process of Film Forming Apparatus> In the film forming apparatus 1, when the film forming is performed, the gate valve 28 is first opened to carry the semiconductor wafer W to be processed into the chamber 10 and placed on the electrostatic chuck 40 . Next, the on/off switch 44 is turned on, and the semiconductor wafer W is attracted and held on the electrostatic chuck 40 by the electrostatic attraction force. Next, the film-forming raw material gas is introduced into the chamber 10 from the raw material gas supply unit 76 at a predetermined flow rate, and the pressure in the chamber 10 is adjusted to a set value by the exhaust device 26. As the film-forming raw material gas, for example, a negative gas such as Ar/O ₂ gas or N ₂ gas can be used. In addition, the high-frequency power supply 30 and the variable DC power supply 80 are turned on, and the superimposed voltage is applied to the upper electrodes 60 and 62. In addition, a heat-conducting gas is supplied between the electrostatic chuck 40 and the semiconductor wafer W. The film-forming raw material gas discharged from the upper electrode 60 is plasmatized by the discharge between the upper electrodes 60 and 62 and the susceptor 12 used as the lower electrode, and free radicals or ions generated by the plasma A film is formed on the surface of the semiconductor wafer W.

<Experimental results of comparative example (film forming raw material gas: Ar/O ₂ )> FIGS. 5 and 6 are diagrams showing an example of experimental results in comparative examples. As shown in FIG. 5 as an experimental result in a comparative example, instead of applying an overlapping voltage to the upper electrodes 60 and 62, only the AC voltage of 450 kHz, 2 MHz, 13 MHz or 40 MHz is applied to the upper electrodes 60 and 62. The relationship between the pressure under the pressure and the electron density. In FIG. 6, it is shown as an experimental result in the comparative example that instead of applying the superimposed voltage to the upper electrodes 60 and 62, only the upper electrodes 60 and 62 are applied with the pressure in the chamber 10 at 500 mTorr. The relationship between ion energy and ion energy distribution (IED: Ion Energy Distribution) in the case of an alternating voltage of 450 kHz.

When only a low-frequency AC voltage with a frequency of 450 kHz is applied to the upper electrodes 60 and 62, as shown in FIG. 5, the electron density in the negative gas plasma containing O ₂ is also high, especially in the chamber 10 The pressure is around 0.7 Torr, and sufficient electron density for film formation can be obtained. On the other hand, as shown in FIG. 6, when the power of the AC voltage is 1000 W, the ion energy becomes higher, and the damage to the resulting film also becomes larger. Furthermore, even when the pressure is increased with the power of the AC voltage set to 1000 W, a large reduction in ion energy cannot be expected. On the other hand, as shown in FIG. 6, by lowering the power of the AC voltage to 300 W, 150 W, or the like, low ion energy can be achieved. However, the lower the power density, the lower the electron density and the lower the film formation rate.

Also, as shown in FIG. 5, if the frequency of the AC voltage is set to a high frequency of 2MHz, 13MHz, 40MHz, etc. in order to reduce the ion energy, the temperature of electrons decreases, so the electrons adhere to radicals and create negative ions to reduce the electron density. . In addition, as shown in FIG. 5, when the pressure is increased in order to reduce the ion energy, the electron temperature decreases. Therefore, as in the case of high frequency, negative ions are made to reduce the electron density.

In this way, when only an alternating voltage is applied to the upper electrodes 60 and 62, it is difficult to achieve a balance between high electron density and low ion energy.

<Experiment result 1 of the embodiment (film forming raw material gas: Ar/O ₂ )> FIG. 7 is a diagram showing an example of the experiment result 1 of the embodiment. In FIG. 7, as shown in the experimental result 1 of the embodiment, instead of applying the superimposed voltage to the upper electrodes 60 and 62, only the upper electrodes 60 and 62 are applied with the pressure in the chamber 10 at 500 mTorr. The relationship between ion energy and ion energy distribution in the case of DC pulse voltage at a frequency of 500 kHz. That is, the experimental result 1 is the experimental result when the on/off switch 92 shown in FIG. 1 is set to off.

When only a low-frequency DC pulse voltage with a frequency of 500 kHz is applied to the upper electrodes 60 and 62, as shown in FIG. 7, the ion energy is not affected by the power of the DC pulse voltage, and the ion energy becomes very low compared with the case of FIG. Furthermore, as shown in FIG. 7, by increasing the power of the DC pulse voltage, only the electron density can be increased while maintaining low ion energy.

In this way, by applying only a DC pulse voltage to the upper electrodes 60 and 62, it is possible to achieve both high electron density for high film formation rate and low ion energy for low damage.

<Experiment result 2 of the embodiment (film forming raw material gas: Ar/O ₂ )> FIGS. 8 and 9 are diagrams showing an example of the experiment result 2 of the embodiment. In FIG. 8, as the experimental result 2 of the embodiment, the relationship between the ion energy and the ion energy distribution when the overlapping voltage is applied to the upper electrodes 60 and 62 in the state where the pressure in the chamber 10 is set to 500 mTorr . In Fig. 8, the frequency of the DC pulse voltage is 500 kHz, the power of the DC pulse voltage is 300 W, the frequency of the AC voltage is 40.68 MHz, and the power of the AC voltage is 200 W or 500 W. In addition, FIG. 9 shows the experimental result 2 of the embodiment as the relationship between the pressure and the electron density when an overlapping voltage is applied to the upper electrodes 60 and 62. In Fig. 9, the frequency of the DC pulse voltage is 500 kHz, and the power of the DC pulse voltage is 300 W. In addition, in FIG. 9, the drawing of 450 kHz, 2 MHz, 13 MHz, and 40 MHz is the same as that of FIG. 5, and the drawing of 40 MHz+DC is when the overlapping voltage is applied.

According to the above experimental result 1, as shown in FIG. 7, even if the power of the DC pulse voltage is changed, the ion energy hardly changes.

On the other hand, in the experimental result 2, as shown in FIG. 8, by changing the power of the AC voltage that becomes the basis of the superimposed voltage, the electron density can be maintained in the same state as in the case of FIG. 7, and the ion energy can be changed.

In this way, when the superimposed voltage is applied to the upper electrodes 60 and 62, compared with the case where only the DC pulse voltage is applied to the upper electrodes 60 and 62, the electron density control based on the DC pulse voltage and the AC voltage can be independently independently controlled. The control of the ion energy. That is, by applying an overlapping voltage to the upper electrodes 60 and 62, both high electron density and low ion energy can be achieved, and the electron density and ion energy can be independently controlled.

Furthermore, as shown in FIG. 9, when the superimposed voltage is applied to the upper electrodes 60 and 62, especially when the pressure in the chamber 10 is near 0.7 Torr, as in FIG. 5, a sufficient electron density for film formation can be obtained .

<Experimental result 3 of the embodiment (film forming raw material gas: N ₂ )> FIG. 10 is a diagram showing an example of the experimental result 3 of the embodiment. As shown in FIG. 10 as the experimental result 3 of the embodiment, the relationship between the wavelength and the luminous intensity when the superimposed voltage is applied to the upper electrodes 60 and 62 with the pressure in the chamber 10 at 500 mTorr.

When only an alternating voltage is applied to the upper electrodes 60 and 62 to generate N ₂ plasma, the nitriding force is weak, and it becomes difficult to form a nitride film with good film quality. In general, the higher the frequency of the AC voltage, the better the quality of the nitride film. Therefore, the film formed by μ-wave plasma becomes the best quality film. The μ-wave plasma is a plasma that has a very high electron temperature just below the upper electrodes 60 and 62 and diffuses into the receiver 12 (that is, the lower electrode).

By applying a direct current pulse voltage to the upper electrodes 60 and 62, the temperature of the electrons directly under the upper electrodes 60 and 62 can be maintained at a very high temperature as in the case of the μ-wave plasma, so the same electricity as the μ-wave plasma can be generated. Pulp. The dissociation of N ₂ requires high-energy electrons. By applying only a DC pulse voltage or an overlapping voltage to the upper electrodes 60 and 62, as shown in FIG. 10, N ₂ can be dissociated efficiently. Shown in Figure 10, by applying a DC pulse voltage from the solution to promote the progress of N _2, N light emission intensity decrease of _2, on the other hand, the light emission intensity of the radical N increases.

In addition, the higher the high frequency, the shorter the wavelength, so the wavelength effect deteriorates the uniformity of the plasma distribution. In contrast, in the conventional technology, it is difficult to reconcile the high dissociation degree of N ₂ and the plasma uniformity. Therefore, it is necessary to increase the distance between the upper electrode and the lower electrode or take measures for the shape of the upper electrode. On the other hand, when the plate-shaped upper electrode and the disc-shaped lower electrode are parallel to each other and face each other, the uniformity of the plasma becomes good by the application of the DC pulse voltage. Therefore, by applying only the DC pulse voltage or the overlapping voltage, the high dissociation degree of N ₂ and the plasma uniformity can be taken into consideration, and the distance between the upper electrode and the lower electrode can be reduced. Therefore, the disclosed technology can be applied to a process such as PEALD (Plasma Enhanced Atomic Layer Deposition) which has a large impact on the production capacity of the process.

As described above, in the embodiment, the film forming apparatus 1 includes the chamber 10 capable of performing vacuum evacuation, the susceptor 12 used as the lower electrode, the upper electrodes 60 and 62, the raw material gas supply unit 76, and the voltage application unit 5. The substrate to be processed is placed on the susceptor 12. The upper electrodes 60 and 62 are arranged to face the receiver 12 in the chamber 10. The raw material gas supply unit 76 supplies the film-forming raw material gas plasmatized in the processing space PS between the upper electrodes 60 and 62 and the susceptor 12 to the processing space PS. The voltage applying unit 5 applies the superimposed voltage, that is, the superimposed voltage of the alternating voltage and the direct current pulse voltage that the reference potential alternates up and down with time to the upper electrodes 60 and 62.

According to this, at the time of film formation, high electron density, low ion energy, and high uniformity can be simultaneously achieved. In addition, both high electron density and low ion energy can be achieved, and electron density and ion energy can be controlled independently.

In addition, in the embodiment, the film forming apparatus 1 includes an impedance adjustment circuit 100 connected between the susceptor 12 and the ground.

According to this, the impedance between the upper electrodes 60 and 62 and the susceptor 12 can be reduced, so the AC voltage component of the superimposed voltage easily reaches the susceptor 12.

In addition, all the points of the embodiment of the present disclosure are only examples and are not intended to be limiting. In fact, the above-mentioned embodiments can be realized in various forms. In addition, the above embodiments can be omitted, replaced, or changed in various forms without departing from the scope of the patent application and its purport.

1: film forming device 5: Voltage application section 10: chamber 12: receiver 60: inner upper electrode 62: outer upper electrode 76: Raw material gas supply unit

[FIG. 1] FIG. 1 is a diagram showing a configuration example of a film forming apparatus according to an embodiment. [Fig. 2] Fig. 2 is a diagram showing an example of a high-frequency voltage according to an embodiment. [Fig. 3] Fig. 3 is a diagram showing an example of a DC pulse voltage according to an embodiment. [Fig. 4] Fig. 4 is a diagram showing an example of superimposed voltage according to the embodiment. [Fig. 5] Fig. 5 is a diagram showing an example of experimental results in a comparative example. [Fig. 6] Fig. 6 is a diagram showing an example of experimental results in a comparative example. [Fig. 7] Fig. 7 is a diagram showing an example of the experimental result 1 of the embodiment. [Fig. 8] Fig. 8 is a diagram showing an example of the experimental results 2 of the embodiment. [Fig. 9] Fig. 9 is a diagram showing an example of the experimental results 2 of the embodiment. [Fig. 10] Fig. 10 is a diagram showing an example of the experimental results 3 of the embodiment.

1: film forming device

5: Voltage application section

10: chamber

12: receiver

14: cylindrical support

16: Tubular support (inner wall)

18: Circular exhaust path

22: Exhaust

24: Exhaust pipe

26: Exhaust

28: Gate valve

30: High frequency power supply

34: matching unit

36: connecting rod

38: Ring

40: electrostatic chuck

42: DC power supply

44: Turn on/off switch

46: Power supply line

48: refrigerant room

50, 52: piping

51: gas supply pipe

56: Gas passage

60: inner upper electrode

62: outer upper electrode

63: insulator

64: electrode plate

66: electrode support

68: electrode plate

70: electrode support

72: Gas diffusion chamber

72a: gas inlet

74: gas discharge hole

76: Raw material gas supply unit

78: gas supply pipe

80: variable DC power supply

84: pulse generator

86: filter

88: power supply line

91: Overlap

92: Turn on/off switch

96: Grounded parts

98: insulator

100: impedance adjustment circuit

101: coil

102: Variable capacitor

PS: processing space

W: Semiconductor wafer

Claims (3)

A film-forming device with: The processing container can be vacuum exhausted; The lower electrode is used to place the substrate to be processed in the processing container; The upper electrode is arranged to face the lower electrode in the processing container; A gas supply unit that supplies the film-forming raw material gas plasmatized in the processing space between the upper electrode and the lower electrode to the processing space; and The voltage applying unit applies an alternating voltage whose reference potential alternates up and down with the passage of time to the upper electrode. For example, the film-forming device according to item 1 of the patent application scope, in which It also includes an impedance adjustment circuit connected between the lower electrode and the ground. A film forming method is a film forming method in a film forming apparatus, the film forming apparatus includes: The processing container can be vacuum exhausted; The lower electrode for placing the substrate to be processed in the processing container; and The upper electrode is arranged to face the lower electrode in the processing container; The film forming method has: Supplying the film-forming raw material gas plasmatized in the processing space between the upper electrode and the lower electrode to the processing space; and An alternating voltage whose reference potential alternates up and down with time is applied to the upper electrode.

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