TWI584343B - Plasma processing device - Google Patents

Description

Plasma processing device

The present invention relates to an inductively coupled plasma processing apparatus for generating a plasma by inducing an electric field in a vacuum vessel by flowing a high frequency current from a high frequency power source to a high frequency antenna (inductive coupling) A plasma is referred to as ICP (inductively coupled plasma), and the substrate is subjected to film formation, etching, ashing, sputtering, etc. by a chemical vapor deposition (CVD) method using the plasma. .

As an example of the inductively coupled plasma processing apparatus, Patent Document 1 describes a plasma processing apparatus in which a flat-plate high-frequency antenna is attached to an opening of a vacuum container via an insulating frame, and is a high-frequency power source. High-frequency power is supplied to one end and the other end of the high-frequency antenna to cause a high-frequency current to flow, and plasma is generated by the induced electric field generated thereby, and the substrate is processed using the plasma.

[Prior Art Literature]

[Patent Literature]

[Patent Document 1] International Publication No. WO 2009/142016 Manual (paragraph 0023-0026, Fig. 1)

In the conventional plasma processing apparatus, in order to cope with a large substrate or the like When the high-frequency antenna is extended, the impedance (especially the inductance) of the high-frequency antenna increases, and the high-frequency current does not easily flow, thereby suppressing the induced electric field generated by the high-frequency antenna, and thus it is difficult to efficiently generate the inductively coupled type. The topic of pulp.

Accordingly, it is a primary object of the present invention to provide a plasma processing apparatus which can efficiently produce an inductively coupled plasma even when a high frequency antenna is extended.

The plasma processing apparatus of the present invention is an inductively coupled plasma processing apparatus that causes a high-frequency current to flow from a high-frequency power source to a high-frequency antenna disposed in a vacuum container into which a vacuum is introduced and into which a gas is introduced. An induced electric field is generated in the vacuum vessel to generate a plasma, and the substrate is processed using the plasma. The plasma processing apparatus includes a sub-antenna disposed along the high-frequency antenna in the vacuum container. The vicinity of both end portions is supported by the vacuum container via an insulator, and is placed in an electrically floating state; and an insulating cover covers the high frequency antenna and the pair of portions located in the vacuum container The antenna is uniformly covered.

According to the plasma processing apparatus, an induced electromotive force is generated in the sub-antenna by flowing a high-frequency current to the high-frequency antenna, whereby even if the sub-antenna is placed in an electrically floating state, the induced current is passed through It mainly flows in the electrostatic capacitance of the insulator portion near the both end portions of the sub-antenna and flows to the sub-antenna. If the induced electric field caused by the induced current flowing through the sub-antenna cooperates with the induced electric field caused by the high-frequency current flowing through the high-frequency antenna, the inductively coupled plasma can be efficiently produced. Therefore, even in the case of extending the high frequency antenna, the efficiency can be excellent An inductively coupled plasma is produced.

The distance between the surface of the radio-frequency antenna and the surface of the sub-antenna may be 25 mm or less (excluding 0).

The high frequency antenna and the sub antenna may be disposed in the insulating cover body with a space therebetween.

According to the invention of the first aspect of the invention, the induced electromotive force is generated in the sub-antenna by flowing the high-frequency current to the high-frequency antenna, whereby the induced current flows mainly through the main antenna even if the sub-antenna is placed in an electrically floating state. The electrostatic capacitance of the insulator portion near the both end portions of the sub-antenna flows to the sub-antenna. If the induced electric field caused by the induced current flowing through the sub-antenna cooperates with the induced electric field caused by the high-frequency current flowing through the high-frequency antenna, the inductively coupled plasma can be efficiently produced. Therefore, the inductively coupled plasma can be efficiently produced even when the high frequency antenna is extended.

Further, since the high-frequency antenna and the sub-antenna of the portion located in the vacuum container are uniformly covered by the insulating cover, it is possible to prevent plasma from being generated between the high-frequency antenna and the sub-antenna, even when plasma is generated in the vacuum container. Ensure that the secondary antenna is electrically floating. Further, since it is possible to prevent the charged particles in the plasma from entering the high-frequency antenna and the sub-antenna, it is possible to suppress an increase in the plasma potential caused by the plasma being incident on the two antennas, and it is possible to suppress the charging of the two antennas by the plasma. Particle contamination causes metal contamination of the plasma and substrate.

According to the invention described in the second aspect of the invention, the following effects are further achieved. which is, Since the distance between the surface of the high-frequency antenna and the surface of the sub-antenna is 25 mm or less (excluding 0), the two antennas are very close, and the following effects can be further improved: by the induced current flowing through the sub-antenna The inductive electric field cooperates with the induced electric field caused by the high-frequency current flowing through the high-frequency antenna, and the inductively coupled plasma is efficiently produced. Further, even if the gas enters the insulating cover, the distance between the two antennas is small and the moving distance of the electrons is short, so that plasma can be prevented from occurring between the two antennas, and the electrical floating state of the sub-antenna can be made more reliable.

According to the invention of the third aspect of the invention, the following effects are further achieved. In other words, since the high-frequency antenna and the sub-antenna are disposed in the insulating cover via the space, the potential of the surface of the insulating cover can be suppressed by the presence of the space, whereby the increase in the plasma potential can be suppressed.

2‧‧‧Vacuum container

4‧‧‧Vacuum exhaust

6‧‧‧ gas inlet

8‧‧‧ gas

10‧‧‧Substrate

12‧‧‧Shelf holder

14‧‧‧ bias power supply

16‧‧‧ openings

18‧‧‧High frequency antenna

20‧‧‧Sub Antenna

22‧‧‧Insulators

23‧‧‧ Space

24‧‧‧Insulation cover

26‧‧‧High frequency power supply

28‧‧‧Matching circuit

30‧‧‧ Plasma

C ₂ ‧‧‧ electrostatic capacitor

D‧‧‧Distance

I ₂ ‧‧‧Induction current

I _R ‧‧‧High frequency current

L ₁ , L ₂ ‧‧‧ self-inductance coefficient

M‧‧‧ mutual inductance

Z ₁ , Z ₂ ‧‧‧ induction electromotive force

Fig. 1 is a schematic cross-sectional view showing an embodiment of a plasma processing apparatus according to the present invention.

2 is a view showing an example of results of measurement of a film formation rate when a lanthanum fluoride nitride film is formed on a substrate in a different configuration.

3(A), 3(B), and 3(C) are equivalent circuit diagrams for explaining the surroundings of the antenna for obtaining the result of FIG. 2.

Fig. 1 shows an embodiment of a plasma processing apparatus of the present invention. The plasma processing apparatus is configured such that the high-frequency current I _R flows from the high-frequency power source 26 to the high-frequency antenna 18 disposed in the vacuum container 2 that is evacuated and introduced into the gas 8, whereby the vacuum container is placed in the vacuum container An induced electric field is generated in 2 to generate a plasma (inductively coupled plasma) 30, and the substrate 10 is treated using the plasma 30.

The substrate 10 is, for example, a substrate constituting a semiconductor device or a solar cell, a substrate constituting a flat panel display (FPD) such as a liquid crystal display or an organic electroluminescence (EL) display, but is not limited thereto.

The treatment performed on the substrate 10 is, for example, film formation by plasma CVD, etching, ashing, sputtering, or the like.

The plasma processing apparatus is referred to as a plasma CVD apparatus in the case of film formation by a plasma CVD method, and is referred to as a plasma etching apparatus in the case of performing etching, and is referred to as ashing in the case of performing ashing. The plasma ashing apparatus is referred to as a plasma sputtering apparatus in the case of sputtering.

The vacuum container 2 is, for example, a metal container, and the inside thereof is evacuated by a vacuum exhaust device 4. The vacuum vessel 2 is electrically grounded in this example.

The gas 8 is introduced into the vacuum vessel 2 via, for example, a plurality of gas introduction ports 6 arranged in the direction of the flow rate regulator (not shown) and the high-frequency antenna 18 . The gas 8 may be a gas corresponding to the content of the treatment performed on the substrate 10. For example, in the case where film formation is performed on the substrate 10 by the plasma CVD method, the gas 8 is a material gas or a gas obtained by diluting the material gas with a diluent gas (for example, H ₂ ). If a more specific example is given, the Si film can be formed on the substrate 10 in the case where the material gas is SiH ₄ , and the SiN film can be formed on the substrate 10 in the case of SiH ₄ + NH ₃ ; In the case of SiH ₄ +O ₂ , an SiO ₂ film can be formed on the substrate 10; in the case of SiF ₄ +N ₂ , a SiN:F film (yttrium fluoride nitride film) can be formed on the substrate 10 on.

A substrate holder 12 holding the substrate 10 is disposed in the vacuum container 2. As in this example, a bias voltage can also be applied from the bias supply 14 to the substrate holder 12. The bias voltage is, for example, a negative DC voltage, a negative pulse voltage, or the like, but is not limited thereto. By such a bias voltage, for example, the energy when the positive ions in the plasma 30 are incident on the substrate 10 can be controlled, and the degree of crystallization of the film formed on the surface of the substrate 10 can be controlled. A heater that heats the substrate 10 may be provided in the substrate holder 12.

The high-frequency antenna 18 is a linear antenna in this example, and is disposed above the substrate 10 in the vacuum vessel 2 so as to be substantially parallel to the surface of the substrate 10 (for example, substantially parallel to the surface of the substrate 10). In the vicinity of both end portions of the high-frequency antenna 18, the two opening portions 16 provided on the opposing wall surfaces of the vacuum container 2 are penetrated. An insulator (for example, an insulating flange) 22 is provided in each of the openings 16 so that the openings 16 are hermetically sealed. The insulators 22 are passed through the vicinity of both end portions of the high-frequency antenna 18, and are supported by the vacuum container 2 via the respective insulators 22.

The distance from the high-frequency antenna 18 to the substrate holder 12 is, for example, about 50 mm to 250 mm, and more specifically, it is 100 mm as an example, but is not limited thereto.

Further, a gasket for vacuum sealing (for example, an O-ring) is provided between each of the insulators 22 and the vacuum container 2, between the high-frequency antenna 18 and the insulator 22, and between the sub-antenna 20 and the insulator 22 which will be described later. ), but the illustrations of these are omitted.

The high-frequency current I _R flows from the high-frequency power source 26 to the high-frequency antenna 18 via the matching circuit 28. The frequency of the high-frequency current I _{R is} , for example, a general 13.56 MHz, but is not limited thereto.

In the vacuum container 2, the sub antenna 20 is disposed along the high frequency antenna 18 (for example, substantially parallel). In this example, the sub antenna 20 is also linear in combination with the high frequency antenna 18. The sub antenna 20 may be, for example, the same length as the high frequency antenna 18. The vicinity of both end portions of the sub-antenna 20 is supported by the vacuum container 2 via the insulator 22, and is placed in an electrically floating state (floating state).

Although the position of the secondary antenna 20 with respect to the high frequency antenna 18 may be any one of the upper and lower sides and the left and right of the high frequency antenna 18, as in this example, it is preferably disposed above the high frequency antenna 18, that is, with respect to the high frequency. The antenna is disposed on the opposite side of the substrate 10. In this manner, the high-frequency antenna 18 in which the high-frequency current I _R flows and the plasma 30 is mainly generated can be brought closer to the substrate 10, so that the plasma 30 can be used more efficiently in the processing of the substrate 10.

In the example shown in FIG. 1, the insulators 22 are penetrated in the vicinity of both end portions of the sub-antenna 20, but this is an experiment for grounding both ends of the sub-antenna 20 to be described later, and it is not necessary to penetrate. Further, the insulator 22 can be divided into a support high frequency antenna 18 and a support secondary antenna 20.

The material of the high-frequency antenna 18 and the sub-antenna 20 is, for example, copper, aluminum, alloys thereof, stainless steel, or the like, but is not limited thereto.

The high frequency antenna 18 may be made hollow, and a refrigerant such as cooling water may flow therein to cool the high frequency antenna 18. The sub-antenna 20 is also the same.

It is preferable that the impedance (especially inductance) of the large diameter (outer diameter) of the high-frequency antenna 18 and the sub-antenna 20 is small. For example, the high frequency antenna 18 and the sub antenna 20 may have a diameter of 12 mm or more. The diameters of the high frequency antenna 18 and the sub antenna 20 may be the same as each other, or the diameter of the high frequency antenna 18 may be larger than the diameter of the sub antenna 20. In the latter case, the impedance (especially the inductance) of the high-frequency antenna 18 as the main antenna is smaller, and thus the high-frequency current I _R easily flows to the high-frequency antenna 18.

The material of the insulator 22 is, for example, ceramics such as alumina, quartz, or engineering plastics such as polyphenylene sulfide (PPS) or polyether ether ketone (PEEK), but is not limited thereto. .

The plasma processing apparatus further includes a cylindrical insulating cover 24 that collectively covers the high-frequency antenna 18 and the sub-antenna 20 located in the vacuum container 2, and is made of an insulator. Both ends of the insulating cover 24 and the vacuum container 2 may not be sealed. This is because even if the gas 8 enters the space in the insulating cover 24, since the space is small and the moving distance of the electrons is short, plasma is not generated in the space.

The material of the insulating cover 24 is, for example, quartz, alumina, fluororesin, tantalum nitride, tantalum carbide, niobium or the like, but is not limited thereto.

In the plasma processing apparatus, by transmitting a high-frequency current I _R to the high-frequency antenna 18, a high-frequency magnetic field is generated around the high-frequency antenna 18, whereby an induction is generated in a direction opposite to the high-frequency current I _R . electric field. By the induced electric field, electrons are accelerated in the vacuum vessel 2 to ionize the gas 8 in the vicinity of the high-frequency antenna 18, and plasma (i.e., inductively coupled plasma) 30 is generated in the vicinity of the high-frequency antenna 18. The plasma 30 is diffused to the vicinity of the substrate 10, and the processing can be performed on the substrate 10 by the plasma 30.

Further, according to the plasma processing apparatus, the induced electromotive force is generated in the sub antenna 20 by flowing the high-frequency current I _R to the radio-frequency antenna 18, whereby the sub-antenna 20 is placed in an electrically floating state, and an induced current is generated ( The induced current I ₂ ) in FIG. 3(C) also flows to the sub-antenna 20 via the electrostatic capacitance of the portion of the insulator 22 which is naturally present in the vicinity of both end portions of the sub-antenna 20 . The induced electric field caused by the induced current flowing through the sub-antenna 20 cooperates with the induced electric field caused by the high-frequency current I _R flowing through the high-frequency antenna 18, and the inductively coupled plasma 30 can be efficiently produced. Therefore, even when the high-frequency antenna 18 is extended, the inductively coupled plasma 30 can be efficiently produced. As a result, the high frequency antenna 18 is extended, and it is easy to cope with an increase in size of the substrate 10. For example, it can also be applied to the case where the length of the high frequency antenna 18 exceeds 2000 mm.

Further, since the high-frequency antenna 18 and the sub-antenna 20 of the portion located in the vacuum container 2 are uniformly covered by the insulating cover 24, generation of plasma between the high-frequency antenna 18 and the sub-antenna 20 is prevented, even in the vacuum container 2. When the plasma 30 is generated, the electrical floating state of the sub-antenna 20 can also be ensured. Further, since it is possible to prevent the charged particles in the plasma 30 from entering the high-frequency antenna 18 and the sub-antenna 20, it is possible to suppress an increase in the plasma potential caused by the plasma 30 entering the high-frequency antenna 18 and the sub-antenna 20, and The case where the high frequency antenna 18 and the sub antenna 20 are sputtered by the charged particles in the plasma 30 causes metal contamination of the plasma 30 and the substrate 10 to be suppressed.

Regarding the case where the plasma 30 can be efficiently produced, a more detailed description will be made below with reference to experimental results.

In the plasma processing apparatus of the configuration shown in Fig. 1, the lengths of the high-frequency antenna 18 and the sub-antenna 20 are both set to 1340 mm, and the distance D between the surfaces of the high-frequency antenna 18 and the sub-antenna 20 is set to 25 mm, and SiF is used. A mixed gas of ₄ (antimony tetrafluoride gas) and N ₂ gas (nitrogen gas) is supplied as a gas 8 from the high-frequency power source 26 to the high-frequency antenna 18 by supplying a high-frequency current I _{R of} 13.56 MHz, by which the induced electric field is in a vacuum An inductively coupled plasma 30 is produced in the container 2, and a SiN:F film (yttrium fluoride nitride film) is formed on the substrate 10. Further, an example of the result of measuring the film formation rate of the SiN:F film is shown as an example of (C) in FIG. 2 . An equivalent circuit around the antenna of this embodiment is shown in Fig. 3(C). In addition, in order to simplify the illustration, the illustration of the matching circuit 28 (refer FIG. 1) is abbreviate|omitted in FIG. 3 (A), FIG. 3 (B), and FIG.

Further, in order to compare with this embodiment, the result of measuring the film formation speed when the sub-antenna 20 was removed was shown as (A) Comparative Example 1 in Fig. 2 . The equivalent circuit around the antenna of Comparative Example 1 is shown in Fig. 3(A). Since the comparative example 1 does not have the sub antenna 20, it corresponds to the prior art similar to the technique described in the above-mentioned patent document 1. Further, the result of measuring the film formation speed when the both end portions of the sub-antenna 20 are grounded is shown as (B) Comparative Example 2 in Fig. 2 . The equivalent circuit around the antenna of Comparative Example 2 is shown in Fig. 3(B). In addition, in Comparative Example 1 and Comparative Example 2, the film formation conditions similar to those in the case of the above-described embodiment were used except for the portion of the sub-antenna 20.

As shown in FIG. 2, the film formation speed of Comparative Example 1 was the smallest. Further, the film formation speed of Comparative Example 2 was increased by about one tenth compared to Comparative Example 1. On the other hand, the film formation speed of the Example was greatly increased as compared with Comparative Example 1 and Comparative Example 2.

The analysis of the behavior of the high frequency near the high-frequency antenna 18 when the high-frequency current I _R flows to the high-frequency antenna 18 is not easy, and the reason for obtaining the measurement result is as follows.

In the case of Comparative Example 1 shown in FIG. 3(A), the antenna is only the high-frequency antenna 18, and if the length thereof becomes longer as described above, the impedance Z ₁ , particularly the self-inductance coefficient L _{1 thereof,} increases. However, the high-frequency current I _R does not easily flow, and thus the density of the plasma 30 is small, so that the film formation speed is also small.

On the other hand, in the case of the embodiment shown in FIG. 3(C), even if the sub-antenna 20 is placed in an electrically floating state, the electrostatic capacitance C ₂ mainly exists naturally (especially even if no capacitor is provided). A portion of the insulator 22 (see FIG. 1) in the vicinity of both end portions of the sub-antenna 20. Further, the two electrostatic capacitors C _{2 are} connected in series between the both ends of the sub-antenna 20 via a grounding circuit such as a vacuum container 2 made of metal, and form a closed circuit together with the sub-antenna 20. In summary, it can be considered that the values of the two electrostatic capacitances C ₂ are substantially equal to each other, and the combined electrostatic capacitance C ₀ of the two electrostatic capacitances C ₂ connected in series to each other is expressed by the following formula.

[Expression 1] C ₀ = C ₂ /2

By causing the high-frequency current I _R to flow from the high-frequency power source 26 to the high-frequency antenna 18, in the sub-antenna 20 linked to the magnetic flux φ thus formed, according to Faraday's law, the following expression is expressed. The induced electromotive force V ₂ . Here, ω is an angular frequency of the high-frequency current I _R , M is a mutual inductance between the high-frequency antenna 18 and the sub-antenna 20, and j is an imaginary unit.

[Expression 2] V ₂ =-dφ/dt=-jωMI _R

The resistance of the secondary antenna 20 is generally much smaller than the reactance caused by its self-inductance coefficient L ₂ . If the reactance is used to approximately represent the impedance Z ₂ of the closed circuit including the secondary antenna 20, the induced electromotive force V _{2 is used} . An induced current I ₂ represented by the following equation flows in the antenna 20. C _{0 is} a synthetic electrostatic capacitance represented by Formula 1. Here, the direction of the high-frequency current I _R and the induced current I ₂ shown in FIGS. 3(A), 3(B), and 3(C) is set to be positive.

[Expression 3] I ₂ =V ₂ /Z ₂ ≒-jωMI _R /j(ωL ₂ -1/ωC ₀ )≒-ωMI _R /(ωL ₂ -1/ωC ₀ )

As described above, the electrostatic capacitance C _{2 is an} electrostatic capacitance mainly existing in the portion of the insulator 22 near the both end portions of the sub-antenna 20, and thus is generally small, so that the synthesized electrostatic capacitance C _{0 is} also small. Therefore, the reactance (ωL ₂ -1/ωC ₀ ) in the equation 3 is a negative value, and as a result, the induced current I ₂ is a positive value. That is, as shown in FIG. 3(C), the sub-antenna 20 has an induced current I _{2 in the} same direction as the high-frequency current I _R flowing through the high-frequency antenna 18.

When the induced current I ₂ flows in the same direction as the high-frequency current I _R , it is considered that the inductance of the impedance Z ₁ constituting the high-frequency antenna 18 is slightly larger than the self-inductance coefficient L ₁ , and the inductance is slightly increased. The high-frequency magnetic field that generates the high-frequency current I _R flowing through the high-frequency antenna 18 and the high-frequency magnetic field that generates the induced current I ₂ flowing through the sub-antenna 20 are in the same direction, so that the high-frequency current I flowing through the high-frequency antenna 18 The induced electric field caused by _R acts to increase the induced electric field caused by the induced current I ₂ flowing through the sub-antenna 20, so that the inductively coupled plasma 30 can be efficiently produced. As a result of the above action, it is considered that the density of the plasma 30 is greatly increased, and the film formation speed is also greatly increased as compared with Comparative Example 1 and Comparative Example 2.

Further, in the case of this embodiment, the electrostatic capacitance C _{2 of the} portion of the insulator 22 naturally existing in the vicinity of both end portions of the sub-antenna 20 placed in the electrically floating state is flexibly utilized, and the sub-antenna is not particularly provided. It is also possible to form a capacitor with a closed circuit. Therefore, compared with the case where a capacitor is provided, the number of parts can be reduced, the assembly work step can be reduced, and the like.

On the other hand, in the case of the comparative example 2 shown in FIG. 3(B), since both ends of the sub-antenna 20 are grounded, the electrostatic capacitance C ₂ does not exist, and therefore the reactance 1 in the equation 3 ωC ₀ is 0, so that the induced current I ₂ is a negative value. That is, in the sub-antenna 20, the induced current I ₂ flows in a direction opposite to the direction shown in FIG. 3(B), that is, in a direction opposite to the high-frequency current I _R flowing through the high-frequency antenna 18. Further, the induced current I _{2 is} larger than the induced current in the case of the above embodiment.

If the induced current I ₂ flows in a direction opposite to the high-frequency current I _R , the inductance of the impedance Z ₁ constituting the high-frequency antenna 18 is slightly smaller than the self-inductance coefficient L ₁ , and is slightly smaller, thereby being high. The frequency current I _R easily flows to the high frequency antenna 18, and on the other hand, the induced electric field caused by the high frequency current I _R flowing through the high frequency antenna 18 acts to cause the induced current I ₂ flowing through the secondary antenna 20 The induced electric field is weakened. As a result of the above action, it was considered that the density of the plasma 30 did not increase so much, and therefore, the film formation rate did not increase much as compared with Comparative Example 1.

Referring again to Fig. 1, the distance D between the surface of the radio-frequency antenna 18 and the surface of the sub-antenna 20 is preferably 25 mm or less (excluding 0). Thus, the high-frequency antenna 18 and the sub-antenna 20 are very close, and the above-described effects can be further enhanced, that is, the induced electric field caused by the induced current I ₂ flowing through the sub-antenna 20 and the high frequency flowing through the high-frequency antenna 18 The cooperation of the induced electric field caused by the frequency current I _R produces the inductively coupled plasma 30 with high efficiency. Further, even if the gas 8 enters the insulating cover 24, the distance between the high-frequency antenna 18 and the sub-antenna 20 is small and the moving distance of electrons is short, so that generation of plasma between the high-frequency antenna 18 and the sub-antenna 20 can be prevented. The electrical floating state of the secondary antenna 20 is more reliable.

An insulator such as a resin may be filled in portions other than the high frequency antenna 18 and the sub antenna 20 in the insulating cover 24. In this way, it is possible to more reliably prevent plasma from being generated in the insulating cover 24.

Further, the high-frequency antenna 18 and the sub-antenna 20 may be disposed in the insulating cover 24 via the space 23 as in the embodiment. As described above, the potential of the surface of the insulating cover 24 can be suppressed by the presence of the space 23, whereby the increase in the potential of the plasma 30 can be suppressed.

The distance D between the high-frequency antenna 18 and the sub-antenna 20 may be within the range, for example, in the range of 5 mm to 25 mm by bending the sub-antenna 20 or the like. In the circumference, it changes in the longitudinal direction of the radio-frequency antenna 18. Thus, the density distribution of the plasma 30 in the longitudinal direction of the high-frequency antenna 18 can be controlled, and the density distribution of the film formed on the substrate 10 can be controlled.

The high-frequency antenna 18 and the sub-antenna 20 covered by the insulating cover 24 may be one antenna unit, and the plurality of antenna elements may be arranged side by side in the direction along the surface of the substrate 10 in accordance with the size of the substrate 10. In this way, the plasma 30 having a larger area can be produced, and the larger substrate 10 can be processed.

2‧‧‧Vacuum container

4‧‧‧Vacuum exhaust

6‧‧‧ gas inlet

8‧‧‧ gas

10‧‧‧Substrate

12‧‧‧Shelf holder

14‧‧‧ bias power supply

16‧‧‧ openings

18‧‧‧High frequency antenna

20‧‧‧Sub Antenna

22‧‧‧Insulators

23‧‧‧ Space

24‧‧‧Insulation cover

26‧‧‧High frequency power supply

28‧‧‧Matching circuit

30‧‧‧ Plasma

D‧‧‧Distance

I _R ‧‧‧High frequency current

Claims (3)

A plasma processing apparatus which is an inductively coupled plasma processing apparatus that causes a high-frequency current to flow from a high-frequency power source to a high-frequency antenna disposed in a vacuum container into which a vacuum is introduced and into which a gas is introduced An induction electric field is generated in the vacuum vessel to generate a plasma, and the substrate is processed using the plasma. The plasma processing apparatus is characterized by comprising: a secondary antenna disposed along the high frequency antenna in the vacuum container a vacuum container supported by the vacuum container in the vicinity of both end portions thereof and placed in an electrically floating state; and an insulating cover body, the high frequency antenna and the sub antenna located in a portion of the vacuum container Unified coverage. The plasma processing apparatus according to claim 1, wherein a distance between a surface of the radio-frequency antenna and a surface of the sub-antenna is 25 mm or less (excluding 0). The plasma processing apparatus according to the first or second aspect of the invention, wherein the high frequency antenna and the sub antenna are disposed in the insulating cover body with a space therebetween.