TW201349943A - Inductively coupled plasma processing method and inductively coupled plasma processing apparatus - Google Patents

Abstract

The subject of the present invention is to perform the inductively coupled plasma processing with a desired processing distribution. The solution is to provide an inductively coupled plasma processing apparatus with a high-frequency antenna for performing a first process and a second process at different times, so as to obtain a desired processing distribution on the substrate at the end of the process. The high frequency antenna comprises an outside antenna to which high-frequency power is supplied to form an outside induction electric field and have a spiral form; and an inside antenna that is concentrically provided inside the outside antenna and to which high-frequency power is supplied to form an inside induction electric field and have a spiral form. The first process employs a current flowing on the inside antenna with a relatively large current value to generate a local plasma corresponding to the inside induction electric field formed on the inside antenna portion for processing. The second process employs the current flowing on the outside antenna with a relatively large current value to generate a local plasma corresponding to the outside induction electric field formed on the outside antenna portion for processing.

Description

Inductively coupled plasma processing method and inductively coupled plasma processing device

The present invention relates to an inductively coupled plasma processing method and an inductively coupled plasma processing apparatus for performing inductively coupled plasma processing on a substrate to be processed such as a glass substrate for manufacturing a flat panel display (FPD).

In a flat panel display (FPD) manufacturing process such as a liquid crystal display (LCD), there is a process of performing plasma processing such as plasma etching or film formation on a glass substrate, and in order to perform such plasma processing, Various plasma processing apparatuses such as a plasma etching apparatus or a plasma CVD apparatus are used. In the plasma processing apparatus, a capacitively coupled plasma processing apparatus has been conventionally used. Recently, an inductively coupled plasma (ICP) processing apparatus having an advantage of obtaining a high density of plasma at a high degree of vacuum has been attracting attention.

In the inductively coupled plasma processing apparatus, a high frequency antenna is disposed above a dielectric window constituting a top wall of a processing container that accommodates a substrate to be processed, a processing gas is supplied into the processing container, and high frequency power is supplied to the high frequency antenna. Thereby forming an induced electric field in the processing container through the dielectric window, thereby inducing an electric field to generate an inductively coupled plasma, thereby inductively coupling the plasma The predetermined plasma treatment is performed on the substrate to be processed. Most of the high-frequency antennas use a loop antenna that forms a spiral shape.

Inductively coupled plasma processing equipment using a planar loop antenna In other words, the plasma is generated in the space directly under the planar antenna in the processing container, but at this time, because of the electric field intensity corresponding to each position directly below the antenna, there is a region of high plasma density and low plasma density. Distribution, so the pattern shape of the planar loop antenna will become an important factor in determining the plasma density distribution. By adjusting the density of the planar loop antenna, the induced electric field is uniformized to produce a uniform plasma.

To this end, the spacing is set in the radial direction with the inner portion and The antenna elements of the two loop antennas in the outer portion adjust the impedances to independently control the current values of the two loop antenna portions, and control the plasma generated by the respective loop antenna portions to form with the diffusion. A technique for controlling the density distribution of the entire inductively coupled plasma is proposed by the overlapping form of the density distribution (Patent Document 1).

[Advanced technical literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2007-311182

However, even if the inductively coupled plasma processing of the antenna unit having the two loop antennas having the inner portion and the outer portion is used, When it is carried out under high pressure conditions of 100 mTorr or more, the plasma is difficult to diffuse, so it is easy to locally concentrate on the position of the plasma which is easy to maintain the arrangement of the two loop antennas, even by the antenna current. It is also difficult to maintain the plasma of the desired density distribution on the entire substrate, and it is sometimes impossible to obtain a desired processing distribution and a typical uniform processing distribution.

And, even if it is not such a high pressure condition, independent control The current values of the two loop antenna portions are also affected by the plasma generated by the respective antennas, and it may be difficult to obtain a desired plasma density distribution. Such a problem is not limited to the case where there are two loop antennas as in Patent Document 1, and all of them occur when there are a plurality of spiral antennas.

The present invention is developed in view of such a situation, to mention It is an object of an inductively coupled plasma processing method and an inductively coupled plasma processing apparatus that perform inductively coupled plasma processing with a desired processing distribution when performing inductively coupled plasma processing using a plurality of vortex shaped antennas.

In order to solve the above problems, the inductively coupled plasma processing method according to the first aspect of the present invention is an inductively coupled plasma processing method for inductively coupling plasma processing of a substrate using an inductively coupled plasma processing apparatus, and the inductively coupled plasma processing method The apparatus includes a processing chamber that houses a substrate and performs plasma processing, a mounting table that mounts the substrate in the processing chamber, and a processing gas supply system that supplies the processing gas in the processing chamber An exhaust system that exhausts the processing chamber; an antenna unit that is planarly disposed corresponding to the substrate in the processing chamber, has a high frequency antenna for generating inductively coupled plasma; and a high frequency The power supply means supplies high-frequency power to the high-frequency antenna, and the high-frequency antenna includes an outer antenna that is supplied with high-frequency power to form a spiral shape that forms an external induced electric field, and an inner antenna. The inner side of the outer antenna is concentrically arranged, and is supplied with high-frequency power to form a spiral shape that forms an inner induced electric field. The first process and the second process are performed with different timings, and the processing ends. Obtaining a desired processing distribution for the substrate, wherein the first processing is performed by comparing a current flowing to the inner antenna and the outer antenna, and a current having a relatively large current value flows to the inner antenna to form a corresponding The inner side induced electric field of the portion of the inner antenna generates a local plasma for processing, and the second processing is performed by a relatively large current value. The flow is applied to the outer antenna to form a local electric field generated by the outer side of the portion corresponding to the outer antenna to generate a local plasma.

In the above first aspect, the antenna unit includes a power feeding unit that is connected to a high-frequency power source for supplying power to the inner antenna and the outer antenna, and has a matching antenna to the inner antenna and The power supply path of the outer antenna further includes an impedance adjustment means for forming an inner antenna circuit and an outer antenna circuit including the antennas and the power supply units, and adjusting impedance of at least one of the inner antenna circuit and the outer antenna circuit. Further, the current value of each of the antennas is adjusted, and the impedance adjustment means can perform adjustment of the current value for generating the localized plasma.

In this case, the first processing system can set the current value of the inner current flowing to the inner antenna to a first current value of a relatively large value, and set the current value of the outer current flowing to the outer antenna to be relatively small. The current value of the second current value of the value is performed, and the second processing method is configured to set the current value of the current flowing to the outside of the outer antenna to a third current value of a relatively large value, and to flow to the inner side of the inner antenna The current value of the current is set to a fourth current value of a relatively small value.

The first process and the second process described above can be performed periodically.

The current value supplied to the inner side of the inner antenna and the current value supplied to the outer side of the outer antenna can be independently changed, and the current value of the inner current is changed to a level for generating the localized plasma for a predetermined period Between the current value and the fourth current value smaller than the first current value, the current value of the outer current is changed to generate the localized electric current in a phase different from the inner current in the predetermined period. Pulp The third current value is between the second current value smaller than the third current value.

In this case, the phase difference between the aforementioned inner current and the aforementioned outer current may be a half cycle. Further, the inner current and the outer current may be supplied in a pulsed manner.

The second current value and the fourth current value may be respectively The outer antenna and the inner antenna do not cause the inductively coupled plasma to have a small value or zero.

The period of the first process and the period of the second process It can be set as appropriate according to the content of the processing and the processing distribution to be obtained. In this case, the period of the first processing and the period of the second processing may be the same.

The local plasma electricity used to generate the first treatment described above The current value and the current value of the local plasma for generating the second processing can be appropriately set in accordance with the content of the processing and the processing distribution to be obtained.

In this case, the local plasma value for generating the first process and the local plasma value for generating the second process may be set to be the same.

An inductively coupled plasma processing method according to a second aspect of the present invention is an inductively coupled plasma processing method for performing inductively coupled plasma processing on a substrate using an inductively coupled plasma processing apparatus, the inductively coupled plasma processing apparatus having: a chamber for accommodating a substrate and performing a plasma treatment; a mounting table for placing the substrate in the processing chamber; and a processing gas supply system for supplying the processing gas to the processing chamber An exhaust system that exhausts the processing chamber; an antenna unit that is planarly disposed corresponding to the substrate in the processing chamber, has a high frequency antenna for generating inductively coupled plasma; and a high frequency The power supply means supplies high-frequency power to the high-frequency antenna, and the high-frequency antenna has a plurality of antennas, and the plurality of antennas are supplied with high-frequency power to form a spiral shape forming an induced electric field, and are characterized by: For different antennas, the time is different to implement a plurality of times, and a current of a relatively large current value flows to at least one of the antennas of the plurality of antennas, and is generated by the aforementioned induced electric field formed at a portion corresponding to the antenna. The treatment by localized plasma can achieve the desired processing distribution for the substrate at the end of the treatment.

Inductively coupled plasma processing apparatus according to a third aspect of the present invention The processing unit includes a processing chamber that houses a substrate and performs a plasma treatment, a mounting table that mounts the substrate in the processing chamber, a processing gas supply system that supplies a processing gas in the processing chamber, and an exhaust system. An exhaust unit is disposed in the processing chamber; the antenna unit is planarly disposed corresponding to the substrate in the processing chamber, and has a high frequency antenna for generating inductively coupled plasma; and a high frequency power supply means Supplying high frequency electricity to the aforementioned high frequency antenna The high-frequency antenna includes an outer antenna that is supplied with high-frequency power to form a spiral shape that forms an external induced electric field, and an inner antenna that is concentrically formed inside the outer antenna and is supplied high. The frequency power is formed in a spiral shape forming an inner induction electric field, and is characterized in that it further includes a control unit that controls the first processing and the second processing to be performed at different times, and obtains the substrate at the time of processing The desired processing distribution is formed by comparing a current flowing to the inner antenna and the outer antenna, respectively, by flowing a relatively large current value to the inner antenna to form an inner antenna corresponding to the inner antenna The portion of the inner induction electric field generates a local plasma for processing, and the second processing is performed by flowing a relatively large current value current to the outer antenna to form a portion corresponding to the outer antenna. The outside induces an electric field to produce a localized plasma for processing.

An inductively coupled plasma processing apparatus according to a fourth aspect of the present invention includes: a processing chamber that houses a substrate and performs plasma processing; a mounting table that mounts the substrate in the processing chamber; and a processing gas supply system Providing a processing gas in the processing chamber; an exhaust system that exhausts the processing chamber; and an antenna unit that is planar in the processing chamber corresponding to the substrate Having a high-frequency antenna for generating inductively coupled plasma, and a high-frequency power supply means for supplying high-frequency power to the high-frequency antenna, wherein the high-frequency antenna has a plurality of antennas, and the plurality of antennas A high-frequency power is supplied to form a spiral shape that forms an induced electric field, and is characterized in that it further includes a control unit that controls a plurality of times for different antennas to have different times, and a relatively large current value The current flowing to at least one of the antennas of the plurality of antennas is processed by generating the localized plasma generated by the induced electric field corresponding to the portion of the antenna, and can be obtained for the substrate at the end of the processing. The distribution of processing that is expected.

According to the present invention, the first processing and the second processing are performed with different times, and the desired processing distribution can be obtained for the substrate at the end of the processing. Therefore, it is difficult to generate the desired inductively coupled plasma even in the entire substrate such as a high voltage condition. At the same time, the desired processing distribution can be obtained by generating a localized electric field at a portion corresponding to the inner antenna by a current having a relatively large current value flowing in the inner antenna. The second processing is performed by generating a localized electric field in a portion of the outer antenna formed by a current flowing at a relatively large current value on the outer antenna.

1‧‧‧ body container

2‧‧‧Dielectric wall (dielectric member)

3‧‧‧Antenna room

4‧‧‧Processing room

13‧‧‧High frequency antenna

13a‧‧‧Outer antenna

13b‧‧‧Inside antenna

14‧‧‧matcher

15‧‧‧High frequency power supply

16a, 16b‧‧‧Power supply components

19,19a,19b‧‧‧wires

20‧‧‧Processing gas supply system

21‧‧‧Variable Capacitors

22a, 22b‧‧‧ terminals

23‧‧‧ mounting table

30‧‧‧Exhaust device

50‧‧‧Antenna unit

51‧‧‧Power Supply Department

61,62,63,64,71,72,73,74‧‧‧Antenna line

91a‧‧‧Outer antenna circuit

91b‧‧‧Inside antenna circuit

100‧‧‧Control Department

101‧‧‧User interface

102‧‧‧Memory Department

G‧‧‧Substrate

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

Fig. 2 is a plan view showing an example of a high-frequency antenna of an inductively coupled plasma antenna unit used in the inductively coupled plasma processing apparatus of Fig. 1;

Fig. 3 is a view showing a power feeding circuit of a high frequency antenna used in the inductively coupled plasma processing apparatus of Fig. 1;

4 is a view schematically showing that the current Iout of the outer antenna circuit and the current Iin of the inner antenna circuit are freely changed by the impedance adjustment of the variable capacitor.

Fig. 5 is a view showing the state and etching rate of plasma when inductively coupled plasma processing is performed by locally generating a local plasma directly under the inner antenna and directly below the inner antenna according to an embodiment of the present invention (E/). Relationship between R) (a) and processing result (b).

FIG. 6 is a view showing an example in which the current value of the inner antenna and the current value of the outer antenna are periodically changed.

FIG. 7 is a view showing an example of a waveform when a current is changed into a pulse shape.

8 is a plan view showing a three-ring antenna of another example of a radio-frequency antenna.

Fig. 9 is a plan view showing another example of an antenna used in a high frequency antenna.

Fig. 10 is a plan view showing a first portion of the antenna used in Fig. 9;

Figure 11 is a plan view showing the second portion of the antenna used in Figure 9 Figure.

Fig. 12 is a plan view showing still another example of an antenna used in a high-frequency antenna.

Fig. 13 is a plan view showing still another example of the radio-frequency antenna.

Hereinafter, the embodiment of the present invention will be described with reference to the accompanying drawings. state. Fig. 1 is a cross-sectional view showing an inductively coupled plasma processing apparatus according to an embodiment of the present invention, and Fig. 2 is a plan view showing an antenna unit used in the inductively coupled plasma processing apparatus. This device is used for etching a metal film, an ITO film, an oxide film, or the like, or an ashing process of a resist film, for example, when a thin film transistor is formed on a glass substrate for FPD. The FPD is, for example, a liquid crystal display (LCD), an electroluminescence (EL) display, a plasma display panel (PDP), or the like.

This plasma processing apparatus is a hermetic body container 1 having a rectangular tube shape, which is made of a conductive material such as aluminum whose inner wall surface is anodized. The body container 1 is decomposable and is electrically grounded by a grounding wire 1a. The main body container 1 is vertically divided into an antenna chamber 3 and a processing chamber 4 by a dielectric wall 2. Therefore, the dielectric wall 2 has a function as a dielectric window through which the induced electric field formed by the high-frequency antenna to be described later is formed as a top wall of the processing chamber 4. The dielectric wall 2 is made of ceramic such as Al ₂ O ₃ or quartz.

A processing gas is embedded in a lower portion of the dielectric wall 2 Shower housing 11 for supply. The shower frame 11 is, for example, formed in a cross shape. It has the function as a beam for supporting the dielectric wall 2 from below. Further, the shower housing 11 that supports the dielectric wall 2 is in a state of being suspended from the ceiling of the main body container 1 by a plurality of booms (not shown).

The shower frame 11 is made of a conductive material, preferably gold. It is composed of, for example, aluminum which is anodized on the inside or the outside in such a manner that contaminants do not occur. This shower frame 11 is electrically grounded.

Here, the shower frame 11 is formed with a horizontally extending gas flow. In the path 12, the gas flow path 12 is connected to a plurality of gas discharge holes 12a extending downward. On the other hand, a gas supply pipe 20a is provided at the center of the upper surface of the dielectric wall 2 so as to be able to communicate with the gas flow path 12. The gas supply pipe 20a penetrates from the ceiling of the main body container 1 to the outside thereof, and is connected to a processing gas supply system 20 including a processing gas supply source, a valve system, and the like. Therefore, in the plasma processing, the processing gas supplied from the processing gas supply system 20 is supplied into the shower casing 11 through the gas supply pipe 20a, and is discharged into the processing chamber 4 from the gas discharge hole 12a on the lower side.

In the side wall 3a of the antenna chamber 3 of the body container 1 and the processing chamber Between the side walls 4a of the 4, there is provided a support scaffolding 5 projecting to the inner side, where the support scaffolding 5 carries the dielectric wall 2.

A high frequency (RF) antenna 13 is provided in the antenna room 3 Antenna unit 50. The high frequency antenna 13 is connected to the high frequency power source 15 via the matching unit 14. Further, the high frequency antenna 13 is separated from the dielectric wall 2 by a spacer 17 formed of an insulating member. Then, high-frequency power having a frequency of 13.56 MHz is supplied from the high-frequency power source 15 to the high-frequency antenna 13, whereby an induced electric field is generated in the processing chamber 4, thereby causing the electric field to be taken from the shower. The processing gas supplied from the casing 11 is plasma. In addition, the antenna unit 50 will be described later.

Below the processing chamber 4, with the dielectric wall 2 interposed The mounting table 23 for mounting a rectangular FPD glass substrate (hereinafter referred to as a substrate) G is provided in a manner opposed to the high-frequency antenna 13. The mounting table 23 is made of a conductive material such as aluminum whose surface is anodized. The substrate G placed on the mounting table 23 is sucked and held by an electrostatic chuck (not shown).

The mounting table 23 is housed in the insulator frame 24 and is The hollow pillars 25 are supported. The support post 25 is inserted through the bottom of the main body container 1 while maintaining the airtight state, and is supported by a lifting mechanism (not shown) provided outside the main body container 1. When the substrate G is carried in and out, the mounting table 23 is lifted by the elevating mechanism. Drive in the up and down direction. Further, between the insulator frame 24 accommodating the mounting table 23 and the bottom of the main body container 1, a bellows 26 that hermetically surrounds the stay 25 is disposed, whereby the processing container 4 can be secured even if the mounting table 23 is moved up and down. Air tightness inside. Further, the side wall 4a of the processing chamber 4 is provided with a carry-out port 27a for carrying in and out of the substrate G, and a gate valve 27 for opening and closing.

The mounting table 23 is provided by being placed in the hollow pillar 25 The electric wire 25a is connected to the high frequency power source 29 via the matcher 28. This high-frequency power source 29 applies high-frequency power for bias voltage, for example, high-frequency power having a frequency of 3.2 MHz to the mounting table 23 during plasma processing. By the high-frequency power for this biasing, self-bias is formed, and ions in the plasma generated in the processing chamber 4 are efficiently introduced to the substrate G.

Moreover, in the mounting table 23, in order to control the temperature of the substrate G A temperature control mechanism including a heating means such as a ceramic heater or a refrigerant flow path, and a temperature sensor (all not shown) are provided. The piping or wiring for these mechanisms or members is led out to the outside of the body container 1 through the hollow struts 25.

At the bottom of the processing chamber 4, the package is connected via the exhaust pipe 31. An exhaust device 30 including a vacuum pump or the like. The processing chamber 4 is exhausted by the exhaust device 30, and during the plasma processing, the processing chamber 4 is set to be maintained in a predetermined vacuum environment (for example, 1.33 Pa).

On the back side of the substrate G placed on the mounting table 23, In other words, a cooling space (not shown) is formed between the surface on which the substrate G of the mounting table 23 is placed and the back surface of the substrate G, and a He gas flow path for supplying He gas (a gas for heat transfer as a constant pressure) is provided. 41. By supplying the heat transfer gas to the back side of the substrate G in this manner, the temperature rise or the temperature change of the substrate G can be avoided under vacuum.

Each component of the plasma processing apparatus is configured to be connected to a control unit 100 composed of a microprocessor (computer). Further, the control unit 100 is connected to a user interface 101 composed of a keyboard, a display or the like, which is an input operation for an operator to input a command or the like for managing the plasma processing apparatus, and the display is a plasma processing apparatus. The operating status is visualized. Further, the control unit 100 is connected to the storage unit 102, which stores a control program for realizing various processes performed by the plasma processing device by the control of the control unit 100, or for processing according to processing conditions. Carrying out the treatment in the various configurations of the plasma processing apparatus The program of the department is also the prescription. The prescription is a memory medium that is memorized in the memory unit 102. The memory medium is a portable device that can be embedded in a hard disk or a semiconductor memory of a computer, or a CDROM, a DVD, a flash memory, or the like. Further, the prescription can be appropriately transmitted from another device, for example, via a dedicated line. Then, if necessary, an arbitrary prescription is called from the storage unit 102 by an instruction from the user interface 101, and the control unit 100 is executed under the control of the control unit 100 to perform the processing in the plasma processing apparatus. Processing.

Next, the above-described antenna unit 50 will be described in detail.

The antenna unit 50 has the high frequency antenna 13 as described above, and has the power feeding unit 51 that supplies the high frequency power that has passed through the matching unit 14 to the high frequency antenna 13.

As shown in FIG. 2, the high-frequency antenna 13 is formed in a planar shape, and the outline is formed in a rectangular shape (rectangular shape), and its arrangement area corresponds to the rectangular substrate G.

The high-frequency antenna 13 has an outer antenna 13a constituting an outer portion and an inner antenna 13b constituting an inner portion. Each of the outer antenna 13a and the inner antenna 13b is a planar type in which a contour is formed in a rectangular shape. Further, the outer antenna 13a and the inner antenna 13b are arranged concentrically.

As shown in FIG. 2, the outer antenna 13a constituting the outer portion is wound with four antenna wires 61, 62, 63, and 64 made of a conductive material such as copper, etc., so that the entire antenna can be formed into a spiral shape. Heavy) antenna. Specifically, the antenna wires 61, 62, 63, and 64 are wound at positions shifted by 90°, and the arrangement area of the antenna wires is formed in a substantially frame shape, and the plasma is weakened. Number of volumes in the center of the side More. In the illustrated example, the number of turns in the corner is 3, and the number of turns in the center of the side is 2.

The inner antenna 13b constituting the inner portion is as shown in FIG. The four antenna wires 71, 72, 73, and 74, which are formed of a conductive material such as copper, and the like, are configured to form a multiplex (quadruple) antenna so that the entire antenna can be formed into a spiral shape. Specifically, the antenna wires 71, 72, 73, and 74 are wound at positions shifted by 90°, and the arrangement area of the antenna wires is formed in a substantially frame shape, and the number of turns of the corner portion tends to weaken the plasma. The number of volumes in the center of the side is more. In the illustrated example, the number of turns in the corner is 3, and the number of turns in the center of the side is 2.

The antenna lines 61, 62, 63, 64 to the outer antenna 13a are Power is supplied via the central four terminals 22a and the power supply line 69. Further, the antenna lines 71, 72, 73, and 74 of the inner antenna 13b are supplied via the four terminals 22b and the power supply line 79 disposed at the center.

In the vicinity of the central portion of the antenna room 3, there is a pair of outer antennas The four first power feeding members 16a that supply electricity to 13a and the four second power feeding members 16b that supply electricity to the inner antenna 13b (only one is shown in Fig. 1), and the lower end of each of the first power transmitting members 16a is The terminal 22a connected to the outer antenna 13a, and the lower end of each of the second power transmitting members 16b is a terminal 22b connected to the inner antenna 13b. The four first power feeding members 16a are connected to the power feeding line 19a, and the four second power feeding members 16b are connected to the power feeding wires 19b, which are the power feeding wires extending from the matching unit 14. 19 differences. Feed wires 19, 19a, 19b, power feeding members 16a, 16b, terminals 22a, 22b, and feeder wires 69, 79 constitute an antenna single The power supply unit 51 of the unit 50.

A variable capacitor 21 is mounted on the way to the wire 19a, at The power supply line 19b is not provided with a variable capacitor. Further, the four outer power feeding members 16a, the electric wires 19a, the variable capacitor 21, and the outer antenna 13a constitute an outer antenna circuit, and the four second power feeding members 16b, the electric wires 19b, and the inner antenna are constituted by the four antennas. 13b constitutes an inner antenna circuit.

By adjusting the capacitance of the variable capacitor 21 as will be described later The impedance of the outer antenna circuit is controlled, thereby adjusting the magnitude relationship of the current to the outer antenna circuit and the inner antenna circuit. The variable capacitor 21 is a function having a current control unit as an outer antenna circuit.

The impedance control of the high frequency antenna 13 will be described with reference to FIG. system. FIG. 3 is a view showing a power feeding circuit of the radio-frequency antenna 13. As shown in the figure, the high frequency power from the high frequency power source 15 is supplied to the outer antenna circuit 91a and the inner antenna circuit 91b via the matching unit 14. Here, since the outer antenna circuit 91a is constituted by the outer antenna 13a and the variable capacitor 21, the impedance Zout of the outer antenna circuit 91a can be changed by adjusting the position of the variable capacitor 21 to change its capacitance. On the other hand, the inner antenna circuit 91b is constituted only by the inner antenna 13b, and its impedance Zin is fixed. At this time, since the current Iout of the outer antenna circuit 91a and the current Iin of the inner antenna circuit 91b change in accordance with the ratio of Zout and Zin, the current Iout and the current Iin can be changed in accordance with the change in the impedance Zout. That is, the variable capacitor 21 can be connected to the outer antenna 13a to adjust the impedance of the outer antenna circuit 91a, so that the pattern is as shown in FIG. As shown, the current Iout of the outer antenna circuit 91a and the current Iin of the inner antenna circuit 91b can be freely changed. Then, by controlling the current flowing to the outer antenna 13a and the current flowing to the inner antenna 13b in this way, the outer induced electric field formed at the position corresponding to the outer antenna 13a and the position corresponding to the position of the inner antenna 13b can be controlled. The inner side induces an electric field, whereby the plasma density distribution generated by the induced electric field can be controlled. Further, a capacitor may be provided in the inner antenna circuit 91b to further improve the controllability of the current.

Next, explain the inductive coupling constructed using the above The plasma processing apparatus is combined to perform plasma processing on the substrate G, for example, a plasma etching process or a plasma ashing process. The following processing operations are performed in accordance with the control of the control unit 100.

First, in the state where the gate valve 27 is opened, the entrance is removed from the entrance. 27a, the substrate G is carried into the processing chamber 4 by a transport mechanism (not shown), and placed on the mounting surface of the mounting table 23, and then the substrate G is fixed by the electrostatic chuck (not shown). Placed on the table 23. Next, the processing gas supplied from the processing gas supply system 20 to the processing chamber 4 is discharged from the gas discharge hole 12a of the shower housing 11 into the processing chamber 4, and the processing chamber is passed through the exhaust pipe 31 by the exhaust device 30. The vacuum is evacuated within 4, whereby the processing chamber is maintained, for example, in a predetermined vacuum environment.

Further, at this time, the cooling space on the back side of the substrate G, In order to avoid temperature rise or temperature change of the substrate G, He gas is supplied as a heat transfer gas via the He gas flow path 41.

Next, the high frequency power source 15 is applied to the high frequency antenna 13 Adding a high frequency of 13.56 MHz, thereby passing through the dielectric wall 2 in the processing chamber 4 Produces a uniform induced electric field. The processing gas is plasma-formed in the processing chamber 4 by the induced electric field thus formed, thereby generating a high-density inductively coupled plasma. By means of the plasma, the substrate G is subjected to a plasma treatment such as a plasma etching treatment or a plasma ashing treatment.

In this case, the high frequency antenna 13 is configured as described above. The outer antenna 13a and the inner antenna 13b constituting the inner portion are arranged concentrically. The outer capacitor 13 can be connected to the outer antenna 13a constituting the outer portion to adjust the impedance of the outer antenna circuit 91a. The current Iout of the antenna circuit 91a and the current Iin of the inner antenna circuit 91b are freely changed.

The inductively coupled plasma is in the space directly below the high frequency antenna 13 The plasma is generated, but the plasma density at each position at this time is the electric field intensity corresponding to each position. Therefore, by controlling the position of the variable capacitor 21, the current flowing to the outer antenna 13a is controlled to flow to The current of the inner antenna 13b controls the electric field intensity distribution, thereby controlling the plasma density distribution.

However, it is carried out under high pressure conditions of 100 mTorr or more. In such an inductively coupled plasma treatment, plasma diffusion becomes difficult, and irrespective of the arrangement of the antenna 13, it is easy to locally concentrate on the position where the plasma is easily maintained, and even if the antenna current is adjusted, it is difficult to maintain the entire substrate. The density distribution of the plasma sometimes fails to achieve the desired processing distribution, typically a uniform processing distribution.

Therefore, the present embodiment is as shown in FIG. The first process and the second process are performed differently in time, and the plasma of the outer antenna 13a and the plasma of the inner antenna 13b are prevented from affecting each other and the plasma is concentrated. Since it is not intended, a desired processing distribution and a typical uniform processing distribution can be obtained at the end of the processing. The first processing is a current control function using the variable capacitor 21, and the current Iin flowing to the inner antenna 13b. In the magnitude relationship between the value and the value of the current Iout flowing to the outer antenna 13a, the current Iin is set to a relatively large first current value, and the value of the current Iout is set to a relatively small second current value, and the inner antenna 13b is positive. The processing is performed by generating a local plasma (internal plasma) which is in the other magnitude relationship between the value of the current Iout flowing to the outer antenna 13a and the value of the current Iin flowing to the inner antenna 13b. The current Iout is set to a relatively large third current value, and the value of the current Iin is set to a relatively small fourth current value, and local plasma (outer plasma) is generated directly under the outer antenna 13a to be processed.

That is, in the inductively coupled plasma processing under high pressure conditions, Even if it is difficult to maintain the plasma in a uniform or intended distribution throughout the substrate G, it is possible to maintain such a localized plasma, and to generate the localized local plasma and the outer portion by making the time difference. Sexual plasma can achieve the desired processing distribution at the end of the process.

For example, as shown in Fig. 5(a), the first half of the processing is set to only The first process of etching is performed by generating a local plasma (internal plasma) directly under the inner inner antenna 13b, and the latter half of the process is set to generate only local plasma directly under the outer antenna 13a (external plasma) As a result of performing the second etching treatment, as shown in FIG. 5(b), a uniform etching rate (E/R) can be obtained in the plane of the substrate.

However, the localized internal plasma and external plasma are divided into places. When the processing is performed in the front and the rear half of the process, a temperature difference occurs in the vicinity of the plasma generating portion and in the vicinity of the non-plasma generating portion, and this temperature difference may affect the member or the substrate G in the processing chamber 4. In such a case, by alternately switching the first treatment of the internal plasma and the second treatment of the external plasma in a short time, it is possible to suppress the influence of such a temperature difference while maintaining the above effects. Typically, as shown in FIG. 6, the current value of the inner antenna 13b is periodically changed between a relatively large first current value and a relatively small fourth current value by changing the position of the capacitor 21, and at the same time The current value of the outer antenna 13a periodically changes between a relatively small second current value and a relatively large third current value. At this time, since the current values of the inner antenna 13b and the outer antenna 13a are changed by the change in the position of the capacitor 21, the period in which the current values of the inner antenna 13b and the outer antenna 13a change is the same, and the phase is shifted by half a period.

In addition, the period of the first process and the period of the second process are The settings may be appropriately set according to the content of the processing and the processing distribution to be obtained, and the periods may be the same or one of the lengths. By making the processing periods the same, it is easy to obtain a uniform processing distribution. Further, the first current value and the third current value for generating the localized plasma may be appropriately set according to the content of the processing and the processing distribution to be obtained, and the values may be the same or larger. By making these values the same, it is easy to obtain a uniform processing distribution.

This embodiment is controlled by the position adjustment of the capacitor 21. Since the current values of the inner antenna 13b and the outer antenna 13a are formed, the current values of the inner antenna 13b and the outer antenna 13a cannot be independently changed, but they can also be borrowed. The current value is independently changed by connecting an individual high-frequency power source or the like to the inner antenna 13b and the outer antenna 13a. In this case, the period in which the current changes by the inner antenna 13b and the outer antenna 13a is the same, but the phase difference of the current value change of the inner antenna 13b and the outer antenna 13a may be other than a half cycle or a half cycle.

Moreover, when the current value is periodically changed, it is also advantageous. The current is changed into a pulse shape by a pulse generator or the like. The waveform in this case is not particularly limited, and may be a rectangular wave as shown in FIG. 7(a) or a linear waveform such as a triangular wave shown in (b). Or a curvilinear waveform such as a sine wave as shown in (c). In either case, the maximum value of the current value may be the first current value and the third current value, and the minimum value of the current value may be the fourth current value and the second current value.

Moreover, the relatively large first used to generate localized plasma The values of the current and the third current may be the same, or may be larger in either direction. Further, the relatively small fourth current value and second current value may be 0 or have a predetermined value. When it is desired to generate localized plasma only directly under the inner antenna 13b and directly below the outer antenna 13a, the fourth current value and the second current value are values which are required to be such that the inductively coupled plasma is not generated.

In addition, the outer antenna 13a and the inner antenna 13b are The four antenna wires are wound at 90° in a staggered manner to form a wrap-around quadruple antenna as a whole, but the number of antenna wires is not limited to four, and may be any number of multiple antennas, and the angle of the staggered Not limited to 90°.

Next, another example of the structure of the radio-frequency antenna will be described.

In the above example, the outer antenna 13a and the inner antenna 13b are shown. The two loop antennas are concentrically formed to form a high-frequency antenna, but three or more loop antennas may be arranged concentrically.

Figure 8 is a diagram showing the height of a three-ring arrangement in which three loop antennas are arranged. Frequency antenna. Here, the outermost antenna 113a disposed on the outermost side, the innermost antenna 113c disposed on the innermost side, and the intermediate antenna 113b disposed in the middle of the outer antenna 113 are arranged in a concentric shape. In FIG. 8, for the sake of convenience, the detailed structure of each antenna is omitted, but the same configuration as the above-described outer antenna 13a and inner antenna 13b can be used.

When setting 3 or more loop antennas, the above setting 2 Similarly, in the case of a high-frequency antenna of a loop antenna, high-frequency power is supplied to each loop antenna from a high-frequency power source, and the current of each antenna can be controlled by providing a variable capacitor to a feed line of the loop antenna. . Moreover, current control can be performed by providing a variable capacitor to a supply line of at least one antenna. When the current control is performed at a different ratio of each loop antenna when the high-frequency antenna is provided with two loop antennas, if the number of loop antennas is n, the loop of n-1 is used. A capacitor can be provided for the wire of the antenna. Of course, it is also possible to independently control the current values by connecting individual high frequency power sources to the respective antennas.

In this case, it may be different in all time to correspond to each Localized plasma of the antenna, or two or more localized plasmas produced at the same time. Further, the value of the current may be periodically changed in a short period of time as described above, or the current may be changed to form a pulse shape.

Next, another example of the structure of each antenna will be described.

In the above example, each antenna (outer antenna 13a, inner side) The line 13b, the outermost antenna 113a, the intermediate antenna 113b, and the innermost antenna 113c are configured to be annularly connected to each other to supply high-frequency power. However, each of the antennas may have a plurality of regions respectively corresponding to portions different from each other. The high frequency power is independently supplied in the plurality of areas. Thereby, more careful plasma distribution control can be performed. For example, the rectangular plane corresponding to the rectangular substrate is formed, and the first portion and the second portion are formed by winding a plurality of antenna wires into a spiral shape, and the first portion is a plurality of antenna lines forming a rectangular plane. The corner portions are provided with four corner portions at different positions from the rectangular plane, and the second portion is a central portion of the four sides in which the plurality of antenna lines form a rectangular plane, and is different from the rectangular plane. The position is set to be combined with the central portion of the four sides, and the high-frequency power can be independently supplied to the first portion and the second portion.

The specific configuration will be described with reference to Figs.

For example, as shown in FIG. 9, the outer antenna 13a is a rectangular (frame-like) plane that corresponds to the rectangular substrate G as a whole, and the portion facing the dielectric wall 2 that forms the induced electric field that contributes to the plasma generation. The first portion 213a and the second portion 213b are formed by winding a plurality of antenna wires into a spiral shape. The antenna line of the first portion 213a is four corner portions that form a rectangular flat surface, and is provided with four corner portions in a position different from the rectangular plane. Further, the antenna line of the second portion 213b is a central portion of the four sides forming the rectangular flat surface, and is disposed at a position different from the rectangular flat surface so as to be coupled to the central portions of the four sides. The power supply to the first portion 213a is performed via the four terminals 222a and the power supply line 269, and the power supply to the second portion 213b is performed via the four terminals 222b and the power supply line 279. The sub-222a, 222b independently supply high-frequency power.

As shown in FIG. 10, the first part 213a is composed of 4 A quadruple antenna in which the antenna wires 261, 262, 263, and 264 of the strip are wound at a position shifted by 90 degrees, and the portions forming the four corner portions of the rectangular plane facing the dielectric wall 2 are the flat portions 261a and 262a. 263a and 264a, the portion between the planar portions 261a, 262a, 263a, and 264a is a three-dimensional portion that is retracted to a position where plasma is not generated in the upper portion so as to be able to form a position different from the rectangular plane. 261b, 262b, 263b, 264b. As shown in FIG. 11, the second portion 213b also constitutes a quadruple antenna in which four antenna wires 271, 272, 273, and 274 are wound at positions shifted by 90 degrees, and the rectangular portion facing the dielectric wall 2 is formed. The central portion of the four sides of the plane is the flat portions 271a, 272a, 273a, and 274a, and the portions between the flat portions 271a, 272a, 273a, and 274a are formed so as to be different from the rectangular plane. The mode is evacuated to the three-dimensional portions 271b, 272b, 273b, and 274b in a state where the upper plasma generation position is not transmitted.

With such a configuration, it is possible to obtain the above-described embodiment In the same manner, a configuration of a relatively simple multiple antenna in which four antenna wires are wound in a predetermined direction is realized, and independent plasma distribution control of the corner portion and the center portion of the side is realized.

Moreover, it is also possible to make the time corresponding to the corner The localized plasma and the localized plasma corresponding to the central portion of the side form the desired processing distribution.

The above example is a multiple day of winding a plurality of antenna lines. The antennas are formed by wires, but as shown in Fig. 12, one antenna wire 181 may be wound into a spiral shape.

Further, the present invention is not limited to the above embodiment, and may be Various variants are implemented. For example, although the above embodiment shows an example in which a plurality of antennas for forming an induced electric field are concentric, the present invention is not limited thereto. For example, as shown in FIG. 13, for example, a plurality of vortex antennas 413 may be arranged in parallel. In this case, the desired processing distribution can be formed by temporally staggering the plasma corresponding to the locality of each antenna 413.

Moreover, the above embodiment is suitable for applying the present invention to plasma An example in which an inductively coupled plasma is generated under high-pressure conditions of diffusion, but is not limited thereto, and a local plasma generated by generating a plurality of antennas corresponding to different plane positions with different timings can be obtained at the end of processing. The processing distributor can be, not limited to the high pressure conditions in which the plasma is difficult to diffuse.

Moreover, the above embodiment is shown to flow in a predetermined antenna. A relatively large current, while producing a localized plasma at a position corresponding to the antenna, but can also produce a plasma that is weaker than the localized plasma in an antenna that flows relatively small current.

Moreover, the form of each antenna may not be the same. For example, one Some of the antennas are the multiple antennas shown in FIG. 2, and the other are the multiple antennas shown in FIGS. 9-11, and the multiple antennas may be mixed with the antennas forming one antenna.

Further, in the above embodiment, each day is adjusted in order to adjust the impedance. The current value of the line is a variable capacitor, but it may be another impedance adjustment means such as a variable coil. Moreover, the above embodiment is a high frequency from one An example in which the power source distributes the high-frequency power supply to each antenna will be described as a center, but a high-frequency power source may be provided for each antenna as described above.

Moreover, the above embodiment is illustrative of the dielectric wall The ceiling portion constituting the processing chamber is configured such that the antenna is disposed on the upper surface of the dielectric wall of the ceiling portion outside the processing chamber. However, the dielectric wall may be insulated between the antenna and the plasma generating region. The antenna is disposed in a configuration inside the processing chamber.

Moreover, the above embodiment is for displaying the application of the present invention. In the etching treatment or the ashing treatment, it is also applicable to other plasma processing apparatuses such as CVD film formation. Further, although a rectangular substrate using FPD is used as an example of a substrate, it may be applied to a rectangular substrate such as a semiconductor wafer when a rectangular substrate such as a solar cell is processed, or is not limited to a rectangular shape.

Claims (15)

An inductively coupled plasma processing method is an inductively coupled plasma processing method for inductively coupled plasma processing of an inductively coupled plasma processing apparatus, the inductively coupled plasma processing apparatus comprising: a processing chamber, which is a receiving substrate And performing a plasma treatment; a mounting table for mounting the substrate in the processing chamber; a processing gas supply system for supplying the processing gas to the processing chamber; and an exhaust system for exhausting the processing chamber; and an antenna unit; A planar antenna is disposed in the processing chamber corresponding to the substrate, and has a high frequency antenna for generating inductively coupled plasma, and a high frequency power supply means for supplying high frequency power to the high frequency antenna. The frequency antenna includes an outer antenna that is supplied with high-frequency power to form a spiral shape that forms an external induced electric field, and an inner antenna that is concentrically formed inside the outer antenna and that is supplied with high-frequency power. Forming a spiral shape forming an inner induction electric field, which is characterized in that the first processing and the second processing are performed with different timings, and the processing ends. The intermediate point can obtain a desired processing distribution for the substrate. The first processing is performed by comparing currents flowing to the inner antenna and the outer antenna, respectively, by flowing a relatively large current value to the inner antenna. In the foregoing part of the portion corresponding to the aforementioned inner antenna The side induces an electric field to generate a localized plasma, and the second process is performed by flowing a relatively large current value to the outer antenna to form the outer side induced electric field corresponding to the portion of the outer antenna. Localized plasma is produced for processing. The inductively coupled plasma processing method according to claim 1, wherein the antenna unit has a power feeding unit connected to a high frequency power source for supplying power to the inner antenna and the outer antenna. The matching device further includes an impedance adjustment means for the power supply path of the inner antenna and the outer antenna, and an inner antenna circuit and an outer antenna circuit including the antenna and each power supply unit, and the inner antenna circuit and the outer antenna are adjusted The impedance of at least one of the circuits further adjusts the current value of each of the antennas, and the impedance adjustment means performs adjustment of the current value for generating the localized plasma. The inductively coupled plasma processing method according to the second aspect of the invention, wherein the first processing method is to apply a current value of a current flowing inside the inner antenna to a first current value of a relatively large value, and to flow to the foregoing The current value of the outer current of the outer antenna is set to a current value of the second current value of a relatively small value, and the second processing system sets the current value of the current flowing to the outer side of the outer antenna to a relatively large value. 3 current value, the current value of the current flowing to the inner side of the inner antenna is set to a fourth current value of a relatively small value Row. The inductively coupled plasma processing method according to the second or third aspect of the invention, wherein the first processing and the second processing are performed periodically. The inductively coupled plasma processing method according to claim 1, wherein the inner current supplied to the inner antenna and the current value supplied to the outer current of the outer antenna are independently changed, and the aforementioned The current value of the inner current is changed between a first current value for generating the localized plasma and a fourth current value smaller than the first current value, and a phase different from the inner current by the predetermined period. The current value of the external current is changed between a third current value for generating the local plasma and a second current value smaller than the third current value. The inductively coupled plasma processing method according to claim 5, wherein the phase difference between the inner current and the outer current is a half cycle. The inductively coupled plasma processing method according to claim 5, wherein the inner current and the outer current are supplied in a pulsed manner. The inductively coupled plasma processing method according to any one of claims 3, 5, 6 and 7, wherein the second current value and the fourth current value are the outer antenna and the inner antenna, respectively. A small value or zero that does not cause the inductively coupled plasma to be generated. Sense of any one of the first to eighth patent applications In the coupled plasma processing method, the period of the first processing and the period of the second processing are appropriately set in accordance with the content of the processing and the processing distribution to be obtained. The inductively coupled plasma processing method according to claim 9, wherein the period of the first processing and the period of the second processing are the same. The inductively coupled plasma processing method according to any one of claims 1 to 10, wherein a local plasma value for generating the first process and a second value for generating the second The localized plasma current value of the treatment is appropriately set in accordance with the content of the treatment and the processing distribution to be obtained. The inductively coupled plasma processing method according to claim 11, wherein the local plasma value for generating the first processing and the local plasma current for generating the second processing The values are the same. An inductively coupled plasma processing method is an inductively coupled plasma processing method for inductively coupled plasma processing of an inductively coupled plasma processing apparatus, the inductively coupled plasma processing apparatus comprising: a processing chamber, which is a receiving substrate And performing a plasma treatment; a mounting table for mounting the substrate in the processing chamber; a processing gas supply system for supplying the processing gas to the processing chamber; and an exhaust system for exhausting the processing chamber; and an antenna unit; It is planar in the aforementioned processing chamber corresponding to the substrate Having a high-frequency antenna for generating inductively coupled plasma, and a high-frequency power supply means for supplying high-frequency power to the high-frequency antenna, wherein the high-frequency antenna has a plurality of antennas, and the plurality of antennas A high-frequency power is supplied to form a spiral shape forming an induced electric field, and is characterized in that a plurality of times are performed for different antennas with different times, and a current of a relatively large current value flows to at least a part of the plurality of antennas. The antenna of one antenna is processed by generating the localized plasma generated by the induced electric field corresponding to the portion of the antenna, and the desired processing distribution can be obtained for the substrate at the end of the processing. An inductively coupled plasma processing apparatus includes: a processing chamber that houses a substrate and performs plasma processing; a mounting table that mounts the substrate in the processing chamber; and a processing gas supply system that supplies the processing in the processing chamber a gas; an exhaust system that exhausts the processing chamber; an antenna unit that is planarly disposed corresponding to the substrate in the processing chamber, has a high frequency antenna for generating inductively coupled plasma; and a high frequency The power supply means supplies high-frequency power to the high-frequency antenna, and the high-frequency antenna includes an outer antenna that is supplied with high-frequency power to form a spiral shape that forms an external induced electric field; The inner antenna is concentrically formed inside the outer antenna, and is supplied with high-frequency power to form a spiral shape that forms an inner induction electric field. The control unit further includes a control unit that controls the time to be different. The first processing and the second processing are performed, and a desired processing distribution can be obtained for the substrate at the end of the processing. The first processing is performed by comparing the currents flowing to the inner antenna and the outer antenna, respectively. A current having a large current value flows to the inner antenna to form a localized electric field corresponding to the inner side induced electric field of the portion corresponding to the inner antenna, and the second processing is performed by using a relatively large current value. The current flows to the outer antenna to form a localized induced electric field in a portion corresponding to the outer antenna to generate a localized plasma for processing. An inductively coupled plasma processing apparatus includes: a processing chamber that houses a substrate and performs plasma processing; a mounting table that mounts the substrate in the processing chamber; and a processing gas supply system that supplies the processing in the processing chamber a gas; an exhaust system that exhausts the processing chamber; an antenna unit that is planarly disposed corresponding to the substrate in the processing chamber, has a high frequency antenna for generating inductively coupled plasma; and a high frequency The power supply means supplies high-frequency power to the high-frequency antenna, and the high-frequency antenna has a plurality of antennas, and the plurality of antennas are supplied with high-frequency power to form a spiral shape that forms an induced electric field. Further, the control unit further includes a control unit that controls the antennas to be applied to the different antennas for different times, and that flows a relatively large current value to at least one of the plurality of antennas. The processing is performed by generating the localized plasma by the aforementioned induced electric field formed in the portion corresponding to the antenna, and the desired processing distribution can be obtained for the substrate at the end of the processing.