TWI508633B - Inductively coupled plasma processing device, plasma processing method and memory medium - Google Patents

Description

Inductively coupled plasma processing device, plasma processing method and memory medium

The present invention relates to an inductively coupled plasma processing apparatus, a plasma processing method, and a plasma processing method for performing plasma processing on a substrate such as a glass substrate for a flat panel display such as a liquid crystal display (LCD). A computer readable memory medium for a program of a plasma processing device.

In the manufacturing process of a liquid crystal display device (LCD) or the like, various plasma processing apparatuses such as a plasma etching apparatus or a plasma CVD film forming apparatus are used in order to perform specific processing on the glass substrate. In such a plasma processing apparatus, a capacitor-bonded plasma processing apparatus has been conventionally used. However, an inductively coupled plasma (ICP) processing apparatus which has a large advantage of obtaining a high-density plasma at a high degree of vacuum has recently attracted attention. .

In the inductively coupled plasma processing apparatus, a high frequency antenna is disposed outside a dielectric window of a processing container that accommodates a substrate to be processed, and a high frequency power is supplied to the high frequency antenna while supplying a processing gas into the processing container, thereby making the inductance The coupled plasma is generated in a processing vessel by which the plasma is processed to perform a specific plasma treatment on the substrate being processed. In the high-frequency antenna of the inductively coupled plasma processing apparatus, a planar antenna having a specific pattern in a planar shape is often used.

The inductively coupled plasma processing apparatus using the planar antenna thus generates plasma in a space directly under the planar antenna in the processing container, which is proportional to the electric field strength at each position directly below the antenna, and has a high plasma density region. With the distribution of the low plasma region, the pattern shape of the 1-plane antenna becomes An important factor in determining the plasma density distribution.

However, the application of one inductively coupled plasma processing device should not be limited to one, and must correspond to a plurality of applications. In this case, in order to perform uniform processing in each application, it is necessary to change the plasma density distribution. Therefore, a plurality of antennas of different shapes can be prepared in such a manner that the positions of the high-density region and the low-density region can be different. Replace the antenna according to the application.

However, in order to prepare a plurality of antennas for a plurality of applications, it takes a lot of labor to replace them according to different applications, and recently, since the glass substrate for LCDs has been significantly enlarged, the antenna manufacturing cost has also become expensive.

Further, even if a plurality of antennas are prepared in this way, it is not necessarily an optimum condition in the application to be applied, and it is necessary to respond by adjustment of the process conditions.

In this regard, Patent Document 1 discloses a plasma processing apparatus that divides a spiral antenna into two portions of an inner portion and an outer portion to allow independent high-frequency currents to flow. According to such a configuration, the plasma density distribution can be controlled by adjusting the power supplied to the inner portion and the power supplied to the outer portion.

However, in the technique described in Patent Document 1, it is necessary to provide two high-frequency power sources for the high-frequency power source for the inner portion of the spiral antenna and the high-frequency power source for the outer portion, or to provide a power distribution circuit, and the device is formed. On a large scale, the cost of the device will become higher. Moreover, in this case, power loss is large, power cost is high, and it is difficult to perform high-precision plasma density distribution control.

Therefore, Patent Document 2 describes an inductively coupled plasma processing apparatus. The arrangement is such that the outer antenna portion that mainly forms an inductive electric field in the outer portion and the inner antenna portion that forms an inductive electric field mainly in the inner portion are disposed in the processing chamber, and the outer antenna portion and the inner antenna portion are connected to each other. The variable capacitor controls the current value of the outer antenna portion and the inner antenna portion by adjusting the capacitance of the variable capacitor, and controls the plasma electron density distribution of the inductively coupled plasma formed in the processing chamber.

[prior technical literature] [Patent Document]

[Patent Document 1] Patent No. 3077009

[Patent Document 2] JP-A-2007-311182

According to the inductively coupled plasma processing apparatus described in Patent Document 2, by controlling the current values of the outer antenna portion and the inner antenna portion, it is possible to control the plasma electron density of the inductively coupled plasma formed in the processing chamber without replacing the antenna. distributed.

However, in Patent Document 2, although the plasma electron density distribution can be controlled, the power efficiency is almost unchanged from the inductively coupled plasma described in Patent Document 1, for example. Therefore, when it is desired to obtain a plasma having a higher density, it is necessary to increase the amount of electric power of the high-frequency power supplied to the outer antenna portion and the inner antenna portion as in the related art.

The present invention has been developed in view of the circumstances, and an object thereof is to provide an inductively coupled plasma processing apparatus and a plasma processing apparatus which are more power efficient. And a computer readable memory medium storing a program for implementing the plasma processing method in an inductively coupled plasma processing apparatus.

In order to solve the problem, the inductively coupled plasma processing apparatus according to the first aspect of the present invention includes a processing chamber that stores a substrate to be processed and performs plasma processing, and a mounting table that mounts the substrate to be processed in the processing chamber. a processing gas supply system for supplying a processing gas to the processing chamber; an exhaust system for exhausting the processing chamber; and an antenna circuit disposed outside the processing chamber via a dielectric member; Forming an inductive electric field in the processing chamber by supplying high-frequency power; and a parallel circuit connected in parallel with the antenna circuit to form an inductance in the processing chamber by forming an impedance between the impedance of the antenna circuit and the impedance of the parallel circuit Coupled plasma.

Moreover, the plasma processing method according to the second aspect of the present invention is a plasma processing method using an inductively coupled plasma processing apparatus, and the inductively coupled plasma processing apparatus includes a processing chamber that houses a substrate to be processed and performs electricity. a slurry treatment; a mounting table for placing a substrate to be processed in the processing chamber; and a processing gas supply system for supplying a processing gas to the processing chamber; An exhaust system that exhausts the processing chamber; an antenna circuit that is disposed outside the processing chamber via a dielectric member, and that generates an inductive electric field in the processing chamber by supplying high-frequency power; and a parallel circuit The antenna circuit is connected in parallel to the antenna circuit, and the impedance of the antenna circuit is opposite to the impedance of the parallel circuit, and an inductively coupled plasma is generated in the processing chamber.

Further, a memory medium according to a third aspect of the present invention is a computer-readable memory medium in which a control program operating on a computer is stored, wherein the control program is configured to control an inductively coupled plasma processing device during execution. Further, the plasma processing method of the second aspect described above can be carried out.

According to the present invention, it is possible to provide a power-efficient inductively coupled plasma processing apparatus, a plasma processing method, and a computer readable storage program for storing the plasma processing method in an inductively coupled plasma processing apparatus. Memory media.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)

Fig. 1 is a view showing an inductively coupled plasma chamber according to a first embodiment of the present invention; FIG. 2 is a plan view showing a high frequency antenna used in the inductively coupled plasma processing apparatus. This device is, for example, an ashing treatment for etching or blocking a film of a metal film, an ITO film, an oxide film, or the like when a thin film transistor is formed on a glass substrate for FPD. Here, 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 an airtight main body container 1 having a rectangular tube shape, which is made of a conductive material such as aluminum whose inner wall surface is anodized. This body container 1 is decomposable and is 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 is the top wall constituting the processing chamber 4. The dielectric wall 2 is made of ceramic such as Al ₂ O ₃ or quartz.

A shower casing 11 for supplying a processing gas is fitted to a lower portion of the dielectric wall 2. The shower housing 11 is formed in a cross shape and has a structure in which the dielectric wall 2 is supported by the lower portion. Further, the shower housing 11 that supports the dielectric wall 2 is in a state of being suspended from the top of the main body container 1 by a plurality of hangers (not shown).

The shower frame 11 is made of a conductive material, and is preferably made of a metal, for example, anodized aluminum is applied to the inner surface thereof in such a manner that contaminants do not occur. The shower housing 11 is formed with a horizontally extending gas flow path 12, and the gas flow path 12 communicates with a plurality of gas discharge holes 12a extending downward. On the other hand, the gas supply pipe 20a is provided at the center of the upper surface of the dielectric wall 2, and is connected to the gas flow path 12. The gas supply pipe 20a is penetrated from the top of the main body container 1 to the outside thereof, and is connected to the The processing gas supply system 20 such as a gas supply source and a valve system is processed. 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 lower gas discharge hole 12a.

A support shed 5 projecting to the inner side is provided between the side wall 3a of the antenna chamber 3 of the main body container 1 and the side wall 4a of the processing chamber 4, and the dielectric wall 2 is placed on the support shed 5.

In the antenna chamber 3, a high frequency (RF) antenna 13 is disposed on the dielectric wall 2 so as to face the dielectric wall 2. The high frequency antenna 13 is spaced apart from the dielectric wall 2 by a spacer 17 made of an insulating member. The high-frequency antenna 13 has an outer antenna portion 13a in which an antenna wire is densely arranged on an outer portion, and an inner antenna portion 13b in which an antenna wire is densely arranged on an inner portion. The outer antenna portion 13a and the inner antenna portion 13b are multiplexed (quadruple) antennas that form a spiral shape as shown in Fig. 2 . Further, the configuration of the multiple antennas may be a configuration in which both the inner side and the outer side are double, or the inner side of the double outer side.

The outer antenna portion 13a is arranged in a substantially rectangular shape by disposing the four antenna wires at 90° each, and the central portion thereof is a space. Further, each antenna line can be powered via the four terminals 22a at the center. Further, the outer end portion of each antenna wire is connected to the side wall of the antenna room 3 via the capacitor 18a in order to change the voltage distribution of the antenna line, and is grounded. However, the capacitor may be directly grounded without passing through the capacitor 18a, or may be inserted in the portion of the terminal 22a or the antenna line, for example, in the bent portion 100a.

Further, the inner antenna portion 13b is at the central portion of the outer antenna portion 13a. In the space, four antenna wires are placed at 90° offset positions, and the entire arrangement is substantially rectangular. Further, each antenna line can be powered via four central terminals 22b. Further, the outer end portion of each antenna wire is connected to the upper wall of the antenna room 3 via the capacitor 18b in order to change the voltage distribution of the antenna line, and is grounded. However, the capacitor may be directly grounded without passing through the capacitor 18b, and the capacitor may be inserted in the portion of the terminal 22b or the middle of the antenna, for example, the bent portion 100b. Then, a large space is formed between the outermost antenna line of the inner antenna portion 13b and the innermost antenna line of the outer antenna portion 13a.

In the vicinity of the center portion of the antenna room 3, four first power feeding members 16a for supplying power to the outer antenna portion 13a and four second power receiving members 16b for powering the inner antenna portion 13b are provided (only one is shown in Fig. 1). The lower end of each of the first power feeding members 16a is a terminal 22a that is connected to the outer antenna portion 13a, and the lower end of each of the second power feeding members 16b is a terminal 22b that is connected to the inner antenna portion 13b. The first and second power feeding members 16a and 16b are connected to the high frequency power source 15 via the matching unit 14. The high-frequency power source 15 and the matching unit 14 are connected to the electric wires 19, and the electric wires 19 are branched into the electric wires 19a and 19b on the downstream side of the matching device 14, and the electric wires 19a are connected to the four first electric power transmitting members 16a. The feed line 19b is connected to the four second power feeding members 16b. A variable capacitor VC is provided between the supply wires 19a. Therefore, the outer antenna circuit is constituted by the variable capacitor VC and the outer antenna portion 13a. On the other hand, the inner antenna circuit is constituted only by the inner antenna portion 13b. Then, by adjusting the capacitance of the variable capacitor VC, as will be described later, the impedance of the outer antenna circuit is controlled, and the magnitude relationship of the current flowing to the outer antenna circuit and the inner antenna circuit can be adjusted.

In the plasma processing, high-frequency power, for example, a frequency of 13.56 MHz from the high-frequency power source 15 is supplied to the high-frequency antenna 13, and is formed by the high-frequency antenna 13 to which the high-frequency power is supplied. The inductive electric field is in the processing chamber 4, and the processing gas supplied from the shower housing 11 is plasmad by the electric field. The density distribution of the plasma at this time is controlled by controlling the impedance of the outer antenna portion 13a and the inner antenna portion 13b of the variable capacitor VC.

Below the inside of the processing chamber 4, a mounting table 23 on which the LCD glass substrate G is placed is provided so as to be able to face the high-frequency antenna 13 via the dielectric wall 2. The mounting table 23 is made of a conductive material such as aluminum whose surface is anodized. The LCD glass 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 supported by the hollow pillars 25. The support post 25 is supported by a lifting mechanism (not shown) disposed outside the main body container 1 while maintaining the bottom of the main body container 1 in an airtight state, and is configured by a lifting mechanism when the substrate G is carried in and out. The mounting table 23 is driven in the vertical direction. Further, a bellows 26 that hermetically surrounds the stay 25 is disposed between the insulator frame 24 that houses the mounting table 23 and the bottom of the main body container 1, thereby ensuring airtightness in the processing container 4 even if the mounting table 23 is moved up and down. Sex. 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 stage 23 is connected to the high-frequency power source 29 via the matching unit 28 via the power supply line 25a provided in the hollow pillar 25. This high frequency power supply 29 In the plasma processing, high-frequency power for bias voltage, for example, high-frequency power having a frequency of 6 MHz is applied to the mounting table 23. The ions in the plasma generated in the processing chamber 4 are efficiently introduced to the substrate G by the high frequency power for this bias.

Further, 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, a refrigerant flow path, and the like, and a temperature sensor (not shown) are provided. The piping or wiring of the mechanisms or members is led out to the outside of the body container 1 via the hollow struts 25.

At the bottom of the processing chamber 4, an exhaust device 30 including a vacuum pump or the like is connected via an exhaust pipe 31. The processing chamber 4 is exhausted by the exhaust device 30, and the plasma processing is performed to maintain the processing chamber 4 in a specific vacuum environment (for example, 1.33 Pa).

A cooling space (not shown) is formed on the back side of the substrate G placed on the mounting table 23, and a He gas flow path 41 for supplying He gas as a heat transfer gas of a constant pressure is provided. 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.

The He gas path 42 is connected to the He gas flow path 41, and the He gas path 42 is connected to a He source (not shown). Here, the He gas path 42 is provided with a pressure control valve 44, and a pipe 43 connected to the He gas tank 47 is provided on the downstream side. An opening and closing valve 45 is provided on the downstream side of the connection portion between the He gas path 42 and the pipe 43, and the opening route 48 is connected to the downstream side thereof, and the opening path 48 is provided with the release valve 49. In the groove 47 is filled to the groove 47 The He gas having the optimum pressure in terms of the capacity allows the cooling space on the back side of the substrate G to have the same pressure as that when it is filled under the set pressure, and the He gas for heat transfer can be quickly supplied to the cooling space from the groove 47. Further, the gas for heat transfer is not limited to He gas, and may be other gases.

Each component of the plasma processing apparatus is configured to be connected to a control unit 50 composed of a computer. Further, the control unit 50 is connected to a user interface 51 composed of a keyboard, a display or the like for inputting a command for the management of the plasma processing apparatus by the engineering manager, and the display is a state of operation of the plasma processing apparatus. Visual display. Further, the control unit 50 is connected to a storage unit 52 that stores a control program for realizing various processes executed by the plasma processing device under the control of the control unit 50, or performs processing according to processing conditions. The program of each component of the plasma processing apparatus is also a prescription. The prescription may be stored in a hard disk or a semiconductor memory, or may be set at a specific position of the memory unit 52 in a state of being accommodated in a portable memory medium such as a CD-ROM or a DVD. Further, the prescription may be appropriately transmitted by another device, for example, via a dedicated line. Then, if necessary, an arbitrary prescription is called from the storage unit 52 by an instruction from the user interface 51, and the control unit 50 is executed, and the desired processing of the plasma processing apparatus is performed under the control of the control unit 50.

FIG. 3 is a view showing an example of a power feeding circuit of the radio-frequency antenna 13 included in the plasma processing apparatus of the first embodiment.

As shown in FIG. 3, the high frequency power from the high frequency power source 15 is supplied to the high frequency antenna 13 via the matching unit 14. The high frequency antenna 13 includes with each other Parallel antenna portions of parallel antenna circuits. The parallel antenna portion of this example has an outer antenna circuit 13a and an inner antenna circuit 13b connected in parallel with the outer antenna circuit 13a.

Further, in this example, the impedance of the outer antenna circuit 13a and the impedance of the inner antenna circuit 13b are set to be opposite to each other. For example, in this example, the impedance of the outer antenna circuit 13a is set to be capacitive, and the impedance of the inner antenna circuit 13b is set to be inductive. Conversely, the impedance of the outer antenna circuit 13a may be set to be inductive, and the impedance of the inner antenna circuit 13b may be set to be capacitive.

In order to set the impedance of the outer antenna circuit 13a and the impedance of the inner antenna circuit 13b to be opposite to each other, for example, the capacitance adjacent to the outer antenna circuit 13a and the capacitance connected to the inner antenna circuit 13b may be changed. An example of such a circuit is shown in FIG.

In the example shown in FIG. 4, both of the outer antenna circuit 13a and the inner antenna circuit 13b are provided with coils La and Lb. Further, one capacitor C is connected to the outer antenna circuit 13a more than the inner antenna circuit 13b. Fig. 5 is a view showing the capacitance dependence of the capacitor C of the impedance.

As shown in FIG. 5, the impedance of the inner antenna circuit 13b does not change even if the capacitor C is changed. In this example, the impedance of the inner antenna circuit 13b is maintained inductive.

In contrast, the impedance of the outer antenna circuit 13a changes once the capacitor C is changed. Specifically, when the capacitance of the capacitor C is large, the impedance of the outer antenna circuit 13a is inductive to the inner antenna circuit 13b (the inner and outer impedances are in phase), but if the value of the capacitor C is reduced, The point A where the impedance is "0" is used as the boundary, and the impedance of the outer antenna circuit 13a is converted from inductive to capacitive (the inner and outer impedances are opposite phases).

As described above, when the impedance of the outer antenna circuit 13a and the impedance of the inner antenna circuit 13b are reversed, the current flowing to the outer antenna circuit 13a (outer current Iout) and the current flowing to the inner antenna circuit 13b (inside current Iin) are Form the reverse phase. FIG. 6 shows the capacitance dependence of the capacitor C of the outside current Iout and the inside current Iin.

As shown in FIG. 6, when the capacitance of the capacitor C is reduced, the outside current Iout tends to increase, but the inside current Iin tends to decrease. The inner current Iin is a point A at which the impedance shown in FIG. 5 is "0", that is, a point at which the impedance of the outer antenna circuit 13a and the impedance of the inner antenna circuit 13b are opposite phases, and the polarities are opposite. That is, the phase of the outside current Iout and the phase of the inside current Iin are opposite to each other.

The outside current Iout is such that the impedance of the outer antenna circuit 13a and the impedance of the inner antenna circuit 13b are opposite phases, and the amount is sharply increased toward the parallel resonance point B. The capacitor C is changed little, and once it passes through the parallel resonance point B, the outer current Iout is reversed, and the amount thereof is sharply decreased.

The inner current Iin is a behavior that is completely opposite to the outer current Iout. After the impedance of the outer antenna circuit 13a and the impedance of the inner antenna circuit 13b are reversed, the parallel resonance point B is opposite to the outer current Iout, but Its amount has increased dramatically. The capacitor C will change little. Once the parallel resonance point B is passed, the inner current Iin is reversed in polarity. After that, the amount is drastically reduced. Fig. 7 is a view showing an absolute value of the outside current Iout shown in Fig. 6 and an absolute value of the inside current Iin.

The phase of the outer current Iout and the phase of the inner current Iin form an opposite phase, which means that the direction of the outer current Iout is opposite to the direction of the inner current Iin as shown in FIG. 8A or FIG. 8B, and the outer antenna circuits are connected in parallel with each other. A circulating current is generated between 13a and the inner antenna circuit 13b. Such a state occurs in a region in which the inner and outer impedances shown in FIG. 5 are opposite phases, and a region in which the inner and outer currents shown in FIG. 6 are opposite phases.

Incidentally, when the phase of the outside current Iout and the phase of the inside current Iin are in the same phase, as shown in FIG. 9A or FIG. 9B, since the direction of the outside current Iout is the same as the direction of the inside current Iin, the circulating current does not occur. Such a state shown in FIG. 9A or FIG. 9B is generated in a region in which the inner and outer impedances shown in FIG. 5 are in the same phase, and the inner and outer currents shown in FIG. 6 are in the same phase.

As described above, in the plasma processing apparatus according to the first embodiment, when the inductively coupled plasma is generated in the processing chamber 4, the impedance of one of the antenna circuits and the impedance of the other antenna circuit are reversed among the parallel antenna circuits. Inductively coupled plasma is generated in the processing chamber 4 in phase. In this example, the impedance of the inner antenna circuit 13b is made inductive, and the impedance of the outer antenna circuit 13a is made capacitive, and inductively coupled plasma is generated in the processing chamber 4.

Next, an advantage in the case where the phase of the outside current Iout and the phase of the inside current Iin form an opposite phase will be described.

Figure 10 is a view showing the plasma on the substrate to be processed placed in the processing chamber Distribution of electron density.

10 is a plasma electron when the phase of the outer current Iout and the phase of the inner current Iin are reversed in a black dot (homogeneous position), a black square (inner dense position), and a black triangle (outer dense position). The distribution of density. In addition, in FIG. 10, the distribution of the plasma electron density when the phase of the outer current Iout and the phase of the inner current Iin are in the same phase is indicated by a white dot (uniform position) as a reference example.

As shown in FIG. 10, when the phase of the outer current Iout and the phase of the inner current Iin are reversed, the plasma electron density is high as compared with when the phase is in the same phase.

That is, the high frequency antenna 13 is a high frequency antenna including a parallel antenna portion having antenna circuits connected in parallel with each other, and among the parallel antenna circuits, the impedance of one antenna circuit and the impedance of the other antenna circuit are used. Inductively coupled plasma is generated in the processing chamber while the circulating current is generated in the parallel connected antenna circuit. Thereby, when the circulating current is not generated, that is, when the impedance of one of the antenna circuits is the same as the impedance of the other antenna circuit, the power efficiency is high, and plasma electrons of higher density can be obtained. Therefore, according to the plasma processing apparatus of the first embodiment, it is possible to obtain a plasma having a higher density without increasing the amount of electric power of the high-frequency power.

Further, as shown in Fig. 10, according to the plasma processing apparatus of the first embodiment, the distribution of the plasma electron density can be controlled.

For example, as shown by the black squares in Fig. 11, when it is desired to increase the plasma electron density on the inner side (near the center) of the substrate to be processed (inner density), as long as the inner side The current Iin and the outside current Iout may be opposite phases, and an inductively coupled plasma may be generated in the processing chamber in a state where the absolute value of the inner current Iin is larger than the absolute value of the outer current Iout (Iin>Iout).

The state in which "Iin>Iout" is formed is, for example, a region in which the impedances on the inner side and the outer side are opposite phases, and the capacitor C is contracted and seen through the region after the parallel resonance point B. The area is a region where the impedance of the inner antenna circuit 13b (inside Z) is smaller than the impedance of the outer antenna circuit 13a (outer Z).

As shown by the black triangle in FIG. 10, when it is desired to increase the plasma electron density on the outer side (near the edge) of the substrate to be processed (outside density), as long as the inner current Iin and the outer current Iout are opposite to each other, When the absolute value of the outside current Iout is larger than the absolute value of the inside current Iin (Iout>Iin), an inductive coupling plasma may be generated in the processing chamber.

The state in which "Iout>Iin" is formed is, for example, a region in which the impedances on the inner side and the outer side are opposite phases, and the capacitor C is reduced to the region of the parallel resonance point B. This area is a region where the impedance of the outer antenna circuit 13a (outer Z) is smaller than the impedance of the inner antenna circuit 13b (inner Z).

Further, as shown by the black dot in FIG. 10, it is desirable to form the plasma electron density from the inside of the substrate to be processed (near the center) to the outside of the substrate to be processed (near the edge) to be uniform (uniform) as long as the inside current Iin and In the state in which the outer currents Iout are opposite to each other and the absolute value of the outer current Iout is substantially equal to the absolute value of the inner current Iin (Iout ≒ Iin), an inductively coupled plasma may be generated in the processing chamber.

The state in which "Iout≒Iin" is formed is, for example, a region in which the impedances on the inner side and the outer side are opposite phases, and in the vicinity of the parallel resonance point B, for example, a region indicated by a symbol C is seen. Further, in this region C, the impedance (outer Z) of the outer antenna circuit 13a and the impedance (inner Z) of the inner antenna circuit 13b are substantially equal.

As described above, according to the plasma processing apparatus of the first embodiment, in the region where the impedances of the inner side and the outer side are opposite phases, the processing chamber can be controlled by controlling the impedance of the outer antenna circuit 13a and the impedance of the inner antenna circuit 13b. The distribution of plasma electron density.

Further, as shown in FIG. 11, for example, if the capacitor C is used as the variable capacitor VC, the distribution of the plasma electron density can be separately controlled in one inductively coupled plasma processing apparatus without replacing the high frequency antenna 13. Into the dense, external and uniform.

Further, a control means may be further provided, in which the impedance adjustment means is preset in such a manner that the optimum plasma density distribution can be obtained for each application, for example, the adjustment parameter of the capacitance of the variable capacitor VC is adjusted. When a particular application is selected, the capacitance of the variable capacitor VC is controlled in such a manner that an optimum value of the preset adjustment parameter can be formed corresponding to the application.

Further, in the case of a film formation process such as CVD, the film thickness of the film to be formed can be uniform, and the capacitance of the variable capacitor VC can be searched for in the film formation process, for example, from inner to outer. And searching for the capacitance of the variable capacitor VC from the outer to the uniform.

Also, the parallel resonance point B and its vicinity are impedances become very high. Therefore, impedance matching using the matcher 14 is difficult.

Thus, the outer antenna circuit 13a and the inner antenna circuit 13b can generate inductively coupled plasma in the processing chamber without using the parallel resonance point B of the parallel resonance.

Further, in addition to the parallel resonance point B, an inductively coupled plasma may be generated in the processing chamber without using a region in the vicinity of the parallel resonance point B.

As an example of a region in the vicinity of the parallel resonance point B, as shown in FIG. 12, a region from the parallel resonance point B to the maximum value D1 of the impedance of the high-frequency antenna 13 in the capacitive region (the total antenna angle: the four corners in the figure), and A region from the parallel resonance point B to the maximum value D2 of the impedance of the high-frequency antenna 13 in the inductive region. The section D from the maximum value D1 of the capacitive region to the maximum value D2 of the inductive region is a section in which the impedance of the radio-frequency antenna 13 is extremely high.

Therefore, for example, when controlling the capacitance of the variable capacitor VC, the capacitance of the variable capacitor VC is not controlled so that the impedance of the high-frequency antenna 13 (antenna total) forms a range of the section D.

Further, for example, when searching for the capacitance of the variable capacitor VC, the interval D is searched for in the search.

As described above, in the region D including the parallel resonance point B, the inductive coupling plasma is not generated or the processing is not performed, and the impedance matching using the matching device 14 can be easily performed, and the power efficiency can be improved.

Further, the inductive coupling plasma is not generated in the region D including the parallel resonance point B, or the processing is not performed, and the capacitor C is not limited to the variable capacitor VC. That is, the use is fixed When the capacitor C of the constant capacitance is set, the value of the capacitor C may be set such that the impedance of the high-frequency antenna 13 (the total of the antennas) does not form the range of the above-described region D.

Next, a description will be given of a processing operation when the plasma glass etching process is performed on the LCD glass substrate G by using the inductively coupled plasma etching apparatus configured as described above.

First, when the gate valve 27 is opened, the substrate G is carried into the processing chamber 4 by a transport mechanism (not shown), and after being placed on the mounting surface of the mounting table 23, the electrostatic chuck (not shown) The substrate G is fixed to the mounting table 23 . Next, in the processing chamber 4, the processing gas is discharged from the gas discharge hole 12a of the shower housing 11 into the processing chamber 4 from the processing gas supply system 20, and the processing chamber 4 is placed in the processing chamber 4 via the exhaust pipe 31 by the exhaust device 30. The vacuum is evacuated, thereby maintaining the processing chamber at a pressure environment of, for example, 0.66 to 26.6 Pa.

In addition, in the cooling space on the back side of the substrate G, He gas is supplied as a heat transfer gas via the He gas path 42 and the He gas flow path 41 in order to avoid temperature rise or temperature change of the substrate G. In this case, the He gas is directly supplied to the He gas path 42 from the gas cylinder, and the pressure is controlled by the pressure control valve. However, as the size of the substrate increases, the distance of the gas path becomes longer, and the gas is filled. The space capacity becomes large, and the time from the supply of gas to the completion of the pressure regulation becomes long. However, since the tank 47 of He gas is provided on the downstream side of the pressure control valve 44, the He gas is filled in advance, so that it can be extremely short. Carry out pressure regulation. In other words, when He gas of the heat transfer gas is supplied to the back surface of the substrate G, first, Since the He gas is supplied from the tank 47, the shortage is filled by the route from the conventional cylinder, whereby the pressure close to the set pressure can be instantaneously obtained, and the amount of gas filled through the pressure control valve is also small, so that the gas can be filled in a very short time. Complete the pressure regulation. In this case, it is preferable that the gas pressure to be filled in the tank 47 is equal to the capacity at which the cooling space is filled under the set pressure, and the capacity of the tank 47 is set to an optimum pressure. In addition, it is preferable that the operation of filling the gas in the groove 47 is performed at the time of transporting the substrate G or the like without affecting the substrate processing time.

Next, a high frequency, for example, 13.56 MHz is applied from the high-frequency power source 15 to the high-frequency antenna 13, whereby a uniform inductive electric field is formed in the processing chamber 4 via the dielectric wall 2. The processing gas is plasma-formed in the processing chamber 4 by the thus formed inductive electric field to generate a high-density inductively coupled plasma.

In this case, the configuration of the radio-frequency antenna 13 includes the outer antenna circuit 13a in which the antenna wires are closely arranged on the outer portion, and the inner antenna circuit 13b in which the antenna wires are closely arranged on the inner portion, and In the outer antenna circuit 13a, for example, as shown in Fig. 1, the variable capacitor VC is connected, and the impedance of the outer antenna circuit 13a can be adjusted. The adjustment of the variable capacitor VC is as described above.

In this case, the optimum plasma density distribution is grasped for each application, and the position of the variable capacitor VC that can obtain the plasma density distribution is set in advance in the memory unit 52, whereby the control unit 50 can select each application. The position of the optimum variable capacitor VC is subjected to plasma processing.

In this way, the plasma density distribution can be controlled by using the impedance control of the variable capacitor VC, so that it is not necessary to replace the antenna, and the antenna does not need to be replaced. Labor or the cost of preparing the antenna first by application.

Further, while performing extremely fine current control by the position adjustment of the variable capacitor VC, the impedance of the outer antenna circuit 13a and the impedance of the inner antenna circuit 13b are set to be opposite to each other. Thereby, the optimum plasma electron density distribution can be obtained according to the application, and the plasma electrons can be formed at a higher density than when the impedance of the outer antenna circuit 13a and the impedance of the inner antenna circuit 13b are in the same phase. .

Further, instead of using a plurality of high-frequency power sources to distribute the power of the high-frequency power, the impedance adjustment is performed only by the variable capacitor VC, and current control and phase control of the outer antenna circuit 13a and the inner antenna circuit 13b are performed, and thus There may be an unfavorable situation due to a large scale of the device, a high cost, or a high power cost, and the control accuracy may be higher than when a plurality of high-frequency power sources are used to distribute power.

Next, several circuit examples of the high frequency antenna 13 will be described.

13A to 13D are circuit diagrams showing examples of the first to fourth circuits of the radio-frequency antenna 13.

As shown in FIG. 13A, the high-frequency antenna 13-1 of the first circuit example is connected to both the outer antenna circuit 13a and the inner antenna circuit 13b which are connected in parallel with each other, and is connected between the matching unit 14 and one end of the planar coils La and Lb. Capacitors VCa and VCb. The other ends of the planar coils La and Lb are commonly connected and connected to a common ground point GND.

In the first circuit example, the capacitances of the variable capacitors VCa and VCb are adjusted, and the impedance of the outer antenna circuit 13a and the impedance of the inner antenna circuit 13b are set to be opposite to each other. Thereby, power efficiency can be improved.

Moreover, since the variable capacitors VCa and VCb are adjustable, the capacitances of the variable capacitors VCa and VCb can be adapted to the application so as to form an optimum value, for example, inner-tight, outer-tight, uniform, and optimal plasma electrons. The way of density distribution is controlled by power efficiency. Further, when the film forming process such as CVD is performed, the variable capacitor VCa or VCb can be searched for in the film forming process. For example, the capacitance of the variable capacitor VCa provided in the outer antenna circuit 13a can be searched for in the film forming process. The film thickness of the film to be formed can be formed into a uniform manner, and the plasma electron density distribution can be searched and controlled between internal density, external density, and uniformity in the film formation process. In this case, the impedance of the outer antenna circuit 13a and the impedance of the inner antenna circuit 13b are first reversed to each other, and the plasma electron density distribution is controlled to be controlled within the inner, outer, and uniform power efficiency.

As shown in FIG. 13B, the high frequency antenna 13-2 of the second circuit example is compared with the high frequency antenna 13-1 of the first circuit example, except that the variable capacitor VCa or VCb is connected to the common ground point GND and the planar coil. Between the other ends of La and Lb, one ends of the planar coils La and Lb are commonly connected to the matcher 14.

In the second circuit example, the capacitances of the variable capacitors VCa and VCb are also adjusted, and the impedance of the outer antenna circuit 13a and the impedance of the inner antenna circuit 13b are reversed from each other.

In the second circuit example as described above, the same advantages as the first circuit example can be obtained.

As shown in Fig. 13C, the high frequency antenna 13-3 of the third circuit example is compared with the high frequency antenna 13-1 of the first circuit example, and is only on the outer antenna circuit 13a. The variable capacitor Va is provided. The third circuit example is the same circuit as the high frequency antenna shown in FIG.

In the third circuit example, under the capacitance of the variable capacitor VCa, the impedance of the outer antenna circuit 13a and the impedance of the inner antenna circuit 13b are set to be opposite to each other.

In the third circuit example as described above, the same advantages as the first and second circuit examples can be obtained.

As shown in FIG. 13D, the high frequency antenna 13-4 of the fourth circuit example is compared with the high frequency antenna 13-3 of the third circuit example, except that the variable capacitor VCa is connected to the common ground point GND and the planar coil La. Between the other ends, one end of the planar coil La and the planar coil Lb are commonly connected to the matcher 14.

In the fourth circuit example, also under the capacitance of the variable capacitor VCa, the impedance of the outer antenna circuit 13a and the impedance of the inner antenna circuit 13b are set to be opposite to each other.

In the fourth circuit example as described above, the same advantages as the first to third circuit examples can be obtained.

Further, in the first to fourth circuit examples, the capacitor provided in the outer antenna circuit 13a and/or the inner antenna circuit 13b is a variable capacitor having an adjustable capacitance, but may be a capacitor to be fixed. The capacitance of the capacitor in this case is set so that the impedance of the outer antenna circuit 13a and the impedance of the inner antenna circuit 13b can be reversed from each other.

When the capacitor thus fixed is used, the impedance of the outer antenna circuit 13a and the impedance of the inner antenna circuit 13b are not reversed. The high-frequency antenna of the phase can increase the electron density of the plasma generated in the processing chamber, and an inductively coupled plasma processing device with a high-frequency antenna with better power efficiency can be obtained.

In the inductively coupled plasma processing apparatus according to the first embodiment of the present invention, the impedance of the outer antenna circuit 13a and the impedance of the inner antenna circuit 13b are reversed. Therefore, during the generation of the inductively coupled plasma, the phase of the current flowing to the outer antenna circuit 13a and the phase of the current flowing to the inner antenna circuit 13b are reversed from each other.

When the phases of the currents are opposite to each other, when the planar coils La and Lb are used for both the outer antenna circuit 13a and the inner antenna circuit 13b, as shown in FIG. 14, the direction and flow of the outer current Iout flowing through the planar coil La are The direction of the inner current Iin of the planar coil Lb is reversed. Therefore, the direction of the outer magnetic field created by the outer current Iout and the direction of the inner magnetic field formed by the inner current Iin are reversed, and the outer magnetic field and the inner magnetic field cancel each other, and the magnetic field introduced into the processing chamber becomes weak. .

In order to prevent such an outer magnetic field and the inner magnetic field from canceling each other, as shown in FIG. 15, the planar coil La of the outer antenna circuit 13a and the planar coil Lb of the inner antenna circuit 13b may be reversed each other. When the planar coils La and Lb are reversed from each other, the direction of the outer current Iout on the circuit is opposite to the direction of the inner current Iin, but the appearance is such that the direction of the outer current Iout coincides with the direction of the inner current Iin. direction. Therefore, the direction of the outer magnetic field and the direction of the inner magnetic field are the same, and the outer magnetic field and the inner magnetic field can be prevented from canceling each other.

(Second embodiment)

In the inductively coupled plasma processing apparatus according to the first embodiment, in the outer antenna circuit 13a and the inner antenna circuit 13b which are connected in parallel, the impedance of one antenna circuit and the impedance of the other antenna circuit are reversed, and the cycle is performed. The current is generated by the two antenna circuits that are connected in parallel. In other words, the configuration in which the capacitive outer antenna circuit 13a is a parallel circuit and the inductive inner antenna circuit 13b is connected requires at least two antenna circuits. However, even if the antenna circuit is one, a circulating current can be generated in the antenna circuit.

FIG. 16 is a circuit diagram showing an example of a power feeding circuit of a radio-frequency antenna used in the inductively coupled plasma processing apparatus according to the second embodiment of the present invention.

As shown in FIG. 16, the inductively coupled plasma processing apparatus according to the second embodiment differs from the inductively coupled plasma processing apparatus according to the first embodiment in that a circuit in which one antenna is connected in parallel is not provided with an antenna. The high frequency antenna 13 is composed of an antenna circuit 13c connected between the matching unit 14 and a ground point, and a parallel variable capacitor 70 connected in parallel with the antenna circuit 13c.

Fig. 17 is a perspective view schematically showing an example of a high-frequency antenna used in the inductively coupled plasma processing apparatus of the second embodiment.

Since the second embodiment does not have the outer antenna circuit 13a and the inner antenna circuit 13b as in the first embodiment, it can be configured by only one antenna circuit 13c. Therefore, as shown in FIG. 17, the radio-frequency antenna 13 can be configured, for example, by one planar coil Lc. Although shown in Figure 17, An example of the configuration of the conductive members is an example of the planar coil Lc, but the planar coil Lc may be configured by a plurality of conductive members.

According to the second embodiment, the capacitance of the parallel variable capacitor 70 is adjusted, for example, such that the impedance of the parallel variable capacitor 70 and the impedance of the antenna circuit 13c form an opposite phase. As a result, as shown in Fig. 18A or Fig. 18B, the direction of the antenna current Ia flowing to the antenna circuit 13c is opposite to the direction of the capacitor current Ic flowing to the parallel variable capacitor 70, and the same as in the first embodiment can be produced. Circulating current. Therefore, the same advantages as those of the first embodiment can be obtained.

19A is a basic configuration diagram showing a case where the matching unit 14 uses an inverse L-type matching circuit, and FIG. 19B is a circuit diagram showing an example of a circuit of the power feeding circuit of the high-frequency antenna shown in FIG. 16 when an inverse L-type matching circuit is used.

As shown in FIG. 19A, the inverse L-type matching circuit is a matching variable reactance element (X _Match ) 80 that connects one end to a high-frequency power source, connects the other end to a load, and connects one end to a matching one. The junction of the variable reactance element (X _Match ) 80 and the high-frequency power source 15 is connected to the tuning variable reactance element (X _Tune ) 81 whose other end is grounded. The reactive element here is a coil or a capacitor, or a composite element.

19B, the load 13 of FIG. 19A becomes a high frequency antenna, and the high frequency antenna is composed of an antenna circuit 13c (including a coil Lc that connects one end to the matching variable reactance element (X _Match ) 80, and One electrode is connected to the other end of the coil Lc, the other terminal is grounded to the terminal capacitor C), and one of the electrodes is connected to the matching variable reactance element (X _Match ) 80 and one end of the coil Lc. A parallel variable capacitor 70 is used to ground the other electrode.

Fig. 20 is a view showing the relationship between the VC position and the impedance of the parallel variable capacitor 70 shown in Fig. 19, and Fig. 21 is a view showing the VC position of the parallel variable capacitor 70 and the flow-to-matching variable reactance element (X _Match ) 80. Current (Match current), current flowing to the tuning variable reactance element (X _Tune ) 81 (Tune current), current flowing to the parallel variable capacitor 70 (parallel VC current), and flow to the terminal capacitor C The relationship between current (terminal C current).

As shown in FIG. 20, in the circuit example shown in FIG. 19, when the VC position of the variable capacitor 70 is about 60%, parallel resonance occurs. Further, as shown in FIG. 21, a current (Match current) flowing to the matching variable reactance element (X _Match ) 80 and flowing to the variable reactance element for tuning are performed in the vicinity of the parallel resonance point and the parallel resonance point. The current (Tune current) of (X _Tune ) 81 is almost zero.

FIG. 22 is a view showing a distribution of plasma electron density on a substrate to be processed placed in a processing chamber of the inductively coupled plasma processing apparatus according to the second embodiment, and FIG. 23 is a view showing an inductively coupled plasma processing apparatus according to a second embodiment; Ashing rate. A case in which the inductively coupled plasma processing apparatus of the type in which the parallel variable capacitor 70 is not held is collectively described in FIG. 22 and FIG.

As shown in FIG. 22, in the inductively coupled plasma processing apparatus according to the second embodiment, when the high-frequency power RF is the same, higher electrical power can be obtained than the inductively coupled plasma processing apparatus of the reference example. Plasma electron density.

Further, as shown in FIG. 23, the inductive coupling according to the second embodiment In the plasma processing apparatus, when the high-frequency power RF is set to be the same, the in-plane uniformity of the ashing rate and the ashing is also improved as compared with the inductively coupled plasma processing apparatus of the reference example.

When the high-frequency power RF is the same, a higher plasma electron density can be obtained. Compared with the reference example, the inductively coupled plasma processing apparatus of the second embodiment has an improved energy efficiency. The improvement in energy efficiency is, for example, an advantage that can be obtained second.

Recently, in order to improve the efficiency of processing, etc., a glass substrate for a substrate such as FPD has a tendency to be significantly enlarged, and a sheet of more than 1 m is produced. Therefore, the inductively coupled plasma processing apparatus for processing the glass substrate is also increased in size, and the dielectric wall that separates the antenna chamber from the processing chamber is also increased in size. When the dielectric wall is enlarged, the thickness thereof has to be increased, so that it can have sufficient strength to withstand the internal pressure difference or self-weight of the processing chamber. However, if the dielectric wall becomes thick, the high-frequency antenna will be far away. In the processing chamber, energy efficiency is deteriorated.

In contrast, Japanese Laid-Open Patent Publication No. 2001-28299 discloses that the metal shower frame constituting the shower head has a function of supporting a beam by which the support beam supports the dielectric wall and prevents the dielectric wall from being opposed. Bending, thereby making the dielectric wall thinner, thereby improving energy efficiency, and making the shower frame orthogonal to the high-frequency antenna, and preventing the inductive electric field from the high-frequency antenna from being blocked by the support beam, thereby preventing energy efficiency. reduce.

However, when the inductively coupled plasma processing apparatus is further increased, the dielectric wall is supported by the support beam and the dielectric wall is thinned as in the technique described in the above-mentioned JP-A-2001-28299. It will be limited and requires further energy efficiency improvements.

In view of such a situation, the inductively coupled plasma processing apparatus according to the second embodiment is improved in energy efficiency as shown in FIG. 22, and thus it is also advantageous in increasing the size of the inductively coupled plasma processing apparatus.

Further, in the second embodiment, as described in the first embodiment, it is also possible to generate an inductance in the processing chamber without using a parallel resonance point of parallel resonance or a region in the vicinity of the parallel resonance point except for the parallel resonance point. Coupled plasma. The definition of the region in the vicinity of the parallel resonance point is as described in the first embodiment.

(Third embodiment)

In the second embodiment, as described with reference to FIG. 21, the current of the tuning variable reactance element (X _Tune ) 81 flowing to the inverse L-type matching circuit is in the vicinity of the parallel resonance point and the parallel resonance point (Tune The current) is almost zero. Therefore, when the inductively coupled plasma processing apparatus is operated in the vicinity of the parallel resonance point and the parallel resonance point, the variable reactance element (X _Tune ) 81 for tuning is not required as shown in FIG. 24A.

Here, the circuit of FIG. 24A of the tuning variable reactance element (X _Tune ) 81 is removed, and if the coil Lc and the terminal capacitor C are considered to be loaded, as shown in FIG. 24B, the parallel variable capacitor is used. 70 is the same as the basic configuration of the T-type matching circuit of the variable reactance element (X _Tune ) 81 for tuning.

T-type matching circuit is implemented: the high-frequency power is connected to the matching one of 80, and is connected to the matching variable reactance element (X _Match) with one variable reactance element (X _Match) other 80 will The other grounded tuning variable reactance element (X _Tune ) 81 is formed.

Fig. 25 is a circuit diagram showing an example of a power feeding circuit of a radio-frequency antenna used in the inductively coupled plasma processing apparatus according to the third embodiment.

As shown in FIG. 25, the power supply circuit of the third embodiment differs from the power supply circuit of the second embodiment in that the matching unit 14 is replaced by an inverse L-type matching circuit into a T-type matching circuit, and the inductively coupled plasma processing device is provided. During the operation, impedance matching can be performed such that the circulating current can flow between the tuning variable reactance element (X _Tune ) 81 and the antenna circuit 13c.

The radio-frequency antenna 13 is constituted by an antenna circuit 13c, and the antenna circuit 13c includes an interconnecting point that connects one end to the matching variable reactance element (X _Match ) 80 and the tuning variable reactance element (X _Tune ) 81. The coil Lc and the terminal capacitor C that connects one electrode to the other end of the coil Lc and the other electrode to the ground.

When the plasma processing is performed, it is possible to operate such that a circulating current can be generated between the tuning variable reactance element (X _Tune ) 81 and the antenna circuit 13c. In a specific example, the tuning variable reactance element (X _Tune ) 81 is adjusted so that the impedance of the tuning variable reactance element (X _Tune ) 81 can be reversed with the impedance of the antenna circuit 13c.

FIG. 26 is a view showing the distribution of plasma electron density on the substrate to be processed placed in the processing chamber of the inductively coupled plasma processing apparatus according to the third embodiment, and FIG. 27 is a view showing the inductively coupled plasma processing apparatus according to the third embodiment. Ashing rate. In the inductively coupled plasma processing apparatus of the type in which the parallel variable capacitor 70 is not provided, and the second embodiment, a reference example is shown in FIG. 26 and FIG.

As shown in FIG. 26, in the inductively coupled plasma processing apparatus according to the third embodiment, when the high-frequency power RF is also the same, compared with the inductively coupled plasma processing apparatus of the reference example, it is possible to obtain higher and The plasma electron density of the second embodiment is equal to or higher than that of the second embodiment.

Further, as shown in FIG. 27, in the inductively coupled plasma processing apparatus according to the third embodiment, when the high-frequency power RF is the same, the ashing rate is higher than that of the inductively coupled plasma processing apparatus of the reference example. And the in-plane uniformity of ashing will also increase. Further, the ashing rate is almost the same as that of the second embodiment, and the in-plane uniformity can be equal to or higher than that of the second embodiment.

Further, in the third embodiment, as described in the first embodiment, it is also possible to generate an inductance in the processing chamber without using a parallel resonance point of parallel resonance or a region in the vicinity of the parallel resonance point except for the parallel resonance point. Coupled plasma. The definition of the region in the vicinity of the parallel resonance point is as described in the first embodiment.

As described above, according to the inductively coupled plasma processing apparatus of the embodiment of the present invention, it is possible to provide an inductively coupled plasma processing apparatus and an inductively coupled plasma processing method which are more power efficient.

Further, the present invention is not limited to the above embodiment, and various modifications may be implemented.

For example, the configuration of the radio-frequency antenna is not limited to the above configuration, and various configurations can be employed only for the configuration having the same function.

Further, in the above embodiment, the high-frequency antenna is divided into an outer antenna portion in which plasma is formed on the outer side and an inner antenna portion in which plasma is formed on the inner side. It is not necessarily divided into the outside and the inside, and various methods can be used.

Further, it is not limited to the antenna portion having different positions at which the plasma is formed, and may be divided into antenna portions having different plasma distribution characteristics.

Further, in the above embodiment, the two antennas are divided into two sides, that is, the outer side and the inner side, but they may be divided into three or more. For example, it may be divided into three parts, an outer part, a center part, and these intermediate parts.

Further, the means for adjusting the impedance is to provide a capacitor and a variable capacitor, but other impedance adjusting means such as a coil or a variable coil may be used.

Further, although the above embodiment is an example in which the ashing apparatus is used as the inductively coupled plasma processing apparatus, it is not limited to the ashing apparatus, and may be used in other plasma processing apparatuses such as etching or CVD film formation.

Further, the substrate to be processed is an FPD substrate, but the present invention is not limited thereto, and may be applied to other substrates such as semiconductor wafers.

1‧‧‧ body container

2‧‧‧Dielectric wall (dielectric member)

3‧‧‧Antenna room

4‧‧‧Processing room

13‧‧‧High frequency antenna

13a‧‧‧Outer antenna circuit

13b‧‧‧Inside antenna circuit

14‧‧‧matcher

15‧‧‧High frequency power supply

16a, 16b‧‧‧Power supply components

20‧‧‧Processing gas supply system

C‧‧‧ capacitor

VC, VCa, VCb‧‧‧ variable capacitor

23‧‧‧ mounting table

30‧‧‧Exhaust device

50‧‧‧Control Department

51‧‧‧User interface

52‧‧‧Memory Department

61a‧‧‧Outer antenna circuit

61b‧‧‧Inside antenna circuit

G‧‧‧Substrate

70‧‧‧Parallel variable capacitor

80‧‧‧matching reactive reactance components

81‧‧‧Variable Reactive Component for Tuning (X _Tune )

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

Fig. 2 is a plan view showing a high frequency antenna used in the inductively coupled plasma processing apparatus of the first embodiment.

FIG. 3 is a view showing an example of a power feeding circuit of a radio-frequency antenna provided in the inductively coupled plasma processing apparatus according to the first embodiment.

Fig. 4 is a circuit diagram showing an example of a circuit of a power feeding circuit.

FIG. 5 is a graph showing the capacitance dependence of the capacitor C of the impedance.

Figure 6 is a diagram showing the capacitance of the capacitor C of the outside current and the inside current. A map of existence.

FIG. 7 is a graph showing the capacitance dependence (absolute value display) of the capacitor C of the outside current and the inside current.

FIG. 8 is a current diagram showing a high-frequency antenna provided in the inductively coupled plasma processing apparatus according to the first embodiment.

FIG. 9 is a current diagram showing a high-frequency antenna provided in the inductively coupled plasma processing apparatus of the reference example.

Fig. 10 is a view showing a distribution of plasma electron density on a substrate to be processed placed in a processing chamber.

Fig. 11 is a circuit diagram showing another example of a circuit of the power feeding circuit.

FIG. 12 is a view showing the capacitance dependence of the capacitor C of the impedance.

13A to 13D are circuit diagrams showing examples of the first to fourth circuits of the radio-frequency antenna 13.

Fig. 14 is a perspective view showing the relationship between the direction of the outside current and the inside current, and the outside magnetic field and the inside magnetic field.

Fig. 15 is a perspective view showing the relationship between the direction of the outside current and the inside current, and the outside magnetic field and the inside magnetic field.

Fig. 16 is a circuit diagram showing an example of a power feeding circuit of a radio-frequency antenna used in the inductively coupled plasma processing apparatus of the second embodiment.

Fig. 17 is a perspective view schematically showing an example of a high frequency antenna used in the inductively coupled plasma processing apparatus of the second embodiment.

FIG. 18 is a current diagram showing a high-frequency antenna provided in the inductively coupled plasma processing apparatus according to the second embodiment.

Figure 19 is a diagram showing a power supply circuit of the high frequency antenna shown in Figure 16 Circuit diagram of the circuit example.

Fig. 20 is a view showing the relationship between the VC position and the impedance of the parallel variable capacitor shown in Fig. 19;

21 is a view showing a VC position of the parallel variable capacitor shown in FIG. 19, a current flowing in the matching variable capacitor, a current flowing in the tuning variable capacitor, a current flowing in the parallel variable capacitor, and a flow in the terminal. A diagram of the current of the capacitor.

Fig. 22 is a view showing a distribution of plasma electron density on a substrate to be processed placed in a processing chamber.

Fig. 23 is a view showing the ashing rate of the inductively coupled plasma processing apparatus of the second embodiment.

Fig. 24 is a circuit diagram for explaining a third embodiment.

Fig. 25 is a circuit diagram showing an example of a power feeding circuit of a radio-frequency antenna used in the inductively coupled plasma processing apparatus of the third embodiment.

Fig. 26 is a view showing a distribution of plasma electron density on a substrate to be processed placed in a processing chamber.

Fig. 27 is a view showing the ashing rate of the inductively coupled plasma processing apparatus of the third embodiment.

13a‧‧‧Outer antenna circuit

13b‧‧‧Inside antenna circuit

14‧‧‧matcher

15‧‧‧High frequency power supply

Claims (12)

An inductively coupled plasma processing apparatus characterized by comprising: a processing chamber for accommodating a substrate to be processed to perform plasma processing; a mounting table for placing a substrate to be processed in the processing chamber; and a processing gas supply system a processing gas is supplied to the processing chamber; an exhaust system is configured to exhaust the processing chamber; and an antenna circuit is disposed outside the processing chamber via a dielectric member, and the processing is performed by supplying high frequency power. Forming an inductive electric field in the room; a matching circuit disposed between the high frequency power supply for supplying the high frequency power and the antenna circuit; and a parallel circuit connected in parallel with the antenna circuit to make the impedance of the antenna circuit and the parallel circuit The impedance forms an inverse phase, and the inductor can be coupled to the processing chamber to generate an inductively coupled plasma. The parallel circuit includes a variable capacitor that is part of the matching circuit and generates the inductively coupled plasma in the processing chamber. The value of the capacitance of the variable capacitor is controlled such that the antenna circuit and the parallel circuit do not become Parallel resonance that kind of value. An inductively coupled plasma processing apparatus characterized by comprising: a processing chamber for accommodating a substrate to be processed to perform plasma processing; a mounting table for placing a substrate to be processed in the processing chamber; and a processing gas supply system Supplying process gas to the aforementioned processing chamber The exhaust system is configured to exhaust the processing chamber; the first antenna circuit is disposed outside the processing chamber via a dielectric member, and an inductive electric field is formed in the processing chamber by supplying high frequency power. a second antenna circuit that is connected in parallel with the first antenna circuit and disposed outside the processing chamber via a dielectric member, and that generates an inductive electric field in the processing chamber by supplying high-frequency power; and an impedance adjusting means And connecting at least one of the first antenna circuit and the second antenna circuit, adjusting an impedance of the connected circuit, and causing an impedance of the first antenna circuit to be opposite to an impedance of the second antenna circuit. Generating an inductively coupled plasma in the processing chamber, and controlling current values of at least one of the first antenna circuit and the second antenna circuit by impedance adjustment of the impedance adjusting means to control the current generated in the processing chamber The plasma electron density distribution of the inductively coupled plasma, when the inductively coupled plasma is generated in the processing chamber, the resistance of the impedance adjusting means System is controlled to adjust the value of the first antenna and the second antenna circuit is not parallel resonance circuit as a value. The inductively coupled plasma processing apparatus according to claim 2, wherein the antenna circuit and the other antenna circuit include a planar coil, and a planar coil included in the antenna circuit has a space inside, and constitutes An outer antenna in which an inductive electric field is formed in an outer portion of the processing chamber, and a planar coil included in the other antenna circuit is disposed in a space inside the planar coil included in the antenna circuit, and is formed in an inner portion of the processing chamber. The inner antenna of the inductive electric field. The inductively coupled plasma processing apparatus according to claim 3, wherein the planar coil included in the antenna circuit and the planar coil included in the other antenna circuit are reversed from each other. The inductively coupled plasma processing apparatus according to claim 2, wherein the impedance adjusting means includes a variable capacitor. The inductively coupled plasma processing apparatus according to claim 1 or 2, wherein the inductively coupled plasma is generated in the processing chamber without using a region in the vicinity of the parallel resonance point. The inductively coupled plasma processing apparatus according to claim 6, wherein the region in the vicinity includes a region from the parallel resonance point to a maximum value of an impedance of the high frequency antenna in the capacitive region, and the juxtaposition A region from the resonance point to the maximum value of the impedance of the above-described high frequency antenna in the inductive region. A plasma processing method is a plasma processing method using an inductively coupled plasma processing apparatus, the inductively coupled plasma processing apparatus comprising: a processing chamber that houses a substrate to be processed to perform plasma processing; and a mounting stage a processing substrate to be placed in the processing chamber; a processing gas supply system for supplying a processing gas to the processing chamber; and an exhaust system for exhausting the processing chamber; The antenna circuit is disposed outside the processing chamber via a dielectric member, and generates an inductive electric field in the processing chamber by supplying high frequency power; and a parallel circuit connected in parallel to the antenna circuit, wherein: Forming an inductively coupled plasma in the processing chamber by forming an impedance of the antenna circuit in an opposite phase to an impedance of the parallel circuit, wherein the antenna circuit and the parallel circuit do not use a parallel resonant point of parallel resonance to generate the inductance in the processing chamber Coupled plasma. The plasma processing method of claim 8, wherein the inductively coupled plasma is generated in the processing chamber without using a region in the vicinity of the parallel resonance point. The plasma processing method according to claim 9, wherein the region in the vicinity includes a region from the parallel resonance point to a maximum value of an impedance of the high frequency antenna in the capacitive region, and a parallel resonance point A region up to the maximum value of the impedance of the aforementioned high-frequency antenna in the inductive region. The plasma processing method according to any one of claims 8 to 10, wherein the inductively coupled plasma processing apparatus further includes an impedance adjusting means connected to the antenna circuit and the parallel circuit At least one of: adjusting an impedance of the connected circuit, and controlling an impedance of the impedance adjusting means to control a current value of at least one of the antenna circuit and the parallel circuit to control an inductive coupling current formed in the processing chamber Plasma electron density of pulp cloth. A computer readable memory medium is a computer readable memory medium in which a control program operating on a computer is stored, wherein the control program is configured to control the inductively coupled plasma processing device during execution. A plasma processing method as described in any one of claims 8 to 11 of the patent application.