JP5329167B2 - Inductively coupled plasma processing apparatus, inductively coupled plasma processing method, and storage medium - Google Patents

Abstract

The invention claims an inductively coupled plasma processing unit and a plasma processing method, where the inductively coupled plasma processing unit can control plasma state during a plasma processing period, free of increasing unit cost or electric power cost. An HF antenna (13) supplied HF electric power so as to form an induction filed in a processing chamber (4) is configured isolated from a dielectric wall (2) above the processing chamber (4). A light emitting state of the inductively coupled plasma formed in the processing chamber through the induction field is detected by means of a plasma light emitting state detection portion (40). According to the detection information of the plasma light emitting state detection portion (40), a control unit (50) controls a regulation unit (21) that regulates properties of antenna circuits including the HF antenna, to thereby control the plasma state.

Description

The present invention relates to an inductively coupled plasma processing apparatus , an inductively coupled plasma processing method, and a storage medium for performing plasma processing such as plasma etching on a substrate such as a glass substrate for manufacturing a flat panel display (FPD) such as a liquid crystal display (LCD). .

  In a manufacturing process of a liquid crystal display (LCD) or the like, various plasma processing apparatuses such as a plasma etching apparatus and a plasma CVD film forming apparatus are used to perform a predetermined process on a glass substrate. Conventionally, a capacitively coupled plasma processing apparatus has been widely used as such a plasma processing apparatus. Recently, however, an inductively coupled plasma (Inductively Coupled Plasma) having a great advantage that a high-density plasma can be obtained at a high vacuum degree. : ICP) processing devices are attracting attention.

  The inductively coupled plasma processing apparatus arranges a high frequency antenna outside a dielectric window of a processing container that accommodates a substrate to be processed, supplies a processing gas into the processing container and supplies high frequency power to the high frequency antenna. Inductively coupled plasma is generated in the processing vessel, and a predetermined plasma process is performed on the substrate to be processed by the inductively coupled plasma. As a high-frequency antenna for an inductively coupled plasma processing apparatus, a planar antenna having a predetermined planar pattern is often used.

  In such an inductively coupled plasma processing apparatus using a planar antenna, plasma is generated in a space immediately below the planar antenna in the processing container. At that time, the plasma is generated in proportion to the electric field strength at each position immediately below the antenna. Due to the distribution of the high plasma density region and the low plasma region, the pattern shape of the planar antenna is an important factor that determines the plasma density distribution.

  By the way, the number of applications that a single inductively coupled plasma processing apparatus should support is not limited to one, and it is necessary to support a plurality of applications. In that case, it is necessary to change the plasma density distribution in order to perform uniform processing in each application.To that end, multiple antennas with different shapes are prepared so that the positions of the high-density region and low-density region are different. The antenna is replaced according to the application.

  However, preparing a plurality of antennas corresponding to a plurality of applications and exchanging them for different applications requires a great deal of labor, and recently, the glass substrate for LCD has been remarkably increased in size. Therefore, the antenna manufacturing cost is also expensive. Further, even if a plurality of antennas are prepared in this way, the given application is not necessarily the optimum condition, and must be dealt with by adjusting process conditions.

  On the other hand, Patent Document 1 discloses a plasma processing apparatus in which a spiral antenna is divided into two parts, an inner part and an outer part, and an independent high-frequency current is allowed to flow in each part. 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, i.e., a high-frequency power source for the inner portion of the spiral antenna and a high-frequency power source for the outer portion, or a power distribution circuit. It becomes a large scale and the equipment cost becomes high. In this case, the power loss is large and the power cost is high, and it is difficult to control the plasma density distribution with high accuracy. Furthermore, in an actual etching process, a plurality of different films may be continuously etched in one etching process. In such a case, the optimum process conditions differ depending on the film. Although adjustment of the antenna is desired, the technique described in Patent Document 1 cannot cope with the adjustment.
Japanese Patent No. 3077709

The present invention has been made in view of such circumstances, and an inductively coupled plasma processing apparatus and an inductively coupled plasma process capable of controlling a plasma state during plasma processing without increasing apparatus cost and power cost. It is an object to provide a method and a storage medium .

In order to solve the above problems, according to a first aspect of the present invention, a processing chamber that accommodates a substrate to be processed and performs plasma processing, a mounting table on which the processing substrate is mounted, and 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 a dielectric member disposed outside the processing chamber and supplied to the processing chamber by high-frequency power. A high-frequency antenna for forming an electric field; plasma detecting means for detecting a state of inductively coupled plasma formed in the processing chamber by the induction electric field; adjusting means for adjusting impedance of an antenna circuit including the high-frequency antenna; and the plasma Control means for controlling the adjustment means based on plasma detection information of the detection means, and controlling the plasma state, and the substrate to be processed is a plurality of laminated layers And the plasma treatment is an etching treatment for etching the plurality of stacked layers, and an adjustment parameter of the adjustment means for obtaining an optimal plasma state for each of the stacked layers is preset. The control means detects an inflection of a layer based on detection information from the plasma detection means, and selects an adjustment parameter of the adjustment means corresponding to a new etching target layer. I will provide a.

  In the first aspect, the high-frequency antenna has a plurality of antenna portions that form induction electric fields having different electric field intensity distributions in the processing chamber when high-frequency power is supplied, and the adjustment unit includes the adjustment unit, Connected to at least one of the antenna circuits including each antenna unit, and adjusts the impedance of the connected antenna circuit, and the control unit controls the adjustment unit to control the current values of the plurality of antenna units. It can be configured to control and thereby control the plasma density distribution of the inductively coupled plasma formed in the processing chamber. In this case, the adjusting means may have a variable capacitor.

Further, it is possible to make the in the first aspect, the adjustment parameters of the adjusting means each for each optimal plasma density distribution of a plurality of layers in which the laminated is obtained is set in advance.

Further, the control means can control the adjustment parameter of the adjustment means in real time so that the plasma state becomes appropriate based on the detection information by the plasma detection means.

  Further, the control means controls the processing gas supply system based on the plasma detection information of the plasma detection means, in addition to controlling the adjustment means based on the plasma detection information of the plasma detection means, and plasma It can be configured to control the state.

In this case, the adjustment parameters of the adjustment means for obtaining the optimum plasma density distribution for each of the plurality of stacked layers, and the processing gas parameters including the processing gas flow rate and the ratio by the processing gas supply system are preset. , the control means, based on the information detected by the plasma detecting means, be adapted to select an adjustment parameter and the process gas parameter of the adjusting means for detecting a turn of layers, corresponding to the new layer to be etched I can .

Further, when the processing gas supply system is also controlled, the control means controls the adjustment parameters of the adjustment means and the processing gas in real time so that the plasma state becomes appropriate based on the detection information by the plasma detection means. Process gas parameters including the process gas flow rate and ratio by the supply system can also be controlled.

  Furthermore, a plurality of the plasma detection means are provided corresponding to different positions of the substrate to be processed, and the control means controls the adjustment means so that detection information of the plurality of plasma detection means is constant, thereby performing plasma processing. The characteristics are made uniform within the surface of the substrate to be processed, and the processing gas supply system is controlled based on any of detection information of the plurality of plasma means to control the plasma processing characteristics. be able to.

  Furthermore, as the plasma detecting means, a device having a light receiving portion that receives light emitted from plasma and a light detecting portion that detects the light emission intensity of light of a predetermined wavelength from the light received by the light receiver is preferably used. Can do. In this case, the light detection unit detects detection light having a predetermined wavelength and reference light having a wavelength in the vicinity of the detection light wavelength, and standardizes the emission intensity of the detection light with the emission intensity of the reference light. It is preferable to use the converted emission intensity as the state of the inductively coupled plasma.

In the second aspect of the present invention, the processing substrate is mounted on a mounting table provided inside the processing chamber, and high-frequency power is supplied to the outside of the processing chamber via a dielectric member, whereby the processing is performed. A high frequency antenna for forming an induction electric field is provided in the chamber, a processing gas is supplied into the processing chamber, and an inductively coupled plasma of the processing gas is formed in the processing chamber by an induction electric field formed by supplying high frequency power to the high frequency antenna. Then, an inductively coupled plasma processing method for performing plasma processing on a substrate to be processed with the plasma, wherein the substrate to be processed has a plurality of stacked layers, and the plasma processing includes the plurality of stacked layers. An etching process for etching, and adjusting parameters of an antenna circuit including the high-frequency antenna that can obtain an optimum plasma state for each of the plurality of stacked layers. The preset, the induced electric field by detecting the state of the inductively coupled plasma formed in the processing chamber, on the basis of the detection information to detect the turn of the layers, the impedance of the antenna circuit including the high-frequency antenna, There is provided an inductively coupled plasma processing method characterized by controlling the plasma state by selecting the adjustment parameter corresponding to a new etching target layer.

  In the second aspect, the high-frequency antenna has a plurality of antenna portions that form induction electric fields having different electric field strength distributions in the processing chamber when high-frequency power is supplied, and based on the detection information A configuration for controlling the plasma density distribution of the inductively coupled plasma formed in the processing chamber by adjusting the impedance value of at least one of the antenna circuits including the antenna units to control the current values of the plurality of antenna units. It can be. In this case, the impedance can be adjusted by adjusting the capacitance of a variable capacitor provided in the antenna circuit for impedance adjustment.

Further, it is possible to make Sulfur butterfly clause parameters before each optimum plasma density distribution for each to obtain a plurality of layers in which the laminated is set in advance.

  Further, the adjustment parameter can be controlled in real time so that the plasma state becomes appropriate based on the detection information by the plasma detection means.

Further, in addition to adjusting the impedance of the antenna circuit including the high-frequency antenna based on the detection information of the inductively coupled plasma, the supply of the processing gas is controlled based on the detection information of the inductively coupled plasma, and the plasma state Can be controlled. In this case, the adjustment parameter for obtaining the optimum plasma density distribution for each layer of the plurality of stacked layers and the processing gas parameters including the processing gas flow rate and the ratio are preset, and the state of the inductively coupled plasma is detected. Based on the information, a change in layer may be detected, and the adjustment parameter and the process gas parameter corresponding to a new etching target layer may be selected.

Further, in the case of controlling also the supply of the process gas, on the basis of the information detected by the plasma detecting means comprises said adjustment parameters in real time such that the plasma state is appropriate and processing gas flow rate, the ratio processing It is also possible to control the gas parameters.

Furthermore, the state of the inductively coupled plasma is detected at a plurality of locations corresponding to different positions of the substrate to be processed, and the impedance of the antenna circuit including the high-frequency antenna is controlled so that the detection information of these detection means is constant. The plasma processing characteristics are made uniform in the plane of the substrate to be processed, and the plasma processing characteristics are controlled by controlling the supply of the processing gas based on any of the plurality of detection information. be able to.

  Furthermore, it is preferable that the state of the inductively coupled plasma is detected by receiving light from the plasma and detecting the emission intensity of light of a predetermined wavelength from the received light. In this case, detection light having a predetermined wavelength and reference light having a wavelength in the vicinity of the detection light wavelength are detected, and light emission intensity obtained by normalizing the light emission intensity of the detection light with the light emission intensity of the reference light is inductively coupled. It is preferably used as a plasma state.

  According to a third aspect of the present invention, there is provided a storage medium that stores a program that operates on a computer and controls an inductively coupled plasma processing apparatus. The storage medium is characterized by causing a computer to control the inductively coupled plasma processing apparatus.

According to the present invention, the adjustment of detecting the state of the inductively coupled plasma formed in the processing chamber by the induction electric field by the plasma detection means and adjusting the impedance of the antenna circuit including the high frequency antenna based on the plasma detection information of the plasma detection means. Since the plasma is controlled by controlling the means, it is not necessary to provide two high-frequency power supplies or a power distributor, and the impedance of the antenna circuit can be controlled during the plasma processing. Therefore, the plasma state can be controlled during the plasma processing without increasing the apparatus cost and the power cost.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a 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 a high frequency antenna used in the inductively coupled plasma processing apparatus. This apparatus is used, for example, for etching a metal film, an ITO film, an oxide film, or the like when forming a thin film transistor on an FPD glass substrate, or for ashing a resist film. Here, as FPD, a liquid crystal display (LCD), an electroluminescence (Electro Luminescence; EL) display, a plasma display panel (PDP), etc. are illustrated.

This plasma processing apparatus has a rectangular tube-shaped airtight main body container 1 made of a conductive material, for example, aluminum whose inner wall surface is anodized. The main body container 1 is assembled so as to be disassembled, and is grounded by a ground wire 1a. The main body container 1 is divided into an antenna chamber 3 and a processing chamber 4 by a dielectric wall 2 in the vertical direction. Therefore, the dielectric wall 2 constitutes the ceiling wall of the processing chamber 4. The dielectric wall 2 is made of ceramics such as Al ₂ O ₃ , quartz, or the like.

  A shower casing 11 for supplying a processing gas is fitted into the lower portion of the dielectric wall 2. The shower casing 11 is provided in a cross shape and has a structure that supports the dielectric wall 2 from below. The shower housing 11 that supports the dielectric wall 2 is suspended from the ceiling of the main body container 1 by a plurality of suspenders (not shown).

  The shower casing 11 is made of a conductive material, preferably a metal, for example, aluminum whose inner surface is anodized so as not to generate contaminants. The shower casing 11 is formed with a gas channel 12 extending horizontally, and a plurality of gas discharge holes 12 a extending downward are communicated with the gas channel 12. On the other hand, a gas supply pipe 20 a is provided at the center of the upper surface of the dielectric wall 2 so as 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 and is connected to a processing gas supply system 20 including a processing gas supply source and a valve system. Therefore, in the plasma processing, the processing gas supplied from the processing gas supply system 20 is supplied into the shower housing 11 through the gas supply pipe 20a and discharged into the processing chamber 4 from the gas supply hole 12a on the lower surface thereof. The

  A support shelf 5 protruding inward is provided between the side wall 3 a of the antenna chamber 3 and the side wall 4 a of the processing chamber 4 in the main body container 1, and the dielectric wall 2 is placed on the support shelf 5. The

  In the antenna chamber 3, a radio 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 separated 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 antenna lines are densely arranged in the outer portion, and an inner antenna portion 13b in which antenna wires are densely arranged in the inner portion. These outer antenna portion 13a and inner antenna portion 13b constitute a spiral multiple (quadruple) antenna as shown in FIG. The configuration of the multiple antennas may be a double configuration on the inside or outside, or a configuration of an inside double outside quadruple.

  The outer antenna portion 13a is arranged so that the four antenna wires are shifted by 90 ° so that the whole becomes a substantially rectangular shape, and the central portion is a space. Each antenna line is fed with power through four terminals 22a at the center. Further, the outer end portion of each antenna line is connected to the side wall of the antenna chamber 3 via the capacitor 18a and grounded in order to change the voltage distribution of the antenna line. However, it is possible to directly ground without passing through the capacitor 18a, and further, a capacitor may be inserted in the terminal 22a portion or in the middle of the antenna wire, for example, in the bent portion 100a.

  In addition, the inner antenna portion 13b is arranged in a central space of the outer antenna portion 13a so that the four antenna wires are shifted by 90 ° and the entire shape is substantially rectangular. In addition, power is supplied to each antenna line via four central terminals 22b. Further, the outer end of each antenna line is connected to the upper wall of the antenna chamber 3 via a capacitor 18b (shown only in FIG. 2) and grounded in order to change the voltage distribution of the antenna line. However, it is also possible to directly ground without passing through the capacitor 18b, and further, a capacitor may be inserted in the terminal 22b portion or in the middle of the antenna line, for example, in the bent portion 100b. 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.

  Near the center of the antenna chamber 3, four first power supply members 16a that supply power to the outer antenna portion 13a and four second power supply members 16b that supply power to the inner antenna portion 13b (only one in FIG. 1). The lower end of each 1st electric power feeding member 16a is connected to the terminal 22a of the outer side antenna part 13a, and the lower end of each 2nd electric power feeding member 16b is connected to the terminal 22b of the inner side antenna part 13b. A high frequency power supply 15 is connected to the first and second power supply members 16a and 16b via a matching unit 14. The high-frequency power supply 15 and the matching unit 14 are connected to a feeding line 19, and the feeding line 19 branches to feeding lines 19 a and 19 b on the downstream side of the matching unit 14, and the feeding line 19 a is connected to the four first feeding members 16 a. The power supply line 19b is connected to the four second power supply members 16b. A variable capacitor 21 is interposed in the power supply line 19a. Therefore, the variable capacitor 21 and the outer antenna portion 13a constitute an outer antenna circuit. On the other hand, the inner antenna circuit includes only the inner antenna portion 13b. Then, by adjusting the capacitance of the variable capacitor 21, as will be described later, the impedance of the outer antenna circuit is controlled, and the magnitude relationship between the currents flowing through the outer antenna circuit and the inner antenna circuit can be adjusted.

  During the plasma processing, high frequency power for inductive electric field formation, for example, high frequency power of 13.56 MHz is supplied to the high frequency antenna 13 from the high frequency power supply 15, and the high frequency antenna 13 thus supplied with the high frequency power supplies the inside of the processing chamber 4. An induced electric field is formed in the gas, and the process gas supplied from the shower casing 11 is turned into plasma by the induced 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 by the variable capacitor 21.

  Below the processing chamber 4, a mounting table 23 for mounting the LCD glass substrate G is provided so as to face the high-frequency antenna 13 with the dielectric wall 2 interposed therebetween. The mounting table 23 is made of a conductive material, for example, aluminum whose surface is anodized. The LCD glass substrate G mounted on the mounting table 23 is attracted and held by an electrostatic chuck (not shown).

  The mounting table 23 is housed in an insulator frame 24 and is supported by a hollow column 25. The support column 25 penetrates the bottom of the main body container 1 while maintaining an airtight state, is supported by an elevating mechanism (not shown) disposed outside the main body container 1, and the loading table 23 is moved by the elevating mechanism when the substrate G is loaded / unloaded. Is driven in the vertical direction. A bellows 26 that hermetically surrounds the support column 25 is disposed between the insulator frame 24 that houses the mounting table 23 and the bottom of the main body container 1. In addition, airtightness in the processing container 4 is guaranteed. Further, on the side wall 4a of the processing chamber 4, a loading / unloading port 27a for loading / unloading the substrate G and a gate valve 27 for opening / closing the loading / unloading port 27a are provided.

  A high frequency power source 29 is connected to the mounting table 23 via a matching unit 28 by a power supply line 25 a provided in the hollow support column 25. The high frequency power supply 29 applies high frequency power for bias, for example, high frequency power having a frequency of 3.2 MHz to the mounting table 23 during plasma processing. The ions in the plasma generated in the processing chamber 4 are effectively drawn into the substrate G by the high frequency power for bias.

  Further, in the mounting table 23, a temperature control mechanism including a heating means such as a ceramic heater, a refrigerant flow path, and the like, and a temperature sensor are provided in order to control the temperature of the substrate G (both not shown). ). Piping and wiring for these mechanisms and members are all led out of the main body container 1 through the hollow support column 25.

  An exhaust device 30 including a vacuum pump or the like is connected to the bottom of the processing chamber 4 via an exhaust pipe 31. The exhaust device 30 exhausts the processing chamber 4, and the inside of the processing chamber 4 is predetermined during plasma processing. The vacuum atmosphere (for example, 1.33 Pa) is set and maintained.

  A cooling space (not shown) is formed on the back side of the substrate G mounted on the mounting table 23, and a He gas flow path 33 for supplying He gas as a heat transfer gas at a constant pressure is formed. Is provided. By supplying the heat transfer gas to the back side of the substrate G in this way, it is possible to avoid a temperature rise or temperature change of the substrate G under vacuum.

A window 32 made of a translucent material such as glass is provided at a portion corresponding to the processing chamber 4 on the side wall of the main body container 1. A plasma emission state detection unit 40 that detects the emission state of plasma in the processing chamber 4 through the window 32 is provided. The plasma light emission state detection unit 40 includes a light receiver 41 provided adjacent to the window 32, a spectroscope 42 connected to the light receiver 41, and a photodetector 43 connected to the spectroscope 42. Yes. Then, the light received by the light receiver 41 is split by the spectroscope 42, and the light emission intensity of light of a specific wavelength therein is detected by the photodetector 43. Thereby, the light from the plasma is received by the light receiver 41, and is dispersed by the spectroscope 42, and the light emission intensity of light of a specific wavelength is detected by the light detector 43, so that the plasma state can be monitored. For example, when etching using a fluorocarbon-based gas is performed as the plasma treatment, the state of the plasma can be monitored, for example, by detecting the emission peak of C ₂ . In this case, with respect to the detection light of wavelength λ1, light of wavelength λ2 having a wavelength near the detection light and having no peak is used as reference light, and the emission intensity of detection light wavelength λ1 and the emission intensity of reference light wavelength λ2 are detected. To do. Then, the plasma state is monitored by using the emission intensity normalized by dividing the emission intensity of the detection light wavelength λ1 by the emission intensity of the reference light wavelength λ2.

  Each component of the plasma processing apparatus is controlled by the control unit 50. The control unit 50 includes a controller 51 including a computer to which each component unit is connected and controls them, a keyboard on which an operator inputs commands to manage the plasma processing apparatus, and the operating status of the plasma processing apparatus. A user interface 52 including a display for visualizing and displaying, a control program for realizing various processes executed by the plasma processing apparatus by the control of the controller 51, and each component of the plasma processing apparatus according to processing conditions And a storage unit 53 in which a program, that is, a recipe, is stored. The recipe is stored in a storage medium in the storage unit 52. The storage medium may be a fixed medium such as a hard disk or a portable medium such as a CDROM, DVD, or flash memory. Moreover, you may make it transmit a recipe suitably from another apparatus via a dedicated line, for example. Then, if necessary, an arbitrary recipe is called from the storage unit 53 by an instruction from the user interface 52 and is executed by the controller 51, so that a desired process in the plasma processing apparatus can be performed under the control of the controller 51. Done.

  Next, the main part of the control system in this embodiment will be described with reference to the block diagram of FIG.

The controller 51 of the controller 50 is connected to the components of the plasma processing apparatus such as the variable capacitor 21 that controls the impedance of the high-frequency antenna 13, the processing gas supply system 20, and the exhaust system 30. A light detector 43 is connected to the controller 51, and the light from the plasma received by the light receiver 41 is split by the spectroscope 42, and the light emission intensity of light of a specific wavelength therein is detected by the light detector 43. And the data is input to the controller 51. For example, the emission intensity is input using the peak of C ₂ as the detection light, and the nearby wavelength is input as the reference light, and the normalized emission intensity is obtained from them in the calculation unit in the controller 51. Then, the controller 51 outputs a control signal to the variable capacitor 21 based on the normalized change in emission intensity, adjusts the capacity, and controls the plasma density distribution by controlling the impedance as will be described later. Can do.

  In addition to this, the controller 51 controls at least the process gas supply system 20 based on the normalized emission intensity, controls process conditions such as the flow rate and flow rate ratio of the process gas, and changes the plasma state. It can also be controlled. In the control of the process conditions, the pressure in the processing chamber 4 can be applied as a control parameter. In this case, the exhaust device 30 is controlled based on the normalized emission intensity, and the pressure in the processing chamber 4 is adjusted. It is also possible to control the plasma state.

Next, impedance control of the high frequency antenna 13 will be described. FIG. 4 is a diagram illustrating a power feeding circuit of the high-frequency antenna 13. As shown in this figure, the high frequency power from the high frequency power supply 15 is supplied to the outer antenna circuit 61a and the inner antenna circuit 61b through the matching unit 14. Here, the outer antenna circuit 61a, because they consist of an outer antenna portion 13a and the variable capacitor 21, the impedance Z _out of the outer antenna circuit 61a, by changing the capacitance by adjusting the position of the variable capacitor 21 Can be changed. On the other hand, the inner antenna circuit 61b includes only the inner antenna portion 13b, and its impedance Z _in is fixed. At this time, the current _{I out} of the outer antenna circuit 61a can be varied in response to a change in impedance _{Z out.} The current I _in of the inner antenna circuit 61b changes according to the ratio between Z _out and Z _in . The changes _in I _out and I _in at this time are shown in FIG. As shown in the figure, by changing the _{Z out} by the volume adjustment of the variable capacitor 21, it is possible to the current _{I out} of the outer antenna circuit 61a and the current _{I in} the inner antenna circuit 61b freely changed. For this reason, the electric current which flows into the outer side antenna part 13a and the electric current which flows into the inner side antenna part 13b can be controlled, and plasma density distribution can be controlled by this. Therefore, in this embodiment, the plasma light emission state detection unit 40 detects a change in the light emission state of the plasma during the plasma processing, and controls the capacitance of the variable capacitor 21 based on the change, thereby obtaining an optimum plasma state. Can be controlled.

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

  First, after the gate valve 27 is opened, the substrate G is loaded into the processing chamber 4 by a transport mechanism (not shown) and placed on the placement surface of the placement table 23, and then the electrostatic chuck (see FIG. The substrate G is fixed on the mounting table 23 by not shown). Next, the processing gas is discharged from the processing gas supply system 20 into the processing chamber 4 through the gas discharge hole 12 a of the shower housing 11 into the processing chamber 4, and the exhaust device 30 passes the exhaust pipe 31 through the exhaust pipe 31. Is evacuated to maintain the processing chamber in a pressure atmosphere of about 0.66 to 26.6 Pa, for example. At this time, He gas is supplied to the cooling space on the back side of the substrate G as a heat transfer gas through the He gas flow path 33 in order to avoid a temperature rise or temperature change of the substrate G.

  Next, a high frequency of 13.56 MHz, for example, is applied from the high frequency power supply 15 to the high frequency antenna 13, thereby forming a uniform induction electric field in the processing chamber 4 via the dielectric wall 2. Due to the induction electric field formed in this manner, the processing gas is turned into plasma in the processing chamber 4 to generate high-density inductively coupled plasma.

  In a state where the inductively coupled plasma is generated in this manner, the LCD glass substrate G is subjected to plasma processing, for example, plasma etching processing. In the case of this plasma treatment, an optimum plasma state may change during one plasma treatment, such as when plasma etching a multilayer structure. Therefore, in the present embodiment, during the plasma processing, the plasma emission state detection unit 40 detects the plasma emission state in real time, and based on the result, the impedance of the antenna circuit of the high-frequency antenna 13 is adjusted, and the plasma state To control.

That is, the high-frequency antenna 13 has a structure having the outer antenna portion 13a in which the antenna lines are densely arranged in the outer portion and the inner antenna portion 13b in which the antenna wires are densely arranged in the inner portion as described above. Since the variable capacitor 21 is connected to the outer antenna portion 13a, the impedance of the outer antenna circuit 61a can be adjusted by adjusting the position of the variable capacitor 21. Therefore, as schematically shown in FIG. 5, it is possible to the current I _out of the outer antenna circuit 61a and the current I _in the inner antenna circuit 61b freely changed. That is, by adjusting the position of the variable capacitor 21, the current flowing through the outer antenna portion 13a and the current flowing through the inner antenna portion 13b can be controlled. The inductively coupled plasma generates plasma in a space immediately below the high-frequency antenna 13, and the plasma density at each position at that time is proportional to the electric field strength at each position, and thus the current flowing through the outer antenna portion 13a in this way. By controlling the current flowing through the inner antenna portion 13b, the plasma density distribution can be controlled. Therefore, the plasma state can be controlled by adjusting (controlling) the position of the variable capacitor 21 based on the change in the plasma emission intensity detected by the plasma emission state detection unit 40.

For example, when plasma etching a multi-layered structure, a change in plasma emission state is detected, for example, by a change in emission intensity of C ₂ at a change of layer, and the position of the variable capacitor 21 is adjusted based on the change. The plasma treatment can be performed by controlling the plasma state suitable for the new layer. In this case, the position of the variable capacitor when etching each layer is set in advance in the table, the change of the layer is detected by the change in the emission intensity, and the position is changed based on the table at that time. To be able to. Further, for example, when it is necessary to change the plasma state by switching the recipe in the middle of the layer, specifically, in order to avoid the over-etching, in the case of reducing the etching rate in the middle, for example, in advance It is possible to know the etching time of the layer and switch the recipe after a predetermined time has elapsed since the plasma emission state has changed.

  Further, the plasma light emission state detection unit 40 detects the light emission intensity of the plasma, grasps the plasma state from the detected value in real time, and controls the position of the variable capacitor 21 as needed based on this detection information, thereby changing the plasma state in real time. It is also possible to control with.

  Further, the plasma state can be controlled by controlling the process conditions such as the flow rate of the processing gas and the pressure in the processing chamber while observing the light emission state of the plasma. In this case, the control is such that a recipe in which process conditions such as the flow rate of the processing gas and the pressure in the processing chamber are set is set in advance in the table, and the change timing of the recipe is grasped by detecting a change in emission intensity. Alternatively, the plasma state is grasped in real time based on the detected value of the emission intensity, and process conditions such as the flow rate of the processing gas and the pressure in the processing chamber are controlled at any time based on this detection information, and the plasma state is controlled. It can also be controlled in real time.

  Furthermore, the position control of the variable capacitor 21 is based on the above table when the position of the variable capacitor when etching each layer is set in advance in the table, and the change of the layer is detected by the change in the emission intensity. Control of process conditions such as the flow rate of the processing gas and the pressure in the processing chamber is performed in real time based on the detected value of the emission intensity, and in real time based on the detected information. You can also

  Such impedance control and process condition control based on the position of the variable capacitor 21 not only changes the plasma state in the course of one etching, but also eliminates changes over time in the plasma state when etching is repeated a plurality of times. It is also applicable to cases.

  By the way, when the plasma state is detected by monitoring the emission intensity of the specific wavelength of the plasma in this way, conventionally, in order to eliminate various unstable elements, in addition to the emission intensity of the specific wavelength, For reference, the emission intensity of an inert gas wavelength is detected, and these quotients are calculated and normalized.

  However, when the window 32 of the plasma processing apparatus is contaminated with a deposit or the like, naturally, the transmittance decreases and the emission intensity decreases as a whole, but the emission intensity of all wavelengths does not change at a constant rate. The degree of decrease in transmittance varies depending on the wavelength, and the emission intensity for each wavelength varies greatly depending on the state of the window 32. Therefore, even if the emission intensity of the inert gas wavelength is used for reference as in the prior art, the normalized emission intensity value varies greatly depending on the state of the window 32.

For example, when the standardized emission intensity is detected using the emission intensity of C ₂ for detecting the plasma emission state and the emission intensity of an inert gas such as Ar as the reference light, As shown in FIG. 6 (a), when the window after the plasma treatment is performed 100 times is dirty, the window is greatly reduced as shown in FIG. 6 (b).

  Therefore, in this embodiment, the reference light wavelength λ2 is a wavelength in the vicinity of the detection light wavelength λ1 and has no peak, and the emission intensity of the detection light wavelength λ1 is divided by the emission intensity of the reference light wavelength λ2. The value is the normalized emission intensity. In other words, if the wavelength is in the vicinity of the detection light wavelength λ1, even if the transmittance of the window 32 changes, its transmission characteristics are almost the same as the detection light wavelength, and since it has no peak, it is standardized with high accuracy. The emission intensity can be determined. In this case, from the viewpoint of obtaining emission intensity normalized with higher accuracy, it is preferable to use a wavelength of ± 10 nm of the detection light wavelength λ2 as the reference light wavelength λ2. In this case, the emission intensity of the reference light wavelength λ2 is preferably 20% or less of the emission intensity of the detection light wavelength λ1.

For example, by using C ₂ as the detection light, and using the vicinity wavelength (within ± 10 nm) as the reference light, the emission intensity of the detection light is divided by the emission intensity of the reference light (15% of the emission intensity of C ₂ ), When the normalized emission intensity is detected, when the window 32 is new, it becomes as shown in FIG. 7A, and after the plasma treatment is performed 100 times, the window 32 becomes dirty as shown in FIG. 7B. As can be seen from the graph, the normalized emission intensity hardly changes even when the window 32 is dirty.

  Next, the result of actually performing the etching process according to the present embodiment will be described.

Here, the case where the plasma etching process is performed on the glass substrate G having the laminated structure for forming the TFT element shown in FIG. 8 will be described. In the glass substrate of FIG. 8, an undercoat film 102 is formed on a glass substrate 101, a polysilicon film 103 is formed on the undercoat film 102, an SiO ₂ film 104 serving as a gate insulating film is formed, and a gate electrode is formed thereon. After forming a metal layer, a gate electrode 105 is formed by etching, and then an SiNx film 106 is formed as an interlayer insulating film on the entire surface, and an SiO ₂ film 107 is further formed thereon as an interlayer insulating film. .

A glass substrate G having such a structure is set in the plasma processing apparatus of FIG. 1, and SiO ₂ film 107, SiNx film 106, SiO ₂ film 104, polysilicon film are formed on both sides of the gate electrode 105 of the glass substrate G. 103 was sequentially etched to form contact holes 108.

Table 1 shows the position and recipe of the variable capacitor 21 when the SiO ₂ film 107, the SiNx film 106, and the SiO ₂ film 104 are etched. As shown in Table 1, when the first SiO ₂ film 107 is etched, the first recipe (gas flow ratio SF ₆ : Ar = 1: 9, pressure 1.0 Pa, upper and lower high frequency 9 kW / 4 kW) is used as a recipe. The etching is performed by generating plasma with the position of the variable capacitor 21 set to 40%. When the SiNx film 106 is etched, the recipe is first maintained in the first recipe, and the position of the variable capacitor 21 is changed to the position of the variable capacitor 21. Etching is performed at 40%, and the recipe is changed to the second recipe (gas flow ratio C ₄ F ₈ : H ₂ : Ar = 1: 1: 3, pressure 1.3 Pa, upper and lower high frequency 5 kW / 5 kW) on the way and further variable Etching is continued by changing the plasma state by changing the position of the capacitor 21 to 45%. When the SiO ₂ film 104 is etched, the recipe is stored in the second recipe. The plasma state is changed and etching is performed by changing the position of the variable capacitor 21 to 85%.

FIG. 9 shows the emission intensity of the plasma during such a plasma etching process. Here, 388 nm, which is the peak wavelength of CN, was used as the detection light wavelength. The change from the first recipe to the second recipe and the change to 45% of the position of the variable capacitor 21 were set 5 seconds after the first emission intensity change point (change from the SiO ₂ film 107 to the SiNx film 106). . Further, when the second light emission intensity change point (change from the SiNx film 106 to the SiO ₂ film 104) was reached, the position of the variable capacitor 21 was changed to 85%. By performing etching in this way, it was possible to perform etching with a good shape. Note that the position 0 to 100% of the variable capacitor 21 corresponds to, for example, a capacitance change of 100 to 500 pF, and the current values of the outer antenna portion 13a and the inner antenna portion 13b can be changed by changing the position of the variable capacitor 21. Is possible. For example, when the position of the variable capacitor 21 is up to 50%, the outer antenna portion 13a has a larger current value than the inner antenna portion 13b, and is almost the same at 50%. Control that the current value becomes larger than that of the outer antenna portion 13a is possible.

  Next, an example in which the plasma state is monitored using a light emission intensity detection method using the detection light wavelength λ1 and the reference light wavelength λ2 will be described.

Contact hole etching using C ₄ H ₈ gas and H ₂ gas was continuously performed on 10 glass substrates in the same recipe, and the plasma state at that time was monitored. Here, using the peak wavelength of C ₂ as detection light wavelength .lambda.1, using the wavelength near the reference wavelength .lambda.2, the detection of luminescence intensity was normalized by dividing the intensity of the detected light intensity of the reference light . The time-dependent change in the luminescence intensity at that time is as shown in FIG. In general, when performing contact hole etching using a fluorocarbon gas, the etching characteristics tend to become unstable due to various changes over time in the apparatus, and even in this etching, the emission intensity tends to increase after the fifth sheet. Is seen. Next, as a result of obtaining the etching rate and the selection ratio (SiO ₂ / poly-Si) of each substrate, as shown in FIG. 10B, specifically, the first sheet has a low selection ratio. On the 10th sheet, where the underlying film disappeared and the selectivity increased, film residue due to etching stop occurred. The result shown in (b) of FIG. 10 substantially corresponds to the monitoring result of (a), and it was confirmed that the monitoring result of the plasma state reflects the actual plasma state.

Next, when contact hole etching is similarly performed using C ₄ H ₈ gas and H ₂ gas, the plasma state is monitored using the same normalized C ₂ emission intensity, and the emission intensity becomes constant. As described above, the flow rates of C ₄ H ₈ gas and H ₂ gas were controlled in real time. The change with time of the normalized emission intensity at that time is as shown in FIG. 11A, and the etching rate and the selection ratio (SiO ₂ / poly-Si) of each substrate at that time are shown in FIG. Thus, stable etching performance could be maintained from the first to the tenth sheet without causing the underlying film to be scraped off or remaining. From this, it was confirmed that the etching state can be controlled with high accuracy based on the monitoring result of the plasma state.

  Next, another embodiment of the present invention will be described.

  FIG. 12 is a horizontal sectional view schematically showing an inductively coupled plasma processing apparatus according to another embodiment of the present invention. In FIG. 12, the same components as those in FIG.

  In this plasma processing apparatus, windows 32 a and 32 b made of a light-transmitting material such as glass are provided in a portion corresponding to the processing chamber 4 on the side wall of the main body container 1. The window 32a is provided at a position corresponding to the center portion of the glass substrate G on the mounting table 23, and the window 32b is provided at a position corresponding to the edge portion. Plasma emission state detection units 40a and 40b that detect the emission state of plasma at the center and edge portions of the glass substrate G in the processing chamber 4 are provided through the windows 32a and 32b. The plasma emission state detection unit 40a includes a light receiver 41a provided adjacent to the window 32a, a spectroscope 42a connected to the light receiver 41a, and a photodetector 43a connected to the spectroscope 42a. . Similarly, the plasma emission state detection unit 40b includes a light receiver 41b provided adjacent to the window 32b, a spectroscope 42b connected to the light receiver 41b, and a photodetector 43b connected to the spectroscope 42b. doing. The light received by the light receivers 41a and 41b is split by the spectroscopes 42a and 42b, and light having a specific wavelength therein is detected by the photodetectors 43a and 43b. As a result, light from the plasma is received by the light receivers 41a and 41b, dispersed by the spectroscopes 42a and 42b, the emission intensity of light of a specific wavelength is detected by the photodetectors 43a and 43b, and the plasma state is monitored. be able to. Specifically, the emission intensity at the detection light wavelength λ1 and the emission intensity at the reference light wavelength λ2 are detected.

  The emission intensity detected by the photodetectors 43 a and 43 b is input to the control unit 70, and necessary calculation is performed by the calculation unit 71 of the control unit 70. Specifically, the emission intensity of the detection light detected by the photodetector 43a is λ1a, the emission intensity of the reference light is λ2a, the emission intensity of the detection light detected by the photodetector 43b is λ1b, and the emission of the reference light If the intensity is λ2b, the standardized emission intensity λ1b / λ2b at the edge, the standardized emission intensity λ1a / λ2a at the center, and the standardized emission intensity at the edge and the standardized emission at the center The ratio (λ1b / λ2b) / (λ1a / λ2a) with the intensity is calculated. The antenna impedance control unit 72 of the control unit 70 adjusts the position of the variable capacitor 21 so that (λ1b / λ2b) / (λ1a / λ2a) calculated by the calculation unit 71 is constant, The in-plane uniformity of the plasma processing is controlled by controlling the impedance of any one of the antenna portions. Further, the gas flow rate control unit 73 of the control unit 70 adjusts the gas flow rate so that λ1b / λ2b or λ1a / λ2a becomes constant, and stabilizes the processing parameters such as the etching rate and the selection ratio to a predetermined value with time. To control. In this case, by performing the antenna impedance control by adjusting the position of the variable capacitor 21 and the gas flow rate control alternately or simultaneously, it is possible to ensure such in-plane uniformity of plasma processing and stability of etching characteristics. it can.

  In the above embodiment, a variable capacitor is used in the range of 100 to 500 pF. However, when the capacitor is inserted into the antenna line or the value of the capacitors 18a and 18b grounded at the outer end of the antenna line, the capacitor By selecting an appropriate value, the variable range of the variable capacitor effective for controlling the plasma density distribution can be changed. For example, a variable capacitor in a part or all of the range of 10 to 2000 pF is sufficient. Applicable.

  Next, a specific example of controlling the adjustment parameter and the processing gas parameter will be described so that the plasma state being controlled becomes the target plasma state.

  In order to control the plasma state being controlled to be a target plasma state, for example, a target emission intensity (hereinafter referred to as target emission intensity) is determined, and a detected emission intensity (hereinafter referred to as control) to be controlled is determined. The adjustment parameters such as the position of the variable capacitor, the processing gas flow rate, the ratio, and the processing gas parameters such as the pressure in the processing chamber may be controlled as needed so that the emission intensity follows the target emission intensity.

  As a method for controlling the adjustment parameter and the processing gas parameter as needed, for example, control using a deviation between the target emission intensity and the control emission intensity can be mentioned. Here, the deviation is defined as a deviation amount between the target light emission intensity and the control light emission intensity (a difference between the target light emission intensity and the control light emission intensity divided by the target light emission intensity).

(First example)
For example, when controlling the flow rate of the processing gas as the processing gas parameter using the deviation, there is a method of controlling the flow rate of the processing gas to be controlled (hereinafter referred to as a feedback flow rate) as a linear function of the deviation. FIG. 13 shows an example of linear function control.

  The vertical axis in FIG. 13 is the feedback flow rate, and the horizontal axis is the deviation. In this example, when the deviation is 10%, the feedback flow rate is 3 sccm. Since it is a linear function control, the feedback flow rate increases in proportion to the magnitude of the deviation.

(Second example)
In the linear function control, since the ratio of the feedback flow rate to the deviation amount is constant, it is necessary to set a large proportional constant of the linear function in order to perform feedback quickly for a large deviation. However, if the proportionality constant is set large, there is a possibility that the feedback flow rate becomes larger than necessary for a small deviation. As a result, for example, as shown in FIG. 14, the control light emission intensity may repeatedly increase and decrease (hunting phenomenon) near the target light emission intensity.

  In the second example, in order to suppress the hunting phenomenon of the control emission intensity as described above, when the deviation is large, the ratio of the feedback flow rate to the deviation amount is large, and when the deviation is small, the ratio of the feedback flow rate to the deviation amount is small. This is an example.

  In the second example, the feedback flow rate is controlled as an exponential function of deviation. FIG. 15 shows an example of exponential function control.

  The vertical axis in FIG. 15 is the feedback flow rate, and the horizontal axis is the deviation. Also in this example, when the deviation is 10%, the feedback flow rate is set to 3 sccm. However, because of the exponential function control, the feedback flow rate increases exponentially with respect to the magnitude of the deviation.

  As described above, according to the exponential function control, when the deviation is large, the ratio of the feedback flow rate to the deviation amount can be increased, and when the deviation is small, the ratio of the feedback flow rate to the deviation amount can be reduced. As a result, when the deviation is large, the control light emission intensity can be made to follow the target light emission intensity at a high speed (high-speed tracking), and as the control light emission intensity approaches the target light emission intensity, the control light emission intensity is slowly changed from the target light emission intensity. (Fine adjustment follow-up). Therefore, as shown in FIG. 16, the hunting phenomenon of the control light emission intensity can be suppressed.

The present invention can be variously modified without being limited to the above embodiment. For example, in the above-described embodiment, an example in which a variable capacitor is connected to the outer antenna portion has been described. However, the present invention is not limited to this, and a variable capacitor 21 ′ may be provided on the inner antenna portion 13b side as shown in FIG. Good. In this case, the impedance Z _in of the inner antenna circuit 61b can be changed by adjusting the position of the variable capacitor 21 ′ and changing the capacitance thereof, whereby the outer antenna circuit 61a is changed as shown in FIG. and the current _{I out,} it is possible to vary the current _{I in} the inner antenna circuit 61b.

  Further, the structure of the high frequency antenna is not limited to the above structure, and various other patterns having the same function can be adopted. In the above embodiment, the high-frequency antenna is divided into an outer antenna portion that forms plasma on the outer side and an inner antenna portion that forms plasma on the inner side. Is possible. Further, the present invention is not limited to the case where the plasma forming positions are divided into different antenna portions, but may be divided into antenna portions having different plasma distribution characteristics. Furthermore, in the above-described embodiment, the case where the high-frequency antenna is divided into two, the outer side and the inner side, is shown, but it may be divided into three or more. For example, it can be divided into three parts: an outer part, a central part, and an intermediate part thereof.

  Further, although a variable capacitor is provided to adjust the impedance, other impedance adjusting means such as a variable coil may be used.

  Furthermore, the method for detecting the plasma emission intensity is not limited to the above-described embodiment. For example, the emission intensity of a specific wavelength may be detected using a filter instead of using a spectroscope.

  Furthermore, the method for controlling the flow rate of the processing gas using the deviation between the target light emission intensity and the control light emission intensity is not limited to the linear function control or the exponential function control. Is graphed as a deviation that is a deviation amount between the target plasma state and the in-control plasma state, as long as the relationship between the deviation and the feedback amount can be expressed by a downwardly convex curve like an exponential curve . For example, examples of a downwardly convex curve include a parabola, a hyperbola, and the like, and can be controlled using an exponential function, a parabola, a function that draws a hyperbola, or an equation.

  Furthermore, in the above-described embodiment, the case where the plasma processing is the plasma etching processing has been described as an example. However, the present invention is not limited to this and can be applied to other plasma processing apparatuses such as ashing and CVD film formation. Furthermore, although the FPD substrate is used as the substrate to be processed, the present invention is not limited to this and can be applied to processing other substrates such as a semiconductor wafer.

  The above-described plasma emission intensity detection method and processing gas supply system control method can be used not only for inductively coupled plasma processing apparatuses but also for plasma processing apparatuses such as capacitively coupled plasma processing apparatuses.

Sectional drawing which shows the inductively coupled plasma processing apparatus which concerns on one Embodiment of this invention. The top view which shows the high frequency antenna used for the inductively coupled plasma processing apparatus of FIG. The block diagram which shows the principal part of the control system in this embodiment. The figure which shows the electric power feeding circuit of the high frequency antenna used for the inductively coupled plasma processing apparatus of FIG. Graph showing changes in current I _in the current I _out and the inner antenna circuitry outside the antenna circuit due to impedance changes in the feeding circuit of FIG. The figure which compares and compares the detected emitted light intensity when the light emission intensity of Ar is used as reference light, when the window is not dirty and when it is dirty. The figure which compares and compares the detected light emission intensity in the case where the wavelength near the detection light is used as reference light, when the window is not dirty and when it is dirty. Sectional drawing which shows the glass substrate which has the laminated structure used when actually performing the plasma etching process according to embodiment of this invention. The graph which shows the emitted light intensity of the plasma at the time of carrying out the plasma etching of the laminated structure of FIG. The figure which shows the actual example of the time-dependent change of the emitted light intensity at the time of using the emitted light intensity which normalized the emitted light intensity of the detection light with the emitted light intensity of the reference light of the wavelength adjacent to it, and the etching characteristic in that case. The figure which shows the actual example of the time-dependent change of the emitted light intensity at the time of using the emitted light intensity which normalized the emitted light intensity of the detection light with the emitted light intensity of the reference light of the wavelength adjacent to it, and the etching characteristic in that case. The horizontal sectional view which shows typically the inductively coupled plasma processing apparatus which concerns on other embodiment of this invention. Diagram showing an example of linear function control Diagram showing the results of linear function control Diagram showing an example of exponential function control Diagram showing the result of exponential function control The figure which shows the other example of the electric power feeding circuit of a high frequency antenna. Graph showing changes in current I _in the current I _out and the inner antenna circuitry outside the antenna circuit due to impedance changes in the feeding circuit of Figure 17.

Explanation of symbols

1; Main body container 2; Dielectric wall (dielectric member)
3; Antenna chamber 4; Processing chamber 13; High-frequency antenna 14; Matching device 15; High-frequency power source 20; Processing gas supply system 21; Variable sensor capacitor (adjustment means)
23; Mounting table 30; Exhaust device 32; Window 40; Plasma emission state detection unit 41; Light receiver 42; Spectroscope 43; Photo detector 50; Control unit 51; Controller 52; User interface 53; Memory unit 61a; Circuit 61b; inner antenna circuit G; substrate

Claims (23)

A processing chamber for accommodating a substrate to be processed and performing plasma processing;
A mounting table on which a substrate to be processed is mounted in the processing chamber;
A processing gas supply system for supplying a processing gas into the processing chamber;
An exhaust system for exhausting the processing chamber;
A high-frequency antenna that is disposed outside the processing chamber via a dielectric member and forms an induction electric field in the processing chamber by being supplied with high-frequency power;
Plasma detecting means for detecting a state of inductively coupled plasma formed in the processing chamber by the induction electric field;
Adjusting means for adjusting impedance of an antenna circuit including the high-frequency antenna;
Control means for controlling the adjustment means based on plasma detection information of the plasma detection means, and controlling the plasma state,
The substrate to be processed has a plurality of laminated layers, and the plasma treatment is an etching process for etching the plurality of laminated layers,
An adjustment parameter of the adjustment means for obtaining an optimum plasma state for each layer of the plurality of stacked layers is preset, and the control means detects a change in layer based on detection information by the plasma detection means. And an adjustment parameter of the adjusting means corresponding to a new etching target layer is selected. The high-frequency antenna has a plurality of antenna portions that form induction electric fields having different electric field strength distributions in the processing chamber when high-frequency power is supplied,
The adjusting means is connected to at least one of the antenna circuits including the antenna units, and adjusts the impedance of the connected antenna circuit.
The control means controls the adjustment means to control current values of the plurality of antenna units, thereby controlling a plasma density distribution of inductively coupled plasma formed in the processing chamber. Item 2. The inductively coupled plasma processing apparatus according to Item 1.   The inductively coupled plasma processing apparatus according to claim 2, wherein the adjusting unit includes a variable capacitor. According to any one of claims 1 to 3, characterized in that the adjustment parameter of the adjusting means optimum plasma density distribution is obtained for each layer of the stacked plurality of layers are set in advance Inductively coupled plasma processing apparatus. It said control means, based on the information detected by the plasma detecting means, any one of claims 1 to 4 in which a plasma state and controls the adjustment parameter of the adjustment means in real time so as to properly 2. The inductively coupled plasma processing apparatus according to item 1.   In addition to controlling the adjusting means based on the plasma detection information of the plasma detection means, the control means controls the processing gas supply system based on the plasma detection information of the plasma detection means, and controls the plasma state. The inductively coupled plasma processing apparatus according to any one of claims 1 to 3, wherein the inductively coupled plasma processing apparatus is controlled. An adjustment parameter of the adjustment means for obtaining an optimum plasma density distribution for each layer of the plurality of stacked layers, and a processing gas parameter including a processing gas flow rate and a ratio by the processing gas supply system are preset, and the control means based on the information detected by the plasma detecting means detects a turn of the layers, in claim 6, wherein selecting the adjustment parameter and the process gas parameter of the adjusting means corresponding to the new layer to be etched The inductively coupled plasma processing apparatus described. Based on the detection information from the plasma detection means, the control means sets the adjustment parameters of the adjustment means, the processing gas flow rate by the processing gas supply system, and the processing gas parameters including the ratio in real time so that the plasma state is appropriate. The inductively coupled plasma processing apparatus according to claim 6 or 7 , wherein the inductively coupled plasma processing apparatus is controlled. A plurality of the plasma detection means are provided corresponding to different positions of the substrate to be processed,
The control means controls the adjustment means so that detection information of the plurality of plasma detection means is constant so that plasma processing characteristics are uniform in a plane of the substrate to be processed, and the plurality of plasmas 9. The inductively coupled plasma processing apparatus according to claim 6, wherein the plasma processing characteristics are controlled by controlling the processing gas supply system based on any of the detection information of the means. . The plasma detecting means, wherein a light receiving portion for receiving the light emitted from the plasma, from claim 1, characterized in that it comprises a light detector for detecting the emission intensity of light of a predetermined wavelength from the light received by the light receiver Item 10. The inductively coupled plasma processing apparatus according to any one of Items 9 to 9 . The light detection unit detects detection light having a predetermined wavelength and reference light having a wavelength in the vicinity of the detection light wavelength,
11. The inductively coupled plasma processing apparatus according to claim 10 , wherein an emission intensity obtained by normalizing an emission intensity of the detection light with an emission intensity of the reference light is used as the state of the inductively coupled plasma. A high-frequency antenna for forming an induction electric field in the processing chamber by mounting a substrate to be processed on a mounting table provided in the processing chamber and supplying high-frequency power to the outside of the processing chamber via a dielectric member A processing gas is supplied to the processing chamber, and an inductively coupled plasma of the processing gas is formed in the processing chamber by an induction electric field formed by supplying high-frequency power to the high-frequency antenna, and the substrate to be processed is formed by the plasma. An inductively coupled plasma processing method for performing plasma processing on
The substrate to be processed has a plurality of laminated layers, and the plasma treatment is an etching process for etching the plurality of laminated layers,
Preliminarily set adjustment parameters of the antenna circuit including the high-frequency antenna that can obtain an optimal plasma state for each of the plurality of layers stacked,
Detecting a state of inductively coupled plasma formed in the processing chamber by the induction electric field;
Based on the detection information, the change of the layer is detected, the impedance of the antenna circuit including the high-frequency antenna is adjusted by selecting the adjustment parameter corresponding to the new etching target layer, and the plasma state is controlled. A feature of the inductively coupled plasma processing method. The high-frequency antenna has a plurality of antenna portions that form induction electric fields having different electric field strength distributions in the processing chamber when high-frequency power is supplied, and includes the antenna portions based on the detection information. and adjusting at least one of the impedance of the antenna circuit, according to claim wherein the plurality of controlling the current value of the antenna unit, and controlling the plasma density distribution of the inductively coupled plasma formed in the processing chamber 12 The inductively coupled plasma processing method described in 1. The inductively coupled plasma processing method according to claim 13 , wherein the impedance is adjusted by adjusting a capacitance of a variable capacitor provided in the antenna circuit for impedance adjustment. Induction according to any one of claims 12 to 14, characterized in that Sulfur butterfly clause parameters before each optimum plasma density distribution for each to obtain a plurality of layers wherein the laminate is set in advance Combined plasma processing method. The inductively coupled plasma according to any one of claims 12 to 15 , wherein the adjustment parameter is controlled in real time so that a plasma state is appropriate based on information detected by the plasma detection means. Processing method. In addition to adjusting the impedance of the antenna circuit including the high-frequency antenna based on the detection information of the inductively coupled plasma, the supply of the processing gas is controlled based on the detection information of the inductively coupled plasma, and the plasma state is controlled. The inductively coupled plasma processing method according to claim 12, wherein the inductively coupled plasma processing method is performed. A process gas parameter including the adjustment parameter and a process gas flow rate and a ratio for obtaining an optimum plasma density distribution for each layer of the plurality of stacked layers is set in advance, and based on the detection information of the state of the inductively coupled plasma detects the turn of the layers, inductively coupled plasma processing method according to claim 17, characterized by selecting the adjustment parameter and the process gas parameter corresponding to the new layer to be etched. Based on the information detected by the plasma detecting means, according to claim 17 wherein the adjustment parameters in real time such that the plasma state is correct and treatment gas flow rate, and controlling the process gas parameters including a ratio to or The inductively coupled plasma processing method according to claim 18 . The state of the inductively coupled plasma is detected at a plurality of locations corresponding to different positions of the substrate to be processed, and the impedance of the antenna circuit including the high frequency antenna is controlled so that the detection information of these detection means is constant. The plasma processing characteristics are made uniform in the plane of the substrate to be processed, and the supply of the processing gas is controlled based on any of the plurality of detection information to control the plasma processing characteristics. The inductively coupled plasma processing method according to any one of claims 17 to 19. The inductive detection of the coupled plasma state, receives light from plasma, according to claim 20 claim 12, characterized in that it is carried out by detecting the light emission intensity of the light of a predetermined wavelength from the received light The inductively coupled plasma processing method according to any one of the above. A detection light having a predetermined wavelength and a reference light having a wavelength in the vicinity of the detection light wavelength are detected, and an emission intensity obtained by normalizing the emission intensity of the detection light with the emission intensity of the reference light is set as the state of the inductively coupled plasma. The inductively coupled plasma processing method according to claim 21 , wherein the inductively coupled plasma processing method is used. A storage medium that operates on a computer and stores a program for controlling an inductively coupled plasma processing apparatus, the program being executed by the inductively coupled plasma processing method according to any one of claims 12 to 22. As described above, a storage medium that causes a computer to control the inductively coupled plasma processing apparatus.

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