JP6317138B2 - High frequency plasma processing apparatus and high frequency plasma processing method - Google Patents

Description

  The present invention relates to a high frequency plasma processing apparatus and a high frequency plasma processing method for performing plasma processing on a substrate to be processed using high frequency power.

  In a manufacturing process of a flat panel display (FPD) such as a semiconductor substrate or a liquid crystal display device (LCD), there is a step of performing plasma processing such as plasma etching or film formation on the substrate, and such plasma processing is performed. In addition, various plasma processing apparatuses such as a plasma etching apparatus and a plasma CVD apparatus are used. A plasma processing apparatus generally generates plasma using high-frequency power.

  As a plasma processing apparatus using high-frequency power, an inductively coupled plasma (ICP) processing apparatus having a great advantage that a high-density plasma can be obtained with a high degree of vacuum has recently attracted attention.

  As an inductively coupled plasma processing apparatus, an antenna chamber is provided on the upper side of a dielectric window that constitutes the top wall of a processing container that accommodates a substrate to be processed, a high-frequency antenna is disposed therein, and a processing gas is introduced into the processing container. In addition, a high frequency power is supplied to the high frequency antenna to generate inductively coupled plasma in the processing vessel, and a predetermined plasma treatment is performed on the substrate to be processed by the inductively coupled plasma (for example, patents). Reference 1).

JP 2004-55895 A

  By the way, although the high frequency antenna in the antenna chamber is held by an insulator, it has been found that creeping discharge may occur mainly in the portion of the insulator when high frequency power is applied to the high frequency antenna. When creeping discharge occurs, there is a possibility that the deterioration of the insulator progresses and leads to dielectric breakdown.

  Such creeping discharges may occur not only in the inductively coupled plasma processing apparatus, but also in an insulating portion that holds an electrode to which high frequency power is applied in a parallel plate type capacitively coupled plasma processing apparatus.

  The present invention has been made in view of such circumstances, and provides a high-frequency plasma processing apparatus and a high-frequency plasma processing method in which creeping discharge is unlikely to occur in an insulating portion that contacts an electrode to which high-frequency power is applied. Objective.

In order to solve the above-mentioned problems, a first aspect of the present invention is a high-frequency plasma processing apparatus having an electrode in contact with an insulator, applying high-frequency power to the electrode, and plasma-treating the substrate with plasma generated thereby. A treatment chamber for performing plasma treatment on the substrate, an electrode housing portion for housing the electrode in contact with the insulator, a high-frequency power source for applying high-frequency power to the electrode, and the inside of the electrode housing portion Humidity adjustment means for adjusting the humidity of the electrode housing portion so that creeping discharge does not occur , the humidity adjustment means has a dry gas supply mechanism for supplying a dry gas to the electrode housing portion, And when the dry gas is supplied to the electrode housing part from the dry gas supply mechanism and the hygrometer for measuring the humidity in the electrode housing part, the measured value of the hygrometer exceeds a predetermined threshold value. In the not allow the operation of the high frequency power source, high-frequency plasma processing apparatus the measured value of the humidity meter, characterized by further comprising a discharge preventing portion for permitting the operation of the high frequency power source in the case of equal to or smaller than the threshold value I will provide a.

  A second aspect of the present invention is a high-frequency plasma processing apparatus that has an electrode in contact with an insulator, applies high-frequency power to the electrode, and plasma-processes the substrate with the plasma generated thereby. A plasma processing chamber, an electrode housing portion that houses the electrode in contact with the insulator, a high-frequency power source that applies high-frequency power to the electrode, and humidity in the electrode housing portion. Humidity adjusting means for adjusting so as not to cause creeping discharge in the section, the humidity adjusting means has a dry gas supply mechanism for supplying dry gas to the electrode accommodating portion, and the electrode accommodating portion A flow rate sensor for measuring a flow rate when the dry gas is supplied, and a humidity in the electrode housing portion when the dry gas is flowed from the dry gas supply mechanism to the electrode housing portion at a predetermined flow rate is predetermined. The required time until the value becomes less than or equal to the value is set, and after the flow rate sensor reaches the predetermined flow rate, the operation of the high frequency power supply is not permitted until the required time has elapsed, and after the required time has elapsed, There is provided a high-frequency plasma processing apparatus, further comprising a discharge prevention unit that permits operation.

In the second aspect, the discharge prevention unit does not allow the operation of the high-frequency power supply when an abnormal flow rate of the dry gas is detected by the flow sensor and the abnormal time exceeds a predetermined time. Can do.

In the first and second aspects, the high-frequency plasma processing apparatus is an inductively coupled plasma processing apparatus, the electrode is a high-frequency antenna that forms an induction magnetic field in the processing chamber, and the electrode housing portion It can be set as the structure which is the antenna chamber which accommodates the said high frequency antenna provided above the process chamber.

According to a third aspect of the present invention, there is provided a high-frequency plasma processing method for applying a high-frequency power from a high-frequency power source to an electrode in contact with an insulator, and plasma-treating a substrate in a processing chamber by plasma generated thereby. the electrode of the contact state accommodated in the electrode accommodating portion, the humidity in the electrode accommodating unit, while adjusting to creeping discharge in the electrode receptacle does not occur, have rows plasma treatment, adjustment of the humidity The measurement is performed by supplying a dry gas to the electrode housing portion, and measuring the humidity in the electrode housing portion with a hygrometer, and when the dry gas is supplied to the electrode housing portion, the measured value of the hygrometer is If it exceeds the predetermined threshold value, the not allow the operation of the high frequency power source, high-frequency plasma measurements of the hygrometer and permits the operation of the high frequency power source in the case of equal to or smaller than the threshold value To provide a management method.

  According to a fourth aspect of the present invention, there is provided a high-frequency plasma processing method in which high-frequency power is applied from a high-frequency power source to an electrode in contact with an insulator, and plasma processing is performed on a substrate in a processing chamber by plasma generated thereby. The electrode in a state of contact with the electrode is accommodated in an electrode accommodating portion, the humidity in the electrode accommodating portion is adjusted so that creeping discharge does not occur in the electrode accommodating portion, plasma treatment is performed, and the humidity adjustment is performed as follows: This is performed by supplying a dry gas to the electrode housing portion, and a flow rate when the dry gas is supplied to the electrode housing portion is measured by a flow sensor, and the dry gas is caused to flow through the electrode housing portion at a predetermined flow rate. The required time until the humidity in the electrode housing part becomes equal to or lower than a predetermined threshold is set, and after the flow rate sensor reaches the predetermined flow rate, the required time elapses. Serial not allow the operation of high-frequency power source, to provide a high frequency plasma processing method and permits the operation of the high frequency power supply after the lapse the time required.

In the fourth aspect, when the flow rate abnormality of the dry gas is detected by the flow rate sensor and the abnormal time exceeds a predetermined time, the operation of the high-frequency power source can not be permitted.

In the third and fourth aspects, the high-frequency plasma is inductively coupled plasma, the electrode is a high-frequency antenna that forms an induction magnetic field in the processing chamber, and the electrode housing portion is located above the processing chamber. It can be set as the structure which is the antenna room which accommodates the said high frequency antenna provided in.

  According to the present invention, since the humidity adjusting means for adjusting the humidity in the electrode housing portion so as to prevent the occurrence of the creeping discharge in the electrode housing portion is provided, the occurrence of the creeping discharge in the electrode housing portion is extremely effectively suppressed. be able to.

It is sectional drawing which shows the high frequency plasma processing apparatus which concerns on one Embodiment of this invention. It is sectional drawing which shows the structure of the test piece used for the experiment which confirms creeping discharge. It is a figure which shows the relationship between the humidity in an antenna chamber, and pressure | voltage resistance. (A) is a figure which shows the relationship between the water vapor amount (absolute humidity) and pressure | voltage resistance when temperature is changed, (b) is a figure which shows the relationship between humidity (relative humidity) and pressure | voltage resistance when temperature is changed. It is. It is a figure which shows the relationship between humidity and pressure | voltage resistance when the distance between electrodes is 20 mm and 30 mm. It is a figure which shows the relationship between dry air supply time at the time of providing a punching plate in the exhaust port of an antenna chamber, and humidity. It is a figure which shows the relationship between dry air supply time at the time of providing an exhaust fan in the exhaust port of an antenna chamber, and humidity. It is a figure which shows the relationship between the supply time of dry air, and humidity at the time of changing the pressure of dry air.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a sectional view showing a high-frequency plasma processing apparatus according to an embodiment of the present invention.

  This high-frequency plasma processing apparatus is configured as an inductively coupled plasma apparatus. For example, a metal film for forming a thin film transistor on an FPD substrate such as a liquid crystal display (LCD), an electroluminescence (EL) display, etc., ITO It is used for etching of films, oxide films, etc., and ashing of resist films.

This high-frequency 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 electrically grounded by a ground wire 1a. The main body container 1 is vertically divided into an antenna chamber 3 and a processing chamber 4 by a dielectric wall (dielectric window) 2. Therefore, the dielectric wall 2 functions as the top 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, for example, and has a function as a beam for supporting the dielectric wall 2 from below. The dielectric wall 2 may be divided by the shower casing 11. The shower casing 11 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. This shower casing 11 is electrically grounded.

  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 discharge 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 high frequency (RF) antenna 13 which is a high frequency electrode is provided. A feed line 19 is connected to the high-frequency antenna 13, and a matching unit 14 and a high-frequency power source 15 are connected to the feed line. The high-frequency antenna 13 is configured as a spiral planar antenna, for example. The antenna wire 13a that constitutes the high-frequency antenna 13 is supported by the insulator 17 and pressed by the insulator 17 so as to be insulated from each other. Then, a high frequency power having a frequency of 13.56 MHz, for example, is supplied from the high frequency power supply 15 to the high frequency antenna 13, thereby generating an induction electric field in the processing chamber 4. The induction electric field supplies the high frequency antenna 13 from the shower housing 11. The processing gas is turned into plasma. Although the material of the insulator 17 is not particularly limited, a resin material having a relatively high rigidity, for example, a polyetherimide (PEI) resin (trade name: Ultem (registered trademark)) can be preferably used.

  A mounting table 23 for mounting a rectangular FPD substrate (hereinafter simply referred to as a substrate) G is provided below the processing chamber 4 so as to face the high-frequency antenna 13 with the dielectric wall 2 interposed therebetween. It has been. The mounting table 23 is made of a conductive material, for example, aluminum whose surface is anodized. The 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 and is supported by an elevating mechanism (not shown) disposed outside the main body container 1. When the substrate G is loaded and unloaded, the mounting table 23 is driven in the vertical direction by the elevating mechanism. The Between the insulator frame 24 that houses the mounting table 23 and the bottom of the main body container 1, a bellows 26 that hermetically surrounds the support column 25 is disposed. Airtightness in the chamber 4 is guaranteed. In addition, on the side wall 4a of the processing chamber 4, a loading / unloading port 27a for loading and unloading the substrate G and a gate valve 27 for opening and 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 6 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 self-bias generated by the bias high-frequency power.

  Furthermore, 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 are provided in the mounting table 23 (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 and the like is connected to the bottom of the processing chamber 4 through an exhaust pipe 31. The exhaust chamber 30 exhausts the processing chamber 4, and the inside of the processing chamber 4 is set and maintained in a predetermined vacuum atmosphere (for example, 1.33 Pa) during the plasma processing.

  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 41 for supplying He gas as a heat transfer gas with 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.

  The high-frequency plasma processing apparatus of the present embodiment has a dry air supply mechanism 58 as humidity adjusting means for adjusting the humidity in the antenna chamber 3. The dry air supply mechanism 58 includes a dry air supply source 51, a dry air pipe 52, and a flow rate adjustment valve 53. In the dry air supply mechanism 58, the dry air is supplied from the dry air supply source 51 into the antenna chamber 3 through the dry air pipe 52, and the flow rate of the dry air is adjusted by the flow rate adjusting valve 53, thereby reducing the humidity in the antenna chamber 3. It is possible.

  The dry air piping 52 is provided with a flow rate sensor 54. The flow sensor 54 is used as monitoring means for monitoring whether a necessary amount of dry air is actually supplied. The antenna chamber 3 is provided with a hygrometer 56 for measuring the humidity therein.

  The antenna chamber 3 is provided with a cover 33 that can be opened and closed, and an exhaust port 55 is provided on the side thereof. The exhaust port 55 is provided with a punching plate, an exhaust fan, or the like for shielding the high frequency supplied into the antenna chamber 3, and has a structure capable of exhausting while suppressing the inflow of high humidity air from the outside as much as possible. ing. The antenna chamber 3 may be sealed without providing the exhaust port 55.

  The information of the flow sensor 54 and the information of the hygrometer 56 are input to the discharge prevention unit 57, and when the flow rate of the dry air is less than a specified amount or when the humidity in the antenna chamber 3 exceeds a predetermined threshold, the high frequency power supply 15 An interlock signal is output to the high-frequency power supply 15 so as not to operate. Further, it is possible to give a control signal from the discharge prevention unit 57 to the flow rate adjustment valve 53.

  Each component of the high-frequency plasma processing apparatus, for example, the gas supply system, the high-frequency power supplies 15 and 29, the exhaust device 30, and the like are controlled by the overall control unit 60. The overall control unit 60 includes a main body unit including a microprocessor (computer), and a user interface unit and a storage unit connected to the main body unit. The user interface unit includes a keyboard for performing an input operation such as command input for managing the plasma processing apparatus by an operator, a display for visualizing and displaying the operating status of the plasma processing apparatus, and the like. The storage unit is a control program for realizing various processes executed by the high-frequency plasma processing apparatus by controlling the main body part, or a program for causing each component of the plasma processing apparatus to execute processes according to processing conditions, that is, Processing recipes are stored. Programs such as processing recipes are stored in a storage medium in the storage unit. The storage medium may be a hard disk built in the computer, or a portable medium such as a CDROM or flash memory. Moreover, you may make it transmit a recipe suitably from another apparatus via a dedicated line, for example. Then, a predetermined processing recipe is called from the storage unit by an instruction from the user interface or the like, and the predetermined processing is executed by the high-frequency plasma processing apparatus.

  Next, a processing operation when performing plasma processing, for example, plasma etching processing, on the substrate G using the high-frequency plasma processing apparatus configured as described above will be described.

  First, the substrate G is loaded into the processing chamber 4 from the loading / unloading port 27a with the gate valve 27 opened, and is loaded on the loading surface of the loading table 23. The substrate G is fixed on the mounting table 23 (not shown). Next, the processing gas supplied from the processing gas supply system 20 into the processing chamber 4 is discharged into the processing chamber 4 from the gas discharge holes 12 a of the shower housing 11 and processed by the exhaust device 30 through the exhaust pipe 31. By evacuating the inside of the chamber 4, the inside of the processing chamber is maintained 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 via the He gas flow path 41 in order to avoid a temperature rise or temperature change of the substrate G.

  Next, a high frequency of, for example, 13.56 MHz is applied from the high frequency power supply 15 to the high frequency antenna 13 which is a high frequency electrode, thereby generating a uniform induction electric field in the processing chamber 4 via the dielectric wall 2. Due to the induction electric field generated in this way, the processing gas is turned into plasma in the processing chamber 4 and high-density inductively coupled plasma is generated. By this plasma, for example, a plasma etching process is performed on the substrate G as a plasma process.

  By the way, when performing such plasma processing, it has been a problem that creeping discharge is generated in a high-frequency antenna that is a high-frequency electrode in the antenna chamber. Creeping discharge is a phenomenon in which discharge occurs along the surface of an insulator when a high voltage is applied to an electrode placed on the insulator. That is, in the apparatus of FIG. 1, in the antenna chamber 3, the high frequency antenna 13 is attached with the antenna wire 13 a supported by the insulator 17, so that high frequency high frequency power is applied from the high frequency power supply 15. As a result, discharge may occur along the insulator 17.

  It has been found that the cause of the creeping discharge is that the humidity in the clean room where the apparatus is installed is high. That is, it has been found that the clean room is maintained at a relatively high humidity in order to prevent static electricity, and therefore creeping discharge is likely to occur in the antenna room.

  At low humidity, space discharge occurs between the electrodes. In this case, the withstand voltage between the electrodes is determined by the spatial distance, and is approximately 1 kV / mm. However, when the humidity increases, the withstand voltage of the space discharge decreases, and when the humidity increases further, creeping discharge occurs at a voltage about 1/5 of the voltage at which the space discharge occurs. In order to confirm this, as shown in FIG. 2, a test piece in which an electrode 102 is arranged on an insulator 101 with an interval of 20 mm and an insulator 104 having a slit 103 is arranged thereon is used. A voltage was applied between the electrodes 102 at a temperature of 25 ° C., and an experiment was conducted on humidity at which creeping discharge occurs. Note that as the insulators 101 and 104, polyetherimide (PEI) resin (trade name: Ultem (registered trademark)) was used. As a result, as shown in FIG. 3, it was confirmed that when the humidity (relative humidity) exceeds 50%, the withstand voltage rapidly decreases and creeping discharge occurs. Further, as a result of investigating the relationship between the amount of water vapor (absolute humidity) and the withstand voltage by changing the temperature, as shown in FIGS. 4A and 4B, the withstand voltage decreases at 25 ° C. (a creeping discharge occurs. ) Even with the amount of water vapor, it was confirmed that the pressure resistance was maintained high when the temperature was raised and the relative humidity was lowered. From this, it became clear that it was not the absolute humidity but the relative humidity that contributed to the creeping discharge. Furthermore, as shown in FIG. 5, it was found that the withstand voltage does not change much even when the distance between the electrodes (conductors) is widened when the humidity at which creeping discharge occurs.

  Therefore, in the present embodiment, a dry air supply mechanism 58 is provided as a humidity adjusting means for adjusting the humidity in the antenna chamber 3, and the humidity (relative humidity) in the antenna chamber 3 is managed so as to be less likely to cause creeping discharge. .

  As a specific method, the first method closes the cover 33 of the antenna chamber 3, flows dry air at a predetermined flow rate from the dry air supply source 51, measures the humidity (relative humidity) of the antenna chamber 3 with the hygrometer 56, The measured value is sent to the discharge prevention unit 57, and the discharge prevention unit 57 determines whether the measured value of the humidity exceeds a value set as a threshold value for preventing creeping discharge in the antenna chamber 3, and the value is a threshold value. Until it becomes below, an interlock signal is outputted from the discharge prevention unit 57 so that the high frequency power supply 15 does not operate, and when the measured value of the hygrometer 56 becomes below the threshold value, an interlock release signal is outputted, and the high frequency power supply 15 is turned off. Let it be in an operable state (ready state).

  After the measured value of the hygrometer 56 becomes lower than the threshold value, the humidity in the antenna chamber 3 is continuously measured by the hygrometer 56, and the measured value is set as a threshold value at which creeping discharge does not occur in the antenna chamber 3. The flow rate adjusting valve 53 may be controlled by the discharge preventing unit 57 so that the flow rate of the dry air from the dry air supply source 51 is controlled in real time so that the predetermined value does not exceed the predetermined value.

  In the second method, when the cover 33 of the antenna chamber 3 is closed and dry air is supplied at a predetermined flow rate from the dry air supply source 51, the time until the humidity in the antenna chamber 3 becomes a predetermined threshold or less is grasped in advance. The discharge prevention unit 57 is set, the cover of the antenna chamber 3 is actually closed, the dry air is supplied from the dry air supply source 51, and the discharge is performed until the set time elapses after the flow rate sensor 54 reaches a predetermined flow rate. An interlock signal is output from the prevention unit 57 so that the high frequency power supply 15 does not operate, and an interlock release signal is output after the set time has elapsed, so that the high frequency power supply 15 is in an operable state (ready state).

  On the other hand, if the flow rate sensor 54 detects a dry air flow rate abnormality (no dry air is flowing or the flow rate of the dry air is less than a specified amount), if the abnormal time exceeds a predetermined time, the humidity exceeds the threshold value. The time is set in the discharge prevention unit 57 in advance, and an interlock signal is output so that the high frequency power supply 15 is not operated (plasma is not generated) when the abnormal time exceeds the set time.

  In the second method, humidity management can be performed without using the hygrometer used in the first method. Further, the first method and the second method may be used in combination.

  By managing the humidity in the antenna chamber 3 below the threshold using the first method or the second method described above, it is possible to extremely effectively suppress the occurrence of creeping discharge in the antenna chamber 3.

  In any of the above methods, as shown in FIG. 3 described above, the occurrence of creeping discharge can be suppressed if the humidity (relative humidity) is 50% or less. The results in FIG. 3 are the results when polyetherimide (PEI) resin (trade name: Ultem (registered trademark)) is used as an insulator. The ease of creeping discharge is determined by the material of the insulator (water absorption rate). However, it has been found that creeping discharge hardly occurs when the humidity is approximately 50% or less regardless of the material.

  Therefore, the humidity in the antenna chamber 3 may be 50% or less, but from the viewpoint of obtaining the effect of stably suppressing creeping discharge regardless of the material, the humidity is preferably 40% or less, and more preferably 30% or less. Is preferred. Further, 20% or less is more preferable from the viewpoint of reliably preventing creeping discharge.

  As the insulator 17, creeping discharge is less likely to occur when the water absorption rate is smaller. From this point of view, the water absorption rate is almost 0 as compared with Ultem (registered trademark) having a water absorption rate of 0.18 to 0.28%. Teflon (registered trademark) is preferable, but Teflon (registered trademark) is a soft material having a large coefficient of thermal expansion, and is not suitable for use for holding the high-frequency antenna 13. For this reason, Ultem (registered trademark) is more preferable for the purpose of holding the antenna.

  In this embodiment, when the humidity in the antenna chamber 3 is managed, the exhaust provided with a punching plate or an exhaust fan while supplying dry air from the dry air supply source 51 with the cover of the antenna chamber 3 closed. Dry air is exhausted from the port 55. Thereby, the inside of the antenna chamber 3 can be kept at a sufficiently low humidity. Changes in humidity over time when a punching plate is provided at the exhaust port 55 and when an exhaust fan is provided are shown in FIGS. As shown in these figures, in any case, it can be seen that a sufficiently low humidity can be obtained by keeping dry air flowing at a predetermined flow rate. Moreover, the effect of cooling the inside of the antenna chamber 3 can also be obtained by flowing dry air at a predetermined flow rate. For this reason, it is possible to prevent inconvenience due to a rise in temperature while suppressing creeping discharge in the antenna chamber 3. However, when an opening is simply provided as an exhaust port, air with high humidity flows into the antenna chamber 3 from the opening, which tends to increase the humidity, which is not preferable.

  When there is no need to cool the inside of the antenna chamber 3, the antenna chamber 3 may be substantially sealed without providing the exhaust port 55. In this case, it is not necessary to always flow dry air, and after the inside of the antenna chamber 3 becomes a dry air atmosphere of a predetermined pressure, the supply of the dry air from the dry air supply source 51 is such that the dry air leaked from the antenna chamber 3 is compensated. Good. FIG. 8 shows the relationship between the dry air supply time and humidity when the dry air pressure is changed. As shown in this figure, the ultimate humidity is lower at 0.1 MPa than when the dry air pressure is 0.05 MPa, but the ultimate humidity does not decrease even when the pressure is increased to 0.19 MPa. The reached humidity is saturated at the degree. Further, it can be seen that it takes a certain time until the humidity decreases after the inside of the antenna chamber 3 reaches a predetermined pressure.

  The present invention can be variously modified without being limited to the above embodiment. For example, in the above embodiment, the dry air supply mechanism is used as the humidity adjusting means, but a dry gas other than dry air may be used. In addition to the dry gas, other means such as one that adjusts the humidity by changing the temperature can be used. Moreover, although the spiral-shaped thing was illustrated as an antenna shape, not only this but the thing of arbitrary shapes can be used according to the plasma to produce | generate.

  Furthermore, in the above-described embodiment, the case where the present invention is applied to the antenna chamber of the inductively coupled plasma processing apparatus has been described. Any high-frequency plasma apparatus in a state where it can occur can be applied to other high-frequency plasma apparatuses such as a capacitively coupled plasma processing apparatus.

  Furthermore, although the case where the present invention is applied to the etching process is shown in the above embodiment, the present invention can be applied to other plasma processing apparatuses such as CVD film formation. Furthermore, although the example which used the rectangular substrate for FPD as a board | substrate was shown, it is applicable also when processing other rectangular substrates, such as a solar cell, and is not restricted to a rectangle, For example, circular, such as a semiconductor wafer It can also be applied to a substrate.

DESCRIPTION OF SYMBOLS 1; Main body container 2; Dielectric wall 3; Antenna chamber 4; Processing chamber 13; High frequency antenna 13a; Antenna wire 14; Matching device 15; High frequency power source 17; Station 30; Exhaust device 51; Dry air supply source 52; Dry air piping 53; Flow rate control valve 54; Flow rate sensor 55; Exhaust port 56; Hygrometer 57; Discharge prevention unit 58; Dry air supply mechanism 60; Overall control unit G;

Claims (8)

A high-frequency plasma processing apparatus having an electrode in contact with an insulator, applying high-frequency power to the electrode, and plasma-treating the substrate with plasma generated thereby,
A processing chamber for performing plasma processing on the substrate;
An electrode housing portion for housing the electrode in contact with the insulator;
A high frequency power source for applying high frequency power to the electrodes;
Humidity adjusting means for adjusting the humidity in the electrode housing portion so that creeping discharge does not occur in the electrode housing portion ,
The humidity adjusting means has a dry gas supply mechanism for supplying a dry gas to the electrode housing portion,
And,
A hygrometer for measuring the humidity in the electrode housing;
When the dry gas is supplied from the dry gas supply mechanism to the electrode housing portion, if the measured value of the hygrometer exceeds a predetermined threshold, the operation of the high-frequency power supply is not permitted, and the hygrometer A discharge prevention unit that permits the operation of the high-frequency power source when the measured value of the
A high-frequency plasma processing apparatus , further comprising: A high-frequency plasma processing apparatus having an electrode in contact with an insulator, applying high-frequency power to the electrode, and plasma-treating the substrate with plasma generated thereby,
A processing chamber for performing plasma processing on the substrate;
An electrode housing portion for housing the electrode in contact with the insulator;
A high frequency power source for applying high frequency power to the electrodes;
Humidity adjusting means for adjusting the humidity in the electrode housing portion so that creeping discharge does not occur in the electrode housing portion;
Comprising
The humidity adjusting means has a dry gas supply mechanism for supplying a dry gas to the electrode housing portion,
And,
A flow rate sensor for measuring a flow rate when the dry gas is supplied to the electrode housing portion;
When a dry gas is flowed from the dry gas supply mechanism to the electrode housing portion at a predetermined flow rate, a required time until the humidity in the electrode housing portion becomes a predetermined threshold value or less is set, and the flow sensor is set to the predetermined flow rate. after becoming the until passage requires time the not allow the operation of high-frequency power source, high frequency you wherein said further and a discharge preventing portion for permitting the operation of the high-frequency power source after elapse of the required time Plasma processing equipment. The discharge prevention unit, said by the flow rate sensor rate of drying gas anomaly is detected, if the abnormal time exceeds a predetermined time, according to claim 2, characterized in that does not allow the operation of the high frequency power source High frequency plasma processing equipment. The high-frequency plasma processing apparatus is an inductively coupled plasma processing apparatus,
The electrode is a high-frequency antenna that forms an induction magnetic field in the processing chamber,
The electrode accommodating unit, provided above the process chamber, high-frequency plasma treatment according to any one of claims 1 to 3, characterized in that the antenna chamber for accommodating the high frequency antenna device . A high-frequency plasma processing method of applying a high-frequency power from a high-frequency power source to an electrode in contact with an insulator, and plasma-treating a substrate in a processing chamber with plasma generated thereby,
Accommodating the electrode in contact with the insulator in an electrode accommodating portion;
The humidity in the electrode accommodating unit, while adjusting to creeping discharge in the electrode receptacle does not occur, have rows plasma treatment,
The adjustment of the humidity is performed by supplying a dry gas to the electrode housing portion,
Measure the humidity in the electrode housing with a hygrometer,
When the dry gas is supplied to the electrode housing portion, if the measured value of the hygrometer exceeds a predetermined threshold value, the operation of the high-frequency power supply is not permitted, and the measured value of the hygrometer is the threshold value. The high-frequency plasma processing method is characterized by permitting the operation of the high-frequency power source in the following cases . A high-frequency plasma processing method of applying a high-frequency power from a high-frequency power source to an electrode in contact with an insulator, and plasma-treating a substrate in a processing chamber with plasma generated thereby,
Accommodating the electrode in contact with the insulator in an electrode accommodating portion;
While adjusting the humidity in the electrode housing portion so that creeping discharge does not occur in the electrode housing portion, performing plasma treatment,
The adjustment of the humidity is performed by supplying a dry gas to the electrode housing portion,
The flow rate when the dry gas is supplied to the electrode housing part is measured by a flow sensor,
After a dry gas is allowed to flow through the electrode housing part at a predetermined flow rate, a time required until the humidity in the electrode housing part falls below a predetermined threshold is set, and the flow rate sensor becomes the predetermined flow rate. the until passage of the required time the not allow the operation of high-frequency power source, high-frequency plasma treatment how to and permits the operation of the high frequency power supply after the lapse the time required. The high frequency plasma processing method according to claim 6 , wherein when the flow rate abnormality of the dry gas is detected by the flow rate sensor and the abnormal time exceeds a predetermined time, the operation of the high frequency power supply is not permitted. The high frequency plasma is inductively coupled plasma,
The electrode is a high-frequency antenna that forms an induction magnetic field in the processing chamber,
The electrode accommodating unit, provided above the process chamber, high-frequency plasma processing method according to claims 5 to any one of claims 7, characterized in that the antenna chamber for accommodating the high frequency antenna .

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