JP6001932B2 - Plasma processing apparatus and filter unit - Google Patents

Description

  The present invention relates to a plasma processing apparatus for performing plasma processing on a substrate to be processed using a high frequency, and in particular, high frequency noise entering a line such as a power supply line or a signal line from a high frequency electrode or other electrical member in a processing container. The present invention relates to a plasma processing apparatus provided with a filter for shutting off.

  In microfabrication for manufacturing semiconductor devices using plasma or FPD (Flat Panel Display), control of plasma density distribution on the substrate to be processed (semiconductor wafer, glass substrate, etc.) and control of substrate temperature or temperature distribution. Is very important. If the temperature control of the substrate is not properly performed, the substrate surface reaction and thus the uniformity of process characteristics cannot be secured, and the manufacturing yield of the semiconductor device or the display device is lowered.

  Generally, a mounting table or susceptor for mounting a substrate to be processed in a chamber of a plasma processing apparatus, particularly a capacitively coupled plasma processing apparatus, functions as a high-frequency electrode that applies a high frequency to a plasma space, and electrostatically attracts the substrate. And a function of a temperature control unit for controlling the substrate to a predetermined temperature by heat transfer. Regarding the temperature control function, it is desired that the distribution of heat input characteristics to the substrate due to non-uniformity of radiant heat from plasma and chamber walls and the heat distribution by the substrate support structure can be corrected appropriately.

  Conventionally, in order to control the temperature of the susceptor and thus the temperature of the substrate, a heater system that incorporates a heating element that generates heat when energized into the susceptor and controls Joule heat generated by the heating element is often used. However, when the heater method is adopted, a part of the high frequency applied to the susceptor from the high frequency power source tends to enter the heater power supply line from the heating element as noise. If high-frequency noise passes through the heater power supply line and reaches the heater power supply, the operation or performance of the heater power supply may be impaired. Further, when a high-frequency current flows on the heater power supply line, high-frequency power is wasted. Under such circumstances, it is customary to provide a filter on the heater power supply line for attenuating or preventing high-frequency noise coming from a heating element with a built-in susceptor. Usually this type of filter is placed outside the processing vessel directly under the susceptor.

  The applicant of Patent Document 1 describes the stability of filter performance in the plasma processing apparatus that blocks high-frequency noise that enters a power supply line, a signal line, or the like from a high-frequency electrode or other electrical member in a processing container. And a filter technique that improves reproducibility. This filter technology uses a regular multiple parallel resonance characteristic of a distributed constant line, so that only one coil can be accommodated in the filter, and a stable high-frequency noise cutoff characteristic with little machine difference can be obtained.

  Further, in the above-mentioned Patent Document 1, the present applicant has disclosed a technique of a parallel resonance frequency adjustment unit that can adjust by shifting at least one of a plurality of parallel resonance frequencies by locally changing the characteristic impedance of the distributed constant line. Is disclosed. According to this parallel resonance frequency adjusting unit, one of the plurality of parallel resonance frequencies can be matched or approximated to the frequency of high-frequency noise that is symmetric with respect to cutoff, so that a desired sufficiently high impedance with respect to the frequency of the high-frequency noise. Can be given. As a result, the heater power supply can be reliably protected and the reproducibility and reliability of the plasma process can be improved.

JP2011-135052

  However, when the filter of Patent Document 1 as described above is mounted on the plasma processing apparatus, the process characteristics or process results on the substrate may be biased in the circulation direction or the azimuth direction depending on the position of the filter. For example, in a plasma etching apparatus, the etching rate on the substrate tends to show a profile that increases or decreases in the vicinity of the position immediately above the filter in the azimuth direction. In particular, when the heating element inside the susceptor is divided into a plurality of zones and independent temperature control is performed for each zone, a plurality of filters corresponding to each of the plurality of zones are disposed here under the processing container. Therefore, the uneven etching rates due to these filters are overlapped, and the profile is likely to be more complicated and non-uniform.

  The inventor examined the cause, among the high-frequency noise entering the power supply line from the heating element inside the susceptor, even if the high-frequency (fundamental wave) noise used for plasma processing is blocked as designed by the filter, It has been found that when the impedance of the filter is not sufficiently high with respect to harmonics having a frequency that is an integral multiple of the fundamental wave, particularly high-frequency second-order harmonics used for plasma generation, the above-described process characteristic deviation occurs.

  Furthermore, it was also found that the parallel resonance frequency adjusting unit as described above does not function so effectively for this kind of process characteristic bias. That is, when the position of a member (typically a ring) that gives local changes to the characteristic impedance of the distributed constant line is adjusted in the axial direction in the parallel resonance frequency adjustment unit, all the parallel resonance frequencies are independent in their own periods. Therefore, it is difficult to stably and reliably give a sufficiently large impedance to both a specific fundamental wave and a specific harmonic.

  The present invention has been made in view of the above-described problems of the prior art, and harmful high-frequency noise that enters a line such as a power supply line or a signal line from a high-frequency electrode or other electrical member in a processing container. In contrast, the present invention provides a plasma processing apparatus and a filter unit that provide a sufficiently large impedance in a simple and stable manner to improve the reproducibility and reliability of a plasma process.

A plasma processing apparatus according to a first aspect of the present invention includes a processing container in which plasma processing is performed, an electrical member provided in the processing container, and an external circuit in which the electrical member is disposed outside the processing container. A line that is electrically connected to the filter, a filter that includes a coil for attenuating or preventing high-frequency noise of a predetermined frequency that enters the line from the electrical member toward the external circuit, and the coil A coil inductance adjusting unit for adjusting the inductance of the coil, and the windings of the coils are closed with an elastic insulator, and the coil inductance adjusting unit makes the winding interval of the coils variable. A coil length adjustment unit for adjustment is provided.

The plasma processing apparatus according to the first aspect attenuates or prevents high-frequency noise on a line connecting an electric member provided in a processing vessel in which plasma processing is performed and an external circuit of a power system or a signal system. The coil inductance of the coil constituting the filter is adjusted by the coil length adjusting unit of the coil inductance adjusting unit in such a manner that the winding interval of the coil in which the windings are closed with an elastic insulator is variably adjusted. By doing so, the impedance of the filter, particularly the impedance with respect to the frequency of the high frequency noise to be attenuated or blocked, can be easily and arbitrarily adjusted.

In the filter unit according to the first aspect of the present invention, an electrical member in a processing container in which plasma processing is performed is electrically connected to an external circuit disposed outside the processing container via a line. In the plasma processing apparatus, a filter unit provided in the middle of the line for attenuating or preventing high-frequency noise of a predetermined frequency entering the line from the electrical member toward the external circuit, A coil that forms part of the line; and a coil inductance adjusting unit that adjusts the inductance of the coil, and a winding between the windings of the coil is closed with an elastic insulator, and the coil inductance adjustment The section has a coil length adjusting section for variably adjusting the winding interval of the coil.

The filter unit according to the first aspect includes an inductance of a coil constituting a part of a line on a line connecting an electric member provided in a processing vessel in which plasma processing is performed and an external circuit of a power system or a signal system. By adjusting the winding interval of the coil in which the windings are covered with an elastic insulator between the windings in a variable manner by the coil length adjusting unit of the coil inductance adjusting unit. The impedance with respect to the frequency of the high frequency noise to be attenuated or blocked can be easily and arbitrarily adjusted.

A plasma processing apparatus according to a second aspect of the present invention includes a processing container in which plasma processing is performed, a first electrode disposed in the processing container, a heating element provided in the first electrode, and the heat generation. A power supply line for electrically connecting a body to a heater power source disposed outside the processing container, and attenuating or preventing high-frequency noise of a predetermined frequency that enters the power supply line via the heating element A coil including a coil for adjusting the coil inductance, and a coil inductance adjusting unit for adjusting the inductance of the coil, the coil windings being covered with an elastic insulator, and the coil inductance adjusting unit Has a coil length adjustment unit for variably adjusting the winding interval of the coil.

The plasma processing apparatus according to the second aspect is provided on a power supply line that connects a heating element provided in a first electrode arranged in a processing vessel in which plasma processing is performed and a heater power source arranged outside the processing vessel. The coil winding constituting the filter for attenuating or preventing the high frequency noise is wound by the coil length adjusting section of the coil inductance adjusting section, and the coil winding is covered with an elastic insulator . By adjusting the line spacing in a variable manner, the impedance of the filter, in particular, the impedance to the frequency of the high frequency noise to be attenuated or blocked can be easily and arbitrarily adjusted.

The filter unit according to the second aspect of the present invention is configured such that a heating element provided on a first electrode in a processing container in which plasma processing is performed is connected to a heater power source disposed outside the processing container via a power supply line. An electrically connected plasma processing apparatus is provided in the middle of the power supply line to attenuate or prevent high-frequency noise of a predetermined frequency that enters the power supply line from the heating element toward the heater power supply. An insulating body having a coil constituting a part of the power supply line and a coil inductance adjusting unit for adjusting the inductance of the coil , and having elasticity between windings of the coil and blocked by the coil inductance adjusting portion, have a coil length adjusting section for adjusting a winding distance of the coil variable That.

The filter unit according to the second aspect is provided on a power supply line that connects a heating element provided in a first electrode arranged in a processing vessel in which plasma processing is performed and a heater power source arranged outside the processing vessel. In the way of adjusting the winding interval of the coil in which the winding is covered with an elastic insulator by the coil length adjustment unit of the coil inductance adjustment unit. By adjusting, the impedance of the filter unit, in particular, the impedance for the frequency of the high frequency noise to be attenuated or blocked can be easily and arbitrarily adjusted.

  According to the plasma processing apparatus or the filter unit of the present invention, harmful high frequencies entering the lines such as the power supply line and the signal line from the high frequency electrode and other electrical members in the processing container by the configuration and operation as described above. The reproducibility and reliability of the plasma process can be improved by giving a sufficiently large impedance to the noise simply and stably.

It is sectional drawing which shows the structure of the plasma processing apparatus in one Embodiment of this invention. It is a figure which shows the circuit structure of the heater electric power feeding part for supplying electric power to the heat generating body of a susceptor in embodiment. It is a figure which shows the structural example of the heat generating body in embodiment. It is a longitudinal cross-sectional view which shows the structure of the filter unit in embodiment. It is a cross-sectional view which shows the structure of the filter unit in embodiment. It is a perspective view which shows the external appearance structure of the coil winding of two systems of air-core coils with which a common rod axis | shaft is mounted | worn in the said filter unit. It is a partial cross section perspective view which shows the structure inside the coil winding in the said filter unit. It is a perspective view which shows the structure of the coil receiving member in the said filter unit. It is a perspective view which shows the structure of the coil length adjustment part in the said filter unit. It is a graph which shows the change of an impedance characteristic when the shortening amount of a coil is changed in the said filter unit. It is a graph which shows the correlation with the shortening amount of a coil in the said filter unit, and the variation | change_quantity of the typical parallel resonant frequency in the impedance characteristic of a filter. It is a figure which shows the etching rate distribution characteristic obtained by the comparative reference example in a 1st Example. It is a top view which shows the arrangement position of the filter unit in a 1st Example. It is a figure which shows the etching rate distribution characteristic at the time of setting the impedance of the filter unit with respect to the 2nd harmonic as a parameter in the 1st Example. It is a figure which shows the etching rate distribution characteristic obtained by the comparative reference example in a 2nd Example. It is a figure which shows the etching rate distribution characteristic at the time of setting the impedance of the filter unit with respect to the 2nd harmonic as a parameter in 2nd Example. It is a side view which shows the structure of the coil length adjustment part in one modification. It is a perspective view which shows the external appearance structure of the coil winding in one modification. It is a partial cross section perspective view which shows the structure inside the coil winding of FIG.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.
[Configuration of the entire plasma processing apparatus]

  FIG. 1 shows the configuration of a plasma processing apparatus according to an embodiment of the present invention. This plasma processing apparatus is configured as a capacitive coupling type plasma etching apparatus of a lower two frequency application system, and has a cylindrical chamber (processing container) 10 made of metal such as aluminum or stainless steel. The chamber 10 is grounded.

  In the chamber 10, a disk-shaped susceptor 12 on which, for example, a semiconductor wafer W is placed as a substrate to be processed is disposed horizontally as a lower electrode. The susceptor 12 is made of aluminum, for example, and is supported ungrounded by an insulating cylindrical support 14 made of ceramic, for example, extending vertically upward from the bottom of the chamber 10. An annular exhaust path 18 is formed between the conductive cylindrical support portion 16 extending vertically upward from the bottom of the chamber 10 along the outer periphery of the insulating cylindrical support portion 14 and the inner wall of the chamber 10. An exhaust port 20 is provided at the bottom of the path 18. An exhaust device 24 is connected to the exhaust port 20 via an exhaust pipe 22. The exhaust device 24 includes a vacuum pump such as a turbo molecular pump, and can reduce the processing space in the chamber 10 to a desired degree of vacuum. A gate valve 26 that opens and closes the loading / unloading port of the semiconductor wafer W is attached to the side wall of the chamber 10.

  First and second high frequency power supplies 28 and 30 are electrically connected to the susceptor 12 via a matching unit 32 and a power feed rod 34. Here, the first high-frequency power supply 28 outputs a first high-frequency HF having a constant frequency (usually 27 MHz or higher, preferably 60 MHz or higher) that mainly contributes to plasma generation. On the other hand, the second high-frequency power supply 30 outputs a second high-frequency LF having a constant frequency (usually 13 MHz or less) that mainly contributes to the drawing of ions into the semiconductor wafer W on the susceptor 12. The matching unit 32 accommodates first and second matching units (not shown) for matching impedance between the first and second high frequency power supplies 28 and 30 and the plasma load.

  The power feed rod 34 is made of a cylindrical or columnar conductor having a predetermined outer diameter, and its upper end is connected to the center of the lower surface of the susceptor 12, and its lower end is the first and second matching units in the matching unit 32. Connected to the high frequency output terminal. A cylindrical conductor cover 35 is provided between the bottom surface of the chamber 10 and the matching unit 32 so as to surround the power supply rod 34. More specifically, a circular opening having a predetermined diameter that is slightly larger than the outer diameter of the power supply rod 34 is formed on the bottom surface (lower surface) of the chamber 10, and the upper end of the conductor cover 35 is connected to the chamber opening. In addition, the lower end of the conductor cover 35 is connected to the ground (return) terminal of the matching unit.

  The susceptor 12 has a diameter or diameter that is slightly larger than that of the semiconductor wafer W. The upper surface of the susceptor 12 is partitioned into a central region that is substantially the same shape (circular) and substantially the same size as the wafer W, that is, a wafer mounting portion, and an annular peripheral portion that extends outside the wafer mounting portion. . A semiconductor wafer W to be processed is placed on the wafer placement portion. On the annular peripheral portion, a ring-shaped plate material so-called a focus ring 36 having an inner diameter larger than the diameter of the semiconductor wafer W is attached. The focus ring 36 is made of, for example, any one of Si, SiC, C, and SiO 2 depending on the material to be etched of the semiconductor wafer W.

  On the wafer mounting portion on the upper surface of the susceptor 12, an electrostatic chuck 38 and a heating element 40 for wafer adsorption are provided. The electrostatic chuck 38 encloses a DC electrode 44 in a film-like or plate-like dielectric 42 integrally formed on or integrally fixed to the upper surface of the susceptor 12, and the DC electrode 44 is disposed outside the chamber 10. The external DC power supply 45 is electrically connected via a switch 46, a high-resistance resistor 48, and a DC high-voltage line 50. By applying a high DC voltage from the DC power supply 45 to the DC electrode 44, the semiconductor wafer W can be attracted and held on the electrostatic chuck 38 by Coulomb force. Note that the DC high-voltage line 50 is a covered wire, passes through the cylindrical lower power feed rod 34, penetrates the susceptor 12 from below, and is connected to the DC electrode 44 of the electrostatic chuck 38.

  The heating element 40 is composed of, for example, a spiral resistance heating wire enclosed in a dielectric 42 together with the DC electrode 44 of the electrostatic chuck 38. In this embodiment, as shown in FIG. 3, the radial direction of the susceptor 12 is formed. 2 is divided into an inner heating wire 40 (IN) and an outer heating wire 40 (OUT). Among these, the inner heating wire 40 (IN) is a dedicated wire disposed outside the chamber 10 via the insulation-coated power supply conductor 52 (IN), the filter unit 54 (IN), and the electric cable 56 (IN). It is electrically connected to the heater power source 58 (IN). The outer heating wire 40 (OUT) is a dedicated heater power source which is also disposed outside the chamber 10 via the insulation-coated power supply conductor 52 (OUT), the filter unit 54 (OUT) and the electric cable 56 (OUT). 58 (OUT) is electrically connected. Among these, the filter units 54 (IN) and 54 (OUT) are main features in this embodiment, and the internal configuration and operation will be described in detail later.

  An annular refrigerant chamber or refrigerant passage 60 extending in the circumferential direction, for example, is provided inside the susceptor 12. A refrigerant having a predetermined temperature, such as cooling water cw, is circulated and supplied to the refrigerant chamber 60 from a chiller unit (not shown) via a refrigerant supply pipe. The temperature of the susceptor 12 can be controlled to decrease according to the temperature of the refrigerant. In order to thermally couple the semiconductor wafer W to the susceptor 12, a heat transfer gas such as He gas from a heat transfer gas supply unit (not shown) is passed through the gas supply pipe and the gas passage 62 inside the susceptor 12. Thus, it is supplied to the contact interface between the electrostatic chuck 38 and the semiconductor wafer W.

  On the ceiling of the chamber 10, there is provided a shower head 64 that is parallel to the susceptor 12 and also serves as an upper electrode. The shower head 64 includes an electrode plate 66 facing the susceptor 12 and an electrode support 68 that detachably supports the electrode plate 66 from the back (upper side) thereof. A gas chamber 70 is provided inside the electrode support 68. A number of gas discharge holes 72 penetrating from the gas chamber 70 to the susceptor 12 side are formed in the electrode support 68 and the electrode plate 66. A space SP between the electrode plate 66 and the susceptor 12 is a plasma generation space or a processing space. A gas supply pipe 76 from the processing gas supply unit 74 is connected to the gas introduction port 70 a provided in the upper part of the gas chamber 70. The electrode plate 66 is made of, for example, Si, SiC, or C, and the electrode support 68 is made of, for example, anodized aluminum.

  Each part in the plasma etching apparatus, for example, the exhaust device 24, the high frequency power supplies 28 and 30, the switch 46 of the DC power supply 45, the heater power supplies 58 (IN) and 58 (OUT), a chiller unit (not shown), a heat transfer gas supply section. Individual operations such as (not shown) and the processing gas supply unit 74 and the operation (sequence) of the entire apparatus are controlled by a control unit 75 including a microcomputer.

  In order to perform etching in this plasma etching apparatus, first, the gate valve 26 is opened, and the semiconductor wafer W to be processed is loaded into the chamber 10 and placed on the electrostatic chuck 38. Then, an etching gas (generally a mixed gas) is introduced into the chamber 10 from the processing gas supply unit 74 at a predetermined flow rate, and the pressure in the chamber 10 is set to a set value by the exhaust device 24. Further, the first and second high-frequency power supplies 28 and 30 are turned on to output the first high-frequency HF and the second high-frequency LF at predetermined powers, respectively. The high-frequency HF and LF are supplied to the matching unit 32 and the power supply rod 34. To the susceptor (lower electrode) 12. Further, the heat transfer gas (He gas) is supplied from the heat transfer gas supply unit to the contact interface between the electrostatic chuck 38 and the semiconductor wafer W, and the electrostatic chuck switch 46 is turned on to perform electrostatic adsorption. The heat transfer gas is confined in the contact interface by force. On the other hand, the heater power supplies 58 (IN) and 58 (OUT) are turned on to cause the inner heating element 40 (IN) and the outer heating element 40 (OUT) to generate heat with independent Joule heat, respectively. Control the temperature distribution to the set value. The etching gas discharged from the shower head 64 is turned into plasma by high-frequency discharge between the electrodes 12 and 64, and the film to be processed on the surface of the semiconductor wafer W is etched into a desired pattern by radicals and ions generated by the plasma. .

  This capacitively coupled plasma etching apparatus applies a first high-frequency HF having a relatively high frequency (preferably 60 MHz or more) suitable for plasma generation to the susceptor 12 to increase the density of the plasma in a preferable dissociated state, thereby lowering the pressure. High density plasma can be formed even under the above conditions. At the same time, a highly selective anisotropic etching is performed on the semiconductor wafer W on the susceptor 12 by applying a second high frequency LF having a relatively low frequency (13 MHz) suitable for ion attraction to the susceptor 12. be able to.

Further, in this capacitively coupled plasma etching apparatus, chiller cooling and heater heating are simultaneously applied to the susceptor 12, and the heater heating is controlled independently at the central portion and the edge portion in the radial direction. Switching or raising / lowering temperature is possible, and the profile of the temperature distribution can be controlled arbitrarily or in various ways.

[Circuit configuration in the filter unit]

  Next, the circuit configuration in the filter units 54 (IN) and 54 (OUT), which is a main characteristic part of the plasma etching apparatus, will be described.

  FIG. 2 shows a circuit configuration of a heater power supply unit for supplying power to the heating element 40 provided in the susceptor 12. In this embodiment, individual heater power supply units having substantially the same circuit configuration are connected to each of the inner heating wire 40 (IN) and the outer heating wire 40 (OUT) of the heating element 40, and the inner heating wire is connected. The heat generation amount or the heat generation temperature of 40 (IN) and the outer heating wire 40 (OUT) are independently controlled. In the following description, the configuration and operation of the heater power feeding unit for the inner heating wire 40 (IN) will be described. The configuration and operation of the heater power supply unit for the outer heating wire 40 (OUT) are exactly the same.

The heater power source 58 (IN) is an AC output type power source that performs a commercial frequency switching (ON / OFF) operation using, for example, an SSR, and is connected to the inner heating element 40 (IN) by a closed loop circuit. More specifically, of the pair of output terminals of the heater power supply 58 (IN), the first output terminal is the first of the inner heating line 40 (IN) through the first power supply line (power supply line) 100 (1). is connected to terminal h ₁ electrically, a second output terminal electrically to the inner heating wire 40 the second terminal h ₂ of (iN) via a second power supply line (power supply line) 100 (2) It is connected to the.

  The filter unit 54 (IN) has first and second filters 102 (1) and 102 (2) provided in the middle of the first and second power supply lines 100 (1) and 100 (2), respectively. ing. The circuit configurations of both filters 102 (1) and 102 (2) are substantially the same.

More specifically, both filters 102 (1) and 102 (2) have coils 104 (1) and 104 (2) grounded via capacitors 106 (1) and 106 (2), respectively. One terminal of the coils 104 (1), 104 (2) or the filter terminals T (1), T (2) are connected to both terminals h _{1 of the} inner heating wire 40 (IN) through a pair of power supply conductors 52 (IN). , H ₂ , and capacitors 106 (1), 106 (2) between the other terminals of the coils 104 (1), 104 (2) and a conductive member (eg, chamber 10) having a ground potential. Are connected to each other. The connection points n (1) and n (2) between the coils 104 (1) and 104 (2) and the capacitors 106 (1) and 106 (2) are connected to an electric cable (pair cable) 56 (IN). Are connected to the first and second output terminals of the heater power source 58 (IN), respectively.

In the heater power supply section having such a configuration, the current output from the heater power supply 58 (IN) is the first power supply line 100 (1), that is, the electric cable 56 (IN), the coil 104 (1), and the coil in the positive cycle. It enters the inner heating wire 40 (IN) from _one terminal h ₁ through the feeding conductor 52 (IN), generates Joule heat by energization at each part of the inner heating wire 40 (IN), and exits from the other terminal h _2. Thereafter, the feedback is made through the second power supply line 100 (2), that is, the power supply conductor 52 (IN), the coil 104 (2), and the electric cable 56 (IN). In the negative cycle, a current flows through the same circuit in the opposite direction. Since the current of the heater AC output is a commercial frequency, the impedance of the coils 104 (1), 104 (2) or the voltage drop thereof is negligibly small, and is grounded through the capacitors 106 (1), 106 (2). The leakage current that escapes is negligibly small.

[Physical configuration in the filter unit]

  4 to 9 show a physical structure in the filter unit 54 (IN) in this embodiment. As shown in FIGS. 4 and 5, the filter unit 54 (IN) includes a coil 104 (1) and a second filter 102 (1) of the first filter 102 (1) in a cylindrical outer conductor 110 made of, for example, aluminum. The coil 104 (2) of 2) is accommodated coaxially, and the capacitor 106 of the first filter 102 (1) is placed in the capacitor box 112 made of, for example, aluminum on the opposite side of the filter terminals T (1) and T (2). (1) and the capacitor 106 (2) (FIG. 2) of the second filter 102 (2) are accommodated together. The outer conductor 110 is connected to a conductive member having a ground potential such as the chamber 10 by screws.

  Each of the coils 104 (1) and 104 (2) is an air-core coil, and functions as a power supply line that allows a sufficiently large current (for example, about 30A) to flow from the heater power supply 52 (IN) to the inner heating wire 40 (IN). In addition, in order to prevent heat generation (power loss), to obtain a very large inductance with an air core without having a magnetic core such as ferrite, and to obtain a large line length, a thick coil wire and a large coil size (For example, the diameter is 22 to 45 mm and the length is 130 to 280 mm).

  In the cylindrical outer conductor 110, both coils 104 (1) and 104 (2) are mounted on a cylindrical or columnar rod shaft 114 made of an insulator, such as a resin, which stands vertically on a capacitor box 112. It is mounted so that it can move freely in any direction. Here, both the coils 104 (1) and 104 (2) have the same winding interval d and coil length while overlapping and translating along the outer peripheral surface of the common rod shaft 114 in the axial direction as shown in FIG. It is spirally wound with s. As shown in FIG. 7, the coil conductors of both coils 104 (1) and 104 (2) are preferably made of a thin plate or a flat copper wire having the same cross-sectional area, and one air-core coil 104 (2 ) Is covered with an insulating tube 116.

  The tube 116 not only has a function of preventing an electrical short circuit between the coils 104 (1) and 104 (2), but also closes a winding gap between the coils 104 (1) and 104 (2). The winding interval d can be adjusted. For this purpose, the tube 116 is made of an insulator having excellent elasticity, such as silicone rubber, and is formed thick. For example, when the coil conductors of both coils 104 (1) and 104 (2) have a thickness of 1 mm, the thickness of the tube 116 is selected to be 1.1 mm. In this case, when the coils 104 (1) and 104 (2) are in the natural length state, d = 3.2 mm (1.1 mm + 1 mm + 1.1 mm). In order to adjust the coil length s or the winding interval d while the winding gap between the coils 104 (1) and 104 (2) is closed by the tube 116, the coil length s is set to a natural length as described later. It is shorter (shortened) than the state, and the amount of shortening is adjusted. In that case, the winding interval d can be adjusted, for example, in the range of about 2 mm to 3.2 mm.

  An upper connector 120 made of resin is attached to the opening at the upper end of the outer conductor 110 via an annular lid 118. The upper end of the rod shaft 114 is fixed to the upper connector 120, and the upper ends of both the coils 104 (1) and 104 (2) are also fixed. The upper ends of the coils 104 (1) and 104 (2) are electrically connected to the filter terminals T (1) and T (2), respectively, inside or around the connector 120.

  The lower end of the bar shaft 114 is fixed to a resin-made lower connector 122 disposed on or above the capacitor box 112. A pair of rigid connection conductors 124 (1) and 124 (2) extending downward from the lower surface of the lower connector 122 are electrically connected to the capacitors 106 (1) and 106 (2) in the capacitor box 112 (FIG. 2). ), And the connector 122 is physically fixed at a fixed position.

  A resin coil receiving member 126 that is coupled or engaged with the lower ends of the coils 104 (1) and 104 (2) is attached to the lower end of the rod shaft 114 so as to be slidable in the axial direction. As shown in FIG. 8, the coil receiving member 126 has a trunk portion 126a extending in the vertical direction and a pair of flange portions 126b and 126b extending in the opposite direction from the lower end portion of the trunk portion 126a in the lateral direction. ing. The body 126a is formed with a screw hole (female thread) 127 penetrating the center portion in the vertical direction. As shown in FIG. 9, the body 126a is fitted into a notch-shaped cavity 114a formed at the lower end of the rod shaft 114 so that it can move (slide) only in the axial direction, and both flange portions 126b and 126b protrude out of the rod shaft 114. Although not shown, the lower ends of the coils 104 (1) and 104 (2) pass through the flanges 126b and 126b and connect to the connection conductors 124 (1) and 124 (2) inside or around the lower connector 122. Each is electrically connected.

  As shown in FIGS. 4 and 9, a bolt (male screw) 128 inserted into the lower end portion of the rod shaft 114 is screwed into a screw hole (female screw) 127 of the body portion 126 a of the coil receiving member 126. A wrench 130 is applied to the head (for example, hexagonal hole) 128a of the bolt 128 through a tool passage hole (not shown) formed in the capacitor box 112 from below the filter unit 54 (IN). When the is turned, the coil receiving member 126 moves upward or downward along the rod shaft 114 while being coupled or engaged with the lower ends of both the coils 104 (1) and 104 (2).

  When the coil receiving member 126 moves upward, the total length s and the winding interval d of each of the coils 104 (1) and 104 (2) are changed. When the coil receiving member 126 moves downward, the total length s and the winding interval d of each of the coils 104 (1) and 104 (2) are changed. When the rotation of the bolt 128 is stopped, the movement of the coil receiving member 126 is stopped, and the coil receiving member 126 is fixed by screwing between the screws 127 and 128 at the stopped position. The head 128 a of the bolt 128 protrudes from the lower end of the rod shaft 114 in FIG. 4, but may be stored in the rod shaft 114.

As described above, in this embodiment, the notch-shaped cavity portion 114a of the rod shaft 114 that slidably supports the body portion 126a of the coil receiving member 126 and the screw hole formed in the body portion 126a of the coil receiving member 126. The coil receiving member 126 is moved up and down along the rod shaft 114 and fixed at an arbitrary position by a (female screw) 127 and a bolt (male screw) 128 screwed into the screw hole (female screw) 127. A feed screw mechanism 132 is configured. Then, the rod body 114 movably penetrating the inside of the coils 104 (1) and 104 (2) and the lower end of the coils 104 (1) and 104 (2) are coupled or engaged with the rods 114 and slid in the coil axis direction. A coil length for adjusting the length s or the winding interval d of the coils 104 (1) and 104 (2) by the coil receiving member 126 that is movably attached to the rod 114 and the feed screw mechanism 132 described above. A height adjusting unit 134 is configured.

[Action of filter unit]

  In the filter unit 54 (IN) of this embodiment, a distributed constant line is provided between the coils 104 (1) and 104 (2) of the first and second filters 102 (1) and 102 (2) and the outer conductor 110. Is formed.

In general, the characteristic impedance Z _o of the transmission line is given by Z _o = √ (L / C) using the capacitance C and the inductance L per unit length when there is no loss. The wavelength λ is given by the following equation (1).
λ = 2π / (ω√ (LC) (1)

A general distributed constant line (especially a coaxial line) is different in that the center of the line is a rod-shaped cylindrical conductor, whereas the filter unit 54 (IN) uses a cylindrical coil as the central conductor. The inductance L per unit length is considered to be predominantly the inductance due to this cylindrical coil. On the other hand, the capacitance per unit length is defined by the capacitance C of the capacitor formed by the coil surface and the outer conductor. Therefore, also in this filter unit 54 (IN), when the inductance and the capacitance per unit length are L and C, respectively, the distributed constant line given by the characteristic impedance Z _o = √ (L / C) It can be considered that it is formed.

  When the filter unit having such a distributed constant line is viewed from the terminal T side, the opposite side is pseudo short-circuited by a capacitor having a large capacitance (for example, 5000 pF), so that a large impedance is repeated at a constant frequency interval. A frequency-impedance characteristic is obtained. Such impedance characteristics are obtained when the wavelength and the distributed line length are equal.

  In this filter unit 54 (IN), not the winding length of the coils 104 (1) and 104 (2) but the axial coil length s (FIG. 4) is the distributed line length. Since the coils 104 (1) and 104 (2) are used as the central conductor, L can be made much larger and λ can be made smaller than in the case of a rod-shaped cylindrical conductor, so that a relatively short line Although it is long (coil length s), it is possible to realize an effective length equal to or greater than the wavelength, and it is possible to obtain an impedance characteristic that repeats having a large impedance at a relatively short frequency interval.

  Here, on the distributed constant line formed between the coils 104 (1), 104 (2) and the outer conductor 110, it is desirable that the characteristic impedance (particularly, inductance and capacitance per unit length) is constant. In this regard, in the illustrated configuration example, the cylindrical coils 104 (1) and 104 (2) are coaxially arranged in the cylindrical outer conductor 110, so that the requirement of constant characteristic impedance is strictly satisfied. ing. However, even if there are some irregularities in the gap (distance interval) between the coils 104 (1), 104 (2) and the outer conductor 110, the allowable range (generally ¼ or less of the wavelength of the high frequency to be cut off). If it is within, the requirement of constant characteristic impedance is substantially satisfied.

  As described above, each of the filters 102 (1) and 102 (2) can achieve a filter characteristic having multiple parallel resonance and excellent impedance characteristic stability and reproducibility.

On the other hand, in the filter unit 54 (IN), the length s or the winding interval d of each of the coils 104 (1) and 104 (2) is variably adjusted using the coil length adjusting unit 134 as described above. By doing so, the inductances L ₁ and L ₂ of the coils 104 (1) and 104 (2) can be variably adjusted.

Here, the theoretical values of the inductances L ₁ and L ₂ of the coils 104 (1) and 104 (2) are given by, for example, the following equations (2) and (3), respectively.
L ₁ = μ ₀ × π × r ₁ ² × n ² / (s + k × r ₁ ) (2)
L ₂ = μ ₀ × π × r ₂ ² × n ² / (s + k × r ₂ ) (3)
Here, μ ₀ is the vacuum permeability, n is the number of turns of the coil, r ₁ and r ₂ are the radius of the coil, and k is the Nagaoka coefficient (for example, k = 0.9).

When the lengths s of the coils 104 (1) and 104 (2) are changed from the theoretical formulas (2) and (3) in the direction of shortening, the inductance L _{1 of the} coils 104 (1) and 104 (2). , L ₂ change in the increasing direction, and conversely, when the length s of the coils 104 (1), 104 (2) is changed in the extending direction, the inductance L of the coils 104 (1), 104 (2). _It can be seen that ₁ and L ₂ change in a decreasing direction.

  In this embodiment, as described above, the elastically deformable tube 116 closes the winding gap of the coils 104 (1) and 104 (2). Thus, when the length s of each of the coils 104 (1) and 104 (2) is changed in the direction of shortening or extending by the coil length adjusting unit 134, the winding gap of the coils 104 (1) and 104 (2) is changed. As a result of the elastic deformation of the tube 116 that closes the coil 104, the winding interval d of the coils 104 (1) and 104 (2) changes so as to increase or decrease substantially uniformly or uniformly in each part. . Thus, the ability to adjust the winding interval d in each part of the coils 104 (1) and 104 (2) substantially uniformly or uniformly is very important for ensuring the fineness, stability and reproducibility of the coil inductance adjustment. is important.

  The inventor manufactured a prototype of the filter unit 54 (IN) in this embodiment, and adjusted the coil 104 (1) with a weak adjustment and a strong adjustment with the coil length adjustment unit 134. In each case, the frequency-impedance characteristics of the first filter 102 (1) viewed from the filter terminal T (1) were measured (acquired). FIG. 10 shows the measurement results.

As shown in FIG. 10, when the compression of the coil 104 (1) is increased, that is, when the amount of shortening of the coil length s from the natural length is increased, each of the parallel multiple resonances in the impedance characteristic of the first filter 102 (1). It can be seen that the resonance frequency changes in the direction of uniformly decreasing as f _i → f _i ′ (i = 1, 2, 3,...). As shown in FIG. 10, the higher the frequency, the lower the impedance of the first filter 102 (1). This is mainly because the impedance of the capacitor 106 (1) decreases in proportion to the frequency.

FIG. 11 shows typical parallel resonance frequencies (f ₁ , f ₂ , f ₅ , f ₆ , f ₁₂ , f ₁₃ ) in the shortening amount of the coil 104 (1) and the impedance characteristic of the first filter 102 (1). The correlation with the amount of change is shown. As shown in the figure, in the low frequency region, the change rate (decrease rate) of each parallel resonance frequency (f ₁ , f ₂ ) with respect to the shortening amount of the coil 104 (1) is small, and the coil 104 (1) is shortened as the frequency is high. It can be seen that the rate of change (decrease rate) of each parallel resonant frequency (f ₅ , f ₆ , f ₁₂ , f ₁₃ ) with respect to the quantity is large.

  As described above, when the length s (or the winding interval d) of the coil 104 (1) is adjusted using the coil length adjusting unit 134, each parallel resonance frequency of the parallel multiple resonance is uniformly increased or increased. As the frequency increases, the rate of change increases. Thus, the fundamental wave (first high frequency HF and second high frequency) used for plasma processing is adjusted by adjusting the length s (or winding interval d) of the coil 104 (1) using the coil length adjusting unit 134. The impedance to a specific harmonic (typically a second harmonic having twice the frequency of the first high frequency HF for plasma generation) is continuously or stepped within a certain range without changing the impedance to LF). Can be adjusted. Therefore, for example, when the first high frequency HF for plasma generation is 100 MHz as in the embodiment described later, the second harmonic is not changed much in the first filter 102 (1) with respect to the first high frequency HF (100 MHz). The impedance to the wave (200 MHz) can be adjusted continuously or stepwise within a certain range.

The second filter 102 (2) also has the same effect as the first filter 102 (1) by adjusting the compression amount or length s of the coil 104 (2) by the coil length adjusting unit 134. can get.

[Example 1]

  The inventor conducted an experiment to verify the action of the filter units 54 (IN) and 54 (OUT) in the plasma etching apparatus of the above embodiment. In this experiment, the case where the heating element 40 inside the susceptor 12 is electrically separated from the heater power feeding portion and the filter units 54 (IN) and 54 (OUT) are not disposed under the chamber 10 is used as a comparative reference example. In the comparative reference example, an etching process, specifically organic film etching, was selected such that the etching rate on the semiconductor wafer W was substantially uniform in the azimuth angle direction. The frequency of the first high frequency HF for plasma generation was 100 MHz, and the frequency of the second high frequency LF for ion attraction was 13 MHz.

  In this organic film etching, when there is no filter unit 54 (IN), 54 (OUT) under the chamber 10, two orthogonal directions (X direction and Y direction) on the semiconductor wafer W as shown in FIG. ) Obtained an experimental result in which the profiles of the etching rate distribution substantially overlap (hence, it can be considered that the etching rate is substantially uniform in the azimuth direction).

  Next, as an example, the filter units 54 (IN) and 54 (OUT) are arranged below the chamber 10 as in the above embodiment, and the heater power feeding unit is electrically connected to the heating element 40 inside the susceptor 12. Then, organic film etching was performed using the same recipe as the comparative reference example, using the impedances of the filter units 54 (IN) and 54 (OUT) for specific frequencies as parameters.

  In this embodiment, as shown in FIG. 13, the filter units 54 (IN) and 54 (OUT) are point-symmetric with respect to a vertical line N passing through the center of the semiconductor wafer W (that is, the center of the susceptor 12). Positions X (IN) and X (OUT) (positions 20 to 25 mm from the wafer edge position). Then, the coil length adjusting unit 134 provided in the filter unit 54 (IN) is used to coil the coils 104 (1) of the first and second filters 102 (1) and 102 (2) in the filter unit 54 (IN). ), 104 (2) by adjusting the length s, the impedance Z (IN) of both filters 102 (1), 102 (2) with respect to the second harmonic (200 MHz) of the first high frequency HF (100 MHz) is set to 40Ω. , 45Ω, 50Ω, 55Ω, and 60Ω were selected. On the other hand, the coil length adjusting unit 134 provided in the filter unit 54 (OUT) causes the coils 104 (1) of the first and second filters 102 (1) and 102 (2) in the filter unit 54 (OUT). , 104 (2) by adjusting the length s, the impedance Z (OUT) of both filters 102 (1), 102 (1) for the second harmonic (200 MHz) is 40Ω, 45Ω, 50Ω, 55Ω, 60Ω. I chose 5 ways. As combinations of [Z (IN), Z (OUT)], [40Ω, 40Ω], [40Ω, 45Ω], [40Ω, 50Ω], [40, 60Ω], [45Ω, 50Ω], [50Ω, 50 Ω], [50 Ω, 55 Ω], [50 Ω, 60 Ω], [55 Ω, 60 Ω], [60 Ω, 60 Ω] are selected, and in each case, the organic film etching of the above recipe is performed to perform the X direction and Y The etching rate distribution on the semiconductor wafer W in the direction was measured (acquired).

  FIG. 14 shows the experimental results of this example. As shown in the figure, when [Z (IN), Z (OUT)] = [40Ω, 40Ω], the etching rate near the left edge in the X direction (near the position directly above the filter unit 54 (OUT)) is in the Y direction. It is greatly different from the etching rate near the left edge. However, as in the case of [Z (IN), Z (OUT)] = [40Ω, 45Ω] and [Z (IN), Z (OUT)] = [40Ω, 50Ω], the second harmonic (200 MHz) When the impedance Z (OUT) of the filter unit 54 (OUT) is increased from 40Ω → 45Ω → 50Ω, the deviation of the etching rate between the X direction and the Y direction is reduced.

  On the other hand, when [Z (IN), Z (OUT)] = [50Ω, 60Ω], the etching rate near the right edge in the X direction (near the position directly above the filter unit 54 (IN)) and the right edge in the Y direction The etching rate is greatly deviated. However, as in the case of [Z (IN), Z (OUT)] = [55Ω, 60Ω] and [Z (IN), Z (OUT)] = [60Ω, 60Ω], the second harmonic (200 MHz) When the impedance Z (IN) of the filter unit 54 (IN) is increased from 50Ω → 55Ω → 60Ω, the etching rate deviation between the X direction and the Y direction is reduced.

  In this embodiment, the impedances Z (IN) and Z (OUT) of both filter units 54 (IN) and 54 (OUT) with respect to the second harmonic (200 MHz) are increased in both the X direction and the Y direction. Accordingly, the uniformity of the etching rate is the highest when [Z (IN), Z (OUT)] = [60Ω, 60Ω].

In addition, compared with the comparative reference example without the filter units 54 (IN) and 54 (OUT) (FIG. 12), the embodiment (FIG. 14) in which the filter units 54 (IN) and 54 (OUT) are provided has an etching rate. Is one step lower. This is because when the filter units 54 (IN), 54 (OUT) or the heater power supply unit is connected to the heating element 40 inside the susceptor 12, one of the high frequency HF, LF applied to the susceptor 12 from the high frequency power supplies 28, 30. Flows into the power supply lines 52 (IN) and 52 (OUT) through the inner and outer heating elements 40 (IN) and 40 (OUT), so that the high frequency HF and LF consumed for plasma generation and ion attraction This is because the power of is reduced. However, regarding the uniformity of the etching rate in the wafer radial direction, the example is far superior to the comparative reference example.

[Example 2]

  The inventor conducted another experiment for verifying the action of the filter units 54 (IN) and 54 (OUT) in the plasma etching apparatus of the above embodiment. Also in this second experiment, the case where the filter units 54 (IN) and 54 (OUT) are not disposed under the chamber 10 is used as a comparative reference example. In this comparative reference example, the etching rate on the semiconductor wafer W is in the azimuth direction. Dry cleaning was selected as another etching process that is substantially uniform.

  In this dry cleaning, when the filter units 54 (IN) and 54 (OUT) are not present, the etch crate distribution profiles on the semiconductor wafer W substantially overlap in the X and Y directions orthogonal to each other as shown in FIG. The experimental results were obtained.

  Next, as an example, dry cleaning was performed under the same conditions as the example of the first experiment except for the recipe, that is, the same recipe as the comparative reference example.

FIG. 16 shows the experimental results of the second example. Even in the second embodiment, the impedances Z (IN) and Z (OUT) of both the filter units 54 (IN) and 54 (OUT) are aligned, although not as much as in the first experiment. The effect of improving the uniformity of the etching rate in the azimuth angle direction was confirmed as the film was higher and higher.

[Other Embodiments or Modifications]

  Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical idea.

  For example, as a modification of the coil length adjusting unit 134 provided in the filter units 54 (IN) and 54 (OUT) of the above embodiment, as shown in FIG. 17, coils 104 (1) and 104 (2) A rod-shaped screw shaft 140 penetrating through the inside of the coil 104 and a coil receiving member 142 attached to the screw shaft 140 so as to be movable in the coil axis direction while being coupled or engaged with one end of the coils 104 (1), 104 (2). A configuration having a nut 146 that is screwed onto the screw shaft 140 to fix the coil receiving member 142 at a desired position via the washer 144 is also possible.

  Also, when the coil 104 (1) of the first filter 102 (1) and the coil 104 (2) of the second filter 102 (2) are arranged separately, the coils 104 (1), 104 (2 ) As described above can be provided individually. In that case, as shown in FIG. 18 and FIG. 19, each coil 104 (1), 104 (2) is wrapped in the above-described elastic tube 116 to form a coil winding structure without a gap. Is preferred.

  Further, the heating element 40 provided in the susceptor 12 is divided into three or more systems in the radial direction, and three or more filter units corresponding to each are arranged below the chamber 10 with an appropriate distance interval in the azimuth direction. In this case, the configuration of the above embodiment can be applied to each filter unit. The same applies to the case where only one filter unit is used without dividing the heating element 40.

  In the above embodiment, the coil length adjustment unit 134 is used to shorten the coils 104 (1) and 104 (2), and adjust the coil length s by changing the shortening amount. However, it is also possible to adjust the coil length s by extending the coils 104 (1) and 104 (2) longer than the natural length using the same coil length adjusting unit 134 as described above and changing the extension amount. Is possible. According to experiments conducted by the present inventor, when the coils 104 (1) and 104 (2) are extended, each resonance frequency of the parallel multiple resonance in the impedance characteristics of the filter is changed (shifted) in a direction in which the resonance frequency is uniformly increased. It has been confirmed that the amount of change (shift amount) of each resonance frequency increases as the coil extension amount increases, and the rate of change increases as the frequency increases.

  In the above embodiment, the input ends (upper ends) of the coils 104 (1) and 104 (2) are fixed as viewed from the high frequency noise entering the power supply lines 100 (1) and 100 (2) through the heating element 40. And the coil length adjustment part 134 was attached to the output end (lower end) side of the coils 104 (1) and 104 (2). As another embodiment, the output ends (lower ends) of the coils 104 (1) and 104 (2) are fixed, and the coil length adjusting unit is arranged on the input ends (upper end) side of the coils 104 (1) and 104 (2). A configuration in which 134 is attached is also possible.

  According to an experiment conducted by the present inventor, the output ends (lower ends) of the coils 104 (1) and 104 (2) are fixed, and the coil 104 (1) is moved from the input end (upper end) side by the coil length adjusting unit 134. ), 104 (2), the resonance frequency of the parallel multiple resonance in the impedance characteristics of the filter changes (shifts) in the direction of uniformly decreasing, and the amount of change in each resonance frequency as the coil shortening amount is increased. It has been confirmed that (shift amount) increases and the rate of change increases as the frequency decreases. Therefore, this embodiment can be suitably used when mainly adjusting the impedance of the filter with respect to the first high frequency HF or the second high frequency LF of the fundamental wave used for the plasma processing.

  The technique of the present invention and the technique described in Patent Document 1 can be used in combination. That is, in the filter or filter unit of the present invention, it is also possible to provide a specific impedance local variable member that gives a local change in the characteristic impedance of the distributed constant line in the middle of the line. Therefore, for example, in the above embodiment, a ring member made of a conductor or an insulator can be provided coaxially between the coils 104 (1), (2) and the outer conductor 110.

  The above embodiment is a capacitively coupled plasma etching apparatus of a lower two-frequency application system that applies a first high-frequency HF for plasma generation and a second high-frequency RF for ion attraction on the susceptor 12 in the chamber 10 in a superimposed manner. Noise of both frequencies is attenuated on the pair of heater power supply lines 100 (1) and 100 (2) that electrically connect the heating element 40 incorporated in the susceptor 12 and the heater power supply 58 installed outside the chamber 10. It was related to the filter. However, a capacitively coupled plasma etching apparatus of an upper and lower two frequency application system that applies a first high frequency HF for plasma generation to the upper electrode 64 and a second high frequency RF for ion attraction to the susceptor 12, or the susceptor 12 is applied. Also in the capacitively coupled plasma etching apparatus of the lower one frequency application system that applies a single high frequency, the filter or filter unit of the above embodiment can be suitably applied as it is.

  Further, the present invention is not limited to a filter for a power supply line such as a heater power supply line, but a predetermined electric member provided in the chamber and an external circuit of a power system or a signal system provided outside the chamber. Can be applied to any filter or filter unit provided on a pair of lines or a single line.

  The present invention is not limited to a capacitively coupled plasma etching apparatus, but can be applied to a microwave plasma etching apparatus, an inductively coupled plasma etching apparatus, a helicon wave plasma etching apparatus, and the like, and further, plasma CVD, plasma oxidation, The present invention can also be applied to other plasma processing apparatuses such as plasma nitriding and sputtering. In addition, the substrate to be processed in the present invention is not limited to a semiconductor wafer, and a flat panel display, an organic EL, various substrates for solar cells, a photomask, a CD substrate, a printed substrate, and the like are also possible.

10 Chamber 12 Susceptor (lower electrode)
24 exhaust device 28 (for plasma generation) high frequency power supply 30 (for ion attraction) high frequency power supply 32 matching unit 40 (IN) inner heating wire 40 (OUT) outer heating wire 54 (IN), 54 (OUT) filter unit 58 (IN), 58 (OUT) Heater power supply 100 (1) First feed line 100 (2) Second feed line 102 (1) First filter 102 (2) Second filter 104 (1), 104 (2) Coil 106 (1), 106 (2) Capacitor 110 Outer conductor 120 (1), 120 (2) Distributed constant line 126 Coil receiving member 132 Feed screw mechanism 134 Coil length adjustment section

Claims (23)

A processing vessel in which plasma processing is performed;
An electrical member provided in the processing vessel;
A line for electrically connecting the electrical member to an external circuit disposed outside the processing container;
A filter including a coil for attenuating or preventing high-frequency noise of a predetermined frequency that enters the line from the electrical member toward the external circuit;
A coil inductance adjustment unit for adjusting the inductance of the coil,
Between the windings of the coil is closed with an elastic insulator,
The coil inductance adjustment unit has a coil length adjustment unit for variably adjusting the winding interval of the coil.
Plasma processing equipment. A processing vessel in which plasma processing is performed;
A first electrode disposed in the processing vessel;
A heating element provided on the first electrode;
A power supply line for electrically connecting the heating element to a heater power source disposed outside the processing container;
A filter including a coil for attenuating or preventing high-frequency noise of a predetermined frequency that enters the power supply line via the heating element;
A coil inductance adjustment unit for adjusting the inductance of the coil,
Between the windings of the coil is closed with an elastic insulator,
The coil inductance adjustment unit has a coil length adjustment unit for variably adjusting the winding interval of the coil.
Plasma processing equipment.   The plasma processing apparatus according to claim 2, further comprising a high frequency power supply for applying a fundamental high frequency wave having a constant frequency to the electrode.   The plurality of heating elements are provided in parallel, and the plurality of filters respectively corresponding to the plurality of heating elements are arranged at a uniform distance in the azimuth direction. Plasma processing equipment.   The plasma processing apparatus according to claim 3, wherein the high-frequency noise includes a second harmonic having a frequency twice that of the fundamental wave.   The plasma processing apparatus according to claim 2, wherein an object to be processed is placed on the first electrode. The power supply line has first and second power supply conductors respectively connected to both ends of the heating element;
The coil includes a first coil unit constituting a part of the first power feeding conductor and a second coil unit constituting a part of the second power feeding conductor,
The first and second coil conductors constituting the first and second coils respectively are spirally wound with the same winding length while being translated,
The plasma processing apparatus as described in any one of Claims 2-6. The coil length adjuster is
A rod shaft that movably penetrates the inside of the coil;
A coil receiving member attached to the rod shaft so as to be slidable in the coil axial direction while being coupled or engaged with one end of the coil;
The plasma processing apparatus according to any one of claims 1 to 7, further comprising: a feed screw mechanism for moving the coil receiving member on the rod shaft and fixing the coil receiving member at a desired position. The coil length adjuster is
A rod-shaped screw shaft that movably penetrates the inside of the coil;
A coil receiving member attached to the screw shaft so as to be movable in the direction of the coil axis while being coupled or engaged with one end of the coil;
The plasma processing apparatus according to claim 1, further comprising: a nut that is screwed onto the screw shaft to fix the coil receiving member at a desired position.   The coil length adjusting unit fixes one end of the coil located on the processing container side and couples or engages the other end of the coil located on the opposite side to the processing container with the coil receiving member. Item 10. The plasma processing apparatus according to Item 8 or Item 9. The insulator is a tube covering the coil, the plasma processing apparatus according to any one of claims 1 to 10. The plasma processing apparatus according to any one of claims 1 to 11 , wherein the coil is an air-core coil. The filter has an outer conductor of the tubular accommodating or enclosing the coil, the characteristic impedance to form a predetermined distributed constant lines, plasma processing apparatus according to any one of claims 1 to 12. The plasma processing apparatus of claim 13 , wherein the outer conductor is electrically grounded. The plasma processing apparatus according to any one of claims 2 to 7, wherein the filter is disposed behind the first electrode when viewed from a processing space side in the processing container. When viewed from the processing chamber side, the coil is provided to the first stage of the filter, opposite terminal of the coil is electrically connected to the conductive member of the ground potential via a capacitor, according to claim 1 to 15 The plasma processing apparatus as described in any one of these. In a plasma processing apparatus in which an electrical member in a processing container in which plasma processing is performed is electrically connected via a line to an external circuit disposed outside the processing container, the electrical member is connected to the external circuit. A filter unit provided in the middle of the line to attenuate or prevent high-frequency noise of a predetermined frequency entering the line toward the line,
A coil constituting a part of the line;
A coil inductance adjustment unit for adjusting the inductance of the coil,
Between the windings of the coil is closed with an elastic insulator,
The coil inductance adjustment unit has a coil length adjustment unit for variably adjusting the winding interval of the coil.
Filter unit. In a plasma processing apparatus in which a heating element provided in a first electrode in a processing container in which plasma processing is performed is electrically connected to a heater power source disposed outside the processing container via a power supply line. A filter unit provided in the middle of the power supply line for attenuating or preventing high frequency noise of a predetermined frequency entering the power supply line from the heating element toward the heater power supply;
A coil constituting a part of the power supply line;
A coil inductance adjustment unit for adjusting the inductance of the coil,
Between the windings of the coil is closed with an elastic insulator,
The coil inductance adjustment unit has a coil length adjustment unit for variably adjusting the winding interval of the coil.
Filter unit. The coil length adjuster is
A rod shaft that movably penetrates the inside of the coil;
A coil receiving member attached to the rod shaft so as to be slidable in the coil axial direction while being coupled or engaged with one end of the coil;
The filter unit according to claim 17 or 18 , further comprising: a feed screw mechanism for moving the coil receiving member on the rod shaft and fixing the coil receiving member at a desired position. The coil length adjuster is
A rod-shaped screw shaft that movably penetrates the inside of the coil;
A coil receiving member attached to the screw shaft so as to be movable in the direction of the coil axis while being coupled or engaged with one end of the coil;
And a nut screwed to the screw shaft in order to fix the coil receiving member, the filter unit according to claim 17 or claim 18. The coil length adjusting unit fixes one end of the coil located on the processing container side and couples or engages the other end of the coil located on the opposite side to the processing container with the coil receiving member. Item 20. The filter unit according to Item 19 or Item 20 . The filter unit according to any one of claims 17 to 21 , wherein the insulator is a tube that covers the coil. The filter unit according to any one of claims 17 to 22 , wherein the coil is an air-core coil.

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