TW201207883A - Plasma processing apparatus and plasma processing method - Google Patents

Abstract

A plasma processing apparatus includes a processing chamber including a dielectric window; a coil-shaped RF antenna, provided outside the dielectric window; a substrate supporting unit provided in the processing chamber; a processing gas supply unit; an RF power supply unit for supplying an RF power to the RF antenna to generate a plasma of the processing gas by an inductive coupling in the processing chamber, the RF power having an appropriate frequency for RF discharge of the processing gas; a correction coil, provided at a position outside the processing chamber where the correction coil is to be coupled with the RF antenna by an electromagnetic induction, for controlling a plasma density distribution on the substrate in the processing chamber; a switching device provided in a loop of the correction coil; and a switching control unit for on-off controlling the switching device at a desired duty ratio by pulse width modulation.

Description

201207883 VI. Description of the Invention: [Technical Field] The present invention relates to a technique for performing plasma treatment on a substrate to be processed, and more particularly to an inductively coupled plasma processing apparatus and a plasma processing method. [Prior Art] In the processing of etching, deposition, oxidation, sputtering, and the like in a semiconductor device or a FPD (Flat Panel Display) process, plasma is often used in order to allow a good reaction to be performed at a relatively low temperature. In the past, such plasma treatments were mostly plasmas using high frequency discharge in the MHz field. The high-frequency discharge plasma is roughly divided into a capacitively coupled plasma and an inductively coupled plasma as a more specific (device) plasma generation method. Generally, an inductively coupled plasma processing apparatus is configured to form at least a portion (for example, a ceiling) of a wall portion of a processing container by a dielectric window, and supply a wire-shaped RF antenna provided outside the dielectric window. High frequency power. The processing container is a vacuum chamber that is decompressible, and a substrate to be processed (for example, a semiconductor wafer, a glass substrate, or the like) is disposed in a central portion of the chamber, and is introduced into a processing space set between the dielectric window and the substrate. Process the gas. The RF magnetic field flowing through the RF antenna through the RF current flowing through the RF antenna is generated around the RF antenna through an RF magnetic field such as a processing space in the chamber, and is processed by the temporal change of the RF magnetic field. An induced electric field is generated in the azimuthal direction in the space. Then, by inducing an electric field, electrons accelerated in the azimuthal direction are ionized and collided with molecules or atoms of the processing gas to form a donut-shaped plasma. -5- 201207883 By providing a large processing space in the chamber, the above-mentioned donut-shaped plasma can be efficiently diffused to the square (especially in the radial direction), and the density of the plasma on the substrate is relatively average. However, the homogeneity of the plasma density that can be achieved on a substrate by using a conventional RF antenna is insufficient in most plasma processes. In the inductively coupled plasma processing apparatus, the uniformity of the plasma density on the substrate is also one of the most important issues in terms of the uniformity, reproducibility, and manufacturing yield of the left and right plasma processes. So far, several techniques for this relationship have been proposed. A conventional technique for uniformizing the plasma density is to divide the RF antenna into a plurality of segments. In the RF antenna division method, the first high frequency power is supplied to each antenna/segment (for example, Patent Document 1), and the impedance of each antenna/segment can be changed by an additional circuit such as a capacitor. The high-frequency power source is allocated to the second aspect of the division ratio of the RF power of all the antennas* segments (for example, Patent Document 2). Further, there is a technique in which a single RF antenna is used, and a passive antenna is disposed in the vicinity of the RF antenna (Patent Document 3). The passive antenna is an independent coil that does not receive the supply of high-frequency power from the high-frequency power source, and the magnetic field generated by the RF antenna (inductive antenna) reduces the magnetic field strength in the loop of the passive antenna while making the passive antenna The strength of the magnetic field near the outside of the loop increases. Thereby, the radial direction distribution of the RF electromagnetic field in the plasma generating region in the chamber is changed. [Advanced Technical Literature] [Patent Literature]

S -6 - 201207883 [Patent Document 1] US Patent No. 540 1 3 0 0 [Patent Document 2] US Pat. No. 5,909,221 [Patent Document 3] Special Table 2005-534150 [Summary of the Invention] However, in the above-described RF antenna division method, the first aspect requires not only a plurality of high-frequency power sources but also the same number of integrators, and the high frequency power supply unit is complicated and the cost is high, which poses a large bottleneck. Further, in the second aspect, not only the impedance of each antenna/segment affects the impedance of the plasma but also the impedance of the other antennas and segments. Therefore, the division ratio cannot be arbitrarily determined by the additional circuit, and the controllability is difficult, and it is not used. Moreover, the conventional method of using the passive antenna disclosed in the above-mentioned Patent Document 3 is that the magnetic field generated by the RF antenna (inductive antenna) is affected by the presence of the passive antenna, whereby the plasma generation region in the chamber can be changed. The RF electromagnetic field is distributed in the radial direction, but the investigation of the role of the passive antenna is not sufficiently verified, and it is impossible to imagine a specific device configuration for controlling the plasma density distribution by using a passive antenna. In today's plasma process, as the substrate is enlarged and the device is miniaturized, a plasma having a lower pressure, a higher density, and a larger diameter is required, and the uniformity of the process on the substrate is a more difficult problem than before. In this point, the inductively coupled plasma processing device generates a donut shape on the inner side of the dielectric window close to the RF antenna, so that the donut-shaped plasma diffuses toward the substrate, but the plasma The diffusion pattern will vary with the pressure of the 201207883 chamber, and the density distribution on the substrate will easily change. Therefore, if the magnetic field generated by the RF antenna (inductive antenna) cannot be corrected, the pressure can be maintained even if the process recipe is changed, and the uniformity of the plasma density on the substrate can be maintained, so that the current plasma cannot be satisfied. The diverse and high process performance required for the processing equipment. The present invention has been made in view of the above-described conventional techniques, and it is not necessary to provide a special technique for the RF antenna or the high-frequency power feeding unit for plasma generation, and it is possible to control the plasma with a simple correction line. Inductively coupled plasma processing apparatus and plasma processing method for density distribution. (Means for Solving the Problem) The plasma processing apparatus according to the first aspect of the present invention includes: a processing container having a dielectric window; and a coil-shaped RF antenna disposed in the dielectric window And a substrate holding portion that holds the substrate to be processed y processing gas supply unit in the processing container, wherein the desired processing gas is supplied into the processing container in order to perform desired plasma processing on the substrate; a power feeding unit that supplies a high-frequency power suitable for a high-frequency discharge of a processing gas to the RF antenna for generating a plasma of a processing gas by inductive affinity in the processing container; In order to control the plasma density distribution on the substrate in the processing container, the RF antenna can be electromagnetically induced.

S -8- 201207883 is disposed outside the processing container; a switching element is disposed in a current path of the correction coil; and a switch control unit is configured to adjust a load ratio by a pulse width modulation ΟΝ/OFF controls the aforementioned switching elements. In the plasma processing apparatus according to the first aspect of the invention, in the above configuration, in particular, the configuration including the correction line 圏, the switching element, and the switch control unit is performed on the RF unit by the high frequency power supply unit. When the antenna supplies high-frequency power, the effect of the correction coil on the RF magnetic field generated around the antenna conductor by the high-frequency current flowing through the RF antenna can be fixedly and stably obtained (by the position overlapping the coil conductor) The plasma density of the core generated by inductive coupling is locally reduced. Moreover, the degree of such a correction coil effect (the effect of locally reducing the plasma density of the core) can be largely linearly controlled. Thereby, the plasma density distribution can be arbitrarily and finely controlled in the vicinity of the substrate on the substrate holding portion, and the uniformity of the plasma process can be easily achieved. A plasma processing apparatus according to a second aspect of the present invention includes: a processing container having a dielectric window; a coil-shaped RF antenna disposed outside the dielectric window; and a substrate holding portion The substrate to be processed is held in the processing container, a processing gas supply unit for supplying a desired processing gas to the processing container for performing a desired plasma treatment on the substrate, and a high frequency power supply unit for a plasma of a processing gas is generated by inductive coupling in the processing container, and high frequency power suitable for processing a high frequency discharge of the gas -9 - 201207883 is supplied to the RF antenna; a correction coil is used to control the foregoing Processing a plasma density distribution on the substrate in the container, and disposing outside the processing container at a position that can be coupled to the RF antenna by electromagnetic induction; and a variable resistor connected to the current path of the correction coil And a resistance control unit that controls the resistance 値 of the variable resistor to a desired 値. In the plasma processing apparatus according to the second aspect of the invention, the RF coiling device, the variable resistor, and the resistor control unit are provided in the above-described configuration, and the RF power supply unit is used to RF. When the antenna supplies high-frequency power, the effect of the correction coil on the RF magnetic field generated around the antenna conductor by the high-frequency current flowing through the RF antenna can be fixed and stabilized (to borrow near the position overlapping the turns conductor) The effect of the local plasma density generated by the inductive coupling is locally reduced. Moreover, the degree of such a correction coil effect (the effect of locally lowering the plasma density of the core) can be controlled substantially linearly. Thereby, the plasma density distribution can be arbitrarily and finely controlled in the vicinity of the substrate on the substrate holding portion, and the uniformity of the plasma process can be easily achieved. A plasma processing apparatus according to a third aspect of the present invention includes: a processing container having a dielectric window; an RF antenna disposed outside the dielectric window; and a substrate holding portion being subjected to the processing The substrate to be processed is held in the container»the processing gas supply portion for performing the desired electricity on the substrate

S -10- 201207883 slurry treatment, wherein the desired processing gas is supplied into the processing container; and the high frequency power feeding portion is adapted to generate plasma of the processing gas by induction pot in the processing container. The high frequency power of the frequency of the high frequency discharge of the processing gas is supplied to the RF antenna; the correction coil is for controlling the plasma density distribution on the substrate in the processing container, and is capable of being electromagnetically induced and the RF The position at which the antenna is coupled is disposed outside the processing container; and the shutter is disposed in the circuit of the correction coil. In the above-described configuration of the plasma processing apparatus according to the third aspect of the present invention, in particular, the configuration of the correction coil and the shutter is used to supply high-frequency power to the RF antenna by the high-frequency power supply unit. The effect of the correction magnetic field on the RF magnetic field generated around the antenna conductor by the high-frequency current flowing through the RF antenna (the core generated by inductive coupling near the position overlapping the coil conductor) can be selectively obtained. The plasma density is locally reduced by the effect). A plasma processing apparatus according to a fourth aspect of the present invention includes: a processing container having a dielectric window; an RF antenna disposed outside the dielectric window; and a substrate holding portion being subjected to the processing The processing substrate » the processing gas supply unit is configured to supply the desired processing gas to the processing container in order to perform the desired plasma processing on the substrate; and the high frequency power feeding unit is disposed in the processing container. The plasma of the processing gas is generated by inductive coupling, and the high frequency power of the high frequency discharge -11 - 201207883 suitable for the processing gas is supplied to the RF antenna: the first and second correction coils are controlled The plasma density distribution on the substrate in the processing container is disposed outside the processing container at a position that can be coupled to the RF antenna by electromagnetic induction; and the first and second switches are respectively provided In the circuit of the first and second correction coils, in the plasma processing apparatus according to the fourth aspect, the above-described first and second compensations are provided by the above-described configuration. When the coil and the first and second shutters supply high-frequency power to the RF antenna by the high-frequency power supply unit, the correction coil can be selectively obtained by generating a high-frequency current flowing through the RF antenna. The action of the RF magnetic field around the antenna conductor (the effect of locally reducing the plasma density of the core generated by inductive coupling in the vicinity of the position where the coil conductor overlaps), and the first correction coil and the second correction coil The working mode (contour) of the entire correction coil is selected in a variety of combinations. The plasma processing method according to the fifth aspect of the present invention is a plasma processing method for performing a desired plasma treatment on the substrate in a plasma processing apparatus. The plasma processing apparatus includes: a processing container having a dielectric window; a coil-shaped RF antenna disposed outside the dielectric window; and a substrate holding portion attached to the processing container Maintaining a substrate to be processed » a processing gas supply unit for supplying a desired processing gas to the processing container in order to perform a desired plasma treatment on the substrate;

S -12-201207883 A high frequency power supply unit that supplies high frequency power suitable for the frequency of high frequency discharge of a process gas to the aforementioned RF in order to generate plasma of a process gas by inductive coupling in the processing container The plasma processing method is: in addition to the processing container, a correction coil that can be combined with the RF antenna by electromagnetic induction is disposed in parallel with the RF antenna, and a switch is provided in the circuit of the correction coil to control The opening and closing state of the shutter is used to control the plasma density on the substrate. In the plasma processing method according to the above fifth aspect, the correction coil and the RF antenna which can be combined with the RF antenna by electromagnetic induction are arranged in parallel, in particular, outside the processing container, and the correction coil is provided in the above-described technique. A switch is provided in the circuit to control the opening/closing (ΟΝ/OFF) state of the switch, and when the high-frequency power supply unit supplies high-frequency power to the RF antenna, the correction coil can be fixedly and stably obtained by flowing to the RF. The high-frequency current of the antenna is generated by the action of the RF magnetic field around the antenna conductor (the effect of locally lowering the plasma density of the core generated by inductive coupling near the position where the coil conductor overlaps). Thereby, the plasma density distribution can be arbitrarily controlled in the vicinity of the substrate on the substrate holding portion, and the uniformity of the plasma process can be easily achieved. A plasma processing method according to a sixth aspect of the present invention is directed to a plasma processing method for performing a desired plasma treatment on a substrate in a plasma processing apparatus, the plasma processing apparatus comprising: a processing container having a dielectric -13-201207883 A coil-shaped RF antenna is disposed outside the dielectric window; and a substrate holding portion that holds the substrate to be processed»the processing gas supply unit in the processing container, Performing a desired plasma treatment on the substrate, and supplying a desired processing gas to the processing chamber; and a high-frequency power feeding portion for generating a plasma of the processing gas by inductive coupling in the processing container. The high-frequency power suitable for processing the frequency of the high-frequency discharge of the gas is supplied to the RF antenna; and the first and second correction coils that can be combined with the antenna by electromagnetic induction are provided outside the processing container. The first and second shutters are provided in the circuits of the first and second correction coils, and the opening and closing states of the first and second switches are controlled. 'From controlling the plasma density on the substrate. In the plasma processing method according to the sixth aspect described above, the first and second correction lines 圏 and the RF antenna which can be combined with the antenna by electromagnetic induction are parallel to the processing container, in particular, in addition to the processing container. In the circuit of the first and second correction coils, the first and second switches are provided to control the opening and closing (ON/OFF) states of the first and second switches. When the power supply unit supplies high-frequency power to the RF antenna, the shape of the RF magnetic field generated by the high-frequency current flowing through the RF antenna is generated and stabilized. The density of the core generated by inductive coupling near the overlapping position is locally low

S -14- 201207883 Reduced effect). Thereby, the plasma density distribution can be arbitrarily controlled in the vicinity of the substrate on the substrate holding portion, and the uniformity of the plasma process can be easily achieved. [Effects of the Invention] According to the plasma processing apparatus or the plasma processing method of the present invention, the RF antenna or the high-frequency power feeding unit for plasma generation does not require special work by the above-described configuration and action. A simple correction coil is used to finely control the plasma density distribution. [Embodiment] Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings. [First Embodiment] A first embodiment of the present invention will be described with reference to Figs. 1 to 10 . Fig. 1 shows the configuration of an inductively coupled plasma processing apparatus according to a first embodiment. This inductively coupled plasma processing apparatus is a plasma etching apparatus using a planar coil-shaped RF antenna, and has a cylindrical vacuum chamber (processing vessel) 10 made of, for example, aluminum or stainless steel. The chamber 10 is safely grounded. First, the configuration of each unit irrespective of plasma generation in the inductively coupled plasma etching apparatus will be described. In the center of the lower portion of the chamber 10, the disk-shaped susceptor 1 2 on which the substrate to be processed, for example, the semiconductor wafer W, is placed is horizontally disposed as a substrate holding table having a high-frequency electrode. This pedestal 2 is made of, for example, aluminum and is supported by an insulating cylinder -15-201207883-shaped support portion I4 which extends vertically from the bottom of the chamber 10 to the upper side. An annular exhaust path is formed between the conductive cylindrical support portion 16 extending vertically from the bottom of the chamber 10 to the upper portion of the insulating cylindrical support portion 14 and the inner wall of the chamber 10 18. An annular baffle 20 is attached to the upper portion or the inlet of the exhaust passage 18, and an exhaust port 22 is provided at the bottom. In order to make the airflow in the chamber 10 uniform with respect to the semiconductor wafer W on the susceptor 12, it is preferable to provide a plurality of exhaust ports 22 at equal intervals in the circumferential direction. Each of the exhaust ports 22 is connected to the exhaust unit 26 via an exhaust pipe 24. The exhaust unit 26 is a vacuum pump having a turbo molecular pump or the like, and can decompress the plasma processing space in the chamber 10 to a desired degree of vacuum. A gate valve 28 that opens and closes the carry-out port 27 of the semiconductor wafer W is attached to the outside of the side wall of the chamber 10. The high frequency power source 30 for RF bias is electrically connected to the susceptor 12 via the integrator 32 and the feed bar 34. This high-frequency power source 30 can output a high-frequency RFL suitable for controlling a certain frequency (below 13.56 MHz) of ion energy introduced to the semiconductor crystal P W with variable power. The integrator 32 is an integrated circuit having a variable reactance for integrating the impedance of the high frequency power supply 30 side with the impedance of the load (mainly the base, plasma, chamber) side. A blocking capacitor for self-bias generation is included in the integrated circuit. An electrostatic chuck 36 for holding the semiconductor wafer W by electrostatic attraction is provided on the upper surface of the susceptor 12, and a focus ring 38 surrounding the periphery of the semiconductor crystal OW is provided on the outer side in the radial direction of the electrostatic chuck 36. The electrostatic chuck 36 is an electrode formed of a conductive film between a pair of insulating films 36b, 36c.

In S-16-201207883 3 6a, the high-voltage DC power source 40 is electrically connected to the electrode 36a via the switch 42 and the covered wire 43. The semiconductor wafer W can be adsorbed and held on the electrostatic chuck 36 by electrostatic force by a DC voltage applied from a DC power source 4〇. An annular refrigerant chamber or a refrigerant flow path 44, for example, along the circumferential direction is provided inside the susceptor 12. The refrigerant chamber 44 is a refrigerant such as cooling water cw that is circulated and supplied to a predetermined temperature from a cooling unit (not shown) via pipes 46 and 48. The temperature in the process of the semiconductor wafer W on the electrostatic chuck 36 can be controlled by the temperature of the refrigerant. In connection with this, a heat transfer gas such as He gas from a heat transfer gas supply unit (not shown) is supplied between the upper surface of the electrostatic chuck 36 and the back surface of the semiconductor wafer W via the gas supply tube 50. Further, a lift pin that can move up and down through the susceptor 12 in the vertical direction for loading/unloading of the semiconductor wafer W, a lifting mechanism (not shown), and the like are provided. Next, the configuration of each portion related to plasma generation in the inductively coupled plasma etching apparatus will be described. The ceiling of the chamber 10 is spaced apart from the base 12 by a large distance, and a circular dielectric window 52 composed of, for example, a quartz plate is hermetically mounted. On the dielectric window 52, a wired antenna RF antenna 54 is generally disposed horizontally coaxially with the chamber 10 or the susceptor 12. Preferably, the RF antenna 54 is a body having, for example, a spiral coil (Fig. 2A) or a concentric circular coil having a constant radius in each week (Fig. 2B), and is fixed to the antenna fixing member (not shown) formed of an insulator. On the dielectric window 52. At one end of the RF antenna 54, the output terminal of the high frequency power source 56 for plasma generation is electrically connected via the integrator 58 and the feed line 60. The other end of the RF antenna 54, -17-201207883, is omitted, but is actually electrically connected to the ground potential via a grounding wire. The high-frequency power source 56 can output a high-frequency rFh at a constant frequency (13.5 6 MHz or more) suitable for plasma generation by high-frequency discharge with variable power. The combiner 58 is an integrated circuit having a variable reactance for integrating the impedance on the side of the high-frequency power source 56 with the impedance of the load (mainly the RF antenna, the plasma 'correction coil' side). The processing gas supply unit for supplying the processing gas to the processing space in the chamber 1 has an annular manifold or buffer portion 62 which is provided in the chamber at a position slightly lower than the dielectric window 52. Among the side walls of 10 (or outside); a plurality of side wall gas discharge holes 64 which face the plasma generation space from the buffer portion 62 at equal intervals in the circumferential direction; and a gas supply pipe 68 which is supplied from the process gas The source 66 extends to the buffer portion 62. Further, the processing gas supply source 66 includes a flow rate controller and an on-off valve (not shown). The inductively coupled plasma etching apparatus includes: a correction coil 70 for variably controlling the density distribution of the inductively coupled plasma generated in the processing space in the chamber 10 in the radial direction, and is disposed in the chamber 1 The antenna room of the atmospheric pressure space on the top plate can be combined with the RF antenna 54 by electromagnetic induction: and the switching mechanism 110 is used to variably control the load ratio of the energization current of the correction coil 7 〇 flow induction current. -18- 201207883 The configuration and function of the correction coil 7 〇 and the switching mechanism 1 1 0 will be described in detail later. The main control unit 74 is, for example, a microcomputer, and controls each unit in the plasma etching apparatus such as the exhaust unit 26, the high-frequency power sources 30 and 56, the integrators 32 and 58 , the switch 42 for the electrostatic chuck, the processing gas supply source 66, and The operation of each of the switching mechanism 110, the cooling unit (not shown), the heat transfer gas supply unit (not shown), and the entire operation (sequence) of the apparatus. In the inductively coupled plasma etching apparatus, in order to perform the etching, the gate wafer 28 is first opened, and the semiconductor wafer w to be processed is carried into the chamber 10 and placed on the electrostatic chuck 36. Then, after the gate valve 28 is closed, the etching gas (generally a mixed gas) is introduced from the processing gas supply source 6 through the gas supply pipe 68, the buffer portion 62, and the side wall gas discharge hole 64 at a predetermined flow rate and flow ratio. The chamber 10 is placed in the chamber 10 and the pressure in the chamber 10 is set by the exhaust device 26. Further, the high frequency power source 56 is turned on (ON) to output the high frequency RFH for plasma generation at a predetermined RF power, and the current of the high frequency RFH is supplied to the RF antenna 54 via the integrator 58 to the electric wire 60. On the other hand, the high-frequency power source 30 is turned on to cause the high-frequency RFL for ion introduction control to be output at a predetermined RF power, and this high-frequency RFL is applied to the susceptor 12 via the combiner 32 and the feed bar 34. Further, the heat transfer gas supply unit supplies the heat transfer gas (He gas) to the contact interface between the electrostatic chuck 36 and the semiconductor wafer W, and the ON switch 42 is electrostatically attracted by the electrostatic chuck 36. The heat transfer gas is shut off at the above contact interface. The etching gas discharged from the side wall gas discharge holes 64 is uniformly processed in the processing space under the dielectric window 52. By the current flowing from the high frequency -19-201207883 RFH of the RF antenna 54, the magnetic field passing through the dielectric window 52 and passing through the plasma generating space in the chamber is generated around the RF antenna 54 by the RF antenna 54. The temporal variation of this RF magnetic field produces an RF induced electric field in the azimuthal direction of the processing space. Then, by inducing the electric field, the electrons accelerated in the azimuthal direction collide with the molecules or atoms of the etching gas to form a donut-shaped plasma. The free radicals or ions of the donut-shaped plasma diffuse in the square in a wide processing space, and the radicals are equally dropped, and the ions are attracted by the DC bias and supplied to the upper surface of the semiconductor wafer W (processed surface). Thus, on the surface to be processed of the wafer W, the active species of the plasma brings about a chemical reaction and a physical reaction, and the processed film is etched into a desired pattern. The inductively coupled plasma etching apparatus is formed as described above under the dielectric window 52 of the RF antenna 54 to form an inductively coupled plasma in a donut shape, so that the donut-shaped plasma is dispersed in a wide area. Within the processing space, the density of the plasma is averaged near the susceptor 12 (i.e., on the semiconductor wafer W). Here, the density of the donut-shaped plasma depends on the intensity of the induced electric field, and even depends on the power of the high frequency RFH supplied to the RF antenna 54 (more correctly, the current flowing through the RF antenna 54). That is, the higher the power of the high-frequency RFH, the higher the density of the donut-shaped plasma, and the higher the plasma density near the susceptor 12 via the diffusion of the plasma. On the other hand, the doughnut-shaped electricity The form in which the slurry diffuses in the square (especially in the radial direction) mainly depends on the pressure in the chamber 10. The lower the pressure, the more plasma is concentrated in the center of the chamber 10, and there is a plasma near the susceptor 1 2 . The density distribution tends to rise at the center. Further, the plasma density distribution in the donut-shaped plasma is in accordance with the power of the high-frequency RFH supplied to the RF antenna 54 or the flow rate of the processing gas introduced into the chamber 10.

S -20- 201207883 and changed. Here, the "doughnut-shaped plasma" is not limited to a plasma that does not form a plasma in the inner diameter (center portion) of the chamber and is rigidly annular only in the radial direction. The bulk density of the slurry is larger than the inner diameter of the chamber 1 径. Further, 'the condition of the gas type of the processing gas or the pressure enthalpy in the chamber 10' also does not mean the so-called "sweet and sweet plasma J. This plasma uranium engraving device is such that the susceptor 12 The vicinity of the plasma density distribution direction is uniformized, and the field generated by the RF antenna 54 is corrected by the electromagnetic field by the correction ring 70, and according to the process conditions (in the chamber 10, etc.), by the switching mechanism 1 1 〇 The energization load of the correction line 圏 70 is changed. Hereinafter, the configuration and action of the correction ring 70 and the switching mechanism 110 which are the main components of the inductively coupled plasma etch apparatus will be described. More specifically, as shown in FIG. The correction coil 70 is an annular single-coil or a rewind coil that is opened by a gap g sandwiched between both ends, and the radial coil conductor can be located near the inner circumference and the outer circumference of the RF antenna 54. The RF antenna 54 is disposed coaxially and horizontally held at a constant height position of the RF antenna 54 by an insulating coil holding structure. The material of the correction coil 70 is preferably a metal having a high conductivity such as a copper system. In addition, in the present invention, "Coaxial" is a positional relationship in which a plurality of coils or respective central axes overlap each other, and not only when the respective coil antenna faces are offset from each other in the axial direction or the longitudinal direction, but also include a plasma accumulation of 10 or a diameter in use. The RF magnetic pressure is moderately proportional to the identifiable portion, so that the proximity coil (or the antenna surface or the same - 21 - 201207883 surface is coincident (concentric positional relationship). Here, there will be no gap g in the correction coil 70. The correction coil 70', which is called a completely endless type, explains the effect of changing the height position of the completely endless type correction coil 70. First, as shown in Fig. 3A, the height correction position of the completely endless type correction coil 7 (Τ) When near the upper limit ,, the RF magnetic field generated around the antenna conductor by the current flowing through the high frequency RFH of the RF antenna 54 is not affected by any of the completely endless type correction coil 70', forming a radial direction A loop-shaped magnetic field line of the processing space under the dielectric window 52. The radial direction (horizontal) component Br of the magnetic flux density of the processing space is independent of the center (0) and the peripheral portion of the chamber 10. The current of the frequency RFH is often zero, and the position where the radial direction overlaps with the vicinity of the inner circumference and the outer circumference of the RF antenna 54 (hereinafter referred to as "antenna intermediate portion") is extremely large, and the current of the high frequency RFh is larger. The higher the maximum value, the intensity distribution of the induced electric field in the azimuthal direction generated by the RF magnetic field 也会 also forms the same contour as the magnetic flux density Br in the radial direction. Thus, in the vicinity of the dielectric window 52 and the RF antenna 54 The donut-shaped plasma is formed coaxially. Then, the doughnut-shaped plasma diffuses to the square (especially in the radial direction) in the processing space. As described above, the diffusion pattern depends on the pressure inside the chamber 1〇. For example, as shown in FIG. 3A, in the radial direction in the vicinity of the susceptor 12, the electron density (plasma density) relatively increases (maintains greatly) at the center portion and the peripheral portion at a position corresponding to the intermediate portion of the antenna. Drop the outline like that. In such a case, as shown in FIG. 3B, if the height position of the completely endless type correction-22-201207883 coil 70' is lowered to the vicinity of the lower limit 例如, for example, as shown in the figure, the flow is high by the RF antenna 54. The RF RF field current generated by the RF field around the antenna conductor is affected by the electromagnetic induction reaction due to the completely endless type correction coil 7〇'. The reaction of this electromagnetic induction is to resist the change of the magnetic field lines (magnetic fluxes) in the circuit of the completely endless type correction coil 071, and the electric current flows in the circuit of the completely endless type correction coil 7〇'. Thus, by the reaction of electromagnetic induction from the completely endless type correction coil, the magnetic flux of the processing space near the dielectric window 52 at the position substantially directly below the coil conductor (particularly the intermediate portion of the antenna) of the completely endless type correction coil The radial direction (horizontal) component Br of the density is locally weakened, so that the intensity of the induced electric field in the azimuthal direction is also locally weakened at the position corresponding to the intermediate portion of the antenna, similarly to the magnetic flux density Br. As a result, in the vicinity of the susceptor 12, the electron density (plasma density) is moderately uniform in the radial direction. The diffusion form of the plasma as shown in Fig. 3A is an example. For example, when the pressure is low, the plasma is excessively concentrated in the center portion of the chamber 10, as shown in Fig. 4A, and sometimes the electrons near the susceptor 12 are displayed. The density (plasma density) becomes a mountain-like contour that is extremely large at the center. In this case, as shown in FIG. 4B, once the completely endless type correction coil 70' is lowered to the vicinity of the lower limit 例如, for example, as shown in the figure, the intermediate portion overlapping the turns conductor of the completely endless type correction coil 70' is shown. The position, the radial direction (horizontal) component Br of the magnetic flux density in the processing space near the dielectric window 52 is locally weakened, whereby the concentration of the plasma toward the center of the chamber is reduced by -23-201207883, The plasma density near the susceptor 12 is moderately normalized in the radial direction. The inventors verified the role of the completely endless type correction line 圏 70' as described above by electromagnetic field simulation. In other words, the relative height position (distance interval) of the RF antenna 54 by the completely endless type correction coil 70' is used as a parameter, and the parameters are selected as 4 types of 5 mm, 10 m, 20 mm, and infinite (uncorrected coil). When the current density distribution (corresponding to the plasma density distribution) in the radial direction of the donut-shaped plasma (the position of 5 mm from the upper surface) is taken, the verification result as shown in Fig. 5 can be obtained. In the electromagnetic field simulation, the outer diameter (radius) of the RF antenna 54 was set to 25 mm, and the inner circumference radius and the outer circumference radius of the completely endless type correction line ’ 70' were set to l 〇〇 mm and 130 mm, respectively. The donut-shaped plasma generated by the inductive coupling in the processing space below the RF antenna 54 is simulated by a disk-shaped resistor, and the diameter of the resistor is set to 500 mm, and the resistivity is set. Set to 100 Vcm and set the skin thickness to 10 mm. The frequency of the high frequency RF η for plasma generation is 13.56 MHz. As can be seen from FIG. 5, if the completely endless type correction coil 70' is disposed at a height position where the RF antenna 54 is coupled by electromagnetic induction, the plasma density in the sweet-shaped plasma is overlapped with the coil conductor of the correction line 70. The position (the example shown in the figure is a position overlapping the intermediate portion of the antenna) is locally lowered, and the more the endless type correction coil 70' approaches the RF antenna 54, the more the local reduction degree becomes substantially linear. In the inductively coupled plasma etching apparatus (Fig. 1) of this embodiment, instead of using the completely endless type correction coil 70' as described above, as shown in Fig. 6, a single roll opened by sandwiching a moderate gap g at both ends is used. Coil (or rewinding line)

The correction line 圏7 Ο ′ formed by the S-24-201207883 circle is connected to the switching element 1 1 2 between the two open ends of the correction coil 70. The switching mechanism 1 10 has a switching control circuit 1 for controlling the switching element 1 12 by a pulse width modulation (PWM) at a certain frequency (for example, 1 to 1 〇〇 kHz) ΟΝ/OFF control or switching (Switching) 14. A specific configuration example of the switching mechanism 110 is shown in FIG. In this configuration example, the switching element Π 2 is a pair of transistors (for example, IGBT or MOS transistors) 112A and 112B that are reversely connected in parallel with each other, and a diode 201A for reverse bias protection is connected in series with each of the transistors 112A and 112B. 116B. The two transistors 112A, 112B are positively induced currents that flow in the positive direction of the correction coil 70 in the positive half of the first half of the high frequency in the ON/OFF » ON period in accordance with the PWM control signal SW from the switch control circuit 114. i + is a negative inductive current i flowing in the first transistor 112A and the first diode 116A and flowing in the reverse direction to the correction coil 70 in the half cycle of the second half of the high frequency, and flows through the second transistor. 112B and second diode 116B. Although not shown, the switch control circuit 1 14 actually has a triangular wave generating circuit that generates, for example, a triangular wave signal of a certain frequency described above, and a variable voltage signal generating circuit that corresponds to a desired duty ratio (pulse of one cycle) a voltage level at a variable voltage level during ON) generates a voltage signal; the comparator 'compares the respective voltage levels of the triangular wave signal and the variable voltage signal to generate a 2-W pWM control according to its magnitude relationship The signal SW; and -25-201207883 drive circuit drives the two transistors 1 1 2 A, 1 1 2B with a PWM control signal SW. Here, the expected duty ratio is given from the main control unit 74 to the switch control circuit 1 14 via the predetermined control signal S D . According to this embodiment, the switching mechanism 110 configured as described above can control the energization load ratio of the correction coil 70 by the PWM control in the plasma process, as shown in Fig. 8, which can be 〇% to 100%. The electric load ratio is controlled to be arbitrarily changed within the range. What is important here is that the duty ratio of energization of the flow induced current i at the correction line 圏70 can be arbitrarily changed in the range of 0% to 100% by the PWM control as described above, and the original position HP near the upper limit position. It is functionally equivalent to arbitrarily change the height position of the completely endless type correction coil 70' as described above between the lower limit position of the proximity RF antenna 54. In other words, the correction coil 70 is fixed to the height position near the RF antenna 54 by the switching mechanism 110, and the characteristics of FIG. 5 can be realized by means of the device, thereby making it possible to easily achieve the plasma density distribution control. Increased freedom and precision. Therefore, the energization load ratio of the control correction coil 70 can be changed via the switching mechanism 1 1〇 every time the process recipe changes all or part of the process conditions, whereby the correction coil 7 can be arbitrarily and finely adjusted. The current flowing through the high frequency RFH of the RF antenna 54 acts on the RF magnetic field around the antenna conductor, that is, the plasma in the donut-shaped plasma near the position where the coil conductor of the correction coil 70 overlaps. The degree to which the density is locally reduced (strength). The inductively coupled plasma etching apparatus of this embodiment is, for example, an application of 多层-26-201207883 for continuously etching a multilayer film on the surface of a substrate in a plurality of steps. Hereinafter, an embodiment of the present invention relating to the multilayer mask method (Multilayer Resist) as shown in Fig. 9 will be described. In FIG. 9, on the main surface of the semiconductor wafer W to be processed, the SiN layer 102 as the lowermost layer (final mask) is formed on the original processed film (for example, Si film for gate) 100, An organic film (for example, carbon) 104 as an intermediate layer is formed thereon, and an uppermost photoresist 108 is formed thereon via a Si-containing anti-reflection film (BARC) 106. The film formation of the SiN layer 102, the organic film 104, and the anti-reflection film 106 is a coating film formed by CVD (Chemical Vacuum Dip Method) or spin coating, and the patterning of the photoresist 108 is by using light micro- Photolithography. First, in the etching process of the first step, as shown in Fig. 9 (A), the Si-containing anti-reflection film 106 is etched using the patterned photoresist 108 as a mask. In this case, the etching gas is a mixed gas using CF4/02, and the pressure in the chamber 10 is set to be relatively low, for example, 10 mTorr. Next, in the etching process of the second step, as shown in Fig. 9 (B), the organic film 104 is etched by using the photoresist 108 and the anti-reflection film 106 as a mask. In this case, the etching gas is a single gas using 02, and the pressure in the chamber 10 is set to be lower, for example, 5 mTorr. Finally, in the etching process of the third step, as shown in (C) and (D) of Fig. 9, the SiN film 102 is etched by using the patterned anti-reflection film 106 and the organic film 104 as a mask. In this case, the etching gas is a mixed gas of CHF3/CF4/Ar/02, and the pressure in the chamber 10 is set to be relatively high, for example, 50 mTorr. 〇-27-201207883 In the multi-step etching process as described above, Each step converts all or a portion of the process conditions (especially the pressure within the chamber 10) whereby the diffusion pattern of the sweet-like plasma changes in the processing space. Here, when the correction coil 70 is completely incapable of functioning (energization), in the processes of the first and second steps (pressures below 10 mTorr), the electron density (plasma density) in the vicinity of the susceptor 12 as shown in FIG. 4A is relatively In the center portion, a steep mountain-shaped contour is formed which is significantly swelled, and the process (pressure 50 mT 〇 rr) in the third step is a mountain-shaped contour in which the center portion is slightly raised. According to this embodiment, for example, in the process recipe, the energization of the correction coil 70 is set by adding a normal process condition (high-frequency power, pressure, gas type, gas flow rate, etc.) or by relating to such a process. The load ratio is one of the prescription information or process parameters. Further, when the etching process of the above-described multi-step process is performed, the main control unit 74 reads out the data indicating the energization load ratio from the memory, and sets the energization load of the correction coil 70 to the comparison by the switching mechanism 1 10 in each step. value. For example, when performing a multi-step etching process using the multilayer photoresist method as shown in FIG. 9, as shown in FIG. 10, in the first step (10 mTorr), switching to a relatively large duty ratio Di, in the second step (5 mTorr) It is switched to a larger duty ratio D2, and in the third step (50 mTorr), it is switched to a relatively small duty ratio D3, and the energization load ratio of the correction coil 70 is switched at each step. Further, from the viewpoint of plasma ignitability, immediately after the start of the process of each step, the energization of the correction line 70 is forcibly held in the (OFF) state to cause the plasma to be surely ignited, in the plasma. After the ignition, it is also effective to set the power-on load ratio of the 値.

S -28-201207883 [Second Embodiment] Next, a second embodiment of the present invention will be described with reference to Figs. 11 to 14 . Fig. 11 shows the configuration of an inductively coupled plasma etching apparatus according to a second embodiment. In the drawings, the same components as those of the apparatus (Fig. 1) of the first embodiment are denoted by the same reference numerals. The feature of the second embodiment is a configuration in which the resistance variable mechanism 1 20 is provided instead of the switch mechanism 1 10 as compared with the first embodiment. More specifically, the correction coil 70 is constituted by an annular single-coil coil or a rewinding coil that is opened by sandwiching an appropriate gap g at both ends, so that the coil conductor in the radial direction can be located between the inner circumference and the outer circumference of the RF antenna 54. The method (preferably in the vicinity of the center) is coaxially arranged with respect to the RF antenna 54, and is horizontally held by an insulating coil holding member (not shown) at a position close to the height of the RF antenna 54. As shown in FIG. 12, the variable resistance mechanism 120 has a variable resistor 122 connected to the two open ends of the correction coil 70: and a resistance control portion 14 which is a resistor of the variable resistor 1 22 The cockroach is controlled to the desired cockroach. A specific configuration example of the resistance variable mechanism 120 is shown in FIG. The variable resistor 1 22 of this configuration example has a metal-based or carbon-based resistor body 128 having a high specific resistance, and the insulator 1 26 is interposed between the open ends of the correction coil 70 so as to block the gap g between the open ends of the correction coil 70. Insertion: and -29 - 201207883 The bridge type short-circuit conductor 130 is short-circuited between the two points at a predetermined distance between the correction coils 7A. The material of the bridge type short-circuit conductor 130 is high in electrical conductivity, and is preferably a copper-based metal. The resistance control unit 124 has a sliding mechanism 132 for supporting the bridge-type short-circuit conductor 130 while sliding on the correction coil. And a resistance position control unit 134 via the sliding mechanism 133 to align the position of the bridge type short-circuit conductor 130 with the desired resistance position. More specifically, the sliding mechanism 132 is constituted by a ball screw mechanism, and rotates the stepping motor 138 of the horizontally extending conveying screw 136 at a predetermined position, and has a nut portion (not shown) screwed to the conveying screw 136. a slider body 140 horizontally moving in the axial direction by the rotation of the conveying screw 136, a compression coil spring 142 coupled to the slider body 140 and the bridge type short-circuit conductor 130, and a slidably fitted in the vertical direction The cylindrical bodies 144, 146 are formed. Here, the outer cylindrical body 144 is fixed to the slider body 140, and the inner cylindrical body 146 is fixed to the bridge type short-circuit conductor 130. The compression coil spring 142 pushes the bridge type short-circuit conductor 130 to the correction coil 70 by an elastic force. The resistance position control unit 134 controls the position of the bridge type short-circuit conductor 130 via the rotation direction and the amount of rotation of the stepping motor 138. The target position of the bridge type short-circuit conductor 130 is given to the resistance position control unit 134 from the main control unit 74 (Fig. 1 1) via the predetermined control signal S R . Here, the resistance variable mechanism 120 will be described with reference to FIGS. 13 and 14A to 14C.

The role of S -30- 201207883. First, when the bridge type short-circuit conductor 130 is set to the position shown in FIG. 13, both ends of the coil conductor of the correction coil 7 不会 are bypassed by the bridge type short-circuit conductor 130 without being electrically connected via the resistor 1 2 8 . . Thereby, the resistance 値 of the variable resistor 1 22 forms the lowest 値 (substantially zero), whereby the coil resistance 全体 of the entire coil 70 is corrected to form the lowest 値. From the state of Fig. 13, the bridge type short-circuit conductor 130 is slid to the right of the figure, and is positioned at the position shown in Fig. 14A. This position is that the contact portion 130R of one end (right end) of the bridge type short-circuit conductor 130 is connected to the one end (right end) portion of the coil conductor as it is, but the contact portion 130L of the other end (left end) is beyond the other end of the coil conductor (left end) And enters into the interval of the resistor body 128. Thereby, the resistance 値 of the variable resistor 1 22 is not zero, and a significant enthalpy is formed, and the coil resistance 全体 of the entire correction coil 70 is higher than that of Fig. 13 . When the bridge type short-circuit conductor 130 is further slid to the right in the state of FIG. 14A, the section length of the resistor body 128 occupied by the current path of the correction coil 70 is increased, and the resistance of the variable resistor 122 is increased. It becomes higher, and the coil resistance 全体 of the entire correction coil 70 is higher than that in Fig. 14A. Then, as shown in FIG. 14B, when the contact portion 130L at the left end of the bridge type short-circuit conductor 130 is moved to the other end of the resistor 126 side of the resistor body 128, the section length of the resistor body 128 occupied by the current path of the correction coil 70 is formed. maximum. Therefore, the resistance 値 of the variable resistor 122 is maximized, and the coil resistance 全 of the entire correction coil 70 is formed to the maximum. Further, when the bridge type short-circuit conductor 130 is further slid to the right in the figure from the state of FIG. 14B, as shown in FIG. 14C, the contact portion 130L of the left-31 - 201207883 end of the bridge type short-circuit conductor 130 is caused to pass over the insulator 126. When moving to the coil conductor on the right side, the correction coil 70 is electrically cut by the insulator 126, and is substantially open at both ends. Another point of view is that the resistance 可变 of the variable resistor 1 22 will be infinite. Thus, in this embodiment, the resistance 値 of the variable resistor 1 22 is variably controlled by the resistance variable mechanism 120, and as described above, the minimum resistance 同等 equivalent to the coil closed at both ends (Fig. 13) The maximum resistance 全 (Fig. 14A, Fig. 14B) of the entire section including the resistor body 1 2 8 can continuously change the coil resistance of the entire correction coil 70, and can also select the coil cut equivalent to the uncorrected coil 70. Off state (Fig. 14C). Thereby, when the RF antenna 54 flows a current of the high-frequency RFH, the current 値 (amplitude 値 or tip 値) of the current flowing to the correction coil 70 by electromagnetic induction can be arbitrarily changed and controlled to 〇%~1. 〇〇% of the range. Here, the current 値1 〇〇% corresponds to the current 流动 at the position where the coil is short-circuited (Fig. 13), and the current 値0% corresponds to the position at the position where the coil is cut (Fig. 14C). Current 値. What is important here is that the current 値 of the current flowing through the correction coil 70 can be arbitrarily changed in the range of 〇% to 1 〇〇% by the variable resistance control of the correction coil 70 as described above, and can be in the vicinity of the upper limit position. It is functionally equivalent to arbitrarily change the height position of the completely endless type correction coil 70' between the original position HP and the lower limit position of the proximity RF antenna 54 as described above. In addition, the resistance variable mechanism 120 fixes the correction coil 70 to the height position in the vicinity of the RF antenna 54 as it is, and can realize the characteristics of FIG. 5 in a device manner, and can be more easily achieved as in the first embodiment. Plasma density distribution control -32-201207883 The degree of freedom and accuracy is improved. Therefore, the amplitude 値 of the current flowing through the correction coil 70 can be changed via the resistance variable mechanism 120 every time the process recipe changes the predetermined process parameter, whereby the correction coil 70 can be arbitrarily and finely adjusted. The action of the RF magnetic field 产生 generated around the antenna conductor by the current flowing through the high frequency RFH of the RF antenna 54, that is, the donut-shaped plasma near the position overlapping the turns conductor of the correction coil 70 The extent to which the plasma density inside is locally reduced (strength). Thereby, the plasma density in the vicinity of the susceptor 12 can be uniformly maintained in the radial direction through the entire step, and the uniformity of the etching process of the multilayer photoresist method can be improved. For example, when the etching process of the multi-step photoresist method as shown in FIG. 9 is performed, the illustration is omitted, but in actuality, the first step (10 mTorr) is switched to a relatively low resistance 电阻 (resistance position) R! The second step (5mT〇rr) is switched to a lower resistance 値 (resistance position) R2, and in the third step (50mT 〇rr) is switched to a relatively high resistance 値 (resistance position) R3 as long as at each step It is sufficient to switch the resistance 値 (resistance position) of the variable resistor 1 22 . Further, from the viewpoint of plasma ignitability, immediately after the start of the process of each step, the correction coil 70 is maintained in an electrically cut state (Fig. 14C) to make the plasma stable and ignited, in the plasma. The method of making the variable resistor 1 22 against a predetermined resistance 値 (resistance position) after ignition is also effective. [Modification] A modification of the correction coil 70 and the switch-33-201207883 configuration 1 1 0 of the first embodiment described above is shown in Fig. 15. In this embodiment, the plurality of (for example, two) correction coils 70A and 70B having different coil diameters are arranged concentrically (or coaxially), and the switching elements 1 are respectively provided in the circuits of the correction coils 70A and 70B. 1 2 A, 1 1 2 B. Then, the switching elements 112A, 112B are controlled/OFF according to the PWM control by the individual switch control circuits 1 14A, 1 14B, respectively, at an arbitrary arbitrary energization load ratio. Fig. 16 shows a modification of the correction coil 70 and the resistance variable mechanism 208 of the second embodiment. In this embodiment, a plurality of (for example, two) correction coils 70A and 70B having different coil diameters are arranged concentrically (or coaxially), and are respectively provided in the circuits of the correction coils 70A and 70B. Resistors 122A, 122B. Then, the resistances 可变 of the variable resistors 122A and 122B are independently and arbitrarily variably controlled by the individual resistance control units 124A and 124B. In the switching mechanism 110 of FIG. 15 and in the resistance variable mechanism 120 of FIG. 16, the combination of the induced current (energization load ratio or tip 値) of the two correction coils 70A, 70B is arbitrary. A wide variety of choices can increase the freedom of plasma density distribution control. Further, as shown in Fig. 17A, the correction coil 70B can be held in the non-actuated (non-energized) state, and only the correction coil 70A can be actuated (energized). Alternatively, as shown in Fig. 17B, the correction coil 70A is held in the non-actuated (non-energized) state, and only the correction coil 70B is actuated (energized). Further, as shown in Fig. 17C, the two correction coils 70A, 70B can be simultaneously actuated (energized). [Third Embodiment] -34-201207883 In the above-described first embodiment, the switching mechanism 110 may be replaced with the opening and closing mechanism 150 as shown in Fig. 18 as another embodiment. The opening and closing mechanism 150 has a shutter 152 connected to the two open ends of the correction coil 7 经由 via a conductor, and an opening and closing control circuit 1 5 4 'switching according to an instruction from the main control unit 74 The opening and closing (ΟΝ/OFF) state of the shutter 152 is controlled. When the shutter 152 is switched to the ON state in the opening and closing mechanism 150, since the induced current does not flow to the correction line 圏7〇', it is equivalent to the case where the correction coil 70 is not formed. When the shutter 152 is switched to the ON state, the correction coil 70 is formed to be equivalent to the wire closed at both ends, and once the current of the high frequency RFH flows in the RF antenna 54, the induced current flows to the correction coil 70. As shown in Fig. 19, such an opening and closing mechanism 150 can be applied to a configuration in which a plurality of correction coils 70A, 70B are arranged concentrically. That is, a plurality of (for example, two) correction coils 70A, 70B having different coil diameters are arranged concentrically, and the correction coils 7A, 70B are respectively inserted into the connection shutters 1 5 2 A, 1 5 2 B. Then, the control shutters 152A' 152B can be independently opened and closed by the individual opening and closing control circuits 154A, 154B. In such a shutter type, although the degree of freedom of control is also limited to some extent, the variable control of the current density (density of the donut-shaped plasma) as shown in Figs. 7 7 to 17 C can be performed. In addition, when the above-described opening and closing mechanism 丨5〇 is provided, the switch 1 can be appropriately controlled by changing, changing, or switching according to the process condition of -35-201207883 in the plasma processing of one substrate to be processed. The method of opening and closing of 50 (1 52A, 152B). For example, in the multi-step etching process (Fig. 9) of the above-described multilayer photoresist method, when the single type correction coil 70 (opener 152) as shown in Fig. 18 is used, as shown in Fig. 20, the first The step is to switch the shutter 152 to the ON state. In the second step, the shutter 152 is switched to the ON state, and in the third step, the shutter 152 is switched to the ON state. Further, in the twin type correction coils 70A and 7B (the shutters 152A and 152B) as shown in Fig. 19, in the first step, the shutters 152A and 152B are switched on and off (OFF). In the second step, the shutters 1 52A, 1 52B are switched to the ON state, and in the third step, the shutter 152A is switched to the ON state, and the shutter 152 B is switched to Closed (ON) state. Further, as shown in FIG. 22, the same number of shutters 152A, 152B, and 152C can be applied to the configuration in which a plurality of (for example, three) correction coils 70A, 70B, and 70c are arranged in the vertical direction and arranged coaxially. And opening and closing control circuits 154A, 154B, 154C (not shown). Another embodiment of the correction coil 70, as shown in FIG. 23, may be selectively switched such that a plurality of (for example, three) coil conductors 70 ( 1 ), 70 (2), 70 ( 3 ) are respectively used as A separate mode of the individual correction coils and a connection mode of one correction coil that is electrically connected in series. In Fig. 23, each of the coil conductors 70(1), 70(2), 70(3) is an annular single-coil coil which is opened by a moderate gap between both ends.

S-36-201207883 (or rewind coil) The gaps can be electrically connected in a plurality of types via the three switching switches 160' 162' 164 and one open/close switch ι 66. The first changeover switch 160 has: a first fixed contact 1 60a 'which is connected to one end of the innermost turn conductor 7〇(1); the movable contact 160b' is connected to the coil conductor 7〇 ( The other end of 1); and the second fixed contact 160c' are connected to one end of the adjacent intermediate coil conductor 70(2). The second changeover switch ι62 has: the first fixed contact 162a' is connected to one end of the intermediate coil conductor 7?(2): the movable contact 162b' is connected to the other of the coil conductor 70(2) And a second fixed contact 1 62c connected to the ~ end of the outer adjacent coil conductor 70 ( 3 ). The third changeover switch 1 64 has: a first fixed contact 164a that is connected to one end of the outer coil conductor 70 (3); and a movable contact 1 64b that is connected to the other of the coil conductor 70 (3) And the second fixed contact 164c is connected to the movable contact 1 6 6 d of the open/close switch 166. -37- 201207883 The fixed contact 16 6e of the open/close switch 166 is connected to one end of the inner coil conductor 70 ( 1 ). In this configuration, when the individual mode is selected, the movable contact 160b of the first changeover switch 160 is switched to the first fixed contact 160a, and the movable contact 162b of the second changeover switch 162 is switched to the first fixed contact. 162a, the movable contact 164b of the third changeover switch 164 is switched to the first fixed contact 164a, and the open/close switch 166 is switched to the open state. When the connection mode is selected, the movable contact 160b of the first changeover switch 160 is switched to the second fixed contact 160c, and the movable contact 162b of the second changeover switch 162 is switched to the second fixed contact l62c. The movable contact 164b of the third changeover switch 164 is switched to the second fixed contact 164c, and the open/close switch 166 is switched to the closed state. In a modification of this embodiment, for example, any two of the three coil conductors 70 ( 1 ) 70 (2) and 70 ( 3 ) may be selected in a connection mode, and the remaining 1 may be selected. The configuration of the switching circuit network selected as a separate mode. Further, in the case where the correction coil of the present invention has a large induced current (sometimes a current flowing to the RF antenna or more), it is important to pay attention to the heat generation of the correction coil. From this point of view, as shown in Fig. 24A, a coil cooling portion in which an air-cooling fan is provided in the vicinity of the correction coil 70 to be air-cooled can be provided. Alternatively, as shown in Fig. 24B, a correction coil 70 may be formed by a hollow copper tube, and a refrigerant may be supplied therein to prevent the coil 圏 cooling portion of the correction coil 7 过热 from being overheated. The configuration of the inductively coupled plasma etching apparatus of the above-described embodiment is -38 - 201207883. In the example, the configuration in which the respective portions of the plasma generating mechanism are not directly related to the plasma generation can be variously modified. For example, in the above embodiment, the correction coil 7 〇 is fixedly disposed at one position. However, a configuration in which the position of the correction coil 7 可 can be changed can be employed, and in particular, the height position can be arbitrarily changed. Further, in the current path or circuit of the correction coil 70, a capacitor (not shown) may be provided in addition to the above-described switching element 112, resistor 122 or shutter 152 (152, 152B, 152C). Further, the basic form of the RF antenna 54 and the correction antenna 70 may be a form other than a planar shape, for example, a dome shape or the like. Further, it may be a form provided outside the ceiling of the chamber 1 ,, for example, a spiral shape provided outside the side wall of the chamber 1 。. Further, it may be a chamber structure of a rectangular substrate to be processed, a rectangular RF antenna structure, and a rectangular correction coil structure. Further, the processing gas supply unit may be configured to introduce a processing gas into the chamber 10 from the ceiling, or may be a form in which the high-frequency RFL for DC bias control is not applied to the susceptor 12. On the other hand, the present invention is also applicable to the use of a plurality of RF antennas or antenna segments to individually supply the plurality of RF antennas (or antenna segments) to the plasma by a plurality of high frequency power sources or high frequency power feeding systems. A plasma device of a high frequency power generation method. Moreover, the inductively coupled plasma processing apparatus or plasma processing method of the present invention is not limited to the technical field of plasma etching, and can also be applied to plasma CVD, plasma oxidation, plasma nitridation, sputtering, and the like. Slurry process. Further, the substrate to be processed of the present invention is not limited to a semiconductor wafer, and may be various substrates, masks, CD substrates, printed substrates, etc. for a flat-angle display of a flat-39-201207883 surface. A longitudinal sectional view showing a configuration of an inductively coupled plasma processing apparatus according to a first embodiment of the present invention. 2A is a perspective view showing an example of a helical coil-shaped RF antenna. FIG. 2B is a perspective view showing an example of a concentric circular coil-shaped RF antenna. Fig. 3A is a view schematically showing an example of the action of an electromagnetic field when the completely endless type correction coil is disposed away from the RF antenna. FIG. 3B is a view schematically showing an example of the action of the electromagnetic field when the completely endless type correction line 圏 is disposed in the vicinity of the RF antenna. FIG. 4A is a view schematically showing the arrangement of the completely endless type correction line 圏 away from the RF antenna. Another example of the role of electromagnetic fields. 4B schematically shows another example of the action of the electromagnetic field when the completely endless type correction coil is disposed in the vicinity of the RF antenna. FIG. 5 is a view showing the dielectric window when the distance between the completely endless type correction coil and the RF antenna is changed. A change in the current density distribution of the nearby processing space. Fig. 6 is a view showing an example of the configuration of a correction coil and a switching mechanism according to the first embodiment; Fig. 7 is a view showing an example of a specific configuration of the above-described switch mechanism. Fig. 8 is a view showing a PWM control chart using the above-described switching mechanism. Fig. 9 is a view showing the construction of the multilayer photoresist method in stages.

-40- 201207883 Fig. 1 〇 is a method of variably controlling the energization load ratio of the correction coil in a multi-step etching process using a multilayer photoresist method. Fig. 11 is a longitudinal sectional view showing the configuration of an inductively coupled plasma etching apparatus according to a second embodiment. Fig. 12 is a view showing an example of the configuration of a correction coil and a resistance variable mechanism according to the second embodiment. Fig. 13 is a view showing an example of a specific configuration of the variable resistance mechanism; Fig. 14A is a view showing a resistance position of one of the variable resistance mechanisms. Fig. 14A is a view showing another resistance position of the variable resistance mechanism. Fig. 14C is a view showing another resistance position of the variable resistance mechanism. Fig. 15 is a correction coil showing a modification of the first embodiment. And an example of the construction of the switching mechanism. Fig. 16 is a view showing an example of the configuration of a correction coil and a variable resistance mechanism according to a modification of the second embodiment. Fig. 17A is a view showing an example of the operation of the configuration example of Fig. 15 or Fig. 16. Fig. 17A is a view showing an example of the operation of the configuration example of Fig. 15 or Fig. 16; Fig. 17C is a view showing an example of the operation of the configuration example of Fig. 15 or Fig. 16. Fig. 18 is a view showing an example of the configuration of a correction coil and an opening and closing mechanism according to the third embodiment. Fig. 19 is a view showing an example of a configuration of a correction coil and an opening and closing mechanism according to a modification. Fig. 20 is a view showing a method of controlling the opening and closing state of the shutter provided in the single type correction coil in the multi-step etching process using the multilayer photoresist method. -41 - 201207883. Fig. 21 is a view showing a method of controlling the opening and closing states of two shutters provided on the twin-type correction line 在 in the multi-step saturation process using the multilayer photoresist method. Fig. 2 is a diagram showing a correction coil and a switch circuit network of another embodiment. Fig. 23 is a view showing a correction coil and a switch circuit network of another embodiment. Fig. 24A shows an embodiment in which the correction coil is cooled by an air cooling type. Fig. 24B is an embodiment in which a correction coil is cooled via a refrigerant. [Description of main components] 10: Chamber 12: Base 5 6: Local frequency power supply 66: Process gas supply source 70: Correction coil 1 1 〇: Switching mechanism 1 1 2 : Switching element 120: Resistance variable mechanism 122: Variable resistor 124: resistance variable mechanism 150: opening and closing mechanism 152, 152A, 152B, 152C: shutter

Claims (1)

201207883 VII. Patent application scope: 1. A plasma processing device, characterized in that: a processing container is a dielectric window; a wire-shaped RF antenna is disposed outside the dielectric window. And a substrate holding portion that holds the substrate to be processed»the processing gas supply unit in the processing container, wherein the desired processing gas is supplied into the processing container in order to perform the desired plasma treatment on the substrate; a portion for supplying a high frequency electric power suitable for a high frequency discharge of a processing gas to the RF antenna in order to generate a plasma of a processing gas by inductive coupling in the processing container; Controlling a plasma density distribution on the substrate in the processing container, and disposing outside the processing container at a position that can be coupled to the RF antenna by electromagnetic induction: a switching element that is coupled to the circuit of the correction coil And a switch control unit that controls the switching element by ΟΝ/OFF by a pulse width modulation at a desired load ratio. 2. A plasma processing apparatus, comprising: a processing container having a dielectric window; a coil-shaped RF antenna disposed outside the dielectric window; and a substrate holding portion The processing substrate 1 processing gas supply unit is held in the processing container, and the desired processing gas is supplied into the processing container in order to perform desired plasma processing on the substrate; -43-201207883 high frequency power supply unit In order to generate plasma of the processing gas by inductive coupling in the processing container, high frequency power suitable for the frequency of high frequency discharge of the processing gas is supplied to the RF antenna; correction coil is used to control the aforementioned processing a plasma density distribution on the substrate in the container, and disposed outside the processing container at a position that can be coupled to the RF antenna by electromagnetic induction; and a variable resistor disposed in the circuit of the correction coil; And a resistance control unit that controls the resistance 値 of the variable resistor to a desired 値. 3. A plasma processing apparatus, characterized by: a processing container having a dielectric window; an RF antenna disposed outside the dielectric window; and a substrate holding portion attached to the processing The processing substrate t processing gas supply unit is held in the container, and the desired processing gas is supplied into the processing container for performing the desired plasma processing on the substrate; and the high frequency power feeding unit is for the processing container. Generating a plasma of the processing gas by inductive coupling, and supplying high frequency power suitable for the frequency of the high frequency discharge of the processing gas to the RF antenna; and correcting the coil for controlling the substrate on the substrate in the processing container The plasma density distribution is disposed outside the processing container at a position where it can be coupled to the RF antenna by electromagnetic induction, and a shutter is disposed in the circuit of the correction coil. 4. The plasma processing apparatus according to claim 3, wherein: -44- S 201207883, the dielectric window is a ceiling constituting the processing container, and the RF antenna is disposed on the dielectric window, The correction coil is arranged in parallel with the aforementioned RF antenna. 5. The plasma processing apparatus according to claim 3, wherein the correction coil is composed of a single coil or a rewind coil closed at both ends, and the RF antenna is coaxially arranged and has a radial direction. The coil conductor is located at a coil diameter between the inner circumference and the outer circumference of the RF antenna. 6. A plasma processing apparatus, characterized by: a processing container having a dielectric window and being vacuum ventilable; an RF antenna disposed outside the dielectric window; a substrate holding portion, The processing substrate » the processing gas supply unit is configured to supply the desired processing gas to the processing container in order to perform the desired plasma processing on the substrate; the high frequency power supply unit is configured to The plasma of the processing gas is generated by inductive coupling in the processing container, and high-frequency power suitable for the frequency of the high-frequency discharge of the processing gas is supplied to the RF antenna; the first and second correction coils are Controlling a plasma density distribution on the substrate in the processing container, and disposing it outside the processing container at a position where it can be coupled to the RF antenna by electromagnetic induction; and the first and second switches are respectively It is provided in the circuit of the first and second correction coils. 7. The plasma processing apparatus of claim 6, wherein the dielectric window is a ceiling constituting the processing container, -45-201207883, the RF antenna is disposed on the dielectric window, the foregoing The first and second correction coils are arranged in parallel with the RF antenna. 8. The plasma processing apparatus according to claim 7, wherein the first and second correction coils are arranged concentrically. 9. The plasma processing apparatus of claim 7, wherein the first and second correction coils are coaxially disposed at different height positions. The plasma processing apparatus according to any one of claims 1 to 9 wherein the coil cooling unit for cooling the correction coil is provided. 11. A plasma processing method, which is a plasma processing method for performing a desired plasma treatment on a substrate in a plasma processing apparatus, the plasma processing apparatus having: a processing container having a dielectric window; The coil-shaped RF antenna is disposed outside the dielectric window, and the substrate holding portion holds the substrate to be processed in the processing container, and the processing gas supply unit is configured to perform desired electricity on the substrate. a slurry treatment to supply a desired processing gas to the processing container; and a high frequency power feeding portion for generating a high frequency of the processing gas by inductively coupling the plasma in the processing container to generate a processing gas The high-frequency power of the frequency of the discharge is supplied to the RF antenna; the plasma processing method is: a correction coil that can be combined with the RF line by electromagnetic induction is disposed in parallel with the RF antenna, in addition to the processing container, -46- S 201207883 A switch is provided in the circuit of the correction coil to control the opening and closing state of the shutter to control the plasma on the substrate Degree. In the plasma processing method of the first aspect of the invention, in the plasma processing of one substrate to be processed, the opening and closing state of the shutter is controlled in accordance with the change, change or switching of the process conditions. . 13. A plasma processing method, which is a plasma processing method for performing a desired plasma treatment on a substrate in a plasma processing apparatus, the plasma processing apparatus having: a processing container having a dielectric window The wire-shaped RF antenna is disposed outside the dielectric window, and the substrate holding portion holds the processed substrate processing gas supply unit in the processing container for performing desired electricity on the substrate a slurry treatment to supply a desired processing gas to the processing container; and a high frequency power feeding portion for generating a high frequency of the processing gas by inductively coupling the plasma in the processing container to generate a processing gas The high frequency power of the frequency of the discharge is supplied to the RF antenna; the plasma processing method is: the first and second correction coils and the RF that can be combined with the RF antenna by electromagnetic induction in addition to the processing container The antennas are arranged in parallel, and the first and second shutters are respectively provided in the circuits of the first and second correction coils, and the respective opening and closing states of the first and second shutters are controlled. Control -47- 201207883 Plasma density on the aforementioned substrate. 1 . The plasma processing method according to claim 13 , wherein in the plasma processing of one of the substrates to be processed, the first and second are controlled according to changes, changes, or switching of process conditions. Each open and close state of the shutter. S -48-