JP7208819B2 - Plasma processing equipment - Google Patents

Description

An embodiment of the present disclosure relates to a plasma processing apparatus.

Plasma processing apparatuses are used in the manufacture of electronic devices. A plasma processing apparatus includes a chamber, a support, and a high frequency power supply. The support table is provided in the interior space of the chamber and is configured to support a substrate placed thereon. The support table includes a lower electrode and an electrostatic chuck. A high frequency power supply is connected to the lower electrode.

In plasma processing performed in a plasma processing apparatus, it is necessary to adjust the temperature distribution in the plane of the substrate. A plurality of heaters are provided in the electrostatic chuck to adjust the temperature distribution in the plane of the substrate. Each of the multiple heaters is connected to the heater controller via multiple power supply lines.

A high frequency power is supplied to the lower electrode of the support base from a high frequency power source. A high frequency supplied to the lower electrode may flow into a plurality of feed lines. A plurality of filters are respectively provided on the plurality of feed lines to block or attenuate high frequencies on the plurality of feed lines. Each of the plurality of filters includes a coil and a capacitor, as described in US Pat. A plurality of filters are positioned outside the chamber. Therefore, the plurality of power supply lines each include a plurality of wires extending from the electrostatic chuck side to the outside of the chamber.

JP 2014-99585 A

As the number of heaters provided in the electrostatic chuck increases, it becomes difficult to secure a space around the chamber for arranging a plurality of filter coils, that is, a plurality of coils. Therefore, as the number of heaters provided in the electrostatic chuck increases, the distance between the electrostatic chuck and each of the plurality of coils increases, and the length of the plurality of wirings constituting the plurality of power supply lines increases. become longer. As the length of the multiple wires increases, the frequency characteristics of the impedances of the multiple filters deteriorate due to their respective parasitic components. Therefore, it is required to shorten the length of a plurality of wires that electrically connect a plurality of heaters provided in the electrostatic chuck and the coils of a plurality of filters.

In one aspect, a plasma processing apparatus is provided. A plasma processing apparatus includes a chamber, a support base, a power feeder, a conductor pipe, a high frequency power source, a filter device, and a plurality of wirings. The support pedestal is configured to support the substrate within the interior space of the chamber. The support table has a lower electrode and an electrostatic chuck. An electrostatic chuck is provided on the lower electrode. The electrostatic chuck has multiple heaters. A plurality of heaters are provided inside the electrostatic chuck. The power feeder is electrically connected to the lower electrode. The power feeder extends downward under the lower electrode. The conductor pipe extends around the power supply outside the chamber. The conductor pipe is grounded. The high frequency power supply is electrically connected to the feeder. The filter device is configured to prevent high frequencies from entering the heater controller from the plurality of heaters. The plurality of wires electrically connect the plurality of heaters and the plurality of coils of the filter device, respectively.

A filter device has the plurality of coils, the plurality of capacitors, and a housing. The multiple coils are electrically connected to the multiple heaters. A plurality of capacitors are respectively connected between the plurality of coils and ground. The housing is electrically grounded and contains a plurality of coils therein. A plurality of coils constitute a plurality of coil groups. Each of the multiple coil groups includes two or more coils. In each of the plurality of coil groups, the two or more coils each have a winding portion extending spirally around the central axis, and each turn extends sequentially along the axial direction along which the central axis extends and It is provided so as to be arranged repeatedly. A plurality of coil groups are provided coaxially with respect to the central axis so as to surround the conductor pipe immediately below the chamber.

In the plasma processing apparatus according to one aspect, a plurality of coil groups each including two or more coils are provided coaxially so as to share a central axis. Therefore, the space occupied by the coils forming the coil groups is small. Therefore, it is possible to arrange a filter device including a plurality of coils directly under the chamber, and the length of a plurality of wirings electrically connecting the plurality of heaters and the plurality of coils provided in the electrostatic chuck is can be shortened. Moreover, since the plurality of coil groups are provided so as to surround the conductor pipe, each of the plurality of coils has a large cross-sectional area. Therefore, even if each of the plurality of coils has a short coil length, the necessary inductance is ensured.

In one embodiment, the multiple lines have substantially the same length as each other.

In one embodiment, the peripheral edge of the electrostatic chuck is provided with a plurality of terminals electrically connected to a plurality of heaters. The plasma processing apparatus further comprises a circuit board, a plurality of first electrical connectors, a plurality of second electrical connectors, and a plurality of flexible circuit boards. Lead wires of a plurality of coils are connected to the circuit board. A plurality of first electrical connectors extend upwardly from the circuit board. A plurality of second electrical connectors are respectively coupled to the plurality of first electrical connectors. A plurality of flexible circuit boards extend from the plurality of second electrical connectors to under the peripheral edge of the electrostatic chuck. Each of the plurality of wires includes a circuit board, a corresponding first electrical connector of the plurality of first electrical connectors, a corresponding second electrical connector of the plurality of second electrical connectors, and a plurality of flexible connectors. It extends within a corresponding flexible circuit board of the circuit board. According to this embodiment, a plurality of traces can extend through the circuit board and the plurality of flexible circuit boards such that their lengths are substantially the same.

In one embodiment, the plasma processing apparatus further comprises a plurality of separate circuit boards. A plurality of separate circuit boards are provided below the plurality of coils. Each of the plurality of capacitors is mounted on a corresponding one of the plurality of separate circuit boards.

As described above, it is possible to shorten the length of the plurality of wires that electrically connect the plurality of heaters and the plurality of filters provided in the electrostatic chuck.

1 is a diagram schematically showing a plasma processing apparatus according to one embodiment; FIG. 2 is an enlarged cross-sectional view of a support base of the plasma processing apparatus shown in FIG. 1; FIG. 2 is a diagram showing circuit configurations of a plurality of filters of the plasma processing apparatus shown in FIG. 1 together with a plurality of heaters and a heater controller; FIG. FIG. 4 is a perspective view of multiple coils of a filter device according to one embodiment. FIG. 5 is a perspective view showing a plurality of coils shown in FIG. 4, broken away; FIG. 5 is a cross-sectional view showing an enlarged part of a plurality of coils shown in FIG. 4; FIG. 2 schematically shows members for providing wires electrically connecting coils of a filter device to terminals of an electrostatic chuck in the plasma processing apparatus shown in FIG. 1 ; 2 is a plan view of the lower surface of the electrostatic chuck of the plasma processing apparatus shown in FIG. 1; FIG. 2 is a plan view of the lower surface of the lower electrode of the plasma processing apparatus shown in FIG. 1; FIG. 2 is a plan view showing a plurality of members providing a plurality of wirings electrically connecting a plurality of coils of a filter device to a plurality of terminals of an electrostatic chuck in the plasma processing apparatus shown in FIG. 1; FIG. FIG. 4 is a perspective view of multiple coils of a filter device according to another embodiment; FIG. 12 is a perspective view showing coil groups in the simulation. FIG. 13(a), FIG. 13(b), and FIG. 13(c) are graphs showing simulation results.

Various embodiments are described in detail below with reference to the drawings. In addition, suppose that the same code|symbol is attached|subjected to the part which is the same or equivalent in each drawing.

FIG. 1 is a diagram schematically showing a plasma processing apparatus according to one embodiment. FIG. 1 shows a partially broken plasma processing apparatus according to one embodiment. A plasma processing apparatus 1 shown in FIG. 1 is a capacitively coupled plasma processing apparatus.

The plasma processing apparatus 1 has a chamber 10 . The chamber 10 provides an internal space 10s. Chamber 10 includes a chamber body 12 . The chamber body 12 has a substantially cylindrical shape. An internal space 10 s is provided inside the chamber body 12 . The chamber body 12 is made of aluminum, for example. The chamber body 12 is grounded. A plasma-resistant film is formed on the inner wall surface of the chamber main body 12, that is, on the wall surface defining the internal space 10s. The membrane may be a membrane formed by an anodizing process, or a ceramic membrane such as a membrane formed from yttrium oxide.

A side wall of the chamber body 12 is formed with an opening 12p. The substrate W passes through the opening 12p when being transported between the inner space 10s and the outside of the chamber 10. As shown in FIG. The opening 12p can be opened and closed by a gate valve 12g. A gate valve 12 g is provided along the side wall of the chamber body 12 . The substrate W is a disk-shaped plate made of a material such as silicon.

The plasma processing apparatus 1 further includes a support base 14 . The support base 14 is provided in the internal space 10s. A substrate W is placed on the support table 14 . The support table 14 is configured to support the substrate W within the internal space 10s. The support base 14 is mounted on and supported by the support portion 15 . The support portion 15 extends upward from the bottom portion of the chamber body 12 .

A member 16 , a member 17 , and a baffle plate 18 are provided around the support base 14 and the support portion 15 . The member 16 has a cylindrical shape and is made of a conductor. The member 16 extends upward from the bottom of the chamber body 12 along the outer peripheral surface of the support portion 15 . The member 17 has a substantially annular plate shape and is made of an insulator such as quartz. The member 17 is provided above the member 16 . A focus ring FR is arranged on the member 17 so as to surround the edge of the substrate W placed on the support table 14 .

The baffle plate 18 has a substantially annular plate shape. The baffle plate 18 is configured, for example, by coating an aluminum base material with ceramic such as yttrium oxide. A large number of through holes are formed in the baffle plate 18 . The inner edge of baffle plate 18 is sandwiched between member 16 and member 17 . Baffle plate 18 extends from its inner edge to the side wall of chamber body 12 . Below the baffle plate 18 , an exhaust device 20 is connected to the bottom of the chamber body 12 . The evacuation device 20 has a pressure controller such as an automatic pressure control valve and a vacuum pump such as a turbomolecular pump. The exhaust device 20 can depressurize the internal space 10s.

The plasma processing apparatus 1 further includes an upper electrode 30 . The upper electrode 30 is provided above the support base 14 . The upper electrode 30 closes the upper opening of the chamber body 12 together with the member 32 . The member 32 has insulation. The upper electrode 30 is supported above the chamber body 12 via a member 32 . The potential of the upper electrode 30 is set to the ground potential when a first high-frequency power source, which will be described later, is electrically connected to the lower electrode of the support base 14 .

Upper electrode 30 includes a top plate 34 and a support 36 . A lower surface of the top plate 34 defines an internal space 10s. The top plate 34 is provided with a plurality of gas ejection holes 34a. Each of the plurality of gas discharge holes 34a penetrates the top plate 34 in the plate thickness direction (vertical direction). The top plate 34 is made of silicon, for example, although it is not limited thereto. Alternatively, the top plate 34 may have a structure in which a plasma-resistant film is provided on the surface of an aluminum base material. The membrane may be a membrane formed by an anodizing process, or a ceramic membrane such as a membrane formed from yttrium oxide.

The support 36 is a component that detachably supports the top plate 34 . Support 36 may be formed from an electrically conductive material such as, for example, aluminum. A gas diffusion chamber 36 a is provided inside the support 36 . A plurality of gas holes 36b extend downward from the gas diffusion chamber 36a. The multiple gas holes 36b communicate with the multiple gas discharge holes 34a, respectively. The support 36 is formed with a gas introduction port 36c. The gas introduction port 36c communicates with the gas diffusion chamber 36a. A gas source group 40 is connected to the gas inlet 36c via a valve group 41, a flow controller group 42, and a valve group 43. As shown in FIG.

Gas source group 40 includes a plurality of gas sources. Each of valve group 41 and valve group 43 includes a plurality of valves. The flow controller group 42 includes a plurality of flow controllers. Each of the plurality of flow controllers in the flow controller group 42 is a mass flow controller or a pressure-controlled flow controller. Each of the plurality of gas sources of the gas source group 40 is connected to the gas introduction port 36c via the corresponding valve of the valve group 41, the corresponding flow controller of the flow controller group 42, and the corresponding valve of the valve group 43. It is connected. The plasma processing apparatus 1 is capable of supplying gas from one or more gas sources selected from a plurality of gas sources in the gas source group 40 to the internal space 10s at individually adjusted flow rates. .

The plasma processing apparatus 1 further includes a controller MC. The controller MC is a computer including a processor, storage device, input device, display device, etc., and controls each part of the plasma processing apparatus 1 . Specifically, the controller MC executes a control program stored in the storage device, and controls each part of the plasma processing apparatus 1 based on the recipe data stored in the storage device. Under the control of the controller MC, the plasma processing apparatus 1 executes the process specified by the recipe data.

Below, the supporting base 14 and the components of the plasma processing apparatus 1 related to the supporting base 14 will be described in detail. FIG. 2 will be referred to together with FIG. 1 below. FIG. 2 is an enlarged cross-sectional view of the support base of the plasma processing apparatus shown in FIG. As shown in FIGS. 1 and 2, the support table 14 has a lower electrode 50 and an electrostatic chuck 52 . In one embodiment, support platform 14 further includes a conductive member 54 .

The lower electrode 50 has a substantially disk shape and is made of a conductor such as aluminum. A channel 50 f is formed inside the lower electrode 50 . A heat exchange medium (for example, refrigerant) is supplied to the flow path 50 f from a chiller unit provided outside the chamber 10 . The heat exchange medium supplied to the flow path 50f is returned to the chiller unit. This lower electrode 50 is provided on a conductive member 54 .

The conductive member 54 is made of a conductor such as aluminum. The conductive member 54 is electrically connected to the lower electrode 50 . The conductive member 54 has a substantially annular plate shape and is formed in a hollow shape. The conductive member 54, the lower electrode 50, and the electrostatic chuck 52 share a common central axis (hereinafter referred to as "axis AX"). Axis AX is also the central axis of chamber 10 .

As shown in FIG. 1, in one embodiment, the plasma processing apparatus 1 further includes a first high frequency power supply 61 and a second high frequency power supply 62 . The first high frequency power supply 61 and the second high frequency power supply 62 are provided outside the chamber 10 . The first high-frequency power source 61 and the second high-frequency power source 62 are electrically connected to the lower electrode 50 via the power supply 65 . The power feeder 65 has a columnar shape or a cylindrical shape. The power feeder 65 extends downward below the lower electrode 50 . In one embodiment, one end of the power supply 65 is coupled to the conductive member 54 and electrically connected to the lower electrode 50 via the conductive member 54 .

The first high frequency power supply 61 generates a first high frequency that mainly contributes to plasma generation. The frequency of the first high frequency is, for example, 40.68 MHz or 100 MHz. A first high-frequency power supply 61 is electrically connected to the lower electrode 50 via a matching device 63 and a feeder 65 . The matching device 63 has a circuit configured to match the output impedance of the first high-frequency power supply 61 and the impedance on the load side. Note that the first high-frequency power supply 61 may be connected to the upper electrode 30 via a matching box 63 .

A second high-frequency power supply 62 outputs a second high-frequency power that mainly contributes to the attraction of ions to the substrate W. FIG. The frequency of the second high frequency is lower than the frequency of the first high frequency, eg 13.56 MHz. A second high-frequency power supply 62 is electrically connected to the lower electrode 50 via a matching device 64 and a feeder 65 . The matching device 64 has a circuit configured to match the output impedance of the second high-frequency power supply 62 and the impedance on the load side.

The plasma processing apparatus 1 further includes a conductor pipe 66 . The conductor pipe 66 is made of a conductor such as aluminum and has a substantially cylindrical shape. The conductor pipe 66 extends so as to surround the power supply 65 outside the chamber 10 . A conductor pipe 66 is coupled to the bottom of the chamber body 12 . The conductor pipe 66 is electrically connected to the chamber body 12 . Therefore, the conductor pipe 66 is grounded. The feeder 65 and the conductor pipe 66 share an axis AX as their central axis.

As shown in FIGS. 1 and 2, the electrostatic chuck 52 is provided on the lower electrode 50 . The electrostatic chuck 52 is configured to hold a substrate W placed thereon. The electrostatic chuck 52 has a substantially disk shape and has a layer formed of an insulator such as ceramics. The electrostatic chuck 52 further has an electrode 52a as an inner layer of a layer made of an insulator. A power source DCS is connected to the electrode 52a via a switch SW (see FIG. 1). When a voltage (for example, DC voltage) from the power supply DCS is applied to the electrode 52a, an electrostatic attractive force is generated between the electrostatic chuck 52 and the substrate W. As shown in FIG. The substrate W is attracted to and held by the electrostatic chuck 52 by the generated electrostatic attraction.

As shown in FIG. 2, the electrostatic chuck 52 includes a central portion 52c and a peripheral portion 52p. The central portion 52c is a portion that intersects the axis AX. A substrate W is placed on the upper surface of the central portion 52c. The peripheral portion 52p extends in the circumferential direction outside the central portion 52c. In one embodiment, the thickness of the peripheral portion 52p is less than the thickness of the central portion 52c, and the upper surface of the peripheral portion 52p extends below the upper surface of the central portion 52c. A focus ring FR is arranged on the peripheral portion 52p and the member 17 so as to surround the edge of the substrate W. As shown in FIG.

A plurality of heaters HT are provided in the electrostatic chuck 52 . Each of the plurality of heaters HT can be composed of a resistance heating element. In one example, the electrostatic chuck 52 has multiple regions that are concentric with respect to the axis AX. One or more heaters HT are provided in each of the plurality of regions of the electrostatic chuck 52 . The temperature of the substrate W placed on the support table 14 is adjusted by the plurality of heaters HT and/or the heat exchange medium supplied to the flow path 50f. A gas line for supplying a heat transfer gas such as He gas may be provided between the substrate W and the electrostatic chuck 52 on the support table 14 .

In one embodiment, a plurality of terminals 52t are provided on the lower surface of the peripheral portion 52p. Each of the plurality of terminals 52t is electrically connected to the corresponding heater among the plurality of heaters HT. Each of the plurality of terminals 52 t and the corresponding heater are connected via internal wiring inside the electrostatic chuck 52 .

Electric power for driving the plurality of heaters HT is supplied from the heater controller HC (see FIG. 1). The heater controller HC includes a heater power supply, and is configured to individually supply power (AC output) to a plurality of heaters HT. The plasma processing apparatus 1 includes a plurality of power supply lines 70 for supplying power from the heater controller HC to the plurality of heaters HT. The plurality of power supply lines 70 respectively supply power from the heater controller HC to the plurality of heaters HT. The plasma processing apparatus 1 further includes a filter device FD. The filter device FD is configured to prevent high frequencies from flowing into the heater controller HC through the plurality of power supply lines 70 . The filter device FD has a plurality of filters FT.

FIG. 3 is a diagram showing circuit configurations of a plurality of filters of the plasma processing apparatus shown in FIG. 1 together with a plurality of heaters and heater controllers. FIG. 3 will be referred to in conjunction with FIGS. 1 and 2 below. The plurality of heaters HT are connected to the heater controller HC via the plurality of power supply lines 70 as described above. The plurality of feed lines 70 includes a plurality of feed line pairs. As shown in FIG. 3, each feed line pair includes a feed line 70a and a feed line 70b. Each of the plurality of heaters HT and the heater controller HC are electrically connected via one feed line pair, that is, the feed line 70a and the feed line 70b.

A filter device FD is provided outside the chamber 10 . The filter device FD has a plurality of filters FT. The filter device FD also has multiple coils 80 and multiple capacitors 82 . One coil among the plurality of coils 80 and one corresponding capacitor among the plurality of capacitors 82 constitute one filter FT. Each of the plurality of coils 80 constitutes a part of the corresponding power supply line among the plurality of power supply lines 70 .

A plurality of coils 80 are housed within a housing 84 . As shown in FIGS. 1 and 2, the housing 84 is a container having a cylindrical shape and is made of a conductor. Housing 84 is grounded. The upper end of housing 84 is fixed to the bottom of chamber body 12 . Therefore, the filter device FD is provided directly below the chamber 10 . In one embodiment, housing 84 includes a body 84a and a bottom lid 84b. The main body 84a has a cylindrical shape. The bottom lid 84b is attached to the lower end of the main body 84a and closes the opening at the lower end of the main body 84a.

A plurality of capacitors 82 are housed below the plurality of coils 80 within a housing 84 . One end of each of the plurality of capacitors 82 is connected to the other end of the corresponding coil 80 opposite to the one end on the heater HT side. The other end of each of the multiple capacitors 82 is connected to the ground. That is, each of the plurality of capacitors 82 is connected between the corresponding coil 80 and ground.

The coil 80 and housing 84 of each of the filters FT constitute a distributed constant line. That is, each of the plurality of filters FT has an impedance frequency characteristic including a plurality of resonance frequencies.

The plurality of coils 80 will be described in detail below. FIG. 4 is a perspective view of multiple coils of a filter device according to one embodiment. FIG. 5 is a perspective view showing a plurality of coils shown in FIG. 4, broken away. 6 is a cross-sectional view showing an enlarged part of the plurality of coils shown in FIG. 4. FIG. Each of the plurality of coils 80 may be an air core coil. Each of the plurality of coils 80 is composed of a conductor and a coating that covers the conductor. The coating is made of an insulating material. The coating may be formed from a resin such as PEEK (polyetheretherketone) or polyamideimide. In one embodiment, the coating of each of the plurality of coils 80 may have a thickness of 0.1 mm or less.

Each of the multiple coils 80 has a lead wire 80a, a lead wire 80b, and a winding portion 80w. The winding portion 80w spirally extends around the center axis AXC and has a plurality of turns. The central axis AXC extends vertically. The lead wire 80a and the lead wire 80a extend along the axial direction Z along which the central axis AXC extends. The lead wire 80a is continuous with one end of the winding portion 80w, and the lead wire 80b is continuous with the other end of the winding portion 80w. The other end of the winding portion 80w is the end of the winding portion 80w on the corresponding capacitor 82 side.

An assembly of a plurality of coils 80 constitutes a coil assembly CA. The coil assembly CA includes multiple coil groups CG. That is, the multiple coils 80 form multiple coil groups CG. The number of coil groups CG may be any number of two or more. In the examples shown in FIGS. 4 to 6, the multiple coil groups CG include a coil group CG1, a coil group CG2, a coil group CG3, a coil group CG4, and a coil group CG5. Each of the multiple coil groups CG includes two or more coils 80 . The number of coils 80 included in each of the plurality of coil groups CG can be any number of two or more. In the examples shown in FIGS. 4 to 6, the coil group CG1 includes eight coils 80, the coil group CG2 includes nine coils 80, and the coil group CG3 includes nine coils 80. The coil group CG4 includes 10 coils 80, and the coil group CG5 includes 11 coils 80.

Each of the two or more coils 80 of each of the plurality of coil groups CG has its respective winding portion 80w spirally extending around the central axis AXC, and arranged sequentially and repeatedly along the axial direction Z. So, it is provided. That is, the winding portions 80w of the two or more coils 80 of each of the plurality of coil groups CG are arranged in multiple layers along the axial direction Z and spirally provided around the central axis AXC. In one embodiment, in each of the plurality of coil groups CG, the distance in the axial direction Z between the conductors of adjacent turns may be 0.2 mm or less.

The winding portions 80w of the two or more coils 80 of each of the multiple coil groups CG share the central axis AXC and have the same inner diameter and the same outer diameter. The cross-sectional shape of the winding portions 80w of the plurality of coils 80 is, for example, a rectangular shape.

A plurality of coil groups CG are provided coaxially so as to share the center axis AXC. In the examples shown in FIGS. 4 to 6, the coil groups CG1 to CG5 are provided coaxially. In the examples shown in FIGS. 4 to 6, the coil group CG1 is provided inside the coil group CG2, the coil group CG2 is provided inside the coil group CG3, and the coil group CG3 is provided inside the coil group CG4. The coil group CG4 is provided inside the coil group CG5.

The outer diameter of the winding portion 80w of one of the two coil groups radially adjacent to the center axis AXC is smaller than the inner diameter of the winding portion 80w of the other coil group. In the examples shown in FIGS. 4 to 6, the outer diameter of the winding portion 80w of each of the two or more coils 80 included in the coil group CG1 is equal to that of each of the two or more coils 80 included in the coil group CG2. It is smaller than the inner diameter of the wire portion 80w. The outer diameter of each winding portion 80w of the two or more coils 80 included in the coil group CG2 is smaller than the inner diameter of each winding portion 80w of the two or more coils 80 included in the coil group CG3. The outer diameter of each winding portion 80w of the two or more coils 80 included in the coil group CG3 is smaller than the inner diameter of each winding portion 80w of the two or more coils 80 included in the coil group CG4. The outer diameter of each winding portion 80w of the two or more coils 80 included in the coil group CG4 is smaller than the inner diameter of each winding portion 80w of the two or more coils 80 included in the coil group CG5.

The pitch between the turns of the two or more coils 80 of any one coil group among the plurality of coil groups CG is the coil group provided inside the one coil group among the plurality of coil groups CG. is greater than the pitch between turns of each of the two or more coils 80 of . In the examples shown in FIGS. 4 to 6, the pitch between turns of the coils 80 of the coil group CG5 is larger than the pitch between turns of the coils 80 of the coil group CG4. The pitch between turns of the coils 80 of the coil group CG4 is larger than the pitch between turns of the coils 80 of the coil group CG3. The pitch between turns of the coils 80 of the coil group CG3 is larger than the pitch between turns of the coils 80 of the coil group CG2. The pitch between turns of the coils 80 of the coil group CG2 is larger than the pitch between turns of the coils 80 of the coil group CG1. In one embodiment, the pitch between turns of the multiple coils 80 is set such that the inductances of the multiple coils 80 are substantially the same.

When multiple coils are simply connected in parallel, the impedances of the multiple filters decrease, but in the filter device FD, the coupling between the multiple coils 80 suppresses the decrease in impedance. Furthermore, since the pitch between turns of two or more coils in the outer coil group is larger than the pitch between turns of two or more coils in the inner coil group, multiple , the difference in inductance of the coils 80 is reduced. Therefore, the difference in impedance frequency characteristics of the plurality of filters FT is reduced.

In one embodiment, multiple coils 80 have substantially the same coil length. The coil length is the length in the axial direction Z between one end and the other end of each winding portion 80w of the plurality of coils 80 . In one embodiment, the difference in coil length between the coil having the largest coil length and the coil having the smallest coil length among the plurality of coils 80 is 3% or less of the smallest coil length. According to these embodiments, the difference in the frequency characteristics of the impedances of the filters FT is further reduced.

In one embodiment, one end of the winding portion 80w of the plurality of coils 80 (the end opposite to the end on the capacitor 82 side) is provided along a plane orthogonal to the center axis AXC. In one embodiment, the lead wires 80a of the two or more coils 80 of each of the multiple coil groups CG are provided at equal intervals in the circumferential direction with respect to the center axis AXC. According to this embodiment, the difference in impedance frequency characteristics of the plurality of filters FT is further reduced.

In one embodiment, of the plurality of coil groups CG, the distance in the radial direction, that is, the distance in the radial direction between any two adjacent coil groups in the radial direction with respect to the central axis AXC, is 1.5 mm or less. is. In this embodiment, the difference in impedance frequency characteristics of multiple filters FT is further reduced.

In one embodiment, the inner diameters of the two or more coils 80 in the outermost coil group among the plurality of coil groups CG are two or more than those in the innermost coil group among the plurality of coil groups CG. is less than or equal to 1.83 times the inner diameter of the coil. In the examples shown in FIGS. 4 to 6, the inner diameter of each of the two or more coils 80 of the coil group CG5 is 1.83 times or less the inner diameter of each of the two or more coils 80 of the coil group CG1. According to this embodiment, the difference in impedance frequency characteristics of the plurality of filters FT is further reduced.

A filter device FD having such a plurality of coils 80 is provided outside the chamber 10 . A plurality of coil groups CG are provided coaxially with respect to the central axis AXC so as to surround the conductor pipe 66 immediately below the chamber 10 . In addition, in a state where a plurality of coil groups CG are arranged directly under the chamber 10, the central axis line AXC coincides with the axis line AX.

As shown in FIG. 3, the plasma processing apparatus 1 further includes multiple wirings 72 . Each of the multiple wirings 72 partially configures the multiple feeder lines 70 . A plurality of wires 72 electrically connect a plurality of coils 80 provided outside the chamber 10 to a plurality of terminals 52 t of the electrostatic chuck 52 . The wiring 72 will be described below with reference to FIGS. 7 to 10 in addition to FIGS. FIG. 7 is a schematic diagram of members providing wires electrically connecting coils of a filter device to terminals of an electrostatic chuck in the plasma processing apparatus shown in FIG. 8 is a plan view of the lower surface of the electrostatic chuck of the plasma processing apparatus shown in FIG. 1. FIG. 9 is a plan view of the lower surface of the lower electrode of the plasma processing apparatus shown in FIG. 1. FIG. 10 is a plan view showing a plurality of members providing a plurality of wirings electrically connecting the plurality of coils of the filter device to the plurality of terminals of the electrostatic chuck in the plasma processing apparatus shown in FIG. 1. FIG.

As shown in FIG. 8, in one embodiment, a plurality of terminals 52t are provided on the peripheral edge portion 52p of the electrostatic chuck 52 . A plurality of terminals 52t are provided along the lower surface of the peripheral portion 52p. The plurality of terminals 52t constitutes a plurality of terminal groups 52g. Each of the plurality of terminal groups 52g includes several terminals 52t. The plurality of terminal groups 52g are arranged at equal intervals over the entire circumference of the peripheral portion 52p. In one example, as shown in FIG. 8, the plurality of terminals 52t constitute 12 terminal groups 52g. Each of the twelve terminal groups 52g includes four terminals 52t.

As shown in FIG. 9, the lower electrode 50 has a central portion 50c and a peripheral portion 50p. A central portion 52 c of the electrostatic chuck 52 is provided on the central portion 50 c of the lower electrode 50 . A peripheral edge portion 52 p of the electrostatic chuck 52 is provided on the peripheral edge portion 50 p of the lower electrode 50 . A plurality of through holes are formed in the peripheral portion 50p of the lower electrode 50 . The upper ends of the plurality of through holes of the peripheral edge portion 50p face a plurality of regions in the peripheral edge portion 52p in which the plurality of terminal groups 52g are formed. A plurality of electrical connectors 73 are provided in the plurality of through holes of the peripheral portion 50p. Each of the plurality of electrical connectors 73 includes the same number of terminals as the number of terminals 52t included in the corresponding terminal group 52g. A plurality of terminals provided by a plurality of electrical connectors 73 are respectively connected to a plurality of terminals 52t.

As shown in FIG. 2 , a plurality of electrical connectors 74 are provided directly below the plurality of electrical connectors 73 and inside the conductive member 54 . A plurality of electrical connectors 74 are coupled to corresponding electrical connectors 73 . Each of the plurality of electrical connectors 74 includes the same number of terminals as the number of terminals of the corresponding electrical connector 73 . The plurality of terminals provided by the plurality of electrical connectors 74 are connected to the plurality of terminals 52t via the plurality of terminals provided by the plurality of electrical connectors 73, respectively.

As shown in FIGS. 2 and 7, lead wires 80 a of the plurality of coils 80 are connected to a circuit board 85 . A circuit board 85 is provided above the plurality of coils 80 . A circuit board 85 is provided within the housing 84 . The circuit board 85 has an annular plate shape and extends around the axis AX. A plurality of wirings are formed on the circuit board 85 . Each of the plurality of wirings of the circuit board 85 constitutes a part of the corresponding wirings among the plurality of wirings 72 .

A plurality of first electrical connectors 86 are connected to the circuit board 85 . A first electrical connector 86 extends upwardly from the circuit board 85 . A plurality of first electrical connectors 86 extend from the interior of the housing 84 to the upper side of the bottom of the chamber body 12 . The plurality of first electrical connectors 86 are arranged at regular intervals around the axis AX. In one example, the number of first electrical connectors 86 is six. Each of the plurality of first electrical connectors 86 has several terminals. A plurality of wires of the circuit board 85 are connected to a plurality of terminals provided by the plurality of first electrical connectors 86 . That is, each of the plurality of terminals provided by the plurality of first electrical connectors 86 constitutes a portion of the corresponding wiring among the plurality of wirings 72 .

A plurality of second electrical connectors 87 are provided directly above the plurality of first electrical connectors 86 . In one example, the number of second electrical connectors 87 is six. Each of the plurality of second electrical connectors 87 is coupled to a corresponding first electrical connector 86 . The plurality of terminals provided by the plurality of second electrical connectors 87 are connected to the plurality of terminals provided by the plurality of first electrical connectors 86 . That is, each of the plurality of terminals provided by the plurality of second electrical connectors 87 constitutes a portion of the corresponding wiring among the plurality of wirings 72 .

A plurality of second electrical connectors 87 are supported by a plurality of circuit boards 88 respectively. A plurality of circuit boards 88 are provided above the plurality of second electrical connectors 87 respectively.

A plurality of flexible circuit boards 89 extend from the plurality of second electrical connectors 87 to below the peripheral edge portion 52 p of the electrostatic chuck 52 . Each of the plurality of flexible circuit boards 89 is, for example, a flexible printed circuit board. Each of the plurality of flexible circuit boards 89 has one or more electrical connectors 74 of the plurality of electrical connectors 74 described above. In one example, each of the plurality of flexible circuit boards 89 has two electrical connectors 74 . Each of the plurality of flexible circuit boards 89 provides several wires. A plurality of wires provided by the plurality of flexible circuit boards 89 connect the plurality of terminals provided by the plurality of second electrical connectors 87 and the plurality of terminals provided by the plurality of electrical connectors 74 . there is That is, each of the plurality of wires provided by the plurality of flexible circuit boards 89 forms part of a corresponding wire of the plurality of wires 72 .

As described above, each of the plurality of wirings 72 is connected to the circuit board 85, the corresponding first electrical connector of the plurality of first electrical connectors 86, and the corresponding second electrical connector of the plurality of second electrical connectors 87. Electrical connectors 87 and extend through corresponding ones of the plurality of flexible circuit boards 89 . The plurality of wirings 72 have substantially the same length as each other.

Returning to FIG. 2 , the plasma processing apparatus 1 further includes a plurality of circuit boards 90 . A plurality of circuit boards 90 (another circuit board) are provided within the housing 84 and below the plurality of coils 80 . A plurality of circuit boards 90 are arranged along the axial direction Z. As shown in FIG. Each of the multiple capacitors 82 is provided on one of the multiple circuit boards 90 . A plurality of circuit boards 90 mount a plurality of capacitors 82 on their upper and lower surfaces. A wiring pattern that connects the corresponding coil 80 and the corresponding capacitor 82 is formed on each of the plurality of circuit boards 90 . By using multiple circuit boards 90 , many capacitors 82 can be supported within housing 84 .

In the plasma processing apparatus 1 described above, a plurality of coil groups CG each including two or more coils 80 are provided coaxially so as to share the center axis AXC. Therefore, the space occupied by the multiple coils 80 forming the multiple coil groups CG is small. Therefore, the filter device FD including the plurality of coils 80 can be arranged directly under the chamber 10, and the plurality of heaters HT provided in the electrostatic chuck 52 and the plurality of coils 80 are electrically connected. It is possible to shorten the length of the plurality of wirings 72 . Also, since the plurality of coil groups CG are provided so as to surround the conductor pipe 66, each of the plurality of coils 80 has a large cross-sectional area. Therefore, even if the coil length of each of the plurality of coils 80 is short, the necessary inductance is ensured.

In one embodiment, each of the plurality of traces 72 is connected to a circuit board 85, a corresponding first electrical connector of the plurality of first electrical connectors 86, and a corresponding one of the plurality of second electrical connectors 87, as described above. A corresponding second electrical connector 87 and extending through a corresponding flexible circuit board of the plurality of flexible circuit boards 89 . In this embodiment, multiple traces 72 may extend through circuit board 85 and multiple flexible circuit boards 89 such that their lengths are substantially the same. That is, it is possible to set the lengths of the plurality of wirings 72 to substantially the same length by the layout of the wiring patterns in the circuit board 85 and the plurality of flexible circuit boards 89 .

A plurality of coils of a filter device according to another embodiment will be described below. FIG. 11 is a perspective view of multiple coils of a filter device according to another embodiment. A plurality of coils 80 shown in FIG. 11 can be used as a plurality of coils of the filter device of the plasma processing apparatus of the embodiment described above. In the embodiment shown in FIG. 11, the multiple coils 80 form multiple coil groups CG. In the embodiment shown in FIG. 11, the number of coil groups CG is two, but the number is not limited to this. Each of the multiple coil groups CG includes two or more coils 80 out of the multiple coils 80 . In the embodiment shown in FIG. 11, each of the multiple coils 80 has a winding portion 80w, a lead wire 80a, and a lead wire 80b, like each of the multiple coils 80 of the above-described embodiments. The lead lines 80a are arranged in the circumferential direction. The lead lines 80b are also arranged in the circumferential direction.

In the embodiment shown in FIG. 11, lead wires 80a of two or more coils 80 included in each coil group CG are gathered in one or more local regions in the circumferential direction. In each coil group CG, the lead wire 80a of the other of the two or more coils 80 is provided at a distance of 18 mm or less from the lead wire 80a of each of the two coils 80 . When the lead wires 80a of two or more coils 80 included in each coil group CG are gathered in one or more local regions in the circumferential direction, the real component of the impedance of each filter FT is reduced. be. As a result, loss of high-frequency power in each filter FT is suppressed.

The lead wires 80b of two or more coils 80 included in each coil group CG may also be gathered in one or more local regions in the circumferential direction. In each coil group CG, the lead wire 80b of another coil among the two or more coils 80 may be provided at a distance of 18 mm or less from the lead wire 80b of each of the two or more coils 80 .

Various embodiments have been described above, but various modifications can be configured without being limited to the above-described embodiments. For example, the plasma processing apparatus according to the modification is a plasma processing apparatus having an arbitrary plasma source, such as an inductively coupled plasma processing apparatus or a plasma processing apparatus that generates plasma using surface waves such as microwaves. good too.

Simulation results for the embodiment shown in FIG. 11 will be described below. FIG. 12 is a perspective view showing coil groups in the simulation. In the simulation, the impedances (synthesized impedances) of two filters whose coils 80 constitute one coil group CG and the frequency characteristics of each of their real components were calculated. In the simulation, the distance between the lead wires 80a and the distance between the lead wires 80b of the two coils 80 were set to 9 mm, 18 mm and 81 mm, respectively. Other conditions in the simulation are as follows.
<Conditions in simulation>
Cross-sectional shape of each coil 80: 3 mm x 0.8 mm rectangular shape Number of turns of each coil 80: 7 turns Coil length of each coil 80: 200 mm
Inside diameter of each coil (diameter): 130mm
Capacitance of capacitor 82: 2200 pF

The simulation results are shown in FIGS. 13(a), 13(b), and 13(c). FIG. 13(a) shows the frequency characteristics of the impedance and the real component of the filter when the distance between the lead wires 80a and the distance between the lead wires 80b of the two coils 80 are each 9 mm. there is FIG. 13(b) shows the frequency characteristics of the impedance and the real component of the filter when the distance between the lead wires 80a and the distance between the lead wires 80b of the two coils 80 is 18 mm. there is FIG. 13(c) shows the frequency characteristics of the impedance and the real component of the filter when the distance between the lead wires 80a and the distance between the lead wires 80b of the two coils 80 are each 81 mm. there is

As shown in FIG. 13(c), when each of the distance between the lead wires 80a and the distance between the lead wires 80b of the two coils 80 is 81 mm, a large peak of the real component ((c) of FIG. 13) A peak surrounded by a dotted line) occurred. As shown in FIG. 13(b), when each of the distance between the lead wires 80a and the distance between the lead wires 80b of the two coils 80 is 18 mm, the peak of the real component (in FIG. 13(b) The peak enclosed by the dotted line) was greatly suppressed. Further, as shown in FIG. 13(a), when the distance between the lead wires 80a of the two coils 80 and the distance between the lead wires 80b of the two coils 80 were each 9 mm, the peak of the real component did not substantially occur. rice field. Therefore, by arranging the lead wire 80a of the other coil of the two or more coils 80 at a distance of 18 mm or less from the lead wire 80a of each of the two or more coils 80 of each coil group CG, each filter It was confirmed that the real component of the FT impedance was reduced.

Reference Signs List 1 plasma processing apparatus 10 chamber 10s inner space 14 support base 50 lower electrode 52 electrostatic chuck 52t terminal HT heater HC heater controller 61 first high frequency Power supply 62 Second high-frequency power supply 65 Feeder 66 Conductor pipe 72 Wiring FD Filter device CG Coil group 80 Coil 80w Winding part 82 Capacitor 84 housing, AX...axis, AXC...center axis.

Claims (5)

a chamber;
a support pedestal configured to support a substrate within the interior space of the chamber;
a lower electrode;
an electrostatic chuck provided on the lower electrode and having a plurality of heaters provided therein;
the support base having
a feeder electrically connected to the lower electrode and extending downward under the lower electrode;
a grounded conductor pipe extending to surround the power feeder outside the chamber;
a high-frequency power supply electrically connected to the feeder;
a filter device configured to prevent high-frequency waves from flowing into the heater controller from the plurality of heaters;
a plurality of wires electrically connecting the plurality of heaters and the plurality of coils of the filter device, respectively;
with
The filter device is
the plurality of coils electrically connected to the plurality of heaters;
a plurality of capacitors respectively connected between the plurality of coils and ground;
an electrically grounded housing containing the plurality of coils therein;
has
The plurality of coils constitute a plurality of coil groups each including two or more coils,
In each of the plurality of coil groups, the two or more coils each have a winding portion extending spirally around a central axis, and each turn extending along an axial direction along which the central axis extends. provided so as to be sequentially and repeatedly arranged in the
The plurality of coil groups are provided coaxially with respect to the central axis so as to surround the conductor pipe immediately below the chamber,
Plasma processing equipment. 2. The plasma processing apparatus according to claim 1, wherein said plurality of wirings have substantially the same length as each other. a plurality of terminals electrically connected to the plurality of heaters are provided on a peripheral edge of the electrostatic chuck;
The plasma processing apparatus is
a circuit board to which a plurality of lead wires of each of the plurality of coils are connected;
a plurality of first electrical connectors extending upwardly from the circuit board;
a plurality of second electrical connectors respectively coupled to the plurality of first electrical connectors;
a plurality of flexible circuit boards extending from the plurality of second electrical connectors to under the peripheral edge of the electrostatic chuck;
further comprising
Each of the plurality of wires includes the circuit board, a corresponding first electrical connector among the plurality of first electrical connectors, a corresponding second electrical connector among the plurality of second electrical connectors, and the extending within a corresponding flexible circuit board of the plurality of flexible circuit boards;
The plasma processing apparatus according to claim 2. Further comprising a plurality of separate circuit boards provided below the plurality of coils,
each of the plurality of capacitors is mounted on a corresponding circuit board out of the plurality of separate circuit boards;
The plasma processing apparatus according to claim 3. each of the plurality of coils has a lead wire continuous with one end of its winding portion and connected to a corresponding wire out of the plurality of wires;
In each of the plurality of coil groups, a lead wire of another coil among the two or more coils is provided at a distance of 18 mm or less from the lead wire of each of the two or more coils.
The plasma processing apparatus according to any one of claims 1-4.

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