Substrate processing apparatus, substrate processing method, and inductively coupled antenna

Abstract

To improve the uniformity of a plasma distribution inside a processing container.SOLUTION: A substrate processing apparatus includes: a plate-shaped window member that divides an inside part of a processing container that accommodates a substrate into an upper antenna chamber and a lower processing chamber; and an inductively coupled antenna that is disposed in the antenna chamber so as to face a mounting table on which the substrate is mounted with the window member interposed therebetween and generates an inductive electric field for generating plasma in the processing chamber. The inductively coupled antenna has an antenna part composed of an antenna line orbiting in a virtual plane opposed to an upper surface of the window member. The antenna part has an offset path formed by a part of an antenna line disposed in the virtual plane being offset upward from the virtual plane. A degree of contribution of a current flowing through an offset path to generation of the plasma is smaller than a degree of contribution of the current flowing through the antenna line disposed in the virtual plane to generation of the plasma.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a substrate processing apparatus, a substrate processing method, and an inductively coupled antenna. [Background technology]

[0002] In a substrate processing apparatus for performing plasma processing on rectangular substrates, the interior of a processing vessel that accommodates the rectangular substrate is divided into an antenna chamber and a processing chamber by a conductive window member. A high-frequency antenna is disposed inside the antenna chamber, and high-frequency power is supplied to the high-frequency antenna, causing a high-frequency current to flow through the antenna wire of the high-frequency antenna. At this time, eddy currents circulating from the upper surface to the lower surface of the window member are induced in the processing chamber, and an induced electric field is generated inside the processing chamber due to the eddy currents. The induced electric field excites the processing gas inside the processing chamber, generating plasma.

[0003] The high-frequency antenna is composed of, for example, an inner antenna, an intermediate antenna, and an outer antenna. In this case, the inner antenna is arranged to face the center of the window member, the intermediate antenna is arranged to surround the inner antenna, and the outer antenna is arranged to surround the intermediate antenna. By adjusting the ratio of high-frequency power supplied to the inner antenna, the intermediate antenna, and the outer antenna, respectively, the distribution of eddy currents induced in the window member can be controlled, and the distribution of the induced electric field generated inside the processing chamber can be adjusted.

[0004] The outer antenna is composed of multiple antenna segments arranged circumferentially so as to face the outer periphery of the window member. Each antenna segment of the outer antenna is composed of a vertically wound antenna wire wound in a direction perpendicular to the surface of the rectangular substrate. When the antenna wire of the antenna segments is wound vertically in this manner, the antenna wire at the bottom of each antenna segment faces the processing chamber via the window member when the multiple antenna segments are arranged circumferentially. Controlling the high-frequency current flowing through each antenna segment can control eddy currents induced in the partition windows facing each antenna segment when the window member is divided into multiple partition windows. This can generate a strong induced electric field in a region inside the processing chamber facing a specific partition window, thereby increasing the plasma density in that region. Therefore, the plasma density can be increased in the region inside the processing chamber facing the corners of the window member, where plasma density tends to be low, thereby generally improving the uniformity of plasma distribution throughout the entire processing chamber. Furthermore, by stacking antenna wires in the antenna segments at the corners, the plasma density at the corners can be increased and the uniformity of the plasma distribution can be further improved (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-136065 Summary of the Invention [Problem to be solved by the invention]

[0006] The techniques according to the present disclosure further improve the uniformity of the plasma distribution inside the processing vessel. [Means for solving the problem]

[0007] One aspect of the technology disclosed herein is a substrate processing apparatus that performs plasma processing on a substrate, the apparatus comprising: a processing vessel that accommodates the substrate therein; a plate-shaped window member that divides the interior of the processing vessel into an upper antenna chamber and a lower processing chamber; a mounting stage that is disposed inside the processing chamber and on which the substrate is placed; and an inductively coupled antenna that is disposed inside the antenna chamber facing the mounting stage across the window member and that generates an inductive electric field for generating plasma inside the processing chamber, the inductively coupled antenna having an antenna portion that is disposed so as to circle within an imaginary plane that faces an upper surface of the window member, the antenna portion comprising at least one antenna wire, the antenna portion having an offset path formed by a portion of the antenna wire that is disposed within the imaginary plane being offset upward from the imaginary plane, and the degree to which the current flowing through the offset path contributes to the generation of the plasma is smaller than the degree to which the current flowing through the antenna wire that is disposed within the imaginary plane contributes to the generation of the plasma. [Effects of the Invention]

[0008] According to the technique of the present disclosure, the uniformity of the plasma distribution inside the processing chamber can be further improved. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view schematically showing a configuration of a substrate processing apparatus according to a first embodiment of the technology disclosed herein. [Figure 2] FIG. 2 is a view of the window member of FIG. 1 as viewed from the processing chamber side. [Figure 3] 3 is a perspective view showing in detail the configuration of a corner antenna segment of the outer antenna part in FIG. 2. FIG. [Figure 4] 3 is a perspective view showing in detail the configuration of a side antenna segment of the outer antenna part in FIG. 2. FIG. [Figure 5] 4 is a diagram for explaining the configuration of a height changing unit in FIG. 3. FIG. [Figure 6] 4 is a diagram for explaining a method of adjusting plasma density using a height changing unit in FIG. 3. FIG. [Figure 7] 4 is a diagram showing an example in which the height of the connection portion of each height change portion in the corner antenna segment in FIG. 3 is changed. FIG. [Figure 8] 10A and 10B are diagrams for explaining an example in which the plasma density distribution is locally improved by using the height change portions of the corner antenna segments. [Figure 9] FIG. 10 is a perspective view showing in detail the configuration of a modified example of a side antenna segment of the outer antenna portion. [Figure 10] 10 is a view of a window member of a substrate processing apparatus according to a second embodiment of the technology disclosed herein, viewed from the processing chamber side. FIG. [Figure 11] FIG. 11 is a perspective view showing in detail the configuration of the corner antenna segment in FIG. [Figure 12] FIG. 11 is a perspective view showing in detail the configuration of a side antenna segment in FIG. [Figure 13] 12 is a diagram showing an example in which the height of the connection portion of each height change portion in the corner antenna segment in FIG. 11 is changed. FIG. [Figure 14] 10A and 10B are diagrams for explaining a state in which one end or the other end of a connecting member protrudes downward from an imaginary plane. [Figure 15] 10A and 10B are diagrams illustrating the configuration of a modified example of the height changing unit. [Figure 16] 10A and 10B are diagrams illustrating how the height of a connecting member from an imaginary plane is changed in a modified example of the height changer. [Figure 17] 10A and 10B are diagrams illustrating a case where the overall length of the connection member is changed by a length adjustment mechanism. [Figure 18] 10 is a partially enlarged view showing rounded chamfering of corners of a first connecting portion and a second connecting portion. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] As described above, the substrate processing apparatus of Patent Document 1 can generally improve the uniformity of plasma distribution throughout the entire processing chamber. However, detailed observation of the plasma distribution reveals that the plasma density distribution is not locally uniform in regions of the processing chamber facing each antenna segment. Meanwhile, with the recent trend toward finer processing of rectangular substrates, there is a demand for a more highly uniform plasma density distribution throughout the entire processing chamber, and it is also necessary to locally uniformize the plasma density distribution.

[0011] However, in the substrate processing apparatus of Patent Document 1, the number and length of the multiple antenna wires facing the processing chamber in each antenna segment cannot be easily changed. Therefore, it is not easy to locally change the strength of the induced electric field in the region inside the processing chamber facing the antenna segment. As a result, it is difficult to uniformly distribute the plasma density in the region inside the processing chamber facing the antenna segment.

[0012] In contrast, the technology disclosed herein partially changes the distances of the multiple antenna wires facing each antenna segment from the processing chamber, thereby partially changing the strength of the induced electric field in the region inside the processing chamber facing each antenna segment, thereby making the plasma density distribution uniform even in the region inside the processing chamber facing the antenna segments, and further improving the uniformity of the plasma distribution inside the processing chamber.

[0013] Hereinafter, an embodiment of the technology according to the present disclosure will be described with reference to the drawings. First, a first embodiment of the technology according to the present disclosure will be described.

[0014] Fig. 1 is a cross-sectional view showing a schematic configuration of a substrate processing apparatus according to the present embodiment. The substrate processing apparatus 10 shown in Fig. 1 is used for plasma processing, such as etching, ashing, and film formation, when forming thin film transistors on a rectangular glass substrate for an FPD (Flat Panel Display).

[0015] The substrate processing apparatus 10 has an airtight processing vessel 11 in the shape of a rectangular cylinder that accommodates a rectangular glass substrate G therein. The processing vessel 11 is made of a metal material, for example, aluminum whose inner wall surface is anodized, and is grounded by a ground wire 12. The interior of the processing vessel 11 is divided into an upper antenna chamber 14 and a lower processing chamber 15 by a window member 13. The window member 13 is a generally rectangular plate-like member composed of multiple dividing windows 16, and has two long sides and two short sides corresponding to the shape of the processing vessel 11 in the shape of a rectangular cylinder.

[0016] Each of the partition windows 16 of the window member 13 is made of a non-magnetic and conductive material, such as aluminum or an alloy containing aluminum. In the window member 13, a partition member 17 made of an insulator is disposed between each of the adjacent partition windows 16. The partition members 17 electrically insulate the adjacent partition windows 16 from each other.

[0017] A gas diffusion chamber 18 is provided inside each partition window 16, and the gas diffusion chamber 18 communicates with the processing chamber 15 via a plurality of gas discharge holes 19 provided below. Meanwhile, a gas supply pipe 20 communicating with the gas diffusion chamber 18 of each partition window 16 is provided in the center of the upper surface of the window member 13. The gas supply pipe 20 penetrates the ceiling of the processing vessel 11 and is connected to a processing gas supply system 21 including a processing gas supply source, a valve system, etc. Therefore, in the substrate processing apparatus 10, processing gas supplied from the processing gas supply system 21 is supplied to the gas diffusion chamber 18 of each partition window 16 via the gas supply pipe 20, and then discharged into the processing chamber 15 from each gas discharge hole 19.

[0018] Furthermore, in the substrate processing apparatus 10, a radio frequency (RF) antenna 22 (inductively coupled antenna) is disposed inside the antenna chamber 14, facing the window member 13. The radio frequency antenna 22 is disposed above and spaced apart from the window member 13 by a spacer 45 made of an insulating material. A mounting table 24 for mounting a rectangular substrate G is disposed at the bottom inside the processing chamber 15, facing the radio frequency antenna 22 across the window member 13. The mounting table 24 has a rectangular shape in a plan view corresponding to the rectangular substrate G, and is made of a metal material, for example, aluminum with an anodized surface. The rectangular substrate G mounted on the mounting table 24 is attracted and held to the mounting table 24 by an electrostatic chuck (not shown). The mounting table 24 is disposed at the bottom of the processing vessel 11 and is supported by an insulating frame 25 having an opening at the bottom. A loading / unloading port 26 for loading and unloading the rectangular substrate G and a gate valve 27 for opening and closing the port are provided on the sidewall of the processing chamber 15.

[0019] A high-frequency power supply 30 is connected to the mounting table 24 via a power supply line 28 passing through an opening in the insulator frame 25 and via a matching box 29. During plasma processing, the high-frequency power supply 30 supplies bias high-frequency power, for example, 3.2 MHz high-frequency power, to the mounting table 24. This bias high-frequency power effectively attracts ions in the plasma generated inside the processing chamber 15 to the rectangular substrate G.

[0020] A temperature control mechanism including a heating means such as a ceramic heater and a coolant flow path, as well as a temperature sensor (all not shown) are provided inside the mounting table 24 to control the temperature of the rectangular substrate G. The piping and wiring of these mechanisms are all led out to the outside of the processing chamber 11 through openings in the insulator frame 25. A shield ring (not shown) that contributes to the distribution of plasma may be provided on the upper part of the side wall of the insulator frame 25 that stands upright and covers the side surface of the mounting table 24.

[0021] An exhaust device 32 including a vacuum pump and the like is connected to the bottom of the processing chamber 15 via an exhaust pipe 31. The exhaust device 32 evacuates the processing chamber 15 and reduces the pressure inside the processing chamber 15 to a predetermined pressure (e.g., 10 mTorr) during plasma processing.

[0022] An extremely thin cooling space (not shown) is formed between the rear surface of the rectangular substrate G placed on the mounting table 24 and the mounting surface of the mounting table 24, and the mounting table 24 is provided with a heat transfer gas flow path 33 for supplying a heat transfer gas to the cooling space. By supplying a heat transfer gas to the cooling space on the rear surface of the rectangular substrate G, the temperature of the rectangular substrate G can be adjusted by the temperature control mechanism even if the inside of the processing chamber 15 is in a reduced pressure environment.

[0023] Furthermore, in the substrate processing apparatus 10, the high frequency antenna 22 is composed of an outer antenna portion 23, an inner antenna portion 34, and an intermediate antenna portion 35. Fig. 2 is a view of the window member 13 in Fig. 1 viewed from the processing chamber 15 side, with the high frequency antenna 22 arranged in the antenna chamber 14 shown by a solid line so that it can be seen through.

[0024] 2, a rectangular virtual plane P facing the upper surface of the window member 13 and slightly spaced from the window member 13 is displayed superimposed on the window member 13. The virtual plane P is parallel to the upper surface of the window member 13 (see FIG. 1) and, like the window member 13, has two long sides and two short sides. The outer periphery of the virtual plane P is divided into a corner area including a corner where one long side intersects with one short side, and a side area sandwiched between the two corner areas. In this case, corner area A, side area A, corner area B, side area B, corner area C, side area C, corner area D, and side area D are arranged in this order clockwise. This virtual plane P is conceptually introduced for ease of explanation and is not a plane that actually exists in the substrate processing apparatus 10. Note that in FIG. 2, the dividing windows 16 and partition members 17 of the window member 13 are not depicted.

[0025] As shown in Figure 2, the inner antenna section 34 is positioned opposite the center of the window member 13, the intermediate antenna section 35 is positioned to surround the inner antenna section 34, and the outer antenna section 23 is positioned to surround the intermediate antenna section 35.

[0026] The inner antenna portion 34 is composed of a single flat antenna wire 36 wound twice around the imaginary plane P in a rectangular shape, with the antenna wire 36 positioned so that its plane is perpendicular to the imaginary plane P. The middle antenna portion 35 is also composed of a single flat antenna wire 37 wound twice around the imaginary plane P in a rectangular shape, with the antenna wire 37 also positioned so that its plane is perpendicular to the imaginary plane P. The antenna wires 36, 37 are both made of a low-resistance conductive material, such as copper. The number of turns of the antenna wires 36, 37 is not limited to two, and may be, for example, three or more. Furthermore, the antenna wires 36, 37 may each be formed by arranging multiple antenna wires staggered in the circumferential direction.

[0027] Further, outer antenna portion 23 is made up of a plurality of antenna segments arranged so as to circle within imaginary plane P, for example, four corner antenna segments 38a to 38d and four side antenna segments 39a to 39d.

[0028] Corner antenna segment 38a is arranged in corner area A, corner antenna segment 38b is arranged in corner area B, corner antenna segment 38c is arranged in corner area C, and corner antenna segment 38d is arranged in corner area D. Furthermore, side antenna segment 39a is arranged in side area A, side antenna segment 39b is arranged in side area B, side antenna segment 39c is arranged in side area C, and side antenna segment 39d is arranged in side area D. The detailed configurations of corner antenna segments 38a to 38d and side antenna segments 39a to 39d will be described later.

[0029] Returning to FIG. 1 , a feeder line 40 is connected to the outer antenna unit 23, a feeder line 41 is connected to the inner antenna unit 34, and another feeder line (not shown) is connected to the intermediate antenna unit 35. For ease of explanation, FIG. 1 depicts a portion of the antenna wire of the outer antenna unit 23 connected to the feeder line 40 and a portion of the antenna wire of the inner antenna unit 34 connected to the feeder line 41 as standing obliquely from the plane. However, each antenna wire does not necessarily have to be partially standing, and each antenna wire may be entirely within the plane. The feeder line 40, the feeder line 41, and the other feeder lines branch off from a main feeder line 42, to which a matching box 43 and a high-frequency power supply 44 are connected. Thus, high-frequency power for plasma generation, for example, high-frequency power having a frequency of 13.56 MHz, is supplied from the high-frequency power supply 44 to the outer antenna unit 23, the inner antenna unit 34, and the intermediate antenna unit 35, respectively. When high-frequency current flows through the antenna wires of the outer antenna unit 23, inner antenna unit 34, and intermediate antenna unit 35 due to the supply of high-frequency power with a frequency of 13.56 MHz, eddy currents are induced in each partitioned window 16 facing each antenna unit, circulating from the top to the bottom. Inside the processing chamber 15, these eddy currents generate an induced electric field, which excites the processing gas in a region inside the processing chamber 15 facing the partitioned window 16, generating plasma. Note that, hereinafter, the region inside the processing chamber 15 facing each antenna unit will be referred to as the "facing region" for short.

[0030] Furthermore, in the substrate processing apparatus 10, variable capacitances (not shown) are installed in the power feeder 40, the power feeder 41, and other power feeders. By controlling these variable capacitances, it is possible to control the proportions of high-frequency power supplied to the outer antenna unit 23, the inner antenna unit 34, and the intermediate antenna unit 35. This makes it possible to change the strength of the induced electric field generated in the facing region of the outer antenna unit 23, the facing region of the inner antenna unit 34, and the facing region of the intermediate antenna unit 35 inside the processing chamber 15. As a result, it is possible to control the distribution of plasma generated inside the processing chamber 15.

[0031] Each component of the substrate processing apparatus 10 is controlled by a control unit 46 consisting of a microprocessor (computer). A keyboard (not shown) that accepts input operations from an operator and a user interface 47 that displays the operating status of the substrate processing apparatus 10 are connected to the control unit 46. Furthermore, a storage unit 48 is connected to the control unit 46, and when various plasma processes are performed, the control unit 46 controls each component of the substrate processing apparatus 10 in accordance with the process recipes stored in the storage unit 48.

[0032] Although processing vessel 11 has a rectangular cylindrical shape, it may have a cylindrical or elliptical cylindrical shape. In this case, mounting table 24 has a circular or elliptical shape in a plan view, and window member 13 also has a circular or elliptical shape in a plan view. In this case, antenna wires 36, 37 of inner antenna unit 34 and intermediate antenna unit 35 are also wound in a circular or elliptical shape, and outer antenna unit 23 is made of multiple antenna segments arranged to circle within a circular or elliptical imaginary plane P. Furthermore, in this case, the substrate mounted on mounting table 24 does not have to be a rectangular substrate G made of glass, but may be, for example, a circular semiconductor wafer.

[0033] Fig. 3 is a perspective view showing in detail the configuration of corner antenna segment 38a of outer antenna unit 23. Since corner antenna segments 38b to 38d have the same configuration as corner antenna segment 38a, the configuration of corner antenna segment 38a will be representatively described in this embodiment. In Fig. 3, imaginary plane P is partially drawn for convenience of explanation.

[0034] In FIG. 3 , corner antenna segment 38a is a vertically wound coil made of a single flat antenna wire 49 wound spirally in a direction perpendicular to imaginary plane P. Corner antenna segment 38a is formed into an L-shape parallel to imaginary plane P in a plan view by bending and winding antenna wire 49. Antenna wire 49 is made of a low-resistance conductive material, such as copper, and is arranged so that its plane is perpendicular to imaginary plane P. Antenna wire 49 is wound multiple times, for example, five times, so that each turn is offset from the outer edge of imaginary plane P, i.e., the outside of the L-shape, to the inside of imaginary plane P, i.e., the inside of the L-shape. Here, "inside the L-shape" refers to the side where antenna wire 49 is bent (the inner corner of the L-shape), and "outside the L-shape" refers to the side opposite to the side where antenna wire 49 is bent (the outer corner of the L-shape).

[0035] The lower portion of the corner antenna segment 38a is disposed within the imaginary plane P, and because the antenna wire 49 is wound spirally in the corner antenna segment 38a, multiple partial antenna wires constituting the antenna wire 49 are disposed parallel to one another within the imaginary plane P. The partial antenna wire here means a part of the antenna wire 49. Therefore, it can be said that the antenna wire 49 is formed by connecting multiple partial antenna wires together. Furthermore, multiple partial antenna wires constituting the same antenna wire 49 can exist within the imaginary plane P, and in this embodiment, as described above, multiple partial antenna wires constituting the same antenna wire 49 are disposed parallel to one another within the imaginary plane P.

[0036] The corner antenna segment 38a has a long-side component 50a arranged to extend along the long side (see FIG. 2) of the imaginary plane P in a plan view, and a short-side component 50b arranged to extend along the short side (see FIG. 2) of the imaginary plane P in a plan view. The long-side component 50a and the short-side component 50b intersect near the corner of the corner area A to form an L-shape in a plan view.

[0037] The long-side constituent portion 50a has a shape that is open on the right side, i.e., on the corner side, in a side view diagonally from below left in Fig. 3. The long-side constituent portion 50a has a lower constituent portion 51a that is arranged in the imaginary plane P, an upper constituent portion 51b that is arranged above the lower constituent portion 51a and faces the lower constituent portion 51a, and a side constituent portion 51c that connects the lower constituent portion 51a and the upper constituent portion 51b.

[0038] The lower component 51a is composed of a plurality of partial antenna wires arranged within the above-mentioned imaginary plane P. The upper component 51b is composed of a plurality of partial antenna wires arranged parallel to the partial antenna wires of the lower component 51a and different from the partial antenna wires of the lower component 51a. The side component 51c is composed of a plurality of partial antenna wires erected perpendicular to the imaginary plane P and different from the partial antenna wires of the lower component 51a and the upper component 51b.

[0039] The short-side constituent portion 50b has a shape that is open on the left side, i.e., on the corner side, in a side view diagonally from below to the right in Fig. 3. The short-side constituent portion 50b also has a lower constituent portion 52a that is arranged in the imaginary plane P, an upper constituent portion 52b that is arranged above the lower constituent portion 52a and faces the lower constituent portion 52a, and a side constituent portion 52c that connects the lower constituent portion 52a and the upper constituent portion 52b.

[0040] The lower component 52a is composed of a plurality of partial antenna wires arranged within the above-mentioned imaginary plane P. The upper component 52b is composed of a plurality of partial antenna wires arranged parallel to the partial antenna wires of the lower component 52a and different from the partial antenna wires of the lower component 52a. The side component 52c is composed of a plurality of partial antenna wires erected perpendicular to the imaginary plane P and different from the partial antenna wires of the lower component 51a and the upper component 51b.

[0041] When high-frequency power is supplied to the corner antenna segment 38a, the high-frequency current flowing through the lower components 51a and 52a induces eddy currents in the partitioned windows 16 facing the corner antenna segment 38a. However, the upper components 51b and 52b and the side components 51c and 52c are farther from the window member 13 than the lower components 51a and 52a. Therefore, the high-frequency current flowing through the upper components 51b and 52b and the side components 51c and 52c hardly contributes to inducing eddy currents in the partitioned windows 16 facing the corner antenna segment 38a. In other words, the induced electric field generated by the high-frequency current flowing through the lower components 51a and 52a contributes to plasma generation, but the induced electric field generated by the high-frequency current flowing through the upper components 51b and 52b and the side components 51c and 52c does not substantially contribute to plasma generation.

[0042] Each partial antenna wire constituting the lower component 51a of the long side component 50a has a height change section 53 (offset path) formed by offsetting a part of the partial antenna wire upward from the imaginary plane P. Similarly, each partial antenna wire constituting the lower component 52a of the short side component 50b has a height change section 54 (offset path) formed by offsetting a part of the partial antenna wire upward from the imaginary plane P. The detailed configurations of the height change sections 53 and 54 will be described later.

[0043] Fig. 4 is a perspective view showing in detail the configuration of side antenna segment 39a of outer antenna section 23. Note that side antenna segments 39b to 39d have the same configuration as side antenna segment 39a, and therefore in this embodiment, the configuration of side antenna segment 39a will be representatively described. Also, in Fig. 4, imaginary plane P is partially drawn for convenience of explanation.

[0044] 4, the side antenna segment 39a is composed of a vertically wound coil made of a single antenna wire 49 wound spirally in a direction perpendicular to the imaginary plane P. Similar to the antenna wire 49 of the corner antenna segment 38a, the antenna wire 49 is arranged so that its plane is perpendicular to the imaginary plane P. In the side antenna segment 39a, the antenna wire 49 is also wound multiple times, for example five times, so that each turn is offset from the outer edge of the imaginary plane P toward the inside of the imaginary plane P.

[0045] The lower portion of the side antenna segment 39a is disposed within the imaginary plane P, and as a result, similar to the corner antenna segment 38a, a plurality of partial antenna lines are disposed within the imaginary plane P parallel to one another.

[0046] Moreover, the side antenna segment 39a has an I-shape extending along the long side of the imaginary plane P in a plan view. Furthermore, the side antenna segment 39a has a closed rectangular loop shape in a side view from diagonally below the left in FIG. 4. The side antenna segment 39a has a lower component 55a arranged within the imaginary plane P and an upper component 55b arranged above the lower component 55a and facing the lower component 55a. The side antenna segment 39a also has side components 55c and 55d that connect the lower component 55a and the upper component 55b.

[0047] The lower component 55a is composed of a plurality of partial antenna wires arranged within the above-mentioned imaginary plane P. The upper component 55b is composed of a plurality of partial antenna wires arranged parallel to the partial antenna wires of the lower component 55a and different from the partial antenna wires of the lower component 55a. The side component parts 55c and 55d are each composed of a plurality of partial antenna wires arranged perpendicular to the imaginary plane P and different from the partial antenna wires of the lower component 55a and the upper component part 55b.

[0048] When high-frequency power is supplied to the side antenna segment 39a, the high-frequency current flowing through the lower component 55a induces eddy currents in each partitioned window 16 facing the side antenna segment 39a. However, the upper component 55b and the side components 55c and 55d are farther from the window member 13 than the lower component 55a. Therefore, the high-frequency current flowing through the upper component 55b and the side components 55c and 55d hardly contributes to inducing eddy currents in each partitioned window 16 facing the side antenna segment 39a. In other words, the induced electric field generated by the high-frequency current flowing through the lower component 55a contributes to plasma generation, but the induced electric field generated by the high-frequency current flowing through the upper component 55b and the side components 55c and 55d does not substantially contribute to plasma generation.

[0049] Unlike the corner antenna segment 38a, in the side antenna segment 39a, a part of each partial antenna wire constituting the lower component 55a is not offset upward from the imaginary plane P.

[0050] As described above, each of the corner antenna segments 38a to 38d has a height change portion 53 and a height change portion 54, while none of the side antenna segments 39a to 39d has a height change portion. Therefore, the outer antenna section 23 has a total of eight height change portions.

[0051] As described above, each of the corner antenna segments 38a to 38d has one long-side component 50a extending along the long side of the imaginary plane P and one short-side component 50b extending along the short side of the imaginary plane P. Therefore, in the outer antenna unit 23, two long-side component parts 50a are arranged corresponding to each long side of the imaginary plane P. Each long-side component part 50a has one height changing part 53, so that in the outer antenna unit 23, two height changing parts 53 are arranged corresponding to each long side of the imaginary plane P. Furthermore, in the outer antenna unit 23, two short-side component parts 50b are arranged corresponding to each short side of the imaginary plane P. Each short-side component part 50b has one height changing part 54, so that in the outer antenna unit 23, two height changing parts 54 are arranged corresponding to each short side of the imaginary plane P.

[0052] Furthermore, with respect to one long side of the imaginary plane P, the side antenna segment 39a is arranged in the center, and the corner antenna segments 38a, 38b are arranged on both ends. Therefore, the long side component parts 50a of each corner antenna segment 38a, 38b are arranged closer to the corner of the imaginary plane P than the center of the one long side of the imaginary plane P. As a result, each height changer 53 is also arranged closer to the corner of the imaginary plane P than the center of the one long side of the imaginary plane P. Similarly, with respect to the other long side of the imaginary plane P, the side antenna segment 39c is arranged in the center, and the corner antenna segments 38c, 38d are arranged on both ends. Therefore, the long side component parts 50a of each corner antenna segment 38c, 38d are arranged closer to the corner of the imaginary plane P than the center of the other long side of the imaginary plane P. As a result, each height changer 53 is also arranged closer to the corner of the imaginary plane P than the center of the other long side of the imaginary plane P.

[0053] Furthermore, with respect to one short side of the imaginary plane P, the side antenna segment 39b is arranged in the center, and the corner antenna segments 38b, 38c are arranged on both ends. Therefore, the short side component parts 50b of each corner antenna segment 38b, 38c are arranged closer to the corner of the imaginary plane P than the center of the one short side of the imaginary plane P. As a result, each height changer 54 is also arranged closer to the corner of the imaginary plane P than the center of the one short side of the imaginary plane P. Similarly, with respect to the other short side of the imaginary plane P, the side antenna segment 39d is arranged in the center, and the corner antenna segments 38d, 38a are arranged on both ends. Therefore, the short side component parts 50b of each corner antenna segment 38d, 38a are arranged closer to the corner of the imaginary plane P than the center of the other short side of the imaginary plane P. As a result, each height changer 54 is also arranged closer to the corner of the imaginary plane P than the center of the other short side of the imaginary plane P.

[0054] Although the corner antenna segment 38a and the side antenna segment 39a are configured by one antenna wire 49, they may be configured by winding a plurality of antenna wires connected in series.

[0055] 5 is a diagram for explaining the configuration of height change unit 53. Since height change unit 54 has the same configuration as height change unit 53, the configuration of height change unit 53 will be representatively explained in this embodiment.

[0056] The height changing unit 53 is composed of a first standing portion 49a and a second standing portion 49b standing upward from the imaginary plane P, and a connecting member 49c connecting the first standing portion 49a and the second standing portion 49b. The first standing portion 49a, the second standing portion 49b, and the connecting member 49c are all part of the partial antenna line of the antenna line 49. Structurally, the partial antenna line of the antenna line 49 is divided by the height changing unit 53 (or the height changing unit 54), but conceptually, the antenna line 49 is also continuous in the height changing unit 53 (or the height changing unit 54) and is considered to be a single antenna line as a whole. Hereinafter, the continuity of the partial antenna lines in the height changing unit 53 and the height changing unit 54 will be considered in the same manner. The first standing portion 49a is provided with a plurality of mounting holes 57a arranged along the height direction, and the second standing portion 49b is also provided with a plurality of mounting holes 57b arranged along the height direction. Each mounting hole 57a is configured to allow one end of a connecting member 49c to be attached with a bolt 58, and each mounting hole 57b is configured to allow the other end of the connecting member 49c to be attached with a bolt 58. One end of the connecting member 49c is attached to one of the mounting holes 57a of the first standing portion 49a, and the other end of the connecting member 49c is attached to one of the mounting holes 57b of the second standing portion 49b, thereby connecting the first standing portion 49a and the second standing portion 49b with the connecting member 49c.

[0057] When one end of the connecting member 49c is attached to the lowest mounting hole 57a of the first upright portion 49a and the other end of the connecting member 49c is attached to the lowest mounting hole 57b of the second upright portion 49b, the connecting member 49c is not separated from the imaginary plane P but is positioned within the imaginary plane P (Figure 5(A)).

[0058] Furthermore, by changing the mounting hole 57a to which one end of the connecting member 49c is attached and by changing the mounting hole 57b to which the other end of the connecting member 49c is attached, the mounting position of the connecting member 49c relative to the first upright portion 49a and the second upright portion 49b can be changed. That is, the height H (offset amount) of the connecting member 49c from the imaginary plane P (hereinafter referred to as the "connection portion height H") can be changed. Here, by attaching one end and the other end of the connecting member 49c to the mounting holes 57a and 57b that are at the same height from the imaginary plane P, the connecting member 49c can be arranged parallel to the imaginary plane P (FIG. 5(B)). Furthermore, by using the height adjustment unit 53 to attach one end and the other end of the connecting member 49c to the mounting holes 57a and 57b that are at different heights from the imaginary plane P, the connecting member 49c can be arranged at an angle relative to the imaginary plane P (FIG. 5(C)).

[0059] The strength of the eddy current induced by the high-frequency current in each partition window 16 is inversely proportional to the distance between the partition window 16 (window member 13) and the high-frequency current. Therefore, moving the high-frequency current away from the window member 13 weakens the eddy current induced in the partition window 16. However, the weaker the eddy current, the weaker the induced electric field caused by the eddy current, which in turn reduces the plasma density in the region opposite the partition window 16. In other words, the farther the high-frequency current is from the window member 13, the less the high-frequency current contributes to plasma generation. This embodiment utilizes this characteristic to adjust the plasma density in the region opposite each height change unit 53 or 54. The degree of contribution to plasma generation is specifically expressed by the effect of increasing plasma density. A "high degree of contribution to plasma generation" means a large effect of increasing plasma density, and a "low degree of contribution to plasma generation" means a small effect of increasing plasma density.

[0060] 6A to 6C are diagrams for explaining a method for adjusting the plasma density using the height changing unit 53. In each diagram in Fig. 6, the distribution of the plasma density in the opposing region of the partial antenna line of the antenna line 49 and the height changing unit 53 is shown below.

[0061] First, we will explain the case where one end of the connecting member 49c is attached to the lowest mounting hole 57a of the first upright portion 49a and the other end of the connecting member 49c is attached to the lowest mounting hole 57b of the second upright portion 49b (Figure 6(A)).

[0062] In this case, connecting member 49c is not separated from imaginary plane P, and the distance from window member 13 of the high-frequency current flowing through connecting member 49c of height changing unit 53 is the same as the distance from window member 13 of the high-frequency current flowing through each partial antenna line arranged within imaginary plane P. Therefore, the degree to which the high-frequency current flowing through height changing unit 53 contributes to plasma generation is the same as the degree to which the high-frequency current flowing through each partial antenna line arranged within imaginary plane P contributes to plasma generation. As a result, the plasma density in the opposing region of height changing unit 53 is the same as the plasma density in the opposing region of each partial antenna line arranged within imaginary plane P.

[0063] Next, a case where the connection member 49c is placed parallel to the imaginary plane P and is moved away from the imaginary plane P will be described (FIG. 6(B)).

[0064] In this case, the distance from the window member 13 to the high-frequency current flowing through the connecting member 49c of the height changing unit 53 is longer than the distance from the window member 13 to the high-frequency current flowing through each partial antenna line arranged within the imaginary plane P. Therefore, the degree to which the high-frequency current flowing through the height changing unit 53 contributes to the generation of plasma is smaller than the degree to which the high-frequency current flowing through each partial antenna line arranged within the imaginary plane P contributes to the generation of plasma. As a result, the plasma density in the opposing region of the height changing unit 53 is lower than the plasma density in the opposing region of each partial antenna line arranged within the imaginary plane P.

[0065] However, since the connecting member 49c is arranged parallel to the imaginary plane P, the distance from the window member 13 of the high-frequency current flowing through the connecting member 49c is uniform, and in the area facing the connecting member 49c, the strength of the induced electric field is also uniform, and the density of the plasma is also uniform.

[0066] Furthermore, a case where the connection member 49c is tilted relative to the imaginary plane P and moved away from the imaginary plane P will be described (FIG. 6(C)).

[0067] In this case, too, the distance from the window member 13 of the high-frequency current flowing through the connecting member 49c of the height changing unit 53 is longer than the distance from the window member 13 of the high-frequency current flowing through each partial antenna line arranged within the imaginary plane P. Therefore, the degree to which the high-frequency current flowing through the height changing unit 53 contributes to the generation of plasma is smaller than the degree to which the high-frequency current flowing through each partial antenna line arranged within the imaginary plane P contributes to the generation of plasma. As a result, the plasma density in the opposing region of the height changing unit 53 is lower than the plasma density in the opposing region of each partial antenna line arranged within the imaginary plane P.

[0068] However, because the connecting member 49c is disposed at an angle with respect to the imaginary plane P, the distance from the window member 13 to the high-frequency current flowing through the connecting member 49c is not uniform. As a result, the strength of the induced electric field is not uniform in the region facing the connecting member 49c, and the plasma density is also not uniform. For example, in the region facing the connecting member 49c, the induced electric field at a location far from the connecting member 49c is weaker than the induced electric field at a location close to the connecting member 49c. As a result, in the region facing the connecting member 49c, the plasma density at a location far from the connecting member 49c is lower than the plasma density at a location close to the connecting member 49c. In other words, the plasma density can be distributed in a gradient in the region facing the connecting member 49c.

[0069] Since the connecting member 49c is inclined with respect to the imaginary plane P, the distance of the connecting member 49c from the window member 13 changes continuously. As a result, in the region facing the connecting member 49c, the plasma density does not change stepwise but changes continuously.

[0070] The total amount of eddy currents induced in the partition window 16 must be constant as they circulate between the front and back sides. Therefore, the strength of the eddy currents is interpreted as the level of current density. Specifically, the eddy currents induced in the partition window 16 circulate from the top surface (the antenna chamber 14 side) of the partition window 16 to the bottom surface (the processing chamber 15 side) while changing their current density distribution. Furthermore, since the eddy currents induced in the partition window 16 are generated by an alternating magnetic field perpendicular to the high-frequency current flowing through the antenna wire 49, the eddy current density distribution on the bottom surface of the partition window 16 is affected by the alternating magnetic field passing through the side surface of the partition window 16 from a direction perpendicular to the direction of the high-frequency current flow. As a result, the current density distribution on the top surface of the partition window 16 is also reflected on the bottom surface of the partition window 16. The current density distribution on the top surface of the partition window 16 also affects the strength distribution of the induced electric field generated in the area facing the antenna wire 49 inside the processing chamber 15, thereby contributing to the plasma density distribution.

[0071] As described above, the height changing unit 53 can change the connection portion height H, and the height changing unit 54 can also change the connection portion height H. However, the connection portion height H of the height changing unit 53 or the height changing unit 54 is limited to a range in which the high-frequency current flowing through the connection member 49c can contribute to the generation of plasma inside the processing chamber 15. That is, in the corner antenna segments 38a to 38d, even if the connection portion height H of the height changing unit 53 or the height changing unit 54 is set to its upper limit, the high-frequency current flowing through the connection member 49c still contributes to the generation of plasma.

[0072] In this embodiment, the connection portion height H is changed by changing the mounting holes 57a, 57b to which one end or the other end of the connecting member 49c is attached. However, the mechanism for changing the connection portion height H is not limited to this. For example, the connection portion height H may be changed by providing slits extending in the height direction in each of the first upright portion 49a and the second upright portion 49b, and sliding one end or the other end of the connecting member 49c along each slit to attach it.

[0073] In the substrate processing apparatus 10, if the plasma density distribution is not locally uniform in the opposing regions of the corner antenna segments 38a to 38d, the connection heights H of the height changing units 53 and 54 are changed to locally adjust the plasma density distribution. In this case, the connection heights H of the height changing units 53 and 54 do not need to be the same; they may each have a different connection height H. It is also possible to arrange the connection members 49c of the height changing units 53 and 54 parallel to the imaginary plane P or at an angle relative to the imaginary plane P. For example, as shown in FIG. 7, the connection member 49c of the height changing unit 53 may be arranged at an angle relative to the imaginary plane P, while the connection member 49c of the height changing unit 54 may be arranged parallel to the imaginary plane P.

[0074] Incidentally, in the height adjusting units 53 and 54 described above, by changing the mounting hole 57a to which one end of the connecting member 49c is attached and the mounting hole 57b to which the other end of the connecting member 49c is attached, it is possible to change the connection portion height H or the inclination angle of the connecting member 49c relative to the imaginary plane P. To increase the change range of the connection portion height H or the inclination angle of the connecting member 49c relative to the imaginary plane P, it is sufficient to increase the number of mounting holes 57a and mounting holes 57b.

[0075] However, in this case, the positions of the lowest mounting holes 57a and 57b are closer to the imaginary plane P, and therefore when the connecting member 49c is arranged at an angle with respect to the imaginary plane P, one end or the other end of the connecting member 49c may protrude below the imaginary plane P, i.e., below the lowest part of the antenna wire 49, by a protrusion amount t, as shown in Fig. 14. Note that hereinafter, such a part of the one end or the other end of the connecting member 49c protruding below the imaginary plane P will be referred to as a protrusion 49d.

[0076] Because such protrusion 49d is closer to the window member 13 than other portions of the antenna wire 49, the high-frequency current flowing through the protrusion 49d locally strengthens eddy currents induced in the partitioned window 16, which in turn locally increases the plasma density in the region facing the partitioned window 16. As a result, the plasma density distribution in the facing region may become distorted. Also, there is a high possibility that abnormal discharge will occur from the protrusion 49d toward the opposing partitioned window 16.

[0077] Therefore, a hypotenuse may be provided at the lower portion of one end or the other end of the connecting member 49c to prevent the one end or the other end of the connecting member 49c from protruding downward from the imaginary plane P.

[0078] Fig. 15 is a diagram illustrating the configuration of a modified example of the height changing unit. In Fig. 15, height changing unit 71, which is a modified example of height changing unit 53 (54), has a first antenna wire end 49e, a second antenna wire end 49f, and a connecting member 49c. First antenna wire end 49e has a first standing portion 49h that stands upward from imaginary plane P, and second antenna wire end 49f has a second standing portion 49i that stands upward from imaginary plane P.

[0079] Furthermore, the connecting member 49c is made of a flat plate-shaped member, and is arranged so that its plane intersects with a virtual plane, for example, so that the plane of the connecting member 49c is perpendicular to the virtual plane P, and one end of the connecting member 49c is formed by a first connecting portion 49j, and the other end of the connecting member 49c is formed by a second connecting portion 49k.

[0080] The first upright portion 49h is provided with a plurality of first mounting holes 57c (first through holes) arranged along the height direction, and is further provided with a first slit 57d (first elongated hole) extending in the height direction. Each of the first mounting holes 57c and the first slit 57d penetrates the first upright portion 49h in the thickness direction. The plurality of first mounting holes 57c also constitute a first mounting hole row 57e, and both the first mounting hole row 57e and the first slit 57d extend perpendicular to the imaginary plane P and are parallel to each other. However, the first mounting hole row 57e and the first slit 57d do not necessarily have to be parallel to each other; the extension direction of the first slit 57d may be slightly inclined relative to the extension direction of the first mounting hole row 57e. Furthermore, the length of first slit 57d in the extension direction is longer than the length of first mounting hole row 57e, and the upper end of first slit 57d protrudes upward by length 11 from the upper end of first mounting hole row 57e, and the lower end of first slit 57d protrudes downward by length 12 from the lower end of first mounting hole row 57e. Note that neither the upper nor lower end of first slit 57d needs to protrude beyond the upper or lower ends of first mounting hole row 57e; it is sufficient that either the upper or lower end of first slit 57d protrudes beyond the upper or lower end of first mounting hole row 57e.

[0081] The second standing portion 49i is provided with a plurality of second mounting holes 57f (second through holes) arranged along the height direction, and is further provided with second slits 57g (second elongated holes) extending in the height direction. Each of the second mounting holes 57f and the second slits 57g penetrates the second standing portion 49i in the thickness direction. The plurality of second mounting holes 57f also constitute a second mounting hole row 57h, and both the second mounting hole row 57h and the second slits 57g extend perpendicular to the imaginary plane P and are parallel to each other. However, the second mounting hole row 57h and the second slits 57g do not necessarily have to be parallel to each other; the extension direction of the second slits 57g may be slightly inclined relative to the extension direction of the second mounting hole row 57h. Furthermore, the length of second slit 57g in the extension direction is longer than the length of second mounting hole row 57h in the extension direction, and the upper end of second slit 57g protrudes upward by length 13 from the upper end of second mounting hole row 57h, and the lower end of second slit 57g protrudes downward by length 14 from the lower end of second mounting hole row 57h. Note that neither the upper nor lower end of second slit 57g needs to protrude beyond the upper or lower ends of second mounting hole row 57h; it is sufficient that either the upper or lower end of second slit 57g protrudes beyond the upper or lower end of second mounting hole row 57h.

[0082] At first antenna wire end 49e, the height from imaginary plane P of the position where first connecting portion 49j is connected to first standing portion 49h can be changed by changing first mounting hole 57c through which bolt 58 is inserted. At second antenna wire end 49f, the height from imaginary plane P of the position where second connecting portion 49k is connected to second standing portion 49i can be changed by changing second mounting hole 57f through which bolt 58 is inserted.

[0083] For example, when a bolt 58 is inserted through the lowest first mounting hole 57c to connect the first connecting portion 49j to the first upright portion 49h, and a bolt 58 is inserted through the lowest second mounting hole 57f to connect the second connecting portion 49k to the second upright portion 49i, the connecting member 49c is not separated from the imaginary plane P but is positioned within the imaginary plane P (Figure 16(A)).

[0084] Furthermore, the connection portion height H can be changed by inserting a bolt 58 through a first mounting hole 57c above the lowest position to connect first connecting portion 49j to first standing portion 49h, and by inserting a bolt 58 through a second mounting hole 57f above the lowest position to connect second connecting portion 49k to second standing portion 49i. For example, by inserting bolt 58 through first mounting hole 57c and second mounting hole 57f that are at the same height from imaginary plane P, connecting member 49c can be arranged parallel to imaginary plane P (FIG. 16(B)). Also, by inserting bolt 58 through first mounting hole 57c and second mounting hole 57f that are at different heights from imaginary plane P, connecting member 49c can be arranged at an angle with respect to imaginary plane P (FIG. 16(C)).

[0085] Furthermore, connecting member 49c has extension portion 49l positioned between first connecting portion 49j and second connecting portion 49k and extending linearly, and connecting member 49c has length adjustment mechanism 49m that can adjust the length of extension portion 49l in the extension direction (longitudinal direction). Extension portion 49l is composed of right extension portion 49n and left extension portion 49o, and right extension portion 49n is provided with elongated hole 49p that extends in the extension direction of extension portion 49l. Bolt 49q inserted through elongated hole 49p is fastened to left extension portion 49o to connect right extension portion 49n and left extension portion 49o. When changing the length of extension portion 49l, bolt 49q is loosened to move left extension portion 49o in the extension direction relative to right extension portion 49n, and then bolt 49q, which has moved in the extension direction relative to elongated hole 49p, is fastened back to left extension portion 49o (see FIG. 17). Therefore, elongated hole 49p and bolt 49q constitute length adjustment mechanism 49m.

[0086] By changing the length of extension portion 49l using length adjustment mechanism 49m, the overall length of connecting member 49c can also be changed. For example, when connecting member 49c is arranged at an angle with respect to imaginary plane P, connecting member 49c needs to be longer than when connecting member 49c is arranged parallel to imaginary plane P. In response to this, the length of extension portion 49l is changed using length adjustment mechanism 49m, thereby lengthening the overall length of connecting member 49c. This eliminates the need to prepare multiple connecting members 49c of different lengths, and reduces the number of parts.

[0087] In addition, in the connecting member 49c, a first oblique side 49r is provided at the lower part of the first connecting portion 49j, and a first angle θ1 formed between the lower side 49s of the first connecting portion 49j and the first oblique side 49r is an obtuse angle, and a second oblique side 49t is provided at the lower part of the second connecting portion 49k, and a second angle θ2 formed between the lower side 49u of the second connecting portion 49k and the second obtuse side 49t is also an obtuse angle.

[0088] Both the first angle θ1 and the second angle θ2 are greater than 90° and smaller than 180°. However, for example, even when a bolt 58 is inserted through the first mounting hole 57c at the highest position to connect the first connecting portion 49j to the first upright portion 49h, and a bolt 58 is inserted through the second mounting hole 57f at the lowest position to connect the second connecting portion 49k to the second upright portion 49i, that is, even when the connecting member 49c is positioned at the highest inclination with respect to the imaginary plane P so that the second connecting portion 49k is lowered, the magnitude of the second angle θ2 is set so that the lower portion of the second connecting portion 49k does not protrude below the imaginary plane P, as shown in FIG. 16(C). Furthermore, for example, even when a bolt 58 is inserted through the first mounting hole 57c at the lowest position to connect the first connecting portion 49j to the first upright portion 49h, and a bolt 58 is inserted through the second mounting hole 57f at the highest position to connect the second connecting portion 49k to the second upright portion 49i, that is, even when the connecting member 49c is positioned at the highest inclination relative to the imaginary plane P so that the first connecting portion 49j is lowered, the magnitude of the first θ1 is set so that the lower portion of the first connecting portion 49j does not protrude below the imaginary plane P.

[0089] Furthermore, in the connecting member 49c, the minimum width W1 of the first connecting portion 49j is set to be equal to or greater than the width W0 of the antenna wire 49, the minimum width W2 of the second connecting portion 49k is also set to be equal to or greater than the width W0 of the antenna wire 49, and the minimum width W3 of the extending portion 49l is also set to be equal to or greater than the width W0 of the antenna wire 49. The widths of the antenna wire 49, the width of the first connecting portion 49j, the width of the second connecting portion 49k, and the width of the extending portion 49l are lengths perpendicular to the respective extending directions (see FIG. 15), and the width of the extending portion 49l is constant. Therefore, in other words, the minimum cross-sectional area of ​​the first connecting portion 49j is equal to or greater than the cross-sectional area of ​​the antenna wire 49, the minimum cross-sectional area of ​​the second connecting portion 49k is also equal to or greater than the cross-sectional area of ​​the antenna wire 49, and the minimum cross-sectional area of ​​the extending portion 49l is also equal to or greater than the cross-sectional area of ​​the antenna wire 49.

[0090] According to the height changer 71, in the connecting member 49c, the first angle θ1 formed between the lower side 49s of the first connecting portion 49j and the first hypotenuse 49r is an obtuse angle, and the second angle θ2 formed between the lower side 49u of the second connecting portion 49k and the second hypotenuse 49t is also an obtuse angle. The magnitude of the first angle θ1 and the magnitude of the second angle θ2 are set so that the lower parts of the first connecting portion 49j and the second connecting portion 49k do not protrude below the imaginary plane P, even when the connecting member 49c is disposed at the maximum inclination with respect to the imaginary plane P. This makes it possible to prevent disturbances in the plasma density distribution in the opposing regions of the partition windows 16 and further to prevent abnormal discharge from the first connecting portion 49j and the second connecting portion 49k toward the partition window 16.

[0091] Furthermore, in the connecting member 49c, the minimum width W1 of the first connecting portion 49j is set to be equal to or greater than the width W0 of the antenna line 49, the minimum width W2 of the second connecting portion 49k is also set to be equal to or greater than the width W0 of the antenna line 49, and the minimum width W3 of the extending portion 49l is also set to be equal to or greater than the width W0 of the antenna line. This prevents the first connecting portion 49j, the second connecting portion 49k, and the extending portion 49l from becoming a bottleneck for the high frequency current when a high frequency current flows through the connecting member 49c, and prevents the first connecting portion 49j, the second connecting portion 49k, and the extending portion 49l from generating heat and increasing the resistance due to the heat.

[0092] Furthermore, in connecting member 49c, the upper end of first slit 57d protrudes upward by a length l1 from the upper end of first mounting hole row 57e, the lower end of first slit 57d protrudes downward by a length l2 from the lower end of first mounting hole row 57e, and further, the upper end of second slit 57g protrudes upward by a length l3 from the upper end of second mounting hole row 57h, and the lower end of second slit 57g protrudes downward by a length l4 from the lower end of second mounting hole row 57h.

[0093] As a result, for example, even when a bolt 58 is inserted through the lowest first mounting hole 57c to connect the first connecting portion 49j to the first standing portion 49h and a bolt 58 is inserted through the highest second mounting hole 57f to connect the second connecting portion 49k to the second standing portion 49i, the bolt 58 inserted through the first slit 57d or the second slit 57g does not restrict the connecting member 49c from tilting with respect to the imaginary plane P. Similarly, even when a bolt 58 is inserted through the highest first mounting hole 57c to connect the first connecting portion 49j to the first standing portion 49h and a bolt 58 is inserted through the lowest second mounting hole 57f to connect the second connecting portion 49k to the second standing portion 49i, the bolt 58 inserted through the first slit 57d or the second slit 57g does not restrict the connecting member 49c from tilting with respect to the imaginary plane P. As a result, the degree of freedom in arranging the connecting member 49c can be increased, and thus the range for adjusting the plasma density in the opposing region of the dividing window 16 can be widened.

[0094] 18, a corner 49v formed by a bottom side 49s and a first oblique side 49r of a first connecting portion 49j may be rounded, and a corner 49w formed by a bottom side 49u and a second oblique side 49t of a second connecting portion 49k may also be rounded. This eliminates the need for sharp corners 49v and 49w, thereby reliably preventing abnormal discharge from occurring at corners 49v and 49w when a high-frequency current flows through connecting member 49c.

[0095] It should be noted that the above-mentioned height change unit 71 is intended to be replaced with height change unit 53 or height change unit 54, but height change unit 71 may also be replaced with height change unit 68 or height change unit 70 described below.

[0096] FIG. 8 is a diagram for explaining an example in which the plasma density distribution is locally improved using the height changing unit 53 and the height changing unit 54. In FIG.

[0097] In the substrate processing apparatus 10, a mixed gas of octafluorocyclobutane (C4F8) gas and argon (Ar) gas was used as the process gas, and plasma was generated from the process gas. The area facing the window member 13, enclosed by the dashed line in FIG. 8(A), was divided into 30 blocks, and the plasma density in each block was observed. The area shown by the dashed line faces a portion of the inner antenna unit 34, a portion of the intermediate antenna unit 35, the corner antenna segment 38c of the outer antenna unit 23, and portions of the side antenna segments 39b and 39c of the outer antenna unit 23. The plasma density in each block is expressed as a relative value, with the average plasma density in the entire area facing the window member 13 being set to "1."

[0098] First, as a comparative example, the applicant observed the plasma density when a corner antenna segment obtained by removing height changing portions 53 and 54 from corner antenna segment 38c was used instead of corner antenna segment 38c. Note that, hereinafter, a corner antenna segment obtained by removing height changing portions 53 and 54 will be referred to as a "conventional corner antenna segment." In the conventional corner antenna segment, all of the partial antenna wires of lower component 51a and lower component 52a are arranged within imaginary plane P without being separated from imaginary plane P.

[0099] Figure 8(B) shows the distribution of plasma density in the comparative example. In Figure 8(B), the blocks facing the conventional corner antenna segments are hatched. As shown in Figure 8(B), when the conventional corner antenna segments were used, the plasma density of the blocks facing the long side component 50a was observed to be higher (1.04, 1.09).

[0100] Therefore, the present applicant investigated reducing the plasma density of the block facing the long side component 50a by changing the connection height H of the height-changing portion 53 of the long side component 50a when using the corner antenna segment 38c. In Example 1, the connection member 49c of the height-changing portion 53 of the long side component 50a of the corner antenna segment 38c was raised parallel to the imaginary plane P. At the same time, the connection member 49c of the height-changing portion 54 of the short side component 50b of the corner antenna segment 38c was also raised parallel to the imaginary plane P. The distance between the connection member 49c of the height-changing portion 53 and the window member 13 was set to 40 mm, and the distance between the connection member 49c of the height-changing portion 54 and the window member 13 was set to 10 mm.

[0101] Fig. 8(C) is a diagram showing the plasma density distribution in Example 1. In Fig. 8(C), the block facing the corner antenna segment 38c is hatched. As shown in Fig. 8(C), when the connecting member 49c of the height changing unit 53 is raised parallel to the imaginary plane P, the plasma density of the block facing the long side component 50a decreases (1.02, 1.02), confirming further improvement in the uniformity of the plasma distribution.

[0102] In Example 2, the connecting member 49c of the height changing portion 53 of the long-side component 50a of the corner antenna segment 38c was tilted with respect to the imaginary plane P. At the same time, the connecting member 49c of the height changing portion 54 of the short-side component 50b of the corner antenna segment 38c was raised parallel to the imaginary plane P. At this time, the distance from the window member 13 to the end of the connecting member 49c of the height changing portion 53 on the corner side was set to 10 mm, and the distance from the window member 13 to the end of the connecting member 49c opposite the corner was set to 90 mm. The distance from the window member 13 to the connecting member 49c of the height changing portion 54 was also set to 10 mm.

[0103] Figure 8(D) is a diagram showing the plasma density distribution in Example 2. In Figure 8(D), the block facing the corner antenna segment 38c is also hatched. As shown in Figure 8(D), when the connecting member 49c of the height changing section 53 is inclined with respect to the imaginary plane P, the plasma density of the block facing the long side component 50a is lowered (1.00, 1.05), confirming further improvement in the uniformity of the plasma distribution.

[0104] According to this embodiment, height changers 53 and 54 are disposed on the long-side component parts 50a and short-side component parts 50b of each corner antenna segment 38a-38d, and the height changers 53 and 54 change the connection height H of the connection member 49c. This allows the high-frequency current to be partially directed away from the window member 13, thereby partially weakening the eddy current induced in the partition window 16. As a result, the induced electric field in the region facing the partition window 16 can be partially weakened, thereby partially reducing the plasma density. As a result, the uniformity of the plasma distribution inside the processing vessel 11 can be further improved.

[0105] In this embodiment, in the side antenna segments 39a to 39d, a portion of each partial antenna wire constituting the lower component 55a is not offset upward from the imaginary plane P. However, as shown in Fig. 9, the lower component 55a of the side antenna segment 39a may be provided with a height changer 59 having a configuration similar to the height changers 53 and 54. Similarly, the lower component 55a of the side antenna segments 39b to 39d may also be provided with a height changer 59.

[0106] Next, a second embodiment of the technology according to the present disclosure will be described. The second embodiment differs from the first embodiment in that the outer antenna portion of the high-frequency antenna is configured by an antenna segment made of a flat antenna wire that circles within an imaginary plane P. Note that, in the following, a description of the same processing contents and configuration as the first embodiment will be omitted, and only the processing contents and configuration that are different from the first embodiment will be described.

[0107] 10 is a view of the window member 13 of the substrate processing apparatus 10 according to the second embodiment viewed from the processing chamber 15 side, with the high-frequency antenna 60 arranged in the antenna chamber 14 shown in solid lines so that it can be seen through. Also in FIG. 10, an imaginary plane P is shown overlapping the window member 13. In the substrate processing apparatus 10 according to the second embodiment, the high-frequency antenna 60 is composed of an inner antenna unit 61 and an outer antenna unit 62. Note that, also in the second embodiment, an intermediate antenna unit may be provided between the inner antenna unit 61 and the outer antenna unit 62.

[0108] In the second embodiment, the outer periphery of the imaginary plane P is also divided into a corner area including a corner where one long side and one short side intersect, and a side area sandwiched between the two corner areas. Corner area A, side area A, corner area B, side area B, corner area C, side area C, corner area D, and side area D are arranged in this order clockwise. Note that in FIG. 10 as well, the dividing windows 16 and the partition members 17 of the window member 13 are not shown. As shown in FIG. 10, the inner antenna unit 61 is arranged to face the center of the window member 13, and the outer antenna unit 62 is arranged to surround the inner antenna unit 61.

[0109] The inner antenna section 61 is composed of four antenna wires 63 arranged in a spiral shape within an imaginary plane P. The outer antenna section 62 is composed of a corner antenna segment 64 and a side antenna segment 65. The corner antenna segment 64 is composed of a plurality of, for example, four spirally arranged antenna wires 66a to 66d (see FIG. 11). The side antenna segment 65 is composed of a plurality of, for example, four spirally arranged antenna wires 67a to 67d (see FIG. 12). The corner antenna segment 64 and the side antenna segment 65 are arranged to face the peripheral edge of the window member 13. The corner antenna segment 64 is arranged to face corner areas A to D, and the side antenna segment 65 is arranged to face side areas A to D.

[0110] Fig. 11 is a perspective view showing the configuration of the corner antenna segment 64 in detail. In Fig. 11, the four antenna wires 66a to 66d of the corner antenna segment 64 are arranged in a spiral shape in the circumferential direction of a rectangular imaginary plane P so that the phases of the rotation angles around the center of the imaginary plane P are shifted from one another, for example, by 90°. Each of the antenna wires 66a to 66d has a start point and an end point in a different corner area from one another. However, the phase shift between the antenna wires 66a to 66d is not limited to 90°.

[0111] Each of the antenna wires 66a to 66d has a height change section 68 (offset path) configured by partially offsetting the antenna wires 66a to 67d of the side antenna segments 65 arranged within the imaginary plane P. The height change section 68 has a structure similar to that of the height change sections 53 and 54, and is configured by a first standing section 66e and a second standing section 66f that stand upright from the imaginary plane P, and a connecting member 66g that connects the first standing section 66e and the second standing section 66f. The connecting member 66g can also change the connection section height H, and can also be arranged at an angle with respect to the imaginary plane P.

[0112] However, the lower limit of the connection portion height H of the connecting member 66g is set to a height that can at least avoid the antenna wires 67a to 67d of the side antenna segment 65. Moreover, unlike the first embodiment, the upper limit of the connection portion height H of the connecting member 66g does not need to be set to a height that is lower than the height at which the high-frequency current flowing through the connecting member 66g can contribute to the generation of plasma inside the processing chamber 15. However, it is sufficient that the connection portion height H of the connecting member 66g includes a minimum height that does not contribute to the generation of plasma, and it is not essential to make the connection portion height H of the connecting member 66g any higher.

[0113] Fig. 12 is a perspective view showing the configuration of the side antenna segment 65 in detail. In Fig. 12, the four antenna wires 67a to 67d of the side antenna segment 65 are arranged in a spiral shape in the circumferential direction of a rectangular imaginary plane P so that the phases of the rotation angles around the center of the imaginary plane P are shifted from one another, for example, by 90°. Each of the antenna wires 67a to 67d has a start point and an end point in a different side area from one another. However, the phase shift between the antenna wires 67a to 67d is not limited to 90°.

[0114] Each of the antenna wires 67a to 67d has a height change section 70 (offset path) configured by a portion of the antenna wires 67a to 67d being offset upward from the imaginary plane P so as to avoid the antenna wires 66a to 66d of the corner antenna segments 64 arranged within the imaginary plane P. The height change section 70 has a structure similar to that of the height change section 68, and is configured by a first standing section 67e and a second standing section 67f standing upward from the imaginary plane P, and a connecting member 67g connecting the first standing section 67e and the second standing section 67f. Note that in FIG. 12, the connecting member 67g linearly connects the first standing section 67e and the second standing section 67f in a plan view, but the first standing section 67e and the second standing section 67f may be connected to form an L-shape in a plan view to match the shape of the corner of the window member. The height H of the connecting portion of this connecting member 67g can also be changed, and the connecting member 67g can also be disposed at an angle with respect to the imaginary plane P.

[0115] However, the lower limit of the connection portion height H of the connection member 67g is set to a height that can at least avoid the antenna wires 66a to 66d of the corner antenna segments 64. Moreover, unlike the first embodiment, the upper limit of the connection portion height H of the connection member 67g does not need to be set to a height that is lower than the height at which the high-frequency current flowing through the connection member 67g can contribute to the generation of plasma inside the processing chamber 15. However, it is sufficient that the connection portion height H of the connection member 67g includes a minimum height that does not contribute to the generation of plasma, and it is not essential to make the connection portion height H of the connection member 67g any higher.

[0116] In the second embodiment, if the plasma density distribution is not locally uniform in the opposing regions of the corner antenna segment 64 and the side antenna segment 65, the connection height H of each height changer 68, 70 is changed to locally adjust the plasma density distribution. In this case, it is not necessary to align the connection height H of the height changer 68 with the connection height H of the height changer 70, and individual connection heights H may be set for each. Also, it is optional whether the connection member 66g of the height changer 68 and the connection member 67g of the height changer 70 are arranged parallel to the imaginary plane P or inclined relative to the imaginary plane P.

[0117] 13, in a corner antenna segment 64, the connecting members 66g of any two height change units 68 may be arranged at an angle with respect to the imaginary plane P. Furthermore, in addition to this, the heights of any other two height change units 68 may be changed while these connecting members 66g remain parallel to the imaginary plane P.

[0118] According to the second embodiment, height changers 68 and 70 are arranged on corner antenna segments 64 and side antenna segments 65, and the connection height H of connection members 66g and 67g of height changers 68 and 70 is changed. This allows the high-frequency current to be partially directed away from window member 13, thereby partially weakening the eddy current induced in partition window 16. As a result, the induced electric field in the opposing region of partition window 16 can be partially weakened, thereby partially reducing the plasma density. As a result, the uniformity of the plasma distribution inside processing vessel 11 can be further improved.

[0119] Although the preferred embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and various modifications and changes are possible within the scope of the gist of the present disclosure.

[0120] For example, the high-frequency antenna may be configured as a single antenna wire wound around the imaginary plane P, rather than as a multiple antenna wire, or as multiple antenna wires connected in series. In this case, multiple height change units having a configuration similar to that of height change unit 53 are provided by offsetting various points of the wound antenna wire upward from the imaginary plane P. Furthermore, although window member 13 is configured from a non-magnetic and conductive material in the above embodiment, window member 13 may also be configured from a dielectric material. [Explanation of symbols]

[0121] G rectangular board H Connection height P Virtual plane θ1 first angle θ2 second angle 10. Substrate processing equipment 11 Processing container 13 Window components 14 Antenna Room 15 Processing Room 16 Split window 24 Mounting table 22 High frequency antenna 23 Outer antenna section 34 Inner antenna section 35 Intermediate antenna section 38a~38d Corner antenna segments 39a-39d Peripheral antenna segments 49 Antenna Wire 49a, 49h First erection part 49b, 49i Second erection part 49c Connecting member 49e First antenna wire end 49f Second antenna wire end 49j First connection 49k Second Connection 49l extension part 49m length adjustment mechanism 49r First hypotenuse 49s, 49u bottom 49t Second hypotenuse 50a Long side component 50b Short side component 53,54 Height change section 57c First mounting hole 57d First slit 57e First row of mounting holes 57f Second mounting hole 57g Second slit 57h Second mounting hole row 58 volts

Claims

1. A substrate processing apparatus that performs plasma processing on a substrate, a processing vessel for accommodating the substrate therein; a plate-shaped window member that divides the interior of the processing vessel into an upper antenna chamber and a lower processing chamber; a mounting table disposed inside the processing chamber and on which the substrate is placed; an inductively coupled antenna disposed inside the antenna chamber so as to face the mounting table across the window member, and which generates an inductive electric field for generating plasma inside the processing chamber; the inductively coupled antenna has an antenna portion arranged so as to circle within an imaginary plane facing the upper surface of the window member, the antenna portion being made up of at least one antenna wire; the antenna unit has an offset path formed by a part of an antenna line arranged in the imaginary plane being offset upward from the imaginary plane, The substrate processing apparatus, wherein the degree to which the current flowing through the offset path contributes to the generation of the plasma is smaller than the degree to which the current flowing through an antenna wire arranged within the imaginary plane contributes to the generation of the plasma.

2. The substrate processing apparatus according to claim 1 , wherein the offset path is formed by two standing portions standing upward from the imaginary plane and a connecting member connecting the two standing portions.

3. The substrate processing apparatus according to claim 2 , wherein the distance of the connecting member from the imaginary plane is variable.

4. The substrate processing apparatus according to claim 2 , wherein the connecting member is tiltable with respect to the imaginary plane.

5. 3. The substrate processing apparatus according to claim 2, wherein the connecting member is made of a flat member, the connecting member is arranged so that its plane intersects with the imaginary plane, oblique sides are provided at the bottom of both ends of the connecting member, and the angle formed between the bottom side of the connecting member and the oblique sides is an obtuse angle.

6. The substrate processing apparatus according to claim 5 , wherein the plane of the connection member is perpendicular to the imaginary plane.

7. The processing vessel has a rectangular cylindrical shape, The substrate processing apparatus according to claim 1 , wherein the window member and the imaginary plane have a rectangular shape having two long sides and two short sides.

8. In the antenna unit, two offset paths are arranged corresponding to each of the long sides, and two offset paths are arranged corresponding to each of the short sides, The substrate processing apparatus according to claim 7 , wherein each of the offset paths is disposed closer to a corner of the imaginary plane where one of the long sides intersects with one of the short sides than to a center of each of the long sides or each of the short sides.

9. the antenna unit is configured by a plurality of antenna segments arranged so as to circle within the imaginary plane, The substrate processing apparatus according to claim 8 , wherein the antenna segment arranged corresponding to a corner of the imaginary plane among the plurality of antenna segments has the offset path.

10. 10. The substrate processing apparatus according to claim 9, wherein the antenna segment is a vertically wound coil made of the antenna wire wound in a direction perpendicular to the imaginary plane, and a plurality of partial antenna wires constituting the antenna wire are arranged within the imaginary plane.

11. the antenna segment arranged corresponding to a corner of the imaginary plane has a long-side component arranged corresponding to the long side and a short-side component arranged corresponding to the short side, In a plan view with respect to the imaginary plane, the long side component and the short side component intersect to form an L-shape, The substrate processing apparatus according to claim 9 , wherein each of the long side component portion and the short side component portion has the offset path.

12. The substrate processing apparatus according to claim 1 , wherein the window member is made of a conductor.

13. A substrate processing method for performing plasma processing on a substrate using a substrate processing apparatus, comprising: the substrate processing apparatus includes a processing vessel that accommodates the substrate therein, a plate-like window member that divides the interior of the processing vessel into an upper antenna chamber and a lower processing chamber, a mounting table that is disposed within the processing chamber and on which the substrate is placed, and an inductively coupled antenna that is disposed within the antenna chamber so as to face the mounting table across the window member and that generates an inductive electric field for generating plasma within the processing chamber; the inductively coupled antenna has an antenna portion arranged so as to circle within an imaginary plane facing the upper surface of the window member, the antenna portion being made up of at least one antenna wire; the antenna unit has an offset path formed by a part of an antenna line arranged in the imaginary plane being offset upward from the imaginary plane, a degree to which the current flowing through the offset path contributes to the generation of the plasma smaller than a degree to which the current flowing through an antenna wire disposed within the imaginary plane contributes to the generation of the plasma.

14. the offset path is configured by two erected portions erected upward from the imaginary plane and a connecting member connecting the two erected portions, The substrate processing method according to claim 13 , wherein the degree to which the current flowing through the offset path contributes to the generation of the plasma is changed by changing the distance of the connecting member from the imaginary plane.

15. the offset path is configured by two erected portions erected upward from the imaginary plane and a connecting member connecting the two erected portions, 14. The substrate processing method according to claim 13, wherein the degree to which the current flowing through the offset path contributes to the generation of the plasma is changed in a region facing the connection member by tilting the connection member with respect to the imaginary plane.

16. A substrate processing apparatus that performs plasma processing on a substrate, a processing vessel for accommodating the substrate therein; a plate-shaped window member that divides the interior of the processing vessel into an upper antenna chamber and a lower processing chamber; a mounting table that is disposed inside the processing chamber and on which the substrate is placed; an inductively coupled antenna disposed inside the antenna chamber so as to face the mounting table across the window member, and which generates an inductive electric field for generating plasma inside the processing chamber; the inductively coupled antenna has an antenna portion arranged so as to circle within an imaginary plane facing the upper surface of the window member, the antenna portion being made up of at least one antenna wire, the antenna portion having an offset path formed by a portion of the antenna wire arranged within the imaginary plane being offset upward from the imaginary plane, The substrate processing apparatus limits the offset amount of the offset path from the virtual plane to a range in which the current flowing through the offset path can contribute to the generation of the plasma.

17. an inductively coupled antenna located above a window member forming a ceiling portion of a processing chamber, for generating an inductive electric field inside the processing chamber to generate plasma, a first antenna wire end portion having a first standing portion standing upward from an imaginary plane facing the upper surface of the window member; a second antenna wire end portion having a second standing portion standing upward from the imaginary plane; a connecting member having a first connecting portion connected to the first standing portion and a second connecting portion connected to the second standing portion, a height from the virtual plane of a position where the first connection portion is connected to the first standing portion and a height from the virtual plane of a position where the second connection portion is connected to the second standing portion are changeable; the connecting member is a flat plate-like member, the connecting member is disposed so that a plane thereof intersects with the imaginary plane, and both ends of the connecting member are configured by the first connecting portion and the second connecting portion, a first oblique side is provided at a lower portion of the first connection portion, and a first angle formed by the lower side of the first connection portion and the first oblique side is an obtuse angle; An inductively coupled antenna, wherein a second oblique side is provided at a lower part of the second connection part, and a second angle formed by the lower side of the second connection part and the second oblique side is an obtuse angle.

18. the first standing portion has a first through-hole row consisting of a plurality of first through-holes arranged along a height direction, and a first elongated hole extending in the height direction, the second standing portion has a second through-hole row consisting of a plurality of second through-holes arranged along a height direction, and a second elongated hole extending in the height direction, a fastening member for connecting the first connection portion to the first standing portion is inserted through one of the plurality of first through holes and the first elongated hole; 18. The inductively coupled antenna according to claim 17, wherein a fastening member for connecting the second connection portion to the second standing portion is inserted through one of the plurality of second through holes and the second elongated hole.

19. the length of the first slot in the longitudinal direction is longer than the length of the first row of through holes; 19. The inductive coupling antenna according to claim 18, wherein the length of the second slot in the longitudinal direction is longer than the length of the second row of through holes.

20. the connecting member has an extending portion that is located between the first connecting portion and the second connecting portion and extends linearly, a minimum width of the first connection portion, a minimum width of the second connection portion, and a minimum width of the extension portion are equal to or greater than a width of an antenna line, The inductive coupling antenna according to claim 17 , wherein the connecting member has a length adjustment mechanism that can adjust the length of the extension portion in the extension direction.

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