Substrate processing device and electromagnetic wave leakage prevention method

Abstract

To stably and directly bring a transparent conductive film of an observation window into contact with a metallic wall part of a processing container or a metallic constitutive member which is disposed in the processing container.SOLUTION: A substrate processing device comprises an observation window for observing the inside of a processing container. The observation window includes a tabular translucent window member with a transparent conductive film formed on a surface on one side, an annular lid member, and an annular inside seal member. When mounting the observation window to a metallic unit installation adapter, the lid member is fixed to the unit installation adapter so as to interpose the translucent window member therebetween. The translucent window member is pressed to the unit installation adapter by a repulsive force which is generated when the inside seal member interposed between the translucent window member and the lid member is compressed, and the transparent conductive film is directly brought into contact with the unit installation adapter. The repulsive force which is generated by compressing the inside seal member is greater than a suction force which is caused by a pressure difference between the inside and the outside of the processing container and sucks the translucent window member into the processing container.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a substrate processing apparatus and a method for preventing electromagnetic wave leakage.

Background Art

[0002] A substrate processing apparatus that performs plasma processing on a substrate includes a processing chamber. After accommodating the substrate inside the processing chamber, plasma is generated inside the processing chamber to perform plasma processing such as film formation processing and etching processing on the substrate. In such a substrate processing apparatus, in order to detect an abnormality during plasma processing, the state of the plasma inside the processing chamber and the state of the substrate are observed. For this observation, an observation window through which the inside of the processing chamber can be observed is provided in the wall portion of the processing chamber.

[0003] By the way, in many cases, a transparent quartz glass light-transmitting window member is provided in the observation window. However, while quartz glass transmits the emission spectrum of plasma, it leaks electromagnetic waves from the electromagnetic field generated inside the processing chamber.

[0004] Therefore, in a substrate processing apparatus, it is known to attach an electromagnetic wave shield made of, for example, a metal mesh or a perforated plate to the light-transmitting window member. In this substrate processing apparatus, by conducting the electromagnetic wave shield to the wall portion of the metal processing chamber, the electromagnetic wave is led from the electromagnetic wave shield to the ground through the wall portion of the processing chamber, thereby preventing electromagnetic wave leakage (see, for example, Patent Document 1).

[0005] Also, in a substrate processing apparatus, it is known to coat a transparent conductive film made of, for example, ITO (Indium Tin Oxide) on the light-transmitting window member. In this substrate processing apparatus, by conducting the transparent conductive film to the wall portion of the metal processing chamber, the electromagnetic wave is led from the transparent conductive film to the ground through the wall portion of the processing chamber, thereby preventing electromagnetic wave leakage (see, for example, Patent Document 2).

Prior Art Documents

Patent Documents

[0006] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 6-21003 [Patent Document 2] Japanese Unexamined Patent Application Publication No. 4-191370 [Summary of the Invention] [Problems to be Solved by the Invention]

[0007] The technology according to the present disclosure stably and directly contacts the transparent conductive film of the observation window with the metal wall portion of the processing container or the metal component arranged in the processing container. [Means for Solving the Problems]

[0008] One aspect of the technology according to the present disclosure is a substrate processing apparatus including plasma generation means for generating plasma and a processing chamber for subjecting a substrate to plasma processing inside a reduced-pressure environment, further including an observation window for observing the inside of the processing chamber, the observation window having a plate-shaped translucent window member, a lid member having a first opening, and an annular first sealing member, in the translucent window member, a transparent conductive film is formed on a first surface which is one side surface, the transparent conductive film is not formed on a second surface which is the surface opposite to the first surface, the observation window is attached to a metal wall portion of the processing chamber or a metal component disposed on the wall portion of the processing chamber from the inside of the processing chamber, when the observation window is attached to the wall portion or the component, the lid member and the translucent window member are arranged in this order from the inside of the processing chamber, the lid member is fixed to the wall portion or the component so that the translucent window member is interposed between the lid member and the wall portion or the component, a second surface of the translucent window member is exposed to the inside of the processing chamber through the first opening, a first sealing member is interposed between the second surface of the translucent window member and the lid member, the first sealing member is arranged so as to surround the first opening, when the first sealing member is compressed, the repulsive force generated causes the translucent window member to be pressed against the wall portion or the component, and the transparent conductive film on the first surface of the translucent window member comes into direct contact with the wall portion or the component, and the repulsive force generated by the first sealing member is greater than the suction force that draws the translucent window member into the inside of the processing chamber due to the pressure difference between the inside and outside of the processing chamber.

Advantages of the Invention

[0009] According to the technology of the present disclosure, the transparent conductive film of the observation window can be stably and directly brought into contact with the metal wall portion of the processing chamber or the metal component disposed in the processing chamber.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Mode for Carrying Out the Invention

[0011] In the substrate processing apparatus provided with the observation window described in Patent Document 1, it is possible to monitor the light emission from the inside of the processing container through the translucent window member. However, when attempting to image the inside of the processing container with a camera, since an electromagnetic wave shield is attached to the translucent window member, there is a risk that the electromagnetic wave shield will be reflected in the image captured by the camera, deteriorating the sharpness of the image. For example, the image of the plasma or the substrate may be blurred in focus with the mesh of the electromagnetic wave shield, or the mesh of the electromagnetic wave shield may overlap with the edge of the substrate, making it impossible to observe the movement of the substrate.

[0012] When coating the translucent window member with a transparent conductive film as in the substrate processing apparatus described in Patent Document 2, the deterioration of the sharpness of the image as described above does not occur. However, in the substrate processing apparatus described in Patent Document 2, the translucent window member coated with the transparent conductive film is attached to the wall portion of the processing container by a metal support jig. And an O-ring covered with a metal mesh is interposed between the support jig and the transparent conductive film of the translucent window member, and the transparent conductive film, the support jig, and thus the wall portion of the processing container are electrically connected through this metal mesh. That is, in the substrate processing apparatus described in Patent Document 2, since the transparent conductive film of the translucent window member does not directly contact the wall portion of the processing container or the support jig, the electrical connection between the transparent conductive film of the translucent window member and the wall portion of the processing container is not stable.

[0013] In contrast, the technology according to the present disclosure directly contacts the transparent conductive film of the translucent window member with a metal component arranged in the processing container.

[0014] Hereinafter, an embodiment of the technology according to the present disclosure will be described with reference to the drawings. FIG. 1 is a cross-sectional view schematically showing the configuration of a substrate processing apparatus according to this embodiment. The substrate processing apparatus 10 in FIG. 1 is used for plasma processing when forming thin film transistors on a glass substrate for an FPD (Flat Panel Display), which is a rectangular substrate, for example, etching processing, ashing processing, and film forming processing.

[0015] The substrate processing apparatus 10 has an airtight processing container 11 with a rectangular tube shape that houses a rectangular substrate G made of glass inside. This processing container 11 is made of a metal material, for example, aluminum with an anodized inner wall surface, is grounded by a ground wire 12, and is partitioned vertically into an antenna chamber 14 and a processing chamber 15 by a window member 13. The window member 13 is made of an insulating material, for example, ceramics such as Al2O3, or quartz.

[0016] A shower housing 16 for supplying processing gas is fitted to the lower part of the window member 13. The shower housing 16 is suspended from the ceiling of the processing container 11 by a plurality of suspenders (not shown) and supports the window member 13 from below. A gas flow path 17 extending horizontally is formed inside the shower housing 16, and the gas flow path 17 communicates with the processing chamber 15 through a plurality of gas discharge holes 18 extending downward.

[0017] On the other hand, a gas supply pipe 19 communicating with the gas flow path 17 is provided at the center of the upper surface of the window member 13. The gas supply pipe 19 penetrates the ceiling of the processing container 11 and is connected to a processing gas supply system 20 including a processing gas supply source and a valve system, etc. Therefore, in the substrate processing apparatus 10, the processing gas supplied from the processing gas supply system 20 is supplied into the shower housing 16 through the gas supply pipe 19, and then is discharged into the processing chamber 15 from each gas discharge hole 18.

[0018] A support shelf 21 that protrudes inward is provided between the side wall of the antenna chamber 14 and the side wall of the processing chamber 15 in the processing container 11, and the window member 13 is placed on the support shelf 21. Also, inside the antenna chamber 14, an antenna unit 23 (plasma generation means) including a radio frequency (RF) antenna 22 is arranged. In the substrate processing apparatus 10, when high-frequency power is supplied to the RF antenna 22, an electromagnetic field is formed inside the processing chamber 15, and the processing gas inside the processing chamber 15 is excited by this electromagnetic field to generate plasma.

[0019] Below the inside of the processing chamber 15, a mounting table 24 for mounting the rectangular substrate G is installed so as to face the RF antenna 22 with the window member 13 interposed therebetween. The mounting table 24 is made of a metal material, for example, aluminum whose surface is anodized. The rectangular substrate G placed on the mounting table 24 is adsorbed and held on the mounting table 24 by an electrostatic chuck (not shown).

[0020] The mounting table 24 is arranged at the bottom of the processing container 11 and is supported by an insulator frame 25 having an opening at the bottom. Also, an inlet / outlet 26 for carrying the rectangular substrate G in and out and a gate valve 27 for opening and closing it are provided on the side wall of the processing chamber 15.

[0021] The mounting table 24 is connected to a high-frequency power supply 30 via a matcher 29 by a power supply line 28 that penetrates the opening of the insulator frame 25. The high-frequency power supply 30 supplies high-frequency power for bias, for example, high-frequency power of 3.2 MHz, to the mounting table 24 during plasma processing. By this high-frequency power for bias, ions in the plasma generated inside the processing chamber 15 are effectively drawn into the rectangular substrate G.

[0022] Also, inside the mounting table 24, a temperature control mechanism including heating means such as a ceramic heater and a refrigerant flow path, as well as a temperature sensor, are provided (both not shown) to control the temperature of the rectangular substrate G. All the pipes and wirings of these mechanisms are led out to the outside of the processing container 11 through the openings of the insulator frame 25. Note that a shield ring (not shown) that contributes to the plasma distribution may be provided at the upper part of the side wall of the insulator frame 25 that stands upright covering the side surface of the mounting table 24.

[0023] At the bottom of the processing chamber 15, an exhaust device 32 including a vacuum pump or the like is connected 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 (for example, 10 mTorr) during plasma processing.

[0024] On the back side of the rectangular substrate G placed on the mounting table 24, an extremely thin cooling space (not shown) is formed between 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 the heat transfer gas to the cooling space on the back side of the rectangular substrate G, even when the inside of the processing chamber 15 is in a reduced pressure environment, the temperature of the rectangular substrate G can be adjusted by the temperature control mechanism.

[0025] The high-frequency antenna 22 of the antenna unit 23 is composed of a first antenna portion 34 and a second antenna portion 35. The first antenna portion 34 and the second antenna portion 35 may be composed of, for example, antennas each wound. In this case, the first antenna portion 34 and the second antenna portion 35 are arranged concentrically, with one arranged outside the other. Also, the first antenna portion 34 and the second antenna portion 35 may be composed of, for example, an antenna arranged to correspond to a corner portion of the rectangular window member 13 and an antenna arranged to correspond to a side portion of the same window member 13. Further, the high-frequency antenna 22 may be an antenna having a triple annular structure in which a third antenna portion is added to the first antenna portion 34 and the second antenna portion 35. A feeding line 36 is connected to the first antenna portion 34, and a feeding line 37 is connected to the second antenna portion 35. The feeding line 36 and the feeding line 37 branch from the feeding line 38, and an impedance matcher 39 and a high-frequency power source 40 are connected to the feeding line 38. Thereby, 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 source 40 to the first antenna portion 34 and the second antenna portion 35, respectively. Due to this high-frequency power having a frequency of 13.56 MHz, an electromagnetic field is generated in the space facing the first antenna portion 34 and the second antenna portion 35 inside the processing chamber 15, and the processing gas inside the processing chamber 15 is excited by this electromagnetic field to generate plasma.

[0026] Also, in the substrate processing apparatus 10, variable capacitors (not shown) are installed in the feeding line 36 and the feeding line 37. By controlling these variable capacitors, the ratio of the high-frequency power supplied to the first antenna portion 34 and the second antenna portion 35 can be controlled. Thereby, the strength of the electromagnetic field generated in the space facing the first antenna portion 34 and the strength of the electromagnetic field generated in the space facing the second antenna portion 35 can be changed, and thus the distribution of the plasma generated inside the processing chamber 15 can be controlled. Note that the high-frequency antenna 22 is arranged at a distance from the window member 13 by a spacer 41 made of an insulating member, and its arrangement region corresponds to the rectangular substrate G.

[0027] Each component of the substrate processing apparatus 10 is controlled by a control unit 42 composed of a microprocessor (computer). A keyboard (not shown) for receiving the input operations of the operator and a user interface 43 for displaying the operating status of the substrate processing apparatus 10 are connected to the control unit 42. Further, a storage unit 44 is connected to the control unit 42. When executing various plasma processes, the control unit 42 controls each component of the substrate processing apparatus 10 according to the processing recipe stored in the storage unit 44.

[0028] Also, the substrate processing apparatus 10 includes two imaging units 45 and 46 for observing the state of the plasma inside the processing chamber 15 and the state of the rectangular substrate G during the plasma process. FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1 and is a diagram for explaining the arrangement form of the two imaging units 45 and 46 in the substrate processing apparatus 10.

[0029] In FIG. 2, the processing container 11 (processing chamber 15) has four wall portions 11a to 11d, and the wall portions 11a to 11d are arranged in this order so as to surround the mounting table 24. The imaging unit 45 is arranged on the wall portion 11a so as to face the wall portion 11c, and the imaging unit 46 is arranged on the wall portion 11b so as to face the wall portion 11d. Both the imaging units 45 and 46 have a wide viewing angle (field angle). When the viewing angles of the imaging units 45 and 46 are overlapped, almost the entire internal space of the processing chamber 15 surrounded by the four wall portions 11a to 11d can be observed by the imaging units 45 and 46. In the figure, the viewing angles of the imaging units 45 and 46 are indicated by dashed-dotted lines. Note that the number of imaging units provided in the substrate processing apparatus 10 is not limited to two, and may be one or three or more.

[0030] Next, the imaging units 45 and 46 and the structures around them will be described. In the present embodiment, the imaging unit 46 and the structures around it have the same configuration as the imaging unit 45 and the structures around it. Therefore, here, only the imaging unit 45 and the structures around it will be described, and the description of the imaging unit 46 and the structures around it will be omitted.

[0031] FIG. 3 is a perspective sectional view taken along line B-B in FIG. 2, and is a view for explaining the imaging unit 45 and the surrounding structure thereof. In FIG. 3, the right side in the figure corresponds to the inside of the processing chamber 15, and the left side in the figure corresponds to the outside of the processing chamber 15. Further, in FIG. 3, for ease of understanding, some of the components are shown in a disassembled state.

[0032] As shown in FIG. 3, a unit mounting hole 47 (second opening) penetrating in the thickness direction is formed in the wall portion 11a where the imaging unit 45 is disposed. A substantially cylindrical unit installation adapter 48 (component member) is inserted into the unit mounting hole 47. At least a part of the inserted unit installation adapter 48 is in contact with the wall portion 11a, and the unit installation adapter 48 and the processing container 11 are electrically connected. Here, since the processing container 11 is electrically grounded, the unit installation adapter 48 is also electrically grounded via the processing container 11.

[0033] The unit installation adapter 48 has a flange portion 48b that expands in the radial direction at the rear end 48a, which is the end on the outside of the processing chamber 15. By the flange portion 48b abutting against the outer surface of the wall portion 11a, the horizontal position of the unit installation adapter 48 in the unit mounting hole 47 is defined. Further, the tip end 48c, which is the end on the inside of the processing chamber 15 of the unit installation adapter 48, forms a wall portion, and a tip opening 48d is provided at the center of the wall portion of the tip end 48c. The imaging unit 45 is inserted inside the unit installation adapter 48.

[0034] The imaging unit 45 includes an imaging section 49 and a double-cylindrical case 50 that houses the imaging section 49. The imaging section 49 has imaging elements such as lenses and CMOS image sensors (none of which are shown) provided at the foremost part in the imaging direction of the imaging unit 45, receives light from inside the processing chamber 15, forms an image, and generates an image signal. This image signal is transmitted via a cable 51 to an external device (not shown) such as a monitor. In the imaging unit 45, in order to secure a wide viewing angle, it is preferable to bring the imaging section 49 as close as possible to the inside of the processing chamber 15. Also, the tip 50a, which is the end on the inside of the processing chamber 15 side of the case 50, forms a wall portion, and a tip opening 50b is provided at the center of the wall portion of the tip 50a. This tip opening 50b is covered by a case window member 52 made of a disk-shaped member having translucency.

[0035] When the imaging section 49 is housed in the case 50, the imaging section 49 faces the case window member 52. Also, when the imaging unit 45 is inserted inside the unit installation adapter 48, the case 50 of the imaging unit 45 and the unit installation adapter 48 are arranged such that their respective central axes coincide. Therefore, the imaging section 49 of the imaging unit 45 faces the tip opening 48d of the unit installation adapter 48 via the case window member 52 and receives light passing through the tip opening 48d.

[0036] In the unit mounting hole 47, the unit installation adapter 48 does not protrude into the processing chamber 15, and the tip 48c of the unit installation adapter 48 remains at a position shifted to some extent toward the outside of the processing chamber 15 from the inner surface of the wall portion 11a. That is, there is a margin for inserting other components from the inside of the processing chamber 15 in the unit mounting hole 47. In the present embodiment, an observation window 53 is inserted into this margin of the unit mounting hole 47 from the inside of the processing chamber 15.

[0037] The observation window 53 has a translucent window member 54, a lid member 55, an inner seal member 56 (first sealing member), and an outer seal member 57 (second sealing member).

[0038] FIG. 4 is a perspective view when the observation window 53 is viewed from the outside of the processing chamber 15, and FIG. 5 is an enlarged longitudinal sectional view showing the configuration around the tip 48c of the unit installation adapter 48 and the observation window 53.

[0039] The light-transmitting window member 54 is made of, for example, a disk-shaped member made of quartz glass, and a transparent conductive film 58 made of, for example, ITO is formed on the surface (one surface, the first surface) on the outside of the processing chamber 15. Note that no transparent conductive film is formed on the surface (opposite surface, the second surface) on the inside of the processing chamber 15 of the light-transmitting window member 54, and the quartz glass is exposed as it is.

[0040] The lid member 55 is made of a metal material, for example, an annular member made of aluminum whose surface exposed inside the processing chamber 15 is anodized, and a light-transmitting window opening 55a (the first opening) is provided inside the annular member. The inner seal member 56 and the outer seal member 57 are O-rings made of an elastic material, for example, an elastomer. Note that neither the inner seal member 56 nor the outer seal member 57 is covered with a metal mesh or the like, and is composed only of an elastic material.

[0041] In the observation window 53, the light-transmitting window member 54, the lid member 55, the inner seal member 56, and the outer seal member 57 are arranged such that their central axes coincide with each other. The observation window 53 is inserted into the processing chamber 15 from the inside through the clearance of the unit mounting hole 47 described above, and is attached to the tip 48c of the unit installation adapter 48. At this time, the observation window 53 is fixed to the unit installation adapter 48 by a plurality of mounting bolts 59.

[0042] When the observation window 53 is attached to the unit installation adapter 48, in the observation window 53, the lid member 55, the inner seal member 56, and the light-transmitting window member 54 are arranged in this order from the inside of the processing chamber 15. A cylindrical protruding portion 48e protruding toward the inside of the processing chamber 15 is provided at the tip 48c of the unit installation adapter 48, and the light-transmitting window member 54 is interposed between the protruding portion 48e and the lid member 55.

[0043] Incidentally, when the observation window 53 is attached to the unit installation adapter 48, the lid member 55 is fixed to the tip 48c of the unit installation adapter 48 by the attachment bolts 59 on the outside in the radial direction with respect to the light-transmitting window member 54. The distance between the tip on the inner side of the protrusion 48e in the processing chamber 15 and the portion of the lid member 55 facing the light-transmitting window member 54 at this time is larger than the sum of the thickness of the light-transmitting window member 54 and the thickness of the transparent conductive film 58. That is, when the observation window 53 is attached to the unit installation adapter 48, the light-transmitting window member 54 is not directly pressed against the protrusion 48e only by the lid member 55.

[0044] On the other hand, an inner seal groove 55b for fitting the inner seal member 56 is formed in the portion of the lid member 55 facing the light-transmitting window member 54. The inner seal groove 55b is arranged so as to surround the periphery of the light-transmitting window opening 55a. When the observation window 53 is attached to the unit installation adapter 48, the inner seal member 56 is fitted into the inner seal groove 55b and is interposed between the surface on the inner side of the light-transmitting window member 54 in the processing chamber 15 and the bottom of the inner seal groove 55b of the lid member 55.

[0045] Here, when the observation window 53 is attached to the unit installation adapter 48 and the lid member 55 is in direct contact with the tip 48c, let the distance from the bottom of the inner seal groove 55b to the tip on the inner side of the processing chamber 15 of the protrusion 48e be "L". Also, let the total value of the thickness of the translucent window member 54 and the thickness of the transparent conductive film 58 be "T". In the present embodiment, "t", which is the difference between L and T, is set to be smaller than the diameter of the inner seal member 56 when not compressed. This "t" corresponds to the distance between the translucent window member 54 and the bottom of the inner seal groove 55b of the lid member 55 when the observation window 53 is attached to the unit installation adapter 48. Therefore, when the observation window 53 is attached to the unit installation adapter 48, the inner seal member 56 is sandwiched and compressed between the translucent window member 54 and the lid member 55. At this time, although the inner seal member 56 is compressed to generate a repulsive force, since the lid member 55 is fixed to the unit installation adapter 48, the generated repulsive force acts on the translucent window member 54 as a pressing force that presses the translucent window member 54 toward the outside of the processing chamber 15. At this time, the translucent window member 54 is pressed against the protrusion 48e of the unit installation adapter 48, and the transparent conductive film 58 comes into direct contact with the protrusion 48e. In other words, when the observation window 53 is attached to the unit installation adapter 48, the lid member 55 presses the translucent window member 54 against the protrusion 48e via the inner seal member 56, and grounds the transparent conductive film 58 of the translucent window member 54 via the unit installation adapter 48 and the processing container 11. As a result, electromagnetic waves attempting to pass through the translucent window member 54 of the observation window 53 are blocked from passing through by the transparent conductive film 58 at the ground potential. As a result, it is possible to prevent electromagnetic waves from leaking from the observation window 53.

[0046] In the observation window 53, as described above, the translucent window member 54 and the lid member 55 are arranged such that their respective central axes coincide. However, the lid member 55 has a translucent window opening 55a on the inside surrounded by an annular member. As a result, most of the translucent window member 54 is not covered by the lid member 55, and only the peripheral portion of the translucent window member 54 is covered by the annular member of the lid member 55. The surface of the translucent window member 54 on the inner side of the processing chamber 15 is exposed to the inside of the processing chamber 15 through the translucent window opening 55a. Also, due to the presence of this translucent window opening 55a, in the observation window 53, it is possible to view the inside from the outside of the processing chamber 15 through the translucent window member 54.

[0047] Then, the observation window 53 is attached to the tip 48c of the unit installation adapter 48 so that the central axes of the observation window 53 and the unit installation adapter 48 coincide. Therefore, the observation window 53 faces the tip opening 48d of the unit installation adapter 48. Also, as described above, the imaging unit 49 of the imaging unit 45 faces the tip opening 48d of the unit installation adapter 48 through the case window member 52. Therefore, the imaging unit 49 of the imaging unit 45 can receive light from the inside of the processing chamber 15 through the case window member 52, the tip opening 48d, and the observation window 53. That is, the imaging unit 45 can observe the inside of the processing chamber 15 through the observation window 53.

[0048] By the way, since the inside of the unit installation adapter 48 communicates with the outside of the processing chamber 15, it is at atmospheric pressure, but the inside of the processing chamber 15 is depressurized. Therefore, it is necessary to seal the inside of the processing chamber 15 from the inside of the unit installation adapter 48. In the substrate processing apparatus 10, the inner seal member 56 and the outer seal member 57 seal the inside of the processing chamber 15 from the inside of the unit installation adapter 48. Hereinafter, the form of sealing by the inner seal member 56 and the outer seal member 57 will be described.

[0049] As shown in FIG. 5, the contact portion between the transparent conductive film 58 of the translucent window member 54 and the protruding portion 48e of the unit installation adapter 48 is adjacent to the tip opening 48d located inside the unit installation adapter 48. Here, although the transparent conductive film 58 and the protruding portion 48e are in direct contact, they are not in close contact enough to be sealed, so the pressure between the transparent conductive film 58 and the protruding portion 48e is atmospheric pressure.

[0050] And since the contact portion between the lid member 55 and the tip 48c of the unit installation adapter 48 is adjacent to and communicates with the contact portion between the transparent conductive film 58 and the protruding portion 48e, the pressure between the lid member 55 and the tip 48c is also at least partially atmospheric pressure. Also, the minute gap between the side portion of the translucent window member 54 adjacent to and communicating with the contact portion between the transparent conductive film 58 and the protruding portion 48e and the inner periphery of the lid member 55 is at atmospheric pressure. For reference, in FIG. 5, the portions at atmospheric pressure among the unit installation adapter 48, the lid member 55, and the translucent window member 54 are shown hatched.

[0051] Correspondingly, in the substrate processing apparatus 10, an inner seal member 56 is disposed in an inner seal groove 55b that communicates with the minute gap between the translucent window member 54 and the lid member 55, and the inner seal member 56 blocks the atmospheric pressure in the minute gap between the translucent window member 54 and the lid member 55. Also, an outer seal member 57 is disposed between the lid member 55 and the tip 48c, and the outer seal member 57 blocks the atmospheric pressure between the lid member 55 and the tip 48c. Thereby, the inner seal member 56 and the outer seal member 57 seal the inside of the processing chamber 15 from the inside of the unit installation adapter 48.

[0052] In the substrate processing apparatus 10, the unit installation adapter 48 contacts at least partially with the wall portion 11a of the processing container 11, but there is a minute gap between the inner surface of the unit mounting hole 47 and the unit installation adapter 48. Since this minute gap communicates with the inside of the processing chamber 15, it is necessary to seal it from the outside of the processing chamber 15. Therefore, a seal member 61 (third sealing member) for sealing this minute gap is provided. The seal member 61 is an O-ring made of an elastic material, for example, an elastomer, and as shown in FIG. 3, it is disposed between the flange portion 48b of the unit installation adapter 48 and the outer surface of the wall portion 11a of the processing container 11. This seal member 61 is compressed and pressed against the flange portion 48b and the wall portion 11a to seal the minute gap between the inner surface of the unit mounting hole 47 and the unit installation adapter 48 from the outside of the processing chamber 15.

[0053] In the substrate processing apparatus 10, as described above, the surface on the inner side of the processing chamber 15 of the translucent window member 54 is exposed to the inside of the processing chamber 15. On the other hand, the surface on the outer side of the processing chamber 15 of the translucent window member 54 is exposed to the inside of the unit installation adapter 48. That is, the translucent window member 54 functions as a member that blocks the atmosphere inside the processing chamber 15 from the atmospheric pressure atmosphere outside the processing chamber 15. At this time, however, a suction force caused by the pressure difference between the outside and the inside of the processing chamber 15 acts on the translucent window member 54. Since this suction force acts to draw the translucent window member 54 toward the inside of the processing chamber 15, there is a possibility that the transparent conductive film 58 of the translucent window member 54 may be separated from the protruding portion 48e of the installation adapter 48.

[0054] Correspondingly, in the substrate processing apparatus 10, the repulsive force generated by the inner seal member 56 is set to be greater than the suction force acting on the translucent window member 54 due to the pressure difference between the outside and the inside of the processing chamber 15. Specifically, the distance t between the bottom of the inner seal groove 55b of the translucent window member 54 and the lid member 55 is set such that the compression amount of the inner seal member 56 when the observation window 53 is attached to the unit installation adapter 48 is greater than the compression amount corresponding to the suction force. Thereby, it is possible to prevent the transparent conductive film 58 of the translucent window member 54 from separating from the protruding portion 48e of the unit installation adapter 48, and the transparent conductive film 58 and the unit installation adapter 48 can be stably in direct contact with each other.

[0055] The setting of the distance t is performed by adjusting the depth of the inner seal groove 55b and the thickness of the translucent window member 54. Also, it is preferable that the margin of the repulsive force generated by the inner seal member 56 with respect to the suction force acting on the translucent window member 54 is larger. For example, it is preferable to set the distance t between the bottom of the inner seal groove 55b of the translucent window member 54 and the lid member 55 such that the repulsive force generated by the inner seal member 56 is twice or more the suction force acting on the translucent window member 54. Further, the distance t can also be adjusted according to the elastic modulus of the material used for the inner seal member 56.

[0056] In the lid member 55, the plurality of mounting bolts 59 are mounted along the circumferential direction of the lid member 55. At this time, as described above, since the distance between the tip on the inner side of the processing chamber 15 of the protruding portion 48e and the portion of the lid member 55 facing the translucent window member 54 is larger than the sum of the thickness of the translucent window member 54 and the thickness of the transparent conductive film 58, the tightening force of each mounting bolt 59 does not directly act on the translucent window member 54. Further, since the gap between the lid member 55 and the tip 48c of the installation adapter 48 becomes zero, the force with which the lid member 55 compresses the inner seal member 56 acts evenly in the circumferential direction of the inner seal member 56. As a result, the pressing force of the inner seal member 56 acting on the translucent window member 54 acts evenly in the circumferential direction of the translucent window member 54. As a result, when the translucent window member 54 is pressed against the protruding portion 48e, the translucent window member 54 does not tilt, and local stress caused by uneven tightening force of each mounting bolt 59 does not occur in the translucent window member 54, so that breakage of the translucent window member 54 can be prevented.

[0057] Further, at least one screw hole 60 (mounting hole) is formed on the surface of the lid member 55 on the inner side of the processing chamber 15. During maintenance or the like, when removing the observation window 53 from the unit installation adapter 48, the outer seal member 57, which is an O-ring, may stick to the unit installation adapter 48, making it difficult to remove the observation window 53. In such a case, a bolt or a removal jig (tool) can be attached to the screw hole 60, making it easier for the operator to apply force to the lid member 55 and easily remove the observation window 53. Further, since each screw hole 60 is directed toward the inner side of the processing chamber 15, the operator can easily attach a bolt or a removal jig.

[0058] Furthermore, as described above, in the substrate processing apparatus 10, the translucent window member 54 is pressed against the protruding portion 48e of the unit installation adapter 48. As a result, even if the translucent window member 54 receives heat input from the plasma inside the processing chamber 15, this heat diffuses to the wall portion 11a of the processing container 11 via the unit installation adapter 48, and the temperature of the translucent window member 54 does not rise excessively. As a result, it is possible to suppress deterioration due to heat and sagging caused by long-term heating in the inner seal member 56 that contacts the translucent window member 54.

[0059] The applicant of the present application measured the intensity of electromagnetic waves leaking from the observation window 53 when plasma was generated inside the processing chamber 15 of the substrate processing apparatus 10. At this time, the applicant prepared a translucent window member 54 without the transparent conductive film 58 (Comparative Example 1) and a translucent window member 54 with a metal mesh attached instead of the transparent conductive film 58 (Comparative Example 2). Also, two translucent window members 54 with different thicknesses of the transparent conductive film 58 were prepared. The thickness of the transparent conductive film 58 of one translucent window member 54 was 3000 Å (Example 1), and the thickness of the transparent conductive film 58 of the other translucent window member 54 was 1500 Å (Example 2).

[0060] The applicant of the present application measured the intensity of electromagnetic waves leaking when using each translucent window member 54 by replacing the translucent window member 54 of Comparative Example 1, the translucent window member 54 of Comparative Example 2, the translucent window member 54 of Example 1, and the translucent window member 54 of Example 2 at the observation window 53.

[0061] Also, in the substrate processing apparatus 10, 2 kW of high-frequency power for bias was supplied from the high-frequency power supply 30 to the mounting table 24. As the processing gas, a mixed gas of CF4 (methane tetrafluoride) gas and O2 (oxygen) gas was supplied into the processing chamber 15, and the pressure inside the processing chamber 15 was set to 10 mTorr. A voltage of 3 kV was applied to the electrostatic chuck, a heat transfer gas with a pressure of 2 Torr was supplied to the cooling space, and the temperature of the mounting table 24 was set to 40°C. Then, 2 kW of high-frequency power for plasma generation was supplied from the high-frequency power supply 40 to the high-frequency antenna 22 for 30 seconds, and the intensity of electromagnetic waves leaking through the observation window 53 from the electromagnetic field generated inside the processing chamber 15 at this time was measured (Experiment 1).

[0062] In Experiment 1, when using the light-transmitting window member 54 of Comparative Example 1, the intensity of the electromagnetic wave leaking from the observation window 53 was 5.2 V / m. However, when using the light-transmitting window member 54 of Comparative Example 2, the intensity of the electromagnetic wave leaking from the observation window 53 was 0.7 V / m. Also, when using the light-transmitting window member 54 of Example 1, the intensity of the electromagnetic wave leaking from the observation window 53 was 0.8 V / m, and when using the light-transmitting window member 54 of Example 2, the intensity of the electromagnetic wave leaking from the observation window 53 was 0.7 V / m. Considering the variation in the measured values due to measurement errors and the like, it was determined that the measured values of Comparative Example 2, Example 1, and Example 2 were of the same degree, and it was confirmed that all were sufficiently small compared to the measured value of Comparative Example 1.

[0063] From the above, it was confirmed that by using the light-transmitting window member 54 having at least a transparent conductive film 58 with a thickness of 1500 Å, the leakage of electromagnetic waves from the observation window 53 can be suppressed to the same extent as the light-transmitting window member 54 with a metal mesh attached.

[0064] Also, the applicant of the present application further measured the intensity of the electromagnetic wave leaking through the observation window 53 while changing both the high-frequency power for bias and the high-frequency power for plasma generation to 5 kW and keeping other conditions unchanged (Experiment 2).

[0065] In Experiment 2, when using the light-transmitting window member 54 of Comparative Example 1, the intensity of the electromagnetic wave leaking from the observation window 53 was 140 V / m. However, when using the light-transmitting window member 54 of Comparative Example 2, the intensity of the electromagnetic wave leaking from the observation window 53 was 0.6 V / m. Also, when using the light-transmitting window member 54 of Example 1, the intensity of the electromagnetic wave leaking from the observation window 53 was 0.6 V / m, and when using the light-transmitting window member 54 of Example 2, the intensity of the electromagnetic wave leaking from the observation window 53 was also 0.6 V / m. The measured values of Comparative Example 2, Example 1, and Example 2 in Experiment 2 were numerically smaller than each measurement in Experiment 1. However, considering the variation in the measured values due to measurement errors and the like, the measurement results of Experiment 2 were also determined to be of the same magnitude as the measurement results of Experiment 1. That is, also in Experiment 2, it was confirmed that the measured values of Comparative Example 2, Example 1, and Example 2 were sufficiently small compared to the measured value of Comparative Example 1.

[0066] Also in this case, it was confirmed that by using the translucent window member 54 having at least the transparent conductive film 58 with a thickness of 1500 Å, the leakage of electromagnetic waves from the observation window 53 can be suppressed to the same extent as that of the translucent window member 54 with a metal mesh attached thereto. Note that, since it becomes easier to receive light from the inside of the processing chamber 15 as the film thickness of the transparent conductive film 58 is thinner, the thickness of the transparent conductive film 58 is preferably 1500 Å.

[0067] As described above, the preferred embodiments of the present disclosure have been described. However, the present disclosure is not limited to the above-described embodiments, and various modifications and changes are possible within the scope of the gist thereof.

[0068] For example, although the observation window 53 is attached to the unit installation adapter 48, the observation window 53 may be attached to another metal component member that communicates with the processing container 11. In this case, the translucent window member 54 is pressed against the other component member by the repulsive force of the inner seal member 56, and the transparent conductive film 58 of the translucent window member 54 comes into direct contact with the other component member.

[0069] Furthermore, the observation window 53 may be directly attached to the wall portion 11a of the processing container 11. In this case, the unit installation adapter 48 is not provided, a partition wall that partitions the inside and outside of the processing chamber 15 is formed as a part of the wall portion 11a in the unit mounting hole 47, and the observation window 53 is attached to this partition wall. Also, the translucent window member 54 is pressed against the partition wall by the repulsive force of the inner seal member 56, and the transparent conductive film 58 of the translucent window member 54 comes into direct contact with the partition wall.

[0070] Note that the rectangular substrate G placed on the mounting table 24 of the substrate processing apparatus 10 is not limited to one sheet, and for example, two relatively small rectangular substrates G may be placed on the mounting table 24 in parallel. Also, the substrate on which the substrate processing apparatus 10 performs plasma processing is not limited to the rectangular substrate G made of glass, and for example, a disk-shaped wafer made of silicon may be used.

Description of Reference Numerals

[0071] G rectangular substrate 10 Substrate processing apparatus 11 Processing container 11a Wall portion 23 Antenna unit 48 Adapter for unit installation 53 Observation window 54 Translucent window member 55 Cover member 55a Opening for translucent window 56 Inner seal member 58 Transparent conductive film

Claims

1. A substrate processing apparatus including a plasma generation means for generating plasma and a processing chamber for subjecting a substrate to plasma processing inside a reduced-pressure environment, further including an observation window for observing the inside of the processing chamber, wherein the observation window includes a plate-shaped translucent window member, a lid member having a first opening, and an annular first sealing member, wherein in the translucent window member, a transparent conductive film is formed on a first surface which is one surface side, and the transparent conductive film is not formed on a second surface which is the surface opposite to the first surface, wherein the observation window is attached to a metal wall portion of the processing chamber or a metal component disposed on the wall portion of the processing chamber from the inside of the processing chamber, when the observation window is attached to the wall portion or the component, the lid member and the translucent window member are arranged in this order from the inside of the processing chamber, the lid member is fixed to the wall portion or the component so that the translucent window member is interposed between the lid member and the wall portion or the component, a second surface of the translucent window member is exposed to the inside of the processing chamber through the first opening, a first sealing member is interposed between the second surface of the translucent window member and the lid member, and the first sealing member is arranged so as to surround the first opening, when the first sealing member is compressed, the repulsive force generated causes the translucent window member to be pressed against the wall portion or the component, and the transparent conductive film on the first surface of the translucent window member comes into direct contact with the wall portion or the component, wherein the repulsive force generated by the first sealing member is greater than the suction force that draws the translucent window member into the inside of the processing chamber due to the pressure difference between the inside and outside of the processing chamber. A substrate processing apparatus.

2. The compression amount of the first sealing member is defined by the distance between the lid member and the wall portion or the component when the lid member is fixed to the wall portion or the component and the thickness of the translucent window member. The substrate processing apparatus according to Claim 1.

3. When the observation window is attached to the component, the component is attached to a second opening provided in the wall portion of the processing chamber, and the component is electrically connected to the wall portion. The substrate processing apparatus according to Claim 1.

4. When the lid member is fixed to the component, a second sealing member is interposed between the lid member and the component, The substrate processing apparatus according to claim 3, wherein when the constituent member is attached to the second opening, a third sealing member is interposed between the constituent member and the wall portion of the processing container.

5. The substrate processing apparatus according to claim 1, wherein a high-frequency power supply for supplying a high-frequency power supply for generating an electromagnetic field inside the processing container is connected to the plasma generation means.

6. The lid member has a mounting hole for mounting a tool for removing the lid member. The substrate processing apparatus according to claim 1, wherein when the lid member is fixed to the wall portion or the constituent member, the mounting hole is directed to the inside of the processing container.

7. An electromagnetic wave leakage prevention method for preventing electromagnetic wave leakage from a substrate processing apparatus including a plasma generation means for generating plasma, a processing container for performing plasma processing on a substrate inside a reduced-pressure environment, and an observation window for observing the inside of the processing container, The observation window includes a plate-shaped translucent window member, a lid member having a first opening, and an annular first sealing member. In the translucent window member, a transparent conductive film is formed on a first surface which is one surface, and the transparent conductive film is not formed on a second surface which is a surface opposite to the first surface. The observation window is attached to a metal wall portion of the processing container or a metal constituent member disposed on the wall portion of the processing container from the inside of the processing container. When the observation window is attached to the wall portion or the constituent member, the lid member and the translucent window member are arranged in this order from the inside of the processing container, and the lid member is fixed to the wall portion or the constituent member so that the translucent window member is interposed between the lid member and the wall portion or the constituent member, and a second surface of the translucent window member is exposed to the inside of the processing container through the first opening, and a first sealing member is interposed between the second surface of the translucent window member and the lid member, and the first sealing member is arranged so as to surround the first opening. The repulsive force generated when the first sealing member is compressed presses the translucent window member against the wall portion or the constituent member so that the transparent conductive film on the first surface of the translucent window member is in direct contact with the wall portion or the constituent member. An electromagnetic wave leakage prevention method for adjusting the compression amount of the first sealing member so that the repulsive force generated by the first sealing member is greater than the suction force that draws the translucent window member into the interior of the processing container due to the pressure difference between the inside and outside of the processing container.

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