JP6794937B2 - Plasma processing equipment - Google Patents

Description

The present invention relates to a plasma processing apparatus in which a quadrangular substrate is placed on a lower electrode whose upper side surface is surrounded by a ring portion made of an insulating member over the entire circumference, and the substrate is processed by plasma.

In the manufacture of flat panel displays (FPDs) such as liquid crystal displays (LCDs), plasmaized processing gas is supplied to the glass substrate, which is the substrate to be processed, and plasma processing such as etching processing and film formation processing is performed. There is a process. For example, the plasma treatment is carried out in a state where the substrate is placed on a mounting table provided in a processing container in which a vacuum atmosphere is formed. The mounting table is formed in the shape of a square cylinder, for example, and an insulating ring member called a focus ring or the like for distributing plasma with high uniformity is provided on the outer peripheral portion thereof. This ring member is a square ring member, and is formed by combining a plurality of members forming one side of the square shape, for example. Since these members have a property of thermal expansion, the members may press each other due to thermal expansion, which may cause deformation or breakage of the ring member. Further, when a gap is formed between the members, plasma enters the gap, which causes abnormal discharge and erosion of the sprayed film formed on the surface of the mounting table.

In Patent Document 1, a square shield member is composed of four components, and the end surface of one component on one end abuts on the side surface of another adjacent component, and on the side surface on the other end. , A technique has been proposed in which components are combined so that the end faces on one end side of another component different from the other adjacent components come into contact with each other. In this example, even if one component is stretched due to thermal expansion, it does not push the other adjacent components, and the generation of a gap between the shield member and the lower electrode is prevented. However, in Patent Document 1, one substrate is placed on a mounting table to perform plasma treatment, and a plurality of substrates are placed side by side on the mounting table and plasma treatment is performed on these plurality of substrates at the same time. No consideration is given to the case of doing so.

Further, in Patent Document 2, in a shadow frame such as a flat panel display in which an edge portion of a large-area substrate is pressed against a substrate support to suppress deformation of the substrate, a mask panel covering the outer edge of the substrate and a center of the substrate are described. A configuration with a mask panel to cover is described. Further, Patent Document 3 states that when an EL material is formed on the surface of a thin-film deposition member such as an EL (Electro-Luminescence) display by vacuum deposition, a thin-film deposition jig for fixing a thin-film deposition mask to the thin-film deposition member is used for vapor deposition. A technique for absorbing thermal deformation of a thin-film deposition mask by forming a groove for expanding and contracting the mask on the jig is described. However, Patent Documents 2 and 3 do not consider the formation of gaps between the members constituting the ring member and the suppression of abnormal discharge, and cannot solve the problems of the present invention.

Japanese Patent No. 5885939 Japanese Patent No. 5064217 Japanese Patent No. 4795842

The present invention has been made in view of such circumstances, and an object of the present invention is a technique for suppressing the occurrence of abnormal discharge in the lower electrode when a plurality of substrates are placed side by side on the lower electrode to perform plasma treatment. Is to provide.

Therefore, the present invention is in a plasma processing apparatus in which a quadrangular substrate is placed on a lower electrode whose upper side surface is surrounded by a ring portion made of an insulating member over the entire circumference, and the substrate is processed by plasma. ,
The lower electrode is configured such that a plurality of substrates are mounted side by side at intervals and each substrate is mounted for each ring portion.
When one of the ring portions adjacent to each other is viewed in a circumferential circuit that orbits clockwise along the four sides of the substrate, if the orbiting direction is defined as forward, it is rearward to the rear end surface of the strip-shaped member on the front side. It is composed of band-shaped members that form four sides so that the side surfaces of the front end of the band-shaped member on the side are in contact with each other.
The other of the ring portions adjacent to each other is defined as the front end surface of the strip-shaped member on the front side when the orbiting direction is defined as the front when viewed in a circumferential circuit that orbits counterclockwise along the four sides of the substrate. It is composed of band-shaped members that form four sides so that the side surfaces of the front end of the band-shaped member on the rear side are in contact with each other.
Each strip-shaped member constituting the ring portion is provided with a regulated portion whose movement in the length direction is restricted on the rear side thereof.
The direction in which the boundary region extending between the lower electrodes corresponding to the substrates adjacent to each other extends is defined as the vertical direction, the strip-shaped member provided in the boundary region is defined as the vertical member, and the strip-shaped member extending in the horizontal direction is defined as the horizontal direction. When defined as a member,
The vertical members provided in the boundary region are common to each of the peripheral circuits of the ring portions adjacent to each other.
The lateral member belonging to one of the ring portions and the horizontal member belonging to the other of the ring portions, each of which the side surface of the front end portion is in contact with the rear end surface of the vertical member, are stretched by the heat of the horizontal member. It is characterized in that a gap is formed for absorbing the heat.

Further, in another invention of the present invention, a quadrangular substrate is placed on a lower electrode whose upper side surface is surrounded by a ring portion made of an insulating member over the entire circumference, and the substrate is treated by plasma. In the processing equipment
The lower electrode is configured such that a plurality of substrates are mounted side by side at intervals and each substrate is mounted for each ring portion.
When both of the ring portions adjacent to each other are viewed as one of a circumferential circuit that orbits clockwise along the four sides of the substrate and a circumferential circuit that orbits counterclockwise, the orbiting direction is defined as forward. , It is composed of band-shaped members forming four sides so that the rear end surface of the band-shaped member on the front side is in contact with the side surface of the front end portion of the band-shaped member on the rear side.
Each strip-shaped member constituting the ring portion is provided with a regulated portion whose movement in the length direction is restricted on the rear side thereof.
The direction in which the boundary region extending between the lower electrodes corresponding to the substrates adjacent to each other extends is defined as the vertical direction, the strip-shaped member provided in the boundary region is defined as the vertical member, and the strip-shaped member extending in the horizontal direction is defined as the horizontal direction. When defined as a member,
The vertical member provided in the boundary region is composed of one vertical member and the other vertical member belonging to one peripheral circuit and the other peripheral circuit of the ring portions adjacent to each other.
In order to absorb the heat elongation of the horizontal member between the side surface of the front end portion of the one vertical member and the front end surface of the horizontal member facing the side surface and belonging to the peripheral circuit of the other ring portion. Gap is formed,
The gap is formed between the side surface of the front end portion of the other vertical member and the front end surface of the horizontal member facing the side surface and belonging to the peripheral circuit of the one ring portion. And.

According to the present invention, when the ring portion is provided so as to surround at least the upper side surface of the lower electrode on which a plurality of substrates are placed side by side, the band-shaped member constituting the ring portion has one end side in the extending direction of the band-shaped member. It is provided so as to form a gap for absorbing heat elongation between strip-shaped members that are open or face each other. Therefore, even if the strip-shaped member thermally expands during the plasma treatment, the strip-shaped member is prevented from being damaged or deformed due to the pressing between the strip-shaped members. Further, the gap for absorbing the heat-induced elongation of these strip-shaped members is formed in a region that does not contact the lower electrode, and the lower electrode is not exposed from the gap between the strip-shaped members. Since the side surface of the lower electrode is not directly exposed to the plasma, it is possible to suppress the occurrence of erosion and abnormal discharge of the sprayed film formed on the surface of the lower electrode.

It is a vertical sectional side view which shows one Embodiment of a plasma processing apparatus. It is a top view which shows one Embodiment of the lower electrode and the ring part provided in the plasma processing apparatus. It is a vertical sectional side view which shows the horizontal member of the band-shaped member which constitutes a ring part. It is a top view which shows the lower electrode and the ring part. It is a top view which shows another example of a ring part. It is a top view which shows the other embodiment of a ring part. It is a top view which shows the other embodiment of a ring part. It is a top view which shows the other embodiment of a ring part.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present specification and the drawings, components having substantially the same configuration are designated by the same reference numerals, so that duplicate description will be omitted. FIG. 1 is a longitudinal side view showing an embodiment of the plasma processing apparatus 1 of the present invention. The plasma processing device 1 is configured as a plasma processing device that generates inductively coupled plasma and performs inductively coupled plasma treatment such as etching treatment and ashing treatment on a quadrangular substrate such as a G6 half substrate. The G6 half substrate is a substrate having a size obtained by dividing the length of the long side of a G6 size (1500 mm × 1850 mm) substrate in half, and is an organic EL display using, for example, an organic light emitting diode (OLED). It is applied to. Hereinafter, the G6 half substrate will be described as the substrate G.

The plasma processing apparatus 1 is provided with an airtight processing container 10 having a square cylinder shape, which is made of a conductive material, for example, aluminum whose inner wall surface is anodized and grounded. The processing container 10 is vertically partitioned into an antenna chamber 11 and a processing chamber 12 by, for example, a ceramic such as alumina (Al ₂ O ₃ ) or a dielectric window 2 made of quartz or the like. A support member 13 projecting inward is provided between the side wall 111 of the antenna chamber 11 and the side wall 121 of the processing chamber 12 in the processing container 10, and the dielectric window 2 is placed on the support member 13. To. A carry-in outlet 14 for delivering the plasma-treated substrate G is provided on the side surface of the processing container 10, and is configured to be openable and closable by a gate valve 15.

A gas supply unit 21 is fitted on the lower side of the dielectric window 2. The gas supply unit 21 is made of, for example, a conductive material, for example, aluminum whose inner surface or outer surface is anodized, and is electrically grounded. A horizontally extending gas flow path 22 is formed inside the gas supply unit 21, and a plurality of gas discharge holes 23 extending downward are communicated with the gas flow path 22. The dielectric window 2 is provided with a gas supply pipe 24 so as to communicate with the gas flow path 22, and the gas supply pipe 24 penetrates from the ceiling of the processing container 10 to the outside thereof and is a processing gas supply source. It is connected to the processing gas supply system 25 including the valve system and the like.

A radio frequency (RF) antenna 3 is arranged in the antenna chamber 11. The high-frequency antenna 3 is configured by arranging an antenna wire 31 made of a good conductive metal such as copper or aluminum in an arbitrary shape such as an annular shape or a spiral shape, and is separated from the dielectric window 2 by a spacer 32 made of an insulating member. It is provided. The high frequency antenna 3 may be a multiple antenna having a plurality of antenna portions. A feeding member 34 extending upward from the antenna chamber 11 is connected to the terminal 33 of the antenna wire 31, and a high frequency power supply 37 is connected to the other end side of the feeding member 34 via the matching device 36 by the feeding line 35. There is.

Below the processing chamber 12, a lower electrode 4 for mounting a plurality of, for example, two G6 half substrates G is provided so as to face the high frequency antenna 3 with the dielectric window 2 interposed therebetween. The lower electrode 4 includes a first electrode body 41 and a second electrode body 42 provided below the first electrode body 41. The first electrode body 41 and the second electrode body 42 are made of, for example, aluminum or stainless steel whose surface is anodized.

The surface of the first electrode body 41 forms a substrate mounting surface, for example, as shown in FIG. 2, the first substrate mounting surface 51 is arranged so that the two substrates G are mounted side by side at intervals. And a second substrate mounting surface 52 is provided. The first substrate mounting surface 51 and the second substrate mounting surface 52 are formed in a rectangular shape in a plan view according to the shape of the substrate G. As shown in FIG. 1, for example, a recess 43 is formed on the surface of the first electrode body 41. The recess 43 forms a boundary region 44 between the lower electrodes 4 corresponding to the substrates G adjacent to each other, and the recess 43 divides the surface of the first electrode body 41 into two. The two substrate mounting surfaces 51 and 52 are formed, respectively. Therefore, the recess 43 is formed in parallel with the long sides of the first and second substrate mounting surfaces 51 and 52, for example, in the central portion of the long side of the first electrode body 41.

An insulating sprayed film 45 made of, for example, alumina is formed on the upper surface and the side surface of the first electrode body 41, including the inner side surface and the bottom surface of the recess 43. Further, for example, electrodes for chucks (not shown) are arranged inside the sprayed films 45 provided on the first and second substrate mounting surfaces 51 and 52, and the substrate G is held by electrostatic adsorption force. It is configured as follows.

The bottom of the lower electrode 4 is supported by a hollow support column 47 via an insulating member 46. The support column 47 penetrates the bottom of the processing container 10 while maintaining an airtight state, and is connected to an elevating mechanism (not shown) arranged outside the processing container 10. For example, at the bottom of the processing chamber 12, substrate transfer mechanisms such as a plurality of transfer pins (not shown) are provided at positions corresponding to the first substrate mounting surface 51 and the second substrate mounting surface 52, respectively. .. Then, as the lower electrode 4 moves up and down, the transfer pin protrudes from the surface of the lower electrode 4, and thus the lower electrode 4 is moved up and down by the raising and lowering mechanism when the substrate G is carried in and out. A bellows 48 that airtightly surrounds the support column 47 is arranged between the insulating member 46 and the bottom of the processing container 10. A high-frequency power supply 55 is connected to the lower electrode 4 composed of the first electrode body 41 and the second electrode body 42 via a matching device 54 by a feeder line 53 provided in the hollow support column 47. .. The high frequency power supply 55 applies high frequency power for bias to the lower electrode 4 during plasma processing.

Inside the first electrode body 41, for example, an annular chiller flow path 411 extending in the circumferential direction is provided. A heat conductive medium having a predetermined temperature, for example, Galden (registered trademark), is circulated and supplied to the chiller flow path 411 from a chiller unit (not shown), and the processing temperature of the substrate G on the lower electrode 4 depends on the temperature of the heat conductive medium. Is now controlled. Further, the upper end of the gas supply path 412 provided inside the first electrode body 41 is opened on the upper surface of the first electrode body 41, and a heat transfer gas such as helium (He) gas is applied to the surface of the lower electrode body 4. It is configured to supply between the substrate G and the back surface of the substrate G.

The second electrode body 42 includes a flow path 421 communicating with the lower end of the gas supply path 412 of the first electrode body 41, and a heat transfer gas pipe is connected to this flow path 421. Further, a vacuum exhaust mechanism 18 is connected to the exhaust port 16 on the bottom surface of the processing container 10 via an exhaust passage 17. A pressure adjusting unit (not shown) is connected to the vacuum exhaust mechanism 18, so that the inside of the processing container 10 is maintained at a desired degree of vacuum.

On the lower electrode 4, a ring portion 6 made of an insulating member such as an insulating ceramic such as alumina is arranged so as to surround the first and second substrate mounting surfaces 51 and 52 over the entire circumference. There is. Since the ring portion 6 is arranged so as to face the plasma generation space, plasma is focused on each of the two substrates G on the lower electrode 4 via the ring portion 6. For example, the upper surface of the ring portion 6 when the ring portion 6 is mounted is configured to be aligned with the first and second substrate mounting surfaces 51 and 52, and the upper side surface of the lower electrode 4 covers the entire circumference. It will be surrounded by the ring portion 6. As shown in FIG. 2, the ring portion 6 is formed by combining, for example, strip-shaped members 61 to 67 which are long bodies.

FIG. 2 is a plan view of the lower electrode 4, showing the first and second substrate mounting surfaces 51 and 52 and the ring portion 6. When viewed in a circumferential circuit that orbits clockwise or counterclockwise along the four sides of the board (first board mounting surface 51, second board mounting surface 52) G, the orbiting direction is defined as forward. I will explain. A first circumferential circuit 71 that orbits counterclockwise is formed around the first substrate mounting surface 51, and strip-shaped members 61 to 64 are on the front side along the first circumferential circuit 71. It is arranged so that the side surface of the front end portion of the rear band-shaped member is in contact with the rear end surface of the band-shaped member. A second circumferential circuit 72 that orbits clockwise is formed around the second substrate mounting surface 52, and strip-shaped members 64 to 67 are placed on the front side along the second circumferential circuit 72. It is arranged so that the side surface of the front end portion of the rear band-shaped member is in contact with the rear end surface of the band-shaped member.

The strip-shaped member 64 is arranged in the recess 43 forming the boundary region 44 of the lower electrode 4. When the band-shaped member 64 is arranged in the recess 43, plasma does not enter through the gap between the recess 43 and the band-shaped member 64, and the height position of the surface of the band-shaped member 64 is the first. And the second substrate mounting surfaces 51 and 52 are formed by matching their shapes so as to be aligned with each other.

Since these strip-shaped members 61 to 67 thermally expand due to heat and extend in the length direction, regulated portions for which movement in the length direction is restricted are provided on the rear side thereof. Of both ends of the strip-shaped members 61 to 67, the front side in the extending direction is the one end side, and the rear side where the regulated portion is provided is the other end side. The other end side is the regulation end 611, 621, 631, 641, 651, 661, 671, and the one end side is the free end 612, 622, 632, 642, 652, 662, 672. Further, the strip-shaped member 64 provided in the boundary region 44 is the vertical member 64, the direction in which the vertical member 64 extends is the vertical direction, and the strip-shaped members 63 and 67 whose side surfaces are adjacent to each other at the regulation end 641 of the vertical member 64 are the horizontal members 63. , 67, and the direction in which the lateral members 63 and 67 extend is the lateral direction.

In this way, in the band-shaped members 61 to 64 forming the first peripheral circuit 71, the end faces of the restricted ends 611 to 641 of the band-shaped members 61 to 64 are adjacent to each other, and the free ends 612 to 642 of the other band-shaped members 61 to 64 are adjacent to each other. The strip-shaped members adjacent to each other are arranged so as to be orthogonal to each other in a state of being in contact with the side surface of the. Further, in the strip members 64 to 67 forming the second peripheral circuit 72, the end faces of the restricted ends 641 to 671 of the strip members 64 to 67 are adjacent to each other, and the free ends 642 to 672 of the other strip members 64 to 67 are adjacent to each other. The strip-shaped members adjacent to each other are arranged so as to be orthogonal to each other in a state of being in contact with the side surface of the. In a configuration in which a common vertical member 64 is provided in the boundary region 44 of the ring portions 6 adjacent to each other as in the ring portion 6 of this configuration, the circumferential directions of the ring portions adjacent to each other are opposite to each other. ..

The horizontal member 63 provided in the first peripheral circuit 71 and the horizontal member 67 provided in the second peripheral circuit 72 are arranged in a straight line. The end face (free end) 632 of the horizontal member 63 and the end face (free end) 672 of the horizontal member 67 face each other, and the heat elongation of the horizontal members 63 and 67 is absorbed between the end faces. The gap 60 is formed on the extension line of the boundary region 44. In this example, the vertical member 64 provided in the boundary region 44 is common to each of the first peripheral circuit 71 and the second peripheral circuit 72, and the end surface of the horizontal member 63 is provided through the gap 60. The end faces 672 of the 632 and the horizontal member 67 are arranged so as to face each other. The fact that the gap 60 is formed on the extension line of the boundary region 44 means that the gap 60 is formed within the width range of the regulation end 641 of the vertical member 64. The width A of the gap 60 is formed in consideration of the thermal elongation of the lateral members 63 and 67.

FIG. 3 shows a longitudinal side view of the horizontal members 63 and 67 in the vicinity of the gap 60. As shown in this figure, step portions are formed on the end faces 632 and 672 of the lateral members 63 and 67 facing each other, and the step portions are configured to be combined with each other. Specifically, the end surface 632 of the lateral member 63 is configured such that the upper portion 633 projects toward the lateral member 67, and the end surface 672 of the lateral member 67 has the lower portion 673 projecting toward the lateral member 63. It is composed. Then, the upper portion 633 of the end surface of the lateral member 63 is combined with each other so as to be located on the lower portion 673 of the end surface of the lateral member 67. A gap 60 is formed in each of the end faces 632 and 672 of the lateral members 63 and 67 facing each other. Therefore, when viewed from the upper side, the lower portion 673 of the end surface of the lateral member 67 is located on the lower side of the gap 60 between the lateral member 63 and the lateral member 67, and the structure is on the lower side of the lateral members 63 and 67. The surface of is not exposed.

Around the first electrode body 41 and the second electrode body 42, side insulating members are formed on the lower side of the ring portion 6 so as to cover the side surfaces of the first electrode body 41 and the second electrode body 42. 73 is arranged. The side insulating member 73 is formed in a ring shape having a rectangular shape in a plan view by, for example, an insulating ceramic such as alumina or an insulating resin such as polytetrafluoroethylene. Further, around the side insulating member 73, an outer ring portion 74 located on the outermost side of the side portion of the lower electrode 4 is arranged so as to cover the side surface of the side insulating member 73. The outer ring portion 74 is formed of, for example, the same material as the ring portion 6 in a ring shape having a rectangular shape in a plan view, and the back surface side peripheral edge portion of the ring portion 6 is placed on the surface of the outer ring portion 74. The lower surface of the side insulating member 73 is supported by the insulating member 46. FIG. 49 in FIG. 1 is an O-ring forming a sealing member.

Subsequently, the mounting structure of the ring portion 6 will be described with reference to FIG. The strip-shaped members 61 to 67 have a hole 75 for regulation provided at each of the regulation ends 611 to 671 and a support hole provided on the front side of the hole 75 for regulation at a distance in the length direction. It has a part 76. At least one support hole 76 is provided, but two or more may be provided depending on the length of the strip-shaped members 61 to 67. The regulation hole 75 functions as a regulated portion for restricting the movement of the regulation ends 611 to 671 of the strip-shaped members 61 to 67 in the length direction. For example, the cross section perpendicular to the regulation hole 75. There is little play in the above, and the shape on the plane is formed in a perfect circle.

The supporting hole 76 functions as a guided portion for guiding the free ends 612 to 672 of the strip-shaped members 61 to 67 so as to be displaceable in the length direction, and is perpendicular to the supporting hole 76. There is play in the length direction in the cross section, and the shape on the plane is formed into a rectangle with both ends being semicircles. The major axis of the support hole 76 is such that even if each band-shaped member 61 to 67 thermally expands, the support pin attached to the support hole 76 does not regulate the thermal expansion of the band members 61 to 67. It is formed to have a length of.

The regulation ends 611 to 671 of the band-shaped members 61 to 67 are fixed to, for example, the upper surface of the side insulating member 73 or the upper surface of the first electrode body 41 by the regulation pins 77 attached to the regulation holes 75, respectively. There is. Further, in the band-shaped members 61 to 67, the free ends 612 to 672 of the band-shaped members are formed by the support pins 78 fitted in the support holes 76, and the free ends 612 to 672 of the band-shaped members are formed on the upper surface of the side insulating member 73 or the first electrode body 41. It is supported so that it can be displaced with respect to the upper surface. In this way, the strip-shaped members 61 to 67 are supported so as to be thermally expandable or thermally contractable along the length direction starting from the regulation ends 611 to 671. An insulating cover member (not shown) is provided above the regulation hole 75 and the support hole 76 so that the regulation pin 77, the support pin 78, the hole 75, and 76 are not exposed to plasma. It may be configured. Further, the hole portion 75 for regulation and the hole portion 76 for support are provided as counterbore holes on the back surface side of each band-shaped member 61 to 67, and the regulation pin 77 and the support pin 78 are provided on the side insulating member 73 side or the first. By providing it on the electrode body 41 side of No. 1, the regulation pin 77, the support pin 78, and the holes 75, 76 may be configured so as not to be exposed to plasma.

The plasma processing device 1 is provided with a control unit 100 including, for example, a computer. The control unit 100 includes a data processing unit including a program, a memory, and a CPU. The control unit 100 sends a control signal to each unit of the plasma processing device 1 to the program, and the substrate is advanced by each step described later. An instruction is built in to apply plasma processing to G. This program is stored in a storage unit (not shown) such as a computer storage medium such as a flexible disk, a compact disk, or an MO (magneto-optical disk), and is installed in the control unit 100.

In the above-mentioned plasma processing apparatus 1, first, the gate valve 15 is opened and, for example, two substrates G are held side by side and carried into the processing chamber 12 by a transfer mechanism (not shown), and the lower electrode 4 is moved up and down. Two substrates on the first substrate mounting surface 51 and the second substrate mounting surface 52 via a substrate transfer mechanism (not shown) with respect to the substrate mounting surface 51 and the second substrate mounting surface 52. G is placed at the same time, and these substrates G are electrostatically attracted to the lower electrode 4. The substrates G are carried in one by one by an external transfer mechanism, and the substrates G are mounted one by one on the first substrate mounting surface 51 and the second substrate mounting surface 52. May be good. Next, the gate valve 15 is closed, the processing gas is supplied from the processing gas supply system 25 into the processing chamber 12 through the gas discharge hole 23 of the gas supply unit 21, and vacuum exhaust is performed from the exhaust port 16 through the exhaust passage 17. By evacuating the inside of the processing chamber 12 by the mechanism 18, the inside of the processing chamber 12 is maintained in a pressure atmosphere of, for example, about 0.66 to 26.6 Pa. Further, He gas is supplied to the back surface side of the substrate G via the gas supply path 412 in order to avoid a temperature rise or temperature change of the substrate G.

Subsequently, a high frequency of, for example, 13.56 MHz is applied from the high frequency power source 37 to the high frequency antenna 3, thereby forming a uniform inductive electric field in the processing chamber 12 through the dielectric window 2, and the inductive electric field causes the processing chamber. The processing gas is converted into plasma in 12 to generate a high-density inductively coupled plasma. In this way, with this plasma, plasma treatment is performed on the two substrates G, for example, plasma etching is simultaneously performed on a predetermined film of the substrate G. At this time, by applying high-frequency power having a frequency of, for example, 6 MHz from the high-frequency power source 55 to the lower electrode 4, the ions in the plasma generated in the processing chamber 12 are attracted to the lower electrode 4 side. Then, the highly vertical etching process proceeds. Further, the ring portion 6 made of an insulating member provided around the substrate G concentrates the plasma on the substrate G, and the etching rate is improved.

The ring portion 6 is exposed to plasma and heated, and as schematically shown in FIG. 4, the band-shaped members 61 to 67 constituting the ring portion 6 thermally expand and extend in the length direction. In FIG. 4, the strip-shaped members 61 to 67 extend in the free end 612 to 672 directions starting from the regulation pin 77 that regulates the regulation ends 611 to 671, and the tip positions of the free ends 612 to 672 extend due to thermal expansion. It is displaced by the dimension corresponding to the length. Further, the lateral members 63 and 67 extend so that the end faces 632 and 672 facing each other approach each other, but since a gap 60 is formed between these extending directions, the elongation due to heat is absorbed by the gap 60. Will be done.

In this way, the band-shaped members 61 to 67 constituting the ring portion 6 have one end side (free end 612 to 672) in the extension direction during thermal expansion open, or between the lateral members 63 and 67 facing each other. A gap 60 is formed in the building to absorb the elongation due to heat. Therefore, even if the strip-shaped members 61 to 67 are thermally expanded during the plasma treatment, the adjacent strip-shaped members 61 to 67 may press each other to generate stress, and the ring portion 6 may be deformed or damaged. Absent.

Further, the gap 60 between the lateral members 63 and 67 is provided on the extension of the boundary region 44 and is formed in a region that does not come into contact with the lower electrode 4. Therefore, when viewed from the gap 60, the rear end surface (regulatory end) 641 of the vertical member 64 exists on the lower electrode 4 side, and the lower electrode 4 is not exposed. Therefore, the gap is formed at the start of the plasma treatment. Even if the plasma enters the 60, it is possible to prevent the side surface of the lower electrode 4 from being directly exposed to the plasma. As a result, the plasma causes an electric field to concentrate at the corners between the upper surface and the side surface of the lower electrode 4, causing an abnormal discharge of the lower electrode 4 and erosion of the thermal spray film 45 on the surface of the lower electrode 4. It is possible to suppress that the thermal sprayed film 45 cannot maintain the insulating property and the risk of abnormal discharge increases. Further, since the end faces 632 and 672 of the horizontal members 63 and 67 facing each other are formed by combining stepped portions, one of the horizontal members exists below the gap 60, and plasma enters the gap 60. However, the contact between the plasma and the side insulating member 73 on the lower side is suppressed.

Here, an example in which the band-shaped members 681 to 685 constituting the ring portion 68 are arranged as shown in FIG. 5 will be described. The strip-shaped members 681 to 684 provided so as to surround the entire circumference of the upper side surface of the lower electrode 4 are rearward to the rear end surface of the strip-shaped member on the front side when viewed in a circumferential circuit that orbits counterclockwise. The strip-shaped members are arranged so that the side surfaces of the front end portions are in contact with each other. The rear side (regulation end side) of these strip-shaped members 681 to 684 has a hole for regulation (not shown) and a regulation pin 691, and a hole for support is located at a position separated from the regulation pin 691 in the length direction. A 692 and a support pin 693 are provided, respectively, so that the free end side extends when the strip-shaped members 681 to 684 are thermally expanded. Further, the restricting end of the strip-shaped member 685 arranged in the boundary region 44 contacts the side surface of the central region of the strip-shaped member 683, and the heat of the strip-shaped member 685 between the free end and the side surface of the strip-shaped member 681 is generated. A gap 69 is formed to absorb the elongation.

In such a configuration, when viewed from the gap 69, the lower electrode 4 forming the first substrate mounting surface 51 and the lower electrode 4 forming the second substrate mounting surface 52 are present on the side of the gap 69. Therefore, when the plasma enters the gap 69, the plasma comes into contact with the lower electrode 4, and the risk of abnormal discharge of the lower electrode 4 and erosion of the thermal spray film 45 increases.

On the other hand, according to the above-described embodiment, when the ring portion 6 is provided so as to surround the upper side surface of the lower electrode 4 on which the two substrates G are placed, the ring portion 6 is provided during the plasma treatment. Even if the constituent strip-shaped members 61 to 67 are thermally expanded, deformation and breakage of the ring portion 6 are suppressed. Further, since the gap 60 formed in advance for absorbing the elongation due to heat is configured so that the lower electrode 4 is not exposed at a position where it does not come into contact with the lower electrode 4, abnormal discharge of the lower electrode 4 due to plasma or abnormal discharge due to plasma occurs. , It is possible to prevent the occurrence of erosion of the sprayed film 45.

Subsequently, the ring portion 8 of another embodiment will be described with reference to FIG. The ring portion 8 includes strip-shaped members 81 to 84 provided along the four sides of the first substrate mounting region 501 and strip-shaped members 85 to 88 provided along the four sides of the second substrate mounting region 502. And, are combined. The band-shaped members 81 to 84 are arranged so that the side surface of the front end portion of the rear band-shaped member is in contact with the rear end surface of the front band-shaped member when viewed by the circumferential circuit 711 that orbits counterclockwise. Has been done. Further, the strip members 85 to 88 are in such a relationship that the side surface of the front end portion of the rear strip member comes into contact with the rear end surface of the front strip member when viewed by the circumferential circuit 712 that orbits counterclockwise. Is located in.

The band-shaped members (vertical members) provided in the boundary regions of the first and second substrate mounting regions 501 and 502 are the first vertical members 84 and the first vertical members belonging to the peripheral circuits 711 and 712, which are adjacent to each other. It is composed of two vertical members 86. Further, a first vertical member 84 is interposed between the band-shaped members (horizontal members) 81 and 85 that belong to the peripheral circuits 711 and 712 and are arranged in a straight line. Then, a first gap 891 for absorbing the heat-induced elongation of the horizontal member 85 is formed between the end surface (free end) of the horizontal member 85 and the side surface of the front end portion of the first vertical member 84. There is.

Further, a second vertical member 86 is interposed between the band-shaped members (horizontal members) 83 and 87 that belong to the peripheral circuits 711 and 712 and are arranged in a straight line. Then, a second gap 892 for absorbing the heat elongation of the horizontal member 83 is formed between the end surface (free end) of the horizontal member 83 and the side surface of the front end portion of the second vertical member 86. There is. These first and second gaps 891 and 892 are formed on the extension line of the boundary region so that the lower electrode 4 is not exposed when viewed sideways from the first and second gaps 891 and 892. Has been done.

A regulation hole (not shown) and a regulation pin 801 forming a regulated portion are provided on the rear side of each band-shaped member 81 to 88, and a guide is provided on the front side of the regulation pin 801. A support hole 802 and a support pin 803 forming a portion are provided, respectively. The regulation hole portion, the regulation pin 801 and the support hole portion 802 and the support pin 803 are configured in the same manner as in the above-described embodiment. Each band-shaped member 81 to 88 is configured so that the free end side is extended by heat in a state where the movement in the length direction is restricted by the regulation pin 801. In a configuration in which vertical members are provided for each ring portion in the boundary region of the ring portions 8 adjacent to each other as in the ring portion having this configuration, the circumferential directions of the ring portions adjacent to each other are the same. ..

Even in such a configuration, when the ring portion 8 is provided so as to surround the upper side surface of the lower electrode 4 on which the two substrates G are placed, the band-shaped members 81 to form the ring portion 8 during plasma processing are provided. Even if the 88 is thermally expanded, the ring portion 8 is suppressed from being deformed or damaged. Further, the gaps 891 and 892 formed in advance for absorbing the elongation due to heat are configured so that the lower electrode 4 is not exposed at a position where it does not come into contact with the lower electrode 4, so that the lower electrode 4 is abnormal due to plasma. It is possible to prevent the occurrence of electric discharge and erosion. Further, in this example, when the first and second vertical members 84 and 86 are integrally formed, the first substrate mounting region 501 side and the second substrate mounting region 502 side of the integrally formed members Since the extension directions are opposite to each other, the vertical member may be cracked at the portion in contact with the regulation pin 801.

In the above, the present invention can also be applied to the case where three or more substrates are placed on the lower electrode 4 at intervals from each other. In the example shown in FIG. 7, the first to third substrate mounting regions 511, 512, and 513 are formed on the surface of the lower electrode 4, and are common to the boundary regions provided between the respective substrate mounting regions. This is an example of arranging vertical members. A counterclockwise circumferential circuit is formed around the first substrate mounting area 511, and along this circumferential circuit, strip members 910 to 913 are arranged on the rear end surface of the strip-shaped member on the front side and the strip-shaped member on the rear side. It is arranged so that the side surfaces of the front end of the are in contact with each other. A clockwise circumferential circuit is formed around the second substrate mounting area 512, and along this circumferential circuit, the strip-shaped members 913 to 916 are attached to the rear end surface of the front strip-shaped member and the rear strip-shaped member. It is arranged so that the side surfaces of the front end are in contact with each other. A counterclockwise circuit is formed around the third substrate mounting area 513, and along this circuit, the strip members 915 and 917 to 919 are rearward to the rear end surface of the front strip member. The strip-shaped members are arranged so that the side surfaces of the front end portions are in contact with each other.

The vertical members 913 and 915 are shared with each of the peripheral circuits adjacent to each other. In a configuration in which a common vertical member is provided in the boundary region of the ring portions adjacent to each other as in the ring portion of this configuration, the circumferential directions of the ring portions adjacent to each other are opposite to each other. Further, between the horizontal members 912 and the horizontal members 916 arranged in a straight line and between the horizontal members 914 and the horizontal members 919 arranged in a straight line, the first for absorbing the heat elongation of the horizontal members, respectively. A gap 921 of 1 and a second gap 922 are formed, respectively. The first and second gaps 921 and 922 are formed on the extension lines of the boundary region, respectively, and are configured so that the lower electrode 4 is not exposed from the first and second gaps 921 and 922. On the rear side of each strip-shaped member 910-919, a regulation hole (not shown) and a regulation pin 923 forming a regulated portion are provided. Further, on the front side of the regulation pin 923, a support hole portion 924 and a support pin 925 forming a guided portion are provided, respectively, and each band-shaped member 910-919 is moved in the length direction by the regulation pin 923. Is regulated, and the free end side is configured to extend due to heat.

In the first gap 921 and the second gap 922 of this example as well, similarly to the gap 60 of the above-described embodiment, the lateral members 912 and 916 and the opposite end faces of the lateral members 914 and 919 are opposed to each other. It is configured so that each step is combined. In this way, even when the first gap 921 and the second gap 922 are viewed from the upper side, the surfaces of the structures on the lower side of the horizontal members 912, 916 and the horizontal members 914, 919 are not exposed.

Further, in the example shown in FIG. 8, when the first to third substrate mounting regions 511, 512, and 513 are formed on the surface of the lower electrode 4, a boundary region is provided between the respective substrate mounting regions. This is an example in which the first vertical member and the second vertical member are arranged in each boundary region. Counterclockwise circumferential circuits are formed around the first to third substrate mounting regions 511 to 513, respectively, and along these circumferential circuits, the strip-shaped members 931-934, the strip-shaped members 941-944, and the strip-shaped members 951 ~ 954 are arranged so that the rear end surface of the front band-shaped member is in contact with the side surface of the front end portion of the rear band-shaped member, respectively.

A first vertical member 934 and a second vertical member 942 are provided in the boundary region of the first and second substrate mounting areas 511 and 512, and the horizontal members 931 and the horizontal members 931 arranged in a straight line are provided. A first vertical member 934 is interposed between the horizontal members 941. A gap 961 is formed between the end surface (free end) of the horizontal member 941 and the first vertical member 934. Similarly, a second vertical member 942 is interposed between the horizontal member 933 and the horizontal member 943 arranged in a straight line. A gap 962 is formed between the end surface (free end) of the horizontal member 933 and the second vertical member 942. These gaps 961 and 962 are for absorbing the elongation of the lateral member due to heat, and are provided on the extension line of the boundary region.

Further, a first vertical member 944 and a second vertical member 952 are provided in the boundary region of the second and third substrate mounting areas 512 and 513. Further, a first vertical member 944 is interposed between the horizontal member 941 and the horizontal member 951 arranged in a straight line. A gap 963 is formed between the end surface (free end) of the horizontal member 951 and the first vertical member 944. Similarly, a second vertical member 952 is interposed between the horizontal member 943 and the horizontal member 953 arranged in a straight line. A gap 964 is formed between the end surface (free end) of the horizontal member 943 and the second vertical member 952. These gaps 963 and 964 are for absorbing the elongation due to heat of the lateral member, and are provided on the extension line of the boundary region.

In a configuration in which vertical members are provided for each ring portion in the boundary region of the ring portions 8 adjacent to each other as in the ring portion having this configuration, the circumferential directions of the ring portions adjacent to each other are the same. .. On the rear side of each strip-shaped member, a regulation hole portion (not shown) and a regulation pin 971 forming a regulated portion are provided. Further, a support hole 972 and a support pin 973 forming a guided portion are provided on the front side of the regulation pin 971, and the movement of each band-shaped member in the length direction is restricted by the regulation pin 971. In the state, it is configured so that the free end side is extended by heat.

Also in the configurations shown in FIGS. 7 and 8, during the plasma treatment, the contact between the band-shaped members constituting the ring portion due to thermal expansion is suppressed, and the gap 961 formed in advance to absorb the elongation due to the heat of the lateral member is 961. Since ~ 964 is provided in a region not exposed from the lower electrode 4, it is possible to suppress the occurrence of abnormal discharge and erosion of the lower electrode 4.

In the present embodiment, the ring portion is composed of insulating ceramics such as alumina, yttria, silicon nitride, and quartz. Further, as the pin, a stainless pin, a ceramic pin, an aluminum pin or the like is used. In addition, although pins were used to regulate the movement of the strip-shaped member in the length direction, for fixing the rear end of the strip-shaped member in addition to the pin, for example, pressure welding by screwing or a clamp, or insulation between the strip-shaped member and the side Fixing by a fitting structure with a member can be used. Further, for the displaceable portion on the free end side, a guide member or the like that can limit the displacement in one direction by a fitting type rail or the like of the band-shaped member and the side insulating member may be used.

Here, the method of arranging the lower electrode 4 at the bottom of the processing chamber 12 is not limited to the case where the lower electrode 4 is provided via the insulating member 46 supported by the elevating support column 47 shown in FIG. For example, a support base made of an insulating member may be fixedly arranged on the bottom surface of the processing chamber 12 composed of the metal processing container 10, and the lower electrode 4 may be provided on the support base. In this case, the transfer of the substrate G to and from the external transfer mechanism is a substrate transfer provided with a drive mechanism for raising and lowering the transfer pin so as to be retractable with respect to the first and second substrate mounting surfaces 51 and 52. It is done using a mechanism.

The plasma formed in the processing container 10 is not limited to the case where the high frequency antenna 3 and the dielectric window 2 forming the inductively coupled plasma are provided. This also applies to the case where the high frequency antenna 3 is provided through a metal wall (metal window) made of a non-magnetic metal, for example, aluminum or an aluminum alloy, instead of the dielectric window 2. In this case, the processing gas may be supplied by providing a gas shower mechanism on the metal wall instead of the gas supply unit 21. Further, a configuration may be adopted in which a capacitively coupled plasma is formed between the lower electrode 4 and the metal gas supply unit.

The type of plasma treatment carried out by using the plasma processing apparatus of the present invention is not limited to the etching treatment and the ashing treatment described above, and may be a film forming treatment on the substrate G. Further, the type of the substrate G is not limited to the above-mentioned example of the G6 half substrate, and a rectangular substrate of another size may be used. Furthermore, it is applicable not only to the rectangular substrate for FPD but also to the case of processing a rectangular substrate for other purposes such as a solar cell.

Claims (3)

In a plasma processing apparatus in which a quadrangular substrate is placed on a lower electrode surrounded by a ring portion composed of an insulating member at least on the upper side surface over the entire circumference, and the substrate is processed by plasma.
The lower electrode is configured such that a plurality of substrates are mounted side by side at intervals and each substrate is mounted for each ring portion.
When one of the ring portions adjacent to each other is viewed in a circumferential circuit that orbits clockwise along the four sides of the substrate, if the orbiting direction is defined as forward, it is rearward to the rear end surface of the strip-shaped member on the front side. It is composed of band-shaped members that form four sides so that the side surfaces of the front end of the band-shaped member on the side are in contact with each other.
The other of the ring portions adjacent to each other is defined as the front end surface of the strip-shaped member on the front side when the orbiting direction is defined as the front when viewed in a circumferential circuit that orbits counterclockwise along the four sides of the substrate. It is composed of band-shaped members that form four sides so that the side surfaces of the front end of the band-shaped member on the rear side are in contact with each other.
Each strip-shaped member constituting the ring portion is provided with a regulated portion whose movement in the length direction is restricted on the rear side thereof.
The direction in which the boundary region extending between the lower electrodes corresponding to the substrates adjacent to each other extends is defined as the vertical direction, the strip-shaped member provided in the boundary region is defined as the vertical member, and the strip-shaped member extending in the horizontal direction is defined as the horizontal direction. When defined as a member,
The vertical members provided in the boundary region are common to each of the peripheral circuits of the ring portions adjacent to each other.
The lateral member belonging to one of the ring portions and the horizontal member belonging to the other of the ring portions, each of which the side surface of the front end portion is in contact with the rear end surface of the vertical member, are stretched by the heat of the horizontal member. A plasma processing apparatus characterized in that a gap is formed for absorbing the plasma. In a plasma processing apparatus in which a quadrangular substrate is placed on a lower electrode surrounded by a ring portion composed of an insulating member at least on the upper side surface over the entire circumference, and the substrate is processed by plasma.
The lower electrode is configured such that a plurality of substrates are mounted side by side at intervals and each substrate is mounted for each ring portion.
When both of the ring portions adjacent to each other are viewed as one of a circumferential circuit that orbits clockwise along the four sides of the substrate and a circumferential circuit that orbits counterclockwise, the orbiting direction is defined as forward. , It is composed of a band-shaped member forming four sides so that the rear end surface of the band-shaped member on the front side is in contact with the side surface of the front end portion of the band-shaped member on the rear side.
Each strip-shaped member constituting the ring portion is provided with a regulated portion whose movement in the length direction is restricted on the rear side thereof.
The direction in which the boundary region extending between the lower electrodes corresponding to the substrates adjacent to each other extends is defined as the vertical direction, the strip-shaped member provided in the boundary region is defined as the vertical member, and the strip-shaped member extending in the horizontal direction is defined as the horizontal direction. When defined as a member,
The vertical member provided in the boundary region is composed of one vertical member and the other vertical member belonging to one peripheral circuit and the other peripheral circuit of the ring portions adjacent to each other.
In order to absorb the heat elongation of the horizontal member between the side surface of the front end portion of the one vertical member and the front end surface of the horizontal member facing the side surface and belonging to the peripheral circuit of the other ring portion. Gap is formed,
The gap is formed between the side surface of the front end portion of the other vertical member and the front end surface of the horizontal member facing the side surface and belonging to the peripheral circuit of the one ring portion. Plasma processing equipment. The plasma processing apparatus according to claim 1 or 2, wherein a guided portion for guiding the strip-shaped member in the length direction is provided on the front side of the restricted portion of the strip-shaped member. ..

Images