JP2019016697A - Plasma processing device - Google Patents

Abstract

To provide a plasma processing device which can suppress a member around an electrode unit to put substrates to be processed on from being affected by RF power application to the electrode unit when concurrently performing a plasma process on the substrates to be processed.SOLUTION: A plasma processing device 1 comprises: a plasma-forming unit 31 which turns a process gas supplied to a processing space to plasma; a first electrode unit 41a subjected to RF power application, which forms a first substrate setting plane 51 to put one substrate G to be processed on; a second electrode unit 41b of a metal to which RF power is applied, which is provided at a location where it is spaced apart from and adjacent to the first electrode part 41a, and which forms a second substrate setting plane 52 to put another substrate to be processed on; a ceramics ring unit 6 provided in a location where it surrounds both the first and second substrate setting planes 51 and 52; and a dielectric member 44 provided on a bottom face side of the ring unit in the location, which includes a dielectric lower, in dielectric constant, than the ceramics.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a technique for supplying plasma to a substrate to be processed and performing plasma processing.

  In the manufacture of a flat panel display (FPD) such as a liquid crystal display (LCD), plasma processing such as etching processing or film formation processing is performed by supplying a plasma processing gas to a glass substrate which is a substrate to be processed. There is a process. For example, the plasma treatment is performed in a state where the substrate is placed on a placement table provided in a processing container in which a vacuum atmosphere is formed.

For example, in Patent Document 1, a plurality of electrode plates surrounded by an insulating member are formed by forming a groove extending vertically and horizontally on the surface of an electrode plate disposed in a vacuum chamber and disposing an insulating member in the groove. A plasma processing apparatus is described in which a substrate is arranged on each surface and etching is performed on a plurality of substrates at once.
Patent Documents 2 and 3 describe techniques for disposing various dielectrics around electrodes when a plurality of substrates are placed on an electrode to perform plasma processing (per Patent Document 2, A dielectric ring surrounding the convex portion of the substrate mounting table made of aluminum, and first and second dielectric covers According to Patent Document 3, the dielectric plate disposed on the upper surface of the metal plate forming the pedestal electrode, and the dielectric A ceramic tray that transports the substrate onto the body plate.

  However, in any of these Patent Documents 1 to 3, when plasma processing is performed in a state where a plurality of substrates to be processed are arranged adjacent to each other, each electrode is applied to members disposed around the substrates to be processed. The effects of high frequency power applied to the parts and countermeasures have not been studied.

Japanese Patent No. 5094307: paragraphs 0011 to 0015, FIGS. Japanese Examined Patent Publication No. 7-30468: the 39th line of the sixth column to the 12th line of the seventh column, FIG. Japanese Patent No. 4361405: Paragraphs 0028 and 0029, FIGS.

  The present invention has been made based on such circumstances, and its purpose is to provide high-frequency power to an electrode portion on which a substrate to be processed is placed when performing plasma processing on a plurality of substrates to be processed simultaneously. It is an object of the present invention to provide a plasma processing apparatus capable of suppressing the influence of the application of the above on surrounding members.

The plasma processing apparatus of the present invention is a plasma processing apparatus that performs plasma processing on a substrate to be processed using a plasma processing gas.
A processing space that constitutes a processing space in which the plasma processing is performed, a processing gas supply unit that supplies a processing gas to the processing space, and a processing container that is connected to a vacuum exhaust unit that evacuates the processing space;
A plasma forming section for converting the processing gas supplied to the processing space into plasma;
A first electrode portion made of metal, to which a high-frequency power is applied, and the upper surface of the first substrate placement surface for placing one substrate to be processed is provided in the processing space; ,
A second substrate for mounting another substrate to be processed, which is provided at a position adjacent to and spaced from the first electrode portion in the processing space, and whose upper surface is different from the one substrate to be processed. A metal second electrode portion to which a high-frequency power is applied while constituting a mounting surface;
A ceramic ring portion surrounding both the periphery of the first substrate placement surface and the periphery of the second substrate placement surface, as viewed from above;
And a dielectric member made of a dielectric having a dielectric constant lower than that of the ceramic provided on the lower surface side of the ring portion located between the first and second substrate mounting surfaces. .

  According to the present invention, the second electrode portion provided around the first substrate mounting surface on the upper surface side of the first electrode portion and at a position adjacent to and spaced from the first electrode portion. Of the ring portions made of ceramic provided so as to surround both the periphery of the second substrate mounting surface on the upper surface side, on the lower surface side of the ring portion located between the first and second substrate mounting surfaces Since the dielectric member made of a dielectric having a dielectric constant lower than that of the ceramic is disposed, the influence of the electric field strength acting on the ring portion at the position can be reduced.

It is a vertical side view of the plasma processing apparatus which concerns on embodiment. It is a top view of the 1st, 2nd electrode part provided in the said plasma processing apparatus. It is a vertical side view which concerns on the said 1st, 2nd electrode part. It is a vertical side view which concerns on the 1st, 2nd electrode part of a comparison form. It is a schematic diagram which shows the alumina thermal spraying operation | work to the 1st, 2nd electrode part which concerns on embodiment. It is a schematic diagram which shows the alumina thermal spraying operation | work to the 1st, 2nd electrode part which concerns on a comparison form. It is a vertical side view which concerns on the 1st, 2nd electrode part of other embodiment. It is a vertical side view concerning the 1st and 2nd electrode part of other embodiments. It is explanatory drawing which shows the simulation result of the electric field strength of the surface of a ring part.

Hereinafter, the configuration of the plasma processing apparatus 1 according to the embodiment of the present invention will be described with reference to FIGS.
The plasma processing apparatus 1 of the present example generates inductively coupled plasma and performs plasma processing using inductively coupled plasma such as etching processing or ashing processing on a rectangular substrate to be processed, 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. For example, an organic EL display using an organic light emitting diode (OLED). Applicable. In the following description, this G6 half substrate is referred to as a substrate G.

The plasma processing apparatus 1 of this example includes an airtight processing vessel 10 having a rectangular tube shape which is made of a conductive material, for example, aluminum whose inner wall surface is anodized and is electrically grounded. The processing container 10 is divided into an antenna chamber 11 and a processing space 12 vertically by a dielectric window 2 made of ceramics such as alumina (Al ₂ O ₃ ), quartz, or the like.

  A support member 13 protruding inward is provided between the side wall 111 of the antenna chamber 11 and the side wall 121 of the processing space 12 in the processing container 10, and the dielectric window 2 is placed on the support member 13. The On the side surface of the processing vessel 10, a loading / unloading port 14 for opening and closing the gate valve 15 when the substrate G to be plasma-treated is delivered is provided.

A gas supply unit 21 is fitted on the lower surface side of the dielectric window 2. For example, the gas supply unit 21 is made of a conductive material such as aluminum whose inner surface or outer surface is anodized, and is electrically grounded (the ground state is not shown). A gas channel 22 extending horizontally is formed inside the gas supply unit 21, and a plurality of gas discharge holes 23 extending downward from the gas channel 22 are provided on the lower surface of the gas supply unit 21. .
On the other hand, a gas supply pipe 24 that passes through the dielectric window 2 and communicates with the gas flow path 22 is connected to the upper surface of the gas supply unit 21. Further, the gas supply pipe 24 extends through the ceiling of the processing container 10 to the outside thereof, and is connected to a processing gas supply system 25 including a processing gas supply source and a valve system. The gas supply unit 21, the gas supply pipe 24, and the processing gas supply system 25 correspond to the processing gas supply unit of this example.

  A radio frequency (RF) antenna 3 is disposed in the antenna chamber 11. The high-frequency antenna 3 is configured by arranging antenna wires 31 made of a highly 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. Is provided. The high frequency antenna 3 may be a multiple antenna having a plurality of antenna units.

A feeding member 34 extending upward of the antenna chamber 11 is connected to the terminal 33 of the antenna line 31, and a high frequency power source 37 is connected to the upper end side of the feeding member 34 via a feeding line 35 and a matching unit 36. . When a high frequency power of, for example, a frequency of 13.56 MHz is supplied from the high frequency power supply 37 to the high frequency antenna 3, an induction electric field is formed in the processing space 12. As a result, the processing gas supplied from the gas supply unit 21 is turned into plasma by the induction electric field, and inductively coupled plasma is generated.
The configuration extending from the antenna line 31 and the terminal 33 to the high-frequency power source 37 corresponds to the plasma forming unit of this example.

  On the lower side in the processing space 12, a first electrode part 41 a and a second electrode part 41 b for mounting a plurality of, for example, two G6 half substrates G at positions adjacent to each other are separated from each other. It is disposed at a position facing the high-frequency antenna 3 with the body window 2 interposed therebetween. The first and second electrode portions 41a and 41b are provided on a common lower electrode 42, the first electrode portion 41a and the lower electrode 42, and the second electrode portion 41b and the lower electrode 42 are Each is electrically connected through the contact surface. For example, the first and second electrode portions 41a and 41b and the lower electrode 42 are made of aluminum, stainless steel, or the like.

  The upper surface of the first electrode portion 41a constitutes a first substrate placement surface 51, on which one substrate G is placed. Further, the upper surface of the second electrode portion 41b constitutes a second substrate mounting surface 52, and another substrate G different from the one substrate G is mounted on the one substrate G and the other substrate. For G, a common plasma treatment is performed. Each of the first and second electrode portions 41a and 41b is made of a metal plate having a rectangular shape in plan view. As shown in FIG. 2, the first and second substrate placement surfaces 51 and 52 are also configured to have a rectangular shape in plan view according to the shape of the substrate G.

As shown in FIGS. 1 to 3, in the plasma processing apparatus 1 of this example, the first electrode portion 41a and the second electrode portion 41b are arranged so that the long sides of the rectangular metal plate are aligned and separated from each other. It is arranged at an adjacent position.
On the upper surface and four side surfaces of the first and second electrode portions 41a and 41b, for example, an alumina sprayed film 45, which is an insulating film, is formed. Further, for example, a chuck electrode (not shown) is disposed inside the sprayed film 45 constituting the first and second substrate mounting surfaces 51 and 52, and is supplied by a DC power supplied from a DC power source (not shown). The substrate G can be adsorbed and held by using the generated electrostatic adsorption force.

The lower electrode 42 that supports the first and second electrode portions 41 a and 41 b from the lower surface side is supported by the insulating member 46 from the lower surface side. For example, the insulating member 46 is configured as a rectangular ring body, and supports a peripheral portion of the lower electrode 42 and a side insulating member 73 described later that covers the lower electrode 42 from the side surface from the lower surface side.
In addition, a plurality of elevating pins (not shown) are provided so as to penetrate the first and second electrode portions 41a and 41b, the lower electrode 42, and the bottom plate of the processing container 10 in the vertical direction, and are driven. Each raising / lowering pin can be raised / lowered using a mechanism (not shown). By the raising / lowering operation of these raising / lowering pins, the front-end | tip part of a raising / lowering pin protrudes from the 1st, 2nd board | substrate mounting surfaces 51 and 52, and the board | substrate G is delivered between the board | substrate conveyance mechanisms outside.

Further, a high-frequency power source 55 is connected to the lower electrode 42 via a feeder line 53 and a matching unit 54. By supplying high-frequency power from the high-frequency power source 55 during the plasma processing, high-frequency power for bias is applied to the first and second electrode portions 41a and 41b via the lower electrode 42.
A space surrounded by the bottom plate of the processing container 10, the insulating member 46, and the lower electrode 42 is airtightly partitioned from the processing space 12, and the above-described lifting pins, power supply lines 53, and the like are provided on the bottom plate of the processing container 10. The processing space 12 is maintained in a vacuum atmosphere even if an opening that allows the air to pass therethrough is provided.

An annular chiller channel 411 extending in the circumferential direction, for example, is provided inside the first and second electrode portions 41a and 41b. The chiller channel 411 is circulated and supplied with a heat conduction medium, for example, Galden (registered trademark), at a predetermined temperature from a chiller unit (not shown). By adjusting the temperature of the heat conduction medium, the first and second The processing temperature of each substrate G placed on the electrode portions 41a and 41b is controlled.
Further, inside the first and second electrode portions 41a and 41b, the inside of each electrode portion 41a and 41b is vertically moved from the lower electrode 42 side toward the first and second substrate mounting surfaces 51 and 52. A plurality of gas supply paths 412 penetrating in the direction are provided. The gas supply path 412 supplies a heat transfer gas, for example, helium (He) gas, toward the back surface of the substrate G placed on the first and second substrate placement surfaces 51 and 52.

  The lower electrode 42 is also used as a heat transfer gas diffusion plate for supplying heat transfer gas to the gas supply passages 412 on the first and second electrode portions 41a, 41b side. For example, a groove is formed on the upper surface of the lower electrode 42. And by arrange | positioning the 1st, 2nd electrode part 41a, 41b on the lower stage side electrode 42, while the gas flow path 421 enclosed by the lower surface and groove part of these electrode parts 41a, 41b is comprised, The lower end of each gas supply channel 412 is in communication with the gas channel 421. A gas supply pipe (not shown) for heat transfer is connected to the gas flow path 421.

Further, between the peripheral edge of the upper surface of the lower electrode 42 and the first and second electrode portions 41a and 41b, between the peripheral edge of the lower surface of the lower electrode 42 and the insulating member 46, the insulating member 46 and the processing container. An O-ring 49 that is a sealing member is provided between the bottom surface of the tenth member.
Further, a vacuum exhaust mechanism 18 is connected to the exhaust port 16 on the bottom surface of the processing container 10 through an exhaust path 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. The exhaust path 17 and the vacuum exhaust mechanism 18 correspond to the vacuum exhaust part of this example.

As shown in FIG. 2, the first and second electrode portions 41a and 41b are made of alumina or the like so as to surround the entire circumference of the first and second substrate mounting surfaces 51 and 52, respectively. A ring portion 6 made of insulating ceramics is disposed.
Since the ring portion 6 is disposed so as to face the plasma generation space, the first and second electrode portions 41a and 41b (first and second substrate placement surfaces 51) are interposed via the ring portion 6. 52) The plasma can be concentrated on each of the two substrates G.

  For example, the upper surface of the ring portion 6 is arranged so that the height position is aligned with the upper surfaces of the first and second substrate mounting surfaces 51 and 52, and at least the upper side surfaces of the first and second electrode portions 41 a and 41 b. Is surrounded by the ring portion 6 over the entire circumference. As shown in FIG. 2, the ring portion 6 is configured by combining a plurality of strip-shaped members that are long bodies, and is configured in a shape in which one strip-shaped member is disposed so as to cross the central portion of the rectangular frame body. Has been. In other words, it can be said that the ring portion 6 is generally configured in a shape obtained by overturning the character “8” displayed on the 7-segment display. In FIG. 2, individual illustrations of the belt-like members are omitted, and the shape of the ring portion 6 after assembly is integrally displayed.

  For example, the thickness of the belt-shaped member constituting the ring portion 6 is set to a value in the range of 5 to 30 mm, and the width dimension of the belt-shaped member is set to a value in the range of 10 to 60 mm. At this time, the distance between the first substrate placement surface 51 and the second substrate placement surface 52 is 10 to 60 mm (the length of the short side of the G6 half substrate G) corresponding to the width dimension of the band-shaped member. (750 mm) is set to a value within a range of 2/25 to 1/75].

  Further, on the lower surface side of the ring portion 6, side insulation is provided so as to cover the four side surfaces when the first and second electrode portions 41 a and 41 b are viewed as a unit, and the side surface of the lower-stage side electrode 42 located therebelow. A member 73 is disposed. The side insulating member 73 is made of, for example, an insulating ceramic such as alumina or an insulating resin such as polytetrafluoroethylene, and has a rectangular ring shape in plan view.

An outer ring portion 74 that covers the side surfaces of the side insulating member 73 and the insulating member 46 is disposed on the outer peripheral side of the side insulating member 73 and the insulating member 46. For example, the outer ring portion 74 is made of the same ceramic as the above-described ring portion 6 and is a ring body having a rectangular shape in plan view.
The rectangular frame body of the ring portion 6 is disposed on the upper surfaces of the side insulating member 73 and the outer ring portion 74 described above. The lower surface of the side insulating member 73 is supported by the insulating member 46.

Here, in the configuration shown as the comparative form in FIG. 4, a large electrode portion 40 that covers the entire upper surface of the lower electrode 42 is provided on the lower electrode 42. Then, the recess 400 is formed so as to cross the center of the upper surface of the electrode unit 40, and a part of the ring unit 6 is disposed in the recess 400, whereby the first substrate mounting surface 51 and the second substrate mounting. The surface 52 was separated.
In addition, in each figure of FIGS. 4-8 demonstrated below, about the same component as what was demonstrated using FIGS. 1-3, the code | symbol same as what was used in FIGS. 1-3 is attached | subjected. is there.

  However, as shown in a simulation result in an example described later, in the comparative example, the electric field strength at the position where the ring portion 6 that separates the first substrate placement surface 51 and the second substrate placement surface 52 is different. I knew it would be expensive. If the electric field strength is high at the position where the ring portion 6 is arranged, the ceramics constituting the ring portion 6 are scraped to generate particles, which may cause contamination of the substrate G.

  In particular, when the rectangular first and second substrate mounting surfaces 51 and 52 are arranged adjacent to each other with their long sides aligned, the region where the electric field strength is high extends over a wide range, and particle generation occurs. Problems can also become noticeable. In this regard, if the distance between the first substrate placement surface 51 and the second substrate placement surface 52 can be increased, the electric field strength may be reduced, but the entire plasma processing apparatus is increased in size. Not realistic.

  Therefore, as shown in FIGS. 1 and 3, in the plasma processing apparatus 1 of this example, two electrode parts (first electrode part 41a and second electrode part 41b) are arranged on the lower electrode 42 so as to be separated from each other. The ring portion 6 is provided so as to surround both the periphery of the first substrate placement surface 51 and the periphery of the second substrate placement surface 52. A dielectric member 44 made of a dielectric having a lower dielectric constant than the dielectric constant of the ceramic constituting the ring portion 6 is provided on the lower surface side of the ring portion 6 located between the first and second substrate mounting surfaces 51 and 52. It was possible to reduce the electric field strength at the arrangement position of the ring portion 6 (see the simulation results of the examples described later).

In the plasma processing apparatus 1 shown in FIGS. 1 and 3, the dielectric member 44 includes side surfaces of the first and second electrode portions 41 a and 41 b facing each other with a gap therebetween, a lower surface of the ring portion 6, and a lower-stage electrode 42. It is provided so as to fill a space surrounded by the upper surface.
When the ring portion 6 is made of alumina having a relative dielectric constant of about 9 to 11, a dielectric having a dielectric constant smaller than that of the alumina is a fluororesin (for example, polytetrafluoroethylene has a relative dielectric constant of about 2). And quartz (having a relative dielectric constant of about 4).

Compared with the electrode part 40 according to the comparative example in which the recess 400 is formed, the first and second electrode parts 41 a and 41 b made of a metal plate having a rectangular shape in plan view are formed by the thermal spray film 45 by the thermal spray nozzle 7. There is also an advantage that a dense sprayed film 45 can be formed easily.
That is, the first and second electrode portions 41a and 41b according to the embodiment do not have a recess where the sprayed film 45 is to be formed, and therefore, as shown in FIG. Thermal spraying can be performed with the spray angle of the thermal spray material from the thermal spray nozzle 7 being substantially perpendicular. As a result, it is possible to form a dense sprayed film 45 having a high adhesion density of the spray material particles.

On the other hand, as shown in FIGS. 6A and 6B, the electrode part 40 according to the comparative embodiment in which the concave part 400 in which the ring part 6 is disposed is formed with the sprayed film 45 on the inner surface of the concave part 400. In this case, the discharge angle of the spray material from the spray nozzle 7 is about 50 to 60 °. As a result, as compared with the case where the discharge angle is made substantially perpendicular, the adhesion density of the spray material particles is lowered, the sprayed film 45 having poor density is formed, and abnormal discharge with the plasma occurs, and the substrate There is also a possibility that normal plasma processing cannot be performed on G.
In this respect, the first and second electrode portions 41a and 41b according to the embodiment capable of forming the dense sprayed film 45 can effectively suppress the occurrence of abnormal discharge with the plasma.

  The plasma processing apparatus 1 having the above-described configuration is provided with a control unit 100 including, for example, a computer. The control unit 100 includes a program, a memory, a data processing unit including a CPU, and the like. The program sends a control signal from the control unit 100 to each unit of the plasma processing apparatus 1 to advance a preset step. Instructions are incorporated to perform plasma processing on the substrate 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 installed in the control unit 100.

The operation of the plasma processing apparatus 1 having the above-described configuration will be described.
First, when the gate valve 15 of the plasma processing apparatus 1 is opened, the substrate G is carried into the processing space 12 by a substrate transport mechanism (not shown). And the board | substrate G is supported by the raising / lowering pin by making the several raising / lowering pin protrude from the 1st board | substrate mounting surface 51. FIG. After retracting the substrate transport mechanism from the processing space 12, the lifting pins are lowered to place one substrate G on the first substrate placement surface 51 side. Next, another substrate G is placed on the second substrate placement surface 52 by repeating the same operation using the lifting pins on the second substrate placement surface 52 side. Note that a substrate transport mechanism capable of transporting two substrates G in a state of being arranged in the horizontal direction is used to simultaneously transport and deliver the substrate G to the first and second substrate placement surfaces 51 and 52. May be performed.
Next, DC power is supplied to a chuck electrode (not shown) in the sprayed film 45 to hold the substrate G by suction.

After retracting the substrate transfer mechanism from the processing space 12, the gate valve 15 is closed, the processing gas (for example, etching gas) supplied from the processing gas supply system 25 is diffused into the gas supply unit 21, and the gas discharge hole 23 Is supplied into the processing space 12 via Further, by evacuating the processing space 12 from the exhaust port 16 to the vacuum evacuation mechanism 18 through the exhaust path 17, the processing space 12 is, for example, 0.66 to 26.6 Pa (5 to 200 mTorr). Adjust to a moderate pressure atmosphere.
Further, in order to avoid the temperature rise or temperature change of the substrate G, He gas, which is a heat transfer gas, is supplied to the back side of the substrate G through the gas supply path 412.

  Next, the aforementioned high frequency power of 13.56 MHz is applied from the high frequency power source 37 to the high frequency antenna 3, thereby forming a uniform induction electric field in the processing space 12 through the dielectric window 2. Due to the induction electric field thus formed, the processing gas supplied into the processing space 12 is turned into plasma, and high-density inductively coupled plasma is generated. With this plasma, plasma processing for the substrate G, for example, plasma etching for a predetermined film of the substrate G is performed.

  At this time, by applying high frequency power for bias from the high frequency power supply 55 to the first and second electrode portions 41a and 41b, the plasma of the processing gas is attracted toward the first and second electrode portions 41a and 41b. The etching process with high perpendicularity can be advanced. Further, by providing a ceramic ring portion 6 as an insulating member around the substrate G, the plasma is attracted to the substrate G side, and the plasma is concentrated on the substrate G to improve the etching rate. Can do.

At this time, a dielectric made of a dielectric having a lower dielectric constant than the dielectric constant of the ceramic constituting the ring portion 6 on the lower surface side of the ring portion 6 disposed between the first and second electrode portions 41a and 41b. By arranging the member 44, the electric field intensity at the arrangement position of the ring portion 6 can be reduced.
As a result, it is possible to suppress the generation of particles accompanying the cutting of the ceramics constituting the ring portion 6 and to reduce the occurrence of contamination on the substrate G during the plasma processing.

  In addition, a metal plate having a rectangular shape in plan view is used as the first and second electrode portions 41a and 41b, and the dense sprayed film 45 is formed on the surfaces of the first and second electrode portions 41a and 41b. The occurrence of abnormal discharge during plasma processing can be suppressed, and normal plasma processing can be performed on the substrate G.

  When plasma etching is performed for a preset time, supply of processing gas and heat transfer gas is stopped, and application of high frequency power to the high frequency antenna 3 and the first and second electrode portions 41a and 41b is stopped. Then, the plasma processing is finished. Thereafter, the pressure in the processing space 12 is adjusted, the suction and holding of the substrate G is released, and the processed substrate G is carried out in the procedure opposite to that during loading.

According to the plasma processing apparatus 1 according to the present embodiment, the periphery of the first substrate placement surface 51 on the upper surface side of the first electrode portion 41a and the first electrode portion 41a are separated from each other and adjacent to each other. Of the ceramic ring portion 6 provided so as to surround both of the periphery of the second substrate mounting surface 52 on the upper surface side of the second electrode portion 41b disposed at the position, the first and second substrates A dielectric member 44 made of a dielectric having a dielectric constant lower than that of the ceramic is disposed on the lower surface side of the ring portion 6 located between the mounting surfaces 51 and 52.
As a result, the electric field strength in the ring portion 6 disposed between the first and second substrate placement surfaces 51 and 52 can be reduced. For example, the first and second substrate placement surfaces 51 and 52 can be reduced. Compared with the case where the electric field strength is reduced by widening the arrangement interval, the generation of particles from the ring portion 6 accompanying the increase in electric field strength can be suppressed while avoiding an increase in the size of the plasma processing apparatus 1.

Here, the first and second electrode portions 41a and 41b that form the first and second substrate mounting surfaces 51 and 52 are flat, as shown in FIGS. It is not limited to the case where it is configured by a rectangular metal plate.
For example, as shown in FIG. 7, the first and second electrode portions 41a ′ and 41b ′ protrude toward the counterpart electrode portions 41b ′ and 41a ′ at the positions on the lower sides of the side surfaces facing each other. Alternatively, a hook-shaped protrusion 413 may be formed that is disposed so that the tip ends face each other. In addition, the front-end | tip parts of the protrusion part 413 arrange | positioned so that it may mutually face | abut may not contact, and the clearance gap of about several millimeters may be formed between these front-end | tip parts.

  At this time, the dielectric member 44 includes the side surfaces of the first and second electrode portions 41a ′ and 41b ′ facing each other with a space therebetween, the lower surface of the ring portion 6, the first and second electrode portions 41a ′, It is provided so as to fill a space surrounded by the upper surfaces of the protrusions 413 and 413 of 41b ′.

In this example, the insulation between the plasma and the lower electrode 42 is improved by covering the upper surface of the lower electrode 42 on which the thermal spray film 45 is not formed with the protrusion 413 on which the thermal spray film 45 is formed. The occurrence of abnormal discharge can be further suppressed.
Note that the thermal spraying process is a combination of the first and second electrode portions 41a ′ and 41b ′ even when the sprayed film 45 is formed on the first and second electrode portions 41a ′ and 41b ′ provided with the protruding portions 413. Since it is performed before, the thermal spraying can be performed with the ejection angle of the thermal spray material from the thermal spray nozzle 7 being substantially perpendicular to the upper surface and the upper surface of the protruding portion 413, and the dense thermal spray film 45 can be formed. is there.

In addition, in the example shown in FIG. 8, in addition to the first and second electrode portions 41a and 41b, the lower electrode is also divided into first and second lower electrodes 42a and 42b.
That is, the first electrode portion 41a is provided on the first lower electrode 42a that is electrically connected to each other, and the second electrode portion 41b is separated from the first lower electrode 42a. It is disposed on an adjacent position and is provided on the second lower electrode 42b that is electrically connected to the second electrode portion 41b.

Between the first electrode part 41a and the first lower electrode 42a, and between the second electrode part 41b and the second lower electrode 42b, heat transfer is performed toward each gas supply path 412. A gas flow path 421 for supplying gas is formed.
The high-frequency power supply 55 is connected to the first and second lower electrodes 42a and 42b, and the first and second electrode portions 41a are connected to the first and second lower electrodes 42a and 42b. , 41b is applied with high frequency power.

In the example shown in FIG. 8, the insulating member 46 is configured by combining a rectangular ring body and a rod body connecting the midpoints of the two long sides of the ring body. "". The dielectric member 44 includes a side surface of the first and second electrode portions 41a and 41b and a side surface of the first and second lower side electrodes 42a and 42b facing each other with a gap therebetween, and a lower surface of the ring portion 6 It is provided so as to fill a space surrounded by the insulating member 46. For example, the dielectric member 44 is supported by the insulating member 46 which is the rod.
Instead of the method of providing the dielectric member 44 by providing the insulating member 46 which is the rod body, a hook-shaped support member is protruded from the first and second lower electrodes 42a and 42b, and the support is performed. The dielectric member 44 may be supported by the member.

Here, the method of arranging the first and second electrode portions 41a and 41b at the bottom of the processing space 12 is the same as that of the insulating member 46 configured as a rectangular ring body shown in FIGS. On the upper surface, the lower electrode 42 (or the first lower electrode 42a and the second lower electrode 42b), the first electrode portion 41a, the second electrode portion 41b (or the first electrode portion 41a ′, the first electrode) 2, the electrode member 41 b ′), the dielectric member 44, the ring portion 6, the side insulating member 73, and the outer ring portion 74. The present invention is not limited to the case where an assembly structure (corresponding to a mounting table for the substrate G) is provided.
For example, a telescopic bellows that airtightly connects the lower electrode 42 and the bottom plate of the processing vessel 10 is provided, and a support column that can be moved up and down so as to penetrate the bottom plate is disposed inside the bellows. The lower electrode 42 may be connected to the portion via an insulating member. In this case, for example, the bottom plate of the processing container 10 is provided with substrate transfer mechanisms such as a plurality of transfer pins (not shown) at positions corresponding to the first and second substrate mounting surfaces 51 and 52, respectively. When the support is lowered, the transfer pins protrude from the first and second substrate placement surfaces 51 and 52, and the transfer of the substrate G to and from the external substrate transfer mechanism is performed via the transfer pins.

  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 that form inductively coupled plasma are provided. The present invention can also be applied to the case where the high frequency antenna 3 is provided via a metal wall (metal window) insulated from the processing vessel 10 instead of the dielectric window 2 and made of a nonmagnetic metal such as aluminum or an aluminum alloy. . 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, in each of the above-described embodiments, the example in which the processing gas is converted into plasma by inductive coupling and the plasma processing is performed has been described. However, the method in which the plasma forming unit converts the processing gas into plasma is not limited to this example.
A capacitively coupled plasma is formed by applying high frequency power between the metal gas supply unit 21 and the first and second electrode portions 41a and 41b to form a processing gas into a plasma, or a microwave in the processing space 12 Plasma processing may be performed using microwave plasma that converts the processing gas into plasma by introducing. Also in these cases, high-frequency power for plasma formation or ion attraction is applied to the first and second electrode portions 41a and 41b.
Therefore, also in these plasma formation methods, the dielectric member 44 is provided on the lower surface side of the ring portion 6 provided between the first and second substrate mounting surfaces 51 and 52, and the electric field at the position where the ring portion 6 is disposed. The strength may be reduced.

Furthermore, the type of plasma processing performed using the plasma processing apparatus 1 of this example is not limited to the etching processing and ashing processing described above, and may be a film forming processing on the substrate G.
Further, the type of the substrate G is not limited to the above-described example of the G6 half substrate, and may be a rectangular substrate of another size. Furthermore, the present invention is applicable not only to processing a rectangular substrate for FPD but also to processing a rectangular substrate for other uses such as a solar cell. In addition, the present invention can be applied to a circular substrate such as a semiconductor wafer.

(simulation)
The difference in electric field strength generated on the surface of the ring portion 6 between when the dielectric member 44 is provided on the lower surface side of the ring portion 6 and when it is not provided was confirmed by simulation.
A. Simulation conditions
(Example 1) A 35 mm wide and 10 mm thick ceramic plate material (relative permittivity: 9.9, corresponding to the ring portion 6) is provided on the lower surface side of a polytetrafluoroethylenic material having a width of 35 mm and a thickness of 35 mm. A dielectric member 44 (relative dielectric constant: 2.0) is disposed, and aluminum corresponding to the first and second electrode portions 41a and 41b is disposed on both sides of the ceramic plate material and the dielectric member 44. A simulation model was created. The model corresponds to the embodiment shown in FIGS. When a predetermined RF voltage was applied to aluminum, the electric field strength at each position of the aluminum exposed on the upper surface side and the ceramic plate was simulated.
(Example 2) A simulation similar to that of Example 1 was performed except that the thickness of the dielectric member 44 was changed to 60 mm. This model corresponds to the embodiment shown in FIG.
(Comparative Example 1) A simulation similar to that of Example 1 was performed except that the dielectric member 44 was not provided and that aluminum was also disposed on the lower surface side of the ceramic plate. This model corresponds to the comparative form shown in FIG.

B. simulation result
The simulation results of Examples 1 and 2 and Comparative Example 1 are shown in FIG. The horizontal axis of FIG. 9 indicates the coordinate position [m] in the width direction when the center position of the width dimension of the ceramic plate corresponding to the ring portion 6 is the origin, and the vertical axis indicates the electric field strength [arbitrary at each position. unit]. Since the simulation results of Examples 1 and 2 were almost the same, the simulation result of Comparative Example 1 is indicated by a broken line.

According to the results of Examples 1 and 2 shown in FIG. 9, in the ceramic plate material in which the dielectric member 44 is arranged on the lower surface side, the electric field strength is the lowest at the center position in the width direction, and the end portion in the width direction. It was found that a distribution in which the electric field strength increases suddenly after the electric field strength gradually increases toward is formed.
Moreover, regarding the simulation of Example 1, the simulation was performed by creating a plurality of simulation models in which the thickness of the dielectric member 44 was changed within a range of 5 to 35 mm. The results of these simulations were almost the same as the results of Example 1 shown in FIG.

On the other hand, in Comparative Example 1, a flat electric field strength distribution is formed in a region inside the position where the electric field strength suddenly increases, and the value is the electric field strength of Examples 1 and 2 at any position. Higher than.
From these simulation results, the ring portion 6 is configured on the lower surface side of the ring portion 6 shown in FIGS. 3, 7, and 8, compared to the method of disposing the ring portion 6 in the recess 400 of the electrode portion 40 shown in FIG. 4. It can be seen that the electric field strength on the surface of the ring portion 6 can be reduced by adopting a method of providing the dielectric member 44 having a dielectric constant lower than that of the ceramic to be used.

G substrate 1 plasma processing apparatus 10 processing container 12 processing space 18 vacuum exhaust mechanism 21 gas supply unit 3 high-frequency antennas 41a, 41a ′
1st electrode part 41b, 41b '
Second electrode portion 412 Gas supply path 413 Projecting portion 42 Lower stage side electrode 42a First lower stage side electrode 42b Second lower stage side electrode 421 Gas flow path 44 Dielectric member 45 Sprayed film 51 First substrate placement surface 52 Second substrate placement surface 6 Ring part

Claims (10)

In a plasma processing apparatus for performing plasma processing on a substrate to be processed with a plasma processing gas,
A processing space that constitutes a processing space in which the plasma processing is performed, a processing gas supply unit that supplies a processing gas to the processing space, and a processing container that is connected to a vacuum exhaust unit that evacuates the processing space;
A plasma forming section for converting the processing gas supplied to the processing space into plasma;
A first electrode portion made of metal, to which a high-frequency power is applied, and the upper surface of the first substrate placement surface for placing one substrate to be processed is provided in the processing space; ,
A second substrate for mounting another substrate to be processed, which is provided at a position adjacent to and spaced from the first electrode portion in the processing space, and whose upper surface is different from the one substrate to be processed. A metal second electrode portion to which a high-frequency power is applied while constituting a mounting surface;
A ceramic ring portion surrounding both the periphery of the first substrate placement surface and the periphery of the second substrate placement surface, as viewed from above;
And a dielectric member made of a dielectric having a dielectric constant lower than that of the ceramic provided on the lower surface side of the ring portion located between the first and second substrate mounting surfaces. Plasma processing equipment.   The first electrode portion and the second electrode portion are provided on a common lower electrode that is electrically connected to the first and second electrode portions, and the first, The plasma processing apparatus according to claim 1, wherein high-frequency power is applied to the second electrode portion.   The dielectric member is provided so as to fill a space surrounded by the side surfaces of the first and second electrode portions facing each other with a gap, the lower surface of the ring portion, and the upper surface of the lower electrode. The plasma processing apparatus according to claim 2, wherein the plasma processing apparatus is provided. Each of the side surfaces of the first and second electrode portions facing each other with a gap therebetween is located at a position on the lower side of each of the first and second electrode portions so as to protrude toward the other electrode portion side and to be in contact with each other. A protruding portion is formed,
The dielectric member is surrounded by the side surfaces of the first and second electrode portions facing each other with a gap, the lower surface of the ring portion, and the upper surfaces of the projecting portions of the first and second electrode portions. The plasma processing apparatus according to claim 2, wherein the plasma processing apparatus is provided so as to be filled in a space.   Between the first electrode portion and the lower electrode, and between the second electrode portion and the lower electrode, a plurality of pieces penetrating the first and second electrode portions in the vertical direction, respectively. A gas flow path for supplying a heat transfer gas toward the back surface of the substrate to be processed placed on the first and second substrate placement surfaces via the gas supply passage is formed. The plasma processing apparatus according to any one of claims 2 to 4, wherein The first electrode portion is provided on a first lower electrode that is electrically connected to each other, and the second electrode portion is spaced apart from the first lower electrode and is adjacent to the first electrode. Disposed on a second lower electrode that is electrically connected to the second electrode portion; and
2. The plasma processing apparatus according to claim 1, wherein high-frequency power is applied to the first and second electrode portions via the first and second lower electrodes.   The dielectric member is filled in a space surrounded by the side surfaces of the first and second electrode portions, the side surfaces of the first and second lower electrodes facing each other with a space therebetween, and the lower surface of the ring portion. The plasma processing apparatus according to claim 6, wherein the plasma processing apparatus is provided.   Between the first electrode part and the first lower electrode, and between the second electrode part and the second lower electrode, the first and second electrode parts are respectively moved up and down. Gas flow path for supplying a heat transfer gas toward the back surface of the substrate to be processed placed on the first and second substrate placement surfaces via a plurality of gas supply passages penetrating in the direction The plasma processing apparatus according to claim 6, wherein: is formed.   The upper surface and side surface of the first electrode portion including the first substrate placement surface, and the upper surface and side surface of the second electrode portion including the second substrate placement surface are made of an insulating film. The plasma processing apparatus according to claim 1, wherein the plasma processing apparatus is covered.   The plasma processing apparatus according to any one of claims 1 to 9, wherein the ceramic constituting the ring portion is alumina, and the dielectric constituting the dielectric member is fluororesin or quartz. .

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