Substrate processing apparatus and substrate processing method

Abstract

To prevent an attachment to a substrate of an accumulation occurring in the circumference of the substrate due to processing on the substrate.SOLUTION: A substrate processing apparatus is constructed so as to comprises: a processing container; a plasma formation mechanism that forms a plasma in a processing space for processing the substrate; a stage that is provided in the processing space in order to mount the substrate, and contains a part formed by metal; a first high-frequency power supply that supplies a high frequency for a bias to the stage; an upper ring that surrounds the stage so as not to be overlapped with the sage in a plan view, and is an insulation body provided so as to face the processing space; a lower ring that is provided below the insulation body ring for supporting the upper ring, and is a ring-shaped insulation body that surrounds a side periphery of the stage; and a metallic member that is provided between the upper ring and lower ring for drawing the plasma to the upper ring, and is formed along the insulation body ring while being separated from the stage.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a substrate processing apparatus and a substrate processing method.

Background Art

[0002] For a substrate, plasma processing such as etching is performed. Regarding an apparatus for performing such plasma processing, in some cases, a ring member surrounding the substrate is provided to converge plasma on the substrate, and a high frequency for applying a bias is supplied to an electrode constituting a stage on which the substrate is placed. Patent Documents 1 to 3 show apparatuses having such configurations.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present disclosure is to provide a technique capable of preventing adhesion of deposits generated around a substrate to the substrate by processing the substrate.

Means for Solving the Problems

[0005] The substrate processing apparatus of the present disclosure includes a processing container having a processing space for storing a substrate therein, a plasma forming mechanism for forming plasma in the processing space to process the substrate, a stage provided in the processing space for placing the substrate and including a portion made of metal, A first high-frequency power supply that supplies a high frequency for bias to the stage, An upper ring that surrounds the stage so as not to overlap the stage in plan view and is an insulator provided facing the processing space, A lower ring that is provided below the upper ring to support the upper ring and is a ring-shaped insulator that surrounds the side circumference of the stage, A metal member that is provided between the upper ring and the lower ring to draw the plasma into the upper ring, is separated from the stage, and is formed along the circumference of the upper ring in plan view, and includes.

Advantages of the Invention

[0006] The present disclosure can prevent the adhesion of deposits generated around the substrate to the substrate by processing the substrate.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0008] An etching apparatus 1 which is an embodiment of the substrate processing apparatus of the present disclosure will be described with reference to FIG. 1 which is a longitudinal side view. This etching apparatus 1 supplies an etching gas as a processing gas to a processing container 12 described later, and etches a film formed on the surface of the substrate G by plasmaizing this processing gas. This plasma is inductively coupled plasma. The substrate G is rectangular in plan view and is, for example, a glass substrate for manufacturing a FPD (Flat Panel Display). More specifically, the substrate G is, for example, a substrate for manufacturing a liquid crystal display (LCD), an electro luminescence (EL) display, a plasma display panel (PDP), or the like.

[0009] The etching apparatus 1 includes a main body container 11 which is a square tube made of metal and is grounded. Inside the main body container 11, a metal window 2 which is a metal member is provided, and the inside of the main body container 11 is partitioned by the metal window 2 into an upper antenna chamber 3 and a lower processing container 12. Therefore, the metal window 2 forms the ceiling wall of the processing container 12. And the inside of the processing container 12 is configured as a processing space 13 for storing and processing the substrate G.

[0010] A support shelf 18 made of metal is provided between the side wall of the antenna chamber 3 and the side wall of the processing container 12, and the support shelf 18 protrudes inside the main body container 11. And the above metal window 2 is supported by the support shelf 18 via an insulating member 21, so that the metal window 2 is insulated from the processing container 12. Further, the metal window 2 is divided in the lateral direction to form a plurality of divided portions 22. As an example, this division is made in the circumferential direction along a radial straight line from the central portion or the vicinity of the central portion of the metal window 2 toward the corner portion. However, for the sake of illustration, in FIG. 1, it is not shown that the division is made along the radial straight line. An insulating member 21 is also provided between the divided portions 22, and the divided portions 22 are insulated from each other. In addition to performing the circumferential division in this way, regions having different distances from the central portion of the metal window 2 may be divided.

[0011] The dividing part 22 includes a main body part 23 and a shower plate 24 provided below the main body part 23. The shower plate 24 has a plurality of gas discharge ports 25, and each gas discharge port 25 communicates with a gas diffusion space 26 formed between the main body part 23 and the shower plate 24. And the processing gas is supplied from the gas supply part 27 to the gas diffusion space 26 of each dividing part 22, and the processing gas is discharged from the gas discharge port 25 to the processing space 13. Therefore, the metal window 2 forms a shower head.

[0012] An antenna 31 is provided in the antenna chamber 3. The antenna 31 is separated from the metal window 2 and faces the metal window. The antenna 31 is formed to circulate along the circumferential direction of the metal window 2. Specifically, the antenna 31 can have, for example, a coil-like configuration that is wound multiple times around the center of the metal window 2 in a plan view. And a high-frequency power supply 33 is connected to the antenna 31 via a matcher 32.

[0013] When high-frequency power is supplied to the antenna 31 by the high-frequency power supply 33, an induced current is generated on the upper surface of each dividing part 22 that constitutes the metal window 2, and this induced current becomes an eddy current that repeatedly flows through the side surface, lower surface, side surface, and upper surface of each dividing part 22 in sequence. An induced electric field is formed in the processing space 13 by the current flowing through the lower surface of the dividing part 22 among this eddy current, and the processing gas is plasmaized. Since the metal window 2 is configured such that the dividing parts 22 are insulated from each other and divided, it is suppressed that the induced current generated on the upper surface of the metal window 2 becomes an eddy current that only loops on the upper surface, and it becomes an eddy current that passes through the lower surface of the metal window 2 (that is, the lower surface of each dividing part 22). In addition, a plurality of coil-like antenna segments each formed so that the winding axis is parallel to the upper surface of the metal window 2 are arranged in the circumferential direction of the metal window 2, and high-frequency waves are supplied to each antenna segment, thereby forming an eddy current that passes through the lower surface of the dividing part 22 described above and performing plasmaization. The metal window 2, the antenna 31, the matcher 32, and the high-frequency power supply 33 which is the second high-frequency power supply constitute a plasma formation mechanism.

[0014] Next, the configuration of the processing container 12 will be described. On the side wall of the processing container 12, a transfer port 15 for the substrate G that is opened and closed by the gate valve 14 is formed. And, at the center of the bottom surface of the processing container 12, a stage 4 for placing the substrate G is provided. And, a plurality of exhaust ports 16 are opened around the stage 4 on the bottom surface. By exhausting from the exhaust port 16 by the exhaust mechanism 17, the plasma described above is formed in a state where the inside of the processing container 12 is in a vacuum atmosphere, and the substrate G is processed.

[0015] Hereinafter, description will also be made with reference to FIGS. 2 and 3 which are longitudinal sectional views of the stage 4. Note that FIGS. 2 and 3 show longitudinal sectional views at different positions with respect to the insulator ring 5 and the focus ring 6 described later. The stage 4 is configured as a rectangular prism with a flat side peripheral surface from the upper surface to the lower surface, and forms a rectangle in a plan view such that the periphery follows the circumference of the substrate G to be placed. The stage 4 includes a lower electrode 43 which is a metal block body.

[0016] Also, the upper side of the stage 4 is configured as an electrostatic chuck 44, and the electrostatic chuck 44 is provided laminated on the lower electrode 43. The electrostatic chuck 44 includes a chuck dielectric film 45 and a chuck electrode 46 embedded in the chuck dielectric film 45. A DC power supply 47 is connected to the chuck electrode 46 so as to obtain an electrostatic adsorption force of the electrostatic chuck 44 with respect to the substrate G. Further, a high-frequency power supply 49 is connected to the lower electrode 43 via a matcher 48. The high-frequency power supply 49 which is a first high-frequency power supply is for applying a bias to the substrate G placed on the electrostatic chuck 44, and ions constituting the plasma are drawn into the substrate G by supplying high-frequency to the lower electrode 43.

[0017] A flow path for a temperature-adjusted fluid is formed within the lower electrode 43. Further, a flow path for a heat transfer gas is formed that extends toward the electrostatic chuck 44 through the lower electrode 43 and opens to the upper surface of the electrostatic chuck 44, and heat transfer between the substrate G and the stage 4 is performed through the heat transfer gas. A lift pin is provided so as to penetrate the stage 4 in the vertical direction and protrude from and retract into the surface of the electrostatic chuck 44 in order to transfer the substrate G between the transfer mechanism outside the etching apparatus 1 and the electrostatic chuck 44. Illustrations of these flow paths for the temperature-adjusting fluid, the flow path for the heat transfer gas, and the lift pin are omitted.

[0018] Also, a support member 40 made of an insulator is provided on the bottom surface of the processing chamber 12. The support member 40 is configured in a rectangular ring shape. The support member 40 is provided along the peripheral edge of the lower electrode 43, and the inner peripheral edge side of the support member 40 supports the peripheral edge of the lower electrode 43. An insulator ring 5 is provided on the support member 40. The insulator ring 5 is configured as a rectangular ring that surrounds the entire side circumference of the stage 4, and has a role of suppressing abnormal discharge on the side circumferential surface of the stage 4 when plasma is formed in the processing space 13. The insulator ring 5 is provided so as to extend from a height position lower than the upper surface of the lower electrode 43 to the height position of the lower surface of the lower electrode 43.

[0019] The insulator ring 5 has a rectangular shape in a vertical cross-sectional view and is composed of insulators that form the inner peripheral edge and the outer peripheral edge of the ring, respectively. The inner peripheral side surface of the insulator ring 5 is in close contact with the outer peripheral side surface of the stage 4, and the bottom surface of the insulator ring 5 is in close contact with the upper surface of the support member 40.

[0020] Regarding each corner of the side surface of the lower electrode 43 described above, a part of the portion in the vertical direction is cut out to form a concave portion 53 (see FIG. 3), and a support member 54 made of an insulator is provided so as to engage with the concave portion 53. A part of the support member 54 protrudes outside the lower electrode 43, fits into a notch 55 on the upper surface at the corner on the inner peripheral side of the insulator ring 5, and is supported by the insulator ring 5. Two upward pins 56 are provided at the portion of the support member 54 protruding from the lower electrode 43 (only one is shown in FIG. 3), and the pins 56 are located near each of the two sides of the rectangular lower electrode 43 as viewed in plan. The insulator ring 5 and the support member 54 form a lower ring that supports the inner peripheral edge side of the focus ring 6.

[0021] Also, on the bottom surface of the processing container 12, a spacer 57 that is square-ring-shaped and made of an insulator is provided so as to surround the insulator ring 5 and the support member 40 over the entire circumference. The inner peripheral side surface of the spacer 57 is in close contact with the outer peripheral side surfaces of the support member 40 and the insulator ring 5.

[0022] An insulator focus ring 6 is provided on the insulator ring 5 and the spacer 57. Note that FIG. 4 shows the lower surface of the focus ring 6. The focus ring 6, which is an upper ring, is a square-ring-shaped member that surrounds the outer side of the upper part of the stage 4 over the entire circumference, and is provided such that its upper surface faces the processing space 13, and a lower surface is provided opposite to (parallel to) the upper surface, and has a role of converging plasma above the substrate G placed on the stage 4. The inner peripheral edge and the outer peripheral edge of the focus ring 6 are respectively located on the inner peripheral end of the insulator ring 5 and the outer peripheral end of the spacer 57. Therefore, the focus ring 6 does not overlap with the stage 4 in plan view. The upper surface of the focus ring 6 is located slightly below the upper surface of the electrostatic chuck 44. On the other hand, with the upper surface of the electrostatic chuck 44 as the placement area, the substrate G is placed such that its peripheral edge is located slightly outside the peripheral edge of the stage 4 described above. Therefore, a slight gap is generated between the back surface of the peripheral edge portion of the substrate G and the upper surface of the inner peripheral edge portion of the focus ring 6.

[0023] The focus ring 6 is composed of four long rectangular plates 61. As described above, since the focus ring 6 is a square ring, it is configured to form a rectangle's perimeter. However, the four plates 61 respectively constitute one corner of the rectangle and one side extending from the corner. Therefore, two of the four plates 61 are longer than the other two plates 61. Each plate 61 has a pair of opposite side faces along the length direction, and a pair of opposite end side faces perpendicular to the length direction. Also, it has an upper surface facing the processing space 13 and a lower surface opposite to the upper surface. To describe the positional relationship between the plates 61 in more detail, one plate 61 faces and is adjacent to the side faces of the other two plates 61 on different side faces. More specifically, one side face in the length direction of one plate 61 is adjacent to one end side face of one of the first other plates 61. And one end side face of one plate 61 is adjacent to the side face in the length direction of a second other plate 61 different from the first other plate in contact with the side face in the length direction. And when looking at any two adjacent plates 61 out of the four, one end of the other plate is located on the extension line in the length direction of one plate 61, and the other end side of the other plate extends in a direction perpendicular to the length direction of one plate 61.

[0024] Recesses 62 are respectively formed on the lower surfaces of one end side and the other end side in the length direction of the four plates 61. The pins 56 of the support member 54 described in FIG. 3 are inserted into the recesses 62 and fitted, and the positions of the plates 61 in the lateral direction are fixed, thereby constituting the focus ring 6. Note that, so as to be able to cope with the expansion and contraction of the plate 61 due to temperature change, one of the two recesses 62 in one plate 61 is longer in the length direction of the plate 61 than the other recess 62. Note that, in addition to having the role of positioning the plate 61, the above-mentioned pins 56 support the focus ring 6. Therefore, via the pins 56, the inner peripheral edge side of the focus ring 6 is supported by the insulator ring 5. Note that the outer peripheral edge side of the focus ring 6 is supported by the spacer 57.

[0025] As shown in Fig. 3, the recess 62 of the plate 61 can be removed with respect to the pin 56. That is, the focus ring 6 is configured to be detachable with respect to the insulator ring 5 and the spacer 57. In addition to using the fitting between the recess 62 and the pin 56, a fixture such as a screw may be used in combination so that the plate 61 can be attached to the insulator ring 5 and the spacer 57. Even when attached using such a fixture, the plate 61 shall be detachable with respect to the insulator ring 5 and the spacer 57 by removing the fixture.

[0026] A metal film 63 and an insulator film 64 are formed, for example, by spraying in a region where the insulator ring 5 overlaps with the lower surface of the focus ring 6 in a plan view. The metal film 63 is made of, for example, W (tungsten), and the insulator film 64 is made of, for example, Y2O3 (yttrium oxide). The metal film 63 is formed along the circumference of the focus ring 6. More specifically, the metal film 63 is formed in a strip shape so as to extend along the length direction of each of the four plates 61. And the metal film 63 of one adjacent plate 61 and the metal film 63 of the other plate 61 are separated from each other, so that when looking at the entire lower surface of the focus ring 6, this metal film 63 is formed in a square-shaped ring with cuts at each corner.

[0027] The edge on the inner peripheral edge side of the focus ring 6 in the metal film 63 is separated from the inner peripheral edge of the focus ring 6. That is, the metal film 63 is formed away from the lower electrode 43. The edge on the outer peripheral edge side of the focus ring 6 in the metal film 63 is located away from the inner peripheral edge of the focus ring 6 toward the spacer 57 and is located closer to the outer peripheral edge of the focus ring 6 than the peripheral edge of the substrate G placed on the stage 4. That is, at least a part of the metal film 63 is located outside the substrate G placed on the stage 4 in a plan view. Although the operation will be described in detail later, the metal film 63 has a potential by the action of the high-frequency power supply 49 and acts on the plasma in the processing space 13, and has a role of preventing the reaction products generated by the processing of the substrate G from depositing in the upper region of the metal film 63 on the upper surface of the focus ring 6.

[0028] The insulator film 64 has a role of preventing abnormal discharge (arcing) from occurring when the plasma that has entered the lower surface of the focus ring 6 from the processing space 13 comes into contact with the metal film 63. For that purpose, the insulator film 64 covers the entire metal film 63 so that the metal film 63 is not exposed, and the edge of the metal film 63 and the edge of the insulator film 64 are separated. Therefore, the insulator film 64 is also formed along the circumference of the focus ring 6, and more specifically, is formed in a square annular shape. The inner peripheral edge of the annular insulator film 64 is aligned, for example, with the position of the inner peripheral edge of the focus ring 6, and the outer peripheral edge of the insulator film 64 is located away from the spacer 57 toward the stage 4. Note that the insulator film 64 and the metal film 63 are not formed in the recess 62 and its periphery in order to avoid interference with the pin 56. In FIG. 4, a large number of points are marked on the insulator film 64 formed on three of the four plates 61, and the edge of the insulator film 64 on the other one plate 61 (the lower part in FIG. 4) is shown by a dashed line. And, in the other one plate 61, the metal film 63 is shown with hatching.

[0029] The reason for providing the above-described metal film 63 and its operation will be described in detail. First, an apparatus configuration in which the metal film 63 is not provided on the focus ring 6 will be described. Regarding the lower electrode 43 that constitutes the stage 4 described above and to which a high frequency for forming a bias is applied, it has a flat and vertical outer peripheral surface. Because of such an outer peripheral surface, unlike the configuration in which a flange in which a part of the outer peripheral surface of the lower electrode 43 protrudes outward is formed as shown in Patent Documents 2 and 3, and the focus ring 6 and the flange overlap in a plan view. And, because of the configuration in which the flange (a part of the lower electrode 43) and the focus ring 6 do not overlap in this way, the formation of an electric field on the focus ring 6 due to the supply of high frequency to the lower electrode 43 is suppressed. Therefore, the pulling of ions, which is one of the active species of plasma, toward the upper surface of the focus ring 6 by the action of this electric field is suppressed. Therefore, the etching action on the upper surface of the focus ring 6 due to ion sputtering is suppressed.

[0030] On the other hand, reaction products are generated from the processing gas for processing the substrate G and the film formed on the surface of the substrate G to be processed. Since the etching action on the upper surface of the focus ring 6 is relatively small as described above, the reaction products accumulate along the upper surface of the focus ring 6 to form an annular film 60 (to be shown later), and there is a possibility that the inner edge of the annular film 60 and the substrate G will become relatively close. If this happens, particles generated by the peeling of the annular film 60 may adhere to the substrate G, which may reduce the yield.

[0031] The metal film 63 has the role of preventing the deposition of reaction products near the substrate G and making the distance between the annular film 60 and the substrate G relatively large. Specifically, regarding its operation, when plasma is formed in the processing space 13, a high frequency is supplied from the high frequency power source 49 to the lower electrode 43, so that an electric field is formed between the lower electrode 43 and the plasma, and ions in the plasma are drawn toward the lower electrode 43 to process the substrate G.

[0032] Although the metal film 63 and the lower electrode 43 are separated from each other, the metal film 63 is located near the lower electrode 43. Therefore, the space between the metal film 63 and the lower electrode 43 is regarded as a capacitance component, and when a high frequency is supplied to the lower electrode 43, a part of the high frequency is supplied from the lower electrode 43 to the metal film 63, and a potential is generated in the metal film 63. Then, since an electric field is also formed above the metal film 63, ions in the plasma are drawn toward the lower electrode 43 by the electric field. Therefore, on the upper surface of the focus ring 6, the etching property in the region directly above the metal film 63 and the regions in the vicinity thereof becomes relatively high, and the formation of the annular film 60 of the deposit in those regions is prevented. That is, as described above, the deposition of the reaction product on the upper surface of the focus ring 6 near the substrate G is prevented.

[0033] By the way, assume that the metal film 63 is closer to the stage 4 side than in the above-described example and is in contact with the lower electrode 43. In that case, since the metal film 63 approaches the end of the insulator film 64, with respect to the contact portion between the metal film 63 and the lower electrode 43, it enters from the processing space 13 to the lower surface of the focus ring 6, and the insulation property with respect to the plasma flowing in the vicinity of the contact portion becomes insufficient, and it is considered that abnormal discharge is likely to occur. Therefore, in order to prevent such discharge, there is a possibility that the structure for shielding the plasma at the contact portion becomes complicated. In other words, by arranging the metal film 63 away from the lower electrode 43, the discharge can be prevented with a simple device configuration in which the insulator film 64 covering the entire metal film 63 is provided, and thus it is preferable to adopt such an arrangement.

[0034] Further, if the metal film 63 is in contact with the lower electrode 43, a part of the power of the high frequency power supply 49 supplied toward the lower electrode 43 used for processing the substrate G is more dispersed and supplied to the metal film 63, which contributes little to the processing of the substrate G. Therefore, it becomes a power loss to the lower electrode 43. Although the volume of the metal film 63 is small compared to the lower electrode 43, and thus the amount of this power loss is small, from the viewpoint of suppressing such loss and processing the substrate G more promptly, it is preferable that the metal film 63 is arranged away from the lower electrode 43 as described above.

[0035] Also, in this configuration where the metal film 63 is provided, the position where the annular film 60 of the deposit is formed is controlled by the range where the metal film 63 is provided. Suppose that in an apparatus having a configuration in which a flange is provided on the lower electrode 43 described above, an attempt is made to control the position where the annular film 60 of the deposit is formed by changing the width of the flange for adjustment and testing of the apparatus. Since the lower electrode 43 is a relatively large member, such a shape change may be a major one, and the sizes and positions of the respective members around the lower electrode 43 also need to be changed as appropriate. That is, since the design change of the apparatus is large-scale, there is a risk that the cost and labor of the apparatus increase. However, according to this configuration in which the metal film 63 is provided, since it is only necessary to change the positions of the metal film 63 and the insulator film 64, the design change of the apparatus remains small-scale, so that the cost and labor can be suppressed.

[0036] Furthermore, since the focus ring 6 on which the metal film 63 and the insulator film 64 are provided is detachable from the insulator ring 5 and the spacer 57 as described above, it is easy to control the position of the annular film 60 of the deposit. For example, a plurality of focus rings 6 having different positions where the metal film 63 is formed are prepared, and the position can be controlled by exchanging and using the focus rings 6.

[0037] By the way, as described above, the metal film 63 is formed only in a part in the width direction of the focus ring 6. And the center position of the metal film 63 in the width direction (denoted as P2 in FIG. 2) is located closer to the stage 4 than the center position in the width direction of the focus ring 6 (denoted as P1 in FIG. 2). By forming the metal film 63 in this way, while the position where the above-described reaction product is deposited is relatively far from the substrate G on the stage 4, the formation range of the metal film 63 and the insulator film 64 covering the metal film 63 can be suppressed from becoming a wide range (for example, the entire lower surface of the focus ring 6), and there is an advantage that the manufacturing cost of the apparatus can be reduced.

[0038] Further, the etching apparatus 1 includes a control unit 10 (see FIG. 1), and the control unit 10 includes a program. In the program, instructions (step groups) are incorporated to execute the processing of the substrate G in the procedure described later by transmitting control signals to each part of the etching apparatus 1. Specifically, operations such as turning on and off the high-frequency power supplies 33 and 49 and the DC power supply 47, supplying the processing gas from the gas supply unit 27, and adjusting the vacuum pressure in the processing space 13 by exhausting with the exhaust mechanism 17 are controlled by transmitting the above control signals. The above program is stored in a storage medium such as a compact disk, a hard disk, or a DVD, and installed in the control unit 10.

[0039] Subsequently, the operation of the etching apparatus 1 will be described. When the substrate G is transported into the processing container 12 by a transport mechanism (not shown), the substrate G is placed on the temperature-adjusted stage 4 via lift pins (not shown). The substrate G is temperature-adjusted via the heat transfer gas, and the inside of the processing container 12 is evacuated to a vacuum atmosphere of a desired pressure. Then, the processing gas is discharged from the shower plate 24 into the processing space 13, and the high-frequency power supplies 33 and 49 are turned on. Eddy currents as described above are formed at the metal window 2, and the processing gas is plasmaized. At this time, on the stage 4, the substrate G is adsorbed by the electrostatic chuck 44.

[0040] FIG. 5 is a schematic diagram showing the state at the time of this plasma formation, and the ions in the plasma are indicated by arrows. An electric field is formed on the lower electrode 43 by the supply of high-frequency waves from the high-frequency power supply 49, and the ions in the plasma in the processing space 13 are drawn downward toward the lower electrode 43, and the surface of the substrate G is etched. Suppose that the reaction products generated at that time adhere to the focus ring 6. However, as described above, the ions are drawn toward the region directly above the metal film 63 on the upper surface of the focus ring 6, and the reaction products in the region and its vicinity are etched. Therefore, the reaction products cannot be deposited in a region where the etching property is relatively high, and are deposited only outside the region. As a result, it is possible to prevent the inner edge of the annular film 60 formed by the deposits from being located near the substrate G.

[0041] Thereafter, when the discharge of the processing gas from the shower plate 24 stops and the high-frequency power supplies 33 and 49 are turned off, the processing of the substrate G stops, and the substrate G is conveyed from above the stage 4 to the outside of the processing container 12 via the lift pins and the transfer mechanism. As described above, according to the etching apparatus 1, since the position of the annular film 60 of the deposit generated by the processing of the substrate G can be relatively greatly separated from the substrate G, the adhesion of the deposit to the substrate G is suppressed.

[0042] Regarding the focus ring 6, in order to surely prevent abnormal discharge by covering the entire metal film 63 formed for each plate 61 with the insulator film 64, as described above, when viewed from the entire focus ring 6, the metal film 63 is formed in an annular shape with a break. Compared with the case where the metal film 63 is not provided, if the formation position of the annular film 60 of the deposit can be separated from the substrate G with respect to the entire circumference of the substrate G, the ring formed by the metal film 63 may be discontinuous. However, if the metal film 63 forms a ring without a break, the entire circumference of the substrate G and the annular film 60 of the deposit can be more surely separated, so a configuration without a break may also be used. That is, the formation of the metal film 63 along the circumference of the focus ring 6 (upper ring) includes both the case where the metal film 63 is formed in an annular shape with a break and the case where the metal film 63 is formed in an annular shape without a break.

[0043] Although the metal film 63 and the insulator film 64 are formed by spraying, the forming method is arbitrary, and for the material constituting the film, the film may be formed using plating, vapor deposition, coating, or the like. Also, the metal constituting the metal film 63 is not limited to tungsten as long as it exhibits the above-described effects, and any metal can be used. Regarding the insulator film 64, it is not limited to Y2O3 as long as it can prevent the occurrence of abnormal discharge due to the provision of the metal film 63, and any insulator can be used.

[0044] By the way, in the above example, a metal film 63 is provided as a metal member to control the position where the annular film 60 of the deposit is formed. However, the metal member is not limited to the metal film 63. For example, a metal plate may be used. When providing a metal plate instead of the metal film 63, for example, a recess is provided on the lower surface of the focus ring 6, and the metal plate is disposed in the recess. Then, the recess is filled with an insulating adhesive or filler to fill the gap between the side wall of the recess and the metal plate with the adhesive or filler, and the lower surface side of the metal film is covered with the adhesive or filler.

[0045] In addition, the recess in which the metal plate is provided and filled with an adhesive or filler may be provided on the upper surface of the insulator ring 5 instead of being provided on the focus ring 6. Therefore, the metal member is provided between the focus ring 6 and the insulator ring 5, but may be configured such that the metal member is fixed to either the focus ring 6 or the insulator ring 5.

[0046] In addition, although an example in which this technology is applied to an etching apparatus has been shown, it is not limited to being applied to such an apparatus. For example, it may be applied to a film forming apparatus. Further, the shape of the substrate to be processed is not limited to the rectangular substrate in plan view described above, and may be circular. In that case, the stage 4 may be circular in plan view according to the shape of the substrate, and each member of the focus ring 6, the insulator ring 5, the metal film 63, and the insulator film 64 may be annular in plan view. Note that even in the case of such an annulus, the metal film 63 may or may not have a cut.

[0047] In addition, the application of this technology is not limited to an apparatus that forms plasma by forming an eddy current by disposing the metal window 2 and the antenna 31 above the stage 4 as described above. For example, a shower head that forms an upper electrode paired with the lower electrode 43 is disposed above the stage 4 so as to face the stage 4. Then, a high-frequency power source 33 can be configured to supply a high-frequency for plasma formation to the shower head. That is, this technology may be applied to a parallel plate type plasma forming apparatus.

[0048] It should be noted that the embodiments disclosed this time should be considered as illustrative in all respects and not restrictive. Without departing from the scope and spirit of the appended claims, the above embodiments may be omitted, substituted, changed, or combined in various forms.

[0049] 〔Evaluation Test〕 The evaluation test related to this technology will be described. In this evaluation test, an etching process was performed on the substrate G using a test apparatus having substantially the same configuration as the above-described etching apparatus 1, and the adhesion state of deposits on the focus ring 6 after the process was examined. Differences between this test apparatus and the etching apparatus 1 include that among the four plates 61 constituting the focus ring 6, metal films 63 and insulator films 64 are not provided on two adjacent ones. Also, for the other two adjacent plates 61, metal films 63 and insulator films 64 are formed in the same manner as in the etching apparatus 1, but the thickness of the insulator film 64 is different between the plates 61.

[0050] As described above, the insulator film 64 has a role of preventing abnormal discharge by covering the metal film 63. From the viewpoint of suppressing the manufacturing cost of the apparatus, it is preferable that the thickness of the insulator film 64 is small, but if the thickness of the insulator film 64 is too small, there is a risk that dielectric breakdown will occur in the insulator film 64 and the above-described discharge will occur. In this evaluation test, in addition to confirming the effects of the metal film 63, it is also aimed at verifying the appropriate thickness of the insulator film 64.

[0051] Specifically, in the test apparatus, the thickness of the insulator film 64 on one plate 61 was 100 μm, and the thickness of the insulator film 64 on the other plate 61 was 150 μm. Also, the thickness of the metal film 63 covering these insulator films 64 was 50 μm. The metal film 63 and the insulator film 64 were each composed of W and Y2O3 as in the examples given in the embodiment. Further, the metal film 63 was formed to have a width of 26.5 cm. The inner peripheral side end of the focus ring 6 in this metal film 63 is 2 mm away from the inner peripheral edge of the focus ring 6. The insulator film 64 was formed to have a width of 30.5 mm. And, as described in the embodiment, the inner peripheral edge side end of the insulator film 64 was formed to align with the inner peripheral edge of the focus ring 6.

[0052] The processing conditions of the evaluation test will be described. As the processing gas, a mixed gas of CF4 gas and O2 gas was used, the pressure in the processing space 13 during processing was 10 mTorr (1.33 Pa), and the supply power to the high-frequency power supplies 33 and 49 was 20 kW each. Also, although the explanation was omitted in the embodiment, temperature adjustment mechanisms such as heaters and cooling channels were provided for the metal window 2 and the side walls of the processing container 12 so that temperature adjustment could be performed. The temperature of the metal window 2 and the processing container 12 was set to 80 °C. Also, the temperature of the stage 4 was set to 15 °C. And the etching processing time for the substrate G was set to 2 hours. Note that, as the substrate G, a polyimide-formed one was used to facilitate confirmation of the adhesion of deposits. That is, the deposits were generated by etching polyimide.

[0053] When observing the upper surface of the focus ring 6 after etching, an annular film 60 due to deposits was formed. Regarding this annular film 60, it had a portion extending linearly along the inner peripheral edge of the focus ring 6. The distance between the linear portion of the annular film 60 and the inner peripheral edge of the focus ring 6 was different between the plates 61. On the two plates 61 where the metal film 63 was not formed, the distance was 18 mm, and on the two plates 61 where the metal film 63 was formed, the distance was 28 mm. Therefore, from this evaluation test, it was confirmed that by providing the metal film 63, the effect described in the embodiment of increasing the distance between the peripheral edge of the substrate G and the annular film 60 of the deposits can be obtained.

[0054] Then, when observing the lower surface side of the two plates 61 provided with the metal film 63 and the insulator film 64 after etching, no traces of abnormal discharge were found. Therefore, it was confirmed that there was no problem with either a film thickness of 100 μm or 150 μm for the insulator film 64. Thus, from this evaluation test, it was confirmed that the film thickness of the insulator film 64 may be, for example, 100 μm or more, and it was shown that it is preferable to set it to 100 μm, which is the smallest film thickness within that range.

Explanation of Reference Numerals

[0055] G Substrate 1 Etching apparatus 12 Processing container 13 Processing space 2 Metal window 33 High-frequency power supply 4 Stage 5 Insulator ring 63 Metal film

Claims

1. A processing container having a processing space for storing a substrate therein, a plasma forming mechanism for forming plasma in the processing space to process the substrate, a stage provided in the processing space for placing the substrate thereon and including a portion made of metal, a first high-frequency power source for supplying a high-frequency for bias to the stage, an upper ring which surrounds the stage so as not to overlap the stage in plan view and is an insulator provided facing the processing space, a lower ring which is provided below the upper ring to support the upper ring and is a ring-shaped insulator surrounding the side periphery of the stage, a metal member provided between the upper ring and the lower ring for drawing the plasma into the upper ring, the metal member being formed along the circumference of the upper ring while being away from the stage, A substrate processing apparatus comprising the above.

2. The substrate processing apparatus according to claim 1, wherein the metal member is provided on the upper ring.

3. The substrate processing apparatus according to claim 2, wherein the metal member is a metal film, and an insulating film covering the metal film is provided.

4. The substrate processing apparatus according to claim 3, wherein the center position in the width direction of the metal film is located closer to the stage than the center position in the width direction of the upper ring.

5. The substrate processing apparatus according to any one of claims 1 to 4, wherein the plasma forming mechanism is composed of an antenna provided above the stage and a second high-frequency power source for supplying high-frequency to the antenna.

6. The substrate processing apparatus according to any one of claims 1 to 5, wherein the upper ring is detachable from the lower ring.

7. A step of storing a substrate in a processing container having a processing space therein, a step of forming plasma in the processing space by a plasma forming mechanism to process the substrate, a step of placing the substrate on a stage provided in the processing space and including a portion made of metal, a step of supplying a high-frequency for bias to the stage by a first high-frequency power source, An upper ring, which is an insulator provided facing the processing space and surrounds the stage so as not to overlap the stage in a plan view, and a lower ring, which is provided below the upper ring to support the upper ring and is a ring-shaped insulator surrounding the side periphery of the stage, are provided between the upper ring and the lower ring. A step of pulling the plasma into the upper ring by a metal member formed along the circumference of the upper ring while being separated from the stage. A substrate processing method comprising the above.

8. The step of forming the plasma and processing the substrate includes The substrate processing method according to claim 7, including a step of supplying a high frequency from a second high frequency power source forming the plasma forming mechanism to an antenna provided above the stage forming the plasma forming mechanism.

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