JP2023067033A - Substrate processing apparatus and substrate processing method - Google Patents

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

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

Plasma processing such as etching is performed on the substrate. The plasma processing apparatus is provided with a ring member surrounding the substrate in order to converge the plasma on the substrate, and a high frequency for bias application is supplied to an electrode constituting a stage on which the substrate is placed. There are cases where it is said to be. Patent Documents 1 to 3 show devices having such a configuration.

JP 2016-127090 A JP-A-11-74099 JP 2014-36026 A

An object of the present disclosure is to provide a technique capable of preventing deposits generated around the substrate from adhering to the substrate due to processing of the substrate.

A substrate processing apparatus of the present disclosure includes a processing container having a processing space for storing substrates therein;
a plasma forming mechanism for forming a plasma in the processing space to process the substrate;
a stage provided in the processing space for mounting 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 is an insulator that surrounds the stage so as not to overlap the stage in a plan view and is provided facing the processing space;
a lower ring, which is a ring-shaped insulator provided below the upper ring to support the upper ring and surrounds the side circumference of the stage;
a metal member provided between the upper ring and the lower ring to draw the plasma into the upper ring, separated from the stage and formed along the circumference of the upper ring in plan view;
Prepare.

INDUSTRIAL APPLICABILITY According to the present disclosure, it is possible to prevent deposits generated around the substrate from adhering to the substrate due to processing of the substrate.

1 is a longitudinal side view of an etching apparatus according to an embodiment of a substrate processing apparatus of the present disclosure; FIG. It is a longitudinal side view of a stage provided in the etching apparatus. It is a longitudinal side view of the said stage. 4 is a schematic bottom view of a focus ring provided on the stage; FIG. It is a longitudinal side view showing a stage during processing by the etching apparatus.

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

The etching apparatus 1 includes a main container 11 which is rectangular and made of metal and which is grounded. A metal window 2, which is a metal member, is provided inside the main container 11, and the inside of the main container 11 is partitioned into an upper antenna chamber 3 and a lower processing container 12 by the metal window 2. As shown in FIG. Therefore, the metal window 2 forms the ceiling wall of the processing vessel 12 . The inside of the processing container 12 is configured as a processing space 13 for storing and processing the substrate G. As shown in FIG.

A supporting 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 supporting shelf 18 protrudes inside the main container 11 . The metal window 2 is insulated from the processing container 12 by being supported by the support shelf 18 via the insulating member 21 . Also, the metal window 2 is divided in the horizontal direction to form a plurality of divided portions 22 . As an example, this division is performed in the circumferential direction along radial straight lines extending from the center or near the center of the metal window 2 to the corners. However, for convenience of illustration, FIG. 1 does not show division along the radial straight lines. An insulating member 21 is also provided between the divided portions 22 so that the divided portions 22 are insulated. In addition to such division in the circumferential direction, regions having different distances from the center of the metal window 2 may be divided.

The dividing portion 22 includes a body portion 23 and a shower plate 24 provided below the body portion 23 . Shower plate 24 has a plurality of gas outlets 25 , and each gas outlet 25 communicates with gas diffusion space 26 formed between main body 23 and shower plate 24 . A processing gas is supplied from the gas supply unit 27 to the gas diffusion space 26 of each division 22 , and the processing gas is discharged from the gas discharge port 25 into the processing space 13 . The metal window 2 thus forms a showerhead.

An antenna 31 is provided in the antenna room 3, and the antenna 31 is separated from the metal window 2 and faces the metal window. The antenna 31 is formed so as to circle along the circumferential direction of the metal window 2 . Specifically, the antenna 31 may have a coil-like configuration that is wound around the center of the metal window 2 in plan view, for example. A high-frequency power source 33 is connected to the antenna 31 via a matching device 32 .

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 divided portion 22 that constitutes the metal window 2. , eddy currents that repeatedly flow on the upper surface. An induced electric field is formed in the processing space 13 by the current flowing through the lower surface of the dividing portion 22 among the eddy currents, and the processing gas is turned into plasma. Since the metal windows 2 are insulated from each other and divided as the divided portions 22, the induced current generated on the upper surface of the metal windows 2 is suppressed from becoming an eddy current that only loops on the upper surface. , eddy currents passing through the lower surface of the metal window 2 (that is, the lower surface of each divided portion 22). In addition, by arranging a plurality of coil-shaped antenna segments each formed so that the winding axis is parallel to the upper surface of the metal window 2 in the circumferential direction of the metal window 2 and supplying a high frequency to each antenna segment, the above-mentioned Plasma may be generated by forming an eddy current passing through the lower surface of the divided portion 22 . The metal window 2, the antenna 31, the matching box 32 and the high frequency power source 33, which is the second high frequency power source, constitute a plasma forming mechanism.

Next, the configuration of the processing container 12 will be described. A side wall of the processing container 12 is formed with a transfer port 15 for the substrate G that is opened and closed by a gate valve 14 . A stage 4 on which the substrate G is placed is provided in the central portion of the bottom surface of the processing container 12 . A plurality of exhaust ports 16 are opened around the stage 4 on the bottom surface. By exhausting the gas from the exhaust port 16 by the exhaust mechanism 17, the above-described plasma is generated and the substrate G is processed while the inside of the processing container 12 is in a vacuum atmosphere.

2 and 3, which are longitudinal side views of the stage 4, will also be referred to. 2 and 3 show longitudinal side surfaces of the insulator ring 5 and the focus ring 6, which will be described later, at different positions. As for the stage 4, the side peripheral surface from the upper surface to the lower surface is configured as a flat prism, and the peripheral edge forms a rectangle along the circumference of the substrate G to be placed in a plan view. The stage 4 has a lower electrode 43 that is a metal block.

Further, the upper side of the stage 4 is configured as an electrostatic chuck 44 , and the electrostatic chuck 44 is laminated on the lower electrode 43 . The electrostatic chuck 44 is composed of a chucking dielectric film 45 and a chucking electrode 46 embedded in the chucking dielectric film 45 . A DC power supply 47 is connected to the chuck electrode 46 so that the electrostatic chuck 44 can obtain an electrostatic attraction force to the substrate G. As shown in FIG. A high frequency power supply 49 is connected to the lower electrode 43 via a matching box 48 . A high-frequency power source 49, which is a first high-frequency power source, is for applying a bias to the substrate G placed on the electrostatic chuck 44. By supplying high-frequency power to the lower electrode 43, ions forming plasma are generated on the substrate G. be drawn into

A temperature-controlled fluid flow path is formed in the lower electrode 43 . Further, a heat transfer gas flow path is formed that faces the electrostatic chuck 44 via the lower electrode 43 and opens to the upper surface of the electrostatic chuck 44, and the substrate G and the stage 4 are connected via the heat transfer gas. Heat transfer takes place between In order to transfer the substrate G between the transport mechanism outside the etching apparatus 1 and the electrostatic chuck 44 , lift pins penetrate the stage 4 in the vertical direction and protrude from the surface of the electrostatic chuck 44 . is provided in The flow path of the fluid for temperature adjustment, the flow path of the heat transfer gas, and the lift pins are omitted from the drawing.

A support member 40 made of an insulating material is provided on the bottom surface of the processing container 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 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 square ring that surrounds the entire side circumference of the stage 4, and suppresses abnormal discharge on the side circumference surface of the stage 4 when plasma is formed in the processing space 13. have a role. 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 a height position lower than the lower surface of the lower electrode 43 .

The insulator ring 5 has a rectangular shape when viewed in longitudinal section, and is composed of insulators forming 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 .

Each corner of the side surface of the lower electrode 43 is partially cut out in the vertical direction to form a recess 53 (see FIG. 3). A supporting member 54 is provided. A part of the support member 54 protrudes outside the lower electrode 43 , fits in a notch 55 in the upper surface of the inner peripheral side corner of the insulator ring 5 , and is supported by the insulator ring 5 . Two pins 56 directed upward are provided at a portion of the supporting member 54 protruding from the lower electrode 43 (only one is shown in FIG. 3), and the pins 56 are rectangular in plan view. It is located near each of the two sides of the lower electrode 43 formed. 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 .

A square ring-shaped spacer 57 which is an insulator is provided on the bottom surface of the processing container 12 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 .

A focus ring 6 which is an insulator is provided on the insulator ring 5 and the spacer 57 . 4 shows the lower surface of the focus ring 6. As shown in FIG. The focus ring 6, which is an upper ring, is a rectangular ring-shaped member that surrounds the outer side of the upper portion of the stage 4 over the entire circumference, and is provided so that its upper surface faces the processing space 13. A lower surface is provided facing (parallel to) 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 located on the inner peripheral edge of the insulator ring 5 and the outer peripheral edge of the spacer 57, respectively. Therefore, the focus ring 6 does not overlap the stage 4 in plan view. The top surface of the focus ring 6 is positioned slightly below the top surface of the electrostatic chuck 44 . On the other hand, the upper surface of the electrostatic chuck 44 is used as a mounting area, and the substrate G is mounted so that its peripheral edge is located slightly outside the peripheral edge of the stage 4 described above. Therefore, a slight gap is formed between the rear surface of the peripheral portion of the substrate G and the upper surface of the inner peripheral portion of the focus ring 6 .

The focus ring 6 is composed of four elongated rectangular plates 61 . As described above, the focus ring 6 is a rectangular ring and is configured to form a circumference of a rectangle. respectively. Two of the four plates 61 are therefore longer than the other two plates 61 . Each plate 61 has a pair of opposing longitudinal sides and a pair of opposing end sides orthogonal to the longitudinal direction. It also has an upper surface facing the processing space 13 and a lower surface facing the upper surface. Describing the positional relationship between the plates 61 in more detail, one plate 61 faces and adjoins the side surfaces of the other two plates 61 on different side surfaces. More specifically, one longitudinal side of one plate 61 abuts one end side of the first other plate 61 . A side surface of one end of one plate 61 is a longitudinal side surface of a second plate 61 that is different from the first other plate that is in contact with the longitudinal side surface. Adjacent. When any two of the four plates 61 adjacent to each other are viewed, one end of the other plate is positioned on the extension line in the length direction of the one plate 61, and the other end of the other plate extends in a direction orthogonal to the length direction of one plate 61 .

Concave portions 62 are formed in the lower surfaces of the four plates 61 on one end side and the other end side in the length direction. The pin 56 of the supporting member 54 described with reference to FIG. 3 is inserted and fitted into the recess 62, and the position of each plate 61 in the lateral direction is fixed, whereby the focus ring 6 is configured. One of the two recesses 62 in one plate 61 has a larger length in the longitudinal direction of the plate 61 than the other recess 62 so as to accommodate expansion and contraction of the plate 61 due to temperature changes. . The pin 56 described above has a role of positioning the plate 61 and also supports the focus ring 6 . Therefore, the inner peripheral edge side of the focus ring 6 is supported by the insulator ring 5 via the pin 56 . Note that the outer peripheral edge side of the focus ring 6 is supported by a spacer 57 .

As shown in FIG. 3, recess 62 of plate 61 is removable from pin 56 . That is, the focus ring 6 is detachably attached to the insulator ring 5 and spacer 57 . It should be noted that the plate 61 may be attached to the insulator ring 5 and the spacer 57 by using fixing tools such as screws in addition to using the fitting between the recess 62 and the pin 56 . It is assumed that the plate 61 can be detached from the insulator ring 5 and the spacer 57 by removing the fixing tool even when the fixing tool is used.

A metal film 63 and an insulator film 64 are formed by thermal spraying, for example, in a region of the lower surface of the focus ring 6 that overlaps with the insulator ring 5 in plan view. The metal film 63 is made of W (tungsten), for example, and the insulator film 64 is made of Y ₂ O ₃ (yttrium oxide), for example. 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 on each of the four plates 61 so as to extend along the length direction of the plate 61 . Since the metal film 63 of one adjacent plate 61 and the metal film 63 of the other plate 61 are separated from each other, when the entire lower surface of the focus ring 6 is viewed, the metal film 63 has a gap at each corner. It is formed in a square annular shape with

The edge of the metal film 63 on the side of the inner peripheral edge of the focus ring 6 and the inner peripheral edge of the focus ring 6 are separated from each other. That is, the metal film 63 is formed apart from the lower electrode 43 . The edge of the metal film 63 on the outer peripheral edge side of the focus ring 6 is located away from the spacer 57 toward the inner peripheral edge of the focus ring 6 and is positioned outside the focus ring 6 relative to the peripheral edge of the substrate G placed on the stage 4 . Located near the periphery. That is, at least a portion of the metal film 63 is located outside the substrate G placed on the stage 4 in plan view. The action of the metal film 63 will be described in detail later, but the metal film 63 acts on the plasma in the processing space 13 by having an electric potential due to the action of the high-frequency power source 49 , and the reaction product generated by the processing of the substrate G is generated on the upper surface of the focus ring 6 . It has a role of preventing deposition on the upper region of the metal film 63 .

The insulator film 64 has a role of preventing abnormal discharge (arcing) from occurring due to contact between the metal film 63 and the plasma that has entered the lower surface of the focus ring 6 from the processing space 13 . For that purpose, the insulator film 64 covers the entire metal film 63 so that the metal film 63 is not exposed, and the edges of the metal film 63 and the insulator film 64 are separated from each other. Therefore, the insulator film 64 is also formed along the circumference of the focus ring 6, and more specifically, is formed in a rectangular annular shape. The inner peripheral edge of the annular insulator film 64 is aligned with, for example, the position of the inner peripheral edge of the focus ring 6 , and the outer peripheral edge of the insulator film 64 is positioned away from the spacer 57 toward the stage 4 . are doing. 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, the insulator films 64 formed on three of the four plates 61 are shown with many dots, and the insulator films 64 on the other one plate 61 (lower in FIG. 4) are indicated by dots. indicates its edge with a dashed line. In the other one plate 61, the metal film 63 is shaded.

The reason for providing the above metal film 63 and its effect will be described in detail. First, a description will be given assuming that the focus ring 6 is not provided with the metal film 63 . The lower electrode 43, which constitutes the stage 4 and to which a high frequency for bias formation is applied, has a flat and vertical outer peripheral surface. Since such an outer peripheral surface is provided, a part of the outer peripheral surface of the lower electrode 43 forms an outwardly protruding flange, as shown in Patent Documents 2 and 3, and the focus ring 6 and the flange are arranged in plan view. It is different from the overlapping configuration. Since the flange (part of the lower electrode 43 ) and the focus ring 6 do not overlap each other, 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 attraction of ions, which are one of the active species of the plasma, toward the upper surface of the focus ring 6, which is the effect 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.

On the other hand, a reaction product is 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 effect on the upper surface of the focus ring 6 is relatively small as described above, the reaction product is deposited along the upper surface of the focus ring 6 to form an annular film 60 (to be illustrated later). and the substrate G are relatively close to each other. If this happens, particles generated by peeling of the annular film 60 may adhere to the substrate G and reduce the yield.

The metal film 63 has the role of preventing deposition of reaction products near the substrate G and making the distance between the annular film 60 and the substrate G relatively large. Specifically, when the 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. The ions are drawn toward the lower electrode 43 and the substrate G is processed.

Although the metal film 63 and the lower electrode 43 are separated from each other, the metal film 63 is positioned near the lower electrode 43 . Therefore, the space between the metal film 63 and the lower electrode 43 is regarded as a capacitive component, and part of the high frequency is supplied from the lower electrode 43 to the metal film 63 when the high frequency is supplied to the lower electrode 43. and a potential is generated in the metal film 63 . 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 etchability is relatively high in the region immediately above the metal film 63 and in the vicinity thereof, and the formation of the annular film 60 of deposits in these regions is prevented. That is, deposition of reaction products on the upper surface of the focus ring 6 in the vicinity of the substrate G is prevented as described above.

By the way, it is assumed that the metal film 63 is closer to the stage 4 side than the example described above and is in contact with the lower electrode 43 . In this case, since the metal film 63 is close to the edge of the insulator film 64, the contact portion between the metal film 63 and the lower electrode 43 is moved from the processing space 13 to the lower surface of the focus ring 6, and near the contact portion. It is considered that the insulation against the plasma flowing into the inner surface becomes insufficient, and abnormal discharge is likely to occur. Therefore, in order to prevent the discharge, the structure for shielding the plasma at the contact portion may become complicated. From a different point of view, by arranging the metal film 63 away from the lower electrode 43, it is possible to prevent the discharge with a simple device configuration in which the insulator film 64 covering the entire metal film 63 is provided. , is preferably such an arrangement.

Further, if the metal film 63 is in contact with the lower electrode 43, part of the power of the high-frequency power supply 49 supplied toward the lower electrode 43 used for processing the substrate G is used for the processing of the substrate G. more dispersedly supplied to the metal film 63 which contributes less to . Therefore, power loss to the lower electrode 43 occurs. Since the volume of the metal film 63 is smaller than that of the lower electrode 43, the amount of power loss is small. is preferably located away from the lower electrode 43 .

In addition, in this configuration in which the metal film 63 is provided, the position where the annular film 60 of the deposit is formed is controlled by the range of the metal film 63 provided. Supposing, in the device having the configuration in which the lower electrode 43 is provided with a flange, the width of the flange is changed for adjustment or testing of the device to control the position where the annular film 60 of the deposit is formed. do. Since the lower electrode 43 is a relatively large member, such a change in shape may be large-scale. Become. In other words, the change in the design of the apparatus is large-scale, which may increase the cost and labor of the apparatus. However, according to the present configuration in which the metal film 63 is provided, since the positions of the metal film 63 and the insulator film 64 can be changed, the design change of the device is limited to a small scale, so that cost and labor can be suppressed.

Further, since the focus ring 6 provided with the metal film 63 and the insulator film 64 is detachable from the insulator ring 5 and the spacer 57 as described above, the position of the annular film 60 of the deposit can be controlled. Easy. For example, by preparing a plurality of focus rings 6 in which the metal film 63 is formed at different positions and using the focus rings 6 interchangeably, the positions can be controlled.

By the way, as described above, the metal film 63 is formed only partially in the width direction of the focus ring 6 . The center position of the metal film 63 in the width direction (indicated as P2 in FIG. 2) is positioned closer to the stage 4 than the center position in the width direction of the focus ring 6 (indicated as P1 in FIG. 2). By forming the metal film 63 in this manner, the metal film 63 and the insulator film 64 covering the metal film 63 are formed while keeping the position where the reaction product is deposited relatively large away from the substrate G on the stage 4 . This is advantageous in that it is possible to prevent the formation range of the .

The etching apparatus 1 also includes a control unit 10 (see FIG. 1), and the control unit 10 includes a program. The program incorporates commands (steps) to process the substrate G according to the procedure described later by transmitting control signals to each part of the etching apparatus 1 . Specifically, each operation such as turning on and off the high-frequency power sources 33 and 49 and the DC power source 47, supplying the processing gas from the gas supply unit 27, and adjusting the vacuum pressure in the processing space 13 by exhausting the exhaust mechanism 17 is performed by the above control. Controlled by sending a signal. The above program is stored in a storage medium such as a compact disc, hard disk, or DVD, and installed in the control unit 10 .

Next, the operation of the etching apparatus 1 will be explained. 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-controlled stage 4 via a lift pin (not shown), and the substrate G is heated via a heat transfer gas. While being adjusted, the inside of the processing container 12 is evacuated to a desired pressure vacuum atmosphere. Then, the processing gas is discharged from the shower plate 24 into the processing space 13, and the high-frequency power sources 33 and 49 are turned on. The above-described eddy current is formed in the metal window 2, and the processing gas becomes plasma. At that time, the substrate G is attracted by the electrostatic chuck 44 on the stage 4 .

FIG. 5 is a schematic diagram showing the state of plasma formation, and arrows indicate ions in the plasma. An electric field is formed on the lower electrode 43 by the high frequency power supplied 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. Assume that the reaction product generated at that time adheres 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 this region and its vicinity are etched. Therefore, the reaction products cannot deposit in such relatively highly etchable areas, but only outside those areas. As a result, the inner edge of the annular film 60 formed by deposits is prevented from being positioned near the substrate G. FIG.

After that, the discharge of the processing gas from the shower plate 24 is stopped, and the high-frequency power sources 33 and 49 are turned off. It is transported to the outside of the processing container 12 . As described above, according to the etching apparatus 1, the position of the annular film 60 of deposits generated by the processing of the substrate G can be separated from the substrate G by a relatively large distance. is suppressed.

As for the focus ring 6, the entire metal film 63 formed for each plate 61 is covered with the insulator film 64 to reliably prevent abnormal discharge. The metal film 63 is formed in an annular shape with a gap when viewed as a whole. Compared to the case where the metal film 63 is not provided, if the formation position of the annular film 60 of deposits 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 can be formed in this way. may be discontinuous. However, if the metal film 63 forms an unbroken ring, the entire circumference of the substrate G can be more reliably separated from the annular film 60 of the deposit. There may be. That is, the formation of the metal film 63 along the circumference of the focus ring 6 (upper ring) means that the metal film 63 is formed in an annular shape with a break, and the metal film 63 is formed in an annular shape without a break. including any of the following:

Although the metal film 63 and the insulator film 64 are formed by thermal spraying, any method may be used for forming the film. good. Further, the metal forming the metal film 63 is not limited to tungsten, and any metal can be used as long as the effect described above is exhibited. The insulator film 64 is also not limited to Y ₂ O ₃ and any insulator can be used as long as it can prevent the occurrence of abnormal discharge due to the provision of the metal film 63 .

By the way, in the above example, the metal film 63 is provided as the metal member in order to control the position where the annular film 60 of the deposit is formed. It may be a metal plate. In providing such a metal plate instead of the metal film 63, for example, a recess is provided in the lower surface of the focus ring 6 and the metal plate is arranged 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 filled with the adhesive or filler. cover.

Incidentally, the recess in which the metal plate is provided and which is filled with the 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, although the metal member is provided between the focus ring 6 and the insulator ring 5, the metal member may be fixed to any one of the focus ring 6 and the insulator ring 5. good.

Moreover, although an example in which the present technology is applied to an etching apparatus has been shown, the present technology is not limited to being applied to such an apparatus, and may be applied to, for example, a film forming apparatus. Further, the shape of the substrate to be processed is not limited to the above-described rectangular substrate in plan view, and may be circular. In that case, the stage 4 may be circular in plan view in accordance with the shape of the substrate, and each member of the focus ring 6, insulator ring 5, metal film 63 and insulator film 64 may be annular in plan view. It should be noted that even in the case of such an annular ring, the metal film 63 may or may not have a break.

In addition, the application of the present technology is not limited to a device that forms plasma by arranging the metal window 2 and the antenna 31 above the stage 4 to form an eddy current as described above. For example, a shower head forming an upper electrode paired with the lower electrode 43 is arranged above the stage 4 so as to face the stage 4 . A high frequency power for plasma formation can be supplied from the high frequency power supply 33 to the shower head. That is, the present technology may be applied to a parallel plate type plasma forming apparatus.

In addition, the embodiment disclosed this time should be considered as an example and not restrictive in all respects. The above-described embodiments may be omitted, substituted, modified, and combined in various ways without departing from the scope and spirit of the appended claims.

〔Evaluation test〕
An 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 etching apparatus 1 described above, and the state of adhesion of deposits to the focus ring 6 after the etching was examined. A difference between this test apparatus and the etching apparatus 1 is that two of the four plates 61 constituting the focus ring 6 are not provided with the metal film 63 and the insulator film 64 on the two adjacent to each other. Further, the other two adjacent plates 61 are formed with the metal film 63 and the insulator film 64 in the same manner as in the etching apparatus 1, but the thickness of the insulator film 64 differs between the plates 61. .

As described above, the insulator film 64 serves to prevent abnormal discharge by covering the metal film 63 . From the viewpoint of suppressing the manufacturing cost of the device, it is preferable that the thickness of the insulator film 64 is small. There is a risk that it will be lost. In addition to confirming the function and effect of the metal film 63, this evaluation test aims to verify the appropriate thickness of the insulator film 64 as well.

Specifically, in the test apparatus, the thickness of the insulator film 64 on one plate 61 was set to 100 μm, and the thickness of the insulator film 64 on the other plate 61 was set to 150 μm. The thickness of the metal film 63 covered with these insulator films 64 was set to 50 μm. The metal film 63 and the insulator film 64 are composed of W and Y ₂ O ₃ , respectively, as in the examples given in the embodiments. Also, the metal film 63 is formed to have a width of 26.5 cm. The edge of the metal film 63 on the inner peripheral side of the focus ring 6 is separated from the inner peripheral edge of the focus ring 6 by 2 mm. The insulator film 64 is formed to have a width of 30.5 mm. As described in the embodiment, the end of the insulator film 64 on the inner peripheral edge side is formed so as to be aligned with the inner peripheral edge of the focus ring 6 .

The processing conditions for the evaluation test are described. A mixed gas of CF ₄ gas and O ₂ gas was used as the processing gas, the pressure in the processing space 13 during processing was 10 mTorr (1.33 Pa), and the power supplied to the high frequency power sources 33 and 49 was 20 kW each. Although not described in the embodiment, the metal window 2 and the side wall of the processing container 12 are provided with temperature control mechanisms such as heaters and cooling channels so as to control the temperature. The temperatures of the metal window 2 and the processing container 12 were set to 80°C. Moreover, the temperature of the stage 4 was set to 15°C. The etching processing time for the substrate G was set to 2 hours. As the substrate G, a substrate made of polyimide was used in order to facilitate confirmation of adhesion of deposits. That is, the deposit was produced by etching polyimide.

Observation of the upper surface of the focus ring 6 after etching revealed that an annular film 60 was formed by deposits, and the annular film 60 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 . The distance was 18 mm on the two plates 61 without the metal film 63, and 28 mm on the two plates 61 with the metal film 63 formed thereon. Therefore, from this evaluation test, it was confirmed that the provision of the metal film 63 provided 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 deposit.

When the lower surfaces of the two plates 61 provided with the metal film 63 and the insulator film 64 after etching were observed, no trace of abnormal discharge was found. It was confirmed that there is no problem with both 100 μm and 150 μm. Therefore, from this evaluation test, it was confirmed that the thickness of the insulator film 64 should be, for example, 100 μm or more, and it was shown that 100 μm, which is the smallest thickness in that range, is preferable. .

G Substrate 1 Etching device 12 Processing vessel 13 Processing space 2 Metal window 33 High frequency power source 4 Stage 5 Insulator ring 63 Metal film

Claims (8)

a processing container having a processing space for storing substrates therein;
a plasma forming mechanism for forming a plasma in the processing space to process the substrate;
a stage provided in the processing space for mounting 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 is an insulator that surrounds the stage so as not to overlap the stage in a plan view and is provided facing the processing space;
a lower ring, which is a ring-shaped insulator provided below the upper ring to support the upper ring and surrounds the side circumference of the stage;
a metal member provided between the upper ring and the lower ring for drawing the plasma into the upper ring and spaced from the stage and formed along the circumference of the upper ring;
A substrate processing apparatus comprising: 2. The substrate processing apparatus according to claim 1, wherein said metal member is provided on said upper ring. 3. The substrate processing apparatus according to claim 2, wherein said metal member is a metal film, and an insulator film covering said metal film is provided. 4. The substrate processing apparatus according to claim 3, wherein the center position of the metal film in the width direction is located closer to the stage than the center position of the upper ring in the width direction. 5. The substrate processing apparatus according to claim 1, wherein said plasma forming mechanism comprises an antenna provided above said stage, and a second high frequency power supply for supplying high frequency to said antenna. 6. The substrate processing apparatus according to claim 1, wherein said upper ring is detachable from said lower ring. storing the substrate in a processing container having a processing space therein;
forming plasma in the processing space by a plasma forming mechanism to process the substrate;
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 from a first high frequency power source;
an upper ring, which is an insulator surrounding the stage so as not to overlap the stage in a plan view and facing the processing space, provided below the upper ring to support the upper ring; A lower ring, which is a ring-shaped insulator surrounding the side circumference of the stage, is provided between the metal member separated from the stage and formed along the circumference of the upper ring to direct the plasma to the upper ring. the process of drawing in;
A substrate processing method comprising: Forming the plasma to process the substrate includes:
8. The substrate processing method according to claim 7, further comprising the step of supplying a high frequency wave from a second high frequency power source forming said plasma forming mechanism to an antenna provided above said stage forming said plasma forming mechanism.

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