JP5207996B2 - Substrate mounting table and substrate processing apparatus - Google Patents

Description

  The present invention relates to a substrate mounting table and a substrate processing apparatus for mounting a substrate to be processed such as a semiconductor wafer or an FPD (flat panel display) substrate.

  In the manufacturing process of a flat panel such as a semiconductor device or a liquid crystal display device, for example, a plasma etching apparatus is used as a substrate processing apparatus in order to perform a processing process such as an etching process or a film forming process on a target substrate such as a semiconductor wafer or a glass substrate. Or a plasma processing apparatus such as a plasma CVD film forming apparatus is used. In a plasma processing apparatus, a substrate to be processed, such as a wafer, is placed on a mounting table disposed in a processing chamber, a processing gas is introduced while the processing chamber is decompressed, and high frequency power is applied to an electrode in the processing chamber to generate By generating plasma, processes such as etching and film formation are performed on the wafer surface.

  The mounting table of such a plasma processing apparatus includes a susceptor that constitutes the mounting table body, a temperature adjusting unit that adjusts the temperature of the wafer by adjusting the temperature of the susceptor, an electrostatic chuck that holds and holds the wafer on the susceptor, and the like. Consists of. In such a mounting table, the peripheral portion of the susceptor is fixed in the processing chamber with a fastening member such as a screw or a bolt in order to facilitate removal during maintenance or the like (see, for example, Patent Documents 1 and 2). ).

Japanese Patent Laid-Open No. 05-217951 Japanese Patent Laid-Open No. 06-53174

  By the way, when plasma is formed in the processing chamber by the plasma processing apparatus as described above, the mounting table is heated by the heat input of the plasma, and the susceptor is thermally expanded. In this case, as described above, in the configuration in which the susceptor is fixed with a fastening member such as a screw, there is a portion where the fastening member is pressed and a part in the height direction of the susceptor is pressed by the fastening member and cannot be thermally expanded freely. On the other hand, in the portion where there is no fastening member, it can be freely thermally expanded in the height direction of the susceptor.

  For this reason, in the peripheral part of a susceptor, the difference of thermal expansion amount generate | occur | produces between the part with a fastening member, and a part without. As a result, the height of the upper surface of the susceptor partially changes, and the upper surface of the mounting table may be bent like a swell. In this way, if the surface of the susceptor, that is, the upper surface of the mounting table is bent, the surface temperature distribution of the wafer mounted thereon is affected, so that the in-plane uniformity of the plasma processing is lowered. .

  Therefore, the present invention has been made in view of such a problem, and the object of the present invention is to provide a surface between a portion having a fastening member and a portion having no fastening member on the surface of the substrate mounting table fixed by the fastening member. An object of the present invention is to provide a substrate mounting table and a substrate processing apparatus capable of preventing the occurrence of bending caused by the difference in thermal expansion amount.

  In order to solve the above-described problems, according to one aspect of the present invention, a substrate mounting table that is provided in a processing chamber of a substrate processing apparatus and that mounts a substrate to be processed, the susceptor constituting the mounting table main body, There is provided a substrate mounting table comprising: a fastening member for fixing a peripheral edge portion of the susceptor in the processing chamber; and an annular groove provided around the side surface of the susceptor.

  In order to solve the above problems, according to another aspect of the present invention, there is provided a substrate processing apparatus for performing plasma processing on a substrate to be processed, a processing chamber configured to be depressurized, and a lower portion of the processing chamber. A substrate mounting table on which the substrate to be processed is mounted, a gas supply unit that supplies a processing gas to the processing chamber, and a gas supply unit that is disposed above the processing chamber and transfers the gas from the gas supply unit to the substrate A gas introduction part that introduces a substrate to be processed on the mounting table, and the substrate mounting table includes a susceptor that constitutes a mounting table main body, a fastening member that fixes a peripheral portion of the susceptor in the processing chamber, There is provided a substrate processing apparatus comprising an annular groove provided around the side surface of the susceptor over the entire circumference.

  According to the present invention as described above, by providing the annular groove around the susceptor, the peripheral portion of the susceptor is fastened by the fastening member and the lower portion including the portion in which the thermal expansion is suppressed and the upper portion that freely thermally expands. Can be divided into parts. As a result, it is possible to prevent the occurrence of bending on the surface of the substrate mounting table due to the difference in the amount of thermal expansion between the portion with and without the fastening member. In particular, according to the present invention, it is possible to suppress the bending of the peripheral portion where the difference in height increases due to thermal expansion, and thus it is possible to more effectively suppress the bending generated on the surface of the susceptor.

  That is, in the peripheral portion of the susceptor, the displacement in the height direction is accommodated in the annular groove even if there is a difference in the amount of thermal expansion between the portion with and without the screw in the portion below the annular groove. The upper part is not affected. In addition, since the portion above the annular groove has the same thickness over the entire periphery, the amount of thermal expansion is also the same. Therefore, since no change occurs in the height direction on the upper surface of the peripheral portion of the susceptor, it is possible to prevent the occurrence of bending caused by the change.

  Moreover, it is preferable that the said annular groove is the depth extended to the inside rather than the site | part in which the said fastening member was provided at least toward the inside from the side surface of the said susceptor. Moreover, it is preferable that the annular groove is formed at a higher portion than a portion fastened by the fastening member. According to this, the part currently pressed down by the fastening member among the peripheral parts of a susceptor can be divided below the annular groove. Thereby, it is possible to effectively prevent the occurrence of the bending caused by the difference in thermal expansion amount between the portion with the fastening member and the portion without the fastening member on the surface of the substrate mounting table.

  The susceptor is configured such that an outer diameter of the susceptor is larger than an outer diameter of the substrate to be processed, and the fastening member is inserted into a hole formed perpendicular to a portion protruding outward from the substrate to be processed. It is preferable that the annular groove is formed across the hole in a portion protruding outward from the substrate to be processed. In this case, a plurality of the hole portions may be formed along a portion protruding outward from the substrate to be processed, and a fastening member may be disposed in each hole portion to fix the susceptor.

  Also by this, the part pressed down by the fastening member among the peripheral parts of the susceptor can be divided below the annular groove. Thereby, it is possible to effectively prevent the occurrence of the bending caused by the difference in thermal expansion amount between the portion with the fastening member and the portion without the fastening member on the surface of the substrate mounting table. Further, the outer diameter of the susceptor is made larger than the outer diameter of the substrate to be processed, and the annular groove is provided at a portion protruding outward from the substrate to be processed, so that the curved surface of the upper edge portion of the susceptor formed by thermal expansion is provided. Can be relaxed. Thereby, since a contact surface with a to-be-processed substrate can be made outside, a to-be-processed substrate can be mounted more stably.

  The annular groove may have an inclined surface that inclines from the side surface of the susceptor toward the inside, and a plurality of the annular grooves may be provided side by side along the vertical direction on the side surface of the susceptor.

  According to the present invention, in the substrate mounting table fixed by the fastening member, by providing an annular groove around the substrate mounting table, the difference in the thermal expansion amount between the portion with the fastening member on the surface of the substrate mounting table and the portion without the fastening member can be reduced. It is possible to prevent the bending caused by the occurrence.

It is sectional drawing which shows the structure of the plasma processing apparatus concerning embodiment of this invention. It is the figure which looked at the mounting base shown in FIG. 1 from the upper side. It is action | operation explanatory drawing of the mounting base shown in FIG. It is operation | movement explanatory drawing of the mounting base concerning a comparative example, Comprising: It is a case where the clamping position by a screw is low. It is operation | movement explanatory drawing of the mounting base concerning a comparative example, Comprising: It is a case where the clamping position by a screw is high. It is a perspective view of a susceptor without an annular groove concerning a comparative example. It is operation | movement explanatory drawing of the mounting base concerning this embodiment. It is a perspective view of a susceptor with an annular groove according to the present embodiment. It is operation | movement explanatory drawing of the mounting base concerning a comparative example, Comprising: It is a case where the diameter of a susceptor is small. It is operation | movement explanatory drawing of the mounting base concerning a comparative example, Comprising: It is a case where the diameter of a susceptor is large. It is operation | movement explanatory drawing of the mounting base concerning this embodiment. It is sectional drawing which shows the modification of the annular groove in this embodiment. It is sectional drawing which shows the other modification of the annular groove in this embodiment.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

(Substrate processing equipment)
First, an embodiment of a substrate processing apparatus to which a substrate mounting table according to the present invention can be applied will be described with reference to the drawings. Here, as an example of the substrate processing apparatus, a plasma processing apparatus that performs plasma processing such as etching and film formation on a semiconductor wafer (hereinafter also simply referred to as “wafer”) W mounted on a substrate mounting table will be described. explain. FIG. 1 is a longitudinal sectional view showing a schematic configuration of the plasma processing apparatus according to the present embodiment. FIG. 2 is a view of the mounting table as viewed from above, and the sectional view of the mounting table shown in FIG. 1 corresponds to the AA sectional view shown in FIG.

  As shown in FIG. 1, the plasma processing apparatus 100 includes a processing chamber (chamber) 102 formed in a cylindrical shape (for example, cylindrical shape) made of metal (for example, aluminum). Note that the shape of the processing chamber 102 is not limited to a cylindrical shape. For example, a rectangular tube shape (for example, a box shape) may be used. The processing chamber 102 is grounded. At the bottom of the processing chamber 102, a mounting table 200 is disposed as a lower electrode on which the wafer W is mounted. A shower head 110 serving as an upper electrode disposed in parallel to the mounting table 200 is provided on the ceiling of the processing chamber 102.

  A first high-frequency power source 150 is connected to the mounting table 200 as the lower electrode via a matching unit 152, and power having a frequency higher than that of the first high-frequency power source 150 is output to the shower head 110 as the upper electrode. A second high frequency power supply 160 is connected via a matching unit 162. A high pass filter 154 is connected to the mounting table 200, and a low pass filter 164 is connected to the shower head 110.

  The mounting table 200 is formed in a substantially cylindrical shape as shown in FIG. In addition, the shape of the mounting table 200 is not limited to a cylindrical shape. For example, a prismatic shape (for example, a polygonal prism shape) may be used. Details of the specific configuration of the mounting table 200 will be described later.

  Above the mounting table 200, a shower head 110 as a gas introduction part that functions as an upper electrode is disposed so as to face the parallel with the mounting table 200. The shower head 110 is attached to the ceiling portion of the processing chamber 102 via a shield ring 112 that covers the peripheral edge portion thereof. The ceiling portion of the processing chamber 102 is configured to be openable as a lid portion, and a seal member 114 such as an O-ring is provided between the lid portion and the side wall to maintain airtightness. The shower head 110 has a diffusion chamber 116 therein, and a plurality of discharge holes 118 for discharging a processing gas are formed on the lower surface facing the mounting table 200.

  A gas supply unit 120 is connected to the shower head 110. The gas supply unit 120 is configured as shown in FIG. That is, a gas inlet 121 is formed in the upper part of the shower head 110, and a gas supply source 122 is connected to the gas inlet 121 via a gas supply pipe 123. In the middle of the gas supply pipe 123, a flow rate controller for controlling the flow rate of the processing gas, for example, a mass flow controller 124 and an opening / closing valve 126 are interposed. According to such a gas supply unit 120, the processing gas from the gas supply source 122 is controlled to a predetermined flow rate by the mass flow controller (MFC) 124 and is supplied from the gas inlet 121 to the shower head 110. Then, the processing gas diffuses in the diffusion chamber 116 of the shower head 110 and is supplied into the processing chamber 102 from each discharge hole 118.

  In FIG. 1, the gas supply unit 120 is represented by a single gas line for the sake of simplicity, but the gas supply unit 120 is not limited to supplying a processing gas of a single gas type. A plurality of gas species may be supplied as the processing gas. In this case, a plurality of gas supply sources may be provided to form a plurality of gas lines, and a mass flow controller may be provided in each gas line.

As a processing gas supplied into the processing chamber 102 by such a gas supply unit 120, for example, a halogen-based gas containing F, Cl or the like is used in etching. Specifically, when etching a silicon oxide film such as a SiO ₂ film, CHF ₃ gas or the like is used as a processing gas. Further, when etching a high dielectric thin film such as HfO ₂ , HfSiO ₂ , ZrO ₂ , ZrSiO ₄ , BCl ₃ gas is used as a processing gas, or a mixed gas of BCl ₃ gas and O ₂ gas is used as a processing gas. Used.

  The shower head 110 according to the present embodiment is a so-called premix type in which a processing gas and an additive gas are mixed in advance and supplied into the processing chamber 102. Instead of the shower head 110, each gas is processed independently. You may make it provide the post mix type shower head supplied in the chamber 102. FIG.

  A gate valve 106 for opening and closing the substrate loading / unloading port 104 is provided on the side wall of the processing chamber 102. An exhaust port is provided below the side wall of the processing chamber 102, and an exhaust device 109 including a vacuum pump (not shown) is connected to the exhaust port via an exhaust pipe 108. By exhausting the inside of the processing chamber 102 by the exhaust device 109, the inside of the processing chamber 102 can be maintained in a predetermined vacuum atmosphere during the plasma processing.

  A control unit (overall control device) 300 is connected to the plasma processing apparatus 100, and each unit of the plasma processing apparatus 100 is controlled by the control unit 300. In addition, the control unit 300 includes an operation unit 310 including a keyboard for an operator to input commands for managing the plasma processing apparatus 100, a display for visualizing and displaying the operating status of the plasma processing apparatus 100, and the like. It is connected.

  Furthermore, the control unit 300 stores a program for realizing various processes executed by the plasma processing apparatus 100 under the control of the control unit 300, recipe data necessary for executing the program, and the like. Is connected.

  The storage unit 320 stores, for example, a recipe for performing necessary processing such as cleaning processing in the processing chamber 102 in addition to a plurality of process processing recipes for executing wafer process processing. These recipes are a collection of a plurality of parameter values such as control parameters and setting parameters for controlling each part of the plasma processing apparatus 100. For example, the process processing recipe has parameter values such as a processing gas flow rate ratio, a processing chamber pressure, and high-frequency power.

  These recipes may be stored in a hard disk or semiconductor memory, and set in a predetermined position of the storage unit 320 while being stored in a portable computer-readable storage medium such as a CD-ROM or DVD. You may come to do.

  The control unit 300 executes a desired process in the plasma processing apparatus 100 by reading out a desired process processing recipe from the storage unit 320 based on an instruction from the operation unit 310 and controlling each unit. The recipe can be edited by an operation from the operation unit 310.

(Configuration example of mounting table)
Next, a specific configuration of the mounting table 200 according to the present embodiment will be described in detail with reference to the drawings. FIG. 3 is a diagram for explaining the operation of the mounting table 200 shown in FIG. In FIG. 3, a part of the configuration shown in FIG. 1 is omitted. As shown in FIG. 1, the mounting table 200 is attached to the bottom of the processing chamber 102 via an insulating plate 202 such as ceramic. The mounting table 200 mainly includes a susceptor 210 that constitutes a lower electrode main body and a susceptor support table 220 that supports the lower electrode body below. The susceptor 210 and the susceptor support 220 are made of, for example, aluminum.

  The susceptor support 220 is provided with a temperature control medium flow path 222 as an example of a temperature adjustment unit. A temperature control medium from a temperature control medium supply source (not shown) is introduced into the temperature control medium flow path 222 through the introduction pipe 224, circulates through the temperature control medium flow path 222, and is discharged from the discharge pipe 226. Examples of the temperature control medium include water and Galden (registered trademark). By circulating such a temperature control medium through the temperature control medium flow path 222, the susceptor 210 can be controlled to a desired temperature, for example, around 60 ° C.

  An electrostatic chuck 212 is formed on the upper surface of the susceptor 210 so as to have approximately the same area as the wafer area. The electrostatic chuck 212 is formed, for example, by sandwiching a conductive film 214 such as copper foil between two polymer polyimide films or ceramics in an insulating state, and the conductive film 214 is connected to a DC high voltage power source 216. . Therefore, by applying a high voltage to the conductive film 214, the wafer W can be attracted and held on the upper surface of the electrostatic chuck 212 by Coulomb force.

  The susceptor support 220 and the susceptor 210 have a gas passage 230 that passes through them to supply a heat transfer gas such as He (back cooling gas) from a heat transfer gas supply source (not shown) to the back surface of the wafer W. Is formed.

  The susceptor support 220 and the susceptor 210 are coupled by a plurality of fastening members such as screws 232. Specifically, as shown in FIG. 2, the susceptor 210 and the susceptor support base 220 are configured to have a diameter larger than the outer diameter of the wafer W, and a screw 232 is provided along the circumferential direction at a portion protruding outward from the wafer W. A hole 234 is formed for inserting the. For example, as shown in FIG. 3, each hole 234 is formed on the susceptor 210 side, and a small-diameter portion 234a into which the screw shaft of the screw 232 can be inserted, and the head of the screw 232 can be inserted by expanding from the small-diameter portion 234a. An enlarged diameter portion 234b and a screw hole 234c formed on the susceptor support base 220 side and screwed with a screw shaft of the screw 232 are formed. The fastening member is not limited to the screw 232 but may be other fastening members such as bolts and claps.

  In the configuration in which the peripheral portion of the mounting table 200 is coupled by a fastening member such as a screw 232 as in the mounting table 200 according to the present embodiment, a part of the height direction is pressed down by the fastening member at a portion where the fastening member is present. In contrast, there are portions that cannot be freely thermally expanded, whereas portions that do not have a fastening member can be freely thermally expanded in the height direction. For this reason, when the mounting table 200 is thermally expanded due to heat input from the plasma when plasma is formed, the height of the peripheral surface of the mounting table changes between the portion with the fastening member and the portion without the fastening member. The surface of 200 may be bent like waviness. In order to prevent this, in this embodiment, an annular groove 240 is provided around the side surface of the mounting table 200 over the entire circumference.

  The mounting table 200 according to the present embodiment will be described in detail while comparing with the mounting table 201 without the annular groove 240. 4 to 6 are explanatory views of the operation of the mounting table 201 without the annular groove 240 as a comparative example. 4 shows a case where the tightening position by the screw 232 is low (when the screw 232 is short), FIG. 5 shows a case where the tightening position by the screw 232 is high (when the screw 232 is long), and FIG. It is a perspective view of the susceptor 210 which does not have. In FIG. 6, the surface state when the susceptor 210 is thermally expanded by generating plasma is schematically shown by a two-dot chain line. 7 and 8 are explanatory views of the operation of the mounting table 200 having the annular groove 240 according to the present embodiment. FIG. 8 is a perspective view of the susceptor 210 with the annular groove 240.

  As shown in FIG. 3, the upper part of the susceptor 210 becomes high temperature by heat input from the plasma P, and the lower part of the susceptor 210 is held at a desired temperature by the temperature adjusting unit. For this reason, a temperature difference (for example, 100 ° C. to 200 ° C.) is generated between the upper portion and the lower portion of the susceptor 210, and the susceptor 210 is thermally expanded in the height direction and the horizontal direction.

First, paying attention to the thermal expansion in the height direction of the susceptor 210, the mounting table 200 with the annular groove 240 according to the present embodiment will be described in comparison with the mounting table 201 without the annular groove 240. As shown in FIG. 4, the amount of thermal expansion in the height direction differs between the peripheral portion of the susceptor 210 where the screw 232 is present (right side of FIG. 4) and where it is not (left side of FIG. 4). This is because, in the portion where the screw 232 is not provided, there is no portion pressed from the lower surface to the upper surface of the susceptor 210, so that the portion expands freely in the height direction. This is because the lower part ₍ hb) from the lower surface of the head of the screw 232 is pressed down, so that it is difficult to thermally expand in the height direction.

That is, in the portion where there is a screw 232, it means that only h _a (upper part from the lower surface of the head of the screw 232) portions not clamped by the screw 232 is free to thermally expand in the vertical direction, the screw of the susceptor 210 There is a difference (h′−h _a ′) in the amount of thermal expansion between the portion with 232 and the portion without 232. Moreover, the higher the clamping position by screws 232 as shown in FIG. 5, freely the height capable of thermal expansion is reduced, the difference in thermal expansion of the parts that no portion of the screw 232 (h'-h _a ') Becomes bigger.

  Although the difference in the amount of thermal expansion is slight, the height of the surface of the susceptor 210 is changed between the portion with the screw 232 and the portion without the screw 232, and thus, for example, the susceptor 210 as shown by a two-dot chain line shown in FIG. Deflection such as undulation occurs along the circumferential direction on the surface of the substrate. This deflection is low in the portion where the screw 232 is present and is high in the portion where the screw 232 is absent. Further, the difference in surface height tends to increase toward the periphery of the susceptor 210, and the difference in surface height tends to decrease toward the center. This tendency is caused because the central portion of the susceptor 210 is hidden by the wafer W and is not easily affected by the heat input of the plasma, whereas the peripheral portion is not hidden by the wafer W, so that the influence of the heat input of the plasma is reduced. It is thought that it is easy to receive.

As described above, when the surface of the susceptor 210 is bent, the surface temperature distribution of the wafer W is affected, so that the in-plane uniformity of the plasma processing is deteriorated. In this respect, if increasing the height of the susceptor 210, among the portion of the screw 232, it is possible to increase relatively the portion h _a freely expand against the portion h _b which is pressed by the screw 232, the screw It is also considered that the difference in thermal expansion between the portion with 232 and the portion without screw 232 can be alleviated. However, this raises the height of the mounting table 200, so that it is necessary to enlarge the processing chamber 102, which leads to an increase in the size of the plasma processing apparatus 100, which is not preferable.

  Therefore, in the present embodiment, the annular groove 240 is formed on the side surface of the susceptor 210 so as to eliminate the difference in the amount of thermal expansion between the portion with the screw 232 and the portion without the screw 232. According to this, it is possible to prevent the bending generated on the surface of the susceptor 210 without changing the height of the mounting table 200. According to the present embodiment, it is possible to more effectively prevent the bending generated on the surface of the susceptor 210 by suppressing the bending of the peripheral portion where the difference in height is increased due to thermal expansion.

Specifically, as shown in FIG. 7, an annular groove 240 is formed on the side surface of the susceptor 210 over the entire circumference. Thus, part no be threaded 232 portions the screw 232 is a susceptor 210 also height by _{h x} in thermal expansion (lower surface until the portion of the susceptor 210 from the bottom of the annular groove 240) lower portion than the annular groove 240 Even if the angle changes, it fits in the annular groove 240. For this reason, the difference (h _x ′ −h _x ″) in the thermal expansion amount between the portion with and without the screw 232 does not affect the portion _hy above the annular groove 240, so that the peripheral portion of the susceptor 210 The height of the surface does not change. Further, since the portion _hy above the annular groove 240 has the same thickness as the portion without the screw 232 of the susceptor 210, the amount of thermal expansion _{hy y in the} height direction is the same.

  According to this, when the susceptor 210 is thermally expanded due to heat input of plasma as shown in FIG. 6, the difference in the surface height of the susceptor 210 can be eliminated, so that the bending generated on the surface of the susceptor 210 is prevented. it can. In this case, since it is possible to suppress the bending of the peripheral portion where the difference in height increases due to thermal expansion, the bending generated on the surface of the susceptor 210 can be more effectively suppressed. Thereby, the temperature of the wafer W can be kept uniform, and the uniformity of plasma processing can be improved.

  Next, paying attention to the horizontal thermal expansion of the susceptor 210 described above, the mounting table 200 with the annular groove 240 according to the present embodiment will be described in comparison with the mounting table 201 without the annular groove 240. 9 and 10 are explanatory views of the operation of the mounting table 201 having no annular groove 240 as a comparative example. FIG. 11 is an operation explanatory view of the mounting table 201 having the annular groove 240 according to the present embodiment. 9 to 11 schematically show the deformation of the susceptor 210 due to thermal expansion. FIG. 9 shows the case of the susceptor 210 having a smaller diameter than the wafer W, and FIG. 10 shows the case of the susceptor 210 having a larger diameter than the wafer W.

  Since the surface of the electrostatic chuck 212 is deformed in the same manner as the surface of the susceptor 210, the deformation of the surface of the susceptor 210 will be described as the deformation of the surface of the electrostatic chuck 212.

  The mounting surface on which the wafer W is mounted is preferably flat so that the entire wafer W can be in close contact. However, in practice, it is difficult to process the mounting surface accurately and flatly. For this reason, normally, the peripheral portion of the wafer W is prevented from floating by processing the center portion of the mounting surface to be slightly concave so that the contact surface with the wafer W is annular. . That is, if the center portion of the mounting surface is convex, the contact surface with the wafer W is near the center portion, so that the peripheral portion of the wafer W may float. On the other hand, if the center portion of the mounting surface is concave, the contact surface with the wafer W is annular in the outer side in the horizontal direction, so that the peripheral portion of the wafer W can be prevented from floating.

  By the way, when the susceptor is thermally expanded, the upper edge portion tends to be a curved surface. In addition, this curved surface tends to be steeper as the mounting table diameter is smaller, and becomes gentler as the mounting table diameter is larger. For example, in the susceptor 210 without the annular groove 240 according to the comparative example, the curved surface generated at the upper edge portion due to thermal expansion becomes sharper when the diameter is smaller than that of the wafer W (FIG. 9). In the case of a large diameter (FIG. 10), the surface becomes loose and the contact surface with the wafer W also moves outward. Therefore, it is preferable that the diameter of the susceptor projects larger than the wafer W.

  In this respect, in the susceptor 210 having the annular groove 240 according to the present embodiment, the curved surface generated at the upper edge due to thermal expansion is further loosened than the case shown in FIG. The surface also moves outward. This is because the amount of thermal expansion in the height direction of the peripheral portion of the susceptor 210 is reduced by forming the annular groove 240. Therefore, according to the mounting table 200 according to the present embodiment, the contact surface with the wafer W can be shifted to the outside, so that the wafer W can be further stabilized.

  As described in detail above, according to the mounting table 200 according to the present embodiment, the annular groove 240 is formed in the peripheral edge portion outside the mounting surface of the wafer W from the side surface to the inside along the circumferential direction. Thus, the difference in thermal expansion between the portion with the screw 232 and the portion without the screw 232 can be eliminated. As a result, it is possible to prevent the bending of the surface of the susceptor 210 without changing the height of the mounting table 200.

  The annular groove 240 is preferably provided at least above the lower surface of the head of the screw 232, and the horizontal depth of the annular groove 240 is at least larger than the diameter-enlarged portion of the hole 234 into which the screw 232 is inserted. It is preferable to be on the center side. Thereby, it is possible to prevent the influence of the thermal expansion of the portion below the annular groove 240 from affecting the portion above the annular groove 240. As a result, a factor causing a difference in the amount of thermal expansion can be wiped off, so that the bending that occurs on the surface of the susceptor 210 can be prevented.

  Further, the shape of the annular groove 240 is not limited to that described above. For example, as shown in FIG. 12, the lower surface of the annular groove 240 may be a slope. Further, as shown in FIG. 13, the annular groove 240 may be composed of a plurality of (for example, two) groove portions 242. The annular groove 240 may be formed so as to cut the outer periphery of one susceptor 210. The susceptor 210 includes an upper susceptor and a lower susceptor, and the lower surface of the upper susceptor and the upper surface of the lower susceptor are formed with cutouts. The annular groove 240 may be formed by the respective notches by joining the upper susceptor and the lower susceptor.

  Moreover, although the said embodiment demonstrated the case where this invention was applied to the mounting base which fixes the susceptor 210 to the susceptor support base 220 with the screw 232, it is not limited to this. For example, you may apply to the mounting base which fixes the susceptor 210 to the insulating board 202 directly. In this case, the temperature adjustment unit may be provided in the susceptor 210.

  The present invention described in detail in the above embodiment may be applied to a system composed of a plurality of devices or an apparatus composed of one device. A medium such as a storage medium storing a software program for realizing the functions of the above-described embodiments is supplied to the system or apparatus, and the computer (or CPU or MPU) of the system or apparatus is stored in the medium such as the storage medium. The present invention can also be achieved by reading and executing the program.

  In this case, the program itself read from the medium such as a storage medium realizes the functions of the above-described embodiment, and the medium such as the storage medium storing the program constitutes the present invention. Examples of the medium such as a storage medium for supplying the program include a floppy (registered trademark) disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a CD-RW, a DVD-ROM, and a DVD-RAM. DVD-RW, DVD + RW, magnetic tape, nonvolatile memory card, ROM, and the like. It is also possible to provide a program downloaded to a medium via a network.

  Note that by executing the program read by the computer, not only the functions of the above-described embodiments are realized, but also an OS or the like running on the computer is part of the actual processing based on the instructions of the program. Alternatively, the case where the functions of the above-described embodiment are realized by performing all the processing and the processing is included in the present invention.

  Furthermore, after a program read from a medium such as a storage medium is written to a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function is determined based on the instructions of the program. The present invention also includes a case where the CPU or the like provided in the expansion board or the function expansion unit performs part or all of the actual processing and the functions of the above-described embodiments are realized by the processing.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the example which concerns. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  For example, the present invention can also be applied to a substrate mounting table of another substrate processing apparatus such as another plasma processing apparatus or a heat treatment apparatus that performs plasma CVD, plasma oxidation, plasma nitridation, sputtering, or the like. Further, the substrate to be processed in the present invention is not limited to a semiconductor wafer, and may be various substrates for flat panel displays, photomasks, CD substrates, printed substrates, and the like.

  The present invention can be applied to a substrate mounting table and a substrate processing apparatus for mounting a substrate to be processed such as a semiconductor wafer or an FPD substrate.

DESCRIPTION OF SYMBOLS 100 Plasma processing apparatus 102 Processing chamber 104 Substrate carrying-in / out port 106 Gate valve 108 Exhaust pipe 109 Exhaust apparatus 110 Shower head 112 Shield ring 114 Sealing member 116 Diffusion hole 118 Gas supply part 121 Gas introduction port 122 Gas supply source 123 Gas supply Piping 124 Mass Flow Controller (MFC)
152 Matching device 154 High pass filter (HPF)
162 Matching device 164 Low pass filter (LPF)
200, 201 mounting table 202 insulating plate 210 susceptor 212 electrostatic chuck 214 conductive film 216 DC high voltage power supply 220 susceptor support base 222 temperature control medium flow path 224 introduction pipe 226 discharge pipe 230 gas passage 232 screw 234 hole 234a small diameter part 234b expansion Diameter part 234c Screw hole 240 Annular groove 242 Groove part 300 Control part 310 Operation part 320 Storage part W Wafer

Claims (8)

A substrate mounting table provided in a processing chamber of a substrate processing apparatus for mounting a substrate to be processed,
A susceptor constituting the mounting table body;
A fastening member for fixing a peripheral portion of the susceptor in the processing chamber;
An annular groove provided around the entire circumference of the side surface of the susceptor;
A substrate mounting table characterized by comprising: 2. The substrate mounting table according to claim 1, wherein the annular groove has a depth extending from the side surface of the susceptor toward the inside to at least a portion where the fastening member is provided. The substrate mounting table according to claim 2, wherein the annular groove is formed in a portion higher than a portion fastened by the fastening member. The susceptor is configured such that its outer diameter is larger than the outer diameter of the substrate to be processed.
The fastening member is inserted and arranged in a hole formed perpendicular to a portion protruding outward from the substrate to be processed,
4. The substrate mounting table according to claim 3, wherein the annular groove is formed across the hole at a portion protruding outward from the substrate to be processed. 5. A plurality of the hole portions are formed along a portion protruding outward from the substrate to be processed,
The substrate mounting table according to claim 4, wherein a fastening member is disposed in each of the holes to fix the susceptor. The substrate mounting table according to claim 1, wherein the annular groove has an inclined surface that is inclined inward from a side surface of the susceptor. 6. The substrate mounting table according to claim 1, wherein a plurality of the annular grooves are provided side by side along the vertical direction on the side surface of the susceptor. A substrate processing apparatus for performing plasma processing on a substrate to be processed,
A processing chamber configured to be depressurized;
A substrate mounting table disposed below the processing chamber and mounting the substrate to be processed;
A gas supply unit for supplying a processing gas to the processing chamber;
A gas introduction unit that is disposed above the processing chamber and introduces a gas from the gas supply unit toward a substrate to be processed on the substrate mounting table;
The substrate mounting table includes a susceptor that constitutes a mounting table main body, a fastening member that fixes a peripheral portion of the susceptor in the processing chamber, and an annular groove that is provided around the side surface of the susceptor. A substrate processing apparatus comprising the substrate processing apparatus.

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