Electrostatic chuck

Abstract

The electrostatic chuck 20 is provided with a ceramic plate 22 in a disc shape having a wafer placement surface 22a on a surface, an electrostatic electrode 30 embedded in the ceramic plate 22, and gas grooves 25a to 25g divided into a plurality of sections Z1 to Z7 when the ceramic plate 22 is viewed from above, which are independently provided on the wafer placement surface 22a in a manner of changing from one of a pair of gas supply and discharge ports 26, 27 to the other in each section.

Description

TECHNICAL FIELD

[0001] The present application relates to an electrostatic chuck. BACKGROUND

[0002] In the past, an electrostatic chuck has been known, which is provided with a ceramic plate in a disc shape having a wafer placement surface on a surface, and an electrostatic electrode implanted in the ceramic plate. As such an electrostatic chuck, for example, as shown in Patent Documents 1 and 2, an electrostatic chuck provided with a gas groove in the wafer placement surface is known. In Patent Document 1, an electrostatic chuck is disclosed, which is provided with one gas introduction port penetrating the center of the ceramic plate in the thickness direction, four gas distribution grooves provided in the wafer placement surface in a manner extending radially from the gas introduction port, and an exhaust port provided in the vicinity of the outer periphery of the ceramic plate in a manner communicating with the gas distribution grooves respectively. In Patent Document 2, an electrostatic chuck is disclosed, in which, when the ceramic plate is viewed from above, is divided into two semicircular sections, and a gas groove is provided in each semicircular section. Specifically, in one semicircular section, gas flows from a gas introduction port provided in the vicinity of the outer periphery of the ceramic plate, through cut portions of a plurality of partition walls in a concentric circular shape, and then to a gas exhaust port provided in the center of the ceramic plate. In addition, in the other semicircular section, gas flows from another gas introduction port provided in the vicinity of the outer periphery of the ceramic plate, through cut portions of a plurality of partition walls in a concentric circular shape, and then to a common gas exhaust port provided in the center of the ceramic plate. The gas flowing in one semicircular section and the gas flowing in the other semicircular section are not completely separated, and are mixed halfway.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT DOCUMENTS

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 10-275854

[0006] Patent Document 2: Japanese Patent Application Laid-Open No. 2012-129547 SUMMARY

[0007] However, in Patent Document 1, the gas flowing in the four gas distribution grooves is the gas supplied to the same gas introduction port, and thus, it is not possible to control the gas for each gas distribution groove respectively. In Patent Document 2, the gas flowing in one semicircular section and the gas flowing in the other semicircular section are mixed halfway, and thus, it is not possible to control the gas for each section respectively.

[0008] The present application is implemented in order to solve the above problems, and its main object is to be able to control the back surface gas of an electrostatic chuck for each section respectively.

[0009] The electrostatic chuck of the present application is provided with:

[0010] A ceramic plate in a disc shape, the ceramic plate having a wafer placement surface on a surface thereof;

[0011] An electrostatic electrode implanted in the ceramic plate; and

[0012] A gas groove divided into a plurality of sections when the ceramic plate is viewed from above, independently provided in the wafer placement surface from one gas supply and exhaust port to another gas supply and exhaust port in each of the sections.

[0013] In the electrostatic chuck, the gas groove is independently provided in the wafer placement surface from one gas supply and exhaust port to another gas supply and exhaust port in each section. The gas groove is used to supply a gas (backside gas) to the backside of a wafer placed on the wafer placement surface. Since the gas groove is independently provided in each section, the backside gas of the electrostatic chuck can be controlled for each section.

[0014] In the electrostatic chuck of the present application, the plurality of sections can include a circular section having the same center as the ceramic plate, and one or more annular sections having the same center as the ceramic plate and provided outside the circular section. Accordingly, the gas flowing through the circular or annular sections can be controlled separately. In this case, the pair of gas supply and exhaust ports provided in each of the gas grooves can be arranged side by side along a predetermined radial direction of the ceramic plate, and in two gas grooves provided in sections adjacent to each other, the direction of the gas flowing through one of the two gas grooves is set to clockwise, and the direction of the gas flowing through the other of the two gas grooves is set to counterclockwise. Accordingly, it is possible to suppress the temperature distribution caused by the gas when the same temperature gas is supplied to, for example, two gas grooves provided in adjacent sections.

[0015] In the electrostatic chuck of the present application, the plurality of sections can be a plurality of fan-shaped sections separated by a radius of the ceramic plate. Accordingly, the gas flowing through the plurality of fan-shaped sections can be controlled separately.

[0016] In the electrostatic chuck of the present application, the plurality of sections can be a plurality of curved sections separated by a curve extending from the center of the ceramic plate toward the outer edge. Accordingly, the gas flowing through the plurality of curved sections can be controlled separately.

[0017] In the electrostatic chuck of the present application, the gas groove provided in each of the sections can be supplied with a gas having a different characteristic. Accordingly, a gas suitable for the characteristic of each section can be supplied. It should be noted that, as the "characteristic", for example, temperature, flow rate, pressure, gas type, etc. can be cited.

[0018] In the electrostatic chuck of the present application, the mode of supplying gas to the gas groove provided in each of the segments can select any one of the following modes: a first mode in which gas flows from one of the pair of gas supply / discharge ports to the other gas supply / discharge port, and a second mode in which gas flows from the other gas supply / discharge port to the one gas supply / discharge port. Accordingly, it is possible to determine whether to flow gas in the first mode or in the second mode for each gas groove.

[0019] The electrostatic chuck of the present application can be provided with a resistance heating element implanted in the ceramic plate from one of the pair of terminals to the other terminal in each of the segments. Accordingly, it is possible to control the degree of heating for each segment individually. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a schematic explanatory view showing the constitution of the plasma processing apparatus 10.

[0021] Figure 2 is a perspective view of the electrostatic chuck 20.

[0022] Figure 3 is a plan view of the electrostatic chuck 20.

[0023] Figure 4 is a partial enlarged view of Figure 3 A-A sectional view.

[0024] Figure 5 is an explanatory view showing the electrical connection of the electrostatic chuck 20.

[0025] Figure 6 is an explanatory view of the gas path 78a connected to the gas groove 25a.

[0026] Figure 7 is an explanatory view of the gas path 78a connected to the gas groove 25a.

[0027] Figure 8 is an explanatory view of the gas path 78a connected to the gas groove 25a.

[0028] Figure 9 is a plan view of the electrostatic chuck 120.

[0029] Figure 10 is a partial enlarged view of Figure 9 B-B sectional view.

[0030] Figure 11 is a B-B sectional view of Figure 9 .

[0031] Figure 12 is a sectional view of the electrostatic chuck 220. DETAILED DESCRIPTION

[0032] Next, a preferred embodiment of the present application will be described with reference to the accompanying drawings. Figure 1 is a schematic explanatory view showing the configuration of a plasma processing apparatus 10, Figure 2 is a perspective view of an electrostatic chuck 20, Figure 3 is a plan view of the electrostatic chuck 20, Figure 4 is Figure 3 an A-A sectional view of Figure 5 is an explanatory view showing the electrical connection of the electrostatic chuck. Note that, Figure 4 in the following description, up and down, left and right, front and back are merely relative positional relationships.

[0033] As shown in Figure 1 , the plasma processing apparatus 10 is provided with the electrostatic chuck 20 and an upper electrode 60 used when plasma is generated, in the interior of a metal (e.g., aluminum alloy) vacuum chamber 12 in which the internal pressure can be adjusted. The electrostatic chuck 20 is provided in the interior of the vacuum chamber 12. A large number of small holes for supplying a reaction gas to the wafer surface are provided on the surface of the upper electrode 60 opposite the electrostatic chuck 20. With the vacuum chamber 12, the reaction gas can be supplied to the upper electrode 60 from a reaction gas introduction path 14, and the internal pressure of the vacuum chamber 12 can be reduced to a prescribed vacuum degree by a vacuum pump connected to an exhaust path 16.

[0034] The electrostatic chuck 20 is provided with: a ceramic plate 22 whose upper surface is provided with a wafer mounting surface 22a capable of adsorbing and holding a wafer W; an electrostatic electrode 30 (see Figure 4 ) implanted in the ceramic plate 22; and resistance heating elements 31 to 37 (see Figure 3 and Figure 4 ) implanted in the ceramic plate 22. The ceramic plate 22 is a ceramic (e.g., alumina, aluminum nitride) disc-shaped plate whose outer diameter is smaller than the outer diameter of the wafer W.

[0035] As shown in Figures 2 to 4 , the wafer mounting surface 22a is provided with: a circular protrusion 29 whose center is the same as that of the ceramic plate 22; and annular protrusions 23a to 23g provided in a concentric circle shape so as to surround the circular protrusion 29, from the ceramic plate 22. In addition, the wafer mounting surface 22a is provided with a partition wall 28. The partition wall 28 extends linearly in the radial direction from the center side of the ceramic plate 22, links the circular protrusion 29 and the annular protrusion 23a, and links adjacent two of the annular protrusions 23a to 23g to each other. The wafer W mounted on the wafer mounting surface 22a is supported on the upper surfaces of the circular protrusion 29, the annular protrusions 23a to 23g, and the partition wall 28.

[0036] The wafer mounting surface 22a of the ceramic plate 22 is divided into sections Z1 to Z7 when viewed from above (see reference). Figure 3 and Figure 4 Section Z1 is the region inside the annular protrusion 23a. That is, section Z1 is a circular section with the same center as the ceramic plate 22. Section Z1 has a C-shaped gas channel 25a in the region outside the circular protrusion 29. A pair of supply and exhaust ports 26a and 27a are provided in the gas channel 25a to supply or exhaust gas relative to section Z1. One supply and exhaust port 26a is provided at one end of the C-shaped gas channel 25a (near the partition wall 28), and the other supply and exhaust port 27a is provided at the other end of the C-shaped gas channel 25a (near the partition wall 28). Section Z2 is the region between annular protrusions 23a and 23b; section Z3 is the region between annular protrusions 23b and 23c; section Z4 is the region between annular protrusions 23c and 23d; section Z5 is the region between annular protrusions 23d and 23e; section Z6 is the region between annular protrusions 23e and 23f; and section Z7 is the region between annular protrusions 23f and 23g. That is, sections Z2 to Z7 are annular sections arranged concentrically with the ceramic plate 22 on the outer side of section Z1. Sections Z2 to Z7 have corresponding C-shaped gas channels 25b to 25g. Gas channels 25b to 25g are provided over approximately the entire area of ​​their respective sections Z2 to Z7. For the C-shaped gas channels 25b-25g, supply and exhaust ports 26b-26g are respectively provided at one end and supply and exhaust ports 27a-27g are provided at the other end. A partition wall 28 is located between the supply and exhaust ports 26a-26g and 27a-27g. One supply and exhaust port 26a-26g and the other supply and exhaust port 27a-27g are both arranged along the partition wall 28. Therefore, a pair of supply and exhaust ports 26a-26g and 27a-27g are arranged side-by-side along a predetermined radius of the ceramic plate 22.

[0037] Electrostatic electrode 30 is capable of utilizing Figure 5 The ESC power supply 71 shown has a planar electrode that applies a DC voltage and is arranged parallel to the wafer mounting surface 22a. When a voltage is applied to this electrostatic electrode 30, the wafer W is attracted and held to the wafer mounting surface 22a by Coulomb force or Johansen-Labec force; when the DC voltage is released, the attraction and holding of the wafer W relative to the wafer mounting surface 22a is released.

[0038] The resistive heating elements 31 to 37 are formed in a single-stroke manner on the same plane parallel to the wafer mounting surface 22a, corresponding to segments Z1 to Z7 respectively. Terminals provided at both ends of the resistive heating element 31 are connected to a power supply component (not shown) inserted from the back of the ceramic plate 22. Figure 5The heater power supply 81 is shown. When the voltage of the heater power supply 81 is applied to the resistive heating element 31, the resistive heating element 31 heats up and heats section Z1. Other resistive heating elements 32 to 37 are also connected to the heater power supplies 82 to 87 respectively, and when a voltage is applied, they heat sections Z2 to Z7 respectively. The resistive heating elements 31 to 37 are formed of conductive materials containing, for example, W, WC, Mo, etc. The shape of the resistive heating elements 31 to 37 is not particularly limited, for example, it can be coil-shaped or strip-shaped. In addition, it can be obtained by printing a paste of conductive material.

[0039] The control device 70 has a built-in well-known microcomputer equipped with a CPU, ROM, RAM, etc. For example... Figure 5 As shown, signals output from temperature sensors 62a-62g and operator commands input from input device 80 (keyboard, mouse, etc.) are input to control device 70. Temperature sensors 62a-62g are configured to measure the temperature at positions corresponding to gas channels 25a-25g. Control device 70 outputs power to electrostatic electrode 30 via ESC power supply 71, or to resistive heating elements 31-37 via heater power supplies 81-87. Furthermore, control device 70 controls gas supply sources 74a-74g, changing the type, temperature, pressure, and flow rate of gas supplied to gas channels 25a-25g, or controlling three-way valves 76a-76g and 77a-77g, thereby controlling the direction of gas flowing through gas channels 25a-25g. It should be noted that alternating current can also be supplied to electrostatic electrode 30, and when plasma is generated, a high-frequency voltage can be applied to electrostatic electrode 30 via high-frequency power supply 72.

[0040] Here, the direction of the gas flowing through gas channels 25a to 25g will be explained. Gas channel 25a will be used as an example in the following explanation. Figures 6 to 8 This is an explanatory diagram of the gas path 78a connected to the gas channel 25a. Through holes 46a and 47a are provided in the ceramic plate 22, extending along the thickness direction. Through holes 46a and 47a communicate with the supply and exhaust ports 26a and 27a respectively provided in the gas channel 25a. Through hole 46a is connected to a first three-way valve 76a. Through hole 47a is connected to a second three-way valve 77a. The first port of the first three-way valve 76a is connected to the through hole 46a, the second port is connected to the gas supply port, and the third port is connected midway through the gas pipe connecting the gas exhaust port and the second three-way valve 77a. The first port of the second three-way valve 77a is connected to the through hole 47a, the second port is connected to the gas exhaust port, and the third port is connected midway through the gas pipe connecting the gas supply port and the first three-way valve 76a. It should be noted that... Figures 6 to 8The numbers 1 to 3 surrounded by o indicate the 1st to 3rd ports of the three-way valve.

[0041] For the mode of supplying gas to the gas channel 25a, the positions of the first three-way valve 76a and the second three-way valve 77a are adjusted by the control device 70, so that the gas can be switched between the first mode in which the gas flows from the supply / discharge port 26a to the supply / discharge port 27a and the second mode in which the gas flows from the supply / discharge port 27a to the supply / discharge port 26a.

[0042] Specifically, the first three-way valve 76a and the second three-way valve 77a are adjusted as follows to supply the gas from the supply / discharge port 26a and make it flow in the gas channel 25a in the counterclockwise direction and be discharged from the supply / discharge port 27a in the clockwise direction. That is, as shown in FIG. 6, the first three-way valve 76a is adjusted in such a manner that the 1st port and the 2nd port thereof are communicated and the 3rd port thereof is blocked, and the second three-way valve 77a is adjusted in such a manner that the 1st port and the 2nd port thereof are communicated and the 3rd port thereof is blocked. Figure 3 Figure 6 Specifically, the first three-way valve 76a and the second three-way valve 77a are adjusted as follows to supply the gas from the supply / discharge port 26a and make it flow in the gas channel 25a in the counterclockwise direction and be discharged from the supply / discharge port 27a in the clockwise direction. That is, as shown in FIG. 6, the first three-way valve 76a is adjusted in such a manner that the 1st port and the 2nd port thereof are communicated and the 3rd port thereof is blocked, and the second three-way valve 77a is adjusted in such a manner that the 1st port and the 2nd port thereof are communicated and the 3rd port thereof is blocked.

[0043] The first three-way valve 76a and the second three-way valve 77a are adjusted as follows to supply the gas from the supply / discharge port 27a and make it flow in the gas channel 25a in the clockwise direction and be discharged from the supply / discharge port 26a in the counterclockwise direction. That is, as shown in FIG. 7, the first three-way valve 76a is adjusted in such a manner that the 1st port and the 3rd port thereof are communicated and the 2nd port thereof is blocked, and the second three-way valve 77a is adjusted in such a manner that the 1st port and the 3rd port thereof are communicated and the 2nd port thereof is blocked. Figure 3 Figure 7 The first three-way valve 76a and the second three-way valve 77a are adjusted as follows to supply the gas from the supply / discharge port 27a and make it flow in the gas channel 25a in the clockwise direction and be discharged from the supply / discharge port 26a in the counterclockwise direction. That is, as shown in FIG. 7, the first three-way valve 76a is adjusted in such a manner that the 1st port and the 3rd port thereof are communicated and the 2nd port thereof is blocked, and the second three-way valve 77a is adjusted in such a manner that the 1st port and the 3rd port thereof are communicated and the 2nd port thereof is blocked.

[0044] The first three-way valve 76a and the second three-way valve 77a are adjusted as follows to fill (seal) the gas channel 25a with gas. That is, as shown in FIG. 8, the first three-way valve 76a is adjusted in such a manner that the 1st port thereof is blocked and the 2nd port and the 3rd port thereof are communicated, and the second three-way valve 77a is adjusted in such a manner that the 1st port thereof is blocked and the 2nd port and the 3rd port thereof are communicated. In this case, the gas supply source 74a can be stopped. Figure 8 The first three-way valve 76a and the second three-way valve 77a are adjusted as follows to fill (seal) the gas channel 25a with gas. That is, as shown in FIG. 8, the first three-way valve 76a is adjusted in such a manner that the 1st port thereof is blocked and the 2nd port and the 3rd port thereof are communicated, and the second three-way valve 77a is adjusted in such a manner that the 1st port thereof is blocked and the 2nd port and the 3rd port thereof are communicated. In this case, the gas supply source 74a can be stopped.

[0045] The first three-way valve 76a and the second three-way valve 77a are adjusted as follows to fill (seal) the gas channel 25a with gas. That is, as shown in FIG. 8, the first three-way valve 76a is adjusted in such a manner that the 1st port thereof is blocked and the 2nd port and the 3rd port thereof are communicated, and the second three-way valve 77a is adjusted in such a manner that the 1st port thereof is blocked and the 2nd port and the 3rd port thereof are communicated. In this case, the gas supply source 74a can be stopped.

[0046] ​​Next, an example of use of the plasma processing apparatus 10 thus configured will be described. First, in a state where the electrostatic chuck 20 is provided in the vacuum chamber 12, the wafer W is placed on the wafer placement surface 22a of the ceramic plate 22. Then, the inside of the vacuum chamber 12 is depressurized by the vacuum pump, and adjusted to a prescribed degree of vacuum, and a direct current voltage is applied to the electrostatic electrode 30 of the ceramic plate 22 to cause it to generate a Coulomb force or a Johannsen-Laplace force, and the wafer W is adsorbed and held to the wafer placement surface 22a of the ceramic plate 22. By this, the gas grooves 25a to 25g are formed as gas spaces together with the wafer W. Next, the inside of the vacuum chamber 12 is made into a reaction gas atmosphere of a prescribed pressure (for example, several 10 to several 100 Pa), and in this state, a high frequency voltage is applied between the upper electrode 60 in the vacuum chamber 12 and the electrostatic electrode 30 of the ceramic plate 22 to cause plasma to be generated. Then, the surface of the wafer W is etched by the generated plasma. At the time of etching, the target temperature T of the wafer W is set in advance. The control device 70 adjusts the voltage applied to the resistance heat generating bodies 31 to 37 of the respective zones Zl to Z7 in such a manner that the output values of the temperature measuring sensors 62a to 62g coincide with the target temperature T, or adjusts the direction of the gas flowing in the gas grooves 25a to 25g of the respective zones Zl to Z7, or the characteristics (temperature, flow rate, pressure, gas kind, etc.) of the gas. For changing the direction of the gas flowing in the gas grooves 25a to 25g, the first three-way valves 76a to 76g and the second three-way valves 77a to 77g are adjusted as described above. For changing the temperature, flow rate, pressure, gas kind of the gas, the gas supply sources 74a to 74g are controlled.

[0047] In the case where a hot spot is generated in the wafer W, a gas of a lower temperature is introduced to the gas groove of the zone corresponding to the hot spot, or a gas of a higher thermal conductivity (for example, He gas) is supplied, so that the heat efficiency of the hot spot is favorably transmitted to the ceramic plate 22. Alternatively, the package pressure of the gas supplied to the gas groove can be increased. Alternatively, the electric power supplied to the resistance heat generating body of the zone corresponding to the hot spot can be decreased, so that the amount of heat generation is suppressed.

[0048] On the other hand, in the case where a cold spot is generated in the wafer W, a gas of a higher temperature is introduced to the gas groove corresponding to the cold spot, or the flow rate of the gas is increased, or a gas of a lower thermal conductivity (for example, Ar gas) is supplied, so that the heat of the cold spot is not easily transmitted to the ceramic plate 22. Alternatively, the package pressure of the gas supplied to the gas groove can be decreased. Alternatively, the electric power supplied to the resistance heat generating body of the zone corresponding to the cold spot can be increased, so that the amount of heat generation is increased.

[0049] In a case where it is desired to suppress a temperature distribution caused by the gas, the flow paths of the gas are switched by the three-way valves 76a, 77a, 76c, 77c, 76e, 77e, 76g, 77g so that the directions of the gas flowing in the gas grooves 25a, 25c, 25e, 25g are the first pattern. At the same time, the flow paths of the gas are switched by the three-way valves 76a, 77a, 76c, 77c, 76e, 77e, 76g, 77g so that the directions of the gas flowing in the gas grooves 25b, 25d, 25f are the second pattern. Accordingly, the gases flowing in the adjacent sections are heat-exchanged with each other, so that the gases of uniform temperature flow in the gas grooves 25a to 25g.

[0050] In the electrostatic chuck 20 described in detail above, the gas grooves 25a to 25g are independently provided in each section from one of the pair of supply and discharge ports to the other of the pair of supply and discharge ports on the wafer mounting surface 22a. The gas grooves 25a to 25g are used to supply a gas (back surface gas) to the back surface of the wafer W mounted on the wafer mounting surface 22a. Since the gas grooves 25a to 25g are independently provided in each section Zl to Z7, the back surface gas of the electrostatic chuck 20 can be controlled for each section Zl to Z7.

[0051] In addition, in the electrostatic chuck 20, the section Zl is a circular section having the same center as the ceramic plate 22, and the sections Z2 to Z7 are annular sections provided outside the section Zl. Therefore, the gases flowing in the circular section Zl or the annular sections Z2 to Z7 can be controlled respectively. Further, in the two gas grooves provided in the adjacent sections, the direction of the gas flowing in one of the gas grooves can be set to clockwise, and the direction of the gas flowing in the other of the gas grooves can be set to counterclockwise. Therefore, a temperature distribution caused by the gas can be suppressed when the same temperature gas is supplied to, for example, the two gas grooves provided in the adjacent sections.

[0052] Further, in the electrostatic chuck 20, different gases having different temperatures, flow rates, pressures, and gas types can be supplied to the gas grooves 25a to 25g provided in the sections Zl to Z7 respectively. Therefore, gases suitable for the characteristics of each section can be supplied.

[0053] Also, in the electrostatic chuck 20, the mode of supplying the gas to each of the gas grooves 25a to 25g can be selected from either of a first mode in which the gas flows from the supply and discharge port 26 to the supply and discharge port 27 and a second mode in which the gas flows from the supply and discharge port 27 to the supply and discharge port 26. Therefore, it can be determined for each gas groove whether the gas flows in the first mode or in the second mode.

[0054] Furthermore, in the electrostatic chuck 20, resistance heating elements 31 to 37 corresponding to sections Z1 to Z7 are embedded in the ceramic plate 22. Therefore, the heating degree can be controlled separately for each section Z1 to Z7.

[0055] It should be noted that the present invention is not limited to any of the above embodiments. Of course, as long as it falls within the technical scope of the present invention, it can be implemented in various ways.

[0056] For example, in the above embodiment, the wafer mounting surface 22a is divided into a circular segment Z1 and annular segments Z2 to Z7 when viewed from above, but is not limited thereto. For example, each segment can be like... Figures 9 to 11 As shown in the electrostatic chuck 120, the wafer mounting surface 122a of the ceramic plate 122, when viewed from above, is divided into multiple fan-shaped segments Z12 separated by the radius of the ceramic plate 122. Each segment Z12 has a fan-shaped gas channel 125 over approximately its entire area. A supply / exhaust port 126 is provided at the center of each gas channel 125, and a supply / exhaust port 127 is provided at its outer periphery. A partition wall 128 extending from the center of the wafer mounting surface 122a toward the outer periphery is provided between adjacent segments Z12. Gas can be supplied to each gas channel 125 independently. Therefore, the gas flowing through the multiple segments Z12 can be controlled individually.

[0057] Or, it can be like Figure 12 As shown in the electrostatic chuck 220, the wafer mounting surface 222a of the ceramic plate 222, when viewed from above, is divided into multiple curved sections Z22 separated by curves extending from the center of the ceramic plate 222 towards the outer edge. Each section Z22 has a curved gas channel 225 over approximately the entire area. A supply / exhaust port 226 is provided on the center side of each gas channel 225, and a supply / exhaust port 227 is provided on the outer periphery side. Between adjacent sections Z22, a partition wall 228 is provided, extending from the center side of the wafer mounting surface 222a towards the outer periphery and curving as it moves from the center side towards the outer periphery. Gas can be supplied to each gas channel 225 independently. Accordingly, the gas flowing through the multiple sections Z22 can be controlled individually.

[0058] In the above embodiment, resistive heating elements 31 to 37 are embedded in the ceramic plate 22; however, it is possible to omit the resistive heating elements 31 to 37. In this case, the temperature of the wafer W is mainly controlled by the gas flowing through the gas channels 25a to 25g.

[0059] In the above embodiments, a metal (e.g., aluminum, aluminum alloy) cooling plate can be bonded or joined to the back of the electrostatic chuck 20. A coolant flow path for circulating coolant (e.g., cooling water) can be provided inside the cooling plate. The temperature of the wafer W can also be controlled by the coolant.

[0060] This application is based on Japanese Patent Application No. 2020-090932 filed on May 25, 2020, the contents of which are incorporated herein by reference in its entirety.

[0061] Industrial Applicability

[0062] The present application can be applied to a semiconductor manufacturing apparatus.

[0063] Symbol Explanation

[0064] 10 plasma processing apparatus, 12 vacuum chamber, 14 reaction gas introduction path, 16 exhaust passage, 20, 120, 220 electrostatic chuck, 22, 122, 222 ceramic plate, 22a, 122a, 222a wafer placement surface, 23a to 23g annular protrusions, 25a to 25g, 125, 225 gas grooves, 26a to 26g, 27a to 27g, 126, 127, 226, 227 supply / discharge ports, 28, 128 partition walls, 29 circular protrusions, 30 electrostatic electrode, 31 to 37 resistance heating elements, 46a, 47a through holes, 60 upper electrode, 62a to 62g temperature measuring sensors, 70 control device, 71 ESC power supply, 72 high-frequency power supply, 74a to 74g gas supply sources, 76a to 76g first three-way valves, 77a to 77g second three-way valves, 78a gas path, 80 input device, 81 to 87 heater power supplies, W wafer, Z1 to Z7, Z12, Z22 segments.

Claims

1. An electrostatic chuck, wherein, Possessing: a ceramic plate in a disc shape having a wafer placement surface on a surface; an electrostatic electrode implanted in the ceramic plate; and a gas groove divided into a plurality of sections when the ceramic plate is viewed from above, independently provided in the wafer placement surface in each of the sections from one of a pair of gas supply and exhaust ports to the other gas supply and exhaust port, a mode of supplying a gas to the gas groove provided in each of the sections can select any one of a first mode in which the gas flows from one of the pair of gas supply and exhaust ports to the other gas supply and exhaust port and a second mode in which the gas flows from the other gas supply and exhaust port to one of the pair of gas supply and exhaust ports.

2. The electrostatic chuck according to claim 1, wherein the plurality of sections include a plurality of ring-shaped sections provided outside a circular protrusion identical to the ceramic plate in the center and two or more ring-shaped sections identical to the ceramic plate in the center.

3. The electrostatic chuck according to claim 2, wherein the pair of gas supply and exhaust ports provided in each of the gas grooves are arranged side by side along a prescribed radial direction of the ceramic plate, and in two gas grooves provided in sections adjacent to each other, the direction of the gas flowing through one gas groove is set to clockwise and the direction of the gas flowing through the other gas groove is set to counterclockwise.

4. The electrostatic chuck according to claim 1, wherein the plurality of sections are a plurality of fan-shaped sections separated by a radius of the ceramic plate.

5. The electrostatic chuck according to claim 1, wherein the plurality of sections are a plurality of curved sections separated by a curved line extending from the center of the ceramic plate toward the outer edge. Possessing:

6. An electrostatic chuck, wherein, a ceramic plate in a disc shape having a wafer placement surface on a surface; an electrostatic electrode implanted in the ceramic plate; and a gas groove divided into a plurality of sections when the ceramic plate is viewed from above, independently provided in the wafer placement surface in each of the sections from one of a pair of gas supply and exhaust ports to the other gas supply and exhaust port, the plurality of sections include a plurality of ring-shaped sections provided outside a circular protrusion identical to the ceramic plate in the center and two or more ring-shaped sections identical to the ceramic plate in the center, the pair of gas supply and exhaust ports provided in each of the gas grooves are arranged side by side along a prescribed radial direction of the ceramic plate, and in two gas grooves provided in sections adjacent to each other, the direction of the gas flowing through one gas groove is set to clockwise and the direction of the gas flowing through the other gas groove is set to counterclockwise.

7. The electrostatic chuck according to any one of claims 1 to 6, wherein a gas different in characteristics can be supplied to the gas groove provided in each of the sections, respectively.

8. The electrostatic chuck according to any one of claims 1 to 6, wherein a resistance heating element implanted in the ceramic plate in each of the sections from one of a pair of terminals to the other terminal is provided.

9. The electrostatic chuck according to claim 7, wherein ​ ​ The resistance heating element is implanted in the ceramic plate from one of a pair of terminals to the other terminal in each section.

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