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CN-122003985-A - Ceramic base

CN122003985ACN 122003985 ACN122003985 ACN 122003985ACN-122003985-A

Abstract

The invention provides a ceramic base which is provided with a purge gas flow path, a vacuum suction path and a thermocouple insertion path in a manner of being contained in 1 layer without damaging respective functions. The ceramic base is provided with a disk-shaped ceramic plate assembly including an upper ceramic plate and a lower ceramic plate, an internal electrode implanted in the ceramic plate assembly, and purge gas grooves, vacuum suction grooves, and thermocouple insertion grooves, which are provided on the joint surface side of the upper ceramic plate or the lower ceramic plate, respectively. The ceramic plate bond has a central section and a peripheral section. The purge gas channel, the vacuum suction channel, and the thermocouple insertion channel each have a straight line portion in the central section. An angle θ 1 formed by the straight line portion of the purge gas groove and the straight line portion of the thermocouple insertion groove, and an angle θ 2 formed by the straight line portion of the purge gas groove and the straight line portion of the vacuum suction groove satisfy 90 ° < θ 1 ＜180°、135°＜θ 2 <225 °, and θ 1 ＜θ 2 .

Inventors

  • AMANO SHINGO
  • Takanoya REO
  • MATSUO YUYA

Assignees

  • 日本碍子株式会社

Dates

Publication Date
20260508
Application Date
20231011

Claims (13)

  1. 1. A ceramic susceptor, comprising: A disc-shaped ceramic plate joined body including an upper ceramic plate and a lower ceramic plate joined to each other at a joint surface, the ceramic plate joined body having a first surface of the upper ceramic plate on a side opposite to the joint surface and a second surface of the lower ceramic plate on a side opposite to the joint surface; At least 1 internal electrode selected from the group consisting of a heater electrode, an RF electrode, and an ESC electrode, the electrodes being implanted in the ceramic plate bond; A purge gas groove provided on the joint surface side of the upper ceramic plate or the lower ceramic plate, and forming a purge gas flow path together with the joint surface; a vacuum suction groove provided on the junction surface side of the upper ceramic plate or the lower ceramic plate so as not to intersect the purge gas groove and forming a vacuum suction path together with the junction surface, and A thermocouple insertion groove provided on the junction surface side of the upper ceramic plate or the lower ceramic plate so as not to intersect the purge gas flow path and the vacuum suction flow path, the thermocouple insertion groove forming a thermocouple insertion path together with the junction surface, The ceramic base is characterized in that, The ceramic plate joined body has a central section and an outer peripheral section outside the central section in plan view, the central section being defined as a circular region where the ceramic shaft is to be arranged in a concentric circle, The purge gas channel has a straight line portion arranged in a straight line from the purge gas inlet in the central section toward the outer peripheral section, and an extension portion extending from the straight line portion in the outer peripheral section and reaching a plurality of purge gas outlets arranged on the outer peripheral portion of the ceramic plate joined body through at least 1 selected from the group consisting of branching, bending, curving, and straight advancing, The vacuum suction groove has a straight line portion arranged in a straight line from the vacuum suction inlet in the central section toward the outer peripheral section, and an extension portion extending from the straight line portion in the outer peripheral section and reaching the ceramic plate joined body through at least 1 selected from the group consisting of branching, bending, curving, and straight line advancing, The thermocouple insertion groove has a linear portion arranged in a linear manner from a thermocouple insertion port in the central section toward a thermocouple insertion path end located in the outer peripheral section, An angle θ 1 formed by the straight line portion of the purge gas groove and the straight line portion of the thermocouple insertion groove, and an angle θ 2 formed by the straight line portion of the purge gas groove and the straight line portion of the vacuum suction groove satisfy the following relationship: 50°<θ 1 <180°、 135 ° < θ 2 <310 °, and θ 1 ＜θ 2 。
  2. 2. The ceramic susceptor of claim 1, wherein, The ceramic base further includes a cylindrical ceramic shaft concentrically mounted on the central section of the second surface of the ceramic plate joined body.
  3. 3. The ceramic susceptor according to claim 1 or 2, wherein, Each path length of the purge gas channel from the purge gas inlet to each of the plurality of purge gas outlets is within ±10% of an average path length of the purge gas channel.
  4. 4. The ceramic susceptor according to claim 1 or 2, wherein, Each path length of the vacuum suction groove from the vacuum suction inlet to each of the plurality of vacuum suction outlets is within ±10% of an average path length of the vacuum suction groove.
  5. 5. The ceramic susceptor of claim 2, wherein, The ceramic base is provided with a purge gas supply hole penetrating through a side wall constituting the ceramic shaft and the lower ceramic plate and communicating with the purge gas inlet, and the purge gas supply hole, the purge gas inlet, the purge gas groove, and the purge gas outlet all constitute the purge gas flow path.
  6. 6. The ceramic susceptor according to claim 1 or 2, wherein, The plurality of purge gas outlets are arranged at equal intervals along an outer peripheral portion of the ceramic plate assembly.
  7. 7. The ceramic susceptor according to claim 1 or 2, wherein, The ceramic base further includes a purge ring provided annularly along an outer peripheral edge of the ceramic plate assembly, the purge ring guiding purge gas discharged from the purge gas outlet to be discharged from an outer peripheral portion of the first surface, and a gap between the outer peripheral edge of the ceramic plate assembly and the purge ring constitutes a purge gas discharge port.
  8. 8. The ceramic susceptor according to claim 1 or 2, wherein, The upper ceramic plate further includes a vertical hole communicating with the first surface from the purge gas outlet, and the vertical hole forms a purge gas discharge port capable of discharging the purge gas from the outer peripheral portion of the first surface.
  9. 9. The ceramic susceptor of claim 2, wherein, The ceramic base is provided with a vacuum suction hole penetrating through a side wall constituting the ceramic shaft and the lower ceramic plate and communicating with the vacuum suction inlet, and the vacuum suction hole, the vacuum suction inlet, the vacuum suction groove and the vacuum suction outlet integrally constitute the vacuum suction path.
  10. 10. The ceramic susceptor according to claim 1 or 2, wherein, The plurality of vacuum suction outlets are arranged rotationally symmetrically with respect to a central axis of the ceramic plate joined body.
  11. 11. The ceramic susceptor according to claim 1 or 2, wherein, The ceramic base further includes a tubular thermocouple guide portion provided on the second surface of the ceramic plate joined body so as to communicate with the thermocouple insertion port in the internal space of the ceramic shaft, for guiding insertion of the thermocouple into the thermocouple insertion path.
  12. 12. The ceramic susceptor of claim 10, wherein, The ceramic base further includes a thermocouple inserted into the thermocouple insertion path through the thermocouple guide portion and the thermocouple insertion port.
  13. 13. The ceramic susceptor according to claim 1 or 2, wherein, In the case where each of the purge gas groove, the vacuum suction groove, and the thermocouple insertion groove is observed in a cross section perpendicular to the longitudinal direction of the groove, The height of the central part of the groove is 0.1-3.0 mm, The height of the end of the groove is 0.5-3.0 mm, The width of the groove is 2.0-10.0 mm, The ratio of the height of the end of the groove to the height of the central part of the groove is 0.2-1.0.

Description

Ceramic base Technical Field The present invention relates to ceramic susceptors. Background In a film forming apparatus and an etching apparatus for a semiconductor manufacturing process, a susceptor is used for supporting a wafer. As such a susceptor, a susceptor having a ceramic plate on which a wafer is placed and a cylindrical ceramic shaft attached to the ceramic plate is widely used. The ceramic plate generally has a structure in which internal electrodes such as a heater electrode, an RF electrode, and an electrostatic chuck (ESC) electrode are implanted in a ceramic substrate made of aluminum nitride (AlN) or the like having excellent heat resistance and corrosion resistance. As the ceramic plate, a ceramic plate having an internal path such as a purge gas flow path for ejecting a purge gas from the outer periphery or the surface of the ceramic plate, a vacuum suction path for enabling vacuum adsorption on the surface of the ceramic plate, and a thermocouple insertion path for accommodating a thermocouple for measuring the temperature of the ceramic plate is known. Patent document 1 (japanese patent application laid-open No. 2017-527984) discloses a substrate support including a first plate having a plurality of purge gas passages on a back side, a second plate disposed directly under the first plate, and an edge ring surrounding the first plate. In the substrate support, a plurality of purge gas channels extend from a single inlet in a central portion of the first plate to a plurality of outlets in a peripheral portion, the plurality of purge gas channels having substantially equal conductance. The document also discloses that the first plate further comprises 1 or more vacuum grooves or the like arranged on the back side. Patent document 2 (japanese patent application laid-open No. 2012-80103) discloses a susceptor that includes a disk-shaped ceramic plate, a thermocouple housing space formed inside the ceramic plate, and a thermocouple housed in the thermocouple housing space. The ceramic plate is obtained by joining a pair of ceramic plates, and the thermocouple housing space is formed by a horizontal groove formed on the joint surface of one or both of the pair of ceramic plates. Prior art literature Patent literature Patent document 1 Japanese patent application laid-open No. 2017-527984 Patent document 2 Japanese patent application laid-open No. 2012-80103 Disclosure of Invention In the case of providing the ceramic plate with a plurality of types of internal paths such as the purge gas flow path (e.g., the purge gas passage described above), the vacuum suction path (e.g., the vacuum groove described above), and the thermocouple insertion path (e.g., the thermocouple housing space or the horizontal groove described above), it is required that the different types of internal paths do not intersect in order to ensure the function of each internal path. Therefore, as an aspect, it is considered that these internal paths are configured in 2 layers by arranging the first bonding surface and the second bonding surface of the ceramic plate configured in 3 layers. However, the manufacturing cost of this method increases. Therefore, it is preferable that the internal paths of the plural kinds can be formed in 1 layer along 1 joint surface of the ceramic board having 2 layers. However, the purge gas flow path, the vacuum suction path, and the thermocouple insertion path have respective unique positional restrictions and requirements, and it is not easy to realize these internal paths in a 1-layer configuration. Recently, the inventors of the present invention have found that a ceramic susceptor having a purge gas flow path, a vacuum suction path, and a thermocouple insertion path so as to be housed in 1 layer without impairing the respective functions can be provided by having straight portions in each of the purge gas groove, the vacuum suction groove, and the thermocouple insertion groove, and by satisfying a predetermined relationship between an angle θ 1 formed by the straight portion of the purge gas groove and the straight portion of the thermocouple insertion groove and an angle θ 2 formed by the straight portion of the purge gas groove and the straight portion of the vacuum suction groove. Accordingly, an object of the present invention is to provide a ceramic susceptor having a purge gas flow path, a vacuum suction path, and a thermocouple insertion path so as to be housed in 1 layer without impairing the respective functions. According to the present invention, the following is provided. Scheme 1 A ceramic susceptor, comprising: A disc-shaped ceramic plate joined body including an upper ceramic plate and a lower ceramic plate joined to each other at a joint surface, the ceramic plate joined body having a first surface of the upper ceramic plate on a side opposite to the joint surface and a second surface of the lower ceramic plate on a side opposite to the joint surface; At least 1 internal