JP6464072B2 - Substrate holding device - Google Patents

Description

  The present invention relates to an apparatus in which a substrate is held or placed on the surface of a base body in which a conductor is embedded.

  In order to apply a voltage to the electrostatic chuck electrode embedded in the base of the electrostatic chuck, a connection terminal having the following configuration has been proposed (see Patent Document 1). That is, a recess for connecting to the electrostatic chuck electrode is formed on the opposite side of the substrate to the suction side where the substrate is sucked. A substantially cylindrical connection terminal is fitted into the recess, and one end face thereof is brazed to the electrostatic chuck electrode. A female screw is formed on the inner side surface of the connection terminal, and a male screw formed on a mounting bracket connected to an external power source is screwed to the female screw.

JP-A-10-189696

  However, if the approximately cylindrical connection terminal is simply shortened in the axial direction in order to reduce the thickness of the base, the screw engagement length with the other substantially cylindrical connection terminal is also shortened, resulting in poor connection between both connection terminals. Etc. may occur.

  Accordingly, an object of the present invention is to provide a substrate holding device capable of improving the stability of the connection state of a power receiving terminal with respect to a power feeding terminal connected to an external power source while reducing the thickness of the base.

  The substrate holding device of the present invention includes a flat base on which a substrate is held or placed on one end surface, a conductor embedded in the base, a power receiving terminal electrically connected to the conductor, And a through hole penetrating through the base at a location spaced from the concave portion, wherein a concave portion is formed on the other end surface of the base to expose a part of the conductor. A first element that is inserted into the recess of the base and joined to the conductor, and a cylindrical second element that is inserted halfway through the through hole of the base. And an intermediate element that connects the first element and the second element.

  According to the substrate holding device of the present invention, the substantially cylindrical member (for example, a bolt) having an external thread formed on the outer peripheral surface thereof, the through hole and the cylindrical second member from the one end surface side (attraction surface side) of the base. The hollow part of the element can be penetrated. Further, a substantially cylindrical member (for example, a nut) having a female screw formed on the inner peripheral surface after passing through a through-hole formed in a base joined to the other end surface side of the base member. The male screw can be screwed onto the female screw formed on the base. Thereby, the connection state of the power receiving terminal joined to the conductor of the first element and the power feeding terminal constituted by the substantially columnar member is stably maintained.

  In this state, a voltage is applied to the conductor embedded in the base body through the power supply terminal connected to the external power source and the power receiving terminal connected to the power supply terminal. When the conductor constitutes an electrostatic chuck electrode, a substrate such as a wafer placed on one end surface side of the substrate is attracted and held on the substrate by a Coulomb force or the like by applying a voltage to the conductor. In the case where the conductor constitutes a resistance heating element, the voltage is applied to the conductor to make the substrate temperature uniform regardless of the location of the substrate. When the conductor constitutes a high-frequency voltage application electrode (or grounding electrode), the grounding electrode (which is embedded in the substrate 1 or arranged outside the substrate 1 and is paired with the conductor and the grounding electrode) Further, when a high frequency voltage is applied between the high frequency voltage application electrodes), plasma such as halogen gas is generated around the substrate.

  Each of the first element and the second element inserted into each of the recess and the through-hole formed in the other end surface of the base is spaced apart from each other while continuing through the intermediate element. For this reason, compared with the power receiving terminal of the structure arrange | positioned so that a 1st element and a 2nd element may overlap in an axial direction, thickness reduction of the power receiving terminal which comprises the board | substrate holding | maintenance apparatus of this invention and by extension, thickness reduction of a base | substrate Is planned.

  In the substrate holding device according to one aspect of the present invention, a recess is formed in the other end surface of the base so as to allow the recess and the through hole to be continuous, and a groove into which the intermediate element of the power receiving terminal is inserted is formed.

  According to the substrate holding device of the said structure, the protrusion amount of the intermediate element of a receiving terminal can be reduced or eliminated from the other end surface of a base | substrate. When the intermediate element of the power receiving terminal does not protrude from the other end surface of the base, it is not necessary to form a recess for receiving the protrusion on the base.

  In the substrate holding device according to one aspect of the present invention, it is preferable that the groove portion of the base body is formed so as to be shallower from the other end surface than the concave portion.

  According to the substrate holding device of the configuration, even if an external force is applied to the power receiving terminal in a direction perpendicular to the thickness direction of the base body, the first element contacts the step portion between the recess and the groove. This further improves the positional stability of the power receiving terminal with respect to, and hence the joining stability between the first element and the conductor.

  In the substrate holding device according to one aspect of the present invention, it is preferable that a counterbore portion in which the second element is inserted into the through hole is formed in the base body.

  According to the substrate holding device having such a configuration, the positions of the second element and the entire power receiving terminal can be further stabilized in the thickness direction of the base body, and further, the joint stability between the first element and the conductor can be further improved. It is done.

The top view of the substrate holding device as one embodiment of the present invention. The bottom view of the substrate holding device as one embodiment of the present invention. IIIA-IIIA sectional view taken on the line of FIG. IIIB-IIIB sectional view taken on the line of FIG. Explanatory drawing regarding the attachment aspect of the base | substrate with respect to the base corresponding to FIG. 3A. Explanatory drawing regarding the attachment aspect of the base | substrate with respect to the base corresponding to FIG. 3B.

(Constitution)
The substrate holding device as one embodiment of the present invention shown in FIGS. 1 to 4 includes a base 1, a first conductor 21, a second conductor 22, a first power receiving terminal 41, and a second power receiving terminal 41. An electrostatic chuck including a power receiving terminal 42.

  The substrate 1 is made of an insulating dielectric such as a ceramic sintered body, and is formed in a flat plate shape having one end surface (the upper surface in FIG. 3A) as an adsorption surface on which a substrate (not shown) such as a wafer is adsorbed and held. . The substrate 1 in the present embodiment has a substantially disc shape, but may have various shapes such as a polygonal plate shape or an elliptical plate shape.

  A plurality of substantially cylindrical, substantially hemispherical, or substantially frustoconical pins 10 protruding from the adsorption surface are formed on the adsorption surface of the base 1 so as to be arranged in a triangular lattice shape. In addition, the arrangement | positioning aspect of the pin 10 may be changed, such as tetragonal lattice shape or concentric circle shape, and the pin 10 may be partially or entirely abbreviate | omitted.

  A substantially cylindrical shape that is recessed to expose a part of the first conductor 21 (in the absence of the first power receiving terminal 41) on the other end surface (the lower surface in FIG. 2) opposite to the adsorption surface of the substrate 1. The first concave portion 111 is formed, and a first through hole 11 having a circular cross section penetrating the base body 1 is formed at a location away from the first concave portion 111 (see FIG. 3A). In the present embodiment, two sets of the first recesses 111 and the first recesses are provided at two locations that are separated from the center of the base 1 by a second specified distance and that are spaced apart from each other by about 90 ° in the circumferential direction of the base 1. A through hole 11 is formed. In the present embodiment, the first through hole 11 is separated from the first recess 111 to the outside in the radial direction of the base body 1, but the separation direction may be a different direction such as a radial inside or a circumferential direction of the base body 1.

  A first groove portion 110 is formed in the other end surface of the base body 1 so as to be continuous with the first concave portion 111 and the first through hole 11 (see FIG. 3A). In other words, the first groove 110 extends in the direction in which the first through hole 11 and the first recess 111 are separated. The first groove 110 is formed so as to be shallower than the first recess 111 from the other end surface. A first counterbore portion 112 is formed in the first through hole 11 so that the diameter of the lower portion is larger than that of the upper portion (see FIG. 3A).

  Similarly, the substantially cylindrical second that is recessed to expose a part of the second conductor 22 (in the state where the second power receiving terminal 42 does not exist) on the other end surface opposite to the suction surface of the base 1. A concave portion 121 is formed, and a second through hole 12 having a circular cross section that penetrates the base 1 is formed at a location spaced from the second concave portion 121 (see FIG. 3B). In the present embodiment, two sets of the second recesses 121 and the second recesses are formed at two locations that are separated from the center of the base 1 by a second specified distance and that are spaced apart from each other by about 180 ° in the circumferential direction of the base 1. A through hole 12 is formed. In the present embodiment, the second through hole 12 is separated from the second recess 121 to the outside in the radial direction of the base body 1, but the separation direction may be a different direction such as a radial inside or a circumferential direction of the base body 1.

  A second groove portion 120 is formed in the other end surface of the base 1 so as to be continuous with the second recess 121 and the second through hole 12 (see FIG. 3B). That is, the second groove portion 120 extends in the direction in which the second through hole 12 and the second recess 121 are separated. The second groove 120 is formed so as to be shallower than the second recess 121 from the other end surface. A second counterbore portion 122 is formed in the second through hole 12 so that the diameter of the lower portion is larger than that of the upper portion (see FIG. 3B).

  The first conductor 21 is made of a thin plate-like or thin-film metal embedded in the base 1 in a posture parallel to the attracting surface, and constitutes an electrostatic chuck electrode. In the present embodiment, two independent first conductors 21 are embedded in the base 1, and each of the two first power receiving terminals 41 is connected to each of the two first conductors 21. ing. The second conductor 22 is made of a thin plate-like or thin-film metal embedded in a posture parallel to the suction surface at a height position farther from the suction surface than the first conductor 21 in the base body 1. Constructs a heating resistor. In the present embodiment, one second conductor 22 is embedded in the base 1, and each of the two second power receiving terminals 42 is connected to each of both ends of the second conductor 22.

  The first power receiving terminal 41 includes a first element 411 having a substantially columnar shape, a second element 412 having a substantially cylindrical shape shorter than the first element 411, and a first element 411 and a second element 412 that are continuous at the base end. A substantially flat intermediate element 410 (see FIG. 3A). The first element 411 is fitted into the first recess 111 of the base 1 and joined (for example, brazed) to the first conductor 21. The second element 412 is fitted into the first counterbore 112 of the first through-hole 11 of the base 1, and its end surface is brought into contact with the stepped portion of the first through-hole 11 formed by the first counterbore 112. ing. The intermediate element 410 is fitted into the first groove 110 of the base body 1. The lower end surface of the first power receiving terminal 41 is flat, and the height position of the lower surface of the base 1 is the same (see FIG. 3A).

  The second power receiving terminal 42 includes a substantially cylindrical first element 421, a substantially cylindrical second element 422 that is the same as or slightly longer than the first element 421, and the first element 421 and the second element 422. And a substantially flat intermediate element 420 that continues at the base end (see FIG. 3B). The first element 421 is fitted into the second recess 121 of the base body 1 and joined (for example, brazed) to the second conductor 22. The second element 422 is fitted into the second counterbore portion 122 of the second through-hole 12 of the base body 1, and its end surface is brought into contact with the step portion of the second through-hole 12 formed by the second counterbore portion 122. ing. The intermediate element 420 is fitted into the second groove 120 of the base body 1. The lower end surface of the second power receiving terminal 42 is flat, and the height position of the lower surface of the base 1 is the same (see FIG. 3B).

(Production method)
The electrostatic chuck (substrate holding device) having the above-described configuration is manufactured, for example, according to a method described in JP2013-157570A. That is, a molded body of the first raw material powder in which the first conductor 21 (electrostatic chuck electrode) is embedded, and a molded body of the second raw material powder in which the second conductor 22 (heating resistor) is embedded. Are hot-press sintered together. Then, the pin 10, the first through hole 11, the second through hole 12, the first recess 111, the second recess 121, and the like are formed on the sintered body according to an appropriate processing method such as blasting or machining. Thus, the electrostatic chuck is manufactured.

  As the first raw material powder and the second raw material powder, for example, a high-purity (for example, purity 99.9% or more) aluminum nitride powder, and if necessary, a sintering aid such as an appropriate amount of yttrium oxide powder was added thereto. Mixed raw material powder is used. In addition, other ceramic powders such as alumina powder may be used as the raw material powder. As the 1st conductor 21 and the 2nd conductor 22, Mo foil (for example, thickness 0.1 [mm]) is used, for example.

  In addition, the first conductor 21 and a pair of first raw material powder compacts sandwiching the first conductor 21, and the second conductor 22 and a pair of second raw material powder compacts sandwiching the first conductor 21 are put together. The electrostatic chuck may be manufactured by hot press sintering. In addition, the compact of the first raw material powder in which the first conductor 21 is embedded and the compact of the second raw material powder in which the second conductor 22 is embedded are separately hot-press sintered. The electrostatic chuck may be manufactured by joining the base portions after the first base portion and the second base portion are manufactured. In this case, an alumina-yttrium oxide-based bonding material may be used as the bonding material for the aluminum nitride sintered body, and a glass-based bonding material may also be used. Quartz, soda-lime glass, borosilicate glass, etc. are employed as the glass material.

(function)
According to the electrostatic chuck having the above-described configuration, as shown in FIG. 4A, the first through hole 11 and the first power receiving terminal 41 from the one end surface side (attraction surface side) of the base body 1 are connected to the bolt X1. The hollow portion 414 of the second element 412 can be penetrated. Further, the bolt X1 is made to pass through a through hole formed in the flat base 5 joined to the other end surface side of the base 1, and then the nut Y1 (or the female formed on the base 5). Screw). The connection state between the first power receiving terminal 41 and the first power supply terminal constituted by the bolt X1 (or its bolt head) connected to the external power supply is stably maintained.

  As shown in FIG. 4B, the bolt X2 passes through the hollow portion 424 of the cylindrical second element 422 of the second through hole 12 and the second power receiving terminal 42 from the one end surface side (attraction surface side) of the base 1. Can be made. Further, the bolt X2 is made to pass through a through hole formed in the flat base 5 joined to the other end surface side of the base 1, and then the nut Y2 (or the female formed on the base 5). Screw). The connection state between the second power receiving terminal 42 and the second power feeding terminal constituted by the bolt X2 (or its bolt head) connected to the external power source is stably maintained.

  In this state, a voltage is applied to the first conductor 21 constituting the electrostatic chuck electrode embedded in the substrate 1 through the bolt X1 constituting the first power supply terminal and the first power receiving terminal 41 by the external power source. As a result, a substrate such as a wafer placed on one end surface side of the base 1 is attracted and held on the base 1 by a Coulomb force or the like. A voltage is applied or current is supplied to the second conductor 22 constituting the heating resistor embedded in the base body 1 through the bolt X2 constituting the second power feeding terminal and the second power receiving terminal 42 by the external power source. As a result, the substrate temperature can be made uniform regardless of the location of the temperature.

  The first element 411 and the second element 412 of the first power receiving terminal 41 inserted into the first recess 111 and the first through hole 11 (or the first counterbore part 112) formed on the other end surface of the base body 1, respectively. Are spaced apart from each other in a direction perpendicular to the thickness direction of the substrate 1 while continuing through the intermediate element 410 (see FIG. 4A). The first element 421 and the second element 422 of the second power receiving terminal 42 inserted into the second recess 121 and the second through hole 12 (or the second counterbore part 122) formed on the other end surface of the base body 1, respectively. Are spaced apart from each other in a direction perpendicular to the thickness direction of the substrate 1 while continuing through the intermediate element 420 (see FIG. 4B). For this reason, compared with the connection terminal of the structure arrange | positioned so that a 1st element and a 2nd element may overlap in an axial direction, thickness reduction of the 1st power receiving terminal 41 and the 2nd power receiving terminal 42 or shortening to an axial direction ) As a result, the substrate 1 can be thinned.

(Other embodiments of the present invention)
In the substrate holding device (electrostatic chuck) in the embodiment, the second conductor 22 may be omitted, and the second through hole 12, the second recess 121, and the second groove 120 may be omitted correspondingly.

  In the substrate holding device in the embodiment, in addition to the first conductor 21 and the second conductor 22, or instead of the first conductor 21 or the second conductor 22, a high-frequency voltage application electrode or a ground electrode is configured. The conductor to be embedded may be embedded in the base 1, and a through hole, a concave portion and a groove corresponding to the conductor may be formed in the base 1, and a power receiving terminal may be provided there.

  One or both of the first groove part 110 and the second groove part 120 may be omitted from the base body 1. In this case, one or both of the lower end surface of the first power receiving terminal 41 and the lower end surface of the second power receiving terminal 42 protrudes downward from the other end surface (lower surface) of the base 1. By forming the recessed part to receive, the lower end surface of the base | substrate 1 can be joined to the upper end surface of the base 5 entirely (refer FIG. 4A and FIG. 4B).

  The depths of the first groove 110 and the first recess 111 from the lower end surface of the base body 1 may match (see FIG. 3A). The depths of the second groove 120 and the second recess 121 from the lower end surface of the base 1 may be the same (see FIG. 3B).

  The first counterbore 112 may be omitted in the first through hole 11 and the first through hole 11 may be formed in a substantially cylindrical shape. The second counterbore part 122 may be omitted in the second through hole 12 and the second through hole 12 may be formed in a substantially cylindrical shape.

DESCRIPTION OF SYMBOLS 1 ... Base | substrate, 10 ... Pin, 11 ... 1st through-hole, 12 ... 2nd through-hole, 21 ... 1st conductor (electrostatic chuck electrode), 22 ... 2nd conductor (heating resistor), 41 ... 1st DESCRIPTION OF SYMBOLS 1 Power receiving terminal, 42 ... 2nd power receiving terminal, 110 ... 1st groove part, 111 ... 1st recessed part, 112 ... 1st counterbore part, 120 ... 2nd groove part, 121 ... 2nd recessed part, 122 ... 2nd counterbore part, 410 Intermediate element 411 First element 412, Second element 420 Intermediate element 421 First element 422 Second element

Claims (4)

A substrate holding apparatus comprising: a flat base on which a substrate is held or placed on one end face; a conductor embedded in the base; and a power receiving terminal electrically connected to the conductor. There,
A recess that is recessed so as to expose a part of the conductor is formed on the other end surface of the substrate, and a through-hole that penetrates the substrate is formed at a location spaced from the recess,
A first element inserted into the recess of the base and joined to the conductor; a cylindrical second element inserted halfway through the through hole of the base; A substrate holding apparatus comprising: one element and an intermediate element that makes the second element continuous. The substrate holding apparatus according to claim 1, wherein
The substrate holding apparatus, wherein the recess and the through hole are continuously formed in the other end surface of the base body, and a groove portion into which the intermediate element of the power receiving terminal is inserted is formed. The substrate holding apparatus according to claim 2, wherein
The substrate holding apparatus, wherein the groove portion of the base body is formed so as to be recessed shallower from the other end surface than the concave portion. In the board | substrate holding | maintenance apparatus as described in any one of Claims 1-3,
The substrate holding device, wherein a counterbore portion into which the second element is inserted into the through hole is formed in the base body.