Substrate holder
There is provided a substrate holder including: a ceramic base member; a plurality of electrodes and at least one conductive member embedded in the ceramic base member; a plurality of connecting parts electrically connecting the plurality of electrodes and the at least one conductive member such that each of the at least one conductive member is connected to at least one of the plurality of electrodes; a plurality of terminals provided on at least one of the plurality of electrodes or the at least one conductive member. A resistance value between a connecting part connected to the at least one conductive member and a terminal provided on the at least one conductive member is smaller than a resistance value between both ends of each of the plurality of electrodes. The number of the plurality of terminals is smaller than two times the number of the plurality of electrodes.
1 . A substrate holder comprising:
a ceramic base member having an upper surface and a lower surface facing the upper surface in an up-down direction, the lower surface having a central region;
a plurality of electrodes embedded in the ceramic base member;
at least two conductive members arranged in a same plane and embedded in the ceramic base member;
a plurality of connecting parts electrically connecting the plurality of electrodes and the at least two conductive members such that each of the at least two conductive members is connected to at least one of the plurality of electrodes;
a plurality of terminals each of which is provided on at least one of the plurality of electrodes or at least one of the at least two conductive members, wherein
a resistance value between a connecting part, of the plurality of connecting parts, connected to the at least one of the at least two conductive members and a terminal, of the plurality of terminals, provided on the at least one of the at least two conductive members is smaller than a resistance value between both ends of each of the plurality of electrodes to suppress the generation of heat in the at least one of the at least two conductive members,
the number of the plurality of terminals is smaller than two times the number of the plurality of electrodes, and
each of the plurality of terminals extends downwardly from the central region of the lower surface of the ceramic base member,
an opening or a cutout is provided in one of the at least two conductive members, and a terminal of the plurality of terminals is located in the opening or the cutout, and
the terminal located in the opening or the cutout is electrically connected to an other of the at least two conductive members via one of the plurality of electrodes and one of the plurality of connecting parts.
2 . The substrate holder according to claim 1 , wherein
the plurality of electrodes and at least a part of the at least two conductive members are a mesh obtained by weaving a wire of at least one kind of metal selected from the group consisting of: tungsten, molybdenum and an alloy including the molybdenum and/or the tungsten.
3 . The substrate holder according to claim 2 , wherein
a thickness of each of the plurality of electrodes and a thickness of the at least two conductive members are in a range of 0.03 mm to 0.2 mm, except for an intersection point of the wire.
4 . The substrate holder according to claim 1 , wherein
the ceramic base member has a shape of a disc, and
a sum of an area of the at least two conductive members has a value which is not less than 40% of an area of a virtual circle having a radius defined by an outer diameter of a greatest electrode, of the plurality of electrodes, of which outer diameter is greatest among the plurality of electrodes.
5 . The substrate holder according to claim 1 , wherein
the ceramic base member has a shape of a disc, and
an area of the at least two conductive members is not less than 40% of a value obtained by dividing, by the number of the plurality of electrodes, an area of a virtual circle having a radius defined by an outer diameter of a greatest electrode, of the plurality of electrodes, of which outer diameter is greatest among the plurality of electrodes.
6 . The substrate holder according to claim 1 , wherein
the plurality of electrodes is made of a same material as a material of the at least two conductive members.
7 . The substrate holder according to claim 6 , wherein
each of the plurality of connecting members has a via structure, or has a structure made of the same material and integrally formed with one of the plurality of electrodes and the at least two conductive members.
8 . The substrate holder according to claim 1 , wherein
the plurality of electrodes is made of a different material from a material of the at least two conductive members.
9 . The substrate holder according to claim 1 , further comprising a tubular shaft joined to the lower surface of the ceramic base member, wherein
the plurality of terminals is arranged on an inner side with respect to an outer diameter of the shaft.
10 . A substrate holder comprising:
a ceramic base member having an upper surface and a lower surface facing the upper surface in an up-down direction, the lower surface having a central region;
a plurality of electrodes embedded in the ceramic base member;
at least two conductive members arranged in a same plane and embedded in the ceramic base member;
a plurality of connecting parts electrically connecting the plurality of electrodes and the at least two conductive members such that each of the at least two conductive members is connected to at least one of the plurality of electrodes;
a plurality of terminals each of which is provided on at least one of the plurality of electrodes or at least one of the at least two conductive members, wherein
a resistance value between a connecting part, of the plurality of connecting parts, connected to the at least one of the at least two conductive members and a terminal, of the plurality of terminals, provided on the at least one of the at least two conductive members is smaller than a resistance value between both ends of each of the plurality of electrodes to suppress the generation of heat in the at least one of the at least two conductive members,
the number of the plurality of terminals is smaller than two times the number of the plurality of electrodes, and
each of the plurality of terminals extends downwardly from the central region of the lower surface of the ceramic base member,
an opening or a cutout is provided in one of the at least two conductive members, and a terminal of the plurality of terminals is located in the opening or the cutout,
the terminal located in the opening or the cutout is electrically connected to an other of the at least two conductive members via one of the plurality of electrodes or one of the plurality of connecting parts, and
a terminal, of the plurality of terminals, that is not located in the opening or the cutout is electrically connected to the other of the at least two conductive members via another of the plurality of electrodes or another of the plurality of connecting parts.
11 . The substrate holder according to claim 10 , wherein
the terminal, of the plurality of terminals, that is not located in the opening or the cutout, is connected to one of the at least two conductive members except for the other of the at least two conductive members, and is electrically connected to the other of the at least two conductive members via another of the plurality of electrodes or another of the plurality of connecting parts.
12 . The substrate holder according to claim 10 , wherein
the terminal, of the plurality of terminals, that is not located in the opening or the cutout, is connected to one of the at least two conductive members, and is electrically connected to the other of the at least two conductive members via another of the plurality of electrodes or another of the plurality of connecting parts.