US 12,334,309 B2
Filter device and plasma processing apparatus
Naohiko Okunishi, Miyagi (JP); and Nozomu Nagashima, Miyagi (JP)
Assigned to TOKYO ELECTRON LIMITED, Tokyo (JP)
Filed by TOKYO ELECTRON LIMITED, Tokyo (JP)
Filed on Oct. 11, 2022, as Appl. No. 17/963,735.
Application 17/963,735 is a continuation of application No. 15/961,001, filed on Apr. 24, 2018, granted, now 11,495,443.
Claims priority of application No. 2017-086492 (KE), filed on Apr. 25, 2017.
Prior Publication US 2023/0031368 A1, Feb. 2, 2023
Int. Cl. H01J 37/32 (2006.01); C23C 16/458 (2006.01); H01L 21/67 (2006.01); H01L 21/683 (2006.01); H01L 21/687 (2006.01)
CPC H01J 37/32577 (2013.01) [C23C 16/4585 (2013.01); H01J 37/32091 (2013.01); H01J 37/32174 (2013.01); H01J 37/32706 (2013.01); H01J 37/32724 (2013.01); H01L 21/68785 (2013.01); H01L 21/68792 (2013.01); H01J 37/32458 (2013.01); H01J 37/32532 (2013.01); H01L 21/67069 (2013.01); H01L 21/6831 (2013.01); H01L 21/6833 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A filter device comprising:
a first coil group including a plurality of coils extending spirally about a central axis and spirally wound with a first inner diameter;
a second coil group including a plurality of coils extending spirally about the central axis along which the plurality of coils of the first coil group is arranged, and spirally wound around the first coil group with a second inner diameter larger than the first inner diameter of the first coil group; and
a third coil group including a plurality of coils the central axis where the plurality of coils of each of the first coil group and the second coil group is arranged, and spirally wound around the second coil group with a third inner diameter larger than the second inner diameter of the second coil group,
wherein a pitch between respective turns of the plurality of coils of the second coil group is larger than a pitch between respective turns of the plurality of coils of the first coil group such that the first coil group and the second coil group have substantially the same inductance,
wherein the second coil group overlaps the first coil group in a radial direction,
wherein the plurality of coils of each of the first to the third coil groups have extension lines, respectively, which extend from one end of the coils in an axial direction in which the central axis extends,
wherein in each of the first to the third coil groups, the extension lines are provided at equal intervals in a circumferential direction about the central axis, and
wherein the extension lines of the plurality of coils of each of the first to the third coil groups are provided in an angular range having an angle of 90° or more and 270° or less about the central axis.