US 11,990,318 B2
Filter circuit
Yohei Yamazawa, Miyagi (JP)
Assigned to TOKYO ELECTRON LIMITED, Tokyo (JP)
Filed by TOKYO ELECTRON LIMITED, Tokyo (JP)
Filed on Nov. 5, 2021, as Appl. No. 17/520,500.
Claims priority of application No. 2020-185717 (JP), filed on Nov. 6, 2020; application No. 2020-217101 (JP), filed on Dec. 25, 2020; and application No. 2021-116623 (JP), filed on Jul. 14, 2021.
Prior Publication US 2022/0148854 A1, May 12, 2022
Int. Cl. H01J 37/32 (2006.01)
CPC H01J 37/32183 (2013.01) [H01J 37/32724 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A filter circuit provided in a plasma processing device for processing a substrate using plasma generated using power of a first frequency of 4 MHz or more and power of a second frequency of 100 Hz or more and less than 4 MHz, the filter circuit comprising:
a first filter provided in a wiring between a conductive member provided in the plasma processing device and a power supply configured to supply power of a third frequency of less than 100 Hz or control power which is direct-current (DC) power, to the conductive member; and
a second filter provided in a wiring between the first filter and the power supply,
wherein the first filter includes:
a first coil which is connected to the wiring in series and which has no core material or has a first core material with a relative permeability of less than 10; and
a series resonant circuit which is connected between the wiring and a ground and which has a coil and a capacitor which are connected in series, and
wherein the second filter includes a second coil which is connected to the wiring provided between the first coil and the power supply in series and which has a second core material with a relative permeability of 10 or more.