US 12,476,082 B2
Radiofrequency signal filter arrangement for plasma processing system
Alexei Marakhtanov, Albany, CA (US); Felix Kozakevich, Sunnyvale, CA (US); Bing Ji, Pleasanton, CA (US); Ranadeep Bhowmick, San Jose, CA (US); and John Holland, San Jose, CA (US)
Assigned to Lam Research Corporation, Fremont, CA (US)
Appl. No. 17/793,372
Filed by Lam Research Corporation, Fremont, CA (US)
PCT Filed Jan. 30, 2021, PCT No. PCT/US2021/015956
§ 371(c)(1), (2) Date Jul. 15, 2022,
PCT Pub. No. WO2021/158451, PCT Pub. Date Aug. 12, 2021.
Claims priority of provisional application 62/970,168, filed on Feb. 4, 2020.
Prior Publication US 2023/0054699 A1, Feb. 23, 2023
Int. Cl. H01J 37/32 (2006.01)
CPC H01J 37/32183 (2013.01) [H01J 37/32541 (2013.01); H01J 37/32577 (2013.01); H01J 37/32642 (2013.01); H01J 37/32724 (2013.01); H01J 2237/3341 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A tunable edge sheath system, comprising:
a coupling ring configured to couple to a bottom surface of an edge ring that surrounds a wafer support area within a plasma processing chamber;
an electrode embedded within the coupling ring, the electrode having an annular shape;
a plurality of radiofrequency signal supply pins coupled to the electrode embedded within the coupling ring, each of the plurality of radiofrequency signal supply pins extending through a corresponding hole formed through a bottom surface of the coupling ring;
a plurality of radiofrequency signal filters respectively connected to the plurality of radiofrequency signal supply pins, each of the plurality of radiofrequency signal filters configured to provide a high impedance to a radiofrequency signal used to generate a plasma within the plasma processing chamber; and
a ring-shaped radiofrequency signal supply conductor, wherein each of the plurality of radiofrequency signal filters is electrically connected between a respective one of the plurality of radiofrequency signal supply pins and the ring-shaped radiofrequency signal supply conductor.
 
12. A plasma processing system, comprising:
a primary electrode having a substantially cylindrical shape defined by a top surface, a bottom surface, and an outer side surface;
a ceramic layer disposed on the top surface of the primary electrode, the ceramic layer configured to receive and support a semiconductor wafer;
a radiofrequency signal generator electrically connected through an impedance matching system to the primary electrode, the radiofrequency signal generator configured to generate and supply radiofrequency signals to the primary electrode;
an edge ring formed of an electrically conductive material and configured to circumscribe the ceramic layer, the edge ring positioned radially adjacent to the ceramic layer;
a coupling ring coupled to a bottom surface of the edge ring, the coupling ring formed of an electrical insulator material, the coupling ring including an embedded electrode;
a plurality of radiofrequency signal supply pins electrically and physically connected to the embedded electrode, each of the plurality of radiofrequency signal supply pins extending through a corresponding hole formed through a bottom surface of the coupling ring; and
a plurality of radiofrequency signal filters respectively connected to the plurality of radiofrequency signal supply pins, each of the plurality of radiofrequency signal filters configured to provide a high impedance to the radiofrequency signals that are supplied to the primary electrode by the radiofrequency signal generator; and
a ring-shaped radiofrequency signal supply conductor, wherein each of the plurality of radiofrequency signal filters is electrically connected between a respective one of the plurality of radiofrequency signal supply pins and the ring-shaped radiofrequency signal supply conductor.