US 12,435,965 B2
Wafer state detection
Noah Elliot Baker, West Linn, OR (US)
Assigned to Lam Research Corporation, Fremont, CA (US)
Appl. No. 18/558,327
Filed by Lam Research Corporation, Fremont, CA (US)
PCT Filed Apr. 29, 2022, PCT No. PCT/US2022/026903
§ 371(c)(1), (2) Date Oct. 31, 2023,
PCT Pub. No. WO2022/235499, PCT Pub. Date Nov. 10, 2022.
Claims priority of provisional application 63/201,522, filed on May 3, 2021.
Prior Publication US 2024/0219165 A1, Jul. 4, 2024
Int. Cl. G01B 7/28 (2006.01); H01J 37/32 (2006.01); H01L 21/67 (2006.01); H01L 21/683 (2006.01)
CPC G01B 7/28 (2013.01) [H01J 37/32715 (2013.01); H01L 21/67288 (2013.01); H01L 21/6833 (2013.01); H01J 2237/2007 (2013.01); H01J 2237/24578 (2013.01)] 27 Claims
OG exemplary drawing
 
1. An apparatus for wafer state detection, comprising:
an RF blocking filter;
a DC blocking filter; and
a controller coupled to a plurality of electrodes associated with an electrostatic chuck (ESC) via the RF blocking filter and the DC blocking filter, wherein the controller is configured to:
cause an input signal to be injected in an input side of a circuit associated with the plurality of electrodes, the RF blocking filter, and the DC blocking filter, wherein the input side corresponds to a first electrode of the plurality of electrodes;
measure characteristics of an output signal at an output side of the circuit, wherein the output side corresponds to a second electrode of the plurality of electrodes; and
calculate wafer state characteristics of a wafer positioned on a surface of a platen of the ESC based on the characteristics of the output signal.