US 12,444,570 B2
Electrostatic chuck heater resistance measurement to approximate temperature
Changyou Jing, Livermore, CA (US); Oleksandr Mikhnenko, San Diego, CA (US); and Christopher Kimball, San Jose, CA (US)
Assigned to Lam Research Corporation, Fremont, CA (US)
Appl. No. 17/437,401
Filed by Lam Research Corporation, Fremont, CA (US)
PCT Filed Mar. 10, 2020, PCT No. PCT/US2020/021836
§ 371(c)(1), (2) Date Sep. 8, 2021,
PCT Pub. No. WO2020/185744, PCT Pub. Date Sep. 17, 2020.
Prior Publication US 2022/0172925 A1, Jun. 2, 2022
Int. Cl. H01J 37/32 (2006.01)
CPC H01J 37/32082 (2013.01) [H01J 37/32266 (2013.01); H01J 37/32522 (2013.01); H01J 2237/2007 (2013.01)] 27 Claims
OG exemplary drawing
 
1. A controller, comprising:
a voltage sensor coupled to a heater trace integrated in an electrostatic chuck, the voltage sensor configured to sense a voltage difference across the heater trace, wherein the heater trace is associated with a heater zone;
a current sensor coupled to the heater trace and configured to directly sense a current in the heater trace;
a resistance identifier configured to identify a resistance of the heater trace based on the voltage difference and the current in the heater trace that are sensed; and
a temperature correlator configured to approximate a temperature of the heater zone based on the resistance of the heater trace and a correlation function of the heater trace,
wherein the correlation function of the heater trace uses a temperature coefficient of resistance of the heater trace,
wherein the correlation function of the heater trace defines a non-linear correlation of temperature and resistance.