US 11,961,712 B2
Combining the determination of single and mutual, preset preserving, impedance loads with advances in single and double sensor calibration techniques in the application of single and pairwise calibration of sensors
Frederick Winter, San Jose, CA (US)
Assigned to Advanced Energy Industries, Inc., Denver, CO (US)
Filed by Advanced Energy Industries, Inc., Fort Collins, CO (US)
Filed on Apr. 26, 2021, as Appl. No. 17/240,139.
Prior Publication US 2022/0375718 A1, Nov. 24, 2022
Int. Cl. H01J 37/32 (2006.01)
CPC H01J 37/32183 (2013.01) 20 Claims
OG exemplary drawing
 
1. A match network configured for impedance matching a radio frequency power generator to a plasma processing chamber, the match network comprising:
a match input;
an output; and
a plasma return input;
a first sensor coupled to a first electrical path between the match input and the output;
a second sensor coupled to a second electrical path between the plasma return input and a ground connection;
a memory storing a first calibration matrix, K1, a second calibration matrix, K2, and a modified second calibration matrix, K2′;
a controller configured to monitor power delivery to the plasma processing chamber via the first and second sensors, wherein data from the first or second sensor is calibrated via the first calibration matrix, K1, and data from the second or first sensor, respectively, is calibrated via the modified second calibration matrix, K2′,
wherein the modified second calibration matrix, K2′, accounts for errors between the first and second sensors when the first and second sensors are calibrated by measuring current and voltage at the output and the plasma return input with a mutual load coupled between the first and second sensors.