US 11,923,174 B2
Plasma processing system and method of supporting plasma ignition
Yuji Kitamura, Miyagi (JP)
Assigned to TOKYO ELECTRON LIMITED, Tokyo (JP)
Filed by TOKYO ELECTRON LIMITED, Tokyo (JP)
Filed on Aug. 28, 2020, as Appl. No. 17/006,557.
Claims priority of application No. 2019-156861 (JP), filed on Aug. 29, 2019.
Prior Publication US 2021/0066044 A1, Mar. 4, 2021
Int. Cl. H01J 37/32 (2006.01); H01L 21/66 (2006.01); H01L 21/67 (2006.01)
CPC H01J 37/32183 (2013.01) [H01J 37/3299 (2013.01); H01L 21/67069 (2013.01); H01L 21/67253 (2013.01); H01L 22/20 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A plasma processing system comprising:
a plasma processing apparatus configured to perform a plasma processing on a substrate and including:
a processing container configured to accommodate the substrate;
a power supply configured to supply a radio-frequency power into the processing container through a conductor; and
a matching box including a variable capacitor connected between the conductor and the power supply and another variable capacitor connected between the power supply and a ground potential, and
a controller configured to control the plasma processing apparatus, wherein the controller is further configured to:
collect a measurement value indicating a matching state of impedance between the power supply that supplies the radio-frequency power to the plasma and the plasma, with respect to each value of a variable that is adjustable related to matching of the impedance;
specify as a passing point, a point corresponding to a value of the variable that maximizes a gradient of change of the measurement value with respect to a vector extending from a point corresponding to the variable to a matching point corresponding to a measurement value in a state where the impedance is matched;
specify as a control start point, a point farther from the matching point than the passing point on a straight line including the passing point and the matching point;
ignite the plasma in the plasma processing apparatus by controlling the variable such that the measurement value changes from the control start point toward the matching point and from a direction in which the gradient of change of the measurement value is relatively steep toward a direction in which the gradient of change of the measurement value is relatively gentle, along the straight line.