Process control for ion energy delivery using multiple generators and phase control
AssigneeLam Research Corporation
InventorsRanadeep Bhowmick, Felix Kozakevich, Alexei Marakhtanov, John Holland, Eric Hudson
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Abstract
A method for applying RF power in a plasma process chamber is provided, including: generating a first RF signal; generating a second RF signal; generating a third RF signal; wherein the first, second, and third RF signals are generated at different frequencies; combining the first, second and third RF signals to generate a combined RF signal, wherein a wave shape of the combined RF signal is configured to approximate a sloped square wave shape; applying the combined RF signal to a chuck in the plasma process chamber.
Claims19
A system for applying radio frequency (RF) power to a chuck in a plasma process chamber, comprising:
- a RF signal generator subsystem with a plurality of RF generators configured to generate a plurality of RF signals of low frequencies that are distinctly different from one another, the plurality of RF signals includes a primary RF signal and a plurality of secondary RF signals, each secondary RF signal of the plurality of secondary RF signals generated by adjusting a phase of the respective secondary RF signal relative to a primary phase of the primary RF signal;
- and
- an impedance matching circuit to combine the plurality of RF signals to generate a combined RF signal for applying to the chuck, the combined RF signal configured to have a wave shape that approximates a sloped square wave shape, the sloped square wave shape configured to compensate for capacitance of the chuck.
A system for applying radio frequency (RF) power to a chuck in a plasma process chamber, comprising:
- a RF signal generator subsystem having,
- a primary RF generator to generate a primary RF signal, and
- a plurality of secondary RF generators to generate a plurality of secondary RF signals,
- wherein each of the plurality of secondary RF generators is configured to generate a respective secondary RF signal of a distinct frequency by adjusting a phase of the respective secondary RF signal relative to a primary phase of the primary RF signal, and
- wherein the RF signal generator subsystem is configured to combine the primary RF signal and the plurality of secondary RF signals to generate a combined RF signal, such that a wave shape of the combined RF signal is configured to approximate a sloped square wave shape, the sloped square wave shape configured to compensate for capacitance of the chuck, the adjusting of the phase of the respective secondary RF signal causing an adjustment to an amount of sloping of the wave shape of the combined RF signal.
Dependencies are inferred from the claim text.