Monitoring of radio frequency (rf) impedance tuning operations

Abstract

A radio frequency (RF) control system includes an RF generator having a power amplifier that outputs an RF signal and a controller. A matching network receives the RF signal and generates at least one RF output signal. In the first mode of operation, the controller can adjust the frequency of the RF signal and the adjustment elements of the matching network to achieve impedance matching, and in the second mode of operation, the controller can only adjust the frequency while the frequency is adjusted to the target frequency. Adjusting element of a matching network to achieve impedance matching. The RF control system operates in continuous mode and pulsed mode of operation.

Description

technical field [0001] The present disclosure relates to radio frequency (RF) power delivery systems and monitoring of RF impedance tuning operations. Background technique [0002] The background description provided herein is for the purpose of generally presenting the context of the disclosure. The work of the inventors presently cited (to the extent described in this Background section) and aspects that may not be appropriate descriptions of prior art at the time of filing are neither expressly nor implicitly admitted with respect to this disclosure for existing technology. [0003] Plasma etching is frequently used in semiconductor manufacturing. In plasma etching, ions are accelerated by an electric field to etch exposed surfaces on a substrate. The electric field is generated based on an RF power signal generated by a radio frequency (RF) generator of the RF power system. The RF power signal generated by the RF generator must be precisely controlled to efficiently ...

AI Technical Summary

Problems solved by technology

A further challenge is introduced when the frequency is measured in the impedance matching network in order to predict the proper adjustment of the impedance actuators of the impedance matching network in traditional feedback methods, rather than control, to achieve the target frequency

Furthermore, to minimize the impact of impedance transient events, it is challenging to achieve process synchronization between frequency measurements and predicting the corresponding positions of the actuators in the matching network.

Still further, it becomes more difficult to achieve repeatability and reproducibility of the process to achieve the target frequency

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