Method and device for acquisition of voltage and current magnitude of radio frequency power wave applied to radio frequency load

Abstract

A technique for measuring the current, voltage and phase of an RF power wave to an RF load, accounts for the finite length of the voltage and current pickups, and corrects for effects of standing wave components of voltage and current. Voltage and current are computed as complex functions of the voltage pickup signal and the current pickup signal, based on coefficients precalibrated for said-predetermined radio frequency. Alternatively, a corrected current value can base on the corrected voltage value and complex load impedance.

Description

technical field [0001] This invention relates to the accurate measurement of the voltage, current and phase of RF power applied to a non-linear load, and more particularly to a method for measuring the current, voltage and phase of radio frequency (RF) electrical power supplied to an RF plasma chamber. The probe that makes the measurement. Background technique [0002] In a typical RF plasma generator arrangement, RF waves are generated at a predetermined frequency, ie, 13.56 MHz, by a high power RF source and transmitted along a power channel to a plasma chamber. Since there is usually a severe impedance mismatch between the RF power source and the plasma chamber, an impedance matching network is inserted between the two. Due to nonlinearities in the plasma chamber, and losses in the wires or in the impedance matching network, not all of the output power of the RF power generator reaches the plasma chamber. Therefore, it is more convenient to set a probe at the power inpu...

AI Technical Summary

Problems solved by technology

Diode detectors are inherently non-linear for low signal levels and suffer from significant temperature drift

Unfortunately, the prior art has not been able to compensate for this, and the calibration algorithm for voltage / current probes is also unknown in the prior art

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