Impedance matching adjusting method and device applied to radio frequency power supply

Abstract

The invention discloses an impedance matching adjusting method and device applied to a radio frequency power supply, and the method comprises the steps: collecting incident and reflected waves between an impedance matching network and a load, determining whether the impedance is matched or not according to the amplitude and phase angle of the incident wave and the reflected wave, and if not, obtaining an amplitude difference voltage and a phase angle difference voltage; acquiring a control signal according to the amplitude difference voltage and the phase angle difference voltage, and inputting the control signal to a controlled current source to obtain a control current; increasing the magnetic induction intensity of a magnetic core by the control current, so as to increase the saturation degree of the magnetic core and influence the effective magnetic conductivity of the magnetic core is influenced, so that the inductance value of an inductor wound around the magnetic core in the impedance matching network is changed, and the impedance of the impedance matching network is further changed. The technical problems that in the prior art, a servo stepping motor is used or the number of parallel capacitors is controlled to change the capacitance value in a matching box to achieve impedance matching, cost is high, the adjustable range is small, the adjusting process is not smooth enough, and the design requirement for the capacitance value is high are solved.

Description

Technical field

[0001] The present application relates to the field of impedance matching regulation, and more particularly to an impedance matching adjustment method and apparatus for use in RF power sources. Background technique

[0002] The RF power system includes a radio frequency power supply, and the RF power source is a supporting power source of the plasma chamber, applied to radio frequency sputtering, PECVD chemical vapor deposition, reactive ion etching and other fields. The impedance of the nonlinear load in the plasma chamber is not equal to the constant output impedance of the radio frequency power source, so there is a severe impedance mismatch between the radio frequency power supply and the plasma chamber, so that there is a large reflection power on the transmission line, radio frequency. The power generated by the power supply cannot be delivered to the plasma chamber, and the power loss is large. In order to solve this problem, it is necessary to adjust the i...

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