| 摘要 |
PURPOSE: A hot switching method for plasma tuner is provided, which is related to a solid-state tuner used to match the impedance of an RF generator to a plasma chamber or similar non-linear load. CONSTITUTION: At step(80), the switching characteristic of the pin diodes is determined. In the presently preferred embodiment, the carrier lifetime is used as being represented of switching characteristic. At step(82) the RF generator is coupled to the plasma chamber through the controlled impedance network. Then, at step(84) RF power is generated. At step(86), a matching characteristic of the interaction between the RF generator and the plasma chamber is measured. In the presently preferred embodiment the matching characteristic that is measured is the voltage standing wave ratio (VSWR). At step(88), the controller determines control signals for the pin diodes based on the measured matching characteristic. At step(90), the controller generates driver input signals for controlling the driver circuits associated with the pin diodes. At step(92), the driver input signal is floated from ground to permit a highside switch to be driven. At step(94), a bias switch is driven by driver input signal such that the transition time of the bias voltage at the output of the bias switch is less than the pin diode carrier lifetime. At step(96), the bias current flowing through the bias switch is regulated to insure predictable RF operation of the pin diode.
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