Daihen Corporation

Daisuke Matsuno

Michio Taniguchi

Koji Itadani

Kazuki Kondo

Yoshiki Fukumoto

Hiroaki Oichi

Yoshinobu Kasai

Eiji Kaneko

An impedance matching device includes an input port connected to a high-frequency power supply, an output port connected to a load, an impedance variable circuit, a T-parameter memory for storing sets of T-parameters in a manner such that each of the sets of T-parameters is related to a corresponding one of adjustable impedance values of the device, an input voltage detector for detecting a forward wave voltage and a reflected wave voltage at the input port, and a p-p value calculator for computation of a p-p value of a high-frequency voltage at the output port. The computation of the p-p value of the high-frequency voltage is performed by using the forward wave voltage and the reflected wave voltage detected at the input port and also using one set of the T-parameters stored in the T-parameter memory.

Impedance matching device

An impedance matching apparatuscalculates a forward wave voltage Vfo and a reflected wave voltage Vro at an output terminal, based on a forward wave voltage Vfi and a reflected wave voltage Vri at an input terminal, on information on variable values of variable capacitors VC, VCacquired in advance through measurement, and on a T parameter of the impedance matching apparatuscorresponding to the information on the variable values of variable capacitors VC, VC. The impedance matching apparatuscalculates an input reflection coefficient &#x393;i at the input terminalcorresponding to the information on the variable values of the variable capacitors VC, VC, based on the forward wave voltage Vfo, the reflected wave voltage Vro and the T parameter. The impedance matching apparatusselects the lowest absolute value out of absolute values |&#x393;i| of the input reflection coefficients corresponding to the variable values of the variable capacitors VC, VC, and adjusts the impedance of the variable capacitors VC, VCbased on the lowest value.

Impedance matching apparatus

Impedance matching apparatus for a plasma chamber comprising two separate storage units and three separate calculators

Impedance matching apparatus for a plasma chamber comprising two separate storage units and calculators

In an impedance matching device having at least two stubs serially provided to a main coaxial tube so as to be separated from each other with a predetermined interval in a tube axial direction, each stub is composed of a variable capacity capacitor to be jointed to an inner conductor of the main coaxial tube, an electrically conductive capacitor cover to be jointed to an outer conductor of the main coaxial tube so as to cover a surrounding of the variable capacity capacitor, and a drive motor arranged on an outside of the capacitor cover so as to drive a movable side electrode of the variable capacity capacitor. The movable side electrode of the variable capacity capacitor is driven directly by the drive motor so that the impedance matching device is made to be compact and response of impedance matching to a fluctuation of a load impedance such as a behavior of a plasma load is improved, and the life is lengthened and degrees of freedom of installation is widened.

The microwave generator with use of a magnetron comprises a microwave detector for detecting microwave output from the magnetron and a filament life diagnostic circuit for judging the life of filament of the magnetron by decreasing an input power to a filament of the magnetron from a normal state of the magnetron while monitoring the microwave output from the magnetron by the microwave detector, comparing the input power in the normal state of the magnetron with that just before the magnetron becomes unstable and judging the filament life based on the difference between the input power of the normal state and that just before the unstable state.

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Osaka, Japan

Daisuke Matsuno