Patent ID: 8686711

Claim:
A method for calibrating voltage values and current value of a high-frequency measuring device that is connected to a connection point between a plasma processing device for generating plasma within a chamber and a high-frequency power supply device for supplying high-frequency electrical power to the plasma processing device, the high-frequency measuring device being configured to detect high-frequency voltage and high-frequency current at the connection point, and to calculate an impedance within the chamber of the plasma processing device based on the detected voltage and current values, the method comprising: a first step of calculating a first parameter for calibrating the voltage and current values based on impedances calculated when the high-frequency measuring device is connected to a first set of three reference loads and impedances of the first set of three reference loads; a second step of calculating a second parameter for respectively converting the detected voltage and current values to voltage and current values within the chamber; a third step of carrying out plasma processing by connecting the high-frequency measuring device to a plasma processing device to be measured, calibrating the detected voltage and current values using the first parameter and the second parameter, and calculating impedances within the chamber based on the calibrated voltage and current values; a fourth step of determining three impedances that encompass, when displayed on a Smith chart, a narrower range than a range encompassed by the impedances of the first set of three reference loads, the narrower range including the impedance calculated in the third step; A fifth step of calculating a third parameter for further calibrating the voltage and current values calibrated using the first parameter and the second parameter, based on impedances measured by the high frequency measuring device connected to the plasma processing device when a second set of three reference loads respectively having the three impedances determined in the fourth step is arranged within the chamber of the plasma processing device to be measured, and based on the impedances of the second set of three reference loads; and a sixth step of connecting the high-frequency measuring device to the plasma processing device to be measured and calibrating detected voltage and current values, using the first parameter, the second parameter and the third parameter.