INSTRUMENT AND METHOD FOR MEASURING GAS DECOMPOSITION RATIO NEAR PLASMA OR IN PLASMA

摘要

PROBLEM TO BE SOLVED: To calculate the decomposition ratio of a gas from a result obtained by measuring special distribution to the plasma of "quartz vibrator sensor calibration value change quantity" cleared in a correlation with the decomposition ratio of the gas and extrapolating the shape of the result of the spacial distribution to the vicinity and a position of the plasma to calculate the "quartz vibrator sensor calibration value change quantity" in that place.SOLUTION: The measurement by a quartz vibrator sensor 1 which can measure a quantity depending on the physical property value (viscosity and molecular weight) of the gas in the reactor 3 of a plasma device, an absolute pressure gauge 2 and a thermometer 18 is performed, the calibration of pressure and a temperature is performed from the output of a quartz vibrator sensor at the time of the generation of the plasma to obtain the quantity depending on the component change of the gas in the plasm device and the decomposition ratio of the gas near the plasma and in the plasma can be calculated from the shape of the spacial distribution of the change quantity to the presence of the plasma of the calibration value of the quartz vibrator sensor.