A fast method for obtaining electron energy distribution function by using Savitzky Golay technique

A numerical method to obtain the electron energy distribution function (EEDF) using Savitzky-Golay technique is proposed. The Savitzky-Golay filter is one of usually adopted methods to smooth the distorted data, and also gives derivatives of data; the second derivative of I-V characteristic curve is used to obtain the EEDF. Thus, we modified the method to analyze the I-V curve by varying filter parameters, such as number of data and polynomial order. From the optimization of the filter parameters, reliable EEDFs are obtained. This method is suitable for fast measurement of the EEDF due to its simple arithmetic operation that makes the method useful in EEDF measurement using Langmuir probe with tunable external filter which needs fast refreshment of the measurement result.