The diagnostics of RF glow discharge plasma by a probe and its data process

Langmuir probe is an important tool to diagnose the plasma in radio frequen cy (rf) glow discharge. A new method has been used to obtain the electron e nergy distribution function in plasma by the numerical differentiation of t he I-V probe characteristic. This method is based on Fourier transform and could overcome the defects of other methods. In this way, the second deriva tive signal of Langmuir probe I-V characteristic is obtained automatically and accurately. The mean electron energy and electron concentrations in rf glow discharge plasma in silane were obtained by Langmuir probe.