A new method of measuring the spatial distribution of depletion fraction of silane plasma by mass spectrometer

A newly established movable sampling apparatus of mass spectrometer is used to measure the spatial distribution of depletion fraction of silane plasma.A straight-line fit method of deducing the depletion fraction of silane is proposed. Theoretical analysis and test results demonstrate that the proposed new method is universal and more accurate than the existing one.There exist a largest peak near the middle of two electrodes and two peaks near the electrodes in the spatial distribution of silane depletion fraction, which are related to the distribution of electric field and the silane plasma sheaths.