Method for plasma treatment and apparatus for plasma treatment

摘要

The high-frequency electric field is subjected to pulse modulation for 10 to 100 mu sec; the rise time of pulse is controlled to be not shorter than 2 mu sec but not longer than 50 mu sec; and the descent time of pulse is controlled to be not shorter than 10 mu sec but not longer than phi mu sec. Thereby, the electron temperature in plasma is controlled at 2 eV or lower and the fluctuation of the density of negative ion in plasma is controlled at 20% or smaller.