| 摘要 |
PURPOSE:To reduce the ion impulse in case of overetching, by installing in the vacuum chamber one electrode on which the high frequency electric power is impressed and the other electrode insulated from the grounded vacuum chamber, and connecting the tunning circuit with the variable inductance and capacity to the latter electrode. CONSTITUTION:When the high frequency electric power is impressed on one electrode 12, the potential difference is produced by the potential of the plasma Vp and the self bias voltage Vs of the electrode 12. Ions are accelerated by this potential drop and illuminate the substrate 25, which is subjected to etching. By adjusting the conductance of the coil 18a and the capacity of the condenser 18b in the tunning circuit 18 connected to the other electrode 13, the phase of the electrode 13 to the high frequency electric power connected to the electrode 12 can be shifted. Thus, in case of overetching, the ion impulse can be reduced by making the phase difference zero and decreasing the self-biased voltage. |
