Patent attributes
A plasma etching apparatus includes an upper electrode and a lower electrode (susceptor) on which a semiconductor wafer is disposed, the upper and lower electrodes being arranged within a process chamber, a first high frequency power source for applying a first high frequency power to the upper electrode, a second high frequency power source for applying a second high frequency power having a frequency lower than the frequency of the first high frequency power to the lower electrode. A third high frequency power source for superposing a third high frequency power having a frequency lower than that of the first high frequency power and higher than that of the second high frequency power on the first high frequency power. A phase controller for adjusting the phase difference between the second high frequency power and the third high frequency power.
