| 摘要 |
A method according to an embodiment comprises an adsorption step of causing a radical generated from a processing gas to become adsorbed onto a layer to be etched, without feeding a high frequency bias to a lower electrode. In a subsequent etching step, a high frequency bias is fed to the lower electrode so as to cause ions generated from the processing gas to be drawn into the layer to be etched. The adsorption step and the etching step are alternately repeated. In the adsorption step, the radical has a density which is not less than 200 times the density of the ions. In the etching step, RF energy with a power density of not more than 0.07 W/cm2 is supplied to the lower electrode, or a high frequency bias with a power density of not more than 0.14 W/cm2 is supplied to the lower electrode for a period of not longer than 0.5 seconds. |
