| abstract |
A method for etching high aspect ratio features through a mask and into a layer to be etched on a substrate. A substrate is placed in a processing chamber capable of providing RF power at a first frequency, a second frequency different from the first frequency, and a third frequency different from the first and second frequencies. 404). An etchant gas is supplied to the processing chamber (408). A first etching step is performed (412), where the first frequency, the second frequency, and the third frequency are power settings as the first etching step. A second etching step is performed (416), where the first frequency, the second frequency, and the third frequency are different power settings. Optionally, a third etching step may also be provided (420). [Selection] Figure 4 |