Patent ID: 7976673

Claim:
An apparatus for providing a plasma etch of a layer over a wafer, comprising: a capacitively coupled process chamber; a gas source is in fluid connection with the capacitively coupled process chamber; a first electrode within the process chamber; a second electrode spaced apart and opposite from the first electrode, wherein the second electrode is spaced from the first electrode so that the space between the first electrode and the second electrode has a ratio to the diameter of the wafer of less than 1:30 and more than or equal to 1:60; a first radio frequency power source, electrically connected to the second electrode, wherein the first radio frequency power source provides radio frequency power of between 150 kHz and 10 MHz; a second radio frequency power source, electrically connected to the second electrode, wherein the second radio frequency power source provides a radio frequency power of between 12 MHz and 200 MHz; a first modulation control connected to the first radio frequency power source, to provide a controlled modulation of the first radio frequency power source at a frequency of between 1 kHz to 100 kHz; and a second modulation control connected to the second radio frequency power source, to provide a controlled modulation of the second radio frequency power source at a frequency of between about 1 kHz to about 100 kHz, wherein the second electrode forms a substrate holder or supporting a wafer and wherein the first radio frequency power source and the second radio frequency power source are electrically connected to the second electrode, wherein first modulation control and the second modulation control provide frequency modulation to the second electrode.