Remote source pulsing with advanced pulse control

A method of processing a substrate in a plasma processing chamber, the method comprising:

• flowing a first gas to a remote source (RS) chamber maintained at a first pressure, the RS chamber being connected to the plasma processing chamber;
• flowing a second gas to the plasma processing chamber maintained at a second pressure, the second pressure being lower than the first pressure;
• and
• performing a cyclic process comprising a plurality of cycles, each cycle of the plurality of cycles comprising:
• generating a first plasma of the first gas to generate radicals;
• providing the radicals to the plasma processing chamber through sidewalls of a plenum chamber separate from and fluidically coupled to the RS chamber, the plenum chamber comprising a radical ballast region bounded by a bottom wall and the sidewalls;
• and
• performing an etch process in the plasma processing chamber to form a recess in the substrate in the presence of the radicals.

A method of etching a substrate, the method comprising:

• performing a radical generation phase comprising exciting a remote plasma comprising radicals in a pressurized remote plasma chamber by applying a remote source (RS) power pulse to a resonator electrode inductively coupled to the remote plasma;
• performing an etch phase after the radical generation phase, the etch phase comprising etching a recess in the substrate located in an etching chamber using the radicals from the remote plasma and ions of an etch plasma by
• exciting the etch plasma comprising the ions by applying a pulse train of process source (PS) power pulses to a source electrode capacitively coupled to the etch plasma,
• accelerating the ions toward the substrate by applying a pulse train of bias source (BS) power pulses to a substrate holder electrically coupled to the substrate;
• and
• repeating the radical generation phase and the etch phase as a cycle.