Apparatuses and methods for processing substrates are disclosed. A processing apparatus includes a chamber for generating a plasma therein, an electrode associated with the chamber, and a signal generator coupled to the electrode. The signal generator applies a DC pulse to the electrode with sufficient amplitude and sufficient duty cycle of an on-time and an off-time to cause events within the chamber. A plasma is generated from a gas in the chamber responsive to the amplitude of the DC pulse. Energetic ions are generated by accelerating ions of the plasma toward a substrate in the chamber in response to the amplitude of the DC pulse during the on-time. Some of the energetic ions are neutralized to energetic neutrals in response to the DC pulse during the off-time. Some of the energetic neutrals impact the substrate with sufficient energy to cause a chemical reaction on the substrate.