A variety of different types of plasma phenomena can lead to plasma induced damage in the fabrication of small geometry devices. Oxide charging (probably the most significant source of damage), macroscopic and microscopic differential charging, over energetic ion beams, UV induced carriers and plasma etch induced silicon substrate roughness are some examples. In this paper, it is argued that simultaneous modulation of source and wafer RF in HDP tools provides a "control knob" for eliminating and/or reducing many of the sources of damage. Data are presented showing improvements resulting from simultaneous source and wafer (on-off) modulation. RF frequency and modulation duty cycle effects are discussed together with damage reduction mechanisms.