The eVoS™ LE is an asymmetric bias waveform generator designed to achieve direct control of wafer-surface voltage and resulting ion energy distributions (IED) in plasma-based etch and deposition processes. The eVoS system is comprised of a bi-directional voltage supply combined with an independent current source to establish and control wafer-surface potential. The asymmetric output of the eVoS eliminates the limitations and restrictions of wafer biasing inherent to sinusoidal RF bias application. Fast digital metrology and novel control algorithms enable the production of near mono-energetic IEDs. Use additional parameters for customizing average and time-varying aspects of the wafer surface voltage and resulting ion energy distribution.