A time varying axial magnetic field induces an electric field which keeps the electrons in a circular orbit and increases the probability to excite another molecule. This way the plasma density can be increased without having to increase the DC bias. RF biasing can be used independently to increase or decrease the energy of the ions impinging on the specimen surface. Inductively-coupled plasma reactive-ion etching (ICP-RIE) can achieve high etch rates by high ion or radical densities, while high material selectivity and low surface damage is achieved by using low ion energies. High density plasmas created by ICP systems can operate at low pressures and can yield significantly improved profile control for very deep, anisotropic etches.