One important characteristic of plasma is their capability to shield out electrical potentials applied to them by redistributing their charged constituents. When an object is placed in plasma, it acquires a net negative charge because the electron thermal speed is much greater than the ion thermal speed, which causes more electrons to hit the object than ions. As the object charges negatively, the electrons start to be repelled. Equilibrium occurs when the electron current collected by the object balances the incident ion current. An electrically polarized region is thereby formed around the object. This polarized region is called a plasma sheath, or sometimes a positive ion sheath, because the electrons are largely excluded from the sheath. The exact form of the electrostatic potential distribution is complicated however in specific cases the potential decays exponentially with a characteristic length scale given by the Debye length.

Similar to the above discussed evaporation kinetics; there are three processes in sputtering also as shown in Fig. 3.29. The source material is to be change to gaseous state, then the transport source atoms to substrate and finally the deposition atoms on substrate.