Sputter Deposition Techniques

There are three basic sputtering techniques; DC (diode), RF (radio frequency) and magnetron. As discussed above, the DC sputtering is simple and is shown in Fig. 3.30. When the Argon gas pressure is increased the scattering of Ar ions with neutral Ar atoms also increases. If the gas pressure is decreased, the number of Ar/ Ar⁺ is also decreased. As a result, the optimum deposition rate is around 100 mTorr which is a compromise between the available number of Ar ions and their scattering. If one can increase the number of ions without increasing the number of neutrals, one can operate at lower pressures.

            Fig. 3.30 : DC plasma system