Sputtering deposition techniques pdf

This process can lead, during prolonged ion or plasma bombardment of a material, to significant erosion of materials, and can thus be harmful. In DC Sputtering, voltage is set from 3-5 kV and in RF Sputtering, power supply is set at 14 MHz. Due to the application of an alternating current, sputtering deposition techniques pdf ions inside the plasma oscillate resulting in an increases in the levels of plasma. Physical sputtering is driven by the momentum exchange between the ions and atoms in the target materials, due to collisions.

Sputtering from a linear collision cascade. The thick line illustrates the position of the surface, and the thinner lines the ballistic movement paths of the atoms from beginning until they stop in the material. The purple circle is the incoming ion. Red, blue, green and yellow circles illustrate primary, secondary, tertiary and quaternary recoils, respectively.

Two of the atoms happen to move out from the sample, i. When such cascades recoil and reach the target surface with an energy greater than the surface binding energy, an atom would be ejected, and this process is known as sputtering. If the target is thin on an atomic scale, the collision cascade can reach the back side of the target and atoms can escape the surface binding energy “in transmission”. For a crystalline target the orientation of the crystal axes with respect to the target surface is relevant. A model for describing sputtering in the cascade regime for amorphous flat targets is Thompson’s analytical model. This may occur when the solid is dense enough, and then the incoming ion heavy enough, that the collisions occur very close to each other.