Chapter 12 Physical Vapor Deposition (PVD)

Basic steps in sputter deposition:
1) plasma generation – glow discharge formed when inert gas
becomes ionized by an E-field; an electron accelerated towards
anode, ionizes Ar atoms upon collision
2) ion bombardment – Ar + impacts the target with high energies and
transfer their momentum to the target material; these collisions
disrupt the atomic surface causing target atoms, ions, and electrons to
be ejected
3) sputtered atom transport – sputtered atoms, ions, are influenced
by collisions they undergo during transport to the film (determined
by background pressure); sputtered particles will lose their energy as
number of collisions increases so important to control the pressure
4) film growth - sputtered material leaves the target and deposits on
surrounding surfaces. The rate of diffusion is dependent upon the
substrate material and Temp. Growth proceeds by diffusion and form
nuclei, linuclei ligrow and eventually form islands; il islands il grow
together until a continuous film is formed.