Synthesis of metal oxide thin films by reactive magnetron sputtering in Ar/O2 mixtures:: An experimental study of the chemical mechanisms

One of the major limitations of reactive magnetron sputtering (RMS) is the low deposition rate when the target is poisoned. With the goal of reducing this phenomenon, we studied the chemical mechanisms involved during conventional and ionized reactive magnetron sputtering (iRMS) of metals (Sn, Ti, Ag) in Ar/O-2 mixtures. Target surface, plasma and film compositions were characterized by target voltage, MS and XPS measurements, respectively. Comparing films and plasma compositions, we demonstrated that oxide film formation proceeds by condensation of sputtered material and reaction between the growing film and the reactive species, especially O. Using iRMS, we promoted the latter process: for example, we prepared fully oxidized Sn films using low O-2 in turn flows which limits target poisoning and,, increases the deposition rate (6 times).