Optical properties of thin Ag films deposited by magnetron sputtering

Thin Ag films grown under varying deposition conditions are analysed by means of photometric measurements. From these measurements the values for n and k are calculated. The films are deposited onto a polyethylene terephthalate (PET) web by DC magnetron sputtering. It is examined to which extent the deposition conditions influence the optical properties of the Ag films. Below a certain critical thickness doc, which is highly-dependent on the sputtering pressure, deviations between the bulk and the calculated values, for the complex refractive index occur. This can be attributed to the growth mode of the Ag films, which is Volmer–Weber-like and a closed film is not formed until the critical thickness doc is reached.