The properties of films prepared by the rf sputtering of PTFE and plasma polymerization of some freons

Fluorocarbon films were prepared by rf sputtering of PTFE at 6.65 Pa in glow discharges operated in the target emission alone and with argon or nitrogen added. A 75 mm dia target and an rf supply of 20 MHz with different power inputs between 100 and 500 W were used. Blank and aluminium-covered glass substrates were rested on grounded or biased supports above the target. The refractive index (NaD) and absorption of each film in the near uv and uv regions of light were measured. Electrical properties like I–V characteristics, dielectric constant and dielectric strength in the sandwich configuration Al-film-Al were also studied. In the second set of experiments the same properties of films prepared by plasma polymerization of certain freons (CF3Cl, CF2Cl2) at a pressure of 15 Pa and higher were investigated at various flow rates and power inputs for comparison.