Deposition and in-situ Plasma Doping of Plasma-Polymerized Thiophene Films Using PECVD

Highly transparent, thin polythiophene (PT) films were successfully synthesized by the plasma polymerization of thiophene. These films were doped with O-2 plasma by in-situ doping technique. The plasma polymerized PT films were deposited at about 50 to 340 nm/min, depending oil the temperature and plasma power. A resultant transparency as high as 85% was achieved, The plasma polymerized PT films exhibited the characteristics of an insulator or semiconductor (10(10-12)Omega/square, 10(-7) S/cm). The conductivity Was immediately increased up to 10 Omega/square and 10(-2) S/cm, when doped with O-2 plasma. The plasma-doped PT films exhibited ail increased Surface roughness resulting in a decreased contact angle. However, the thickness of the PT layer was partially decomposed and/or etched with increasing voltage above 40 W.