Hydrogenated amorphous carbon films deposited by low-frequency plasma chemical vapor deposition at room temperature

Abstract
Hydrogenated amorphous carbon (a‐C:H) films were prepared at room temperature by low‐frequency (50‐Hz) plasma chemical vapor deposition using CH4 and H2 . The a‐C:H films were transparent, highly resistive, and very uniform. Infrared absorption measurements, as well as Raman spectroscopy, indicated that the C bonding in the a‐C:H films was predominantly sp3 . Moreover, the optical band gap of the a‐C:H films was measured.