Infrared spectroscopic study on deposition process of the amorphous carbon film with benzene molecule as a source in plasma enhanced chemical vapor deposition

Deposition process of amorphous carbon film during plasma enhanced chemical vapor deposition was investigated with “in-situ” and “real-time” infrared absorption spectroscopy in multiple internal reflection geometry. We can observe the peaks due to the CD of deuterated benzene molecules and that due to the CD in alkane. These facts indicate that there is a mode that the film grows with retaining the molecular structure of benzene. We also examine the increasing behaviour of two peak intensties with the plasma exposure time. The increasing rate of the peak, due to the CD of benzene decreased at longer exposure time, compared with that due to the CD in alkane. It is suggested that the amorphous carbon film is deposited through addition reaction of adsorbed benzene with benzene generated in the plasma.