Diamond and Related Materials, 3 (10) 1230-1234 (1994).[PDF]

Precursor Gas Effect on the Structure and Properties of Diamond-like Carbon Film

Kwang-Ryeol Lee, Young-Joon Baik, Kwang Yong Eun and Seunghee Han

The effect of precursor gases on the diamond-like carbon (DLC) film deposition was investigated in the r.f. plasma-assisted CVD method. DLC films were deposited using methane or benzene as the presursor gas. The residual stress, hardnesses, total hydrogen concentrations and electron loss spectra were compared at the same value of Vb/sqrt(P). (Here, Vb is the self-bias volrage of cathode and P the deposition pressure.) The values of Vb/sqrt(P) ranges from 33 to 250 V/sqrt(mTorr) for methane and from 33 to 900 V/sqrt(mTorr) for benzene by changing the negative bias voltage from -100 to -900 V and deposition pressure from 1 to 100mTorr. We observed significant differences between structures and properties of these films. In the same range of Vb/sqrt(P), the structure and properties of films deposited from benzene show characteristic behaviors of lower energy deposition than those from methane. The present observations aer discussed in terms of the difference in the ion energy per carbon atom at the growth surface. The totla hydrogen concentration in the films deposited from benzene is smaller by about 7 at.% in this experimental range.