IR Spectroscopy and Structure of RF Magnetron Sputtered a‐SiC:H Films

Amorphous hydrogenated silicon carbide (a‐SiC:H) films are prepared by magnetron sputtering of crystalline silicon in an argon—hydrogen—methane atmosphere. The specific absorption modes (wagging, rocking, deformation, stretching) of the SiC, (CH m ) n C/Si( n = 1, 2, 3; m = 2, 3), and SiH m −( m = 1,2) groups are assigned and analyzed. The composition of the films is determined by nuclear reaction techniques. Structural, electrical, and optical properties of the films show characteristic changes near an alloy composition of a‐Si 1− x C x :H, x = 0.5 which indicate the transition to a structure with threefold coordinated carbon. For x ⪆ 0.75 in the infrared absorption spectra an absorption band is identified which arises from graphitic constituents.