Ma. Elkhakani et al., EFFECT OF RAPID THERMAL ANNEALING ON BOTH THE STRESS AND THE BONDING STATES OF A-SIC-H FILMS, Journal of applied physics, 74(4), 1993, pp. 2834-2840
The stress evolution of plasma enhanced chemical vapor deposition a-Si
C:H films was studied by increasing the annealing temperature from 300
to 850-degrees-C. A large stress range from -1 GPa compressive to 1 G
Pa tensile was investigated. Infrared absorption, x-ray photoelectron
spectroscopy, and elastic recoil detection analysis techniques were us
ed to follow the Si-C, Si-H, and C-H absorption band evolutions, the S
i2p and C1s chemical bondings, and the a-SiC:H film hydrogen content v
ariations with the annealing temperatures, respectively. It is pointed
out that the compressive stress relaxation is due to the hydrogenated
bond (Si-H and C-H) dissociation, whereas the tensile stress is cause
d by additional Si-C bond formation. At high annealing temperatures, a
total hydrogen content decrease is clearly observed. This total hydro
gen loss is interpreted in terms of hydrogen molecule formation and ou
terdiffusion. The results are discussed and a quantitative model corre
lating the intrinsic stress variation to the Si-H, C-H, and Si-C bond
density variations is proposed.