THERMAL MODIFICATION OF WIDE-BANDGAP HYDROGENATED AMORPHOUS SILICON-CARBON ALLOY-FILMS GROWN BY PLASMA-ENHANCED CHEMICAL-VAPOR-DEPOSITION FROM C2H2+SIH4 MIXTURES
Yc. Liu et al., THERMAL MODIFICATION OF WIDE-BANDGAP HYDROGENATED AMORPHOUS SILICON-CARBON ALLOY-FILMS GROWN BY PLASMA-ENHANCED CHEMICAL-VAPOR-DEPOSITION FROM C2H2+SIH4 MIXTURES, Philosophical magazine. B. Physics of condensed matter. Statistical mechanics, electronic, optical and magnetic, 75(4), 1997, pp. 485-496
The thermal stability of hydrogenated amorphous silicon-carbon (aSi(1-
x)C(x):H) alloy films grown by plasma-enhanced chemical vapour deposit
ion from C2H2+SiH4 mixtures was characterized by means of infrared spe
ctroscopy, electron spin resonance, transmittance-reflectance spectros
copy and photoluminescence (PL) spectroscopy. It is demonstrated that
the network undergoes relaxation and reconstruction under the conditio
n of low-temperature annealing. Weak C-C, Si-Si and C-Si bonds will be
broken, and a new stage of hydrogen effusion and structural rearrange
ment will occur under the condition of high-temperature annealing. The
thermal stability a-Si1-xCx:H of films increases with increase in car
bon content. In carbon-poor a-Si1-xCx:H networks, the dangling bonds a
re the main non-radiative recombination channel, which causes a strong
correlation of the PL signal with defect density. In carbon-rich a-Si
1-xCx:H networks, pi-bonded clusters play an important role in the lum
inescence process. The PL intensity has little dependence on defects i
n carbon-rich a-Si1-xCx:H.