Study Of Si-doped Diamond-like Carbon Films

In this thesis/Hydrogenated amorphous carbon (a-C:H) films were successfully fabricated by low pressure plasma chemical vapor deposition (LPP-CVD) technology in Trans-2-butene(T2B)/tetramethylsilane(TMS)/hydrogen (H2) gas mixtures. The deposited rate, composition, microstructure, and optical properties of the as-deposited films were measured and presented employing a-step instrument, X-ray photoelectron spectra (XPS), Fourier transform infrared spectroscopy(FTIR),ultraviolet-visible spectroscopy(UV-VIS),etal. The technologic parameters influence on the film deposited rate, microstructure, properties were showed and the optimized technologic parameters were obtained.In this thesis, the main parameters such as the source of gas flow ratios, work pressure, RF power affect the deposition rate. The results showed that DLC films can deposited with the deposition rate is 12.0 nm/min under the conditions of pressure is 10 Pa,RF power is 10 W, the hydrogen flow is 0.5 sccm,.Trans-2-butene flow is 0.6 sccm.and tetramethylsilane flow is 0.05 sccm.The FTIR spectrum shows that the structure and composition of the DLC films changed with the T2B/H2 flow ratios, pressure and RF power. The results show that DLC films mainly contain sp3C-H bonds, films which have low T2B/H2 flow ratio possess more C=C bonds. Less C=C bonds in the films as the pressure increased, the films contain more C=C bonds which prepared under high RF power. This paper have studied the structure and property of Si-doped glow discharge plasma (GDP) films which made with TMS flow from 0.6 to 2.0 sccm. The results indicated that Si element successfully doped into the GDP films. The Si element of the Si-doped GDP film mainly exists in the form such as Si-C, Si-H bonds. The silicon atomic concentration of Si-GDP films increased from 0.72 at.% to 1.35at.% as the TMS flow increased from 0.5sccm to 2sccm.The UV-VIS spectrum shows that the transmission ratios can reach 98% in the visible light range, the films have strong absorption in the ultraviolet bands, and optical band gap ranges from 2.33～2.82eV. The optical band gap has a close relationship with the structure, particularly the sp3 hybrid bonds and the C=C bonds.The thermogravimetric analysis shows that the mass will loss more when excessive or too little hydrogen in the films, only the hydrogen with appropriate proportion can prepare solid films. The results also verify the important of hydrogen in the process of preparation films. Films prepared under higher pressure which cracking temperature relatively higher. By changing the parameters can gain films with better thermal stability. Therefore the diamond-like carbon films will have a better prospect in inertial confinement fusion (ICF) experiment.