Silicon Carbon Nitride Thin Film Grown By Hot-Filament Chemical Vapor Deposition

Silicon carbon nitride(SiCN) thin film is a new type of wide band-gap semiconductor materials,the research on it has become a hot piont in the field of the materials science because of its excellent physical and chemical properties.Studies have shown that it has a high hardness and excellent anti-oxidation,anti-corrosion,wear resistance,thermal stability and good luminescence properties.Therefore,the research on SiCN has important application value.In this dissertation,the SiCN thin films were synthesized on Si substrate by hot-filament chemical vapor deposition which is very simple and cost-low.We explore the preparation process(substrate temperature,N₂,CH₄ and H₂ flow,reaction chamber pressure) on adult film quality systemetically,and use FT-IR,SEM and XPS to study the influence on thin-film structure,surface morphology and nitrogen content under different processes.Finally the optimum process of SiCN thin films is obtained:Tungsten filament at the temperature of 2100℃,while substrate at 900℃,tungsten filament and substrate at the distance of 8 mm, SiH₄,CH₄ and N₂ at flow of 1 SCCM,2 SCCM and 4 SCCM respectively,reaction chamber at the pressure of 6.0×10² Pa.By SEM,AFM,XRD,FT-IR,XPS and Raman,we characterized the surface morphology,crystal structure and chemical composition of optimized thin film.The AFM and SEM results indicate that SiCN films grow in the pattern of two-dimensional island,the film surface is at a degree of 515nm vertical high,the dimension of larger particles isΦ2μm,meanwhile these particles are neatly arranged in an orderly manner and closely together,particle size is also distributed evenly.The XRD analysis indicates that the thin film has already crystallized,but the crystallization is not complete,having the microcrystalline and the amorphous ingredient,the crystallinlty of the thin film through the fitting is 43.99%by Jade software;XPS,FT-IR and Raman results indicate that the relative nitrogen content in the films reached 27.20%,SiCN films is not simple mixture of SiC and Si3N4,Si,C and N,the thin film has many kinds of combination conditions,among which the main combination conditions is Si-N,Si-C-N,Si-N-C,C-N, C=N,C-N,N=C and N-Si-C bonds,but the Si-C bonds absent.We can conclude that the complex network architecture has formed in the thin film.