Cvd Growth Of Sic Whisker Research

Besides the element semiconductors, such as Si (called the first generation semiconductor), and the compound semiconductors, such as GaAs, InP (called the second generation semiconductor), silicon carbide (SiC) is one of the wide band-gap semiconductor materials (called the third generation semiconductor). Because of its excellent properties, such as large band gap, high thermal conductivity and high breakdown electric field, SiC is appropriate for the electronic devices which can operate at extremely high temperatures and high radiation. In addition, due to the unique performances of one dimension and quasi one-dimension materials of SiC, SiC whiskers has great potential for application in the field of opto-electronic devices, field emission devices and micro-machine. The synthesis of SiC whisker is an interesting research activity.β-SiC whiskers have been grown on Si substrate with Ni film as its catalyst and a mixture of C2H2-SiH4-H2 as precursor via chemical vapor deposition technique in this dissertation. The effect of growth parameters on the morphology, structure and chemical compositon of SiC whiskers have been characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS) and transmission electron microscope (TEM).SiC whiskers have been successfully synthesized through a two-step reaction scheme. Carbon nanotubes (CNTs) with diameters of 30 nm to 70 nm were firstly grown by thermal decomposition of C2H2 at the temperature between 1050℃and 1200℃. Then,β-SiC whiskers were synthesized by the reaction between CNTs and SiH4. This process is called carbon nanotube-reaction. The shape of the SiC whiskers produced by carbon nanotube-reaction is consistent with that of the starting carbon nanotubes, and the whisker is hollow.β-SiC whiskers were also prepared by the reaction between C2H2 and SiH4 with CNTs as a template. This process is called carbon nanotube-confined reaction. SiC grains and solid SiC whiskers with the diameter of 120 nm to 160 nm are formed by carbon nanotube-confined reaction. The size of grains and the whisker diameters increase...