Preparation Of A-SiC: H Films By PECVD And Research Of Laser Annealing

Silicon carbide (SiC) has become a good choice of high-temperature, high-frequency, high-power and anti-radiation material due to its excellent physical and chemical properties such as wide band gap, high electron saturation drift velocity, high electron mobility, high breakdown electric field, high thermal conductivity, small dielectric constant and excellent chemical stability. This paper describes preparation, testing and laser annealing effect of amorphous hydrogenated silicon carbide (a-SiC:H) films.The films prepared on Si(100) substrate by plasma enhanced chemical vapor deposition (PECVD) at different temperature and RF power were studied. It is found that the films have a uniform formation, compact structure, and good substrate adhesion. The results indicate that when temperature increases, growth rate decreases, refractive index increases, crystallinity gets better and the content of hydrogen decreases. Meanwhile, when the RF power increases, growth rate increases, refractive index is invariable, crystallinity gets better and the content of hydrogen increases.a-SiC:H films were annealed by KrF excimer laser. The results indicate that laser annealing at a proper density is an effective way to realize material crystallization and dehydrogenation. Crystallinity gets better as the incident laser power increases. It is observed that when the incident laser power is over 200mJ/cm~2, the phenomena of surface corrugation caused by thermal elastic wave come into being on the surface of films after laser annealing, and the films transform by liquid crystallization. When the films are annealed by several pulses of laser, the increase of pulses has little impact on the films' crystallinity.By comparing the laser annealing with conventional thermal annealing, It's observed that the thick films were susceptible to fracture after conventional thermal annealing and relatively complete after laser annealing. In contrary to conventional thermal annealing, laser annealing has advantage on less damage and better crystallinity as well as disadvantage on dehydrogenation.