Study on growth processes of particulates in helium-diluted silane rf plasmas using scanning electron microscopy

Size, density, and morphology of particulates in helium-diluted silane rf plasmas are studied using a scanning electron microscopic method. The experimental results show that particulates grow through three phases of nucleation, rapid growth, and growth saturation. Particulates in two different size ranges coexist after the initiation of the rapid growth phase, the size distribution of particulates in each size group is found to be well expressed by both the lognormal and normal distributions with a narrow size dispersion, and coagulation of particulates plays a crucial role in the rapid growth phase. The dependencies of size and density of particulates in the large-size group on rf-power-on period are very similar to their temporal evolutions obtained by an in situ laser light scattering method.