Observation of growing kinetics of particles in a helium-diluted silane rf plasma

Abstract

Growing process and behavior of particles in a helium-diluted silane rf plasma are studied using two kinds of laser light scattering methods. The region where particles began to be observed appears in a sheath edge region near the periphery of the rf electrode, and then tends to extend inward along the rf electrode and also toward the grounded electrode. From this result, it can be concluded that particles are mainly produced around the sheath edge of the rf electrode. In the sheath of the rf electrode and its neighborhood, larger particles tend to reside closer to the rf electrode, which suggests that they are suspended by an electrostatic force due to the time-averaged sheath electric field and some force increasing with particle size. The size and density of particles around the sheath edge of the rf electrode are ≳60 nm and ≲109 cm−3 under our experimental conditions.