NUCLEATION, GROWTH, AND MORPHOLOGY OF DUST IN PLASMAS

An account is given of the dust particles appearing in weakly ionized plasmas. The dust is found in many discharges, especially in electronegative gas plasmas under conditions of rf excitation similar to those used in plasma processing of integrated circuits. Measurements have been made of the plasma-trapped dust, interrogated by Mie scattering of laser light. It appears that the rapid early growth is controlled by ion accretion across the surface of the relatively large Debye sheath. The microscopic properties of the dust reveal that the particles are often almost monodispersive in size. Under some conditions, the dust morphology has fractal characteristics and considerations of growth conditions point to the critical role of negative ions and ion-assisted deposition