Particle growth and detection in low temperature plasmas

Laifa Boufendi (1) , Catherine Dupuis (1) , Gaëtan Wattieaux (1) , Yves Tessier (1) , Maxime Mikikian (1)

1 GREMI - Groupe de recherches sur l'énergétique des milieux ionisés

Dust particle nucleation and growth has been widely studied these last 15 years in different chemistries and experimental conditions. This phenomenon is correlated with various electrical changes at electrodes, including self-bias voltage and amplitudes of the various harmonics of current and voltage. Some of these changes, such as the appearance of more resistive plasma impedance, are correctly attributed to loss of electrons in the bulk plasma to form negative molecular ions and more precisely charged nanoparticles. These changes were studied and correlated to the different phases on the dust particle formation. It is well known now that, in silane argon gas mixture discharges, in the first step of this particle formation we have formation of nanometer sized crystallites. These small entities accumulate and when their number density reaches a critical value, they start to aggregate to form bigger particles. The different phases are well defined and determined thanks to the time evolution of the different electrical parameter changes. The purpose of this contribution is to compare different chemistries to highlight similarities and/or differences in order to establish possible universal dust particle growth mechanisms. The chemistries we studied concern SiH4-Ar, CH4, CH4-N2 and Sn(CH3)4. We also refer to works performed in other laboratories in different discharge configurations.

Domaines: Plasmas; Physique des plasmas [physics.plasm-ph]

Laifa Boufendi, Catherine Dupuis, Gaëtan Wattieaux, Yves Tessier, Maxime Mikikian. Particle growth and detection in low temperature plasmas. 35th EPS Plasma Physics Conference, Jun 2008, Hersonissos, Crète, Greece. ⟨hal-00328177⟩