Modelling of silicon hydride clustering in a low-pressure silane plasma

A new silicon hydride clustering model was developed to study the nucleatio n of particles in a low-temperature silane plasma. The model contains neutr al silanes, silylenes, silenes and silyl radicals as well as silyl and sily lene anions. Reaction rates were estimated from available data. Simulations were carried out for typical discharge parameters in a capacitive plasma. It was shown that the main pathway leading to silicon hydride clustering wa s governed by anion-neutral reactions. SiH2 radical insertion was found to be important only in the initial stages of clustering, whereas electron-ind uced dissociations were seen to lead to dehydrogenation. Increased ion dens ity (radiofrequency power density) leads to faster clustering due to increa sed formation of reactive radicals.