Flow and Temperature Dependence of Particle Formation in Ar-Silane Rf Capacitively Coupled Plasmas

Temperature dependence of nucleation and growth of nanoparticles in low pressure Ar/CH4RF discharges

“…Characteristic decrease times are 24 ± 3 ms and 30 ± 3 ms for gas temperatures of 40 • C and 100 • C, respectively, having a ratio of 1.25 ± 0.19. This is in good agreement with observations in SiH 4 discharges [3,14], where the rapid decrease in n e is explained by the formation of negative ions. Here, negative ions might be formed by dissociative electron attachment to CH 4 with CH − 2 and H − as main reaction products [21].…”

“…A Smart PIM radio frequency plasma impedance monitor (PIM) of scientific systems-Smart PIM TM has been used to characterize the discharge electrically in a non-intrusive way. In the past researchers already proved that electrical characterization of the discharge gives useful information regarding particle nucleation and growth processes in chemical reactive plasmas [3,14,18]. The used system consists of a sensor head, a data acquisition and control unit and, finally, a PC to store and display measured values.…”

“…For measuring the electron density, the non-intrusive microwave cavity resonance technique has been used. In the past this technique has been successfully used to monitor the electron density directly and negative ion concentrations and dust particle charge after laser-induced photo-detachment in fluorocarbon and silane RF discharges [14,19,20]. The technique is described extensively in these references.…”

“…In the recent past, researchers have investigated nucleation and growth processes of hydrocarbon particles in low pressure Ar/CH 4 , Ar/C 2 H 2 and Ar/C 3 H 6 RF discharges [9][10][11][12]. Other researchers have shown a significant gas temperature dependence of the nucleation and growth of dust particles in low pressure SiH 4 discharges [3,13,14]. A numerical study of Bhandarkar et al [15] in 2003 suggests that the delay in nucleation in SiH 4 discharges is explained by a combined effect of increasing diffusion losses due to the strong temperature dependence of the Brownian diffusion coefficient and a reduced particle growth rate due to the decreasing plasma density in cases where the pressure is kept constant.…”

Gas temperature dependence of coagulation onset times for nanoparticles in low pressure hydrocarbon plasmas

“…It was experimentally observed that nucleation in low pressure argon-silane discharges significantly delays when T g is increased. 3,4,[11][12][13] In order to understand this delay, several explanations have been proposed. Fridman et al…”