Theoretical Analysis of Si 2 H 6 Adsorption on Hydrogenated Silicon Surfaces for Fast Deposition Using Intermediate Pressure SiH 4 Capacitively Coupled Plasma.

The rapid and uniform growth of hydrogenated silicon (Si:H) films is essential for the manufacturing of future semiconductor devices; therefore, Si:H films are mainly deposited using SiH₄-based plasmas. An increase in the pressure of the mixture gas has been demonstrated to increase the deposition rate in the SiH₄-based plasmas. The fact that SiH₄ more efficiently generates Si₂H₆ at higher gas pressures requires a theoretical investigation of the reactivity of Si₂H₆ on various surfaces. Therefore, we conducted first-principles density functional theory (DFT) calculations to understand the surface reactivity of Si₂H₆ on both hydrogenated (H-covered) Si(001) and Si(111) surfaces. The reactivity of Si₂H₆ molecules on hydrogenated Si surfaces was more energetically favorable than on clean Si surfaces. We also found that the hydrogenated Si(111) surface is the most efficient surface because the dissociation of Si₂H₆ on the hydrogenated Si(111) surface are thermodynamically and kinetically more favorable than those on the hydrogenated Si(001) surface. Finally, we simulated the SiH₄/He capacitively coupled plasma (CCP) discharges for Si:H films deposition. [ABSTRACT FROM AUTHOR]