Aspects of Silane Thermal Decomposition

Silicon deposition is central to monolithic device integration, yet the fundamental growth mechanism of silane thermal decomposition remains incompletely rationalized. Here, the ostensibly simple chemical transformation is revisited with the aim of constructing a coherent macroscopic model for silicon growth. A meta-analysis combining conventional thermal decomposition studies with industrial chemical vapor deposition data yields substantial insight into the governing mechanisms of heterogeneous silane decomposition. Silane thermal decomposition is approximated as a quasi-static chemical transformation. And a simple zero-dimensional thermodynamic model, grounded in silane dissociation and bond energetics, reproduces thin-film growth rates with remarkable accuracy. The available evidence further indicates an unexpected multiplicity of activation energies which are then tentatively mapped for Si{100}. The implications for industrial chemical vapor deposition are significant. The contrasts in activation energy between crystallographic facets govern selectivity, faceting, and the transition from conformal to non-conformal growth, while increasingly elaborate homogeneous gas-phase mechanisms appear largely redundant in zero-dimensional thin-film modeling.