Aspects of Silane Thermal Decomposition

Silicon deposition is central to monolithic device integration, yet the fundamental growth mechanisms remain incompletely rationalized. Here, silane thermal decomposition is revisited with the aim of constructing a coherent macroscopic model of silicon growth. A meta-analysis integrating conventional thermal decomposition studies with industrial CVD data provides substantial insights into the mechanism governing the heterogeneous catalysis of an ostensibly simple chemical reaction. A straightforward zero-dimensional thermodynamic model, anchored in silane decomposition and bond energetics, reproduces correctly thin film growth rate. The available evidence also points to an unsuspected multiplicity in energy of activation. The several domains are then tentatively mapped for Si{100}. The implications for industrial CVD are significant, activation-energy contrasts between facets govern selectivity, faceting, and the transition from conformal to non-conformal growth, while overly complex homogeneous gas-phase mechanisms are largely redundant for zero-dimensional thin-film modeling.