Computational investigation of surface reactivity of functionalized silicon surfaces in deposition processes

Abstract

Recent advances in chemical vapor deposition and atomic layer deposition coupled with the ever-increasing demand for better control over the interface formation driven by practical applications require understanding and controlling chemical reactions, leading to the deposition of metal-based films onto semiconductor substrates at a truly atomic level. Computational investigation of possible surface-mediated reactions of metalorganic precursors used to deposit thin films used in practical applications allows for an efficient screening of the parameters needed to optimize the process of interface formation. Here, we will use a simple frontier orbital analysis coupled with cluster calculations to explore the surface reactions of functionalized silicon surfaces with test metalorganic precursor molecules. Two molecular precursors are investigated. Trimethylaluminum allows us to investigate the contribution of relatively simple C–Al and C–H dissociation processes in determining the mechanism of surface reaction with a silicon surface either terminated with hydrogen or modified with several nitrogen- or oxygen-containing functional groups. Following similar processes with tetrakis(dimethylamido)titanium provides an opportunity to expand the type of processes investigated and to decouple electronic and steric factors determining surface reactivity.