Experimental and theoretical investigation of BCl3 decomposition in H2

A combined experimental and theoretical study of the homogeneous decomposition of BCl3 in a H2 carrier gas is presented. A detailed description of the B/Cl/H thermodynamic equilibrium is first obtained from ab-initio calculations from which a restricted low energy chemical mechanism is identified to model the decomposition of BCl3. Transition state theory is then invoked to obtain reaction rates and the resulting kinetic mechanism is incorporated in a 1D model of a CVD reactor. Comparison of calculated steady state concentrations with in-situ FT-IR measurements shows a good agreement at low temperatures, thus validating the kinetic model. The divergence observed at higher temperatures is attributed to boron deposition.