Gas Phase Chemistry of Trimethylboron in Thermal Chemical Vapor Deposition

High Resolution Image Download MS PowerPoint Slide Alkylboranes, such as trimethylboron (TMB) and triethylboron (TEB), are promising alternative precursors in low-temperature chemical vapor deposition (CVD) of boron-containing thin films. In this study, CVD growth of B–C films using TMB and quantum-chemical calculations to elucidate a gas phase chemical mechanism were undertaken. Dense, amorphous, boron-rich (B/C = 1.5–3) films were deposited at 1000 °C in both dihydrogen and argon ambients, while films with crystalline B 4 C and B 25 C inclusions were deposited at 1100 °C in dihydrogen. A script-based automatization scheme was implemented for the quantum-chemical computations to enable time efficient screening of thousands of possible gas phase CVD reactions. The quantum-chemical calculations suggest TMB is mainly decomposed by an unimolecular α-H elimination of methane, which is complemented by dihydrogen-assisted elimination of methane in dihydrogen.