| 1. |
- Imam, Mewlude, et al.
(författare)
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Gas phase chemical vapor deposition chemistry of triethylboron probed by boron-carbon thin film deposition and quantum chemical calculations
- 2015
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Ingår i: Journal of Materials Chemistry C. - : ROYAL SOC CHEMISTRY. - 2050-7526 .- 2050-7534. ; 3:41, s. 10898-10906
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Tidskriftsartikel (refereegranskat)abstract
- We present triethylboron (TEB) as a single-source precursor for chemical vapor deposition (CVD) of BxC thin films and study its gas phase chemistry under CVD conditions by quantum chemical calculations. A comprehensive thermochemical catalogue for the species of the gas phase chemistry of TEB is examined and found to be dominated by beta-hydride eliminations of C2H4 to yield BH3. A complementary bimolecular reaction path based on H-2 assisted C2H6 elimination to BH3 is also significant at lower temperatures in the presence of hydrogen. Furthermore, we find a temperature window of 600-1000 degrees C for the deposition of X-ray amorphous BxC films with 2.5 less than= x less than= 4.5 from TEB. Films grown at temperatures below 600 degrees C contain high amounts of H, while temperatures above 1000 degrees C result in C-rich films. The film density and hardness are determined to be in the range of 2.40-2.65 g cm(-3) and 29-39 GPa, respectively, within the determined temperature window.
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| 2. |
- Imam, Mewlude, et al.
(författare)
-
Gas Phase Chemistry of Trimethylboron in Thermal Chemical Vapor Deposition
- 2017
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Ingår i: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 121:47, s. 26465-26471
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Tidskriftsartikel (refereegranskat)abstract
- 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 degrees C in both dihydrogen and argon ambients, while films with crystalline B4C and B25C inclusions were deposited at 1100 degrees 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 alpha-H elimination of methane, which is complemented by dihydrogen-assisted elimination of methane in dihydrogen.
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