Laser Induced Dielectric Breakdown for Chemical Vapor Deposition by Hydrogen Reduction of Volatile Boron Halides BCl 3 a
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Laser Induced Dielectric Breakdown for Chemical Vapor Deposition by Hydrogen Reduction of Volatile Boron Halides BCl3 and BF3 I. B. Gornushkin1 · P. G. Sennikov2 · R. A. Kornev2 · A. A. Ermakov2 · V. E. Shkrunin2 Received: 20 April 2020 / Accepted: 4 June 2020 © Springer Science+Business Media, LLC, part of Springer Nature 2020
Abstract A possibility of deposition from laser-induced plasma is investigated in search for an economic and simple method for obtaining isotopic compounds from enriched gaseous precursors although no isotopic compounds are used in this the proof-of-principle work. A break Cl3 with hydrogen, argon, and methane are studied both down in mixtures of BCl3 and B theoretically and experimentally. Equilibrium chemistry calculations show the deposition of boron, boron carbide, and carbon is thermodynamically favorable in B Cl3 systems and only carbon in B F3 systems. Dynamic calculation of expanding plasma is performed using fluid dynamics coupled with equilibrium chemistry. Condensed phases of boron, boron carbide, and graphite are predicted with maximum concentrations in peripheral zones of the plasma. In experiment, plasma is induced in mixtures BCl3, H2 + BCl3, H2 + Ar + BCl3, H2 + BCl3 + CH4, BF3, H2 + BF3, H2 + Ar + BF3, and H2 + Ar + BF3. The gases are analyzed before, during, and after laser irradiation by optical and mass spectrometry methods. The results show the composition of reaction products close to that predicted theoretically. The conversion of precursor gases BCl3 and BF3 into gaseous and condensed products is 100% F3. Solid deposits of up to 30 mg are obtained from all reaction for BCl3 and 80% for B mixtures. Due to technical reasons only FTIR characterization of the BCl3 + H2 + CH4 deposit is done. It points to presence of condensed boron and boron carbide predicted by the model. Overall, the calculations and preliminary experimental results imply the chemical vapor deposition with laser induced plasma is promising for conversion of gaseous enriched precursors into elemental isotopes and their isotopic compounds. Keywords Chemical vapor deposition · Laser induced dielectric breakdown · Hydrogen reduction · Boron halides
* I. B. Gornushkin [email protected] 1
BAM Federal Institute for Materials Research and Testing, Richard‑Willstätter‑Strasse 11, 12489 Berlin, Germany
2
G.G. Devyatykh Institute of Chemistry of High-Purity Substances of RAS, 49 Tropinin Str., Nizhny Novgorod, Russia 603951
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Plasma Chemistry and Plasma Processing
Introduction Plasma enhanced chemical vapor deposition (PECVD) is a well-established technique for production of thin films [1], protective coatings [2], carbon-based nanostructures [3], high purity isotopic materials [4], biomaterials [5], and many other products [6]. The method is based on using plasma to create unstable bonding states in a precursor gas and activate chemical reactions. In comparison with the traditional chemical vapor deposition (CVD), PECVD exhibits significantly higher d
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