Si/C Phases from the IR Laser-induced Decomposition of Silacyclobutane and 1,3-Disilacyclobutane

Abstract

CO2 laser‐induced infrared multiphoton decomposition (IRMPD) and SF6 photosensitized decomposition (LPD) of silacyclobutane (SCB) and 1,3‐disilacyclobutane (DSCB) in the gas phase results in the very efficient deposition of Si/C/H and SiC materials, and it is inferred that the process is dominated by formation of transient silene; silene rearrangement to methylsilylene; silene and methylsilylene dehydrogenation; and polymerization of SiCHn (n < 4) species. The deposits are sensitive to oxygen. Decomposition and SiC formation are favoured with IRMPD experiments conducted with high‐energy fluxes. The laser technique is promising for low‐temperature chemical vapour deposition of amorphous SiC.

IR laser-induced process for chemical vapor deposition of polyselenocarbosilane films

“…4) reveals that the deposited films show, regardless of the irradiation conditions and the educts ratio, a fluffy morphology consisting of irregularly shaped agglomerates. These features were also observed with the deposits from IR laser decomposition of DSCB alone [19] and are very different from the round-shape and oval particles of elemental selenium deposited by IR laser-induced decomposition of DMS [20]. The XPS surface stoichiometry (of ca.…”

“…The CO 2 laser-induced decomposition of DSCB is known [19] to yield minute amounts of methane, ethene, ethyne, propene and methylsilanes and large amounts of a solid polycarbosilanes. It was accounted for [19] as dominated by the formation of silene and its dehydrogenative polymerization (DSCB !…”

“…The FTIR spectra of the deposits show the typical pattern of polycarbosilanes, and are very similar to those of the films produced upon laser-induced decomposition of DSCB [19]. Those of the deposits obtained from the DSCB-DMS mixtures rich in DSCB consist of strong bands at 780-845 cm À1 , a weak band at 1246-1250 cm À1 , a medium band at 2127-2148 cm À1 and very weak bands between ca.…”

Gas-phase formation of SiSe in IR laser-co-decomposition of dimethyl selenide and 1,3-disilacyclobutane

“…It is known that the IR laser multiple photon decomposition (IRMPD) of DSCB results in efficient deposition [4] of SiC/H and Si/C materials and is dominated [5][6][7] by the formation of transient SiCH 4 species (silene (H 2 Si@CH 2 ) and methylsilylene (CH 3 )HSi:) that decompose [8,9] into silylene (H 2 Si:) and methylene (H 2 C:). It is also known that the IR laser-induced decomposition of DMS, affording CVD of elemental selenium and poly(selenoformaldehyde), is dominated by the homolysis of the C-Se bonds [10].…”

IR laser decomposition of 1,3-disilacyclobutane in presence of carbon disulfide: chemical vapour deposition of polythiacarbosilane

“…Laser-induced thermal decomposition of gaseous silacyclobutanes and disilacyclobutanes yields transient silenes (and silylenes) that efficiently undergo dehydrogenative polymerization in the gas-phase and allow chemical vapour deposition of solid polycarbosilane films (e.g., [1][2][3][4][5][6]). …”