Thermodynamic Analysis and Kinetic Implications of Chemical Vapor Deposition of Sic from Si‐C‐C1‐H Gas Systems

Abstract

Experimental results compiled from the literature were compared to thermodynamic calculations of the most stable proportion of condensed phases to deposit from gas mixtures of Si-C-CI-H. The calculations indicated that the predominant gas molecules participating in a deposition process are chlorides and chlorosilanes for silicon and methane and acetylene for carbon. The mismatch of the calculated and experimentally determined phase boundaries at 1473 and 1600 K led to the conclusion that silicon deposition occurs faster than carbon deposition in proportion to their partial pressures. The probable reason is that silicon-bearing gas molecules have a greater sticking probability on polar Si and Sic surfaces because of their asymmetric geometries.

Thermodynamics of the Production of Condensed Phases in the CVD of Methyltrichlorosilane Pyrolysis

“…shown that the composition of the condensed phases significantly depends on the molar ratio of H 2 /MTS. This point of view can also be found in many studies, [11,31,33,35,36,41,42,46,52,55,60,66,70,71,86] however most of the work dealt with the problem only in the lower ratio region. For example, ratios up to 10 were studied in a number of papers.…”

“…[74] Since a large number of short-lived radicals or highly reactive intermediates (the experimental data of which are temporarily unavailable) must be produced and may also play important roles in the equilibrium system, a theoretical study involving as many species as possible is desirable. As the main features of the co-deposition of the solid phases as a function of the experimental parameters of the process are already known, [11,[20][21][22][23][24][25][26][27][28][29]43,[57][58][59][60][61][62][63][64][65][66][67][68][69][70][71] an optimization and application of a new database is another main motivation for our work. For these reasons, we carried out thermodynamic data evaluations in the H 2 /MTS system [75][76][77][78][79][80][81] with accurate model chemistry methods.…”

The effect of temperature on the growth and properties of chemical vapor deposited ZrC films on SiC-coated graphite substrates

“…This phenomenon is related to a different sticking tendencies between the Zr-containing and C-containing gas species. This implies that the Zr-containing gas species are more reactive with the substrate surfaces than the C-containing gas species at lower temperatures [20,21]. However, above 1400 1C, the reaction rate of the C-containing gas increased due to the higher deposition temperature and a stoichiometric ZrC film was grown.…”

CVD of SiC from Methyltrichlorosilane. Part I: Deposition Rates

“…The gas phase composition was determined using in-situ FTIR [30±33] and Raman spectroscopy, [37] as well as gas chromatography [1±6] and mass spectrometry. [21] A few studies have been concerned with modeling the gas phase composition based on thermodynamics [8,9,27,28] or kinetics of elementary reactions. [24±26,29] Energy dispersive X-ray (EDX) analysis [11] and elemental analysis [2,3] are the most frequently used techniques to determine the composition of the deposit.…”

“…They are based on molecular, [1±4,36] radical, [8,12,33] or both molecular and radical reactions. [27] In one study, a model to simulate SiC deposition from DMS and hydrogen was applied. [3,4] In most cases, reduced models were discussed.…”