Far-infrared RAIRS studies of the adsorption of chlorometylsilanes on carbon and tungsten surfaces.

摘要

As part of our investigation into the mechanisms of the chemical vapour deposition (CVD) of SiC on to various substrates we have stuied the adsorption of the commonly-used prrecursors for SiC growth, dochlorometylsilane (DCMS) and trichlormethylsilane (TCMS), on both tungsten soil and sputter-deposited caron surfaces using the far-IR relfection-absorption IR spectroscopy (RAIRS) facility based at the Daresbury Synchrotron Radiation Source. At liquid nitrogen temperatures adsoprtion occurs readily yielding multlayer structures which gnerate s pectra consistent with the presence of molecularly-adsorbed species. Allowing the adlayer to warm to room temperature facilitated desorption only, with no evidence of the presence of the adlayer or a resisue resulting from reaction being observed. The stability of the precursors in the adlayer is discussed in terms of an example of CVD system where simple adsorption of the precursors at the substrate surface is insufficient to initiate reaction.