STM study on the interactions of C70 with the Si(100)2 x 1 surface.

We have conducted a study of the adsorption, thin-film growth, and the reaction of ${\mathrm{C}}_{70}$ on the Si(100)2\ifmmode\times\else\texttimes\fi{}1 surface. It is found that the crystalline thin film can be grown with good quality by keeping the substrate at approximately 120 \ifmmode^\circ\else\textdegree\fi{} C during deposition. ${\mathrm{C}}_{70}$'s above the first layer can desorb at temperatures above approximately 250 \ifmmode^\circ\else\textdegree\fi{}C, which is similar to the situation in the bulk phase, but the first layer of the ${\mathrm{C}}_{70}$ film which is directly bonded to the Si(100) surface does not desorb or decompose upon heating to 1000 \ifmmode^\circ\else\textdegree\fi{}C. It reacts with the Si(100) substrate at temperatures above 1000 \ifmmode^\circ\else\textdegree\fi{}C to form the SiC(100)3\ifmmode\times\else\texttimes\fi{}2 islands. The reaction products can finally desorb at temperatures above 1300 \ifmmode^\circ\else\textdegree\fi{}C, resulting in surface roughening.