The adsorption and desorption of allylamine on the silicon(100) surface

The adsorption and desorption of the bifunctional molecule-allylamine on the Si(100)-(2x1) has been presented in this study. As comparison objects, the adsorption and desorption of propylamine and propylene were also studied under the same conditions as allylamine. The adsorption experiments were processed at room temperature in an ultra-high vacuum chamber with temperature-programmed desorption (TPD). Surface tools like Auger electron spectroscopy (AES) and low-energy electron diffraction (LEED) are also used to measure the reaction.;AES studies on the saturation coverage of propylamine and propylene yielded results with large uncertainties. The non-ideal results might be due to ineffective surface cleaning methods in the present configuration of the chamber. TPD experiments on propylamine and allylamine gave results closely matching earlier computational estimations. Allylamine's thermal desorption behavior indicates that a multiple dimer surface reaction pathway is likely to be preferred compared to a single dimer pathway. So, both the amino group and the C=C bond play important roles in allylamine's adsorption on the Si surface. The carbon chain of allylamine appears to crack with a little lower desorption energy than that of propylamine. But the HCN products desorbed with nearly the same energy for both species. The experimental results for propylene showed a larger deviation from the computational studies. However, the desorption energies of the propylene products were lower than for those of their counterparts in propylamine and allylamine desorption, as predicted by computation.;The AES studies showed propylene saturated on the Si surface by 1 molecule/2 surface dimers, while propylamine saturated on the surface by 1 molecule/2 surface dimers or 1 molecule/2 surface dimmers. The TPD experimental results indicate that all three species can form thermally stable CN or carbide films on the Si surface. Although the silicon carbide film from propylene adsorption possessed higher thermal stability, the formation of the CN film from propylamine and allylamine was energetically favored.