Investigation of the reactions during alkylation of chlorine-terminated silicon (111) surfaces

Absorption infrared spectroscopy (IRAS) and Rutherford backscattering (RBS) have been used to investigate the react ion of chlorine-terminated Si(I I I) surfaces with organometallic molecules (Grignard reagents). Although the predominant reaction leads to alkylation, with formation of covalent Si-C bonds, evidenced by a 678 cm(-1) feature assigned to the Si-C stretch mode, solvents typically used during alkylation (tetrahydrofuran and methanol) can also react with CI/Si(111) surfaces, either during the alkylation reaction or during the rinsing/cleaning process to form Si-OCnH2n+l as observed by the presence of a SiO-C stretch mode at 1090 cm-1. We also address the origin of some silicon oxidation observed after the methylation or ethylation reactions.