Silica substrates were functionalized with a covalent 4-ClCH(2)C(6)H(4)SiCl(3) monolayer. Additional covalent bonding of appropriate functional molecules to the silylated substrates was further achieved. The surface chemical characterization was carried out by angle resolved x-ray photoelectron measurements. Moreover, surface morphological characterizations were performed by atomic force microscopy measurements. Present results provide step by step information on the covalently linked monolayer during the synthetic procedure.