The influences of the size, position, nature of different silyl protecting groups on resulting covalently bound films obtained by electroreduction of ethynyl-aryldiazonium salts were investigated in view of preparing robust and functional interfaces with well-controlled structure and properties. Three different protecting groups where the active function was introduced on one meta position of the aryl ring were considered: trimethylsilyl (TMS), triethylsilyl (TES) and tri(isopropyl)silyl (TIPS). As a general tendency, ultra thin and robust active functional layers were obtained on carbon substrates after deprotection (loss of the silyl group) by treatment with nBu 4 BF 4 . Multilayer formation occurs when the protective group is just a TMS but becomes negligible when TIPS is used. Interestingly, the structure of the final layer keeps a memory of the silyl group used during the electrografting that permits a tweaking of the blocking properties and of the layer thicknesses. As a remarkable feature, all layers present large density of active alcyne terminations that remain totally available for further “click chemistry” coupling. These possibilities were tested with a redox label (azidomethylferrocene).