Silicon substrates were coated with well‐defined glycidyl and alkyne groups containing terpolymer that was synthesized by NMRP. The polymer was successfully tethered on silicon wafers and the resulting solvent stable, homogeneous, smooth thin films were characterized by means of atomic force microscopy (AFM), spectroscopic ellipsometry in the visible (Vis), and infrared (IR) spectral range. Subsequently, the films were modified in a heterogeneous reaction, converting the alkyne groups of the surface efficiently and quantitatively with azides by click chemistry. Appropriate film analysis allowed to directly verify the reaction of the alkyne groups with the azides and revealed that the chemical and physical properties of the thin films have changed while their morphology and topography is preserved.magnified image