Formation of covalently attached polymer overlayers on Si(111) surfaces using ring-opening metathesis polymerization methods

We describe a method for growing uniform, covalently attached polymer onto crystalline Si(111) surfaces. H-Terminated Si was first chlorinated, and the surface-bound chlorine was then replaced by a terminal olefin using a Grignard reaction. A ruthenium ring-opening metathesis polymerization catalyst was then crossed onto the terminal olefin, and the resulting surface was subsequently immersed into a solution of monomer to produce the desired surface-attached polymer. The method provides a direct linkage between the polymer and the Si without the presence of an electrically defective oxide layer. Growth of the polymeric layer could be controlled by varying the concentration of monomer in solution, and polynorbornene films between 0.9 and 5500 nm in thickness were produced through the use of 0.01-2.44 M solutions of norbornene.