Octadecyltrimethoxysilane OTMS self-assembled monolayers have been grafted on micrometric and nanometric areas of SiO2 /Si substrates using a process combining nanoimprint lithography and atmospheric chemical vapor deposition. The optimization of the process has lead to monolayer square patterns of OTMS with lateral sizes ranging from 2 m down to 50 nm. Their coverage uniformity extends on several square millimeters. Their coverage density can be accurately tuned by the deposition time. © 2007 American Vacuum Society. DOI: 10.1116/1.2402144