This paper describes a simple procedure for patterning Si substrate using a combination of surface functionalization and microcontact printing (μCP). The Si/SiO₂ surfaces were chemically modified to present self-assembled monolayers (SAMs) of siloxanes terminating in reactive carboxylic anhydride groups and then patterned with poly(ethylene imine) (PEI) by μCP. We used the patterned thin films of PEI as etch resists on Si surfaces.