Directed integration of ZnO nanobridge devices on a Si substrate

We demonstrate the directed assembly and integration of ZnO nanobridges into working devices on silicon-on-insulator substrates. The "pick and place" method of nanowire integration is avoided and metal catalysts are not used. ZnO nanowires (NWs) were grown selectively via a vapor-solid method using a patterned ZnO thin-film seed layer that was deposited on Si trench sidewalls via atomic layer deposition. ZnO NWs grew to span the trench and self-terminate on the opposing surface, effectively forming electrically accessible horizontal ZnO nanobridge devices. Vertical bridge devices were also constructed using undercut islands. Directly grown horizontal ZnO nanobridge devices were operated as gas and UV sensors, demonstrating that this method represents a significant step towards practical large-scale integration of nanodevices into Si microelectronics.