Si nanowire field effect transistors (SiNW FETs) with multiple nanowire channels and different gate lengths have been fabricated by using a directed assembly approach combined with a standard photolithographic process. The electrical characteristics of SiNW FETs containing different numbers of nanowire channels were measured and compared. The multi-channel SiNW FETs show excellent performance: small subthreshold slope (approximate to 75 mV/dec), large ON/OFF ratio (approximate to 10(8)), good break-down voltage (>30 V) and good carrier mobility (mu(p) approximate to 100 cm(2) V(-1)s(-1)). These excellent device properties were achieved by using a clean self-alignment process and an improved device structure with Schottky barriers at the source and drain contacts. Such high-performance multi-nanowire FETs are attractive for logic, memory, and sensor applications. (C) 2012 Elsevier Ltd. All rights reserved.