The demonstration of a normally-off n-channel AlGaN/GaN hybrid metal-oxide-semiconductor heterojunction field-effect transistor (MOS-HFET) on Si substrate for large-current operation is reported. The AlGaN/GaN hybrid MOS-HFET has the merits of both a MOS channel and an AlGaN/GaN heterostructure with high mobility two dimensional electron gases (2DEG). The maximum drain current of over 100 A with 2 mu m channel length and 340 mm channel width is performed. This is the best value for a normally-off GaN-based field-effect transistor. The specific on-state resistance is 9.3 m Omega cm(2). The fabricated device also exhibits good normally-off operation with the threshold voltage of 2.7 V and the breakdown voltage of over 600 V. (C) 2010 Elsevier Ltd. All rights reserved.