In0.75Ga0.25As channel layers with a record mobility exceeding 12,000 cm(2)/Vs for use in high-kappa dielectric NMOSFETs have been fabricated. The device structures which have been grown by molecular beam epitaxy on 3" semi-insulating InP substrate comprise a 10 nm strained In0.75Ga0.25M channel layer and a high-kappa oxide based dielectric layer (K congruent to 20). Electron mobilities of 12,033 and 7,042 cm(2)/Vs have been measured for sheet carrier concentrations n(s) of 2.5 x 10(12) and 6 x 10(12) cm(-2), respectively. (c) 2006 Elsevier Ltd. All rights reserved.