Achievement of low interfacial densities of states, small equivalent oxide thickness, high kappa values, and thermal stability at high temperatures in the high kappa dielectrics on high carrier mobility semiconductors, the leading candidates for technology beyond Si CMOS, has been made using MBE. This paper reviews our recent advances in meeting the unprecedented demands in materials and physics for the new technology. Moreover, self-aligned inversion-channel InGaAs and Ge MOSFETs using MBE-Ga(2)O(3)(Gd(2)O(3)) as the gate dielectric are compared favorably with those using the gate dielectrics made from other thin film techniques. (C) 2010 Elsevier B.V. All rights reserved.