High-quality Ge-on-insulator (GOI) structures are essential to realize next-generation large-scale integrated circuits, where GOI is employed as active layers of functional devices, as well as buffer layers for epitaxial growth of functional materials. In line with this, in-depth analysis of crystallinity of rapid-melting-grown GOI is performed. Structural and electrical measurements combined with a thinning technique reveal that the crystallinity of GOI (500 nm thickness) is very high and uniform in-depth direction, where high hole mobility (similar to 1000 cm(2)/V s) is achieved throughout the grown layers. These findings open up a possibility of application of rapid-melting- grown GOI to various advanced functional devices. (c) 2013 Elsevier B. V. All rights reserved.