Fabrication of High-quality GOI and SGOI Structures by Rapid Melt Growth Method: Novel Platform for High-mobility Transistors and Photonic Devices

摘要

High-quality germanium-on-insulator (GOI) and fully relaxed silicon germanium(SiGe)-on-insulator (SGOI) structures have been demonstrated by the rapid melt growth method. We successfully fabricated single-crystalline local GOI structures, that is, Ge wires over 100 μm long within microcrucibles of a few μm wide by means of lateral liquid phase epitaxy (lateral LPE). GOI MOSFETs produced by lateral LPE exhibited superior carrier mobility and on/off current ratio to those of conventional SOI devices, indicating excellent electrical properties of Ge-channel and MOS interface formed by LPE. Moreover, dislocation-free fully relaxed SiGe layers on SOI substrates were demonstrated by vertical LPE, in which crystallographic defects were found to be confined within the compositionally graded SiGe interlayer between the epitaxcially grown relaxed SiGe and SOI layers. These novel methods based on the rapid metal growth will open up a new pathway to realize platform for next-generation Ge-based high-mobility transistors and photonic devices.