Lateral liquid-phase epitaxy of Ge on insulator using Si seed for ultrahigh speed transistor

摘要

Recent our progress in the lateral liquid-phase epitaxy of Ge-on-insulator (GOI) using Si seeds has been reviewed. Giant single-crystalline GOI(100) structures with ～400 μm length are obtained using Si(100), (110), and (111) seeds. The very long growth is explained on the basis of the solidification temperature gradient due to Si-Ge mixing around the seeding area and the thermal gradient due to the latent heat around the solid/liquid interface at the growth front. In addition, growth with rotating crystal orientations observed for samples with Si(111) seeds is investigated. The rotation angle depends on the growth direction in plane to the surface. The rotation angle changes with a 60° period and becomes 0° and about 30° for <011> and <121> directions, respectively. The rotating growth is explained on the basis of the bonding strength between lattice planes at the growth front.