Growth-Direction Dependent Rapid-Melting-Growth of Ge-On-Insulator (GOI) and its Application to Ge Mesh-Growth

Abstract

Single crystal Ge-on-insulator (GOI) structures with various crystal orientations are necessary for realization of advanced high-speed and multi-functional devices. SiGe mixing triggered rapid-melting-growth of GOI is investigated as a function of seed-orientations and growth-directions. Single crystal growth of (100)-Ge strips is possible for all growth directions using (100)-oriented Si-seeds. However, rotational-growth is observed for some directions when Si-seeds with (110) and (111) orientations are employed. Such rotational-growth is completely suppressed by selecting the growth-directions deviating from the <111> direction by more than 35o. Based on this finding, growth of large mesh-patterned Ge layers with (100), (110), and (111) orientations are demonstrated.