Single-Crystal Germanium by Elevated-Laser-Liquid-Phase-Epitaxy (ELLPE) Technique for Monolithic 3D ICs

This paper proposes and demonstrates single-crystal Germanium (Ge) growth by elevated-laser-liquid-phase-epitaxy (ELLPE) and the fabrication of Ge Fin field-effect transistors (FinFETs) for the monolithic three-dimensional integrated circuits (monolithic 3D ICs). This technique permitted the fabrication of single-crystalline (100) Ge film and FinFETs without random grain boundaries. In comparison with the poly-Ge FinFETs, the ELLPE Ge FinFETs exhibit superior performance and uniformity. Moreover, the ANSYS simulated maximum temperature of bottom circuits during the ELLPE technique does not exceed 400°C, therefore allowing monolithic 3D integration of ICs.