Si surface orientation is one of the crucial factors to determine the performance of 3D-structured devices such as fin-, nanosheet-and vertical-field-effect transistors. We reveal that the crystallization annealing temperature, remnant polarization (Pr), and coercive field (Ec) of the ferroelectric HfZrOx stack on Si show strong surface orientation dependence. We evaluate HfZrOx - based FEFET on Si with different orientations for both memory and logic applications. Based on the findings, the impact of surface orientation in SOI FE FinFET is shown. Finally, we suggest a strategy for 3Dstructured FEFET with targeted applications.