The present invention provides a design of three-dimensional non-volatile NOR flash memory devices consisting of arrays of basic NOR memory group in which individual memory cells (field-effect-transistors) are stacked along a direction (or directions) either out of or parallel to the plane of the substrate and electrically connected in parallel to achieve high storage densities approaching 1 TB with lower manufacturing cost. Offering full random access to every individual memory cells and also capability of parallel programming/erasing in blocks of memory cells, such three-dimensional non-volatile NOR flash memory can be widely used for both executable-code storage and mass data storage applications.