A method of fabricating a multilevel semiconductor integrated circuit is provided, comprising: forming on a first active semiconductor structure a first plurality of transistors with respective gate structures disposed on a first substrate and source or drain regions disposed within the first substrate; depositing a first insulation layer on the first substrate and the gate structures; etching the insulation layer to form a plurality of openings exposing portions of the first substrate contacting the bottoms of the openings; forming a semiconductor seed layer filling the openings; forming an amorphous layer on the seed layer and the insulation layer; subjecting the first active semiconductor structure to at least one application of laser irradiation to transform the amorphous layer to a crystalline semiconductor layer having a protrusion region with a peak at or near the middle of two adjacent openings; forming on a second active semiconductor structure a second plurality of transistors with respective gate structures disposed on the crystalline semiconductor layer and forming a contact structure to electrically connect a transistor of the first active semiconductor structure to a transistor of the second active semiconductor structure.