A method for manufacturing a memory device includes forming a plurality of active layers alternating with insulating layers on a substrate where the active layers include an active material, etching the active layers and insulating layers to define a plurality of stacks of active strips, and after the etching, causing crystal growth in the active strips. The substrate can have a single crystalline surface with a crystal structure orientation, and the crystal growth in the active material can form crystallized material having the crystal structure orientation of the substrate at least near side surfaces of the active strips. Causing crystal growth includes depositing a seeding layer over the plurality of stacks and the substrate, where the seeding layer is in contact with the side surfaces of the active strips, and in contact with the substrate. The method can include, after causing crystal growth, removing the seeding layer.