A device includes a substrate with a recess, having a bottom and sides, extending into the substrate from the substrate's upper surface. The sides include first and second sides oriented transversely to one another. A stack of alternating active and insulating layers overlie the substrate's surface and the recess. At least some of the active layers have an upper and lower portions extending along upper and lower planes over and generally parallel to the upper surface and to the bottom, respectively. The active layers have first and second upward extensions positioned along the first and second sides to extend from the lower portions of their respective active layers. Conductive strips adjoin the second upward extensions of the said active layers. The conductive strips can comprise sidewall spacers on the sides of the second upward extensions, the conductive strips connected to overlying conductors by interlayer conductors.