A method for manufacturing a semiconductor device comprises depositing alternating layers of a plurality of first dielectric layers and a plurality of second dielectric layers on a substrate in a stacked configuration, forming one or more first openings in the stacked configuration to a depth penetrating below an upper surface of a bottom second dielectric layer of the plurality of second dielectric layers, forming one or more second openings in the stacked configuration to a depth corresponding to an upper surface of the substrate or below an upper surface of the substrate, removing the plurality of second dielectric layers from the stacked configuration to form a plurality of gaps, and epitaxially growing a semiconductor material from a seed layer in the one or more second openings to fill the one or more first and second openings and the plurality of gaps, wherein defects caused by a lattice mismatch between the epitaxially grown semiconductor material and a material of the substrate are contained at a bottom portion of the one or more second openings.