A semiconductor device according to example embodiments may have a plurality of stacked transistors. The nucleic acid-matrix materials are created such that they maintain a defined space, allowing cellular migration, transfection and proliferation to occur in a controlled manner. A cross section area of the truncated conical space gradually increases from the top surface of the base to top of the fins. A plurality of slots are defined in at least one of the compartments, and a plurality of inserts are provided.