A design structure is provided for a semiconductor device having radiation hardened buried insulators and isolation insulators in SOI technology. The device includes a first structure and a second structure. The first structure includes: a radiation hardened BOX layer under an active device layer; radiation hardened shallow trench isolation (STI) structures between active regions of the active device layer and above the radiation hardened BOX layer; metal interconnects in one or more interlevel dielectric layers above gates structures of the active regions. The second structure is bonded to the first structure. The second structure includes: a Si based substrate; a BOX layer on the substrate; a Si layer with active regions on the BOX; oxide filled STI structures between the active regions of the Si layer; and metal interconnects in one or more interlevel dielectric layers above gates structures. At least one metal interconnect is electrically connecting the first structure to the second structure.