Methods of forming semiconductor devices include providing a substrate including a layer of semiconductor material on a layer of electrically insulating material. A first metallization layer is formed over a first side of the layer of semiconductor material. Through wafer interconnects are foamed at least partially through the substrate. A second metallization layer is formed over a second side of the layer of semiconductor material opposite the first side thereof. An electrical pathway is provided that extends through the first metallization layer, the substrate, and the second metallization layer between a first processed semiconductor structure carried by the substrate on the first side of the layer of semiconductor material and a second processed semiconductor structure carried by the substrate on the first side of the layer of semiconductor material. Semiconductor structures are fabricated using such methods.