Semiconductor device includes pair of active devices, composite spin Hall electrode, and a magnetic tunnel junction. Composite spin Hall electrode is electrically connected to pair of active devices. Magnetic tunnel junction is disposed on opposite side of composite spin hall electrode with respect to pair of active devices. Spin Hall electrode includes pair of heavy metal layers, and spacer layer disposed in between pair of heavy metal layers. Pair of heavy metal layers is made of a heavy metal in a metastable state. Spacer layer comprises first material different from the pair of heavy metal layers.