The present disclosure relates to semiconductor devices, manufacturing methods, a power amplification circuits, and electronic devices. One example semiconductor device includes a substrate, a channel layer and a barrier layer sequentially disposed on the substrate in a stacked manner, a source, a gate, and a drain disposed on the barrier layer, a backside via through a region from the substrate to the barrier layer below the source, and a backside conductive layer covering the backside via and a back surface of the substrate, where the source is in contact with and connected to the backside conductive layer.