The present application provides a semiconductor device and a method for manufacturing the same. The method includes: sequentially forming a buffer layer and a barrier layer on a substrate, wherein a two-dimensional electron gas is formed between the buffer layer and the barrier layer; etching a source region and a drain region of the barrier layer to form a trench on the buffer layer, and doped layers are formed on the trench; forming a passivation layer on the barrier layer and the doped layers, and etching the passivation layer to expose a portion of the barrier layer, wherein the portion of the barrier layer is in contact with the doped layers; and doping ions into a portion of the buffer layer in contact with the portion of the buffer layer.