The present invention discloses a semiconductor device, which comprises a substrate, a buffer layer on the substrate, an inversely doped isolation layer on the buffer layer, a barrier layer on the inversely doped isolation layer, a channel layer on the barrier layer, a gate stack structure on the channel layer, and source and drain regions at both sides of the gate stack structure, characterized in that the buffer layer and/or the barrier layer and/or the inversely doped isolation layer are formed of SiGe alloys or SiGeSn alloys, and the channel layer is formed of a GeSn alloy. The semiconductor device according to the present invention uses a quantum well structure of SiGe/GeSn/SiGe to restrict transportation of carriers, and it introduces a stress through lattice mis-match to greatly increase the carrier mobility, thus improving the device driving capability so as to be adapted to high-speed and high-frequency application.