Strained germanium device with cantilever structure and preparation method thereof

The invention provides a strained germanium device with a cantilever structure and a preparation method thereof, which relate to the field of semi-conductor photoelectrons. The preparation method includes steps of providing a substrate which contains germanium and consists of a supporting substrate, a sacrificial layer and a top germanium containing layer sequentially; imaging the top germanium containing layer to form a cantilever; corroding and removing the sacrificial layer; and applying external force to any position of the cantilever. The strained germanium device comprises the supporting substrate, the sacrificial layer and the top germanium containing layer sequentially, and the top germanium containing layer comprises a suspended cantilever. The strained germanium device and the preparation method have the advantages that CMOS (complementary metal-oxide semiconductor transistor) process is compatible, a band gap structure of germanium film materials is adjusted by changing external force, the strained germanium device is simple and convenient in process, provides basis materials for on-chip light source or even laser source and has the function of tuning lighting wavelength since the applied external force on the cantilever structure is adjustable, and lighting gains of the germanium materials can be improved in the near-infrared band and the middle-infrared band.