Method for preparing supersaturated-doping semiconductor thin film

The invention discloses a method for preparing a supersaturated-doping semiconductor thin film. The method includes the following steps: step one, a substrate is chosen; step two, the surface of the substrate is cleaned up; step three, at a low growth temperature, a semiconductor amorphous thin film is deposited on the surface of the substrate, wherein through control over a deposition speed ratio of atoms, a supersaturated-doping semiconductor amorphous thin film is obtained; step four, laser annealing is carried out on the supersaturated-doping semiconductor amorphous thin film by the utilization of ultra-fast lasers, and the preparation of the supersaturated-doping semiconductor thin film is completed. According to the preparation method, the molecular beam epitaxy technology is used for preparing the supersaturated-doping thin film which is even in doping concentration. Depth distribution of impurities in the prepared supersaturated-doping silicon thin film is very even.