Semiconductor epitaxial structure and preparation method of semiconductor epitaxial structure

The embodiment of the invention provides a semiconductor epitaxial structure and a preparation method of the semiconductor epitaxial structure, and relates to the technical field of semiconductor epitaxy, the semiconductor epitaxial structure comprises a substrate, a nucleating layer and a buffer layer, the nucleating layer is formed on the substrate, and then the buffer layer is formed on the nucleating layer, the nucleating layer comprises a plurality of layers of periodically doped and repeatedly arranged semiconductor periodic laminated layers, so that the nucleating layer forms doped superlattice structures with different doping types, and the crystal quality of the nucleating layer is improved by adopting the doped superlattice structures with different doping types; according to the embodiment of the invention, the formed doped superlattice can reduce the penetration dislocation of the epitaxial layer to obtain the epitaxial film with high crystal quality, can simply and efficiently obtain the high-qua