Semiconductor structure and manufacturing method therefor

Abstract

Embodiments of the present application provide a semiconductor structure and a manufacturing method therefor. A buffer layer is disposed on a substrate layer, and the buffer layer includes a first buffer layer and a second buffer layer. By doping a transition metal in the first buffer layer, a deep level trap may be formed to capture background electrons, and diffusion of free electrons toward the substrate may also be avoided. By decreasing a doping concentration of the transition metal in the second buffer layer, a tailing effect is avoided and current collapse is prevented. By doping periodically the impurity in the buffer layer, the impurity may be as an acceptor impurity to compensate the background electrons, and then a concentration of the background electrons is reduced. By using the periodic doping method, dislocations, caused by doping, in the buffer layer may be effectively reduced.