Semiconductor structure and preparation method thereof

Abstract

Disclosed are a semiconductor structure and a preparation method thereof. The semiconductor structure includes a substrate, including a first region arranged at the center of the substrate and a second region arranged at the periphery of the first region; and a composite buffer layer arranged on the substrate, including a carbon-containing first buffer layer including at least one set of a first sub-buffer layer and a second sub-buffer layer stacked in layers; therein, a carbon concentration of the first sub-buffer layer arranged at the first region is higher than that arranged at the second region; and a carbon concentration of the second sub-buffer layer arranged at the first region is lower than that at arranged the second region. Therefore, uniformity of the carbon concentration of the composite buffer layer is improved to improve resistivity of the composite buffer layer, so as to increase breakdown voltage and improve device performance.

Dependencies are inferred from the claim text.