Semiconductor base substance having a boron containing buffer layer, semiconductor device including the same, and methods for manufacturing the semiconductor base substance and the semiconductor device

摘要

A semiconductor base substance includes: a substrate; a buffer layer which is made of a nitride semiconductor and provided on the substrate; and a channel layer which is made of a nitride semiconductor and provided on the buffer layer, wherein the buffer layer includes: a first region which is provided on the substrate side and has boron concentration higher than acceptor element concentration; and a second region which is provided on the first region, and has boron concentration lower than that in the first region and acceptor element concentration higher than that in the first region. As a result, the semiconductor base substance which can obtain a high pit suppression effect while maintaining a high longitudinal breakdown voltage is provided.