Substrate structure, semiconductor device fabricated from the same, and method of fabricating the semiconductor device

Abstract

According to example embodiments, a substrate structure may include a GaN-based third material layer, a GaN-based second material layer, a GaN-based first material layer, and a buffer layer on a non-GaN-based substrate. The GaN-based first material layer may be doped with a first conductive type impurity. The GaN-based second material layer may be doped with a second conductive type impurity at a density that is less than a density of the first conductive type impurity in the first GaN-based material layer. The GaN-based third material layer may be doped with a first conductive type impurity at a density that is less than the density of the first conductive type impurity of the GaN-based first material layer. After a second substrate is attached onto the substrate structure, the non-GaN-based substrate may be removed and a GaN-based vertical type semiconductor device may be fabricated on the second substrate.