A semiconductor device comprises a base substrate, a pattern on the base substrate, a buffer layer on the base substrate, and an epitaxial layer on the buffer. The pattern is a self-assembled pattern. A method for growing a semiconductor crystal comprises cleaning a silicon carbide substrate, forming a self-assembled pattern on the silicon carbide substrate, forming a buffer layer on the silicon carbide substrate, and forming an epitaxial layer on the buffer layer. A semiconductor device comprises a base substrate comprising a pattern groove and an epitaxial layer on the base substrate. A method for growing a semiconductor crystal comprises cleaning a silicon carbide substrate, forming a self-assembled projection on the silicon carbide substrate, forming a pattern groove in the silicon carbide, and forming an epitaxial layer on the silicon carbide.