A method of manufacturing a semiconductor device may include sequentially forming an n-type epitaxial layer, a p type epitaxial layer, and an n+ region on a first surface of an n+ type silicon carbide substrate; forming a buffer layer on the n+ region; forming a photosensitive film pattern on a part of the buffer layer; etching the buffer layer using the photosensitive film pattern as a mask to form a buffer layer pattern; sequentially forming a first metal layer and a second metal layer which include a first portion and a second portion; removing one or more components to expose a part of the n+ region; and etching the exposed part of the n+ region using the first portion of the first metal layer and the first portion of the second metal layer as masks to form a trench.