Provided are a semiconductor device and a method of fabricating the same. The semiconductor device may include a substrate including first and second junction regions, a word line buried in the substrate, a bit line provided over the word line to cross the word line, a first contact provided between the substrate and the bit line and electrically connected to the first junction region, and a second contact provided between the bit lines and electrically connected to the second junction region. An overlapping area of a lower portion of the second contact may be greater than an overlapping area of an upper portion of the second contact with respect to the second junction region.