Provided are a method of fabricating a semiconductor integrated circuit device and a semiconductor integrated circuit device fabricated using the method. The method includes: forming a mask film, which exposes a portion of a substrate, on the substrate; forming a first buried impurity layer, which contains impurities of a first conductivity type and of a first concentration, in a surface of the exposed portion of the substrate by using the mask film; removing the mask film; forming a second buried impurity layer, which contains impurities of a second conductivity type and of a second concentration, using blank implantation; and forming an epitaxial layer on the substrate having the first and second buried impurity layers, wherein the first concentration is higher than the second concentration.